流量计故障诊断

Click to edit Master title style,*,Click to edit Master text styles xxxxxxxxxxxxxxxxxx,Second level,Third level,Jan. 24th, 2004,故障诊断指南,數顯靶式,流量計,SBL,型,數顯靶式流量計,1700R,型,Flow Meter,Troubleshooting Guideline,新安装还是旧表?,方法,1,Page 4,Page 7,旧,新,怀疑,Micromotion,有问题,管道无流量,Transmitter,有输出,管道有流量,Transmitter,无输出,管道有流量,Transmitter,输出不正确,Page 10,2,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道无流量,Vortex,有输出,(,Page 1 of 1),可能的原因:,1.,流量计受到振动或电磁干扰影响,:,检查:,明显的管道振动,Vortex,靠近大的电磁干扰源,(,电机, 电炉,),技术措施:,通过275观察流量和频率值. 见,Appendix A.,如果发生体频率,= 50,或 60,Hz,有可能是电磁干扰,. (,HART,命令: 1,4,3,2,1,3),增加流量计滤波 - 见,Appendix A.,滤波调整后能够消除大多数振动, 但可能影响测量小流量哪里.,如果是分体安装, 是否能改为一体化安装.,通过加支撑来改善振动影响.,工程措施:,将流量计翻转90度. 改变受振动影响的方向.,如果实在不行, 安装一个缩径涡街,(8800,CR Reducer Vortex),可能解决问题 - 改变测量频率.,3,可能的原因:,1.,电源没有正确安装,Items to look for:,4,mA,无变化, 或没有信号输出,技术措施,检查接线,2.,流量计方向装反,检查:,4,mA,无变化, 或在高流量时也非常小,技术措施,确保箭头方向与流量一致.,3.,组态不正确,检查:,Vortex,测量质量流量还是标准体积流量,流量计上游不满足,35,D,而且 ,Installation Effects”,输入不正确,工程/技术措施:,验证流量计,Basic Setup,参数是否正确.,见,appendix A.,验证密度,(,用于质量)或密度比,(,用于标准体积,),是否正确,.,验证,“,Installation Effects”,是否正确,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,无输出 - 新安装,(,Page 1 of 3),4,可能的原因:,4.,流量低于小流量切除:,检查:,阀门是否完全开启,技术/工程措施:,开大阀门, 增加流量,验证过程状态和流量计口径以确保实际流量高于仪表的小流量切除.,提高仪表灵敏度 - 见,appendix A.,可以调节滤波来读取低流量, 但是对振动会较敏感.,如果实际流量大大低于小流量切除, 可能需要更换缩径涡街.,5.,不满管,检查:,流量计是否竖直安装且介质向下流.,流量计读数间歇性 - 但是大多数时间无显示,技术/过程措施:,将流量计水平安装或竖直向上流,6.,气蚀/气化,检查:,管道压力接近气化压力,管道压力极低和/或流速极高,技术/工程措施,验证过程状态和流量计口径以确保背压足够.,尝试提高管道压力. 或者,-,逐渐关小下游阀提高背压(阀门可能会几乎关死).,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,无输出 - 新安装,(,Page 2 of 3),5,可能原因:,7.,堵塞/挂壁,检查:,介质含有大块固体颗粒.,流量计垫圈伸进流体.,技术措施,检查上游垫圈是否堵塞流量,附加工程措施,开闭阀门以,清洗,流量计,.,可能会将发生体上的附着物冲出.,实在不行, 则要拆卸流量计来清洁.,8.,电子部件故障,技术/工程措施,根据,Appendix A,完成电子部件的故障诊断,9.,传感器故障,检查:,介质温度是否超过压电传感器的耐温.,对于蒸汽, 团流或水击可能损坏流量计,技术/工程措施,根据,Appendix A.,完成压电传感器故障诊断,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,无输出 - 新安装,(,Page 3 of 3),6,POTENTIAL ROOT CAUSES:,1.,电子部件故障,技术/工程措施,根据,Appendix A,完成电子部件的故障诊断,2.,传感器故障,检查:,介质温度是否超过压电传感器的耐温.,对于蒸汽, 团流或水击可能损坏流量计,技术/工程措施,根据,Appendix A.,完成压电传感器故障诊断,3.,流量低于小流量切除:,检查:,过程状态变化会影响流速和/或密度.,工程措施:,验证过程状态和流量计口径以确保实际流量高于仪表的小流量切除.,提高仪表灵敏度 - 见,appendix A.,可以调节滤波来读取低流量, 但是对振动会较敏感.,如果实际流量大大低于小流量切除, 可能需要更换缩径涡街,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,无输出 - 旧表,(,Page 1 of 3),7,可能的原因:,4.,不满管,检查:,流量计是否竖直安装且介质向下流.,流量计读数间歇性 - 但是大多数时间无显示,技术/过程措施:,将流量计水平安装或竖直向上流,5.,气蚀/气化,检查:,管道压力接近气化压力,管道压力极低和/或流速极高,技术/工程措施,验证过程状态和流量计口径以确保背压足够.,尝试提高管道压力. 