Numerical Study on Flow Evolution and Erosion Assessment in Steam Tracing Pipes of Heat Exchangers

ABSTRACT Flow‐induced erosion–corrosion causes wall thinning and cracks in steam tracing pipes, threatening equipment safety. This work conducts numerical investigation on a 304 stainless steel steam tracing pipe, identifying three flow patterns, that is, superheated steam, gas–liquid coexistence, and subcooled pure liquid. It is found that for superheated steam, condensation at weld seams disturbs mainstream flow and enhances wall turbulent kinetic energy. In the gas–liquid coexistence, the slug flow formed from condensed droplets induces significant velocity fluctuation and stress concentration, which is the primary cause of transverse cracks. For subcooled pure liquid, stable flow with low turbulent kinetic energy lowers the erosion risk. Increasing steam superheat can suppress slug flow formation in steam tracing pipes and effectively mitigate crack initiation. These findings offer theoretical guidance for the optimized design, safe operation, and risk control of steam tracing pipes.