Simulation And Analysis Of The Complete Process Of Multi-Layer And Multi-Span Petrochemical Piperack Under Fire

It is common knowledge that ordinary non-refractory steel members are limited in fire resistance. Nevertheless, raw materials and products used in petrochemical industry have higher heat release value, which brings difficult problems to the design of steel structures with regard to fire resistance for the petrochemical industry. In view of high accident frequency in the industry in recent years, great importance has been attached by countries and regions worldwide to studies on design of steel structures while taking fire resistance into consideration. This research topic is made under the commission of Liaoning Huajin Ethylene Chemical Industry Corp.Ltd.. The topic focuses on the integral fire ressitance of multi-layer and multi-span ethylene steel structure piperack. Construction of the multi-layer and multi-span ethylene steel structure piperack is a key subproject of the reconstruction and extension project of the corporation. It is for purpose of transportation of ethylene. Ethylene and other hydrocarbon materials are flammable and explosive. However, almost all of the steels used as building materials for petrochemical piperack are limited in fire resistance. It goes without saying that fire caused by such building materials will threaten the safety of the integral structure of the piperack.By combining the theory of plastic limit analysis and the theory of steel member stability check analysis, analysis on integral fire resistance of multi-layer and multi-span ethylene steel piperack under high temperature (fire) is made in this research topic based on actual conditons, proceeding from the angle of research. Complete process of collapse of steel piperack under high temperature (fire) is simulated. Method used in this paper features small data size and higher accuracy. With this method, effects of temperature variations and support conditions on steel members is taken into account; performance of the members under fire can be analyzed from the overall point of view; actual displacement of steel structure and internal forces under fire can be calculated and changes in structure can be traced; orders of plastic hinge occurance and points of plastic hinges formed in steel frame structure can be determined; and allowable limiting temperature withstood by steeel structure can finally be defined. The followings have been covered in my research topic:1. Reduction of yield strength of construction steels under high temperature (fire), i.e. softening of the construction steels; 2. Reduction of elastic modulus of the construction steels under high temperature (fire), i.e. weakening of cross section;3. Changes in overall performance of the structure after formation of plastic hinge resulted from cross section yield under high temperature (fire), i.e. changes in structure;4. Study on integral stability of construction steels under high temperature (fire).Based on the above-mentioned analysis, a program for simulation and analyzing thecomplete process of the integral fire ressitance of multi-layer and multi-span ethylene steel structure piperack is developped by using Fortran language. Actual projects are analyzed. Correctness and authenticity of the program are checked and proven by using the large finite element analyse software ANSYS. This paper is used in the analysis relating to fire risk assessment and design of the reconstruction and extension of steel piperack structure of Liaoning Huajin Ethylene Chemical Industry Corp.Ltd.. Specific optimized analysis is provided as well.