Problem of liquid accumulation in the liquid nitrogen cooling chamber
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1. What is the difference between the operations when there is a liquid level in the nitrogen washing tower and the hydrogen separator, and the operations at each specific liquid level? How should the operation of various valves be changed once a liquid level is present? 2. After the nitrogen washing tower has been operating with liquid for some time, the cold end of E03 has reached below -170°C, the cold end of E02 is around -100°C (it reached -170°C at one point), while the cold end of E01 remains around 20°C and will not drop lower. What actions should be taken to lower the temperature at this location? (The nitrogen washing valve is nearly closed, while the coarse nitrogen valve is open at about half its capacity.) 3. After the liquid levels in the nitrogen washing tower and the hydrogen separator reach 89–91%, the liquid level in the hydrogen separator drops to near 0%, whereas the liquid level in the nitrogen washing tower remains above 90% ； After opening the liquid level control valve of the nitrogen washing tower, the liquid level in that tower does not drop, nor does the liquid level in the hydrogen separator rise ； Attempts were made to increase the pressure in the nitrogen scrubber in order to raise the pressure difference between the nitrogen scrubber and the hydrogen separator, so as to push the pressure into the hydrogen separator as well, but the pressure in the separator also increased as a result ； What should be done? :Dizzy: (Current status: The liquid level in the nitrogen washing tower is above 90, with a pressure of nearly 1.0 MPa; the liquid level in the separator is close to 0, with a pressure of 0.8 MPa. The opening degree of the control valve for the liquid level in the nitrogen washing tower is around 90, while the opening degree of the control valve for draining liquid from the lower part of the separator (TV-39) is around 60. The opening degree of the vent valve for the fuel gas zone is 100, and the fuel gas flow rate exceeds 3000 (above the upper limit indicated by the instruments). The opening degree of the vent valve for the gaseous phase (circular hydrogen) coming out of the hydrogen separator is also 100.) Please help! It’s urgent! ! Waiting online! ! !
Please provide the flowchart, design data, and current actual operation data; these are necessary to conduct an analysis
The nitrogen washing valve is closed – how can I wash it? Everything is subject to the actual traffic volume.
The liquid nitrogen washing system designed by Hangyang features a raw gas flow rate of 100,000 cubic meters; the process flow is more or less the same in all cases
It’s currently cooling down and the fluid has not been connected to air yet
1. When there is no liquid, pay attention to the pressure in the hydrogen separation tank; do not allow overpressure to occur； When there is a liquid level present, increase the opening degree of the liquid level control valves in the nitrogen scrubber and separator (or open them fully) to accelerate the cooling rate of the plate exchanger ； 2. The E01 you mentioned is the medium-pressure nitrogen cooler, right? At 20°C, it’s normal and no action is needed; that’s the maximum cooling capacity it has. Once gas flow is restored, everything will return to normal – just ensure there is an appropriate temperature difference across the end faces ； 3. First, check whether all the drainage drains are closed; it seems that everything is normal in your case, with no major issues. The liquid level in the nitrogen washing tower is 90, which isn’t high. Make sure to monitor the pressure difference in the nitrogen washing tower to keep it below 10 kPa
The fuel gas is vented, and the amount of recycled hydrogen released is too high, resulting in all the cooling capacity being lost. The liquid level in the hydrogen separation tank rises rapidly, and it becomes impossible to transfer the cooling capacity to E01. Consider reducing the venting of fuel gas and hydrogen
If tank V2 is empty of liquid, it is either because the opening degree of TV39 is too high, or because the pressure difference between tower T1 and tank V2 is too small, preventing liquid from flowing in