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本文采用二维非稳态数学模型、周期性充分发展边界条件对混合板式换热器中的板通道内的流动和换热进行数值模拟。在Re=4407～22035工况范围内,计算了半圆型、半椭圆Ⅰ型和半椭圆Ⅱ型三种不同纵截面形状波纹板通道内的流动和换热性能。数值模拟结果分析表明,波纹通道内的流动会因为流体从凸面流向凹面时产生回流而形成涡,即产生扰动,强化了后面的换热,但同时增大了阻力。并得出半圆型通道换热最强,Nu为椭圆Ⅱ型的1.4倍;但其阻力最大,压降为椭圆Ⅱ型的1.9倍。
In this paper, a two-dimensional unsteady mathematical model is used to simulate the flow and heat transfer in the plate channel of a hybrid plate heat exchanger periodically with full development of boundary conditions. In the Re = 4407 ~ 22035 working condition, the flow and heat transfer performance in three corrugated channels with different longitudinal section shapes of semicircle, semi-ellipse and semi-ellipse were calculated. The numerical simulation results show that the flow in the corrugated channel is vortexed due to the backflow when the fluid flows from the convex surface to the concave surface, that is, the disturbance is generated, which enhances the heat exchange in the back, but at the same time increases the resistance. The results show that the semicircular channel has the strongest heat transfer, Nu is 1.4 times of the elliptic type Ⅱ, but its resistance is the highest, with the pressure drop being 1.9 times of the elliptic type Ⅱ.