空调水系统VWV节能控制(下)

分析空调水系统定水量运行方式存在的弊端,变水量运行的可行性,介绍几种常用的变水量控制策略,通过水泵工作曲线和管网特性曲线对空调水系统变水量运行进行了节能分析,并比较了几种变水量控制策略下水泵的节电率。     

空调水系统VWV节能控制（上）

分析空调水系统定水量运行方式存在的弊端，变水量运行的可行性，介绍几种常用的变水量控制策略，通过水泵工作典线和管网特性曲线对空调水系统变水量运行进行了节能分析，并比较了几种变水量控制策略下水泵的节电率。     

数据中心冷空调系统节能措施研究与应用

数据中心水冷空调系统的高可靠性、冗余配置需要投入较高的建设成本,降低能耗成本成为运维绿色数据中心的关键。数据中心空调制冷系统能耗是除IT设备能耗之外的最大能耗,降低制冷系统能耗、提升制冷系统能效比对于提高数据中心经济效益显得尤为重要。结合数据中心水冷空调系统构成及原理,研究数据中心制冷模式、循环水泵变频调节、末端空调联机群控、机房全生命周期管理,定性分析水冷系统的节能措施,对运维过程中实现水冷空调系统安全可控、高效运行、节能降耗具有重要意义。     

大温差水系统运用于数据中心空调节能性分析

对大温差空调水系统应用于数据中心项目进行了节能性分析,基于假定的系统模型对不同冷冻水供回水温差条件下系统的制冷主机能耗、冷冻水泵能耗以及末端精密空调设备能耗进行了计算。计算结果表明,增大供回水温差对于数据中心空调系统能效提升具有积极意义。     

减阻技术在集中供热与空调水输配系统中的应用

集中供热与空调系统在我国已经成为耗能大户 ,其中大量能耗消耗在水泵上用来输送热水或冷冻水、冷却水。减阻技术在集中供热及空调水输配系统的应用可以极大地降低泵耗 ,从而具有广阔的节能前景。本文介绍了可用来降低泵耗的粘性减阻技术的减阻机理、减阻方法 ,并介绍了国、内外减阻技术在暖通空调领域的应用研究情况。     

地铁车站空调冷却水系统节能控制策略研究

为了降低空调冷却水系统的能耗,根据郑州某地铁车站的实际情况,提出冷却水泵变频结合冷却塔风机变频的节能控制策略;基于瞬时系统模拟程序（Trnsys）完成系统模型的搭建与动态模拟仿真工作,获得系统中各设备的运行能耗情况,并与水系统基础模型的模拟结果进行对比。结果表明：冷却泵变频结合冷却塔风机变频水系统的节能率为15.23%,节能效果显著。     

能源审计在既有中央空调节能改造中的应用

为了降低空调能耗,对某大型中央空调系统的用能现状和节能改造措施进行了研究。根据建筑能源审计理论和既有空调系统节能改造的要求,确定了系统参数实测、能效分析与审计、分析节能改造方案的顺序;对某中央空调的制冷机房的运行参数进行了实测,对系统和设备分别进行了初步能源审计和单一能源审计,并对各审计能效值与标准能效值进行了比较,总结出节能改造措施。结果表明,该制冷机房主要存在的问题是在低负荷区间设备和系统的工作能效偏低,水泵的功率调节未能与冷负荷变化保持一致,低负荷区间的冷水机组群运行策略不够合理,可见系统至少存在20%以上的节能空间;节能改造措施主要是加强水系统的变流量,以降低水泵能耗和优化特别是低负荷区间的设备运行控制策略;说明了能源审计和能效标准比较法能定量地得到既有中央空调的用能现状和节能改造潜力。     

空调水系统的能耗问题及节能方法

针对目前空调水系统能耗大的问题,对管网系统、循环水泵和冷水机组提出了改造措施和方法,达到节能目的。     

医院空调系统物联网改造与节能优化案例分析

医院能耗结构复杂,而物联网技术能为医院空调系统的节能运行管理提供大量的数据支持。本文以某医院的空调系统现状,结合医院能耗特征,分析了医院空调系统物联网改造方案,并对医院空调系统节能优化策略下的能耗情况进行了分析。通过医院空调系统的物联网改造,为医院后勤人员提供空调系统的详细的运行情况,并为空调系统的节能运行提供数据支持。通过优化冷冻水出水温度和适当关闭风冷热泵机组的夜间运行,可有效降低空调系统的运行能耗。     

