Monte Carlo Simulation-based Decision-making Model for the Water Conservation and Intermediate Water Recycling of Conservationminded Buildings

Through analyzing the life cycle cost of the water conservation and intermediate water application project of conservation-minded buildings,net present value(NPV) was applied as the index to establish the life cycle economic decision-making model.Monte Carlo simulation was used in demonstration cases,modeling analysis of water-saving projects in conservation-minded and traditional buildings verified rationality and practicability of this model and simulation method.It was to provide a referential and operable method for the decision-making of conservation-minded construction projects,as well as a scientific approach and theoretic basis for the precise decision-making of government organs,decision-making departments and developers.

Numerical Simulation of Wind Field Characteristics around Two Adjacent High-Rise Buildings

This paper based on Reynolds-averaged Navier-Stokes equations standard ?model [1];the surface pressure on the wind field around two adjacent high-rise buildings was numerically simulated with software Fluent. The results show that with the influence of adjacent high-rise building, numerical simulation is a good way to study the wind field around high-rise building and the distribution of wind pressure on building’ surface. The pressures on the windward surface are positive with the maximum at 2/3 H height and have lower values on the top and bottom. The pressures on the leeward surface and two sides were negative. Due to the serious flow separation at the corner of building’s windward, the wind field has a high turbulent kinetic energy.

Building dynamic thermal simulation of low-order multi-dimensional heat transfer

Multi-dimensional heat transfers modeling is crucial for building simulations of insulated buildings,which are widely used and have multi-dimensional heat transfers characteristics.For this work,state-model-reduction techniques were used to develop a reduced low-order model of multi-dimensional heat transfers.With hot box experiment of hollow block wall,heat flow relative errors between experiment and low-order model predication were less than 8% and the largest errors were less than 3%.Also,frequency responses of five typical walls,each with different thermal masses or insulation modes,the low-order model and the complete model showed that the low-order model results agree very well in the lower excitation frequency band with deviations appearing only at high frequency.Furthermore,low-order model was used on intersection thermal bridge of a floor slab and exterior wall.Results show that errors between the two models are very small.This low-order model could be coupled with most existing simulation software for different thermal mass envelope analyses to make up for differences between the multi-dimensional and one-dimensional models,simultaneously simplifying simulation calculations.

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.

Optimisation of Climate Robust Buildings under Summer Conditions with ＂Primero-Comfort＂ Simulation Software Including Detailed User Behaviour and Comfort Expectance

In this paper the possibilities for avoiding active air conditioning by all means of the room itself （window size, glazing, shading system, natural ventilation, and furniture）, artificial light and control strategy of these systems are investigated. A very important component of the system is the user with his ability to adapt to changing conditions in his surrounding and with his possibilities to manipulate the window, the shading system, the light switch etc. All these aspects interact together. It is necessary to optimize them simultaneously. But real planning often separates them into single sections. Simulation tools also handle normally only one or a few aspects, we know for example the thermal simulation or the daylight simulation. Primero-Comfort （2009） is a simulation tool based on energy＋, what is able to consider thermal simulation as well as daylight simulation as well as user behaviour in regard to the probability of window openings. The resulting thermal comfort is rated by an adaptive comfort model, the Dutch ISSO 74 （2004）. This allows designing office rooms more realistic. And it shows that an optimized solution has to include the interactions of aU mentioned aspects. Investigations with Primero-Comfort for a moderate European climate （Hamburg） show that a very good comfort can be reached only by passive means of building design also for hot summer weather just like the summer in the year 2003. The keys for such hot-summer-robust-buildings are night ventilation with height difference, heat protection glazing and good shading system, reduced internal heat gains for artificial light by accepting a threshold of 300 lx of daylight as comfortable and a reduced window size oriented on daylighting and the view out of the window.

