矿井排风流热湿能量提取理论研究

Thermo-hydro energy of exhaust airflow of mine ventilation constitutes sensible heat energy caused by temperature difference and latent heat energy caused by moisture difference, as well as there is always the difficult problem of extracting thermo-hydro energy from this airflow affected by two-phase transmit of spraying droplet cluster and inner flowing air, mutual influence of flow and transfer, coupled relation of heat transfer and moisture transfer. Aimed at a theoretical problem of effectively extracting thermo-hydro energy from exhaust airflow of mine ventilation, a study of object is thermo-hydro transfer from the airflow to sprayed droplet cluster in our project. By virtue of theoretical deduce, numerical calculations and model experiments, this project discusses the transmit law droplet cluster in heat exchanging space, the mechanism on sensible heat transfer of this cluster and irreversible loss in this process, the mechanism on moisture content transfer of this cluster and its irreversible loss, the mechanism of coupled optimization thermo-hydro transfer in heat exchange enclosure constrained by space-time. Through discussion of this project, it will be demonstrated the process of irreversible factor related with extensive parameters, intensity parameters with irreversible non-equilibrium whole region and reversible equilibrium local region, firstly, secondly, be clear up the relation of potential difference, irreversible loss, characteristic droplet diameter and contact resistances; thirdly, the thermo-hydro boundary condition of droplet will be found out, and the mechanism of thermal contact resistance coupled with hydro contact resistance will be illuminated. Lastly, optimized method of irreversible losses in the process of thermo-hydro transfer will be explored out, and the mechanism and process of this transfer will be disclosed. The anticipated achievements of this project will support theoretical foundation for optimized heat exchange of sprayed water and effectively extracting thermo-hydro energy from this airflow.

矿井排风热湿能量由温差显热能和湿差潜热能构成，而喷淋液滴与内流排风的两相输运、流动与传递的互为影响、传热与传湿的耦合关系一直是能量提取中难题。针对液滴群高效提取矿井排风流热湿能量的理论问题，本项目以排风流与液滴群之间的热湿传递为研究对象，通过理论分析、数值计算和实验室实验，研究换热空间内液滴群运移规律，液滴群显热传递及不可逆因子形成机理，液滴群湿量传递及不可逆因子形成机理，受限换热空间内热湿传递耦合优化机理，探明全域非可逆非平衡与局域平衡可逆之间的不可逆因子形成过程，明确势差、不可逆因子、特征粒径和接触阻力之间的关系，确定接触阻力耦合的边界条件，阐明接触热阻与接触湿阻的耦合机制，建立热湿传递不可逆因子的优化方法，揭示热湿传递过程及优化机理，为喷淋水换热优化及排风热湿能量高效提取提供理论依据。

围绕液滴雾化特性、空间拓扑结构、运动学和动力学特性、热力学特性、潜力分区等，运用理论分析、数学推导、数值仿真及模型实验等手段，揭示了矿井排风热湿能量高效提取机理，具体为：.（1）基于两相流体动力学理论基础，设计和优化了受限空间雾化实验装置。具体包括通风机变频调节及其控制、流线型扩散器优化设计、液滴喷淋方式的选择、恒压雾化装置的设计、喷嘴类型的选择等；通过实验实测的方法，进一步揭示了空心圆锥形喷嘴对液滴的雾化机理，观察到液滴破碎的一次雾化和二次雾化，量化了喷雾压力、气相速度及液相物理参数对液滴雾化过程的影响程度，同时得出了不同喷射压力和风流扰动下液滴二次破碎过程。.（2）引入分形理论，形成液滴分形维数表征液滴粒径分布特性的方法，依据该方法对喷嘴雾化效果进行优选，建立起液滴输运控制方程，对液滴极限运移距离进行了预测，验证了液滴群雾化机理。.（3）理论上推导出液滴与排风流热湿传递控制方程，建立气液两相换热过程的热效率和㶲效率评价方法，搭建喷淋式矿井排风能量回收实验平台，得到了装置出口的液滴与空气状态参数以及热交换效率和㶲效率的变化规律。.（4）针对热交换效率和㶲效率在分析热湿交换过程中存在的不足，引入火积（Entransy）理论，得到了我国气候区典型地区的全年逐时排风Entransy效率，划分出低频区、中频区和高频区三个矿井排风流热湿能量提取区域。.在项目研究期间，共计发表论文16篇次，其中，SCI期刊论文6篇，EI期刊2篇，CSCD期刊论文5篇；授权专利发明专利12项，其中，国际发明专利1项；科技成果奖励6项次，其中，省部级2项；培养研究生3人次，其中，博士研究生1人；依托专利技术，签订企事业单位委托合同5项次，累计合同经费突破300万元。