外文翻译--系统的设计功能.doc

SystemstructureandcontrolschemesystemdesignfeaturesThecontrolsystemofventilationunitswithcentrifugalactivationofinterlockingandover-temperatureprotection.Andconventionalrelayscomparedtotheimplementationoftheventilationsystem,PLCsystemhasalowfailurerate,highreliabilityandwiringissimple,easymaintenanceandmanyotheradvantages,PLCcontrolfunctionssothatthventilationsystemsgreatlyenhancethedegreeofautomation,reducingthelaborjobsintensity.PLCandfrequencyconverterwiththeuseofairpressuretransmitter,allowingthesystemtocontrolthesecurity,reliability,greatlyimproved,butalsorunthefansignificantlyreducethefailurerate,notonlysavesenergybutalsoimprovetheoperationrateofequipment.Mineventilationsystemtomeettherequirementsofautomaticcontrolsystemthespecificdesignrequirementsareasfollows:(1)Thissystemprovidesmanual/automaticmodeofthetwo,withastateofalarmdisplayandfeaturessuchasfaults.(2)AnalogPIDoperatorviapressureinput,outputanalogconvertercontrol.(3)Intheautomaticmode,whenthedownholepressurebelowthesetpressurelimit,twosetsoffanswillberunningtoworkatthesametime,atthesametimeandissuedinstructionsandalarmsignals.(4)Analoginputgas,whenthegasconcentrationisgreaterthantheupperlimitofalarmsettings,andreporttothepolicetogivedirections.Whenthegasconcentrationisgreaterthantheupperlimitofpowersettings,PLCwillcutoffthefaceandwindpowergeneratingunitstopreventthegasexplosion.(5)Theuseoftemperaturesensorsmeasuredtemperatureorthewindbearingunitstatortemperature,bearingtemperatureorwhenthestatortemperatureexceedsthesetalarmontheline,givedirectionsandwarningsignals.Whenthestatortemperatureorthewindbearingtemperatureexceedsthesettemperatureofthelineunitconversion,PLCwillcutofftheinstructionsandalarmsignalandautomaticallycutofftheairunitiscurrentlyrunninginautomaticmodeandcanautomaticallyaccessanotherrunTyphoonunit,ifinthehanddynamicmanner,staffmanuallyswitch1.(6)Inordertopreventfatiguecentrifugalfanoperationinanystate,setthefantoruninatotaltimewillautomaticallyswitchtoanotherunitoperationtyphoon.systemarchitectureandprogramVentilationcontrolsystemismainlycomposedof2setsofcentrifugalfans,centrifugalfanseachhavetwomotors,eachmotordrivesasetoffanfilms,twofilmsontherotatingfanandasetofwindsuction,agrouptoincreasewindspeed,forthewindtocarryoutunderground.Undergroundairvolumeinaccordancewiththedifferent,usingdifferenttypesoffans.Thedesignof2×45kWfanasanexample,theselectionofaS72200PLC,theairpressuresensorandtransducer,suchastheformationofacompleteclosed-loopcontrolsystem.Includingcontactors,intermediaterelays,thermalrelays,MineExplosion-proofmagneticstarter,circuitbreakerprotectionofelectricalsystems,electricalandPLCtoachieveeffectiveprotection,aswellasmotorcontrolswitch.PLCcontrolsystemwiththefanmotortostartandrun,monitor,interlockandover-temperatureprotection.PLCandwiththeuseofairpressuretransmitter,allowingthesystemtocontrolthesecurity,reliability,greatlyimproved,butalsorunthefansignificantlyreducethefailurerateandimprovetheoperationrateofequipment2.Forcoalmineventilationsystemtomeettherequirementsofautomaticcontrol,designofcontrolprogramsisasfollows:Thesystemprovidesmanual/automaticmodeofthetwo,withscenecontrol,statusdisplayandalarmfailure.Inmanualmode,thefancontrolthroughtheswitchfromtheeffectsofairpressureinsidethemine.Inordertopreventfatiguefanrunning,inanystateinthecumulativefanruntimesettoswitchtoanothermachinerunningthetyphoon.AGroupBGroupcentrifugalfancentrifugalfanwithtwoswitchescanbeconverted.Timecyclesandtimingcanberandomlyset.Aresoundandlightalarmsignalform.VoiceAlarm(electricflute)buttoncanbeusedtolift,alarmtroubleshootinginstructionsautomaticallydisappear.Inautomaticmode,theuseofairpressureFarEasToneminedetectionsensorswithinthepressuresignal,thesignaltransmitterwilltransformthesiteintoaunifiedstandardsignal(eg,420mADCcurrentsignal,05VDCvoltagesignal,etc.),intotheA/Dconverteranalog-digitalconversionmodule,andthenintothePLC,PLCtodetectthepressurevaluewithsetvaluesofpressureanddealwiththeworkoftheoutputsignaltocontrolfan.Whentheairpressureinsidethemineinanatmosphericpressureorinthesettingofavalueaboveatmosphericpressure,theworkofcentrifugalfancentrifugalfanwithback-upcycleofthework；whenasuddenaccident,theminesairpressureislowerthanasetofatmosphericpressurevalue,theworkofcentrifugalfancentrifugalfanwithback-upcycleisnolongerwork,andautomaticallyswitchtotheworkatthesametime,increasethevolumeofthemineventilation,mineuntilthepressurerosetovaluessetaboveatmosphericpressure,theworkofventilationcentrifugalfanwithback-upmachinetoresumethecycleofwork3.Gasinthemineforwindsystems,coalminegasconcentrationinthegasconcentrationdetectionsensorwithatransmittersignalwillbethesitetransformintoaunifiedstandardsignal,intotheA/Dconverteranalog-digitalconversionmodule,andthenintothePLC,thesamewillbedetectedbythePLCandsetnumericalvaluesforcomparison,whenthegasconcentrationgreaterthanthevalueaftertheset,PLCoutputsignalstocontrolfantostopworking,andtheoutputsignalpowerwasautomaticallycutminetomeettherequirementsofwindpowerinterlocktoavoidelectronicsparkslitthegastopreventgasexplosionaccident.系统的设计功能本控制系统具有离心通风机组的启动、互锁和过热保护等功能。与常规继电器实施的通风系统相比，PLC系统具有故障率低、可靠性高、接线简单、维护方便等诸多优点，PLC的控制功能使通风系统的自动化程度大大提高，减轻了岗位人员的劳动强度。PLC和变频器与空气压力变送器配合使用，使系统控制的安全性、可靠性大大提高，也使通风机运行的故障率大大降低，不仅节约了电能，而且还提高了设备的运转率。为满足矿井通风系统自动控制的要求，系统的具体设计要求如下：（1）本系统提供手动自动两种工作模式，具有状态显示以及故障报警等功能。（2）模拟量压力输入经PID运算，输出模拟量控制变频器。（3）在自动方式下，当井下压力低于设定压力下限时，两组风机将同时投入工作运行，同时并发出指示和报警信号。（4）模拟量瓦斯输入，当矿井瓦斯浓度大于设定报警上限时，发出指示和报警。当瓦斯浓度大于设定断电上限时，PLC将切断工作面和风机组电源，防止瓦斯爆炸。（5）运用温度传感器测定风机组定子温度或轴承温度，当定子温度或轴承温度超过设定报警上线时，发出指示和报警信号。当定子温度或轴承温度超过设定风机组转换温度界线时，PLC将切断指示和报警信号并自动切断当前运行风机组，在自动方式下并能自动接入另一台风机组运行，若在手动方式下，工作人员手动切换1。（6）为防止离心风机的疲劳运行，在任何状态下，风机在累计运行设定时间后都会自动切换至另一台风机组运行。结构和方案通风控制系统主要由2台离心风机组成，每台离心风机有两台电机，每台电机驱动一组扇片，两组扇片是对旋的，一组用于吸风，一组为增加风速，对井下进行供风。根据井下用风量的不同，采用不同型号的风机。本设计以风机2×45kW为例，选用一台S72200PLC、空气压力传感器和变频器等组成一个完整的闭环控制系统。其中还包括接触器、中间继电器、热继电器、矿用防爆型磁力启动器、断路器等系统保护电器，实现对电机和PLC的有效保护，以及对电机的切换控制。本PLC控制系统具有对通风机的电动机启动与运行，进行监控、联锁和过