热交换器管子与管板尺寸偏差分析

Analysis of Dimensional Deviation of Tube and Tube Sheet Hole of Heat Exchanger

为了研究热交换器管子与管板发生间隙腐蚀时的间隙大小,基于标准GB/T 151—2014《热交换器》中规定的换热管外径及管板管孔允许偏差,对一、二级管束换热管外径与管板管孔直径构成的间隙尺寸范围进行了确定,并分析了二者分别与相应允许偏差的关系。结果表明:一、二级管束平均间隙分别在0.23~0.60 mm和0.28~0.65 mm,并且一级管束的允许偏差更具稳定性。另外,随着管束管板管孔直径的增大,要将偏差值适当降低,以保证换热管与管板管孔的焊接质量和贴胀效果。

In order to study the size of the clearance between the tube and the tube sheet of heat exchanger when crevice corrosion occurs, based on the outer diameter of the heat exchange tube and the allowable deviation of the tube sheet hole specified in GB/T 151-2014 "The Heat Exchanger", the clearance range between the outer diameter of the first grade tube and the second grade tube and the diameter of tube sheet hole is determined, and the relationships between the outer diameter of the first grade and the second tubes and the diameter of tube sheet hole and their allowable deviation are analyzed. The results show that the average clearance between the outer diameter of the first grade and the second tubes and the diameter of tubesheet hole is 0.23 ~ 0.60 mm and 0.28 ~ 0.65 mm respectively, and the allowable deviation of the outer diameter of the first grade tube is more stable than that of the second grade tube. With the increase of tubesheet hole diameter, its deviation value should be properly controlled to be smaller, so as to ensure the welding quality and expansion contact effect between heat exchange tube and tubesheet hole.