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 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.

Energy consumption pattern and indoor thermal environment of residential building in rural China

With the continuous deepening of China’s rural construction and development,people’s living conditions are improved day by day,while accompanied by energy and environment crisis issues.This paper mainly analyzes the energy consumption pattern and the indoor environment of rural households in China and discusses the energy-saving optimization strategies for improving the thermal environment of buildings.Questionnaire surveys and field surveys were conducted in three villages in Guanghan,China.The measurement results show that the annual indoor temperature range of the region in the summer is 15-31℃and the relative humidity range is 34%-96%.The average indoor temperatures in summer and winter are 28℃and 16℃respectively.The indoor thermal environment of rural buildings is usually poor and cannot meet the requirements of Chinese standards.At the same time,the architectural design and energy consumption pattern of rural households are different from those in urban areas as countryside has unique characteristics.Finally,we put forward certain energy-saving improvement measures at the end of the article.

Method for determining climatic design conditions based on the indoor thermal environment risk level

Currently,climatic design conditions are usually selected according to the frequency of climatic parameters them-selves,which method cannot reflect the indoor thermal environment risk level of the building in design.In this regard,the research proposes to construct the correlation between climatic design conditions and indoor thermal environment risk level,and explore the effect of uncertainty in building thermal performance on this correlation from the perspective of probability,thus realizing the process of selecting the climatic design conditions based on the requirement for indoor thermal environment risk level.Taking Guangzhou in China as an example,the new process of determining climatic design conditions is realized.On this basis,the difference between the traditional method and the present research method is compared.In the Chinese norm method,the indoor thermal environ-ment risk level of the building is between 0 and 0.03%when the climatic design conditions are selected with 0.57%cumulative frequency of occurrence;in the research method,the indoor thermal environment risk level of the building is between 0.2%and 0.6%when the climatic design conditions are selected with 0.57%indoor thermal environment risk level and 100%confidence level.The results indicate that the research method can meet the designer’s expectation for indoor thermal environment risk level in design more directly and accurately.

Effect of natural resource on improving indoor thermal environment in Chongqing

This paper analyzes the potential of natural resources to improve the indoor thermal environment in Chongqing through the statistical analysis of natural resources including solar energy,wind,water,and earth,etc.The building form,systems,and principle of usage of natural resources are briefly analyzed through the building site decision,building form design,and computer simula-tion,which will be the real reference for the design of building energy efficiency.

A Study for the Influence of the Location of PCMs Assembly System on Improving Thermal Environment inside Disaster-Relief Temporary Houses

Currently,people pay more and more attention to the transitional resettlement of victims after various natural disasters.There is an urgent need for a large number of temporary houses to resettle the victims after natural disasters.Disaster-relief temporary houses(DTHs)played an important role in the post-disaster resettlement in the past,which can not only be produced on a large scale,but also can be quickly and conveniently erected,which were the main means to solve the problem of transitional resettlement.However,due to their temporary nature,there was no extra energy consuming system installed in the DTHs generally.Hence the indoor thermal environment inside the DTHs was severe in summer.In this study,combined with the field experimental tests of the DTHs in Wenchuan Earthquake and Lushan Earthquake and the experimental study of the full-size DTH,it found that the thermal environment inside the DTH was intolerably high in summer.It had negative impact on victims.In order to improve the thermal environment inside DTHs during post-disaster period which lacked of extra energy resources,this study used the method of combining phase change materials(PCMs)with walls of the DTH to explore its feasibility and effectiveness.The results showed that PCMs could effectively improve the thermal environment inside the DTH in summer.Furthermore,the difference of the composite positions between PCMs and the wall affected the improvement effect.The energy release rate of the PCMs assembly system(PAS)varied according to the positions of the PCMs.

