The plant operation cycle between two large heating is related to many factors. From an operational point of view, this mainly depends on when the air passage of the main heat exchanger is blocked. The main reason for the blockage is that the moisture and carbon dioxide content in the air entering the unit exceeds the standard, which accumulates and freezes in the main heat exchanger until it is blocked.
The abnormal operation of molecular sieve purification system will shorten the operation cycle of the unit. It is mainly caused by the following reasons:
1.The molecular sieve adsorption bed is short circuited. In the process of operation, due to the unstable gas velocity control or switching, the pressure difference between the two tanks is too large, which will affect the bedlayer, make the molecular sieve bed uneven and make the bed layer short circuit. In serious cases, the dust screen of the adsorber will break and the molecular sieve powder will enter the heat exchanger channel, causing blockage;
2.Spray cooling columnwith water. The air velocity passing through the spray cooling columnis too high, which causes the water mist to enter the adsorber, thus greatly increasing the load of the adsorber to remove the water. The moisture and carbon dioxide content in the outlet air exceeds the standard and is taken into the main heat exchanger and frozen, increasing the resistance. If the resistance in the cold part increases, the carbon dioxide freezes. If the resistance of the hot part increases, the moisture freezes. The resistance of the whole heat exchanger increases, and they are frozen or the molecular sieve powder is blocked.
3.The chiller works abnormally, which leads to the cold water temperature rising and the air cannot be cooled to normal temperature. On the one hand, the amount of saturated water in the air from the spray columnincreases; on the other hand, the adsorption capacity of the molecular sieve decreases.
4.if the spray columnis cut off or the water level is too high, the temperature of the molecular sieve adsorber will increase or cause the water ladenaccident.
