text:
Combined energy storage and fuel generation with reversible fuel cells
An electrochemical system includes a reversible fuel cell system which generates electrical energy and reactant product from fuel and oxidizer in a fuel cell mode and which generates the fuel and oxidant from the reactant product and the electrical energy in an electrolysis mode. The system also includes a reactant product delivery device which is adapted to supply the reactant product to the reversible fuel cell system operating in the electrolysis mode, in addition to or instead of the reactant product generated by the reversible fuel cell system in the fuel cell mode, and a fuel removal device which is adapted to remove the fuel generated by the reversible fuel cell system operating in the electrolysis mode from the electrochemical system.
Sridhar K. R. (Los Gatos, CA, US)
Gottmann, Matthias (Sunnyvale, CA, US)
Bloom Energy Corporation
205/343, 429/442, 429/465, 429/495
H01M8/02; C25B1/00; H01M8/04; H01M8/06; H01M8/18; H01M16/00; H01M8/10; H01M8/12
20090146604 COMPLEX LITHIUM SECONDARY BATTERY AND ELECTRONIC DEVICE EMPLOYING THE SAME June, 2009 Choi et al.
20100071979 Electric Vehicle Battery System March, 2010 Heichal et al.
20090325010 ADAPTIVE COMPRESSOR SURGE CONTROL IN A FUEL CELL SYSTEM December, 2009 Kirklin
20080241643 Vanadium redox battery incorporating multiple electrolyte reservoirs October, 2008 Lepp et al.
20100009257 Lithium Secondary Battery Comprising Electrode Active Material Containing Surfactant January, 2010 Kang et al.
20010028972 Apparatus for recovering water for an electrical/fuel-cell system October, 2001 Autenrieth et al.
20100092848 MIDDLE OR LARGE-SIZED BATTERY PACK CASE PROVIDING IMPROVED DISTRIBUTION UNIFORMITY IN COOLANT FLUX April, 2010 Choi et al.
20040253490 Method and device for deionizing cooling media for fuel cells December, 2004 Wulff et al.
20090011338 Method of Manufacturing Lithium Secondary Battery and Lithium Secondary Battery January, 2009 Kimura
20030232231 Device and method for supplying air to a fuel cell December, 2003 Stute et al.
20060040181 Electrode assembly and lithium rechargeable battery using the same February, 2006 Kim et al.
MAPLES, JOHN S
THE MARBURY LAW GROUP, PLLC (RESTON, VA, US)
1. A method of operating a reversible fuel cell system, comprising cyclically operating the reversible fuel cell system in a fuel cell mode to generate electrical energy and reactant product from fuel and oxidizer at a first equilibrium temperature and in an electrolysis mode to generate the fuel and oxidant from the reactant product and the electrical energy at a second equilibrium temperature, wherein the first equilibrium temperature is different from the second equilibrium temperature.
2. The method of claim 1, further comprising selecting the first equilibrium operating temperature independently from the second equilibrium operating temperature to optimize at least one of an amount of fuel produced in the electrolysis mode and a unit cost of the fuel produced in the electrolysis mode.
3. The method of claim 2, wherein the first equilibrium operating temperature is selected to maximize the amount of fuel produced in the electrolysis mode.
4. The method of claim 2, wherein the first equilibrium operating temperature is selected to minimize the unit cost of the fuel produced in the electrolysis mode.
5. The method of claim 2, wherein the first operating temperature is selected by adjusting an amount of current density provided to the reversible fuel cell system.
6. The method of claim 2, wherein the first operating temperature is selected by adjusting an amount of the reactant product provided to the reversible fuel cell system.
7. The method of claim 2, further comprising: providing excess reactant product to the reversible fuel cell system operating in the electrolysis mode from outside the reversible fuel cell system, in addition to or instead of the reactant product generated by the reversible fuel cell system in the fuel cell mode, such that fuel in excess of fuel required to operate the reversible fuel cell system in the fuel cell mode is generated in the electrolysis mode over a predetermined number of operating cycles; and removing the excess fuel generated by the reversible fuel cell system operating in the electrolysis mode from an electrochemical system in which the reversible fuel cell system is located.
8. The method of claim 7, wherein: the reversible fuel cell system generates more fuel in the electrolysis mode than it consumes in the fuel cell mode over the predetermined number of cycles; and the reversible fuel cell system comprises a stack of solid oxide regenerative fuel cells.
This application is a divisional application of U.S. application Ser. No. 10/653,240, filed Sep. 3, 2003, which is incorporated herein by reference in its entirety.
The present invention is generally directed to fuel cells and more specifically to reversible fuel cells and their operation.
Fuel cells are electrochemical devices which can convert energy stored in fuels to electrical energy with high efficiencies. There are classes of fuel cells that also allow reversed operation, such that oxidized fuel can be reduced back to unoxidized fuel using electrical energy as an input. The ability to generate electricity and regenerate fuel makes these fuel cells suitable for electrical energy storage.
BRIEF SUMMARY OF THE INVENTION
One preferred aspect of the present invention provides an electrochemical system which includes a reversible fuel cell system which generates electrical energy and reactant product from fuel and oxidizer in a fuel cell mode and which generates the fuel and oxidant from the reactant product and the electrical energy in an electrolysis mode. The system also includes a reactant product delivery device which is adapted to supply the reactant product to the reversible fuel cell system operating in the electrolysis mode, in addition to or instead of the reactant product generated by the reversible fuel cell system in the fuel cell mode, and a fuel removal device which is adapted to remove the fuel generated by the reversible fuel cell system operating in the electrolysis mode from the electrochemical system.
Another preferred aspect of the present invention provides an electrochemical system, comprising a first means for cyclically operating in a fuel cell mode to generate electrical energy and reactant product from fuel and oxidizer and in an electrolysis mode to generate the fuel and oxidant from the reactant product and the electrical energy. The system also comprises a second means for providing excess reactant product to the first means operating in the electrolysis mode from outside the electrochemical system, in addition to or instead of the reactant product generated by the first means in the fuel cell mode, such that fuel in excess of fuel required to operate the first means in the fuel cell mode is generated in the electrolysis mode over a predetermined number of operating cycles, and a third means for removing the excess fuel generated by the first means operating in the electrolysis mode from the electrochemical system.
Another preferred aspect of the present invention provides a method of operating an electrochemical system containing a reversible fuel cell system, comprising cyclically operating the reversible fuel cell system in a fuel cell mode to generate electrical energy and reactant product from fuel and oxidizer and in an electrolysis mode to generate the fuel and oxidant from the reactant product and the electrical energy. The method also comprises providing excess reactant product to the reversible fuel cell system operating in the electrolysis mode from outside the reversible fuel cell system, in addition to or instead of the reactant product generated by the reversible fuel cell system in the fuel cell mode, such that fuel in excess of fuel required to operate the reversible fuel cell system in the fuel cell mode is generated in the electrolysis mode over a predetermined number of operating cycles, and removing the excess fuel generated by the reversible fuel cell system operating in the electrolysis mode from the electrochemical system.
FIG. 1 is a schematic of an electrical energy storage system.
FIG. 2 is a schematic of an electrical energy storage system with a reversible fuel cell system.
FIG. 3 is a schematic of an electrical energy storage system with a reversible fuel cell system, which can also generate fuel for use outside the electrical energy storage system.
FIG. 4 is a schematic cross section of a single SORFC operating in the electrolysis mode according to a preferred embodiment of the present invention.
FIG. 5 is a schematic cross section of a single SORFC operating in the fuel cell mode according to a preferred embodiment of the present invention.
FIG. 6 is a schematic side of view of a Sabatier reactor according to a preferred embodiment of the present invention.
FIG. 7 is a system schematic of the major SORFC components operating in the fuel cell mode, according to a preferred embodiment of the present invention.
FIG. 8 is a system schematic of the major SORFC components operating in the electrolysis mode, according to a preferred embodiment of the present invention.
The present inventors have realized that regenerative or reversible operation of fuel cells can be applied beyond mere energy storage to produce fuel for uses outside the fuel cell system. A reversible fuel cell is used to reversibly store electrical energy. When electrical energy is needed from the storage system, the fuel cell operates in a fuel cell or discharge mode. In this mode, fuel is oxidized in the fuel cell, electricity is generated, and part or all of the reactant product is stored, if desired. The system is then recharged in an electrolysis or charge mode. In this mode, the system is recharged by supplying electrical power to the fuel cell, electrolyzing the stored and/or supplied reactant product, thereby regenerating the fuel. The regenerated fuel and optionally the regenerated oxidant are stored and available for energy generation in the fuel cell mode. The system cyclically or alternatively switches operation between the fuel cell and electrolysis modes for any suitable number of cycles. If more electrical energy and reactant product than needed to regenerate the fuel is supplied to the reversible fuel cell over a predetermined number of operating cycles, then excess or additional fuel can be generated during the electrolysis mode during some or all of these cycles. In other words, more fuel is generated when the system operates in the electrolysis mode than the fuel needed to operate the system in the fuel cell mode. This excess fuel can be used outside the energy storage system.
FIG. 1 shows an energy source 100 connected via a conduit 110 to an energy storage system 120. The energy storage system 120 is connected via conduit 130 to the energy consumer 140. The energy storage system 120 supplies the required power to the energy consumer 140 at all times or at predetermined times, if desired. The energy supplied to the consumer comes from the energy source 100, or from the energy storage system 120, or a combination of the two. The system shown in FIG. 1 decouples the amount of power drawn by the energy consumer 140 from the amount of energy drawn from the energy source 100.
Examples of the energy source 100 include, but are not limited to the electrical grid, electrical generators and renewable energy sources. Preferred renewable energy sources include photovoltaic sources, such as solar cell arrays, wind power sources, such as wind turbines, tidal power sources in which power is generated from forces of ocean, sea or lake tides, and geothermal power sources in which power is generated from geothermal heat.
The energy storage system 120 is preferably a reversible or regenerative fuel cell system, as will be described in more detail below with respect to FIG. 2. Examples of the energy consumer 140 include, but are not limited to residential households, commercial building, such as factories, hospitals and office building, electrical subgrids, and remote transmitters.
The system 120 will draw more power from the energy source 100 than what is supplied to the energy consumer 140 in the electrolysis mode and the additional power is stored in the form of regenerated fuel. In the fuel cell mode the system 120 provides electrical power or energy to the consumer 140 instead of or in addition to the power provided to the consumer 140 from the energy source 100. As used herein, the terms "electrical power" and "electrical energy" refer to features of electricity provided by the energy source 100 and to features of electricity provided to the consumer 140.
FIG. 2 shows details of the energy storage system 120. The system 120 is preferably an electrochemical system which contains a power management system 160, a reversible fuel cell system 190, a fuel storage device 210 and an optional reactant product storage device 230. The system also contains electrical connection conduits or wires 150, 170 and 180, as well as a fuel conduit 200 and a reactant product conduit 220 which allow the fuel and reactant product to pass between the reversible fuel cell system 190 and the fuel storage 210 and product storage 230 devices, respectively.
The power management system 160 may be any suitable controller device, such as a computer or microprocessor, and preferably contains logic circuitry which decide how to route the power streams. Energy from the electrical energy source 100 can be directed fully to the electrical energy consumer 140, fully to the reversible fuel cell system 190, or can be partitioned between the electrical energy consumer 140 and the reversible fuel cell system 190. It is also possible to feed electrical energy back towards the electrical energy source 100, which can be applied for example where the electrical energy source 100 is the electrical grid. The power management system 160 also controls from where power is supplied to the electrical energy consumer 140. Power can be supplied from the electrical energy source 100, the reversible fuel cell system 190, or a combination thereof.
The reversible fuel cell system 190 may comprise one or more reversible fuel cells or one or more fuel cell/electrolyzer pairs. A reversible fuel cell is a single electrochemical device which generates reactant product and electrical energy or power in the fuel cell mode and which generates fuel from reactant product and electrical energy in the electrolysis mode. A fuel cell/electrolyzer pair includes two separate devices, where a non-reversible fuel cell device generates energy, and the other electrolyzer device regenerates fuel.
Examples of the fuel cells and electrolyzers include but are not limited to high temperature fuel cells, such as solid oxide fuel cells (SOFC), and also include proton exchange membrane fuel cells (PEM). Reversible or regenerative SOFC's (SORFCs) are well suited to combine energy generation and fuel regeneration in a single device. However, other fuel cells, such as molten carbonate fuel cells, may also be used in the system 190. Preferably, the system 190 contains at least one stack of reversible fuel cells or stacks of fuel cell/electrolyzer pairs.
The fuel and reactant product storage devices 210 and 230 may comprise any suitable gas, liquid or solid storage devices. Preferably, these devices 210, 230 comprise gas or liquid tanks which are opened and closed with a valve.
