In order to reduce the risk of sealing and improve the structural strength for a coal mine mobile refuge chamber,a new type of one-piece model was designed.Mechanical and mathematical calculation performed an importan...In order to reduce the risk of sealing and improve the structural strength for a coal mine mobile refuge chamber,a new type of one-piece model was designed.Mechanical and mathematical calculation performed an important role.Calculated according to statics and relevant contents,the structure had the same total volume as the traditional segmented structure,but had shorter length,wider width and greater height.Those prevented the structure from stress or deformation failure.Some reinforcing ribs with enough moments of inertia were welded in the external shell.Because of the one-piece structure,this refuge chamber reduced the risk of sealing which was a serious problem of segmented structure.Impact load with 300 ms duration and0.6 MPa over-pressure was settled.Explicit nonlinear dynamic analysis program was used to simulate the response of the refuge chamber.The maximum stress and the maximum displacement were obtained.The refuge chamber including blast airtight doors could meet the rigidity requirement.Weak parts of the chamber were the front and back end shell where bigger displacement values occurred than others.Thus,the calculation indicated that the refuge chamber could meet structural safety requirements.Based on the numerical analysis,suggestions were put forward for further resistance ability improvement.Only large inclined shaft with larger wellhead was suitable for this one-piece coal mine mobile refuge chamber.展开更多
In order to investigate detonation propagation and distribution problems of premixed CH_4 ＋ 2O_2 mixture around a concrete structure such as a refuge chamber,detonation experiments in one small size tube were conduct...In order to investigate detonation propagation and distribution problems of premixed CH_4 ＋ 2O_2 mixture around a concrete structure such as a refuge chamber,detonation experiments in one small size tube were conducted. A simulation method was developed to obtain the flow field load distribution in the coal mine lane and pressure load of each part for the refuge chamber. Firstly,a physical model of a full-size explosiontest lane was established,which included the refuge chamber. With the calculations of the exact initial detonation pressure,the propagation characteristics of CH_4 ＋ 2O_2 premixed mixture detonation in the lane was simulated. Simulation results of various parts from AUTODYN are recorded,and the shock wave arrival time and the pressure peak can be observed from the detonation pressure-time curve over the changing propagation distance. So curve differences in different locations cannot be ignored. Then by detonation experiments in the small size tube,detonation pressure-time curves and velocity were obtained. Finally the simulation waveform of variation curve agreed well with the experimental results,which validated the detonation simulation method. The difference between shockwaves of the two sensors confirmed that detonation wave changed along with distance and time. These results should be taken into serious consideration for the detonation progration and distribution problem in future researches.展开更多
The 1,000 MPa ultra-high strength hot-rolled plate steel with low-carbon bainitic microstructure was developed in the laboratory for coal mine refuge chamber. The static recrystallization behavior, microstructure evol...The 1,000 MPa ultra-high strength hot-rolled plate steel with low-carbon bainitic microstructure was developed in the laboratory for coal mine refuge chamber. The static recrystallization behavior, microstructure evolution, and mechanical properties of this hot-rolled plate steel were investigated by the hot compression, continuous cooling trans- formation, and tensile deformation test. The results show that the developed steel has excellent mechanical properties at both room and elevated temperature, and its microstructure mainly consists of lath bainite, granular bainite, and ferrite after thermal-mechanical control process （TMCP）. The ultra-high strength plate steel is obtained by the TMCP process in hot rolling, strengthened by bainitic transformation, microstructure refinement, and precipitation of alloying elements such as Nb, Ti, Mo, and Cu. The experimental steel has relatively low welding crack sensitivity index and high atmospheric corrosion resistance index. Therefore, the developed steel has a good balance of strength and ductility both at room and elevated temperature, weldability and corrosion resistance, and it can suffice for the basic demands for materials in the manufacture of coal mine refuge chamber.展开更多
基金Supported by the Major State Basic Research Development Program of China(973Project)(2011CB706900)
文摘In order to reduce the risk of sealing and improve the structural strength for a coal mine mobile refuge chamber,a new type of one-piece model was designed.Mechanical and mathematical calculation performed an important role.Calculated according to statics and relevant contents,the structure had the same total volume as the traditional segmented structure,but had shorter length,wider width and greater height.Those prevented the structure from stress or deformation failure.Some reinforcing ribs with enough moments of inertia were welded in the external shell.Because of the one-piece structure,this refuge chamber reduced the risk of sealing which was a serious problem of segmented structure.Impact load with 300 ms duration and0.6 MPa over-pressure was settled.Explicit nonlinear dynamic analysis program was used to simulate the response of the refuge chamber.The maximum stress and the maximum displacement were obtained.The refuge chamber including blast airtight doors could meet the rigidity requirement.Weak parts of the chamber were the front and back end shell where bigger displacement values occurred than others.Thus,the calculation indicated that the refuge chamber could meet structural safety requirements.Based on the numerical analysis,suggestions were put forward for further resistance ability improvement.Only large inclined shaft with larger wellhead was suitable for this one-piece coal mine mobile refuge chamber.
基金Supported by the National Science Foundation of China(E041003)the Fundamental Research Funds for the Central Universities(FRF-TP-15-105 A1)the Postdoctoral Science Foundation of China(2015M580049)
文摘In order to investigate detonation propagation and distribution problems of premixed CH_4 ＋ 2O_2 mixture around a concrete structure such as a refuge chamber,detonation experiments in one small size tube were conducted. A simulation method was developed to obtain the flow field load distribution in the coal mine lane and pressure load of each part for the refuge chamber. Firstly,a physical model of a full-size explosiontest lane was established,which included the refuge chamber. With the calculations of the exact initial detonation pressure,the propagation characteristics of CH_4 ＋ 2O_2 premixed mixture detonation in the lane was simulated. Simulation results of various parts from AUTODYN are recorded,and the shock wave arrival time and the pressure peak can be observed from the detonation pressure-time curve over the changing propagation distance. So curve differences in different locations cannot be ignored. Then by detonation experiments in the small size tube,detonation pressure-time curves and velocity were obtained. Finally the simulation waveform of variation curve agreed well with the experimental results,which validated the detonation simulation method. The difference between shockwaves of the two sensors confirmed that detonation wave changed along with distance and time. These results should be taken into serious consideration for the detonation progration and distribution problem in future researches.
基金supported by the National Natural Science Foundation of China (Nos. 51174057 and 51274062)the National High Technology Research and Development Program of China (No. 2012AA03A503)Research Fund for the Doctoral Program of Higher Education of China (No. 20130042110040)
文摘The 1,000 MPa ultra-high strength hot-rolled plate steel with low-carbon bainitic microstructure was developed in the laboratory for coal mine refuge chamber. The static recrystallization behavior, microstructure evolution, and mechanical properties of this hot-rolled plate steel were investigated by the hot compression, continuous cooling trans- formation, and tensile deformation test. The results show that the developed steel has excellent mechanical properties at both room and elevated temperature, and its microstructure mainly consists of lath bainite, granular bainite, and ferrite after thermal-mechanical control process （TMCP）. The ultra-high strength plate steel is obtained by the TMCP process in hot rolling, strengthened by bainitic transformation, microstructure refinement, and precipitation of alloying elements such as Nb, Ti, Mo, and Cu. The experimental steel has relatively low welding crack sensitivity index and high atmospheric corrosion resistance index. Therefore, the developed steel has a good balance of strength and ductility both at room and elevated temperature, weldability and corrosion resistance, and it can suffice for the basic demands for materials in the manufacture of coal mine refuge chamber.
