The steam temperature after temperature reduction by the control valve is determined
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The steam entering the device is saturated steam at 1.75 MPag and a temperature of 208 degrees; it is reduced in pressure to 0.35 MPag via a control valve. There is no humidification unit, and we now want to determine the temperature of the steam after pressure reduction. Are there any reference materials available?
The steam that has been depressurized without any humidification is likely superheated steam; the depressurization process of steam is an isenthalpic process. In other words, the enthalpy values before and after temperature reduction are equal. The enthalpy value of the steam can be determined from the pressure energy before pressure reduction; once the pressure after reduction is known, the temperature can be calculated back using the enthalpy value before reduction.
Steam undergoes throttling expansion, and its temperature drops; it’s not clear how much the temperature decreases. . I forget the expert’s guidance.
The temperature of steam is related to pressure； When under pressure, consult the chart to find the temperature. 0.35 is approximately between 140-150°C.
How do I look up a temperature-entropy diagram? Are there any recommended textbooks? I noticed that the temperature has dropped a lot – in the example I gave, isn’t the temperature around just over 150 degrees? Seeking advice
Let’s do a simple calculation for Aspen: 171.323699℃
As an example for reference: For 3.5 MPa steam (at 430 degrees Celsius), under conditions without moisture addition, when the pressure is reduced to 2.0 MPa, the temperature drops to 250 degrees Celsius; when the pressure is further reduced to 1.0 MPa, the temperature falls to only 220 degrees Celsius. As mentioned on the third floor, the temperature drop during throttling expansion is significant, and it is related to factors such as pipe diameter. Saturated steam at 1.75 MPag and a temperature of 208 degrees is reduced in pressure to 0.35 MPag through a control valve; the estimated temperature at this point is around 160–170°C.
There’s this on the power forum~~ It’s used quite often in boilers and turbines with this program