Simulation and experiment on pneumatic defrosting of evaporators with heat storage
In order to solve the problem of frosting on surface of the evaporators in rapid freezing equipment, a new defrosting system was proposed based on pneumatic defrosting and heat storage defrosting. A three-dimensional flow model including an evaporator and a thermal flow defrosting system was establi...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-11-01
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| Series: | Case Studies in Thermal Engineering |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214157X23009024 |
| _version_ | 1827794104666292224 |
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| author | Peiyong Ni Zhili Lv Hangyu Jiang Ruidong Hua Xiangli Wang Xuewen Zhang Xiang Li |
| author_facet | Peiyong Ni Zhili Lv Hangyu Jiang Ruidong Hua Xiangli Wang Xuewen Zhang Xiang Li |
| author_sort | Peiyong Ni |
| collection | DOAJ |
| description | In order to solve the problem of frosting on surface of the evaporators in rapid freezing equipment, a new defrosting system was proposed based on pneumatic defrosting and heat storage defrosting. A three-dimensional flow model including an evaporator and a thermal flow defrosting system was established to observe the temperature distributions of the fins and gas flowing outside the evaporator and to reflect the defrosting effect. The correctness of the model was verified by a freezing experiment. On this basis, the effects of the nozzle placement hole sizes, hot air inlet temperatures and velocities on the fins and cold air temperatures were simulated. The results show that the appropriate horizontal distance between the nozzle and the evaporator is 40 mm considering the large area of heat transfer. The initial temperatures of the hot gas and nozzle sizes have little effects on the heat exchange areas, but the initial velocities of the hot gas have great effects on the heat exchange areas. It takes 180 s for the air outlet temperature of the heat accumulator with the decrease of the temperature from 44 °C to 25 °C. The frost on the surface of the fin melts rapidly within the time that the heat accumulator can maintain a certain temperature range. More studies are required to perform defrosting experiments by choosing appropriate heat storage materials and elevating gas pressure and temperature. |
| first_indexed | 2024-03-11T18:28:59Z |
| format | Article |
| id | doaj.art-75f4108f1da84b16806d363792485cc4 |
| institution | Directory Open Access Journal |
| issn | 2214-157X |
| language | English |
| last_indexed | 2024-03-11T18:28:59Z |
| publishDate | 2023-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Case Studies in Thermal Engineering |
| spelling | doaj.art-75f4108f1da84b16806d363792485cc42023-10-13T13:53:57ZengElsevierCase Studies in Thermal Engineering2214-157X2023-11-0151103596Simulation and experiment on pneumatic defrosting of evaporators with heat storagePeiyong Ni0Zhili Lv1Hangyu Jiang2Ruidong Hua3Xiangli Wang4Xuewen Zhang5Xiang Li6School of Mechanical Engineering, Nantong University, Nantong, 226019, ChinaSchool of Mechanical Engineering, Nantong University, Nantong, 226019, ChinaSchool of Mechanical Engineering, Nantong University, Nantong, 226019, ChinaSchool of Mechanical Engineering, Nantong University, Nantong, 226019, ChinaSchool of Electrical Engineering, Nantong University, Nantong, 226019, China; Corresponding author.School of Mechanical Engineering, Nantong University, Nantong, 226019, ChinaSchool of Mechanical Engineering, Nantong University, Nantong, 226019, ChinaIn order to solve the problem of frosting on surface of the evaporators in rapid freezing equipment, a new defrosting system was proposed based on pneumatic defrosting and heat storage defrosting. A three-dimensional flow model including an evaporator and a thermal flow defrosting system was established to observe the temperature distributions of the fins and gas flowing outside the evaporator and to reflect the defrosting effect. The correctness of the model was verified by a freezing experiment. On this basis, the effects of the nozzle placement hole sizes, hot air inlet temperatures and velocities on the fins and cold air temperatures were simulated. The results show that the appropriate horizontal distance between the nozzle and the evaporator is 40 mm considering the large area of heat transfer. The initial temperatures of the hot gas and nozzle sizes have little effects on the heat exchange areas, but the initial velocities of the hot gas have great effects on the heat exchange areas. It takes 180 s for the air outlet temperature of the heat accumulator with the decrease of the temperature from 44 °C to 25 °C. The frost on the surface of the fin melts rapidly within the time that the heat accumulator can maintain a certain temperature range. More studies are required to perform defrosting experiments by choosing appropriate heat storage materials and elevating gas pressure and temperature.http://www.sciencedirect.com/science/article/pii/S2214157X23009024DefrostingEvaporatorNozzleHeat accumulatorSimulation |
| spellingShingle | Peiyong Ni Zhili Lv Hangyu Jiang Ruidong Hua Xiangli Wang Xuewen Zhang Xiang Li Simulation and experiment on pneumatic defrosting of evaporators with heat storage Case Studies in Thermal Engineering Defrosting Evaporator Nozzle Heat accumulator Simulation |
| title | Simulation and experiment on pneumatic defrosting of evaporators with heat storage |
| title_full | Simulation and experiment on pneumatic defrosting of evaporators with heat storage |
| title_fullStr | Simulation and experiment on pneumatic defrosting of evaporators with heat storage |
| title_full_unstemmed | Simulation and experiment on pneumatic defrosting of evaporators with heat storage |
| title_short | Simulation and experiment on pneumatic defrosting of evaporators with heat storage |
| title_sort | simulation and experiment on pneumatic defrosting of evaporators with heat storage |
| topic | Defrosting Evaporator Nozzle Heat accumulator Simulation |
| url | http://www.sciencedirect.com/science/article/pii/S2214157X23009024 |
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