高加危疏阀泄漏对汽轮机性能试验热耗率的影响

Influence of High Pressure Heater Emergency Drain Value Leakage on Heat Rate of Steam Turbine Performance Test

针对某电厂2号机组性能试验中3号高加危疏阀无法测量泄漏量导致计算热耗率比实际值虚高的情况,基于ASME PTC6标准,以凝结水流量为基准进行推导分析,认为高加危疏阀存在泄漏但又无法测量泄漏量,会对给水流量和热耗率的计算产生严重干扰。通过建模仿真计算了不同高加危疏阀泄漏量对汽轮机热耗率的真实影响、特性关系及泄漏未被考虑时对热耗率的影响,进而建议性能试验前特别关注高加危疏阀的隔离效果,确保高加危疏阀不存在泄漏,以保证试验结果的客观性。

Due to the leakage flow cannot be measured by the No.3 high pressure heater emergency drain value in the performance test of Unit 2 of a power plant,resulting in the calculated heat rate being higher than the actual value,based on the ASME PTC6 standard and based on the condensate flow,it is derived and analyzed by formula that if there is leakage in the emergency valve of the high pressure heater but the leakage flow cannot be considered,it will seriously interfere with the calculation of feed water flow and heat rate.The real influence and characteristic relationship of different high pressure heater emergency drain values on the rate of the steam turbine and the influence on the heat rate without taking the leakage into consideration are calculated through modeling and simulation.Therefore,it is recommended that special attention should be paid to the emergency valve isolation effect of the high pressure heater before the performance test to ensure that there is no leakage and to guarantee the objectivity of the test results.