Research On The Expanding-jiont Of The Titanium Tube And The Tubesheet

Heat exchanger is a kind of equipment which occupies a very important position in the field of petrochemical. Due to the advantages of titanium, such as corrosion resistance,heat resistance,thermal conductivity, titanium exchanger is getting more and more application. But titanium is very expensive, which limits the application of titanium exchanger in some extent.The aim of this paper is to investigate the properties of hydraulically expanded titanium tube-to-steel tubesheet joints. Through theoretical analysis and calculation, the model and some parameters is obtained. Through simulating the expansion course using finite element software, the changing process of contact pressure and the distribution of residual contact pressure is obtained. The main results obtained are as follows:Residual contact pressure can be improved through increasing the expanded pressure or manufacturing tubesheet with grooves. The expanding sequence produce an effect on the residual contact pressure of the jionts. Comparing the residual contact pressure of middle tubesheet hole is only expanded with the case of different expanding sequence,some conclusion can be obtained. In the case of middle tubesheet hole is expanded, the expansion of the other tubesheet holes will result in increment of residual contact pressure of the middle hole jiont, and the residual contact pressure of themselves'reduced.