Simulation And Analysis On Explosion Accidents Of Boilers Based On Virtual Reality

The boilers play an important role in the national economy, used widely in electric power, machinery industry, chemical industry, light industry, transportation and daily life, but because of enduring the high pressure and temperature, contacting the corrosive medium, the complicated local pressure, the difficult examination, they can cause the accidents very easily and the explosion accidents of the boilers are the most seriously and destructively in the accidents of the boilers. The explosion accidents of the boilers contain the vapor explosion, the overpressure explosion, the explosion caused by defects and the explosion caused by serious water shortage. The fracture of boiler not only causes the leak accidents of water and vapor, but also causes the vapor evaporating sharply and the boiler exploding violently as more serious accidents. Because the bearing pressure parts suffer the destruction, the steam-water mixture with the definite pressure and temperature dashes out of the boiler and its volume increases thousand times because of the pressure decreases suddenly for an instant. The impact force of the steam-water mixture can throw the boiler away from the ground and the boiler can be thrown out tens even hundreds of meter. At the same time, the shock wave of the steam wave could destroy and break the building and consequently causes serious damage and casualty. In order to prevent and control the accidents of the explosion accidents of the boiler effectively, it's necessary to analyze and simulate the process, influence scope and serious degree.Virtual Reality is a high technology developed from the end of 80's in 20 century, the latest and highest level of analog and emulates technology and one of forward science composed of computer graphics, multimedia technology, artificial intelligence, man-machine interface technology, sensor technology, highly computerized technology and behavior. Simulating the process of the explosion of the boilers by Virtual Reality is low in investment, credible and can be repeated. Furthermore, it's important to do the safety training for the stokers by the simulation software of the boiler explosion.The paper contains five chapters. In the chapter I, the paper introduces the background, significance, necessarily of the item, the reality of safety production of the boilers at home and abroad and the reality of research and application of Virtual Reality. In addition, the paper describes the main research contents and problems solved in the research. The chapter II analyzes Boiling Liquid Expanding Vapor Explosion (BLEVE) as the main form of the boiler explosion and researches the mechanism of the explosion and the simulation on the accident consequence. According to the small-scale simulation test of the Boiling Liquid Expanding Vapor Explosion of a Boiler made by State Key Laboratory of Fire Science under the China National University of Science & Technology, the paper describes the physics process of the saturated water and steam, and analyzes the simulation on the accident consequence by theory. In the discussion of the simulation on the accident consequence of the boiler, the paper introduces the modeling process of BLEVE, including the analysis on the explosion energy, the highest overpressure on the wave front of the explosion shock wave and the destructive action of the shock wave. In addition, the paper deducts the whole modeling process by the calculation instance.The chapter III mainly analyzes the reality of research and application of Virtual Reality. Virtual Reality has three prominent characteristics and they are interaction, Immersion and Imagination which are said as '3I'. In addition, it should have holographic property. It can be divided into immersing VR and un-immersing VR. Because of the limitation of the hardware, the un-immersing VR is used in the design. Finally, this paper introduces the main software used in design and development of the simulation system of the boiler explosion, including 3DS Max, Quest3D, Endorphin.The chapter IV discusses and analyzes the process of design and simulation of the simulation system of the explosion accident of the boiler. The design of this system follows the principle of authenticity, maneuverability, comprehensive layout and realization by stages, complete and unified data. According to the need of simulation, the system structure is composed of static environment, dynamic simulation, character simulation, GUI and logic control. This paper discusses the design and development of every part and analyzes the process of the accident simulation.The chapter V summarizes the work finished in this design, points out the deficiency in the work and predicts the application of Virtual Reality in the safety engineering.According to the statistics of General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, a lot of accidents of boilers and boilers illegally made explosion, so the boiler which is absolutely necessary special equipment used in industry is a sort of important hazards. If BLEVE happens, the destructive power can't be resisted by the safety precautions of the factory at present. Consequently, simulating the vapor explosion of the boiler is significant for the safety of the boiler, establishing the emergency plan and do the safety training. But at present, much key technology of Virtual Reality is developing and many problems haven't solved. Because Virtual Reality applying in the simulation of the boiler explosion is primary, the simulation system merely has basic function and needs consummation.