Research On High-temperature Heat Transfer Characteristic Of A Porous Volumetric Solar Thermal Receiver

Solar concentrator and high-temperature solar receiver are the two key components inside solar thermal systems. The aggregate effect and the heat transfer efficiency make big influence onto the whole solar thermal system. Since its special characteristics such as heat safety, high specific surface, high thermal conductivity and stable performance, the metal foam is widely used in the applications of solar absorber with non-air flow. Based on the sixteen-dish concentrator as the energy input platform, considering about the aggregate performance constraints, efficiently heat transfer technology of the high-temperature with pressure airflow was investigated through development of the thermal receiver, experimental measurements and theoretical analysis in this paper.Several adjustments and fixing processes have been adopted to the sixteen-dish concentrator. The concentrated solar flux distribution of the sixteen-dish concentrator was measured by experimental method. In addition, the heat transfer characteristics during the gathering light transmission process through heat conversion elements were studied through experimental method using the water-cooled heat flow meter and the infrared camera, et al.According to the solar flux conditions of the sixteen-dish concentrator, a highly efficient thermal conversion apparatus was designed, and a compact and efficient technical solution of the solar thermal conversion experimental device was constructed. Solar absorption, thermal radiation, convection and heat conduction coupling process during optical window and heat exchanger were involved in solar high-temperature heat transfer experiment. Thermal conversion process in the heat receiver was numerically analyzed using Fluent software,3D temperature distribution in the thermal conversion experimental device was obtained.The high temperature heat transfer performance of current design was investigated and analyzed using the developed experimental apparatus based on the sixteen dish concentrator. Temperature of optical window and the absorber wall was measured by the infrared camera. In addition, heat loss and conversion efficiency can be obtained according to the result of the temperature measurement.Through the investigations, volumetric high-temperature solar thermal conversion technology was well understood. The concentration properties of the sixteen-dish concentrator and transmission characteristics through thermal conversion element were obtained. Simulation analysis and experimental research was investigated through the high-temperature solar thermal conversion process. The achievement presented in this dissertation will provide significant reference value to the design and analysis of the high-temperature solar thermal receiver.