CFD Simulation And Optimization For Solar Chimney Electricity Generation System

Solar chimney technology for electricity generation is a new technology to use the greenhouse effect technology, chimney technology and turbine technology synthetical-ly.It's a new way to develop and make use of the solar energy.The large-scale erective solar chimney power plant fails to be constructed mainly due to its low efficient and its disadvantages of less engineering safety and the extremely high construction cost caused by the super high chimney.The distribution of the velocity field and the temperature field of the airflow in the solar chimney system has dramatic effect on the energy conversion and the output of the turbine rotor in the Solar chimney system.The size of the solar chimney system is one of the key elements which form its the velocity field and the temperature field.Thereby , it is necessary to study the influence of the solar chimney system on the generated output.The traditional method to study the flow and heat convection of the airflow is experimental research.Because of the high cost of the solar chimney system, it is unrea-sonnable to carry out a great deal of research directly.As the wide application of the nu merical calculation technology in the convection, it is feasible to simulate and study the airflow in the solar chimney system by the numerical calculation technology.In this paper , based on some hypotheses, a suitable numerical mathematical model about the airflow in the solar chimney system is established, by which the common commercial CFD software FLUENT is used to simulate the velocity field and the temperature field in the solar chimney system.According to the analysis on the simulation result: when other size condition are changeless, the height of solar collector is no influence on the generated output; there is a optimal value of the solar chimney diameter, by which the generated output of the solar chimney system is most; the generated output and the construction cost of the solar chimney system become greater with increase in the solar collector diameter and the solar chimney height, but the increase rate of generated output and the construction cost are different, there is a better ratio Hc/D_coll by which more generated output is obtained while the construction cost is less expended.The fact above offer the theory and guidance for the establishment and optimal design of the future practical solar chimney power plant.Finally, based on the regular methods of chimney design, VC++ programme has been designed to calculate the strength of some solar chimney obtained from the simulation result.The calculation shows that it is feasible in intensity to erect a high solar chimney using regular construction and design method.