Study on various hot-gas defrosting configurations for CO2-NH3 cascade deep freezer
Abstract Four hot-gas bypass defrosting configurations for CO2-NH3 cascade blast freezer for application in fish processing firm are numerically investigated. Due to the high moisture content of fish, defrosting is necessary after every 4 to 5 h of batch operation. A thermodynamic model for the casc...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Springer
2024-02-01
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| Series: | International Journal of Air-Conditioning and Refrigeration |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/s44189-024-00049-9 |
| _version_ | 1797274175460605952 |
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| author | B. S. Arun George Ninan S. Murali Manoj Samuel Sumit Kumar S. Vaishak Mani Sankar Dasgupta Sarun Kumar Kochunni Armin Hafner Kristina Norne Widell |
| author_facet | B. S. Arun George Ninan S. Murali Manoj Samuel Sumit Kumar S. Vaishak Mani Sankar Dasgupta Sarun Kumar Kochunni Armin Hafner Kristina Norne Widell |
| author_sort | B. S. Arun |
| collection | DOAJ |
| description | Abstract Four hot-gas bypass defrosting configurations for CO2-NH3 cascade blast freezer for application in fish processing firm are numerically investigated. Due to the high moisture content of fish, defrosting is necessary after every 4 to 5 h of batch operation. A thermodynamic model for the cascade system and defrosting was developed to study various defrosting configurations formulated by rearranging the existing compressor to operate as a defrosting compressor and with the addition of an external defrosting compressor. From the simulation findings, it can be summarized that the conventional hot-gas bypass defrosting without defrost compressor is suitable for a high-capacity cascade refrigeration system with more than three evaporators. For low cooling capacity refrigeration systems, a defrosting compressor is necessary to elevate the temperature above the cascade condensing temperature. A dedicated defrosting compressor with a power consumption of 3.1 kW and a modified refrigeration/defrosting compressor with a power consumption of 6.8 kW can deliver 33.3 kW of heating at a temperature of +10 °C (45 bar). Incorporating a desuperheater between the main and defrosting compressors reduces compressor temperature and maintains the lubricating oil stability, without change in defrosting energy consumption and less exergy loss. The defrosting efficiency is obtained in the range of 39.7–42% which is in agreement with published literature. |
| first_indexed | 2024-03-07T14:55:37Z |
| format | Article |
| id | doaj.art-8aa4d33a9ac148deba78b93817901497 |
| institution | Directory Open Access Journal |
| issn | 2010-1333 |
| language | English |
| last_indexed | 2024-03-07T14:55:37Z |
| publishDate | 2024-02-01 |
| publisher | Springer |
| record_format | Article |
| series | International Journal of Air-Conditioning and Refrigeration |
| spelling | doaj.art-8aa4d33a9ac148deba78b938179014972024-03-05T19:28:55ZengSpringerInternational Journal of Air-Conditioning and Refrigeration2010-13332024-02-0132111710.1007/s44189-024-00049-9Study on various hot-gas defrosting configurations for CO2-NH3 cascade deep freezerB. S. Arun0George Ninan1S. Murali2Manoj Samuel3Sumit Kumar4S. Vaishak5Mani Sankar Dasgupta6Sarun Kumar Kochunni7Armin Hafner8Kristina Norne Widell9Engineering Section, ICAR-Central Institute of Fisheries TechnologyEngineering Section, ICAR-Central Institute of Fisheries TechnologyEngineering Section, ICAR-Central Institute of Fisheries TechnologyCentre for Water Resources Development and ManagementSchool of Energy Science and Engineering, Indian Institute of TechnologyDepartment of Mechanical Engineering, Birla Institute of Technology and ScienceDepartment of Mechanical Engineering, Birla Institute of Technology and ScienceDepartment of Energy and Process Engineering, Norwegian University of Science and TechnologyDepartment of Energy and Process Engineering, Norwegian University of Science and TechnologyFisheries and New Biomarine Industry, SINTEF Ocean ASAbstract Four hot-gas bypass defrosting configurations for CO2-NH3 cascade blast freezer for application in fish processing firm are numerically investigated. Due to the high moisture content of fish, defrosting is necessary after every 4 to 5 h of batch operation. A thermodynamic model for the cascade system and defrosting was developed to study various defrosting configurations formulated by rearranging the existing compressor to operate as a defrosting compressor and with the addition of an external defrosting compressor. From the simulation findings, it can be summarized that the conventional hot-gas bypass defrosting without defrost compressor is suitable for a high-capacity cascade refrigeration system with more than three evaporators. For low cooling capacity refrigeration systems, a defrosting compressor is necessary to elevate the temperature above the cascade condensing temperature. A dedicated defrosting compressor with a power consumption of 3.1 kW and a modified refrigeration/defrosting compressor with a power consumption of 6.8 kW can deliver 33.3 kW of heating at a temperature of +10 °C (45 bar). Incorporating a desuperheater between the main and defrosting compressors reduces compressor temperature and maintains the lubricating oil stability, without change in defrosting energy consumption and less exergy loss. The defrosting efficiency is obtained in the range of 39.7–42% which is in agreement with published literature.https://doi.org/10.1007/s44189-024-00049-9Ammonia (R717)Carbon dioxide (R744)Cascade refrigerationDefrostingBlast freezer |
| spellingShingle | B. S. Arun George Ninan S. Murali Manoj Samuel Sumit Kumar S. Vaishak Mani Sankar Dasgupta Sarun Kumar Kochunni Armin Hafner Kristina Norne Widell Study on various hot-gas defrosting configurations for CO2-NH3 cascade deep freezer International Journal of Air-Conditioning and Refrigeration Ammonia (R717) Carbon dioxide (R744) Cascade refrigeration Defrosting Blast freezer |
| title | Study on various hot-gas defrosting configurations for CO2-NH3 cascade deep freezer |
| title_full | Study on various hot-gas defrosting configurations for CO2-NH3 cascade deep freezer |
| title_fullStr | Study on various hot-gas defrosting configurations for CO2-NH3 cascade deep freezer |
| title_full_unstemmed | Study on various hot-gas defrosting configurations for CO2-NH3 cascade deep freezer |
| title_short | Study on various hot-gas defrosting configurations for CO2-NH3 cascade deep freezer |
| title_sort | study on various hot gas defrosting configurations for co2 nh3 cascade deep freezer |
| topic | Ammonia (R717) Carbon dioxide (R744) Cascade refrigeration Defrosting Blast freezer |
| url | https://doi.org/10.1007/s44189-024-00049-9 |
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