LCC analysis for energy-saving in residential buildings with different types of construction masonry blocks

Space heating in cold climates requires large quantities of heat energy to be spent. Therefore, considerable energy-savings can be obtained using construction wall materials with low thermal conductivity in the buildings. In this study, an economic analysis (LCC analysis) was performed in order to estimate the optimum thickness, saving and pay-back period which minimizes the total cost including the masonry material and the energy consumption costs. The LCC analysis was carried out for external walls of buildings in Afyonkarahisar, Turkey. Considering long term and current outdoor air temperature records, degree-days (DD) values were used, and the variation of annual energy requirement of the building was investigated for various masonry (product) types for per unit area. Masonry products were block elements with one, two, three and four row-hollows, hollow-brick and aerated concrete. As the fuel types, fuel-oil, natural gas, coal and electricity were considered in the analysis. The functional unit of the LCC was the use of 1 m² of the building's living area over 50 year's period. As a conclusion, the highest energy-saving was obtained by the use of hollow blocks with 4 rows. Moreover, the most suitable fuels for all climate zones appear to be electricity and fuel-oil. But, the natural gas is a better choice when the atmospheric pollution is an important consideration.     

夏热冬冷地区办公建筑降低供暖空调能耗的技术路径

以上海地区某办公建筑为例,基于EnergyPlus能耗模拟,探讨了围护结构性能提升和暖通空调系统优化这2条节能技术路径对夏热冬冷地区办公建筑降低供暖空调全年能耗的有效性.结果 表明:围护结构性能提升的节能潜力较小,经济性较差;单纯提高围护结构保温隔热性能并不能保证降低建筑年耗冷量,应综合分析全年供热供冷能耗确定围护结构...     

复合供能系统优化配置和运行策略研究

针对由微小型燃气轮机分布式供能系统和地下水地源热泵组成的复合供能系统,以北京市某典型医院为应用对象,分别以年总费用和天然气年节能率为优化目标,对系统在经济最优、以热定电和节能最优3种运行策略下的优化配置和运行规律进行了研究。结果表明,与电制冷机+燃气锅炉+市电的常规分供方案和地下水地源热泵+市电方案相比,复合供能系统具有经济、节能与电力调峰性能明显等综合优势;与联合循环+燃气锅炉+电制冷机模式相比,复合供能系统在传统的经济最优和以热定电运行策略下并不节能,但在节能最优运行策略下可实现节能。     

Energy-saving estimation model for hypermarket HVAC systems applications

Energy saving estimation model (ESEM) use normal distribution (Gaussian) probability theory to predict potential savings for previously determined system improvements. Those improvements are low/high cost investments based on data gathered during one year monitoring of typical hypermarket facility HVAC system. The consumption of electrical energy and natural gas has been monitored and system segments with largest amount of energy consumption have been marked. Gathered data pointed out to fan units as the biggest energy consumers and suggested that system energy-saving improvement must be focused on fans energy consumption control. This paper deals with ESEM inputs and outputs in order to provide correct financial estimation of specific investment.     

Prediction of energy savings with anidolic integrated ceiling across different daylight climates

The subject of this article is building energy saving on electrical lighting by anidolic integrated ceiling (AIC), compared in different daylight climates. This particular device collects diffuse daylight with an anidolic external collector and channels it into a reflective ceiling plenum. The exit apertures located at the rear of the room will discharge the daylight to the deep and gloomy zones of the room and thus reduce demand for electrical lighting. This paper analyses the savings on building energy for different locations. Two cases were studied with Singapore representing a location of high sun altitude and high building density, while Sheffield representing a location of lower sun altitude and moderate urban density. The performance criteria Daylight Autonomy (DA) was used to quantify the energy saving, after the AIC was integrated into the default ribbon window façade of a standard office room. Computational simulations show that more than 20% of energy for electrical lighting can be saved. The energy savings are quite similar for both locations, with 21% for Singapore and 26% for Sheffield. Therefore, it is valid to conclude that AIC is a universal remedy to improve daylighting and energy efficiency in deep buildings.     

寒冷地区医院门诊大厅物理环境调研与建筑性能分析——以天津市为例

以医院门诊大厅为研究对象,对我国寒冷地区典型城市——天津市的5所典型医院门诊大厅的空间形式进行了归纳总结,并分别在冬季、春季、夏季对室内物理环境进行了监测及数据分析,以了解既有医院门诊大厅室内热环境和光环境的现状,并结合软件模拟进行分析总结,为医院门诊大厅的设计提供参考。     

热电(冷)联产系统运行调节的双目标规划

针对热电（冷）联产系统的运行调节问题建立了包含经济性和节能要求的双目标规划模型,根据热、电、冷负荷的全年变化提出了合理的运行模式和运行方案,探讨了经济性和节能要求的权重变化对总目标函数的影响,分析了分时电价、燃料价格对系统运行策略的影响.     

