Research Of Subway Tunnel Cleaning Equipment Structure And Analysis Of Flat Fan Nozzle

The cleanliness of the subway tunnel not only affects the environment, but also affects the respiratory health and safety of passengers. High pressure water jet cleaning has great advantages in environmental protection, the working conditions of cleaner and improving the efficiency. Combined with pollution in the subway tunnel construction, design a set of with high and low pressure water system, adjustable flushing angle of the wall, track bed, drain device of metro tunnel cleaning equipment. Nozzle is the executive component of the cleaning equipment, and its jet performance such as its spray angle, strike force, dynamic pressure distribution play a decisive role in the cleaning effect. In this paper, the fan nozzle is used as the research object. Through the FLUENT software simulate and analyze the influence of the 3 aspects of the cleaning effect, the nozzle structure parameters, hydraulic parameters (cleaning pressure, flow) and working parameters (target distance, jet angle, layout). Now get the following conclusions:(1) Influence of main structural parameters on the spray angle and flow of the fan nozzle.a) The size of the spray angle is mainly determined by the thickness of the jet, the increase of the thickness of the jet will increase the surface tension, which makes the jet flow not easy to spread, and eventually leads to the decrease of the jet angle. With the increase of V-shaped groove half-angle, spray angle decreases; with the increase of V-shaped groove cutting depth, spray angle increases; with the increase of the diameter, spray angle increases; with the increase ratio of outlet blind end length and diameter, spray angle decreases.b) The size of the flow is mainly determined by the size of the area of the exit. With the increase of V-shaped groove half-angle, spray angle increases; with the increase of V-shaped groove cutting depth, spray angle decreases; with the increase of the diameter, spray angle increases; with the increase ratio of outlet blind end length and diameter, spray angle increases.c) BP neural network can better predict the comprehensive effect of various structural parameters on the spray angle and flow of the fan nozzle, which greatly facilitates the design and properties of the fan nozzle.(2) Analysis of V-shaped groove half-angle of 45 degree, V-shaped groove cutting groove depth of Omm, ratio of outlet blind end length and diameter of 1 for the different diameter of the flat fan nozzle. With the same flat fan nozzles, pressure between 1～21MPa, strike force will increase with increasing pressure, but the magnitude of the increase will decrease; under the same jet pressure, fan nozzle outlet diameter between 1～3mm, strike force will increase with increasing outlet diameter, but the magnitude of the increase will decrease; the same power, the greater the jet pressure, the smaller the impact force; to obtain the same strike force, the greater the jet pressure, the greater the required power. The low pressure part of the metro tunnel cleaning choose 1.5MPa, and the 2.5mm nozzle, which can save energy and have a higher cleaning efficiency.(3) Under the same working condition, the impact force of the jet on the object increases first and then decreases with the increase of the target distance. The reasonable target distance of the low pressure cleaning part is between 80d-180d, and the best target distance of the paper is 200mm; when the angle is 30°, it can obtain the larger axial force and the shear force, and the larger and more uniform distribution of shear stress, so the choice of the 30° is more appropriate. The uniform flow and dynamic pressure distribution can be obtained when the nozzle spacing is 13mm and the nozzle deflection angle is 8°.