建筑能耗比例与建筑节能目标

本文从建筑能耗在全国总能耗中的比例、建筑节能的目标值等两个方面,阐述了对我国建筑节能发展战略的观点。作者指出,建筑能耗在总能耗中的比例是经济发展的晴雨表;应该用我国未来能耗限额作为建筑节能的目标值。     

Comparative study of room temperature control in buildings with and without the use of PCM in walls

The concept of thermal energy storage in building gains a specific importance in the present energy scenario related to energy consumption and indoor thermal comfort. The material used to store the thermal energy which undergoes a phase change referred as PCM and it is considered as a possible solution for reducing energy consumption in the building by storing and releasing heat within a certain temperature range; it raises the building inertia and also stabilizes indoor air temperature fluctuations. The room temperature is controlled by imposing PCM inside the walls. An attempt has been made to compare room air temperature with and without the use of PCM inside the walls of constructed modular building unit. The PCM imposed modular building shows the reduced temperature fluctuations in room, the PCM absorbs and liberates excess heat which is gained from the outer side of the room and maintains constant inner room temperature. The PCM imposed walls of modular building unit have an ability to reduce 10–30% of heat load in comparison with the plain wall. The results showed that reduction in room temperature is about 2–4°C and it has been concluded that the PCM imposed modular building unit has more energy saving opportunities than normal modular building unit.     

南宁市办公建筑空调节能途径

根据广西建筑能耗公示的情况,通过分析4栋低能耗办公建筑的空调能耗状况,提出了南宁市办公建筑空调节能途径.建议有条件的地方政府通过制定办公建筑全年能耗标准及奖励办法,来鼓励各单位积极探索节能途径,降低办公建筑能耗.     

夏热冬暖地区办公建筑能耗模拟与分析

夏热冬暖地区是我国经济和建筑产业最发达的地区之一,也是建筑能耗最多的地区之一。分析和研究夏热冬暖地区建筑能耗的特点对建筑节能有重要的意义。本文用eQUEST建筑能耗模拟软件模拟了夏热冬暖气候下不同的建筑围护结构的能耗性能,并与实际调查结果进行了比较。结论表明:办公类建筑中的空调是最大的能耗终端,全年的能耗以办公设备和照明的能耗最稳定。有外保温措施和同时具有内、外保温措施最大区别在于节省空调电力消耗31.3%和39.1%。说明建筑外墙保温系统是建筑节能的重要手段。     

Artificial intelligence implementation framework development for building energy saving

In this study, artificial intelligence (AI) control tools were developed to construct an AI implementation framework for energy saving for buildings. Although numerous AI studies related to energy conservation have been conducted, most of them have reported computing algorithms and control effects for single objects. This is the first study to use a framework to integrate five-category AI control tools to execute three-level building energy conservation; the three levels consist of equipment-level control, facility-level control, and whole building energy saving. Energy-saving effects were tested in a real building. The complex three-floor building primarily with a total area of 9072 m² serves as an office space and a semiconductor production line. Seventy percent energy consumption comes from air conditioning system and motor power. Twenty percent is lighting system and the other 10% is plug power and office automation equipment. Before implementation, the yearly energy cost reached US$1004339. In 2018, an AI implementation framework was introduced to systematically deploy AI at the site. A total of 47.5%, 37%, and 36.9% of energy was saved at equipment, facility, and whole building levels; up to US$385203 was saved. These energy savings proved the feasibility of the implementation framework. Furthermore, unmet demands of AI studies were met, and an approach to fill the research gap is discussed.     

Energy saving by integrated control of natural ventilation and HVAC systems using model guide for comparison

Integrated control by controlling both natural ventilation and HVAC systems based on human thermal comfort requirement can result in significant energy savings. The concept of this paper differs from conventional methods of energy saving in HVAC systems by integrating the control of both these HVAC systems and the available natural ventilation that is based on the temperature difference between the indoor and the outdoor air. This difference affects the rate of change of indoor air enthalpy or indoor air potential energy storage. However, this is not efficient enough as there are other factors affecting the rate of change of indoor air enthalpy that should be considered to achieve maximum energy saving. One way of improvement can be through the use of model guide for comparison (MGFC) that uses physical-empirical hybrid modelling to predict the rate of change of indoor air potential energy storage considering building fabric and its fixture. Three methods (normal, conventional and proposed) are tested on an identical residential building model using predicted mean vote (PMV) sensor as a criterion test for thermal comfort standard. The results indicate that the proposed method achieved significant energy savings compared with the other methods while still achieving thermal comfort.     

