温度突变下人体热响应随时间的变化特性及评价

通过人工气候室模拟偏热环境下中性-热-中性温度突变,对20名受试者开展了不同突变温差和突变方向下的人体热响应实验。结果显示:突变温差越大,人体的平均皮肤温度增量越大,达到稳定所需时间越长;引入修正的Knothe时间函数,量化了突变环境下平均皮肤温度随突变温差、方向及暴露时间的调节特点;结合皮肤温度预测模型,建立了包含平均皮肤温度及其变化率的人体热感觉预测模型,简化了动态环境下人体热感觉预测模型应用。     

综合皮肤指标及其与热感觉关系的探讨

平均皮肤温度和皮肤湿度是表征人体对热环境生理调节功能的重要参数,是人体热感觉的外在表现,但是二者在单独用于评价人体热感觉时均有一定的局限性。提出了综合皮肤指标的概念,研究了综合皮肤指标与热感觉的关系,并给出了不同活动水平下接近舒适状态时平均皮肤温度与皮肤湿度的波动范围。     

空气压力对人体皮肤温度及热感觉影响的实验研究

以问卷调查的方式,对低压环境下人体皮肤温度随空气压力的变化及其对人体热感觉的影响进行了研究.结果表明,在其他环境参数一定的条件下,人体平均皮肤温度和人体热感觉均随压力降低而降低,且二者变化趋势基本一致.经过统计学分析可知,二者在低压环境下具有较好的相关性,因此在低压环境下皮肤温度可作为表征人体热感觉的一个重要指标.     

厦门高校教室冬季热环境测试及热舒适预测

为考察冬季非空调环境下人体热感觉,对厦门某高校教室的热舒适度进行了现场测试.在测量室内外热舒适参数的同时,通过问卷调查得到了人体热反应样本.分析样本得出厦门高校教室冬季非空调工况下人体热中性温度和热期望温度分别为19.3和19.4℃.综合考虑温度、相对湿度、平均辐射温度、风速及服装热阻对坐姿轻度活动状态人体的热舒适影响,使用MATLAB软件进行非线性回归,得到非空调工况下热舒适预测方程.该预测方程与实测得到的人体热舒适投票两者结果有较高相关度,同时较大程度上反映了冬季非空调环境下人体热感觉的变异.     

室外硬化体育场地热环境测试及分析

介绍了对西安建筑科技大学三种不同室外硬化运动场地的热环境测试,得出了空气干球温度和地表温度在一天中的变化规律,分析了不同运动场地材料对热环境的影响,结合人体热舒适理论,分析了人体在相应热环境条件下运动时的热感觉状况,对合理安排运动时间提出了建议。     

严寒地区人体热适应性研究(1):住宅热环境与热适应现场研究

通过对哈尔滨市集中供暖住宅进行供暖开始前、供暖初期、供暖中期、供暖末期、供暖结束后5个阶段的连续调查,得到各阶段室外气候特征、建筑室内热环境的特征参数及人体热反应特征和热中性温度。发现住宅中人体的热中性温度随室内热环境和室外气候的变化而变化,得到了一系列热适应证据。     

严寒地区人体热适应性研究(3):散热器供暖环境下热反应实验研究

为了考察冬季供暖期间室外气温变化时不同室内温度对人体生理反应和心理热反应的影响,在散热器供暖的微气候室中,对受试者的皮肤温度、心率和血压等生理参数进行了测试,并对其热感觉和热舒适等主观热反应进行了问卷调查,研究供暖初期、中期和末期人体生理反应和心理热反应的变化规律。结果表明:随着冬季室外气温的下降,人们会更容易从心理上接受偏冷的环境,对室内温度期望不高,在相同的室内环境中感觉越来越热;相同的室外气温下,随着室内温度的降低,人体的皮肤温度会降低,心率下降;当室外气温下降而室内温度相同时,人体手臂皮肤温度显著升高,心率加快。说明随着冬季供暖期室外气温的逐渐降低,人们对偏冷环境的热适应性增强,这为严寒地区人体心理适应和生理习服提供了证据。     

温湿度突变对人体热反应的影响

在中性-热和中性-冷工况下,对30名湿热地区受试者开展了温湿度突变对人体热反应影响的实验研究,从生理、心理反应的变化及其相互关系等方面分析了实验现象。研究发现心理超前和热感超越现象,发现突变条件下的热感觉与皮肤温度呈二次多项式关系,与皮肤温度变化率呈线性关系,得到了突变环境下人体热反应的预测模型。     

夏季高温条件下室外热感觉特性研究

本文针对夏季城市中的高温天气情况,通过现场的环境测试和问卷调查,得到了人体高温条件下室外热感觉的基本规律,并在此基础上,采用BIN分析法得到了人体室外的热感觉、湿感觉、风感觉对室外热环境参数的量化模型,并对模型进行了可接受区间值的求解,得到了在室外高温环境条件下人体可接受参数分布范围,相关参数的提出为室外人体热感觉的相关研究提供了参考。     

