风机盘管占空比模糊控制仿真研究

分析了风机盘管在断水状态下的动态换热特性.建立了用于研究风机盘管占空比模糊控制方法的系统仿真器,研究了量化因子Ke,Kec和控制周期τCYC对控制效果的影响.结果表明,在保证空调房间温度达到一定控制效果的前提下,τCYC的优化使风机盘管综合耗能量减少18%,对控制效果影响最大,Ke减少16%,Kec减少8%.对所研究的办公建筑,控制周期宜取风机盘管断水状态下(低档运行时)出风温度上升时间的1.2倍.     

地铁变风量空调风系统控制方法研究

对地铁站变风量空调风系统提出三种控制方法,即送回风温度控制法、优先控制水阀法和优先控制风机法。以武汉地铁2号线螃蟹甲站的空调系统作为模拟研究对象,建立了房间、风机、水阀、盘管和控制器等数学模型,以TRNSYS为仿真平台,搭建了地铁站变风量系统的模型,比较三种控制方法与定风量控制下系统在制冷季节的运行情况。模拟结果表明,送回风温度控制法能较好地控制室内温度,且在适当的出风温度设定值下,功耗能达到最小。在不考虑送风结露和考虑送风结露的情况下,节能率分别达到67.0%和55.9%。     

浅谈柔性静压风机盘管机组

风机盘管机组由于出口静压的局限性,一旦设计阻力与实际阻力有偏差,对风量会产生很大影响。为了满足风量要求,需要更换整台机组或机组内的部件。由于风机盘管机组安装位置的限制,更换十分不便。针对这种不便,介绍一种可调机组出口静压的风机盘管机组,讲解了机组的结构和具体的实现方法。为同行在新产品的研发和风机盘管的选用方面给予启发。     

风机盘管空调器的温度控制及防结露问题

带有恒温控制器的低噪声风机盘管空调器在旅馆、医院、实验室正得到越来越广泛的应用。房间内室温能否控制是旅游饭店级别高低的标志之一。国外风机盘管的温度控制是利用双金属感温控制电动三通阀以使水路通断,从而维持室温不变。温控范围为13～32℃。一、温度控制目前国内生产的双金属室温控制器能自动测定室内温度并指示读数,其内有一组触点作为电路上的开关,用以控制三通电动调     

干工况风机盘管系统适用性探讨

选取3类典型气候区域,结合将空调负荷与干盘管特性相联系的5个指标,探讨了干工况风机盘管系统的适用性.比较了干湿工况的几种判别方法,总结了保障风机盘管干工况运行的控制方法.介绍了该系统中冷水系统的形式和控制方式以及干盘管系列产品的测试研究成果.     

风机盘管的集中控制和遥控

风机盘管的集中控制和遥控北京青云仪器厂刘宗源１引言风机盘管机组的集中控制，是指利用一个调速开关控制多台机组同步运转的控制方法。风机盘管作为集中空调系统的末端设备，当今使用范围日渐广泛。尤其高静压大风量机组的迅速发展，更为风机盘管应用范围的拓宽创造了条...     

基于调查的风机盘管控制方式与应用

调查结果显示风机盘管系统是当前应用的主要空调系统之一。将常用风机盘管控制器进行分类,指出了实际应用中出现的问题。分析了不同控制逻辑下风机盘管的运行对室内温度的影响,指出PID控制在反应速度和风机能耗上优于位式控制。     

长江流域住宅中混凝土辐射地板与风机盘管供暖性能实测

针对目前长江中下游流域住宅供暖末端形式选择的问题,在位于合肥的住宅中测试了以空气源热泵为热源的混凝土辐射地板和安装在天花板下方的风机盘管供暖效果和系统性能。实测结果表明,混凝土辐射地板供热系统室内竖直方向温度均匀,室温波动小,室内舒适度高。而风机盘管系统由于热空气积聚在天花板附近,导致室内竖直温差较大。连续运行下,维持相同的室内操作温度,混凝土辐射地板和风机盘管的供热量相近,而辐射地板的系统EER比风机盘管系统高14%。间歇运行下,风机盘管系统的动态响应时间小于混凝土辐射地板,风机盘管具有较强的快速启动性能,舒适性较高。     

DWK系列室温控制器

该系列室温控制器是由北京四季青电器修造厂研制成功的最新产品。它是根据国内外对室温控制器的要求,博采各家之长,应用先进的电子技术研究而成。主要功能如下:1.和冷热风机盘管配套,可控制室温在16°～28℃范围内的任一数值,灵敏度为     

