Refrigerant R600A/R134A Fluorine-free Refrigerator Repair Technology, Beijing Panasonic Air Conditioning After-sales Service Hotline
R600A, also known as isobutane, belongs to hydrocarbons with a molecular weight of 58 and is the main component of commonly used lighter gas. It is highly flammable and explosive.
I. Advantages
1. ODP value = 0, no ozone layer destruction (environmentally friendly)
2. GWP = 0, greenhouse effect coefficient
3. Energy saving and electricity saving, refrigerant is only 40% of R12
4. Simple manufacturing process, low cost
5. Low noise (low working pressure), minimum air, self-ignition temperature 462℃
3. Ignition energy > 170J
Explosion can only occur when all three conditions happen simultaneously.
III. Operation techniques and safety requirements for repairing R600a refrigerators
1. Operation techniques and safety requirements for repairing R600A refrigerators
2. Check if there are any ignition devices around and maintain good ventilation
3. Avoid wearing "silk, fiber" clothing during repair to avoid static electricity, do not carry mobile phones to prevent electromagnetic induction, ensure reliable grounding of the refrigerator.
4. High requirement for R600A in the system, accurate charging required. In the case of no compressor replacement, the charging requirement = charging amount * 95%
5. When welding, ensure that there is no refrigerant in the system, use nitrogen to blow wash the pipeline
6. When welding the process pipe, the pipe opening should not be facing people
7. After the compressor is removed, pour out the ester-type freezing oil and weld it sealed
8. Compressors for R134A, R152/R22 refrigerants cannot be interchanged (the cylinder volume of R600A compressors is increased by 60%-70% compared to R152/R22 refrigerant compressors)
9. The desiccant filter uses XH7 or XH9, which has about 20% more molecular sieve than the R12 desiccant filter XH4XH5
10. Two clamps for sealing, third seal
Repair technology for R134A refrigerators
January 22, 2009, Thursday, 19:00
1. R134A
Compared with R12 compressors, R134A compressors will have slightly increased noise, and the cylinder volume needs to increase by 10%~15% to ensure the same cooling capacity. In motor design, R134 requires more efficient motors to adapt to harsher system operating environments. The lubricating oil in the compressor must be replaced with ester oil, mineral oil or benzene-based oil does not have good affinity with R134 and cannot be used. Since ester oil has stronger water absorption than all lubricating oils currently used in R12 compressors, the water content of ester oil should be strictly controlled below 0.006%, and the time of exposure after replacing the compressor should not exceed 15 minutes.
2. Drying Filter
Compared with the drying filter used in R12, the drying filter of R134 increases the amount of molecular sieve by 20%. The drying filter must be replaced every time HFC-134 is recharged.
3. Condenser and Evaporator
These two heat exchangers are dedicated to HFC-134 and cannot be mixed with R12.
4. R134 Injection Amount
The injection amount of R134 should be reduced by 5%~10% compared to R12, and the equipment used for R12 injection must be dedicated.
5. Other Special Requirements for R134 Green Refrigerator Maintenance Operations
(1) The time from opening the compressor port to vacuuming should be less than 10 minutes, and the time for other components to open should not exceed 15 minutes.
(2) Vacuuming time should be no less than 20 minutes.
(3) If leakage is found in the refrigerator, the compressor needs to be replaced, and nitrogen should be blown before welding.
(4) If the refrigerator is dirty blocked, it can be unblocked with nitrogen without replacing the compressor; otherwise, the body is scrapped (evaporator is wasted).
(5) If a problem is found in the refrigerator, the compressor should be replaced.
(6) As long as the refrigeration system is opened, the drying filter must be replaced.
(7) When brazing the refrigeration system, try to use dry flux. If there is no dry flux, copper-silver welding rods or low-silver welding rods can also be used for welding without flux.
(8) All tools such as cold filling hoses, joints, three-way repair valves, steel bottles, and everything related to R12 and other refrigerants used for ordinary refrigerator repairs cannot be used for green refrigerator refrigeration system inspections. If they must be used, they must first be cleaned with HFC-134.