合成气-煤粉气固两相火焰传播及灾变的协同动力学研究

气流床粉煤气化技术中采用合成气输送煤粉能有效解决载气污染产品问题，降低能耗并提高煤气中的有效气含量，推动煤气化制氢的高效化发展。但合成气-煤粉一旦泄漏，具有较高的燃爆危险性，成为其推广应用的最大障碍。相关安全科学研究还存在很大的不足。本项目综合利用实验、理论分析及CFD数值模拟等手段，首先研究合成气协同作用下的煤粉燃爆基本参数，建立反应动力学机理模型；再针对合成气-煤粉泄漏的不同阶段，分别研究射流火焰和非均相气粉云爆炸的动力学过程，剖析火焰诱导流场与反应动力学的相互作用机制，掌握合成气对煤粉火焰的耦合致灾效应，揭示不同阶段火焰传播及灾变机制，建立特征参量的理论预测模型；最后基于OpenFOAM平台，建立合成气-煤粉火焰传播及灾变的协同动力学模型，开展多尺度模拟和分析，揭示合成气与煤粉协同燃爆灾害的内在机理和临界控制条件。本项目成果可以为煤气化制氢工艺的本质安全化设计和事故防控提供科学指导。

Using syngas as carrier to convey the pulverized coal in entrained flow gasification can effectively avoid polluting the product by carrier gas, decrease the energy consumption, increase the content of syngas in the gasification product, and consequently propel the development of efficient hydrogen production from coal gasification. However, once syngas-pulverized coal mixture leaks, it would give rise to high risk of combustion and explosion, which therefore becomes the largest barrier to convey the pulverized coal with syngas. But relevant scientific research on the safety issues is scarce. In this project, experiment, theoretical analysis and CFD modelling will be employed in combination. Firstly, the fundamental combustion and explosion parameters of coal with synergetic effect of syngas will be collected and a comprehensive chemical kinetic mechanism will be established. Then, the dynamic processes of jet flame and heterogeneous gas-dust cloud explosion at different stages of leakage will be scrutinized, respectively. The interaction between flame-induced flow field and chemical kinetics will be analyzed to interpret the coupling disaster-deducing effect of syngas on pulverized coal flame. The regimes of flame propagation and catastrophic transition will be revealed, and the predicting model of characteristic parameters will be proposed. Finally, a CFD model for synergetic dynamics of syngas-pulverized coal two-phase flame propagation and catastrophic transition will be built on OpenFOAM platform. Thereafter, multi-scale simulation and discussion will be performed to deeply explore the underlying mechanism and critical conditions of synergetic combustion and explosion disasters by syngas and pulverized coal. The outcome of this project is supposed to provide scientific advice to intrinsically safe design, accident prevention and control for hydrogen production process from coal gasification.