LiCl 수용액을 이용한 충전탑식 액체 제습기의 성능평가

전동순 대한설비공학회 2024 설비공학 논문집 Vol.36 No.2

본 연구에서는 충전탑식 액체 제습기의 성능평가를 위하여 실험장치 구축하고, 처리공기의 입구온도, 상대습도 및 풍속변화에 따른 성능실험 및 분석을 수행하였으며, 다음과 같은 결론을 얻었다. (1) 처리공기의 열전달률 및 제습률은 처리공기의 온도 및 풍속이 증가함에 따라 증가되는 경향을 보인다. 또한, 처리공기의 열전달률은 풍속의 변화보다 입구공기온도가 커짐에 따라 상대적으로 크게 증가되는 것으로 알 수 있다. 이는 풍량이 동일할 때 처리공기의 입구온도에 따른 수증기 분압의 변화가 상대습도보다 크기 때문으로 판단된다. 전체 실험범위에서 처리공기의 열전달률은 0.28~1.28 kW, 제습효율은 25~39%, 제습률은 18.7~34.8 g/min의 범위를 나타내었다. (2)제습과정에서 처리공기의 입·출구 온도차를 보면 입구온도가 높을수록 크게 나타나는 것을 확인할 수 있었다. 이는 제습의 경우 처리공기와 액체제습제인 LiCl 수용액의 수증기 분압차 및 처리공기의 풍속에 의하여 열 및 물질전달이 동시에 이루어지지만 LiCl 수용액 및 처리공기 입구온도의 온도차가 커질 경우 열전달 비중이 커질 수 있음을 의미한다. 그리고 전체 실험범위에서의 온도차는 최대 3.7℃로 나타난다. 본 연구의 실험범위에서는 큰 값이 아닌 것으로 생각되지만 향후 두 유체간의 온도차가 더욱 커질 경우 이 부분을 고려한 분석이 필요할 것으로 판단된다. (3) 제습과정에서의 제습률은 실험결과 분석을 통하여 두 유체간의 수증기 분압차 및 풍속에 의한 영향이 주요한 것을 알 수 있었다. 그리고 본 연구에서는 향후 제습기 설계에 활용할 수 있도록 통계분석을 통하여 수증기 분압차와 처리공기의 속도를 인자로 한 제습률 상관식(식(8))을 도출하였으며, 향후 제습기 설계 등에 활용이 가능할 것으로 판단된다. Liquid desiccant dehumidification systems are among the air conditioning systems that can individually control humidity. Also, these systems have the advantage of effectively removing latent heat from humid air, as well as using low-grade energy sources such as solar heat and waste heat. Because of these advantages, liquid desiccant dehumidification systems have attracted increasing attention, as a potential alternative to the conventional dehumidification methods. Therefore, in this paper, the performance of the liquid dehumidifier according to the process of air conditioning was evaluated. LiCl aqueous solution was used as a working fluid. A material of 150 mm in width, 300mm in depth, and 400 mm in height was used for the experiment. Experimental conditions were chosen using general full factorial DOE, and dehumidification performance according to the experimental conditions was analyzed. The experimental conditions were temperature (30 ~ 40℃), relative humidity (50 ~ 70%), and velocity of (0.75 ~ 1.75 m/s). From the results, the dehumidification effectiveness was mostly affected by the velocity and humidity of the supply air. The dehumidification rate was about 18.7 ∼ 34.8 g/min and dehumidification effectiveness was 25 ∼ 39%.

Low GWP 냉매적용 셸-튜브형 응축기 개발

전동순,김선창 대한기계학회 2017 기계저널 Vol.57 No.9

쉘-튜브 형 응축기에서의 냉매가스 분배판형상 최적 설계

전동순(Dong-Soon Jeon),고지운(Ji-Woon Ko) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.4

수평 평활관에서 관직경 및 표면 과냉도가 R1234ze(E) 및 R1233zd(E) 막응축 열전달에 미치는 영향

전동순(Dong-Soon Jeon),고지운(Ji-Woon Ko),김선창(Seon-Chang Kim) 대한설비공학회 2017 설비공학 논문집 Vol.29 No.5

HFO refrigerants have recently come to be regarded as promising alternatives to R134a for use in turbo chillers. This study provides results from experiments evaluating the film condensation heat transfer characteristics of HFO refrigerants R1234ze(E) and R1233zd(E) on smooth horizontal laboratory tubes. The experiments were conducted at a saturation vapor temperature of 38.0℃ with surface sub-cooling temperatures in the range of 3~15℃. We observe that the film condensation heat transfer coefficient decreases as surface sub-cooling temperatures increase. In the case of laboratory tubes with a diameter of 19.05 mm, the film condensation heat transfer coefficients of R1234ze(E) and R1233zd(E) were approximately 11% and 20% lower than those of R134a, respectively. Furthermore, our investigation of the effect of tube diameter on film condensation heat transfer coefficients, demonstrates an inverse relationship where the film condensation heat transfer coefficient increases as laboratory tube diameter decreases. We propose experimental correlations of Nusselt number for R1234ze(E) and R1233zd(E), which yield a ±20% error band.