Comparison of Illuminance in Different Environments: A Case Study on Subway Stations

With urbanization and the rapid development of social economy,China’s rail transit industry has developed rapidly in recent years.In order to alleviate the pressure of road network,subways provide convenience as they are fast and space-saving.Subway stations are major energy consumers of urban power grid due to their large traffic volume and long operation time.On the premise of ensuring operation safety,reducing the energy consumption of subway helps in energy conservation and emission reduction as proposed in the 13th Five-Year Plan.According to the statistics of the energy-saving evaluation report of rail transit engineering,the lighting system accounts for 20%-30%of the total power consumption of the subway station.Due to the single lighting control mode of the lighting system in the subway station,the actual station illumination cannot be reported and adjusted in time,resulting in the waste of lighting energy and high power consumption of the system.Through in-depth research on the intelligent lighting system of subway station,this paper improves the system control,and finally summarizes the optimization scheme of subway station lighting design which can effectively save the power consumption of lighting system.The main contents of this paper are as follows:The research results of this paper can provide effective measures for energy saving of electric lighting in subway stations and reduce electric energy consumption;on the other hand,as an integral part of building lighting energy-saving system,it also has certain guiding significance for the research of building lighting energy-saving.

暖通空调系统的环境影响价值工程

本文将暖通空调系统所营造的建筑室内舒适环境与暖通空调系统耗能引起的温室气体排放相结合,提出了一个新的评价概念——暖通空调系统的环境影响价值工程。本文在对此概念给予理论定义的同时,讨论了其量化计算方法。并在此基础上,以重庆市一酒店建筑为例,进行了实例计算分析。暖通空调系统的环境影响价值工程作为一个性能化评价方法,将暖通空调系统的价值、环境功能和环境成本作为一个整体同时来考虑,充分体现了建筑节能与室内环境改善的统一,旨在对暖通空调系统给予科学合理的评判。

四川红原牧民新居室内热环境测试研究

以四川省阿坝州红原县典型新建定居房为研究对象,在冬夏两季典型气候条件下,对太阳辐射强度、温度、湿度等室内热环境参数进行测试,并分析了各参数的变化特点。基于测试数据,总结出红原县民居建筑的优点和不足,提出改善策略。

室内热环境对生物体血液力学特性的影响

从与人的身心健康密切相关的血液力学特性出发,通过动物实验,研究室内热环境对生物体血液力学特性的影响。通过把实验样本12只豚鼠置于可调节温度、湿度和通风方式的通风装置中,喂养10天后抽取心脏血检测表征血液力学特性的一系列指标,对所得数据进行显著性分析。显著性分析的结果表明热环境对生物体血液力学特性有影响,对不同的指标影响的程度也不同。为进一步研究室内环境品质(IEQ)的状况,以及从血液力学特性的角度来评价室内热环境提供依据,对暖通空调系统的设计以及运行管理有指导作用。

原竹龙骨组合结构喷涂式环保墙体试验房冬季室内热环境测试

为验证原竹龙骨组合结构喷涂式环保墙体作为建筑围护结构时室内热环境的保温性能,对试验房的冬季室内外温湿度进行现场测试。结果表明,该新型墙体具有良好的热稳定性能,试验房在兼顾绿色环保的条件下可达到与黏土砖墙相同的保温效果,但二者保温效果均一般。建议结合目前墙体热工性能实验数据对试验房的围护结构构造层次进行优化。

Indoor Environment Control Effect Based on Multi-Impeller Air Conditioner

Air conditioner is the key air supply device to improve the indoor air heat transfer cycle and thermal environment. In this paper, according to the similarity theory, six kinds of the multi-impeller air conditioners(MIAC) with different numbers of axial-flow impeller are first proposed based on air conditioners with cross-flow fan(CFAC). The effects of different multi-impeller air supply modes on the indoor airflow field and temperature field are investigated by using the numerical simulation method. The validity of the computational model and method is verified by comparing the experimental measurements and numerical results. Compared with other air supply modes, the air supply distance is relatively far and the indoor environment is also improved obviously when the six-impeller air conditioner(SIAC) is used. The independent multiple impellers and outlets of SIAC make the mutual interference between the outlet airflow less, which effectively reduces the friction between the airflow and the degree of loss along the way and makes the cold and heat exchange of the whole indoor space more sufficient. The indoor thermal environment is also analyzed by using the PMV-PPD method and prototype experiment. Under the working condition of no wind, the indoor thermal comfort of human body with SIAC is better than that of CFAC. Especially in the horizontal plane of 0.6 m above the human foot, the indoor thermal environment improvement effect is the most obvious. Simultaneously, the temperature difference along the indoor height direction with the SIAC is only 1.7℃, which is 70% lower than that of the CFAC. The blowing angle between the left and right side of the SIAC is 106°, which is 31% higher than that of the CFAC. Therefore, the overall thermal comfort of the six-impeller mode is better, and the control effect of indoor environment is satisfactory.

