预制舱类工业建筑能耗模拟软件PCES的设计与开发

  [目的]  建筑能耗模拟软件是建筑节能设计与建筑能耗评估重要的支持工具,而现行的建筑能耗模拟软件难以满足预制舱类工业建筑能耗分析及机柜级微环境控制设计的需求。  [方法]  提出了预制舱类建筑热平衡模型,基于该物理模型开发出预制舱类建筑能耗计算软件PCES,通过工程案例证明了PCES能客观地反映建筑物的能耗分布规律。  [结果]  计算表明:PCES可以实现对预制舱建筑围护结构、舱内热状况以及机柜级热环境状况进行求解,适用于工程节能设计与能耗分析。  [结论]  研究成果可实现建筑参数设定、能耗模拟与建筑热过程及能耗分析。     

Can envelope codes reduce electricity and CO2 emissions in different types of buildings in the hot climate of Bahrain?

The depletion of non-renewable resources and the environmental impact of energy consumption, particularly energy use in buildings, have awakened considerable interest in energy efficiency. Building energy codes have recently become effective techniques to achieve efficiency targets. The Electricity and Water Authority in Bahrain has set a target of 40% reduction of building electricity consumption and CO₂ emissions to be achieved by using envelope thermal insulation codes. This paper investigates the ability of the current codes to achieve such a benchmark and evaluates their impact on building energy consumption. The results of a simulation study are employed to investigate the impact of the Bahraini codes on the energy and environmental performance of buildings. The study focuses on air-conditioned commercial buildings and concludes that envelope codes, at best, are likely to reduce the energy use of the commercial sector by 25% if the building envelope is well-insulated and efficient glazing is used. Bahraini net CO₂ emissions could drop to around 7.1%. The simulation results show that the current energy codes alone are not sufficient to achieve a 40% reduction benchmark, and therefore, more effort should be spent on moving towards a more comprehensive approach.     

Improvements of building envelope using passive cooling techniques to reduce the cooling load in hot‐dry regions

In developed countries, the buildings are responsible for massive energy consumption. When the construction is based on the use of nonsustainable methods, the buildings were dependent on the active systems, for ensuring a maximal indoor comfort. This has increased energy consumption and related greenhouse gas emissions. In this study, a reduction technique of cooling load and power consumption in buildings is proposed. This technique involves the combination of three passive cooling techniques, thermal insulation, phase change materials (PCMs), and electrochromic double glazing. These techniques are applied through simulation software “DesignBuilder” to a building envelope model in various areas like walls, roofs, and glazing. For this purpose, a standard building model is compared with 16 other cases that incorporated the passive cooling techniques for determining the effectiveness of the proposed method. The results show that a combination of PCMs, thermal insulation, and double glazing can reduce the cooling load from 70.37 to 50.53 kW and the energy consumption from 1.51 to 0.90 kWh/m ².     

Application of improved grey relational projection method to evaluate sustainable building envelope performance

Buildings are energy gluttons. Improving thermal performance of building envelopes will reduce energy consumption in buildings. The development of advanced building envelope systems reducing energy losses is a critical research frontier. This study introduces a simple but reliable methodology for building envelope evaluation and optimization in the conceptual stage. An improved grey relational projection method is proposed to select the optimum building envelope alternative. A combination weighting method combining the subjective weighting method and the objective weighting method is adopted to calculate the weights of the factors and sub-factors. The relative projection values of the alternatives are calculated. And the optimum alternative is obtained. An example is given to demonstrate the proposed method. Finally the proposed method is verified. The results show that this method is simple and practical, and it has potential as a powerful tool in building envelope evaluation and optimization for building owners, manufacturers, designers, and evaluators.     

A marketable all-electric solar house: A report of a Solar Decathlon project

This paper reports a design and building process of a net-zero-energy modular house, named ElementHouse, which was entered for the 2007 Solar Decathlon competition that was organized by the U.S. Department of Energy. This paper discusses the development of the ElementHouse from its initial concept to the actual construction, which integrated multi-disciplinary knowledge of architecture, mechanical engineering, and electrical engineering. By employing computer-aided simulation tools, several design approaches were developed to achieve the optimal balance among function, aesthetics, economy, and energy—a challenge in many sustainable building designs. A simplified energy model helped to form the building configuration at the preliminary design stage by showing how energy use is affected by various parameters, leading to optimization studies that provided design guidelines towards an energy-efficient building envelope and opening design. Energy modelling also estimated the annual energy use and electricity generation, as well as the costs associated with long-term operation of the house. The energy demand estimate and its daily power profile helped to design the photovoltaic (PV) system. The modular configuration of the building and its roof structure was then iteratively altered to accommodate the PV panels in such a way as to generate the most power and to facilitate interstate transportation of ElementHouse. With the progress of the design process, detailed energy simulation using EnergyPlus provided more accurate estimates of power use and generation and, coupled with daylighting simulation performed with Radiance, permitted finalizing the building envelope, opening, and electric lighting design. The building envelope embraced the passive and low energy philosophy to minimize the annual heating and cooling load and to optimize natural lighting. By illustrating the whole picture of ElementHouse design, this paper discusses a way of effectively designing and building a comfortable and affordable solar house.     

