Thermal environment

热环境
  • 文章类型: Journal Article
    激烈的城市发展和高密度城市导致城市中心的热环境持续恶化,影响生活环境的质量。在这项研究中,长沙中部地区707.49公顷土地被划分为121个地块。综合选择了11个与小气候相关的形态学指标,采用K-means法进行聚类分析。然后,通过ENVI-met模拟研究区的热环境,探索了形态簇与热环境之间的关系。首先,发现了五种空间类型来表征该区域:高层和高容积率,低密度,低绿化;高容积率高密度的中层;高密度和小体积的中等容量;低密度和高绿化的低层;和低容积率,低密度,和高绿色。第二,建筑物迎风表面密度,天空开放,建筑密度,容积率和绿地率影响热环境。第三,集群3的平均气温(Ta)最高,其次是Cluster5,此外Clusters4、1和2的Ta相对较低。集群1中的空间活力指数和绿地率;面积加权建筑形状指数,集群2的平均建筑体积和天空开放度;集群3的绿地率;集群4的容积率和绿地率等指标;集群5的不透水表面率和绿地率等指标对Ta的影响较大。第四,简单地增加绿地面积并不能最大限度地提高绿地的降温效果。相反,构建均衡的绿化网络可以更好地调节热环境。第五,研究结果为城市中心区的设计和调控提供了科学依据。
    Intense urban development and high urban density cause the thermal environment in urban centers to deteriorate continuously, affecting the quality of the living environment. In this study, 707.49 hectares of land in the central area of Changsha were divided into 121 plots. 11 microclimate-related morphological indicators were comprehensively selected, and the K-means method was used for cluster analysis. Then, the relationship between morphological clusters and the thermal environment was explored by simulating the thermal environment of the study area with ENVI-met. First, five spatial types were found to characterize the area: high-level with high floor area ratio, low density, and low greenery; middle-level with high floor area ratio high density; medium-capacity with high density and small volume; low-level with low density and high greenery; and low floor area ratio, low density, and high greenery. Second, the building windward surface density, sky openness, building density, floor area ratio and green space rate affect the thermal environment. Third, Cluster3 had the highest average air temperature (Ta), followed by Cluster5, furthermore Clusters4, 1, and2 had relatively low Ta. The spatial vitality index and green space rate in Cluster1; the area-weighted building shape index, average building volume and sky openness in Cluster2; green space rate in Cluster3; indicators such as the floor area ratio and green space rate in Cluster4; indicators such as the impervious surface rate and green space rate in Cluster5 had greater influences on Ta. Fourthly, simply increasing the area of green space cannot maximize the cooling effect of green spaces. Instead, constructing an equalized greening network can better regulate the thermal environment. Fifthly, the results provide a scientific basis for the design and the regulation of urban centers.
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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: English Abstract
    随着城市规模的不断扩大,改变了该地区的土地覆盖类型,大量的自然景观被人造景观所取代,环境温度上升。研究城市空间格局与热环境的响应关系,为改善生态环境、优化城市空间布局提供一定的指导。基于合肥市2020年Landsat8系列遥感影像数据和ENVI、ARCGIS等分析平台,皮尔逊相关和剖面线被用来反映两者之间的相关性。然后,选取相关性最大的3个空间格局分量,构建多元回归函数,研究城市空间格局对城市热环境的影响及其作用机制。结果表明:①2013-2020年合肥市高温区随时间的提前而显著增加。对于不同的季节,城市热岛效应表现为夏季>秋季>春季>冬季。②在中心城区,建筑物占用,建筑物高度,不透明的占用,人口密度明显高于郊区,而部分植被覆盖度的郊区高于市区,主要表现为市区的点分布和水体的不规则分布。③城市高温区主要分布在城市各开发区,而城市地区的其他地方则以中高温和高温分区为主,郊区以中低温为主。④各要素空间格局与热环境之间的皮尔逊系数与建筑物占有率呈正相关(0.395),不透水表面占有率(0.333),人口密度(0.481),和建筑物高度(0.188),并与植被覆盖度(-0.577)和水占有率(-0.384)呈负相关。构造的多元回归函数的系数,包括建筑物占用,人口密度,和部分植被覆盖率,分别为8.372、0.295和-5.639,常数为38.555。研究结果可为优化城市空间布局、提高城市居住质量提供参考依据。
