전자부품 냉각을 위한 Vapor chamber heat sink의 열성능 연구

김윤호(Yoon-Ho Kim),전현수(Hyeon-Soo Jeon),배수호(Soo-Ho Bae),차호진(Hojin Cha),구홍모(Hong-Mo Koo) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

As the electronic devices is more accelerated the compact size, the light-weight and the high integrated trend of electronic components, the most increasingly the heat generation problem rises. Recently, there are growing interests in developing alternative heat sink devices. Vapor chamber heat sinks are heat-spreading systems that develop phase change to spread heat and are of increasing interest in the electronics industry. Vapor chambers are increasingly being investigated as a way to spread the heat generated by an electronic component to the base of a heat sink for typical heat sink applications. In this study, vapor chamber heat sinks have been performed to investigate the thermal performances under the natural convection and forced convection conditions and to compare their performance against copper base heat sink. It is fabricated to be used a real telecommunication equipment specifications. The thermal characteristics of vapor chamber heat sinks are studied according to various input power using dummy heater, test jig and fan. The study shows that vapor chamber heat sinks can thermally perform better than a copper block heat sink. The thermal conductivity of the vapor chamber is also numerically analyzed using CFD simulation and is compared to the experiment results. Thus vapor chamber heat sinks provide good performance alternative to typical heat sinks.

다단압축 중간주입을 통한 폐열회수 히트펌프 시스템 연구

이상욱(Sangwook Lee),김귀택(Gwitaek Kim),정융(Yoong Chung),김민수(Min Soo Kim) 대한설비공학회 2020 대한설비공학회 학술발표대회논문집 Vol.2020 No.6

This study suggest a multi-level heat pump system with vapor injection using waste heat recovery. Electric vehicle (EV) cannot obtain waste heat from power generation system like internal combustion engine. Therefore, EV needs extra heat from heat pump or positive tempeature coefficient heater (PTC) in winter for cabing heating. These auxiliary devices consume power from battery, resulting in reduction of driving range. And this phenomenon cause a fear called ‘Range anxiety’, which is a major obstacle from purchasing EV. To solve this problem, this study suggests a vapor injection system using waste heat from electric devices, including motor and battery. General waste heat recovery system in EV absorbs heat at the evaporator. However, large temperature difference between refrigerant and waste heat recovery system entails low heat exchange efficiency and high irreversibility. Suggested mid-level waste heat recovery can recover heat more efficiently. The performance of this heat pump system is investigated with numerical model. Results shows improvement in heating capacity, consequently coefficient of performance and driving range.

태양열과 재열기를 사용한 VI heat pump의 성능 특성에 관한 연구

이진국(Lee Jin-Kook),최광환(Choi Kwang-Hwan) 한국태양에너지학회 2015 한국태양에너지학회 논문집 Vol.35 No.6

In this study, heating performance of the air-cooled heat pump with vapor-injection (VI) cycles, re-heater and solar heat storage tank was investigated experimentally. Devices used in the experiment were comprised of a VI compressor, re-heater, economizer, variable evaporator, flat-plate solar collector for hot water, thermal storage tank, etc. As working fluid, refrigerant R410A for heat pump and propylene glycol (PG) for solar collector were used. In this experiment, heating performance was compared by three cycles, A, B and C. In case of Cycle B, heat exchange was conducted between VI suction refrigerant and inlet refrigerant of condenser by re-heater (Re-heater in Fig. 3, No. 3) (Cycle B), and Cycle A was not use re-heater on the same operating conditions. In case of Cycle C, outlet refrigerant from evaporator go to thermal storage tank for getting a thermal energy from solar thermal storage tank while re-heater also used. As a result, Cycle C reached the target temperature of water in a shorter time than Cycle B and Cycle A. In addition, it was founded that, as for the coefficient of heating performance(COPh), the performance in Cycle C was improved by 13.6% higher than the performance of Cycle B shown the average COPh of 3.0 and by 18.9% higher than the performance of Cycle A shown the average COPh of 2.86. From this results, It was confirmed that the performance of heat pump system with refrigerant re-heater and VI cycle can be improved by applying solar thermal energy as an auxiliary heat source.

배열회수형 초저온 아르곤기화기 시스템 개발

이종욱(Jong-Wook Lee),김원석(Won-Seok, Kim) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.5

To enhance thermal efficiency of thermal facility through recovery of low and medium temperature waste heat. 300kW Argon vaporizer system was designed and developed. The exhaust gas of 90˚C at air compressor in steel works were selected as the representative of low and medium temperature waste heat in industrial process for the heat source of the Argon vaporizer system. The vaporizing characteristic of argon vaporizer with water has fixed ice and causes a low efficiency. Enhanced type of argon vaporizer is optimized. The HTRI design program over predicted the performance of Ar vaporizer and the field test shows that parallel configuration using two vaporizers is better than series configuration for reducing pressure drop. The aims of this study are to investigate the recovery of waste heat in a system and to predict the performance of a shell and tube heat exchanger in the light of super low temperature argon application. Conventional argon vaporizer is used using the steam as heat source which is expensive to supply.

LPG 엔진의 베이퍼라이져 전산 열전달 해석

윤정의(Jeong-Eui Yun),김명환(Myung-Hwan Kim),남현식(Hyeon-Sik Nam),정태형(Tae-Hyung Jeong) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The vaporizer is the core component in the LPG gas injection engine. Its major function is to change liquid phase LPG fuel into gas phase using hot coolant as heat source. Therefore, it is important to improve the efficiency of heat exchange between coolant and LPG fuel. In this study, using the commercial thermal and fluid analysis code STAR-CD, we studied computational thermal and fluid analysis to figure out the heat exchange phenomena in vaporizer. Finally, the comparison between original and modified coolant passage was simulated on the efficiency of heat exchange.