寒冷地区过渡季节下室外环境热舒适研究

室外热舒适性一直是城市环境研究的热点问题。针对室外微气候环境利用主客观现场调查研究,明确影响人体室外热感觉的影响因素。为确定户外环境的设计策略、营造具有吸引力的良好公共空间提供重要研究基础。文中研究通过对寒冷地区过渡季节的确定,利用热舒适主观问卷调查和同步微气候数据现场调查,获取了1050份有效主观问卷及相对应气象参数。通过主客观拟合分析获取了基于通用热气候指数UTCI(Universal Thermal Climate Index)的热中性温度为20.7℃。同时对室外三种不同环境分别探究其热舒适性变化规律,在阳光直射下的人体热感觉较为敏感,而在树荫和建筑阴影下较不敏感。建筑阴影下热舒适更容易受到影响。明确了空气温度与平均辐射温度是影响过渡季节下人体室外热感觉的主要因素。研究结果为寒冷地区城市的室外公共空间的场地规划和环境设计提供了参考依据。     

Thermal model of human body fitted with individual characteristics of body temperature regulation

To develop a thermal model that can predict the thermal responses of the human body under given environmental conditions, it is necessary for the model to be fitted with the individual characteristics of human body temperature regulation. As the basis for this, in this paper, it is shown that the coefficients that represent the thermoregulatory responses in the two-node model (thermal model of human body) can be identified for individuals. Six coefficients related to the regulation of sweating and skin blood flow in the two-node model are tuned for the individuals involved in the experiments—the core and skin temperatures calculated by the model are fitted with the measured results for the entire thermal transient processes, including exposures to heat and cold.     

Thermal sensation and comfort models for non-uniform and transient environments: Part I: Local sensation of individual body parts

A three-part series presents the development of models for predicting the local thermal sensation (Part I) and local comfort (Part II) of different parts of the human body, and also the whole-body sensation and comfort responses (Part III). The models predict these subjective responses to the environment from thermophysiological measurements or predictions (skin and core temperatures). The models apply to a range of environments: uniform and non-uniform, transient and stable. They are based on diverse results from the literature and from body part-specific human subject tests in a climate chamber. They were validated against a test of passengers in automobiles. This series is intended to present the rationale, structure, and coefficients for these models so that others can test and develop them further as additional empirical data becomes available. The experimental methods and some measured results from the climate chamber tests have been published previously.Part I describes thermal sensation models representing 19 individual local body parts. The models' structure and coefficients were derived by regression of skin and core temperatures against thermal sensation votes obtained in the chamber experiments. The sensation for each local body part is predicted by a logistic function with four inputs: local skin temperature, mean-skin temperature presenting the whole-body thermal state, and the time derivatives of skin and core temperatures representing the response to transients. These inputs can be obtained from thermophysiological computer programs that treat the body as multiple segments.     

Evaluation of enhanced conduction-corrected modified effective temperature ETFe as the outdoor thermal environment evaluation index

The purpose of this paper is made to clarify that the relationship between the human physiological and psychological responses and the enhanced conduction-corrected modified effective temperature ETFe as the outdoor thermal environment evaluation index upon the human body. Environmental factors and human physiological and psychological responses were measured. It was made clear that the variables by which summer outdoor environmental factors influence the thermal sensation vote are heat conduction, humidity and short-wave solar radiation. The variables that affect the thermal comfort vote are air velocity, heat conduction and humidity. ETFe, into which the environmental factors that are the variables for human response are incorporated, showed good correspondence with the thermal sensation vote. Similarly, ETFe has a good correspondence with thermal comfort vote. The usage of ETFe as a thermal environment evaluation index for summer outdoor spaces is valid. The threshold for the human body with regards to thermal environment stimuli in an outdoor space is higher than the thermal environment stimuli in a summer indoor space.     

Validity of the two-node model for predicting steady-state skin temperature

The validity of the two-node model for predicting the skin temperature in the thermal steady state is studied by comparing the calculated and experimental results for various thermal conditions. For the experimental results of steady-state skin temperature, in addition to the authors’ original experimental data, literature data for mean skin temperature are collected, incorporating 56 conditions and 233 subjects in total. The results show that the two-node model (the 1986 edition) that is widely used for calculating SET* predicts effectively the steady-state skin temperature in the low-activity conditions. Additionally, the changes that were made to the two-node model by Gagge et al. and ASHRAE are summarized. It is shown theoretically and by experimental validations that, of these changes, the addition of the shivering model represents the most significant improvement in terms of predicting the skin temperature in the steady state.     

