{"title":"在非冷藏园艺产品运输中使用湿布毯进行蒸发冷却:实验研究","authors":"","doi":"10.1016/j.jafr.2024.101339","DOIUrl":null,"url":null,"abstract":"<div><p>Due to the high cost of mechanical refrigeration, Evaporative Cooling (EC) can be an alternative technology for small farmers in developing countries, such as Thailand. This study aimed to experimentally investigate the performance of EC using a wet fabric blanket. A real-scale cargo chamber, commonly used in Thailand, was constructed, and equipped with axial fans to simulate airflow during transportation. Two pallets of test products (hollow plastic balls) were loaded into the cargo and covered with the wet blanket. During the experiment, the inlet air velocities varied from 0.8 m s<sup>−1</sup> to 3.6 m s<sup>−1</sup> while the constant climate conditions were maintained (29–30 °C and 70–73 %RH). The air and product temperatures and air relative humidity were measured every minute for 3 h using thermocouples and hygrometers, respectively. The proposed EC method allowed the air temperature to decrease by approximately 3–4 °C. When the inlet air velocity decreased, a lower temperature reduction was observed. Simplified heat and mass transfer models were developed to interpret the load temperature evolution from the inlet to the outlet positions at different air velocities. The comparison between the measured and calculated data revealed a maximum mean relative error of 1.2 %. The quality preservation performance was also evaluated based on lettuce mass loss. Lower mass loss was observed for the product stored inside the cargo chamber (<6 %) compared to those outside (8–10 %). This study suggests the potential use of a wet blanket as an EC cooling medium for a short-distance transport to enhance the cold chain performance in Thailand.</p></div>","PeriodicalId":34393,"journal":{"name":"Journal of Agriculture and Food Research","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666154324003764/pdfft?md5=14e6b798866b1bc089634800f09b17db&pid=1-s2.0-S2666154324003764-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Evaporative cooling with a wet fabric blanket for non-refrigerated horticultural produce transport: An experimental study\",\"authors\":\"\",\"doi\":\"10.1016/j.jafr.2024.101339\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Due to the high cost of mechanical refrigeration, Evaporative Cooling (EC) can be an alternative technology for small farmers in developing countries, such as Thailand. This study aimed to experimentally investigate the performance of EC using a wet fabric blanket. A real-scale cargo chamber, commonly used in Thailand, was constructed, and equipped with axial fans to simulate airflow during transportation. Two pallets of test products (hollow plastic balls) were loaded into the cargo and covered with the wet blanket. During the experiment, the inlet air velocities varied from 0.8 m s<sup>−1</sup> to 3.6 m s<sup>−1</sup> while the constant climate conditions were maintained (29–30 °C and 70–73 %RH). The air and product temperatures and air relative humidity were measured every minute for 3 h using thermocouples and hygrometers, respectively. The proposed EC method allowed the air temperature to decrease by approximately 3–4 °C. When the inlet air velocity decreased, a lower temperature reduction was observed. Simplified heat and mass transfer models were developed to interpret the load temperature evolution from the inlet to the outlet positions at different air velocities. The comparison between the measured and calculated data revealed a maximum mean relative error of 1.2 %. The quality preservation performance was also evaluated based on lettuce mass loss. Lower mass loss was observed for the product stored inside the cargo chamber (<6 %) compared to those outside (8–10 %). This study suggests the potential use of a wet blanket as an EC cooling medium for a short-distance transport to enhance the cold chain performance in Thailand.</p></div>\",\"PeriodicalId\":34393,\"journal\":{\"name\":\"Journal of Agriculture and Food Research\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2024-08-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S2666154324003764/pdfft?md5=14e6b798866b1bc089634800f09b17db&pid=1-s2.0-S2666154324003764-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Agriculture and Food Research\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2666154324003764\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"AGRICULTURE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Agriculture and Food Research","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666154324003764","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
由于机械制冷成本高昂,蒸发冷却(EC)可以成为泰国等发展中国家小农户的替代技术。本研究旨在利用湿布毯对蒸发冷却的性能进行实验研究。研究人员建造了一个泰国常用的真实规模的货舱,并配备了轴流风扇,以模拟运输过程中的气流。两个托盘的测试产品(空心塑料球)被装入货舱,并覆盖湿布毯。实验期间,进气速度从 0.8 m s-1 到 3.6 m s-1 不等,同时保持恒定的气候条件(29-30 °C 和 70-73%RH)。使用热电偶和湿度计分别在 3 小时内每分钟测量一次空气和产品温度以及空气相对湿度。拟议的 EC 方法可使空气温度降低约 3-4 °C。当入口气流速度降低时,观察到的降温幅度也更小。我们建立了简化的传热和传质模型,以解释不同风速下从入口到出口位置的负载温度变化。测量数据和计算数据的比较显示,最大平均相对误差为 1.2%。还根据莴苣的质量损失评估了保质性能。观察发现,储存在货仓内的产品的质量损失(6%)低于储存在货仓外的产品(8-10%)。这项研究表明,湿毯作为 EC 冷却介质可用于短途运输,从而提高泰国的冷链性能。
Evaporative cooling with a wet fabric blanket for non-refrigerated horticultural produce transport: An experimental study
Due to the high cost of mechanical refrigeration, Evaporative Cooling (EC) can be an alternative technology for small farmers in developing countries, such as Thailand. This study aimed to experimentally investigate the performance of EC using a wet fabric blanket. A real-scale cargo chamber, commonly used in Thailand, was constructed, and equipped with axial fans to simulate airflow during transportation. Two pallets of test products (hollow plastic balls) were loaded into the cargo and covered with the wet blanket. During the experiment, the inlet air velocities varied from 0.8 m s−1 to 3.6 m s−1 while the constant climate conditions were maintained (29–30 °C and 70–73 %RH). The air and product temperatures and air relative humidity were measured every minute for 3 h using thermocouples and hygrometers, respectively. The proposed EC method allowed the air temperature to decrease by approximately 3–4 °C. When the inlet air velocity decreased, a lower temperature reduction was observed. Simplified heat and mass transfer models were developed to interpret the load temperature evolution from the inlet to the outlet positions at different air velocities. The comparison between the measured and calculated data revealed a maximum mean relative error of 1.2 %. The quality preservation performance was also evaluated based on lettuce mass loss. Lower mass loss was observed for the product stored inside the cargo chamber (<6 %) compared to those outside (8–10 %). This study suggests the potential use of a wet blanket as an EC cooling medium for a short-distance transport to enhance the cold chain performance in Thailand.