基于Modelica风机盘管空调系统动态控制过程仿真平台的开发与验证

为准确仿真风机盘管空调系统的实际运行过程及控制特性,本文利用Modelica语言和劳伦兹伯克利实验室Buildings Library建立了包括空调房间模型、风机盘管换热模型以及典型控制模型的动态仿平台。通过设计数据和已有文献的实验数据对模型进行验证,结果表明所建模型具有良好的准确性,空调房间负荷预测值与设计值的误差在3%以内;风机盘管出口运行参数模拟值与实测值的误差在5.05%以内,换热量误差在6.65%以内。通过对夏季典型日进行动态仿真,结果表明所建仿真系统可真实模拟风机盘管空调系统的实际运行控制过程。该仿真系统的开发不仅为风机盘管空调系统优化控制研究提供了准确的动态仿真平台,同时也为暖通专业人员的技术培训提供了有效的虚拟实践工具。     

Experimental study on a duty ratio fuzzy control method for fan-coil units

This paper presents a novel energy-efficiency control method for a fan-coil unit, the duty ratio fuzzy control method (DRFCM), which employs the concept of duty ratio on the electric valve control to fully utilize the cooling and dehumidifying capacity of a fan-coil unit when the control valve is closed. By means of mamdani-type fuzzy rules and functioning-fuzzy-subset inference methods, the duty ratio of valve and fan speed signals are decided according to the deviation and deviation changes of the room temperature. This paper adopts a two-water-pipe FCU system with a three-fan speed control and an electric water valve on-off control as test objects to verify the application effect of DRFCM. Program controllers and software tools are employed to conduct DRFCM. The conventional control method is applied by individual FCU controllers. Experimental results show that DRFCM could obtain at least 30% energy savings (not including chilled pump power savings) over the conventional control method. A preferable room temperature control effect could be achieved as well.     

A novel control logic for fan coil unit considering both room temperature and humidity control

This paper proposes a novel fan coil unit (FCU) control logic, which controls fan speed level and water valve duty ratio to make both temperature and humidity match the set-points. The performance of the proposed control logic is compared with two other control logics using simulation. One of them is to open/close water valve to make room air temperature match the set-point, which is the usually used control logic. Another control logic is to open/close water valve according to a duty ratio decided by a fuzzy logic. The simulation results show that the proposed control logic can achieve control performance: the temperature is t _set ± 0.5°C and humidity is d _set ± 3% when duty ratio period is 300 s, and the temperature is t _set ± 1°C and humidity is d _set ± 7% when duty ratio period is 600 s. The control performance of proposed control logic is better than the valve on/off control logic and the fuzzy control logic.     

蒸发冷却+干式风机盘管的空调系统探讨

本文在温湿度独立控制的原理基础之上，根据西北地区的气候特点，提出了将干式风机盘管与蒸发冷却相结合的半集中式空调系统。该系统解决了目前蒸发冷却空调系统中存在的风管尺寸大、难以分室控制等问题。最后，结合工程实例对该系统的设计过程进行了分析，指出了使用蒸发冷却＋干式风机盘管半集中式空调系统比直流式全新风系统节省能耗21．9％以上。     

泉州综合交通枢纽站通风空调及节能设计

根据泉州综合交通枢纽站不同功能区域的特殊要求,有针对性地采用不同形式的空调系统,在候车厅、进出站大厅采用全空气一次回风系统;售票厅、值班室、监控室及快餐厅等采用风机盘管加自然新风系统;贵宾候车室、调度室、站长室及广播(PAS)兼监控室采用风机盘管加新风系统;消防控制室需要24h值班,设置VRV空调系统。冷源采用了螺杆和离心式冷水机组相结合的方式,候车大厅的空调机组采用吊顶式安装。本工程的通风空调及其节能设计,有效地满足了综合交通枢纽站特有的使用功能要求,并能够使其实现节能和可持续发展。     

Maintaining uniform hydraulic conditions with intelligent on–off regulation

An advanced control method for central heating systems is used in precise room temperature control. In this method, based on room temperature changes and user demand, the duty cycle of the control valve for each cycle was predicted and the valve was regulated according to the duty cycle to maintain room temperature at set point. However, this control method could allow all of the valves to easily open or close at the same time, resulting in large fluctuations in hydraulic conditions. In response to this issue, this article proposed a method that achieves hydraulic uniformity by staggering the control cycle of each user, which allows the number of opening users in the on/off control heating system to be uniformly distributed over time and space. The results from theoretical analysis and practical application revealed that this method was effective in solving practical problems. Furthermore, staggering the control cycles could actively manipulate the actions of valves without requiring a specific number of users as opposed to the conventional on–off adjustment mode, which achieved hydraulic uniformity primarily through the random cumulative effects of a certain number of users.     

