Problems with the circulating water pump
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Pump parameters: Centrifugal pump with Q=5300 m3/h and H=60 m; associated motor with P=1120 kW, V=10000 V, and n=990 r/min. Equipment requirements: The outlet pressure of the pump should be controlled at 6 kilograms, but when this pressure is achieved, the flow rate is only 4150 m3/h. Currently, the outlet valve of the circulation pump is set at 40°, and the valve in the water tower is also set at 40° (as a pressure of 2 kilograms is required for the bypass filter). With two pumps in operation, the pressure at the water supply side is 4.2 kilograms, while the pressure on the return side is 2 kilograms； Actually, this is a contradiction: the equipment needs to be optimized for its own operation, while the process must take into account the pressure and flow rates in the piping system. I’m curious to know how other water treatment professionals manage these parameters ；
I suggest that the original poster include a simple diagram to help everyone understand the actual situation more clearly; I’ll keep an eye on it
What is the inlet pressure of the pump? If the inlet pressure is at atmospheric level and the outlet pressure is 6 kilograms, then when the pump operates at its rated speed, the flow rate should be around 5300 cubic meters.
The pump outlet pressure is maintained at around 5.8 kilograms, with the inlet pressure at atmospheric level
Perhaps the pump itself is not capable of achieving this flow rate, or the gap in the sealing ring is too large
I encountered a similar situation, but I don’t have a side filter. By increasing the opening degree of the outlet valve, the operating pressure and flow rate of the equipment can reach the design parameters of the pump itself ； If you can’t operate it due to the side filtration, then I would say that it’s your responsibility to meet the operating pressure and flow rate requirements for a process scale-up pump. Alternatively, you can set the side filtration in the cooling tower unit; there’s no diagram available, so it’s just a guess – hoping this helps.
Your problem lies in the control of return water; the flow rate should be regulated using the water supply valve on the cooling tower (the main return water valve), while each water usage circuit can be controlled as needed. The outlet valves of each pump should be set at a degree of opening specified by the pump’s rated current, without exceeding the allowable open degree under overload conditions.
I think that’s also the case, but in that situation we won’t be able to control the outlet pressure of the pump at a certain level. Although the current doesn’t exceed the limit, the equipment still requires that the pump’s outlet pressure be controlled
I think that’s also the case, but in that situation we won’t be able to control the outlet pressure of the pump at a certain level. Although the current doesn’t exceed the limit, the equipment still requires that the pump’s outlet pressure be controlled
It is still necessary to make adjustments based on the actual conditions on site; this requires finding the optimal control point through specific adjustments. In my opinion, the opening degree of the pump outlet valve is too small. At our facility, both the inlet and outlet valves are kept fully open, and generally, the system pressure is controlled by the valve that regulates water flow back to the tower