67.770PaР管段9-10的阻力Р∆P9-10=∆Pm,9-10+∆Pj,9-10=39.546+67.770=107.316PaР9)管段10-11Р摩擦阻力Р∆Pm,10-11=∆pm,10-11 l10-11=0.8589×6.413≈5.508PaР局部阻力Р2个90°弯头Рr/W=1РHW=6001200≈0.5Р查附录1查得ξ=0.25Р变径РF0F1=1.75×0.41.2×0.6≈0.97Р用插值法查附录1求得ξ=0.0042Рξ=0.25×2+0.0042=0.5042Р局部压力损失:Р∆Pj,10-11=ξV10-112ρ2=0.5042×8.7962×1.22≈23.407PaР管段10-11的阻力Р∆P10-11=∆Pm,10-11+∆Pj,10-11=5.508+23.407=28.916PaР10)管段11-12Р摩擦阻力Р∆Pm,11-12=∆pm,11-12 l11-12=1.1633×1.905≈2.216PaР局部阻力РT形分流三通РLSLC=2090022800≈0.91Р查附录1用插值法算得ξ=0.0135Р 图4.5 矩形风管T形分流三通Рξ=0.0135Р局部压力损失:Р∆Pj,11-12=ξV11-122ρ2=0.0135×9.0482×1.22≈0.663PaР管段11-12的阻力Р∆P11-12=∆Pm,11-12+∆Pj,11-12=2.216+0.663=2.879PaР11)管段12-13Р摩擦阻力Р∆Pm,12-13=∆pm,12-13 l12-13=0.9839×9.737≈9.580PaР局部阻力РT形分流三通РLSLC=1900020900≈0.91Р查附录1用插值法算得ξ=0.0135Р90°弯头Рr/W=1РHW=4001750≈0.23Р查附录1取ξ=0.27Рξ=0.27+0.0135=0.2835
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