R744 Carbon Dioxide Refrigerant

r744 40l

R744 refrigerant, carbon dioxide, is an inorganic substance, a colorless and odorless gas at room temperature. The following is a detailed introduction to carbon dioxide refrigerant R744.

Introduction of carbon dioxide refrigerant

R744 refrigerant, currently popular in Japan, is a new generation of heat pumps that use carbon dioxide as the working fluid. CO2 is an inexhaustible natural substance on the earth. As early as the beginning of the twentieth century, it has been used in industrial and fishery refrigeration systems, code-named R744. CO2 has a high-volume-ratio volume freezing capacity characteristic, which is about 5 times higher than that of R22, so the size of the system can be greatly reduced.

Application of carbon dioxide refrigerant

The high efficiency of R744 ultra-low temperature refrigerant is obvious to all. With the maturity of processing technology, the use of high-pressure natural refrigerants such as CO2 is no longer out of reach. Under the relevant laws and regulations to protect the environment, it is urgent to find another way to solve the refrigerant demand. From the development of other countries in related fields, it is not difficult to find that under the consideration of safety permits, the use of natural refrigerants can fully improve the current problem of replacing refrigerants, not only to improve related technologies and promote industrial upgrading but more importantly, to prevent the environment from being affected harm.

Characteristics of carbon dioxide refrigerant

  1. Does not damage the ozone layer.
  2. A global warming potential (GWP) of 1.
  3. It is easy to obtain (it can be obtained from industrial waste gas) and the cost is extremely low.
  4. It is harmless to human health and the living environment, so it does not need to be recycled or reprocessed.
  5. Non-toxic and will not decompose irritating substances.
  6. Non-flammable and non-explosive.
  7. Excellent thermal properties.
  8. The CO2 refrigerant system can use traditional mineral lubricating oil.
  9. The heat dissipation process of the CO2 system under general summer outside air conditions is a process of crossing the critical point or exceeding the critical point. Since there is no actual condensation phenomenon, the heat exchanger used for heat dissipation is called a gas cooler.
  10. For the same outlet temperature of the gas cooler, the higher the discharge pressure of the compressor, the greater the cooling capacity.
  11. Low compression ratio. When the condensation temperature of R-134a is 50°C and the evaporation temperature is 0°C, the compression ratio is 4.3. However, when the outlet temperature of the CO2 gas cooler is 37°C and the evaporation temperature is 0°C, the compression ratio is 2.6. At the same time, the compression ratio of the compressor is reduced, and the compression process can be closer to isentropic compression to improve efficiency.
  12. The asymptotic temperature of the gas cooler is much smaller than the 10~15°K of R-134a.
  13. For an evaporator with the same volume, the CO2 tube diameter is small and the number of tube rows is large.
  14. Due to the high system pressure, the refrigerant distribution of CO2 in the evaporator is relatively uniform.
  15. The gas density is high, which can reduce the size of pipelines and compressors used, and make the system lighter in weight, compact in structure, and small in size.


More Posts

Get A Quote