建筑环境与能源应用工程专业英语14课件.ppt

1、Unit FourteenControl and Building Automation SystemFire AutomationSystemCommunicationAutomation SystemSecurity AutomationSystemBuilding AutomationSystemSystem IntegratedCenterOffice AutomationSystemWhat is an intelligent building?Schematic Diagram of an Intelligent Building SystemUp to now,there has

2、 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

3、stupid people feel not as stupid as they are”.Intelligent Building can bring usReduced Resource ConsumptionBoth home and building technology offer tremendous potential savings through intelligent controls.Optimized Convenience and More ComfortApart from minimizing consumption costs,private home owne

4、rs 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 cent

5、ralized command interfaces such as a touch screens,keypads,universal remote controllers,internet browser,telephone,and even your LCD TV screen.Smart Home SystemsCCTV:Closed Circuit TelevisionCCTV:China Central TelevisionOn/off ControlThe control device can be positioned only to a maximum or minimum

6、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 ControlDead(neutral)zone盲区盲区 停滞区停滞区In floating control,the contro

7、ller 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 th

8、e c o n t r o l l e r.W h e n t h e controlled variable falls outside the differential of the controller,the controller moves the controlled device in the proper direction.openshutTimeUpper limitLower limitneutral zoneTemperatureValveset pointcontrolled variableproportional band outputoffsetProporti

9、onal 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.)()(teKtuProportional control signalresponse)(d)(dteKttuInte

10、gral controlttteKtu0 d)()(tteKtu d)(d)(Derivative control signalresponseProportional plus Integral(PI)ControlProportional-Integral-Derivative(PID)ControlProportional Action.Closed loop controlFeedbackA closed loop or feedback control measures actual changes in the controlled variable and actuates th

11、e 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 C

12、ontrolRoom Air Temperature ControlOpen loop controlAn 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

13、 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

14、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 单座阀单座阀 双座阀双座阀Three-Way Mixing Valves Three-Way Di

15、verting Valves 三路混合阀三路混合阀 三路换向阀三路换向阀SensorsTemperature Sensors Humidity SensorsPressure Transmitters and TransducersFlow Rate Sensors Indoor Air Quality SensorsLighting Level SensorsControllersPneumatic Receiver-ControllersElectric/Electronic ControllersDigital ControllersThermostats1.Control Modes

16、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 control3.Building Automation Systems 3.1 General 3.2 Basic Considerations 3.3 Computer Based Systems Frequent

17、ly used words and phrases:control mode 控制模式控制模式 On/Off Control 开开/关控制关控制Proportional control 比例控制比例控制 Floating control 浮动控制浮动控制Integral control 积分控制积分控制 Derivative control 微分控制微分控制Proportional plus Integral(P+I)Control 比例加积分控制比例加积分控制Proportional plus Derivative(PD)Control 比例加微分控制比例加微分控制Proportional

18、plus Integral plus Derivative(P+I+D)Control 比例加积分加微分控制比例加积分加微分控制final control element(FCE)终端控制元件终端控制元件Open loop control 开环控制开环控制 Closed loop control 闭环控制闭环控制signal 信号信号 heater battery 加热器组加热器组air curtain 空气幕空气幕 sensor 传感器传感器electro-mechanical system 电动机械系统电动机械系统pneumatic system 气动系统气动系统 pressure swi

19、tch 压力开关压力开关humidistat 湿度控制器湿度控制器 time switch 定时开关定时开关building automation system(BAS)建筑自动化系统建筑自动化系统energy management system(EMS)能源管理系统能源管理系统direct digital control(DDC)直接数字控制直接数字控制1.A controller can be made to operate a final control element(FCE),e.g.a valve,damper,or luminaire in a number of differe

20、nt 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.

21、and operates such that below the set point the contacts open.controller:控制器控制器 final control element(FCE):终端控制元件终端控制元件damper:闸板闸板 luminaire:照明照明 signal:信号信号control mode:控制模式控制模式 electro-mechanical:机电的机电的pneumatic:气动的气动的on/off:开或关开或关 pressure switch:压力开关压力开关humidistat:湿度调节器湿度调节器 恒湿器恒湿器4.Proportional

22、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 mov

23、e 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

24、outside the dead zone.proportional control:比例控制比例控制dead(neutral)zone:停滞区停滞区 中性区中性区 correcting element:修正元件修正元件pulsed:搏动的搏动的 跳动的跳动的proportional band:比例带比例带 full open:完全打开完全打开8.This action is used to eliminate overshoot during a fast load change.Derivative control is mainly applied in special process

25、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:超出超出 超过超过 过分过分 load change:负荷变化负荷变化derivative control:微分控制微分控制How to translate?10.Control systems are applied to con

26、trol 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

27、in the controlled variable and reassessed by sensor which continuously provides feedback to the controller.control loops:控制环路控制环路 comprising:构成构成reheater:再热器再热器 smoke alarm:烟雾报警器烟雾报警器closed loop control:闭环控制闭环控制 detect:探测探测 initiate:触发触发 开始开始reassess:再评估再评估 feedback:反馈反馈13.The simplest form of such

28、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

29、 fire protection systems.alarm:报警器报警器 smoke sensor:烟雾传感器烟雾传感器thermostatic:温度调节装置的温度调节装置的 market:使使进入市场进入市场security:安全安全 fire protection systems:防火系统防火系统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 servic

30、es automation.18.One other area which requires emphasis is the possible susceptibility of all processor based systems to electrical interference,however caused.advisable:可取的可取的 明智的明智的 question:提出问题提出问题 质询质询validity:有效性有效性 context:上下文上下文 领域领域emphasis:强调强调 susceptibility:易感性易感性 interference:干扰干扰 干涉干涉1

31、9.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 interfac

32、e conditions for every facility required.point:控制点控制点 outstation:设在边远地区的分站设在边远地区的分站 边远哨所边远哨所 远程控制中心远程控制中心BAS:building automation systems 建筑自动化系统建筑自动化系统detail:详述详述 细说细说 in terms of:按照按照 根据根据 functional sequence:功能顺序功能顺序interface condition:界面条件界面条件 facility:设施设施22.The centralization of the logic equip

33、ment allows greater flexibility of operations than conventional hard wired systems and also frees maintenance staff from watch keeping duties,enabling more effective use of manpower.23.It must be considered very early on in the building/plant design concept.If it is added at a later stage it will du

34、plicate a number of other elements which are complete in themselves.centralization:集中集中 logic equipment:逻辑设备逻辑设备 flexibility:灵活性灵活性hard wired system:硬件系统硬件系统 staff:人员人员 职员职员later stage:后期后期 duplicate:复制复制 使使成双倍成双倍25.If process control is to be achieved by direct digital control(DDC)then savings will

35、 occur in the elimination(of)local loop controllers and in the avoidance of duplicating sensors for control and monitoring purposes.process control：过程控制过程控制 direct digital control(DDC):直接数字控制直接数字控制elimination:减少减少 avoidance:避免避免26.Planned and programmed maintenance schedules can also be produced and monitored by the computer based systems but this normally requires a large memory storage capability and considerable project orientated input data.schedule:日程计划日程计划 时间计划时间计划 orientate:调整方向调整方向