Study On A 1kW Dish-stirling Solar Power Engine And The Solar Collecting System

At present, solar power tower, parabolic trough and dish system are three main types of solar thermal power generation system.This work deals with the investigation of a solar dish concentrating system, which mainly consists of a solar collector and a proposed cavity receiver, that could provide adequate thermal power for a 1 kW beta type solar Stirling prototype engine, which has been manufactured and tested in the Cryogenic and refrigeration laboratory of Huazhong University of Science and Technology.With respect to the state of the art, the presented proposed receiver has an additional quartz glass window and a secondary reflector, aimed to reduce radiation and convection heating losses.In order to predict radiation characteristics of the solar collector system by calculating radiative exchange factors, a Monte-Carlo ray-tracing method coupled with optical properties was adopted. The results show that the total flux launched into the proposed cavity receiver is 5003 W, the optical efficiency of this receiver is 70.8%. A comparison of the heat losses among four different types of receiver was made. The investigated receivers differ for the presence or absence combination of a quartz glass window and a secondary trumpet reflector. The simulation with thermodynamic software shows that the receiver with both quartz glass window and secondary reflector has the least heating losses, about 56.8% less than the initial receiver without both quartz glass window and secondary reflector. Hence, the receiver with less heating losses is more deeply studied, investigating how the radiation and convection heat transfer are affected by orientation, temperature and emissivity of the inner surface.The research indicates that the proposed receiver is suitable for Stirling engine applications.