When the t-welded steel pipe contains Ni, it has strong corrosion resistance in acidic environment. In the environment containing sulfuric acid or hydrochloric acid, the higher the content of Ni in the t-welded steel pipe, the stronger the corrosion resistance. In general environment, corrosion can be prevented only by adding CR to t-welded steel pipe. The poor condition of steel strip edge is another important reason for misalignment. Effects of mass flow, heat flux and structural parameters (ratio of spiral curvature diameter to t-welded steel pipe diameter DC / D) on saturated bubbly boiling heat transfer coefficient in vertical spiral pipe.
In the production of t-welded steel pipe, misalignment occurs from time to time, and there are many influencing factors. In production practice, the steel pipe is often degraded due to dry misalignment and out of tolerance. Therefore, it is necessary to analyze the causes of misalignment of spiral steel pipe and its preventive measures.
Due to the poor shape and dimensional accuracy of the head and tail of the non trimming steel strip, it is easy to cause hard bending of the steel strip and wrong edge during butt joint. Simulation parameter range: vertical pipe: pipe diameter d = lomm, pipe length L = 660mm; Three kinds of vertical t-welded steel pipes: pipe diameter d = 10mm, the ratio of curvature diameter of t-welded steel pipe to spiral pipe diameter is DC / D = 15, 20 and 25, spiral pitch Pt = 20mm, and pipe length is L = 503mm, l = 660mm and L = 817mm respectively. Mass flow g = 200 ~ 400kg / (m'2 · s), heat flux q = 5 ~ 15kw / m'2, saturation pressure P, saturation = 0.414880mpa, saturation temperature T, saturation = 283.15k.
