颗粒帘换热单元的稳态换热特性研究

Steady heat transfer characteristics of a particle curtain based heat exchanger

提出了一种全新的颗粒帘换热器的概念及基于其换热单元的空气预热器(空预器)概念,并在固体与气力快速热平衡的假定条件下构建了换热计算数学模型,研究了各工况下热颗粒-冷气流及冷颗粒-热气流的换热特性及规律。结果发现:颗粒帘换热单元中,当颗粒质量流量足够时,冷流体加热后的出口平均温度可无限接近热流体初始温度,冷热流体之间能够实现深度换热,换热效果明显。基于颗粒帘的气固两相换热器技术是空预器及各种工业尾气余热回收技术的重要发展方向。

The conceptions of a new particle curtain heat exchanger and the particle curtain heat exchanger units based air preheater were proposed. Moreover, under the assumption that the solid and gas had reached thermal equilibrium instantaneously, the mathematical model of heat transfer was established. At last, the characteristics of heat transfer between hot particles and cold air flow, and cold particles and hot air flow under different operation conditions were investigated. The results show that, when the particle mass flow is sufficient, the average temperature of the outlet cold fluid can be infinitely close to the initial temperature of the hot fluid, indicating the particle-curtain based unit can achieve absolute heat transfer between the falling particle curtain and the horizontally-flowing gas stream. In conclusion, the gas-solid heat exchanger based on particle curtains shows a great technological advantage in comparison with the traditional shell and tube air preheater,which will provide a new research direction for the present study of air preheaters and the exhaust heat recovery technologies in industry.