Mechanism Research On Expanding Connection Between Tubesheets And Tubes In Heat Exchanger

Owing to many advantages of hydraulic expanding, it has been a major connecting way of tubesheets and tubes. Although domestic and foreign research and engineering technical personnel have done a lot of work, but research on impact of different working environments on the strength of hydraulic expansion is less, and the problem of linking failure has not been impactful controlled. Under the conditions of basic assumptions and theoretical analysis of combined thick-walled cylinder at different stages of deformation, with considering impacts of material nonlinearity, geometric nonlinearity, bordering nonlinearity and temperature of tubesheets and tubes expanding joints on material properties, this paper establishes a three-dimensional finite elemental testing model and actual structural model. Through numerical simulation of the testing model, we get the best expanding pressure, then we do hydraulic expanding test of joints and drop-down test at different temperatures. Results of the numerical simulation analysis and experimental analysis anastomosis basically, we find that the error is within 10%. Considering real structure of the tubesheets and tube joints and influence of temperature and pressure of tubesheet-way and tube-way at working conditions, we do numerical simulation analysis to the real structure of tubesheets and tube joints, specially analyzing the sealing performance and pull-out force at different environments. The results show that the contact pressure and residual contact pressure grow with the increase of expanding pressure when the tubesheets does not yield, The tubesheet holes has a small impact to the residual contact pressure of joints ,the temperature impact is great when the tube is high-temperature heat exchanging medium and shell is low-temperature cooling medium, residual contact pressure and pull-out force increase first and then decrease with the increase of temperature of tube-way media, and the residual contact pressure and pull-out force are the biggest when the temperature of tube-way media is about 100℃, the sealing performance and pull-out force stabilizes when the temperature is over 300℃. The results provide a theoretical basis for the design and construction of hydraulic expanding connection between tubesheets and tubes. Nonlinear...