基于正交试验的90°弯管冲刷腐蚀数值模拟及实验研究

Marine seawater pipeline and various fittings play an important role in cooling and firefighting, among which square elbow is widely used. However, it is found from daily maintenance that the square elbow is also the part mostly prone to leakage. In this paper, the effect of related parameters for pipe, such as diameter (A), inlet velocity (B), liquid flow direction (C), sand diameter (D) and sand mass flow (E) on the erosion-corrosion behavior of square elbow in the condition of liquid-solid two-phase flow was studied by means of orthogonal test and numerical simulation. The results show that the order of influence of different factors on erosion-corrosion of square elbow may be ranked as: B>A>E>C>D. The erosion rate of the square elbow reaches the maximum in case that B is 5 m/s, A is 30 mm, E is 0.03 kg/s, C is the flow direction horizontal and vertical upward, and D is 500 μm respectively. The area with large erosion rate is concentrated in the range between 60° and 90° of the axial angle of the elbow, whilst near 180° of the radial angle, i.e., where located on the outside of the elbow near the exit. The experimental results also verify that the corrosion rate on the outside of the elbow near the exit is higher in this working condition. At the same time, the results of tests by factors of optimal level also show that reducing the inlet velocity and increasing the pipe diameter can greatly reduce the erosion rate.

Keywords： erosion-corrosion ; orthogonal test ; numerical simulation ; 90° elbow ; corrosion rate