The change in the efficiency factor of the pumping unit with a frequency converter

Abstract

This paper gives the results of the investigation of the operation of a pumping unit equipped with a frequency converter. As a rule, it is widely assumed that when changing the speed up to 50 %, the pump efficiency almost does not change, and the possibility of decrease of its efficiency is not taken into consideration when calculating the economic efficiency of the operation of the pumping unit equipped with a frequency converter. However, failure to take account the efficiency decrease may cause inaccurate assessment of the economic efficiency of the use of the frequency converter and, consequently, improper selection of the method of control of the operation of the pumping units. This is particularly important for irrigation pumping plants the operation of which is characterized by large volume of the pumpable volume and less severe requirements for provision of the water pressure required for the consumer. The purpose of this paper is to carry out experiments on a test-bed equipped with a pumping unit, parameter measuring instrument, and a frequency converter, and detection of the pattern of efficiency variation with speed. The paper presents the results of the carried out experiments, the obtained characteristic curves of the variation of different types of the efficiency at variation of the pump shaft speed, as well as their analysis.

Methodology for assessing the efficiency of water jet pumps in auxiliary systems of irrigation pumping stations

“…kW. The efficiency of an installation with jet pumps is in the range of 10-30 % [5], and of a pumping unit with a vane cantilever pump-40-70 % [9,21].…”

“…Jet pumps are really very simple in design, reliable in operation and can pump contaminated liquids. But for all that, they have one significant disadvantage -very low efficiency, incomparable with the efficiency of vane pumps [7,8,9,10]. Despite numerous studies of working processes [11,12,13,14,15], improvement of designs and calculation methods [16,17,18], improvement of operating modes and regulation [4,8,19], it was not possible to significantly increase the efficiency of water jet pumps.…”

Consumption of Irrigation Pumps Pumping Water with a High Content of Mechanical Impurities

“…Therefore, the effective functioning of hydraulic systems with pumping stations ensures energy saving requirements [2,3]. To solve the problems of energy saving at pumping stations, various methods and methods are used: the use of frequency converters [4,5,6], methods for choosing energy-efficient methods for regulating the operation of pumping units taking into account specific conditions [7], improving methods for calculating structures of structures [8], choosing equipment during reconstruction and modernization [9,10] and a rational control system of pumping stations [11,12,13]. Accurate energy consumption accounting is necessary to ensure the energy saving requirement and the application and implementation of the above methods and means [14,15].…”

Research of the optimal method of control of the first rise pumps electric drives operated in conditions of negative temperatures

“…Решением описанных проблем существующих систем водоснабжения является использование систем автоматического управления производительностью электроприводов насосов. Обзор существующих решений показал, что наиболее эффективно данная задача решается путем частотного регулирования электропривода насоса [4][5][6][7][8][9][10]. При этом изменяется частота питающего напряжения, что пропорционально влияет на гидравлические параметры насоса.…”