Thermal Performance Analysis of Plaster Reinforced with Raffia Vinifera Particles for Use as Insulating Materials in Building

The present study focuses on the formulation of new composite consisting of plaster and raffia vinifera particle (RVP) with the purpose to reducing energy consumption. The aim of this study is to test this new compound as an insulating eco-material in building in a tropical climate. The composites samples were developed by mixing plaster with raffia vinifera particles (RVP) using three different sizes (1.6 mm, 2.5 mm and 4 mm). The effects of four different RVP incorporations rates (i.e., 0wt%, 5wt%;10wt%;15wt%) on physical, thermal, mechanicals properties of the composites were investigated. In addition, the use of the raffia vinifera particles and plaster based composite material as building envelopes thermal insulation material is studied by the habitable cell thermal behavior instrumentation. The results indicate that the incorporation of raffia vinifera particle leads to improve the new composite physical, mechanical and thermal properties. And the parametric analysis reveals that the sampling rate and the size of raffia vinifera particles are the most decisive factor to impact these properties, and to decreases in the thermal conductivity which leads to an improvement to the thermal resistance and energy savings. The best improvement of plaster composite was obtained at the raffia vinifera particles size between 2.5 and 4.0 mm loading of 5wt% (C95P5R) with a good ratio of thermo-physical-mechanical properties. Additionally, the habitable cell experimental thermal behavior, with the new raffia vinifera particles and plaster-based composite as thermal insulating material for building walls, gives an average damping of 4°C and 5.8°C in the insulated house interior environment respectively for cold and hot cases compared to the outside environment and the uninsulated house interior environment. The current study highlights that this mixture gives the new composite thermal insulation properties applicable in the eco-construction of habitats in tropical environments.

Analysis and numerical simulation of indoor thermal environments in some university classrooms

In order to study the indoor thermal environments in university classrooms in Tianjin,a field study and a questionnaire survey for a main teaching building are carried out.First,the thermal sensations of participants in the typical classrooms are studied by 180 questionnaires.Then,based on the measured data,the temperature changes in the classrooms during a year are simulated by the DeST software.The results show that the indoor thermal environments in the northern classrooms on the first floor are better than those in other classrooms.And the measurement results accord with the simulation results.These results can be used as a reference for the study of the indoor thermal environments in other seasons.

Impact of cold indoor thermal environmental conditions on human thermal response

To explore the thermal responses under the non-thermal equilibrium cold environmental conditions,a laboratory study was conducted in climate chamber.The local skin temperatures and thermal sensation of 20 subjects were recorded at 10 min intervals for 90 min under air temperatures of 7.4,9.1,11 and 15 °C.The results show that both local skin temperatures and mean skin temperature decrease not only with the drop of ambient air temperature but also with the exposure time.Local thermal sensation and overall the thermal sensation have the similar temperature-varying and time-varying characteristics.Predicted mean vote(PMV) model cannot correctly predict the thermal sensation under non-thermal equilibrium cold environment.The correlation between local thermal sensation and local skin temperatures shows that thermal sensation is closely related to skin temperature.Skin temperature is an effective indicator of thermal sensation.A linear relationship model between overall thermal sensation and mean skin temperature,considering both ambient temperature and exposure time,was established in the non-thermal equilibrium cold environment,which makes the evaluation of thermal sensation more objective.

Indoor Human Detection Based on Thermal Array Sensor Data and Adaptive Background Estimation

Low Resolution Thermal Array Sensors are widely used in several applications in indoor environments. In particular, one of these cheap, small and unobtrusive sensors provides a low-resolution thermal image of the environment and, unlike cameras;it is capable to detect human heat emission even in dark rooms. The obtained thermal data can be used to monitor older seniors while they are performing daily activities at home, to detect critical situations such as falls. Most of the studies in activity recognition using Thermal Array Sensors require human detection techniques to recognize humans passing in the sensor field of view. This paper aims to improve the accuracy of the algorithms used so far by considering the temperature environment variation. This method leverages an adaptive background estimation and a noise removal technique based on Kalman Filter. In order to properly validate the system, a novel installation of a single sensor has been implemented in a smart environment: the obtained results show an improvement in human detection accuracy with respect to the state of the art, especially in case of disturbed environments.