    With the continuous expansion of cities, the land cover type of the region is transformed, a large number of natural landscapes are replaced by man-made landscapes, and the environmental temperature rises. The study of the response relationship between urban spatial pattern and thermal environment provides some guidance for improving the ecological environment and optimizing the urban spatial layout. Based on the Landsat 8 series remote sensing image data of Hefei City in 2020 and analysis platforms such as ENVI and ARCGIS, Pearson correlation and profile lines were used to reflect the correlation between the two. Then, the three spatial pattern components with the greatest correlation were selected to construct multiple regression functions to investigate the influence of urban spatial pattern on urban thermal environment and its mechanism of action. The results showed that:① the high temperature area of Hefei City increased significantly with the advance of time during 2013-2020. For different seasons, the urban heat island effect showed that summer>autumn>spring>winter. ② In the central urban area, the building occupancy, building height, imperviousness occupancy, and population density were significantly higher than those in the suburbs, whereas fractional vegetation coverage presented a higher suburban than urban area and mainly showed a point distribution in the urban area and an irregular distribution of water bodies. ③ The urban high-temperature zone was mainly distributed in various development zones in urban areas, whereas other places in urban areas were dominated by medium-high temperature and above-temperature zoning, and suburban areas were dominated by medium-low temperature. ④ The Pearson coefficients between the spatial pattern of each element and the thermal environment were positively correlated with the building occupancy (0.395), impervious surface occupancy (0.333), population density (0.481), and building height (0.188) and negatively correlated with fractional vegetation coverage (-0.577) and water occupancy (-0.384). The coefficients of the constructed multiple regression functions, including building occupancy, population density, and fractional vegetation coverage, were 8.372, 0.295, and -5.639 respectively, with a constant of 38.555. The results of this study can provide a reference basis for optimizing urban spatial layouts and improving urban living quality.
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  • 文章类型: Journal Article
    口袋公园,具有小尺寸和灵活布局的绿色基础设施,适用于绿地有限的城市建成区的热环境改善。为了量化中国西部口袋公园与热环境之间的关系,选择了西安建筑街区的两个公园。通过现场测量,冷却效果可以从公园边界延伸100米,连接两个公园。此外,通过回归分析,街区内的道路和绿化对冷却扩散具有重要影响。基于ENVI-met仿真,树和草的比例,树和草的布局,并分析了公园不同绿化和铺装比例下的铺装布局。最后,提出了将白天生理等效温度(PET)和夜间空气温度(AT)相结合的方法来选择最佳布局:树木集中在中心,道路较多。结果可以为基于热环境改善的口袋公园设计提供见解。
    Pocket parks, the green infrastructures with small sizes and flexible layouts, are suitable for thermal environment improvement in the urban built-up block with limited green space. To quantify the relationship between pocket parks and the thermal environment in western China, two parks in the built-up block of Xi\'an were selected. By field measurement, the cooling effect could be extended 100 m from the park boundary, connecting two parks. Furthermore, the road and greening within the block demonstrate significant influence on the cooling diffusion by regression analysis. Based on ENVI-met simulation, the ratio of the tree and the grass, the layout of the tree and the grass, and the layout of the paving were analyzed at different proportions of greening and paving of the park. Finally, a combination of the daytime physiological equivalent temperature (PET) and nighttime air temperature (AT) was proposed to choose the optimum layouts: the trees concentrated in the center and the pavement with more roads. Results can provide insights for designing pocket parks based on the thermal environment improvement.