Prediction of monthly global solar radiation using adaptive neuro fuzzy inference system (ANFIS) technique over the State of Tamilnadu (India): a comparative study

Enormous potential of solar energy as a clean and pollution free source enrich the global power generation. India, being a tropical country, has high solar radiation and it lies to the north of equator between 8°4′ &; 37°6′ North latitude and 68°7′, and 97°5′ East longitude. In southindia, Tamilnadu is located in the extreme south east with an average temperature of gerater than 27.5° (> 81.5 F). In this study, an adaptive neuro-fuzzy inference system (ANFIS) based modelling approach to predict the monthly global solar radiation(MGSR) in Tamilnadu is presented using the real meteorological solar radiation data from the 31 districts of Tamilnadu with different latitude and longitude. The purpose of the study is to compare the accuracy of ANFIS and other soft computing models as found in literature to assess the solar radiation. The performance of the proposed model was tested and compared with other earth region in a case study. The statistical performance parameters such as root mean square error (RMSE), mean bias error (MBE), and coefficient of determination (R2) are presented and compared to validate the performance. The comparative test results prove the ANFIS based prediction are better than other models and furthermore proves its prediction capability for any geographical area with changing meterological conditions.     

马鞍山市多层住宅典型围护结构的空调能耗对比

选取马鞍山市某居住建筑为研究对象，运用eQUEST软件对其空调能耗进行了动态模拟。采用2000年与2008年市场主流建筑结构材料进行对比，计算和分析结果表明：改善居住建筑围护结构材料节能率可达到7．5％。     

Adaptive Neuro-Fuzzy Inference System modelling for performance prediction of solar thermal energy system

This study investigates in details the applicability of Adaptive Neuro-Fuzzy Inference System (ANFIS) approach for predicting the performance parameters of a solar thermal energy system. Experiments were conducted on the system under a broad range of operating conditions during different Canadian seasons and weather conditions. The experimental data were used for developing the ANFIS network model. This later was then optimised and applied to predict various performance parameters of the system.The predicted values were found to be in excellent agreement with the experimental data with mean relative errors less than 1% and 9% for the stratification temperatures and the solar fractions, respectively. The results show that ANFIS approach provides high accuracy and reliability for predicting the performance of energy systems.Furthermore, the ANFIS prediction results were compared against the ANNs predictions of Yaïci and Entchev [Appl Therm Eng 2014; 73:1346–57]. Results showed that the ANFIS model performed slightly better than the ANNs one. However, the ANNs method provided more flexibility in terms of model implementation and computing speed capabilities.Finally, this investigation demonstrates that ANFIS is an alternative powerful and reliable method comparable to the ANNs; they can be used with confidence for predicting the performance of complex renewable energy systems.     

Analysis of variables that influence electric energy consumption in commercial buildings in Brazil

Air conditioning systems in commercial buildings in Brazil are responsible for about 70% share of their energy consumption. According to BEN 2009 (The Brazilian Energy Balance), energy consumption in the residential, commercial and public sectors, where most buildings are found, represents 9.3% of the final energy consumption in Brazil. This paper aims to examine design factors that could contribute to greater reductions of electric energy consumption in commercial buildings, with emphasis on air conditioning. Simulations were carried out using shades and different types of glass, walls, flooring and roofing. The VisualDOE 2.61 was used as a simulation tool for calculating energy consumption of the analyzed building. This paper shows that the energy performance of the building is considerably influenced by the façade protection and shows, through tables, the impact that decisions related to the top-level and façades have on the energy consumption of the building. The authors concluded that the results confirm the importance of taking energy use into account in the very first design stages of the project, since appropriate choices of types of glass, external shading and envelope materials have a significant impact on energy consumption.     

