Abstract: Provided is a method of designing a coaxial dual-tube type hot gas duct for a very-high-temperature reactor. When determining the outer diameter of an inner tube and the inner diameter of a pressure tube, both of which defines an annular part of the hot gas duct having a dual-tube shape, one selected from hydraulic heads, flow rates, and hydraulic heads of very-high-temperature helium gas flowing to a very-high-temperature region and low-temperature helium gas flowing to a low-temperature region is taken into consideration as well as is a relation of about heat balance model, so that it is possible to minimize flow induced vibrations caused by the flow of a fluid.

Abstract: Provided is a method of designing a coaxial dual-tube type hot gas duct for a very-high-temperature reactor. When determining the outer diameter of an inner tube and the inner diameter of a pressure tube, both of which defines an annular part of the hot gas duct having a dual-tube shape, one selected from hydraulic heads, flow rates, and hydraulic heads of very-high-temperature helium gas flowing to a very-high-temperature region and low-temperature helium gas flowing to a low-temperature region is taken into consideration as well as is a relation of about heat balance model, so that it is possible to minimize flow induced vibrations caused by the flow of a fluid.