Comprehensive evaluation and analysis of a nearly zero-energy building heating system using a multi-source heat pump in severe cold region

The integrated application of multi-energy coupled technology in nearly zero-energy building(NZEB)is promising from the perspective of low-carbon development to achieve the goal of net zero energy.PVT(photovoltaic/thermal),air,and ground sources were combined organically to establish an experimental platform of a multi-source heat pump(MSHP)system,which can realize flexible switching of multi-energy sources.The paper presents the analytical hierarchy process and fuzzy comprehensive evaluation method to comprehensively evaluate the five modes of the MSHP system with regard to energy,economic and environmental benefits.The results indicate that the waste heat of the PVT cavity can improve the coefficient of performance of the heat pump unit(COP)by approximately 8.0%.The initial investment in air source heat pump(ASHP)modes is lower than that of a coal-powered system.The ground source heat pump(GSHP)modes have high stability and their payback period is 8.81–10.66 years.The photovoltaic/thermal-dual source heat pump(PVT-DSHP)mode presents the most appropriate system applied in the NZEB in severe cold region,followed by the DSHP,GSHP,ASHP,and PVT-ASHP mode.When compared with other modes,COP,annual saving cost,carbon dioxide emission reduction,and comprehensive value of the PVT-DSHP mode have improved by 7.07%–29.57%,2.21%–23.88%,3.38%–14.83%,and 27.91%–52.62%,respectively.The study provides important insights into the practical application and sustainable development of multi-energy coupled systems in the NZEB in severe cold region.

Demonstration of the Nearly Zero Energy Building Concept

Nearly zero energy buildings (nZEB) will become an obligatory energy efficiency standard in Europe. Following to common guidelines in European legislation, the countries investigated technical and economic framework for the preparation of detailed national technical definition of nZEB. Slovenia accepted the nZEB criteria in early 2015. This paper describes the technical and economic background for identification of economically viable concepts of highly energy efficient apartment building. The highrise demonstration building Eco Silver House revealed that meeting nZEB standards was not an easy task, not so much for technical reasons, but mostly due to the processes, inadequate skills, not fully compliant regulation and insufficient possibilities for interaction between the building and energy networks. Analysis of cost effectiveness showed that the Eco Silver House fulfilled minimal requirements of cost-optimal for apartment building with Net Present Value of 272 EUR/m2 and Primary energy use of 79 kWh/ m2?a in line with the Slovenian national cost optimal study of minimum energy performance requirements from the year 2014. At the time, the requirement of 50% share of renewables in final energy use is not fulfilled, but will be easily reached when EU2020 energy efficiency targets set in the Slovenian Energy Act regarding the RES share in district heating systems and public power grid will be gradually implemented. The demonstration project FP7 EE-HIGHRISE confirms that in spite of the barriers, the nZEB minimum requirements defined on profound theoretical studies can be met in practice.

Modeling and optimization of a multi-carrier renewable energy system for zero-energy consumption buildings

For the carbon-neutral,a multi-carrier renewable energy system(MRES),driven by the wind,solar and geothermal,was considered as an effective solution to mitigate CO2emissions and reduce energy usage in the building sector.A proper sizing method was essential for achieving the desired 100%renewable energy system of resources.This paper presented a bi-objective optimization formulation for sizing the MRES using a constrained genetic algorithm(GA)coupled with the loss of power supply probability(LPSP)method to achieve the minimal cost of the system and the reliability of the system to the load real time requirement.An optimization App has been developed in MATLAB environment to offer a user-friendly interface and output the optimized design parameters when given the load demand.A case study of a swimming pool building was used to demonstrate the process of the proposed design method.Compared to the conventional distributed energy system,the MRES is feasible with a lower annual total cost(ATC).Additionally,the ATC decreases as the power supply reliability of the renewable system decreases.There is a decrease of 24%of the annual total cost when the power supply probability is equal to 8%compared to the baseline case with 0%power supply probability.

