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응축수를 활용한 열전 냉각장치의 회로 모델링 및 시뮬레이션
이상윤(Sang-Yun Lee),장석윤(Sukyoon Jang),박민용(Mignon Park),윤창용(Changyong Yoon) 한국지능시스템학회 2015 한국지능시스템학회논문지 Vol.25 No.2
본 논문에서는 응축수를 활용하는 새로운 열전 냉각장치를 소개하고 이 냉각장치에 대한 전기적 등가회로 모델을 제안한다. 소개된 냉각장치는 수집된 응축수를 히트싱크로 분무함으로써 응축수를 처리함과 동시에 냉각 효율을 향상시킬 수 있다. 기존의 열전 냉각장치에 대한 회로 모델과 열전소자-응축수 간의 열교환 방정식을 결합함으로써 소개된 냉각장치의 전기적 등가회로 모델을 유도한다. 유도된 모델의 파라미터는 별도의 실험을 통한 데이터 측정 없이 열전소자의 데이터시트 정보만으로 결정되기 때문에 소개된 냉각장치의 제어기를 설계하는 단계에서 해당 모델이 유용하게 사용될 수 있다. 제안된 모델의 타당성을 모의실험을 통해 확인하고 기존의 열전 냉각장치와 성능을 비교함으로써 응축수를 활용한 열전 냉각장치의 우수성 또한 검증한다. In this paper, a novel thermoelectric cooling system utilizing condensed water is introduced and its electrical equivalent circuit model is proposed. The introduced system can deals with the condensed water and improves efficiency by spraying the condensed water on heat sink. The electrical equivalent circuit model is derived by combining the circuit model of the classical thermoelectric cooling system with equation of heat exchange. Because the parameters of the model can be defined from not other experimental data but just the data sheet of the thermoelement, the model can be useful to design and develop the controller of the proposed system. We verify that the proposed model is valid and the introduced system is more efficient than the previous thermoelectric cooling system through simulations.
사출금형 냉각회로 자동최적화를 위한 설계변수 감소 방안
이병옥(B. O. Rhee),최재혁(J. H. Choi),태준성(J. S. Tae) 한국생산제조학회 2009 한국생산제조학회지 Vol.18 No.4
The injection mold cooling circuit optimization was studied with a response surface method in the previous research. It took so much time to find an optimum solution for a large product due to an extensive amount of calculation time for the CAE analysis. In order to use the optimization technique in the actual design process, the calculation time should be much reduced. In this study, we tried to reduce the number of design variables with the concept of the close relationship between the depth and the distance of cooling channel. The optimum ratio of the distance to the depth of cooling channels for a 2-dimensional problem was 2.0 so that the optimum ratio was again sought out for 4 large automotive parts. Therefore, the number of design variables for the cooling circuit optimization can be reduced in half, resulting in much faster running time for the optimization as a design tool.
고밀도 발열 Amplifier를 사용한 안테나 방열설계에 관한 연구
강성욱(Sung-Wook Kang),김호용(Ho-Yong Kim),김기완(Ki-Wan Kim),안창수(Chang-Soo Ahn),김선주(Seon-Ju Kim) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11
High thermal density amplifier, which is mainly composed of RADAR, is used to amplify transmit and receive signals. In this paper the antenna system includes that amplifier, which is accompanied by very significant heat dissipation levels and have narrow cooling space. So, We suggested the liquid-cooling system to ensure thermal reliability and investigated a circulation of cooling water which have the optimized temperature, flow rate and pressure loss. In this paper, we find the optimum values of design factors through theoretically with TDC(Thermal Design with CFD) and evaluated by product test. As the results, the performance of the Cooling system shows the propriety under the high operating temperature condition, +63℃
100kw급 수소전기차용 열관리시스템의 최적제어를 위한 통합유량제어밸브의 수치모델 검증
정수진(Soo-Jin Jeong),문성준(Seong-Joon Moon),최지현(Ji-Hyun Choi),강지훈(Jihoon Kang),이검수(GumSu Lee) 한국자동차공학회 2022 한국자동차공학회 지부 학술대회 논문집 Vol.2022 No.5
The ever growing importance of effective and efficient thermal management will no doubt benefit the quest for more efficient fuel-cell vehicle. Therefore, delicate electrical based cooling system enhanced functionalities are in high demand. To meet such demand, an ICCV(integrated coolant control valve) which will replace the former wax thermostat has been developed. Analysis of cooling system at initial phase of product development will help in optimum design of the system and better performance of engine. Hence, 1D (one dimensional) simulation tools place a major role. The aim of this study is to validate several thermodynamic and 3D CFD models of Penta-Control Coolant Valve in terms of accuracy and cost-effectiveness by comparing each models. PCCV was numerically modeled based on junction and chamber with 1D pipes and its prediction performance is validated by the results of 3D CFD simulations. The results show that thermodynamic models produced very large discrepancies ranging from 30% to 150% in case of large opening area of stack port because of strong three-dimensional turbulence effect. From the results of this study, it is found that thermodynamic models is not able to reflect the complex three dimensional flow characteristics in PCCV leading to a erroneous pressure drop and flow distribution in case of large opening area of stack port.
