桂林市某高校教学楼冬季室内热环境和热舒适性调查研究

以桂林市某高校教学楼第3层的4间教室为研究对象，对冬季室内热环境和学生的热舒适性感觉进行为期两天的直接测量和问卷调查，并对结果进行分析。结果表明：桂林高校教室冬季普遍温度过低且相对湿度较大，室内引入的新风量少、闷感强烈导致热环境较差；大部分学生对环境具有一定的适应能力，通过采取一些适应性行为调节自身的热舒适程度；桂林高校教室非空调环境下，冬季中性温度为19.9℃，期望温度为20.7℃。     

秦岭山区民居冬季室内热环境测试

为考察秦岭山地民居冬季室内热舒适状况,选取当地典型二层生土和砖砌民居作为研究对象,对其冬季室内温度、相对湿度、室内照度和壁面温度进行现场测试并记录室外温湿度与太阳辐射强度.通过对测试数据分析,给出了不同外围护材料下民居室内热环境的定量评价,在此基础上提出改进其室内热环境的建议.     

突变热环境中桌面风扇作用下的热舒适研究

为了研究温度突变工况下使用风扇对人体热舒适的影响,在人工环境实验室内,营造了不同的温度突变环境(34℃-26℃-34℃、34℃-28℃-34℃、34℃-30℃-34℃)对20名青年受试者开展了人体热反应的实验研究。实验对比分析不同工况下受试者心理和生理反应的变化。实验结果表明,温度突降时,会出现“冷感超越”现象,且温差越大,超越现象越明显,热感觉稳定时间更长。使用桌面风扇可以使热感觉更快地达到稳定。皮肤温度也随温度突变发生显著变化。同时得到受试者在三种不同温度工况下的偏好风速,发现使用风扇能显著改善热湿环境中受试者的热舒适。     

基于等效温度的太阳辐射影响下冬季室内人体热舒适研究

该文在青岛某办公楼进行现场实测,研究冬季太阳辐射对坐姿人体皮肤温度和热感觉的影响。结果表明,受到照射时,左大腿皮肤温度上升3.3℃,左上臂皮肤温度上升2℃。根据实测数据,计算人体显热散热量,得到人体各部位与整体的等效温度,给出了太阳辐射影响下的等效温度热舒适区,对于高源强太阳辐射下的室内热环境标准及设计具有重要指导意义。     

低温热水地板辐射供暖间歇运行研究

建立了低温热水地板辐射供暖系统间歇运行时室内热环境数学模型，利用模型计算了不同运行方式、内围护结构和内热源作用下室内热环境变化规律。发现此类供暖系统采用适当间歇运行即可满足室内热环境要求，运行时间主要受室外温度和内热源变化规律影响。当系统按冬季室外供暖计算温度设计时，在冬季室外平均条件下，系统夜间运行半天左右即可基本保证全天室内热环境要求。     

基于载客量的地铁车厢冬季热舒适研究

以郑州地铁为例,对车厢热环境与乘客数量进行现场实测,对空载、半载、满载这3种工况车内温度进行对比分析,得到地铁车厢的空调设定应考虑载客量的情况分早晚高峰时段和日间平峰时段进行设定。模拟高峰满载和平峰半载车厢不同送风温度、送风速度的热环境状况,最后根据PMV指标对其进行热舒适评价,提出地铁车厢冬季平峰期与高峰期的空调设计参数,以期在满足乘客舒适性的同时降低空调能耗,为车厢的温度设定、地铁热舒适的改善提供参考。     

青岛地铁地下站厅层工作区冬季热环境研究

我国北方城市冬季地铁站内厅层工作区热环境特性对工作人员热舒适感非常重要。以青岛城市地铁有代表性的两个地下站的站厅层工作区热环境为研究对象,实验跟踪测试了站台层屏蔽门上部溢流活塞风扩散至站厅层的风量及气流温度变化规律;继而对厅层进出口自然流通的新风进行了风量和温度测试。实验研究发现,站厅层工作区的风速和气温受溢流活塞风和新风的耦合作用,呈现的周期性频率近似于溢流活塞风,而温度接近于新风,则站厅层热环境明显偏离常规热舒适性。面向站厅工作人员热环境及热舒适性进行研究,获取了青岛地铁地下站厅层工作区冬季热环境的特性。     

