Study On The Effect Of Microchannel Structure On Transmission Characteristics

Micro-channel reactor is the core of the advanced chemical technology,which aims at safety,high efficiency,energy saving and environmental protection.It is an efficient part of mass transfer,heat transfer and reaction.Micro-channel reactor,as a process strengthening technology,brings new vigor and challenge to chemical industry,and accords with the strategic goal of social sustainable development.The characteristic size of channel in microchannel reactor is usually between submicron and submillimeter.The miniaturization of the characteristic size shows many advantages compared with the traditional reaction equipment.In this paper,the transmission characteristics in the wave microchannel are studied by CFD simulation,and the amplification strategy of the wave microchannel is preliminarily explored.The main contents of this subject are as follows:The formation and development of secondary flow in the wave microchannel were studied by CFD simulation.The vortex shape of secondary flow in different Re number channels was described intuitively.The effects of fluid properties on the mixing properties of wave microchannels were studied by changing the diffusion coefficients.In order to improve the mixing performance of microchannels,the effect of radius R and aspect ratio a/b of circular and elliptical wave microchannels on the mixing performance was studied.Mixing performance and pressure loss increase with the decrease of wave radius R in circular wave microchannel,and increase with the decrease of half axis length ratio a/b in elliptical wave microchannel.When a/b equals 0.75,the mixing performance of the wave microchannel increases by a maximum of 38%,while the pressure drop decreases by 15%.In order to verify this rule,the circular wave microchannel is amplified in equal proportion.It is also found that the mixing performance of the channel is the best when the average De number is maximum.When the secondary flow has not been generated or the intensity is low,the average Nu number is small and invariant.With the increase of the secondary flow intensity,the average Nu number increases and the heat transfer performance increases.On this basis,the effect of circular and elliptical wave microchannel structures on heat transfer performance is studied.It is found that different structures have great influence on mixing performance,but little on heat transfer performance.Finally,explore the wave microchannel size amplification effect the performance of the relay,respectively for the size of the export of microchannel one dimension and two dimensions of amplification,under the same flow rate,the increase of the size are not conducive to mixing and heat transfer,but through the way of increasing traffic,make the large size of microchannel get better performance of mixing and heat transfer.