Design And Research Of Centripetal Turbines For On-board Exhaust Gas Heat Recovery Power Generation Systems

In this paper,a radial inflow turbine suitable for the exhaust heat generation system was designed,and the simulation and experimental research were carried out,using CFD software to analyze the factors affecting the performance of the radial inflow turbine under different working conditions and stable conditions,and verified by experiments which provided the basis for the performance optimization resesrch of radial inflow turbine.The main research contents are as follows:1.According to the working conditions of the exhaust gas waste heat power generation system,the types of turbine needed for the system were analyzed,using the design parameter screening method to obtain the initial design data.According to these data,through the thermal aerodynamic triangle calculation and velocity analysis,got the design parameters of radial inflow turbine size of each part,provided data support for design and numerical simulation and experimental research of the radial inflow turbine.2.Three dimensional modeling of the radial inflow turbine was carried out by using three-dimensional software Solidworks,and the internal flow field simulation was carried out.Analysis of factors affecting the performance of the turbine under variable conditions,found that with the entrance temperature and pressure increasing the turbine had a better performance,the outlet temperature has little influence on the performance of the radial inflow turbine,the optimal entrance pressure value at about 2.15MPa,there is a reasonable speed range of the turbine isentropic efficiency and wheel efficiency reaches the maximum value,the range of 4864-5068r/min.3.The rotational speed,inlet temperature,outlet temperature,inlet pressure and outlet pressure were set to 4965r/min,102 ?,82 ?,2.15MPa,1.54MPa,respectively.The analysis of the internal flow of radial inflow turbine shows that there is a large gas vortex in the part near the middle of the volute,causing energy loss;The high speed gas turns sharply at the inlet of the volute and then hits the inlet of the volute,resulting in the stagnation loss;the velocity and static pressure distribution of the 55%blade height are relatively uniform,and the flow condition of the 10%blade height and the 90%blade height is relatively bad,there is a clear low pressure area at the exit,so it is necessary to improve the corresponding impeller.4.An experimental platform of exhaust heat generation system for vehicle exhaust was built,and the radial inflow turbine had been experimentally studied.The results show that the thermodynamic parameters of radial inflow turbine agree well with the simulated values under steady and variable operating conditions,the increase of inlet temperature and rotation speed of radial inflow turbine improved isentropic efficiency and wheel efficiency of radial inflow turbine,and the experimental results further verify the reliability of numerical simulation results.