• Journal of Advanced Marine Engineering and Technology
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• v.28 no.5
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• pp.728-734
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• 2004

Environmentally friendly refrigerants with zero ozone layer depletion potential are required to be used in refrigerators and air conditioners due to the difficulties related to ozone layer depletion and global warming. A rigorous study for the system performance with new refrigerants having zero ozone layer depletion potential is inevitable before adopting that as a new fluid. The HFC(Hydrofluorocarbon) potential has been recommended as alternatives. In this paper. system performance in the heat pump facilities were studied using R-290, R-600a. R-1270 as an environment friendly refrigerant. R-22 as a HCFC's refrigerant. The experimental apparatus has been set-up as a conventional vapor compression type heat Pump system. The test section is a horizontal double pipe heat exchanger. A tube diameter of 12.70mm with 1.315mm wall thickness is used for this investigation. The test results showed that the COP of hydrocarbon refrigerants were superior to that of R-22 and the maximum increasing rate of COP was found in R-1270. The refrigeration capacity of hydrocarbon refrigerants were higher than that of R-22. The compressor work was obtained with the maximum value in R-1270 and the minimum one in R-22.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.1143-1148
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• 2005

Experimental results for heat transfer characteristic and pressure gradient of HCs refrigerants R-290, R-600a, R-1270 and HCFC refrigerant R-22 during condensing inside horizontal double pipe heat exchangers are presented. The test sections which have one tube diameter of 12.70 mm with 0.86 mm wall thickness, another tube diameter of 9.52 mm with 0.76 mm wall thickness are used for this investigation. The local condensing heat transfer coefficients of hydrocarbon refrigerants were higher than those of R-22. The average condensing heat transfer coefficient increased with the increase of the mass flux. It showed the higher values in hydrocarbon refrigerants than R-22. Hydrocarbon refrigerants have higher pressure drop than those of R-22 in 12.7 mm and 9.52 mm. This results from the investigation can be used in the design of heat transfer exchangers using hydrocarbons as the refrigerant for the air-conditioning systems.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.205-205
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• 2012

선박에서는 화재안전목표를 달성하기 위해 선박을 방화구획화 함으로써 발화의 지점에서 화재를 차단하여 인근지역으로 확산 되지 않도록 하고 있다. 또한 방화구획을 관통하는 파이프, 덕트 및 전선관통부 등을 통하여 유독가스 및 화염이 순식간에 이동하게 되며, 한쪽 구역에서 발생한 화재의 영향이 다른 구역으로 영향을 미치게 되므로 화염에 의한 피해를 방지하고 불길을 차단하기 위하여 관통부재에 대하여 해당 방화구획과 동등한 성능을 요구하고 있다, 선박에 적용되고 있는 방화구획의 등급은 용도에 따라 일반 상선 등에는 "C ~ A"급, 해양플랜트에는 "C ~ H"급 등급이 요구되고 있다. 그러나 현재 국내 선박 기자재 제작 기술은 "A"급에 머물러 있고 최근 국내 조선소의 해양플랜트 수주 증가와 해양플랜트로의 사업전환으로 관련기자재기업에서 "H"급 기자재 개발에 많은 관심을 가지고 개발 시도를 하고 있다. 이에 본 논문에서는 "H" 급 방화구획에 적용되고 있는 탄화수소계(Hydrocarbon Fire) 내화시험기준과 "H"급 Fire Damper의 단열두께에 따른 탄화수소계(Hydrocarbon Fire) 내화성능실험을 통한 방화 댐퍼의 비 노출면에 대한 방열성능 확보방안에 대하여 언급하고자 한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.5
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• pp.47-53
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• 2000

To overcome the shortage of conventional TWC that is activated at high temperature, higher than 25$0^{\circ}C$, photocatalyst is considered as an new technology. Because the photocatalytic reaction of photocatalyst is not a thermo mechanical reaction, it is necessary to heat the system to start the reaction. It can be activated just by ultra violet light that includes wavelengths shorter than 400 nanometers even at ambient temperature. In this study photocatalytic reduction of hydrocarbon was investigated with a model gas test. To understand the effects of co-existence gases on the hydrocarbon reduction by photoreaction, CO and NO, $O_2, H_2O$ gases those are components of exhaust gases of gasoline engine are supplied with C3H8/N2 to a photoreactor. The photoreactor contains $TiO_2$ photocatalyst powders and a UV bulb. The results show that oxygen is the most important factor to reduce HC emission with photocatalyst. Photocatalyst seems to have a good probability for automotive application to reduce cold start HC emissions.