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  • 文章类型: Journal Article
    考虑到热环境方面不仅对职业健康和安全(OH&S)性能有重大影响,而且对工人的生产率和满意度也有重大影响。该案例研究的目的是评估一家汽车工业公司的33名工人的热舒适度,从不同工作场所收集有关热环境的数据开始,继续使用预测平均投票(PMV)和预测不满意百分比(PPD)指数的计算来分析和解释热舒适度,根据标准ISO7730:2005的规定,并通过应用个人问卷将结果与工人的主观感知进行比较。研究结果是为分析工作场所制定预防和保护措施的重要输入要素,并与解决其他特定风险的措施相关,还,可以作为在未来研究中扩展和应用于其他类似工作场所的模型。此外,用于本研究案例的数学模型和软件工具可用于对更大的工人群体和任何工业领域的进一步类似研究。
    Considering thermal environment aspects have a major impact not only on occupational health and safety (OH&S) performance but also on the productivity and satisfaction of the workers, the aim of the case study was to assess the thermal comfort of a group of 33 workers in an automotive industry company, starting with collecting data about the thermal environment from different workplaces, continuing with the analytical determination and interpretation of thermal comfort using the calculation of the Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) indices, according to provisions of the standard ISO 7730:2005, and comparing the results with the subjective perception of the workers revealed by applying individual questionnaires. The results of the study represent an important input element for establishing the preventive and protective measures for the analysed workplaces in correlation with the measures addressing other specific risks and, also, could serve as a model for extending and applying to other similar workplaces in future studies. Moreover, the mathematical model and the software instrument used for this study case could be used in further similar studies on larger groups of workers and in any industrial domain.
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  • 文章类型: Journal Article
    城市化地区绿地的流失引发了城市环境的潜在热风险。虽然现有文献研究了城市温度与健康风险之间的直接关系,对城市可持续性和健康风险的关键组成部分之间的因果关系知之甚少,通过涉及城市温度的途径。这项研究考察了城市化土地利用之间的多重联系,城市绿化,哈里斯县的城市温度和健康风险,德克萨斯州。来自500个城市项目(疾病控制和预防中心)的人口普查道级别的健康数据用于分析。结构方程模型分析表明,城市温度在城市化土地利用之间的关系中起着中介作用,城市绿化和健康风险。城市植被与健康风险的降低有关,而城市土地利用与健康风险增加有关。研究结果表明,为在附近地区提供丰富的城市绿化而量身定制的积极政策可以减轻城市土地利用对健康风险的影响。
    The loss of green spaces in urbanized areas has triggered a potential thermal risk in the urban environment. While the existing literature has investigated the direct relationship between urban temperatures and health risks, little is known about causal relationships among key components of urban sustainability and health risks, through a pathway involving urban temperature. This study examined the multiple connections between urbanized land use, urban greenery, urban temperatures and health risks in Harris County, Texas. The census tract-level health data from the 500 Cities Project (Centers for Disease Control and Prevention) is used for analysis. Structural equation model analyses showed that the urban temperature played a mediating role in associations between urbanized land use, urban greenery and health risk. Urban vegetation is associated with a decrease in health risks, while urban land use has associations with an increase in health risks. Findings suggest that proactive policies tailored to provide rich urban greenery in a neighborhood can alleviate urban land use effects on health risks.
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  • 文章类型: Journal Article
    最近对灯架的研究发现,通过将光伏(PV)模块应用于灯架反射器,可以最大程度地提高建筑物的能源效率。尽管光伏组件产生大量的热量并改变室内加热和冷却能量的消耗,到目前为止,进行的绩效评估还没有考虑到这些因素。这项研究验证了光伏组件灯架的有效性,并在考虑加热和冷却节能的同时确定了最佳规格。建立了一个全面的测试平台,以根据轻型货架变量评估性能。发现均匀性比率根据光架角度值而提高,并且随着PV模块安装面积的增加而降低。确定了光伏组件在灯架的设计中应考虑其采光和聚光效率根据其角度而变化。还发现安装在灯架上的光伏组件会改变室内的冷却和加热环境;随着光伏组件面积的增加,这种变化的程度也会增加。最后,降低建筑能耗的轻型货架规格,包括加热和冷却能源,没有发现适用于光伏组件,因为光架反射器上的光伏组件增加了建筑能耗。
    Recent studies on light shelves found that building energy efficiency could be maximized by applying photovoltaic (PV) modules to light shelf reflectors. Although PV modules generate a substantial amount of heat and change the consumption of indoor heating and cooling energy, performance evaluations carried out thus far have not considered these factors. This study validated the effectiveness of PV module light shelves and determined optimal specifications while considering heating and cooling energy savings. A full-scale testbed was built to evaluate performance according to light shelf variables. The uniformity ratio was found to improve according to the light shelf angle value and decreased as the PV module installation area increased. It was determined that PV modules should be considered in the design of light shelves as their daylighting and concentration efficiency change according to their angles. PV modules installed on light shelves were also found to change the indoor cooling and heating environment; the degree of such change increased as the area of the PV module increased. Lastly, light shelf specifications for reducing building energy, including heating and cooling energy, were not found to apply to PV modules since PV modules on light shelf reflectors increase building energy consumption.
