▎ 摘　　要

NOVELTY - The tube has graphene layer loop system for nuclear power plant steam generator. Both sides of U-shaped tube main portion have cylindrical shaped tubes. The tube wall comprises graphene layer having outer diameter of 17 to 22mm, and wall thickness of 0.08 to 2mm and thickness of graphene layer is about 0.08 to 0.2mm. The deposition conditions comprises methane as growth gas with access rate of about 15 to 25sccm, growth temperature ranges from 920 to 980 degrees C and cooling speed of 8 to 12 degrees C/min. U-shaped tube main portion has side open end to establish annular resistance element. USE - U-shaped tube with graphene layer. ADVANTAGE - The U-shaped tube has low thermal resistance, high power generation efficiency, mechanical strength and more economical and practical features.