• Journal of Aquaculture
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• v.10 no.2
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• pp.189-197
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• 1997

A series of short (8 hours) and long term (96 hours) exposure studies was conducted on a laboratory scale to evaluation (1) the threshold concentrations of petroleum hydrocarbon in seawater which can lead to tainting problems in yellow tail (Seriola quinqueradiata) and (2) the time to recover (depuration period) once the tainting has occurred. The water-soluble fraction (WSF) of crude oil was prepared by stirring the oil with cold seawater. The main component of the WSF were low-boiling aromatics, although these were only al small proportion of the starting oil. From the sencory evaluation it was concluded that the threshold hydrocarbon levels in seawater which will impart a taint in yellow tail fillets within a 8-hour exposure period (short exposure period) are in the range of 0.4 to 1.0 ppm and within a 96-hour exposure period (long exposure period) are in the range of 0.2 to 0.5 ppm. Depuration trials were carried out with WSF from crude oil. The fish were exposed for 48 hours to concentration of 2.5 ppm hydrocarbons. After 48-hour exposure period, the fish were allowed to depurate in fresh, uncontaminated seawater. Depuration time for these fish was 10 days. The taste panelists were able to detect the contaminated fillets very easily while the depurated fish could not be distiguished from the control.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.12a
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• pp.87-100
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• 2007

Marine controlled source electromagnetics (CSEM) or sea bed logging (SBL) is an emerging technology which can provide quantitative information on hydrocarbon reservoir embedded in marine sediment. Electromagnetic responses to the resistive formation saturated with a certain amount of hydrocarbon can be characterized by less attenuated profile otherwise exponentially attenuated fields in conductive sea water or through sediments, and thus can be regarded as a direct indicator of hydrocarbon. In this paper, we introduce the technology of marine CSEM in terms of its physical characteristics and in comparison of typical three-dimensional (3-D) seismic method. History and evolution of commercial marine CSEM are also briefly summarized. We then introduce a representative case history showing how marine CSEM works in reality. Outlook of future applications and technical advances to be made are discussed. Finally, we demonstrate a test example of 2.5-D inversion of synthetic data as the groundwork of 3-D inversion of field data that is to be the ultimate goal of technical development.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.5
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• pp.713-723
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• 1997

Performance and heat transfer characteristics of an air conditioning system filled with hydro- carbon 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 working fluids in the air conditioning system. Performances of each refrigerant are obtained at several compressor speeds and temperature levels of secondary heat transfer fluids. The cooling capacity and the coefficient of performance are obtained as test results. Heat transfer data of selected refrigerants are achieved from overall conductance measurement. Average heat transfer coefficients at different mass fluxes are shown and they are also displayed for different heat capacities of the system. Experimental results show that some hydrocarbon refrigerants have better characteristics than R22.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.5
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• pp.78-84
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• 2007

In the regeneratively cooled combustion chambers of liquid rocket engine using hydrocarbon fuels, coking occurs as the wall temperature increases which results in compounds deposition on the wall of cooling channels. This phenomenon reduces cooling capability of the coolant which finally causes damage to the combustor by overheating of the chamber wall. In this paper, experiment results using an electrical heating equipment to simulate the regeneratively cooled channel are introduced and based on the results the compatibility of copper alloy with hydrocarbon fuel Jet A-1 is investigated.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.3
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• pp.218-224
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• 2006

The performance of an air to water vapor compression heat pump has been investigated experimentally. The main purpose of this study was to study the possibilities of using hydrocarbon refrigerants as a working fluid to replace R-22 for vapor compression heat pumps. Pure R-22 and R-290, R-600a, R-1270 were considered as working fluids. The performance of the system was characterized by compression shaft work, refrigeration capacity, pressure ratio, discharge temperature and COP. The experimental apparatus has basic parts of cycle that uses the air as a heat source. The experimental results show that refrigeration capacity of HC refrigerants is same or higher than that of R-22. On the other hand, compression shaft work of HC refrigerants is lower than that of R-22. Compression shaft work is lower than that of R-22. Come to the conclusion that, it is possible that hydrocarbon refrigerants could be drop-in alternatives for R-22.

• Journal of the Korean Society of Safety
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• v.25 no.2
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• pp.12-17
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• 2010

Numerical simulations were performed for the prediction of the flame structure during the interaction between hydrogen and hydrocarbon flames. A counterflow flow geometry was introduced to establish the interacting two flames. Methane was used as a representative hydrocarbon fuel in this study. A well-known numerical code for the counterflow flame, OPPDIF, was used for the simulations. The detailed chemistry was adopted to predict the flame structure reasonably. The interaction of two one-dimensional premixed flames established in counterflow burner was investigated with the global strain rate and velocity ratio. It was found that the maximum temperature located near the methane flame surface while the heat release rate of methane was lower than hydrogen flame. The flame thickness become narrow with increasing the velocity ratio while the global strain rate was fixed. The local strain rate and heat release rate at the methane flame surface were correlated with the global strain rate, while those at the hydrogen flame were not correlated with the global strain rate. However, the maximum temperature of the interacting flames was correlated with the global strain rate.