Doubts about cold box operation
Thread Content
Which situation will cause the temperature difference between the hot end of the LNG cold box cryogenic heat exchanger and the pre-cooling heat exchanger to be large? The temperature of the upper part cannot be lowered, and the temperature of the refrigerant leaving the cold box is still low. The liquid phase JT valve is opened enough, and the temperature of the cryogenic heat exchanger can be lowered, but the temperature of the refrigerant leaving the cryogenic heat exchanger is too high? ?
If the temperature of the refrigerant leaving the cold box is low, it means that the designed heat exchange capacity has not been reached, that is, the cooling and heating loads do not match. I wonder if the LNG end temperature of your cryogenic heat exchanger is not low enough or the temperature is not low enough when increasing production. If this phenomenon occurs, I think the opening of your cryogenic JT valve is too large. As a result, the liquid phase is not completely vaporized in the cryogenic heat exchanger due to the quantity, and the cold energy is brought to the pre-cooling heat exchanger. As a result, the heavy component liquid phase in the pre-cooling heat exchanger that should be vaporized is brought out of the cold box with the circulation without phase change, causing the temperature of your refrigerant to leave the cold box to be low. It’s not that the larger the opening of the JT valve, the better.
Liquid phase refrigerant in j_Will there be a phase change before and after the t valve? How to explain it?
Well, we have two pre-cooling heat exchangers, and there is also a bias flow phenomenon during operation.