The Structural Design And Experimental Research Of Centripetal Turbine With Adjustable Stationary Blades

The centripetal turbine with adjustable stationary blades is a power unit which is using compressed gas under small compression ratio. The power in compressed gas can be converted to the shaft work, and transfered to the load. Due to its adjustable stationary blade, the device can play its advantage of online adjustment under complex conditionsThe centripetal turbine with adjustable stationary blades has a lot of parameters, which are influenced by each other. In this paper, the theory of mechanical triangle, numerical simulation research method and experimental research method are used to find the relationship between these parameters. The main work as follows:(1) An experimental equipment has been designed and the experimental platform is established for experimental research. By experimental studies, the best angle of the stationary blades are founded for the turbine. The performance when not at the best position are also researched. The impact on the performance by the shape of the front-end and back-end of the stationary blades are researched. Different shapes and numbers of the impeller blade are compared for improve the performance.(2) The output of the turbine shaft work, rotation speed of load and turbine efficiency are analyzed under different inlet pressure, outlet pressure and flow rate. Make the conclusion that The output power of the shaft increases but the efficiency declines when the pressure ratio increases.(3) The internal flow field is analyzed by using CFD software FLUENT for optimizing the turbine structure. Found that the best angle is consistent with that from equipment. The more stationary blades exist, the better turbine performance seems, but the adjustable performance deteriorates. The efficiency is increased4%by optimizing the shape of the stationary blades. The gap between stationary blades and impeller is the crucial point for improve turbine performance. The greater the gap, the lower the efficiency.(4) The method of using volute to optimize the flow field is proposed by numerical simulation. The efficiency improved obviously by using volute. Smaller volute is better than the bigger one. The efficiency decreases if only using volute but without stationary blades. The reliable basis for improving the performance of turbine structural and operating parameters under small compression ratio is provided by experimental studies and numerical simulation analysis.