Under the same lighting brightness condition, LED can save 40% energy when used in tunnel lighting. However, the photoelectric conversion efficiency of LED is only 15%-20%, and heat dissipation has become one of the key factors restricting the promotion and application of LED lighting system. The intrinsic characteristics of LED research hotspots and difficulties, such as narrow and semi-closed, make tunnel lighting particularly complicated, and the heat dissipation of LEDs in tunnels also shows differences. Under normal circumstances, due to the existence of mechanical ventilation and traffic wind, the air in the tunnel presents a one-way flow, and LED heat dissipation is a heat transfer problem under forced convection. However, in extreme cases, the tunnel is in a temporary near-windless state. At this time, the heat generated by the LED chip is completely dissipated by natural convection, and the heat dissipation effect is weak. Therefore, only by fully considering the most unfavorable situation, can we maximize the advantages of LEDs and ensure their normal use in the tunnel. Domestic and foreign scholars have done a lot of research on the heat dissipation problem of LED under natural convection.
SenolBaskaya and other numerical simulations and tests on the plate fin heat exchange heatsink) geometric parameters and substrate heat flux on the thermal resistance and heat transfer performance of different types of cylindrical tubes, longitudinal finned radiators (cylindricaltube, Ren-Tsung, etc. Experiments on the heat transfer of rectangular pin fins. However, these studies focus on the heat transfer of heat dissipation structures in open spaces. The research on the heat dissipation of LEDs in semi-closed spaces of tunnels is still rare. The full-field 3D mathematical model of the heat dissipation structure and the surrounding fluid space is built and tested by a test platform. The verified model is used to simulate the high-level effect of the tunnel LED heat dissipation, and the field synergy principle is used to reveal the essence of the phenomenon to ensure the tunnel function. Under the premise of the requirements of use, improving the utilization of tunnel section and controlling the project cost have important scientific significance and practical engineering application value.
Eco-friendly fabrics are made from fibers that do not require the use of any pesticides or chemicals to grow. They are naturally resistant to mould and mildew and are disease free.
Organic cotton (or natural cotton) is another great eco friendly fabric. It is grown without the use of pesticides, herbicides or other chemical fertilizers, and is simply better for your health and the environment.
We proudly offer recycled fabrics which are made by efficiently breaking post-consumer waste fabrics and converting them into new usable fabrics.
Span Fleece,Bamboo Fleece,Bamboo Span Fleece,Poly Span Double Jersey
Shaoxing Blange Import&Export Co.,Ltd , https://www.blg-yc.com