Finned-Flat-Tube heat exchangers for adsorptive cooling: Review of the current studies

The functionality of adsorptive cooling (AC) units hinges on a pivotal component, the "adsorbent-heat exchanger" (Ad-HEx). The objective of this paper is to overview the current research on finned-flat-tube heat exchangers (FFT HExs), which are widely utilised in AC units. Despite their original design for engine cooling, their adaptation for AC requires careful analysis and potential optimisation. This paper presents a review of recent experimental studies on the use of FFT HExs for AC, with the objective of identifying the most optimal HExs from the array of available options or proposing new advanced designs. The review includes a discussion of the current literature as well as an analysis of AC in closed systems utilising loose adsorbent grains. The analysis is based on an analytical expression previously derived for the thermal conductance of common gas-to-liquid FFT HExs, which is proposed to apply for gas-to-adsorbent FFT HExs. The conductance is analysed as a function of various relevant parameters, such as the HEx surface extension, the fin thermal efficiency, and the thermal conductivity of the HEx body material. Furthermore, additional considerations are made regarding other pivotal aspects pertinent to FFT Ad-HExs. These encompass the apparent density of the adsorbent bed located inside the confined space between the HEx fins, heuristic relations between several relevant HEx parameters, mass transfer restrictions, etc.