The system 120 operates as follows. Power from the electrical energy source 100 enters through conduit 110 and conduit 150 to the power management system 160. When the reversible fuel cell system 190 operates in the fuel cell mode and provides electrical energy, fuel is fed from the fuel storage device 210 to the reversible fuel cell system 190 via the fuel conduit 200. In the reversible fuel cell system 190, the chemical energy of the fuel is converted to electrical energy, which is then supplied to the power management system 160. Optionally, all or part of the reactant product from the reversible fuel cell system are transferred to the product storage device 230 via the reactant product conduit 220. Products that are not stored are released.
When the reversible fuel cell system 190 operates in the electrolysis mode, electrical energy from the power management system 160 is provided to system 190 and the reactant product from the product storage device 230 and/or from outside the electrochemical energy storage system 120 is provided via the reactant product conduit 220 to the system 190. The fuel is regenerated in the reversible fuel cell system 190 and provided to the fuel storage 210 via the fuel conduit 200.
Any suitable fuels, oxidizers and reactant product may be used. One preferred example for the fuel is hydrogen which is reacted with oxygen from ambient air to produce a water reactant product. However, other fuels and oxidants can be used. For example, a hydrocarbon gas, such as methane, may be used as a fuel to produce water and carbon dioxide reactant product. Other hydrocarbon gases, such as natural gas, propane, hexane, etc., may also be used as fuel. Furthermore, these hydrocarbon materials may be reformed into a carbon containing fuel, such as carbon monoxide, or previously supplied carbon monoxide may also be used as fuel.
If surplus energy is available from the electrical energy source 100 and an excess reactant product is supplied to the reversible fuel cell system 190, then the system 190 can generate more fuel than what is needed by the system 190 in the fuel cell mode. This excess fuel may be removed from the system 120 and provided for any suitable end use outside the system 120.
FIG. 3 illustrates the system 120 when the excess reactant product is supplied to the system 120 and the excess fuel is removed from the system. The system 120 is identical to the system 120 illustrated in FIG. 2 with the exception of the fuel removal device 240 and the reactant product delivery device 250. Excess fuel is provided out of the system 120 through the fuel removal device 240, while the excess reactant product is replenished through reactant product delivery device 250. The devices 240 and 250 may comprise any suitable devices which may deliver fuel and reactant product.
For example, the fuel removal device 240 may be a gas or liquid conduit such as a pipe or hose which delivers fuel, such as hydrogen or methane, from the reversible fuel cell system 190 and/or from the fuel storage device 210 outside the system 120. Alternatively, the device 240 may comprise a movable gas or liquid storage container, such as a gas or liquid tank, which is physically removed from the system 120 after the container is filled with fuel. If the device 240 comprises a container, then the device 240 may be used as both the fuel storage device 210 while it remains in the system 120, and as a fuel removal device 240, when it is removed from the system 120.
The reactant product delivery device 250 may be one or more gas or liquid conduits which deliver reactant product, such as water and/or carbon dioxide to the system 120. For example, the device may comprise a water pipe or hose which delivers water to the product storage device 230 or directly to the reversible fuel cell system 190. The device 250 may comprise two conduits when the reactant product comprises two separate components, such as water and carbon dioxide. Alternatively, the device 250 may comprise a movable gas or liquid storage container, such as a gas or liquid tank, which is physically delivered to the system 120 filled with reactant product. If the device 250 comprises a container, then the device 250 may be used as both the reactant product storage device 230 while it collects reactant product during the fuel cell mode, and as a reactant product delivery device 250 when it provides reactant products during the electrolysis mode.
The reactant product delivery device 250 is adapted to supply excess reactant product to the reversible fuel cell system 190 operating in the electrolysis mode, in addition to or instead of the reactant product generated by the reversible fuel cell system in the fuel cell mode. In other words, the device 250 supplies the reactant product 250 in excess of the amount generated by the reversible fuel cell system 190 operating in the fuel cell mode. In one example, if the reactant product is water, then the water generated by the system 190 in the fuel cell mode is stored in the storage device 230 and the device 250 provides additional water to the device 230. In another example, the water generated by the system 190 in the fuel cell mode is discarded and the 250 provides water to the device 230 and/or to the system 190 in excess of the amount produced by the system 190 in the fuel cell mode.
In either example, the excess reactant product allows the system 190 to generate an amount of fuel in the electrolysis mode in excess of the amount of fuel required to operate the system 190 in the fuel cell mode over a predetermined number of operating cycles. Thus, while anomalies, such as breakdowns, early shut downs, etc., may occur during individual fuel cell mode and electrolysis mode cycles, when the system 190 is operated cyclically over a predetermined number of such cycles, such as over 10 cycles, for example over 100 to 1,000 cycles, the system 190 produces the excess fuel.
The reversible fuel cell system 190 may generate more fuel in the electrolysis mode than it consumes in the fuel cell mode over the predetermined number of cycles under several conditions. In a first preferred embodiment of the present invention, the reversible fuel cell system operates at a higher current level in the electrolysis mode than in the fuel cell mode over the predetermined number of cycles.
In a preferred aspect of the present invention, the reversible fuel cell system 190 includes a SORFC stack. It is desirable for the energy storage system 120 to operate at high round-trip efficiencies, which is the ratio of energy provided to the electrical energy consumer 140 to the electrical energy from source 100. In order to achieve high round-trip efficiencies, the SORFC is preferably operated at comparably low current densities thereby minimizing losses in the SORFC. Theoretically, the round-trip efficiency increases with decreasing current density. However, the SORFC should be maintained at an elevated operating temperature, which typically ranges between 600° C. and 1000° C. The losses within the SORFC can be used to provide make-up heat to keep the SORFC at the desired temperature. If the current and thereby the losses become too small, the desired operating temperature cannot be maintained. Therefore, a practical low limit for the current density exists in the electrolysis mode and in the fuel cell mode. This current density limit depends on the thermal losses from the system and the heat generated at a specific current.
Operation of a fuel cell at low current implies a fuel cell voltage close to the open circuit voltage (OCV), which is the fuel cell voltage at zero current. Operation below OCV implies power generation, while operation above OCV implies fuel regeneration/electrolysis. When the fuel cell is operated in the electrolysis mode, additional constraints on the minimum allowable current density can exist. In the example of water electrolysis at high temperature, operation of the fuel cell only slightly above OCV is an endothermic reaction. There is a minimum voltage for electrolysis, termed the thermal neutral voltage at which the electrolysis reaction is thermally neutral. In order to thermally sustain the SORFC without the use of thermal storage during electrolysis, electrolysis should be performed above the thermal neutral voltage. On the other hand, power generation can be performed very close to OCV. As a result the desired minimum current density for electrolysis is significantly larger than the desired minimum current for power generation in the fuel cell mode. The difference between the minimum currents depends on the thermal management system and the choice of fuel and oxidizer. In a SORFC without additional fuel generation, the current in power generation and electrolysis mode also should be balanced with respect to the available time for power generation and electrolysis. If, for example, energy is generated for 16 hours per day while fuel is regenerated for 8 hours per day, the current during regeneration has to be twice as large as the power generation current in order to balance fuel consumed and regenerated.
The two constraints for current densities outlined above generally lead to different values for the minimum current density in the fuel cell and electrolysis modes. As a result of the higher current density in the electrolysis than in fuel cell mode, the energy storage system 120 typically has additional/unused fuel regeneration capacity. If additional or excess power or electrical energy and reactant product is available during fuel regeneration in the electrolysis mode, this excess fuel generation capacity can be utilized to generate additional fuel, which can be used outside the electrical energy storage system.
Thus, the system 120 may be used as a regenerative power supply to remote residences or commercial operations or to residences or commercial operations connected to the power grid. The electrical power generator has to be sized to meet the peak load of the user. This sizing requirement allows a surplus of fuel to be generated during charge times. Examples include, but are not limited to systems sized to meet high electrical power peak demands which occur during less than 100 percent of the system operation in the fuel cell mode or systems with relatively low energy consumption (i.e., below the maximum possible energy consumption) during the fuel cell mode.
Thus, in one preferred aspect of the first embodiment, the reversible fuel system 190 is operated at a load lower than a peak load that the reversible fuel cell system is capable of providing at least during a portion of a time that the reversible fuel cell system operates in the fuel cell mode. Thus, the reversible fuel system 190 is operated for at least a portion of its fuel cell mode at a current density below its peak or maximum possible current density. In contrast, the reversible fuel system 190 is operated at a higher current density, such as at a peak current density, in the electrolysis mode to produce the excess fuel.
Since the systems 120, 190 are designed and sized for a desired energy storage, the size of the fuel cell stack and the size of the balance of plant are based on the desired energy storage. Thus, the size of the fuel cell stack is based on the minimum number of fuel cells that operate in the fuel cell mode to provide the desired peak power, rather than on the number of fuel cells or electrolyzers that are required for the electrolysis mode. Thus, extra fuel cells or stacks may be required ensure that the system 120 provides the desired peak power in the fuel cell mode during a worst case scenario. However, the energy generation capability of all of the fuel cells may not be used in the fuel cell mode outside of the worst case scenario. In contrast, the fuel regeneration capability of all fuel cells may be used during electrolysis mode to regenerate the fuel needed for future fuel cell mode(s) and to generate excess fuel for use outside the system 120.
In another preferred aspect of the first embodiment, the reversible fuel cell system 190 is electrically connected to an electrical energy source 100 which comprises a photovoltaic energy generation system which provides electrical energy to the reversible fuel cell system during daytime to generate and store fuel. The photovoltaic energy generation system also provides electrical energy to the consumer 140, as illustrated in FIG. 1. The reversible fuel cell system 190 generates electrical energy during night time from the stored fuel and provides this electrical energy to the consumer 140 during night time. Often, the night time load on the reversible fuel cell system 190 is lower than a peak load that the reversible fuel cell system is capable of providing, at least during a portion of the night time period. Thus, the reversible fuel system 190 is operated in the fuel cell mode during at least a portion of the night time period at a current density below its peak current density. In contrast, the reversible fuel system 190 is operated at a higher current density, such as at a peak current density, in the electrolysis mode during the day time period to produce the excess fuel.
In a second preferred embodiment, the reversible fuel cell system 190 operates for a longer duration in the electrolysis mode than in the fuel cell mode over the predetermined number of cycles. This difference in operating time may be used to produce the excess fuel. For example, the system 190 may operate during one portion of the electrolysis mode to regenerate sufficient fuel for the entire next fuel cell mode period, and then operate for the remainder of the electrolysis mode period to produce the excess fuel.
Examples of the second embodiment include system 190 operation where charging and discharging follows a day/night cycle. Such a system often operates with a photovoltaic electrical energy source 100 described above. If the night time discharge period is shorter than the day time charge period, a surplus or excess fuel can be generated.
Another example is where the system 190 is used to provide emergency backup power when the electrical energy source 100 is unable to provide electrical energy to the consumer 140. For example, the system 190 may be used as a backup power source for a time when an electrical grid energy source 100 stops providing electrical energy. In this example, the system 190 operates at least 90 to 99 percent of the time in the electrolysis mode and occasionally operates in the fuel cell mode when the source 100 does not provide electrical energy. Thus, the system 190 is used as an electrolyzer which provides fuel for non-system uses and as an emergency backup power generator. This mode of operation reduces the cost of the emergency backup energy generation system.
If desired, the first and second embodiments may be combined, and the system 190 may operate in the electrolysis mode for a longer time period and at a higher current density than in the fuel cell mode.
In a third preferred embodiment, the reversible fuel cell system 190 is electrically connected an electrical energy source 100 which comprises a renewable energy source. Any suitable renewable energy source may be used. An excess capacity of the renewable energy source is used to provide electrical energy to the reversible fuel cell operating in the electrolysis mode to generate the excess fuel. Different renewable energy sources have different types of excess capacities.
