In multistoried or the high-rise civil constructions the full-time machinery hot water circulation supply system design

whether the design parameters for the flow and the lift of circulating pump are appropriate or not

will be related to continuously

safe

stably running of the hot water supply system.This paper introduces parameter selections of hot water circulating pump both at home and abroad.Based on the difference of these selection means it analyzes the calculating means of the flow and the lift of circulating pump.Whether the circulator flow should join the additional circulating flow or not is the focal point in the argument.In China's present "Code for design of building water supply and drainage" the additional circulating flow is considered not flowing through the circulating pump

so in calculation the additional circulating flow does not contain the circulator flow.By analysis of the water distribution operating mode and various ring circuits difference

as well as considering that for the very small circulator flow it is more difficult to use the valve regulation and to achieve balance between various ring circuits resistance loss

inaccessible absolute circulation in the same regulation

short circuit and so on

the circulator flow should be the sum of circulating flow and additional circulating flow.To calculate lift head the additional circulating flow should be considered through the calculating loop.