Thermal environment

热环境
  • 文章类型: Journal Article
    在这项研究中,我们使用湿球温度(WBGT)表评估了不同网球场的热环境。WBGT仪表安装在室外硬地球场,充满沙子的人造草地球场,和红土球场(垒球场),并在2022年6月1日至9月21日的工作日从9:00到17:00每小时进行测量。根据日本体育协会预防中暑的运动指南,将结果与来自不同法院和最近的日本气象厅站(JMAWBGT)的数据进行了比较。在“警告”(25≤JMAWBGT<28)或以上的硬地球场上,每个球场的WBGT中位数明显更高,“严重警告”(28≤JMAWBGT<31)水平或以上的填沙人造草地球场,和红土球场的“危险”级别(31≤JMAWBGT)高于JMAWBGT。与JMAWBGT相比,坚硬和充满沙子的人造草地球场在特别炎热的条件下进行。这项研究的结果可以向锦标赛组织者和教练表明,从早期阶段开始测量每个球场表面上的WBGT以防止与热有关的事件的重要性。
    In this study, we evaluated the thermal environments of different tennis courts using wet-bulb globe temperature (WBGT) meters. WBGT meters were installed in an outdoor hard court, sand-filled artificial grass court, and clay court (a softball field), and measurements were taken hourly from 9:00 to 17:00 on weekdays from June 1 to September 21, 2022. The results were compared with data from different courts and the nearest Japan Meteorological Agency station (JMA WBGT) based on the Japan Sports Association\'s guidelines for exercise to prevent heat stroke. The median WBGT on each court was significantly higher for hard courts at the \"Warning\" (25 ≤ JMA WBGT < 28) level or above, sand-filled artificial grass courts at the \"Severe Warning\" (28 ≤ JMA WBGT < 31) level or above, and clay courts at the \"Danger\" (31 ≤ JMA WBGT) level than the JMA WBGT. Compared with the JMA WBGT, hard and sand-filled artificial grass courts are played on under particularly hot conditions. The results of this study could indicate to tournament organizers and coaches the importance of measuring the WBGT on each court surface from an early stage to prevent heat-related incidents.
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  • 文章类型: Journal Article
    极端天气条件,比如热浪事件,随着气候变化变得越来越频繁。动物经常改变自己的行为来应对环境变化和极端情况。在热应力条件下,个体改变他们的空间行为,增加阴影区域的使用,以协助体温调节。这里,我们建议对于社会物种,这些行为变化和环境条件有可能影响个人在其社交网络中的地位,以及整个社会网络结构。我们调查了热应力条件(通过温度湿度指数量化)和由此产生的阴影区域的使用,影响社会网络结构和个人在其中的连通性。我们在澳大利亚干旱地区的自由放养绵羊中进行了研究,GPS跟踪羊群中的所有48个人。当热应力条件恶化时,个人在阴凉处花费更多的时间,网络更紧密(密度更高),结构更少(模块化更低)。此外,然后,我们确定了导致网络结构改变的行为变化,并表明个人的阴影使用行为影响了其社会连通性。有趣的是,中间使用阴影的个体联系最紧密(程度,力量,介数),表明它们在热应激条件下对社交网络连通性的重要性。热应力条件,预计由于气候变化的严重程度和频率会增加,影响生态环境内的资源利用。重要的是,我们的研究表明,这些热应激条件也通过改变社会网络结构影响动物的社会环境。最终,由于社会结构驱动信息和疾病传播,这可能会对社会觅食和个人健康产生进一步的影响。
    Extreme weather conditions, like heatwave events, are becoming more frequent with climate change. Animals often modify their behaviour to cope with environmental changes and extremes. During heat stress conditions, individuals change their spatial behaviour and increase the use of shaded areas to assist with thermoregulation. Here, we suggest that for social species, these behavioural changes and ambient conditions have the potential to influence an individual\'s position in its social network, and the social network structure as a whole. We investigated whether heat stress conditions (quantified through the temperature humidity index) and the resulting use of shaded areas, influence the social network structure and an individual\'s connectivity in it. We studied this in free-ranging sheep in the arid zone of Australia, GPS-tracking all 48 individuals in a flock. When heat stress conditions worsened, individuals spent more time in the shade and the network was more connected (higher density) and less structured (lower modularity). Furthermore, we then identified the behavioural change that drove the altered network structure and showed that an individual\'s shade use behaviour affected its social connectivity. Interestingly, individuals with intermediate shade use were most strongly connected (degree, strength, betweenness), indicating their importance for the connectivity of the social network during heat stress conditions. Heat stress conditions, which are predicted to increase in severity and frequency due to climate change, influence resource use within the ecological environment. Importantly, our study shows that these heat stress conditions also affect the animal\'s social environment through the changed social network structure. Ultimately, this could have further flow on effects for social foraging and individual health since social structure drives information and disease transmission.
