A Research of the Causes of the Vacuum Leak in Steam Turbine and of Measures of Improvement

We had measured the vacuum tightness of the steam turbine group of Xuzhou Power Plant through a helium mass spectrum leak detector. And we found out that the major causes of vacuum leak lied in a leakage in the low-pressure explosion-proof door, a bigger low-pressure vapor seal radial clearance, and the low tightness of the cylinder. Hence, we made some improvements aiming at the above problems, and as demonstrated in a following test, the vacuum tightness had been greatly improved.