Thermodynamic analysis of GAX and hybrid GAX aqua-ammonia vapor absorption refrigeration systems

A thorough analysis of aqua-ammonia generator-absorber-heat exchanger (GAX) and hybrid GAX (HGAX) absorption refrigeration cycles based on energy and exergy has been carried out in this communication. The coefficient of performance (COP) and exergetic efficiencies are calculated at various operating conditions to study the effect of generator temperature, condenser temperature and evaporator temperature on them. The influence of generator temperature on exergetic efficiency is more pronounced than on COP. The effects of degassing range and approach temperature on first and second law efficiency are also examined. It is observed that the increase in approach temperature from 0 °C to 14 °C causes decrease in COP of GAX cycle by 30% and of HGAX cycles by 40%-45%. Desorber and absorber together accounts for highest exergy destruction.