Determining multidimensional diffuse reflection effects in city tunnel lighting environment

Abstract

Traditional tunnel lighting luminance is calculated based on road surface reflection and few researches have been able to draw on any systematic research into methods considering multidimensional diffuse reflection. This research first defines the principles of multidimensional tunnel lighting environment and provides the comprehensive assessment of energy efficiency of multidimensional tunnel lighting. An estimation method for the influences of corresponding factors on tunnel lighting energy efficiency was proposed. With respect to the multi-factors in tunnel lighting environment, we developed a tunnel lighting environment of Hangzhou Boao tunnel based on DIAlux simulation, then conducted experimental verifications of the model. The effects of sidewall reflectivity, roof reflective property, road surface material and lighting patterns were investigated and discussed. The result shows that the energy-saving effect of sidewall reflection is influenced by the reflection coefficient of the roof, and the greater the reflection coefficient of the roof, the more obvious the effect of increasing the sidewall reflection coefficient on lighting energy saving. The energy-saving effect of the roof reflection depends on the performance of the sidewall reflection. If the sidewall reflection coefficient is smaller, the high roof reflection coefficient still has a limited effect on lighting energy saving. The reflection of the roof has a weaker effect on the energy efficiency of the lighting than the effect on the sidewalls. The greater luminance of concrete at the same illumination level indicates that concrete pavements are more energy efficient.