Pain points with heating systems
Thread Content
I work in the field of selecting and designing chemical processing equipment, as well as heat exchange equipment and power systems for heating applications. I’m facing a tricky problem at the moment: we supplied a heat exchanger unit to a company, but during operation, the flow rate and head of the pump were not as specified on the label (the flow rate and head were lower than indicated). Additionally, there was a high pressure drop across the heat exchanger. When the pressure drop across the heat exchanger decreased, the pump’s flow rate increased slightly. Could you help analyze this? What are the main factors at play here? Will the pump operate properly once the pressure drop across the heat exchanger reaches its designed value?
According to the pump’s performance curve, flow rate is inversely proportional to head, while head is directly proportional to pressure drop. When the pressure drop in the heat exchanger decreases, the flow rate must increase. As for whether the pump can operate properly when the pressure drop in the heat exchanger reaches its design value, that depends on whether the pump chosen is appropriate; if a too large pump is selected, it will not be able to meet its design requirements when the pressure drop in the heat exchanger reaches the design value, and thus it will not function properly.
As a supplementary note, the situation described by the original poster is likely due to an excessive margin chosen when selecting the pump; the performance of the pump can be adjusted by cutting the impeller, allowing the system to function properly.