长大公路隧道无动力通风系统试验模型的太阳能集热效率数值模拟
Numerical simulation of solar collector efficiency for experimental model of unpowered ventilation system in long highway tunnel

为了研究太阳能空气管集热器对隧道自然通风系统强化作用的特性，设计了一种综合利用太阳能、风能的长大公路隧道无动力通风系统的强化集热试验模型。采用基于计算流体动力学的FLUENT软件，对试验模型的太阳能空气管集热系统内的温度场进行数值模拟，将太阳辐射强度作为边界条件处理，分析不同辐射强度及不同通风量条件下集热管横截面温度分布、系统进出口温差和集热效率特性的变化。研究结果表明：在系统总风量一定的条件下，集热管进出口温差随太阳辐射强度的增大而增大，集热效率基本不变；在相同的太阳辐射强度与环境条件下，太阳能集热管进出口温差随系统总风量的增大而减小，集热效率随着总风量的增大而增大。太阳能集热器对长大公路隧道自然通风效果有明显的强化作用，但在实际工程应用时，还需要在通风量和集热效率之间进行平衡选择，并对系统整体性能进行综合评估。
In order to reveal the characteristics of strengthening effect of solar air tube heat collector on natural ventilation system of tunnel, a model of intensified heat collection test for unpowered ventilation system in long highway tunnel to comprehensively use solar and wind energy was designed. The FLUENT software of computational fluid dynamics (CFD) was used to simulate the temperature field in the solar air tube collector system of the experimental model. The solar radiation intensity was treated as the boundary condition. Temperature distribution of the cross section of the collector tube, the temperature difference between inlet and outlet and heat collection efficiency of the system under different radiation intensity and ventilation rate was analyzed. The results show that the temperature difference between inlet and outlet of the collector increases with the increase of solar radiation intensity and the heat collection efficiency basically remains unchanged under the condition that total air volume is constant. The temperature difference between inlet and outlet of solar collector decreases with the increase of total air volume, and the heat collection efficiency increases with the increase of the total volume under the same solar radiation intensity and environmental condition. Solar collector has an obvious strengthening effect on the natural ventilation of long highway tunnel. But in actual application, it is necessary to make a balance between heat collection efficiency and ventilation volume. The overall performance of system also needs to be assessed comprehensively