对热舒适、空气感觉质量及能耗的模拟研究

室内空调设计温度和新风量对热舒适，室内空气质量及能耗量有重要影响，然而对它们之间相互关系进行研究的文献却较少。通过计算机模拟空调系统在7种室内设计温度和7种新风量条件下的运行情况，得到不同的设计条件组合对热舒适、人体感觉空气质量及建筑能耗量的影响。基于这项分析，提出了此办公建筑合理的室内设计温度和新风量取值。     

The effect of heat-pipe air-handling coil on energy consumption in central air-conditioning system

A study was carried out to investigate the effect of heat-pipe air-handling coil on energy consumption in a central air-conditioning system with return air. Taking an office building as an example, the study shows that compared with conventional central air-conditioning system with return air, the heat-pipe air-conditioning system can save cooling and reheating energy. In the usual range of 22–26 °C indoor design temperature and 50% relative humidity, the RES (rate of energy saving) in this office building investigated is 23.5–25.7% for cooling load and 38.1–40.9% for total energy consumption. The RES of the heat-pipe air-conditioning system increases with the increase of indoor design temperature and the decrease of indoor relative humidity. The influence of indoor relative humidity on RES is much greater than the influence of the indoor design temperature. The study indicates that a central air-conditioning system can significantly reduce its energy consumption and improve both the indoor thermal comfort and air quality when a heat-pipe air-handling coil is employed in the air-conditioning process.     

Hygrothermal behavior modeling of the hygroscopic envelopes of buildings: A dynamic co-simulation approach

High levels of humidity in buildings lead to building pathologies. Moisture also has an impact on the indoor air quality and the hygrothermal comfort of the building’s occupants. To better assess these pathologies, it is necessary to take into account the heat and moisture transfer between the building envelope and its indoor ambience. In this work, a new methodology was developed to predict the overall behavior of buildings, which combines two simulation tools: COMSOL Multiphysics© and TRNSYS. The first software is used for the modeling of heat, air and moisture transfer in multilayer porous walls (HAM model: Heat, Air and Moisture transfer), and the second is used to simulate the hygrothermal behavior of the building (BES model: Building Energy Simulation). The combined software applications dynamically solve the mass and energy conservation equations of the two physical models. The HAM-BES coupling efficiency was verified. In this paper, the use of a coupled (HAM-BES) co-simulation for the prediction of the hygrothermal behavior of building envelopes is discussed. Furthermore, the effect of the 2D HAM modeling on relative humidity variations within the building ambience is shown. The results confirm the importance of the HAM modeling in the envelope on the hygrothermal behavior and energy demand of buildings.     

温湿度独立控制系统在办公楼中的应用及运行效果

本文阐述了北京市建筑设计研究院F座办公楼空调系统组成及运行方式,通过实测数据对其室内空气质量进行评估,并通过建筑能耗模拟软件Dest对该楼采用的空调系统和普通空调系统的能耗进行比较。结果表明该楼所采用的空调系统具有较好的节能效果和较高的热舒适性。     

Simulation of a VAV air conditioning system in an existing building for the cooling mode

In this study, simulation of a variable air volume (VAV) air conditioning system in an existing office building is presented for the cooling mode. A building simulation package was used for the simulation [DOE, EnergyPlus Engineering Document, Version 1.3., U.S. Department of Energy, Washington, DC, 2005]. The design information of the existing office building, the actual number of the internal load sources such as occupants, lighting, office equipments and the manufacturer's data for the existing rooftop unit (RTU) and the VAV boxes were used in the building simulation package. The simulation results; RTU power consumption, indoor zone temperature and relative humidity, were validated with the data obtained from the on-site measurements performed in the existing office building under the same outdoor conditions. It was found that 71.1% of all simulated power consumption data falls within ±15% range from the experimental data. The reason for the existence of some data out of band is due to the possible errors associated with the difference in the solar data used for the location 40 km away from the experimental location. It was found that 90.6-94.7% of the indoor temperature experimental data fall within ±1.5 °C range from the simulated data, and 88.3-91.3% of the indoor relative humidity data fall within ±18% range from the simulated data.     

