煤炭脉冲气力输送中精准增压降尘与颗粒系统动力学行为研究

For the problems of environmental pollution and frequent safety accidents in coal open air transmission, the coal particle solids-plug and pulse conveying flow field as the research objects, using the laser three-dimensional scanning imaging technology, particle dynamics theory, gas-solid two-phase flow theory and CFD-DEM coupling method, the research on precise pressurization-dedusting and system dynamics behavior in pulse pneumatic conveying of coal particle is carried out by combining of theoretical analysis, numerical simulation and experiment. The coal particle shape characteristics, the chain of parallel bonding forces between micro particles, the relationship between particle shape and particle dynamics behavior, the interaction dynamics behavior between particle solids-plugs and pipe wall are analyzed. The precise discrete element model of coal particle, the coupled model of particle and flow field, the coupled model of particle solids-plug and flow field are built to illuminate the formation and dissipation mechanism of solids-plug, the formation mechanism of coal dust, the pressurization mechanism of solids-plug pneumatic conveying, the dedusting mechanism of spray in-pipe, the evolution mechanism of solids-plug shape and structure under the coupling between the particle, flow flied and pipe wall, and reveal influence law of solids-plug dynamics behavior to flow-field static pressure and pipe dust, the influence law of in-pipe pressurization-dedusting to solids-plug dynamics behavior , the function of conveying flow field, air blade flow field and pressurization flow field in the formation and dissipation of solids-plug which reduces the dust and improves the environmental protection and safety efficiency of coal convey. It provides a new way for coal convey.

针对煤炭露天输送中环境污染和安全事故频发的问题，以煤炭颗粒料栓和脉冲输送流场为研究对象，采用激光三维扫描成像技术、颗粒动力学理论、气固两相流理论、流固耦合方法，将理论分析、数值模拟和实验相结合，开展煤炭脉冲气力输送中精准增压降尘与颗粒系统动力学行为研究，分析煤炭颗粒形状特征、微颗粒间平行粘结作用力链、颗粒形状与颗粒动力学行为关系、料栓与管壁互作用动力学行为，建立煤炭颗粒精准离散元实体模型、颗粒与流场耦合动力学模型、料栓与流场耦合动力学模型，阐明料栓形成与消散机理、管内粉尘形成机理、料栓输送增压机理、管内喷雾降尘机理以及颗粒、流场和管壁耦合作用下料栓形状与结构演化机理，揭示料栓动力学行为对流场静压及管内粉尘影响规律、管内增压降尘对料栓输送行为影响规律以及输送流场、气刀流场和增压流场在料栓形成及消散过程中的作用，以降低煤炭输送粉尘，提高煤炭输送清洁环保性和安全高效性，为煤炭输送供新方法。

我国燃煤企业的厂内煤炭输送多为露天输送系统，主要的输送设备为皮带输送机，在卸车、堆垛、取料、输送等过程中煤炭直接与大气接触，导致煤尘大量扩散，污染周边环境、造成资源浪费，严重时诱发煤尘爆炸事故。为改变厂内煤炭露天输送方式、提高煤炭输送系统的清洁环保性和安全高效性，本项目针对煤炭露天输送中环境污染和安全事故频发的问题，将气力输送技术引入煤炭输送领域，利用脉冲气力输送技术的耗气量低、输送效率高、占用空间小等优点，以煤炭颗粒料栓和脉冲输送流场为研究对象，采用激光三维扫描成像技术、颗粒动力学理论、气固两相流理论、流固耦合方法，将理论分析、数值模拟和实验相结合，开展了煤炭脉冲气力输送中精准增压降尘与颗粒系统动力学行为研究，获得了煤炭颗粒形状特征、微颗粒间平行粘结作用力链、颗粒形状与颗粒动力学行为关系、料栓与管壁互作用动力学行为，建立了煤炭颗粒精准离散元实体模型、颗粒与流场耦合动力学模型、料栓与流场耦合动力学模型，揭示了料栓形成与消散机理、料栓输送增压机理、管内喷雾降尘机理以及颗粒、流场和管壁耦合作用下料栓形状与结构演化机理，掌握了料栓动力学行为对流场静压及管内粉尘影响规律、管内增压降尘对料栓输送行为影响规律以及输送流场、气刀流场和增压流场在料栓形成及消散过程中的作用，旨在研究一种清洁高效的煤炭全封闭输送方式，建立清洁、安全、高效的厂内煤炭气力输送系统，对改善用煤企业周边环境、避免安全生产事故、实现煤炭资源的绿色使用都具有极其重要的意义。