办公室内颗粒污染物动态特性测试研究

通过测试一个典型办公室内颗粒污染物的质量浓度和粒子数浓度,分别研究了开窗和不开窗两种条件下的烟燃烧、室内人员走路日常活动、以及室外污染源作用下室内颗粒污染物的动态特性,研究结果表明,当室外污染物浓度较小时,开窗既降低了室内颗粒物浓度的增幅,又降低了室内颗粒物浓度下降到较低水平的时间。人员走路这种情况下,部分颗粒物会由于二次悬浮作用而引起室内颗粒物增长,随后又由于重力作用而发生沉降。在室外污染严重的地区,由于渗透作用,室外污染物浓度对室内颗粒物浓度影响最为显著。     

控制室内建材散发挥发性有机物浓度分布的空调系统提前开启时间研究

提前开启通风或空调系统可保证室内空气品质或温度在人员进入室内时达到可接受的水平。基于污染源可及性和数值模拟,分别研究了等温和非等温通风条件下污染物浓度分布达到稳定所需的时间与提前开启时间。结果显示:在等温通风条件下,当换气次数为1h-1时,8种典型通风方式下污染源可及性达到稳定的时间为6~16h;在非等温通风条件下,空调系统提前开启时间可由污染物浓度分布达到稳定的时间来决定;而在较高的换气次数(≥4h-1)下,空调环境室内平均温度和呼吸区挥发性有机物(VOC)平均浓度达到稳定所需的时间接近,为1~3h,为控制污染物浓度分布设计的空调通风系统提前开启时间仍可根据为加热或冷却房间空气温度设计的提前开启时间来确定。     

混合通风下源项特征对污染物分布影响的研究

以计算流体力学(CFD)为基础,建立混合通风房间不同气流组织形式的物理和数学简化模型,模拟了不同送回风口位置和不同污染源分布形式下室内流场和污染物的扩散特征。对不同条件下室内的流场及污染物浓度分布进行了比较,并且针对不同污染物源项分布,通过引入排污效率这一概念,对各种通风方式的排污效率进行了对比。本文结果表明,当污染源平均分布,异侧送回风较为适宜,而当污染源单一分布时,同侧送风较为适宜。     

住宅通风技术

<正>一、自然通风的作用通风对于建筑环境的影响主要表现在以下两个方面:1.卫生健康的空气质量一般来讲,居室是一个相对封闭的空间,加之室内污染源较多,因此室内的污染物浓度要比室外高2～5倍,严重的高达数十倍以上。因此若不对其进行稀释将严重影响居住者的健康,而室内通风换气是十分简便而且行之     

层流无菌病房卫生间通风方案研究

本文首先采用计算流体力学(CFD)模拟方法对某层流无菌病房3种不同卫生间送风方案进行了对比分析,分别比较了污染源在马桶和地板时室内污染物浓度的分布情况和关注区域的平均浓度情况,通过对比选出了适用于层流无菌病房内卫生间的最佳通风方案.其次,对房间内的风速和污染物浓度进行了测试,模拟结果与实测结果吻合很好,验证了该模拟模型的准确性.     

雾霾天气下住宅开窗通风与空气净化联合策略可行性研究

雾霾天气的频繁出现导致关窗并开启空气净化器成为住宅中常用的净化手段,而长时间关窗带来的危害往往被忽视。模拟了雾霾天气下住宅中全时开窗及短时开窗2种开窗方式与空气净化联合使用时对室内细颗粒物(PM2.5)和CO_2浓度的控制情况,结果表明:当室外雾霾在中度污染(室外PM2.5质量浓度200μg/m~3)以下时,可以采取全时开窗与空气净化联合策略控制室内污染物的浓度;当室外雾霾污染严重(室外PM2.5质量浓度300μg/m~3)时,可以采取短时开窗与空气净化联合策略将室内污染物浓度在大多数时间段内控制在限值以下。合理的开窗通风与空气净化联合控制策略为住宅中应对室外雾霾与室内多种污染物提供了一种途径。     

