• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.7
• /
• pp.681-687
• /
• 2005

Experimental results for heat transfer characteristic and pressure gradients of HCs refrigerants R-290, R-600a, R-1270 and HCFC refrigerant R-22 during evaporating inside horizontal double pipe heat exchangers are presented. The test sections which has one tube diameter of 12.70 m 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 evaporating heat transfer coefficients of hydrocarbon refrigerants were higher than that of R-22. The average evaporating 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 R-22 in 12.7 mm and 9.52 mm. This results form the investigation can be used in the design of heat transfer exchangers using hydrocarbons as the refrigerant for the air- conditioning systems.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.3
• /
• pp.141-147
• /
• 2012

A direct injection diesel engine with large amount of exhaust gas recirculation was used to investigate low temperature diesel combustion. Pilot injection strategy was adopted in low temperature diesel combustion to reduce high carbon monoxide and hydrocarbon emissions. Combustion characteristics and exhaust emissions of low temperature diesel combustion under different pilot injection timings, pilot injection quantities and injection pressures were analyzed. Retarding pilot injection timing, increasing pilot injection quantity and higher injection pressure advanced main combustion timing and increased peak heat release rate of main combustion. As a result of these strategies, carbon monoxide and hydrocarbon emissions were reduced. Soot emission was slightly increased with retarded pilot injection timing while the effect of pilot injection on nitrogen oxides emission was negligible under low combustion temperature condition. Spatial distribution of fuel from the spray targeting visualization was also investigated to provide more insight into the reason for the reduction in carbon monoxide and hydrocarbon emissions.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.04a
• /
• pp.199-202
• /
• 2002

Many methods have been developed for the remediation of contaminated soil and groundwater. Among those technologies, in-situ bioremediation is most likely to be cost-effective method for petroleum hydrocarbon contamination. But the in-situ bioremediation can require more time to remediate hydrocarbon-contaminated soil and groundwater than other methods. Therefore we intended to save time of in-situ bioremediation using a biological additive to activate indigenous microbes in soil. The additive, 'Inipol EAP 22' stimulates the growth of specific flora, significantly accelerating the speed at which hydrocarbons are biodegraded. And it hans been tested in accordance with protocol approved by the USEPA and is registered on the National Contingency Plan Product Schedule List. In the experiment, three soil samples contaminated with fuel oil were prepared in the same concentration. Inipol EAP 22 was not added to one sample and was added to the other two samples with 5% and 10% of hydrocarbon by weight respectively. And $CO_2$gas derived from bacterial respiration was analyzed in each samples for 15 days. As a result, 145% and 153% of $CO_2$ evolution (microbial respiration) against the sample without 'Inipol EAP 22' occurred in samples with 'Inipol EAP 22' addition of 5% and 10%, respectively

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.5
• /
• pp.362-367
• /
• 2014

This study was performed to test the applicability of the ozone/hydroxy radical reaction system, which applied advanced oxidation processes, to remove total petroleum hydrocarbon (TPH) from the fine soil in washing water of the soil washing process. Removal efficiency was tested on 40 L of washing water in a pilot reaction tank. Fine soil contaminated with $800mg\;kg^{-1}$ TPH was prepared at 5% and 10% suspended solids. Testing conditions included ozone/hydroxy radical flow rates of 40, 80, and $120L\;min^{-1}$, and processing time of 2 to 12 hours. The removal efficiency of petroleum hydrocarbon from water waster by ozone/hydroxy radical was increased with higher flow rates and lower percentages of suspended solids. Optimal efficiency was achieved at $80L\;min^{-1}$ flow rate for 4 hours for the 5% suspended solids, and $120L\;min^{-1}$ for 6 hours for the 10% suspended solids. These results verified the efficiency of hydroxy radical in removing TPH and the applicability of the ozone/hydroxy radical reaction system in the field.

• 한국연소학회:학술대회논문집
• /
• 2000.12a
• /
• pp.33-46
• /
• 2000

In the present study, a systematic chemical kinetic calculations were made to investigate the augmentation of NO-$NO_2$ conversion due to the addition of various hydrocarbons (methane, ethylene, ethane, propene, propane) in the nonthermal plasma treatment. It is included in the present conclusion that the reaction between hydrocarbon and oxygen radicals induced by electron collision, is believed to be a primarily process for triggering the overall NO oxidation and the eventual NOx reduction. Upon the completion of the initiating step, various radicals (OH, $NO_2$ etc.) successively produced by hydrocarbon decomposition form the primary path of NO-$NO_2$ conversion. When the initiating step is not activated, hydrocarbon consumption rate appeared to be very low, thereby the targeted level of NO conversion can only be achieved by the addition of more input energy. Present study showed ethylene and propene to have higher affinity with 0 radical under all conditions, thereby both of these hydrocarbons show very fast and efficient NO-$NO_2$ oxidation. It was also shown that propene is superior to ethylene in the aspect of NOx removal.

