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1、总蒸汽流量计算方法我厂测量总蒸汽的流量计为喷嘴式流量计，它属于差压式的流量 计的一种，根据该仪表的原理气体的流量与通过节流元件的差压的开 方成正比（k值）.计算公式如下：Qm :蒸汽的质量流量k :修正值 P :通过喷嘴节流元件前后的差压P：在一定温度一定压力下蒸汽的密度1、由流量计所带仪表（差压变送器）测出通过节流元件的前后 差压2、用压力变送器测量出蒸汽管道内蒸汽的压力，用热电阻测量 出管道内蒸汽的温度3、机内编写一 PO 的功能块，其作用是对测量出的蒸汽流量 进行密度补偿。即在不同的压力和不同的温度下，选择蒸 汽在该温度压力下的密度，以计算出其质量流量。详细取 值情况如下（pi蒸汽压力力
2、蒸汽温度，mp蒸汽的密度）:IF pi=0.00 AND pi=0.025 THENIF ti=140 AND ti170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=0.36;END_IFELSIF pi0.025 AND pi=0.10 THENIF ti=140 AND ti150 AND ti170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=0.54;END_
3、IFELSIF pi0.10 AND pi=0.20 THENIF ti=140 AND ti150 AND ti170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=0.90;END_IFELSIF pi0.20 AND pi=0.28 THENIF ti=140 AND ti150 AND ti170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=1.30;END_IF
4、ELSIF pi0.28 AND pi=0.33 THENIF ti=140 AND ti150 AND ti170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=1.45;END_IFELSIF pi0.33 AND pi=140 THEN mp:=2.34;ELSIF ti=140 AND ti150 AND ti170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=1
5、.66;END_IFELSIF pi0.40 AND pi=0.475 THENIF ti=140 AND ti150 AND ti170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=1.66;END_IFELSIF pi0.475 AND pi=0.525 THENIF ti=140 AND ti150 AND ti170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=
6、2.18;END_IFELSIF pi0.525 AND pi=0.600 THENIF ti=140 AND ti150 AND ti170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=2.36;END_IFELSIF pi0.600 AND pi=0.800 THENIF ti=170 AND ti190 AND ti210 AND ti230 AND ti250 AND ti270 AND ti290 AND ti310 THEN mp:=3.10;END_IFELSIF pi0.80 AND pi=0.900 THENIF ti170 THEN mp:=4.76;
