1、 If the compressor has been burned out, mechanical failure, wear and tear, the refrigerant system will inevitably be polluted, and the situation is as follows:

1. The residual refrigeration oil has been carbonized, acid and dirty in the pipe.

2. After the compressor is removed, the pipe of the original system must be corroded with air, resulting in condensation effect, increasing the residual water content, and causing dirt film after corrosion with copper pipe and parts on the pipeline, which will affect the operation function after the next replacement of the compressor.

3. The worn copper, steel and alloy dirty powder must have flowed into the pipeline and blocked some fine pipes.

4. The original dryer has quickly absorbed a large amount of water.

In the above cases, the system has a bad smell, which is known as soon as it is smelled.

2、 The results are as follows after replacing the system with a new compressor

1. It is impossible to pump vacuum completely, and the vacuum pump is easy to be damaged.

2. After adding new refrigerant, the refrigerant can only clean the parts of the system, but the pollution of the whole system still exists.

3. The new compressor, refrigeration oil and refrigerant were all contaminated within 0.5-1 hour. The second pollution started immediately as follows:

3-1 after the oil is impure, it begins to destroy the original lubricating property.

3-2 metal dirt powder entering the compressor may break through the insulation film of the motor and short circuit, and then burn out.

3-3 the metal dirt powder sinks into the oil, causing the friction between the shaft and the shaft sleeve or other running parts to increase, and the machine will bite.

3-4 the mixture of refrigerant, oil, original pollutants and acidic substances will cause more acidic substances and water content increase.

3-5 copper plating phenomenon starts, the mechanical clearance decreases, increases friction and gets stuck.

4. If the original dryer is not replaced, the original water absorption and acid substances will be released.

5. Acid will slowly erode the insulation film of motor enameled wire.

6. The cooling effect of the refrigerant itself is reduced.

Under the above conditions, the new compressor will be completely burned in about one month.

3、 How to deal with the refrigerant system of a main engine which has been burned out or failed is a more serious and technical problem than the production of a new one. However, it is often completely ignored by most technicians, and even think that if it is broken, it can be replaced with a wrong idea. This leads to some disputes about the poor quality of compressor or improper use by others.

1. The compressor is damaged, of course, it needs to be replaced, and it is very urgent, but before taking action to prepare materials and tools, the following work should be done:

1-1 whether the contactor, overload device, or computer and temperature control in the control box have problems in quality, they must be checked one by one and confirmed to be OK.

1-2 whether various set values have been changed, and analyze whether the compressor is burnt out due to the change of setting value or wrong adjustment.

1-3 check and correct the abnormal conditions on the refrigerant pipeline.

1-4 confirm that the compressor is burnt out, stuck or half burnt out:

1-4-1 measure insulation with megger and coil resistance with triple meter.

1-4-2 talk with the relevant personnel of the customer to understand the general situation of the causes and consequences, as a reference for judgment.

1-5 try to drain the refrigerant from the liquid pipe, observe the residual matter discharged from the refrigerant, smell its taste and observe its color. (after burning, it is sour and sometimes pungent)

1-6 after removing the compressor, pour out a little frozen oil and observe its color to judge the situation. Before leaving the main engine, wrap the high and low pressure branch pipes with tape or close the valve.

2. According to the above inspection work, there may be three kinds of compressor faults:

The motor of 2-1 compressor is not burnt out, the current is normal, only the noise is loud. (mechanical problems)

The motor of 2-2 compressor is not burnt out and can run well. However, the motor is overloaded due to large current and easy tripping.

The motor of 2-3 compressor has been burnt out and can not run, and the mechanical quality is unknown.

According to the three conditions, the procedure for updating the compressor is as follows:

The motor of 2-1 compressor is not burnt out, the current is normal, only the noise is loud. (mechanical problems)

2-1-1 in this case, the oil is not odorous, and the pollution is only in the form of powder gray, which settles in the compressed interior, and the pollution in the system pipe is not obvious.

2-1-2 remove the original dryer, use nitrogen as much as possible (the pressure is at least 7kg / cm2) to clean the high-pressure end pipeline, the liquid pipe and some parts of the low-pressure end from the high-pressure end, and observe whether the blown out is oil, dirt, water or other abnormal or foreign matters.

2-1-3 after the new compressor is replaced, install a new dryer and add nitrogen pressure to 10kg / cm2 to detect the leakage. If there is no leakage, the remaining nitrogen will be discharged into the atmosphere through the high-pressure end filling valve.

2-1-4 vacuumize at least 1000 microns from high and low pressure ends simultaneously.

2-1-5 add liquid refrigerant into the liquid pipe part, when the amount of refrigerant reaches 80% ~ 90%, the machine can be started for test. (the compressor must be heated for 2 hours)

The motor of 2-2 compressor is not burnt out and can run well. However, the motor is overloaded due to large current and easy tripping.

2-2-1 in this case, the oil is slightly burnt and discolored, the system pipeline is clean, but the metal surface has been acidified, the inner wall of copper pipe turns red.

2-2-2 after the new compressor is replaced, install a new dryer and add nitrogen pressure to 10kg / cm2 to detect leakage. If there is no leakage, the remaining nitrogen will be discharged into the atmosphere through the high-pressure end angle valve.

2-2-3 vacuumize at least 1000 microns from high and low pressure ends simultaneously.

