火电与核电常规岛主给水泵组汽蚀性能比较

Comparison Analysis of Cavitation Performances for Main Feed⁃water Pump Unit in Thermal Power Plant and Nuclear Power Conventional Island

结合火电机组、核电常规岛的蒸汽参数与主给水泵的结构特点,分析比较了主给水泵组的汽蚀性能,指出前置泵的设置兼顾了可靠性与经济性,对于火电机组与核电常规岛机组都是必要的,在极端瞬态工况下,核电常规岛的前置泵发生汽蚀的概率高于火电机组。所调研火电机组与核电常规岛的主给水泵吸入比转速均在8000~9000(m3/h,r/min,m),低于SH/T 3139标准中规定的吸入比转速常规上限12780(m3/h,r/min,m),属于兼顾效率与抗汽蚀性能的类型。采用高吸入比转速会降低泵的可靠性与效率,在未经实践验证的条件下,不能轻易接受以标准中的极值作为吸入比转速的设计值。

Based on the characteristics of steam parameters and the structural characteristics of the main feed water pump,the cavitation performance of the main feed water pump unit of the thermal power unit and the nuclear power conventional island is analyzed and compared.The booster pump for main feed⁃water pump is necessary,which could give a well balancing between reliability and economy.The cavitation probability of booster pump in nuclear power conventional island is higher than that in thermal power plant under extreme transient condition.The pump suction specific speeds of the main feed water pump in thermal power plant and nuclear power conventional island are in range of 8000~9000(m3/h,r/min,m),which are lower than suction specific speed margin 12780(m3/h,r/min,m)provided in SH/T3139 and belong to the type of anti⁃cavitation performance and efficiency.The blind pursuit of high suction specific speed will reduce the reliability and efficiency of the pump.Engineering companies shall not easily accept the extreme value provided in standard as a suction specific speed design value without any proven work in practice.