Performance Analysis of Low-Capacity Water–LiBr Absorption–Cooling Systems Using Geothermal Heat-Sinks in Hot Climates

Abstract

This paper addresses the use of a geothermal heat-sink to remove the heat released in domestic-sized single and double-effect water–LiBr absorption chillers operating in hot climates. This study is the continuation of a previous work, which demonstrated the operational constraints of these absorption chillers working in hot Algerian climate-zones. After localizing the non-operation zones for both systems, the thermo-physical properties of the soil at several depths are investigated for the implementation of the underground heat-exchanger. This heat-exchanger is connected to the condenser and the absorber of both systems, to supply cooling water at inlet temperatures of 33 °C in hot climate conditions, with ambient temperatures varying from 38 °C to 42 °C. The results show a steady operation for both absorption chillers in climate conditions which had not previously allowed the two systems to operate in water or air-cooled modes. A maximum coefficient of performance of 0.76 and 1.25 is obtained for single- and double-effect absorption cycles, respectively, with chilled water at 7 °C. The underground-tube length required is between 4.5 and 18 m, depending on the absorption-cycle configuration and the temperature of the chilled water.

The Application of Barocaloric Solid-State Cooling in the Cold Food Chain for Carbon Footprint Reduction

“…In this context, research increasingly considers alternatives to traditional vapor compression systems: On the one end of the spectrum, there are renewable-energy-based technologies such as solar [19][20][21][22] or geothermal [23][24][25][26] technologies, while on the other, there are solid-state technologies based on the caloric effect [27][28][29][30]. These alternatives do not use refrigerant gases, thus ensuring a negligible contribution to the greenhouse effect [31].…”

Study of the Structure and Infrared Spectra of LiF, LiCl and LiBr Using Density Functional Theory (DFT)

“…Lithium bromide solutions are used mainly in air cooling systems' absorption chillers, where water is the refrigerant and a solution of LiBr acts as the absorbent [27,28]. Chillers of this kind can provide useful room cooling using waste heat or renewable energy [29,30]. Highly concentrated (50-60%) LiBr brines are employed as liquid desiccants [31].…”