Uncertainty-based life-cycle analysis of near-zero energy buildings for performance improvements

Near-zero energy buildings( nZEBs) are considered as an effective solution to mitigating CO_2 emissions and reducing the energy usage in the building sector. A proper sizing of the nZEB systems( e. g. HVAC systems,energy supply systems,energy storage systems, etc.) is essential for achieving the desired annual energy balance,thermal comfort,and grid independence. Two significant factors affecting the sizing of nZEB systems are the uncertainties confronted by the building usage condition and weather condition,and the degradation effects in nZEB system components. The former factor has been studied by many researchers; however,the impact of degradation is still neglected in most studies. Degradation is prevalent in energy components of nZEB and inevitably leads to the deterioration of nZEB life-cycle performance. As a result,neglecting the degradation effects may lead to a system design which can only achieve the desired performance at the beginning several years. This paper,therefore,proposes a life-cycle performance analysis( LCPA) method for investigating the impact of degradation on the longitudinal performance of the nZEBs. The method not only integrates the uncertainties in predicting building thermal load and weather condition,but also considers the degradation in the nZEB systems. Based on the proposed LCPA method,a two-stage method is proposed to improve the sizing of the nZEB systems.The study can improve the designers "understanding of the components"degradation impacts and the proposed method is effective in the life-cycle performance analysis and improvements of nZEBs. It is the first time that the impacts of degradation and uncertainties on nZEB LCP are analysed. Case studies showthat an nZEB might not fulfil its definition at all after some years due to component degradation,while the proposed two-stage design method can effectively alleviate this problem.

Simulation Technology of Environmental Impacts by Zero-energy Residential Buildings Based on Emergy Analysis Method

This paper presents a simulation technology of environmental impact for the building. By emergy analysis method,emergy costs of building( or construction engineering) can be calculated in the life cycle. It includes the engineering cost, environmental cost and social cost of building. Through integrating GIS technology with multi-agent technology,life cycle substance and energy metabolism of building( construction engineering) can be simulated and their environmental influence can be dynamically displayed. Based on the case study of entries works‘Sunny Inside'by Xiamen University in 2013 China International Solar Decathlon Competition,we discovered the changing pattern of surrounding environmental impact from waste streams of the zero-energy building and ordinary construction. The simulation results verified and showed the Odum principles of maximum power. This paper provides a new research perspective and integration approach for the environmental impact assessment in building and construction engineering. The result will help decision-making in design and construction engineering scheme.

Necessity and adequacy of near-source factors for not-so-tall fixed-base buildings

Nonlinear response history analyses and use of strong ground motion data including near-field effects has become a common practice in both performance based design of tall buildings and design of base-isolated buildings. On the other hand, ordinary buildings are commonly analysed via response spectrum analysis following the rules of conventional seismic codes, most of which do not take near-field effects into account. This study evaluates the necessity and the adequacy of near-source factors for ordinary fixed-base buildings that are not specifically classified as tall, by comparing dynamic responses of 3, 8, and 15-story benchmark buildings obtained via （1） linear time history analyses using 220 record components from 13 historical earthquakes and 45 synthetic earthquake records of different magnitudes and fault distances and （2） response spectrum analyses in accordance with the Turkish Earthquake Code 2007 -representing seismic codes not taking near-field effects into account- and the Uniform Building Code 1997 which takes near-field effects into account via near-source factors that amplify design response spectrum. It is shown that near-source factors are crucial for the safe design of not-so-tall ordinary fixed-base buildings but those defined in UBC97 may still not be adequate for those located in the vicinity of the fault.

EDUCATIONAL EFFECTIVENESS OF A VIRTUAL DESIGN STUDIO ON ZERO-ENERGY BUILDING DESIGNS:THE CASE OF THE U.S.SOLAR DECATHLON DESIGN CHALLENGE

Ongoing global architectural agendas span climate change,energy,a carbon-neutral society,human comfort,COVID-19,social justice,and sustainability.An architecture studio allows architecture students to learn how to solve complicated environmental issues through integrated thinking and a design process.The U.S.Department of Energy’s Solar Decathlon Design Challenge enables them to broaden their analytic perspectives on numerous subjects and strengthen their integrated thinking of environmental impacts,resilience,sustainability,and well-being.However,the unprecedented impact of the global COVID-19 pandemic transformed the physical studio-based design education system into an online-based learning environment.Mandatory social distancing by the global COVID-19 pandemic restricted interactive discussions and face-to-face collaborations for the integrated zero-energy building design process,which requires features of architecture,engineering,market analysis,durability and resilience,embodied environmental quality,integrated performance,occupant experience,comfort and environmental quality,energy performance,and presentation.This study emphasizes the educational effectiveness of virtual design studios as a part of the discourse on architectural pedagogy of zero-energy building(ZEB)design through integrated designs,technological theories,and analytic skills.The survey results of ten contests show educational achievement with over 90%of the highest positive tendency in the categories of embodied environmental quality and comfort and environmental quality,whereas the positive tendency of educational achievement in the categories of integrated performance,energy performance,and presentation were lower than 70%.The reason for the low percentage of simulation utilization and integrated performance was the lack of a proper understanding of and experience with ZEB simulations and evaluations for undergraduate students.Although VDS is not an ideal pedagogical system for the iterative design critique process,it can support the learning of the value of architectural education,including integrative design thinking,problem-solving skills,numerical simulation techniques,and communicable identities through online discussions and feedback during the COVID-19 pandemic.