新型平板热管式PV/T热泵系统的集热模块优化研究

建立了新型平板热管式PV/T热泵系统的数学模型,通过实验测量得到系统在各工况下运行时的实验数据,并验证了模型的准确性和可靠性。基于验证后的数学模型,对系统的热性能、电性能和热泵系统的性能进行模拟研究。结果表明,在冬季工况下,系统的日平均热功率、电功率和COP分别为274.5 W、93.5 W和2.7。由于冬季室外环境温度较低,在冬季运行时,集热系统会通过光伏板表面向周围环境散失大量的热,导致系统的集热量不能满足热泵侧的热需求,直观表现为蒸发侧集热水箱水温在全天呈现下降的趋势。因此通过增加集热器对系统的集热模块进行优化,优化后系统的日平均热功率提升至654.2 W,COP提升至6.9。     

某城市商业综合体公共空间热环境数值模拟

用数值模拟方法,对北京某城市商业综合体内部公共空间空调工况热环境进行了研究,分析了各层不同送风比例下,综合体内部公共空间纵截面温度分布情况和人员活动区域内的温度分布情况。通过比较,确定了满足综合体内部公共空间各层热舒适要求的空调送风方案。数值模拟结果表明,对于城市商业综合体内部公共空间采用各层均匀送风,顶层与公共空间相连的走廊区域温度在夏季不能满足热舒适要求,适当减少内部公共空间下层的送回风量,增加至顶层,在冬夏工况下均可有效改善内部公共空间热环境,增加舒适度,有效解决顶层走廊温度偏高及温度不均等问题。     

基于太阳能新风系统室内热环境分析研究

太阳能新风技术的应用,不仅可以降低建筑能耗,而且能够改善建筑环境的舒适性,它的研究与开发对于能源的可持续利用具有重要的价值.通过建立以太阳能为热源的太阳能新风房间,利用温度、热流巡检仪以及便携式热舒适仪等装置对太阳能新风房间与普通房间的温度、热流等参数变化进行了对比实验.分析冬季工况下太阳能新风房间热特性情况,同时利用...     

Design of energy efficient and thermally comfortable air-conditioned university classrooms in the tropics

This study aims to design energy efficient and thermally comfortable air-conditioning system in university classrooms. The research has been conducted in two steps. The first step was a survey of students’ thermal comfort under air-conditioning classrooms, which collecting 175 questionnaires from 92 students. The second step was the calculation of cooling energy consumption using the EnergyPlus software. With the air temperature ranged from 23.0 to 27.0°C about 53% of respondents felt uncomfortable (cold or cool). The neutral temperature of students was found to be 27.0°C, which is higher than the classrooms’ temperature. The energy simulation results show that the most significant factors affecting energy use is the temperature setting. Therefore, there is a possibility to reduce the cooling energy while improving the thermal comfort of students. To this end, it is recommended to raise the air temperature setting from 25.0°C to a minimum of 26.0°C.     

Optimal control strategy for a multi-zone air conditioning system using a genetic algorithm

This paper examines optimal control strategies of variable air volume air conditioning system. The control strategies included a base control strategy of fixed temperature set point and two advanced strategies for insuring comfort and indoor air quality (IAQ). The first advanced control adjusts the fresh air supply rate and the supply air temperature to maintain the temperature set point in each zone while assuring indoor air quality. The second strategy controls the fresh air rate and the supply air temperature to maintain an acceptable thermal comfort and IAQ in each zone. The optimization problem for each control strategy is formulated based on the cost of energy consumption and constrained by system and thermal space transient models. The optimization problem is solved using genetic algorithm. The optimization scheme/model is applied to a case study for a building floor in Beirut weather. The thermal space and system component models were validated for the base strategy using Visual DOE 4.0 software [Architectural Energy Cooperation, San Francisco, USA; 2005 〈www.archenergy.com〉]. Energy savings up to 30.4% were achieved during the summer season of four months with the optimized advanced strategies when compared with the conventional base strategy while comfort and IAQ were satisfied.     

