中型办公楼照明节能控制措施的效果

本文就利用照明控制系统和计量系统对中小型建筑物开展节能活动的情况进行介绍。把相应系统导人中型办公楼,实施多项照明控制措施,对节能效果进行了验证。特别是如何结合各个运行点的使用方式,设置恰当的系统,能获得可喜的节能效果。     

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.     

Ground source heat pump systems: current status

Geothermal energy is critical to achieving more sustainable and environmentally friendly energy usage. Geothermal energy and the availability of the technology, Ground Source Heat Pump (GSHP) systems are becoming increasingly popular for heating and cooling of buildings. GSHP installations in different countries are increasing at a rate greater than 25–60%. The GSHPs produce near zero emissions rates of greenhouse gases (GHGs).     

Intrinsic relationship between energy consumption,pressure, and leakage in water distribution systems

The basic implications of changes in delivery pressure on system energy use and cost, on leakage, excess pressure, and environmental impacts are explored. An analytical expression is first developed to characterize the primary relationships between energy use, leakage and pressure for a simple pipe segment. Then, two more realistic case studies, based on varying versions of the Anytown network, are considered. The results indicate that energy use responds more to changes in the delivery pressure in systems with higher leakage rates while reductions in pressures curtail energy use and leakage more dramatically in low resistance systems. Perhaps more surprisingly, systems with more effective water storage and thus uniform pressures tend to have higher leakage rates, greater energy usage, and higher GHG emissions relative to systems relying on direct pumping. The generalization that results from these studies is perhaps predictable but has profound implications: the higher the delivery pressure the greater will likely be the amount of water wasted and energy dissipated.     

现代建筑与智能遮阳

透明玻璃在现代建筑上的应用提出了遮阳和节能的问题，智能遮阳系统是合理解决节能和有效利用日光能源的理想途径，电动卷帘是智能遮阳系统形式之一。从遮阳效果看，户外卷帘比室内卷帘更节能、有效。     

A comparison of wet and dry anaerobic digestion processes for the treatment of municipal solid waste and food waste

A main distinction between anaerobic digestion (AD) technologies for treatment of municipal and industrial biodegradable wastes is the operating process solids content. Wet AD systems operate at low total solids (<10–20% TS) and dry systems have high operating solids (20–>40% TS). The performance of wet and dry AD systems was quantified in relation to: technical operation (footprint, capacity, feedstock characteristics, pretreatment and post‐treatment, retention time, water usage), energy balance (biogas productivity, parasitic energy, methane [CH₄] content, utilization of biogas and produced energy), digestate management and economic performance (capital and operational costs, revenues, specific capital costs [per t of waste and per m³ biogas]). Wet AD plants had improved energy balance and economic performance compared to dry AD plants. However, dry AD plants offered several benefits, including greater flexibility in the type of feedstock accepted, shorter retention times, reduced water usage and more flexible management of, and opportunities for marketing, the end‐product.     

Potential of renewable energy system utilisation at decentralised level in the state of Uttarakhand in India

ABSTRACT

Design and implementation of an effective dissemination programme for decentralised renewable energy system necessitate an accurate estimate of its utilisation potential. Hence, in this study, an attempt has been made to develop frameworks to estimate the utilisation potential of decentralised renewable energy systems in the state of Uttarakhand in India. Estimations imply large resource, technical and economic potentials of the domestic solar water heater, solar home system, solar lantern, family size biogas plant and improved biomass cookstove in Uttarakhand. With higher impact on the purchasing power of households, prevailing soft loan scheme has been found to be more appropriate than a capital subsidy for promoting the usage of decentralised renewable energy systems.     

Energy simulation in the variable refrigerant flow air-conditioning system under cooling conditions

As a high-efficiency air-conditioning scheme, the variable refrigerant flow (VRF) air-conditioning system is finding its way in office buildings. However, there is no well-known energy simulation software available so far which can be used for the energy analysis of VRF. Based on the generic dynamic building energy simulation environment, EnergyPlus, a new VRF module is developed and the energy usage of the VRF system is investigated. This paper compares the energy consumption of the VRF system with that of two conventional air-conditioning systems, namely, variable air volume (VAV) system as well as fan-coil plus fresh air (FPFA) system. A generic office building is used to accommodate the different types of heating, ventilating, and air-conditioning (HVAC) systems. The work focuses on the energy consumption of the VRF system in the office buildings and helps the designer's evaluation and decision-making on the HVAC systems in the early stages of building design. Simulation results show that the energy-saving potentials of the VRF system are expected to achieve 22.2% and 11.7%, compared with the VAV system and the FPFA system, respectively. Energy-usage breakdown for the end-users in various systems is also presented.     

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.     

建筑能源审计中暖通系统能耗拆分方法的讨论

暖通空调能耗在建筑能耗中所占比重较大,同时,暖通空调系统庞大、用能设备多、使用较为分散。通过对两个建筑和能耗数据的分析,采用两种不同的暖通空调拆分方法,计算出建筑分项能耗指标。通过两种方法的应用,认为能源审计的拆分应根据建筑能耗的特点变换不同的拆分方法,最终将不影响能耗拆分质量。     

关于城市污水热能资源化相关概念和分类的探讨

从污水热能利用的技术角度将城市污水分为原生污水、一级污水、二级污水三大类,分析了不同污水的应用特点和应用前景,指出原生污水的热能利用在未来所占的主导地位。定义和区分了污水热能资源化、污水类冷热源、污水源热泵、污水源热泵系统等概念,指出了它们的类属关系和各自的地位。从技术角度对污水源热泵系统进行了分类,比较了直接和间接污水源热泵系统的优缺点,指出直接系统具有巨大的发展前景。介绍了直接系统的两种可实现的形式。     

