Simulation And Optimum Of The Stirling Engine And The Dish-Stirling Solar Power Generation System

Under the background of environmental pollution and energy situation, the development of solar energy and other renewable energy has become the urgent need of human beings. Dish-Stirling solar power generation system is the leader in the solar thermal utility and has broad prospect.This thesis takes the four-cylinder double-acting Stirling engine as the research key. Based on the Schmidt analysis method, all kinds of flow friction losses and heat losses are analyzed and a model which adapt to the performance of the four-cylinder double-acting Stirling engine is built. Compared the calculation results of the program with the experimental data, this program is proved to be validated. This thesis builds optimal model which takes the four-cylinder double-acting Stirling engine model as objective function and takes actual conditions as constraints, and use quasi-Newton method and penalty function method to slove this problem.Based on the analysis above, this thesis designs a series of the four-cylinder double acting Stirling engines whose output power are from 5kW to 25kW, and optimizes the parameters of the engines. The impact of working condition, working fluid and heat exchanger on the 25kW engine performance is emphatically analyzed. The analysis results indicate that, in the aspect of the working condition, improving the hot metal temperature and cycle pressure can improve the engine efficiency, and improving the engine speed and the cycle pressure can improve the engine power; in the aspect of working fluid, the effect of hydrogen is best, nitrogen is second and air is worst; in the aspect of heat exchanger, the effect rules of the parameters of the exchanges to the power and efficiency of the engine which include number, length, inner diameter of the heater, number, length, inner diameter of the cooler and number, wire diameter, length, inner diameter of regenerator are objected.At last, this thesis analyzes the concentrator and the receiver, builds a whole model of Dish-Stirling solar power generation system and designs a set of 25kW Dish-Stirling system. The diameter of the concentrator is 11.9102m, and the system efficiency is 28.77%. The dynamic simulation result indicate that, the system would not start until the direct solar radiation intensity is above 474.4471 W/m2, and the system working time is from 8:00 to 16:10. The system output power is about 25kW and the output efficiency is above 28.5% when time is from 11:00 to 13:00.The average system efficiency reaches 25.2823%.