In one example, the renewable energy source 100 may comprises a photovoltaic system, such as a solar cell array. The photovoltaic system contains extra capacity during a first portion, such as the first 95 to 99.9 percent, of its designed lifespan. In other words, the capacity of the photovoltaic system decreases as the system ages during its life span. Thus, a photovoltaic system is often designed to provide a desired amount of electrical energy based on the remaining second portion of its expected lifespan, to prevent the photovoltaic system from providing an insufficient amount of electrical energy in the second portion of its expected life span. Therefore, the photovoltaic system is designed and sized to provide electrical energy in excess of that required by the consumer and that required by the reversible fuel cell system 190 to regenerate fuel for operation in the fuel cell mode. The excess capacity of the photovoltaic system during the first portion, such as the 95 to 99.9 percent, of its life span may be used to provide electrical energy to the reversible fuel cell system 190 to generate the excess fuel.
In another example, the photovoltaic system 100 is designed and sized to provide a sufficient amount of electrical energy required by the consumer and required by the reversible fuel cell system 190 to regenerate fuel for operation in the fuel cell mode over a predetermined number of day and night cycles, even if a large amount of days are cloudy. In other words, the photovoltaic system 100 is designed to provide a sufficient amount of electrical energy in a worst case weather scenario, such as when a predetermined percent, X, of day time periods are cloudy. However, the worst case weather scenario occurs occasionally. Thus, when less than X percent of day time periods are cloudy, and the system 190 is fully recharged for operation in the next fuel cell mode period or periods, the photovoltaic system 100 may be used to provide electrical energy to system 190 to generate excess fuel during the excess sunny portions of the day time periods. For example, the photovoltaic system 100 is designed and sized to provide a sufficient amount of electrical energy required by the consumer and required by the reversible fuel cell system 190 in the winter, when the number of sunny days is at a minimum and/or when the day length is shortest compared to the night length. Thus, there is no sufficient sunlight during X percent of the time during winter. The photovoltaic system 100 has excess capacity in the summer, when there is no sufficient sunlight during only X-Y percent of the time. The photovoltaic system 100 may be used to provide electrical energy to system 190 to generate excess fuel during Y percent of the time during the summer.
In another example, the renewable energy source 100 may comprise a wind turbine system which is designed to provide a minimum amount of electrical energy at a predetermined wind speed. Such systems often contain rotatable blades coupled to a generator which generates electricity when the wind rotates the blades. This system 100 contains extra capacity during periods when the wind speed exceeds a predetermined wind speed.
The wind turbine system 100 is designed and sized to provide a sufficient amount of electrical energy required by the consumer and required by the reversible fuel cell system 190 to regenerate fuel for operation in the fuel cell mode over a predetermined number of cycles, even if a there is no wind or the wind speed is low during a large portion of a predetermined number of cycles. In other words, the system 100 is designed to provide a sufficient amount of electrical energy in a worst case weather scenario, such as when a predetermined percent, X, of the time there is no wind or the wind speed is lower than desirable. However, the worst case weather scenario occurs occasionally. Thus, when less than X percent of the time period has little or no wind and the system 190 is fully recharged for operation in the next fuel cell mode period or periods, the system 100 may be used to provide electrical energy to system 190 to generate excess fuel during the excess windy portions of the time period. For example, if X-Y percent of the time period has no wind or insufficient wind, then the system 100 may be used to provide electrical energy to system 190 to generate excess fuel during Y percent of time period.
In another example, the renewable energy source 100 may comprise a tidal energy generation system which is designed to provide a minimum amount of electrical energy at a predetermined tidal force. Such a system 100 contains movable members, such as plates, located under a body of water, such as a sea, ocean or lake. The movable members are connected to a generator. The movable members are moved by the tides and the movement causes the generator to generate electricity. This system contains extra capacity during periods when the tidal force exceeds the predetermined tidal force.
The tidal energy generation system 100 is designed and sized to provide a sufficient amount of electrical energy required by the consumer and required by the reversible fuel cell system 190 to regenerate fuel for operation in the fuel cell mode over a predetermined number of cycles, even if a there is no tide or the tidal force is low during a large portion of a predetermined number of cycles. In other words, the system 100 is designed to provide a sufficient amount of electrical energy in a worst case tidal scenario, such as when a predetermined percent, X, of the time the tidal force is lower than desirable. However, the worst case tidal scenario occurs occasionally. Thus, when less than X percent of the time period has insufficient tidal force and the system 190 is fully recharged for operation in the next fuel cell mode period or periods, the system 100 may be used to provide electrical energy to system 190 to generate excess fuel during the excess high tidal force portions of the time period. For example, if X-Y percent of the time period has insufficient tidal force, then the system 100 may be used to provide electrical energy to system 190 to generate excess fuel during Y percent of time period.
In another example, the renewable energy source 100 may comprise a geothermal energy generation system which is designed to provide a minimum amount of electrical energy at a predetermined geothermal energy. Such a system 100 uses the heat and/or steam emitted from the earth and converts the heat and/or steam into electrical energy. This system contains extra capacity during periods when the geothermal energy exceeds a predetermined, worst case thermal energy supply scenario. For example, ambient losses for the geothermal energy differ between warm summer ambient temperatures and cold winter ambient temperatures.
Thus, as described above, co-production of fuel in an energy storage device using a fuel regenerating device can be realized in any situation where the fuel consumed during discharge is less than the fuel regenerated during charging periods, preferably over a predetermined number of charge and discharge cycles. The system 190 generates fuel during the entire electrolysis mode time period. From about 1 to about 99 percent of the generated fuel, such as about 10 to about 30 percent of the generated fuel is excess fuel which may be used for non-system 120 uses, while the remaining fuel may be used to operate the system 190 in the fuel cell mode.
It is preferred, but not required to use the system 120 with a renewable energy source 100 in remote locations that are not connected to the power grid. In this case, the reversible fuel cell system 190 of the electrical energy storage system 120 may be used to generate fuel for air, land or water vehicles. A vehicle fuel infrastructure is not required in this case and the system 120 may be used to supply the necessary fuel to power the vehicles at the remote location. For example, the vehicles may be powered by hydrogen, methane or other hydrocarbon fuel. Furthermore, since the system 190 may be used to generate electricity and an environmentally clean fuel, such as hydrogen, without emission of greenhouse gases and carbon dioxide, the system 190 improves the environment and reduces the emission of greenhouse gases for transportation and other uses.
The excess generated fuel may be used for any suitable application outside the system 120. For example, the excess fuel may be provided to power an airborne vehicle, such as a rocket, airplane, helicopter or blimp, a water based vehicle, such as a ship or submarine, a land based vehicle, such as a car, truck, motorcycle, tank or train, a chemical reaction in a chemical manufacturing process, such as a semiconductor manufacturing or chemical production process, or a heating system of a building, such as a commercial building, including office buildings, factories and hospitals and a residential building.
In another preferred embodiment of the present invention, the equilibrium operating temperature of the reversible fuel cell system 190, such as a fuel cell stack, in the electrolysis mode is selected independently from the equilibrium operating temperature of the fuel cell stack in the fuel cell mode to optimize the amount and/or cost of the fuel produced in the electrolysis mode. Thus, in this embodiment, the equilibrium operating temperature of the fuel cell stack in the electrolysis mode is preferably, but not necessarily different from the equilibrium operating temperature of the fuel cell stack in the fuel cell mode.
In one preferred aspect, the equilibrium operating temperature of the fuel cell stack in the electrolysis mode may be selected to optimize or maximize the amount of fuel produced. In another preferred aspect, the equilibrium operating temperature of the fuel cell stack in the electrolysis mode may be selected to optimize or minimize the unit cost of the fuel produced. In this aspect, in certain situations, depending on different fuel cell stack design and operating variables, one or more minima may be observed on a curve of unit fuel cost versus amount of fuel produced. The equilibrium operating temperature of the fuel cell stack in the electrolysis mode may be optimized to operate at or near one of the minima on this curve. In another preferred aspect, the equilibrium operating temperature of the fuel cell stack in the electrolysis mode is selected to maximize the amount of fuel produced during some time periods, such as during periods of high fuel demand or price, and at other time periods it is selected to minimize the fuel unit cost, such as during periods of low fuel price or demand. Thus, the equilibrium operating temperature of the fuel cell stack in the electrolysis mode may be higher or lower than that in the fuel cell mode depending on the desired optimized condition, such as fuel amount or fuel unit cost.
Preferably, the equilibrium operating temperature of the fuel cell stack in the electrolysis mode is obtained by adjusting the current density provided to the fuel cell stack for a given reactant product flow rate. For example, the power management system 160 may be used to control the current density provided to the fuel cell stack (i.e., the reversible fuel cell system 190). As discussed above, the system 160 may be any suitable control system, such as a computer or microprocessor. Alternatively, the system 160 may comprise a manual current density control system, such as a manually rotated knob, lever, dial or one or more push buttons.
Alternatively, the equilibrium operating temperature of the fuel cell stack may be adjusted by other methods. For example, the current density may be held constant while the reactant product flow rate may be adjusted manually or automatically by a controller, such as by a manual or automatic valve. If desired, both the current density and the reactant product flow rate may be adjusted to select the desired temperature.
The selection of an optimum equilibrium operating temperature of the fuel cell stack in the electrolysis mode independent of the equilibrium operating temperature of the fuel cell stack in the fuel cell mode provides an operational advantage. As noted above, in order to thermally sustain the SORFC without the use of thermal storage during electrolysis, electrolysis should be performed above the thermal neutral voltage. Thus, the thermal losses keep the fuel cell stack at a desired temperature. If the fuel cell stack is used to generate fuel for use outside the system during electrolysis, the total amount of heat generated in the electrolysis mode is the same. However, some of the heat is used to generate the excess fuel rather than being lost, which reduces the thermal losses and provides an operational cost advantage for the fuel cell stack that is used to generate excess hydrogen.
As discussed above, the reversible fuel cell system 190 may comprise any suitable system, such as a SORFC system, a PEM system or fuel cell/electrolyzer pairs and may be used with any suitable electrical energy source 100 described above, such as a power grid or a renewable energy source. A SORFC stack is the preferred reversible fuel cell system 190.
A single SORFC 10 operating in the electrolysis mode is shown in FIG. 4. The SORFC contains an anode electrode 11, an electrolyte 13 and a cathode electrode 12. An anode gas chamber 14 is formed between the electrolyte 13 and an anode side interconnect (not shown for simplicity). A cathode gas chamber 15 is formed between the electrolyte 13 and a cathode side interconnect (also not shown for simplicity).
A reaction product gas mixture 17 may contain primarily water if hydrogen is used as a fuel. Alternatively, the reaction product gas mixture 17 may contain primarily water vapor and carbon dioxide if a carbon containing gas or liquid is used as a fuel. The reaction product gas mixture 17 is introduced into the cathode gas chamber 15. A direct current power source (not shown) is connected to the anode electrode 11 and the cathode electrode 12 in such a way that when electrical current is flowing, the anode electrode 11 takes on a positive voltage charge and the cathode electrode 12 takes on a negative voltage charge. When the electric current is flowing, the gas mixture 17 gives up oxygen ions 16 to form cathode discharge mixture 19 consisting primarily of hydrogen and optionally carbon monoxide if mixture 17 contained carbon dioxide. Oxygen ions 16 transport across the electrolyte 13 under the electrical current. The oxygen ions 16 are converted into the oxidant, such as oxygen gas 18 on the anode electrode 11 under the influence of the electrical current. The oxygen gas 18 is discharged from the anode chamber 14, while the electrolysis product (e.g., hydrogen and optionally carbon monoxide) is collected from the cathode chamber.
A single SORFC 20 operating in the fuel cell mode is shown in FIG. 5. SORFC 20 is the same as SORFC 10, except that the cathode and anode designations of its electrodes are reversed. Cathode electrode 21 is the same electrode as that identified as the anode electrode 11 in FIG. 4 when operating in the electrolysis mode. Anode electrode 22 is the same electrode as that identified as the cathode electrode 12 in FIG. 4 when operating in the electrolysis mode. Solid oxide electrolyte 23 is the same electrolyte as that identified as electrolyte 13 in FIG. 4 when operating in the electrolysis mode. Cathode gas chamber 24 is the same gas chamber as that identified as the anode gas chamber 14 in FIG. 4 when operating in the electrolysis mode. Anode gas chamber 25 is the same gas chamber as that identified as the cathode gas chamber 15 in FIG. 4 when operating in the electrolysis mode.
