Determine the main working technological parameters of a centrifugal pump pumping oil from a tank with absolute pressure above the oil level P0. The pressure at the inlet and outlet of the pump is equal to P1 and P2, respectively, and is measured by pressure gauges at points with geodetic marks Z1 and Z2. The pump flow meter and the pump motor wattmeter are Q and W.
The main parameters of the pump: the diameters of the suction and discharge nozzles are equal to each other and equal to D, the pump shaft speed n, the rated parameters of the pump Qo and Нo, the permissible cavitation reserve of the pump during oil transfer, hdop.
The pump pumps oil with density ρ and with saturated vapor pressure Ps. Loss of pressure in the suction pipe should be equal to 3m.
Note.
The main working technological parameters of the pump include: pressure developed by the pump; permissible suction height; speed factor, net pump power; efficiency pump unit.
Given: mark of the central nervous system pump 500-160; P0 = 1.03 kG / cm2 = 101.01 * 103 Pa; P1 = 3.33 kG / cm2 = 326.56 * 103 Pa; P2 = 52.2 kG / cm2 = 5119.07 * 103Pa; Z1 = 1.1m; Z2 = 1.8m; Q = 315m3 / h = = 0.0875m3 / s; W = 515 kW = 515 * 103 W; D = 250mm = 0.25m; n = 1500 rpm; hdop = 4,5m; ρ = 0.860t / m3 = 860kg / m3; Ps = 1415mm Hg = 188620Pa; hВС = 3.0 m.