Development of an adsorption cooling facility using metal organic framework-based adsorbents

Abstract

With conventional refrigeration utilising refrigerants such as HFCs, these refrigerants have taken a huge toll on the environment due to them having the potential global warming. Therefore, a challenge of cooling Science today is to develop an environmentally friendly chiller that is compact, has fewer moving parts and is highly efficient. These thermally-driven adsorption chillers utilise water as a refrigerant and silica gel/zeolite as an adsorbent and require low-grade thermal heat source of 50- 80°C. With the growing interest and research into adsorption cooling, the development of a novel adsorbent such as Metal Organic Framework (MOF) adsorbents shows promising results with higher water uptake per cooling cycle and faster kinetics. In this project, a two-bed adsorption cooling cycle employing MOF as an adsorbent was designed and installed. Based on experimentally confirmed isotherms and kinetics data of Aluminium Fumarate/CH3-Aluminium Fumarate-water systems, the performance of an adsorption chiller was evaluated in terms of specific cooling power(SCP) and coefficient of performance(COP). The report also presents the thermodynamic frameworks of the adsorption chiller using the mass and energy balances for each component of the chiller. The optimal hot water inlet temperature is found to be 60°C with the optimal cycle time of 400s. It is concluded that the optimal COP is 0.5 with the corresponding SCP of 0.125kW/kg for the CH3-Al-Fum MOF.