高效通风——健康建筑发展的基础

通常情况下与室外相比,室内环境更易产生各种污染物,因此室内的空气质量常不如室外。建筑室内空气质量对人体健康至关重要。高效通风是维持、改善室内空气质量的重要途径。文章针对在室内污染物产生的情况下,从室内通风系统的有效通风评估、室内污染物控制评估、换气能力评估等三个方面,阐述了在健康建筑视角下,通过高效通风改善室内空气质量的理论与方法。     

机械通风与自然通风对办公建筑室内环境营造差异性的模拟分析

通风换气对营造室内环境有着重要作用,同时对室内热湿环境与供暖空调能耗也有很大影响。通风对室内空气质量具有两重性,可以排除室内污染,又在室外出现严重污染时引入室外污染;对供暖空调能耗也具有两重性,室外环境好时可以节能,室外环境差时增加能耗。现有的通风方式主要有自然通风和机械通风两种,机械通风是一种定量持续恒定的通风方式,而自然通风是一种不定量间歇反馈的方式,这两种通风方式在营造室内环境上存在很多差异。本文以北京夏季的中小型办公建筑为典型案例进行模拟计算,通过对比分析两种通风方式的CO2浓度、温度及冷负荷,探讨两种通风方式的差异及适宜性。     

集中空调系统控制室内污染物的非稳态模型

本文综合考虑室内污染源散发,室外污染物进入,净化器效率等因素对室内污染物浓度的影响。对采用集中空调系统的房间,建立了非稳态模型,以可挥发性有机物为例,理论分析了净化器效率和室外VOCs浓度对室内VOCs浓度的影响。该模型可为净化器效率的选择提供理论依据。     

温度控制与污染物浓度控制相独立的通风空调系统

为解决传统通风空调系统温度控制与污染物浓度控制需求风量不匹配的问题,提出了一种温度控制与污染物浓度控制相独立的通风空调系统结构和控制方法。通过室内负荷计算及PM2.5浓度计算,对比分析了北京、上海、深圳地区在保证室内温湿度需求时典型办公室内的PM2.5浓度水平。结果表明,该通风空调系统可以同时满足室内温度和PM2.5浓度的控制要求,尤其在室外气候温和且大气污染较重时期对室内环境的保障效果更为明显。以北京地区2018年为例计算,在室内温度相同情况下,采用该通风空调系统室内PM2.5浓度全面达标,而采用传统通风空调系统则有10.3%的时间超标。     

Relationships Between Indoor and Outdoor Contaminants in Mechanically Ventilated Buildings

Abstract It is shown that comparing measured indoor and outdoor contaminant concentrations can be misleading if the concentrations vary with time and if the averaging periods are too short. In this article an alternative methodology aimed at estimating the internal source and sink effects in mechanically ventilated buildings is described. The methodology is based on both the results from continuous measurements, and calculations under transient conditions. The relative importance of indoor sources and outdoor sources is established by a comparison of the measured indoor concentration and a calculated indoor concentration of a compound. Furthermore, dynamic calculations are used to investigate how the indoor concentrations of contaminants originating outdoors and contaminants emitted from indoor sources are influenced by temporal reductions of the airflow rate. Reducing the outdoor airflow rate during periods with high outdoor concentrations can significantly reduce the indoor levels of pollutants for situations in which the outdoor sources are more important than the indoor sources.     

Outdoor Air Contaminants and Indoor Air Quality under Transient Conditions

The indoor concentrations of contaminants originating from outdoor sources have been measured and calculated under transient conditions. The results show that contaminants that are supplied to an office building via the ventilation system can reach considerably high concentration levels. The indoor/outdoor concentration ratio and time lag are dependent on the air change rate. In buildings with low air change rates the indoor concentration variations are smoothed out compared to buildings with high air change rates. The results from the theoretical model are compared to the results from both laboratory and field measurements and the model is verified for well mixed conditions in a 20 m³ test chamber. The model can be used to simulate different control strategies for reduction of indoor contaminant concentrations related to outdoor sources. One such control strategy is based on reduction of the outdoor air change rate during periods with peak outdoor contaminant concentrations.     

