通风对住宅夏季空调能耗的影响

采用数值模拟方法,对一栋住宅分别位于北京、上海和广州时,不同通风量和不同通风模式下的夏季空调能耗进行了计算分析.结果表明,位于北京时,1.0h-1是最节能的通风换气次数,位于上海时,0.4h-1是最节能的通风换气次数,位于广州时,空调能耗随着换气次数的增加而线性增大,在这三个地区,间歇机械通风都有利于减少空调能耗.     

控制室内建材散发挥发性有机物浓度分布的空调系统提前开启时间研究

提前开启通风或空调系统可保证室内空气品质或温度在人员进入室内时达到可接受的水平。基于污染源可及性和数值模拟,分别研究了等温和非等温通风条件下污染物浓度分布达到稳定所需的时间与提前开启时间。结果显示:在等温通风条件下,当换气次数为1h-1时,8种典型通风方式下污染源可及性达到稳定的时间为6~16h;在非等温通风条件下,空调系统提前开启时间可由污染物浓度分布达到稳定的时间来决定;而在较高的换气次数(≥4h-1)下,空调环境室内平均温度和呼吸区挥发性有机物(VOC)平均浓度达到稳定所需的时间接近,为1~3h,为控制污染物浓度分布设计的空调通风系统提前开启时间仍可根据为加热或冷却房间空气温度设计的提前开启时间来确定。     

机场航站楼能耗构成特征案例分析

通过对寒冷地区某干线机场进行能耗统计,详细分析了机场能耗构成,重点阐述了电耗构成特征,指出了航站楼空调系统节能的关键点与技术方向。结果表明:机场主要能源消耗为电力,约占机场总能耗的66%,其中航站楼是电力消耗的主要部分,约占机场总耗电量的70%;航站楼中的空调系统耗电量约占航站楼耗电量的35%,空调系统中空调箱风机耗电量最大,约占空调系统总耗电量的50%。为了降低空调末端风机电耗,提高空调系统能效比,航站楼空调设计可采用分布式空气处理末端、辐射空调末端、变频风机等节能技术。     

南方地区星级酒店空调通风系统节能改造适用型技术研究与应用集成——广州白天鹅宾馆空调通风系统节能改造项目实施方案

以广州白天鹅宾馆为例,以现有能耗数据为基础,分析了南方地区既有星级酒店的用能特点,发现该酒店通风空调系统能耗最大,占常规能耗的66.9%;其中空调主机能耗所占空调通风系统总能耗的比例最大,为49.66%;其次为空调末端(空气处理机、新风处理机、风机盘管)能耗,为25.54%;第3位为水泵能耗,为14.39%。为此,有针对性地提出节能改造对策:采用高效制冷机,冷水大温差(8℃),冷水泵、冷却水泵变频,直流无刷风机盘管变风量控制,高效节能风机、空气处理机组,双工况高效水-水热泵热回收热水系统等措施和技术,逐一论证了其实现的可行性及节能效果。通过分析酒店空调通风系统各部分节能效益,获得了空调通风系统节能改造的节能目标。     

关于城市轨道交通地下车站公共区通风空调系统运行模式的思考

针对国内典型地铁车站公共区空调系统控制模式的设计进行了分析研究,提出全新风工况不开启回排风机的前提下,应以设计回风比焓与等效比焓差之和作为工况切换点,为环境设备监控系统或通风空调节能控制系统的控制逻辑设计提供了参考,以实现车站公共区空调系统的进一步节能运行。     

芯片厂房洁净空调系统节能运行影响因素研究

从芯片厂房洁净空调系统的运行特点出发,通过理论分析得到了芯片厂房洁净空调系统的能耗影响因素,通过实测梳理了芯片厂房洁净空调系统的能耗现状及节能潜力。DesignBuilder软件模拟结果表明,冷水机组COP、换气次数、风机效率、新风量、水泵效率、室内设计温度的空调电耗最大节能率分别为39.7%、23.0%、15.4%、11.2%、10.8%、6.0%。SPSS偏相关分析表明,显著性影响因素为冷水机组COP、换气次数和新风量。研究成果可为预期节能量的预测提供依据。     

西直门综合交通枢纽工程空调通风系统设计

介绍了西直门综合交通枢纽工程空调通风系统的优化设计。采用了多项空调节能措施:大冷量离心冷水机组搭配变频小冷量机组,二次泵变频变流量空调水系统,四管制风机盘管冬季用冷却塔换冷供冷设计,商业外区风机盘管、内区全空气空调系统,送风机、排风机变频控制,过渡季、冬季利用室外新风通风降温的焓值控制设计。     

