Where is t...

In the start-up phase of the air separation equipment, the cooling capacity is first used to cool the unit, reduce the temperature, produce liquid air, and accumulate the liquid required for rectification in the tower. After the internal temperature, liquid level and other working conditions reach normal, the required cooling capacity is greatly reduced compared with the starting stage, mainly to maintain the normal working condition in the tower. At this time, the equipment is in a low temperature state, the external heat must be constantly incoming, in the hot end of the heat exchanger must exist heat transfer temperature difference. In order to maintain the stability of working condition, the generated cooling capacity should first make up for the two cold losses of running cooling and incomplete heat exchange. When the device has a small low temperature leakage or other cold loss, the amount of cooling required increases. In addition, when some liquid products produced by the device are exported to the device, the cold quantity brought by low-temperature products, Q0, also needs to produce more cold quantity to make up for it. Therefore, the cooling capacity Q produced by air separation equipment is equal to the cooling loss and cooling consumption, so as to maintain a stable working condition, which is called "cooling balance".

If the cooling capacity consumption is greater than the cooling capacity, it is "insufficient cooling capacity". If the consumption of cooling capacity is less than the cooling capacity, it is "excess cooling capacity". In both cases, the cooling balance will be disturbed, which is reflected in the decrease of the liquid oxygen level or the rise of the liquid oxygen level. At this time, the refrigerating capacity needs to be adjusted accordingly in order to reach a new balance on the new basis.