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  • 文章类型: Journal Article
    在资源有限的南非教育部门,在其他国家被视为临时或备用的基础设施被用作永久性教室,主要但不限于低收入地区。室内空气质量直接影响儿童的认知表现和舒适度。温度,相对湿度,颗粒物和二氧化碳水平,空气质量和热舒适度的重要决定因素,尚未对不同的教室建筑和基础设施类型进行调查。我们在斯泰伦博斯学校的24个教室中以11分钟的间隔测量这些参数,南非。这些教室由一系列不同的基础设施类型组成。带绝缘和不带绝缘的集装箱教室,移动(预制)教室,包括不同配置的砖教室。测量在十个月(249天,仍在进行中)跨多个季节使用相关元数据,包括环境天气条件,上学的日子和时间,和(南)非洲背景下的电力供应,这会影响空调的使用。该数据集提供了有关南非教室真实学习条件的宝贵见解。
    In the resource-constrained South African education sector, infrastructure considered temporary or a backup in other countries is used as permanent classrooms, primarily but not exclusively in lower-income areas. Children\'s cognitive performance and comfort are directly impacted by indoor air quality. Temperature, relative humidity, particulate matter and CO2 levels, substantial determinants of air quality and thermal comfort, have not been investigated across different classroom building and infrastructure types. We measure these parameters with 11-min intervals in 24 classrooms at schools in Stellenbosch, South Africa. These classrooms consist of a range of different infrastructure types. Container classrooms with and without insulation, mobile (prefabricated) classrooms, and brick classrooms of different configurations are included. Measurements are concurrently sampled over ten months (249 days, still ongoing) across multiple seasons with relevant metadata, including ambient weather conditions, school days and times, and electricity availability in the (South) African context, which impacts air conditioning usage. This dataset provides valuable insights into true learning conditions in South African classrooms.
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  • 文章类型: Journal Article
    由于能源的限制和人们对室内热舒适的要求越来越高,在确保热舒适性的同时提高能源效率已成为暖通空调系统设计和运行研究的重点。本研究以武汉市很少有人居住的办公室为研究对象。采用EnergyPlus-Fluent联合模拟方法研究了12种形式的空气分布对热环境和空调能耗的影响。结果表明,3m/s的送风速度和45°的送风角度更适合本研究的案例模型。本文所采用的EnergyPlus-Fluent联合仿真方法为研究很少有人占用的办公室室内环境提供了参考。
    Due to energy constraints and people\'s increasing requirements for indoor thermal comfort, improving energy efficiency while ensuring thermal comfort has become the focus of research in the design and operation of HVAC systems. This study took office rooms with few people occupying them in Wuhan as the research object. The EnergyPlus-Fluent co-simulation method was used to study the impact of 12 forms of air distribution on the thermal environment and air-conditioner energy consumption. The results indicate that 3 m/s supply air velocity and 45° supply air angle are more suitable for the case model in this study. The EnergyPlus-Fluent co-simulation method used in this paper provides a reference for the study of indoor environments in offices with few people occupying them.
