• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.318-323
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• 1993

Pentachloroethane($CHCl_2CCl_3$) was synthesized and reacted with hydrogen fluoride using antimony pentahalide catalyst($SbCl_xF_y$) in order to manufacture HCFC-123$(CF_3CHCl_2)$, a potential CFC-11$(CFCl_3$) substitute candidate. Products analyses showed the fluorination proceeds through fluorine-chlorine exchanges between $HF/SbCl_xF_y$ and $SbCl_xF_y/CCl_3CHCl_2$ respectively. The degree of fluorination of $CCl_3$ group in pentachloroethane was greatly affected on the reaction temperature, but the effect of catalyst concentration was relatively small. Mechanistic study was also performed to elucidate the pathway to the formation of side-products such as $CCl_3CFCl_2$, $CFCl_2CFCl_2$ and $CF_2ClCFCl_2$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.3
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• pp.381-388
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• 2003

An experimental study was carried out to measure the heat transfer coefficient in flow boiling to mixtures of HFC-l34a and HCFC-123 in a uniformly heated horizontal tube. Tests were run at a pressure of 0.6 MPa and in the ranges of heat flux 1-50 kw/$m^2$, vapor quality 0-100 % and mass velocity 150-600 kg/$m^2$s. Heat transfer coefficients of mixture were less than the interpolated values between pure fluids both in the low quality region where the nucleate boiling is dominant and in the high quality region where the convective evaporation is dominant. Measured data of heat transfer are compared to a few available correlations proposed for mixtures. The correlation of Jung et. al. satisfactorily predicted the present data, but the data in lower quality was overpredicted and underpredicted the high quality data. The correlation of Kandlikar considerably underpredicted most of the data. and showed the mean deviation of 35.1%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.443-444
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• 2006

The influence of the heat sources on LED junction temperature are Engine room air, Back plate, Electric power device, and so on. LED lamp cooling system is considered to be an important subject fur high light efficiency. Because LED Chip will be problem When LED junction temperature be over $135^{\circ}C$, In this Study, The Looped Heat Pipe System is considered to prevent LED Chip fall. The LHPS is consist of evaporator part, condenser part, heat pipe part. The working fluid of LHPS is HCFC-123. In this study, to prevent LED Chipfall, we study thermal characteristics for Looped Heat Pipe System with LED lamp.