节能建筑全寿命周期成本研究

通过对建筑产品生命期能耗成本评估分析,建立现金流的寿命期经济效益分析模型。结合工程实例,运用造价和经济原理计算分析节能投入前后建筑物寿命期费用变化,从技术、经济和管理角度分析,得出同寿命期时,总成本现值随折现率的增大而减小,总成本年值随折现率的增大而增加;相同折现率时,总成本现值随寿命期的增大而增加,实证了优化建筑能耗带来的寿命期收益。     

谈现代化建筑的电气节能技术应用

在能源消耗中,建筑能耗大概占社会总能耗的1/4。在建筑能耗中,建筑电气能耗所占比重非常之大。因此,如何设计电气节能,是建筑节能的主要突破口。本文探讨了建筑电气节能的现状和原则,提出了具体的电气节能技术的应用。     

Optimum, technical and energy efficiency design of residential building in Mediterranean region

Jordan heavily relies on imported oil and gas for meeting its energy need as the same time the construction sector consumed more than half of the total electricity consumption in Jordan in 2008. In order to provide the occupants with thermal comfort at least cost, applying energy saving measures into early design stage can be significant to achieve this goal.This paper discusses an assessment of best orientation of the building, windows size, thermal insulation thickness from energetic, economic and environmental point of view for typical residential building located in Mediterranean region. The results show that about 27.59% of annual energy consumption can be saved by choosing best orientation, optimum size of windows and shading device, and optimum insulation thickness. The Life Cycle Cost (LCC) is reduced by 11.94%. The specific energy consumption per square meter is 64 kWh/m² a.     

Modeling and economic analysis of gas engine heat pumps for residential and commercial buildings in various climate regions of Iran

There is an increasing trend in using heat pumps in air conditioning (heating/cooling) systems of residential and commercial buildings. The required power to drive the compressor of vapor compression heat pump cycles may be provided by either an electrical motor or an internal combustion engine. In this paper thermal modeling and economic analysis of gas engine heat pumps (GEHPs) are presented based on energy and mass balance equations as well as the gas engine operating parameters (such as thermal efficiency, fuel consumption and fuel mass flow rate) and heat pump operating parameters (such as evaporator and condenser capacity and compressor input power). Based on the modeling results and with estimating GEHP fuel consumption, the economic analysis of using gas engine heat pumps (in comparison with the electrical heat pumps) at various climate regions of Iran, for both residential and commercial (office) buildings, and for both cooling and heating modes, was performed. Appropriate cost functions for predicting GEHP capital investment were proposed. Three approaches including equivalent uniform annual cost (EUAC), the annual cost of energy consumption, and payback period were applied in the economic analysis.     

Uncertain programming of building cooling heating and power (BCHP) system based on Monte-Carlo method

Uncertainty of building energy demands has large influence on accuracy of building cooling heating and power (BCHP) programming model. Uncertain programming model is proposed to optimize BCHP system with consideration of uncertainty of energy demands. Monte-Carlo method (MCM) and mixed-integer nonlinear programming (MINLP) are integrated in the model (M-M model for short). MCM can be used to simulate the uncertainty of energy demands avoiding dimension disaster and complex calculation. Correlation between different energy demands can also be considered in the model. And facility scheme and operation strategy can be optimized simultaneously in MINLP model. A numerical example is calculated with the M-M model. Convergence rate of expected values of the variables optimized in the model is high. Influence of energy demand uncertainty is studied with investigation of expected values, standard deviations of evaluation indicators and facility capacities. Sensitivity of the parameters to energy demand uncertainty is much different. It is unnecessary to consider uncertainty of energy demands when evaluating system feasibility with indicators of annual cost saving rate and annual natural gas saving rate, for they are influenced only a little by uncertainty of energy demands. While uncertainty of energy demands must be considered when studying parameters related to assistant facilities, which are very sensitive to the uncertainty. The result is valuable for designing strategy of facility scheme.     

Influence of energy demands ratio on the optimal facility scheme and feasibility of BCHP system

Building cooling heating & power (BCHP) system has advantages of energy saving and environment protection. Accurate feasibility evaluation and rational match between energy supply and energy demands are necessary for the realization of advantages of BCHP system. The influence of energy demands on the optimal facility scheme and feasibility of BCHP system needs especially to be studied. Mixed-integer nonlinear programming model is established with integrated optimization of facility scheme and operation strategy of BCHP system. A series of energy demands with different heat-electricity ratio and cooling-electricity ratio are achieved based on the energy demands of a hotel. Sensitivity analysis about energy demands ratios is carried out in this paper to study their influence on optimal capacity of facilities and feasibility indices. And the reason of the results is analyzed. Indices of feasibility evaluation include annual cost, annual cost saving rate and annual natural gas saving rate. It is shown in result that energy demands of different type have different weight in optimal capacities. Optimal capacities of facilities should be designed with consideration of all three kinds of energy demands. Different feasibility evaluation are achieved with different indices. The BCHP system is preferable for buildings with high heat demand.     

