• 설비공학논문집
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• 제10권6호
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• pp.683-694
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• 1998

The application of hydrocarbon refrigerants in a hermetic reciprocating compressor for refrigerator is investigated. The selected refrigerants are isobutane(R600a), propane(R290), R12, binary mixture of R600a/R290, and OS-21CII. Both theoretical and experimental investigations have been performed for the selected refrigerants. The test results of hydrocarbon refrigerants have been compared to the traditional refrigerant(R12). The results show that hydrocarbon refrigerants(HC-Blend, OS-21C II) are very good alternatives in the refrigeration system for R12.

• 설비공학논문집
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• 제12권11호
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• pp.1031-1037
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• 2000

Isothermal vapor-liquid equilibrium(VLE) data have been obtained for the systems of propane(R290)+1,1,1,2-tetrafluoroethane(R134a) and 1,1,1,2-tetrafluoroethane(R134a)+isobutane(R60A) in the temperature range of 253.15 to 323.15K. Experiments were performed in a circulation type apparatus by injecting vapor through liquid pool using a magnetic pump. Both systems form azeotropes in the temperature range of this study. The experimental results were estimated with the Peng-Robinson equation of state. When the temperature-dependent binary interaction parameter was used in the Peng-Robinson equation of state, the absolute average deviation of the measured bubble point pressures from the values correlated by the Peng-Robinson equation was 0.65% and 0.78% for R290+R134a and R134a+600a, respectively. Azeotropic compositions for both systems were presented.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1945-1950
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• 2004

In this paper, The performance of Kim-Chi refrigerator with three evaporator and one compressor was investigated in employing 55% propane and 45% isobutane (R290/R600a) refrigerant mixture as an alternative refrigerant of R134a. The drop in test was performed by varying both refrigerant charge amount and capillary tube length in order to find both the performance and reliability of a small multi-refrigeration system. As a result, Both the power consumption and COP is increased by about 15% and 10%, respectively as compared to the baseline R134a system. In addition, the propane/isobutene refrigerant mixture system took advantage of the minimization of modification and redesigning of system components because of similar thermodynamic properties with R134a such as saturation pressure, temperature, normal boiling point(NBP) characteristics

• 한국조리학회지
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• 제13권1호
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• pp.119-128
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• 2007

식품의 조리과정 중에 부산물로 나오는 갑각류 폐기물을 이용하여 소스를 제조하여 canister system을 이용하여 농축한 후 GC/MSD를 이용해 휘발성 성분을 동정하였다. 그 결과 총 휘발성 성분의 개수는 72종이었으며 그 중 새우를 사용하여 만든 소스의 휘발성 성분이 45개로 가장 많았다. 새우 소스의 휘발성 성분은 10종의 alkane, 4종의 ketone, 3종의 aldehyde 및 7종의 alcohol이었으며 3-methyl-2-butanone, 2-pentanamine, isobutane, 3- methyl-butanal, furan, carbon disulfide, dimethyl sulfide가 주요한 성분이었다. 꽃게 소스에서는 18개의 휘발성 성분이 동정되었고, 4종의 alcohol류, 5종의 alkane류, 3종의 aldehyde류 및 ketone, acid와 amine이 각각 1종 검출되었으며, 2-methoxy ethanol, trimethyloxirane, 3-buten-1-ol이 꽃게 소스에서 주요한 휘발성 성분으로 나타났다. 바다가재 머리부분을 이용한 소스에서 16종의 휘발성 성분이 동정되었으며 alkane류 2종, aldehyde와 alcohol이 각각 1종씩 동정되었고 formic acid, 1-propanethiol, $\beta$-pinene, allyl sulfide가 주요한 향기 성분으로 나타났다. 바다가재 껍질을 이용한 소스에서 휘발성 성분이 18종 검출되었으며, acid류, pentane, 3-methyl 1-butanol 및 2, 4-dimethyl- 3-pentanone이 주요한 휘발성 성분인 것을 알 수 있었다.

• 공업화학
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• 제8권2호
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• pp.211-219
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• 1997

1-부텐과 i-부탄의 알킬화반응에 의한 i-옥탄 생성반응을 Cs 혹은 $NH_4$가 치환된 $H_3PW_{12}O_{40}$ 촉매상에서 액상 및 기상으로 수행하였다. 액상알킬화반응의 경우 반응전 촉매의 전처리 온도가 헤테로폴리산 촉매의 반응성에 매우 중요한 역할을 하였다. 액상알킬화반응에서 치환염은 모산보다 매우 우수한 총수율과 i-옥탄 선택도를 보였으며, $(NH_4)_{2.5}H_{0.5}PW_{12}O_{40}$ 촉매는 $Cs_{2.5}H_{0.5}PW_{12}O_{40}$ 보다 1-옥탄 선택도면에서 더욱 효과적인 것으로 나타났다. 기상알킬화반응의 경우 Cs 혹은 $NH_4$가 치환된 $H_3PW_{12}O_{40}$ 촉매의 활성은 촉매의 산특성(산점의 비활성화)과 관련이 있었다. 기상알킬화반응에서 반응초기에는 촉매의 강한 산특성 때문에 $C_5-C_7$가 주로 생성되나 반응이 진행되면서 촉매 산점의 비활성화가 진행되어 $C_8$ 및 $+C_9$가 주로 생성되었다. 기상알킬화반응에서 대상 촉매중 $Cs_{2.5}H_{0.5}PW_{12}O_{40}$이 가장 우수한 총수율을 나타내었다.