• 한국연소학회:학술대회논문집
• /
• 2000.05a
• /
• pp.178-188
• /
• 2000

In the present study, a systematic chemical kinetic calculations were made to investigate the augmentation of $NO-NO_{2}$ conversion due to the addition of various hydrocarbons (methane, ethylene, ethane, propene, propane) in the nonthermal plasma treatment. It is included in the present conclusion that the reaction between hydrocarbon and oxygen radicals induced by electron collision, is believed to be a primarily process for triggering the overall NO oxidation and the eventual NOx reduction. Upon the completion of the initiating step, various radicals (OH, $HO_{2}$ etc.) successively produced by hydrocarbon decomposition form the primary path of $NO-NO_{2}$ conversion. When the initiating step is not activated, hydrocarbon consumption rate appeared to be very low, thereby the targeted level of NO conversion can only be achieved by the addition of more input energy. Present study showed ethylene and propene to have higher affinity with 0 radical under all conditions, thereby both of these hydrocarbons show very fast and efficient $NO-NO_{2}$ oxidation. It was also shown that propene is superior to ethylene in the aspect of NOx removal.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.12
• /
• pp.2139-2152
• /
• 2007

Ruthenium complex-catalyzed reactions often require highly qualified tuning of reaction conditions with substrates to attain high yield and selectivity of the products. In this review, our strategies for achieving characteristic ruthenium complex-catalyzed co-oligomerization of different alkenes are disclosed: 1) The codimerization of 2-norbornenes with acrylic compounds by new ruthenium catalyst systems of RuCl3(tpy)/Zn [tpy = 2,2':6',2''-terpyridine] or [RuCl2(η6-C6H6)]2/Zn in alcohols, 2) A novel synthesis of 2-alkylidenetetrahydrofurans from dihydrofurans and acrylates by zerovalent ruthenium catalysts, such as Ru(η4-cod)(η6-cot) [cod = 1,5-cyclooctadiene, cot = 1,3,5-cyclooctatriene] and Ru(η6-cot)(η2-dmfm)2 [dmfm = dimethyl fumarate], 3) Regio- and stereoselective synthesis of enamides by Ru(η6-cot)(η2-dmfm)2-catalyzed codimerization of N-vinylamides with alkenes, and 4) Unusual head-to-head dimerization of styrenes and linear codimerization of styrenes with ethylene by Ru(η6-cot)(η2-dmfm)2 catalyst in the presence of primary alcohols.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.485-488
• /
• 2008

Fire intensity in tunnel fire is very severe, which might cause the spalling on the surface of shotcrete and concrete lining exposed to the heat as well as rapidly-reducing stress due to heat transfer by steel material such as anchor embedded in tunnel which plays the critical role in securing the stability of the tunnel. In this study, a fire test to identity the heat intensity(Modifired Hydrocarbon Curve) and the fire resistance of steel materials embedded as parameters, was carried out. And the evaluation to identify the thermal damage, which was based on critical temperature range for thermal damage of steel materials determined according to the road tunnel fire resistance standard established by ITA(International Tunneling Association).

• Proceedings of the KSME Conference
• /
• 2001.11b
• /
• pp.800-805
• /
• 2001

Recently, our world is faced with very serious and hard problems related to the air pollution due to the exhaust emissions of the diesel engine. So, lots of researchers have studied to reduce the exhaust emissions which influenced the environment strong. In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for diesel engine. And, we tried to analysis the quantities of the low and high hydrocarbon among the exhaust emissions in diesel engine. It have been investigated by the quantitative analysis of the hydrocarbon $C_1\simC_6$ using the gas chromatography. This study carried out by comparing the chromatogram with diesel fuel and diesel fuel blended DGM(diethylene glycol dimethyl ether) 5%. The results of this study show that the hydrocarbon $C_1\simC_6$ among the exhaust emissions of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed. In particular, high boiling point hydrocarbons such as $C_5$ and $C_6$ were reduced remarkably in high speed and load region.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1358-1359
• /
• 2008

HC(hydrocarbon)센서는 최근 내연기관의 과도상태의 연소 효율 및 배기가스 저감 효율을 높이기 위하여 산소센서와 함께 연소제어 분야에서 많이 사용되고 있다. 현제 HC센서는 전기화학식 및 current limiting 방식을 많이 사용하고 있으며 이는 HC가스의 이온화를 유도하는 촉매를 매질로 하는 전기화학식 센서이다. 이러한 촉매의 경우 장기 사용 시 촉매의 열화 및 변형 등으로 신뢰도가 떨어지게 된다. 본 논문에서는 촉매를 이용하지 않고 HC 가스의 이온화를 위하여 고전압 하전방식의 hydrocarbon센서를 고안하였으며[1], 여러 배출가스를 통한 센서의 전기화학적 성능을 분석하였고 온도 및 HC성분에 따른 전류치 변화를 이용하여 이론적 계산식을 제안하였다.