Centrifugal water pump flow control valves adjustment

by：J&T 2021-01-13

centrifugal pump flow control mode, the pump flow control way

by changing the water pump outlet pipe valve opening on the road, cause a change in the local resistance lines to change the piping system characteristic, achieve the goal of changing the pump point, called the valve adjustment, also known as throttling. The way is the most commonly used the simplest way of centrifugal pump flow control.

as shown in figure 4 9 for using regulating valve, pump unit in the case of a change point. Point point A in figure said valve fully open, the limit point of the device. Down gradually as control valves, piping local resistance increases, the S value increase, characteristic curve steepened piping system, the operation condition of the water pump device points gradually shift to the left to point B, C, etc. , water yield decrease. When the valve is seated, the equivalent of S is infinite, flow rate Q = 0, at this point, the pipeline system characteristic curve and the vertical overlap. Therefore, by changing the control valve open degree, can make the operation condition of the water pump from no-load condition to limit point of continuous change, achieve the goal of control flow. It is recommended to use ZZYP self-reliance type regulator is the most ideal.

however, a variety of centrifugal water pump flow control valves adjustment is to increase the valve resistance ( Impedance increase S) The cost of, consumption of water pump excess energy. If the pump at point A, the pump provides lift and the lift line need equal, no waste of energy, but when the pump work at point B, lift pump provide the HB, the lift line need for HB & # 39; Waste, lift & Delta; HB- HB' Consume more power, corresponding to & Delta; NB =ρ gQBΔ HB /η The power of B. Therefore, in the design and operation of pump station, in general, not easy to adopt flow adjusting valve. However, due to the curve of centrifugal pump is rising, using a throttle valve, with the decrease of the flow rate, pump shaft power also is less, the prime mover no harm of overload, also won't happen the danger of water pump cavitation. And the adjustment method is simple, easy to control, convenient management, therefore in the actual operation of the pumping station centrifugal pump flow control valves adjustment is still a common method.

related products: multistage centrifugal pump