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用实验的方法以水为介质研究了同轴换热器的流动与传热,Re范围为30000到100000。研究表明管内摩擦阻力系数是相同情况下圆管的4到5倍,总体传热系数随管内Re的增大而增大,当Re较大时提高壳侧速度对换热性能的提升更有利。采用数值模拟的方法分别研究了同轴换热器整体的换热与流动,且和实验结果进行了比较,研究表明,受离心力的影响流体在管内产生了掺混流动,掺混流动的程度随螺距的减小而加剧,增加槽深减少了参与掺混的流体量,流体之间的掺混对换热具有积极的影响。
The flow and heat transfer of coaxial heat exchangers were studied experimentally using water as a medium, Re range of 30,000 to 100,000. The results show that the coefficient of friction in the tube is 4 to 5 times of that of the tube under the same condition. The overall heat transfer coefficient increases with the increase of Re in the tube. Increasing the velocity of the shell side when the Re is larger is more favorable for improving the heat transfer performance. The heat transfer and flow of the coaxial heat exchanger were investigated by numerical simulation and compared with the experimental results. The results show that the flow of the mixed fluid is generated in the tube by the influence of centrifugal force. Pitch reduction is aggravated. Increasing the groove depth reduces the amount of fluid involved in mixing. The mixing between fluids has a positive effect on heat transfer.