In the start-up phase of the air separation unit, the cooling capacity is first used to cool the unit, reduce the temperature, generate liquid air, and accumulate the liquid required for distillation in the tower.
After the internal temperature, liquid level and other working conditions are normal, the cooling capacity required is greatly reduced compared with that in the startup stage, mainly to maintain the normal working conditions in the tower. At this time, the equipment is in a low temperature state, there is heat from the outside, and there is a temperature difference in heat transfer at the hot end of the heat exchanger. The generated cooling capacity should first make up for the two cooling losses, namely, cold running and incomplete heat exchange, to maintain the stability of the working conditions. When the device has a small amount of low temperature leakage or other cold losses, the required cooling capacity will increase. In addition, when part of the liquid products produced by the device are exported to the device, the cold capacity brought by low-temperature products also needs to be made up by producing more cold capacity. Therefore, the refrigeration capacity produced by the air separation plant is equal to each cooling capacity loss and consumption to maintain stable working conditions, which is called "cooling capacity balance".
If "insufficient cooling capacity" or "excess cooling capacity" are both cases, the cooling capacity balance will be broken, which is reflected in the decline of liquid oxygen surface or the rise of liquid oxygen surface. At this time, the cooling capacity needs to be adjusted accordingly to achieve a new balance on a new basis.
DEAR Air Separation is specialized in R&D, manufacturing and installation of various complete sets of air separation equipment to provide customers with the required project design scheme.
