http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
윤린 한국수자원공사 2020 저널 물 정책·경제 Vol.33 No.-
수열에너지는 여름철 수온이 대기보다 낮고, 겨울철에는 대기보다 높아 히트펌프의 우수한 열원으로 재생가능하며, 2019년 10월 1일 이후 신재생에너지로 지정되었다. 이로써 수열원 히트펌프를 활용하는 시스템의 설계, 장치개발 및 생산, 시공, 운전, 관리 등 관련사업이 일련의 산업 형태로 발전할 것으로 예상된다. 현재까지 국내에서는 13개의 정수장과 제 2 롯데월드의 건물 공조에 수열원 히트펌프가 활용되고 있고, 해외에서는 캐나다, 미국, 일본, 프랑스 등에서 호소수와 하천수를 이용한 수열원 히트펌프 시스템이 활용되고 있다. 수열에너지 시스템의 핵심기기는 히트펌프라고 할 수 있는데 현재 유럽에서는 기존 화석에너지 활용 대비 히트펌프의 전 운전기간의 에너지효율성을 고려하여 신재생에너지로 평가하고 있어, 향후 수열원 특성에 맞는 대용량, 친 환경적 냉매를 적용한 히트펌프의 개발이 필요하다. 국내 수열에너지의 잠재량은 하천의 경우 갈수량을 기준으로 159,693 TJ/year, 댐 호소수의 경우 월 1%를 활용할 때 19,486 TJ/year, 그리고 취수장에서 정수장으로 관로를 통해 이송되는 원수의 경우 이를 50% 정도 활용할 때 70,053 TJ/year로 나타나고 있다. 향후 이와 같이 풍부한 잠재량을 갖고 있는 수열에너지를 이용한 히트펌프 시스템의 산업화를 위해서는 히트펌프 시스템의 구성요소 기기의 개발, 전공정 엔지니어링 기술, 열 네트워크와 연계하는 기술 등의 기술개발과 더불어 수열원 히트펌프 시스템을 개발, 활용할 수 있는 전문 인력의 양성도 반드시 필요하다.
INFLOW CONDENSATION HEAT TRANSFER CHARACTERISTICS OF CO2 IN MICROCHANNEL
윤린,황윤호 대한설비공학회 2014 International Journal Of Air-Conditioning and Refr Vol.22 No.2
In this study, we investigated two-phase flow patterns and effects of oil concentration on the heattransfer coefficient and pressure drop of CO2 undergoing condensation process in a microchannel,and from the data collected, we developed a prediction model of CO2 condensation heat transfer coefficient in smooth tube and microchannels. The narrow single rectangular channel was utilizedto observe flow patterns of CO2 under the condensation process. Experimental results show thatthe transition of vapor quality from intermittent flow to annular flow advances with increase ofmass flux and with decrease of condensation temperature. The heat transfer coefficient decreased by 50% as compared to that of the pure CO2 when the oil concentration was increased from 0.7 to1.2 wt.% for the mass flux of 600 kg m2 s1. The pressure drop slightly decreased with oilconcentration as compared to that of pure CO2. We developed the prediction model for the heattransfer coefficient of CO2 undergoing condensation process in microchannel by considering the effects of the liquid film thickness and of the interface shape between liquid and vapor phases onthe heat transfer coefficient. The present prediction model estimated the experimental data within18.9% of mean deviation. For the pressure drop in microchannel tubes, the existing modelsdeveloped by Mishima and Hibiki, and Garimella showed the marginal predictability.
수평원관 내 CO<sub>2</sub> R-22 및 R-134a의 증발열전달 특성에 관한 실험적 연구
윤린,황준현,최영돈,김용찬,Yun, Rin,Hwang, Jun-Hyeon,Choi, Young-Don,Kim, Yong-Chan 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.7
Evaporation heat transfer coefficients of carbon dioxide($CO_2$), R-22, and R-134a in a horizontal smooth tube were measured and analyzed as a function of heat flux, mass flux, and evaporating temperature. The experiments were carried out by varying heat flux from 10 to 20 $kW/m^2$, mass flux from 170 to 340 $kg/m^2s$, and saturation temperatures of 5 and $10^{\circ}C$. It was found that the heat transfer coefficient of $CO_2$ decreased with a rise of quality due to an earlier liquid-film dryout as compared to R-22 and R-134a. Averaged heat transfer coefficients of $CO_2$ were 22-63% higher than those of R-22 and R-134a at all test conditions. The effects of mass flux and heat flux on averaged heat transfer coefficients were much greater in $CO_2$ than in R-22 and R-134a. When comparing $CO_2$ test results with the correlations in the literature, the existing models yielded large deviations at medium and high qualities. Therefore, a generalized correlation for $CO_2$evaporation heat transfer needs to be developed by including the effects of dryout phenomenon.
이산화탄소 냉동 시스템 내 CO₂와 PAG오일의 혼합비에 대한 실시간 측정 센서개발
윤린 한밭대학교 2006 한밭대학교 논문집 Vol.23 No.-
The relation between the capacitance of OCR sensor at suction side of the CO2 cycle was obtained. The solubility of coz used in calculating the actual OCR amount was obtained from the measured mixture density. The capacitance of the OCR sensor decreased with the increase of the mixture density under the present test conditions. The capacitance of the OCR sensor depends on the mixture density and the uniformity of the oil distributed inside the OCR sensor, The distribution of the OCR sensor is strongly affected by the density ratio between the oil and CO2. It can be concluded from the present results that the oil droplet distribution across the plates inside the sensor is the dominant factor in deciding the capacitance under the present test conditions.
나선형 핀튜브 열교환기의 열전달 특성에 관한 실험적 연구
윤린,김용찬,김슬우,최종민 대한설비공학회 2005 설비공학 논문집 Vol.17 No.6
This study experimentally examines the air-side performance of spiral finned tube heat exchangers. The effects of fin spacing, fin height, and tube alignment were investigated. Reduction of fin spacing decreased the Colburn j factor. However, the effect of fin height on the Colburn j factor was negligible. An increase of tube row decreased the Nusselt number for both staggered and in-line tube alignments. However, the decrease of the Nusselt number for the in-line tube alignment was much more significant than that of the staggered tube alignment. The average Nusselt number of the staggered tube alignment was larger than that of the in-line tube alignment by 10% when the Reynolds number ranged from 300 to 1700. An empirical correlation of the Nusselt number was developed by using geometric parameters of heat exchanger and correction factors. The correction factor considered the effects of tube alignment and number of tube rows on the heat transfer. The proposed correlation yielded a mean deviation of 4% from the present data.