板式通风换热器的研究进展

新风系统中的余热回收是重要的建筑节能技术之一。板式通风换热器因其结构简单、经济且与建筑一体化程度好等优点，已得到广泛应用。本文首先简述了板式通风换热器的特点，然后系统地介绍了目前国内外的试验和理论研究现状，最后展望其发展和应用前景。     

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％。     

非节能住宅节能改造方案研究

基于矿区老式居民住宅楼冬季供暖单耗的考察、测试数据,遵循封闭式门窗抑制楼内热量向外扩散和外墙敷设保温层降低墙体热值传导系数的原理,制定出了铁法矿区老式住宅楼供暖节能改造总体方案。至2009年10月仅完成了该方案中的封闭式门窗增设工程,投资1 323万元,实现节省热值45.33 GJ/h,已供扩展挂网增收1 600万元。预计2011年10月全部完成节能改造总体方案,将完成总投资13 737万元,节省热值达99.32 GJ/h,供扩展挂网增收总额9 486万元,年增收取暖费2 134.35万元,经济效益和社会效益都十分明显。     

Application of energy storage enclosure with phase change materials in building energy saving

相变材料具有高效的能量储存功能。相变材料与建材基体结合,制成一种具有储热功能的围护结构。该围护结构可发挥相变储热功能,降低建筑室内温度波动,增强建筑热舒适度,能够更加有效地减少建筑物运行能耗,从而实现建筑节能。本文对当前现有相变材料的优缺点、相变材料在不同围护结构中的应用、相变储能围护结构对室内热环境的影响及对建筑运行能耗的影响、相变储能围护结构应用的经济性等方面进行了分析,提出相变储能围护结构在工程应用中所存在的不足及其发展前景。     

Regenerative rotary heat exchanger for heat recovery in residential ventilation

Increased energy costs have brought about increased concern by building owners as well as governments about the operating costs and energy budgets for buildings and power plants. This growing energy conservation consciousness has brought a considerable interest in reclaiming waste heat from residential, commercial, industrial, and institutional ventilation systems. Based on theoretical considerations, the design and performance of a small rotary heat exchanger for residential houses is discussed in this paper. Laboratory results reveal a high sensible heat recovery maximum effectiveness of 85 percent with acceptable levels of pressure drop and cross leakage. Cost saving analysis indicates annual energy savings up to 15 percent, with even larger savings in the size of the heating and cooling equipment up to 42 percent. As expected the greatest savings could occur when large amounts of outside air are required for ventilation.     

高层办以建筑能耗调查与节能潜力分析

通过对深圳市高层办公建筑进行抽样调查,得到了其建筑能耗的基本状况,并对深圳市该类建筑的节能潜力进行了分析。     

A model-based optimal ventilation control strategy of multi-zone VAV air-conditioning systems

This paper presents a model-based optimal ventilation control strategy for multi-zone VAV air-conditioning systems aiming at optimizing the total fresh air flow rate by compromising the thermal comfort, indoor air quality and total energy consumption. In this strategy, one scheme is used to correct the total fresh air flow rate dynamically by utilizing the unvitiated fresh air from the over-ventilation zones based on the detected occupancy of each zone and the related measurements. At the meantime, another scheme is developed to optimize the temperature set point for the temperature control of critical zones with the aim at reducing the variation of the required fresh air fractions among all the zones and further reducing the total fresh air intake from outdoors for energy saving when the first scheme is implemented. This scheme is based on a constructed cost function relating thermal comfort, indoor air quality and total energy consumption together while the cost function is calculated based on the prediction of system responses using dynamic simplified models. Genetic algorithm is used for optimizing the temperature set point of critical zones in the optimization process. This strategy was evaluated in a simulated building and air-conditioning environment under various weather conditions.     

水泥熟料烧成系统节能技术改造分析

选用四风道全自动智能节煤燃烧器对水泥熟料烧成系统进行节能改造,代替三通道燃烧器;通过加强煅烧操作、实时监测窑内温度场变化,自动调节各风道配风的流量、压力及供煤量,形成合理的火焰形状以及满足煅烧要求所需的火焰温度;充分利用二次风的热量,从而达到调高熟料煅烧产量的要求和节煤的目的。通过实践证明,此项技术改造有效提高了单位产品能耗,2009年项目年节能量为9594.5tce,相比2008年,单位产品节能量为18.8kg/t,约13.7%。     

Cost-optimal energy performance measures in a new daycare building in cold climate

New municipal service buildings must be energy effective, and cost-optimality is one of the criteria for selecting the suitable energy performance improvement measures. A daycare building in a cold climate was studied by means of simulation-based, multi-objective optimisation. Using a genetic algorithm, both target energy use and life-cycle cost of the selected measures were minimised. It was found that extensive insulation of the building envelope is not a cost-optimal method to reduce the daycare building energy use. Improving energy efficiency of the ventilation system, utilising solar energy on-site and employing a light control strategy are preferable ways of improving the building energy performance. Ground-source heat pump is a more cost-optimal heating system for the daycare building than district heating. The cost-optimal sizing of the heat pump is small, only 28% of the required maximum heating power.

