METHOD FOR ESTIMATING ENERGY SAVING BY VARIABLE-SPEED CONTROL OF CENTRIFUGAL PUMP

摘要

Estimation of energy saving by variable-speed control of centrifugal pumps using the affinity laws is erroneous if the pumping system has a static head or back pressure. This paper aims at providing a better estimate by presenting a simplified model of centrifugal pumps using the minimum number of pump and system parameters. This model yields dimensionless pump characteristics as functions of dimen-sionless flow rate at an arbitrary pump speed, and is used to construct a pump power consumption chart. Computation of power consumption by variable-speed pumps using this chart shows that as the static head of the pumping system increases, the deviation from the affinity laws increases.