双列调节级在低负荷工况下的汽流弯应力是叶片强度振动的重要因素之一.本文分析了汽流弯应力的影响因素以及不同配汽方式对汽流力的影响.为降低动叶的汽流力,提出对发电用汽轮机配汽方式的改造方案.在第4、第5组阀不变的情况下,对前3组调节汽阀进行了重新设计,得到了改造后的流量特性.为验证配汽方式的改造效果,对发电用汽轮机进行了不同负荷下的试验研究.试验结果表明,调节汽阀流量特性、喷嘴前压力等参数的试验值与计算结果一致性较好,说明计算方法是合理准确的.通过对汽轮机调速性能的试验研究,得到了改造前后调速性能的差异,结果表明配汽方式的改造不会对汽轮机调速控制系统带来明显影响,可满足设计要求.%The steam bending stress of the curtis stage in turbine under low load conditions is an important factor of blade vibration. Investigate the influences of the steam bending stress and analysis effect of different steam distribution modes to the steam force. In order to decrease steam force of the rotor blades, measures of changing the steam distribution mode of steam turbine in power plant were proposed. In the case of keeping the fourth and fifth control valves, the first three control valves were designed newly, and the flux characteristic of steam control valves was obtained. To verify the effect of the change of steam distribution mode,the experimental research of steam turbine under different loads were carried on. The results showed that the experimental and calculated parameters such as flux characteristic,nozzle pressure agree well, which indicated the method of calculation is reasonable and accurate. Through the experiment of speed control system of turbine, the performance difference before and after change showed that change of steam distribution mode will not bring significant impact to speed control system, which can meet the design requirement.
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