Steam generator installed with heat-transfer tubes (HTT) is an enormous heat exchanger that uses heat energy derived from a reactor to generate steam. The steam drains into turbine generator of an nuclear power plant, and plays an important role in producing electric power in nuclear power plant. Lately, demand of advanced manufacturing technology, especially related with high quality heat transfer tubes used for the steam generator of APR1400, has been increased. And the quality of final product as the heat transfer tube, which is manufactured by using Alloy 690, depends upon several process variables such as angular speed, bending angle and bending radius, and so on. For satisfying the required quality of the heat transfer tube, several factors such as permissible ovality, minimum wall thickness, tolerance of bending radius, residual stress have to be secured. In this study, numerical and experimental approaches on the U-bending process to manufacture the heat transfer tube from the straight and long tube are performed with considering the elastic recovery of the deformed tube after the U-bending. Furthermore the ovality, the minimum wall thickness and the tolerance of the U-bending tube are predicted and measured. From the results, it is shown that main process variable, which plays an important role to the formability such as the ovality and the minimum wall thickness of the heat transfer tube used for the steam generator, is the angular speed.

This content is only available via PDF.
You do not currently have access to this content.