Crawlspace heating system in detached house with insulated foundation

Two practical crawlspace heating systems introduced in detached houses have been chosen as a field study. One is the crawlspace warm air heating system and the other is the crawlspace hot water circulation system. Based on the field study result, by using the simulation sol, ware, THERB, the effectiveness of the crawlspace warm air heating system has been examined. The effect of the factors, such as the wind amount circulating between crawlspace and indoor space, foundation insulation condition, and heat amount into the crawlspace, on the indoor thermal environment has been analyzed. Based on these analyses, the measured crawlspace heating system can make the average temperature of the living room above 20℃. These two houses have excellent thermal environment. According to the simulating result, heat amount input into crawlspace, which can make comfortable indoor thermal environment, for every month in heating period has been roughly concluded, and they are 600 W in December and March and 800 W in February and January, respectively.

天津市住宅冬季室内环境现状调查及分析评价

以当前人们的居住环境质量与日益增长的生活水平之间产生的矛盾为背景，采用主观评价和客观评价相结合的方式，对天津市住宅冬季室内环境状况进行调查及分析评价．在天津市市内六区的200户住宅进行了问卷调查，并对其中入住时间不同且有代表性的20户多层住宅进行环境参数的实际测量．利用模糊综合评价对住宅室内环境进行了总体客观评价．通过此次调查发现居民对热湿环境、室内空气品质、声环境等的感觉是基本满意．但通过实测及客观评价发现装修不到1年便入住的居民室内甲醛、苯的含量较高，评判结果为室内空气质量为中级污染；而入住1～3年、3～5年的住宅也均属中级污染，不容乐观．

室内空气质量和照明色温对人体环境感知及健康的影响

通过改变室内环境条件,使用主观问卷填写和生理参数测量相结合的方法,研究3种温度水平下室内空气质量和照明色温对青年受试者环境感知和病态建筑综合症症状的综合作用影响。16名身体健康的青年受试者暴露于12种不同工况下,环境变量包括室内空气温度、室内空气质量和照明色温。结果显示,照明色温对受试者的热感觉投票和空气质量评价有明显影响。冷光使热感觉投票降低,空气质量评价提升。在22℃和28℃时,照明色温对感知空气质量投票有显著影响(p<0.05)。在3个温度水平下,室内空气质量和照明色温的交互作用均对脉率的变化影响显著(p<0.05)。仅在28℃时,发现照明色温对血氧饱和度产生显著影响(p<0.05)。受试者出现病态建筑综合症症状的比例与室内空气温度呈正相关。在18℃时,眼部不适症状的出现与室内空气质量和照明色温的交互作用显著相关(p<0.001)。

基于工作效率最大化的室内热环境控制方法研究

本文在关于室内热环境对办公人员工作效率影响的实验研究基础上,提出了一种基于工作效率最大化的室内热环境控制方法,即以室内人员工作效率、休息效率最大化为目标,以PMV值为控制参数进行室内热环境控制,同时兼顾舒适度要求.本文对所提方法的运行效果进行了分析计算,结果表明该方法不仅提高了室内人员的工作效率和休息效率,还有更高的室内热环境舒适度.

室内环境因素对人体热舒适度影响的试验

室内环境质量由热、声、光和空气品质等多方面因素共同决定。采用现场试验、问卷测试、数据分析等研究方法,对公共建筑室内环境影响因素进行了试验研究,分析了空气温度、相对湿度、风速等室内微环境参数对员工工作环境舒适度的影响,为建筑室内空调设计提供借鉴。

基于室内环境评价指标的空调系统控制方法综述

室内环境评价指标是进行空调系统控制的重要变量,合理的评价指标选择是实现室内环境高效控制和建筑节能的关键。文章首先对传统的空调控制方法及其采用的室内环境评价指标进行了分析。然后从基于热舒适和空气品质的控制需求出发,分别综述了空调系统控制方法及其相应室内环境评价指标的最新进展。最后对室内环境控制所面临的挑战进行讨论。