Overpressure in closed-loop water systems
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It is a closed-loop water circulation system; inadequate consideration was given during its design, with an excessively high head selected for the circulation pump (with pipeline losses of around 0.3 MPa and a pump head of 45 m). As a result, overpressure occurred once the system started operating, reportedly reaching up to 0.7 MPa. How can this situation be handled to minimize costs? The measures we consider include: 1. Adjusting the opening degrees of various valves in the pipeline to increase the head loss in the pipeline; 2. Reducing the diameter of the impeller in the water pump by one stage. Also, such a closed system with an excessively high water pump head should also have a balance point, right? How can overpressure occur? 0.7 MPa is higher than the closed-valve head on the water pump performance curve
It is caused by the rise in the temperature of the circulating water; has the diameter of the return pipe been increased?
Is it the conversion of excess energy by the water pump that causes the water to heat up and expand? Now the system’s loss is already lower than the water pump’s head; wouldn’t it be even lower if it were increased further? I heard from the person in charge; I’m planning to go and take a look in person
The measures of cutting the impeller and closing valves along the line are incorrect! It has nothing to do with the pump~~~~ The water expansion mentioned by the person above is one possibility, though it’s not very likely~~~~ It’s more probable that in your closed-loop system, the valves on the main pipelines or most of the branch pipelines have limited opening degrees~~~~~~~~~~~~~~~
Based on the design analysis, the head generated by the water pump is higher than the head loss when the system valves are fully open; therefore, measures such as using impellers with reduced efficiency or increasing pipeline losses are planned to achieve balance in the system. There is a closed-loop cooling tower in the system, so the water temperature will fluctuate, but it certainly won’t be a general increase in temperature throughout the system
High head and high energy consumption; replacing the impeller is a good solution.
It seems there’s a problem with the valve in that part of the piping system
Rising water temperature causes the volume of water in the piping system to increase, but the piping system restricts this expansion, resulting in an increase in pressure.