A Study on the Principle of Heat Pipe Using Water's Specific Heat 1. the purpose of inquiry Recently, as electronic devices are in a trade-off relationship between performance and device size, how to effectively remove the amount of heat generated has been raised as an important issue. This is a problem that arises not only in electronic devices and semiconductors, but also in the field of medicine that I want to study, so it is a task that an engineering student should continue to research. While exploring with curiosity, "Wouldn't it be used for heating electronic devices after learning about the specific heat of water in class and helping maintain body temperature with high specific heat?" I learned that the heat pipe used in smartphones uses the specific heat of water. 2. the contents of one's inquiry (1) Principles of Smartphone Heat Pipe A heat pipe is a copper pipe with water flowing through it. It is vertically elongated and is located near the AP. This unfamiliar copper pipe is a key device that keeps smartphones from getting too much heat. Copper has the property of increasing the temperature faster and more easily than water. The amount of heat required to raise a 1 g material by 1 degree is called 'specific heat', and water is 1 ㎈, while copper is only 0.09 ㎈. AP가 슬슬 뜨거워지기 시작하면 구리관이 달아오르면서 재빨리 물에게 온도를 전달한다. 구리로부터 열 을 전달받는 물은 뜨거워지다 결국 기화하게 된다. 기화된 수증기는 낮은 온도로 이동하는 특성이 있기 As a result, they travel in copper pipes in search of less hot places. The water vapor releases heat and is liquefied again when it reaches a low-temperature environment, and the water returns to a place with a high temperature. This process automatically repeats to prevent heat generation. Water must flow into your cell phone, and if there is a traffic jam, the cell phone receives heat and becomes hot. (2) the limit The heat dissipation/cooling system of the heat pipe temporarily lowers the heat around the AP because the vaporization of water is an endothermic reaction, but since vaporization and liquefaction (heating reaction) occur simultaneously inside the sealed heat pipe, heat is only dispersed by the first law of thermodynamics and cannot be lowered. Accordingly, it is difficult to control heat above a certain level, and the heat sink area must be secured. Recently, the trend of electronic products is becoming slimmer and smaller again in a trade-off situation, and new cooling devices and heat dissipation devices for electronic devices are required. (3) a new plan Thermoelectric cooling refers to a cooling method using the principle of absorbing heat when a current flows through two different metal joints. It can be used for heat generation or cooling, and the main use is cooling. Thermoelectric cooling is a semiconductor that makes electricity and heat at the same time, and its characteristic is that when electricity is supplied, the cooling/heating function can be used. The cooling/heating function is a principle that when electricity is supplied, electrons move to generate heat, and a temperature difference occurs at both ends. When a temperature difference occurs on both sides, one side generates heat and the other side cools. In order to apply the thermoelectric cooling method, which is a likely alternative to heat dissipation in future communication devices such as smartphones and tablet PCs, it is necessary to solve the current problem consumed during thermoelectric cooling. In the related paper, if the thermoelectric generation stage and the thermoelectric cooling stage are arranged in a checkerboard form, thermoelectric generation is performed using heat generated at one end, and thermoelectric cooling is performed at the other stage by receiving the generated current, it was found and applied that cooling is performed up to the temperature formed by thermal equilibrium without current supply from an external battery. The following effects are expected through this. First, it is configured in a form in which a thermoelectric generation stage and a thermoelectric cooling stage are placed on a part that generates heat and a thermoelectric cooling stage are first converted into electricity through thermoelectric generation, thereby cooling. Second, there is a secondary cooling effect in which heat is released additionally by supplying the generated electricity to the thermoelectric cooling stage and performing thermoelectric cooling. Third, it can be used in parallel with a thermal conduction tape or a thermal diffusion tape to further increase the heat dissipation efficiency. Fourth, if the thermoelectric cooling stage exists at the same time as the thermoelectric generation stage, it can actively perform strong cooling by supplying external current if cooling is insufficient with only the thermoelectric generation amount, solving the existing problem that heat dissipation was not sufficient only by means of heat conduction, thermal diffusion tape, and heat sink in smartphones and tablet PCs with high performance trends. Currently, thermoelectric cooling is only used as a smartphone external device, cooler, etc., but it is expected that it can be used as a new cooling device inside the smartphone by continuing to study it.