或者,-,逐渐关小下游阀提高背压(阀门可能会几乎关死).,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,无输出 - 旧表,(,Page 2 of 3),8,POTENTIAL ROOT CAUSES:,6.,堵塞/挂壁,检查:,介质含有大块固体颗粒.,流量计垫圈伸进流体.,技术措施,检查上游垫圈是否堵塞流量,附加工程措施,开闭阀门以,清洗,流量计,.,可能会将发生体上的附着物冲出.,实在不行, 则要拆卸流量计来清洁,堵塞/挂壁,检查:,介质含有大块固体颗粒.,流量计垫圈伸进流体.,技术措施,检查上游垫圈是否堵塞流量,附加工程措施,开闭阀门以,清洗,流量计,.,可能会将发生体上的附着物冲出.,实在不行, 则要拆卸流量计来清洁,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,无输出 - 旧表,(,Page 3 of 3),9,问题: 读数持续偏高或偏低,可能的原因:,1.,组态不正确,检查:,Vortex,测量质量流量还是标准体积流量,流量计上游不满足,35,D,而且 ,Installation Effects”,输入不正确,以什么作为参考?,工程/技术措施:,验证流量计,Basic Setup,参数是否正确.,见,appendix A.,验证密度,(,用于质量)或密度比,(,用于标准体积,),是否正确,.,验证,“,Installation Effects”,是否正确,涡街是否测量是准确的.,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,输出不正确,(,Page 1 of 5),10,问题,:,读数远远低于正常值, 而且变化不显著,可能的问题:,1.,堵塞/挂壁,检查:,介质含有大块固体颗粒.,流量计垫圈伸进流体.,技术措施,检查上游垫圈是否堵塞流量,附加工程措施,开闭阀门以,清洗,流量计,.,可能会将发生体上的附着物冲出.,实在不行, 则要拆卸流量计来清洁,堵塞/挂壁,检查:,介质含有大块固体颗粒.,流量计垫圈伸进流体.,技术措施,检查上游垫圈是否堵塞流量,附加工程措施,开闭阀门以,清洗,流量计,.,可能会将发生体上的附着物冲出.,实在不行, 则要拆卸流量计来清洁,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,输出不正确,(,Page 2 of 5),11,问题,:,流量变化时读数不变,可能的问题,:,1.,流量计受到振动或电磁干扰影响,:,检查:,明显的管道振动,Vortex,靠近大的电磁干扰源,(,电机, 电炉,),技术措施:,通过275观察流量和频率值. 见,Appendix A.,如果发生体频率,= 50,或 60,Hz,有可能是电磁干扰,. (,HART,命令: 1,4,3,2,1,3),增加流量计滤波 - 见,Appendix A.,滤波调整后能够消除大多数振动, 但可能影响测量小流量哪里.,如果是分体安装, 是否能改为一体化安装.,通过加支撑来改善振动影响.,工程措施:,将流量计翻转90度. 改变受振动影响的方向.,如果实在不行, 安装一个缩径涡街,(8800,CR Reducer Vortex),可能解决问题 - 改变测量频率,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,输出不正确,(,Page 3 of 5),12,问题,:,流量不变时读数乱跳,可能的原因:,1.,脉动流或流量波动,检查:,流量计可能测量到真实的流量/泵的波动, 而且阻尼较低. 工厂默认,2,秒,.,工程/技术措施:,如果是闭环控制且动态响应时间非常重要, 则根据,appendix A,增加阻尼.,2.,气蚀/气化,检查:,管道压力接近气化压力,管道压力极低和/或流速极高,技术/工程措施,验证过程状态和流量计口径以确保背压足够.,尝试提高管道压力. 或者,-,逐渐关小下游阀提高背压(阀门可能会几乎关死).,3.,物体附着,检查:,流量是否间歇性下降,工程措施,检查是否有附着物.,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,输出不正确,(,Page 4 of 5),13,问题:,读数在低流量稳定, 但是在高流量读数跌下来,可能的原因:,1.,气蚀/气化,检查:,管道压力接近气化压力,管道压力极低和/或流速极高,技术/工程措施,验证过程状态和流量计口径以确保背压足够.,尝试提高管道压力. 