Field study of thermal comfort and indoor air quality in gymnasium

To analyze the thermal comfort and indoor air quality (IAQ) in a medium-sized mechanically ventilated gymnasium in Beijing,a field study was carried out. PHOENICS,one of the CFD software,was chosen to simulate the distribution of the indicators of indoor air in the gymnasium to check the air-conditioning parameters reasonable or not. And there was a questionnaire for audiences and staff about the acceptance and satisfaction of the thermal comfort,simultaneously,some environmental parameters were monitored. Then an experiment was carried out in gymnasium with the plate sedimentation to the biological aerosol in the air. Finally,the thermal comfort and IAQ in the gymnasium were assessed based on the results of above questionnaire survey and measurements. The results show that most parameters of the environmental are within the standard limits of thermal comfort and IAQ in the monitored period,and the biological contaminants initially come from human beings. The main species in the gymnasium are streptobacillus,coccus,cladosporium,penicillium and neurospora.

Impact of indoor thermal comfort on physiological parameters of human body

With the living standards gradually improved,the buildings with safe,comfortable,healthy indoor thermal environment would be the ideal pursuit. But to create the preferable indoor thermal environment,it is necessary to research physiological influence of indoor thermal environment on human body. So a typical region of hot-humid climate in Chongqing,China,was considered as the object to study physiological indexes of human body. And the indoor thermal environment parameters and physiological indexes of human body were the main measurements. 20 volunteer students were organized to take part in the experiments in the laboratory during this summer. And two methods,physical measuring and questionnaire investigation,were used in the experiments. The results show that the increase in indoor air temperature reduces the uncomfortable feeling of air draft. Indoor air temperature has visible effects on MCS (motor nerve conduction speed),SCS (sensory nerve conduction speed),HR (heart rate),the ECG (electrocardiogram)-QT segment and SSEP (short somatosensory evoked potential)-latent period of N9. Therefore,a safe,comfortable and healthful indoor environment can be created by considering these factors.

Indoor Thermal Environment of Korean Rural Housing Yanbian Region of China in Winter

For the rural housing in Yanbian region in winter,the indoor thermal environment is bad but the energy consumption is high.And in order to solve the problem,the life particularities of the local residents,such as the inhabitation custom and the different living ways,were analyzed.The comfortable temperature felt by the local residents was surveyed and summarized according to different age's stage.The subjective comfortable temperature was calculated by using the thermal comfort formula set up by D.A.Mcintyre.The result shows that the comfortable temperature between the survey and the calculation is different.After analyzing the survey and the result calculations,the range of local indoor comfortable temperature was given,which provides a reference basis for calculating the thermal comfort and energy efficiency as well as designing green rural houses.

Optimization Method for Indoor Thermal Comfort Based on Interactive Numerical Calculation

In order to implement the optimal design of the indoor thermal comfort based on the numerical modeling method, the numerical calculation platform is combined seamlessly with the data-processing platform, and an interactive numerical calculation platform which includes the functions of numerical simulation and optimization is established. The artificial neural network （ANN） and the greedy strategy are introduced into the hill-climbing pattern heuristic search process, and the optimizing search direction can be predicted by using small samples; when searching along the direction using the greedy strategy, the optimal values can be quickly approached. Therefore, excessive external calling of the numerical modeling process can be avoided, and the optimization time is decreased obviously. The experimental results indicate that the satisfied output parameters of air conditioning can be quickly given out based on the interactive numerical calculation platform and the improved search method, and the optimization for indoor thermal comfort can be completed.

Indoor thermal environment of wooden-plank wall dwellings in summer in Chongqing

There are a large number of wooden-plank wall dwellings, a kind of traditional house with regional characteristics, existing in Chongqing area. We chose a typical house in Chongqing as the subject and measured it during summer to research the situation of the indoor thermal comfort of wooden-plank wall dwellings. Based on the particularity of local residents' living habit and the characteristics of the local buildings, we analyzed the data of the field measurement and evaluated the thermal environment with APMV. The results show that the indoor thermal comfort of wooden-plank wall dwellings in summer is improved mainly by natural ventilation.

Indoor Air Quality and Thermal Comfort Evaluation in Latvian Daycare Centers with Carbon Dioxide, Temperature and Humidity as Indicators

Latvian children under the age of 7 can spend up to 60 hours per week in daycare centers and therefore it is very important to establish a healthy and comfortable daycare environment that children will find pleasant and stimulating to stay in. This study investigates indoor air quality and thermal comfort within six daycare centers （old, renovated and new-built） in moderate climate zone of Latvia. Measurements of carbon dioxide, air temperature and relative humidity were carried out, and data regarding daycare center characteristics and maintenance activities was collected via combination of field visits, record analysis and interviews. It was found that carbon dioxide concentrations exceeded 1000 ppm in 75% of daycare centers studied, with the highest （1356 ppm） measured in a renovated facility with the natural ventilation system. Thus installation of more efficient ventilation system （mechanical） is recommended to provide acceptable indoor air quality, since opening of windows itself cannot provide the optimal conditions indoors. In all facilities the temperature was kept above 20℃ and the average relative humidity was 40±35%, creating comfortable thermal environment for children.

