【摘要】 在套管式换热器中,流体的脉冲流动可以提高其传热系数。当糖汁流速u=1.2m/s时,可提高70%。同时,指出湍流度增高、边界层减薄和气蚀现象是脉冲流动强化传热的主要机理。根据实验结果,还建立了工程上可用的传热准数关联式。更多还原

【Abstract】 In a double-pipe steam-to-fluid heat exchanger,pulsating flow of fluid in pipes can improve heat transfer coefficient. When Sugar juice velocity u was equal to 1.2 meter per second, the overall heat transfer coefficient can te increased by 70 percent. And it is the enhancement of turtulent current velocity, the reduction of boundary-layer thinkness and the cavitation phenomenon that compose the main machenism of improving heat transfer by pulsating flow.Moreover, in the light of the experimental results, an equation of dimensionless groups on heat transfer is developed, which can be applied to the calculation in engineering.更多还原