Capacitive effect on the heat transfer through building glazing systems

In recent years, several intensive studies have been carried out in order to reduce the energy consumption of buildings. One solution lies on whole building energy simulation that permits to enable the heat (and moisture) transfer through the building envelope and, consequently, is a way to understand how to improve the building performance. This article aims to analyze the modeling level needed to successfully evaluate the heat transfer through glazing parts of windows in such whole-building simulations as it is well-known that windows are the thermally weakest elements of the building envelope.     

Daylighting and its implications to overall thermal transfer value (OTTV) determinations

The overall thermal transfer value (OTTV) and daylighting are two approaches controlling building energy use. In Hong Kong, although OTTV calculations are mandatory in the submission of building plans for approval, daylighting credits are not included in building envelope designs. To promote energy-efficient building designs we use the computer simulation tool, DOE-2, to illustrate the energy performance of a generic commercial building due to various daylighting schemes and OTTV designs. The year-round energy expenditures and loads are determined from the simulation results. Analysis is carried out in terms of the reduction in electric lighting requirement and the cooling penalty due to solar heat. Regression techniques are conducted to correlate the annual incremental electricity use with OTTV and daylighting aperture (DA) (product of window-to-wall ratio (WWR) and light transmittance (LT)). Contours of equal annual incremental electricity use for different building envelope parameters are developed. Important features for daylighting schemes are highlighted and implications for OTTV designs are discussed.     

Investigation on the feasibility and performance of ground source heat pump (GSHP) in three cities in cold climate zone,China

As a renewable energy technology, ground source heat pump (GSHP) system is high efficient for heating and cooling in office buildings. However, this technology has strong dependence on the meteorological and building envelope thermal characteristic parameters. For the purpose of quantitative investigation on the feasibility and performance GSHP, three cities located in cold climate zone, Qiqihaer, Shenyang and Beijing, were sampled. Firstly, the office building dynamic loadings in these cities were calculated on basis of the different meteorological and envelope thermal characteristic parameters. The TRNSYS, one kind of energy simulation software, were employed to simulate the operation performances of GSHP on basis of these parameters. The simulation revealed the data on the outlet/inlet temperature of buried pipes, soil temperature, energy consumption distribution and the coefficient of performance (COP) for one year operation. Furthermore, ten years operation was also simulated to show the stability of the performance based on the outlet/inlet temperature of buried pipes and soil temperature. From these results, the GSHP had shown its most suitable performance in Beijing, second in Shenyang and worst in Qiqihaer. These results could be used as a reference on suitable utilization of GSHP systems in office buildings located in cold climate zone, China.     

The transient house heating condition—the daily changes of the building envelope response factor (BER)

The current paper presents a logical extension of previous work [Lukić N. The transient house heating condition—the building envelope response factor (BER). Renewable Energy 2003;28:523–32.]. The daily changes of the earlier introduced building envelope response factor (BER) are shown, under transient heating conditions, during the first three heating days after a long non-heating period. Four simulation cases were studied: two-layered thermal-insulation-concrete house walls where the thermal-insulation had in, out and middle position according to inside of house and one-layered concrete house walls. Three different behaviors of central radiator heating system were simulated. The BER factor is considered an important pointer on influence of house walls to heating/cooling energy consumption and thermal comfort during transient conditions. In numerous simulations, using BER factor presentation, the start heating-period was investigated up to the achievement of defined thermal comfort inside the building walls. Alongside of the expected start peak, local peaks and off-peaks of BER factor appeared during first three heating days. Recognition of the daily changes of BER factor could enable aims, lower energy consumption and a rapid achievement of good thermal comfort. In this attempt, a building envelope, as a passive source of energy, is a critical factor.     

用云计算和物联网技术对建筑能源管理的思路

叙述了传统的建筑能耗监测平台存在的问题,指出云计算、物联网技术的内涵,提出,构建以云计算和物联网技术管理建筑能耗监测系统的思路。     

Optimization of building window system in Asian regions by analyzing solar heat gain and daylighting elements

This paper presents and optimizes the annual heating, cooling and lighting energy consumption associated with applying different types and properties of window systems in a building envelope. Through using building simulation modeling, various window properties such as U-value, solar heat gain coefficient (SHGC), and visible transmittance (Tvis) are evaluated with different window wall ratios (WWRs) and orientations in five typical Asian climates: Manila, Taipei, Shanghai, Seoul and Sapporo. By means of a regression analysis, simple charts for the relationship between window properties and building energy performance are presented as a function of U-value, SHGC, Tvis, WWR, solar aperture, effective aperture, and orientation. As a design guideline in selecting energy saving windows, an optimized window system for each climate is plotted in detailed charts and tables.     

