EXPRESS ESTIMATION OF THE ENERGY EFFICIENCY OF A CENTRIFUGAL PUMP WITHOUT EXPERIMENTAL DETERMINATION OF ITS EXPENSES

Abstract

Using a mathematical model, created on the basis of the electrohydraulic analogy method, a methodology for express estimation of the energy efficiency of a centrifugal pump was developed. The design load angle for analyzing the efficiency of operating modes of hydraulic machines is determined. The dependence of the power-driven engine shaft and the total efficiency of the centrifugal pump on its calculated load angle is established. The relationship between load angle and speed coefficient, which is a prototype of an electromagnetic load angle which characterizes the synchronous machine operating mode, is determined. It is established the dependence of the main pump head on the calculated load angle and the differential pressure created by the centrifugal pump. The developed methodology makes it possible to avoid significant technical and financial difficulties, since flow meters have a high cost and certain requirements for installation, while manometers are established by the standard requirements of the technological process. The estimated value of the load angle of the centrifugal pump through its catalog parameters is determined. The operating characteristics for the main centrifugal pump of type НМ-7000-210 were calculated and built without experimental determination of its head. Such approach showed a good coincidence of calculated and experimental characteristics. Relative error of energy characteristics does not exceed ten percents.  The proposed methodology can be used for express estimation of the efficiency of energy transformations of the whole electric drive pump unit. Express-analysis is a key to successful management of the energy economy through timely detection of inefficient modes of operation of electric-driven pump units and makes energy research cheaper.