Carbon Footprint Analysis of Buildings Based on LCA Theory Under Carbon Neutrality Goals:Taking the 3rd China International Solar Decathlon Competition as an Example

This paper focuses on the design of residential buildings oriented to the efficient use of solar energy,and selects the entries HUI HOUSE of Hefei University of Technology and Lille I University of France in the 3rd China International Solar Decathlon China Competition,based on the theory of the life cycle assessment(LCA)of buildings,and analyzes the carbon footprint from four aspects:building materials production and transportation stage,building construction stage,building operation stage,and building demolition stage.Through the calculation of the carbon footprint of buildings,the socio-economic benefits of HUI HOUSE in carbon reduction were analyzed;the result of the calculation was that HUI HOUSE achieved carbon neutrality in the ninth year,and continued carbon reduction after that,contributing a cumulative total of 947.54 tons of carbon negative in the life cycle of buildings.

Review on the recent progress of nearly zero energy building frontiers in China

Energy efficiency improvement in Chinese construction has progressed rapidly over the past two decades.Nearly zero energy buildings(NZEBs),as an integrated solution for energy-efficient construction,have gained significant attention during China's 13th Five-Year Plan period,with continuous maturation of the technical system.In this study,a research framework built upon the accomplishments of China's National Key Research and Development Program is developed,and an in-depth analysis of the most cutting-edge research is provided by thoroughly reviewing the work conducted earlier.Developing NZEB in China has been categorized into three stages based on the characteristics of technological development:(1)definition and standards,(2)demonstration and promotion,and(3)cross-domain integration.This study discerns four noteworthy development trends by examining comprehensive data spanning the last decade from 100 NZEB and zero energy building.Further,a comprehensive analysis of essential technology advancements in line with these identified trends is performed.The issues and challenges arising from the increased application of renewable energy in the context of China's carbon peak and carbon neutrality goals have also been discussed.Finally,based on this analysis,the challenges and corresponding suggestions for future research directions were proposed to help guide future studies exploring emerging trends in the NZEB field.

Development of seismic force requirements for buildings in Taiwan

This paper describes static and dynamic procedures to calculate seismic demand specified by the current seismic design code for buildings in Taiwan, which was issued in 2005. For design levels with a return period of 475 years, the design spectral response acceleration can be developed for general sites, near-fault sites and Taipei Basin. In addition, in order to prevent building collapse during extremely large earthquakes and yielding of structural components and elements during frequent small earthquakes, the required seismic demands at the maximum considered earthquake level （MCE, 2%/50 years） and operational level are also included in the new seismic design code.For dynamic analysis procedures, both the response spectrum method and time history method are specified in the new seismic design code. Finally, procedures to generate spectrum compatible ground motions for time history analysis are illustrated in this paper.

INTEGRATED ARCHITECTURAL AND ENGINEERING DESIGN STRATEGIES FOR A ZERO-ENERGY BUILDING:Illinois Institute of Technology’s Design Entry for the 2018 U.S.Department of Energy Race to Zero(Solar Decathlon Design Challenge)

This paper describes the design of InterTech,a zero-energy mixed-use student residence hall,developed in 2018 by an interdisciplinary team of Illinois Institute of Technology(Illinois Tech)students for the U.S.Department of Energy Solar Decathlon Design Challenge,formerly known as Race to Zero.The main focus is the team’s integrated and iterative approach,which blended architectural design and engineering concepts and led to achieving the high-performance goal.InterTech aims to provide an innovative housing solution to Illinois Institute of Technology’s graduate students and their families.Located along State Street in between Illinois Tech’s main campus and downtown Chicago,it offers a mix of living options providing both independence and access to the campus and to the city.In addition to the residential program,the project includes a small grocery/cafe con-nected to an outdoor public plaza,and an underground garage.Energy modeling was introduced in the early design stages.The potential of on-site renewable energy generation defined the project’s target Energy Use Intensity(EUI)of 37 kBtu/sqft.Several passive and active strategies were implemented to reduce the building’s total energy needs and meet the target EUI.The implementation of energy conservation measures led to a 25%reduction of the building’s cooling load and a 33%reduction of the heating load.A design EUI of 28 kBtu/sqft was calculated,validating that this design met and exceeded the zero-energy goal.

