建筑环境与能源应用工程专业英语14.ppt

,Unit Fourteen Control and Building Automation System,What is an intelligent building?,Schematic Diagram of an Intelligent Building System,Up to now, there has not been a universally accepted definition for an Intelligent Building. Most existing definitions of IB around the world centre on the need for a building to be suitable for the occupants to work and live in safely, comfortably, effectively and efficiently. “Intelligent building is something that make stupid people feel not as stupid as they are”.,Intelligent Building can bring us Reduced Resource Consumption Both home and building technology offer tremendous potential savings through intelligent controls. Optimized Convenience and More Comfort Apart from minimizing consumption costs, private home owners will be interested in higher levels of convenience, safety and security.,Smart Home is an integration of various systems at home such as security, home automation, lighting control, CCTV and entertainment system which is coordinated by a smart home controller and controlled by users using various centralized command interfaces such as a touch screens, keypads, universal remote controllers, internet browser, telephone, and even your LCD TV screen.,Smart Home Systems,CCTV: Closed Circuit Television CCTV: China Central Television,On/off Control,The control device can be positioned only to a maximum or minimum state (e.g., on or off). Because On/off control is simple and inexpensive, it is used extensively for both industrial and commercial control. A typical home thermostat that starts and stops a furnace is an example of On/off action.,Floating Control,Dead (neutral) zone,盲区 停滞区,In floating control, the controller can perform only two operations moving the controlled device toward either its open or closed position, usually at a constant rate. Generally, a neutral zone between the two positions allows the controlled device to stop at any position when the controlled variable is within the differential of the controller. When the controlled variable falls outside the differential of the controller, the controller moves the controlled device in the proper direction.,open,shut,Time,Upper limit,Lower limit,neutral zone,Temperature,Valve,set point,controlled variable,proportional band,output,offset,Proportional control requires a continuously variable output of the controlled device. The control system produces an output which is proportional to the error signal, i.e. the difference between the value of the controlled variable and the set point.,Proportional control,signal,response,Integral control,Derivative control,signal,response,Proportional plus Integral (PI) Control,Proportional-Integral-Derivative (PID) Control,Proportional Action.,Closed loop control,Feedback,A closed loop or feedback control measures actual changes in the controlled variable and actuates the controlled device to bring about a change. The corrective action continues until the variable is brought to a desired value within the design limitations of the controller. This arrangement of having the controller sense the value of the controlled variable is known as feedback.,Example of Feedback Control Room Air Temperature Control,Open loop control,An open loop control does not have a direct link between the value of the controlled variable and the controller. An open loop control anticipates the effect of an external variable on the system and adjusts the set point to avoid excessive offset. An example is an outdoor thermostat arranged to control heat to a building in proportion to the calculated load caused by changes in outdoor temperature. In essence, the designer presumes a fixed relationship between outside air temperature and the heat requirement of the building and specifies control action based on the outdoor air temperature. The actual space temperature has no effect on this controller. Because there is no feedback on the controlled variable (space temperature), the control is an open loop.,Single-Seated Valves Double-Seated Valves 单座阀 双座阀,Three-Way Mixing Valves Three-Way Diverting Valves 三路混合阀 三路换向阀,Sensors Temperature Sensors Humidity Sensors Pressure Transmitters and Transducers Flow Rate Sensors Indoor Air Quality Sensors Lighting Level Sensors Controllers Pneumatic Receiver-Controllers Electric/Electronic Controllers Digital Controllers Thermostats,1. Control Modes On/Off control Proportional control Floating control Integral control Derivative control Variation and Combination of basic modes 2. Open and closed loop control open loop control closed loop control 3. Building Automation Systems 3.1 General 3.2 Basic Considerations 3.3 Computer Based