Thermodynamic Analysis Of Dish Solar Thermal Power System With Different Engines

Shortage of fuel resources has become a serious global Problem, solar thermal power generation technology, which can convert the solar energy resources into electric energy, provides a good way to solve the problem in the future, and Dish solar thermal power technology with Efficient photoelectric conversion efficiency gets more attention. However, it needs more in-depth study on its optimization to support commercial operation. In this paper, performance of engines under different thermal cycles in the dish solar thermal power generation system is compared, and parameters of the dish Stirling system is optimized.In this paper, firstly a thermal model for the dish solar system with Stirling engine and Brayton engine is developed based on Finite time thermodynamics theory, Through which the system’s Performance is compared and the proper engine is selected. Secondly, A mathematical model based on Schmidt theory aimed at the output power of α-, β-and γ-stirling engine is developed. And the result suggests that the α-Stirling engine is a good choice. Finally, the thermal model of condenser and the Stirling engine is coupled, and the functions that express the mathematical relationship between system output and intensity of solar radiation, collector aperture area, concentration ratio, dead volume ratio and its ratio in expansion cavity, temperature ratio, the phase angle and the swept volume ratio is deduced. The performance of the system in Changsha city is analyzed, which is optimized considering several important irreversibilities about dead volume, while the reasonable value range of temperature ratio is discussed.This paper compares the performance of dish solar system with different heat engine and derive the formulas that describe the relationship between the system output and parameters, Which provides a theoretical basis for the heat engine selection and optimization.