Along with the coming of summer, the inevitable is hot, everyone also led display also more easy to heat, high temperature can lead to electronic components failure probability increase rapidly, thus resulting in a decline in the reliability of the led display. In order to control the temperature of the led display the internal electronic components, in the led display working environment conditions, the allowable temperature shall not exceed the stipulated, the need for thermal design of led display. The thermal design of led display, how to be low cost, high quality, is the content of this article.
There are three basic types of heat transfer: heat conduction, convection and radiation.
Heat conduction: the gas conductivity is the result of the collision of the gas molecules. The heat conduction in a metal conductor is achieved by the movement of free electrons. Heat conduction in non-conductive solids is achieved through vibration of lattice structures. The heat conduction mechanism in the liquid is mainly dependent on the function of elastic waves.
Convection: the heat transfer process caused by the relative displacement of the parts of a fluid. Convection occurs only in the fluid and must be accompanied by a thermal conduction phenomenon. The heat transfer process that occurs when a fluid flows through the surface of an object is called convection heat transfer. The convection of natural convection is caused by different density of different parts of the hot and cold water. If the movement of fluid is caused by external forces (fans, etc.), it is called forced convection.
Radiation: the process by which an object transmits power in electromagnetic waves is called heat radiation. The radiation can transmit energy in a vacuum, and the conversion of energy form, that is, heat energy into radiant energy and radiation can be converted into heat.
Choosing the cooling way, should consider the following factors: the heat flux led display, power density, total power consumption volume, surface area, volume, work environment conditions (temperature, humidity, air pressure, dust, etc.), etc.
By heat transfer mechanism, natural cooling, forced air cooling, direct liquid cooling; Evaporative cooling; Thermoelectric refrigeration; Heat tube heat transfer, etc.
There are a few things to note when the led display box is designed:
The vent should be placed on the upper side of the box. The inlet hole should be placed on the lower side of the box, but not too low to prevent the dirt and water from entering the box in the ground.
Design should allow natural convection to help force convection. Air should be circulated from the bottom of the box and should be used for special vent or vent. Cooling air should be allowed to flow through the hot electronic parts and prevent short circuit. Filter the inlet and outlet to prevent the clutter from entering the box.
When designing, ensure the inlet and outlet are far away from the vent. Avoid reusing the cooling air.
To ensure the direction of the sink is parallel to the direction of the wind, the sink can't stop the wind path.
Fans are installed in the system, and because of structural constraints, the inlet and outlet are often blocked, and their performance curves change. According to the practical experience, the fans will have the best of 40mm in the inlet outlet, and at least 20mm if there is a space limit.