How can it be seen from these two tables that propylene can be used as a refrigerant?

I don’t know much about this; could an expert help me?

Requirements for refrigerants – Thermodynamic requirements: At atmospheric pressure, the evaporation temperature (boiling point) ts of the refrigerant must be low. This is a very important performance metric. The lower the ts, the lower temperature can be achieved, and at a certain evaporation temperature to, its evaporation pressure Po can be made higher than atmospheric pressure. To prevent air from entering the refrigeration system, making leaks easier to detect. This meets the requirements, right? It is required that the condensation pressure Pc of the refrigerant at normal temperature be as low as possible, in order to avoid excessive strength requirements for equipment such as compressors, condensers, and exhaust pipes that operate under high pressure. Furthermore, excessively high condensing pressure can also lead to refrigerant leakage and result in increased power consumption. This meets the requirements, right? For large piston compressors, it is necessary to have as high a cooling capacity per unit volume of refrigerant, qv, as possible, in order to reduce the size of the compressor and minimize the amount of refrigerant that needs to circulate ； For small or micro compressors, the cooling capacity per unit volume can be lower ； For small centrifugal compressors as well, it is required that the refrigerant QV be low, in order to expand the range of applications for such compressors and to avoid the difficulties associated with manufacturing impellers of small size. This has little impact; just choose the appropriate model and occasion. The critical temperature of the refrigerant should be higher, and the condensation temperature should be lower. The level of the critical temperature determines whether the refrigerant can be liquefied at normal temperatures or in the range of ordinary low temperatures. This meets the requirements, right? The freezing temperature is the lower limit of the range in which a refrigerant can be used; the lower the condensation temperature, the wider the range of applications for that refrigerant. This meets the requirements, right? Requirements for physical chemistry (the following are not apparent from the table. ) The viscosity of the refrigerant should be as low as possible to reduce flow resistance in the pipes and enhance the heat transfer efficiency of the heat exchange equipment. The thermal conductivity of the refrigerant should be high to improve the efficiency of heat exchange equipment and reduce the heat transfer area. Intermiscibility of refrigerant and oil: The property of a refrigerant to dissolve in lubricating oil should be analyzed from two aspects. If the refrigerant and lubricating oil can mix with each other freely, the advantage is that the lubricating oil can penetrate together with the refrigerant into all the components of the compressor, thereby creating favorable conditions for lubricating the machinery ； Moreover, an oil film is not likely to form on the heat exchange surfaces of the evaporator and condenser, thereby preventing heat transfer. Its disadvantage is that it causes an excessive amount of oil to be carried away by the compressor, and it can raise the evaporation temperature in the evaporator. Refrigerants that are partially or slightly soluble in oil have the advantage of requiring less oil to be carried away by the compressor, resulting in a more stable evaporation temperature in the evaporator. Its drawback is that an oil film that is difficult to remove forms on the heat exchange surfaces of the evaporator and condenser, affecting heat transfer. It should have a certain level of water absorption, so as to prevent the formation of an \"ice plug\" in the refrigeration system, which could disrupt normal operation. It should possess chemical stability: it must not burn or explode, and it must not decompose or deteriorate during use. At the same time, the refrigerant itself, or when mixed with oils, water, etc., should not have a significant corrosive effect on metals, and it should cause little swelling of sealing materials. Safety requirements: Since refrigerants may leak during operation, it is required that the working substance be harmless to human health, non-toxic, and non-irritating. This post was last edited by sister on 2009-2-3 01:51]

Of course. In ethylene production, both propylene and ethylene can be used as refrigerants, serving both as a cooling medium and as the substance to be cooled.

The liquid volume of propylene varies at different temperatures; the higher the temperature, the greater the liquid volume and the lower the liquid density. When propylene absorbs heat, its liquid volume increases and the pressure rises.

It works on the same principle as the refrigerators and air conditioners in your home; once you understand the cooling mechanism of ammonia and Freon, it becomes clear why propylene can be used as a refrigerant. The latent heat of propylene is higher than that of ammonia and Freon, so it is not a conventional refrigerant; however, propylene may be used for cooling in situations where propylene is produced or utilized. Additionally, their safety and stability may also be inferior to those of ammonia and Freon.