Entwicklung und Validierung einer hygrothermischen Raumklima‐Simulationssoftware WUFI®‐Plus

Development and validation of the hygrothermal indoor climate simulation software WUFI®‐Plus. Well‐balanced conditions of thermal, moisture and air quality are very important in buildings because an imbalance of these factors could have significant influences on the construction and the inhabitants. The focus of this paper is the influence of different materials on the fluctuation of relative humidity specifically humidity peaks. In lieu of complicated and expensive laboratory testing several different software tools have been developed to estimate the indoor environmental conditions of buildings. The Fraunhofer‐Institute for Building Physics (IBP) developed a hygrothermal simulation tool. With this software the temperature and moisture conditions of the walls, ceiling and floor constructions, of the indoor air and the energy consumption for the building can be calculated. In the context of the IEA‐Annex 41 project “Moist‐Eng“ a common exercise has been carried out for the validation of such software tools. For the common exercise at the free field investigation area in Holzkirchen (Germany) two identical rooms were used to measure the moisture buffering capacity of several interior finish systems. To address the questions of buffering capacity the IBP developed a hygrothermal simulation tool, WUFI®‐Plus [1]. Using the measurement data from the common exercise calculations were carried out with several software tools for the validation of it. In this paper the results of the laboratory tests and simulation results are described.     

Optimization of a liquid desiccant based dedicated outdoor air-chilled ceiling system serving multi-zone spaces

A liquid desiccant based dedicated outdoor air-chilled ceiling (DOAS-CC) system is proposed to serve a multi-zone space. The outdoor airflow rate and the supply air humidity ratio are two crucial variables in such a system, which significantly influence indoor thermal comfort, indoor air quality and energy consumption. Two strategies are presented to optimize these two variables in the study. They are the demand-controlled ventilation (DCV) strategy and the supply air humidity ratio set-point reset strategy. To evaluate the performances of these two strategies, a basic control strategy, i.e., the strategy adopting constant ventilation flow rate and constant supply air humidity ratio, is selected as the benchmark. Performances of the two strategies in terms of indoor air temperature, relative humidity and CO₂ concentration as well as energy consumption are analyzed using simulation tests. The results show that the supply air humidity ratio set-point reset strategy is effective for the indoor air humidity control. It can save about 19.4% of total energy consumption during the whole year. The DCV-based ventilation strategy can further reduce about 10.0% of energy consumption.     

A development of easy-to-use tool for fault detection and diagnosis in building air-conditioning systems

There are many reports about faulty status in building air-conditioning systems recently. It becomes difficult to keep indoor air temperature appropriately as faults occur, and the faults cause waste of building energy consumption. The model-based fault detection and diagnosis (FDD) methods have been researched for specific parts of air-conditioning system such as chillers, coils, variable air volume units (VAV units), etc. It needs, however, much time and labor to monitor and check every single part because we cannot predict where and when the faults occur. The purpose of this study is to examine indoor air temperature changes and energy consumption increase when faults occur and to develop an easy-to-use FDD tool that helps to find out the faulty place through the whole building air-conditioning system. And then, we treat the reliability of the proposed FDD tool and effectiveness to control of indoor environment deterioration and energy consumption increase by the tool is evaluated based on building air-conditioning system simulation in this paper.     

Increasing the indoor humidity levels in buildings with ventilation systems: Simulation aided design in case of passive houses

In modern societies, people spend about 90 percent of their time inside buildings. The challenge of building physics is to ensure that buildings are planned, constructed and built to provide a comfortable and healthy working and living environment. As construction style has changed during recent years, the planning phase has to be much more precise and the need of simulation programs that respond to every little change arises. An increasing problem in Austria is the indoor humidity. In the field of renovated buildings with airtight new building envelopes, mould growth due to high indoor relative humidity (RH) is a persistent problem. On the other hand, in recently realized Austrian passive houses with an air treatment system, the low humidity level of the indoor air is a problem with which scientists have been struggling for some time. It has been observed in numerous measurements and it is also easily computationally detectable that in winter period the indoor relative humidity level often drops below 30% RH. Low and high relative humidity levels have negative effects on the comfort feeling and health of the occupants of the dwelling and should therefore be avoided. However, it is expensive to increase or decrease the humidity in houses mechanically. Therefore, the existing room moisture should be used sensibly in buildings with a ventilation system. In buildings with a high indoor humidity it is necessary to adjust the ventilation depended on moisture production. This paper focuses on low indoor humidity and presents some different methods by which the indoor relative humidity can be regulated. The effects of adapting parameters such as ventilation rate and buffering material in the dwelling were clearly reflected in the measured temperature and relative humidity. “BuildOpt_VIE” software developed at the Vienna University of Technology was used for the dynamic building simulation in this study.     

