Comparative analysis of conventional and low-GWP refrigerants with ionic liquid used for compression-assisted absorption cooling cycles

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Hongyu Huang
  • Yu Bai
  • Lisheng Deng

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number115145
Journal / PublicationApplied Thermal Engineering
Volume172
Online published2 Mar 2020
Publication statusPublished - 25 May 2020

Abstract

To address the problems of conventional absorption technologies, various working pairs consisting of low-global-warming-potential hydrofluorocarbons/hydrofluoroolefins and ionic liquid were numerically investigated for two compression-assisted absorption cooling cycles driven by heat sources at lower temperatures. The property prediction model and thermodynamic performance model were established and verified. The performance improvements were evaluated and the compression ratio was optimized. With the compression-assisted absorption cycle, the coefficient of performance (COP) was enhanced from 0.191–0.463 to 0.366–0.670, while the minimum generation temperature was reduced by about 20 °C, reaching 45 °C. For both basic and compression-assisted absorption cycles, difluoromethane yielded the highest COP, followed by fluoroethane and 1,1-difluoroethane with slightly lower COPs; 2,3,3,3-tetrafluoropropene performed the worst in most conditions; 1,1,1,2-tetrafluoroethane performed worse than trans-1,3,3,3-tetrafluoropropene using the basic cycle but outperformed trans-1,3,3,3-tetrafluoropropene using the compression-assisted absorption cycle. The thermal COP varies similarly to but higher than the COP, while the mechanical COPs are much higher for all the working pairs, reaching 11–14 (R152a showing the highest) with a CR of 1.5. The mechanical COP decreases dramatically with the compression ratio. For the low-pressure compression-assisted absorption cycle with a generation temperature of 70 °C, the optimal compression ratios were 1.9–3.4 with the maximum COPs of 0.546–0.663 and were 1.3–2.2 with the maximum exergy COPs of 0.192–0.289. The low-pressure compression-assisted absorption cycle was better than the high-pressure compression-assisted absorption cycle due to the higher cycle efficiency and lower compressor discharge temperature. This study provides suggestions on the selection of compression-assisted absorption cycles, working pairs and optimal parameters for renewable/waste cooling.

Research Area(s)

  • Compression-assisted absorption cycle, Ionic liquid, Low global warming potential, Novel working pair, Renewable cooling, Waste cooling

Citation Format(s)

Comparative analysis of conventional and low-GWP refrigerants with ionic liquid used for compression-assisted absorption cooling cycles. / Wu, Wei; Leung, Michael; Ding, Zhixiong et al.

In: Applied Thermal Engineering, Vol. 172, 115145, 25.05.2020.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review