• 한국수소및신에너지학회논문집
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• 제26권3호
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• pp.278-286
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• 2015

This paper presents the analytical results of the thermodynamic performance characteristics for a cogeneration system using regenerative organic Rankine cycle (ORC) driven by low-grade heat source. The combined heat and power cogeneration system consists of a regenerative superheated ORC and an additional process heater in a series circuit. Eight working fluids of R134a, R152a, propane, isobutane, butane, R245fa, R123, and isopentane are considered for the analysis. Special attention is paid to the effect of turbine inlet pressure on the system performance such as thermal input, net power and useful heat productions, electrical, thermal, and system efficiencies. The results show a significant effect of the turbine inlet pressure and selection of working fluid on the thermodynamic performance of the system.

• 대한화학회지
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• 제7권2호
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• pp.128-132
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• 1963

A study has been made on the applicability of gas-liquid partition chromatography to the qualitative and quantitative analysis of complex mixture of gaseous hydrocarbons. While phthalate columns are widely used for this $purpose^9$, they separates neither saturated hydrocarbons from the unsaturated nor n-butane from isobutene or butene-1, therefore combined columns such as phthalate and dimethylsulfolane have been used for the perfect separation of gaseous hydrocarbons. It is shown by this study, however, that hydrocarbons having $C_1$ through $C_4$ can be separated with a 2-meters tetraethyleneglycol dimethylether column except ethane from ethylene, and trans-from cis-2-butene especially operated at $15^{\circ}C$$ using helium as the carrier gas. The column effluents were in order of methane, (ethane, ethylene), propane, propylene, isobutane, n-butane, isobutylene, butene-1, (trans-& cis-2-butene, isopentane), (butadiene-1, 3, n-pentane). Two kinds of liquified petroleum gases in market are analysed qualitatively and quantitatively. The results indicate that use of this 2-meters TEGDE column permits the separation and identification of all the commonly encountered aliphatic gaseous hydrocarbons.

• 한국수소및신에너지학회논문집
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• 제22권5호
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• pp.699-705
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• 2011

A combined heat and power cogeneration system driven by low-temperature sources is investigated by the first and second laws of thermodynamics. The system consists of Organic Rankine Cycle (ORC) and an additional process heater as a series circuit. Seven working fluids of R152a, propane, isobutane, butane, R11, R123, isopentane and n-pentane are considered in this work. Maximum mass flow rate of a working fluid relative to that of the source fluid is considered to extract maximum power from the source. Results indicate that the second-law efficiency can be significantly increased due to the combined heat and power generation. Furthermore, higher source temperature and lower turbine inlet pressure lead to lower second-law efficiency of ORC system but higher that of combined system. Results also show that the optimum working fluid varies with the source temperature.

• 한국태양에너지학회 논문집
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• 제31권6호
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• pp.49-56
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• 2011

In this study a novel cogeneration system driven by low-temperature sources at a temperature level below $190^{\circ}C$ is investigated by first and second laws of thermodynamics. The system consists of Organic Rankine Cycle(ORC) and an additional heat generation as a parallel circuit. Seven working fluids of R143a, R22, R134a, R152a, $iC_4H_{10}$(isobutane), $C_4H_{10}$(butane), and R123a are considered in this work. Maximum mass flow rate of a working fluid relative to that of the source fluid and optimum turbine inlet pressure are considered to extract maximum power from the source. Results show that due to a combined heat and power generation, both the efficiencies by first and second laws can be significantly increased in comparison to a power generation, however, the second law efficiency is more resonable in the investigation of cogeneration systems. Results also show that the working fluid for the maximum system efficiency depends on the source temperature.

• 동력기계공학회지
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• 제18권6호
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• pp.140-145
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• 2014

Exploitation of renewable energies is on the increase to mitigate the reliance on fossil fuels and other natural gases with rocketing prices currently due to the depletion of their reserves not to mention their diverse consequences on the environment. Divergently, there are lots of industries "throwing" heat at higher temperatures as by products into the environment. This waste heat can be recovered through organic Rankine systems and converted to electrical energy with a waste heat recovery organic Rankine cycle system (WHR-ORC). This study uses the annual average condenser effluent from Namhae power plant as heat source and surface seawater as cooling source to analyze a waste heat recovery organic Rankine cycle using the Aspen HYSYS simulation software package. Hydrocarbon mixtures are employed as working fluid and varied in a ratio of 9:1. Results indicate that Pentane/Isobutane (90/10) mixture is the favorable working fluid for optimizing the waste heat recovery organic Rankine cycle at the set simulation conditions.