旅馆建筑采用干盘管系统时新风机组的研究

通过对旅馆标准客房的计算,得到了此类建筑在采用干盘管系统时新风机组的送风含湿量在不同地区差异较大,在选用新风机组时不能一概而论的结论。并针对送风含湿量较低的干盘管系统,提出了一种应用普通冷水机组作为冷源的新型新风机组。     

卧式风机盘管机组舒适性能的评价

阐述了卧式风机盘管机组在什么性能方面的问题及其产生的原因，运用常规的计算方法，获得了风机盘管机组的气流运动轨迹、温度和速度衰减。分析结果表明，该机组的大送风温差及低流速，导致使用区内强烈“吹风感”，远不能满足舒适条件。开发一种全新的风机盘管机组是非常必要的。     

A novel on-off TRV adjustment model and simulation of its thermal dynamic performance

Field test results show that about 15% to 40% of building heat loss in China is attributable to poor heating systems regulation. The current method for addressing this problem is to install thermostatic radiator valves (TRVs) to the ends of radiators, a method adapted from northern Europe. However, this method has resulted in poor performance from delayed controlling action due to thermal inertia as well as insufficient system control accuracy. This is further compounded by incorrect operation by system users and a lack of financial incentives to regulate the system if users are not billed for their heat consumption. We present a new method for simultaneously heat controlling and metering. The core challenge is to design a control strategy that will maintain the room’s temperature. Thus, we established dynamic heat transfer models for water flow, the radiator and the building so as to obtain the optimal heating strategy. We also simulated the indoor thermal dynamic performance of the heating system with different heating loads, supply water temperatures, and supply water flow rates using three methods: a continuously changing flow rate (Method 1), a step-change flow rate based on temperature deviation (Method 2) and an intelligent step-change flow rate (Method 3) which predicts the duty cycle of the valve in the proceeding period and controls the valve’s on-time. The simulation results indicate the performance of these three methods. For Method 1, as the room temperature is above the set point, the flow rate can be automatically reduced to a level which is proportional to the room temperature deviation. Further, the scale factor of the flow rate is designed according to the +2°C deviation, so it is accepted that the room temperature is higher than the set point by +2°C using this method. However, this low control precision is unsatisfactory. The mean temperature is higher than the set point and greatly affected by the heating load and supply water’s temperature and flow rate. For Method 2, the controlling action is delayed by thermal inertia, the room temperature fluctuates between the highest and lowest levels, and the temperature deviation can be greater than the set value. For Method 3, both the simulation and field test results showed that room temperature deviation was maintained within a ±0.5°C range under the various conditions. This method appears relatively robust and adaptable, and was the best control strategy of the three methods.     

亚洲金融大厦标准办公单元变风量空调系统自控策略分析

重点分析了幕墙侧风机盘管结合变风量空调系统在主风管变静压调节过程中有效实现整体控制的运行策略。将幕墙侧风机盘管纳入变风量空调自控系统进行整体控制,避免了以往项目中同一区域2种系统独立控制时容易产生的温度失调问题,同时,采用静压设定值定步长调整法,通过简单有效的控制逻辑实现了主风管变静压调节。经过冬、夏季的运行测试,结果显示上述空调自控系统达到了变静压调节的要求,并且实现了幕墙侧风机盘管与变风量空调系统的整体控制。     

Design of test method and detailed ratings of variable air volume fan-coil units

The purpose of this paper is to proceed with a series of performance tests for variable air volume (VAV) fan-coil units to establish complete testing and rating procedures. Based on the guidelines described in ASHRAE standard 79-1984 (ANSI/ASHRAE 79-1984. Methods in testing for rating room fan-coil air conditioners) for constant air-volume (CAV) fan-coil units, we have proposed a unique testing method by considering VAV features and established a testing platform for VAV fan-coil units. It is expected that the difference between VAV and CAV fan-coil units can be differentiated as a result of using our proposed platform and procedures. The present VAV fan-coil units have proven to be very energy efficient through detailed ratings.