KR20050017738A - Two-phase vertical bar Thermosyphon using Nano Fluid as working fluid - Google Patents

Two-phase vertical bar Thermosyphon using Nano Fluid as working fluid

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Publication number
KR20050017738A
KR20050017738A KR1020030054899A KR20030054899A KR20050017738A KR 20050017738 A KR20050017738 A KR 20050017738A KR 1020030054899 A KR1020030054899 A KR 1020030054899A KR 20030054899 A KR20030054899 A KR 20030054899A KR 20050017738 A KR20050017738 A KR 20050017738A
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KR
South Korea
Prior art keywords
heat
fluid
vertical rod
nanofluid
working fluid
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KR1020030054899A
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Korean (ko)
Inventor
이세용
이충구
이세균
이계복
이석호
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이세용
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Priority to KR1020030054899A priority Critical patent/KR20050017738A/en
Publication of KR20050017738A publication Critical patent/KR20050017738A/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
    • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
    • F28D15/0266—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D20/00—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00
    • F28D20/0034—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00 using liquid heat storage material
    • F28D2020/0047—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00 using liquid heat storage material using molten salts or liquid metals

Abstract

PURPOSE: A two-phase flow vertical rod thermosiphon using nanofluid is provided to radiate or exchange heat of electronic appliances such as semiconductors or computers by injecting actuating fluid including metal nanoparticles to the enclosed pipe with the vacuum-sealed vertical rod structure. CONSTITUTION: Actuating fluid is charged in a thermal conductive metal pipe(3) with the vacuum-sealed vertical rod structure, and heat from a heat exchange material is transferred by convection and gravity of the actuating fluid. A two-phase vertical rod thermosiphon is composed of an evaporating unit(10) absorbing heat from the heat exchange material and transferring heat from the heat exchange material to the actuating fluid in the enclosed pipe, an insulation unit(20) transmitting gas generated in evaporating to the upper part of the enclosed pipe, and a condensing unit(30) radiating heat from the actuating fluid to the upper part of the enclosed pipe by condensing and liquefying gas and circulating the liquefied actuating fluid to the evaporating unit along the inner wall of the enclosed pipe by gravity and pressure difference of the actuating fluid. The actuating fluid is formed of nanofluid(1) including metal nanoparticles to increase the heat capacity of fluid and the heat transfer area.

Description

나노유체를 이용한 2상 유동 수직막대형 서모사이펀{Two-phase vertical bar Thermosyphon using Nano Fluid as working fluid}Two-phase vertical bar thermosyphon using nano fluid as working fluid

본 발명은 나노유체(Nano Fluid)를 이용한 2상 유동 수직막대형 서모사이펀에 관한 것으로, 특히 종래의 서모사이펀의 원리에 그 작동유체로서 나노금속입자가 함유된 나노유체를 주입하여서 된 수직막대형 관의 구조를 이룸으로써 열전달 성능을 현저히 향상시킬 수 있고, 이러한 나노유체에 의한 서모사이펀을 전자제품 등의 냉각 또는 열교환장치로서 적용할 수 있게 한 나노유체를 이용한 2상 유동 수직막대형 서모사이펀에 관한 것이다.The present invention relates to a two-phase flow vertical rod thermosiphon using nano fluid, and in particular, a vertical rod type obtained by injecting a nanofluid containing nano metal particles as a working fluid to the principle of a conventional thermosiphon. The heat transfer performance can be remarkably improved by forming the tube structure, and this nanofluidic thermosiphon can be applied to a two-phase flow vertical rod type thermosiphon using nanofluids that can be applied as a cooling or heat exchanger for electronic products. It is about.

일반적으로, 서모사이펀(Thermosyphon)은 자기증발, 온도차 등의 열적(熱的) 불균형으로 인하여 형성되는 유체의 밀도차이에 의해 유체 유동이 이루어지는 열전달 원리(사이펀 작용)나 그 장치를 의미한다. 본 발명에서는 2상 유동 수직막대형 서모사이펀에 한하여 그 개량된 구조를 제안하고자 한다.In general, thermosyphon (Thermosyphon) refers to a heat transfer principle (siphon action) or a device in which fluid flow is caused by a density difference of a fluid formed due to thermal imbalance such as evaporation and temperature difference. The present invention proposes an improved structure only for a two-phase flow vertical rod thermosiphon.

