Effect of impeller inlet blade angle on the flow field and performance of centrifugal turbine expanders
The centrifugal turbine expander is a key component in the energy release phase of compressed air energy storage systems.The inlet blade angle of the impeller has a significant impact on the flow characteristics of the expander.Choosing the appropriate blade angle according to the design conditions can improve the distribution of the flow field,reduce energy loss,and enhance the performance of the turbine expander.A numerical simulation method was used to study the turbine expanders with different inlet blade angles.The results show that the inlet blade angle mainly affects the flow field at the junction of the impeller and guide vane,the throat of the impeller,and the outlet flow field.When the inlet blade angle is small,the energy loss at the throat of the impeller inlet is greater,the vortex is more obvious,and the turbine efficiency of the expander is lower.When the blade angle is 100°,there is no vortex in the impeller flow field,the pressure distribution on the moving blade is more uniform,the flow field distribution is relatively better,the turbine efficiency is 80.75%,the output power is 142.77 kW,and the overall performance of the turbine expander is better.