| Based on the waste of surplus energy of the electric-powered water turbine used for cooling towers and the insufficient energy supply of the water-powered water turbine under special working conditions,a hydro-electric hybrid water turbine used for cooling towers is proposed.The water turbine is used to recycle the excess energy in the cooling tower circulating water system,and the power components can provide power compensation to ensure the stable and effective operation of the cooling tower under any working conditions.Taking the hydroelectric hybrid turbine used in the cooling tower as the research object,the working efficiency of the turbine is the research goal,and the research is carried out around its structure,hydraulic performance and hybrid control strategy,and the turbine runner is optimized from the perspective of fluid dynamics.And determine the hybrid power range and hybrid control strategy within the range of operating conditions according to the working characteristics of the turbine.First,the basic principles of the hydraulic turbine and its internal fluid flow are studied and analyzed,the structure of the hydroelectric hybrid turbine used in the cooling tower is determined,and the basic equations of the hydraulic turbine,the control equation for fluid motion calculation,the turbulence model,and the discrete method are studied and analyzed.And grid types,it is analyzed that RNG model and structured grid are the best turbulence model and grid division method for fluid motion calculation,which provides a theoretical basis for further structural design and hydraulic performance analysis of hydraulic turbines.In view of the unique working environment of the cooling tower turbine,combined with the basic principles and flow analysis of the turbine,the structure model of the hydroelectric hybrid turbine is designed,and the turbine is designed in detail.Use the unary theory design method to complete the preliminary design of the runner,the guide vane ring,the volute and the draft tube of the turbine,and the modeling and assembly of the three-dimensional model;use Ansys ICEM to complete the meshing study of the model and determine the optimal number of meshes;According to the determined boundary conditions,the Ansys CFX is used to carry out numerical simulation calculations to study the hydraulic performance of the internal flow field.The research results show that the internal flow field of the turbine has a good flow state,normal pressure distribution,no obvious impact and vortex,and the working head of the runner The efficiency of the runner is 9.32m,the efficiency of the runner reaches93.86%,the working head of the turbine is 10.54m,the overall efficiency of the turbine reaches 83.02%,and the output power meets the requirements,which proves that the preliminary design of the turbine is reasonable and effective.Further optimize the design of the turbine,combine parameterized modeling,sensitivity analysis,experimental design methods and proxy model fitting,and propose an optimization method that combines the Kriging model with the NLPQL optimization algorithm.Use the three-dimensional parameterized optimization method to carry out the parameterized modeling of the runner;use sensitivity analysis to select the parameters that are more sensitive to the efficiency of the runner from the various parameters,and determine the variable parameters,y2,3y,1x?,2x?,3x?,?2 and??as the optimization of the runner Variables;use space-filling Latin hypercube sampling method for experimental design,obtain sample points;select Kriging model to construct a proxy model of runner efficiency,and study the corresponding law between structural parameters and efficiency.Using the NLPQL algorithm for optimization,the optimized runner efficiency is increased to 95.34%,the working head of the runner is raised to 9.69m,the overall efficiency of the hydraulic turbine is raised to84.99%,and the working head of the hydraulic turbine is raised to 10.87m.The efficiency of the whole machine is increased by 1.97%compared with before optimization,and the working head is increased by 0.33m,which proves the feasibility of this optimization method.Finally,the hybrid control strategy of the hydroelectric hybrid turbine is studied.According to the structural composition of the designed power components,the multi-operating point numerical calculation is carried out based on the adaptability of the turbine,and the performance curve of the turbine in the operating condition is determined,and the operating head is determined.Fit the function with the output power to obtain the flow-working head and flow-output power expressions,and finally combine the working characteristics of the wind turbine to calculate and solve the compensation power expressions of the power components and the hybrid power range within the working condition range,and propose It is used for hydroelectric hybrid control equations and hybrid control strategies in the hybrid power interval of hydroelectric hybrid power turbines. |
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