Improving the fuel efficiency of internal combustion engines has been of interest for many years. Gasoline is a standard fuel for internal combustion engines, but many of the bi-products of incomplete gasoline combustion are harmful to the environment. This has given rise to much concern over the long term effects of the prolific use of internal combustion engines. Many approaches have been taken to reducing these harmful emissions, some more successful than others, but further measures are necessary in order to meet increasingly strict emission standards. Also gasoline is a non-renewable resource, and given worldwide trends in the supply and demand of gasoline, the upward pressure on the price of gasoline and other petroleum products will undoubtedly continue. As the cost of fuels such as gasoline continues to rise, it becomes ever more desirable to increase the fuel efficiency of internal combustion engines to limit increases in fuel-related costs in areas such as transportation, power generation, construction, mining and forestry.
Recently it has been estimated that enhancing combustion with a small stream of hydrogen gas may result in a potential improvement in fuel economy of 20 percent or more, depending on the engine, due to increased combustion efficiency. The expected improvement in internal combustion engine combustion efficiency is achieved by adding hydrogen into the air-fuel mixture. The effect of hydrogen and its unique diffusion properties is believed to increase the speed of laminar flame in the air-fuel mixture at the initiation phase of the combustion cycle. The high rate of flame growth reduces the overall combustion cycle time resulting in more complete combustion, reduced fuel consumption and reduced emissions.
Hydrogen gas may be produced by employing an electrolyzer, which uses electrical current to produce hydrogen gas from water (or an electrolyte solution), powered by an alternator or generator running off the internal combustion engine. However, there are many obstacles to employing an electrolyzer in every day use, especially in transportation applications such as motor vehicles, including automobiles.
The pressure of hydrogen gas must be controlled to prevent explosion, and the hydrogen gas must be delivered to the engine in a controlled stream in order to maximize its efficient usage while not interfering with the combustion of the gasoline. There are other products resulting from the electrolysis process, oxygen gas and electrolyte (if used), which must be kept separate from the hydrogen stream. Pure oxygen is highly explosive, and must be safely discharged either into the atmosphere, or directly into the engine for combustion. The electrolyte can be harmful to the environment, and must either be reused or discarded in an environmentally friendly manner.
In the automotive application, the environmental conditions also present significant difficulties. In cold climates the water used to produce the hydrogen gas will freeze at temperatures below 0 degrees Celsius. While an electrolyte such as potassium hydroxide (which has a lower freezing temperature) may be used in the electrolysis cell itself, it is advantageous to provide a store of distilled water on board the vehicle to replenish the electrolyte solution as it is depleted. Although an electrolyte solution such as potassium hydroxide is unlikely to freeze because of its lower freezing temperature, water freezes at temperatures that are quite commonly encountered in winter months in many regions. This can cause supply lines to crack.
Thus, it would be advantageous to provide a system for preventing freezing of any line supplying water for (or as) the electrolyte solution in and electrolyte delivery system.