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  • 文章类型: Journal Article
    热环境是生态环境的重要组成部分。研究热环境的分布和生成对区域可持续发展至关重要。矿区,以农业区和城区为研究对象,和遥感数据用于研究热环境的时空分布特征。分析了热环境与土地利用类型的关系,强调了采矿和复垦对热环境的影响。主要发现:(1)研究区热效应区分散。热效应区面积比例占69.70%,68.52%,65.85%,2000年、2003年、2009年、2013年和2018年分别为74.20%和74.66%。对整体热效应的贡献依次为农业区>矿区>市区。(2)森林比例与平均网格温度在不同尺度上始终呈显著负相关,且相关性最高,影响最大。(3)露天地区地表温度(LST)高于周边温度,温差为3-5℃。开垦场地的LST低于周围温度,温差为-7至0℃。定量研究发现,复垦模式,形状和空间位置可能会影响回收场地的冷却效果。该研究可为类似区域协调发展中缓解热效应、识别开采复垦对热环境的影响提供参考。
    The thermal environment is a crucial part of ecological environments. It is vital to study the distribution and generation of thermal environments for regional sustainable development. Mining area, agricultural area and urban area were taken as the research object, and remote sensing data were used to study the spatiotemporal distribution characteristics of the thermal environment. The relationship between the thermal environment and land use types was analyzed, and the effect of mining and reclamation on the thermal environment was emphasized. The main findings were: (1) the thermal effect zone in the study area was dispersed. The area ratio of the thermal effect zone accounted for 69.70%, 68.52%, 65.85%, 74.20% and 74.66% in the year 2000, 2003, 2009, 2013 and 2018, respectively. The contribution to the overall thermal effect was in the order of agricultural area > mining area > urban area. (2) The proportion of forest and the average grid temperature always showed a significant negative correlation in different scales and had the highest correlation and the greatest influence. (3) The land surface temperature (LST) of opencast areas was higher than the surrounding temperature, and the temperature difference was 3-5 °C. The LST of reclaimed sites was lower than the surrounding temperature, and the temperature difference was -7 to 0 °C. The quantitative study found that reclamation mode, shape and spatial location could affect the cooling effect of the reclaimed site. This study can provide a reference for the mitigation of thermal effects and the identification of influences of mining and reclamation on the thermal environment in the coordinated development of similar regions.
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  • 文章类型: Journal Article
    2020年初爆发的COVID-19疫情减少了人类户外活动,改变了人群的时空分布。寻找其变化对城市热环境的影响,我们从城市土地利用和当地气候带(LCZ)方案的角度应用Pearson相关分析和OLS线性回归模型,并选取了中国武汉市作为案例研究。结果表明,受春节和疫情影响,大部分城市土地利用和LCZ类人口规模有所减少,导致居民离开武汉市。因此,城市层面的归一化地表城市热岛变化(SUHInc)下降了9.41%,更大的SUHInc发生在商业和工业用地中。在LCZ班级中,Thebuilded-upclassalsotendedtohavealargerSUHIncthanthenaturallandcoverclass.然而,人口规模和人类户外活动的变化并没有改变城市热环境的空间分布,因为在各种城市土地利用和LCZ类别中观察到相同的趋势,说明人为热排放对城市热环境的贡献相对较弱。以上发现表明,有必要对各种城市土地利用应用不同的方法,缓解城市热岛。
    The outbreak of the COVID-19 epidemic in early 2020 reduced human outdoor activities and changed the spatial-temporal distribution of the population. To find its changes on the impact of urban thermal environment, we applied Pearson correlation analysis and OLS linear regression model from the perspective of urban land use and the local climate zone (LCZ) scheme, and selected Wuhan City in China as a case study. The results showed that the population size decreased in most urban land use and LCZ classes due to the Spring Festival and epidemic effects, which caused residents to leave Wuhan City. As a result, the normalized surface urban heat island changes (SUHInc) decreased by 9.41% at the city level, and a larger SUHInc occurred in commercial and industrial land. Among the LCZ classes, the built-up classes also tended to have a larger SUHInc than the natural land cover classes. However, the population size and human outdoor activity changes did not modify the spatial distribution of the urban thermal environment, because the same trends were observed for various urban land use and LCZ classes, which illustrated that the contribution of anthropogenic heat discharge on the urban thermal environment is relatively weaker. The above findings imply that it is necessary to apply different methods for various urban land uses and alleviate urban heat island.
