Energy and exergy analysis of NH3/CO2 cascade refrigeration system with subcooling in the low-temperature cycle based on an auxiliary loop of NH3 refrigerants
This paper proposes a NH3/CO2 cascade refrigeration system that sets an auxiliary refrigeration loop in the high-temperature cycle to increase the subcooling degree in the low-temperature cycle (CRSS). Based on the basic principles of thermodynamics, a mathematical model is established and theoretic...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-11-01
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| Series: | Energy Reports |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S235248472200004X |
| _version_ | 1828011146327621632 |
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| author | Xiaonan Chen Qichao Yang Weikai Chi Yuanyang Zhao Guangbin Liu Liansheng Li |
| author_facet | Xiaonan Chen Qichao Yang Weikai Chi Yuanyang Zhao Guangbin Liu Liansheng Li |
| author_sort | Xiaonan Chen |
| collection | DOAJ |
| description | This paper proposes a NH3/CO2 cascade refrigeration system that sets an auxiliary refrigeration loop in the high-temperature cycle to increase the subcooling degree in the low-temperature cycle (CRSS). Based on the basic principles of thermodynamics, a mathematical model is established and theoretical simulation is carried out to obtain the influence of key parameters on the cycle performance. Compared with the conventional cascade refrigeration system (CCRS), the conclusions find that there exists an optimal condensation temperature of low-temperature cycle (TMC.opt) to maximize COP. The maximum COP of CRSS is 4.58% higher than that of CCRS when the subcooling degree is 10 °C. The maximum exergy efficiency is 0.391, increasing by 4.40%. With the increase of the subcooling degree, both the COP and the TMC.optof CRSS increase. When the subcooling degree increases from 5 °C to 15 °C, the performance increment increases from 2.73% to 6.00%. When the evaporation temperature of the system changes, both the COP and exergy efficiency decreases slightly and it is found that the performance is better when the evaporation temperature is lower when condensation temperature is kept constant. Besides, the discharge temperature of the NH3 compressor in CRSS can be reduced by 9.9 °C when the evaporation temperature is −30 °C. |
| first_indexed | 2024-04-10T09:11:58Z |
| format | Article |
| id | doaj.art-3fb549c8e30d42389b4d775ee20c932d |
| institution | Directory Open Access Journal |
| issn | 2352-4847 |
| language | English |
| last_indexed | 2024-04-10T09:11:58Z |
| publishDate | 2022-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Energy Reports |
| spelling | doaj.art-3fb549c8e30d42389b4d775ee20c932d2023-02-21T05:10:05ZengElsevierEnergy Reports2352-48472022-11-01817571767Energy and exergy analysis of NH3/CO2 cascade refrigeration system with subcooling in the low-temperature cycle based on an auxiliary loop of NH3 refrigerantsXiaonan Chen0Qichao Yang1Weikai Chi2Yuanyang Zhao3Guangbin Liu4Liansheng Li5College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266100, ChinaCorresponding author.; College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266100, ChinaCollege of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266100, ChinaCollege of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266100, ChinaCollege of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266100, ChinaCollege of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266100, ChinaThis paper proposes a NH3/CO2 cascade refrigeration system that sets an auxiliary refrigeration loop in the high-temperature cycle to increase the subcooling degree in the low-temperature cycle (CRSS). Based on the basic principles of thermodynamics, a mathematical model is established and theoretical simulation is carried out to obtain the influence of key parameters on the cycle performance. Compared with the conventional cascade refrigeration system (CCRS), the conclusions find that there exists an optimal condensation temperature of low-temperature cycle (TMC.opt) to maximize COP. The maximum COP of CRSS is 4.58% higher than that of CCRS when the subcooling degree is 10 °C. The maximum exergy efficiency is 0.391, increasing by 4.40%. With the increase of the subcooling degree, both the COP and the TMC.optof CRSS increase. When the subcooling degree increases from 5 °C to 15 °C, the performance increment increases from 2.73% to 6.00%. When the evaporation temperature of the system changes, both the COP and exergy efficiency decreases slightly and it is found that the performance is better when the evaporation temperature is lower when condensation temperature is kept constant. Besides, the discharge temperature of the NH3 compressor in CRSS can be reduced by 9.9 °C when the evaporation temperature is −30 °C.http://www.sciencedirect.com/science/article/pii/S235248472200004XCascade refrigeration systemSubcoolingEnergy and exergy analysisMechanical subcooling |
| spellingShingle | Xiaonan Chen Qichao Yang Weikai Chi Yuanyang Zhao Guangbin Liu Liansheng Li Energy and exergy analysis of NH3/CO2 cascade refrigeration system with subcooling in the low-temperature cycle based on an auxiliary loop of NH3 refrigerants Energy Reports Cascade refrigeration system Subcooling Energy and exergy analysis Mechanical subcooling |
| title | Energy and exergy analysis of NH3/CO2 cascade refrigeration system with subcooling in the low-temperature cycle based on an auxiliary loop of NH3 refrigerants |
| title_full | Energy and exergy analysis of NH3/CO2 cascade refrigeration system with subcooling in the low-temperature cycle based on an auxiliary loop of NH3 refrigerants |
| title_fullStr | Energy and exergy analysis of NH3/CO2 cascade refrigeration system with subcooling in the low-temperature cycle based on an auxiliary loop of NH3 refrigerants |
| title_full_unstemmed | Energy and exergy analysis of NH3/CO2 cascade refrigeration system with subcooling in the low-temperature cycle based on an auxiliary loop of NH3 refrigerants |
| title_short | Energy and exergy analysis of NH3/CO2 cascade refrigeration system with subcooling in the low-temperature cycle based on an auxiliary loop of NH3 refrigerants |
| title_sort | energy and exergy analysis of nh3 co2 cascade refrigeration system with subcooling in the low temperature cycle based on an auxiliary loop of nh3 refrigerants |
| topic | Cascade refrigeration system Subcooling Energy and exergy analysis Mechanical subcooling |
| url | http://www.sciencedirect.com/science/article/pii/S235248472200004X |
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