蒸汽流量计的选择
仪器信息网 · 2011-03-24 00:23 · 10688 次点击
重视蒸汽流量计量仪表的正确选型:选择蒸汽流量计量仪表,应重点考虑两个因素。
Steamflowmeasurementinstrumentonthecorrectselection:choosesteamflowmeasurementinstrument,twofactorsshouldbeconsidered.
一是量程问题。
Aproblemisrange.
蒸汽流量计量仪表计量不正常,主要是由于选型时量程不正确造成的。用汽旺季用汽量相当大,而用汽淡季用汽量又很小,用汽量相差过于悬殊,一般蒸汽计量仪表的流量范围就难以适应。必须明确流量测量范围,在此基础上选择符合相关运行参数的蒸汽计量仪表,使其能充分发挥作用。
Steamflowmeasurementinstrumentmeasurementisnotnormal,ismainlyduetotheselectionofincorrectwhenrange.SteamYongQiLiangseasonisquitelarge,andsteamYongQiLiangoff-season,YongQiLiangvarytoolittleandgeneralsteamflowmeter,theflowrangeisdifficulttoadapt.Mustbeclearabouttheflowmeasurementrange,onthebasisofchoiceinconformitywiththerelevantoperationparametersofthesteamflowmeter,whichcanbringintofullplay.
二是管道直径问题。
Secondisthepipediameter.
在设计节流装置时,基本上都采用工艺提供的公称名义管径值,其实公称名义管径值与实际管径值还是有误差的,特别是卷管,公称名义管径值与实际值有时差值还较大,造成计量误差增大,测量的准确度就难以达到设计要求。
Whenthethrottledeviceinthedesignprocess,basicallyadoptsthenominaldiametervaluesprovidedunderthenameofnominaldiametervalues,withtheactualdiametervaluesorerror,especiallythecoilpipediameter,thenominalvalueandpracticalvalueofnominalvalueislarger,thedifferenceiscausedbymeasuringerrorincreases,theaccuracyofthemeasurementisdifficulttomeetthedesignrequirements.
国标规定:用来计算节流件直径比的管道直径D值应为上游取压口的上游0.5D长度范围内的内径平均值。该内径平均值应是至少在垂直轴线的二个横截面内所测得内径的平均值,内径的数值(用于设计的管道内径)应达到±0.3%。设计前最好实测管径,以减少计算误差。
Gbregulation:usedtocalculatethethrottlethingthanthediameterofpipediameterDvalueshouldtaketheupstreampressureupstream0.5Dwithinthescopeoftheaveragelength,diameter.Theaveragediameterverticalaxisshouldbeatleasttwocross-sectionalinsidediameteroftheaveragediameter,thenumerical(fordesignofpipediameter)shouldachieve±0.3%.Beforethedesign,inordertoreducethebestmeasureddiameterscalculationerror.