基于双向反射分布函数的公路隧道照明计算方法及节能措施

隧道内壁作为隧道光照环境的重要组成部分，现有的照明计算方法在解决隧道内壁反光增效时，漫反射系数无法准确描述侧壁材料的反射特性，计算结果和实测值之间有较大偏差，不利于隧道照明安全与节能。为解决上述问题，提出一种改进的照明计算方法，借助离散元思想，将隧道侧壁离散为若干个反射单元，引入侧壁的双向反射分布函数，借此计算侧壁反射增光作用对路面的影响。研究发现： 相比隧道照明相关规范中的计算方法，改进方法的计算结果与实测值差距更小，仅有3.5%； 对不同材料用作隧道侧壁材料时的辅助照明效果，从路面、墙面的照度、均匀度等方面进行评价可知，相比于隧道专用腻子材料，隧道侧壁采用蓄能反光发光材料更有助于照明节能。

Calculation Method of Highway Tunnel Lighting Based on BidirectionalReflectance Distribution Function and Energy Saving Measures

The inner wall of tunnel is an important part for the tunnel′s lighting environment. The existing lighting calculation methods cannot accurately describe the reflective characteristics of the sidewall materials when solving the reflective enhancement of the inner wall of tunnel, the deviation between the results of calculation method and the measured data is large, which is not conducive to tunnel lighting safety and energy saving. To address these problems, an improved lighting calculation method is proposed. With the help of discrete element thinking, the tunnel sidewall is considered as a number of reflective units, the bidirectional reflectance distribution function (BRDF) of the sidewall is introduced, and based on which the effect of sidewall reflection brightening on the path surface is calculated. The results show that: (1) Compared with the calculation methods in the related specifications of tunnel lighting, the difference between the calculated results and the measured values of the improved method is much smaller, only 3.5%. (2) The auxiliary lighting effect of different materials used as tunnel sidewall materials is evaluated in terms of the illumination and evenness of the pavement wall and sidewall; and compared with the dedicated putty material, the energy storage reflective luminescent material on tunnel sidewall is more conducive to energy saving.