A fuel gas 27 is introduced into the anode gas chamber 25. Oxygen gas 28 is introduced into the cathode chamber 24. The fuel may comprise hydrogen, a hydrocarbon gas, such as methane, and/or carbon monoxide. Water may be added to the fuel if desired. An electrical fuel cell load (not shown) is applied to the SORFC 20 and the oxygen gas 28 forms oxygen ions 26 under the influence of the electrical load. Oxygen ions 26 transport across the electrolyte 23 under the influence of the electrical current. On the anode electrode 22, the oxygen ions 26 combine with hydrogen and optionally carbon, if present, from gas mixture 27 to form gas mixture 29 containing water vapor and optionally carbon dioxide, if a carbon containing gas is present in the fuel 27. Gas mixture 29 is discharged from the anode chamber and stored as the reaction product. In the process described above, the SORFC 20 has made electrical energy or power, which is output through its electrodes.
An optional Sabatier reactor subsystem 30 to be used when the fuel comprises methane is shown in FIG. 6. The reactor tube 31 contains a catalyst, such as a platinum family metal on an alumina support. Preferably, the catalyst comprises ruthenium. A gas mixture 32 consisting primarily of hydrogen and carbon monoxide is introduced into reactor tube 31 and contacts the catalyst therein. The gas mixture 32 undergoes an immediate exothermic reaction and produces gas mixture 33 consisting primarily of methane and water vapor. Gas mixture 33 is then discharged from the reactor tube 31. When the Sabatier reactor is used with the SORFC 10 operating in the electrolysis mode, the hydrogen and carbon monoxide discharge mixture 19/32 is provided from the SORFC into the Sabatier reactor 30.
Because the reaction within reactor tube 31 is highly exothermic, a heat exchanger 34 located in or adjacent to tube 31 is used to capture the generated heat. Gas mixture 35, consisting primarily of carbon dioxide and water, flows through heat exchanger 34 to absorb the exothermic reaction heat. When the Sabatier reactor is used with the SORFC 10 operating in the electrolysis mode, the water vapor and carbon dioxide inlet mixture 17/35 is heated in the Sabatier reactor by the reaction of the outlet or discharge mixture 19/32. The water vapor and carbon dioxide inlet mixture 17/35 is then provided from the Sabatier reactor into the SORFC 10.
The SORFC system 50 of a preferred embodiment operating in a fuel cell mode is shown of FIG. 7 as a simplified schematic. The system 50 as shown operates with methane as a fuel. However, if desired, a hydrogen fuel may be used instead, as discussed above. A single SORFC 20 previously shown in FIG. 5 as a cross section operating in the fuel cell mode is shown again in FIG. 7. While a single SORFC is shown, it should be understood that the system 50 contains a plurality of SORFC stacks. A hydrogen recovery unit 51 transfers hydrogen gas from within a first gas mixture stream into a second gas stream. The hydrogen recovery unit 51 can be a device which recovers hydrogen based on absorption/adsorption processes or based on an electrochemical proton exchange process. The electrochemical exchange process is preferred.
An enthalpy recovery unit 52 transfers water vapor from first gas stream to a second gas stream. The enthalpy recovery unit 52 can be a device which transfers water vapor based on cyclic desiccant beds or a rotating desiccant wheel. The desiccant wheel (i.e., "enthalpy wheel") is preferred. An optional purge valve 53, such as a normally closed powered open solenoid valve may be used if pure oxygen is used. A heat exchanger 54 is a counter flow gas-gas heat exchanger. The SORFC power output, such as output electrode(s), is connected to a power distribution system. The oxidizer (i.e., oxygen or air) enters the system 50 through the oxidizer inlet or conduit 55, while the fuel enters the system through the fuel inlet or conduit arrangement 56/57. The fuel exhaust exits through conduit arrangement 58/59.
A method of operating the system 50 in the fuel cell mode is now described. Within the SORFC system 50 shown in FIG. 7, oxidizer, such as pure oxygen reactant gas from an oxygen storage vessel, such as a liquid oxygen tank, or air, is delivered to the cathode chamber of SORFC 20 through inlet conduit 55. If oxygen reactant is highly pure, then it is normally dead headed within the cathode chamber of SORFC 20. However, even the purest of gases will include trace non reactant gas species. As a result the cathode chamber of SORFC 20 should be occasionally purged of these non reactant species. Oxygen purge valve 53 is used to accomplish this purging.
High purity hydrocarbon inlet stream, such as a methane stream, is introduced into the SORFC system 50 from a hydrocarbon storage vessel, such as a tank (not shown for clarity), through conduit 56 into the hydrogen recovery unit 51. As noted above, a hydrogen fuel inlet stream may be used instead. Within the hydrogen recovery unit 51, hydrogen gas is transferred from the fuel exhaust outlet stream in conduit 58 into the methane stream. This hydrogen supports a uniform methane reformation process within the anode chamber of SORFC 20. The methane and hydrogen mixture next is introduced into the enthalpy recovery unit 52, where a portion of the water vapor is transferred from the fuel exhaust outlet stream in conduit 58 into the methane and hydrogen inlet stream. Preferably, the enthalpy recovery unit also transfers heat from the outlet stream to the inlet stream. From the enthalpy recovery unit 52, the methane, hydrogen and water vapor mixture is introduced into the heat exchanger 54, where the gas mixture temperature is increased near to the operational temperature of 600 C to 1000 C using the high temperature waste heat from the outlet stream in conduit 58. From heat exchanger 54, the hot mixture of methane, hydrogen, and water vapor is delivered to the anode chamber of SORFC 20 through conduit 57. Some steam reformation of the methane will occur in the heat exchanger 54 and conduit 57 but the amount is suppressed by the existence of the hydrogen. The completion of the steam reforming of the methane is accomplished in the anode chamber of the SORFC 20.
Within the anode chamber of the SORFC 20, the steam reforming of methane and the oxidation of carbon and hydrogen in the fuel cell reactions converts the discharged gas mixture (i.e., fuel exhaust) in conduit 58 to carbon dioxide, additional water vapor, and excess hydrogen. If hydrogen rather than methane is used as a fuel, then no carbon dioxide is produced. The discharged gas mixture in conduit 58 passes through heat exchanger 54, releasing waste heat, and then through the enthalpy recovery unit 52 to supply a portion of the water vapor to support the input methane reformation. The discharged gas mixture in conduit 58 is then directed to the hydrogen recovery unit 51 where virtually all but trace quantities of the hydrogen is transferred to the inlet fuel stream. Using the preferred electrochemical proton exchange process as the hydrogen recovery unit 51, provides an exact measure of the hydrogen content within the discharged gas mixture in conduit 58 which is used to adjust the input methane flow rate. The outlet mixture in conduit 59 from hydrogen recovery unit 51 contains only carbon dioxide and water which are stored separately (not shown).
The SORFC system 60 of a preferred embodiment operating in an electrolysis mode is shown of FIG. 8 as a simplified schematic. A single SORFC 10 previously shown in FIG. 4 as a cross section operating in the electrolysis mode is shown again in FIG. 8. The hydrogen recovery unit 51 transfers hydrogen gas from within a first gas mixture stream into a second gas stream. The hydrogen recovery unit 51 can be a device which recovers hydrogen based on absorption/adsorption processes or based on an electrochemical proton exchange process. The electrochemical exchange process is preferred.
If methane is used as a fuel, then the system 60 also includes the Sabatier reactor subsystem 30, described with respect to FIG. 6, which converts carbon monoxide and hydrogen into methane and water vapor. If methane is used as a fuel, then the reactant product comprising carbon dioxide and water enter the system 60 through inlet or conduit 61, which may be the same or different than conduit 56, shown in FIG. 7. If hydrogen is used as a fuel, then water is used as a reactant product. The generated oxygen exits through outlet or conduit 65, while the methane and water exit through outlet or conduit arrangement 63/64. Conduits 63/64 and 65, respectively, may be the same or different conduits as conduits 58/59 and 55, respectively, shown in FIG. 7.
Thus, the system 60 operating in the electrolysis mode is the same system as system 50 operating in the fuel cell mode, except that the inlet and outlet streams are steered through the optional Sabatier reactor subsystem 30 instead of through the heat exchanger 54 and the enthalpy recovery unit 52, which remains inactive in the electrolysis mode. The inlet and outlet streams may be steered using valves and parallel conduits (not shown for clarity). Furthermore, the electrode designations in the SORFC 10 of system 60 are reversed compared to SORFC 20 of system 50, as explained in detail with respect to FIGS. 1 and 2 above.
A method of operating the system 60 in the electrolysis mode is now described. If methane is used as a fuel, then carbon dioxide and water are introduced into the SORFC system 60 through conduit 61 into hydrogen recovery unit 51. Carbon dioxide may be introduced from a carbon dioxide storage vessel or from a conduit. If hydrogen is used as a fuel, then the carbon dioxide is omitted. Within the hydrogen recovery unit 51, hydrogen gas is transferred from the outlet stream in conduit 63 into the carbon dioxide and water inlet stream. This extra hydrogen eventually assures that all the carbon bearing gases are converted into methane within the Sabatier reactor subsystem 30. The carbon dioxide, water, and hydrogen inlet mixture next is introduced into the Sabatier subsystem 30 heat exchanger where it is heated by the exothermic reaction. From the Sabatier subsystem 30, the carbon dioxide, hydrogen and water vapor mixture is delivered to the cathode chamber of SORFC 10 through conduit 62. Within the cathode chamber of SORFC 10, the carbon dioxide and water vapor are reduced by electrolysis to carbon monoxide and hydrogen. Excess water and some unreacted carbon dioxide will be discharged from the cathode chamber of SORFC 10 along with the carbon monoxide and hydrogen through conduit 63.
The discharged gas mixture in conduit 63 passes through the Sabatier subsystem 30 to convert all the carbon oxides to methane and water with the excess hydrogen. If hydrogen is used as a fuel, then the Sabatier subsystem 30 is omitted and the discharged water vapor comprises the reactant product. The discharged gas mixture in conduit 63 is then directed to the hydrogen recovery unit 51 wherein virtually all but trace quantities of the hydrogen is transferred to the inlet carbon dioxide and water stream. Using the preferred electrochemical proton exchange process as the hydrogen recovery unit 51, provides an exact measure of the hydrogen content within the discharged gas mixture in conduit 63 which is used to adjust the input carbon dioxide flow rate. The outlet mixture in conduit 64 from hydrogen recovery unit 51 contains only methane and water which are stored separately (not shown). If desired, the water may be discharged and fresh water from a water pipe may be used for the SORFC reactions.
In the meantime, pure oxygen gas is generated in the SORFC 10 anode during the electrolysis process. The oxygen is discharged from the SORFC 10 anode through conduit 65 and on to discharge, direct metabolic use and/or to liquefied storage (not shown).
The Sabatier reactor which generates methane is advantageous because it operates at a temperature of about 400-900° C. degrees, which is a suitable temperature for heating the inlet stream being provided into the SORFC to or near to a desired SORFC operating temperature. However, other reactors which generate hydrocarbon gases other than methane may be used instead of the Sabatier reactor.
For example, reactors which convert an exhaust gas which contains hydrogen and carbon oxides, such as carbon monoxide and/or carbon dioxide, and optionally water, to methanol may be used instead. The methanol reactors typically, but not necessarily, contain a copper catalyst which converts hydrogen, carbon oxides and/or water vapor to methanol. These reactors may be catalyst bed type reactors, such as ARC reactors, quench converters, tube cooled converters, isothermal reactors where a continuous catalyst bed surrounds a spiral wound heat exchanger, and other suitable reactor types.
The following exothermic reactions are involved in the synthesis of methanol: CO+2H2=CH3OH; CO2+3H2=CH3OH and CO+H2O=CO2+H2. The use of a SORFC operating in the electrolysis mode to generate methanol is advantageous because the SORFC exhaust gas contains a similar composition to synthesis gas that is used as a source gas for methanol production. The synthesis gas is usually specially prepared in a separate catalytic steam reforming of natural gas in conventional methanol synthesis process.
If desired, additional reactors may be present downstream of the Sabatier or methanol reactors to further purify the methane or methanol if desired. Alternatively, the additional reactors may be used to convert methane or methanol to other hydrocarbon gases, such as ethane, propane, octane, formic acid, formaldehyde and/or other suitable hydrocarbon gases. These hydrocarbon gases may be used as a fuel for the SORFC in the fuel cell mode and/or may be removed from the SORFC system for other use, sale or storage. Thus, the SORFC system may be used to generate various hydrocarbon fuels for storage or sale when the system is not generating power in the fuel cell mode. Alternatively, suitable reactors may be used to convert the hydrogen and carbon oxide containing SORFC electrolysis mode exhaust to the other hydrocarbon gases, such as ethane, propane, octane, formic acid, formaldehyde and/or other suitable hydrocarbon gases.
The SORFC systems described herein may have other embodiments and configurations, as desired. Other components, such as fuel side exhaust stream condensers, heat exchangers, heat-driven heat pumps, turbines, additional gas separation devices, hydrogen separators which separate hydrogen from the fuel exhaust and provide hydrogen for external use, fuel preprocessing subsystems, fuel reformers and/or water-gas shift reactors, may be added if desired, as described, for example, in U.S. application Ser. No. 10/300,021, filed on Nov. 20, 2002, in U.S. Provisional Application Ser. No. 60/461,190, filed on Apr. 9, 2003, and in U.S. application Ser. No. 10/446,704, filed on May 29, 2003 all incorporated herein by reference in their entirety.
The foregoing description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The description was chosen in order to explain the principles of the invention and its practical application. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents.
Previous Patent: Evaporatively cooled hybrid PEM fuel cell power plant assembly
Next Patent: FUEL CELL SYSTEM


