Study Of Optimal Design For Waste Heat Boiler Steel Frame

Boiler is the lifeline of industrial production, many large companies are using boiler to provide energy. If the boiler turns to accident it will be very serious. The boiler steel frame is the main bearing part of the boiler. It plays an important role of making sure the boiler equipments run safely and normally. The mass of boiler steel frame takes up considerable proportion in total mass of the boiler. So the designing of the boiler steel frame has potential capacity in saving steel and cutting cost and so on. Studying the mechanical property of the boiler steel frame to make sure the boiler equipments run safely and design more economical, more reasonable boiler steel frame is an object which the design engineers pursuit.With the help of modeling by ANSYS and application of finite element method,3D static analysis of exhaust-heat boiler steel frame and dynamic response analysis of the whole structure to seismic load are carried out in this thesis. Based on the static analysis results, the frame section parameters are taken as design variables, the structure maximum displacement is taken as optimization constraint to minimize the mass of whole structure. The dynamic response analysis is employed to clarify the aseismic performance of the optimum design of the boiler steel frame. The results provide reference for relative projects in the future.(1) The static analysis of the steel frame structureAccording to the structural type and size of the boiler steel frame structure, beaml88 element is applied to simplified 3D finite element model of exhaust-heat boiler steel frame and its bypath system steel frame. Considering the combination of constant load, live load, wind load, etc., the structure is spatial-statically calculated and analyzed. The results show that the strength and stiffness of exhaust-heat boiler steel frame and its bypath system steel frame are both up to the required standards. Furthermore, the steel frames are so safety as to be optimized to reduce the steel quantity which can save the cost. The results provide reference for relative projects in the future.2) Dynamic response analysis of the integral steel frame under seismic actionAccording to the rules of boiler steel structure aseismic design, in particular seismic intensity levels, input seismic load then do the dynamic response analysis of the integral steel frame under seismic action. The results show that the exhaust-heat boiler steel frame performs single torsion feature obviously, otherwise, its bypath system steel frame shows single bend feature under single direction seism load. The response of the frames reduces with the reduction of the single direction seism load. The responses under bidirectional seism load are more significant than those under single seism load. Comparing with the results under single seism load, the displacement responses of frames show the hysteresis performance. The analysis results show that the steel frame aseimic performance needs to improve. The results provide reference for relative projects in the future.(3) The frame structure optimizationBased on the static analysis, the design optimization procedures of the frames are performed. The optimum design of the frames satisfies the design criterion of steel structure and reduces the mass of the steel frames simultaneously, which meets the purpose of cutting cost. The aseismic analysis is employed to clarify the aseismic performance of the optimum design of the boiler steel frame.