长江中下游地区梅雨季节的室内热湿环境

经过调研得到长江中下游地区(以南京为例)梅雨季节住宅建筑室内热湿状况,并分析3种不同建筑能耗计算模型(整体建筑热湿空气流动耦合模型HAM,传递函数模型CTF,有效湿渗透深度模型EMPD)的准确性。数值模型基于Matlab-Simulink编写,使用调研数据进行验证,进而使用梅雨季节典型气象参数模拟分析。调研结果显示在2013年梅雨季节,多数时间内建筑室内温度高于28℃,相对湿度高于70%。数值模拟结果显示3种能耗模型对室内温度模拟的差异较小,而对室内湿度的模拟存在较大差异,特别是CTF模型误差最大。结果显示在长江中下游地区梅雨季节,当房间换气次数小于2ACH时,围护结构对于室内环境湿缓冲的作用明显,选择合适的吸放湿材料可有效降低建筑能耗30%以上。     

Optimization of air-conditioning system operating strategies for hot and humid climates

This paper describes research into the optimal operation of building heating, ventilation, and air-conditioning (HVAC) systems focusing on both temperature and humidity control. While most previous work on HVAC optimization has been limited to evaluation of conventional temperature-based control systems, this study emphasizes the humidity control issue in meeting both sensible and latent building loads. The analysis is based on a combination of a realistic simulation of a direct expansion (DX) air-conditioning system and a direct-search numerical optimization technique. The simulation models have been validated through comparisons with field data. Optimization was performed on five different system control variables to minimize system power consumption while meeting building loads and maintaining comfort. Indoor temperature and humidity are also optimized within standard comfort constraints. Building loads were modeled using an extended bin method that allows consideration of the interactions between loads and indoor conditions. Results indicate that minimum energy use typically occurs at low airflow rates, with indoor humidity levels below the upper comfort limit. Results also show that coil air bypass and evaporator circuiting control are typically not necessary unless operation would otherwise result in overcooling. The optimization results also translate to relatively simple strategies for system control. Significant savings are demonstrated over conventional control strategies used in packaged DX equipment.     

卷烟厂绿色工房项目中的建筑环境模拟

简要介绍了在几个卷烟厂绿色工房实践中涉及到的建筑环境模拟,包括建筑能耗模拟、室外新风利用的模拟、非空调状态下室内温湿度的模拟、室外风环境模拟、自然通风模拟、日照模拟和室内采光模拟.     

长沙市住宅室内热湿环境的测试与分析研究

介绍了2002年8月份和2003年1月份在长沙进行的住宅建筑室内环境的问卷调查和现场测试的对象、方法及所用仪器。问卷调查结果揭示了住宅的概况、居民的生活方式、能源的消耗以及他们对室内环境的主观评价等。测试所得的温湿度曲线反映了长沙夏季高温高湿，冬季低温高湿的特征。分析了楼层高度、建筑平面设计、住户的生活习惯、住户的消费观念等因素对室内热环境的影响，并对室内热环境进行了评价。     

Setpoint control for air heating in a church to minimize moisture related mechanical stress in wooden interior parts

The paper presents the setpoint control for air heating in a church to minimize moisture related mechanical stress in wooden interior parts, with the focus on the preservation of a monumental organ. The setpoint operation of the heating, ventilation, and air conditioning (HVAC) system is evaluated by simulation using MatLab, COMSOL and Simulink models. The main model components are presented and combined in a single integrated Simulink model: (1) a HAMBase Simulink building model for simulating the indoor temperature and relative humidity, (2) a COMSOL partial differential equation model for simulating detailed dynamic moisture transport and related mechanical stresses in the monumental wood (organ) and (3) a Simulink controller model. The main advantage of the integrated model is that it directly simulates the impact of HVAC control setpoint strategies on the indoor climate and the related mechanical stresses in wooden objects, like a monumental organ. As control strategy the limited indoor air temperature changing rate is discussed. Recommendations from international literature suggest that a limitation of the relative humidity changing rate of 2 to 5RH%/h will preserve the interior of churches. This study shows that a limitation of indoor air relative humidity changing rate of 2RH%/h can reduce mechanical stresses by a factor of 2.5, compared to maximum capacity heating.     

