The effect of the properties of the refrigerant and solvent on the compresson/absorption cycle

The compression/absorption, or compression cycle with solution loop, has been known for many years /1/. Historically it has always been considered for low temperature applications, such as refrigeration or space heating /2/. More recently it has been considered for high temperature applications such as district heating, industral heat recovery and steam raising /3, 4/. This is because the vapour pressure of the refrigerant over the solvent is less than that of the pure refrigerant, enabling the working range of the refrigerant to be extended to higher temperatures. Thus ammonia (R717) could be used beyond its nomal maximum condensing tarperature of 60 "c by using water as solvent, possibly exterding its use to as high as 150 "c. Thus the canpression/absorption cycle could be used as an alternative to R12 and Rl14 in the range of evaporating temperatures 10-80 "c and condensing 80-120 "c which covers the applications already mentioned. Additional possible benefits coull be its use instead of the cascade system for tarperatures up to at least 150 "c which requires two separate refrigerants (e.g. when an Rl14/steam compression system is currently the only cption), or the replacerrent of refrigerants currently suspected of depleting the ozone layer by others which are considered less harmfull (e.g. NH3/H20 or R22/organic solvent could replace R12 and Rl14)