What to do if the cold storage compressor is frosted, what is the problem with the cold storage comp

There are two main reasons:

1.The opening of the thermodynamic expansion valve is too large, or the installation error of the temperature sensing bubble and the fixation and loosening will cause the above situation. The main reason is that in this case, the temperature sensor may feel that the temperature is too high, causing the valve core to open automatically due to abnormality.

The thermostatic expansion valve mainly reflects the superheat of the evaporator outlet. If there is a deviation in the superheat of the evaporator outlet, the refrigerant flow of the evaporator is automatically adjusted.

When the value detected by the transmitter deviates from a given value, the physical quantity of the transmitter changes. And it generates enough energy to directly push the actuator into action. Often, changes in the position of the actuator are directly related to the set parameters.

The opening adjustment of the thermodynamic expansion valve is too large, and the installation of the temperature sensing ball is incorrect or loosely fixed, which makes the sensing temperature too high, resulting in abnormal opening of the valve core, and a large amount of wet steam is sucked into the compressor, resulting in frosting of the cylinder head.

Thermostatic expansion valves are used to regulate overheating while the evaporator is operating. The overheating at the outlet of the evaporator is too high, and the superheating section after the evaporator is too long, and the refrigeration capacity is significantly reduced. If the outlet is overheated or too small, it may cause compressor fluid hammer or even cylinder head frosting.

Generally speaking, it is advisable to adjust the superheat of the evaporator outlet to 3 8.

2.When the supply solenoid valve leaks or the expansion valve is not tightly closed during shutdown, a large amount of refrigerant liquid has accumulated in the evaporator before start-up. Temperature relays and solenoid valves are used together to control the temperature in the warehouse.

The bulb of the relay is placed in the cold storage. When the temperature of the cold storage is higher than the upper limit of the set value, the temperature relay contact is turned on, the solenoid valve coil is energized, the valve is opened, and the refrigerant enters the evaporator for cooling. When the reservoir temperature is lower than its lower set value, the temperature relay contact is disconnected, the solenoid coil current is cut off, the solenoid valve is closed, and the refrigerant stops entering the evaporator, so that the reservoir temperature is controlled within the required range.

Frosting at the return port of the cold storage compressor is a very common phenomenon in the refrigeration system, which will not immediately form a system problem under normal conditions, and the subtle frosting does not need to be dealt with, and the phenomenon will be improved or aggravated with the change of some cold storage working conditions.

If the frost is severe, then the cause of the frost needs to be clarified first. The root cause of this is that the refrigerant flowing through the evaporator cannot fully absorb the heat required to expand itself to a predetermined pressure and temperature value.

The temperature, pressure, and volume values that lead to the return air are relatively low, and there are two problems that can lead to this problem.

1. The evaporator cannot absorb heat normally, or the cold energy generated by the evaporator cannot be taken away. The appearance is that the temperature and pressure of the return liquid are normal or slightly low, and frost gradually forms in the direction of the evaporator from the compressor return port, and after a long time, all the sections from the compressor return port to the evaporator and the throttle valve to the evaporator are frozen, and finally low pressure appears.

2. Due to the small amount of refrigerant, the evaporation temperature is low due to the low evaporation pressure of the evaporator, which will gradually lead to the condensation of the evaporator to form a thermal insulation layer and transfer the expansion point to the compressor return air to cause the compressor return air frosting. If the amount of fluorine is normal or too high, and if there is a situation such as excessive condensation heat transfer that causes the high pressure to be low, then the refrigerant at the front of the throttle valve at the same volume will reflect the low pressure and high quality.

The amount of refrigerant liquid flowing through the throttle valve at the initial throttle valve opening will be more than normal, and the amount of heat that needs to be absorbed from the evaporator will be too high, and if the corresponding heat cannot be completely absorbed from the evaporator, the compressor return pipe temperature will be low. At the same time, due to the low pressure at the front end of the throttle valve, the pressure at the rear end of the throttle valve will also be low.

Finally, I would like to remind you that if the evaporator outlet freezes and the return air superheat decreases, it is possible that there is too much refrigerant, because one of the necessary conditions for the evaporator to freeze is that the evaporation temperature must be below 0 degrees! Too much refrigerant will lead to an increase in evaporation temperature.

If the cold storage installation system uses an expansion valve (detecting the temperature and pressure of the return pipe, decreasing the opening of the pipe temperature and increasing the pressure reduction) will not make much adjustment compared to the normal state of the opening, then the low pressure will be maintained until the compressor return air frosts. In this way, it seems that there is a lack of fluoride (low pressure, low pressure, low pressure), and the low temperature of the return air duct leads to frosting.

1. Check whether the cold storage has the function of defrosting 2. It is recommended to install a heating wire on the fin of the air cooler to de-ice; 3. Install an air curtain on the door of the freezer; 4. Install plastic curtains for cold storage. Causes: 1. The humidity of the cold storage is high 2. The refrigerant of the refrigeration system is insufficient; 3. There is a problem with the expansion valve.

The expansion valve is blocked (the filter screen at the inlet), do not disassemble and adjust the opening degree during operation, and try to knock the valve body left and right.

Frosting at the return gas port of the cold storage compressor indicates that the return gas temperature of the cold storage compressor is too low, so what will cause the return gas temperature of the cold storage compressor to be too low?

1. Frosting at the return port of the cold storage compressor.

For the same quality of refrigerant, if the volume and pressure are changed, the temperature will behave differently. If the return gas temperature of the cold storage compressor is low, it will generally show both low return pressure and high amount of refrigerant of the same volume, which can cause this problem because the refrigerant flowing through the evaporator cannot completely absorb the heat required for its own expansion to the predetermined pressure and temperature value.

Second, there is less fluorine in cold storage.

