Numerical Simulation Of Airflow Distribution In Underground Hydropower Station

In recent y ears, with China is carryi ng out western developm ent and West-East electricity transmission project, the cons truction of hydr opower station has been booming. As the under ground hydropower stati on is deeply buried under ground and airproof, the indoor air has th e characteristics of swelter, damp, dirtiness. So the Reasonable airflow organization is significant to the living environment and the security of operation in the underground hydropower station.According to the research results at home and abroad have been published, model experimental, zonal m odel and CFD are m ainly research m ethods in the airflow organization of the hydropower station. Al though the three m ethods have their own characteristics, CFD has the characteristi cs of being unrestricted by the actual conditions, keeping the relevance between the chambers and the research results more intuitive so that it is wi dely used in the airflow or ganization field of under ground hydropower station. With the limitation of the basic theory and calculation m ethod, there are some urgent technical problems of CFD in calculation precision, grid structure, heat source model and param eter setting. Th is article is one of the National Natural Science Foundation of surface projects(5 1178482) “Deep Under ground Station Thermal Environment and Energy Regulation formation mechanism”.Paper with Baihetan Hydropower Station as the object of the research, using FLUENT software co mpared and discussed the m athematical model, m eshing, boundary conditions of the airflow s tation underground powerhouse organization,witch established by CFD simulation, obtained the suitable CFD numerical simulation method for underground powerhouse air station. By the same condition, the results of the model test and CFD numerical simulation compared to be similared, which describes the CFD numerical simulation method of underground powerhouse air station the paper obtained is correct and reliable. In this pap er, specific research work and obtained results are as follows:① The underground irregular geometry structure of m ain building upper workspace for hydropower station are simplified to the geometry of the structure of the model by using volume method, which can get the same numerical simulation results as the actual size of structure model. And it also can reduce the workload of modeling and the difficulty of meshing.② Setting the heating device to heat even ly body heat source or even heating surface heat source can obtain the sam e numerical simulation results. But the h eat evenly heat source can help Convergence, setting boundary conditions and meshing.③ Setting the lighting equipm ent is set to the model of the heat unif orm heat source, which can obtain the sam e numerical simulation results as the actual size lighting equipment. In addition, it is able to make it easier for model convergence.④ As for the mixed mesh combines with the advantages of high precision of hexahedral mesh and high adaptable to complex calculation area of tetrahed ral mesh,when m ake the m esh of under ground Powerhouse, it can both to m eet the accuracy requirements and further reducing the grid cells number.⑤ In numerical sim ulation of air distribution of under ground hydropower station,the radiation heat transfer in a heating device cannot be ignored. Heat transfer of heating equipment,which is m ore reasonable, should be the conve ction heat transfe r combined with radiation heat exchanger.⑥ The value of turbulent kinetic energy and dissipation rate of air supply outlet of the underground hydropower sta tion was calculated by the empirical formula, the error will not be within obvious impact on ve locity field and tem perature field in the workshop, wich can satisfy the precision requirement in engineeringThis paper provides a theoretical basis for the numerical simulation of airflow distribution in other underground hydropower station.