Zero-Energy-Buildings in Different Climates： Design Strategies, Simulation and Prognosis METHOD for Energy Demand

The European Directive 2010/31 claims that by 2020 only （nearly-） ZEB （zero-energy-buildings） may be built. To reach this goal, it is pertinent for buildings to be energetically optimized first. The remaining energy demand must then be covered by on-site renewable energies （PV, geothermal, etc.）. With the area of use （energy demand） and the size of the building envelope/estate （renewable energy supply） in competition with each other, the maximum number of building stories will be most likely limited. For 15 different climatic locations worldwide, the energy demand of optimised office rooms has been simulated and compared with the possible renewable energy production on site. For every location, a good correlation has been found between the simulated energy demand and data like heating and cooling degree hours. Correspondent linear equations are given here. As another result, the maximum numbers of possible stories for ZEBS have been derived, being between 3 and 10 depending on the location.

Numerical simulation study on the hygrothermal performance of building exterior walls under dynamic wind-driven rain condition

Wind-driven rain(WDR)has a significant influence on the hygrothermal performance,durability,and energy consumption of building components.The calculation of WDR loads using semi-empirical models has been incorporated into the boundary conditions of coupled heat and moisture transfer models.However,prior research often relied on fixed WDR absorption ratio,which fail to accurately capture the water absorption characteristics of porous building materials under rainfall scenarios.Therefore,this study aims to investigate the coupled heat and moisture transfer of exterior walls under dynamic WDR boundary conditions,utilizing an empirically obtained WDR absorption ratio model based on field measurements.The developed coupled heat and moisture transfer model is validated against the HAMSTAD project.The findings reveal that the total WDR flux calculated with the dynamic WDR boundary is lower than that obtained with the fixed WDR boundary,with greater disparities observed in orientations experiencing higher WDR loads.The variations in moisture flow significantly impact the surface temperature and relative humidity of the walls,influencing the calculation of cooling and heating loads by different models.Compared to the transient heat transfer model,the coupled heat and moisture transfer model incorporating dynamic WDR boundary exhibits maximum increases of 17.6%and 16.2%in cooling and heating loads,respectively.The dynamic WDR boundary conditions provide more precise numerical values for surface moisture flux,offering valuable insights for the thermal design of building enclosures and load calculations for HVAC systems.

Development and Application of Decision Support Model for the Performance Optimization of Office Buildings Based on Grasshopper

With the expansion of the office building area,the energy consumption of office buildings is growing.High⁃performance building design contributes to energy saving and the development of green buildings.However,there is a lack of high⁃performance building tools and the workflow is often time⁃consuming.The building performance simulation,multiple objective optimizations,and the decision support model are the new approaches of high⁃performance building design.This paper proposes a newly developed decision support model,a high⁃performance building decision model named HPBuildingDSM,which integrates the building performance simulation,building performance multiple objective optimizations,building performance sampling,and parameter sensitivity analysis to design high⁃performance office buildings.In this research,the HPBuildingDSM was operated to search for the desirable office building design results with low⁃energy and high⁃quality daylighting performances.The simulated results had better daylighting performance and lower energy consumption,whose UDI100-2000 was 37.94%and annual energy consumption performance was 76.28 kWh/(m2·a),indicating a better building performance than the optimized results in the previous case study.

Groundwater Utilisation for Energy Production in the Nordic Environment: An Energy Simulation and Hydrogeological Modelling Approach

Groundwater provides one option to utilise renewable energy sources. The long-term groundwater energy potential for three building complexes, situated at latitude of 64°, was investigated by combining an energy demand simulation for the buildings with hydrogeological modelling. First, a reference year for the building energy demand was created. Secondly, groundwater flow requirements were calculated. The results of the previous stages were utilised in groundwater heat transport modelling in an environment where the natural temperature of groundwater was 4.9°C. Finally, the long-term (50 years) groundwater energy potential was calculated. The groundwater maintained its heating potential during 50 years of operation. When both heating and cooling power were demanded, the long-term pumping rate of groundwater decreased by 60,000 m3/a. Energy utilisation created a cold groundwater plume downstream, in which the temperature decreased by 1 to 2.5°C within a distance of 300 m from the site. Groundwater can provide a long-term energy source for large building complexes in the Nordic climate. Results indicate that groundwater could effectively be utilised until the temperature reaches approximately 4°C. Accurate information on the building energy demand and hydrogeology is essential for successful operation.

