Why doesn’t the temperature drop significantly when methane at 3.4 MPa and -162°C undergoes throttling expansion to a pressure of 0.4 MPa?
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An adjustment valve is installed near the bottom of the methane-hydrogen separation tank; the tank’s parameters are 3.4 MPa and -162.11°C℃； 0.4 MPa after the control valve, -161.29℃ ； Thank you to all the experts
The methane in the hydrogen tank is in a supercooled liquid phase. The boiling point of methane is -161.5°C; in this stream, the hydrogen content is approximately 3% by mole, and the temperature remains essentially unchanged after depressurization. Because this is determined by the physical properties of methane.
Our -161 after throttling to -168,
The temperature here in the cryogenic tank is also around -168, but according to the design specifications, it should be -161.29 after using the control valve
The low temperature generated is due to the gas-phase throttling at the top of the hydrogen tank, rather than by the cooling effect of the methane liquid phase at the bottom.
I still don’t understand. Could you explain it in more detail?
If it contains ethane, the temperature will rise again after throttling
Normal, let’s take a look at the Joule-Thomson effect of methane.