Occupants’ adaptive responses and perception of thermal environment in naturally conditioned university classrooms

A year-long field study of the thermal environment in university classrooms was conducted from March 2005 to May 2006 in Chongqing, China. This paper presents the occupants’ thermal sensation votes and discusses the occupants’ adaptive response and perception of the thermal environment in a naturally conditioned space. Comparisons between the Actual Mean Vote (AMV) and Predicted Mean Vote (PMV) have been made as well as between the Actual Percentage of Dissatisfied (APD) and Predicted Percentage of Dissatisfied (PPD). The adaptive thermal comfort zone for the naturally conditioned space for Chongqing, which has hot summer and cold winter climatic characteristics, has been proposed based on the field study results. The Chongqing adaptive comfort range is broader than that of the ASHRAE Standard 55-2004 in general, but in the extreme cold and hot months, it is narrower. The thermal conditions in classrooms in Chongqing in summer and winter are severe. Behavioural adaptation such as changing clothing, adjusting indoor air velocity, taking hot/cold drinks, etc., as well as psychological adaptation, has played a role in adapting to the thermal environment.     

基于性别的严寒地区高校教学楼自然通风热舒适性研究

严寒地区夏季采用自然通风作为被动式降温手段,改善空气品质的同时减少能耗,其热舒适性会受到多因素影响。对严寒地区夏季自然通风条件下两种建筑布局的高校教学楼热环境进行实测,对影响热舒适的三种因素,温度、湿度以及受试者体重指数(bady mass index,BMI)进行调查研究,基于在室人员不同性别,进行差异性、相关性和显著性对比分析。结果表明:内廊式教学楼较中庭式教学楼有更好的热舒适性;操作温度与热舒适性密切相关,中性温度为27.96℃,其中男性为27.51℃,女性为28.26℃;相对湿度与操作温度负相关,且对热舒适性有较大影响;BMI与热舒适性呈现较低的相关性,其并不能明显影响热舒适性,但相同BMI下,男性热感觉略高于女性;利用Griffiths评价模型能准确预测严寒地区夏季舒适温度。     

A new thermal comfort approach comparing adaptive and PMV models

In buildings with heating, ventilation, and air-conditioning (HVAC), the Predicted Mean Vote index (PMV) was successful at predicting comfort conditions, whereas in naturally ventilated buildings, only adaptive models provide accurate predictions. On the other hand, permeable coverings can be considered as a passive control method of indoor conditions and, consequently, have implications in the perception of indoor air quality, local thermal comfort, and energy savings. These energy savings were measured in terms of the set point temperature established in accordance with adaptive methods. Problems appear when the adaptive model suggests the same neutral temperature for ambiences with the same indoor temperature but different relative humidities. In this paper, a new design of the PMV model is described to compare the neutral temperature to real indoor conditions. Results showed that this new PMV model tends to overestimate thermal neutralities but with a lower value than Fanger’s PMV index. On the other hand, this new PMV model considers indoor relative humidity, showing a clear differentiation of indoor ambiences in terms of it, unlike adaptive models. Finally, spaces with permeable coverings present indoor conditions closer to thermal neutrality, with corresponding energy savings.     

Comparative studies of the occupants’ behaviour in a university building during winter and summer time

The paper focuses on the assessment of indoor comfort and energy consumption of a university building in Cyprus, during winter and summer of 2012 and 2013. The aim was to make a comparative study of the occupants’ behaviour and its effects on the building's energy consumption, along with the indoor thermal and visual comfort between the two seasons. American Society of Heating, Refrigerating and Air conditioning Standards are used through a questionnaire campaign and the thermal comfort of occupants is analysed with the indicators of predicted mean vote and predicted percentage dissatisfied. The answers are analysed using SPSS software. The air temperature, the relative humidity and the lighting levels of the building are monitored using temperature, humidity and lux meter tools. The monthly energy consumption cost is also calculated. The results are analysed and comparative studies of the occupants’ behaviour conclude to various patterns of effects on the thermal and visual comfort of the building, as well as on its energy consumption.     

Thermal comfort in Japanese schools

Comfort standards (ASHRAE 55, ISO 7730) specify exact physical criteria for producing acceptable thermal environments, which include temperature, air movement, and humidity limits that are often difficult to comply with, particularly in the subtropical climate of Japan. Changing expectations of comfort are important in evaluating comfort since schools in Japan are not typically air-conditioned. With the rapid growth of school buildings in the US and all over the world, provisions for comfort are critical to student performance and occupant well-being. Are these temperate-climate, air-conditioning based standards applicable in these locations? This paper builds upon previous thermal comfort work that has focused primarily on office environments. For this project we adapt traditional methods of data collection and inquiry for use in the school environment. During the late summer 2000, we conducted surveys in naturally ventilated and air-conditioned schools, polling responses from 74 students, while simultaneously measuring indoor climate variables. Air-conditioned classrooms had conditions within the comfort zone, causing occupants to report ‘slightly cool’ thermal sensations. The naturally ventilated classrooms were 3 °C warmer than the air-conditioned classrooms and occupants voted that conditions were also within the central three categories (surrounding neutral) of the ASHRAE thermal sensation scale—therefore equated with comfort. These ‘neutral’ sensations, however, do not correlate to people’s preferred thermal state. Comfort responses are discussed in terms of comparisons to ASHRAE Standard 55-92 Thermal Conditions for Human Occupancy.     