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Monday Night Football (abreviado como MNF y también conocido como ESPN Monday Night Football on ABC en las transmisiones simultáneas) es una transmisión de televisión en vivo estadounidense de los juegos de los lunes por la noche de la National Football League (NFL) que se hace actualmente por ESPN, ABC (juegos seleccionados), ESPN2 (transmisión alternativa de "Manningcast") y ESPN+ en los Estados Unidos.

De 1970 a 2005, se emitió en ABC antes de pasar exclusivamente a ESPN, que sigue siendo el principal canal de transmisión. En 2020 regresó a ABC, en transmisiones simultáneas seleccionadas con ESPN, y desde 2022 también cuenta con transmisiones exclusivas seleccionadas. Monday Night Football fue, junto con Hallmark Hall of Fame y la serie de televisión de antología de Walt Disney, uno de los programas de horario estelar de mayor duración en la televisión comercial y de mayor audiencia, particularmente entre los espectadores masculinos.MNF es precedido en ESPN por Monday Night Countdown.

Monday Night Football también se transmite en Canadá en TSN y RDS, y en la mayor parte de Europa. El 7 de septiembre de 2013, la NFL anunció que British Eurosport transmitiría los partidos del Monday Night Football en vivo en el Reino Unido para las temporadas 2013 y 2014. Las transmisiones también se ven en la mayor parte de Oceanía en ESPN Australia, mediante Sport TV 3 y SportTV HD en Portugal, en TV 2 Sport en Dinamarca, y en algunas otras regiones del mundo fuera de EE. UU. en ESPN International. Una versión en español se transmite por ESPN Deportes en los EE. UU. (disponible en ESPN+) y por ESPN Latinoamérica en América Latina, mientras que una versión en portugués se transmite por ESPN Brasil (disponibles en Star+). De acuerdo con una política de transmisión de la NFL destinada a permitir que aquellos que no están suscritos a la televisión por cable o satelital vean los juegos televisados por una cadena de televisión paga, los juegos también están disponibles en las estaciones de televisión terrestre en el mercado local de cada equipo participante.

