太阳能板式换热器的脉动流相变传热特性

为了研究脉动流对太阳能板式换热器相变传热特性的影响，对太阳能光热板式换热器建立三流道模型，模拟脉动条件下流道内部流动相变传热过程。结果表明：脉动流动下，波纹流道内漩涡周期性形成和脱落，波纹凹角处流体与主流区流体的掺混增强。与稳态相比，脉动流场传热效果的强化程度随振幅和频率增大而增大。稳态流动气相在凹角和换热壁面上堆积，形成明显的气膜。脉动流动下，随着脉动振幅增大，脉动流场的气相体积先减小后增大，振幅为0.02时到达最小值，随着脉动频率的增加，气相体积的变化幅值开始减小，气相体积均值在逐渐增大。

Heat transfer characteristics of pulsating flow phase transition of solar panel heat exchanger

In order to study the influence of pulsating flow on the phase-transition thermal characteristics of the solar panel heat exchanger, a three-channel model of the solar thermal plate heat exchanger is established to simulate the phase-transition heat process of the pulsating flow inside the solar panel heat exchanger. channel under pulsating conditions.The results show that under the pulsating flow, the vortices in the corrugated channel periodically form and fall off, and the mixing of the fluid at the concave corner of the corrugation and the fluid in the main flow area is enhanced. Compared with the steady state, the intensification degree of the heat transfer effect of the pulsating flow field increases with the increase of the amplitude and frequency. The steady-state flowing gas phase accumulates on the concave corners and heat exchange walls, forming an obvious gas film. Under pulsating flow, with the increase of the pulsation amplitude, the gas phase volume of the pulsating flow field first decreases and then increases, and reaches the minimum value reaching the minimum when the amplitude is 0.02. With the increase of the pulsation frequency, the variation amplitude of the gas phase volume begins to decrease, and the average value of the gas phase volume gradually increases.