Problems with water pump operation in 50% ethylene glycol aqueous solutions
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This post was last edited by idao on 2025-1-13 at 22:50. It deals with a 55kW horizontal single-stage single-suction centrifugal pump, manufactured in 2023, with a flow rate of 200 m³/h and a head of 64 m. The fluid handled is a 50% ethylene glycol aqueous solution at room temperature. Current operating conditions: frequency conversion at 46 Hz, flow rate of approximately 100 m³/h (as measured by an ultrasonic flow meter), inlet pressure of 0.2 MPa, outlet pressure of 0.4 MPa, and energy consumption of 42 kW. Why are the flow rate and pressure so low under these conditions? The difference is quite large from the rated values. What impact does an increase in the viscosity of the ethylene glycol aqueous solution have on the flow rate and head pressure of the water pump?
The issues related to the operation of water pumps that you mentioned involve multiple parameters, including power, flow rate, head, frequency, and the properties of the medium. Based on the data you provided, we can conduct some basic analysis and offer suggestions. ### Basic parameters of the water pump – **Power**: 55 kW – **Design flow rate**: 200 m³/h – **Design head**: 64 m – **Frequency**: 46 Hz – **Medium**: 50% ethylene glycol aqueous solution. ### Current operating conditions – **Actual flow rate**: 100 m³/h – **Inlet pressure**: 0.2 MPa – **Outlet pressure**: 0.4 MPa – **Energy consumption**: 42 kW. ### Analysis 1. **Reduced flow rate**: The design flow rate is 200 m³/h, while the actual flow rate during operation is 100 m³/h, representing a 50% reduction in flow rate. This may lead to a decrease in pump efficiency, as centrifugal pumps generally experience reduced efficiency when operating away from their design point. 2. **Energy Consumption and Efficiency**: Despite the reduced flow rate, the pump’s energy consumption remains high (42 kW), indicating that it may be operating at low efficiency. 3. **Head and Pressure**: The actual head (exit pressure – inlet pressure = 0.4 MPa – 0.2 MPa = 0.2 MPa) corresponds to a water column height of approximately 20.4 m, which is far lower than the designed head of 64 m. This may be due to a decrease in traffic. ### Recommendation – **Check the pump’s operating point**: It is recommended to verify whether the actual operating point of the pump is close to the optimal point on its efficiency curve. If not, it may be necessary to adjust the operating parameters of the pump or consider replacing it with a different model that better meets the current requirements for flow rate and head. - **Variable frequency control**: Consider adjusting the settings of the frequency converter in order to optimize the pump’s operating frequency and achieve a higher energy efficiency ratio. - **System inspection**: Check for any unnecessary pressure losses or flow restrictions in the system, such as valves that are partially closed or clogged filters; these can all affect the efficiency of the pump. Through the above analysis and adjustments, the overall efficiency of the system can be improved and energy consumption can be reduced. If further detailed analysis and specific technical support are required, it is recommended to contact professional pump equipment technicians for on-site inspection and evaluation. .
I would like to ask what material the pumps used for transporting this ethylene glycol are made of?
Sir, an expert from Wolong, may I ask what kind of pump is suitable for ethylene glycol aqueous solutions? Actually, stainless steel should work; I’m not sure if carbon steel will do as well
I have encountered clients choosing 316L as well as carbon steel.
If the properties of the liquid change, such as an increase in density, it will result in a decrease in the pump’s head pressure