수치해석을 이용한 발전기 냉각용 열 교환기 최적화

전동순(Dong-Soon Jeon),고지운(Ji-Woon Ko) 대한설비공학회 2020 설비공학 논문집 Vol.32 No.5

In this study, numerical analysis investigations were conducted on the design optimization of a heat exchanger for the cooling of a power generator. A heat exchanger using coolant was selected after investigating the suitability of cooling methods applicable to power generator cooling. The fractional factorial design of the experiment and response surface method were used for the optimization process. Minitab and Design Experts, which are statistical programs, were used to establish the analysis conditions and analyze the results. The heat transfer rate of the heat exchanger, the pressure drop of the coolant, and the efficiency of the heat exchanger were selected as the heat exchanging performance index. The first optimization step was conducted to derive the main design factors that could influence the heat exchanging performance. The main derived design factors were the width and height of the heat exchanger channel and the volumetric flow of the coolant. The second optimization step was conducted to optimize the main design factors derived in the first optimization step. Although the pressure drop somewhat increased compared to the standard condition, the heat transfer rate and efficiency increased by 1.15 kW and 6.28%, presenting the optimized heat exchanger shape and conditions.

Low GWP 냉매를 적용한 단단 증기 압축식 사이클 성능 특성비교

전동순(Dong-Soon Jeon),고지운(Ji-Woon Ko),문지현(Ji-Hyun Mun),김영률(Young-Lyoul Kim) 대한설비공학회 2015 대한설비공학회 학술발표대회논문집 Vol.2015 No.11

This paper presents the study on a single stage vapor compression cycle using low GWP refrigerants. Also, investigation for the alternative refrigerants was performed. Developed program was used to predict performance of single stage vapor compression cycle according to evaporating and condensing temperatures. This Program included refrigerants(R134a, R410A, R404A, R245fa, R1234yf, R1234ze(E), R1233zd(E), R32). The effects on COP(Coefficient Of Performance) and CR(Compression Ratio) of vapor compression cycle were analyzed according to evaporating and condensing temperature. As a result, it was found that R1233zd(E) refrigerant was a good alternative refrigerant at the evaporating temperature 7.2℃. And R1234yf refrigerant showed good performance when evaporating temperature was –28℃.

판형 열교환기식 제습기에서 LiCl 수용액의 열 및 물질전달 특성

전동순(Dong-Soon Jeon),이해승(HaeSeung Lee),김선창(Seon-Chang Kim),김영률(Young-Lyoul Kim) 대한설비공학회 2012 설비공학 논문집 Vol.24 No.1

Experimental investigations were carried out to examine the heat and mass transfer characteristics of LiCl aqueous solution for a plate heat exchanger type dehumidifier. Cooling dehumidification was adopted vertical type heat exchanger. Also non woven fabric is attached surface of the heat exchanger for spreadability of LiCl aqueous solution. Mass flow-rate of LiCl aqueous solution and concentration were selected as experimental conditions. Also, In this study, the effects of relative humidity of process air and velocity were investigated experimentally. As a result of heat transfer coefficient and mass transfer coefficient of were increased film reynolds number increased. heat transfer coefficient and mass transfer coefficient of LiCl aqueous solution were 0.14~0.24 kW/m2℃ and 1.3×10-63~6.2×10-6 m/s respectively.

액체식 제습시스템용 판형 열교환기식 제습기의 제습 성능에 관한 연구

전동순(Dong-Soon Jeon),문지현(Ji-Hyun Mun),김선창(Seon-Chang Kim),김영률(Young-Lyoul Kim) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

본 논문은 판형 열교환기식 제습기의 제습성능에 대한 것이다. 작동유체로서 LiCl 수용액을 사용하였다. 제습량과 제습효율에 대하여 LiCl 수용액의 질량유량 처리공기 상대습도가 미치는 영향에 대하여 연구하였다. 결과로, LiCl 수용액의 질량유량이 증가함에 따라 제습량이 증가함을 알 수 있었다. 또한 처리공기의 입구 상대습도가 클수록, 제습량이 많아지는 결과를 얻었지만, 제습효율은 감소하는 것으로 나타났다. In this study, experimental investigations have been carried out to examine the dehumidification performance of a plate heat exchanger type dehumidifier, LiCl aqueous solution is employed as a working fluid. Effects of mass flowrate of LiCl aqueous solution and relative humidity of process air on the dehumidification rate and effectiveness have been examined. The dehumidification rate increases with the increase in mass flowrate of LiCl aqueous solution. And il is found that the higher the relative humidity of process air, the higher the dehumidification rate. However the higher the relative humidity of process air, the lower the dehumidification effectiveness.

그루브가 형성된 판형 열교환기식 액체 제습기에서의 열 및 물질전달

전동순(Dong-Soon Jeon),문지현(Ji-Hyun Mun),김선창(Seon-Chang Kim),김영률(Young-Lyoul Kim) 대한설비공학회 2011 대한설비공학회 학술발표대회논문집 Vol.2011 No.7

In this study, experimental investigations have been carried out to examine heat and mass transfer of a grooved plate heat exchanger type liquid dehumidifier. LiCl aqueous solution is employed as a working fluid. Mass flow-rate of LiCl aqueous solution and relative humidity of precess air were selected as experimental conditions. As results of heat transfer coefficient and mass transfer coefficient of LiCl aqueous solution were 0.11∼0.12 ㎾/㎡℃ and 11.2×10￣?~17.8×10￣? ㎧ respectively.

Low GWP 냉매를 적용한 2 단 증기 압축식 사이클의 특성 비교

전동순(Dong-Soon Jeon),고지운(Ji-Woon Ko) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.5