Regarding the issue of pressure reduction of saturated steam?
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What state is the water at saturated vapor pressure in after pressure reduction? For example, water at 150 degrees temperature and 0.5 MPA pressure (saturated water) – when the pressure is reduced to 0.1 MPA – is it in the form of water vapor, water, or both? Will the temperature drop at this time? Is what comes out saturated water and saturated steam at 120 degrees and 0.2 MPa?
After the pressure is reduced, the saturation temperature of water decreases; the saturation temperature at 0.1 MPa is 120°C, while it is 150°C at 0.5 MPa. After depressurization, a vapor-water mixture is formed at 0.1 MPa, with the steam being saturated steam and the water being saturated water, and the temperature of this vapor-water mixture is 120°C. Based on the heat balance, the flow rates of water and steam can be calculated separately. This post was last edited by hb*zi121 on 2009-4-17 13:24.]
What should come out is water vapor. The temperature should remain unchanged; the heat is constant
After the pressure is reduced, the boiling point of the substance should decrease; at the original temperature it should turn into water vapor. Under high temperature and pressure, the latent heat of vaporization of water also decreases
When the pressure decreases, a phase change should occur; vaporization absorbs heat, causing the water temperature to drop. If the temperature still reaches that of saturated steam at 0.1 MPA, then what is produced is steam; otherwise, it should be a mixture of vapor and liquid.
When pressure drops, the temperature decreases because the vaporization of water absorbs heat, causing the steam to become superheated.