A novel hybrid generator-absorber heat exchange (GAX)-ejector
absorption refrigeration (hybrid GAX-E) cycle, with ammonia-water as
working fluid, is proposed and analysed in detail. Thermodynamic models are
developed for the hybrid GAX-E, hybrid GAX, simple GAX and single effect
ammonia–water absorption refrigeration cycles. A comparison among the
performances of these four cycles, at an absorber temperature of 70°C and a
generator temperature of more than 170°C, shows that the coefficient of
performance (COP) of the hybrid GAX-E cycle is higher than those of the
other three cycles. The maximum COP for the hybrid GAX-E cycle is around
1.8 which is about 20%, 125% and 260% higher than the corresponding values
for the hybrid GAX, the simple GAX and the single effect cycles, respectively.
Results indicate that as the ejector expansion ratio increases from 6.1 to 8.8, the
COP of the hybrid GAX-E cycle decreases by up to 53.3%.