Toward sustainable energy usage in the power generation and construction sectors—a case study of Australia

To be sustainable in energy usage in the future, there are two aspects that need to be considered: the energy supply or generation and the consumption side, including the closely linked construction and building industries which consume a large amount of energy. Essential requirements for energy efficiency are to produce less greenhouse gas emissions and to rely more on renewable energy sources for future sustainability. Policies for mitigation of the environment impact are having effects on both the supply and demand. While the former requires more alternate sources in smart grids and improved technologies for carbon capture and storage, the latter involves the reduction of energy wastes and greenhouse gas (GHG) emissions as prerequisites to green certification within the construction and building sector. Thus, access to sustainable, affordable, and secure energy is one of the major global strategic priorities to maintain and improve public health, sustain economic growth, and mitigate the effects of climate change. Toward this goal, many countries, including Australia, are investing in clean, efficient, reliable energy systems for a prosperous and environmentally sustainable future. Hence, exploring various options to ensure energy security by diversification of energy sources is an important step in meeting the future requirements and delivering clean energy to different industry sectors. This paper discusses options to manage the use of energy sources in the power generation and construction industries. Options for mitigation of environmental impact and for achievement of sustainable energy usage, such as building design with BIM, are discussed.     

深圳大型公共建筑能耗调查与节能改造案例分析

大型公共建筑普遍存在功能多样、系统复杂、能耗大的特点。本文首先通过对深圳市某大型公共建筑的能耗调查及现场测试,分析了建筑的能耗特征,并根据建筑的实际运行特点,提出了节能改造的建议。而后对改造效果进行了跟踪测试。     

Verification of energy efficiency of district heating and cooling system by simulation considering design and operation parameters

This paper aims to verify the advantages of district heating and cooling (DHC) systems in terms of energy efficiency. From the measurement data, the parameters that characterize the energy efficiency of a heating/cooling plant are identified for DHC and an individual building. A simulation model that considers the difference in these parameters is developed. This model examines both the advantages and disadvantages of DHC systems and the effect of each parameter. The results show that the energy efficiency for cooling in DHC systems is superior to that in the case of individual cooling systems because of the “concentration effect” and “grade of operation”.     

基于交易费用理论的建筑节能服务市场分析

分析了建筑节能服务的交易成本和建筑节能服务市场出现的必要条件,研究了建筑能效审计制度、建筑能效测评标识制度、建筑节能服务市场激励政策等建筑节能服务协同机制对交易费用的影响,探讨了影响建筑节能服务发展的因素。     

A sensitivity analysis method for water distribution system tank siting for energy savings

Energy savings in water distribution system (WDS) pumping can save the municipality money and reduce the amount of greenhouse gas emissions. A straightforward method is introduced here that allows any WDS manager to determine source-tank location and connectivity that minimizes pumping energy usage. The method is demonstrated on twelve diverse WDSs to investigate whether less pumping energy is used by having the tank at four key locations. It was found that the new method worked well and identified that having the tank near to the system and connected directly to the source saves pumping energy in all of the WDSs analyzed. If the initial cost of relocating the tank for existing systems or locating the tank near to the source in new systems is less than the cost of energy savings over the lifetime of the tank, then having the tank near to the source is financially worth it.     

大型办公建筑照明及插座系统电耗逐时使用率聚类分析

逐时使用率对于预测办公建筑照明与插座系统电耗,以及核定节能改造的节能量有十分重要的意义。选取重庆17幢办公建筑作为研究对象,根据建筑全年逐时照明与插座系统的实测电耗数据,计算各建筑全年每个工作日24h的逐时使用率。利用聚类分析方法,根据日逐时使用率的不同,将办公建筑快速分为3类。根据是否经常加班以及午休时是否关闭部分用电设备,可以快速判断办公建筑属于哪一分类。最后对3类建筑分时段计算典型逐时使用率,便于实际应用中快速查询。     

吸收式热泵用于热电联产改造新技术

热电厂的循环冷却水系统存在大量的低位热能。热泵系统具有将低位热能提升为高位热能的能力。本文即是根据山西某热电厂的节能改造方案介绍了利用吸收式热泵系统回收电厂冷凝余热用于集中供热的新技术;并对新型供热系统做出能效和经济性评价,认为新技术应用具有经济和环境的双重效益,有广阔发展前景。     

A comparison of residential and commercial energy use in the United States and Sweden

The differences between the U.S. and Sweden in residential and commercial energy use are discussed in terms of energy efficiencies. The lower Swedish per capita energy consumption in these sectors is principally explained by these factors: (1) better insulation and construction standards in buildings to give considerably higher overall heating efficiencies, (2) more realistic commercial lighting standards, and (3) significant differences in residential end-use devices and end-use choices. Also centralized water heating systems and the practice of district heating contribute to Sweden's more efficient usage of residential and commercial energy.     

Inter connection of wind and photovoltaic systems: modelling,conversion and control

The importance and usage of renewable energy resources such as wind, photo voltaic systems, fuel cell, etc., has been increased exponentially day by day. This importance is mainly due to its abundant availability and low running cost. However, efficient energy harnessing from these sources is still a challenging task. Further, interconnection of these sources caters the needs of rural villages, which not only reduce the transmission losses but also improves the local controlling capability. Perhaps, interconnection of these intermittent resources increase the complexity in control. Hence, in this article, an exhaust review about the interconnection of Photo Voltaic (PV), Fuel and Wind energy system has been performed. In particular, it focusses on modelling, conversion and control of interconnected systems, which will help a researcher to pinpoint the problem of research and can investigate further to solve.