Evaluation of the thermal performance indices of a ventilated double window through experimental and analytical procedures: Uw-values

Simulations to evaluate energy demand for heating and cooling and thermal comfort are becoming more and more common place in the building design process, at least in the most complex cases. In all detailed or simplified calculations, to analyse heat transfer to and from a building, several input parameters are needed. The inputs for the simulation of a whole building are at least the building geometry, the building envelope thermal indices (like thermal transmittance or the solar heat gain coefficient) and typical local climatic data. In a ventilated double window, the air flow through the channel between the two windows makes its thermal performance highly dynamic and dependent on the air flow characteristics. For a whole building simulation, single coefficients or easily calculated coefficients are needed for each facade system, including ventilated systems. In this paper, equivalent thermal transmittance coefficients for a ventilated double window are assessed and presented. For that, experimental measurements in the absence of solar radiation (night period) were used to identify tendencies and validate calculations. Furthermore, simulations were done in order to estimate the U_w-values of the ventilated double window under different windows configuration and different air flow rates. These values can then be used in whole building simulation programmes.     

Optimisation of buildings’ solar irradiation availability

In order to improve the sustainability of new and existing urban settlements it is desirable to maximise the utilisation of the solar energy incident on the building envelope, whether by passive or active means. To this end we have coupled a multi-objective optimisation algorithm with the backwards ray tracing program RADIANCE which itself uses a cumulative sky model for the computation of incident irradiation (W h/m²) in a single simulation. The parameters to optimise are geometric (the height of buildings up to their facade and the height and orientation of roofs), but with the constraint of maintaining an overall built volume, and the objective function is heating season solar irradiation offset by envelope heat losses. This methodology has been applied to a range of urban typologies and produces readily interpretable results. The focus of this work is on the design of new urban forms but the method could equally be applied to examine the relative efficiency of existing urban settlements, by comparison of existing forms with the calculated optima derived from relevant specifications of the building envelope.     

Simulation of indoor temperature and humidity conditions including hygrothermal interactions with the building envelope

The hygrothermal behaviour of the building envelope affects the overall performance of a building. Numerous tools exist for the simulation of the heat and moisture transfer in the building envelope and whole building simulation tools for energy calculations. However, working combinations of both models for practical application are just about to be developed. In this paper such a combined model, that takes into account moisture sources and sinks inside a room, input from the envelope due to capillary action, diffusion and vapour absorption and desorption as a response to the exterior and interior climate conditions as well as the well-known thermal parameters will be described. The new model is validated by performing a series of field experiments and the moisture buffering capacity of the building envelope is investigated. In the conclusions the possible range of future applications of hygrothermal building performance models is addressed and the needs for further research are identified.     

A discussion on potentials of saving energy use for commercial buildings in Hong Kong

A typical commercial building was selected for a detailed study of energy use by mechanical ventilation and air-conditioning (MVAC) systems. Data from preliminary building energy auditing were analyzed and compared with the energy use of other similar buildings. Correlation relationships between the building envelope heat gain and the electrical energy use for MVAC system with key parameters were derived with approaches similar to the Princeton Scorekeeping Method (PRISM). Further, the energy simulation program TRACE 600 was used to justify the results. A total of 20 energy-saving measures were investigated for possible use in local commercial buildings. The results provided are useful for engineers in designing energy-efficient commercial buildings or generating new design concepts for better MVAC systems.     

Simulation of façade and envelope design options for a new institutional building

This paper presents a simulation case study of façade and envelope preliminary design options for the new Engineering building of Concordia University in Montreal. A major principle of the analysis was to create a high quality building envelope in order to optimally control solar gains, reduce heating and cooling energy demand and reduce electricity consumption for lighting, while at the same time maintain a comfortable and pleasant indoor environment. The stated approach of the design team was to aim for an energy-efficient building, employing innovative technologies and integrating concepts such as daylighting and natural ventilation. Detailed energy simulations were therefore performed from the early design stage, in order to present recommendations on the choice of façade, glazings, shading devices, lighting control options, and natural ventilation. Integrated thermal studies, a daylighting analysis and the impact of the above on HVAC system sizing were considered. Simulation results showed that, using an optimum combination of glazings, shading devices and controllable electric lighting systems, the energy savings in perimeter spaces can be substantial. Perimeter heating could be eliminated if a high performance envelope is used. The building is currently being commissioned.