상기의 2상 유동 수직막대형 서모사이펀은 펌프 등의 기계요소에 의한 별도의 동력공급이 없이도 자연대류에 의해 작동되는 것이며, 현재 이것은 열교환기, 전자제품의 냉각장치(온도상승으로 인해 제품성능이 저하되는 히트페이드(Heat Fade) 현상을 저감시켜주기 위한 냉각용 방열기(Heat Sink)) 또는 의료장비 등에 다양하게 적용되어 있고, 그 응용범위가 계속 확산되는 추세에 있다.The two-phase flow vertical rod thermosiphon is operated by natural convection without a separate power supply by a mechanical element such as a pump. Currently, this is a heat exchanger, a cooling device for electronic products (product performance is increased due to temperature rise. Various applications have been applied to cooling heat sinks or medical equipment for reducing the heat fade, which is deteriorated, and its application range is continuously spreading.

상기 2상 유동 수직막대형 서모사이펀은, 윅(Wick)을 갖는 히트파이프와는 달리, 수직막대 구조의 밀폐관체에 작동유체가 충만된 단순구조를 이루는 것으로서, 그 구성은 상하로 배치된 응축부와, 증발부 및 이들을 연결하는 단열부로 이루어져 있다. 이러한 구조의 2상 유동 수직막대형 서모사이펀에 있어서, 상기 증발부와 응축부 간의 원활한 유체 순환이 이루어지기 위해서는 이들간에 중력이 작용하여야 하므로 상기 응축부가 증발부에 대해서 일정거리 이상을 두고 그 상부에 위치하도록 배치한 형태가 일반적이다.The two-phase flow vertical rod thermosiphon, unlike a heat pipe having a wick (Wick), forms a simple structure filled with a working fluid in a closed tube of the vertical rod structure, the configuration is a condensation part arranged up and down And an evaporation section and a heat insulating section connecting them. In the two-phase flow vertical rod thermosiphon having such a structure, gravity must act between the evaporator and the condenser to achieve smooth fluid circulation. It is generally arranged to be located.

그러나, 이러한 종래의 수직막대형 서모사이펀은 그 작동유체로서 물(증류수) 등을 사용하므로 이를 전자제품의 냉각장치 등으로 적용하는 경우에 기대할만한 열전달 성능(열전도율)을 발휘할 수 없는 문제점이 있었다.However, since the conventional vertical rod-type thermosiphon uses water (distilled water) as its working fluid, there is a problem in that it cannot exhibit the heat transfer performance (heat conductivity) that is expected when it is applied as a cooling device for electronic products.

또한, 현재의 기술 수준에서 상기 수직막대형 서모사이펀의 열전달 성능을 향상시키기 위해서는, 다양한 작동유체를 사용하거나, 증발부와 응축부의 열전달 면적을 크게 증대시키는 구조상의 최적화 설계가 이루어져야 하므로 이에 따른 제작상의 어려움이 있었다.In addition, in order to improve the heat transfer performance of the vertical rod thermosiphon at the current state of the art, it is necessary to use a variety of working fluids, or structural optimization design to greatly increase the heat transfer area of the evaporator and condensation part must be made accordingly There was a difficulty.

본 발명은 상기한 바와 같은 제반 문제점을 해결하기 위하여 안출된 것으로, 그 목적은, 2상 유동 수직막대형 관내에 열전도성이 높은 극 초 미세 크기의 금속재 나노입자를 함유한 나노유체가 작동유체로서 주입된 구조를 이룸으로써 관 구조 등의 최적화 설계를 고려하지 않고도 열전달 성능을 현저히 향상시킬 수 있고, 이를 전자제품 등의 냉각 또는 열교환장치로 다양하게 적용할 수 있도록 된 나노유체를 이용한 2상 유동 수직막대형 서모사이펀을 제공함에 있다.SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The object of the present invention is to provide a working fluid in which a nanofluid containing ultra-fine metal nanoparticles having high thermal conductivity in a two-phase flow vertical bar tube is used as a working fluid. By injecting the structure, the heat transfer performance can be significantly improved without considering the optimized design of the tube structure, etc., and the two-phase flow vertical using the nanofluid can be applied to various cooling or heat exchanger devices such as electronic products. It is to provide a rod thermosiphon.

