Preliminary Exploration Of The Principle And Design Of Tubular Solar Air Receiver In CSP

As energy crisis and environmental crisis become worse and worse, as an important part of new energy utilization, the solar energy utilization has made great progress. And Concentrating Solar Power System (CSP) also has gotten widely attentions in recent years for its environment friendly during the processes of producing. Trough system and tower system of CSP have successfully to generate power. Compared to these two kinds of CSP system, solar air turbine system has advantages of high efficiency, waterneedless in the cycle and flexible installing. Due to these advantages, solar air turbine power generation systems began to get widely attentions. However, in order to develop a successful solar air turbine power generation system solar air receiver which supplies the energy for the system needs to be developed as a key point in the developing of the whole system. Tubular solar air receiver was researched in this thesis as the main research object.First, this paper briefly introduced the investment and development of the CSP system all over the word and the advantages of dish-solar air turbine power generation system. After comparing the advantages and disadvantages of several kinds of CSP system, technical barriers that exist in the development of the dish-solar air turbine power generation system were elaborated. At last, this thesis talked about the science questions and technical difficulties that need to be solved during the developing of the solar air receiver.Secondly, the principles in designing the solar air receiver were talked and analyzed in this thesis. The design method, including heat transfer calculation and pressure loss calculation model, of the solar air receiver were also developed in thesis. According to the heat transfer characteristics of heat absorbing tubes, the order of the heat conduction and convection heat transfer in different directions were analyzed. Then the heat transfer model of the heat absorbing tubes was built. The air flow characteristics in the cone of the receiver were analyzed by the simulation. Considering the thermal efficiency, the pressure loss and the cost of manufacturing of the receiver together, the principles in designing the solar air receiver were developed.Thirdly, a detail solar air receiver was designed in the thesis. The experiment platform for the solar air receiver was a parabolic dish which was built in Ningxia province by Zhejiang Huayi Cangdisi. This dish can automatic track the sun during all the day and has a total area of54.4square meters. According to the existing conditions of the experiment platform, a tubular solar air receiver was designed by the following conditions. The input energy was30kW; the difference between the temperature of the inlet and the outlet of the receiver was more than500degrees; the mass flow was0.05kg/s; the difference between the temperature of the outlet of the receiver and the highest temperature of the whole receiver can’t exceed400degrees. Besides, the three-dimensional numerical simulation of the receiver gave a good result of the flow field analysis in the receiver.Finally, the tubular solar air receiver which was designed in this thesis was tested the performance on the experiment platform, the parabolic dish which was built in Ningxia province by Zhejiang Huayi Cangdisi. This experiment test parameters and test method were introduced in detail in the thesis. The experimental results showed the flowing result. The outlet temperature of the solar air receiver reached to552degrees; the highest efficiency of the receiver could reach to88%at the designing mass flow; the pressure loss of the receiver was lower than3kPa; the highest temperature of the whole receiver was852degrees when the temperature of the outlet was552degrees. Temperature distribution was very uniform at the end of each heat absorbing tubes. This uniform temperature distribution showed the air flow in different heat-absorbing tubes was uniform. Due to machining problem, the cone of the receiver didn’t reach the original design requirements.