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Inverse Problem and Variation Method to Optimize Cascade Heat Exchange Network in Central Heating System

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Journal of Thermal Science 2017年第6期26卷 545-551页

作者： zhang Yin WEI Zhiyuan zhang yinping WANG Xin College of Architecture and Environment Sichuan University Department of Building Science Tsinghua University

Urban heating in northern China accounts for 40% of total building energy usage. In central heating systems, heat is often transferred from heat source to users by the heat network where several heat exchangers are installed at heat source, substations and terminals respectively. For given overall heating capacity and heat source tempera- tore, increasing the terminal fluid temperature is an effective way to improve the thermal performance of such cascade heat exchange network for energy saving. In this paper, the mathematical optimization model of the cas- cade heat exchange network with three-stage heat exchangers in series is established. Aim at maximizing the cold fluid temperature for given hot fluid temperature and overall heating capacity, the optimal heat exchange area dis- tribution and the medium fluids＇ flow rates arc determined through inverse problem and variation method. The preliminary results show that the heat exchange areas should be distributed equally for each heat exchanger. It al- so indicates that in order to improve the thermal performance of the whole system, more heat exchange areas should be allocated to the heat exchanger whore flow rate difference between two fluids is relatively small. This work is important for guiding the optimization design of practical cascade heating systems.

关键词： District heating Heat exchanger Thermal performance optimization Inverse problem Lagrange variation

General analytical mass transfer model for VOC emissions from multi-layer dry building materials with internal chemical reactions

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Chinese Science Bulletin 2011年第2期56卷 222-228页

作者： WANG XinKe zhang yinping Department of Building Environment and Services Engineering Xi'an Jiaotong University Xi'an 710049 China Department of Building Science Tsinghua University Beijing 100084 China

A general mass transfer based model was developed for analyzing volatile organic compound (VOC) emissions from dry multi-layer building materials with two emission *** model adds to an earlier multi-layer model by considering chemical reactions within the ***,it can be used to analyze the effect of these chemical reactions on removing VOCs,and for characterizing secondary VOC emissions from the building *** model was validated with literature data and our experimental *** typical secondary emissions were analyzed using this model,and obviously differed from the primary *** model is a useful tool for predicting,analyzing and "designing" the VOC emission characteristics,including secondary emissions,of building materials.

关键词：挥发性有机化合物传质模型化学反应排放量建材质量挥发性有机物排放废气

China, Children, Homes, Health(CCHH)

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Chinese Science Bulletin 2013年第34期58卷 4179-4181页

作者： SUNDELL Jan LI BaiZhan zhang yinping Department of Building Science Tsinghua University School of Urban Construction & Environment Engineering Chongqing University

Asthma and allergies have been increasing worldwide during the last 5 *** years ago,prevalences of asthma and allergies were less than 1%;compared to today when up to 1/3 of children in some regions have been diagnosed with *** burden on families and the health care system is *** increase in asthma,rhinitis,and eczema(whether atopic

关键词：中国大陆儿童健康肠道微生物菌群机体免疫系统建筑装饰材料环境空气危险因素

Air purifier or fresh air system?A comparison of energy consumption and cost in urban China residential buildings

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Science China(Technological Sciences) 2024年第9期67卷 2637-2647页

作者： GUO Yong SUN ZhiWei WESCHLER Louise B zhang yinping Department of Building Science Tsinghua UniversityBeijing 100084China Beijing Key Laboratory of Indoor Air Quality Evaluation and Control Beijing 100084China Independent Researcher Colts Neck 07722NJUSA

Chinese urban residential buildings face serious indoor air quality *** purification systems(e.g.,air purifiers,fresh air systems)that supply fresh air or purify indoor air are widely used in residential buildings to improve indoor air *** the challenges of energy conservation and emission reduction,it is urgent to guide residents on choosing appropriate air purification *** key problem is how to identify the best air purification system with the lowest energy consumption or operating *** of air purification systems have rarely been conducted on the premise that they should deliver air such that the main indoor pollutant concentrations all meet air quality *** ignored in comparisons are the increased filtration resistance caused by dust accumulation on the filter and the cost of filter *** this study,we propose a method to compare residential air purification systems based on energy consumption and total cost,and we provide methods to select air purification systems in China's different climatic *** used a standard two-person bedroom as the example,and determined the most suitable(minimum cost or energy consumption)air purification systems for the capital cities of the provinces in Chinese mainland.

关键词： IAQ fresh air system air purifier energy consumption cost

Labeling of volatile organic compounds emissions from Chinese furniture:Consideration and practice

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Chinese Science Bulletin 2013年第28期58卷 3499-3506页

作者： LIU WeiWei zhang yinping YAO Yuan Department of Building Science Tsinghua University

Volatile organic compounds(VOCs)emitted from furniture are recognized as a main cause of bad indoor air *** European countries and the U.S.,labeling systems for furniture have been established with good effect to address this ***,there are problems with these labeling *** example,too many VOCs were targeted,and the testing time was too long(7–28 d).Aiming at solving these problems,solutions are put forward to establish furniture VOCs emissions labeling system in China and some practices are introduced in this *** are:some furniture popular in the market were tested and main VOCs emitted from these furniture were identified;furniture loading factors in residential homes were surveyed,and reference bedroom and reference living room were established according to the survey results to make emission rate thresholds of furniture;C-history method was developed and applied to testing furniture which could shorten the testing time to 3 d;a reference toluene sample for assessing the precision of the test results of chamber system was *** works are technically helpful for establishing furniture VOCs labeling system in China.