상기의 목적을 달성하기 위한 본 발명에 따른 나노유체를 이용한 2상 유동 수직막대형 서모사이펀은, 진공상태로 밀봉된 수직막대형의 구조를 형성하는 열전도성이 우수한 금속재 밀폐관내에 소정의 작동유체가 충전되어 상기 작동유체의 열대류 및 중력 작용에 의해 임의의 열교환 대상물로부터 발생된 열을 외부로 전열시켜주는 상하 열전달 구조를 형성하되, 상기 밀폐관상의 하측 외부에 배치되는 열교환 대상물로부터 흡열 반응하는 접촉부위로서 상기 열교환 대상물로부터 밀폐관내의 작동유체로 전열시켜주는 증발부와, 상기 증발부로부터의 증발 과정에 의해 생성된 기체를 밀폐관내 상부로 전달하기 위한 경로를 형성하는 단열부와, 상기 밀폐관상의 상측 외부로 발열 반응하는 접촉부위로서 상기 단열부를 통해 상부로 전달된 기체를 응축 과정에 의해 액화하여 밀폐관내의 작동유체로부터 밀폐관 외부로 전열시킴과 아울러 액화된 작동유체가 중력 및 압력차에 의해 상기 밀폐관의 내벽을 타고 상기 증발부로 순환되도록 하는 응축부를 구성하는 2상 유동 수직막대형 서모사이펀에 있어서, 상기 작동유체로서, 열전달 면적과 유체의 열용량을 증가시킬 수 있도록 나노단위 크기의 극히 미세한 금속재 입자를 소정량 함유한 소정의 충전유체로 이루어진 나노유체가 적용된 것을 특징으로 한다.The two-phase flow vertical rod thermosiphon using the nanofluid according to the present invention for achieving the above object is a predetermined working fluid in a closed metal tube with excellent thermal conductivity forming a vertical rod-type structure sealed in a vacuum state. Is filled to form an up-and-down heat transfer structure that heats heat generated from any heat exchange object to the outside by the tropical flow and gravity action of the working fluid to the outside, endothermic reaction from the heat exchange object disposed on the bottom outside of the closed tube An evaporation unit for transferring heat from the heat exchange object to a working fluid in the hermetic pipe as a contact portion, a heat insulating part forming a path for transferring a gas generated by the evaporation process from the evaporation part to the upper part of the hermetic pipe, Condensation of the gas delivered to the upper part through the heat insulating part as a contact part exothermic reaction to the outside of the tubular upper part A two-phase flow constituting a condensation unit that liquefies by jeong and transfers heat from the working fluid in the closed tube to the outside of the closed tube and circulates the liquefied working fluid through the inner wall of the closed tube by gravity and pressure difference to the evaporator. In the vertical rod type thermosiphon, as the working fluid, a nanofluid consisting of a predetermined filling fluid containing a predetermined amount of extremely fine metal particles having a nano unit size is applied to increase the heat transfer area and the heat capacity of the fluid. do.

여기서, 상기 나노입자는 열전도성이 우수한 금, 은, 구리 중 선택된 어느 하나의 금속으로 이루어진 것이 바람직하다.Here, the nanoparticles are preferably made of any one metal selected from gold, silver, and copper having excellent thermal conductivity.

또한, 상기 나노입자의 크기는 100nm 이하인 것이 바람직하다.In addition, the size of the nanoparticles is preferably 100nm or less.

이하, 본 발명의 바람직한 실시예에 따른 나노유체를 이용한 2상 유동 수직막대형 서모사이펀을 첨부 도면에 의거하여 상세히 설명하면 다음과 같다.Hereinafter, a two-phase flow vertical rod type thermosiphon using nanofluid according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

도 1은 본 발명에 따른 나노유체를 이용한 2상 유동 수직막대형 서모사이펀을 개념적으로 나타낸 것이다.1 conceptually illustrates a two-phase flow vertical rod thermosiphon using nanofluid according to the present invention.