不同制冷量空调器在住宅中应用的实测对比研究

通过实验测试对比了不同制冷量的定速房间空调器用于住宅卧室中时的室内温湿环境状况和空调器的耗电量情况。实验结果表明,当空调器容量过大时,空调器的除湿能力下降,室内相对湿度偏高,空调器耗电量大,实验日条件下,使用1.5 HP空调器时的室内相对湿度比使用1 HP空调器的室内相对湿度高5%,而1 HP空调器耗电量比1.5 HP空调器减少12.7%。     

湿热湿冷地区夏季房屋热稳定性测试分析

湿热湿冷地区夏季室外空气相对湿度大,太阳辐射强度偏低,现有建筑的房屋热稳定性状况缺少基础性研究数据。本文选取该地区典型的居住建筑,对其夏季太阳辐射、室内外空气相对湿度、室内外空气温度和壁面温度等进行了现场测试。分析表明在该气候特征下,所测试居住建筑在夏季典型周期内的室内空气平均温度波幅为4.3℃,幅度较大且受朝向、围护结构构造做法等因素影响明显。     

The effect of structures on indoor humidity--possibility to improve comfort and perceived air quality

The research presented in this paper shows that moisture transfer between indoor air and hygroscopic building structures can generally improve indoor humidity conditions. This is important because the literature shows that indoor humidity has a significant effect on occupant comfort, perceived air quality (PAQ), occupant health, building durability, material emissions, and energy consumption. Therefore, it appears possible to improve the quality of life of occupants when appropriately applying hygroscopic wood-based materials. The paper concentrates on the numerical investigation of a bedroom in a wooden building located in four European countries (Finland, Belgium, Germany, and Italy). The results show that moisture transfer between indoor air and the hygroscopic structure significantly reduces the peak indoor humidity. Based on correlations from the literature, which quantify the effect of temperature and humidity on comfort and PAQ for sedentary adults, hygroscopic structures can improve indoor comfort and air quality. In all the investigated climates, it is possible to improve the indoor conditions such that, as many as 10 more people of 100 are satisfied with the thermal comfort conditions (warm respiratory comfort) at the end of occupation. Similarly, the percent dissatisfied with PAQ can be 25% lower in the morning when permeable and hygroscopic structures are applied.     

夏热冬暖地区小城镇住宅建筑节能潜力的调研与评价

通过对福建省永定县凤城镇居住建筑围护结构、住宅能耗水平及室内温湿度的实地调研和测试,对比分析了夏热冬暖地区小城镇住宅单位面积能耗与全国非采暖城镇平均能耗的差异;并测评了其居住热舒适环境.在此基础上,结合当地实际情况提出以下3种研究方法探讨该地区小城镇的建筑节能潜力,即①现状建筑条件下未来(空调普及后)的建筑能耗;②仅采...     

Modelling of heat and moisture transfer in buildings: I. Model program

The overall objective of this work is to develop an accurate model for predicting heat and moisture transfer in buildings including building envelopes and indoor air. The model is based on the fundamental thermodynamic relations. Darcy’s law, Fick’s law and Fourier’s law are used in describing the transfer equations. The resultant nonlinear system of partial differential equations is discretised in space by the finite element method. The time marching scheme, Crank–Nicolson scheme, is used to advance the solution in time. The final numerical solution provides transient temperature and moisture distributions in building envelopes as well as temperature and moisture content for building’s indoor air subject to outdoor weather conditions described as temperature, relative humidity, solar radiation and wind speed. A series measurements were conducted in order to investigate the model performance. The simulated values were compared against the actual measured values. A good agreement was obtained.     

西北村镇单体建筑室内空气质量研究

基于西北村镇传统单体建筑能源利用率低、室内空气质量差的现状,将传统建筑的供能系统改为冬季主要由太阳能热水系统为室内供暖且为住户提供生活热水,并对建筑室内空气质量进行试验测试,测试结果得到:室内SO_2、NO_2、CO含量的1 h平均值,TVOC含量的8 h平均值,CO_2、PM_(10)含量的日平均值、室内风速和室内空气相对湿度在试验周期内都符合GB/T 18883—2002《室内空气质量标准》的相关规定,室内温度平均值在太阳能热水系统供暖期间符合GB/T 50824—2013《农村居住建筑节能设计标准》的相关规定;经综合指数对室内空气质量进行评价,得出太阳能热水系统供能的西北村镇单体建筑空气质量级别属于Ⅱ级,空气质量评价结果为未污染。