The relationship between a steam trap and heat
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The heating in the lounge here uses steam, and a steam trap is installed after the heating system. When some of these steam traps break, they are simply removed to allow air to escape. However, it seems that the temperature is higher when there is a steam trap compared to when there isn’t one. I’ve heard before that temperatures are higher with a steam trap in place. What is the relationship between these two factors?
The function of a steam trap is to quickly remove condensate from the steam pipeline, thereby maintaining optimal heating efficiency of the steam. Normally, steam traps are installed at the lowest point of steam pipes or on longer steam pipes. When the steam trap is operating properly, it only releases the condensed water from the steam pipeline, without releasing steam, thus preventing waste of steam ； If the steam trap is damaged and water is drained directly by removing it, some steam will be released as well, which reduces the amount of steam that can be transported and affects its heating efficiency – it’s not worth it!
In heating pipes (plates), when a steam trap is present, condensation heat transfer occurs within the pipe, with a coefficient as high as 10 to the fourth power； Without a steam trap, heat is transferred within the pipe through convection of steam; the coefficient in this case is two orders of magnitude lower, and that’s the reason.
I agree with the view from the 3rd floor: when a steam trap is present, a large amount of heat is released after the steam condenses (which is equivalent to latent heat), thereby ensuring a higher indoor temperature； If steam is discharged directly, since the indoor atmospheric pressure is lower than the steam pressure inside the pipes, a large amount of steam does not condense; instead, it turns into water vapor at a lower temperature with a pressure equal to that of the atmosphere. The heat released is merely the sensible heat of the steam. The latent heat of steam is much greater than its sensible heat; therefore, if steam is released directly, the temperature inside the room will be lower.
In my humble opinion, regarding heat transfer, the driving force is the temperature difference; the greater the temperature difference, the more heat is transferred! Due to the absence of a steam trap, the pressure at the outlet is low, which results in low steam pressure in the pipes; as a consequence, the steam temperature is also low. The temperature difference is therefore smaller compared to when a steam trap is installed, and this is what causes this phenomenon! In this issue, two main factors are involved: temperature and heat exchange area. When there is a large amount of liquid accumulated in the pipeline, I think the temperature will be lower compared to when there is no steam trap!
I see two points: first, with a steam trap, there is condensate heating; second, with a steam trap, the pressure inside the pipeline is high and the steam temperature is high.
Great knowledge point, I’ve learned it! !
Combining the 3rd, 4th, and 5th floors gives the complete answer regarding total heat; the key lies in the relationship between sensible heat and latent heat – when latent heat is high, there is no waste! !