办公建筑空调系统能耗评价及节能潜力分析

本文根据长沙市一办公建筑空调系统的全年运行记录和实测数据,分析了空调系统的能耗特征.并用温频数(BIN)法计算了空调年假想负荷及空调系统年能耗.用空调能耗系数CEC评价了空调系统的运行情况.在此基础上,从空调机组、水系统的运行管理及室内空气参数的设定三个方面进一步对空调系统进行节能潜力分析.结果标明,(1)在空调系统全年实际能耗量中,冷热水机组能耗高达54%,末端设备能耗为25%,水系统的能耗也高达21%.(2)该宾馆CEC系数为2.0,比日本的办公楼CEC的判断基准1.5大30%以上.这说明该办公楼空调系统能量利用效率较低,存在很大节能潜力.(3)空调机组和水系统的科学运行管理及室内空气参数的合理设定对该空调系统节能具有重大意义:笔者通过比较当负荷率在80%下,开启一台主机和同时开启两主机的能耗情况发现,开启一台主机,系统的总EER提高近23%.空调系统的总功率也可以减小25.9 kW;而和该空调设定温度25℃,相对湿度50%的情况相比,当空调设定温度提高到26℃,相对湿度提高到60%,空调能耗可节省6%.     

The analysis of energy consumption of a commercial building in Tianjin,China

According to statistics and field investigation, the energy consumption situation and reality of commercial building is described in this paper. As the first step of large-scale public building energy efficiency supervision system encouraged by central government of China, the energy consumption of several typical commercial buildings and public buildings was analyzed in detail. The main contents of investigation are as follows: basic information of building, operational record of energy consumption equipment, energy consumption of indoor equipments, energy-efficiency assessment of energy consumption systems and equipments, investigation of behavior energy saving, etc. On this basis further analysis and diagnosis including indoor thermal and humid environment, operation state of air-conditioning water system, operation state of air-conditioning duct system and operation management of air-conditioning system were implemented. The results show that the most energy consumption of buildings in this city is commercial buildings, which can reach to about 240 W/m² per year. Further analysis tells that air conditioning systems play the major role of building energy consumption, and building energy saving has great potential in this city. In this paper, the ways of diagnosis work for building energy consumption are also described and discussed. Reasonable test, diagnosis and analysis are meaningful for building energy efficiency retrofit and management.     

空调变水量冷冻水系统运行工况下的管网特性曲线

针对变水量空调冷冻水系统实际运行时管网特性曲线随末端负荷变化和水泵实际工作点难以确定的问题 ,分析了传统的绘制管网特性曲线的方法不适用的原因 ,从实际出发 ,根据曲线拟合原理 ,提出了一种切实可行的分析运行工况下管网特性曲线的方法 ,并应用到实践中     

土壤源--水环式热泵空调系统的设计

本文简要阐述了土壤源———水环式热泵空调系统的工作原理,以及该系统不同于常规水环热泵空调系统的特点,接着介绍了某应用土壤源———水环式热泵空调系统所具有的设计特点。     

Cold Storage Capacity for Solar Air-Conditioning in Office Buildings in Different Climates

The building sector accounts for more than 40% of the global energy consumption. This consumption may be lowered by reducing building energy requirements and using renewable energy in building energy supply systems. Solar air-conditioning systems(SACS) are a promising solution for the reduction of conventional energy in buildings. The storage, especially the cold storage, plays an important role in SACS for unstable solar irradiation. In this paper, we took the absorption refrigerating unit as an example, and the solar air-conditioning system of an office building in Beijing was simulated. The accuracy of this model was verified by comparing with the SACS operation data. Moreover, based on the simulation data, the cold storage capacity of the solar air-conditioning system in different climatic regions was studied. The cold storage capacities of SACS in 20 cities distributed in different climate regions were studied systematically. The results simulated by our proposed model will be beneficial to the SACS design, and will enlarge the application of SACS.     

