管壳式换热器矩形薄管板与换热管焊接工艺研究

发布时间：2018-03-24 06:22

本文选题：有限元数值计算　切入点：焊接工艺　出处：《北京石油化工学院》2016年硕士论文

【摘要】：常见的管壳式换热器多采用圆形管板且管板厚度基本都在60mm以上,而采用矩形薄管板的管壳式换热器则较为少见。与常见的圆形厚管板相比,矩形薄管板与换热管焊接时对工艺的要求更高,否则容易产生焊接缺陷并且造成管板变形,一旦有焊接缺陷或者是较为严重的管板变形产生就会造成换热器的密封性能下降或者内部介质泄漏,甚至造成严重的安全问题,因此对具有类似矩形薄管板设计的换热器而言,管接头焊接质量和矩形薄管板的变形控制是换热器生产过程中至关重要的一环。本课题以北京燕化正邦设备检修有限公司生产的E-411系列换热器为研究对象,该系列换热器的特点是采用了矩形薄管板且管板厚度只有30mm,利用有限元数值模拟技术对管接头的焊接应力场以及管板变形情况进行了计算并根据数值模拟结果提出了相应的改进措施,有效的提高了换热器的生产质量,并为以后类似的研究提供相应的技术和理论支持。课题的主要研究内容如下:1、焊接工艺参数优化。根据实际生产过程中的焊接情况确定了五组焊接工艺参数,每组参数都有不同的电流电压和焊接速度,利用有限元数值模拟计算管接头在五组焊接工艺参数下的焊接应力场,将计算结果进行对比来找出最佳工艺参数;2、焊接顺序优化。焊接顺序的不同会造成管板上不同区域受热顺序的不同,可能会对管板的变形造成影响。本课题研究了两种焊接顺序:平行状和放射状,利用有限元数值模拟计算管板在两种焊接顺下的应力应变,通过计算结果的对比找出最优的焊接顺序;3、管板变形的控制。针对焊后管板内凹的问题,考虑根据焊接反变形原理设计一种焊接工装夹具,从有限元数值模拟和实验两个方面对该工装的效能进行验证。
[Abstract]:Most of the common tube and shell heat exchangers use circular tubes and plates and the thickness of tubes and plates is above 60mm, while the shell and tube heat exchangers with rectangular thin tubes and plates are less common. When the rectangular thin tube plate and the heat transfer tube are welded, the process requirements are higher, otherwise, the welding defects are easy to occur and the tube plate will be deformed. Once there are welding defects or serious tube plate deformation, the sealing performance of the heat exchanger will decline or the internal medium will leak, and even cause serious safety problems, so for the heat exchanger with rectangular thin tube plate design, The welding quality of pipe joint and the deformation control of rectangular thin tube plate are very important in the process of heat exchanger production. In this paper, the E-411 series heat exchanger produced by Beijing Yanhua Zhengbang equipment repair Co., Ltd is taken as the research object. The characteristic of this series of heat exchangers is that the rectangular thin tube-plate is used and the thickness of the tube-plate is only 30mm. The welding stress field and the tube-plate deformation of the tube joint are calculated by using the finite element numerical simulation technique, and the results of the numerical simulation are presented. Corresponding improvement measures have been put forward. Effectively improve the production quality of the heat exchanger, And provide corresponding technical and theoretical support for similar research in the future. The main research contents of the subject are as follows: 1, optimization of welding process parameters. Five groups of welding process parameters are determined according to the welding conditions in actual production process. Each group of parameters has different current, voltage and welding speed. The welding stress field of tube joint under five groups of welding process parameters is calculated by finite element numerical simulation. The results of calculation are compared to find out the best process parameters and welding sequence optimization. Different welding sequence will result in different heating order of different regions on the tube and plate. In this paper, two kinds of welding sequences, parallel and radial, are studied. The stress and strain of tube and plate under two kinds of welding are calculated by finite element numerical simulation. Through the comparison of the calculation results, we find out the optimal welding sequence and the control of the tube plate deformation. In view of the problem of the inner concave of the pipe and plate after welding, we consider the design of a welding fixture according to the principle of welding reverse deformation. The effectiveness of the tooling is verified by finite element numerical simulation and experiment.
【学位授予单位】：北京石油化工学院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK172;TG44

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