太阳能反应器内CO2/H2O共气化中的参与性介质辐射与气固旋转射流耦合机理研究

Solar synergistic gasification with CO2 and H2O can obtain clean gas efficiently and adjust the ratio of H2 to CO, so it has become focous of the solar thermochemical. Solar vortex-flow reactor is the key component for high temperature solar thermochemical deposition. The reactive gas-particles are radiative participating mediums which directly absorb the solar radiation and involving complex heat and mass transfer, multiscale gas-solid swirling jet flow, synergistic gasification chemical kinetics and coupling effects within them in the reactor.This project aims to research the solar vortex-flow reactor. In order to overcome the shortcomings of the current research, the radiative heat transfer of participating mediums with complex compounds which intensively depend on their wavelength distribution and penetrating depth, multiscale gas-solid swirling jet flow, synergistic gasification chemical kinetics and their mutual coupling mechanism in the solar reactor will be investigated under strong directional and high incident solar radiation conditions. On the one hand, the model of the whole conversion process in the reactor will be established to reveal the mechanism of radiative heat transfer with participating mediums and coupling effect with multi-scale gas-solid swirling jet flow in the synergistic gasification process. Then the non-dimensional correlation of residence time distribution /reactor flow type with Stokes number and other operation parameters will be obtained, and the influence of reaction conditions on the reaction conversion efficiency and thermal performance can also be summarized. On the other hand, on-sun experiments will be done to test the performance of vortex-flow reactor and validate the numerical results. The outputs of the project will provide the theoretical basis for of reactor, and methods to improve the performance and safety of solar vortex-flow reactor.

由于太阳能CO2/H2O共气化可清洁、节能地制取气体燃料并调节比例，因此成为太阳能热化学研究热点，而其中太阳能旋流反应器是核心部件，反应物作为参与性介质直接吸收太阳辐射，同时涉及到复杂的传热、传质、多尺度旋转气固射流及共气化反应。针对当前研究的不足，本课题拟开展强方向性、高焦比太阳辐射条件下，太阳能旋流反应器中复杂组分参与性介质强光谱性和各向异性对辐射传递特性的影响、多尺度旋转气固射流、竞争性反应下化学动力学及其相互耦合作用的机理研究。一方面建立反应器内介质转换过程的完整数学物理模型，揭示共气化过程中参与性介质辐射与多尺度旋转气固射流的耦合作用机制，得出反应器流型的特征参数与滞留时间分布的无量纲关联式，以及反应条件对于热化学反应器转化率和热效率的影响规律；另一方面通过实验测试反应器运行性能，为数值模型提供验证，并据此提出提高反应器效率和安全性的方法，为反应器的设计开发奠定理论基础。

太阳能气化可清洁、节能地制取气体燃料，是实现双碳战略的重要技术路径。申请人近年来致力于太阳能旋流反应器的研究，明晰了高焦比、强方向性的聚光条件下各向异性的参与性介质的辐射特性，阐明了旋转气固两相射流中颗粒滞留时间分布特性，揭示了参与性介质辐射、气固旋转射流、及化学反应动力学耦合规律。具体结果如下：. 开发高精度间接式能流密度测量和误差分析方法，测量了高焦比太阳模拟器的不同平面位置的热流密度分布，实验测得焦点位置热流密度峰值为9.59MW/m2，实现世界第二聚光能流密度。利用米氏散射理论得到颗粒群辐射特性。提出太阳能反应器最优开口半径关联式及设计模型，确定反应器参数并搭建10kW旋流反应器实验台。建立高焦比点聚焦下气固两相流-参与性介质辐射-反应耦合模型，阐明反应器转化率主要由滞留时间决定，明确石英玻璃窗表面沉积煤颗粒的影响规律，研究了进气质量流量等影响因素对于反应器安全性、反应特性和热性能的影响规律。揭示制约旋流反应器效率主要因素：质量流和能量流不匹配，提出焦点和颗粒群分布调控方法。得到最高实测反应器效率23.30%，能量提升因子为1.18。. 以上研究取得了丰富的研究成果，培养博士研究生1人，发表学术论文13篇，授权专利2项。