Building Information Modeling for Environmental Impact Assessment in Early Design Phases: A Literature Review

The building sector is the largest consumer of energy in industrial countries. Saving energy in new buildings or building renovations can thus lead to significant global environmental impacts. In this endeavor, building information modeling (BIM) and building energy modeling (BEM) are two important tools to make the transition to net-zero energy buildings (NZEB). So far, little attention has been devoted, in the literature, to discuss the connection between BIM, BEM, and Life-cycle assessment (LCA), which is the main topic of this article. A literature review of 157 journal articles and conference proceedings published between 1990 and 2020 is presented. This review outlines knowledge gaps concerning BIM, BEM, and environmental impact assessment. It suggests that defining the process with the right technology (at the right time) would result in a more integrated design process (IDP) and bridge current gaps. The most efficient way to improve process and technology is related to the competences of the architects, engineers and constructors (AEC). The review also indicates that the IDP in the early design phases (EDP) is in need of improvement for architects and engineers, where a better connection between design phases, specific levels of development (LOD) and BIM tools is needed. Competences, process and technology are the three main themes addressed in the review. Their relation to design phases and LOD is discussed. The aim is to propose possible solutions to the current hinders in BIM-to-BEM (BIM2BEM) and BIM-for-LCA (BIM4LCA) integration.

A Method for the Application of Numerical Simulations during Firefighting Operations Using Pre-Simulated, Model-Based Fire Scenarios

The spread of fire and smoke during a fire incident plays a crucial role in rescuing people from the burning building. So it is important for the decision makers (the head of rescue staff) to get a prediction about the spread of fire inside the building through computational techniques like numerical fire simulations. But these techniques require advanced mathematical knowledge and are very time consuming. This paper presents a new method which employs a set of pre-simulated and model-based scenarios to find the closest one to the real fire and present its results to the decision makers. For this purpose, we shift the performance consuming numerical fire simulations into a former phase by integration of these simulations into the planning process of the building. This is realized by enhancing the methods of Building Information Modeling (BIM). To provide the fire simulation results during a real case, our new concept includes a scenario database where all simulated fire scenarios will be collected. In a real case, a special search algorithm will go through this database to find the closest pre-simulated fire scenario to the real fire on the basis of reported information from the burning building.

On the applicability of various levels of detail for occupant behavior representation and modeling in building performance simulation

Occupant behavior(OB)is one of the significant sources of uncertainty in building performance simulation.While OB modeling has received increased attention in the past decade,research on the degree of granularity or level of detail(LoD)required for representing occupants is still in the nascent stages.This paper analyzes the modeling and applicability of three LoDs to represent occupants in building performance assessment.A medium-sized prototype office building located in Chicago,Illinois is used as the simulation case study.Ten occupant-centric attributes are adopted to develop the LoDs for OB representation.We first demonstrate the different modeling approaches required for simulating the three fidelity levels.Later,we illustrate the suitability of the developed LoDs in supporting six building performance use cases across different lifecycle stages.This study intends to provide guidance for the building simulation community on appropriate OB representation to support various use cases.

Effect of typical meteorological year selection on integrated daylight modeling and building energy simulation

The complete description of outdoor luminous and thermal environment is the basis for daylight utilization design with simulation tools.Nevertheless,Typical Meteorological Year(TMY)and generation method specifically developed for the energy simulation of daylight-utilized buildings is still unavailable currently.Luminous environment parameters have not been taken into consideration in existing TMY generation methods.In this study,the feasibility of existing TMY generation process has been examined.A generic office model implementing sided window daylighting is established.Historical meteorological data of Hong Kong region from 1979 to 2007 have been collected and three existing weighting schemes are applied during the Typical Meteorological Month(TMM)selection procedures.Three TMY files for Hong Kong are generated and used to conduct integrated Climate-Based Daylight Modeling and building energy simulation.The result demonstrates that,on annual basis,the energy consumption results obtained from the generated TMY files are in good agreements with the long-term mean annual value.The maximum deviation of annual energy consumptions for the generated TMY files is only 1.8%.However,further analysis on monthly basis shows that all the three generated TMY files fail to fully represent the long-term monthly mean level.The maximum deviation of monthly energy consumptions for the generated TMY files can reach up to 11%.As the energy performance daylight utilization is subject to weather change,analysis on daily and monthly energy level is important,especially during design stage.The deficiency of existing TMM selection process and TMY generation method indicates the necessity to develop a corresponding typical weather data input with finer resolution for the energy simulation of daylight-related buildings.