不同通风方案对建筑能耗影响的模拟分析

针对济南某办公楼采用如下4种不同自然通风方案后的能耗情况进行模拟分析:①采用空气调节结合自然通风;②加大夜间通风换气次数;③改变通风时段;④改变气候条件。模拟结果表明结合自然通风,全年累计可减少冷负荷58.2%;当夜间通风换气次数增大为1.5 n/h时,综合节能效果最好;选择2:00-7:00时作为通风时段进行自然通风,通风效率最高,能耗费用最低;对于昼夜温差比较大的地区采用自然通风的节能方案最可行。     

对城市轨道交通通风空调系统设计若干习惯做法的质疑

在城市轨道交通建设中,通风空调系统设计的习惯做法是:站内隧道采用横向通风;特殊隧道区段配置射流风机;空调系统采用双风机一次回风全空气系统、上送上回的气流组织形式;定新风量运行,最小换气次数取5h-1;水系统采用一级泵定流量系统、集中供冷等。结合城市轨道交通工程的特点,从系统经济性及安全性的角度对这些习惯作法的合理性进行了探讨。     

夏热冬暖地区近零能耗居住建筑气密性研究

近零能耗建筑对气密性有较高要求,良好的气密性可以降低无组织渗风导致的冷、热负荷,避免湿气侵入造成的建筑发霉、结露和损坏,减少室外不良因素对室内环境的影响。目前,我国对夏热冬暖地区近零能耗建筑气密性要求尚不明确。本文以夏热冬暖地区典型近零能耗居住建筑为研究对象,确定了建筑气密性(50 Pa)与常压下空气渗透换气次数的转换方法,计算了得到不同气密性等级对应的年平均空气渗透换气次数(常压)。并在TRNSYS能耗模拟平台建立了典型建筑模型,模拟计算了气密性对近零能耗居住建筑室内热湿环境和空调通风能耗的影响。最后以营造更加节能和热湿舒适的室内环境为目标,建议自然通风策略下建筑气密性N50≤3. 0 h-1,机械通风策略下建筑气密性N50≤1. 0 h-1。     

The impact of air filter pressure drop on the performance of typical air-conditioning systems

Filters are used in heating, ventilation, and air-conditioning (HVAC) systems for both commercial and residential buildings to protect the equipment and improve indoor air quality in conditioned spaces. Although there are many benefits of using the air filter in an air-conditioning system, the resistance associated with it can increase fan energy use and may adversely affect air-conditioning system performance and efficiency. The paper explores the impact of air filtration on energy consumption for a typical air-conditioning (AC) system with constant- or variable-speed fan. A whole building simulation model is used to simulate the annual energy consumption for various air-conditioning system capacities, different levels of filter cleanliness, and various filter minimum efficiency reporting values (MERV). The results indicate that with a constant-speed fan, the cooling energy use increases as the filter gets dirty over time and the energy use in the fan may increase but this depends heavily on the investigated fan performance curve. With a variable-speed fan, the fan energy use increases with a dirty filter but the cooling and heating energy uses are slightly affected. The fan energy use rise due to the dirty filter depends mainly on air system capacities, filter MERV ratings, and the degree of the filter cleanliness.     

通信基站通风冷却技术的节能效果评价与运用策略

通信基站通风冷却技术节能效果显著,运用广泛。本文提出了在不同环境气候条件下,不同类型基站运用该技术的节能效果评价方法。计算分析了不同影响因素,如室内发热量、空调系统设定温度、风机风量、风机功率和空调系统性能等与通风冷却技术全年节电量之间的关系。总结了该技术的运用策略,并给出了各类型基站适合运用该技术的最低室内发热量和运用该技术可获得的最大全年节电量。     

Effects of outdoor air conditions on hybrid air conditioning based on task/ambient strategy with natural and mechanical ventilation in office buildings

This research aims to clarify the effects and indoor environmental characteristics of natural and mechanical hybrid air-conditioning systems in office buildings during intermediate seasons and to obtain design data. Natural and mechanical hybrid air conditioning is an air-conditioning system that utilizes natural ventilation and mechanical air-conditioning systems to improve the quality of the indoor thermal and air environment, and to reduce energy consumption. This report first categorizes the available natural ventilation conditions and estimates the amount of natural ventilation available in a model building. Furthermore, based on the concept of task-ambient air conditioning, after controlling the average temperature in the task zone to a target air conditioning temperature (26°C), changes in the outdoor temperature/humidity and the inflow rate, and the indoor environment and amount of cool heat input were studied with changes in the size of the natural vent using three-dimensional Computational Fluid Dynamics (CFD) analysis. The results of these studies indicated that natural ventilation at temperatures lower than the indoor temperature effectively covered the lower indoor task zone through negative buoyancy, which enabled energy-saving air conditioning in the task zone.     

