Improving the performance of a commercial absorption cooling system by using ejector: A theoretical study
Absorption cooling systems (ACS) have lower coefficients of performance (COP) compared to direct expansion (DX) cooling systems. Nevertheless, ACS offers a green alternative to typical DX systems. In this study, a numerical model was developed for the commercial low-capacity Robur® absorption coolin...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-05-01
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| Series: | Case Studies in Thermal Engineering |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214157X23002733 |
| _version_ | 1827953420564168704 |
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| author | Hamza K. Mukhtar Saud Ghani |
| author_facet | Hamza K. Mukhtar Saud Ghani |
| author_sort | Hamza K. Mukhtar |
| collection | DOAJ |
| description | Absorption cooling systems (ACS) have lower coefficients of performance (COP) compared to direct expansion (DX) cooling systems. Nevertheless, ACS offers a green alternative to typical DX systems. In this study, a numerical model was developed for the commercial low-capacity Robur® absorption cooling system (RACS). The model was developed based on mass, concentration, and energy balance equations, in addition to heat transfer equations. The model results were validated against experimental data available in the literature for the same cooling unit yielding a good agreement. Hence, to improve the COP of the RACS, a vapor ejector was introduced between the generator and the condenser. An improvement of 70.6% in the COP was obtained at the design condition. A parametric analysis was implemented to study the significance of the key parameters in the RACS performance. It was found that the increase in the ambient temperature not only increased the activation temperature, but it also decreased the COP and increased the circulation ratio (CR). Consequently, in hot environments, lowering the evaporator temperature is recommended to avoid the need for higher CR. Optimizing the nozzle throat and the mixing tube diameter improves the ejector performance, and hence the RACS performance, as long as the ejector operates under critical conditions. Finally, the absorber coil was found to have the most significance on the RACS performance in comparison with the rectifier coil and the refrigerant heat exchanger. |
| first_indexed | 2024-04-09T14:13:40Z |
| format | Article |
| id | doaj.art-f966f85b89234c77ae4e4bedf53996aa |
| institution | Directory Open Access Journal |
| issn | 2214-157X |
| language | English |
| last_indexed | 2024-04-09T14:13:40Z |
| publishDate | 2023-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Case Studies in Thermal Engineering |
| spelling | doaj.art-f966f85b89234c77ae4e4bedf53996aa2023-05-06T04:38:04ZengElsevierCase Studies in Thermal Engineering2214-157X2023-05-0145102967Improving the performance of a commercial absorption cooling system by using ejector: A theoretical studyHamza K. Mukhtar0Saud Ghani1Corresponding author.; Department of Mechanical and Industrial Engineering, Qatar University, P.O. Box 2713, Doha, QatarDepartment of Mechanical and Industrial Engineering, Qatar University, P.O. Box 2713, Doha, QatarAbsorption cooling systems (ACS) have lower coefficients of performance (COP) compared to direct expansion (DX) cooling systems. Nevertheless, ACS offers a green alternative to typical DX systems. In this study, a numerical model was developed for the commercial low-capacity Robur® absorption cooling system (RACS). The model was developed based on mass, concentration, and energy balance equations, in addition to heat transfer equations. The model results were validated against experimental data available in the literature for the same cooling unit yielding a good agreement. Hence, to improve the COP of the RACS, a vapor ejector was introduced between the generator and the condenser. An improvement of 70.6% in the COP was obtained at the design condition. A parametric analysis was implemented to study the significance of the key parameters in the RACS performance. It was found that the increase in the ambient temperature not only increased the activation temperature, but it also decreased the COP and increased the circulation ratio (CR). Consequently, in hot environments, lowering the evaporator temperature is recommended to avoid the need for higher CR. Optimizing the nozzle throat and the mixing tube diameter improves the ejector performance, and hence the RACS performance, as long as the ejector operates under critical conditions. Finally, the absorber coil was found to have the most significance on the RACS performance in comparison with the rectifier coil and the refrigerant heat exchanger.http://www.sciencedirect.com/science/article/pii/S2214157X23002733Absorption coolingCooling systemAmmonia-waterRobur chillerEjector |
| spellingShingle | Hamza K. Mukhtar Saud Ghani Improving the performance of a commercial absorption cooling system by using ejector: A theoretical study Case Studies in Thermal Engineering Absorption cooling Cooling system Ammonia-water Robur chiller Ejector |
| title | Improving the performance of a commercial absorption cooling system by using ejector: A theoretical study |
| title_full | Improving the performance of a commercial absorption cooling system by using ejector: A theoretical study |
| title_fullStr | Improving the performance of a commercial absorption cooling system by using ejector: A theoretical study |
| title_full_unstemmed | Improving the performance of a commercial absorption cooling system by using ejector: A theoretical study |
| title_short | Improving the performance of a commercial absorption cooling system by using ejector: A theoretical study |
| title_sort | improving the performance of a commercial absorption cooling system by using ejector a theoretical study |
| topic | Absorption cooling Cooling system Ammonia-water Robur chiller Ejector |
| url | http://www.sciencedirect.com/science/article/pii/S2214157X23002733 |
| work_keys_str_mv | AT hamzakmukhtar improvingtheperformanceofacommercialabsorptioncoolingsystembyusingejectoratheoreticalstudy AT saudghani improvingtheperformanceofacommercialabsorptioncoolingsystembyusingejectoratheoreticalstudy |