高低热导率相间表面强化饱和池沸腾的格子玻尔兹曼模拟

采用格子玻尔兹曼方法模拟高低热导率相间表面的饱和池沸腾过程,研究不同表面高低热导率区域热导率比值、低热导率区域宽度和深度对沸腾换热性能的影响。对比均匀热导率表面与高低热导率相间表面的沸腾曲线发现：高低热导率相间表面的沸腾过程可被分为5个阶段,并且其临界热流密度最高可达均匀表面的12倍;高低热导率相间可促使表面维持一定的温度差异,从而保持明显的气液流动;随着低热导率区域宽度增大,气液分离更加明显,低热导率区域宽度存在一个最优值,其与毛细长度的量级接近;随着低热导率区域的深度增大,表面过热度的差异更加明显。

Simulation of Increased Saturated Pool Boiling Heat Transfer on Bi conductive Surfaces by Lattice Boltzmann Method

Adopting the lattice Boltzmann method to simulate the saturated pool boiling process on bi conductive surfaces,the effects of thermal conductivity ratio,low thermal conductivity region width and low thermal conductivity region depth on boiling heat transfer performance were studied. By comparing the pool boiling curves of uniform conductive surfaces and bi conductive surfaces were investigated,it is found that the pool boiling curve of bi conductive surfaces is divided into five stages,and its critical heat flow density can achieve 12 times of uniform conductive surfaces maximumly. Bi conductive surfaces create in plane variations in the local surface temperature which promots the distinct vapor and liquid flows. The separation of liquid and vapor is more obvious as the width of low thermal conductivity region increases,and there is an optimal width value close to the magnitude of capillary length; the degree of super heat difference of surface enhances with the increase of the depth of low thermal conductivity region.