Does the temperature of the steam change with flow rate?
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This post was last edited by sxf1028102800 on 2017-9-3 20:22. If the temperature of steam at 4.0 Mpa is 280 degrees, then if that steam leaks out, will the temperature of the leaked steam also be 280 degrees? Regardless of the extent of the leakage, is the temperature still 280 degrees? Please ask an expert to explain; it will earn extra points
The temperature of saturated steam at 4 MPa is around 250°C, while the normal design temperature is around 420°C. When the steam flow rate is low, heat loss is high, and the temperature drops. Increasing the flow rate raises the temperature; when the increased flow rate is much greater than the heat lost, the steam temperature rises. At 280°C, steam condenses easily, causing water hammer.
When released into the atmosphere, under adiabatic decompression, the temperature is above 280°C.
Is a little steam leaking out, and is the temperature also 280 degrees?
The theory is that it is adiabatic depressurization.
Yes, even a small leak amounts to 280
My understanding is as follows: 1. At the leak site, the temperature remains at 280 degrees, regardless of the amount of leakage. 2. When the leakage is severe, it causes pressure to be released in the main pipeline, resulting in a drop in pressure. If it is superheated steam, then the impact is minimal ； If it is saturated steam, then condensate will emerge, and the temperature at the leak site will drop. 3. When steam escapes from the leak site, two forces immediately act to affect the temperature. One is to do work on the outside, exchanging heat with the surroundings ； The other is the condensation of steam into liquid droplets, which releases latent heat. Specifically, these two trends are opposite to each other: one is a decrease in temperature, and the other is an increase in temperature. Whether the steam temperature rises or falls depends on which trend is dominant. 5. The first trend is related to the external temperature, pressure, pipeline pressure, and temperature; it has nothing to do with the amount of leakage, so in that case everything remains the same. The second trend is related to the working time and the amount of leakage. In other words, when it first emerges from the leak site, the steam is at a higher temperature; as the distance from the leak site increases, the temperature begins to drop. And this distance is related to the leakage amount. I imagined the model; it’s similar to the flame model, except that the isotherms are in the opposite direction.
You’re not kidding, 4MPA? What concept?