Increasing Service Life and System Efficiency of Parallel Pumps Using Combined Pump Regulation

Safarbek Oshurbekov,Vladimir Dmitrievskii,Vladimir Prakht,Vadim Kazakbaev

doi:10.3390/w13131808

Abstract

The paper discusses the use of the combined control for a system of two parallel pumps to increase its service life. Using the combined control, the pumping system is controlled together by change the speed, throttling, and bypass. The power consumption of the pumping system is calculated for three methods of flow control: with minimum energy consumption, with maximum reliability, and control with a trade-off between efficiency and reliability. In the case of control with maximum reliability, the energy consumption of the pumping system is higher than in the case of control with minimum energy consumption by 29.2%. In the case of the proposed trade-off control, which provides acceptable reliability, the power consumption is higher than with the minimum energy consumption control by only 7.3%.

Highlights

Pumps consume about 20% of the electricity generated worldwide
When optimizing the overall life cycle costs, in addition to taking into account the initial cost of equipment and energy costs, it is necessary to consider the costs of maintenance and repair, which are affected by the reliability of the pump [1]
An analysis of the energy consumption of a pumping system consisting of two 5.5 kW pumps operating in parallel is carried out, considering the reliability constraints

Summary

Introduction

Pumps consume about 20% of the electricity generated worldwide. The largest part of the pump’s life cycle costs is the price of the electricity it consumes. Such systems are widely used in low-power electric drives [11,12] This makes it possible to significantly reduce the initial costs of multi-unit pumping stations, while providing smooth control of their head or flow [6]. The adjustment is performed by changing the speed, and by throttling and bypassing both pumps Using this control method, all operating points of the pumps will be located on the curve maximum service life. The flowrate is adjusted by changing the rotational speed of the first pump, as well as throttling and bypassing both pumps Using this control method, all operating points of the pumps will be in the range from 0.7·QBEP to 1.2·QBEP during the whole considered operating cycle.

Proposed Control Method for the Considered Parallel Pump System

Deviation of the Flow Rate from BEP Applying the Different Control Methods

Methods

Control Method

Findings

Conclusions