• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.441-448
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• 2001

Hot air heater with light oil combustion is used as the most common heater for greenhouse heating in the winter season. However, exhaust gas heat discharged to atmosphere through chimney reaches up to 10~20% of total heat capacity of the oil burred. In order to recover the heat of this exhaust gas and to use for greenhouse heating, the heat pipe type exhaust heat recovery system was manufactured and tested in this experiment. The system consisted of a heat exchanger made of heat pipes, ø15.88${\times}$600mm located in the rectangular box of 675(L)${\times}$425(W)${\times}$370(H)mm, an air suction fan and air ducts. The number of heat pipe was 60, calculated considering the heat exchange amount between exhaust gas and air and heat transfer capacity of a heat pipe. The working fluid of heat pipe was acetone because acetone is known for its excellent heat transfer capacity. The system was attached to the exhaust gas path. According to the performance test it could recover 53,809 to 74,613kJ/h depending on the inlet air temperature of 12 to -12˚at air flow rate of 1.100㎥/h. The temperature of the exhaust gas left the heat exchanger dropped to 100$^{\circ}C$ from 270$^{\circ}C$ after the heat exchange between the suction air and the exhaust gas.

• Transactions of the Korean Society of Mechanical Engineers
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• v.1 no.2
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• pp.95-103
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• 1977

The expermental research was carried out to investigate the thermal performance of the locally manufactured radiators for 1300cc automobiles. The choice of .epsilon. value (the ratio of water tube surface area to the total heat transfer area ) resulted in remarkable difference in their performance including the Louver effect, the overrall heat tranfer coefficient and the heat dissipation capability.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.363-368
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• 2001

Abutments in Kumdang bridge are massive concrete structures of which total height is l0m, length is 30m, and width is 7m. Therefore, there is every probability that early age thermal cracking such as hydration heat occur. We measure heat of hydration, strains of rebar, and stresses of concrete abutment during construction. Using analysis of measuring data, we examine thermal stresses, and make use of results as method which control thermal cracking. Finally, we develope thermal stress analysis program which have pre/post processor to be easy of accessing and the usefulness of that is estimated through comparison of results.

• Fire Protection Technology
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• s.24
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• pp.32-39
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• 1998

A room-corner fire scenario of ISO 9705 with flame spread model developed by Quintiere is applied to the interior finish materials to show the sensitivity of properties derived from AST, E-1321 and ASTM E-1354 is investigated and various range of thermal properties by the author were analyzed in the model. There are including flame heat flux and thermal inertia, lateral flame spread parameter, heat of combustion and effective heat of gasfication. The time for total energy release rate to reach 1MW is examined. Though some areas are neede for improvements, The model appears to predict good results with all the range of input properties and could be

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.4
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• pp.61-68
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• 2013

As an advance study for the development of a heat sink for special purpose high power illumination, an investigation was made to find feasibility for the application of copper plated EP to a heat sink of small LED light of less than 10W installed in commercial product. In this study, the plated heat sink with EP copper was fabricated for the conventional LED light. It was used actually for finding heat radiation property and effectiveness of the heat sink accompanied with measurement of luminous intensity. The heat is radiated by transfer and dissipation only through the copper plated surface due to extremely low heat conductivity of EP in case of EP heat sink; however the total area of the plate plays the function of heat transfer as well as heat radiation in case of the aluminum heat sink. It seems that the volume difference of heat radiating material is so big that the temperature $P_1$ is 9.0~12.3% higher in 3W and 42.7~54.0% higher in case of 6W volume difference of heat radiating material is so big that the temperature $P_1$ is 9.0~12.3% higher in 3W and 42.7~54.0% higher in case of 6W even though heat transfer rate of copper is approximately 1.9 times higher than that of aluminum. It was thought that this is useful to utilize for heat sink for low power LED light with the low heating rate. Also, the illumination could be greatly influenced by the surrounding temperature of the place where it is installed. Therefore, it seems that the illumination installation environment must be taken into consideration when selecting illumination. Further study was expected on order to aims at development of an exterior surface itself made into heat radiation plate by application of this technology in future.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.3
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• pp.694-701
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• 1990