En 2011 ESPN extendió su contrato del MNF por ocho temporadas adicionales, lo que le otorgó los derechos de las transmisiones hasta 2021. El nuevo acuerdo, valorado en alrededor de $15 000 millones de dólares, también otorga a ESPN los derechos para ampliar los aspectos destacados, internacionales y de transmisión. Un nuevo acuerdo firmado en 2021 hace que ESPN retenga estos derechos hasta 2033. El nuevo acuerdo también incluye los derechos a dos Super Bowls en 2027 y 2031, la introducción de programación flexible y dos dobles carteleras adicionales durante la temporada, con un juego del domingo por la mañana en ESPN+.

Comentaristas

En la época de ABC, el narrador fue Keith Jackson en 1970, Frank Gifford desde 1971 hasta 1985, y Al Michaels desde 1986 hasta 2005. Numerosos comentaristas participaron en el programa, destacándose Howard Cosell (1970-1983), Don Meredith (1970-1973, 1977-1984), Frank Gifford (1986-1997), Dan Dierdorf (1987-1998) y John Madden (2002-2005). En la era de ESPN, el narrador ha sido Mike Tirico desde 2006 hasta 2015 y Sean McDonough en 2016, mientras que entre los comentaristas se destacaron Tony Kornheiser (2006-2008), Ron Jaworski (2007-2011) y Jon Gruden (2009-2017). Con Gruden regresando a los banquillos de la NFL para entrenar a los Oakland Raiders y después de anunciar su retirada, el Tight end de los Dallas Cowboys Jason Witten se incorpora a MNF a partir de la temporada 2018. Para la temporada 2022, el nuevo narrador para los juegos de "Monday Night Football" es Joe Buck, que fue narrador de MLB y NFL para FOX Sports de 1996 a 2021 y lo acompaña el exjugador miembro de Salon de la Fama Troy Aikman como comentarista.

Los presentadores de Monday Night Football en ESPN Deportes para América Latina y Estados Unidos son Álvaro Martín, Raúl Allegre y John Sutcliffe desde los estadios y Eduardo Varela con Pablo Viruega desde estudios. Desde la temporada 2007, Martín y Allegre relatan el partido remotamente desde estudios, y solo Sutcliffe comenta desde el campo de juego.

Estadísticas

 Más puntos anotados por el equipo ganador: 59, Philadelphia vs Washington (15 de noviembre de 2010)
 Más puntos anotados por el equipo perdedor: 51, Los Ángeles Rams (54) vs Kansas city Chiefs (51) (19 de noviembre de 2018)
 Menos puntos anotados por el equipo ganador: 3 (3-0), Pittsburgh vs Miami (26 de noviembre de 2007)
 Victoria más amplia: 48-3, Baltimore vs Green Bay (19 de diciembre de 2005)

 Resultados por equipo

 Miami Dolphins: 40 victorias, 39 derrotas
 Dallas Cowboys: 47 victorias, 32 derrotas
 San Francisco 49ers: 48 victorias, 25 derrotas
 Pittsburgh Steelers: 44 victorias, 24 derrotas
 Oakland Raiders: 39 victorias, 26 derrotas
 Denver Broncos: 30 victorias, 35 derrotas, 1 empate
 Washington Redskins: 28 victorias, 37 derrotas
 Chicago Bears: 27 victorias, 37 derrotas
 Green Bay Packers: 29 victorias, 31 derrotas, 1 empate
 Minnesota Vikings: 27 victorias, 30 derrotas
 Los Angeles / St. Louis Rams: 26 victorias, 31 derrotas
 New York Giants: 21 victorias, 35 derrotas, 1 empate

Referencias

Enlaces externos

 NFL en ESPN
 ESPN.com - NFL Index
 ABCSports.com
 John Madden

Programación original de ESPN
Programas de televisión de Estados Unidos
MNF

redpajama_set_name: RedPajamaWikipedia


DESCRIPTION The cksum utility shall calculate and write to standard output a cyclic redundancy check (CRC) for each input file, and also write to standard output the number of octets in each file. The CRC used is based on the polynomial used for CRC error checking in the ISO/IEC 8802-3:1996 stan- dard (Ethernet).
1. The n bits to be evaluated are considered to be the coefficients of a mod 2 polynomial M( x) of degree n-1. These n bits are the bits from the file, with the most significant bit being the most signif- icant bit of the first octet of the file and the last bit being the least significant bit of the last octet, padded with zero bits (if necessary) to achieve an integral number of octets, followed by one or more octets representing the length of the file as a binary value, least significant octet first. The smallest number of octets capable of representing this integer shall be used.
2. M( x) is multiplied by x**32 (that is, shifted left 32 bits) and divided by G( x) using mod 2 division, producing a remainder R( x) of degree <= 31.
3. The coefficients of R( x) are considered to be a 32-bit sequence.
file A pathname of a file to be checked. If no file operands are specified, the standard input shall be used.
STDIN The standard input shall be used only if no file operands are speci- fied. See the INPUT FILES section.
INPUT FILES The input files can be any file type.
If no file operand was specified, the pathname and its leading <space> shall be omitted.
APPLICATION USAGE The cksum utility is typically used to quickly compare a suspect file against a trusted version of the same, such as to ensure that files transmitted over noisy media arrive intact. However, this comparison cannot be considered cryptographically secure. The chances of a damaged file producing the same CRC as the original are small; deliberate deception is difficult, but probably not impossible.
Although input files to cksum can be any type, the results need not be what would be expected on character special device files or on file types not described by the System Interfaces volume of IEEE Std 1003.1-2001. Since this volume of IEEE Std 1003.1-2001 does not specify the block size used when doing input, checksums of charac- ter special files need not process all of the data in those files.
The algorithm is expressed in terms of a bitstream divided into octets. If a file is transmitted between two systems and undergoes any data transformation (such as changing little-endian byte ordering to big- endian), identical CRC values cannot be expected. Implementations per- forming such transformations may extend cksum to handle such situa- tions.
RATIONALE The following C-language program can be used as a model to describe the algorithm. It assumes that a char is one octet. It also assumes that the entire file is available for one pass through the function. This was done for simplicity in demonstrating the algorithm, rather than as an implementation model.
The historical practice of writing the number of "blocks" has been changed to writing the number of octets, since the latter is not only more useful, but also since historical implementations have not been consistent in defining what a "block" meant. Octets are used instead of bytes because bytes can differ in size between systems.
The algorithm used was selected to increase the operational robustness of cksum. Neither the System V nor BSD sum algorithm was selected. Since each of these was different and each was the default behavior on those systems, no realistic compromise was available if either were selected-some set of historical applications would break. Therefore, the name was changed to cksum. Although the historical sum commands will probably continue to be provided for many years, programs designed for portability across systems should use the new name.
The algorithm selected is based on that used by the ISO/IEC 8802-3:1996 standard (Ethernet) for the frame check sequence field. The algorithm used does not match the technical definition of a checksum; the term is used for historical reasons. The length of the file is included in the CRC calculation because this parallels inclusion of a length field by Ethernet in its CRC, but also because it guards against inadvertent collisions between files that begin with different series of zero octets. The chance that two different files produce identical CRCs is much greater when their lengths are not considered. Keeping the length and the checksum of the file itself separate would yield a slightly more robust algorithm, but historical usage has always been that a sin- gle number (the checksum as printed) represents the signature of the file. It was decided that historical usage was the more important con- sideration.
Early proposals contained modifications to the Ethernet algorithm that involved extracting table values whenever an intermediate result became zero. This was demonstrated to be less robust than the current method and mathematically difficult to describe or justify.
The pseudo-code is reproduced exactly as given; however, note that in the case of cksum, A[i] represents a byte of the file, the words X and Y are treated as a single 32-bit value, and the tables f and fare a single table containing 32-bit values.
The referenced Sarwate article also discusses generating the table.


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Dhaka January 18, 2022, 9:55 pm
FT Online | Published: 2019-11-05 16:58:34 BdST
9th Dhaka Lit Fest set kicks off Thursday
The ninth edition of Dhaka Lit Fest, an international literature festival, begins on Thursday on the Bangla Academy premises, aiming to create a bridge between native and international literary figures.
Organisers announced the details of the three-day event at a press conference at the Jatiya Press Club on Tuesday.
This year's fest line-up features award-winning author and Booker Prize finalist Monica Ali (Bangladeshi-born British writer), literary icon Shankar (India), Pulitzer Prize-winning writer Jeffrey Gettleman (American journalist), historian William Dalrymple (Scottish historian and writer), writer Shashi Tharoor (India), DSC Prize-winning writer HM Naqvi (Pakistan), poet Tishani Doshi (India), award-winning author Swapnamoy Chakraborty (India), poet and journalist Mridul Dasgupta (India), Bangladeshi writers Syed Manzoorul Islam, Imdadul Haq Milon, Kaiser Haq and Shaheen Akhtar , among others.
Sadaf Saz, one of the directors of the event, said over 200 speakers, performers and thinkers, representing five continents, will take part in the 3-day event in over 100 sessions with parallel sessions going on in both Bangla and English, which are free and open to all.
"One of the special highlights of this year will bescreening of 'Hasina: A daughter's tale' and an appearance by Shankar on the closing day," she added.
Gemcon Literary Awards, the highest monetary value literary prize in Bangladesh, will be awarded at the festival.
"Our sole purpose is to uphold Bangladesh's secularism, democracy and literature to the world," said SadafSaz.
She also announced that the DLF 2020 will be dedicated to Father of the Nation Bangabandhu Sheikh Mujibur Rahman.
Dhaka Lit Fest is supported by the Ministry of Cultural Affairs and hosted by Bangla Academy. Dhaka Tribune and Bangla Tribune are the Title Sponsors of the event.
Dhaka Tribune Editor Zafar Sobhan said, "The goal of Dhaka Lit Fest is to bring the world to Bangladesh and Bangladesh to the world...we're focusing on Bangladeshi writers."
Bangla Tribune Editor Zulfiqer Russel and City Bank Managing Director Masrur Arefin also spoke at the press conference.
Independent University Bangladesh is the gold sponsor while BRAC Bank, South East Bank and Dhaka Bank are the silver sponsors. Other partners include Mutual Trust Bank, Nagad, bikash, Scholastica, University of Asia Pacific, British Council, Hotel Intercontinental, Norwegian Embassy in Dhaka, Goethe Institut and EMK Center.
However, free online registration is open at www.register.dhakalitfest.com while any update of the event will be shared through the festival's website at dhakalitfest.com and at facebook.com/dhakalitfest.

