1. Field of the Invention
The present invention relates to solar power production, and more particularly, to spray stations for temperature control of solar receiver panels in solar boilers.
2. Description of Related Art
Solar power generation has been considered a viable source to help provide for energy needs in a time of increasing consciousness of the environmental aspects of power production. Solar energy production relies mainly on the ability to collect and convert energy freely available from the sun and can be produced with very little impact on the environment. Solar power can be utilized without creating nuclear waste as in nuclear power production, and without producing pollutant emissions including greenhouse gases as in fossil fuel power production. Solar power production is independent of fluctuating fuel costs and does not consume non-renewable resources.
Solar power generators generally employ fields of controlled mirrors, called heliostats, to gather and concentrate sunlight on a receiver to provide a heat source for power production. A solar receiver typically takes the form of a panel of tubes conveying a working fluid therethrough. Previous solar generators have used working fluids such as molten salt that have the ability to store enough energy to allow power generation when there is little or no solar radiation. The heated working fluids are typically conveyed to a heat exchanger where they release heat into a second working fluid such as air, water, or steam. Power is generated by driving heated air or steam through a turbine that drives an electrical generator.
More recently, it has been determined that solar power production can be increased and simplified by using water/steam as the only working fluid in a receiver that is a boiler. This can eliminate the need for an inefficient heat exchanger between two different working fluids. This development has lead to new challenges in handling the intense solar heat without damage to the system. One such challenge is the fact that solar boilers can be subject to very rapid changes in temperature when compared to fossil fuel boilers. It is possible, for example, for solar receiver panels to go from a high-heat receiving state, to a state in which little or no heat is received, and then back to the high-heat receiving state within minutes. This can happen, for example, with the passing of a rogue cloud over the field of heliostats. In such instances, steam temperature will undergo huge fluctuations in a short period of time, which can damage the receiver panels.
While the known systems of solar power production have generally been considered satisfactory for their intended purposes, there has remained a need in the art for controlling steam temperature in the event of rapid changes in heat flux at the boiler panels. There is also a need for such systems and methods that are easy to make and use. The present invention provides a solution to these problems.