Study And Optimization Dish Solar Thermal Systems Cavity Absorber Of Light And Heat Performance

Solar energy is the most abundant and permanent energy in the world, and it has unlimited reserves, existence of universality and the use of clean and economic characteristics. What’s more, enhance the awareness of environmental protection and sustainable development strategy emphasis on the improvement, clean and long-term utilization of new energy sources has attracted worldwide attention. So, solar energy has been widely applied to all aspects of industry, agriculture and daily life. Also, the devolvement of the solar energy for thermal power generation has thrived during the last century.During to the solar power has a variety of significant, such as the flexible layout, wide application prospects, low initial investment, simple structure, cost reduction potential and system optimization potential, the disk solar thermal power system has become the focus of the relative research. Receiver is the key component of solar thermal utilization, and the dish solar thermal systems applicable to cavity absorber, which is placed in the focal point of the condenser in the conditions of high temperature. And, it received the high heat flux from the concentrator solar energy and converts it into thermal energy. The system’s efficiency and economy is influenced by the performance of receiver. Therefore, according to the interior cavity heat flux distribution and other research results, the cavity absorber structure optimization is to improve the dish solar thermal conversion efficiency effective way. In various cavity absorber type, in which a hemispherical heat sink thermal performance optimum, so the simulation and experiment are used hemispherical cavity absorber.Energy flow will be uneven distribution of absorber cavity after the condenser focused, and will become hot spots in the absorber cavity, also, will impact the performance of absorber. Based on the existing laboratory hemispherical cavity absorber,optimize its structure, reflective cone placed in the heat sink of the dome. Study the effect of changing in the reflective cone angle of the optical performance of the hemispherical absorber, find the optimal geometry of the reflected light cone. Numerical simulation results show that the reflective cone angle 120 °, the optical properties of the absorber is best.Change the installation location of the heat sink to explore the impact from the changeof the optical performance of the system. To measure the flux density at the focal plane of the optical numerical simulation, the receiver is replaced disk, changing the distance between disc and concentrator, observation regular pattern of focused energy received. The regular pattern of receiver and disc is the same, optical properties show two small middle large normal.Numerical simulations and experiments all to further explore the combination of dish solar thermal systems. Test changing the distance between receiver and condenser thermal performance and also the changing distance from the temperature disc and condenser to find their thermal performance. The results showed that the actual focal plane of the light spot on the disk is not a regular shape, but showing the approximate oval, the actual focal length with the theoretical focal length of the condenser have a certain gap, but the receiver and disk come to the same regular pattern in 1030 mm thermal performance is optimal.