Analysis of Designs of Heat Exchangers Used in Adsorption Chillers

Abstract

In the face of increasing demands with regard to the share of renewable energy sources in the energy mix, adsorption chillers are becoming a potentially important part of the energy transition. A key component of this type of equipment is the heat exchanger in the adsorption bed, the design of which affects both heat and mass transfer. This study includes an analysis of the geometry and materials used to manufacture such heat exchangers. The geometry analysis is mainly based on the evaluation of the impact of the different dimensions of the exchanger components on heat and mass transfer in the bed. The second part of the study focuses on material-related issues where the main emphasis is on the analysis of the thermal inertia of the exchanger. The paper analyses the latest research on the design of exchangers in adsorption beds, mainly from 2015–2021. Currently, the commonly used SCP and COP coefficients and various test conditions do not provide sufficient information for comparative analysis of adsorption bed heat exchangers, so the authors propose to introduce a new index for the evaluation of heat exchangers in terms of the effect of the design parameters on the energy efficiency of an adsorption chiller.

Review of Fluidized Bed Technology Application for Adsorption Cooling and Desalination Systems

“…Moreover, the adsorption materials used in the beds are characterized by low thermal conductivity [29,48]. The design of the heat exchangers and the materials in which they are constructed also act as a barrier to high heat transfer rates [49]. This contributes to a significant increase in adsorption and desorption times.…”

Review of Micro- and Nanobubble Technologies: Advancements in Theory and Applications and Perspectives on Adsorption Cooling and Desalination Systems

“…In recent years, researchers have proposed a number of improvements to increase the ability of these devices to produce cold and make them more and more competitive with compressor refrigerators. Bujok et al [66] provided a comprehensive discussion on critical design factors of heat exchangers influencing their performance. Plate−fin heat exchangers and fin−tube heat exchangers were discussed.…”

“…It is also worth mentioning that the unique properties of nanobubbles, such as their size, sizeable interfacial space and long residence time, stimulate further research into their potential applications [88]. From a heat exchanger design perspective, maintaining turbulent flow through the heat exchanger tubes is a desirable effect [66]. Therefore, introducing micro/nanobubbles into the circulation of water flowing through the exchanger can help increase the heat transfer between the fluid and the exchanger walls.…”