海上稠油油田多元热流体吞吐增产机理研究与实践

多元热流体为蒸汽、氮气、二氧化碳的高温高压混合气体,具有降低稠油黏度、提高地层压力、改善油藏剖面、提高稠油油藏开发效果等作用。多元热流体吞吐技术在海上稠油高效开发中应用广泛,随吞吐轮次增加,对多元热流体吞吐机理缺乏认知,开采效果降低。为有效提升稠油油田的开采效果,采用油藏模拟分析和多元热流体吞吐及驱替室内试验方法,探究了不同多元热流体组分对增产的贡献,进一步明晰多元热流体吞吐增产机理,为多元热流体热采方案优化设计和吞吐后开发调整提供理论指导和有效措施。试验结果表明:海上油田通过多元热流体热采示范应用,油田日产油由热采前218m^(3)·d^(-1)升至最高641m^(3)·d^(-1),增幅195%,热采效果明显。

民居建筑室内空间热环境多点能耗精准预测

在民居建筑室内热环境多点能耗预测时,若不能有效确定热环境下室内当前状态下舒适程度,会直接影响能耗预测精度。因此,提出考虑舒适度的民居建筑室内空间热环境多点能耗预测方法。根据室内状态建立民居建筑内热环境模型,采用主元分析法获取能耗评价指标,构建热环境下室内能耗指标评价体系,并利用指标建立评价模型,从而确定室内当前热环境能耗;将确定指标作为模型输入向量,利用RBF神经网络构建室内能耗多点预测模型;通过建立的模型实现对民居建筑室内空间多点能耗的精准预测。实验结果表明,所提方法开展室内能耗多点预测时,预测精度高、效果好。

气候变化下窑居建筑屋顶适宜性改造研究

调研发现陕北地区自2010年以来降水量开始呈现明显增加的趋势,而传统窑洞屋顶缺少良好的防水设计,易导致窑洞在经受暴雨时漏水甚至坍塌。村民采取在原屋顶上加建彩钢板的改造方式防雨,然而这种窑洞屋顶构造的自更新不仅未能充分解决屋顶防水问题,还在一定程度上破坏了窑洞村落的传统风貌。以陕北地区传统民居的典型代表窑洞为研究对象,通过调研测试与软件模拟分析窑洞屋顶加盖彩钢板构造对室内热环境的影响,发现加盖彩钢板能够提升屋顶的耐久度和防雨性能,但是不能改善室内热环境,并且不能充分融入到传统的乡村环境中。在此基础上提出了新型窑洞屋顶构造,以期进一步改善屋顶防水性能并延续传统民居建筑风貌,为后期窑居建筑更新改造提供参考。

高校历史建筑夏季室内热舒适研究——以宋卿体育馆为例

该文研究武汉大学早期历史建筑宋卿体育馆夏季室内热环境现状及热舒适评价,通过对体育馆室内热环境现场实测和问卷调查相结合的方法,对建筑室内相关物理参数及使用者主观评价进行收集。对室内热环境实际热感觉投票值TSV与预测热舒适指标PMV进行对比分析,评测该历史建筑夏季室内热舒适性后,发现宋卿体育馆在夏季自然通风状态下室内热环境较差,主要是因为建筑大面积西向开窗设计很容易受到太阳辐射的影响,室内风速过低,使用者运动强度高,从而导致实际热感觉投票值偏高。因此对该历史建筑提出了相应的优化策略,如增设外窗遮阳、机械通风以及必要的空调系统。

鄂东南传统民居室内热环境评价及围护结构优化设计研究——以赤壁市安丰村但耔臾宅为例

文章以湖北省赤壁市安丰村但耔臾宅为研究对象,对民居现场温湿度、风速、围护结构热工性能进行实测,通过软件仿真模拟及预计适应性平均热感觉指标(APMV)对其室内热环境进行评价。实测与模拟分析表明:民居夏季闷热(室内平均温度为33.41℃,峰值温度达37.20℃,平均风速为0.073m/s),冬季湿冷(室内平均温度为6.90℃,相对湿度为68.8%);屋顶和窗户材料单一,构造做法简易,热工性能较差;全年热环境时间占比分别为Ⅰ级22.0%、Ⅱ级41.8%和Ⅲ级36.2%,整体热环境质量较低。因此,提出屋顶增设2mm厚沥青卷材作防水层,40mm厚聚苯乙烯泡沫(XPS)板作保温层;窗户改用空气层厚度9mm的普通双层中空玻璃窗;北墙调整窗户尺寸为1000mm×1200 mm,东墙增设安装遮阳装置的800mm×1000mm小尺寸窗户等优化策略,并模拟验证其优化效果。为鄂东南地区传统民居的室内热环境改善提供了实用的参考依据。