或者,-,逐渐关小下游阀提高背压(阀门可能会几乎关死).,Rosemount 8800 Vortex Meter Troubleshooting Guideline,管道有流量,Vortex,输出不正确,(,Page 5 of 5),14,故障诊断指南,APPENDIX A,Rosemount Model 8800 Vortex,电子部件,Viewing Process Variables,Configuration,Filter Adjustments,Verifying Calibration,Appendix A - 8800 Vortex,综述,压电传感器,Electrical Health,Mechanical Health,表体,16,Appendix A -,8800 Vortex,电子部件,电子部件,Viewing Process Variables,Configuration,Basic Setup & Installation Effects,Filter Adjustments,增加流量计灵敏度以测量低流量,增加流量计滤波以降低干扰和振动影响,滤波指南,Low Flow Cutoff,Low Pass Corner Frequency,Trigger Level,Optimize Flow Range: Filter Auto Adjust,Filter Restore,Verifying Calibration,4-20 ma (D/A) Trim,Internal Flow Simulation,External Flow Simulation,17,Appendix A - 8800 Vortex Electronics,Basic Setup,组态,以下参数必须组态:,Service Type:,Liquid or Gas/Steam,PV Units:,Process Variable Flow Units (Volumetric or Mass),Range Values:,Set Lower Range Value (LRV) and URV (Upper Range Value). 4 and 20 ma points in Analog,Process Temperature:,Nominal Process Temperature and units for Thermal Expansion calculations,Mating Pipe ID:,Inside Diameter of mating Pipe I.D. for Entrance Effect Correction,K-factor:,Reference K-factor determined in Flow Lab. Stamped on meter tag.,18,Appendix A - 8800 Vortex Electronics,Basic Setup,组态 -,HART 275 Menu Tree,19,Appendix A - 8800 Vortex Electronics,Basic Setup,组态 -,HART 275 Menu Tree,20,每个流量计的,Reference K-factor,是在,Rosemount Flow Lab,标定的.以下是各个口径的额定,K-Factors.,Appendix A - 8800 Vortex Electronics,Basic Setup,组态,-,Reference K-factor,21,Electronics,Viewing Process Variables,Configuration,Basic Setup & Installation Effects,Filter Adjustments,增加流量计灵敏度以测量低流量,增加流量计滤波以降低干扰和振动影响,滤波指南,Low Flow Cutoff,Low Pass Corner Frequency,Trigger Level,Optimize Flow Range: Filter Auto Adjust,Filter Restore,Verifying Calibration,4-20 ma (D/A) Trim,Internal Flow Simulation,External Flow Simulation,Appendix A -,8800 Vortex Electronics,22,增加灵敏度以测量低流量,降低,Trigger Level,增加灵敏度,-,在测量低流量的低密度气体时必须,.,干扰可能影响精度,增加,Low Pass Filter,对于大多数应用不推荐,在测量低密度气体时必须,干扰可能影响精度,降低,Low Flow Cutoff,提高量程,干扰可能影响精度,Appendix A - 8800 Vortex Filter Adjustments,增加流量计灵敏度以扩展量程,23,增加流量计滤波以降低干扰,增加,Trigger Level,在所有频率段降低灵敏度,在量程的,10-20%,可有效解决问题,降低,Low Pass Filter,在量程的30% -,100%,降低灵敏度,增加,Low Flow Cutoff,在量程的 10%以下降低灵敏度,减小量程,Appendix A - 8800 Vortex Filter Adjustments,增加流量计滤波以降低干扰,24,Trigger Level,Above Trigger Level = Counted,Below Trigger Level = Not Counted,Appendix A - 8800 Vortex Filter Adjustments,滤波指南:,Vortex,信号原理,25,Trigger Level,Appendix A - 8800 Vortex Filter Adjustments,Vortex,信号和未经滤波的高频及低频干扰,26,Trigger Level,Appendix A - 8800 Vortex Filter Adjustments,滤波指南:,Vortex,信号原理,干扰被小流量切除,ADSP,和低通滤波限制到低于,Trigger Level,Preferred “Signal to Trigger” Ratio (Signal