Systems,Frequently used words and phrases: control mode 控制模式 On/Off Control 开/关控制 Proportional control 比例控制 Floating control 浮动控制 Integral control 积分控制 Derivative control 微分控制 Proportional plus Integral (P+I) Control 比例加积分控制 Proportional plus Derivative (PD) Control 比例加微分控制 Proportional plus Integral plus Derivative (P+I+D) Control 比例加积分加微分控制 final control element (FCE) 终端控制元件 Open loop control 开环控制 Closed loop control 闭环控制 signal 信号 heater battery 加热器组 air curtain 空气幕 sensor 传感器 electro-mechanical system 电动机械系统 pneumatic system 气动系统 pressure switch 压力开关 humidistat 湿度控制器 time switch 定时开关 building automation system (BAS) 建筑自动化系统 energy management system (EMS) 能源管理系统 direct digital control (DDC) 直接数字控制,1. A controller can be made to operate a final control element (FCE), e.g. a valve, damper, or luminaire in a number of different ways in response to a signal. 2. The control mode does not define the means by which control is effected, which may be through mechanical, electro-mechanical, electronic or pneumatic systems. 3. The control sensor usually takes the form of an on/off thermostat, pressure switch, humidistat, time switch, etc. and operates such that below the set point the contacts open.,controller: 控制器 final control element (FCE): 终端控制元件 damper: 闸板 luminaire: 照明 signal: 信号,control mode: 控制模式 electro-mechanical: 机电的 pneumatic: 气动的,on/off: 开或关 pressure switch: 压力开关 humidistat: 湿度调节器 恒湿器,4. Proportional control action refers to a control element having an output signal proportional to its input signal. 5. If the scale range of a temperature controller is from 0oC to 100oC and the proportional band setting is such that the controlled variable must change from through 40oC to 80oC to make the valve move from full open to shut, then the proportional band is (80-40)/100=40%. 6. This mode of operation depends on the use of a dead (neutral) zone in the controlled variable. In this zone the correcting element is not power controlled and remains in its last pulsed position until the controlled variable moves outside the dead zone.,proportional control: 比例控制,dead (neutral) zone: 停滞区 中性区 correcting element: 修正元件 pulsed: 搏动的 跳动的,proportional band: 比例带 full open: 完全打开,8. This action is used to eliminate overshoot during a fast load change. Derivative control is mainly applied in special process systems. 9. While floating and proportional control actions may be used on their own, derivative control must always be used in combination with proportional or floating action.,overshoot: 超出 超过 过分 load change: 负荷变化 derivative control: 微分控制,How to translate?,10. Control systems are applied to control loops, each loop normally comprising one section of an overall plant, e.g. reheater, smoke alarm. 11. When the condition of the controlled variable changes in closed loop control the sensor detects the change and initiates correcting action to final control element. 12. The effect of this is reflected in the controlled variable and reassessed by sensor which continuously provides feedback to the controller.,control loops: 控制环路 comprising: 构成 reheater: 再热器 smoke alarm: 烟雾报警器,closed loop control: 闭环控制 detect: 探测 initiate: 触发 开始,reassess: 再评估 feedback: 反馈,13. The simplest form of such a loop would be the detection of smoke where a local/or remote alarm is initiated by a smoke detector without any feedback to the smoke sensor. 15. Most thermostatic control manufacturers now market buildings automation systems to monitor and control other building services such as energy, security and fire protection systems.,alarm: 报警器 smoke sensor: 烟雾传感器,thermostatic: 温度调节装置的 market: 使进入市场 security: 安全 fire protection systems: 防火系统,16. It is always advisable to question the level and validity of the software offered to perform the tasks required in the context of building services automation. 18. One other area which requires emphasis is the possible susceptibility of all processor based systems to electrical interference, however caused.,advisable: 可取的 明智的 question: 提出问题 质询 validity: 有效性 context: 上下文 领域,emphasis: 强调 susceptibility: 易感性 interference: 干扰 干涉,19. The principles apply whether the system has one unit with 10-20 points or multiple processors and outstations serving 10,000 points. 20. It is essential that the specification for any BAS is precisely detailed in terms of all performance, requirements, functional sequences and clearly defined interface conditions for every facility required.,point: 控制点 outstation:设在边远地区的分站 边远哨所 远程控制中心,BAS: building automation systems 建筑自动化系统 detail: 详述 细说 in terms of: 按照 根据 functional sequence: 功能顺序 interface condition: 界面条件 facility: 设施,22. The centralization of the logic equipment allows greater flexibility of