• Journal of Advanced Marine Engineering and Technology
• /
• v.24 no.1
• /
• pp.25-30
• /
• 2000

In present paper, mass transfer over a flat plate with film condensation including noncondesable gas is analyzed with the help of similarity methods. Couette flow was assumed in liquid film and boundary-layer approximation was used in the ambient flow. Governing equations were transformed into the ordinary differential equtions by the similarity methods. Runge-Kutta and shooting method were used in order to fine the effect of mass transfer on the velocity and concentrations at the liquid-vapor interface.

• Proceedings of the KSME Conference
• /
• 2005.11a
• /
• pp.41.1-41.1
• /
• 2005

• Journal of the KSME
• /
• v.35 no.7
• /
• pp.638-646
• /
• 1995

직접접촉 얼교환 기술은 냉각탑, 접촉급수 가열기 및 공기분리기 등과 같은 장치에 예전부터 이용되어 왔는데, 그 주요한 적용이유는 가열유체와 수열유체의 사이에 일어나는 전열이 일반 열교환기와는 달리 고체벽(금속 열전달표면)을 통과하지 않고 열교환을 함으로써, 종래의 열교 환기에 비하여 상대적으로 설비의 간단화, 부식 및 스케일 부착문제가 경감됨에 따른 적은 유 지보수비 및 높은 열전달률을 얻을수 있는 이점이 있으며, 저 온도차에서의 효율적인 사용이 가능하기 때문이다. 이 글에서는 직접접촉응축 현상의 장점을 이용하는 직접접촉식 교환기의 구조와 형태, 그리고 그 응용분야에 대해서 알아보고자 한다.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.5
• /
• pp.285-292
• /
• 2015

In this study, we were clearly identify the behaviour characteristics on particle size distribution of a condensing species by injection condition of HMDS (Hexa Methyl Di-Silazane, silica precursor that is one of liquid adsorbents) to remove condensing gaseous species as using pyroligneous liquor generated during carbonization process of biomass as precursor of condensing gaseous species. When using HMDS to remove the condensing gaseous species by growth machanism of particles, we could be controlled properly particles size such as amount of adsorbent injection, residence time, heating temperature and MFC flux. Especially, in case of using the silica precursor, in consideration of the physical and chemical properties of the boiling point, the specific gravity and the molecular weight, we found that the condensing species could be effectively controlled by particles granulation.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.2
• /
• pp.161-167
• /
• 2015

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.

• Transactions of the KSME C: Technology and Education
• /
• v.2 no.1
• /
• pp.47-55
• /
• 2014

A new concept of an Eco-friendly desalination method is introduced in this study. The main idea of the desalination method of seawater is the condensation of the vaporized seawater by solar heat energy on the surface of seashore. The wind turbine blade plays a role of heat exchanger condensing the vaporized water in the air. In this analytical study, the availability of the proposed desalination system was studied. First, an analytical condensation theory of the vaporized water in air was arranged and the parametric study was conducted to estimate the amount of freshwater produced from the system with the change of the temperature difference between the humid air and turbine blade, and the relative humidity in air, and wind speed. From the analytical calculation, 2,927(ton/year) of freshwater was produced at the vertical-type wind turbine (Diameter=4m, Height=3m) as the relative humidity is 100%, the temperature difference between the impeller blade and the humid air is $40^{\circ}C$ and the wind speed is 10m/s.

• Clean Technology
• /
• v.14 no.1
• /
• pp.53-60
• /
• 2008

The condensation heat transfer coefficients and pressure drops of hydrocarbon refrigerants (R-290 and R-600a) and hydrochlorofluorocarbon (HCFC) refrigerants were measured in the two horizontal double pipe heat exchangers with inner diameters of 10.07 mm and 5.80 mm at a mass flux of $35.5{\sim}210.4\;kg/m^2s$ and the condensation temperature of $40^{\circ}C$. The average condensation heat transfer coefficients of hydrocarbon refrigerants were higher than that of HCFC refrigerant(R-22). The pressure drop had a magnitude in the order of R-600a > R-290 > R-22. The pressure drops in the tubes with inner diameter of 10.07 mm were approximately $6{\sim}15%$, $9.8{\sim}12.5%$ and $2.1{\sim}4.6%$ higher for R-600a, R-290 and R-22, respectively, than those with inner diameter of 5.80 mm. The condensation heat transfer coefficients were compared with the published experimental data, and showed the best agreement with Haraguchi et al.'s correlation.

• Proceedings of the KSME Conference
• /
• 2001.11b
• /
• pp.191-198
• /
• 2001

A numerical analysis of the heat and mass transfer and pressure drop characteristics in modular shell and tube bundle heat exchanger was carried out. Finite Concept Method based on FVM and $k-\varepsilon$ turbulent model were used for this analysis. Condensation heat transfer enhanced total heat transfer rate $4\sim8%$ higher than that of dry heat exchanger. With increasing humid air inlet velocity, temperature and relative humidity, and with decreasing heat exchanger aspect ratio and cooling water velocity, total heat and mass transfer rate could be increased. Cooling water inlet velocity had little effect on total heat transfer.

• The Magazine for Energy Service Companies
• /
• s.39
• /
• pp.70-73
• /
• 2006

클린 에너시 시장 "2015년 1672억 달러로 성장"/대림산업 양주 택지지구에 구역형 집단에너지 사업/산자부 에너지진단의무화 입법예고/동아전람 '제2회 동아 빌딩박람회'참가업제 모집/에너지기술연 제지설비 응축열 재활용 '열교환기'상용화/산자부 환경친화 산업구조개선 법률 개정/미국 냉동공조공학회 이진원 교수·이상민 박사에 최고논문상/광주시 그린빌리지, 수소연료전지 본격가동/대전 신동아파트 소형열병합 ESCO자금 상황 '끝'/기획예산처 교육세 일부 환경,에너 지 분야에 활용/유기태양전지 개방 '청신호'/중소기업청 신기술 제품 공공구매 본격 확대/에노지관리공담 혁신도시 건설을 위한 신·재생에너지보급 촉진 간담 회 개최/산자부 온실가스 배출통계 시스템 구축

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.21 no.12
• /
• pp.1656-1667
• /
• 1997

Condensing heat transfer characteristics of hydrocarbon refrigerants are experimentally investigated. Single component hydrocarbon refrigerants (propane, isobutane, butane and propylene) and binary mixtures of propane/isobutane and propane/butane are considered as test fluids. Local condensing heat transfer coefficients of selected refrigerants are obtained from overall conductance measurement. Average heat transfer coefficients at different mass fluxes and heat transfer rates are shown and compared with those of R22. Pure hydrocarbon refrigerants have higher values of heat transfer coefficient than R22. It is also found that there is a heat transfer degradation for hydrocarbon mixtures due to composition variation during condensation. Measured condensing heat transfer coefficients are compared with predicted values by available correlations. An empirical correlation for pure and mixed hydrocarbon is developed, and it shows good agreement with experimental data.