487 / 2018-12-31 15:51:23

Numerical Calculation and Analysis of Low Flow Rate of 600MW Generator Steam Turbine Low Pressure Cylinder

low-pressure cylinder; small flow condition; blade temperature; blade strength; numerical calculation(低压缸；小流量工况；叶片温度；叶片强度；数值计算)

全体主题 > 涡轮机

In order to ensure the safe operation of the 600MW generator steam turbine low-pressure cylinder under low flow conditions. A seven-stage blade model of the steam turbine low-pressure cylinder was established. The numerical simulation method was used to calculate and analyze the six flow conditions, the distributed condition of the whole flow field and the last stage temperature field of the low-pressure cylinder under six different inlet parameters was obtained. The effects of the inlet steam flow and inlet steam temperature of low-pressure cylinder on the whole flow field and last stage blade temperature. Through the calculation of the strength of the last stage rotor blade, the maximum limit temperature of the last stage rotor blade and the corresponding inlet flow of the low-pressure cylinder are obtained. The results show that the outlet area began to reflux when the inlet mass flow rate of the low-pressure cylinder is 140t•h-1, and the reflux appears in the bottom of the outlet area earliest. Under the condition of small mass flow, the highest temperature of the last stage blade appears near the exit edge on the top of stator blade. The smaller the inlet flow rate, the more serious the reflux, the higher the surface temperature of the blade. Reducing the inlet steam temperature of the low-pressure cylinder is beneficial for improving the blast effect and reducing the surface temperature of the last stage blade. The maximum stress of the last stage rotor blade appears in the top pin hole of the blade groove. The temperature should be controlled below 100°C to meet the strength requirement which needs the inlet mass flow rate should be more than 52t•h-1.