DETERMINING THE WATER REMOVAL CAPACITY OF THE "MASH'AL" PUMPING STATION BASED ON NATURE-EXPERIMENTAL RESEARCH

УДК 628.135

Abstract

The article examines the characteristics of the "Mash'al" pumping station using each unit. During the analysis of each unit of the "Mash'al" pumping station, tests were conducted in the downstream pool; specifically, a method for measuring water discharge using a SONTEK S5 Doppler profiler with a GPS device was proposed, and the results were analyzed. According to the analysis of measurement results, relative to the measurement conditions, the water level in the advance chamber, the connection of the lower pool with pressure pipelines, and the power and voltage of the electrical energy supply allow for a good water consumption during the simultaneous operation of the entire pumping station unit. An even higher discharge rate is achieved if pumps are used without lowering the water level in the pump station's outlet chamber by at least the specified height. Furthermore, it will be possible to achieve more efficient use of the pumping station without observing the cavitation process occurring in the pumps.

Аннотация

В статье рассматриваются характеристики насосной станции «Машаль» с использованием каждого блока. В ходе анализа каждого блока насосной станции «Машаль» были проведены испытания в нижнем водоеме; в частности, предложен метод измерения расхода воды с использованием доплеровского профилометра SONTEK S5 с GPS-устройством, и результаты были проанализированы. По результатам анализа измерений, относительно условий измерения, уровень воды в приемной камере, соединение нижнего водоема с напорными трубопроводами, а также мощность и напряжение электроснабжения позволяют обеспечить хороший расход воды при одновременной работе всего блока насосной станции. Еще более высокая производительность достигается при использовании насосов без понижения уровня воды в выходной камере насосной станции как минимум на заданную высоту. Кроме того, можно добиться более эффективного использования насосной станции без наблюдения за процессом кавитации, происходящим в насосах.

Keywords: Pump, water flow rate, GPS device, Doppler profile, experimental, channel, pressure.

Ключевые слова: Насос, расход воды, устройство GPS, доплер-профилограф, экспериментальный, канал, давление.

Introduction

 Based on the tasks and objectives of the research work, measurement and experimental determination of water discharge using a SONTEK S5 Doppler profiler with a GPS device were carried out in the lower reach using each unit of the "Mash'al" pumping station on May 7-8, 2025.[1]

At the "Mash'al" pumping station, there are 5 OP-5-110 pumping units and 5 VDC215-24-14 units for each unit.

Electric motors are installed at a speed of 428 rpm, with an electrical voltage of 6 kV and a capacity of 800 kWh. The water-lift height is 11.5 meters.[2]

Materials and methods

 It is known that according to the technical data sheets of the OP-5-110 pumping units, the discharge capacity is 19,200 m³/h, or 5.0 m³ per second. These pumping units must be equipped with electric motors with a minimum power of 800 kW/h, an electric voltage of 6 kV, and a rotation speed of 500 rpm to raise 5.0 m³ of water per second to a height of 11–11.5 meters. If electric motors smaller than the above parameters are installed for pumping units, it may lead to a decrease in discharge capacity.[3]

In this regard, we calculate the water discharge capacity of 1 OP-5-110 pump unit at the "Mash'al" pumping station with a capacity of 800 kW/h, an electric voltage of 6 kV, and a VDC215-24-14 electric motor with a rotation speed of 428 rpm:

In pumping stations, the discharge capacity of the pumping unit is considered a critical technical indicator. The water transfer rate of the pump depends on its rotation speed, power, and pressure height. In centrifugal pumps, water consumption decreases as the rotation speed decreases.

Pumping station parameters:

• Q = water flow rate - 5 m³/s.

• H = pressure height - 11.5 m.

• N = electric motor power - 800 kW/h.

• U = electric voltage - 6 kV.

• n = speed of rotation - 428 rpm.

According to the laws of similarity for centrifugal pumps, the water discharge of the pump is directly proportional to the rotation speed [7].:

Q₁ / Q₂ = n₁ / n₂                                    (2.1)

Here:

Q is the water flow rate (m³/s).

n is the rotation speed (rpm).

Results and discussion

In practice, the water flow rate of a pump operating at a speed of 500 rpm is taken as 5 m³/s.

We determine the discharge capacity of a pumping unit with an electric motor operating at a speed of 428 rpm using the following formula[4],[6]:

Q₁ = 5 × (428 / 500) = 4,28 m³/s

Thus, according to the calculation results, the OP-5-110 pumping unit with an electric motor operating at a speed of 428 rpm is capable of discharging an average of 4.28 m³ of water per second. This indicator indicates that the pump's productivity depends on the rotation speed.

Due to the low rotation speed of the pump, its discharge capacity is also considered relatively low. As the pump's rotation speed increases, its water discharge rate also increases. Therefore, the rotation speed is of great importance when selecting pumping units.

In 2025, when the measurement and experimental studies were conducted

On May 7-8, the water level in the pump station's outlet chamber was 1.6 meters, and the electricity voltage was 6 kV.

Water flow measurement studies were conducted based on the requirements established in regulatory documents for the organization and conduct of hydrometric work, as well as generally accepted hydrometric and morphometric regulatory methods and techniques. Water flow measurements were carried out on a hydro bridge located at PK0+55 of the water outlet canal.[5]

Based on measurements, water flow, velocity, and channel morphology were studied using a SONTEC S5 Doppler profiler in the water outlet channel of the lower pool of the pumping station.

The technical characteristics of the SONTEK S5 Doppler profiler with a GPS device are presented in Table 2.1 and Fig. 2.1.

Table 2.1. Specifications of the SONTEK S5 Doppler Profilograph

The pumping units of the pumping station were put into operation separately in turn, and measurements were taken after 40-50 minutes.[6][7]

Water discharge, velocity, and channel morphology in the canal the research and measurement results are presented in Table 2.2 and photographs from field experimental studies in Figure 2.2.

Table 2.2. Results of research measurements on the "Mash'al" pumping station discharge canal

When studying the water discharge capacity of the "Mash'al" pumping station based on research using a SONTEC S5 Doppler profiler, the following was established [4][6]:

- pumping units of the pumping station were put into operation separately in turn, and measurements were carried out after 40-50 minutes, including:

- water level rack in the pump station's outlet chamber;

1.6 meters and an electrical voltage of 6 kV.

The water discharge capacity of unit 2 was 3.14 m³/s, unit 3 was 3.34 m³/s, unit 4 was 3.56 m³/s, and unit 5 was 3.21 m³/s.

Currently, it has not been possible to operate section 1 because it is not in working condition.

Based on the analysis of measurement results, it is possible to produce a water flow rate of 13.3 m³/s during the simultaneous operation of 4 pumping station units relative to the measurement conditions (water level in the advance chamber, connection of the lower pool with pressure pipelines, power and voltage).[8]

An even higher discharge rate is achieved if pumps are used without lowering the water level in the pump station's outlet chamber below a level of at least 2.3–2.5 m. Furthermore, without observing the cavitation process occurring in the pumps, it is possible to achieve more efficient use of the pumping station.

 Figure 2.6. Photo report from research measurements at the "Kattagar Katlavan" pumping station water intake canal