R 134a refrigerant

R 134a refrigerant is a new type of pollution-free refrigerant, which belongs to hydrofluorocarbon (tetrafluoroethane). It has similar thermophysical properties with R 12, and its standard boiling point is -26. 1℃. But the ozone depletion potential is zero, and the greenhouse effect potential is between 0.24 and 0.29. At normal temperature and pressure, R 134a is colorless, slightly ethereal, nonflammable and has no measurable flash point. No irritation to skin and eyes, no skin allergy, but slight toxic gas will be produced when it comes into contact. The workplace should be well ventilated. R 134a is a refrigerant insoluble in mineral oil, which uses lipid oil, synthetic oil (for reciprocating compressor) or alkylbenzene oil (for rotary compressor). Compared with R 12 refrigerant, R 134a refrigerant is non-toxic and nonflammable. R 134a refrigerant has stable chemical properties, and its thermodynamic properties are very close to those of R 12, but its material compatibility is poor, and it is incompatible with mineral oil and easy to absorb water.

See table 6- 1- 1 (-40℃, PPM) for the maximum saturated water absorption content of R 134a and R 12.

Table 6- 1- 1

Comparison of R 134a and R 12

situation

R 134a

R 12

liquid

150

1.6

gas

45

Forty-four

2.2 technical requirements. R 134a is used for refrigeration system parts (relative to R 12 refrigerant).

(1) The compressor selection should be one level larger than the cylinder volume.

(2) The capillary should be lengthened by 10%~ 15%.

(3) The evaporator and condenser can remain unchanged, and the area of the condenser can be appropriately increased to reduce the condensation pressure.

(4) The refrigerant charge is reduced by 10%~ 15%.

(5) Use XH-7 or XH-9 dry filter.

3.R 134a Refrigerant Purity Technical Requirements

(1) purity

≥99.95%

(2) evaporation residue

≤ 10ppm

(3) Acid (calculated by hydrochloric acid)

≤ 1ppm

(4) Water

≤ 10ppm

(5) CFCs and HCFCs

≤ 100ppm