关键词：挥发性有机化合物中国家具标签系统排放量测试时间室内空气质量标签制度 VOCs

Study on characteristics of double surface VOC emissions from dry fiat-plate building materials

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Chinese Science Bulletin 2006年第18期51卷 2287-2293页

作者： WANG Xinke zhang yinping ZHAO Rongyi Department of Building Science Tsinghua University Beijing 100084 China

This paper sets up an analytic model of double surface emission of volatile organic com- pound (VOC) from dry,flat-plate building materials. Based on it,the influence of factors including air change rate,loading factor of materials in the room,mass diffusion coefficient,partition coefficient,con- vective mass transfer coefficient,thickness of mate- rials,asymmetric convective flow and initial VOC concentration distribution in the building material on emission is discussed. The conditions for simplifying double surface emission into single surface emission are also discussed. The model is helpful to assess the double surface VOC emission from flat-plate building materials used in indoor furniture and space partition.

关键词：建筑材料室内空气质量室内化学污染挥发性有机物

Chlorobenzenes and organochlorinated pesticides in vegetable soils from an industrial site, China

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Journal of Environmental Sciences 2012年第3期24卷 362-368页

作者： Yang Song Fang Wang Yongrong Bian yinping zhang Xin Jiang State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China

Organochlorinated compounds are ubiquitous contaminants in the environment, especially in industrial sites. The objective of the work was to investigate whether a vegetable field near an industrial site is safe for vegetable production. The residues of chlorobenzenes （CBs）, hexachlorocyclohexanes （HCHs） and dichlorodiphenyltrichloroethanes （DDTs） in a vegetable field which was near a chemical plant in China were characterized. Point estimate quotient was used for ecological risk assessment of the investigated site. The results showed that all CBs except monochlorobenzene （MCB） were detected in soils. The total concentrations of ∑ CBs ranged from 71.06 to 716.57 ng/g, with a mean concentration of 434.93 ng/g. The main components of CBs in soil samples were dichlorobenzenes （DCBs）, trichlorobenzenes （TCBs） and tetrachlorobenzenes （TeCBs）, while for single congeners, 1,2,4-TCB had the highest concentration, which ranged from 13.21 to 210.35 ng/g with a mean concentration of 111.89 ng/g. Residues of hexachlorobenzene （HCB） in soil samples ranged from 0.9 to 11.79 ng/g, significantly lower than ∑ DCB, ∑ TCB and ∑ TeCB. Concentrations of ∑ HCHs and ∑ DDTs in soils ranged from 11.32 to 55.24 ng/g and from 195.63 to 465.58 ng/g, respectively, of which the main components were α-HCH and p,p＇-dichlorodiphenyldichloroethylene （p,p＇-DDE）. Ecological risk assessment for the investigated site showed that the most potential risks were from TCBs and TeCBs, based on the hazard quotients. The higher residues of CBs and DDTs compared to the target values and the higher than 1 hazard quotients indicated that this area is not safe for vegetable production and thus soil remediation is needed.

关键词： chlorobenzenes hexachlorocyclohexanes dichlorodiphenyltrichloroethanes degradation risk assessment

Spatial flow influence factor: A novel concept for indoor air pollutant control

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Science China(Technological Sciences) 2006年第1期49卷 115-128页

作者： zhang yinping LI Xiaofeng WANG Xinke DENG Wei QIAN Ke Department of Building Science Tsinghua University Beijing 100084 China Department of Building Science Tsinghua University Beijing 100084 China Department of Building Science Tsinghua University Beijing 100084 China Department of Building Science Tsinghua University Beijing 100084 China Department of Building Science Tsinghua University Beijing 100084 China

This paper puts forward a novel concept, the spatial flow influence factor (SFIF), which provides a new insight into the airflow structure. This concept is very helpful in the control of indoor air pollutants since: (1) for a given indoor airflow; given sources of volatile organic compounds (VOCs), the optimal arrangement of the VOC sources can easily be obtained; (2) for given positions of VOC sources; occupied regions (or target regions), the optimal indoor airflow pattern or organization can be determined; (3) the SFIF for an indoor space can also be regarded as the indoor air safety index of that space. To illustrate this concept, we present several examples of applying a SFIF to indoor air VOC control.

关键词： volatile organic compounds, indoor air quality, indoor air pollutant control, spatial flow influence factor.

Review on thermal performance of phase change energy storage building envelope

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Chinese Science Bulletin 2009年第6期54卷 920-928页

作者： WANG Xin zhang yinping XIAO Wei ZENG RuoLang zhang QunLi DI HongFa Department of Building Science Tsinghua University Beijing 100084 China

Improving the thermal performance of building envelope is an important way to save building energy consumption. The phase change energy storage building envelope is helpful to effective use of re-newable energy, reducing building operational energy consumption, increasing building thermal com-fort, and reducing environment pollution and greenhouse gas emission. This paper presents the con-cept of ideal energy-saving building envelope, which is used to guide the building envelope material selection and thermal performance design. This paper reviews some available researches on phase change building material and phase change energy storage building envelope. At last, this paper pre-sents some current problems needed further research.

关键词：建筑围护结构热性能相变蓄能综述可再生能源建筑能耗业务建设