黄土高原三类窑洞民居及砖混农宅夏季室内热环境对比研究

为进一步了解窑洞民居夏季室内热环境状况,选取独立式、靠崖式、下沉式窑洞进行调研测试并与当地砖混农宅进行对比分析,研究其夏季室内外空气温度、相对湿度、壁面温度等影响热环境参数。结果表明窑洞民居室内热环境优于砖混农宅,窑洞室内温度波动小,相对湿度大,热环境能基本满足人体热舒适要求。通过剖析窑洞民居的空间布局与围护结构热工性能在创造室内热环境中的作用,发现窑洞相对封闭的空间及厚重围护结构较大的热惰性可有效抵御室外温度波动,使得内壁面温度稳定,是窑洞“夏凉”的主要原因;由于下沉式窑洞窗墙面积比小,室内空气温度更低;靠崖式和下沉式窑洞围护结构土层更厚,蓄水能力强,室内相对湿度更大。研究可为黄土高原窑居建筑生态经验传承及新民居建设提供理论支撑。

北京高校宿舍供暖前后室内热环境变化及其对学生睡眠热舒适的影响

为探究供暖前后宿舍内热环境差异及其对学生睡眠热舒适的影响,在北京某高校实地调研了8个不同朝向宿舍的室内热环境,并采用问卷调研和睡眠手环监测结合的方式获得了16名高校学生的睡眠质量情况。结果表明:供暖前宿舍内夜间平均温度为(18.6±1.1)℃,供暖初期为(20.2±1.4)℃,满足标准要求;实测期间宿舍夜间相对湿度高于30%,满足舒适度要求;床褥系统总热阻约为3.5~4.9 clo,其中,睡衣热阻大约为0.03~0.40 clo;供暖初期受试者睡前热中性温度为18.0℃,可接受温度范围为16.0~19.8℃,早晨醒后倾向更暖的环境;睡前热感觉与睡眠质量存在显著关联,当受试者睡前热感觉偏暖时,睡眠满意度及深睡眠比例较高,有利于睡眠。

基于光伏窗技术的室内热环境营造特性研究

半透明光伏窗由于其主动节能的优势,近年来引起了广泛关注。由于半透明光伏窗表面覆盖太阳能电池,可能引起室内热环境过热,影响人体热感觉。然而,目前有关半透明光伏窗建筑室内热环境营造特性的研究仍存在不足。针对上述问题,通过实测半透明光伏窗与白玻房间室内空气温度、辐照度等参数,比较了空调运行工况下两房间内受试者热感觉投票结果。结果显示,在窗户表面高温长波辐射及透过辐照度的短波辐射作用下,半透明光伏窗室内热环境受到较大热辐射的影响。半透明光伏窗房间热感觉投票为中性的结果远高于白玻房间,能够满足人体热舒适和建筑节能的双重要求。

西安地区开放式办公建筑夏季人体热舒适调查研究

以西安地区6栋典型开放式办公建筑为研究对象,通过热环境参数测试和主观问卷调查相结合的方式进行了现场调研,分析了实际办公建筑中人员的热舒适需求,并将调研结果与现有标准及其他气候区现场研究进行了对比。结果显示,西安地区夏季办公建筑受访者的中性温度为25.4℃,偏好温度比中性温度低0.2℃,80%可接受温度上限为28.2℃。

高原铁路站房地板辐射系统的分区供暖效果

为了解决高原铁路站房部分区域在强太阳辐射的影响下出现过热、地板辐射供暖系统能耗浪费的问题,以某高原铁路车站为研究对象,根据站房内太阳照射情况对地板辐射系统提出了分区供暖方案;利用建筑能耗模拟软件Energyplus对该铁路站房进行模拟分析,对比了地板辐射系统分区前后站房内的热环境和系统供暖量.结果表明:地板辐射系统采用统一的设计及运行控制方案供暖时,站房内太阳直射影响区的平均操作温度在日间最高可达27℃,与非直射影响区之间的温差超过5℃;在地板辐射系统分区供暖时,直射影响区的平均操作温度最高为26℃,室内温度分布更为均匀,局部过热现象得到缓解;在保证站房热舒适性的前提下,地板辐射系统的分区供暖方案能够使直射影响区整个供暖季的供暖量降低38.2%.