When the T-shaped welded steel pipe contains Ni, it has strong corrosion resistance in acidic environments. In environments containing sulfuric acid or hydrochloric acid, the higher the Ni content in the T-shaped welded steel pipe, the stronger the corrosion resistance. In general environments, simply adding Cr to T-welded steel pipes can prevent erosion. The poor condition of the steel strip edges is another important reason for misalignment. The influence of changes in mass flow rate, heat flux density, and structural parameters (ratio of spiral curvature diameter to T-shaped welded steel pipe diameter Dc/D) on the saturated bubbly boiling heat transfer coefficient in vertical spiral tubes.
During the production of T-shaped welded steel pipes, misalignment often occurs, and there are many influencing factors. In production practice, the degradation of steel pipes is often caused by exceeding the tolerance of dry edge misalignment. Therefore, it is necessary to analyze the causes and preventive measures of misalignment in spiral steel pipes.
Due to the poor shape and dimensional accuracy of the head and tail of the uncut steel strip, it is easy to cause hard bending of the steel strip during docking and cause misalignment. Simulation parameter range: vertical pipe: pipe diameter D=lOmm, pipe length L=660mm; Three types of vertical T-shaped welded steel pipes: pipe diameter D=10mm, the ratio of the curvature diameter of the T-shaped welded steel pipe to the spiral pipe diameter varies by Dc/D=15,20,25, the spiral pitch Pt=20mm, and the pipe length is L=503mm, L=660mm, and L=817MM, respectively. Mass flow rate G=200~400Kg/(m’2 · s), heat flux density q=5~15KW/m’2, saturation pressure p, saturation=0.414880MPa, saturation temperature T, saturation=283.15K.