Use of centrifugal pumps with canned asynchronous motors in irrigation systems

Abstract

Abstract In most cases, taking into account the local geology and hydrology, water entering the system of humidified mobile irrigation from underground sources, such as from the depth of artesian wells, has an initial temperature below 12 degrees. Low temperature of irrigation water adversely affects the growth and absorption activity of plant roots, and the life of microorganisms, impairing the supply of plants with nutrients, mainly nitrogen. As a result, the use of water from aquifers in irrigation systems requires its preliminary settling in barrels or special storage ponds. Given that the water from the well rises to the surface using a pump (group of pumps), the choice of the type of pumping unit has a significant impact on the structure and composition of the equipment of the irrigation plant. The paper shows the features of using special-shaped centrifugal pumps in terms of increasing the water temperature at the outlet of the pumping unit due to its indirect heating in the design elements of the pump drive motor. Using the heat balance equation for the secondary conductive shells of the pump motor, the interval values of the water temperature at its outlet are calculated, proving the possibility of its further use for its intended purpose in the irrigation system without additional technical water treatment.