Full-scale testing of the pump unit with a frequency converter

Abstract

It is generally agreed that when using the frequency converter at pumping stations, the economic effect of its use far exceeds the losses in efficiency, and naturally, no comparison between the alternative methods of regulation is given. But, as a practice has shown at the application of the given control method, losses in efficiency can be essential. Quantitatively these losses depend on many factors (degree of regulation, type of the applied frequency converter, pumps and the driving electric motor, operating modes etc.). Therefore, for an accurate assessment of the efficiency of the control method, field tests of the unit with a frequency converter are necessary. Full-scale tests were carried out at the Teshik-Tash-1 pumping station located in the Andijan region of the Republic of Uzbekistan. The field tests consisted of determining the efficiency of the pump unit when the drive shaft speed changes. Graphical dependencies of changes in the energy parameters of the pump unit when changing the rotation frequency of the impeller shaft using a frequency converter are obtained. Tests have shown that loss values can reach significant values when using a frequency converter. If you reduce the speed of the pump impeller by 10 %, the efficiency of the electric drive (motor and converter) will also decrease by 10 %, and if you change it by 25 %, the efficiency of the electric drive may decrease by up to 40 %. The test results can be applied in the selection and feasibility study of the regulation method at irrigation pumping stations equipped with pumps of type D.

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

“…It is not possible to determine the nature of these changes analytically. The pump's efficiency primarily depends on the size of the pump, the shape of the flow part, the impeller and the design of the pump, and then on the properties of the pumped liquid [3,4,5]. Therefore, by conducting full-scale parametric tests of the pump using indirect measurement methods [32] for liquids with different sediment concentrations, it will be possible to identify the nature of the influence of the content of mechanical impurities in the pumped water on the change in parameters by comparing the obtained pump performance characteristics (pressure, power, efficiency, and cavitation) at different concentrations and mechanical size of sediments.…”

“…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].…”

“…One of the main negative factors that significantly worsen the operating conditions of pumping equipment is the saturation of the pumped water with mechanical impurities. The technical and economic consequences of the presence of a significant content of mechanical impurities in the pumped water are expressed in the deterioration of the operating parameters of the pumping unit (pressure, supply, efficiency) and the associated increase in electricity consumption and in significant labor and material costs for repair work to eliminate the consequences of waterjet wear of the pump flow parts [1,4,5,7,10]. The presence of suspended sediments in the pumped water leads to overspending electricity spent on lifting water or undersupplying this water at a constant value of the amount of electricity consumed.…”

The method of hydraulic flushing calculation of the reservoir of the "Indian type" hydrosystem

“…Under such conditions, the organization of rational leaching of the headwater is of paramount importance. [4,5,7,8,9,10,14] The department "Use of water energy and pumping stations" of the Tashkent Institute of Irrigation and Agricultural Mechanization Engineers purposefully deals with the issues of improving the efficiency of operation of hydraulic structures and equipment of hydropower facilities (pumping stations and hydroelectric power plants) [15,16,17,18,19]. This article proposes a method for calculating the duration of washing the headwater of Indian-type hydrosystems to improve the conditions for water intake into the supply channels of the hydroelectric power station.…”

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

“…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. This factor considerably limits the scope of their application.…”