烟气余热回收换热器强化传热特性实验研究

发布时间：2019-04-04 14:39

【摘要】：烟气换热器是烟气余热回收过程中的一种重要的设备,其换热元件换热性能优劣对于整个烟气余热回收系统具有深远的意义。酒窝结构管型换热管是一种双面强化换热管,目前将其利用在烟气余热回收系统中的研究还鲜有报道。为评价酒窝结构管型应用在烟气余热回收系统中的换热性能,本文通过自主设计并搭建实验系统,对酒窝结构管型换热管管内沸腾换热特性进行实验研究,为其利用在烟气余热回收系统的热设计计算提供一定的理论参考依据,具有一定的学术意义和工程应用价值。首先,以实验室燃气轮机产生烟气为热源,水为换热工质,对光管、涡节管、酒窝管的管内沸腾换热特性进行实验研究。结果表明,在实验参数范围内,涡节管的总传热系数能够达到同工况下光管的1.3~1.6倍、管内沸腾换热系数约为光管的1.6~2.1倍、管外传热系数约为光管的1.3~1.5倍。酒窝管的总传热系数可以达到同工况下光管的1.8~2.3倍,管内沸腾换热系数约为光管的2.03~2.5倍、管外传热系数约为光管的1.8~2倍。酒窝结构管型有显著的换热性能提升。其次,对已有的管内沸腾传热经验计算公式进行归纳总结,对酒窝结构管型的强化传热机理进行理论分析。并根据本次实验工况下实验数据对涡节管和酒窝管进行线性回归,得到适合本实验工况下的涡节管和酒窝管的管内沸腾传热关联式。最后,以四川某纸业有限公司10t/h锅炉尾部烟气余热回收利用项目进行优化计算为例,对酒窝管换热器加装在锅炉尾部烟道产生的经济效果和环境效益进行全面评价。本项目相关设计方法和经验可以为其他烟气余热回收项目提供一定的参考。
[Abstract]:Flue gas heat exchanger is an important equipment in the process of flue gas waste heat recovery, and its heat exchanger performance is of profound significance to the whole flue gas waste heat recovery system. Dimple structure tube type heat exchanger is a kind of double-sided reinforced heat transfer pipe. At present, there is little report on how to use it in flue gas waste heat recovery system. In order to evaluate the heat transfer performance of dimple structure tube used in flue gas waste heat recovery system, the boiling heat transfer characteristics of dimple structure tube were studied by designing and building an experimental system independently in this paper. It provides a certain theoretical reference for the thermal design calculation of flue gas waste heat recovery system, and has certain academic significance and engineering application value. Firstly, the boiling heat transfer characteristics of smooth tube, vortex tube and dimple tube were studied by using gas turbine as heat source and water as heat exchanger. The results show that in the range of experimental parameters, the total heat transfer coefficient of vortex tube can reach 1.3 脳 1.6 times of that of smooth tube under the same working condition, and the boiling heat transfer coefficient of tube is about 1.6 times of that of smooth tube. The heat transfer coefficient outside the tube is about 1.3 times as much as that of the smooth tube. The total heat transfer coefficient of the dimple tube can reach 1.8 脳 2.3 times of that of the smooth tube under the same working condition, the boiling heat transfer coefficient of the tube is about 2.03 times of that of the smooth tube, and the heat transfer coefficient of the outside tube is about 1.8 times of that of the smooth tube. Dimple structure tube type has a significant improvement in heat transfer performance. Secondly, the existing formula of boiling heat transfer in tube is summarized, and the mechanism of heat transfer enhancement of dimple structure tube is analyzed theoretically. According to the experimental data, the linear regression of vortex tube and dimple tube is carried out, and the correlation of boiling heat transfer between vortex tube and dimple tube is obtained. Finally, taking the waste heat recovery and utilization project of the tail flue gas of a 10t/h boiler in Sichuan Paper Co., Ltd as an example, the economic and environmental benefits caused by the installation of the wine-nest tube heat exchanger in the tail flue of the boiler are evaluated in an all-round way. This project related design method and experience can provide certain reference for other flue gas waste heat recovery projects.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK172

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