NEAR模型的外墙面裂缝连接算法

在利用数字图像技术检测大型建筑物外墙面裂缝时,墙面上的裂缝宽度过窄,或是被灰尘填充而变得不清晰,又或是图像预处理过度导致提取到的裂缝出现断裂等情况,均会影响到后续如裂缝面积、长度、宽度、走势等参数的测量和评估.为了解决这个问题,本文提出了一种基于山脊线邻域的评价模型(NEAR)来判断和描述裂缝间的连续性,并根据其判断和描述结果,结合二次贝塞尔插值完成裂缝间的平滑连接.此外,本文还进行了对比试验,利用基于Hausdorff距离的最小二乘法对NEAR算法结果和K-D树算法结果进行评估比较.实验结果表明,该算法能明显提高判断裂缝连续性的准确程度.

Scientometric of Nearly Zero Energy Building Research: A Systematic Review from the Perspective of Co-Citation Analysis

As an important building type to diminish energy use and greenhouse gas emissions in the construction industry, nearly zero energy building(nZEB) has attracted much attention from many scholars, with volumes of research findings published. However, quantitative and systematic reviews on those findings are rarely conducted by researchers. Therefore, a visualized presentation regarding the advancement of nZEB research was made in this study by applying the scientometric method of co-citation analysis to 704 publications retrieved from the Web of Science database from 2006 to 2018. Here, the key conclusions drawn after the research are as follows:(1) Italy, the USA and Spain are the top three nations by the number of nZEB publications;(2) Energy and Buildings, Applied Energy and Energy are the journals with the highest number of published nZEB articles;(3) Politecnico di Milano, Aalto University and Politecnico di Torino are the most influential core organizations in the field of nZ EB;(4) Professor Kurnitski J, Professor Corgnati SP and Professor D’Agostino D are the leading nZEB experts;(5) "cost optimal", "life cycle assessment", "technical system", "design" and "indoor environment quality" are the major research directions in the field of nZEB;(6) A multi-stage optimization method for cost-optimal and nearly zero-energy building solutions in line with the EPBD 2010, co-authored by Hamdy M, is the most cited nZEB reference;(7) "residential building", "building energy saving technology", "simulation method" and "thermal comfort", etc. are the hot topics in nZEB research at present and in the future. This research is designed to provide valuable information for scholars interested in the field of nZEB.

Indoor environment of nearly zero energy residential buildings with conventional air conditioning in hot-summer and cold-winter zone

According to the few researches on Nearly zero energy residential buildings(NZERB)in hot-summer and cold-winter zone,although it could reduce the cooling load of buildings due to its high thermal insulation and air tightness,it still needed for certain cooling in summer.This paper studied indoor environment of NZERB un-der three kinds of air-conditioners(split-type air-conditioner,multi-line air-conditioner and ceiling radiant air-conditioner).Firstly,a simulation model of NZERB was established based on Nanjing,a typical city in hot-summer and cold-winter zone.Secondly,variation of indoor air temperature and building load characteristics with outdoor air temperature were studied.Thirdly,indoor environment and energy consumption under three selected con-ventional air-conditioners in summer were simulated.Finally,the discussion was given,and an air-conditioner combining with convective and radiant cooling were proposed.The results indicated that the air-conditioner needed to be turned on in NZERB in hot-summer and cold-winter zone due to the room air temperature in off-air condition ranged from 32℃to 36℃,which was higher than designed indoor environment temperature in sum-mer,but the indoor environment of NZERB under three selected conventional air-conditioners could not meet the requirements of energy saving and comfort at the same time,and a proposed convective-radiant air-conditioner could be fast,stable,and energy saving.The findings can provide a reference for conducting active technology in NZERB.

沈阳地区典型办公建筑运行阶段碳减排潜力研究

以沈阳某办公建筑为例,将GB 50189—2015《公共建筑节能设计标准》作为节能基准,对比分析多种近零能耗建筑技术情形对建筑碳排放的影响,并对其碳减排潜力进行评估测算。利用模拟软件Design Builder对沈阳市某办公建筑建立典型模型,通过模拟计算得到几种不同技术情形下的能耗强度。碳排放强度由不同类型能源碳排放因子与能耗强度计算得出。结果表明:可再生能源利用技术和暖通空调设备能效提升技术可明显减少碳排放,碳减排率分别可达到44.88%和39.99%;另外,建筑围护结构改造以及自然通风和自然采光结合技术,减排率分别为8.18%、7.22%。按照近零能耗建筑技术要求,综合6种技术情形,办公建筑运行阶段的减排率可达51.08%。

