①1　传统计算方法在阶段式变流量系统的设计中 ,各种技术资料对水泵的计算提出了要求 ,当系统出于节电考虑而采用阶段式变流量质调节时 ,循环水泵按以下原则进行选择 :对中小型系统 ,多采用二阶段式变流量 ,2台循环水泵的流量分别为计算值的 10 0 % ,75 % ;扬程分别为计算值的 ① The traditional method of calculation In the design of variable flow system, various technical data put forward the requirements for the calculation of the pump. When the system adopts the variable flow mass adjustment for the sake of electricity saving, the circulating pump selects according to the following principles : For small and medium-sized systems, more use of two-stage variable flow, two circulating pump flow were calculated as 10%, 75%; head were calculated