It can evaporate and become fluid under the applicable pressures.
Vaporizing heat should be as low as possible.
There should not be chemical dissolution and burning. Also it should not be toxic and get into reaction with metal surfaces.
It can be able to operate under low power.
Costs must be low and easy to obtain.
Not to pollute the environment.
Not to oxidize the pipe it is going through.
In these embodiments, the low temperature source of heat, cool storage area to be sent to the high temperature environment or habitat. Heat from the high temperatures normally acts to lower temperature. Hence the importance of isolation in the practices is enormous. Therefore, insulating materials having low thermal conductivity is used. Polyurethane is among those commonly used in today's systems. Insulation to maintain low temperature in the refrigerated space and to reach a low temperature is used to reduce the required energy and power. The principle of the cooling cycle has been described mathematically by Sadi Carnot in 1824, with a heat machine. The most common form of cooling system , phase change heat pump uses is based on the cycle, however absorbel (Should it cools ) is used in many applications in heat pumps.
R401A R22, R124 and R152a consisting (by weight were 52% / 33/ 15 rate ) and a zeotropic mixture accepted alternative to R12. HCFCs that can be used until 2030 contained not a final alternative.
R402AR22, R125 and R290 consisting of (by weight, respectively 38% / 60/ 2 ratio) and a zeotropic mixture of acceptable alternative for R502. HCFCs that can be used until 2030 contained not a final alternative.
R404A R125, R134a and R143a consisting of (by weight were 44% / 4/52 ratio) is a zeotropic mixture and accepted alternative for R502. HCFCs that can be used until 2030 contained not a final alternative . R407 A / R407B / R407C, R32, R125 and consisting of R134a (by weight respectively 20% / 40/ 40 % 10/70 /20 and 23% / 25/52 ratios ), and a zeotropic mixture acceptable alternative to R502.
R410AConsisting of R32 and R125 ( wt% 50/50 ratio) and a near azeotropic mixture accepted alternative to R22. Theoretical thermodynamic properties are not as good as R22. However, heat transfer capability is very good. R22 - R410 transformation is necessary to redesign the system. If this change is made in the efficiency of the system it is better than 5 % compared to the R22. The biggest drawback is the high greenhouse effect.
R500 R500 is an azeotropic mixture of R12 and R152a . The mixture ratio of 73.9 % by weight of R12, R152a is 26.2 %. Low rate is used as an alternative to R12 . Better COP by R12 and 10 - 15% has a higher volumetric cooling capacity.
R502R502 is an azeotropic mixture of R22 and R115 . Mixing ratio of 48.8 % by weight of R22, R115'T is 51.2 % . Most used are refrigerated transport and commercial refrigeration field. That CFC production has stopped. At low temperatures it has a high volumetric cooling capacity. -20 , Are higher than R22 between 1% and 7% in the range of -40 ° C. The COP of R22, depending on the operating conditions of 5 % - 15 is lower.
R507R507, R125 and R134a consisting of ( % by weight 50/50 ratio) is an acceptable alternative for R502.