Study of Habitat’s Thermal Performance Equipped with an Adsorption Cooling Unit by Geothermal Heat Pump

Abstract

This work concerns a modeling of habitat equipped with an adsorption cooling unit powered by a geothermal heat pump in the context of the climate of the Comoros Islands. Cooling unit is a simple system consisting of an adsorber, condenser and evaporator. The modeling of the habitat-air conditioning system was based on a description of heat and mass transfers. The first law of thermodynamics on the energy conservation using the analogies between heat and electrical transfers is used to establish the equations of the model. Zeolite-methanol pair and Dubinin-Astakhov adsorption model are used to describe the amount of adsorbed mass. The finite difference method applied to a point of the considered exchange surface is used to discretize equations and resolve them. The coupling of the system takes place through a convective transfer between the air inside habitat and the evaporator's surface. This article presents results for typical November days in Comoros. Different temperatures of habitat with and without a cooling unit show that using the adsorption cooling unit can help lower internal temperatures. We observe a temperature difference of 2.14 K in particular at 2 p.m., if the air conditioning starts at 8 a.m. The influence of the input parameters on the air inside the habitat makes it possible to assess the impact on indoor comfort. The COP th can reach 0.46. However, we can get a high performance if we optimize temperature thresholds. These show that this type of cooling unit can help improve the habitat thermal comfort in a tropical and dry climate.

Design and Modelling of a Cooling Unit by Adsorption Geothermal Heat Pump in a Tropical Climate Zones

“…The cycle working principle is described perfectly by [4]. According to this study, the base cycle of the cooling unit is closed and intermittent.…”

“…We use the Dubinin-Astakhov thermodynamic model and the equation expressing the mass adsorbed is given by the following expression [4]:…”

“…Reducing this energy passes by the improvement of the energy efficiency of the building's envelope, the thermal renovation of buildings or the development of low energy consumption systems. Adsorption cooling heat pumps are thermodynamic devices capable of producing cooling effects [4], with a low energy or renewable source. For several decades, they are used in industrial installations or in buildings' air conditioning systems [5].…”