China's coal-dominated energy structure highlights the critical role of clean coal technology in addressing both energy and environmental challenges. Among various clean coal technologies, coal gasification stands out as a key component, especially in integrated gasification combined cycle (IGCC) systems. As a central device in coal gasification, the fluidized bed gasifier plays a vital role. Developing accurate mathematical models for this equipment not only enhances our understanding of its dynamic and static behavior but also offers practical guidance for design and industrial application. This paper presents a dynamic mathematical model of a bubbling fluidized bed gasifier, followed by detailed simulation studies.
Compared to other gasification methods, fluidized bed gasifiers utilize fluidization technology and circulating coke to separate combustion and gasification zones, producing a high-calorific, nitrogen-free gas. The system operates with a high carbon concentration in the bed due to significant coke circulation, maintaining temperatures between 850°C and 950°C. This temperature range promotes the water-gas reaction, leading to higher gas yields. Additionally, the process is relatively simple and independent, making it a promising option for efficient coal utilization.
To accurately capture the changes in substance concentrations and temperatures within the gasifier, the system is divided into multiple continuous chambers along the main flow direction. Each chamber is treated as an ideal reactor, assuming uniform pressure and temperature within small segments. This segmented approach allows for more precise analysis of concentration parameters. Each chamber is analyzed for mass and energy balance, considering factors such as flow dynamics, coal particle conversion, and gas-phase chemical reactions.
The flow model divides the gasification chamber into two distinct phases: the bubble phase and the emulsion phase. It assumes that the emulsion phase remains in a minimum fluidization state, while the remaining gases pass through it in the form of bubbles. This approach helps better represent the complex interactions within the gasifier and improves the accuracy of the overall model.
living room sofa,living room couch,modern side table,modern sofa with chaise,soft sofa,canape sofa,plush couches,corduroy ottoman
Famous Home Living(Dongguan)Co.,ltd , https://www.famoushomeliving.com