Urgent! Urgent! Urgent! The level in the liquefied gas reflux tank is rising abnormally! ! !
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Recently, it was observed that the level in the liquefied hydrogen return tank (V1303) was rising abnormally, increasing in spurts. On-site verification confirmed that the liquid level and interface level of the oil-gas separator (V1302) at the compressor outlet are both normal ； The circulating water pressure in the heat exchanger is around 0.4–0.5 MPa, which is relatively low ； The reboiler at the bottom of the distillation column is heated using steam at 1.0 MPa, which is significantly lower than the feed pressure of the stabilizer column ； The stabilizer bottom reboiler is used for distilling the middle-stage oil; the pressure at the outlet of the pump associated with this distillation process is around 0.7 MPa, so leakage is not possible. At the same time, both the on-site level and liquid level of V1303 are accurate; when the DCS-level transmission value increases, the on-site glass gauge also rises accordingly. Which expert in this field could please offer some guidance? I’m in a hurry; waiting online! ! !
If there are no significant changes in the top temperature and the temperatures in the middle and upper sections, then sudden changes in water level can be ruled out. You can check whether there is any blockage in the outlet of your glass plate; one of ours is already blocked. Also, if it’s convenient, take two DCS images to take a look.
Could it be that the reboiler at the bottom of the tower is leaking?
Has there been any change in the position of the V1302 level control valve?
No change, it’s normal. At that time, it was also thought that the high level of V1302 might be the cause, so the level of V1302 was lowered a bit, but that didn’t help either.
The heat source for the reboiler at the bottom of the tower is the middle fraction oil from distillation; if there is a leak in this system, only gasoline will leak into the middle fraction oil. The outlet pressure of the middle fraction pump is around 0.7 MPa, while the pressure in the stabilizer tower is around 1.0 MPa. The heat source at the bottom of the distillation tower is 1.0 MPa steam, with the pressure also around 0.9 MPa; the possibility of it leaking into gasoline is virtually zero.
Sample and analyze the water content; does the distillation column have an intermediate reboiler? Analyze it all, and then build a simple coil cooler – it’s safe and the analysis is accurate
Excessive gas volume results in insufficient residence time in V1302
Check whether there is a correlation between changes in the level and the opening degree of the thermal bypass; also, if the level rises abnormally, does the liquid level in the return tank rise as well?
1. What is the pressure in the distillation tower? Could steam leak into Column 2? Is the level gauge malfunctioning, or is it affected by other signals? 3. Whether the acidic water from this section backflows due to an obstructed return path; for example, the acidic water from the condensate tank at the compressor outlet shares the same return path with V1302, and backflow occurs as a result of the obstruction in that path.
The pressure at the top of the distillation tower is around 1.15 MPa, and the steam pressure at 1.0 MPa is around 0.9 MPa; it should be impossible for steam to leak into the distillation tower； Both the on-site level gauge and the remote transmitter give accurate readings ； The discharge of acidic water from the liquefied gas reflux tank is smooth, and the level signal can be transmitted effectively.