본 발명에 따른 나노유체를 이용한 2상 유동 수직막대형 서모사이펀은, 상기 도면에 도시된 바와 같이, 열전도성이 좋은 금속재의 밀폐관(3)의 내부에 열전달 매체로서의 나노유체(1)를 충전하여 진공상태로 밀봉 처리한 구조를 이룬다. 상기 밀폐관(3)의 형상은 수직막대형의 구조로 되어 있다.In the two-phase flow vertical rod thermosiphon using the nanofluid according to the present invention, as shown in the drawing, the nanofluid 1 as a heat transfer medium is filled inside the closed tube 3 made of metal having good thermal conductivity. To form a sealed structure in a vacuum state. The closed tube 3 has a vertical rod-like structure.

상기 밀폐관(3)은 열전달 반응의 과정에 따라 증발부(10)와, 응축부(30)와, 상기 증발부(10)와 응축부(30)를 연결하는 단열부(20)로 구분된다.The closed tube 3 is divided into an evaporator 10, a condenser 30, and a heat insulating part 20 connecting the evaporator 10 and the condenser 30 according to a heat transfer reaction. .

상기 증발부(10)는, 상기 밀폐관(3)상의 하측 외부에 배치되는 열교환 대상물(4)로부터 흡열 반응하는 접촉부위로서, 상기 열교환 대상물(4)로부터 밀폐관(3)내의 나노유체(1)로 전열시켜주는 부분에 해당한다.The evaporation unit 10 is a contact portion for endothermic reaction from the heat exchange object 4 disposed on the bottom outside of the sealed tube 3, and the nanofluid 1 in the sealed tube 3 from the heat exchange object 4. Corresponds to the part that heats up with).

상기 단열부(20)는, 상기 증발부(10)와 응축부(30)를 연통시켜 상기 증발부(10)로부터의 증발 과정에 의해 생성된 기체를 밀폐관(3)내 상부의 응축부(30)로 전달하기 위하여 나노유체(1)가 열대류(Heat Convection)될 수 있는 경로를 형성하는 부분에 해당한다. 이때, 상기 증발부(10)로부터 응축부(30)로 열대류되는 과정에서는 상기 나노유체(1)가 기체(증기)(2)로 상변화된다.The heat insulating part 20 communicates the evaporator 10 and the condenser 30 so that the gas generated by the evaporation process from the evaporator 10 is condensed in the upper portion of the closed tube 3 ( 30) corresponds to the part forming the path through which the nanofluid 1 can be heat convection. At this time, in the process of tropical flow from the evaporator 10 to the condensation unit 30, the nanofluid 1 is phase-changed into a gas (vapor) (2).

상기 응축부(30)는, 상기 밀폐관(3)상의 상측 외부로 발열 반응하는 접촉부위로서, 상기 단열부(20)를 통해 상부로 전달된 기체를 응축 과정에 의해 액화하여 밀폐관(3)내의 나노유체(1)로부터 밀폐관(3) 외부로 전열시킴과 아울러 액화된 나노유체(1)가 중력(G) 및 압력차에 의해 상기 밀폐관(3)의 내벽을 타고 상기 증발부(10)쪽으로 흘러내려 순환하며 열전달 작용을 연속적으로 수행하게 된다. 상기 응축부(30)에 의한 응축 과정에서는 액체로 상변화되므로 상기 증발부(10)에서의 기화 과정과 함께 그 나노유체(1)가 2상의 상태를 유지하며 순환되는 것이다.The condensation unit 30 is a contact portion that exothermicly reacts to the outside of the upper side of the sealing tube 3, and liquefies the gas delivered to the upper portion through the heat insulating part 20 by the condensation process. In addition to the heat transfer from the nanofluid (1) to the outside of the closed tube (3), the liquefied nanofluid (1) rides on the inner wall of the closed tube (3) by gravity (G) and the pressure difference, the evaporator (10) It flows down to) and circulates and performs heat transfer continuously. In the condensation process by the condensation unit 30, the phase change to liquid is performed, and the nanofluid 1 is circulated while maintaining the state of the two phases together with the evaporation process in the evaporation unit 10.

