太阳能驱动甲烷重整泡沫反应器聚光特性研究及优化设计

RESEARCH ON CONDENSATION PERFORMANCE AND OPTIMIZATION OF SOLAR-DRIVEN METHANE REFORMING FOAM REACTORS

针对太阳能光热驱动CH_(4)/CO_(2)重整体系中自然聚光条件下高斯分布入射热流特性,采用有限容积法(FVM)建立二维CFD模型,耦合导热对流、非等温平衡、辐射传热与化学反应动力学等多物理模型,结合蒙特卡洛光线追迹进行光学模拟,系统研究聚光特性对前表面能流分布、温度场分布和组分分布的影响,以及前表面温差和太阳能-燃料转化效率之间的联系。在对孔隙尺度参数优化的基础上,将泡沫外形优化为抛物凹面的结构,可使前表面温差显著减小,温度不均匀性显著改善,泡沫反应器性能进一步提高。随着凹面深度h从5 mm增至12.5 mm时,前表面最大温差从481.2 K降至95.49 K。其中当h=12.5mm时太阳能-燃料转化效率达到最优值50.5%,与平面泡沫反应器相比提升20.4%。

Aiming at incident Gauss flux radiation conditions caused by the natural light concentration in solar-driven CH_(4)/CO_(2) reforming system,the two-dimensional CFD model is established by finite volume method(FVM)coupled with thermal conduction and convection,non-isothermal flow,radiation transfer,chemical dynamics and Monte Carlo ray tracing,the effects of concentrated solar flux,temperature distribution and component distribution on temperature difference and the solar-to-fuel efficiency are comprehensively studied.On the basis of the optimization of pore scale parameters,the foam inlet is optimized into parabolic concave shape,the results show that the parabolic concave shape can significantly reduce the temperature difference on the front surface,with further improvement on temperature inhomogeneity and foam reactor efficiency.As the concave depth h increases from 5 mm to 12.5 mm,the maximum temperature difference on the front surface decreases from 481.2 K to 95.49 K.Besides,when h=12.5 mm,the solar-to-fuel efficiency reached the optimal value of 50.5%,which is increased by 20.4%compared with the planar foam reactor.