Modified vapour absorption refrigeration cycles

Abstract

The aim of this review paper is to present a comprehensive understanding of both simple and complex refrigeration cycles. Moreover, current status emphasising any improved performance in vapour absorption refrigeration cycles has been discussed. A theoretical investigation of different vapour absorption cycles, incorporating an ejector, generator absorber heat exchanger and booster compressor, has been made. A hybrid vapour compression-absorption refrigeration system has much higher COP than the conventional vapour compression refrigeration system, triple-effect system and GAX system. The maximum COP of the triple-effect cycle goes up to 1.955 which is around 132% higher than the single-effect cycle with its gas requirement reduced to around 122% at the same conditions. Compared to the GAX cycle, the HGAX cycle demonstrates a better performance when evaluated as per the first and second laws of thermodynamics. However, the unit product cost for the HGAX cycle is higher. COP of the ejector cycle is 30% higher than that of the conventional single-effect absorption refrigeration cycle, while the cooling capacity of the cycle for waste heat with a large temperature glide is about 20% higher. Normally, the alternative cycles offer numerous benefits to vapour absorption refrigerators such as reduced losses, increased performance and decreased energy consumption.