波纹管管内降膜流动与传热特性的研究

INVESTIGATION ON FALLING FILM FLOW AND HEAT TRANSFER CHARACTERISTICS INSIDE CORRUGATED TUBE

应用CFD软件模拟分析流体在竖波纹管和竖直圆管内的降膜流动情况,采用立式蒸发式冷凝器试验平台,在不同喷淋密度下,测量温度和流量等参数,计算波纹管管内各相间传热传质系数,并与相同参数(流速、温度)条件下圆管管内传热传质系数进行比较。模拟结果表明,在相同的喷淋密度下,波纹管竖管内水膜分布较圆管均匀;试验结果表明,随着喷淋密度在一定范围内增加,水膜传热系数、空气-水当量传热系数、总传热传质系数均增大,且波纹管的传热性能明显优于圆管。

Falling film flow in vertical corrugated tube and circular tube was simulated by CFD software respectively, and a vertical evaporative condenser test platform was adopted to measure the temperature and flow rate under various spray densities. The heat and mass transfer coefficient of each phase interface inside corrugated tube was calculated based on the experimental data, and it was compared with that of inside circular tube under the same conditions. Simulation results indicate that at the same spray density, the water-film distribution in vertical corrugated tube is better than that of in circular tube. Experimental results show that with the increase of spray density in a certain range, the heat transfer coefficient of water-film, equivalent heat transfer coefficient of air-water and total heat and mass transfer coefficient increase. In addition, the heat transfer performance of corrugated tube is significantly better than that of circular tube.