Numerical study on boiling flow and heat transfer characteristics of LNG in mini-channels
Based on the working requirements of LNG in subcritical state,the boiling flow and heat transfer character-istics of LNG in the mini-channels with diameters of 1.5 mm,2 mm and 2.5 mm were studied by using VOF phase change model.The operating pressure is 0.IMPa,the heat flux is 40.9～385.4 kW/m2,and the mass flux is 110～600 kg/m2·s.The results revealed that bubble,slug,wavy-annular,transition and mist flows in the mini-channels with diameters of 1.5 mm,2 mm and 2.5 mm were observed.Whereas,for the 1 mm diameter channel,there was no slug and transition flows;however,the confined bubble and plug flows were observed.Also,the transition of flow pattern was accelerated with the de-crease of channel diameter,and the type and proportion of flow patterns in different channel diameters were different.When the channel diameter reduced from 2.5 mm to 1 mm,the heat transfer coefficient in the wave-annular flow region was in-creased by 24.6％while the pressure drop increased by 50.1％.When the mass flux increased from 110 to 600 kg/m2·s,the heat transfer coefficient was enhanced by 22.6％and the pressure drop increased by 55.8％.
mini-channelflow boilingflow patternflow and heat transfernumerical simulation
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NSTL
万方数据
