Why is there a branch line in the circulating water system that does not pass through the heat exchanger?
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I used to think it was about adjusting the outlet temperature, but the valves on the branch line are gate valves, so that can’t be the reason.
Should we post the process diagrams so that everyone can see how it works? I think it’s about adjusting the temperature. Can the opening of the valve be adjusted? That way, it can be opened wider when the water temperature is high, and it doesn’t need to be opened at all when the temperature is low. I’m not sure if I understand it correctly
It is highly likely to be a tubular heat exchanger calculated using a bypass design; it is suitable for situations where the flow rate on the circulation side is high and the temperature rise or drop is small. If the entire circulation stream passed through the heat exchanger, the pressure drop would be too large. In such cases, a bypass can be introduced on that side, allowing some of the water to bypass the heat exchanger. This reduces the pressure drop across the heat exchanger, while the temperature rise or drop of the water that does pass through the heat exchanger is higher than the values specified in the design, so that the desired temperature rise or drop is achieved after mixing at the outlet. However, bypasses generally use control valves, but other types of valves can also achieve the purpose of regulation.
I guess there are two reasons: 1. Bypassing for easier maintenance; there should be separate valves at the inlet and outlet of the heat exchanger, so that it can be serviced when not in use during winter； 2 Adjusting temperature: Gate valves can also be used for adjustment.
Is the pipeline a bit thinner? It’s used to prevent freezing in winter
Yes, it’s very thin, DN20. Thank you
Provide a flowchart; it may also involve the removal of non-condensable gases. The question is rather vague.
1. Bypass for easy maintenance; separate valves should be provided at the inlet and outlet of the heat exchanger. 2. There should be other valves as well, but gate valves can also be used for temperature regulation.
It is used when the heat exchanger is not in use during winter; only the bypass valve is opened to prevent freezing and condensation.
Its main function is to reduce the heat exchange volume in winter; since less water flows into the heat exchanger and the flow rate is low, freezing damage can occur. Therefore, a bypass is added to ensure smooth circulation of the circulating water and prevent such damage. Heat exchangers in the north generally have this feature, and their pipe diameters are usually relatively small. :)
Well, it’s probably used for preventing freezing in winter~!