水平管道气水两相流摩擦压降特性研究.pdf

北京建筑工程学院硕士学位论文水平管道气水两相流摩擦压降特性研究姓名:曹健申请学位级别:硕士专业:市政工程指导教师:吴俊奇 20060301 摘要摘要本论文以水平管道内气水两相流为研究对象,对不同管径内两桐流的流型及单位摩擦压降进行了试验和分析,对影响两相流摩擦阻力系数的因素进行了研究,并提出了计算两相流摩擦压降的简化方法。研究结果表明,气相折算流速的大小会影响弥散泡状流的长度大小,液相折算流速的大小会影响气泡的上浮,本试验条件下,管道内出现了气塞流和弥散泡状流,根据分析和试验中观察到的结果,确定了判别流型的标准。液相折算流速和气水比会影响气水两相流单位摩擦压降的大小,在弥散泡状流时的单位摩擦压降比气塞流时大,原因是弥散泡状流时界面浓度大、相间能量的交换程度高所致, 当液相折算流速达到一定程度后,界面浓度趋于稳定,相间的能量交换程度对单位摩擦压降的影响减弱。影响两相流摩擦阻力系数的主要因素为管壁的相对粗糙度、干度、液相表观雷诺数和气相表观雷诺数。根据试验结果,提出了利用单相水流摩擦压降计算气水两相流摩擦压降的简化方法。关键词:气水两相流流型单位摩擦压降液相折算流速摘要 Abstract InthispapeL ajr-water two—phase inhOrizOntal pipe was taken astheresearch object,two—phase’s玎owpattem and unit仃iction pressure dmp fordif!ferentpipe diameter was tested and analyzed, the innuence factors of friction resistance coe仃icient was researchcd,simple memod ofcalculation frictionpressure dmp was brought forward aswell. Research resultshows thatsuperficial Velocity of airphase can the leng出of dispersed bubbly f|ow,superfjcial Velocity ofIiquidphase can innuence bubble’srise,in this test’scondition,plug flOw anddispersed bubbly nOw印pearcd in pipe,according toanalysis aJldobservation rcsultduringtest,differentiation staIIdard offlow Velocjty ofliquidphase and mtio could innuence two—phase’s unit打iction pressufe drop,unit frictiOnpressure dmp under dispersed bubbly now isbiggerthan plug now’s,the reason as follows: under dispersed bubbly now,interface tration isbiggcr than plug now’s, degree ofene唱y chaIlging be咐een gasphase aIIdIiquidphase ishi曲eL when superficial Velocity ofliquidphase reaches to acertainextent,inte—.ace concentration goes stable, tounitfrictionpressure dmp ofene唱ychaⅡ百ng beMeen gas phase and liquidphase influence factOrsOffrictionresistance coef甄cient are relatiVefoughness,mass Void fraction,superficial Renault ofliquidphase and superficial Renault of gaS to test result,simple method of calculation fridion pressuredmp wasbfouglIt forward. Key words: ai卜watertwo-phase now pattern unitfrj