The cycle of heat engine which produces the maximum power output is constructed when heat sources are finitely constant, and the maximum power as a thermodynamic limit of the engine, is obtained. The characteristics of the maximum power cycle are as follows, which represent the operation conditions and design conditions of the heat engine to produce the maximum power output. In heat exchangers, the temperature profiles of the heat source and the working fluid have the same functional formula and the ratio of the working fluid temperature to the heat source temperature is constant. When heat capacity flow rates(product of the specific heat and the mass flow rate) of the working fluid as well as the heat source are constant, the values of those of working fluid exist between those of two heat sources. The relation of the temperature and the heat capacity flow rate is established without the states of the heat sources and the capacities of heat exchangers, which is ( $T_{h}$/ $T_{H}$)( $C_{h}$/ $C_{H}$)=( $T_{1}$/ $T_{L}$)( $c_{1}$/ $c_{L}$)=1. The capacity of the heat exchanger of hot side is equal to that of cold side regardless of the states of the heat sources and the total capacities of heat exchangers.hangers.ers.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.5
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• pp.696-701
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• 2000

Stockings are considered to be excellent in retention of heat in cool weather. This study was to investigate the physiological effects of wearing support panty stocking when exposed to the cool environment from mild environment. Five healthy female college students wearing(ST) or not wearing(NST) support panty stocking, rested at 25$\pm$1$^{\circ}C$, 50$\pm$5% R.H. and were exposed to 18$\pm$1$^{\circ}C$, 50$\pm$5% R.H. for 90 minutes. The results obtained were as follows: Rectal Temperatures were lower in ST than in NST at both environments. Skin temperatures in ST were revealed higher at $25^{\circ}C$, but lower at 18$^{\circ}C$ than in NST. Heat production and total weight loss didn't show significant difference between ST and NST. Total thermal conductance from the body to the environment was higher in ST than in NST at 18$^{\circ}C$. It was suggested that wearing support panty stocking would keep the body warm in mild environment, but facilitate heat loss from the body in cool environment.

• Journal of Chest Surgery
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• v.15 no.2
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• pp.259-265
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• 1982

We have designed a new type of bubble oxygenator (KOREA-KIM VENOTHERM OXYGENATOR) made of PVC sheet and deforming mesh incorporated in the heat exchanger, and evaluated in experimental animal for the analysis of it`s efficiency. The Oxygenator has low priming volume with high flow rate up to 6 L/rain, and efficiency of heat exchanger was excellent as 1-$1.5^{\circ}C.$ using total cardiopulmonary bypass method under moderate to deep hypothermia. Average priming volume of 1317 ml with 30% hemodilution method was perfused with an average of 1.1-3.0 L/min.$M^2$of arterial blood and pure oxygen at a rate of 2-3.4 L/min for 49.6 minutes continuously in average. During total cardiopulmonary bypass, average $PaO_2$ was $159.8{\pm}60$mmHg, $PaCO_2$ $41.0{\pm}3$mmHg respectively under $SaO_2$ over 96% with systolic arterial pressure of 70 mmHg and CVP of 5-10 cm$H_2O$. Plasma free Hemoglobin was $7.0{\pm}4$ mg/dl with 25% drop of hemoglobin and hematocrit at the end of cardiopulmonary bypass. This KKV Oxygenator was observed to have excellent capabillty of oxygen and carbon dioxide gas transfer with small amount of blood trauma, and the efficiency of heat exchanger was satisfactory during cooling and rewarming of the bubbled blood. Disadvantages have included the somewhat poor deforming effect due to loose PVC fiber mesh, the extracompact character of Teflon filters, and the rough inner surface of the heat exchanger copper pipes.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.11
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• pp.1525-1533
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• 2003

In the precision hot plate for wafer processing, uniform temperature of the upper plate is one of key factors affecting the quality of wafers. The state-of-the-art precision hot plates require temperature Variations less than $\pm$0.4$^{\circ}C$ during heating to 15$0^{\circ}C$, Which is difficult to be obtained only by the improvement of manufacturing techniques alone. In this study, computer aided heat transfer analysis was carried out to obtain the temperature distribution of the currently used reference hot plate for 200mm wafer. The analysis on the reference model assuming constant heat generation rate and uniform heating area showed total variation of 0.926$^{\circ}C$ at 15$0^{\circ}C$. One of the new design approaches based on the change of heating location together with different heat generation rate resulted in total variation of 0.297$^{\circ}C$ which is a 68% improvement compared to that of the reference model.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.474-481
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• 2005

In this study, modeling and optimization work were performed to obtain nearly pure anhydrous ethanol from aqueous ethanol mixtures using benzene as an entrainer. NRTL liquid activity coefficient model was adopted for phase equilibrium calculations and PRO/II with PROVISION 6.01, a commercial process simulator, was used to simulate the azeotropic distillation process. We used the total reboiler heat duties as an objective function and the concentration of ethanol at concentrator top as a manipulated variable. As a result, 76 mole percent of ethanol at concentrator top gave an optimum value which minimized the total reboiler heat duties of three distillation columns.