中低温烟气换热器气侧积灰、磨损及腐蚀的研究  

Gas-side fouling, erosion and corrosion of heat exchanger for middle and low temperature flue gas waste heat recovery

作　　者：何雅玲[1] 汤松臻[1] 王飞龙[1] 赵钦新[1] 陶文铨[1] 

机构地区：[1]西安交通大学,热流科学与工程教育部重点实验室,西安710049

出　　处：《科学通报》2016年第17期1858-1876,共19页Chinese Science Bulletin

基　　金：国家重点基础研究发展计划(2013CB228304)资助

摘　　要：工业烟气具有含灰量大、含黏性物质及含腐蚀性气体多的特点,易造成烟气换热器换热表面积灰、磨损和腐蚀等一系列严重问题,是余热回收领域目前亟待解决的研究课题.本文对中低温余热回收所用的管排式烟气换热器的积灰、磨损及腐蚀特性等方面的研究进行了总结和回顾,分析了换热器换热表面积灰、磨损及腐蚀的形成原因及影响因素,同时介绍了近年来作者团队在换热表面飞灰颗粒沉积、磨损及腐蚀特性方面开展的有关研究结果.首先,对现有的和前期作者团队建立的颗粒碰撞沉积模型进行了简要回顾,并以前期团队开展的工作为例,具体介绍了管排式烟气换热器的积灰特性及其影响因素,并给出了能有效减轻积灰的椭圆管换热器设计;接着,介绍了气固两相绕流换热管的流动和磨损特性,以及烟气参数对磨损特性的影响规律;随后,介绍了一种预测换热器表面酸蒸气凝结的耦合计算方法,说明了运行参数和几何参数对换热器局部腐蚀特性的影响规律,并给出了相应条件下的H型翅片管换热器的酸传质计算关联式;同时,介绍了团队前期提出的在线检测和实验室低温腐蚀装置,说明了不同材料的抗腐蚀特性及换热面积灰与酸的耦合作用机理.最后,对中低温烟气换热器积灰、磨损及腐蚀特性的研究前景进行了展望.With the ongoing emphasis on the efficient use of energy, much effort is put on the development and application of various heat recovery technologies. Heat exchangers play an important role in energy transfer and utilization and are widely used to recover waste energy from different kinds of heat sources in many fields such as energy and power engineering, petroleum and chemical engineering, air conditioning and refrigeration, aviation and aerospace, etc. In the heat exchangers for waste heat recovery, the gas-side fluid mediums usually are unclean and corrosive. The problems of fouling, erosion and corrosion of heat exchangers in the middle and low temperature flue gas-side caused by the high ash content, viscous and corrosive components are inevitable, and how to effectively solve the problems has been the subject of much research in recent years. In this paper, the researches of fouling, erosion and corrosion characteristics in middle and low temperature flue gas heat exchangers are reviewed. The causes and influence factors are discussed. Firstly, the fouling mechanisms of heat exchangers are introduced and the existing theoretical models, empirical models, and numerical methods of particle transport, impact and deposition are reviewed. The ash fouling characteristics of 6-row tube heat exchangers are presented and the effects of flue gas velocity, particle diameter, spanwise tube pitch, longitudinal tube pitch, tube shape and geometry conditions on fouling rate are discussed. Both decrease of the longitudinal tube spacing and increase of spanwise spacing can effectively reduce the deposition of particles. The geometry of elliptical tubes can fulfill this requirement for fouling reduction with smaller longitudinal spacing and larger spanswise pitch. The feasibility of using oval tube is explored for the fouling reduction. Compared with the circular tube arrangement, the deposition rate of the elliptical tube was decreased by 68.8%. Secondly, the existing erosion mechanisms, theories and methods are introduced

关 键 词：工业余热 烟气换热器 积灰特性 磨损特性 腐蚀特性 

分 类 号：TK172[动力工程及工程热物理—热能工程]