强化换热管型对超声波传播特性及空化效果的影响研究
发布时间:2018-04-05 10:16
本文选题:超声波 切入点:强化传热 出处:《东北电力大学》2015年硕士论文
【摘要】:工业中广泛使用的换热设备在其换热表面总会产生结垢问题,,这不仅影响设备换热性能,使换热效率下降,严重的还会影响设备的安全运行。超声波除垢因其有着简单、高效、无污染、可连续运行、自动化程度高、工作性能可靠等优点,近年来被广泛用于换热设备中。 目前对于超声波除垢效果影响因素的研究主要局限在超声波参数和换热介质参数两方面,而对于管道几何结构对超声波除垢效果影响的研究少有报道。为解决这一问题,通过自制超声波实验台分别采用圆管、波纹管、螺纹管和横纹管测量不同管道出口处的声强和空化噪音积分数,对超声波在不同管道中的传播特性和空化效果进行了分析,并深入分析了影响机理。 本文以超声波在强化换热管内的传播和空化为研究重点,通过实验分析了影响超声波在管内传播和空化效果的因素:换热介质参数、换热管型。通过实验结果研究分析了最佳换热介质参数以及最有利于超声波除垢的换热管型。 结果表明:管道的几何结构对超声波传播特性和空化效果有着明显影响,在各种管型中,圆管最有利于超声波的传播,相比于圆管超声波在强化换热管中的传播特性较差。超声波在横纹管和螺纹管中的传播特性比圆管差,在波纹管中的传播特性最差。在横纹管和螺纹管内,由于湍流强度升高,更有利于超声空化产生。超声波在横纹管和螺纹管中的空化效果要优于圆管,但在波纹管中,由于过高的湍流强度,反而对超声空化起抑制作用。管型的几何参数对超声波的传播有着明显的影响,相比于改变流体介质的参数,管道的几何参数对超声空化的影响更加明显。
[Abstract]:The problem of scaling will always occur on the heat transfer surface of the widely used heat transfer equipment in industry, which not only affects the heat transfer performance of the equipment, reduces the heat transfer efficiency, but also seriously affects the safe operation of the equipment.Ultrasonic scale removal has been widely used in heat exchanger in recent years because of its advantages such as simple, high efficiency, no pollution, continuous operation, high degree of automation, reliable working performance and so on.At present, the research on the influencing factors of ultrasonic scale removal effect is mainly limited to ultrasonic parameters and heat transfer medium parameters, but there are few reports on the influence of pipeline geometry on ultrasonic scale removal effect.In order to solve this problem, the sound intensity and cavitation noise integral number at the outlet of different pipes were measured by using a self-made ultrasonic test bench with circular pipe, corrugated tube, threaded tube and transverse tube, respectively.The propagation characteristics and cavitation effect of ultrasonic wave in different pipelines are analyzed, and the influence mechanism is analyzed.This paper focuses on the propagation and cavitation of ultrasonic wave in the enhanced heat transfer pipe. The factors influencing the propagation and cavitation effect of ultrasonic wave in the tube are analyzed experimentally: the heat transfer medium parameters and the heat transfer tube type.The optimum parameters of heat transfer medium and the type of heat transfer pipe which is most favorable for ultrasonic scale removal are studied and analyzed by the experimental results.The results show that the geometrical structure of the pipe has obvious influence on the ultrasonic propagation characteristics and cavitation effect. Among the various pipe types, the circular tube is the most favorable for the ultrasonic propagation, compared with the circular ultrasonic wave in the enhanced heat transfer pipe, the propagation characteristics of the pipe is worse.The propagation characteristics of ultrasonic wave in transverse and threaded tubes are worse than those in circular tubes, and the propagation characteristics in bellows are the worst.In transverse and threaded tubes, ultrasonic cavitation is more favorable to ultrasonic cavitation due to the increase of turbulence intensity.The cavitation effect of ultrasonic wave in transverse and threaded tube is better than that in circular tube, but in bellows, the ultrasonic cavitation is inhibited because of the excessive turbulence intensity.The geometric parameters of the tube have an obvious influence on the propagation of ultrasonic wave. Compared with changing the parameters of the fluid medium, the geometric parameters of the pipe have more obvious influence on the ultrasonic cavitation.
【学位授予单位】:东北电力大学
【学位级别】:硕士
【学位授予年份】:2015
【分类号】:TK172
【参考文献】
相关期刊论文 前10条
1 李万鹏 ,王钧;应用超声波技术进行热交换设备在线防垢[J];世界有色金属;2002年06期
2 邱振波;高富荣;郭翠;;凝汽器水侧污垢对机组真空的影响及其技术对策[J];电力科学与工程;2009年07期
3 徐志明,杨善让,郭淑青,赵贺,齐冰;电站凝汽器污垢费用估算[J];动力工程;2005年01期
4 朱金颖,陈龙珠,严细水;混凝土受力状态下超声波传播特性研究[J];工程力学;1998年03期
5 徐志明;张仲彬;詹海波;邵天成;;缩放管混合污垢特性的实验研究[J];工程热物理学报;2008年02期
6 徐志明;张艾萍;张仲彬;黄健;;凝汽器超声波防除垢效果在线评价方法研究[J];工程热物理学报;2010年07期
7 张艾萍;刘超;徐志明;;除垢超声波传播影响因素的理论研究[J];工程热物理学报;2012年03期
8 徐金球,贾金平,徐晓军,宁平;超声空化效应降解焦化废水中有机物的研究[J];高校化学工程学报;2004年03期
9 白忻平,任建新,梁成浩;超声处理在阻垢方面的研究[J];工业水处理;2000年01期
10 王萍辉;超声空化影响因素[J];河北理工学院学报;2003年04期
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