Comparison of models to predict air infiltration rate of buildings with different surrounding environments

The air infiltration rate of buildings strongly influences indoor environment and energy consumption.In this study,several traditional methods for determining the air infiltration rate were compared,and their accuracy in different scenarios was examined.Additionally,a method combining computational flow dynamics(CFD)with the Swami and Chandra(S-C)model was developed to predict the influence of the surrounding environment on the air infiltration rate.Two buildings in Dalian,China,were selected:one with a simple surrounding environment and the other with a complex surrounding environment;their air infiltration rates were measured.The test results were used to validate the accuracy of the air infiltration rate solution models in different urban environments.For the building with a simple environment,the difference between the simulation and experimental results was 0.86%–22.52%.For the building with a complex environment,this difference ranged from 17.42%to 159.28%.We found that most traditional models provide accurate results for buildings with simple surrounding and that the simulation results widely vary for buildings with complex surrounding.The results of the method of combining CFD with the S-C model were more accurate,and the relative error between the simulation and test results was 10.61%.The results indicate that the environment around the building should be fully considered when calculating the air infiltration rate.The results of this study can guide the application of methods of determining air infiltration rate.

Optimal Design and Dynamic Simulation of Mountain Bike with Rear Suspension

This paper investigates the dynamic design methodology of mountain bikes with rear suspension. Firstly, a multi-rigid body dynamic model of rider and mountain bike coupled system is constructed. The rider model includes 19 skeletons, 18 joints and 118 main muscles. Secondly, to validate the feasibility of the model, an experiment test is designed to reflect the real cycling status. Finally, aiming at enhancing the performance of the rider vibration comfort, the scale parameters of rear suspension are optimized with computer simulation and uniform design. The mathematical model in the vibration performance and the design variables is constructed with regression analysis. The result shows that when the length of side link is 90 mm, the length of connected rod is 336.115 1 mm and the included angle between absorber and side link is 60°, the mountain bike has better vibration comfort. This study and relevant conclusions are of practical importance to the design of the mountain bike＇s rear suspension system.

Dynamic response characteristics of super high-rise buildings subjected to long-period ground motions

Spectrum characteristics of different types of seismic waves and dynamic response characteristics of super high-rise building structures under long-period ground motions were comparatively analyzed. First, the ground response wave （named LS-R wave） of a soft soil site with deep deposit, taking long-period bedrock seismic record as input, was calculated by wave propagation method. After that, a TOMAKOMAI station long-period seismic record from the Tokachi-Oki earthquake and conventional E1-Centro wave were also chosen. Spectrum characteristics of these waves were analyzed and compared. Then, a series of shaking table tests were performed on a 1：50 scale super high-rise structural model under these seismic waves. Furthermore, numerical simulation of the prototype structure under these excitations was conducted, and structure damages under different intensive ground motions were discussed. The results show that： 1） Spectrum characteristics of ground response wave are significantly influenced by soft soil site with deep deposit, and the predominant period has an increasing trend. 2） The maximum acceleration amplification factor of the structure under the TOM wave is two times that under the E1-Centro wave; while the maximum displacement response of the structure under the TOM wave is 4.4 times that under the E1-Centro wave. Long-period ground motions show greater influences on displacement responses than acceleration responses for super high-rise building structures. 3） Most inelastic damage occurs at the upper 1/3 part of the super high-rise building when subjected to long-period ground motions.

