基于Matlab/Simulink环境下空调房间仿真模型的建立

分析了采用变风量空调系统空调房间的特性,推导出变风量送风方式下空调房间的数学模型,利用Matlab软件中的Simulink工具箱建立了空调房间的仿真模型。并通过算例对所建模型进行仿真分析,结果证明,该模型能够充分反映实际变风量空调房间的特性。     

办公建筑变风量分区空调系统设计问题探讨

使用DeST软件对办公建筑两个空调方案进行了模拟分析,指出供暖期内外区合用的变风量空调系统内区房间室温过高,能耗增加,外区房间的室温基本满足设计要求;内外区独立设置的变风量空调系统各房间室温能满足设计要求,且能耗较低。对内外区合用的变风量空调系统提出了改进建议。     

变风量空调系统的建模与控制

介绍了变风量空调系统的基本原理。结合变风量空调系统的特点,在基于被控房间数学模型的基础上,将模糊控制和常规PID控制相结合,提出了一种模糊PID控制方法并将其应用于变风量空调室温控制中。     

上海期货大厦变风量空调系统实际运行状况的分析与总结

该大厦采用变风量空调系统，对变风量空调系统新风供给的控制方式进行了分析。测试了大厦部分房间CO2浓度，比较了采用定送风温度与定回风温度两种控制方式的特点，讨论了吊顶回风、空调系统运行能耗等问题。     

变风量系统设计与施工协调：末端装置选择

变风量系统20世纪60年代诞生于美国、变风量空调的原理很简单,就是通过改变送入房间的风量来满足室内变化的负荷,由于空调系统大部门时间在部分负荷下运行,所以,风量的减少带来了风机能耗的降低。变风量系统出现后并没有迅速推广,70年代爆发的石油危机促使变风量系统在美国得到广泛应用,并在其后20年中不断发展,已经成为美国空调系统的主流,并且在其他国家得到广泛引用。     

基于分布式控制系统(DCS)的变风量空调系统的设计

对变风量空调系统进行设计,将整个变风量空调控制系统设计划分为5个控制回路:房间温度控制、送风静压控制、送风温度控制、新风控制和室内正压控制.整个控制系统由以太网、BACnet、Modbus这3层网络组成.从控制器和上位组态软件的应用两方面详细介绍了变风量智能空调分布式控制系统,经过分析与比较上位机监测得到的试验结果,系...     

变风量空调系统室温滞后响应数学模型及动态特性研究

基于能量守恒定律和变风量空调房间的热工特性,建立了变风量空调房间室温变化动态响应数学模型,并分析了引起室温滞后响应的影响因素。通过阶跃响应试验获得了室温对风量调节机构的滞后动态响应特性。建立了室温对各执行机构滞后响应的辨识模型,通过Simulink对辨识模型进行了仿真。结果表明,辨识模型拟合度较高,可以较好地反映室温滞后响应特性。     

变风量空调系统控制分析及其应用（上篇：变风量系统介绍）

1变风量系统的概述 变风量系统(Variable Air Volume System，简称VAV系统)20世纪60年代诞生在美国，是目前国内大中型建筑工程中新型的一种空调方式。按处理空调负荷所采用的输送介质分类，变风量(VAV System)空调系统是属于全空气系统的一种，是通过变风量箱调节送入房间的风量，并相应调节空调机(空气处理机组)的风量来控制某一空调区域温度的一种空调系统。     

北京南银大厦空调设计

概要介绍了采用ＶＡＶ空调方式的该办公楼空调设计,指出变风量空调系统具有使用标准高、运行节能、便于维护管理和房间装修分隔等特点,认为空调设计控制方式选择和施工安装质量优劣是决定ＶＡＶ系统能否正常运行的关键因素,而ＤＤＣ系统是变风量控制系统的基础。总结了设计经验教训,对存在的新风量不平衡、噪声偏大等问题进行了剖析。     

真实建筑中变风量空调末端装置故障在线检测与诊断研究

本文针对真实建筑中变风量空调末端装置故障进行了研究,开发了一个在线检测与诊断变风量空调末端装置故障的工具。该故障诊断工具采用一个基于混合方法的故障检测与诊断策略。累积和控制图被用于累加房间温度测量值及其设定值之间的偏差,如果计算的累积和大于控制图上限值,或者小于控制图下限值,就意味着在变风量空调末端装置中存在故障或者异常。基于规则的故障分类器被用于分离和诊断故障源。故障诊断工具已经在香港某大型办公建筑进行了在线应用和验证,验证结果表明该故障诊断工具可以准确有效地检测和诊断变风量空调末端装置故障。     

浙江中控电子VAV空调控制系统的设计

在空调系统中,VAV空调系统以其节能、方便等优势,将逐渐成为空调系统的主流系统。本文通过介绍某写字楼的VAV空调系统应用设计,阐述了浙江中控电子技术有限公司楼宇自动化控制系统在VAV这一类型空调系统的具体设计方法。     

压力无关型VAV空调系统数学仿真模型的研究

主要研究变风量(VAV)空调系统的水力特性数学模型的建立。以一个实际的压力无关型、无动力空调末端的VAV空调系统为研究对象,利用MATLAB语言编制程序,建立了系统主要部件的阻力特性数学模型。结合图论和流体管网的基本理论,运用"MKP"计算方法建立了空调风系统管网的数学模型。在此基础上搭建了可对管网进行任意工况下的水力分析的水力计算平台,并给出了一组系统仿真结果。     

