Compressibility Factors for Refrigerant

Dashes indicate inaccessible states blanks indicate no available data. TABLE 2-183 Compressibility Factors for Refrigerant 124... 

Calculated from pressure-volume-temperature tables in the Vasserman monographs Usted under Table 2-165. TABLE 2-181 Compressibility Factors for Refrigerant 32 ... 

While the ideal gas law works well for pressures up to about 10 atm and higher temperatures above 25°C, many common processes (air conditioning, refrigeration) involve higher pressures and lower temperatures. If the ideal gas law is tmly imiversal we could define the compressibility factor as... 

Now consider the main factors affecting the choice of refrigerant for compression refrigeration. 

Process costs are influenced by various factors which are mutually dependent, so that it is not initially clear which extraction and separation conditions are the most favourable. A large value for AY is favourable, since the yield of hop extract per kg C02 is then high. A low pressure ratio p /p is also favourable, since the mechanical work for compression is then small. Solubility data are however most favourable for extraction when the pressure is high, whilst conditions for separation are most favourable at low pressure. A low initial compressor temperature tt is favourable, since the mechanical work is then small. Too low a temperature, however, requires a refrigeration unit which increases the mechanical work requirement and is thus unfavourable. 

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