redpajama_set_name: RedPajamaCommonCrawl


text:
Anthropology & Sociology (4)
Architecture, Design, Urban Planning (1)
Community Activism & Social Reform (2)
(-) Education (11)
(-) Environment, Ecology (11)
Feminism, Women, Women's Studies (2)
Healthcare, Medicine, Mental Health (1)
Native American History & Culture (1)
Science and Science Writers (5)
Theology, Religion, Religious Organizations (1)
Working, Labor, Economy (2)
World History & Politics (2)
Historians (1)
Medical personnel (1)
Social Reformers (2)
Social Scientists (1)
Education Environment, Ecology
Vine Deloria discusses his book "The Metaphysics of Modern Existence"
Vine Deloria discusses his book "The Metaphysics of Modern Existence", religion, ethics, Native Americans, Native American culture, and Native American history. Includes a previous interview with Vine Deloria at O'Hare Airport.
Studs Terkel, Dr. Bertram Carnow, and Joan and Bob Ericksen discuss health hazards in work environments
Discussing health hazards in work environments and environmental pollution. Interviewing Dr. Bertram Carnow and Bob and Joan Ericksen.
R. Buckminster (Richard ) Fuller talks with Studs Terkel
A sprawling conversation with R. Buckminster Fuller including his great aunt Margaret Fuller, future communication, the nature of work, human nature, and physics.
Miles Horton and Elliot Wigginton discuss the Foxfire Project
Discussing the Foxfire books and interviewing Miles Horton and Elliot Wigginton. Wigginton is one of the editors/compilers of several of the books in the series about traditional handicrafts and practical methods used in rural life.
Mildred Loomis discusses the green revolution and the back to the land movement ; part 2
Discussing the green revolution and the "modern homestead" and interviewing Mildred Loomis. Mildred Loomis discusses the back to the land movement.
Interviewing Austrian biology teacher Albert Kaufmann, a winner of the Kohl International Peace Prize for his work in peace education
Francis S. Chase discusses education, art, and science ; part 2
Francis S. Chase discusses education, art, and science. Chase also discusses creativity, human behavior, and technology among other topics.
Donald Johanson discusses his book "Lucy: The Beginnings of Humankind"
Studs talks with Donald Johanson about his book "Lucy: The Beginnings of Humankind," in which the famed paleoanthropologist describes his discovery of the female hominin fossil in Ethiopia. The conversation includes talk of Charles Darwin, Eugène Dubois' Java Man discovery, what makes a hominid, holes in the fossil record, fossil dating, his disagreements with Louis and Richard Leakey, site discovery, and his belief that the Hadar Formation in the Afar Triangle of Ethiopia holds the keys to the evolutionary puzzle. Includes snippets of the Beatles' "Lucy in the Sky with Diamonds."
Discussing the book "Shadows of Forgotten Ancestors: A Search for Who We Are" with Ann Druyan
Discussing the book "Shadows of Forgotten Ancestors: A Search for Who We Are" about the evolution and the future of the human species. Includes an excerpt of the astronomer Harlow Shapley speaking at the beginning. Includes Carl Sagan reading an excerpt from the book at the end.
Bob and Joan Ericksen discuss the literary work of Peter Weiss and environmental ecology
Bob and Joan Ericksen, both educators, artists, and environmental ecologists, discuss the literary work of Peter Weiss' "I Come Out of My Hiding Place" and environmental ecology. Excerpt of Peter Weiss reading from "I Come Out of My Hiding Place." The book speaks of why he writes and why he pursues his art (unknown source). The interview ends with a reading by Studs of an excerpt fro, Gustav Meyrink's "The Green Face."


I threw together this simple marinade the other morning, let it sit with some lovely pastured chicken legs all day, and then roasted them up for dinner night. The legs came out incredibly juicy and delicious. So good, in fact, that I wondered just what I had done to deserve such great flavor out of such a simple recipe. But I knew what I had done right – I had followed the basic rules for creating a marinade and had allowed adequate time for the meat to marinate.
So what are my rules for creating a great marinade? You only need to remember three things: oil, acid, and flavor. Ratios are important in a marinade, but only very generally. You'll need slightly more acid then oil (about 1/3 oil to 2/3 acid – more on that later), but flavorings are limited only by your imagination.
Oil: Any oil that is liquid at room temperature will work well. As you probably know, I avoid "vegetable oils" due to their excessively high omega-6 content. Some of my favorite non-vegetable oils for marinades are olive, sesame, walnut, and avocado oils.
Acid: Fresh squeezed lemon, lime, or orange juice, vinegar of any kind (sherry vinegar and apple cider vinegar are my favorites), wine, yogurt, tomato, etc.
Flavorings: Garlic, red onion, shallots, ginger, chiles, citrus zest, rosemary, oregano, cilantro, or any fresh herb that you like, any number of spices (garam masala, turmeric, cumin, coriander, and smoked or sweet paprika are some of my favorites), SALT, and on and on.
When making your marinade, begin with your oil and acid, remembering the 1/3 oil, 2/3 acid ratio. If you're using something less acidic as your primary acidic ingredient (oranges, wine, or yogurt for example), I recommend including a little bit of a more strongly acidic component to ensure the most tender and flavorful result (for example avocado oil + orange (less acidic) + lime (more acidic) + smoked paprika + salt). After all, the acid in a marinade is what works to break down and tenderize the meat, paving the way for the flavorings you choose to really get in there.
Now you can add your flavorings and the last very important component, plenty of salt. When salting your marinade, think about how much salt you would use to season the amount of meat that you have, and then double it. This is a good idea because what's left of your marinade will be thrown away (along with a lot of the salt) before cooking.
So without further ado, here is my recipe Syrian Roasted Chicken, made with a marinade of olive oil, lemon, oregano, and Aleppo pepper.
While visiting the butchershop of my favorite Latino Grocery last week, I noticed bags of large, dried shrimp sitting on the meat counter. They shrimp had been left in their shells when they were dried, so they looked particularly beautiful. I knew that the dried shrimp would last for months or longer, so I picked up a bag and started turning over ideas in my head.
When I got home, I broke in to one of the shrimp and gave it a taste. It was surprisingly sweet, different from the more pungent, small dried shrimp I've used in the past for Vietnamese and Thai dishes. With such a mild, friendly flavor, I knew I should make a dish that would allow the dried shrimp to really shine through.
I decided on a traditional, Mexican-style red chile soup with guajillo chiles, onion, and fire-roasted tomatoes, and I added the dried shrimp to the broth while it simmered to give it an extra-rich flavor. I then pureed everything together, strained the broth to ensure the silkiest texture, and used it as a base for this delicious Shrimp and Red Chile Soup.
The idea for this over-the-top recipe came to me in a flash last summer. I was thinking about an amazing dish I once ate at a taverna in Greece of broiled mussels with feta cheese and somehow at the same moment I was thinking about poutine, the classic Montreal dish of french fries with gravy and cheese curds (the mind works in mysterious ways). This recipe is the love child of these two incredible recipes, my Mussels Poutine with Tomato-Bacon Gravy.
For this dish, crispy, fried Russet potato slices are topped with a tomato and bacon gravy made with sweet caramelized onions and garlic. The acidity of the tomato gravy helps to cut down on the richness of the other ingredients and makes a great base for steaming the mussels. The dish is assembled, topped with cheese curds, and then placed under the broiler to get amazingly melty. I think this dish would be equally wonderful with feta cheese, but I used traditional cheddar curds in honor of my husband's Wisconsin roots.
Between three of us, we couldn't quite finish this poutine, so don't get any wild ideas about doubling the recipe unless you're serving this for a party. Enjoy the poutine with the rest of the bottle of dry white wine you used for the mussels. You're going to need it!
It's that time of year when summer gardens are starting to wilt and blacken in the cold night, but here in the Willamette Valley some varieties of tomatoes have managed to hold on thanks to a handful of warm, sunny November days. My uncle's backyard garden has several enormous, Sungold cherry tomato plants, and what started in the beginning of November as sweatshirt pocket-fulls of sweet tomatoes gathered for snacks has turned suddenly into a mad dash to save all of the beautiful, unripe tomatoes as the weather has suddenly taken a turn for the colder.
Sometimes after days of cooking and cooking and more cooking, all I really want to eat is the simplest thing. This summer it was a tomato and fresh mozzarella salad with olive oil and salt – I must've eaten that salad for lunch twenty times. With winter around the corner and a head cold hanging on for days now, I've been really craving meat. I needed a recipe that didn't require much of me but that would offer a big reward in terms of flavor and comfort.
Beef Bourguignon, the long-simmered beef stew made famous by Julia Child, is the perfect choice for a cool-weather Sunday dinner. I simplified Julia's already no-nonsense recipe even further, using only beef, bacon, onion, garlic, and tomato paste as the base. I then simmered the beef for several hours in approximately equal parts Red Burgundy wine and beef broth. The result was incredibly tender and unbelievable rich. We enjoyed the stew with simple mashed potatoes made with butter and sour cream, as well as some roasted Brussel sprouts from the farmer's market.
Some may find a stew that takes several hours to cook overwhelming or tedious, but I couldn't disagree more. I find it so rewarding to spend 30 minutes getting a dish off on the right foot and then allowing it to do its thing all afternoon while I spend the rest of the day doing whatever I'd like to. This dish is proof that with minimal effort you can end up with a meal that tastes incredibly rich and complex and feels wonderfully comforting.
Crab Cakes have a reputation as a super decadent dish, but they are really quite simple to make. In this recipe, one pound of crab meat is tossed gently with fresh herbs, mustard, sour cream, and almond flour, briefly chilled, and then quickly pan fried in a little olive oil or butter.
Dungeness Crab season is approaching in Oregon and I am fantasizing about sitting on a Newport dock, sipping on a robust stout while my crab pot sits on the bottom of the bay, luring my dinner in through its one-way door. It's a terribly sunny day with no wind on the Oregon Coast in this fantasy, by the way.
Whether or not you make it out crabbing this winter, fresh Dungeness will be readily available from December through April, and when it's not in season, canned claw meat is not at all difficult to find.
So on a harried weeknight this winter, when you're sick and tired of roasting every darned thing, remember this recipe, and know that a dinner of tender crab cakes is less than an hour away.


