新型强化换热管管外流动与换热特性

Flow and heat transfer characteristics of novel enhanced tube

中文关键词: 扭曲管  波节管  波纹管  场协同  强化换热  数值模拟

英文关键词: twisted tube, wave knuckle tube, corrugated pipe, field synergy, enhanced heat transfer, numerical simulation

中文摘要:

      针对新型强化换热管的几何特征，采用三维数值模拟方法，分别从速度—压力场协同性、综合评价因子ε、速度—温度场协同角三个方面对扭曲管、波节管、波纹管开展研究。对波纹管的实验测量结果与数值模拟结果最大相对偏差为2.35%。数值模拟结果表明，纹管管外Re从569~7 399变化，总压降从3.78增长到317.30Pa；扭曲管Re从508~7 622变化，总压降从0.84增大到62.50Pa；波节管Re为580~7 550变化，总压降从1.29增长到110.00Pa，波纹管阻力相比波节管最大提高186.7%，相比于扭曲管提高408.4%，Re<4 500时扭曲管Nu数比波纹管最大提高13.30%，比波节管最大提高6.97%，Re>4 500时波节管换热性能逐渐超越扭曲管以及波纹管，在计算范围内Nu比扭曲管最大提高5.17%，比波纹管最大提高5.40%；波节管的周期性波峰对于强化换热和减阻作用显著；波纹管的压降、强化换热表现均弱于波节管和扭曲管。根据计算结果拟合出Nu数与Re、Pr的实验关联式，为管壳式换热器设计提供一定的理论和依据。

英文摘要:

      Aiming at the new type of reinforced heat exchanger which can be used in gas wall-mounted furnace, this paper uses three-dimensional numerical simulation method to study the twisted tube, wave joint tube and bellows from three aspects: velocity-pressure field synergy, comprehensive evaluation factor epsilon, velocity-temperature field synergy angle. The results show that the enhanced effect of the twisted tube on the flow outside the tube is better than that of the wave tube and bellows, and the coordination of the three field is the best. In Re<4500, Nu of the twisted tube is higher than wave pipe at 13.3%, higher than joint pipe at 6.97% , the heat transfer coefficient of the 4500