,Q=1453.5W,0.04m/sG=52.0kg/h,Q=1511.6W,0.04m/s用内插法可求得当G=50.55kg/h,0.04m/s最不利环路其他管段的管径见表2-3。(4)计算各管段的压力损失(参照简明供热手册137页,5-17)(2-8)=(参照简明供热手册112页5-2)(2-9)V=(参照简明供热手册114页5-1)(2-10)R=P(参照简明供热手册112页5-2)(2-11)式中:—管段压力损失,Pa;—摩擦系数;—管道直径,m;—管道长度,m;—比摩阻,Pa/m;—局部阻力系数;—热媒密度,kg/m3;—热媒在管内的流速,m/s。管段1:热媒密度=961.92kg/m3,流速=0.04m/s沿程压力损失:=Rl=1.34×4=5.38Pa(参照简明供热手册116页,5-16)(2-9)局部压力损失:==1×=1.54Pa(参照简明供热手册115页5-15)(2-12)该管段总压力损失:=6.92Pa(参照简明供热手册117页5-1)(2-13)依次计算将最不利环路各管段的压力损失列入表2-3.表2-3管路压力损失计算表管段号管道长度(m)比摩阻(Pa/m)管径(公称直径)(mm)流量G(kg/h)流速(m/s)沿程损失(Pa)局部损失(Pa)压力损失(Pa)141.342050.550.045.381.546.92272.2925101.10.0516.002.4118.4131.88.321547.10.0714.974.7119.6846.58.321547.10.0754.064.7158.78547.571544.70.0630.303.4333.7361.24.282074.30.065.143.468.6073.58.321547.10.0729.114.7133.8285.32.2925101.10.0512.122.4114.52
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