Lisheng’s “common formulas” on the mechanical failure of refrigerating system


It is difficult for the newcomer to judge the mechanical failure of the refrigerating system of the cold water chillers. Here I want to share a simple formula for judging the mechanical failure of the cold water chillers’ refrigerating system .

  1. Low pressure high, high pressure low, replace the compressor.
  2. Double pressure height should exhaust, or there’s trouble with heat dissipation.
  3. Hand shakes system has water vapor, vacuum must be more thorough.
  4. Double pressure low due to refrigerant, Otherwise the system has congestion.

The following is a detailed meaning analysis of the formula:

  1. When the pressure gauge of the chiller is used to detect that the low pressure of the chiller system is higher than normal and the high pressure is lower than normal, the cold water chiller can never achieve the effect of the normal chiller at this time. According to the formula, the general fault is caused by the wear in the chiller pump, which leads to the decrease of power. Under this circumstance it often needs to replace the compressor to solve the problem.
  2. When detected high and low pressure of the system are both higher than normal, the common trouble is that the system has too much air or refrigerant. If we make the system to be re-vacuumed, and add a moderate amount of refrigerant can solve the problem. However, there is another situation, which is poor heat dissipation, especially when the ambient temperature is relatively high, which often leads to worse heat dissipation. This fault is usually due to heat sink, dirty, not enough fan speed, and so on.
  3. When the chiller system is working, if the pressure gauge needle keeps shaking, that means the system has water. The solutions for this problem usually involves re-vacuuming, at least 15 minutes, and replacing the drying bottle if necessary to completely drain the water from the system.
  4. When both high and low pressure tend to be low, there are two possibilities: One is the system blockage. When the system is blocked, there will be throttling in the blockage area. And there will be an apparent temperature difference in the throttling area, which can be found out by hand feelings. Another possibility is the release of refrigerant, resulting in insufficient refrigerant. This situation is relatively common and it is necessary to use the chiller detector to find out the leaking area to change or repair it.