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UDC 628.12:62-531.3

KARGIN S. A.

Analysis of Electric Power Losses in the Course of Operation of a Group of Pumps Equipped with Adjustable Drive

Summary

Calculations of the power losses in pump units with aggregates operating simultaneously, one of them is adjustable, are presented. The main advantage of a control scheme with one adjustable pump is a relatively low cost of an apparatus part. But additional power losses connected with reduction of rotation frequency of a pump impeller of the adjustable pump in the course of operation of unregulated pumps under conditions of maximum output are unavoidable. Calculations of these losses made with the use of vector diagrams of hydraulic capacity of pumps make it possible to develop a structure of a power efficient pumping unut characterized by acceptable cost of equipment and minimal power expenditures to maintain the preset pressure in a pressure line.

Key words:

pressure , pump unit , frequency of pump impeller rotation , capacity , hydraulic capacity , frequency of feeding voltage , frequency converter

DOI 10.35776/MNP.2019.09.05
UDC 628.112.23: 351.852.14

Prokof’eva P. S., Chizhik K. I.

Artesian wells of the Moscow region of the 19th–20th centuries

Summary

A historical review is presented that describes the results of the completed stage of work on the search and study of underground water intake structures of the pre-revolutionary period in the Moscow Region. The materials presented concern mainly the so-called «artesian wells». These structures are scarcely covered in modern professional books. By design these wells had a large diameter and depth and were located above artesian boreholes. Their construction was caused by the need to place large-sized pumping units that were an integral part of the process of constructing an artesian well. The article presents a brief overview of such underground water intakes that existed as part of the city water pipelines in Moscow, documentary information on the methods of their construction, as well as a description of the artesian well discovered by the authors in Serpukhov, Moscow Region.

Key words

pump unit , artesian well , ground water source , design of the wells , shaft well , drill unit

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UDC 628.15:62-531.3.004.18

LEZNOV B. S., Vorobiev S. V.

Assessment of Water Saving When Using the Regulated Electric Drive in Pumping Plants of Water Supply Systems

Summary

Methods of the assessment of water saving developed by specialists of the Yagorba Ltd. and the automation laboratory of the NII VODGEO PC are described. The assessment of water saving when using a regulated drive for various variants of pumping plants operation in the water supply systems can be made with the help of these methods. Results of the calculation are close sufficiently to the results of operational supervision on real objects. This procedure can be used for estimation of reduction of wastewater disposal into the sewerage owing to the reduction of non-productive discharges in a water delivery system. The example of calculation of predicted water saving for a pump installation with one and several units is presented.

Key words

adjustable electric drive , pressure , water supply , pump unit , water supply system , water saving , energy , non-productive discharges of water

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UDC 628.1:614.842.62

Zaiko V. A., Il'in N. A., Sargsyan A. M.

Water supply systems for firefighting in small communities

Summary

The issues of arranging firefighting in small communities that usually lack firefighting water systems and the arrival of firefighting machinery sometime is delayed are discussed. The information on the availability of firefighting water systems in Russian communities and the number of fire accidents against population is presented. It is noted that special attention should be paid to establishing advanced water supply systems in small communities that can be also used for firefighting. A water supply scheme is proposed that provides for domestic water supply and external firefighting from fire hydrants eliminating the use of mobile pumping units. To accomplish this it would be reasonable to use regulating and reserve tanks to store a reserve water stock for firefighting; pumping units with variable speed drives; pipe fittings with electric operators; advanced automation equipment and water supply and distribution control systems. The options of operating modes of such water supply system in normal conditions and in case of fire are presented.

Key words

pump unit , water supply system , firefighting arrangement , fire water supply , fire hydrant