振荡气流煤炭气力输送中颗粒起动响应及系统动力学特性

For the problems of high power consumption, pipe erosion, and particle degradation in coal pneumatic conveying, the coal particle pickup responses and conveying system dynamic characteristics of oscillating airflow pneumatic conveying will be studied in this project. Based on the science nature of gas-solid two-way coupling and interaction in pneumatic conveying, the strategies will consist of utilizing oscillating airflow disturbance particle pickup to reduce conveying velocity, and revealing gas-solid coupling dynamic mechanism to optimize conveying system performance. Firstly, the parameters of oscillating airflow are defined on the basis of flow field characteristics analysis, the numerical simulation and experimental system of coal particle pickup and pneumatic conveying processes are established on the strength of real coal physical properties and airflow compositions. Secondly, the influence rule of oscillating airflow characteristics on coal particle pickup response is revealed, and the optimization parameters matching of oscillating airflow on account of the most significant coal particle pickup response gain is confirmed with the purpose of minimum pickup velocity. Finally, the gas-solid two-phase dynamic model of coal oscillating airflow pneumatic conveying system is established to acquire the dynamic parameters' time series in the gas-solid coupling process such as oscillating airflow decay, pressure loss, and energy conversion for the gas phase and coal particle displacement, velocity, and acceleration for the solid phase. The research results will provide theory support for coal low velocity pneumatic conveying popularization, and contribute to application field extension and basic theory enrichment of pneumatic conveying.

针对煤炭气力输送系统能耗高、颗粒破碎和管壁磨损严重等问题，根据气力输送过程气固两相双边耦合、互为激励的科学本质，采用振荡气流激扰颗粒起动以降低输送气流速度、明确输送系统气固耦合动力学机制以优化输送性能的研究策略，进行振荡气流煤炭气力输送中颗粒起动响应及系统动力学特性研究。首先，明确振荡气流流场结构特征及指标参数，构建具有真实物理属性和流场气流组成特征的煤炭颗粒起动和输送过程数值模型及试验系统；然后，揭示振荡气流对煤炭颗粒起动响应的影响规律，以最小气流速度为目标确定起动响应增益最显著的振荡气流形式和参数优化匹配；最后，建立振荡气流煤炭气力输送系统气固两相动力学模型，得到气固耦合过程中振荡气流衰减、压力损失、能量转换和煤炭颗粒位移、速度、加速度等动力学参量的时间序列。研究成果将为实现煤炭低速气力输送提供理论支撑，扩展气力输送技术适用领域并丰富气力输送基础理论。

气力输送是解决煤炭输运途中生态污染和资源浪费问题的有效途径。针对气力输送系统能耗高、颗粒破碎和管壁磨损严重等问题，以及煤颗粒粗重且粗细掺混的固有属性，根据气力输送过程气固两相双边耦合、互为激励的科学本质，提出采用振荡气流激扰颗粒起动以降低输送气流速度、明确输送系统气固耦合动力学机制以优化输送性能的研究策略，进行振荡气流煤炭气力输送中颗粒起动响应及系统动力学特性研究。首先，明确了振荡气流流场结构特征及指标参数，构建了具有真实物理属性和流场气流组成特征的煤炭颗粒起动和输送过程数值模型及试验系统，采用数值和试验相结合方法获得煤颗粒在临界起动过程中的动力学系统参量的时间序列，揭示了煤炭颗粒气力起动过程的理论机制；然后，搭建煤炭颗粒气力输送实验系统，定义输送系统性能指标，分别进行煤炭颗粒轴流场和优化流场气力输送实验，研究不同条件优化气流对系统输送能效和平稳性的影响，获得煤炭颗粒输送系统的性能特性，并根据输送实验结论提出压力和流态联控气力输送技术和轻介共流气力输送技术，对其进行系统设计；最后，进行颗粒栓流气力输送料栓全周期试验观测和数值模拟进阶研究，提取颗粒团聚、弥散的形式和速度变化历程，获得气力输送过程颗粒输运形状、颗粒速度、料栓速度，以及料栓弥散过程颗粒动力学参量变化历程。研究成果为煤炭低速稳定气力输送提供理论支撑，并扩展气力输送技术适用领域并丰富气力输送基础理论。