Difficulty in returning liquid to the refrigerator
Thread Content
Our department has a modular chiller unit. The condenser uses a single-evaporation cooling system, and it has recently been found that the return of the condensate is difficult. As soon as it is turned on, the liquid level in the reservoir drops sharply and remains low for a long time. As soon as it stops, all the refrigerant returns to the receiver. I think one possible reason is that the diameter of the balance pipe is too small, and another reason could be the presence of a large amount of non-condensable gases inside the unit. Seek confirmation!
The issue regarding the liquid level height mainly concerns how large the maximum pressure difference on both sides can be, as well as what the height of the liquid layer in the U-tube is. It’s not a very complicated issue, right? Both the pressure drop inside the heat exchanger and the pressure drop in the pipes need to be calculated.
It is difficult to conduct a detailed analysis of that issue based on this single phenomenon alone; it can be considered from the following aspects: 1. Whether there is enough refrigerant； 2. Has the evaporation efficiency of the evaporator decreased? ； 3. Is there a liquid seal on the evaporator return line? If so, there may be sediment at the bottom of the liquid seal ； 4. Can the valves on the return line be fully opened? There are generally no issues with the balance lines; during operation, the pressure in the liquid storage tank is lower than that in the evaporator.