Strength) is 4:1,Signal Amplitude,27,Appendix A - 8800 Vortex Electronics,滤波指南:,Vortex,信号原理,High,Pass,Low,Pass,Low Pass Corner Frequency,Low Flow Cut-Off,2,HZ,7200,HZ,ADSP Filter Tracking,28,Appendix A - 8800 Vortex,综述,压电传感器,Electrical Health,Mechanical Health,表体,电子部件,Viewing Process Variables,Configuration,Filter Adjustments,Verifying Calibration,29,Sensor and sensor lead wire can be checked for shorts:,Appendix A - 8800 Vortex Sensor,压电传感器 - 电气状态诊断,1.,Loosen the three housing rotation screws with Allen head wrench,2. Slowly pull electronics housing - NOT MORE THAN 2 INCHES from top of support tube (To avoid damage to lead wire).,3. Loosen and remove sensor cable nut (using a 5/16” wrench,),4.,Using Multi-meter touching co-axial connector pin (and grounded to meter body), verify that sensor impedance is 5,megohms,.,5. If multi-meter reads short, sensor must be replaced*.,* -,Although no process seal is broken, it is recommended that the pipe be de-pressurized when replacing sensors,30,只有当其它的潜在故障点都排除后才建议检查机械损坏,.,Sensor/Post interface,非常重要, 在移开和插入传感器时易损坏,.,传感器应该和接头紧密结合. 如果其很容易地被移开, 则有可能被团流或水击损坏, 需要更换传感器.,Sensor/Post interface,应该是圆的. 如果其损坏, 会变成椭圆型.,传感器最多只能拆卸一次!,Sensor/Post Interface,Appendix A - 8800 Vortex Sensor,压电传感器 - 检查机械损坏,* -,Although no process seal is broken, it is recommended that the pipe be de-pressurized when replacing sensors,31,Appendix A - 8800 Vortex,综述,压电传感器,Electrical Health,Mechanical Health,表体,电子部件,Viewing Process Variables,Configuration,Filter Adjustments,Verifying Calibration,32,Appendix A - 8800 Vortex Meter Body,Meter Body - Potential for Plugging, Corrosion,In general, issues with the meter body or shedder bar are very rare.,Rosemount 8800 meter body design has no ports or crevices to plug.,Very large chunks or large obstructions (,ie,- hard hats, building materials, etc) may become lodged on the shedder bar and cause poor or no reading.,As a final option, process may need to be shutdown to check for this, but only if it is suspected and all other options have been exhausted.,The 8800 Vortex performance is nearly insensitive* to shedder bar wear (,erosion,).,* - Even some erosion of shedder bar edge does not significantly impact ability to shed consistent vortices.,Proper material of construction selection is important to minimize potential for,corrosion,All Cast/All Welded,* No Crevices,* No Gaskets,33,