Whole building energy simulation and energy saving potential analysis of a large public building

This article explores how to use EnergyPlus to construct models to accurately simulate complex building systems as well as the inter-relationships among sub-systems such as heating, ventilation and air conditioning (HVAC), lighting and service hot water systems. The energy consumption and cost of a large public building are simulated and calculated for Leadership in Energy and Environmental Design (LEED) certification using EnergyPlus. American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) baseline model is constructed according to ASHRAE 90.1 standard and the comparison of annual energy consumption between ASHRAE baseline model and proposed model is carried out. Moreover, an energy efficiency (EE) model is built based on the design model. Meanwhile, other energy conservation measures (ECMs) such as daylighting dimming and occupant sensors are considered. The simulation results show 4.7% electricity consumption decrease but 6.9% gas consumption increase of the EE model compared to ASHRAE baseline model. In summary, the annual energy cost of the EE model is reduced by 7.75%.     

Energy efficiency and economic feasibility analysis of cogeneration system driven by gas engine

A cogeneration system driven by gas engine is proposed and studied. The cogeneration system can provide electricity generation and cooling/heating for buildings. The cogeneration system has a large potential for energy saving and economical benefits. Primary energy rate (PER) and comparative primary energy saving are used to evaluate and compare the performances of the cogeneration system and conventional separate system. The comparative primary energy saving of the cogeneration system is more than 37% compared to conventional separate system at the required energy flows. The total annual income, the total annual saving and payback period of the cogeneration system are used to analyze its economy. The calculation result of economic analysis shows that the cogeneration system has a good economic benefits.     

双层玻璃幕墙的自然采光及照明系统节能研究

自然光通过双层玻璃幕墙后其照度显著下降,透光率仅为10%~20%,在减少空调系统能耗时却影响了自然采光。通过室内自然光的照度测量发现,自然光照度在室内随纵深呈指数形式递减,在晴天和全阴天时距玻璃幕墙较近的位置(玻璃幕墙到1/2纵深)照度值都是高于500 lux的,而在3/4纵深后的工作面照度低于300 lux,室内可以采用部分自然光照明。结合建筑照明平面图,采取优化灯具控制回路开关设置的方法提高自然光利用率时,照明系统能耗将降低50%;采用主动式的采光设计,利用自然光时则照明系统将节能75%以上。     

建筑节能技术在奥运场馆中的应用

结合奥运场馆建设实例,介绍了场馆建设应严格执行的节能标准,从围护结构、太阳能、地源热泵、自然采光通风、水资源综合利用等方面阐述了建筑节能技术在奥运场馆中的应用,从而不断提高我国建筑节能技术水平.     

造纸企业污水处理沼气脱硫

以上海某造纸企业沼气的回收利用工程为例,提出改造后沼气利用工艺流程,比较干法脱硫、湿法脱硫、生物脱硫工艺的特点和经济性,比较一体式生物脱硫和分离式生物脱硫工艺,改造工程采用分离式生物脱硫工艺进行沼气脱硫。沼气用于沼气锅炉后,该造纸企业天然气总用量下降12%,取得了良好的节能效果和经济效益。     

Automatic generation of energy conservation measures in buildings using genetic algorithms

Building energy simulations are key to studying energy efficiency in buildings. The state-of-the art building energy simulation tools requires a high level of multi disciplinary domain expertise from the user and many technical data inputs that curb the usability of such programs. In this paper an IT tool is presented, which has the capability of predicting a building's energy utilization configuration based on the reported annual energy and a few non-technical inputs from the user; and correspondingly generates cost effective energy conservation measures for the intended savings.The approach first identifies the system variables that are critical to a building's energy consumption and searches for the combination of these parameters that would give rise to the annual energy consumption as reported by the facility. Genetic algorithms are utilized to generate this database. A statistical fit is formulated between the system variables and the annual energy consumption from the database. Using this correlation, system configuration for the target energy efficiency is determined with corresponding energy conservation measures. A cost analysis is carried out to prescribe the most cost effective energy conservation measures. Competency of the tool is demonstrated in the paper through case studies on three geographies with different climate conditions.     

The daylighting dashboard – A simulation-based design analysis for daylit spaces

This paper presents a vision of how state-of-the-art computer-based analysis techniques can be effectively used during the design of daylit spaces. Following a review of recent advances in dynamic daylight computation capabilities, climate-based daylighting metrics, occupant behavior and glare analysis, a fully integrated design analysis method is introduced that simultaneously considers annual daylight availability, visual comfort and energy use: Annual daylight glare probability profiles are combined with an occupant behavior model in order to determine annual shading profiles and visual comfort conditions throughout a space. The shading profiles are then used to calculate daylight autonomy plots, energy loads, operational energy costs and green house gas emissions. The paper then shows how simulation results for a sidelit space can be visually presented to simulation non-experts using the concept of a daylighting dashboard. The paper ends with a discussion of how the daylighting dashboard could be practically implemented using technologies that are available today.