Experimental Study and Performance Analysis of a Li-Br Single-Effect/Two-Stage Hybrid Absorption Chiller

In order to maximize the use of low-temperature heat sources for refrigeration, a Li-Br absorption chiller combined with single-effect absorption refrigeration cycle and two-stage absorption refrigeration cycle (STAC) was developed. Experimental research on STAC was conducted on a prototype with a refrigeration capacity of 500 KW. A numerical model validated by experimental data was used to study the refrigeration performance of STAC under variable operating conditions. Compared to single-effect units and two-stage units, STAC demonstrates remarkable heat source conservation capability and adaptability to a broad spectrum of heat source temperatures. This advantage renders the STAC unit more adaptable to new energy or waste heat scenarios characterized by unstable heat sources. As the inlet temperature of the hot water increases, the temperature difference between the inlet and outlet of the hot water also increases. When the inlet temperature of the hot water is 70 °C, 90 °C and 120°C, the temperature difference between the inlet and outlet of the hot water is 10 °C, 30°C and 70 °C, respectively. Both increasing the inlet temperature of hot water and decreasing the temperature of cooling water will enhance the cooling capacity and coefficient of performance (COP) of STAC. As the flow rate of chilled water increases, the refrigeration capacity of STAC will also increase, but the COP will first increase and then decreases