Why is there condensation water on the walls of pipelines with flowing medium?
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Everyone, I have a question: why does condensation form on the pipe walls when the medium inside the pipe is flowing at high speed, while the pipe walls remain dry in the same conditions when there is no flow of medium? What causes the formation of condensation water? I have made a preliminary summary: it seems that the lower the density of the flowing medium, the easier it is for condensation water to form. I’m not sure if this summary is accurate.
Changes in pressure, the mutual conversion of energy! When high pressure is reduced to low pressure, heat is released by the medium, causing its temperature to drop below the ambient temperature; if there is moisture in the environment, it will condense into water!
Have you seen pipes with rapidly flowing steam, with water on their outer walls?
I’m referring to media at room temperature; how could condensation water form when the steam temperature is so high? I hope you can discuss the issues properly instead of being stubborn.
There is no pressure change in normal flow either. Moreover, even if there is a pressure change, why doesn’t condensation form in the flow of some fluids?
Why do you call it \"condensate\"? It’s because the temperature on the pipe wall reaches the dew point temperature corresponding to the humidity level of the air at that time, which causes condensation to occur. Essentially, it has little direct relation to what medium is flowing in the pipe or the flow velocity. Dew prevention is an important consideration in heat and cold insulation.
Then why have only pipelines with high-speed flowing media reached the dew point temperature? There is no condensate water in the other pipelines. This situation indicates that the wall temperature of the pipelines through which fluid is flowing is lower than the ambient temperature. And that’s the key question: why does its temperature drop?
I do have an explanation: as the medium flows at high speed within the pipeline, a negative pressure is created inside it. Under this negative pressure, the medium in the pipeline vaporizes, and vaporization requires heat to be absorbed from the surrounding environment; therefore, the temperature of the pipe walls decreases. Why is it easier to form condensation water at lower densities? It is because the lower the density, the easier it is to vaporize. I’m not sure if this explanation is reasonable; I hope fellow sailors will discuss it.
Generally, gases cool down through throttling, but it seems this phenomenon does not occur with liquids
The temperature of the fluid flowing within the pipe is lower than the ambient temperature; especially when transporting materials through stationary pipes in summer (where the temperature inside the pipe is higher than that inside the tank), condensation droplets form on the pipe walls.
It’s just a natural phenomenon; there’s condensation on the outside of water pipes in summer as well