Computer-aided molecular design of diffusion–absorption refrigeration modules for low-temperature solar collectors
File(s)
Published version
Author(s)
Harraz, Asmaa A
Haslam, Andrew J
Mac Dowell, Niall
Markides, Christos N
Type
Journal Article
Abstract
Diffusion absorption refrigeration (DAR) is an attractive thermally-driven cooling technology that can be
powered using renewable heat, e.g., from solar-thermal collectors. This technology can address refrigeration
security challenges, rising electricity costs, as well as energy, resource-use and emissions concerns. Commercial
DAR modules typically use NH3—H2O as the working fluid pair, which requires temperatures above 150 ◦C
to be supplied to initiate cooling. Due to their lower saturation temperatures, organic working fluids can
be attractive substitutes in enabling DAR modules to be used in conjunction with low-cost, non- or low concentrating solar-thermal collectors (50 ◦C to 150 ◦C). In this paper, an integrated computer-aided molecular and DAR (CAMD-DAR) system design framework is proposed that uses a group-contribution equation-of-state
based on the statistical associating fluid theory (SAFT-𝛾 Mie) for working-fluid design and property prediction
simultaneously with the DAR module design. Following a detailed presentation of this CAMD-DAR system
framework, the framework is employed to identify optimal organic working fluids and DAR-system designs
simultaneously for a specified solar-cooling application. The results suggest that non-polar organic refrigerants
with polar absorbents are to be selected if maximum cooling rates are required from an otherwise conventional
DAR module design. In particular, a mixture of 2-butene (2-C4H8
) and ethanol (C2H5OH) pressurised by He is
identified as the optimum working fluid for a wide range of cooling and ambient temperatures. The use of this
fluid can produce maximum cooling rates up to 146 W from 440 W of heat supplied to the generator at 82 ◦C,
corresponding to a specific purchase cost (𝑆𝑃 𝐶) of £ 7.46 per W of cooling, and a coefficient of performance
(COP) of 0.33 at a cooling temperature of 4
◦C and an ambient of 20 ◦C. Overall, the proposed CAMD-DAR
framework is capable of suggesting alternative organic working fluid mixtures that compete with the standard
NH3—H2O pair, thanks to the lower generator temperatures (< 150 ◦C) required by these fluids to activate the
DAR modules, which is especially advantageous in solar-cooling applications, when non- or low-concentrating
collectors are to be used.
powered using renewable heat, e.g., from solar-thermal collectors. This technology can address refrigeration
security challenges, rising electricity costs, as well as energy, resource-use and emissions concerns. Commercial
DAR modules typically use NH3—H2O as the working fluid pair, which requires temperatures above 150 ◦C
to be supplied to initiate cooling. Due to their lower saturation temperatures, organic working fluids can
be attractive substitutes in enabling DAR modules to be used in conjunction with low-cost, non- or low concentrating solar-thermal collectors (50 ◦C to 150 ◦C). In this paper, an integrated computer-aided molecular and DAR (CAMD-DAR) system design framework is proposed that uses a group-contribution equation-of-state
based on the statistical associating fluid theory (SAFT-𝛾 Mie) for working-fluid design and property prediction
simultaneously with the DAR module design. Following a detailed presentation of this CAMD-DAR system
framework, the framework is employed to identify optimal organic working fluids and DAR-system designs
simultaneously for a specified solar-cooling application. The results suggest that non-polar organic refrigerants
with polar absorbents are to be selected if maximum cooling rates are required from an otherwise conventional
DAR module design. In particular, a mixture of 2-butene (2-C4H8
) and ethanol (C2H5OH) pressurised by He is
identified as the optimum working fluid for a wide range of cooling and ambient temperatures. The use of this
fluid can produce maximum cooling rates up to 146 W from 440 W of heat supplied to the generator at 82 ◦C,
corresponding to a specific purchase cost (𝑆𝑃 𝐶) of £ 7.46 per W of cooling, and a coefficient of performance
(COP) of 0.33 at a cooling temperature of 4
◦C and an ambient of 20 ◦C. Overall, the proposed CAMD-DAR
framework is capable of suggesting alternative organic working fluid mixtures that compete with the standard
NH3—H2O pair, thanks to the lower generator temperatures (< 150 ◦C) required by these fluids to activate the
DAR modules, which is especially advantageous in solar-cooling applications, when non- or low-concentrating
collectors are to be used.
Date Issued
2025-11-01
Date Acceptance
2025-06-09
Citation
Energy Conversion and Management, 2025, 343
ISSN
0196-8904
Publisher
Elsevier BV
Journal / Book Title
Energy Conversion and Management
Volume
343
Copyright Statement
© 2025 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
License URL
Identifier
10.1016/j.enconman.2025.120067
Publication Status
Published
Article Number
120067
Date Publish Online
2025-07-23