Performance Examination of a CSP Plant Based on Fresnel Mirrors Coupled to Stirling Engine and Its Comparison with an Organic Rankine Cycle

The present work consists of an investigation of a proposed CSP plant using Fresnel mirrors and a Stirling engine. Different parameters were studied: average working fluid pressure effect on plant efficiency, ratio of engine heater exchange area and absorber tubes collecting area and then ratio of engine heater exchange area and absorber tubes collecting area, considering the hot cylinder. Besides, a comparative study between LFRs-Stirling engine coupling and LFRs-ORC was done. It was found that the working fluid pressure increases Stirling engine efficiency as well as the whole plant efficiency and the efficiency of the coupling can reach 24.6% at a temperature of 800 ℃ depending on the exchange surface between the heater and the HTF as well as the heater and the working fluid. The comparison between LFRs-Stirling engine and LFRs-ORC stated that the LFRs-Stirling engine coupling is competitive with the LFRs-ORC because it provides a slightly lower efficiency for a large difference in field area.