민선기(Sunki Min) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5
As turbo-charged engines are more popular, engine cooling becomes more important. Turbo-charged engine makes more heat in a smaller volume compared to NA engines of similar power and needs more cooling because of bigger heat rejection. But turbo-charged engines have smaller water jacket and the surface area of water jacket which contacts with cooling water is smaller. In this study, coolant flow analysis was done with AMESim to improve coolant flow rate. At first, base AMESim model of cooling circuit was correlated with test result. After correlation was completed, various AMESim models were made by increasing diameter of hose and pipe connected to each part ? radiator, heater & oil cooler and T/C cooler. Flow rate of increased hose or pipe resulted in increasing of flow rate to connected part, but flow rate of other parts were decreased. To change flow rate distribution of each parts, the base cooling circuit was modified. By modifying cooling circuit, total flow rate to all parts decreased while flow rate to radiator was maintained.
가정용 연료전지 시스템의 열관리 해석을 위한 시스템 운전 모델 개발
유상석(Sangseok Yu),이영덕(Youngduk Lee),안국영(Kookyoung Ahn) 대한기계학회 2010 大韓機械學會論文集B Vol.34 No.1
이온교환막 연료전지는 전세계적인 에너지 고갈 문제와 온실효과에 대한 대응책의 하나이다. 특히, 이온교환막 연료전지는 전기화학반응에 의해 전기를 생산함과 동시에 열을 발생하기 때문에 가정용으로 적용하기에 적당하다. 가정용 연료전지의 열관리 목적은 연료전지가 최적조건에서 운전할 수 있도록 적절히 온도를 제어해 주는 것으로, 본 연구에서는 부하 변화 시 가정용 연료전지 시스템의 응답 특성과 열관리 특성을 알아보기 위한 해석 모델을 개발하였다. 열관리 해석 모델은 연료전지의 온도를 조절하기 위한 펌프와 열교환기로 구성된 1차측, 주택에 온수를 공급하기 위한 탱크와 펌프 계통의 2차측으로 구성되었다. 부하를 순차적으로 증가시킬 때와 감소시킬 때를 구분하여 열관리 계통의 응답특성을 확인하였다. 결과적으로 탱크의 초기 승온에 많은 시간이 소요되기 때문에 부하를 다단으로 오랜 시간 동안 서서히 증가시키면서 시스템 응답 특성을 확인하였다. 또한, 본 연구에서는 가정용 연료전지의 부하 변화시의 열관리 특성을 고려한 운전 전략에 대해서도 조사하였다. A PEMFC(proton exchange membrane fuel cell) is a good candidate for residential power generation to be coped with the shortage of fossil fuel and green house gas emission. The attractive benefit of the PEMFC is to produce electric power as well as hot water for home usage. The thermal management of PEMFC for RPG is to utilize the heat of PEMFC so that the PEMFC can be operated at its optimal efficiency. In this study, thermal management system of PEMFC stack is modeled to understand the dynamic response during load change. The thermal management system of PEMFC for RPGFC is composed of two cooling circuits, one for controling the fuel cell temperature and the other for heating up the water for home usage. The different operating strategy is applied for each cooling circuit considering the duty of those two circuits. Even though the capacity of PEMFC system (1kW) is enough to supply hot domestic water for residence, heat-up of reservior takes some hours. Therefore, in this study, time schedule of the simulation reflects the heat-up process. Dynamic responses and operating strategies of the PEMFC system are investigated during load changes.