FUNCTIONAL ASPECTS OF PUMPS AND CENTRIFUGAL PUMP MODELS

Аннотация

This article presents the principle of operation of a centrifugal pump and the classification of impellers. The geometric and kinematic parameters of the impeller were calculated, the spiral outlet was calculated, the axial force acting on the rotor and the radial force acting on the impeller were found. The impeller was designed based on the calculation results. A strength calculation of the shaft connection with the impeller was performed. The pump drive and the centrifugal pump model were selected. Keywords: hydraulics, centrifugal pump, aspect, component, efficiency, performance, rotation frequency, design. Introduction. Hydraulic power engineering is the field of study and practice concerned with the transmission and control of energy (in the form of fluid under pressure) for the purpose of moving and applying forces to machine elements. This field currently employs new technologies related to hydraulic power engineering. The amount of fluid that a pump can deliver is determined by two main parameters: the pump displacement and the drive shaft speed. The pump displacement mainly depends on the design geometry. This paper provides analytical procedures for determining the pump functions of specific positive displacement pumps [1] Of these, centrifugal pumps are widely used in water supply systems, wastewater disposal, thermal power engineering, food industry, chemical industry, petrochemical industry, nuclear industry, aviation and rocket engineering, etc. A centrifugal pump is a mechanical device that uses a rotating impeller to create a flow inside the pump casing, thereby increasing the fluid pressure; it is commonly used for pumping liquids in various industries. The principle of operation of a centrifugal pump is to create a centrifugal force that moves the liquid through the pump. This is achieved by the rotation of a central rotor inside the stator or by using a difference wheel, which creates a pressure difference and moves the liquid.[4] Small centrifugal pumps (e.g. aquarium pumps) are capable of developing a maximum pressure of 0.05 bar (i.e. creating a water head of up to 0.5 141 ISSN (E): 2181-4570 ResearchBib Impact Factor: 6,4 / 2023 SJIF 2024 = 5.073/Volume-2,Issue-10 meters). Some industrial positive displacement pumps (e.g. plunger pumps) are capable of developing pressures of up to 200 bar or even more. There are no seals between the suction and discharge sides of the pump. This means that centrifugal pumps are ineffective with gases and are not capable of pumping air out of the suction line when the liquid level is below the impeller. The method of regulating the performance of a centrifugal pump is to bypass a portion of the fluid being pumped from the pump outlet to its inlet through a bypass line with a regulating gate valve and a suction gate valve on the pump inlet pipe to the bypass line[11]. The simplest way to change the flow rate of a centrifugal pump is to adjust the opening of the pump outlet valve, while the pump speed remains constant (usually rated). The idea is to change the position of the pipeline characteristic curve to change the pump's operating point. Almost all centrifugal pumps will consume more power as the head decreases and the flow increases. So, if your head (pressure) decreases, your flow increases and the operating point shifts to the right of the pump curve where more power is required. The most common method of controlling the pump discharge pressure is to use a regulating valve . This valve is installed in the discharge line and is used to restrict the flow of fluid, thereby increasing the pressure[10]. Regulating valves can be manually or automatically controlled, depending on the system requirements [5]. Almost all centrifugal pumps will use more power when the head drops and the flow increases. So if your head (pressure) decreases, your flow increases, and the operating point shifts to the right of the pump curve, where more power is required. Almost all centrifugal pumps will use more power when the head drops and the flow increases. So if your head (pressure) decreases, your flow increases, and the operating point shifts to the right of the pump curve, where more power is required.[2] Method and methodology of the research. The material uses the methods of mathematical statistics and analysis. The main components of a centrifugal pump are the impeller, casing, suction and discharge nozzles, shaft, bearings and mechanical seals. The functional aspects of the pump are related to the performance of the layout of the elements of the hydraulic system of a given machine. In addition, how well does the pump meet the performance requirements as a converter of mechanical energy into fluid energy? If the selected pump does not satisfy the functional aspects of the 142 ISSN (E): 2181-4570 ResearchBib Impact Factor: 6,4 / 2023 SJIF 2024 = 5.073/Volume-2,Issue-10 application, there is no need to worry about how well it resists damage to the structure and the