THE POTENTIAL ENERGY IMPACT OF THE SUCTION TUBE OF PUMPING FACILITIES ON THE MARK OF PUMP AXIS INSTALLATION AND THE POWER CONSUMPTION OF DRIVE MOTORS

Purpose: to substantiate theoretically the impact of the potential energy of suction tube of pumping facilities on the installation mark of the pump axis and the drive motor power. Materials and methods. The theoretical studies were based on the substantiation of the impact of potential energy in the pump housing on head, on the analysis of dependence of hydraulic resistances coefficients in the suction tube on the installation height of the pump axis relative to the water source surface and on the impact of potential energy in the suction tube on the useful power of drive motors. Results. It has been determined that when designing pumping facilities, the pump axis mark and the drive motor power are affected by the potential energy in the suction tube, ranging from positive to negative value. When analyzing the K90/85 pump characteristics, it was found that there was no significant effect of kinetic energy. The main influencing factor on potential energy is the hydraulic resistance coefficient, which varies during operation due to corrosion of the inner surface of the pipeline. When hydraulic resistance coefficient changes from 0.02 to 0.5, the pump axis installation mark ranges from +1.92 to –31.11 m, which leads to a complete stop of the supply feed. Studying the influence of the pipeline length, it was found that the height of the pump axis installation varies from +3.24 to –3.43 m, which indicates the degree of the pumping station building depth. In the study of impact of potential energy on the drive motor power, a decrease from 23.59 to 17.8 kW with a corresponding increase in the total energy in the suction pipeline from 3.28 to 26.92 m was stated. Conclusions: when operating existing and newly designed pumping stations, it should be borne in mind that there is a constant value of the velocity head in the suction pipeline not exceeding 0.2–0.3 m with appropriate diameter selection and the possibility of increasing the coefficient of hydraulic resistance for the inner surface during operation.