叶尖间隙对涡轮性能影响的计算与试验研究

Calculation and Test of Influence of Rotor Tip Clearance on Turbine Performance

采用电容型叶尖间隙测量系统,在国内首次对单级涡轮级性能试验状态下的转子叶尖间隙进行了实时测量,并利用获得的叶尖间隙热态试验数据,完善了涡轮转子叶尖间隙计算方法。同时,开展了变叶尖间隙的涡轮级性能试验,总结了叶尖间隙对涡轮性能的影响规律。另外,还对试验方案进行了数值模拟,并与试验结果进行对比分析,进一步研究了叶尖间隙对涡轮性能的影响。结果表明,电容型叶尖间隙测量系统具有较高的准确性,利用该系统有助于掌握叶尖间隙真实变化规律,提高试验安全;通过对叶尖间隙实时测量,可正确评估涡轮性能随叶尖间隙的变化规律,具有较高的工程应用价值。

The tip clearance was measured real time with capacitive probe in the single-stage turbine per- formance test. And it is the first time to measure it at home. The data of tip clearance was obtained in the test condition and the method of tip clearance calculation was consummated. Simultaneously, the equation between tip clearance and turbine efficiency was established via the turbine stage tests of different tip clear- ance. A further investigation of the influence of tip clearance on turbine efficiency was carried out with the numerical simulation method. Comparing the calculation results and the test results, it showed that the cal- culation data agreed well with the test data. The application of capacitive probe was beneficial to master the changing rules of tip clearance and improve test security. Also the influence of tip clearance on turbine effi- ciency could be properly evaluated by real time measurement of tip clearance.