text:
package scala
package collection
package mutable

import scala.language.higherKinds

/** Base type of mutable Maps */
trait Map[K, V]
  extends Iterable[(K, V)]
    with collection.Map[K, V]
    with MapOps[K, V, Map, Map[K, V]]
    with Growable[(K, V)]
    with Shrinkable[K]
    with MapFactoryDefaults[K, V, Map, Iterable] {

  override def mapFactory: scala.collection.MapFactory[Map] = Map

  /*
  //TODO consider keeping `remove` because it returns the removed entry
  @deprecated("Use subtract or -= instead of remove", "2.13.0")
  def remove(key: K): Option[V] = {
    val old = get(key)
    if(old.isDefined) subtract(key)
    old
  }
  */

  /** The same map with a given default function.
    *  Note: The default is only used for `apply`. Other methods like `get`, `contains`, `iterator`, `keys`, etc.
    *  are not affected by `withDefaultValue`.
    *
    *  Invoking transformer methods (e.g. `map`) will not preserve the default value.
    *
    *  @param d     the function mapping keys to values, used for non-present keys
    *  @return      a wrapper of the map with a default value
    */
  def withDefault(d: K => V): Map[K, V] = new Map.WithDefault[K, V](this, d)

  /** The same map with a given default value.
    *  Note: The default is only used for `apply`. Other methods like `get`, `contains`, `iterator`, `keys`, etc.
    *  are not affected by `withDefaultValue`.
    *
    *  Invoking transformer methods (e.g. `map`) will not preserve the default value.
    *
    *  @param d     default value used for non-present keys
    *  @return      a wrapper of the map with a default value
    */
  def withDefaultValue(d: V): Map[K, V] = new Map.WithDefault[K, V](this, x => d)
}

/**
  * @define coll mutable map
  * @define Coll `mutable.Map`
  */
trait MapOps[K, V, +CC[X, Y] <: MapOps[X, Y, CC, _], +C <: MapOps[K, V, CC, C]]
  extends IterableOps[(K, V), Iterable, C]
    with collection.MapOps[K, V, CC, C]
    with Cloneable[C]
    with Builder[(K, V), C]
    with Growable[(K, V)]
    with Shrinkable[K] {

  def result(): C = coll

  @deprecated("Use - or remove on an immutable Map", "2.13.0")
  final def - (key: K): C = clone() -= key

  @deprecated("Use -- or removeAll on an immutable Map", "2.13.0")
  final def - (key1: K, key2: K, keys: K*): C = clone() -= key1 -= key2 --= keys

  /** Adds a new key/value pair to this map and optionally returns previously bound value.
    *  If the map already contains a
    *  mapping for the key, it will be overridden by the new value.
    *
    * @param key    the key to update
    * @param value  the new value
    * @return an option value containing the value associated with the key
    *         before the `put` operation was executed, or `None` if `key`
    *         was not defined in the map before.
    */
  def put(key: K, value: V): Option[V] = {
    val r = get(key)
    update(key, value)
    r
  }

  /** Adds a new key/value pair to this map.
    *  If the map already contains a
    *  mapping for the key, it will be overridden by the new value.
    *
    *  @param key    The key to update
    *  @param value  The new value
    */
  def update(key: K, value: V): Unit = { coll += ((key, value)) }

  /**
   * Update a mapping for the specified key and its current optionally-mapped value
   * (`Some` if there is current mapping, `None` if not).
   *
   * If the remapping function returns `Some(v)`, the mapping is updated with the new value `v`.
   * If the remapping function returns `None`, the mapping is removed (or remains absent if initially absent).
   * If the function itself throws an exception, the exception is rethrown, and the current mapping is left unchanged.
   *
   * @param key the key value
   * @param remappingFunction a partial function that receives current optionally-mapped value and return a new mapping
   * @return the new value associated with the specified key
   */
  def updateWith(key: K)(remappingFunction: Option[V] => Option[V]): Option[V] = {
    val previousValue = this.get(key)
    val nextValue = remappingFunction(previousValue)
    (previousValue, nextValue) match {
      case (None, None) => // do nothing
      case (Some(_), None) => this.remove(key)
      case (_, Some(v)) => this.update(key,v)
    }
    nextValue
  }

  /** If given key is already in this map, returns associated value.
   *
   *  Otherwise, computes value from given expression `op`, stores with key
   *  in map and returns that value.
   *
   *  Concurrent map implementations may evaluate the expression `op`
   *  multiple times, or may evaluate `op` without inserting the result.
   *
   *  @param  key the key to test
   *  @param  op  the computation yielding the value to associate with `key`, if
   *              `key` is previously unbound.
   *  @return     the value associated with key (either previously or as a result
   *              of executing the method).
   */
  def getOrElseUpdate(key: K, op: => V): V =
    get(key) match {
      case Some(v) => v
      case None => val d = op; this(key) = d; d
    }

  /** Removes a key from this map, returning the value associated previously
    *  with that key as an option.
    *  @param    key the key to be removed
    *  @return   an option value containing the value associated previously with `key`,
    *            or `None` if `key` was not defined in the map before.
    */
  def remove(key: K): Option[V] = {
    val r = get(key)
    if (r.isDefined) this -= key
    r
  }

  def clear(): Unit = { keysIterator foreach -= }

  override def clone(): C = empty ++= toIterable

  @deprecated("Use filterInPlace instead", "2.13.0")
  @inline final def retain(p: (K, V) => Boolean): this.type = filterInPlace(p)

  /** Retains only those mappings for which the predicate
    *  `p` returns `true`.
    *
    * @param p  The test predicate
    */
  def filterInPlace(p: (K, V) => Boolean): this.type = {
    if (nonEmpty) {
      val array = this.toArray[Any] // scala/bug#7269 toArray avoids ConcurrentModificationException
      val arrayLength = array.length
      var i = 0
      while (i < arrayLength) {
        val (k, v) = array(i).asInstanceOf[(K, V)]
        if (!p(k, v)) {
          this -= k
        }
        i += 1
      }
    }
    this
  }

  @deprecated("Use mapValuesInPlace instead", "2.13.0")
  @inline final def transform(f: (K, V) => V): this.type = mapValuesInPlace(f)

  /** Applies a transformation function to all values contained in this map.
    * The transformation function produces new values from existing keys
    * associated values.
    *
    * @param f  the transformation to apply
    * @return   the map itself.
    */
  def mapValuesInPlace(f: (K, V) => V): this.type = {
    iterator foreach {
      case (key, value) => update(key, f(key, value))
    }
    this
  }

  @deprecated("Use m.clone().addOne((k,v)) instead of m.updated(k, v)", "2.13.0")
  def updated[V1 >: V](key: K, value: V1): CC[K, V1] =
    clone().asInstanceOf[CC[K, V1]].addOne((key, value))

  override def knownSize: Int = super[IterableOps].knownSize
}

/**
  * $factoryInfo
  * @define coll mutable map
  * @define Coll `mutable.Map`
  */
@SerialVersionUID(3L)
object Map extends MapFactory.Delegate[Map](HashMap) {

  @SerialVersionUID(3L)
  class WithDefault[K, V](val underlying: Map[K, V], val defaultValue: K => V)
    extends AbstractMap[K, V]
      with MapOps[K, V, Map, WithDefault[K, V]] with Serializable {

    override def default(key: K): V = defaultValue(key)

    def iterator: scala.collection.Iterator[(K, V)] = underlying.iterator
    override def isEmpty: Boolean = underlying.isEmpty
    override def knownSize: Int = underlying.knownSize
    override def mapFactory: MapFactory[Map] = underlying.mapFactory

    override def clear(): Unit = underlying.clear()

    def get(key: K): Option[V] = underlying.get(key)

    def subtractOne(elem: K): WithDefault.this.type = { underlying.subtractOne(elem); this }

    def addOne(elem: (K, V)): WithDefault.this.type = { underlying.addOne(elem); this }

    override def concat[V2 >: V](suffix: collection.IterableOnce[(K, V2)]): Map[K, V2] =
      underlying.concat(suffix).withDefault(defaultValue)

    override def empty: WithDefault[K, V] = new WithDefault[K, V](underlying.empty, defaultValue)

    override protected def fromSpecific(coll: scala.collection.IterableOnce[(K, V)]): WithDefault[K, V] =
      new WithDefault[K, V](mapFactory.from(coll), defaultValue)

    override protected def newSpecificBuilder: Builder[(K, V), WithDefault[K, V]] =
      Map.newBuilder.mapResult((p: Map[K, V]) => new WithDefault[K, V](p, defaultValue))
  }

}

/** Explicit instantiation of the `Map` trait to reduce class file size in subclasses. */
@SerialVersionUID(3L)
abstract class AbstractMap[K, V] extends scala.collection.AbstractMap[K, V] with Map[K, V]

redpajama_set_name: RedPajamaGithub


Well I can't speak to the two vessel cord per se. My BFF had one with her son, and she was able to deliver vaginally. He was tiny, but he has other genetic issues that make it hard for him to gain weight, so it's hard to say what impact that had.
I will say, try not to let a "high risk" diagnosis scare you. For the most part, it just means you'll get monitored more closely. You'll probably get a bunch of bonus sonograms to keep an eye on things. I'd much rather have it that way then have any bad surprises at the end.
Thank you both. I read an article that gave more medical information that helped me kind of understand it. All I want is a healthy baby. Which is he so far and I'm extremely thankful.
Happy due date to me (baby is 3wkold). Just need to vent.