稳态环境耐寒与非耐寒人体热反应实验研究

为了探究不同体质人体对冷环境的生理和心理热反应,开展了耐寒与非耐寒受试者热反应稳态实验研究。分析了不同体质受试者的皮肤温度、热流、心率、心率变异性、热感觉和热舒适投票随环境温度的变化。结果发现:无论是在生理还是心理上,非耐寒与耐寒受试者存在一定的差异性。非耐寒受试者皮肤温度、心率高于耐寒受试者,而热流低于耐寒受试者;在相同的低温环境下,非耐寒受试者比耐寒受试者感觉更冷,更不舒适。由此推出,在稳态环境中,皮肤温度、热流、热感觉和热舒适投票等可以作为区分耐寒和非耐寒体质的指标,但是心率有待进一步验证。此外,心率变异性随环境温度变化规律不明显,个体差异对其影响大于环境温度的影响。     

Study on outdoor thermal environment of apartment block in Shenzhen,China with coupled simulation of convection,radiation and conduction

Shenzhen City in China is developing rapidly now. Correspondingly, deterioration of the outdoor environment in phenomena such as heat island has become a serious problem. This aggravation of the thermal environment has spoiled urban sustainability. In this paper, (1) in order to predict the outdoors thermal environment in summer in an apartment block, unsteady coupled simulation of convection, radiation, and conduction is developed and used. The velocity, temperature, humidity, and MRT in the urban area are obtained from the simulation. In order to estimate the pedestrian level of thermal comfort in the outdoor thermal environment, the spatial distributions of New Standard Effective Temperature (SET¹) is calculated using the above results. (2) The actual situation of the outdoors thermal environment in summer in an apartment block in Shenzhen City is investigated by field measurements. (3) The effect of schemes to improve the outdoor thermal environment in this apartment block, such as changing building shapes, planting arrangements, etc. are examined using this prediction method.     

Thermal design tool for outdoor spaces based on heat balance simulation using a 3D-CAD system

This paper focuses on the development of a thermal design tool for use in planning outdoor spaces by combining a heat balance simulation for urban surfaces, including buildings, the ground and greenery, with a 3D-CAD system that can be run on a personal computer. The newly developed tool is constructed by improving the previous simulation model, which uses the geographic information system (GIS) for the input data. The simulation algorithm is constructed so as to predict the surface temperature distribution of urban blocks while taking into account the actual design of the outdoor space using the 3D-CAD system. A method of multi-tracing simulation to calculate the sky view factor and radiative heat transfer is established. The optimal mesh size is examined for the tool so as to provide detailed spatial geometry within a suitable calculation time. The simulation model is integrated with an all-purpose 3D-CAD software, and the pre-processing method are constructed for practical use. The results obtained by applying this simulation tool to an area of detached houses reveals that the tool is able to evaluate the effects of building shape, materials, and tree shade on the surface temperature distribution, as well as the MRT and HIP, which are evaluation indices of the outdoor thermal environment.     

Analysis of the microclimatic and human comfort conditions in an urban park in hot and arid regions

Urban parks have complex surface structure that produces an environment with specific microclimatic qualities. These qualities affect the balance of energy of the human body and are applicable to an individual’s thermal perception. They have impacts on using outdoor spaces especially in hot and arid regions. This study investigates users’ thermal comfort in an urban park in Cairo, Egypt. The investigation was carried out during the hot and cold months using subjective surveys and field measurements. The campaign consisted of a subjective survey using questions on the perception of the thermal environmental applying seven-point ASHRAE 55 thermal sensation votes (TSV) in nine different zones in the urban park. At each zone, the thermal environment parameters – air temperature, solar radiation, air relative humidity and wind speed were measured. Through these data, the values of the Physiologically Equivalent Temperature (PET) were calculated in each zone using the RayMan model. The current people clothing and metabolic rate were recorded. The results of the field measurements were compared with judgements about the thermal environment. Results demonstrate that differences in the PET index among these zones due to different sky view factors (SVF) and wind speed. Results revealed an alteration in human comfort sensation between different landscape zones. This paper suggests that the thermal requirements of visitors and qualities of the local climate should be carefully considered when designing landscapes for the future urban parks in the hot and arid regions.     

Application of human thermal load into unsteady condition for improvement of outdoor thermal comfort

Human thermal comfort is studied as a countermeasure to the thermal stress in outdoor urban space. Outdoors, people experience the strong impact of solar radiation in states that are unsteady and non-uniform. The feeling of comfort is a mixed sensation that can be easier to improve overall, as compared with a global large-scale effort, and can lead to improved ways of saving energy and reducing costs. Moreover, this can be directly beneficial to human experience and fulfill natural human desires. Since a thermal comfort index is a useful tool for understanding the present state and evaluating the impact of countermeasures, we examine the effects of the human thermal load, which is a thermal comfort index based on the energy balance of the human body. In a steady state, and even in an unsteady state with its variations in weather and human factors, thermal comfort values can generally be obtained by using the overall human thermal load. The reason for this is that the human thermal load takes physiological factors in account as well as weather parameters. This leads to the idea that thermal sensations follow from the human thermal load, which can then well describe a given human environment. As a result, human sensations as expressed by the human thermal load pave the way to the creation of comfortable urban spaces that require minimum expense and energy as an example of simple heat transport model focusing on urban outer structure.