The Thermal Comfort and Hygrothermal Performance of the First Certified Passive House in Estonia

This study presents the thermal comfort and hygrothermal performance of building envelope of the first certified passive single-family detached house in Estonia.Temperature and humidity conditions were measured from different rooms and building envelopes.This article presents analysis of measurement results during the first year after construction.Results showed high room temperature,achieved mainly due to large windows with southern exposure and the small heat loss of the building envelope.High indoor temperature decreased the indoor RH(relative humidity)to quite low levels.Even the RH was low,the moisture excess was high indicating that the design of PH(passive houses)indoor humidity loads cannot be decreased.Humidity in the externally insulated cross-laminated timber panels was observed to be high,caused by drying out of the constructional moisture and the high diffusion resistance of the wood fibre sheathing board.That caused water vapour condensation and risk for mould growth.In conclusion,while planning buildings with high-energy efficiency,more focused attention should be paid to the performance of the building service systems and moisture safety already in the preliminary stages of design.

西咸自由贸易企业服务中心超高层建筑结构设计

西咸自由贸易企业服务中心地处高烈度区,与渭河断裂之间的距离约2km,应考虑近场效应。项目采用钢管混凝土框架(钢梁)+钢筋混凝土核心筒混合结构,存在扭转不规则、刚度突变、有加强层和通高层等不规则项。为提高结构刚度,在避难层设置了2道伸臂桁架加强层。采用YJK、MIDAS Building软件进行了小震弹性对比分析,采用YJK进行了小震弹性时程分析。根据设定的抗震性能目标,对主体结构主要部位和关键构件进行了性能化设计;采用SAUSAGE软件进行了罕遇地震作用下的动力弹塑性时程分析;采用ANSYS软件对伸臂桁架关键节点进行有限元分析。结果表明:各项指标均符合设计要求,结构及构件均达到预设性能目标,结构体系合理,安全可靠。本工程部分墙体为钢板混凝土剪力墙,设计中应注重钢板混凝土剪力墙的构造措施,施工中应采取措施控制钢板变形。

近场近地爆炸下建筑柱爆炸荷载分布规律及简化模型

为了快速评估近场近地爆炸荷载下建筑柱的动力响应和破坏模式,通过数值仿真方法,探究了近场近地爆炸工况下冲击波在建筑柱迎爆面的分布规律,并提供了该工况下的爆炸荷载简化模型。为此,首先利用已有实验数据验证数值模型,并建立典型近地近场爆炸工况的数值模型,然后研究比例爆距和比例爆高对建筑柱冲击波特征参数的影响规律,最后拟合出柱迎爆面反射冲量和正相超压持续时间的计算公式,将柱迎爆面各点爆炸荷载转化为等效三角形荷载模型,为工程实践中建筑柱遭受近场近地爆炸作用下的抗爆设计提供荷载输入。研究结果表明:当比例爆高小于0.3 m/kg1/3、比例爆距在0.4~0.6 m/kg1/3范围时,最大反射冲量沿柱高可简化为三折线分布;当比例爆距在0.6~1.4 m/kg1/3范围时,最大反射冲量沿柱高可近似简化为双折线分布;在同一比例爆距和比例爆高工况下,随着炸药当量的增加,柱迎爆面相同比例高度处反射超压峰值保持不变而反射冲量正比于当量的立方根。

寒冷地区近零能耗建筑参数优化研究

针对寒冷地区近零能耗建筑的围护结构在夏季会增加室内制冷能耗的问题,提出在夏季和过渡季采用空调与自然通风系统相结合的节能方法,运用EnergyPlus软件模拟研究窗墙面积比、外窗太阳得热因数、窗户传热系数、外墙传热系数、外遮阳悬挑梁长度等5个参数对建筑能耗的影响,通过正交试验确定最优因素水平组合.研究结果显示,优化建筑与既有建筑相比,全年供暖制冷综合能耗可节约43.7%.

近零能耗建筑发展简述

随着城镇化的高速发展,建筑业规模不断扩大,建筑能耗在全社会总能耗中的比重也在逐年增加。作为影响环境的一个重要方面,能耗问题历来受到各国的重视。如何降低建筑能耗需求,成为城镇发展过程中不可避免的问题。主要总结了各国在低能耗建筑实践过程中的经验与成果,同时介绍了我国关于低能耗建筑的相关政策标准,讨论了近零能耗建筑在我国发展的难点并提出相关建议,以期推动建筑行业绿色、低碳发展。