Analysis of the thermal management of a high power LED package with a heat pipe

Kim, Jong-Soo,Kim, Eun-Pil The Korean Society of Marine Engineering 2016 한국마린엔지니어링학회지 Vol.40 No.2

The thermal management of high-power LED components in an assembly structure is crucial for the stable operation and proper luminous function. This study employs numerical tools to determine the optimum thermal design in LEDs with a heat sink consisting of a crevice-type vapor-chamber heat pipe. The effects of the MCPCB are investigated in terms of the substrate thicknesses on which the LEDs are mounted. Further, different placement configurations in a system module are considered. This study found that for a confined area, a power of 40 W/LED is applicable to a high-power package. Furthermore, the thermal conductivity of dielectric layer materials should ideally be greater than 0.9 W/m.K. The temperature conditions of the vapor chamber in a heat pipe greatly affect the thermal performance of the system. At an offset distance of 9.0 mm and a $2^{\circ}C$ increase in the temperature of the heat pipe, the resulting maximum temperature increase is approximately $1.9^{\circ}C$ for each heat dissipation temperature. Finally, at a thermal conductivity of 0.3 W/m.K, it was found that the total thermal resistance changes dramatically. Above 1.2 W/m.K, the resistance change reduces exponentially.

Analysis of the thermal management of a high power LED package with a heat pipe

김종수,김은필 한국마린엔지니어링학회 2016 한국마린엔지니어링학회지 Vol.40 No.2

The thermal management of high-power LED components in an assembly structure is crucial for the stable operation and proper luminous function. This study employs numerical tools to determine the optimum thermal design in LEDs with a heat sink consisting of a crevice-type vapor-chamber heat pipe. The effects of the MCPCB are investigated in terms of the substrate thicknesses on which the LEDs are mounted. Further, different placement configurations in a system module are considered. This study found that for a confined area, a power of 40 W/LED is applicable to a high-power package. Furthermore, the thermal conductivity of dielectric layer materials should ideally be greater than 0.9 W/m.K. The temperature conditions of the vapor chamber in a heat pipe greatly affect the thermal performance of the system. At an offset distance of 9.0 mm and a 2 °C increase in the temperature of the heat pipe, the resulting maximum temperature increase is approximately 1.9 °C for each heat dissipation temperature. Finally, at a thermal conductivity of 0.3 W/m.K, it was found that the total thermal resistance changes dramatically. Above 1.2 W/m.K, the resistance change reduces exponentially.

증기직접가열방식의 비염치료기 개발

전창완(Chang-Wan Jeon),강태삼(Taesam Kang) 제어로봇시스템학회 2013 제어·로봇·시스템학회 논문지 Vol.19 No.4

Recently many people have been troubled with perennial allergic rhinitis. But there is no way to cure for root of it until now. Therefore many medical treatments to release symptoms of perennial allergic rhinitis have been researched. One of them is localized aerosol hyperthermia, which injects 42℃~43℃ vapor into nasal cavity. Vapor inhalator for localized aerosol hyperthermia has been researched in foreign country. But on the other hand it has rarely been researched inside of the country. Since most clinics and hospitals have used imported vapor inhalator, it is needed to develop domestic vapor inhalator. In the paper, a superior vapor inhalator compared to former developed one is developed. The superiority of it comes from direct-vapor heating instead of water heating to control vapor temperature. The developed vapor inhalator has shorter rising time than the existing one because of direct-vapor heating. Furthermore vapor generation part and control part of the vapor inhalator developed as one piece mock-up. It enables the vapor inhalator to have smaller size. Many laboratory tests are performed and compared to existing results to prove its performance.

Vapor-injection cycle 이용 히트펌프의 난방 성능 향상에 미치는 중간압력 영향에 관한 연구

노철우(Chul Woo Roh),김민수(Min Soo Kim) 대한설비공학회 2011 대한설비공학회 학술발표대회논문집 Vol.2011 No.7

In this study, the target system which has an additional expansion valve at the outlet of condenser is presented. The concept of intermediate pressure is applied to the target system, whose cycle characteristic is analyzed. Effect of the intermediate pressure on the heating performance for various injection ratios was measured and analyzed for compressor frequency ranging from 60 to 100 ㎐. Unlike conventional vapor-injection cycle, the maximum injection ratio is highly affected by the intermediate pressure. The high intermediate pressure provides high initial heating capacity and COP; but it restricts the available range of vapor-injection within narrow limits. The result indicates that a proper operating strategy is needed for the vapor-injection cycle in this study.

사업장간 폐열이동용 배관건설 및 이를 열원으로 이용한 흡수식냉동기 적용에 의한 온실가스 저감사례

최동규(Dong Kyoo Choi),도양희(Yang Hee Do),김해봉(Hae Bong Kim),인성범(Seong Bum In) 대한설비공학회 2022 대한설비공학회 학술발표대회논문집 Vol.2022 No.11

This study aimed to make the solution that the industries do not recover the waste heat because of its low temperature. Industries like the chemical plant have the process in higher temperature comparing the temperature of waste heat. Main purpose of transporting the heat from one site to the other site is to use waste heat effectively. The pilot project has been done by constructing the piping to move waste heat between two sites and installing the absorption chiller to use waste heat transported in the other site. The site supplying heat can make a profit by selling waste heat and the other site also save the cost by using cheaper chilled water. Feasibility study also has been done to show the reduction of green house gas.