压缩机气阀设计基础.pdf

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1、Valves-FundamentalDesign气阀设计基础PaulModern–ChiefEngineerValves&FlowControlProductsValveDesignPrinciples气阀设计原理ValveFundamentalOperation气阀基本工作原理ValveTechnicalDesign气阀技术设计MaterialConsiderations材料选择2PROPRIETARYANDCONFIDENTIALValveDesignPrinciples气阀设计原理ValveFundamentalOperation气阀基本工作

2、原理ValveTechnicalDesignMaterialConsiderations3PROPRIETARYANDCONFIDENTIALValveFundamental气阀基础Thesheerquantityofoperationcyclesinvolvedsoonhighlightsanyproblemswithdesign下面例子中，气阀运动周期之多足以说明气阀设计所要面临的问题Example1–API618typecompressorat400RPM–Valvesopenandclose210milliontimesinoneyear(

3、8000hrs)举例1，假如压缩机转速400RPM-气阀开启关闭2.1亿次每年（8000h）Example2–Highspeedcompressorat1200RPM–Valvesopenandclose630milliontimes举例2-假如压缩机转速1200RPM-气阀开启关闭6.3亿次每年（8000h）Carengine–average3000RPM–20,000km–Around300hrsand54millioncycles.Easy!汽车发动机-平均转速3000RPM-2万公里-约300hs，约5.4千万运动周期。Conclusion-

4、Compressorvalveshaveaveryhardlife!Valvedesignshavedevelopedovermanyyearstodevelopspecifictypesforspecificapplications从这个角度看，压缩机气阀能运行8000h真不容易。气阀设计经过多年发展，针对具体工况，需要设计特定的气阀。4PROPRIETARYANDCONFIDENTIALValveFundamental气阀基础BasicValvePrinciples:气阀基本原理Valvesrelysolelyonpressuredifferent

5、ialandflowforcestooperate气阀仅仅依靠压差和气体力启闭Inlet(Suction),Outlet(Discharge)areonewayvalves气阀是单向阀Sealingelement/s(plate/ring/poppets)movebetweenseatandguard密封原件在阀盖阀座之间运动Valveclosingiscontrolledbyspringforces弹簧控制气阀的启闭7PROPRIETARYANDCONFIDENTIALValveFundamental气阀基础BasicValvePrinciples

6、气阀基本原理:•Startofpistonmotionatbottomdeadcentre(BDC),zerovelocity,allvalvesclosed活塞在下止点的时候，速度为零，所有气阀处于关闭状态SuctionHeadEnd(HE)盖侧CrankEnd(CE)轴侧8PROPRIETARYANDCONFIDENTIALDischargeValveFundamental气阀基础BasicValvePrinciples气阀基本原理:•Pistonstartstotravel,gaspressurechangesduetoexpansionofvolu

7、mebelowpiston(CE),compressionofvolumeabovepiston(HE)活塞开始运动，轴侧气阀膨胀，压力下降，盖侧气阀受压缩，压力上升。SuctionPressureIncreasingPressureDropping9PROPRIETARYANDCONFIDENTIALDischargeValveFundamental气阀基础BasicValvePrinciples气阀基本原理:•Pressuredifferentialopenssuctionvalveagainstsprings(lightersprings)oncra

8、nkend气缸内外的压差克服轴侧进气阀弹簧力，气阀打开Suctio