한편, 상기 나노유체(1)는, 열전달 면적과 유체의 열용량을 증가시킬 수 있도록 미량의 금속재 나노입자(1b)를 함유한 증류수, 즉, 충전유체(1a)로 이루어진다. 그러나, 상기의 충전유체(1a)로서 반드시 증류수를 사용하여야 하는 것은 아니며, 열전달 성능을 활성화할 수 있는 액체이면 어느 것이든 적용할 수 있음을 밝혀둔다.On the other hand, the nanofluid (1) is made of distilled water, that is, the filling fluid (1a) containing a small amount of metal nanoparticles (1b) to increase the heat transfer area and the heat capacity of the fluid. However, it is not necessary to use distilled water as the filling fluid (1a), it is clear that any liquid can be applied as long as it can activate the heat transfer performance.

그리고, 상기의 나노입자(1b)란, 크기에 따라 물리 화학적 성질이 변화되는 입자를 말한다. 그 일례로서, 금 입자의 경우 크기가 μm order인 경우에는 융점이 1,063℃이지만 입자의 크기가 5nm(5×10-9m)인 경우에는 융점이 300℃로 감소되어 나타난다. 이는 입자의 표면 대 질량의 비율이 증가됨에 따라 단위질량당 표면적 및 그 입자의 표면에너지도 증가하면서 물리 화학적 성질이 변화되기 때문이다. 즉, 입자의 크기가 작아지면 작아질수록 동일체적 기준으로 표면적이 대폭 증가하여 기존의 재료가 갖는 성질과는 전혀 다른 특성들이 나타난다.In addition, said nanoparticle 1b means the particle whose physicochemical property changes with size. For example, in the case of gold particles, the melting point is 1,063 ° C. when the size is μm, but the melting point is reduced to 300 ° C. when the particle size is 5 nm (5 × 10 −9 m). This is because as the ratio of the surface to mass of the particles increases, the surface chemical per unit mass and the surface energy of the particles also increase, changing the physicochemical properties. In other words, the smaller the particle size, the larger the surface area on the same volume basis, resulting in completely different properties from those of the conventional materials.

본 발명에서는, 특히 여러 가지 금속중 전도성이 좋은 것으로서 그 입자크기가 1∼100nm 정도를 유지하는 금(Au), 은(Ag) 또는 구리(Cu) 등의 금속재 나노입자(1b)를 적용하였다.In the present invention, metal nanoparticles (1b) such as gold (Au), silver (Ag), copper (Cu), and the like, which have particularly good conductivity among various metals and have a particle size of about 1 to 100 nm, are applied.

이러한 상기의 나노입자(1b)를 이용하여 본 발명의 나노유체(1)를 생성한다. 즉, 본 발명의 수직막대형 서모사이펀에 주입되는 작동유체로서의 상기 나노유체(1)는, 전통적 열전달 유체인 물(증류수)에 상기 나노입자(1b)를 미량 혼합하여 제조한다.The nanofluid 1 of the present invention is produced using the nanoparticles 1b. That is, the nanofluid 1 as a working fluid injected into the vertical rod thermosiphon of the present invention is prepared by mixing a small amount of the nanoparticle 1b with water (distilled water) which is a conventional heat transfer fluid.

상기 나노유체(1)는, 이에 혼합된 나노입자(1b)에 의해 열전달 면적과 유체의 열용량(Heat Capacity)를 증가시켜 유체의 유효전도성을 향상시키게 되고, 상기 나노입자(1b)와 충전유체(1a)간 유동면적에서의 상호작용 및 융합을 강화시킬 뿐만 아니라, 상기 충전유체(1a)의 혼합 및 난류 유동성을 강화시키며, 상기 나노입자(1b)의 확산에 의해 상기 충전유체(1a)의 역 온도구배를 감소시킬 수 있게 되는 등의 특성을 갖는다.The nanofluid (1), by increasing the heat transfer area and the heat capacity (Heat Capacity) of the fluid by the nanoparticles (1b) mixed therein to improve the effective conductivity of the fluid, the nanoparticles (1b) and the filling fluid ( Not only enhances the interaction and fusion in the flow area between 1a), but also enhances mixing and turbulent flowability of the filling fluid 1a, and inverses of the filling fluid 1a by diffusion of the nanoparticles 1b. It is possible to reduce the temperature gradient and the like.

