Simulation Study On Gasification Of Space Furnace

Coal is an indispensable raw material for industrial processes in China.Coal accounts for a large part of China's total energy consumption.The sustainable development of clean coal utilization technology is of great significance for the protection of national energy security.It can fundamentally reduce environmental pollution and promote the rapid and effective development of national economy.Coal gasification is an important part of clean coal utilization technology.Its development not only promotes the efficiently and cleanly use of coal,but also reduces environmental pollution.Thus,it is of great practical significance to model and optimize the gasification process.In this work,Barracuda software is used to simulate the process of pulverized coal gasification of the HT-L gasifier.The simulation results are in good agreement with actual production.Based on the established model,simulations are performed to study the characteristics the flow field insider gasifier.The influence of the nozzle structure on the flow field is also studied.Finally,by simulations of the hot state conditions and the industrial scale gasifier,the characteristics of hot state flow field and the scaling-up law are sumerized,which can be used as a guideline for the actual production.The first chapter mainly introduces the current energy structure of our country.Then the main coal gasification technology are introduced with highlights on HT-L coal gasification technology for its unique advantages.Because the simulation research is more effective and cheaper then the experimental research,numerical simulation method is adoped in this study.The second chapter introduces the commercial software Barracuda used in this study.In the third chapter,the main characteristics of the flow field in the HT-L under the cold condition are studied,including the influences of angular jet and nozzle structure on the flow field.The reliability of the drag model adopted in this work is verified,which provides the basis for the hot state simulation of HT-L gasifier.In the fourth chapter,the flow field and product gas species in the test furnace and industrial scale furnace under the hot condition are studied.In the fifth chapter,the conclusion of this research is summarized,and the innovation of the research and the prospect of the futer research are introduced.The results show that the angular jet will accelerate the particle diffusion and intensify particle back mixing.Simulation with ditailed nozzle structure makes the simulation result more close the reality.The existence of nozzle structure makes the particle diffusion more obvious.The turbulent vortex will be generated earlier and the jet deflection will occur.The EMMS/DP drag model can capture the non-uniform structure such as particle agglomeration,thus help to deepen our understanding of the flow field inside gasifier.Because of the obvious heat absorption and release in the hot state simulation,the flow field in the gasifier is more complex,and the pressure and gas velocity distributions changes obviously in comparison with those of the cold state cases.