Modeling and Experimental Study on Drying Characteristics of Corn Particles with Hot Air in Downward Moving Bed
With regard to drying fresh grain prior to storage, the drying tower with a downward moving bed with hot air is often used, which always has high energy consumption during operation. To optimize the operation, according to the actual operating parameters of a corn drying tower with hot air, a heat b...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-02-01
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| Series: | Fluids |
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| Online Access: | https://www.mdpi.com/2311-5521/8/2/63 |
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| author | Hairui Wang Shuangming Zhang Haodong Fan Man Zhang Nan Hu Hairui Yang |
| author_facet | Hairui Wang Shuangming Zhang Haodong Fan Man Zhang Nan Hu Hairui Yang |
| author_sort | Hairui Wang |
| collection | DOAJ |
| description | With regard to drying fresh grain prior to storage, the drying tower with a downward moving bed with hot air is often used, which always has high energy consumption during operation. To optimize the operation, according to the actual operating parameters of a corn drying tower with hot air, a heat balance model was established, and the heat transfer between the hot air and corn flow in a downward moving bed was analyzed. Since the downward moving time is short, the heat absorbed by corn significantly depends on the heat transfer coefficient, mainly the convective heat transfer, between the hot air and corn surface. To determine the convective heat transfer coefficient, a hot air drying experimental system for corn grains was established, and the effects of hot air temperature and wind speed on the central temperature and moisture content of corn grains were analyzed. Utilizing the heat balance model, the convective heat transfer coefficients between corn particles and hot air were calculated. The total convective heat transfer coefficients are in the range of 39.4–53.8 W/m<sup>2</sup> · K. With an average value of 46.7 W/m<sup>2</sup> · K, drying energy efficiencies in different drying zones in the drying tower were calculated, and the accuracy of the model was verified by the operation data. Due to the high inlet temperature of hot air, the maximum energy efficiency of the first zone is 60.15%, whereas when the temperature of hot air in the second drying tower is 140 °C, the energy efficiency is only 41.97%. Therefore, under the premise of ensuring the drying rate, the temperature of hot air of the second zone should be appropriately reduced to improve the whole drying energy efficiency. |
| first_indexed | 2024-03-11T08:49:32Z |
| format | Article |
| id | doaj.art-18d4a38cf13247bc91b01a6703deb33e |
| institution | Directory Open Access Journal |
| issn | 2311-5521 |
| language | English |
| last_indexed | 2024-03-11T08:49:32Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fluids |
| spelling | doaj.art-18d4a38cf13247bc91b01a6703deb33e2023-11-16T20:28:53ZengMDPI AGFluids2311-55212023-02-01826310.3390/fluids8020063Modeling and Experimental Study on Drying Characteristics of Corn Particles with Hot Air in Downward Moving BedHairui Wang0Shuangming Zhang1Haodong Fan2Man Zhang3Nan Hu4Hairui Yang5Changchun Institute of Technology, Changchun 130012, ChinaState Key Laboratory of Power Systems, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, ChinaState Key Laboratory of Power Systems, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, ChinaState Key Laboratory of Power Systems, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, ChinaChangchun Institute of Technology, Changchun 130012, ChinaState Key Laboratory of Power Systems, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, ChinaWith regard to drying fresh grain prior to storage, the drying tower with a downward moving bed with hot air is often used, which always has high energy consumption during operation. To optimize the operation, according to the actual operating parameters of a corn drying tower with hot air, a heat balance model was established, and the heat transfer between the hot air and corn flow in a downward moving bed was analyzed. Since the downward moving time is short, the heat absorbed by corn significantly depends on the heat transfer coefficient, mainly the convective heat transfer, between the hot air and corn surface. To determine the convective heat transfer coefficient, a hot air drying experimental system for corn grains was established, and the effects of hot air temperature and wind speed on the central temperature and moisture content of corn grains were analyzed. Utilizing the heat balance model, the convective heat transfer coefficients between corn particles and hot air were calculated. The total convective heat transfer coefficients are in the range of 39.4–53.8 W/m<sup>2</sup> · K. With an average value of 46.7 W/m<sup>2</sup> · K, drying energy efficiencies in different drying zones in the drying tower were calculated, and the accuracy of the model was verified by the operation data. Due to the high inlet temperature of hot air, the maximum energy efficiency of the first zone is 60.15%, whereas when the temperature of hot air in the second drying tower is 140 °C, the energy efficiency is only 41.97%. Therefore, under the premise of ensuring the drying rate, the temperature of hot air of the second zone should be appropriately reduced to improve the whole drying energy efficiency.https://www.mdpi.com/2311-5521/8/2/63downward moving bedcorn particleshot air dryingconvective heat transfer coefficientenergy efficiency |
| spellingShingle | Hairui Wang Shuangming Zhang Haodong Fan Man Zhang Nan Hu Hairui Yang Modeling and Experimental Study on Drying Characteristics of Corn Particles with Hot Air in Downward Moving Bed Fluids downward moving bed corn particles hot air drying convective heat transfer coefficient energy efficiency |
| title | Modeling and Experimental Study on Drying Characteristics of Corn Particles with Hot Air in Downward Moving Bed |
| title_full | Modeling and Experimental Study on Drying Characteristics of Corn Particles with Hot Air in Downward Moving Bed |
| title_fullStr | Modeling and Experimental Study on Drying Characteristics of Corn Particles with Hot Air in Downward Moving Bed |
| title_full_unstemmed | Modeling and Experimental Study on Drying Characteristics of Corn Particles with Hot Air in Downward Moving Bed |
| title_short | Modeling and Experimental Study on Drying Characteristics of Corn Particles with Hot Air in Downward Moving Bed |
| title_sort | modeling and experimental study on drying characteristics of corn particles with hot air in downward moving bed |
| topic | downward moving bed corn particles hot air drying convective heat transfer coefficient energy efficiency |
| url | https://www.mdpi.com/2311-5521/8/2/63 |
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