이와 같은 나노유체(1)의 특성들은 본 발명과 종래의 수직막대형 서모사이펀에 대한 성능비교 실험결과를 통해 명확히 입증된다. 즉, 상기 성능비교 실험결과에 의하면, 상기 나노유체(1)의 열전도율은 기존 작동유체의 경우에 비해 약 3배정도 크게 나타나 열전달 성능을 현저히 향상시킨다는 것을 알 수 있었다.These characteristics of the nanofluid (1) is clearly demonstrated through the performance comparison experiment results for the present invention and the conventional vertical rod thermosiphon. That is, according to the performance comparison test results, it was found that the thermal conductivity of the nanofluid 1 was about three times larger than that of the conventional working fluid, thereby significantly improving the heat transfer performance.

참고적으로, 관내를 흐르는 유체에 대한 열전도율과 열전달계수 간의 상관관계를 일반적 이론식에 의거하여 설명하면 다음과 같다.For reference, the correlation between the heat conductivity and the heat transfer coefficient for the fluid flowing in the pipe will be described based on the general theory.

관내의 난류 열전달계수(h)는,Turbulent heat transfer coefficient (h) in the pipe,

----------------------- [1] ----------------------- [One]

로 표시된다. 여기서, V는 유속, k는 유체의 열전도율을 나타낸다.Is displayed. Where V is the flow rate and k is the thermal conductivity of the fluid.

상기의 식[1]에 의하면, 열전달계수(h)는 유속(V)이나 유체의 열전도율(k)에 따라 변화할 수 있는 것임을 알 수 있다. 특히, 유속(V)을 일정하게 유지하여 동일하다고 가정하면, 열전도율(k)의 변화에 따라 열전달계수(h)가 비례적으로 변화하게 된다는 것을 알 수 있다. 나노유체(1)를 작동유체로 사용하는 본 발명의 경우에 있어서는, 열전도율이 10배 증가하면 (대류)열전달계수는 처음보다 약 4.6배 증가하는 것으로 알려져 있다.According to the above formula [1], it can be seen that the heat transfer coefficient h can be changed depending on the flow rate V and the thermal conductivity k of the fluid. In particular, it can be seen that the heat transfer coefficient h is proportionally changed in accordance with the change in the thermal conductivity k, assuming that the flow rate V is kept constant. In the case of the present invention using the nanofluid 1 as the working fluid, it is known that the (convective) heat transfer coefficient increases by about 4.6 times when the thermal conductivity is increased by 10 times.

이에 비하여, 기존의 일반 작동유체를 사용한 서모사이펀에 있어서의 밀폐관(3)내 속도효과는, 밀폐관(3)내의 난류압력강하 관계식에 훼닝(Fanning)의 마찰인자를 도입하였을 때 다음과 같은 펌프동력(Pumping Power)에 의한 식으로 표시할 수 있다.On the other hand, the velocity effect in the closed tube 3 in the thermosiphon using a conventional general working fluid is obtained by introducing a fanning friction factor into the turbulent pressure drop relation in the closed tube 3 as follows. It can be expressed by the expression of pumping power.

----------------------- [2] ----------------------- [2]

여기서, ho는 초기 열전달계수, Po는 초기 펌프동력, P는 변화된 펌프동력을 각각 나타낸다. 상기의 식[2]에 의하면, 일반 작동유체를 사용한 서모사이펀에 있어서는 펌프동력(P)을 10배 증가시켰을 때 그 열전달계수(h)가 1.9배 증가하게 되는 것을 알 수 있다.Where h o is the initial heat transfer coefficient, P o is the initial pump power, and P is the changed pump power. According to Equation [2], in the thermosiphon using a general working fluid, the heat transfer coefficient h is increased by 1.9 times when the pump power P is increased by 10 times.

즉, 상기의 식[1] 및 식[2]에 의한 산출결과에 의하면, 종래의 서모사이펀에서는 열전달 능력을 2배 증가시키려면 펌프동력(P)을 10배 증가시켜야 하지만, 나노유체(1)를 사용한 본 발명의 수직막대형 서모사이펀에서는 열전도율(k)을 대략 3배 정도 증가시키는 것만으로도 동일한 효과를 발휘할 수 있게 되는 것이다.That is, according to the calculation results according to the above formulas [1] and [2], in order to increase the heat transfer capacity by 2 times in the conventional thermosiphon, the pump power (P) must be increased 10 times, but the nanofluid (1) In the vertical rod-type thermosiphon of the present invention, the same effect can be obtained by merely increasing the thermal conductivity k by about three times.

따라서, 본 발명에서와 같이 나노유체를 이용한 2상 유동 수직막대형 서모사이펀은, 종래의 장치에 비해 그 열전달 성능을 향상시키는데 크게 기여할 수 있다.Therefore, the two-phase flow vertical rod thermosiphon using nanofluid as in the present invention can greatly contribute to improving its heat transfer performance compared to the conventional apparatus.

이상에서 살펴본 바와 같이 본 발명의 나노유체를 이용한 2상 유동 수직막대형 서모사이펀은, 2상 유동 수직막대형 관내에 열전도성이 높은 극 초 미세 크기의 금속재 나노입자를 함유한 나노유체가 작동유체로서 주입된 구조를 이룸으로써 관 구조 등의 최적화 설계를 고려하지 않고도 상기 나노유체에 의한 열대류 작용에 의해 장치의 열전달 성능을 현저히 향상시킬 수 있고, 이를 반도체나 컴퓨터 장치와 같은 각종 전자제품 등의 냉각 또는 열교환장치로 적용할 경우 장치의 성능 향상을 도모할 수 있으므로 매우 유용한 가치가 있다.As described above, in the two-phase flow vertical rod thermosiphon using the nanofluid of the present invention, the nanofluid containing the ultra-fine metal nanoparticles having high thermal conductivity in the two-phase flow vertical rod tube is a working fluid. By forming the injected structure, the heat transfer performance of the device can be remarkably improved by the tropical flow action of the nanofluid without considering the optimized design of the tube structure and the like. When applied as a cooling or heat exchanger, the performance of the device can be improved, which is very useful.

본 발명은 첨부된 도면에 도시된 하나의 실시예를 기준하여 설명되어 있으나 이는 예시적인 것이라 할 수 있고, 당해 기술분야에서 통상의 지식을 가진 자라면 이로부터 다양한 변형 및 균등한 실시예들을 생각해 낼 수 있으므로 이러한 균등한 실시예들 또한 본 발명의 특허청구범위 내에 포함되는 것으로 보아야 함은 극히 당연한 것이다. 따라서 본 발명의 진정한 보호범위는 첨부된 청구범위에 의해서만 결정되어야 할 것이다.Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, which may be regarded as illustrative, and those skilled in the art will come up with various modifications and equivalent embodiments therefrom. As such, it should be considered that such equivalent embodiments are also included within the claims of the present invention. Therefore, the true scope of protection of the present invention should be determined only by the appended claims.

도 1은 본 발명에 따른 나노유체를 적용한 2상 유동 수직막대형 서모사이펀의 구조를 도시한 개념도이다.1 is a conceptual diagram showing the structure of a two-phase flow vertical rod thermosiphon to which the nanofluid according to the present invention is applied.

< 도면의 주요부분에 대한 부호의 설명 ><Description of Symbols for Major Parts of Drawings>

1 ; 나노유체 1a ; 충전유체One ; Nanofluid 1a; Filling fluid

1b ; 나노입자 2 ; 기체(증기)1b; Nanoparticles 2; Gas (Steam)

3 ; 밀폐관 4 ; 열교환 대상물3; Closed tube 4; Heat exchange object

10 ; 증발부(열흡수부) 20 ; 단열부10; Evaporation unit (heat absorption unit) 20; Insulation

30 ; 응축부(열방출부) G ; 중력30; Condensation unit (heat dissipation unit) G; gravity

Claims (3)

