Optimization Design And Aerodynamic Performance Analysis Of Radial Inflow Turbine With Organic Working Fluid

China’s industrial sector consumes a significant portion of the country’s total energy.Abundant heat energy is generated by industrial processes.In recent years,there has been growing interest in the recovery of heat energy generated by industrial processes.The Organic Rankine Cycle(ORC)system has been demonstrated to be an effective technology for recovering low-grade heat energy.The efficient turbine is critical to the recovery of low-grade heat energy in the Organic Rankine Cycle.Investigating the appropriate design of the turbine is essential.The present paper focuses on the optimization design and aerodynamic performance analysis for a 590 k W radial inflow turbine with organic working fluid.An in-house code of the preliminary design for the radial inflow turbine is programmed with MATLAB language,and the physical properties of the organic working fluid are acquired from REFPROP software.The validity of the current code is firstly proven in comparison with the published data.This paper examines the impact of seven design parameters on the total-to-static efficiency,and recommends suitable values for these parameters.The optimization work is finally performed to find the maximum total-to-static efficiency and the relevant design parameters using the particle swarm optimization algorithm.It is shown that the total-to-static efficiency is improved by performing the optimization work,and the value of 84.84%is achieved.The rotor inlet and outlet velocity triangles,meridian geometries,and energy loss coefficients are compared and analyzed between the initial and optimum designs.The reduction of leaving velocity loss has the largest contribution to enhancing the total-to-static efficiency.Based on the results of the optimal preliminary design of the radial inflow turbine,a three-dimensional model of radial inflow turbine rotor and stator is developed.The turbine design is validated using a three-dimensional numerical simulation method.The numerical simulation results are in good agreement with the results obtained from the preliminary optimization design,and the relative error is less than 3%.The three-dimensional flow characteristics within the turbine and the offdesign performance of the turbine are analyzed.This paper proposes design parameters and performance predictions for a radial inflow turbine with the organic working fluid.Three design points are selected to establish the model,and numerical simulation methods are employed to verify the accuracy of the prediction.The impact of the rotor axial width on the performance of the turbine was investigated,and the results indicate that reducing the axial width can enhance the total-to-static efficiency.Combined with the Bézier curve method,the rotor meridian shape is optimized and the curvature of shroud and hub becomes smaller.The total-to-static efficiency of the radial inflow turbine with an organic working fluid is 87.54% according to the threedimensional numerical simulation.