Thermal Performance And Thermal Stress Analysis Of Parabolic Trough Solar Collector

Parabolic trough solar collector is the key of trough solar thermal power generation,which converts solar energy into heat energy.The thermal performance and safety of heat pipe will directly affect the efficiency and economy of the entire solar thermal power generation system.Therefore,this paper uses Fluent software and ANSYS software to simulate the thermal performance and thermal stress of parabolic trough solar collector respectively.The research results are as follows:(1)Firstly,the distribution of heat flux on the outer surface of metal tube was obtained by Monte Carlo ray tracing method and compared with the literature to verify the correctness of the heat flux distribution;in addition,heat transfer model is verified to prove the effectiveness of the model.(2)Based on the surface heat flux of the solar collector tube,the physical model and mathematical model of the parabolic trough solar collector under the non-uniform heat flux density are established.The Heat transfer and flow of the collector tube were simulated by Fluent software and the temperature distribution of metal tube,bellows and glass tube is also simulated.The influence of solar radiation intensity(DNI),temperature,velocity and ambient temperature of heat conducting oil on heat collection efficiency and heat loss are analyzed.The influence law of temperature distribution of metal tube,bellows and glass tube is analyzed in detail.(3)The heat loss is one of the important thermal performance indexes of the parabolic trough solar collector.The heat loss laboratory bench of the parabolic trough solar collector is built in this paper and two collector tubes of a company are tested.The numerical simulation results of Fluent software is compared with the test results,the error within 6% and the comparison is better.After the test,the heat loss of the collector and the inner tube temperature of the collector are fitted,and the fitting value of the heat loss at different temperatures is obtained,which is used in the design and operation efficiency calculation of the parabolic trough thermal power generation system,Solar thermal power generation system designed to provide important thermal performance parameters;In addition,collector manufacturing company can also test the heat loss.(4)The temperature field of parabolic trough solar collector under non-uniform heat flux boundary condition was simulated by Fluent software.The temperature field of the collector tube was inducted into ANSYS Mechanical software for thermal stress simulation,and the thermal stress field and strain field of the collector tube are obtained.The stress distribution of metal tube,glass tube and bellows are analyzed in detail.The effects of solar radiation intensity(DNI),temperature and flow velocity of Heat transfer fluid on its maximum equivalent stress are also analyzed.The influence of temperature and velocity on Z direction displacement,axial displacement and axial displacement of glass tube were also studied.Through the research of this paper,it provides the theoretical reference for the optimal design and safe operation of parabolic trough solar collector.