Structural design and strength analysis of the calorimeter pipeline joint for the negative neutral beam injection system of China fusion engineering test reactor

Abstract

The negative ion-based neutral beam injection (NNBI) verification prototype system is one of the core components of China Fusion Engineering Test Reactor (CFETR). To effectively cut off the beam and debug the neutral beam device, the power measurement system plays an indispensable role. In this study, we examine the detailed design of the pipeline joint structure of the calorimeter verification prototype, focusing on the impact of the structural design of the target panel pipeline joint on the structural strength and manufacturing process required by the cooling circular pipeline joint of the calorimeter. Based on this, the manufacturing process and strength of the integrated pipeline structure of the target panel are inspected under a design pressure of 4 MPa, including theoretical analysis of the integrated pipeline pressure-bearing structural design, welding technology design, and finite element simulation under high pressure. Accordingly, the feasibility of the final manufacturing scheme and key technologies are analyzed. The pressure test of the sample under an internal N2 pressure of 4 MPa verifies that its structure can meet the design requirements, thereby providing reference for the effective structural design and manufacturing of the NNBI calorimeter prototype.