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The importance of heat sink management system
The thermal-related problem of batteries is a key factor of its usage performance, safety, lifespan and cost. First of all, the temperature level of lithium ion battery directly affects its energy and power performance.
When the temperature is low, the available capacity of the battery will decay rapidly. Charging the battery at a too low temperature (less than 0°C) may cause an instantaneous overcharge of the voltage, which will result in internal lithium discharges and a short circuit.
Methods of heat sink
1. Conduction: the transfer of heat from the hotter part of an object to the cooler part.
2. Convection: the transfer of heat by the flow of a liquid or gas.
3. Radiation: Heat released from an object along a straight line.
Heat sink of vehicle batteries
1. Natural Cooling:
In the natural environment, heat was sent into the air by the way of convection and radiation.For example, the previous generation of smart phones were all released into the air by conduction and radiation. Eg. Bga heat sink.
2. Led Cooling:
Eg. Led sunflower heat sink & LED Active Cooling Solutions
3. Air Cooling:
Air convection by fan, eg. Cpu heat sink
4. Liquid Cooling:
Eg. Cold Plate Simulation & Liquid cooling for IGBT&Automotive engine cooling
5. Heat pipe heat sink:
Eg.Desktop CPU heat pipe heat sink& laptop CPU heat sink.
As we all know, high temperature is the enemy of integrated circuits.The high temperature will not only cause the system to run unstably, the service lifespan to shorten, but also cause some parts to burn out.The heat that causes high temperatures does not come from the outside , but inside.The role of the heat sink is to absorb this heat keeping the temperature of the computer components normal.
The kind of heat sink is various, CPU, video card, power supply and so on, among which Cpu heat sink can be the most frequently touched .Subdivision of heat dissipation, can be divided into air cooling, heat pipe, water cooling and so on.
Cpu heat sink is one of the necessary accessories in the computer, and plays an inportant role in the system , the current mainstream of the CPU heat sink mode is mainly divided into two categories, one is liquid cold plate, another is air-cooling heat sink. Liquid cold plate includes water cooling, oil cooling, etc., mainly water cooling, and air cooling is a common heat sink with a fan embedded in the heat dissipation, which is the most various and the most commonly used. Water cooling using liquid in the pump driven by forced circulation can take away the heat of the heat sink. Compared to air cooling, it has cooling stability, less dependence on the environment and other advantages.
Generally speaking, water cooling has a better ability than air cooling, but the price is more expensive. And the performance of integrated water cooling heat sink is equivalent to the top air cooling.
Fan cooling is the addition of a small fan in the led heatsinks. When the LED is lit up, the small fan in the tail also works with the LED. Through the fan, the heat of the aluminum seat is released into the air in the form of air convection.
LED headlight is sensitive to temperature changes. If the LED is continuously lit at high temperature, it will generate more heat. If there is no heat dissipation, it is easy to reduce the power and its lifespan. To some extent, the lifespan of a headlight is directly based on its heat dissipation.
Fan cooling: fan is the active cooling, when the light is lit, the fan of the headlight starts to operate. In terms of structure, the LED headlights of the fan have a compact structure, which can be installed in many vehicles. There is no need to punch holes, and the original structure will not be damaged. Since LED heat sink is generally longer, many vehicle models need to be punched holes on the back cover.
Heat sink cooling: When heat sink cooling works, it needs to reach a certain temperature relying on the natural convection of the air, through the heat sink to the air. Due to the lack of space, the heat sink can not be opened, after the heat sink is installed. And then the cooling system will be effected.
Which is a better heatsink copper or aluminum? It's a complex question, with many factors. Let's look at some physical properties:
· thermal conductivity (Wm⋅KWm⋅K)
· volumetric heat capacity (Jcm3⋅KJcm3⋅K)
· density (gcm3gcm3)
· anodic index (VV)
· copper: 400
· aluminium: 235
· copper: 3.45
· aluminium: 2.42
· copper: 8.96
· aluminium: 2.7
· copper: -0.35
· aluminium: -0.95
What do these properties mean? For all the comparisons that follow, consider two materials of identical geometry.
Copper's higher thermal conductivity means the temperature across the heatsink will be more uniform. This can be advantageous since the extremities of the heatsink will be warmer (and thus more effectively radiating), and the hot spot attached to the thermal load will be cooler.
Copper's higher volumetric heat capacity means it will take a larger quantity of energy to raise the heat sink's temperature. This means copper is able to "smooth out" the thermal load more effectively. That might mean brief periods of thermal load result in a lower peak temperature.
Copper's higher density makes it heavier, obviously.
The differing anodic index of the materials might make one material more favorable if galvanic corrosion is a concern. Which is more favorable will depend on what other metals are in contact with the heat sink.
Based on these physical properties, copper would seem to have superior thermal performance in every case. But how does this translate to real performance? We must take into account not only the heatsink material, but how this material interacts with the ambient environment. The interface between the heatsink and its surroundings (air, usually) is very significant. Furthermore, the particular geometry of the heatsink is significant as well. We must consider all these things.
A study by Michael Haskell, Comparing the Impact of Different Heat Sink Materials on Cooling Performance performed some empirical and computational tests on aluminium, copper, and graphite foam heatsinks of identical geometry. I can grossly simplify the findings: (and I'll ignore the graphite foam heatsink)
For the particular geometry tested, aluminium and copper had very similar performance, with copper being just a little bit better. To give you an idea, at a 1.5 m/s airflow, copper's thermal resistance from the heater to the air was 1.637 K/W, while aluminium was 1.677. These numbers are so close it would be difficult to justify the additional cost and weight of copper.
As the heatsink becomes large compared to the thing being cooled, copper gains an edge over aluminium due to its higher thermal conductivity. This is because the copper is able to maintain a more uniform heat distribution, drawing the heat out to the extremities more effectively, and more effectively utilizing the entire radiating area. The same study did a computational study for a large CPU cooler and calculated thermal resistances of 0.57 K/W for copper and 0.69 K/W for aluminium.
Extruded aluminum heatsinks are the most common heat sinks used for thermal management today. They are manufactured by pushing hot aluminum billets through a steel mold to produce the final shape. The most common aluminum alloy is 6063-T5, but other 6XXX aluminum alloys can also be examined as needed. When the material is extruded, the initial sticks are 30-40 feet and length and are very soft. The aluminum material is stretched by grabbing both ends to produce a straight stick. After the stretching, the aluminum material can be either air or over aged depending upon the required final hardness of the material. After aging process, the extruded aluminum enclosure is cut to the final length and any final fabrication (holes, pockets, or other secondary machining) can be done. Extruded aluminum heatsink is usually supplied with a “finish”, such as anodizing, which can enhance its thermal performance. The heat sink can also be supplied with a chromate finish, which provides some corrosion protection, or can be used as a primer before a final paint or powder coating is applied. While each extruded shape is unique to the requirements that it was designed for, extruded aluminum heatsinks are the most cost-effective cooling solution. Each shape is engineered to achieve the optimal thermal and structural performance. Lori is the good aluminum heat sink suppliers in china,our lori partners with a large list of vendors which insures that you have the best thermal solution based on your system structure and thermal requirements.