Seeking assistance regarding the circulating water pump
Thread Content
At present, our company has 2 200KW circulating water pumps, with a flow rate of 1000 cubic meters per hour, a head of 50 meters, and inlet and outlet pipe diameters of 500mm. During the current debugging process, the following issue was encountered: the pressure at the pump outlet can reach 0.48 MPa, but after passing through a 50-meter-long underground pipeline network as well as a few branches, the pressure drops to only 0.12 MPa. I would like to ask whether it is insufficient motor power that prevents the water from filling the underground pipeline network properly Or is it still because the pipe diameter chosen is too large?
This situation may occur when the system piping network is not fully filled at the beginning of pump operation. Another possibility is that there is no pressure drop in the system pipes, meaning the fluid cannot be held back. Additionally, there could be a leak somewhere, though this is less likely
It was missed, or a valve somewhere is open and water is leaking away
I’ve never worked with a pump of this size before. Generally, according to the pump’s performance curve, there is an optimal operating point for flow rate and head pressure. Check the flow rate; head pressure is mainly indicated by the outlet pressure of the pump. If the fluid is sent to underground pipelines, a high flow rate will result in a much lower outlet pressure. Also, check whether the motor current falls within the rated range. Generally, the outlet flange of a pump is one size smaller than the inlet flange. Check the pump’s manufacturer’s instructions and the performance curves to compare them. If there are specific requirements regarding flow rate and head, the piping will need to be modified
First, check what the pressure is at the highest point where water is used
Since the outlet pressure of the pump can be determined to be 0.48 MPa, what is the outlet flow rate of the pump at this time? If it is 1000 m3/h, then there will be no problem with the pump’s operation; as long as the motor is selected appropriately, there will also be no issues with its use. There is a bypass; please check the flow control of each branch. If everything is correct yet the pressure is low. Then it is likely that the pump head selected was too low, or the calculated pipeline head loss was underestimated, resulting in a higher actual loss.
This leakage issue should be ruled out. . It seems most likely that it’s not fully filled inside. .
This is unlikely; Ming’s pipelines have been checked, and thorough inspections were carried out when the underground pipeline network was installed. .
:Oh, it’s because the circulating water can’t reach the equipment at the highest point, that’s why this issue needs to be taken into consideration
:Oh, it’s because the circulating water can’t reach the equipment at the highest point, that’s why this issue needs to be taken into consideration
If the flow rate is increased, the pressure drop becomes quite significant, which further prevents the achievement of the desired head. So the outlet pressure of 0.48 MPa I mentioned actually means that the outlet valve is only opened to about 40%.