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  • 文章类型: Journal Article
    婴儿具有低的热适应其环境的能力,因此必须充分考虑其热环境。在调查婴儿的热环境时,这项研究的目的是阐明婴儿在婴儿车中的姿势在自然对流中的传热系数。传热系数是通过使用热人体模型测量的。实验热环境条件设置为8例,在:16°C,18°C,20°C,22°C,24°C,26°C,28°C,30°C,空气和墙壁表面温度相等,创造一个均匀的热环境。对于每种情况,空气速度(小于0.2m/s)和相对湿度(50%RH)相同。将热敏人体模型的每个部分的表面温度控制在34°C。平均表面温度和空气温度之间的差异(AT[K])是婴儿在婴儿车中姿势的自然对流中传热系数的驱动力(hc[W/(m2·K)])。我们建议使用经验公式hc=2.16ΔT0.23。本研究的自然对流中的对流传热系数公式可适用于3岁左右的婴儿。
    Infants have a low capacity to thermally adapt to their environment and so sufficient consideration must be given to their thermal environment. In investigating an infant\'s thermal environment, the purpose of this study is to clarify the heat transfer coefficient in natural convection for the posture of an infant in a stroller. The heat transfer coefficients were measured by means of using a thermal manikin. The experimental thermal environment conditions were set for eight cases, at: 16 °C, 18 °C, 20 °C, 22 °C, 24 °C, 26 °C, 28 °C, and 30 °C, and the air and wall surface temperatures were equalized, creating a homogeneous thermal environment. The air velocity (less than 0.2 m/s) and relative humidity (50%RH) were the same for each case. The surface temperature of each part of the thermal manikin was controlled to 34 °C. The difference between the mean surface temperature and air temperature (ΔT [K]) is the driving force for the heat transfer coefficient in natural convection for the posture of an infant in a stroller (hc [W/(m2·K)]). We propose the use of the empirical formula hc = 2.16 ΔT 0 .23. The formula of the convective heat transfer coefficient in natural convection of this study can be applied to infants up to about 3 years old.
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  • 文章类型: Journal Article
    随着2019年冠状病毒病等传染病的爆发,医务人员在孤立的地块紧张工作,医用一次性防护服(MDPC)的空气条件和湿度渗透性差,严重降低了医务人员的热舒适度。在本文中,通过实验研究了室内热环境和活动水平对MDPC内热舒适性的影响。在MDPC内部测量了身体的五个部分,并选择了适当的运动来模拟不同的劳动强度。同时,生理参数和主观热感觉进行统计分析。结果表明,室内温度对MDPC内部温度和湿度的影响范围约为1°C和10%,分别表明,降低室内温度可以改善MDPC内部的环境,也就是说,提出了一种交叉智能调节模式。劳动强度对MDPC内部温度的影响明显小于湿度。20分钟内,中等和重劳动强度下的湿度变化甚至超过10%,受试者的主观不适阈值提高了近50%。此外,通过集中冷却可以获得最大的好处,前额,胸部和上臂。工作时间的理论模型,劳动强度,给出了不同室内温度和不同部位下MDPC内部的温度和湿度。此外,MDPC内部可接受的区域,在焓湿度图中大约为平行四边形。这些结论可为未来MDPC内部热舒适性研究提供参考。
    With the outbreak of infectious diseases such as Corona Virus Disease 2019, medical staff work intensively in isolated plots, medical disposable protective clothing (MDPC) has poor air condition and humidity permeability, which seriously reduces the thermal comfort of medical staff. In this paper, the effect of indoor thermal environment and activity levels on thermal comfort inside MDPC was studied by experiment. Five parts of the body were measured inside MDPC and the appropriate movements were chosen to simulate different levels of labor intensity. Meanwhile, physiological parameters and subjective thermal sensation were statistically analyzed. The results showed the influence range of different indoor temperatures on the temperature and humidity inside MDPC was about 1 °C and 10 %, respectively; it indicated that the environment inside MDPC could be improved by reducing indoor temperature, that is, a cross intelligent adjustment mode was proposed. The effect of labor intensity on the temperature inside MDPC was significantly less than that of humidity. Within 20 min, the humidity changes under moderate and heavy labor intensity were even more than 10 %, and the subjective discomfort threshold of the subjects increased by nearly 50 %. Furthermore, the maximum benefit could be obtained by concentrating cooling on back, forehead, chest and upper arm. Theoretical models of working time, labor intensity, and temperature and humidity inside MDPC under different indoor temperatures and different parts were given. In addition, acceptable regions inside MDPC which were approximately parallelogram in the enthalpy-humidity chart. These conclusions could be a reference for future thermal comfort inside MDPC research.
