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Five Common Problems In Chiller Systems

Mar 26, 2018

Five common problems in chiller systems

First, the lack of refrigerant treatment:


1, failure phenomenon:

The cooling effect of the whole machine is poor, the outlet is only a little cool, and the pressure on the high pressure side and the low pressure side is low with the manifold pressure gauge inspection. (At the normal rotation speed of the compressor, when the ambient temperature is around 35°C, the index of the low pressure table is lower than 1kg. /cm2, high-pressure meter index is lower than 10kg/cm2), and bubble flow is seen from the sight glass.


2, the cause of the failure:

The refrigeration system has refrigerant leaks that result in insufficient refrigerant.


3, processing methods:

1) Use an electronic leak detector to detect leaks and repair or replace parts.


2) If only the amount of refrigerant is not replaced, replace the parts. If the parts are replaced, add appropriate amount of refrigeration oil as required and add enough refrigerant to the system after vacuuming.


Five common problems in the refrigeration system, each breaking!


Second, refrigerant overfill:


1, failure phenomenon:


The cooling effect is poor. When the manifold pressure gauge is checked, it is found that both the high pressure side and the low pressure side are too high (when the compressor speed is normal, the ambient temperature is 35°C, the high pressure gauge pressure is about 19kg/cm2, and the low pressure gauge pressure is 2.3 Kg/cm2, and no bubble flow is seen in the sight glass.


2, the cause of the failure:

The refrigerant in the refrigeration system is overfilled so that the cooling capacity cannot be fully exerted, resulting in a poor cooling effect.


3, processing methods:

In the system, connect the manifold pressure gauge and slowly loosen the manual valve on the low pressure side of the manifold pressure gauge to slowly discharge the refrigerant (cannot be discharged from the high pressure side because the refrigerant discharged from the high pressure side will bring out a large amount of refrigeration oil), Until the pressure on the high and low sides is normal, the clear flow of refrigerant can be seen from the sight glass, and bubbles occasionally flow through.


Third, the refrigeration system mixed with air:


1, failure phenomenon:

The cooling capacity of the complete machine decreased; when the pressure gauge of the manifold was inspected, the pressure on the high pressure side was found to be high, and the pressure on the low pressure side was sometimes higher than the normal value. (When the compressor rotation speed is normal and the ambient temperature is 35°C, the pressure on the high pressure side Above 20kg/cm2; and the high-pressure meter pointer is oscillating; on the other hand, many bubbles flow can be seen from the sight glass.


2, the cause of the failure:

Air is mixed in the system. The main reason is that after the assembly or overhaul, the vacuum is not exhaustive; when the refrigerant is charged or the refrigeration oil is added, the air is brought into the system, or when the system is working under negative pressure, the air is mixed through the imperfections. After the air enters the refrigerant, it has a certain pressure, and the refrigerant also has a certain pressure. In a closed container, the total pressure of the gas is equal to the sum of the partial pressures, so the readings of the high and low pressure meters are all higher than normal.


3, processing methods:

1) Release the refrigerant (slowly released from the low pressure side with a pressure gauge).

2) Check the cleanliness of the compressor oil.

3) Re-fill the refrigerant after vacuuming.


Fourth, the refrigeration system appears "ice block"


1, failure phenomenon:

The refrigeration system periodically refrigerates, but does not cool. During operation, the low pressure side pointer on the manifold pressure gauge often fluctuates between the negative pressure and the normal value.


2, the cause of the failure:

The refrigerant in the refrigeration system is mixed with moisture because the moisture is incompatible with the refrigerant. When the refrigerant flows through the orifice of the expansion valve, the temperature suddenly drops, and the moisture mixed in the refrigerant is easily Around the orifice of the throttle valve or the ice particles around the valve pin hole, small ice particles are formed in a spherical or hemispherical shape. When the ice particles reach a certain degree, the throttle channel is blocked and the ice blocking fault is formed. When the ice is blocked, the refrigeration system does not work properly, and the cooling effect is significantly reduced, even without cooling.

At this time, the negative pressure appears on the low pressure gauge, so the temperature at the ice blocking area rises obviously, the ice blocking ice melts into water, the ice blocking phenomenon disappears, the refrigeration system resumes normal work, the cooling is good, and the low pressure side pressure returns to normal. Ice blocking occurred again in the system and the system was not working properly.


3, processing methods:

1) Because the desiccant is in a supersaturated state, the reservoir with the desiccant must be replaced and 30 ml of refrigeration oil must be added.

2) Vacuum the system and add the specified amount of refrigerant.


Fifth, dirty plug troubleshooting:


1, failure phenomenon:

The cooling effect is poor or not cooling. When the air conditioning system is running, the readings of the high/low pressure gauges on the manifold pressure gauge are all less than normal. (When the compressor speed is normal and the ambient temperature is around 35°C, the pressure on the high pressure side is lower than 9kg/cm2, and the pressure on the low pressure side is at Negative pressure), and there is frost or condensation on the pipelines before and after the filter and the capillary.


2, the cause of the failure:

The dust in the refrigeration system adheres to or attaches to the strainer at the inlet end of the filter, or the capillary tube and the strainer interface, so that a local throttling phenomenon occurs at this position, and the temperature drops rapidly, resulting in condensation or frost formation.


3, processing methods:

1) If there is frost at the inlet of the filter and intermittent sound of air is heard, tapping on the filter body with a small hand will change the sound of the air flow. At the same time, the filter will melt with the pre-frost layer of the capillary to determine the filter. Import filter plugged.

This should:

1 Remove the capillary, clean the filter, blow dry, and reinstall it. Or replace the filter

2 Vacuum, add refrigerant to the specified amount.