The effect of heat-pipe air-handling coil on energy consumption in central air-conditioning system

A study was carried out to investigate the effect of heat-pipe air-handling coil on energy consumption in a central air-conditioning system with return air. Taking an office building as an example, the study shows that compared with conventional central air-conditioning system with return air, the heat-pipe air-conditioning system can save cooling and reheating energy. In the usual range of 22–26 °C indoor design temperature and 50% relative humidity, the RES (rate of energy saving) in this office building investigated is 23.5–25.7% for cooling load and 38.1–40.9% for total energy consumption. The RES of the heat-pipe air-conditioning system increases with the increase of indoor design temperature and the decrease of indoor relative humidity. The influence of indoor relative humidity on RES is much greater than the influence of the indoor design temperature. The study indicates that a central air-conditioning system can significantly reduce its energy consumption and improve both the indoor thermal comfort and air quality when a heat-pipe air-handling coil is employed in the air-conditioning process.     

Model-based commissioning for filters in room air-conditioners

This paper proposes a model that can estimate filter resistance using estimated air-conditioner indoor unit air flow rate, which is tightly related to filter fouling conditions. Two sorts of value are used as inputs to estimate air flow rate. One is the power consumed by the fan in the indoor unit of a room air-conditioner and the other is the thermal performance of a room air-conditioner. For the room air-conditioners that the real-time indoor unit fan power consumption is available, fan power consumptions are used as inputs to estimate filter resistance. For the room air-conditioners that are equipped with refrigerant pressure and temperature sensors, this model estimates filter resistance using refrigerant pressure and temperature, air temperature or enthalpy difference between supply and indoor air. This model was validated using a really running multi-evaporator Gas-engine Heat Pump (GHP) system. The maximum and average difference between estimated and measured filter resistance are 12.72% and 5.89% when using the fan power consumption as inputs. When using the air-conditioner thermal performance data, the maximum and average estimation errors are 13.12% and 5.96%. The validation results show that this model is accurate enough for estimating filter resistance. Based on this model, the method for commissioning filters in air-conditioner is discussed. This method is useful for automatically estimating filter resistance and reminding users timely to clean or replace a filter to prevent wasting energy and to maintain desirable indoor environment.     

夏热冬暖地区住宅建筑节能措施

夏热冬暖地区夏季能耗较高，其建筑节能的重点是降低夏季的空调能耗。自然通风可以为居住建筑改善空气品质，并最大限度的减少空调使用时间，改善室内热环境；而建筑外遮阳技术也可以有效降低空调能耗，同样可以减少空调使用时间。在夏热冬暖地区自然通风和建筑外遮阳技术是建筑节能的关键技术和重要组成部分。     

京津地区夏季着装行为对办公建筑空调能耗的影响

着装行为通过影响室内空气参数的设定而影响建筑空调能耗。利用能耗模拟软件DeST,计算出该地区典型着装行为下实测运行参数与期望参数对应的建筑空调能耗比推荐标准下能耗分别降低了10.86%和13.16%。而基于典型着装行为的实验热学性能参数下,平均只降低4%,说明由着装热阻关联的主观温度需要按地区着装行为进行修正。提出了控制建筑空调能耗的着装行为调节模型,着装行为节能率εc为负值时节能,为正值时不节能。京津地区办公建筑节能率为0的临界服装热阻为0.563clo,空调系统设计和运行节能的前提是,着装热阻低于临界值。着装行为调节模型为地区着装形式和着装面料提供了量化标准,为精确控制建筑能耗提供了一种方法。     

能量法变风量技术在某卷烟厂中的应用

介绍了某卷烟厂用能量法变风量的方式调节室内送风量。室内外焓差作为能量法变风量调节的主要参数,用以调节风机的频率,进而改变室内送风量以及室外新风量。建立能量法变风量的数学模型,对卷烟厂应用能量法变风量的经济性进行了分析,证明能量法变风量具有较好的节能效果。     

A development of easy-to-use tool for fault detection and diagnosis in building air-conditioning systems

There are many reports about faulty status in building air-conditioning systems recently. It becomes difficult to keep indoor air temperature appropriately as faults occur, and the faults cause waste of building energy consumption. The model-based fault detection and diagnosis (FDD) methods have been researched for specific parts of air-conditioning system such as chillers, coils, variable air volume units (VAV units), etc. It needs, however, much time and labor to monitor and check every single part because we cannot predict where and when the faults occur. The purpose of this study is to examine indoor air temperature changes and energy consumption increase when faults occur and to develop an easy-to-use FDD tool that helps to find out the faulty place through the whole building air-conditioning system. And then, we treat the reliability of the proposed FDD tool and effectiveness to control of indoor environment deterioration and energy consumption increase by the tool is evaluated based on building air-conditioning system simulation in this paper.     

毛细管平面空调系统简介

传统的空调系统普遍采用温湿度耦合的控制方法,存在能源利用品位上的浪费、难以适应温湿度比的变化以及室内空气品质差等问题,针对我国日益高涨的提高室内环境舒适性和降低建筑能耗的大好形势,介绍一种高效节能的室内环境调节系统:毛细管平面空调系统,分析了其具有的优点及面临的问题和机遇.