How to do a good job of heat dissipation of LED display?

          In order to control the temperature of the electronic components inside the led display screen so that it does not exceed the specified maximum allowable temperature under the working environment conditions where the led display screen is located, the heat dissipation design of the led display screen is required. The heat dissipation design of led display, how can low cost, high quality, is the content of this article.

          There are three basic ways of heat transfer: heat conduction, convection and radiation.  

          Heat conduction: The heat conduction of gas is the result of collision of gas molecules when they move irregularly. The heat conduction in metal conductors is mainly accomplished by the movement of free electrons. Heat conduction in non-conductive solids is achieved by the vibration of the lattice structure. The heat conduction mechanism in the liquid mainly relies on the action of elastic waves.

          Convection: refers to the process of heat transfer caused by relative displacement between various parts of the fluid. Convection only occurs in the fluid, and it must be accompanied by the phenomenon of heat conduction. The heat exchange process that occurs when the fluid flows over the surface of an object is called convective heat transfer. The convection caused by the different densities of the hot and cold parts of the fluid is called natural convection. If the movement of the fluid is caused by external forces (fans, etc.), it is called forced convection.

          Radiation: The process by which an object transfers its ability in the form of electromagnetic waves is called thermal radiation. Radiant energy transfers energy in a vacuum, and there is a conversion of energy form, that is, thermal energy is converted into radiant energy and radiant energy is converted into thermal energy.         

         When choosing a heat dissipation method, the following factors should be considered: heat flux density, volume power density, total power consumption, surface area, volume, working environment conditions (temperature, humidity, air pressure, dust, etc.) of the led display.         

         According to the heat transfer mechanism, there are natural cooling, forced air cooling, direct liquid cooling; evaporative cooling; thermoelectric cooling; heat pipe heat transfer and other heat dissipation methods.

         The heat dissipation design method of LED screen         

         The heat exchange area between the heating electronic parts and the cold air, and the temperature difference between the heating electronic parts and the cold air, directly affect the heat dissipation effect. This involves the design of the air volume entering the LED display box and the design of the air duct. 

         When designing ventilation ducts, try to use straight ducts to transport air and avoid sharp bends and bends. Ventilation ducts should avoid sudden expansion or sudden contraction. The expanded angle should not exceed 20°, and the contracted cone angle should not exceed 60°. The ventilation ducts should be sealed as far as possible, and all overlaps should follow the direction of flow.         

         When designing the led display cabinet, there are several points to note:         

         The exhaust hole should be located near the upper side of the box. The air inlet should be set on the lower side of the box, but not too low to prevent dirt and water from entering the box installed on the ground.           The design should make natural convection help forced convection. The air should circulate from the bottom to the top of the box, and special air intake or exhaust holes should be used. 

         The cooling air should be allowed to flow through the heat-generating electronic parts, and the air current should be prevented from short-circuiting. Filters should be installed at the air inlet and outlet to prevent debris from entering the box. 

         When designing, make sure that the inlet and outlet are kept away from each other. Avoid repeated use of cooling air. To ensure that the direction of the radiator cogging is parallel to the wind direction, the radiator cogging cannot block the wind path.         

          The fan is installed in the system. Due to structural limitations, the air inlet and outlet are often blocked by various obstacles, and its performance curve will change. According to actual experience, the air inlet and outlet of the fan should be 40mm away from the obstruction. 

          If there is space limitation, it should be at least 20mm.  Some methods to improve the heat dissipation of LED display  

          1. Fan heat dissipation, use a long-life and high-efficiency fan inside the lamp housing to enhance heat dissipation. This is a common method with low cost and good effect.  

          2. Use aluminum fins, which is the most common way to dissipate heat. Use aluminum fins as part of the housing to increase the heat dissipation area.  

          3. Integration of heat conduction and heat dissipation-the use of high thermal conductivity ceramics, the purpose of lamp housing heat dissipation is to reduce the working temperature of the LED high-definition display chip, because the expansion coefficient of the LED chip is very different from the expansion coefficient of our usual metal heat conduction and heat dissipation materials. The LED chip cannot be directly soldered to avoid high and low temperature thermal stress from damaging the LED display chip.  

          4. Heat pipe heat dissipation, using heat pipe technology to conduct heat from the LED display chip to the heat dissipation fins of the shell.  

          5. Air fluid mechanics uses the shape of the lamp housing to create convective air, which is a cost-effective method of enhancing heat dissipation. 

          6. Surface radiation heat dissipation treatment, the surface of the lamp housing is treated with radiation heat dissipation. The simpler is to apply radiation heat dissipation paint, which can take the heat away from the surface of the lamp housing by radiation.  

          7. The thermally conductive plastic shell is filled with thermally conductive material when the plastic shell is injection molded, so as to increase the thermal conductivity and heat dissipation capacity of the plastic shell.         

         There are many ways to dissipate the heat of the LED display. When dissipating the equipment, you must choose a more suitable method according to the actual situation, so as to have a better effect and extend the service life of the equipment.