Study On Performances Of Dish Solar Power Generation System

Under the background of environmental pollution and energy situation, Dish solar thermal power technology is favored by governments and research institutions due to the high photoelectric conversion efficiency, easy installation in recent years. China has abundant solar energy resources, vast unused land, as well as a more complete infrastructure and other favorable conditions for the development of solar power plants. By establishing dish solar thermal power system model to simulate analyze system performance, a comprehensive analysis of performance parameters characteristics provide the basis for the development of solar thermal dish under typical weather conditions of power generation technology.Firstly, the analysis on energy loss was carried out under the concentrator system error, interception factor, receiver opening diameter and the absorber temperature on the collector system, obtained the final output energy function of the concentrator. Analyse the convective heat loss at the receiver working, the radiation heat loss, thermal loss and reflection loss, draw a receiver heat loss is mainly convective heat loss and radiant heat loss, and ultimately determine the effective energy concentrating collector output subsystem; Introduce the types of Stirling machines, and different types of advantages and disadvantages. For a-type Stirling engine cycle work process was analyzed and determined Stirling machine function of output power. Based on the analysis of concentrator, receiver and Stirling engine energy transfer, establish the model of the dish solar thermal power system, obtain the functional relationship between the modules, the system determines the final output of a function of energy.Secondly, the simulation and analysis on the performances of stirling-dish system was carried out under different climates conditions, the impact of operational and structural parameters. The results indicate that the engine pressure has linear relationship with the solar direct normal insolation; when the hot-end temperature keeps in setting range, the net output power of the system increases with the engine pressure increasing; while the ambient temperature decreases, the Stirling engine efficiency increases and net output power increases slightly; while the wind speed increases, the receiver efficiency and the net output power increase. Considering the Stirling engine output power and stability, determine the optimal setpoint temperature of the thermal head. The influence of the receiver aperture of the receiver and power efficiency, and determine the best receiving aperture.Finally, the exergy and exergy economic analysis on system was carried. The exergy analysis on the system based on Gray box model, the system of exergy efficiency up to 30.9%, exceeding the exergy efficiency of the parabolic trough solar power generation. The power system is the weakest sector with exergy efficiency 46.8%, exergy loss of 50.8% of the total exergy loss, exergy 35.1% of the total amount of input. Secondly exergy efficiency concentrating collector subsystem 66.0 percent, accounting for 34.0 percent exergy exergy loss total input volume,49.2% of the total exergy losses. The key to improving the efficiency of the system is to improve exergy efficiency of the power conversion process. The exergy economic analysis on system was carried. The results indicate that with the extension of the system life cycle, reducing the initial investment in fixed assets will reduce product exergy cost of the system, followed by high intensity radiation may be in the sun, sunshine long time, the establishment of the World region solar thermal power generation system to increase the annual output exergy of the system, so the product exergy costs will be reduced.