Energy Efficiency Analysis of Fixed-Speed Pump Drives with Various Types of Motors

Abstract

The paper presents a comparative analysis of energy consumption by 2.2 kW electric motors of various types and energy efficiency classes in the electric drive of a pump unit with throttle control in a water supply system. Line-start permanent-magnet synchronous motors of the IE4 energy efficiency class and induction motors of the IE4 and IE3 energy efficiency classes of various manufacturers were considered (IE4 and IE3 are labels of energy efficiency classes of electric motors according to IEC 60034-30-1 standard). Energy consumption at a hydraulic load changing under a typical duty cycle was calculated based on the nameplate data of the pump and electric motors. The developed method shows that selecting an electric motor based on the IE energy efficiency class under the IEC 60034-30-1 standard (i.e., based on efficiency at a rated load) may not provide the minimum energy consumption of a variable flow pump unit over a typical duty cycle. In particular, the considered IE4 class line-start permanent-magnet synchronous motors do not provide significant advantages over IE4 class induction motors, and sometimes even over IE3 class induction motors when they are used in variable flow pump units.

Energy Consumption Comparison of a Single Variable-Speed Pump and a System of Two Pumps: Variable-Speed and Fixed-Speed

“…Based on the considerations given above, in the case of calculating the joint operation of two pumps in multi-pump system, the working points of the variable speed pump are determined in the same way as in the case of operation of one pump with a flow Q req /2 according to Equations (1)- (3). The working point of the pump with a non-adjustable drive is determined by the intersection of its Q-H characteristics and vertical line Q req /2.…”

“…These systems account for approximately 22% of the energy consumed by electrical motors [1]. The problem of the energy efficiency of pumping systems is topical among the researchers [2,3]. Although most of the pumping units are still using drives without variable speed control [3], in some countries almost 20-30% of pumping systems are already supplied with variable speed drives (VSDs), due to their high efficiency [4].…”

Comparative Study of Induction Motors of IE2, IE3 and IE4 Efficiency Classes in Pump Applications Taking into Account CO2 Emission Intensity

“…In [20], the comparison of the energy consumption of 2.2 kW line-start permanent magnet motors (LS-PMSM) and induction motors of IE3 and IE4 classes in a pump unit with throttling control is considered. The annual energy consumption, the annual electricity costs, and the life-cycle cost savings were assessed for these motors.…”

“…It is also necessary to take into account the efficiency values of the motor under partial load conditions. Still, in [20], the payback period and CO 2 emissions, depending on the electricity consumed by different motors, were not estimated.…”

CFD-Rotordynamics Sequential Coupling Simulation Approach for the Flow-Induced Vibration of Rotor System in Centrifugal Pump

“…As an indispensable important energy conversion device, centrifugal pump is extensively applied in various agricultural and industrial fields. For the reduction of equipment investment and energy consumption, modern centrifugal pumps have developed towards the direction of higher flow capacity, rotation speed, head, and efficiency [1][2][3][4][5]. This means that the vibration problem of centrifugal pump tends to become more prominent due to the increased energy density, and it will inevitably bring about unfavorable effects on the operational safety, stability, and life.…”