Experimental study of a new ejector-absorption refrigeration cycle driven by multi-heat sources

Abstract

This paper proposes a new ejector-absorption refrigeration cycle driven by two heat sources at different temperature levels to realize the economic optimization in low-grade heat recovery application. The cycle uses the exergy of steam from a high-pressure generator and entrains the steam out of a low-pressure generator. The quantity of the steam that comes out of the low-pressure generator for the new cycle is greater than that of a conventional double-effect cycle, which means that more low-temperature-level heat, such as non-focused solar thermal heat, can be used. Therefore, the heat required to input into the system and the temperature level required to drive the cycle declines. In this study, water-lithium bromide as the working pair and a hot air temperature level ranging from 185 °C to 215 °C is used as the high level driving heat source, while the hot water heated by a solar energy collector is the low level driving heat source. In some conditions of the new cycle’s COP, 0.95 can be achieved for refrigeration, which is about 20% higher than that of the single-effect cycle. Besides this, the proposed chiller requires lower driven temperature than that of a conventional double-effect cycle.