室内颗粒污染的源辨识与源解析

辨识室内颗粒物来源与分析室内颗粒物元素特征称为源辨识与源解析,是进行室内空气污染控制与净化的理论依据与前提条件。本文通过对室内空气品质（IAQ）模型进行理论分析,阐明了室内外污染源与室内颗粒物浓度之间的关系。指出室内颗粒污染物研究应根据污染源已知与未知两种情况进行讨论,并针对不同的情况分别采用源辨识与源解析技术。     

Relationship between outdoor and indoor air quality in eight French schools

In the frame of the French national research program PRIMEQUAL (inter-ministry program for better air quality in urban environments), measurements of outdoor and indoor pollution have been carried out in eight schools in La Rochelle (France) and its suburbs. The buildings were naturally ventilated by opening the windows, or mechanically ventilated, and showed various air permeabilities. Ozone, nitrogen oxides (NO and NO(2)), and airborne particle (particle counts within 15 size intervals ranging from 0.3 to 15 mum) concentrations were continuously monitored indoors and outdoors for two 2-week periods. The indoor humidity, temperature, CO(2) concentration (an indicator of occupancy), window openings and building permeability were also measured. The temporal profiles of indoor and outdoor concentrations show ozone and nitrogen oxides behave differently: NO and NO(2) indoor/outdoor concentration ratios (I/O) were found to vary in a range from 0.5 to 1, and from 0.88 to 1, respectively, but no correlation with building permeability was observed. On the contrary, I/O ratios of ozone vary in a range from 0 to 0.45 and seem to be strongly influenced by the building air-tightness: the more airtight the building envelope, the lower the ratio. Occupancy, through re-suspension of previously deposited particles and possible particle generation, strongly influences the indoor concentration level of airborne particles. However, this influence decreases with particle size, reflecting the way deposition velocities vary as a function of size. The influence of particle size on deposition and penetration across the building envelope is also discussed by analyzing the I/O ratios measured when the buildings were unoccupied, by comparing the indoor concentrations measured when the buildings were occupied and when they were not (O/U ratios), and by referring to previously published studies focussing on this topic. Except one case, I/O were found to vary in the range from 0.03 to 1.79. All O/U are greater than one and increase up to 100 with particle size. PRACTICAL IMPLICATIONS: Assessing children's total exposure requires the knowledge of outdoor and indoor air contaminant concentrations. The study presented here provides data on compared outdoor and indoor concentration levels in school buildings, as well as information on the parameters influencing the relationship between outdoor and indoor air quality. It may be used as a basis for estimating indoor concentrations from outdoor concentrations data, or as a first step in designing buildings sheltering children against atmospheric pollution.     

Inverse identification of multiple outdoor pollutant sources with a mobile sensor

Air pollution is becoming more and more severe in large cities. Accurate and rapid identification of outdoor pollutant sources can facilitate proper and effective air quality management in urban environments. Traditional “trial–error” process is time consuming and is incapacity in distinguishing multiple potential sources, which is common in urban pollution. Inverse prediction methods such as probability based adjoint modelling method have shown viability for locating indoor contaminant sources. This paper advances the adjoint probability method to track outdoor pollutant sources of constant release. The study develops an inverse modelling algorithm that can promptly locate multiple outdoor pollutant sources with limited pollution information detected by a movable sensor. Two numerical field experiments are conducted to illustrate and verify the predictions: one in an open space and the other in an urban environment. The developed algorithm promptly and accurately identifies the source locations in both cases. The requirement of an accurate urban building model is the primary prerequisite of the developed algorithm for urban application.     

