Kev sib piv ntawm cov cua txias thiab cov kua dej txias txias tshuab
With the continuous development of power electronic technology, the volume of converter equipment tends to be compact and the system tends to be complex. High heat density has become an irresistible development trend. In order to meet the demand of high heat density, traditionalthermal solutions such as fans and heatsinks continue to innovate, and novel and efficient heat dissipation methods emerge in tsis kawg. Nyob rau hauv pem hauv ntej ntawm ntau txoj kev tshav kub dissipation, nws tau dhau los ua ib qho kev txhawj xeeb zoo rau cov neeg tsim khoom kom paub qhov txawv ntawm cov cua sov dissipation muaj peev xwm ntawm ntau yam cua sov dissipation txoj kev, thiaj li xaiv txoj kev txuag hluav taws xob thiab txhim khu kev qha tshav kub dissipation.
Thermal conductivity:
For air, the heat transfer coefficient of natural air cooling is very low, with a maximum of 10W / (m2k). If the temperature difference between the radiator surface and the air is 50 degree , the heat taken away by the air per square centimeter of heat dissipation area is up to 0.05W. The heat transfer mode with the strongest heat transfer ability is the heat transfer process with phase change, and the order of heat transfer coefficient of water is 103 104. The reason why the heat transfer capacity of heat pipe is great is that the heat transfer process of evaporation section and condensation section is phase change heat transfer.
Cua txias:
The aircooling mode has low cost and high reliability, but due to its small heat dissipation capacity, it is only applicable to the case of small heat dissipation power and large heat dissipation space. At present, the research hotspot of air-cooled heatsink is to integrate the heat pipe and radiator fin, use the high heat transfer capacity of heat pipe to transfer heat evenly to the fin surface, improve the uniformity of fin surface temperature, and then improve its heat dissipation efficiency. Air forced convection cooling is a common cooling method for power electronic components, and its common structure is the form of radiator and fan. Although the structure has convenient implementation and low cost, its heat dissipation capacity is limited.
Liquid Cooling:
Although the air cooling technology continues to improve, the air cooling itself is limited by the heat dissipation capacity. With the continuous improvement of heat flux, the application of liquid cooling devices with greater heat dissipation capacity will be popular. According to the attached table, the approximate range of gas forced convection heat transfer coefficient is 20 100W / (M2 degree ), and the heat transfer coefficient of water forced convection is as high as 15000w / (M2 degree ), which is more than 100 times that of gas forced convection.
Cov ntsiab lus:
1. When limited by heat dissipation space, the heat dissipation limit of air cooling system is about 5W / cm2. If not limited by the heat dissipation space, increasing the fan air volume and increasing the radiator area will make the heat dissipation capacity of the air cooling system higher.
2. The heat dissipation capacity of the liquid cooling system is one order of magnitude higher than that of the air cooling system, and its heat dissipation potential has not been fully exploited. At present, the forced convection cooling mode of water in the microchannel is the mode with the maximum heat dissipation capacity in the water cooling system, and its heat dissipation capacity can reach 790W / cm2.
3. The evaluation of heat dissipation capacity of radiator is restricted by many factors, including environmental conditions, component size, radiator table temperature and other factors. The specific conditions need to be analyzed.