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  • 文章类型: Case Reports
    IoT-based monitoring devices can transmit real-time and long-term thermal environment data, enabling innovative conversion for the evaluation and management of the indoor thermal environment. However, long-term indoor thermal measurements using IoT-based devices to investigate health effects have rarely been conducted. Using apartments in Seoul as a case study, we conducted long-term monitoring of thermal environmental using IoT-based real-time wireless sensors. We measured the temperature, relative humidity (RH), and CO2 in the kitchen, living room, and bedrooms of each household over one year. In addition, in one of the houses, velocity and globe temperatures were measured for multiple summer and autumn seasons. Results of our present study indicated that outdoor temperature is an important influencing factor of indoor thermal environment and indoor RH is a good indicator of residents\' lifestyle. Our findings highlighted the need for temperature management in summer, RH management in winter, and kitchen thermal environment management during summer and tropical nights. This study suggested that IoT devices are a potential approach for evaluating personal exposure to indoor thermal environmental risks. In addition, long-term monitoring and analysis is an efficient approach for analyzing complex indoor thermal environments and is a viable method for application in healthcare.
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  • 文章类型: Journal Article
    The aim of the study was to establish to what extent extreme thermal conditions have changed and how they affected mortality, and what conditions favor lower mortality rates or conversely, higher mortality rates. Heat/cold exposure was measured with the Universal Thermal Climate Index (UTCI). Daily mortality and meteorological data for 8 large Polish cities (Białystok, Gdańsk, Kraków, Lublin, Łódź, Poznań, Warszawa, and Wrocław) in the period 1975-2014 were analyzed. Generalized additive models were used to investigate the relationship between UTCI and mortality, and TBATS models were used for the evaluation of time series UTCI data. Most of the cities experienced a clear and statistically significant at p ≤ 0.05 decrease in cold stress days of 0.8-3.3 days/year and an increase in the frequency of thermal heat stress days of 0.3-0.6 days/year until 1992-1994. There was a clear difference as regards the dependence of mortality on UTCI between cities located in the \"cooler\" eastern part of Poland and the \"warmer\" central and western parts. \"Cool\" cities were characterized by a clear thermal optimum, approx. in the range of 5-30 °C UTCI, changing slightly depending on cause of death, age, or sex. For UTCI over 32 °C, in most of the cities except Gdańsk and Lublin, the relative risk of death (RR) rose by 10 to 20%; for UTCI over 38 °C, RR rose to 25-30% in central Poland. An increase in mortality on cold stress days was noted mainly in the \"cool\" cities: RR of total mortality increased even by 9-19% under extreme cold stress.
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  • 文章类型: Journal Article
    在这篇文章中,对夏季不同驾驶状态下的车厢热环境和人体热舒适性进行了实验研究。采用加权预测平均投票模型和加权等效温度模型进行计算,并与实验值进行比较。实验结果表明,舱内空气温度和相对湿度分布受空间位置和行驶状态的影响。客舱座椅的温度,受到太阳辐射和机组人员的影响,在加热阶段略高于空气温度,而冷却阶段的冷却速率远低于空气温度。预测平均投票模型和等效温度模型与随时间变化的怠速和驾驶工况下人体实际热舒适性基本一致。两种模型在怠速工况下的预测精度均高于行车工况下的预测精度,等效温度模型的总体预测精度高于预测均值投票模型。
    In this article, the thermal environment and the human thermal comfort of car cabin under different driving states in summer were studied experimentally. The weighted predictive mean vote model and the weighted equivalent temperature model were used for calculation and compared with the experimental values. The experimental results show that the air temperature and relative humidity distribution in cabin are affected by the space position and driving state. The temperature of the cabin seat, which is affected by solar radiation and crew, in the heating stage is slightly higher than the air temperature, while the cooling rate in the cooling stage is much lower than the air temperature. The predictive mean vote model and the equivalent temperature model are basically consistent with the actual thermal comfort of human body under the idle and driving conditions with the change of time. The prediction accuracy of the two models under the idle condition is higher than that under the driving condition, and the overall prediction accuracy of the equivalent temperature model is higher than that of the predictive mean vote model.
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