Heat exchanger vibration
Thread Content
We have a heat exchanger on site, which is used to cool the condensate water. However, if the condensate inlet is opened wider, it will cause vibration in the heat exchanger. Is it because the condensate has flashed again, generating steam? What are the common reasons for vibration in heat exchangers?
Does condensate turn into steam when it enters the heat exchanger? First, is the incoming condensate in a saturated state? Second, under what conditions can it turn into steam? I think it’s due to a decrease in pressure, because when the pressure drops, the condensate will evaporate. But you said that vibration only occurs when the water inlet is opened wide. I think it might be the case that when the water flow rate is high, more steam is generated, which causes vibration in the heat exchanger. Regarding the reasons for vibration in heat exchangers, the original poster can take a look at the index attached to GB151. If the vibration is caused by flashing, the best solution is to subcool the water in the heat exchanger located earlier in the process. I hope your problem is resolved soon
For the heat exchangers that are currently in use, you can only slow down or address the issue through operational measures. But in any case, the original heat exchanger has relatively poor vibration resistance in terms of design. When updating the equipment or piping bundles, consider improving their structure. Such as baffle rod type, hollow ring plate support type, spiral baffle plate support type, etc. Once these structures are properly designed, the heat exchange capacity will not decrease, and the pressure drop will not increase. After the structural change, even with some steam flashing-induced effects, no significant vibration will occur anymore.
Thank you for the explanation above. Very detailed. It was very rewarding. Wish you success in your work
Thickening the tube wall may improve vibration conditions
It’s possible that the temperature of the condensate is already relatively high; if the outlet is opened wider, a certain negative pressure or reduced pressure is created inside the cooler, causing the condensate to flash vaporize. With a gas-liquid mixture present, gas obstruction occurs, which leads to vibration. To eliminate vibration, the outlet must not be opened wide ； Either add a cooler in front to cool it down first (in the case of an enlarged outlet) ； Another option is to increase the pressure (flow rate) of the liquid entering the cooler (for example, by adding a pump), but this may affect the cooling effect.