Effect of neutral temperature on energy saving of centralized air-conditioning systems in subtropical Hong Kong

Higher room temperature can still let the occupants have a neutral thermal sensation if higher air speed is provided. With a suitable scheme of neutral temperature and comfort air speed, reduction of energy consumption of the central chiller plant may surpass the additional energy requirement of the air side equipment, then both energy saving and thermal comfort can be achieved for the entire air-conditioning system. To evaluate this, the energy consumptions of a centralized air-conditioning system using the common air side alternatives were studied for the subtropical Hong Kong. The alternatives are variable air volume (VAV) system, constant air volume (CAV) system and fan coil (FC) system. Each of them was associated to a central chiller plant to serve a high-rise office building. The studying range of the room air temperature was from 23 °C to 30 °C. It is found that the VAV and FC systems can provide both thermal comfort and energy saving for higher room temperature, but CAV system is not feasible when the room air temperature is above 27 °C. If the indoor air speed threshold is considered, the neutral temperature can be brought up to 26.5 °C, and the energy saving potentials of VAV and FC systems would be 12.9% and 9.3% respectively.     

Thermal-comfort analysis and simulation for various low-energy cooling-technologies applied to an office building in a subtropical climate

Simulation of buildings’ thermal-performances is necessary to predict comfort of the occupants in buildings and to identify alternate cooling control-systems for achieving better indoor thermal environments. An analysis and prediction of thermal-comfort using DesignBuilder, based on the state-of-the-art building performance simulation software EnergyPlus, is carried out in an air-conditioned multi-storeyed building in the city of Rockhampton in Central Queensland, Australia. Rockhampton is located in a hot humid-region; therefore, indoor thermal-comfort is strongly affected by the outdoor climate. This study evaluates the actual thermal conditions of the Information Technology Division (ITD) building at Central Queensland University during winter and summer seasons and identifies the thermal comfort level of the occupants using low-energy cooling technologies namely, chilled ceiling (CC), economiser usages and pre-cooling. The Fanger comfort-model, Pierce two-node model and KSU two-node model were used to predict thermal performance of the building. A sophisticated building-analysis tool was integrated with the thermal comfort models for determining appropriate cooling-technologies for the occupants to be thermally comfortable while achieving sufficient energy savings. This study compares the predicted mean-vote (PMV) index on a seven-point thermal-sensation scale, calculated using the effective temperature and relative humidity for those cooling techniques. Simulated results show that systems using a chilled ceiling offer the best thermal comfort for the occupants during summer and winter in subtropical climates. The validity of the simulation results was checked with measured values of temperature and humidity for typical days in both summer and winter. The predicted results show a reasonable agreement with the measured data.     

基于代换合成法的高校教室综合舒适度研究

教室内的温度、相对湿度和空气流速对学生的健康和学习起着至关重要的作用，在2019年的夏季采用主观问卷调查对上海某高校教室内的操作温度、相对湿度与空气流速舒适感进行评价，并提出了综合舒适评价指标。建立了单个物理参数的无量纲函数，并利用向量相似度法计算出操作温度、相对湿度与空气流速对综合舒适评价指标的影响权重分别为0.462,0.291,0.247，通过代换合成法建立了基于操作温度、相对湿度和空气流速的人体综合舒适评价模型。利用控制变量法将三种评价指标两两组合，验证各评价指标对综合舒适评价指标的影响程度，得出操作温度偏离其所在舒适区时，引起的综合舒适度评价值变化量越最大，既而成为影响综合舒适评价指标的主导因素。结合了向量相似度法和代换合成法的综合舒适度评价模型，完全基于数据驱动，摆脱了传统热舒适模型的框架，更能体现出受试者的实际舒适感。这可为制定教室环境综合舒适度定义及相关标准的修订提供参考，同时可为教室热环境的热环境设计参数、评价与设计提供合理依据，减少能源浪费。