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  • 文章类型: Journal Article
    冷却度日(CDD)可以有效地指示热气候对能源消耗和热环境舒适度的影响。然而,很少关注时空特征的研究,影响因素,和全局CDD的模拟。本研究分析了1970年至2018年以及未来全球CDD的时空特征,探索了五个决定因素,和模拟CDD及其年际变化率。结果表明,在低纬度和海拔地区,全球CDD普遍较高。许多地方的CDDs出现了显著的正变化(p<0.05),在较低的纬度和态度下,利率变得更大。在未来,大多数CDD具有可持续性趋势。此外,不仅CDDs之间存在显著的负偏相关,而且它们与纬度的变化率也存在显著的负偏相关,高度,和夏季平均增强植被指数,虽然与年PM2.5呈正相关,但与大型水体的距离(p=0.000)。此外,使用广义回归神经网络方法可以推导出CDD的值和变化率。均方根误差分别为231.73°C*天和1.71°C*天*年-1。这些结论有助于随着气候变化进行降温节能和热环境优化。
    The cooling degree days (CDDs) can indicate the hot climatic impacts on energy consumption and thermal environment comfort effectively. Nevertheless, seldom studies focused on the spatiotemporal characteristics, influence factors, and simulation of global CDDs. This study analyzed the spatial-temporal characteristics of global CDDs from 1970 to 2018 and in the future, explored five determinants, and simulated CDDs and their interannual changing rates. The results showed that the global CDDs were generally higher at lower latitudes and altitudes. Many places experienced significant positive changes of CDDs (p < 0.05), and the rates became larger at lower latitudes and attitudes. In the future, most CDDs had the sustainability trends. Besides, significant negative partial correlations existed between not only CDDs but also their variation rates with latitude, altitude, and average enhanced vegetation index in the summer, while positive with the annual PM2.5, distance to large waterbodies (p = 0.000). Moreover, the values and variation rates of CDDs can be deduced using the generalized regression neural network method. The root-mean-square errors were 231.73 °C * days and 1.71 °C * days * year-1, respectively. These conclusions were helpful for the energy-saving for cooling with the climate change and optimization of thermal environment.
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  • 文章类型: Journal Article
    冠状病毒大流行的传播在世界范围内造成了巨大的破坏,人们已经开始反思公共场所的防疫策略。乘客人数众多的机场航站楼已成为2019年冠状病毒病(COVID-19)气溶胶传播的潜在高风险区域。在这项研究中,欧拉-拉格朗日方法和可实现的k-ε湍流模型用于数值模拟乘客在一条线上缓慢移动时的气流组织和气溶胶传输。在气溶胶传播期间,蒸发被认为是影响人类气溶胶传播开始时粒度分布的关键因素。此外,通过采用动态网格算法实现机场航站楼的乘客移动。根据航站楼排队时乘客和出风口的相对方向,我们研究了三个条件:迎风行走,背风行走,和侧风行走。研究结果表明,行走对液滴分布有重要影响。液滴分布表明,在排队运动期间站在患者后面的个体比站在他们前面的个体具有更高的感染风险。当乘客同时移动时,在患者后方0.5m处发现了明显的气溶胶积聚。与乘客的步行方向对齐的15s的气溶胶传输距离可以达到9.32m。此外,尽管大液滴的蒸发时间比小液滴的蒸发时间长,大液滴和小液滴在呼气后迅速蒸发。侧风影响使液滴在垂直于人体运动的方向上行进得更远,与不存在侧风影响相比,该距离增加了约1.26m。
    The dispersion of the coronavirus pandemic has caused immense damage worldwide, and people have begun to ruminate epidemic prevention strategies for public places. Airport terminals with a high number of occupied passengers have become potentially high-risk regions for aerosol transmission of coronavirus disease 2019 (COVID-19). In this study, the Eulerian-Lagrangian approach and realizable k-ε turbulence model were used to numerically simulate airflow organization and aerosol transmission when passengers are moving slowly in a line. During the aerosol transmission period, evaporation was considered a key factor influencing the particle size distribution at the beginning of aerosol transmission from humans. Moreover, passenger movement at the airport terminal was attained by employing dynamic mesh algorithms. Based on the relative direction of passengers and air vents when queuing in the terminal building, we studied three conditions: windward walking, leeward walking, and crosswind walking. The results of this study showed that the walking has an important influence on droplet distribution. Droplet distribution indicates that individuals standing behind patients during queuing movements have a higher risk of infection than those standing in front of them. A significant aerosol accumulation was discovered at 0.5 m behind the patient when passengers moved simultaneously. An aerosol transmission distance of 15 s aligned with the passenger\'s walking direction could reach up to 9.32 m. Furthermore, although the evaporation time of the large droplets was longer than that of the small droplets, both large and small droplets evaporated rapidly after exhalation. The crosswind influence caused the droplets to travel farther away in a direction perpendicular to human movement, which increased the distance by approximately 1.26 m compared to the absence of the crosswind influence.
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