Abbreviations: AHU: air handling unit; CAV: constant air volume; COMBI: comprehensive development of nearly zero-energy municipal service buildings; COP: coefficient of performance; DH: district heating; DHW: domestic hot water; EPBD: energy performance of buildings directive; EU: European Union; FINVAC: Finnish Association of HVAC Societies; GSHP: ground-source heat pump; HRU: heat recovery unit; IDA ICE: IDA Indoor Climate and Energy; LED: light-emitting diode; MOBO: multi-objective building optimisation tool; NSGA-II: Non-dominated Sorting Genetic Algorithm II; nZEB: nearly zero-energy building; PV: photovoltaic; TRY: test reference year; VAV: variable air volume; ZEB: zero-energy building     

Energy performance of a hybrid space-cooling system in an office building using SSPCM thermal storage and night ventilation

Thermal performance of a hybrid space-cooling system with night ventilation and thermal storage using shape-stabilized phase change material (SSPCM) is investigated numerically. A south-facing room of an office building in Beijing is analyzed, which includes SSPCM plates as the inner linings of walls and the ceiling. Natural cool energy is charged to SSPCM plates by night ventilation with air change per hour (ACH) of 40 h⁻¹ and is discharged to room environment during daytime. Additional cool-supply is provided by an active system during office hours (8:00-18:00) necessary to keep the maximum indoor air temperature below 28 °C. Unsteady simulation is carried out using a verified enthalpy model, with a time period covering the whole summer season. The results indicate that the thermal-storage effect of SSPCM plates combined with night ventilation could improve the indoor thermal-comfort level and save 76% of daytime cooling energy consumption (compared with the case without SSPCM and night ventilation) in summer in Beijing. The electrical COPs of night ventilation (the reduced cooling energy divided by fan power) are 7.5 and 6.5 for cases with and without SSPCM, respectively.     

严寒地区单体建筑太阳能-相变墙系统蓄热特性研究

利用太阳能对水加热并通入相变墙进行蓄热,对减少严寒地区单体建筑供热能耗有重要意义。以大庆市某单体建筑为例,结合该地区太阳能分布特点及建筑热负荷大小,对适用于该地区的太阳能-相变墙系统进行集热与储热能力计算,并采用CFD方法研究单一工况下该系统的热工变化规律及不同热水参数、换热管规格对相变墙蓄热特性的影响。结果表明：该相变墙热稳定性良好,但受自然对流影响,底部相变材料熔化较慢;管径DN25、入口流速0.3m/s、供水温度310.15K、回水温度309.15K、管间距107mm可使相变材料在4小时内完成蓄热,平均节能率为31.8%。研究结果可望为降低严寒地区建筑供热能耗提供新思路。     

1.5Mt/a加氢裂化装置节能降耗措施与成效

金陵石化1.5Mt/a加氢裂化装置投用初期,能耗超过40kg标油/t原料,通过几次大的技术改造,能耗明显下降,2011年1～11月装置综合能耗为26.89kg标油/t原料.能耗划分显示,燃料气消耗占装置能耗的最大部分,所占比例达42.47％,其次为电能和蒸汽消耗,分别占总能耗的41.05％和12.76％.这3项能耗占到装置总能耗的96％以上.装置的节能降耗工作主要采取以下措施:优化换热网络,回收低温余热;新氢机增加无级气量调节系统,降低压缩机的无用功;脱硫溶剂采取溶剂在线清洗,提高溶剂质量,减少溶剂损耗,同时减缓溶剂系统腐蚀和塔盘结垢;分馏加热炉空气预热器改型以及火嘴改造;保证装置高负荷运行,提高循环氢压缩机、新氢压缩机、原料泵等设备的用能效率;利用变频技术,投用液力透平,实现节电目标;通过热料直供,减少作为溶剂再生塔底热源的1.0MPa蒸汽消耗.     

Numerical assessing energy performance for building envelopes with phase change material

In hot climate, phase change material (PCM) can be incorporated into building envelopes to reduce heat gain through the building envelopes and therefore reduce its cooling demand. In this study, the energy performance of building envelopes integrated with PCM has been explored using a popular dynamic building performance simulation package, EnergyPlus, and the energy saving mechanism of PCM was investigated. The simulation results reflected that PCM could effectively help to reduce the building's annual energy consumption by 20.9% for Guangzhou, China. In addition, for the Guangzhou city, 27°C transition temperature, smaller thermal conductivity of roof, and higher amount of PCM can all help to improve the building's energy performance. Additionally, it is suggested that in real building development/retrofit projects, the selection of PCM needs to be based on both their thermal properties and the local climatic conditions of the building.