Too little refrigerant will form a low temperature in the evaporator locally, and the evaporator frosting phenomenon occurs, and due to the formation of a thermal insulation layer on the surface of the evaporator and the heat exchange in this area is low, the refrigerant expansion will be transferred to other areas, and gradually the entire cold storage evaporator frosting or icing phenomenon, the entire evaporator forms a thermal insulation layer, so the expansion spreads to the compressor return pipe and causes the cold storage compressor return air frosting.

3. Frosting of the cylinder head of the cold storage compressor.

Frosting at the cylinder head of a cold storage compressor is caused by a large amount of wet steam or refrigerant being sucked into the compressor. The main reasons for this situation are: the opening of the thermostatic expansion valve is adjusted too large, the temperature sensor package is installed incorrectly or the fixation is loose, so that the temperature is too high and the valve core is opened abnormally, the liquid supply solenoid valve leaks or the expansion valve is not closed tightly when it is stopped, and there is too much refrigerant in the system.

Depending on the situation, it can be cleaned, the thermostatic expansion valve replaced, the temperature sensor bag re-wrapped, leak detected, leak filled, and refrigerant filled.

The flow rate of the refrigerant is very small, which will cause the refrigerant to expand after the first expandable space begins to expand after the rear end of the throttle valve, we mostly see that the frosting of the separator head at the back end of the expansion valve is often caused by the lack of fluorine or the flow rate of the expansion valve, too little refrigerant expansion will not use all the evaporator area, and will only form a low temperature in the evaporator locally, and some areas will expand sharply due to the small amount of refrigerant, resulting in low local temperature and evaporator frosting.

After local frosting, due to the formation of a thermal insulation layer on the surface of the evaporator and the low heat exchange in this area, the refrigerant expansion will be transferred to other areas, and gradually the whole evaporator frosting or icing phenomenon appears, and the entire evaporator forms a thermal insulation layer, so the expansion will spread to the compressor return pipe to cause the refrigeration compressor return air frosting.

The opening of the thermodynamic expansion valve is adjusted too large, the temperature sensor package is installed incorrectly, or the temperature is too high due to the loosening of the fixation, and the valve core is abnormally opened.

The main reason for frosting in the air conditioning compressor 1 1, the refrigerant charge is insufficient, and it will form from the evaporator to the compressor. 2. The refrigerant charge is too much, which occupies part of the volume of the condenser and increases the condensation pressure, and the liquid entering the evaporator increases.

1. The amount of liquid refrigerant in the throttle valve is normal, but the evaporator cannot absorb heat normally, and the refrigerant expands.

2. The evaporator absorbs heat normally, but the amount of refrigerant in the throttle valve is too much, that is, the refrigerant flow is too much, which we usually understand as too much fluorine, that is to say, too much fluorine will also cause low pressure.

It may be that the refrigerant is insufficient, which can be solved by adding enough refrigerant; It may be a compressor failure, which can be solved by replacing the compressor; It may also be that there is too much refrigerant and you need to find professional personnel to operate; It may also be that the evaporator is too dirty, which can be solved by cleaning the evaporator; It is also possible that the thermostat is faulty, which can be resolved by replacing the thermostat. 1. After the refrigerant in the refrigeration system is reduced, the evaporation pressure is too low, which leads to the freezing of the evaporator, and the location of the freezing is generally in the front part of the evaporator. 2. The efficiency of the compressor will be reduced after the air conditioner is used for a long time, and the volcanic or compressor parts system will be damaged, which will cause the pressure to be too low and freeze, and the refrigerant needs to be replenished to eliminate the fault.

3. Insufficient refrigerant will cause the air conditioner to freeze, and the air conditioner bears more refrigerant is generally because the air conditioner re-disperses the hall chain to inject refrigerant due to leakage, and many times it will be added due to improper operation, so it is necessary to release excess refrigerant. 4. After the air conditioner is used for a period of time, the dust in the air will remain on the evaporator, and the evaporator is too dirty to cause the air conditioner to frost. 5. If the thermostat fails and will cause frost, then it is necessary to replace the thermostat with a new one to solve the problem.

The reason may be frosting at the compressor return port caused by the low temperature of the compressor return gas; Frosting of compressor return gas due to low fluorine; Frosting of the compressor cylinder head caused by large amounts of wet steam or refrigerant being sucked into the compressor.

The refrigerant flow rate is very small, resulting in the first expandable space after the refrigerant flows out of the rear end of the throttle valve, and some areas expand sharply due to the small amount of refrigerant, resulting in low local temperature and frosting of the evaporator.

Due to the formation of an insulating layer on the surface of the evaporator and the low heat transfer in this area, the refrigerant expansion is transferred to other areas, so the expansion gradually spreads to the compressor return pipe, causing frosting of the compressor return air.

It is because of severe frost in the evaporator on the inside of the refrigeration system or excessive refrigerant in the refrigeration system pipeline.

When these two situations occur, the low-temperature and low-pressure liquid refrigerant after throttling and depressurization cannot be effectively evaporated in the indoor unit evaporator, and part of the liquid refrigerant will directly return to the low-pressure return pipe or even the compressor, resulting in local frosting of the pipeline and compressor.

This situation is relatively dangerous, it is recommended to frost and deice the evaporator of the indoor unit first, or it cannot be completely solved, and the state of the refrigeration system should be readjusted.

Find a cold storage maintenance manufacturer - Maung Sheng Refrigeration.

It's a tide car. The reason is that the compressor has sucked in an excess of the refrigerant liquid. At this time, the small suction valve should be closed, and the liquid supply of the cold storage pipe should be reduced or closed to prevent the liquid from being inhaled again. After the frost of the compressor has completely melted, it will slowly return to normal working condition.