基于FCB试验的转子转动惯量计算

汽轮机转子转动惯量测取,主要是通过甩负荷试验计算得来。现在很多电厂都要进行机组快速甩负荷（FCB）试验,鉴于FCB试验也有对汽轮机调节系统动态特性的考核作用,而FCB试验和常规甩负荷试验又都是破坏性试验,对汽轮机转子的寿命有一定影响,所以大多数电厂希望只进行FCB试验,并能达到常规甩负荷试验的目的。目前国内尚未有通过FCB试验进行转子转动惯量计算的方法,因此基于FCB试验的转子转动惯量的计算将非常有必要。介绍了常规甩负荷试验计算转子转动惯量的方法,提出了基于FCB试验计算转子转动惯量的方法,并将2种计算方法进行了对比。结果表明基于FCB试验计算与常规甩负荷试验的结果差值为1.29%,可以认为此种计算方法可以替代常规甩负荷试验。

Calculation of Moment of Inertia for Turbine Rotors Based on FCB Tests

The moment of inertia of turbine rotor is mainly measured and obtained from the computing of load-rejection tests. Now that the fast cut back (FCB) tests are carried out in many power plants which can also be applied for the assessment of the dynamic characteristics of steam turbine control systems, most of the plants would like to do the FCB test only while the objective of load-rejection tests reached as well due to the harmful effect of destructive FCB tests or regular load-rejection tests on the steam turbine rotors. So far, there has been no method proposed for calculating the rotor moment of inertia by FCB tests. In this paper, the regular method to calculate the moment of inertia based on load-rejection tests is explained and then the new method based on FCB tests is proposed. The comparisons between the two methods are conducted afterwards, which indicates that the difference between the two computing results is as low as 1.29%. In conclusion, the method based on FCB tests is qualified substitute for load-rejection tests.