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전력기기용 히트파이프 냉각장치에서 온도 편차의 통계적 평가
한창우(Chang-Woo Han),성상철(Sang-Chul Sung),정승붕(Seung-Boong Jeong) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
The difference of the cooling performance between the heat sinks may vary depending on the operator or the time of production, even if a number of heat sinks are manufactured under the same process. And even in the same control algorithm and physical configuration, there is the difference of the electric loss between the power devices due to the current unbalance in the phase or between phases. In this paper, the deviation of the cooling performance of the heat sinks was statistically analyzed by measuring the temperature on the heat sink with heating blocks. The temperature of the heat sink with IGBT modules was then measured under various losses to assess the deviation of the cooling performance between heat sinks due to mechanical parameters such as the airflow rate and the electric parameters such as the current unbalance. As a result, the deviation of the cooling performance among a number of heat sinks was about ±5%, and the deviation of the cooling performance for the sub-system was found to be ±12%. The upper and lower specification limits on the IGBT stack compared to the heat sink component was increased due to uncontrollable factors such as the state of the power system. The heat sink with heat pipes applied the power conditioning system connected in a power system is expected to reduce the operating range by nearly 14% than ideal manufacturing and experimental conditions.
IGBT 모듈의 냉각성능 향상을 위한 전력변환장치의 유로 설계
한창우(Chang-Woo Han),문유림(You-Lim Moon),정승붕(Seung-Boong Jeong),오명도(Myung-Do Oh) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11
In the thermal design stage, a design engineer of the power conversion system (PCS) which is used in wind power, photovoltaic, and energy storage system should evaluate whether the design criterion of the junction temperature in a power semiconductor device such as an insulated-gate bipolar transistor (IGBT) is satisfied or not. Here, an engineer designs the airflow passage structure of the PCS in order to exhaust effectively the heat that is generated by electronic components in the PCS. In this paper, it was compared with different airflow passage structures of the PCS using the numerical method to thermal performance indexes that are the airflow rate of the heat sink attached at the IGBT module and the junction temperature of the IGBT module. In order to satisfy the design criterion of the junction temperature of 130℃, the structure of the airflow passage is that the appearance and the dimension of the prototype is maintained in the same manner as the design 2, and the area of supply side louvers is maintained at least 0.3 ㎡ under the rated load condition considering the numerical error of 5 percent.
루프식 히트파이프의 수직 평판형 증발부 내부 열전달계수의 특성에 관한 연구
최윤덕(Yun Deok Choi),부준홍(Joon Hong Boo),한창우(Chang Woo Han),정승붕(Seung Boong Jeong) 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.12
Experimental investigation was conducted on the convective heat transfer coefficient in a vertical flat-plate evaporator of a loop-type heat pipe, of which the working fluid was distilled water. The evaporator was made of copper and the heating area dimensions were 190×114 ㎟. The condenser was an air-cooled fin-tube heat exchanger. Heat flux was varied from 5 to 139 kW/㎡, while the evaporator was maintained below 100°C. Three different evaporator surface conditions were compared: bare surface, screen mesh covered, and hybrid wick covered. The wick-covered surfaces exhibited distinctly higher heat transfer to bare surface, for heat fluxes higher than 88 kW/㎡. The bare surface showed moderately higher heat transfer coefficients for heat fluxes up to 69 kW/㎡, but decreased thereafter and eventually resulted in overheating at 106 kW/㎡. The surface with a hybrid wick exhibited a heat transfer coefficient of 10,300 W/㎡·K at a heat flux of 139 kW/㎡.
전력반도체 모듈 냉각용 루프식 열사이펀에서 충전률이 작동 특성에 미치는 영향
배장현(Jang Hyun Bae),조영탁(Young Tak Cho),최윤덕(Yun Deok Choi),부준홍(Joon Hong Boo),한창우(Chang Woo Han),정승붕(Seung Boong Jeong) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
A series of experiments was conducted to investigate the operational characteristics of a loop-type thermosyphon for cooling of a power transistor module under high heat flux. The flat evaporator was made of copper and the heating area was 150 ㎜ × 190 ㎜, and the working fluid was water. The transport lines were made of polyethylene tubes and the inner diameters of the vapor and liquid lines were 16.0 ㎜ and 12.4 ㎜, respectively. The condenser was a fin-tube heat exchanger cooled by forced air convection. The condenser was separated from the evaporator by 1.3 m horizontally, and positioned 0.6 m higher to utilize the gravity for liquid return. The thermal performance varied greatly with the working fluid fill charge. For a fill charge ratio of 60%, the loop thermosyphon transported a maximum heat load of 3.3 ㎾ maintaining the evaporator temperature below 100℃, with air cooling at room temperature.