• 한국가스학회:학술대회논문집
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• 1997.09a
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• pp.260-265
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• 1997

Analysis of trace impurities in the bulk .gas has been very important with the development of semi-conductor related industry. In the paper, we reported the analysis of the trace impurites of carbon monoxide and methane in the bulk helium and hydrogen by the GC-TCD with a cold nitrogen trap. We compared these results by the paraallel analysis. All data showed a good correspondence, showing reliable statistical error ranges.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.61-64
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• 1997

1. 서론 : 적절한 이산화탄소의 분리는 지구온난화의 가속현상을 늦출 수 있을 뿐만 아니라 각종 탄화수소가스의 원료로 분리 정제된 이산화탄소를 재이용할 수 있으므로 경제적으로 매우 중요하다. 이산화탄소 분리에 사용되던 기존 공정들의 단점을 보완할 수 있는 대체방안으로 최근에 개발되기 시작한 것이 소수성의 다공성 고분자 분리막(hydrophobic porous ploymeric membrane) 방법인데, 이는 모듈의 유효 막 표면적이 상대적으로 크고 기체와 액체의 흐름을 독립적으로 제어할 수 있으므로 범람 등의 현상이 없으나 막 자체의 저항이 비교적 큰 단점을 가지고 있다. Qi와 Cussler는 이러한 특성을 가지는 중공사막 모듈에서의 기-액 흐름에 대한 물질전달 상관관계식을 얻었으며[1], Karoor 등은 여러 가지 중공사막 모듈을 사용하여 순수물과 diethanolamine(DEA) 등의 흡수제에 대한 이산화탄소의 물질전달 거동을 수치모델과 실험을 통하여 고찰하였다[3]. 또한 중공사막 접촉기의 실제적 응용에 대하여 Matsumoto 등은 화력발전소에서 발생하는 연소가스 내의 이산화탄소 흠수에 대한 연구를 수행하였다[4]. 본 연구에서는 중공사막 접촉장치를 사용하여 흡수제를 순수물과 탄산칼륨($K_2CO_3$)을 사용했을 경우의 이산화탄소의 분리 거동을 수치모델과 실험을 통하여 고찰하였다. 수치모델의 경우 이전까지의 연구가 반응이 없는 경우나 반응식을 간략화시킨 경우에 한정되었는데 비하여, 반으이 있는 경우 각각의 반응물질들의 거동을 고려한 반응식을 유도하여 해를 구하고자 하녔다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.74-77
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• 2009

Ignition performance tests were performed to develop a catalytic ignitor which used hydrogen peroxide and kerosene. Ignition characteristics were investigated by exit area of the catalytic bed, shape of kerosene injector and lead time of purge gas. The results showed that exit area of catalytic bed must be enough for non chocking condition and kerosene must be sprayed with swirl in the middle of catalytic bed. Also in case without preheating of catalytic bed, hydrogen peroxide must be leaded by 3sec, and purge gas must be supplied simultaneously or lately with kerosene.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.4
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• pp.448-454
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• 2010

The strengthened regulations for atmospheric emissions from ships have caused a necessity of new, alternative power system in ships for the low pollutant emissions and the high energy efficiency. Recently, new kinds of propulsion power system such as fuel cell system, which use hydrogen as an energy source, have been sincerely considered. The purpose of this work is to predict the performance of methanol fueled SOFC system and to analyze the influence of operating temperature, current density, S/C, and $H_2$ utilization ratio.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.3
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• pp.39-51
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• 2010

Theoritical principles about the real gas equation of state are investigated and comparisons for the thermophysical properties of oxygen, hydrogen, and methane as the propellants of liquid rocket engine are carried out for the various conditions of pressure and temperature including supercritical conditions. The properties obtained using the real gas equation of state(Soave modification of Redlich-Kwong, Peng-Robinson equation of state, and extended corresponding states principle) have been compared with the results of applying the ideal gas equation of state. Differences of thermophysical properties among the models specifically at the liquid phase regime and their error ranges are addressed.

• Journal of Energy Engineering
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• v.5 no.1
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• pp.19-27
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• 1996

Self-pressurization of cylindrical container of cryogen is numerically analyzed. The container is axi-symmetric and heated from side wall with constant heat flux. Natural convection by external heat flux is studied numerically using finite difference method. Oxygen, nytrogen and hydrogen are working fluids in this paper. Liquid is considered incompressible fluid and vapor is assumed to behave as gas meeting with virial equation of gas. The Second virial coefficients of gas are obtained from Lennard-jones model. The important variables which have effects on self-pressurization are external heat flux, heat capacity of wall and initial ullage in container. The most important variable of them is external heat flux. The pressure rise calculated from the virial gas model is slightly different from that calculated using Ideal gas model for oxygen.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.8
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• pp.823-833
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• 2010

For the study of thermophysical properties of kerosene for the liquid rocket and aviation fuels, the surrogate models are investigated. The density distributions based on the real gas equations of state(Soave modification of Redlich-Kwong and Peng-Robinson equation of state) and NIST SUPERTRAPP(extended corresponding state principle) are compared with the previous experimental results at supercritical conditions. The error range of thermophysical properties analyzed for the surrogate models as well. Peng-Robinson equation of state and extended corresponding state principle are especially accurate for the hydrocarbon fuels but the appropriate surrogate models need to be chosen to the operation conditions such as pressure and temperature.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.131-136
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• 1992

New graft copolymers were synthesized by grafting 2,2,2-trifluoroethylmethacrylate on polyvinylalcohol in aqueous solution with $Ce^{4+}$ ions as initiator. Surface free energies of copolymers having various grafting percentages were studied by measurements of contact angles for various liquids. As the grafting of perfluoroalkyl group increases, surface free energy of solid decreases. Estimation of critical surface free energy should be accounted for molecular properties because the polar force components of these solids are relatively great. ${\gamma}_c$ was calculated from the plot of ${\gamma}_{si}$ vs ${\Phi}_{sl}$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.95-98
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• 2010

A multi-injector rocket engine using high concentrated hydrogen peroxide and kerosene as the oxidizer and fuel was designed and fabricated. Six coaxial swirl injectors were mounted on the mixing head and flow analysis in the manifold was performed to minimize stagnation and recirculation zones. Finally, uniformity of mass flow rate and spray pattern was evaluated by cold flow tests and the mixing head design process was successfully verified the results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.81-84
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• 2010

In this study, a coaxial swirl injector using hydrogen peroxide and kerosene was designed and combustion performance tests were performed to evaluate combustion characteristic according to mixture ratio. Spray characteristic of the injector was verified by cold flow test and combustion performances according to mixture ratio were evaluated by the characteristic exhaust velocity. Test results showed that the combustion efficiency at the design condition was about 95% and the pressure fluctuation was very small.