2-2-4 add liquid refrigerant into the liquid pipe part, when the amount of refrigerant reaches 80% ~ 90%, the machine can be started for test. (the compressor must be heated for 2 hours)

In this case, we must pay attention to: the stability of the original power supply and the possible load are too similar, or the result of stopping control is too frequent. If these problems are not solved, the danger always exists, or can not be completely solved.

The motor of 2-3 compressor has been burnt out and can not run, and the mechanical quality is unknown. (there are two ways to solve the problem and fix it)

a. Method 1

A-1 this kind of situation * is that the oil and refrigerant stink, scorch and spicy, and the oil turns black like black ink. The pipe is covered with dirty black film and there will be water.

A-2 remove the dryer and short connect this part to a copper pipe joint or a temporary detachable nozzle.

A-3 use a chemical pump to pump the cleaning agent (trichloroethane, dichloromethane) into the pipeline system from the high-pressure pipe for cleaning and circulating flow.

Note: 1. Pay attention to the safety of operators when cleaning.

2. During cleaning, it will be found that the cleaning agent is clear and dirty. If necessary, it is necessary to replace the cleaning agent and clean it several times.

A-4 the pressure of nitrogen for replacement is about 7kg / cm2 ~ 10kg / cm2, and the whole system will be dried. If the compressor has been burned or mechanical failure or worn out, the refrigerant system will inevitably be polluted. The situation is as follows:

1. The residual refrigeration oil has been carbonized, acid and dirty in the pipe.

2. After the compressor is removed, the pipe of the original system must be corroded with air, resulting in condensation effect, increasing the residual water content, and causing dirt film after corrosion with copper pipe and parts on the pipeline, which will affect the operation function after the next replacement of the compressor.

3. The worn copper, steel and alloy dirty powder must have flowed into the pipeline and blocked some fine pipes.

4. The original dryer has quickly absorbed a large amount of water.

In the above cases, the system has a bad smell, which is known as soon as it is smelled.

After a-5 is replaced with a new compressor, install a new dryer and add nitrogen pressure to 10kg / cm2 to detect leakage. If there is no leakage, the remaining nitrogen will be discharged into the atmosphere through the high-pressure end valve.

A-6 is vacuumized from both high and low pressure ends to at least 1000 microns.

A-7 check all electrical equipment and power supply.

A-8 the liquid refrigerant is added into the liquid pipe to reach 80% ~ 90% of the refrigerant quantity before starting the machine for testing. (the compressor must be heated for 2 hours)

b. Method 2

B-1 remove the dryer and blow through the whole pipeline with high-pressure nitrogen of about 10kg / cm2.

B-2 replace the dryer with a new one (the filtration capacity of the liquid tube dryer is twice the capacity of the original system). )

B-3 check all parts, the quality of external control parts must be good.

B-4 leak detection of the whole system, the remaining nitrogen is discharged into the atmosphere by the high-pressure end angle valve.

B-5 is vacuumized to at least 1000 microns from both high and low pressure ends.

B-6 the liquid refrigerant is added into the liquid pipe part to reach 80% ~ 90% of the refrigerant quantity before starting the machine for test. (the compressor must be heated for 2 hours)

After the operation of B-7, special attention must be paid to the occurrence of abnormal conditions and emergency treatment.

B-8 runs for about half an hour after starting, replace the dryer immediately, and observe its dirt

B-9 for the second time, the new dryer must be operated for another 3 hours. Observe the results and replace it if necessary until the system is completely clean.

After B-10 *, change the refrigeration oil of the compressor and observe the new oil of the original * *.

Note: A. when the dryer is replaced, the air should not enter the system again.

b. In serious cases, the compressor should be removed and replaced with oil, and the refrigerant should be discharged and replaced.

Note: 1. Make another visual inspection for the whole machine before starting up.

2. Pay special attention to power supply and voltage insulation.

3. Do not start the compressor while adding refrigerant after vacuumizing, which will cause the compressor to lose oil and lose all previous efforts.

4. Do not add liquid refrigerant directly from the low pressure end, which will cause liquid hammer and mechanical failure.

5. When the above procedures are completed completely, before starting up, it is necessary to correct some poor quality electrical appliances found in the original inspection of the machine.

4、 The results are as follows after replacing the system with a new compressor

1. It is impossible to pump vacuum completely, and the vacuum pump is easy to be damaged.

2. After adding new refrigerant, the refrigerant can only clean the parts of the system, but the pollution of the whole system still exists.

3. The new compressor, refrigeration oil and refrigerant were all contaminated within 0.5-1 hour. The second pollution started immediately as follows:

3-1 after the oil is impure, it begins to destroy the original lubricating property.

3-2 metal dirt powder entering the compressor may break through the insulation film of the motor and short circuit, and then burn out.

3-3 the metal dirt powder sinks into the oil, causing the friction between the shaft and the shaft sleeve or other running parts to increase, and the machine will bite.

3-4 the mixture of refrigerant, oil, original pollutants and acidic substances will cause more acidic substances and water content increase.

3-5 copper plating phenomenon starts, the mechanical clearance decreases, increases friction and gets stuck.

4. If the original dryer is not replaced, the original water absorption and acid substances will be released.

5. Acid will slowly erode the insulation film of motor enameled wire.

6. The cooling effect of the refrigerant itself is reduced.

Under the above conditions, the new compressor will be completely burned in about one month.