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착상조건에서 R134a와 R1234yf를 적용한 핀-관 형태의 증발기 성능 비교
신윤찬(Shin, Yunchan),김진현(Kim, Jin-Hyun),조홍현(Cho, Hong-Hyun) 한국산학기술학회 2015 한국산학기술학회논문지 Vol.16 No.9
식생활의 향상 및 다양화로 신선한 제품에 대한 요구가 증가하고 있으며, 이에 따라 냉장 및 냉동식품의 저온유통 또한 점차 증가되고 있다. 현재 냉동산업에는 주로 R134a 냉매가 사용되고 있으며 GWP(Global Warming Potential)가 1300으 로써 매우 높아 지구온난화에 영향을 미친다. 이를 대체하기 위한 냉매로써 R1234yf 냉매가 있으며, GWP는 4로써 매우 낮 다. 냉동탑차 냉장시스템에 사용되는 증발기는 저온조건에서 작동되기 때문에 서리가 형성되어 시스템의 성능을 급격히 감 소시킨다. 따라서, 본 연구에서 R134a와 R1234yf 냉매를 작동유체로 사용한 증발기의 성능을 착상조건 하에서 다양한 운전 조건으로 분석하였다. 해석결과, 서리성장 조건에서 공기측 입구온도, 상대습도, 증발온도 변화에 대하여 R134a 증발기의 성능이 R1234yf 증발기보다 더욱 민감하게 나타났으며 서리의 성장 또한 R134a 증발기가 더 크게 나타났다. The low temperature distribution of the refrigerated and frozen food has been increased gradually. Refrigeration industry is using R134a refrigerant, which GWP is 1300. R1234yf is an alternative refrigerant of R134a because GWP of R1234yf refrigerant is just 4. Evaporator used in refrigeration truck refrigeration system is operated on low temperature condition. Accordingly, evaporator is formed frost and the formation of frost is rapidly decreased performance of evaporator. In this study, the performance of evaporator using R134a and R1234yf refrigerant was analyzed with operating conditions under frost condition. As a result, the performance of R134a evaporator according to air inlet temperature, relative humidity and evaporating temperature was more sensitive than R1234yf evaporator. Besides, the frost growth of R134a evaporator is steeper than that of R1234yf one.
토출유량변화에 따른 배수용 수중펌프 성능 특성에 대한 해석적 연구
신윤찬(Yunchan Shin),유지호(Jiho Ryu),김태중(Tae-Jung Kim) 한국산업기술융합학회(구. 산업기술교육훈련학회) 2023 산업기술연구논문지 (JITR) Vol.28 No.4
기후변화에 따른 이상기후가 일상화되며 매년 크고 작은 홍수가 꾸준히 발생하고 있어 농경지 침수로 인한 피해가 증가하고 있다. 최근에는 집중호우로 인해 농경지의 침수를 막아주는 빗물펌프장이 충남 청양군 일대에서 설치된 4곳중 3곳이 제대로 가동되지 않아 농작물과 시설하우스만 여러 동이 침수되는 피해가 발생하였다. 본 연구에서는 토출유량 변화에 따른 배수용 수중펌프의 성능 특성에 대한 해석적 연구를 수행하였으며, 토출유량에 따라 실험과 해석에 대한 수중펌프의 효율은 ±3.4%이내임을 확인하였다. Abnormal weather owing to climate change has become commonplace. Large and small floods have steadily occurred annually, increasing damage owing to flooding of agricultural land. Recently, owing to torrential rain, three of four rainwater pumping stations installed in Cheongyang-gun, Chungcheongnam-do, had failed to operate properly, thereby flooding several buildings and facility houses. In this study, an analytical study was conducted on the performance characteristics of centrifugal submersible pumps according to changes in the discharge flow rate. The results confirmed that the efficiency of the submersible pump for the experiment and analysis was within ±3.4% with the discharge flow rate.
R134a와 R1234yf 냉매 적용에 따른 냉동탑차 냉장시스템의 성능비교
신윤찬 ( Yunchan Shin ),김진현 ( Jinhyun Kim ),조홍현 ( Honghyun Cho ) 조선대학교 공학기술연구원 2017 공학기술논문지 Vol.10 No.2
Recently, the importance of delivery system has being developed according to the growth of online and mobile shopping market. Especially, transportation of frozen food by online and home shopping is increasing significantly. Therefore, the demand of refrigeration truck is also increasing. In this study, performance characteristics of refrigeration system using R134a and R1234yf in a refrigeration truck were compared by experimental method. When the refrigerant charging amounts increased from 1.1 to 1.4 kg, COP of R134a system was increased and the maximum COP was 2.63 at the charge amount of 1.4 kg. And that of R1234yf system was 2.49 at the optimal charge amount of 1.3 kg. The optimal EEV opening of R134a and R1234yf system was 60% and 50%, respectively. Besides, the COP was 2.69 and 2.49 for R134a and R1234yf at the optimal EEV opening. When the outdoor air temperature increased from 25℃ to 35℃, the system COP of R134a and R1234yf decreased by 15.0% and 11.6%, respectively. Besides, When the compressor rotating speed increased from 1000 to 2000 rpm, the system COP of R134a and R1234yf decreased by 37.5% and 35.9%, respectively. The R134a system showed a higher performance than R1234yf system, but the R134a system showed the larger reduction in the performance according to compressor rotating speed.
독립지주식 영농형 태양광 하부 농지 내 일사량 전산모사 및 실측 비교 연구
신윤찬(Shin Yunchan),박정우(Park Jeong-woo),조건영(Jo Geon-young),임철현(Lim Cheol-hyun),박정재(Park Jung-jae) 한국태양에너지학회 2023 한국태양에너지학회 논문집 Vol.43 No.1
This study entailed computational simulations and empirical measurements on solar radiation changes in farmland owing to shade generated from the lower part of an independent pillar-type agrophotovoltaic system structure with improved performance and economic feasibility. The computational simulation and empirical results show a relatively low average solar radiation incident ratio at positions 3-7. In particular, at position 5, the average solar radiation incident ratio exhibits the lowest value, as indicated by the computer simulation and demonstration results. Consequently, three types of improved models were devised to improve the long-term shading area at positions 3-7. The average solar radiation incident ratio on the direct rear side of the module in Model 1 is lower than that of the existing system, whereas that on the direct rear side of Model 2 is 74.4%, which is the highest value. Furthermore, the corresponding value on the direct rear side of the module in Model 3 is 70.0%, which was higher than that of the existing system. Therefore, Models 2 and 3 demonstrate that the growth environment of crops could be improved using an agrophotovoltaic system.