Abstract:

The gas temperature in the oscillating tube changes periodically, and the wall surface of the tube bundle will perform the same frequency pulsation heat transfer with the gas in the tube, which will have a certain impact on refrigeration. The static experimental platform of oscillating tube was built to measure the wall temperature. At the same time, the numerical model of unsteady flow and heat transfer was established to study the convective heat transfer. The experimental results show that a certain temperature distribution is formed on the wall of the tube bundle, and the temperature distribution on the stable wall will be steeper by thinning the outer wall thickness of the oscillating tube bundle to change the axial heat conduction area. The numerical calculation shows that the convection heat transfer between the cold end wall and the cold air will make the cold air heated, and finally reduce the refrigeration depth. The experimental results show that the maximum cooling depth increases by 0.2 K (1.6 expansion ratio), 0.5 K (1.8 expansion ratio) and 0.4 K(2.0 expansion ratio) when the wall thickness of tube bundle is reduced from 10 mm to 5 mm, which verifies the effect of pulsating wall heat transfer on refrigeration performance.

Key words: refrigeration, unsteady flow, heat conduction, numerical analysis, convection

摘要：

振荡管内气体温度周期性变化，管束壁面会与管内气体进行同频脉动传热作用，对制冷产生一定影响。搭建振荡管静止式气波制冷实验平台，对壁面温度进行测量研究；同时建立非定常流动传热数值模型，对对流换热量进行研究。实验结果表明，管束壁面最终形成一定温度分布，减薄振荡管束外壁面厚度以改变轴向导热面积，会使稳定后的壁面温度分布更陡峭。数值计算表明，冷端壁面与冷气的对流换热会加热冷气，降低制冷深度。将管束壁厚从10 mm降低至5 mm，制冷性能实验结果表明最大制冷深度提升0.2 K（1.6膨胀比）、0.5 K（1.8膨胀比）与0.4 K（2.0膨胀比），验证了脉动壁面传热对制冷性能的影响。

关键词: 制冷, 非定常流动, 热传导, 数值分析, 对流