A study on the energy penalty of various air-side system faults in buildings

Automatic fault detection and diagnosis (FDD) can help enhance building energy efficiency by facilitating early detection of occurrence of system faults, especially those of air-conditioning systems, thus enabling rectification of the faults before much energy is wasted due to such faults. However, building owners may not invest in FDD unless they are convinced of the energy cost savings that can be achieved. This paper presents the results of a study on the energy cost impacts of a range of common system faults in variable air volume (VAV) air-conditioning systems, which are widely adopted for their good part-load energy efficiency. The faults studied include room air temperature sensor offset, stuck VAV box damper, supply air temperature sensor offset, stuck outdoor air damper and stuck/leaking cooling coil valve. The simulation results indicate that some faults may significantly increase energy use in buildings, for example, negative room air temperature sensor offset, stuck open VAV box damper, negative supply air temperature sensor offset, stuck open outdoor air damper and stuck open and leaking cooling coil valve. Since building occupants may adapt to the symptoms of these faults, such as reduced room air temperature, and thus may not complain about them, the occurrence of such faults are not immediately apparent unless a FDD system is available. Some other faults, e.g. positive supply air temperature sensor offset, positive room air temperature sensor offset, stuck closed cooling coil valve and stuck closed VAV box damper, may allow less energy to be used but will lead to unbearable indoor environmental conditions, such as high indoor temperature. Such faults, therefore, can easily be detected even without a FDD system, as there will be feedback from the building occupants.     

A fault detection and diagnosis strategy of VAV air-conditioning systems for improved energy and control performances

This paper presents the results of a site survey study on the faults in variable air volume (VAV) terminals and an automatic fault detection and diagnosis (FDD) strategy for VAV air-conditioning systems using a hybrid approach. The site survey study was conducted in a commercial building. 20.9% VAV terminals were ineffective and 10 main faults were identified in the VAV air-conditioning systems. The FDD strategy adopts a hybrid approach utilizing expert rules, performance indexes and statistical process control models to address these faults. Supported by a pattern recognition method, expert rules and performance indexes based on system physical characteristics are adopted to detect 9 of the 10 faults. Two pattern recognition indexes are introduced for fault isolation to overcome the difficulty in differentiating damper sticking and hysteresis from improper controller tuning. A principal component analysis (PCA)-based method is developed to detect VAV terminal flow sensor biases and to reconstruct the faulty sensors. The FDD strategy is tested and validated on typical VAV air-conditioning systems involving multiple faults both in simulation and in situ tests.     

某检化验中心大楼通风空调系统设计

介绍了某大型钢铁企业检化验中心各实验室室内环境需求,及所设置的排风净化系统,新风空调系统,风机盘管空调系统等。阐述了所采取的变风量控制、排风最大同时使用系数、吊顶补风等相关节能措施。     

地铁站变风量空调冬季工况节能研究

对于冬季仍然要送入冷风来消除室内余热的场所,变频变风量运行不但可以节约风机的运行费用,还可以节省空调系统用于制冷的能量。本文基于Matlab/Simulink仿真平台,模拟了地铁车站冬季最冷天的空调运行能耗。结果证明,变频变风量系统冬季直接用室外冷源制冷节能效果明显。     

A CFD-based test method for control of indoor environment and space ventilation

System dynamic simulation has been adopted to test and evaluate the local and supervisory control of air-conditioning systems for over twenty years, while the modeling of the space ventilation was usually simulated using perfect mixing models. However, the complete-mixing air model fails to consider the impact of non-uniform air temperature stratifications. This paper presents a CFD-based virtual test method for control and optimization of indoor environment by combining a ventilated room with a ventilation control system. The ventilated room and its dynamic ventilation control system are represented by a computational fluid dynamics (CFD) model and models of the temperature sensor, PID controller and actuator and VAV damper model respectively. The ventilation and its control system are programmed using the user defined function program and interfaced with the CFD model. A space temperature offset model is developed to improve the accuracy of temperature measurement and control at the occupied zone as a virtual sensor. Case studies show that the ventilation control models can interoperate with the CFD simulation of the space online which presents a new application approach of CFD simulation for testing and developing control and optimal control strategy before a system is constructed practically. The use of the virtual sensor can effectively compensate the effect of non-uniform stratification on the temperature control and improve system control reliability in a mechanical ventilated room.     

户式中央空调变风量系统设计探讨

本文分析了户式中央空调的各种形式及存在的问题,指出住宅采用变风量系统是提高住宅室内空气品质的最佳手段,文章重点对户式中央空调变风量的构成及控制进行了详细论述。     

变风量空调系统设备特性研究

运用计算机仿真技术对变风量空调系统的设备特性进行了研究。空调系统在部分负荷情况下,变风量可降低风机功耗;要进一步提高VAV系统能量使用效率,降低系统能耗,尚必须调节表冷器的冷冻水量。     

中国联通大厦变风量空调系统设计

介绍了中国联通大厦采用的变风量空调系统的原理、组成、特点。