Three-dimensional Finite Element Simulation Analysis Of Boiler Opening Strength

Boiler usually works under the condition of pressure, which contacts with high temperatures or flammable and explosive media. It causes incalculable damage to people’s lives and property as soon as it has an accident. And it needed to be intercalated because of the demand on the structure and process. Opening holes can weaken the strength of the vessel, it will produce a greater stress concentration. Many accidents have occurred in discrete areas to boilers, especially the joint of pipe and cylinder. This area is often become the weakest link due to temperature stress, manufacturing technology and a variety of loads.This paper mainly studies the boiler with a nozzle, adopt the method of three-dimensional finite element to simulate pipe openings’ strength. Considering the openings’ stress characteristics of boiler, constraint condition and symmetry, a quarter model is established, analyze the opening nozzles’ strength of the non-reinforcement and reinforcement structure. This article established two kinds of models in the reinforcement structure, it divided into stretch type and flush. To obtain the location and maximum value three main stress. Analyze the characteristics of the first, third theoretical strength’s stress. Reinforced structure using flush-type connection, analyze the openings’nozzle of reinforcing ring and thickness nozzle. Obtain the distribution law of three main stress. Change in the thickness of the reinforcement ring and the thickness nozzle, to study stress concentration characteristics in different thickness.Using the finite element simulation results to conclude using the reinforcing structure can effectively reduce the stress concentration factor; In terms of reducing the stress concentration factor, thickness nozzles superior to reinforcing ring; Comparing stretch type with flush type, the former can reduce the stress concentration factor.