Criteria of Effectiveness Evaluation of centrifugal pumps in district heating systems

The goal of this research is the derivation of criteria of effectiveness evaluation of centrifugal pumps in district heating systems.For this purpose, efficiency level of centrifugal pumps of various designs has been analyzed at certain head and flow range.The change of efficiency level of circulators has also been investigated in the article. It’s been done at different deviations from nominal pump head.As a criterion, the effectiveness of proportional pressure control has been analyzed for pumps with variable speed motors. It’s been done if proportionalpressure control is used in comparison with constant pressure control.For these reasons, a great number of energy analyses have been realized for different pumps and regression equations with coefficients of determination have been derived.As the result, the three criteria of effectiveness evaluation of centrifugal pumps have been derived and the trend of reduction of energy consumption has beendetermined.The conclusions are as follows: • vertical in-line single-stage pumps are less efficient in comparison with horizontal end-suction singlestage pumps, when the flow rate varies from 20 to220 m3/h at the definite range of the head (from 10 to 72 m); • the reduction of annual energy consumption can be achieved up to 33%, if proportional pressure is applied and deviations from head value of duty point at zero flow declines up to 60%; • efficiency level drops up to 3% if the deviation ofthe head value of best efficiency point is up to 30% from its nominal value.

کلیدواژه ها:

centrifugal pump ، control mode ، efficiency