【作者】 臧云俊；

【导师】 赵大传； 雷渊默；

【作者基本信息】 山东大学 ， 环境工程， 2009， 硕士

【摘要】 换热设备的结垢是一种极为普遍的现象,其存在于自然界、日常生活和各种工业生产过程,特别是各种传热过程中。积炭作为污垢一种,同样存在于各种换热设备中,并且对于换热设备安全经济运行有着严重危害。因而,不仅对于解决工程实际问题而言积炭研究非常有价值,而且对于强化换热抑制污垢的理论来讲积炭研究而言也是势在必行。首先,本文基于对于积炭在各种换热设备中的形成机理以及其成分和性质分析,同时在借鉴污垢研究的基础上,提出了针对糠醛废水闭路循环系统中糠醛废水换热器的积炭形成原因,并得出了换热器积炭的危害和影响:(1)积炭可导致换热器的导热性大大降低,当积炭厚度较大时,容易造成换热不均匀。积炭的积聚也常常引起换热面的局部腐蚀乃至穿孔,严重威胁了换热设备的安全运行。(2)积炭在管内沉积使管内截面面积变小,增加了流动阻力,必然引起整个换热器的流动阻力压降增大,为了维持换热器的性能和传热量不变,只有增大泵的消耗功率因而导致消耗功率增加。(3)随着运行时间的增加,换热器列管内积炭的数量越来越多,大量的积炭甚至将管道阻塞,造成整个糠醛废水闭路循环系统停车,使生产无法进行下去,停车清洗降低了设备连续运转的周期。其次,针对积炭的性质、构形等特点,提出了积炭清洗方法,清洗剂的选取,以及针对不同的在线清洗方法及其应用作了详细探讨。最后,针对一种典型的糠醛废水闭路循环系统中糠醛废水换热器积炭问题,通过分析糠醛废水的来源、成份,从清洗剂的选取、在线清洗装置的构造等方面入手,提出一套行之有效的在线清洗方法,其对于工程应用具有较高的参考价值。更多还原

【Abstract】 Scaling in heat-exchange equipment is very common. It can be found in natural environment, daily life and various industrial processes, especially in heat transmission process. Carbon deposit is s a type of scaling, which occurs in many heat-exchange equipments and poses a serious threat to the safety and economical operation of equipment. Therefore, carbon deposit research is of great significance, not only in that it can facilitate the solution of practical problems, but also improve the theoretical research regarding scale inhibition through intensified heat exchange.Based on the analysis of the mechanism of scale formation, composition and property, as well as on the current scale research, the thesis firstly explains the reason for carbon deposit in furfural wastewater heat exchanger in furfural closed-circuit circulating system, and discusses the hazard and influence of carbon deposit in heat exchanger.(1)Carbon deposit can significantly reduce the thermal conductivity of heat exchanger. Thick carbon deposit can result in uneven heat exchange. Accumulation of carbon deposit often leads to local corrosion and even punches in heater surface, posing a serious threat to the safety of equipment.(2)Carbon deposit in pipes can reduce the sectional area and increase flow resistance, thus resulting in increased pressure drop within the entire heat exchanger. To maintain the performance of heat exchanger and heat transfer capacity, the power consumption of pump has to be increased.(3)As the equipment continues to work, there are more carbon deposits in the heat exchanger, which can block the pipe and cause the breakdown of the entire furfural closed-circuit circulating system. Cleaning will reduce the continuous service span of equipment.Secondly, the paper deals with carbon deposit cleaning method and selection of detergent, and then provides a thorough discussion of various online cleaning methods and their application.Finally, the paper focuses on carbon deposit in furfural wastewater heat exchanger with respect to a typical furfural closed-circuit circulating system. Through analysis of the source and composition of furfural wastewater, selection of detergent, and structure of online cleaning device, the paper proposes a series of effective online cleaning methods, which can serve as a good reference for engineering application.更多还原