| With the rapid development of China's national economy,the scale of the grid is increasing.The role and status of the pumped storage power station(PSPS)in the power grid become more and more obvious.From the early peaking the valley,improving the power quality,and gradually become the indispensable tools for power system control.The inlet/outlet of the PSPS is an important part of the water conveyance system.It has the characteristics of bi-directional flow.For the upper reservoir of a PSPS,the inlet/outlet acts as an inlet when water is released down to a lower reservoir to produce electric power and as an outlet when water is pumped back up to the upper reservoir.The inlet/outlet is the throat of the PSPS,and its hydraulic condition is directly related to the operation safety and economic benefit of the PSPS.The inlet/outlet of PSPS has complex bidirectional flow characteristics,which is different from that of conventional hydropower station.At present,the research on the hydraulic characteristics of inlet/outlet,namely bi-directional flow law,is still not systematic.The previous research results were mainly based on the specific engineering experience and focusing on the influence of the shape parameters on the hydraulic characteristics of the inlet/outlet.For the inlet/outlet shape optimization,that is,shape optimization method research is not perfect.The research results of the past were often optimized by means of numerical simulation.It is mainly based on the design criteria and experience to make the artificial adjustment of the optimization scheme.In the absence of a combination of numerical simulation and optimization algorithm or the model of implanted surrogate model,the shape optimization of inlet/outlet is more scientific,efficient and fully automated,without intervention.In this paper,the inlet/outlet of PSPS is studied in two aspects: bi-directional flow law and shape optimization method.(1)The bi-directional flow characteristics of inlet/outlet are systematically studied by model test and numerical simulation.The PSPS of Wendeng with three lateral inlet/outlet are arranged side by side as the research background.The model test and numerical simulation are carried out to analyze the head loss and velocity distribution and discharge distribution,and the sensitivity of the shape parameters to the inlet/outlet hydraulic characteristics are analyzed.For the study of open channel of the inlet/outlet,the PTV technique is used to monitor the surface flow of the open channel under the pumping or power generation condition.Under the condition of pumping and generating electricity,the numerical simulation method is used to analyze surface flow ofthe open channel.(2)Based on CFD and optimization algorithm to establish a fully automated,no human intervention 3D optimization platform.The optimization of the platform is realized by parametric modeling,automatic grid generation and CFD numerical calculation as platform components.The optimization functions,optimization algorithm and trade-off strategy are used as optimization strategies to optimize and determine the final optimization scheme.Using the platform software,The need for commercial software to be integrated without real intervention.At the same time,the traditional method is used to optimize the body shape as the original scheme.The optimization platform of CFD and genetic algorithm(GA)is used to optimize the shape of inlet/outlet.The optimization results show that the optimized inlet/outlet to obtain better hydraulic performance.(3)Based on the surrogate model optimization platform technology,RSM model,RBF model and Kriging model are used to construct the agent model.The design of the inlet/outlet of the Qingqi PSPS was used as the original shape type.The optimization results show that the triple-objective optimization can obtain better results,and the total the head loss decreased by 2.71%,the total velocity uneven distribution decreased by 21.05%,and the total discharge uneven distribution decreased by 2.24%. |
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