Chinese prototype building models for simulating the energy performance of the nationwide building stock

Building energy modeling(BEM)has become increasingly used in building energy conservation research.Prototype building models are developed to represent the typical urban building characteristics of a specific building type,meteorological conditions,and construction year.This study included four residential buildings and 11 commercial buildings to represent nationwide building types in China.With consideration of five climate zones and different construction years corresponding to national standards,a total of 151 prototype building models were developed.The building envelope properties,occupancy and energy-related behaviors,and heating,ventilation,and air-conditioning(HVAC)system characteristics were defined according to the corresponding building energy efficiency design standards,HVAC design standards,and through other sources,such as questionnaire surveys,on-site measurements,and literature,which reflect the real situation of existing buildings in China.Based on the developed prototype buildings,a large database of 9225 models in 270 cities was further developed to facilitate users to simulate building energy in different cities.In conclusion,the developed prototype building models can represent realistic building characteristics and construction practices of the most common residential and commercial buildings in China,serving as an important foundation for BEM.The models can be used for analyses related to building energy conservation research on typical individual buildings,including energy-saving technologies,advanced controls,and new policies,and providing a reference for the development of building energy codes and standards.

Climate change and building ageing impact on building energy performance and mitigation measures application:A case study in Turin, northern Italy

This study uses a building energy performance simulation to investigate the impact of predicted climate warming and the additional issue of building ageing on the energy performance for a library in Turin,Italy.The climate and ageing factors were modelled individually and then integrated together for several decades.Results from the climate-only simulation showed a decrease in thebuilding heating energy usage which outweighed the increase in the on-site cooling energy demand occurring in a warming scenario.The study revealed a high sensitivity of energy performance to building ageing,in particular due to HVAC(Heating,Ventilation and Air Conditioning) equipment efficiency degradation.Building ageing was seen to negatively affect the energy performance as it induced a further increase of the cooling energy usage in a warming climate,while it also counteracted the reduction of the heating energy usage resulting from warming.Simulations on the combination of mitigation techniques showed a number of potentially retrofit measures that would be beneficial for buildings to avoid an increase in the cooling energy usage due to climate warming.The combination of these retrofit techniques showed a potential decrease of 87.3% in the final cooling energy usage for the considered building.

Method for Evaluating the Influence of Obstruction of Sea Breeze by Clusters of High-Rise Buildings on the Urban Heat Island Effect

This study aims to propose a method for quantitatively evaluating the influence which the obstruction of sea breezes by clusters of high-rise buildings has on the urban heat island effect using a weather simulation model and Geographic Information Systems (GIS). Specifically, a method of evaluating the influence of the obstruction of sea breeze by high-rise buildings on the urban heat island effect was proposed. In the method, two scenarios that imagine urban forms which differ with regard to whether or not they contain high-rise buildings are created and weather simulation is conducted, and the results of the simulations are comparatively analyzed focusing on temperature and wind speed. Evaluation was conducted in two stages, and Shiodome of Minato City in the Tokyo Metropolis was selected as the region for evaluation. In two stages of evaluation, a rise in temperature of approximately 0.3 K and a reduction in wind speed of approximately 1 m/s were observed in a region approximately five to ten kilometers square downwind of high-rise buildings in the period 6 PM to 9 PM, and a higher temperature caused by the obstruction of sea breeze by high-rise buildings was identified. The fact that such a higher temperature was confirmed in the time period from 6 PM onwards, in which the temperature decreases, reveals that obstruction of sea breeze by high-rise buildings dulls the decrease in temperature which occurs from evening onwards, and influences nighttime urban heat island formation.

基于Simulink平台的变压器纵联差动保护的仿真研究

电力系统实验综合性强、复杂且抽象难懂,实验仿真相较传统实验在电力系统实验教学中具有一定优势。采用Simulink仿真平台设计电力变压器纵联差动保护实验仿真。从已知案例出发做了相关计算,设计变压器、电流互感器等关键元件的参数,构建主电路仿真模型,分析变压器正常或区外故障时电流互感器在计算变比和选择变比情况对差动回路电流的影响、变压器内部短路故障时的差动保护等。通过参数计算、建模及实验仿真分析等过程,使得抽象问题具体化,展现了实验仿真灵活性、优越性、创新性等特点。