水轮机节能技术在石化行业循环水冷却塔中的应用

水轮机利用循环水泵的富余扬程带动风机运转,以取代风机电机,实现节能的目的。以高效反击混流式水轮机在青岛石化循环水冷却塔中的应用为例,通过监测单开水轮机风机或电动风机时循环水的温降程度,来对比两种风机的运行效果,并在维持系统管网压力、流量不变的条件下,监测水轮机风机正常运行、转速减半、停运至系统稳定,以及重开风机系统、恢复稳定状态下的运行数据,测试水轮机风机运行对循环水系统的影响,从而验证水轮机节能技术的应用效果及经济效益。结果证明,循环水系统存在富余能量,水轮机利用该富裕能量带动风机运转,不增加循环水系统新的能耗;且水轮机风机降温效果与电动风机相当,可替代电机风机运行,满足精细化操作需要。采用水轮机运转风机,可优化循环水系统配置,减少维护保养费用,经济效益较高,具有较好的推广价值。     

基于实测数据的酒店空调系统用能问题诊断

随着社会的进步与经济的繁荣,我国建筑行业对能源的需求进一步加深。而建筑节能的研究在我国尚未成熟,且主要集中于办公、商业类建筑。基于上述现状,针对酒店行业的复杂用能特点,提出利用酒店现场实测数据对酒店空调系统用能进行诊断。选取上海市区某酒店现场实测后发现该酒店空调系统冷水机组实际运行COP小于额定COP,偏差在10%以上。主要原因是由于空调系统长期处于欠负荷状态运行所致。对主机及水泵加装热回收装置及变频器后,发现可降低酒店能耗费用18.16万元,效果显著。对酒店进行实测分析可以有效节省能源,响应国家节能减排政策要求,为建筑业的可持续发展提供更先进的技术指导。     

Energy evaluation of optimal control strategies for central VWV chiller systems

Under various conditions, the actual load of the heating, ventilation and air conditioning (HVAC) systems is less than it is originally designed in most operation periods. To save energy and to optimize the controls for chilling systems, the performance of variable water volume (VWV) systems and characteristics of control systems are analyzed, and three strategies are presented and tested based on simulation in this paper. Energy evaluation for the three strategies shows that they can save energy to some extent, and there is potential remained. To minimize the energy consumption of chilling system, the setpoints of controls of supply chilled water temperature and supply head of secondary pump should be optimized simultaneously.     

Year round experimental study on a constant temperature and humidity air-conditioning system driven by ground source heat pump

Numerous studies about the ground source heat pump building heating and cooling systems have been constructed in office building, hotel, residential building and school et al. However, few researches about the constant temperature and humidity air-conditioning system driven by ground-coupled heat pumps were carried out. In this paper, a constant temperature and humidity air-conditioning system driven by ground source heat pump was designed and constructed in an archives building in Shanghai, China. During the operation in the cooling mode, the heat extraction from the condenser of the heat pump was divided: part was rejected to the soil while another was used to reheat the air in AHUs. According to the experimental results, the indoor temperature and relative humidity fulfilled the “Archives Design Code”. In summer, the heat rejected to the soil was reduced by 32%, which was helpful for the earth energy conservation. The soil temperature increased only 0.5 °C after the GSHP system operating for a year. The energy cost of the air-conditioning system was 56.1 kWh/m². Compared with air source heat pump system and water cooled unit with boiler system, the operating cost of ground source heat pump was reduced by 55.8% and 48.4%, respectively.     

Alternative power sources for residential air-conditioning systems

An integrated system which utilise three sources of energy for the purpose of airconditioning (i.e. heating and cooling) a residential building is considered. The system includes a control unit which determines (according to a built-in programmed logic) which energy source is to be used. The system's three power provisions are: (a) line electricity, (b) electric power generated by an appropriate wind turbine and (c) a hot water system heated by solar collectors. System requirements and operation were simulated by a computer program which calculated the air-conditioning load and the energy provisions throughout a twenty-four hour period. In winter operation, about 68 per cent of the required heating was supplied by solar heating and 32 per cent by wind-generated power and in summer operation, in a typical day, all the required cooling energy was provided by wind-generated power.     

某智能大厦空调系统冷源方案比较

对某智能大厦空调系统冷源方案—水冷冷水机组与风冷冷水机组，分别从设备性能数据、设备初投资、全年运行维护费用、补水量、制冷性能、震动和噪声等方面进行比较。指出两种方案技术经济性比较相当，但由于群楼屋面未能提供足够空间放置风冷冷水机组，最终选用水冷冷水机组作为本项目的冷源方案。