진공상태로 밀봉된 수직막대형의 구조를 형성하는 열전도성이 우수한 금속재 밀폐관내에 소정의 작동유체가 충전되어 상기 작동유체의 열대류 및 중력 작용에 의해 임의의 열교환 대상물로부터 발생된 열을 외부로 전열시켜주는 상하 열전달 구조를 형성하되, 상기 밀폐관상의 하측 외부에 배치되는 열교환 대상물로부터 흡열 반응하는 접촉부위로서 상기 열교환 대상물로부터 밀폐관내의 작동유체로 전열시켜주는 증발부와, 상기 증발부로부터의 증발 과정에 의해 생성된 기체를 밀폐관내 상부로 전달하기 위한 경로를 형성하는 단열부와, 상기 밀폐관상의 상측 외부로 발열 반응하는 접촉부위로서 상기 단열부를 통해 상부로 전달된 기체를 응축 과정에 의해 액화하여 밀폐관내의 작동유체로부터 밀폐관 외부로 전열시킴과 아울러 액화된 작동유체가 중력 및 압력차에 의해 상기 밀폐관의 내벽을 타고 상기 증발부로 순환되도록 하는 응축부를 구성하는 2상 유동 수직막대형 서모사이펀에 있어서,A predetermined working fluid is filled in a metal-conducting tube excellent in thermal conductivity forming a vertical bar-shaped structure sealed in a vacuum state, and heat generated from any heat exchange object by the tropical flow and gravity action of the working fluid to the outside. An evaporation unit which forms an upper and lower heat transfer structure for conducting heat transfer, and which heat-transfers from the heat exchange object to a working fluid in the closed tube as a contact portion for endothermic reaction from a heat exchange object disposed on the bottom outside of the sealed tube; A heat insulation part forming a path for delivering a gas generated by the evaporation process to the upper part of the closed tube, and a gas delivered to the upper part through the heat insulating part as a contacting part exothermicly reacting to the outside of the upper part of the closed tube by a condensation process. Liquefied to transfer heat from the working fluid in the sealed tube to the outside of the sealed tube In the two-phase flow vertical rod thermosiphon constituting the condensation unit to circulate through the inner wall of the closed tube to the evaporation unit by the gravity and pressure difference, 상기 작동유체는 열전달 면적과 유체의 열용량을 증가시킬 수 있도록 나노단위 크기의 극히 미세한 금속재 입자를 소정량 함유한 소정의 충전유체로 이루어진 나노유체인 것을 특징으로 하는 나노유체를 이용한 2상 유동 수직막대형 서모사이펀.The working fluid is a two-phase flow vertical membrane using nanofluids, characterized in that the nanofluid consists of a predetermined fill fluid containing a predetermined amount of extremely fine metal particles having a nano unit size to increase the heat transfer area and the heat capacity of the fluid. Large thermo siphon. 제 1 항에 있어서,The method of claim 1, 상기 나노입자는 열전도성이 우수한 금, 은, 구리 중 선택된 어느 하나의 금속으로 이루어진 것을 특징으로 하는 나노유체를 이용한 2상 유동 수직막대형 서모사이펀.The nanoparticle is a two-phase flow vertical rod thermosiphon using a nanofluid, characterized in that made of any one metal selected from gold, silver, copper having excellent thermal conductivity. 제 1 항 또는 제 2 항에 있어서,The method according to claim 1 or 2, 상기 나노입자는 그 크기가 100nm 이하인 것을 특징으로 하는 나노유체를 이용한 2상 유동 수직막대형 서모사이펀.The nanoparticles are two-phase flow vertical rod type thermosiphon using a nanofluid, characterized in that the size of 100nm or less.
KR1020030054899A 2003-08-08 2003-08-08 Two-phase vertical bar Thermosyphon using Nano Fluid as working fluid KR20050017738A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10012417B2 (en) 2012-05-07 2018-07-03 Phononic, Inc. Thermoelectric refrigeration system control scheme for high efficiency performance
US10458683B2 (en) 2014-07-21 2019-10-29 Phononic, Inc. Systems and methods for mitigating heat rejection limitations of a thermoelectric module
WO2019225982A1 (en) * 2017-06-16 2019-11-28 에스디(주) Thermosyphon having curved perforated plate

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10012417B2 (en) 2012-05-07 2018-07-03 Phononic, Inc. Thermoelectric refrigeration system control scheme for high efficiency performance
US10458683B2 (en) 2014-07-21 2019-10-29 Phononic, Inc. Systems and methods for mitigating heat rejection limitations of a thermoelectric module
WO2019225982A1 (en) * 2017-06-16 2019-11-28 에스디(주) Thermosyphon having curved perforated plate

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