Outdoor LED lamp design considerations
Because of the complex working environment, the LED outdoor lighting fixture is affected by the temperature, ultraviolet, humidity, rain, dust, chemical gas and other natural conditions in rainy days. For a long time, it will lead to the serious problem of LED light decay. The design of outdoor LED lighting fixture is different from that of indoor lighting fixture, which has higher technical requirements for heat dissipation. Outdoor lighting designers must consider the working environment of outdoor LED lamps.
Outdoor LED lamps should pay attention to the selection of heat dissipation materials: the shell and radiator are designed as a whole to solve the heating problem of LED. In this way, aluminum or aluminum alloy, copper or copper alloy, and other alloys with good heat conduction are generally selected. Heat dissipation includes air convection, strong wind cooling and heat pipe cooling. (air jet cooling is similar to heat pipe cooling, but its structure is more complex.
The radiator of LED lamp is a key component of LED lamp. Its shape, volume and surface area of heat dissipation should be designed to meet the benefits. If the radiator is too small, the working temperature of LED lamp is too high, which affects the luminous efficiency and life. If the radiator is too large, the consumption of materials will increase the product cost and weight, and reduce the competitiveness of the product. It is very important to design a proper radiator for LED lamp.
The radiator is designed as follows:
1. Make sure the power of LED lamps to be cooled.
2. Some parameters for radiator design: specific heat of metal, thermal conductivity of metal, chip thermal resistance, radiator thermal resistance, ambient air thermal resistance, etc.
3. Determine the type of heat dissipation: natural convection heat dissipation, strong wind cooling, heat pipe heat dissipation, and other heat dissipation methods. From the cost comparison: natural convection cooling cost is the lowest, strong wind cooling medium, heat pipe cooling cost is higher, jet cooling cost is the highest.
4. Determine the maximum allowable working temperature of LED lamps.
5. Calculate the volume and area of radiator, and determine the shape of radiator.
6. Combine the radiator and LED lamp into a complete lamp, and work for more than eight hours with power on. Check the temperature of the lamp under the environment of room temperature 39 ℃ - 40 ℃ to see whether it meets the heat dissipation requirements, so as to check whether the calculation is correct. If it does not meet the use conditions, recalculate and adjust the parameters.
7. the seal of radiator and lampshade should be waterproof and dustproof. It is necessary to pad anti-aging rubber pad or silicon rubber pad between lampshade and radiator, and tighten with stainless steel bolts to seal waterproof and dustproof.
Through the above points of attention, and then refer to the latest technical specifications of outdoor lighting issued by our country, as well as the urban road lighting design standards, which is the basic knowledge of outdoor lighting designers.