斯派莎克教材_蒸汽输送系统.

蒸汽输送分配系统蒸汽流量计典型的蒸汽流程煮锅煮锅锅炉给水泵给水箱补给水大槽冷凝水冷凝水蒸汽蒸汽蒸汽制程设备空间加热系统正确的蒸汽分配系统应该1高压输送2正确选择管道口径3为了避免水锤和冷凝水达到用汽点:在以下点进行疏水:在蒸汽管道的每一低点;每隔30-50米之间;在主管和分支管道的末端;在可能关闭的阀门以前•在流动方向,管道应该有一定的坡度•排水点的集水罐应正确选型•使用偏心缩小管,不要安装同心缩小管•蒸汽支管应该从主管的上方取蒸汽•过滤器应安装在侧面4所有蒸汽主管应有效保温温度－压力曲线05010015020025001234567891011121314压力(barg)温度(oC)饱和蒸汽比容和压力之间的关系00.20.40.60.811.21.41.61.801234567891011121314压力(barg)比容(m3/kg)蒸汽表EnthalpyinkJ/kgGaugepressureTemp.WaterEvaporationSteamVolumeDrySat.barkPa篊hfhfghgm3/kg00100419225726761.6731100120506220127070.8812200134562216327250.6033300144605213327380.4614400152671210827490.3745500159641208627570.3156600165697206627630.2727700170721204827690.248800175743203127740.2159900180763201527780.194101000184782200027820.177111100188799198627850.163121200192815197327880.151131300195830196027900.141141400198845194727920.132高压输送蒸汽高压输送的优点:蒸汽管道口径小,热损失少.蒸汽管道费用低,支撑费用少,人工费用降低.管道的隔热费用低.通过减压在使用点可以获得更加干燥的蒸汽.锅炉操作在高压更容易达到最佳运行状态,运行效率高.锅炉的蓄热能力增加,容易处理负载的变化,减少汽水共腾和携带的可能性.低压使用蒸汽的优点压力降低可以提供蒸汽中更大比例的潜热减少冷凝水所含热量，减少二次蒸汽经过减压后蒸汽具有更高的干燥度减压站如何确定管道口径?两种基本方法:流速法压降法管道选型费用增加热损失增加形成的冷凝水增加蒸汽使用点压力下降没有足够的蒸汽量容易产生水锤和冲蚀蒸汽管道口径选型图(kg/h)PressureVelocityPipeSizeNominal/ActualInsideDiameterbargm/s152025324050658010012515015.820.9326.6435.0440.952.562.777.92102.26128.2154.0515915254358951362103625698220.4251425417197159227350603948136940234066113154254363561965151721911510182951691141632514336819830.7251730498511519027141972211351638402848781361853044346711155181526211512213459811331892925037911142125203557991342213154878391319190440325691158215354505779134221103046151831508611819427742773511561669225295183144196323461712122619272782404782133230314517737113919613083445115234065113154254362559962151221833253867109188256423603931160325203639406110717430141067696414902565403258221528508013919031344668911861864269142547831342323165217431148197631064485407513221537150683311891836316249707176153459961652253715298171408221331955255698159276375619882136223473688532540901572554416019901411218037555901852115396811119126143061394716312563370062565114184319435716102215782718427161674010418229551169611461635252543486834986715447712521729648769510731848290441947257412920936249381211581788308048416989401182063345797881299185328614928774511183水锤主管下沉冷凝水占据蒸汽管道水锤引起震动和噪音冷凝水长距离管道布置蒸汽重新布置至高点冷凝水排放点30-50m坡度1/250蒸汽流向蒸汽管道向上布置增大管道直径，减低流速至15m/s蒸汽流速最高可至40m/s30-50m30-50m无效和正确的疏水点布置冷凝水集水槽疏水阀组25/30m剖面剖面疏水阀组蒸汽流向蒸汽流向正确不正确蒸汽管道的缩小冷凝水CorrectIncorrect蒸汽蒸汽冷凝水分支管的连接正确不正确蒸汽蒸汽冷凝水下降管控制阀疏水阀组主蒸汽管过滤器过滤器控制阀蒸汽系统过滤器安装液体系统过滤器安装汽水分离器流向汽水分离器排除空气SteamMain热动力疏水阀空气蒸汽排空气阀起机负载/运行负载(kg每50m主蒸汽管)SteamPressureSteamMainSize(mm)(barg)50658010012515020025030035040045050060099.515.119.728.138.149.4711051391642162723204369.311.314.116.520.624.531.53946.551.560647288109.915.720.429.239.651.3771091441712242823324639.811.914.616.921.32533414954626775901110.416.521.630.741.754.181.111515218023629835048810.91315.717.722.5263645535967738197斜体表示运行负载环境温度为200C,保温效率为80%光管的热损失Temp.DifferenceSteamtoAirPipeSize(mm)1520253240506580100150oCW/m5654657910310813215518823332467688210012213616819823629641078831001221491662032412983605008999120146179205246289346464601100116140169208234285337400501696111134164198241271334392469598816125159191233285321394464555698969139184224272333373458540622815113315321025531238242952862374793913051672412923574374896.27138381093149218027432940849455667680895911901660194309372461566634758909108013031852实例:光管的热损失输送蒸汽压力:10bar温度:180C蒸汽输送质量:3000kg/h管道口径:DN100管道长度:100米环境温度:20C热损失:1016W/m蒸汽潜热:2000kJ/kg,蒸汽冷凝率:1.016X3600/2000=1.83Kg/m.h100米常的冷凝总量:183Kg/h，蒸汽损失百分比:183/3000=6.1%蒸汽泄漏的浪费一个7.5mm的小孔，在6bar下泄漏蒸汽每小时会泄漏110kg如果每年工作8400h70000升/年的重油或者110吨/年的煤压力(barg)比热(kJ/kg)饱和蒸汽全热能蒸发潜热能显热能（冷凝水能量）大气压力下冷凝水能量可作为二次蒸汽的能量冷凝水回收回收冷凝水的节约(一)燃料费用冷凝水回收温度为80oC补给冷水温度为20oC温度差60oC升高1kg的补给水至90oC,所需能量为,1x60x4.1868=251KJ如果蒸汽负载为5000Kg/h,冷凝水回收率为70%，则每小时节约的能量为251x5000x70%＝878,500KJ/hr工厂运行20小时/天,300天/年,则节约的热量为：878,500x20x300=5,271,000,000KJ如使用燃油，每公斤燃油的热量为42,000kJ,锅炉效率为80％,则需要燃油：5,271,000,000/(42000x0.8)=156,875公斤总的燃油费用为3x156875=470,625元回收冷凝水的节约(二)水的费用每年节约水为5000x0.7x20x300/1000=21000吨如果每吨水费用为1.5元总计21000x1.5=31500元(三)水处理费每吨水处理费为1.2元总计1.2x21000=25200元回收冷凝水的节约总节约燃料+水+水处理470625+31500+25200=527325元还有其它…….