Location identification for indoor instantaneous point contaminant source by probability-based inverse Computational Fluid Dynamics modeling

Indoor pollutions jeopardize human health and welfare and may even cause serious morbidity and mortality under extreme conditions. To effectively control and improve indoor environment quality requires immediate interpretation of pollutant sensor readings and accurate identification of indoor pollution history and source characteristics (e.g. source location and release time). This procedure is complicated by non-uniform and dynamic contaminant indoor dispersion behaviors as well as diverse sensor network distributions. This paper introduces a probability concept based inverse modeling method that is able to identify the source location for an instantaneous point source placed in an enclosed environment with known source release time. The study presents the mathematical models that address three different sensing scenarios: sensors without concentration readings, sensors with spatial concentration readings, and sensors with temporal concentration readings. The paper demonstrates the inverse modeling method and algorithm with two case studies: air pollution in an office space and in an aircraft cabin. The predictions were successfully verified against the forward simulation settings, indicating good capability of the method in finding indoor pollutant sources. The research lays a solid ground for further study of the method for more complicated indoor contamination problems. PRACTICAL IMPLICATIONS: The method developed can help track indoor contaminant source location with limited sensor outputs. This will ensure an effective and prompt execution of building control strategies and thus achieve a healthy and safe indoor environment. The method can also assist the design of optimal sensor networks.     

两典型办公室室内颗粒物浓度监测与分析

对一普通办公楼及甲级办公楼办公室内、外颗粒物浓度进行监测。监测结果显示建筑室外颗粒物污染严重;普通办公楼室内颗粒物污染严重,甲级办公楼室内颗粒物浓度较低;甲级办公楼室内外颗粒物浓度I／O比值较普通办公楼小;两办公楼室内、外的PM2．5污染均较PMIO污染频繁;室内人和物的剧烈活动、吸烟等活动会造成严重的室内颗粒物污染。     

Indoor air environment of residential buildings in Dalian,China

In recent years, more and more people have started to recognize the importance of indoor air environment. In order to obtain the comprehensive knowledge about the indoor environment situation and find out the main source of indoor air pollution, 550 residents living in different buildings/apartments were subjected to a questionnaire survey and field measurements were conducted in 30 of these buildings/apartments in Dalian from January to February 2002. From the questionnaire survey and field measurements, we found that many residential buildings had good outdoor surroundings. Dust and automobile emissions are main sources of outdoor air pollution. Though air tightness of these buildings is fairly good, outdoor air quality still has great impact on indoor air environment. The most serious indoor air pollutant is formaldehyde which is mainly caused by decoration.     

The analysis of PM2.5 and associated elements and their indoor/outdoor pollution status in an urban area

In this study, elemental composition of PM2.5 and the status of indoor/outdoor pollution were investigated in a commercial building near a roadside area in Daejeon, Korea. A total of 60 parallel PM2.5 samples were collected both on the roof (outdoor) and in an indoor office of a building near a highly congested road during the spring and fall of 2008. The concentrations of 23 elements were analysed from these PM2.5 samples using instrumental neutron activation analysis. PM2.5 levels in indoor environment (47.6 ± 16.5 μg/m(3)) were noticeably higher than the outdoor levels (37.7 ± 17.2 μg/m(3)) with the I/O concentration ratio of 1.37 ± 0.33 [correlation coefficient (r) = 0.89, P < 0.001]. Principal component analysis results coincidently showed the predominance of sources such as soil dust, traffic, oil/coal combustion and road dust for both indoor and outdoor microenvironments. An isolated source in the indoor environment was assigned to environmental tobacco smoke (ETS) with high factor loading of Ce, Cl, I, K, La and Zn. The overall results of our study indicate that the sources of indoor constituents were strongly dependent on outdoor processes except for the ones affected by independent sources such as ETS. PRACTICAL IMPLICATIONS: An improved understanding of the factors affecting the indoor PM2.5 concentration levels can lead to the development of an efficient management strategy to control health risks from exposure to indoor PM2.5 and related toxic components. A comparison of our comprehensive data sets indicated that most indoor PM2.5 and associated elemental species were strongly enriched by indoor source activities along with infiltration of ambient outdoor air for a naturally ventilated building.     

建筑室内外空气真菌浓度相关性案例测试分析

选取某高校学生办公室进行室内外空气真菌浓度相关性和粒径的研究.结果表明:室内空气真菌浓度变化范围为1 698～4 429 cfu/m3,最大值出现在12:00;室外浓度范围为3 569?29 452 cfu/m3,最大值也出现在12:00.室内外空气真菌浓度比值均小于1,Spearman相关性分析显示室内外空气真菌呈显...