Mitigating heat stress for agricultural workers using computational fluid dynamics (CFD) simulations

IF 6.6 2区 工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY Energy and Buildings Pub Date : 2024-12-12 DOI:10.1016/j.enbuild.2024.115186
Yoonhong Yi, Neslihan Akdeniz, Christopher Y. Choi, John M. Shutske
{"title":"Mitigating heat stress for agricultural workers using computational fluid dynamics (CFD) simulations","authors":"Yoonhong Yi, Neslihan Akdeniz, Christopher Y. Choi, John M. Shutske","doi":"10.1016/j.enbuild.2024.115186","DOIUrl":null,"url":null,"abstract":"The Venlo ventilation system is one of the most widely adopted designs for greenhouses, and it is known for its distinctive roof structure that promotes natural airflow. However, despite its widespread use, it is often inadequate in maintaining the desired temperatures during the summer. This increases the risk of heat stress for greenhouse workers, particularly under the high humidity conditions typically encountered in aquaponic greenhouses. In this study, we developed computational fluid dynamics (CFD) models simulating temperature and air velocity distributions using a commercial-scale Venlo-style aquaponic greenhouse as a reference. The study aimed to evaluate the impact of applying reflective whitewash and installing positive pressure ventilation tubes (PPVT) in worker areas on the heat stress experienced by the workers. The standard k-ε turbulence and solar ray tracing models were employed in CFD simulations. A total of 1,776 lettuce at three different growth stages were placed inside the aquaponic pools. The CFD models were validated using an experimental-scale greenhouse, and with these validated models, air velocities at the worker’s height were calculated to be 3.1±0.13 m s<ce:sup loc=\"post\">−1</ce:sup>, 3.2±0.16 m s<ce:sup loc=\"post\">−1</ce:sup>, and 3.8±0.04 m s<ce:sup loc=\"post\">−1</ce:sup> for the control, whitewash, and PPVT + whitewash conditions, respectively. When whitewash and positive pressure ventilation tubes were both in use, the air exchange rate increased from 27.3 to 31.8 per hour. Although there was only a 4.5 increase in air exchanges, strategically placing the ventilation tubes resulted in a 7.3 °C decrease in temperature at the average worker height. This reduction shifted the heat index from the “extreme danger” to the “caution” zone, allowing workers to safely work up to four consecutive hours with adequate water intake. The annual cost for running the PPVT inline fans was calculated to be as low as $245, which was 2.6 times less than the previously reported operating costs for greenhouse ventilation systems.","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"13 1","pages":""},"PeriodicalIF":6.6000,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Energy and Buildings","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1016/j.enbuild.2024.115186","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
引用次数: 0

Abstract

The Venlo ventilation system is one of the most widely adopted designs for greenhouses, and it is known for its distinctive roof structure that promotes natural airflow. However, despite its widespread use, it is often inadequate in maintaining the desired temperatures during the summer. This increases the risk of heat stress for greenhouse workers, particularly under the high humidity conditions typically encountered in aquaponic greenhouses. In this study, we developed computational fluid dynamics (CFD) models simulating temperature and air velocity distributions using a commercial-scale Venlo-style aquaponic greenhouse as a reference. The study aimed to evaluate the impact of applying reflective whitewash and installing positive pressure ventilation tubes (PPVT) in worker areas on the heat stress experienced by the workers. The standard k-ε turbulence and solar ray tracing models were employed in CFD simulations. A total of 1,776 lettuce at three different growth stages were placed inside the aquaponic pools. The CFD models were validated using an experimental-scale greenhouse, and with these validated models, air velocities at the worker’s height were calculated to be 3.1±0.13 m s−1, 3.2±0.16 m s−1, and 3.8±0.04 m s−1 for the control, whitewash, and PPVT + whitewash conditions, respectively. When whitewash and positive pressure ventilation tubes were both in use, the air exchange rate increased from 27.3 to 31.8 per hour. Although there was only a 4.5 increase in air exchanges, strategically placing the ventilation tubes resulted in a 7.3 °C decrease in temperature at the average worker height. This reduction shifted the heat index from the “extreme danger” to the “caution” zone, allowing workers to safely work up to four consecutive hours with adequate water intake. The annual cost for running the PPVT inline fans was calculated to be as low as $245, which was 2.6 times less than the previously reported operating costs for greenhouse ventilation systems.
查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
芬洛通风系统是最广泛采用的温室设计之一,以其独特的屋顶结构促进自然气流而闻名。然而,尽管这种通风系统被广泛使用,但在夏季却往往无法维持理想的温度。这增加了温室工人热应激的风险,特别是在水生植物温室通常遇到的高湿度条件下。在这项研究中,我们开发了计算流体动力学(CFD)模型,以商业规模的芬洛式水产栽培温室为参考,模拟温度和气流速度分布。该研究旨在评估在工人工作区域使用反光粉刷和安装正压通风管(PPVT)对工人热应力的影响。在 CFD 模拟中采用了标准 k-ε 湍流和太阳光线跟踪模型。在三个不同生长阶段,共有 1,776 棵生菜被放置在水培池中。利用实验规模的温室对 CFD 模型进行了验证,通过这些验证模型计算得出,在对照、粉刷和 PPVT + 粉刷条件下,工人高度处的气流速度分别为 3.1±0.13 m s-1、3.2±0.16 m s-1 和 3.8±0.04 m s-1。当同时使用粉刷和正压通气管时,空气交换率从每小时 27.3 次增加到 31.8 次。虽然换气次数只增加了 4.5 次,但战略性地放置通风管却使工人平均身高处的温度降低了 7.3 °C。温度的降低将热指数从 "极度危险 "区转移到了 "警戒 "区,使工人能够在摄入足够水分的情况下安全地连续工作四个小时。据计算,PPVT 直列式风机的年运行成本低至 245 美元,比之前报告的温室通风系统运行成本低 2.6 倍。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 去求助
来源期刊
Energy and Buildings
Energy and Buildings 工程技术-工程:土木
CiteScore
12.70
自引率
11.90%
发文量
863
审稿时长
38 days
期刊介绍: An international journal devoted to investigations of energy use and efficiency in buildings Energy and Buildings is an international journal publishing articles with explicit links to energy use in buildings. The aim is to present new research results, and new proven practice aimed at reducing the energy needs of a building and improving indoor environment quality.
期刊最新文献
Surface temperature distribution prediction model for prefabricated ceiling radiant panel A novel solution for data uncertainty and insufficient in data-driven chiller fault diagnosis based on multi-modal data fusion Study on a ventilating vest with thermoelectric cooling to improve thermal comfort and cognitive ability Field study on pressure differential mechanisms under static and dynamic disturbances in non-isobaric building zones Developing a spatial optimization design approach towards energy-saving and outdoor thermal comfortable densely-built residential blocks using a dynamic local energy balance model
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1