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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Journal of Air-Conditioning and Refrigeration Engineering
Journal Basic Information
Journal DOI :
The Society of Air-Conditioning and Refrigerating Engineers of Korea
Editor in Chief :
Volume & Issues
Volume 18, Issue 12 - Dec 2006
Volume 18, Issue 11 - Nov 2006
Volume 18, Issue 10 - Oct 2006
Volume 18, Issue 9 - Sep 2006
Volume 18, Issue 8 - Aug 2006
Volume 18, Issue 7 - Jul 2006
Volume 18, Issue 6 - Jun 2006
Volume 18, Issue 5 - May 2006
Volume 18, Issue 4 - Apr 2006
Volume 18, Issue 3 - Mar 2006
Volume 18, Issue 2 - Feb 2006
Volume 18, Issue 1 - Jan 2006
Selecting the target year
Design of a Pin-Fin Structure in a Channel Considering the Heat Transfer and Pressure Drop Characteristics
Shin, Jee-Young ; Son, Young-Seok ; Lee, Dae-Young ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 18, issue 6, 2006, Pages 459~467
Rapid development of electronic technology requires small size, high density packaging and high power in the electronic devices, which results in more heat generation. Suitable heat dissipation is required to ensure the guaranteed performance and reliable operation of the current state-of-the-art electronic equipment. The aim of the present study is to find out the forced-convective thermal-hydraulic characteristics of a pin-fin heat exchanger as a candidate for cooling system of the electronic devices through the analysis and experiment. Various configuration of the pin-fin array is selected in order to find out the effect of spacing and diameter of the pin-fin on the heat transfer and pressure drop characteristics. Experimental results are compared with the analyses and correlations of several researchers. Finally, the design guide are provided for the required pressure drop and/or the heat transfer characteristics of the heat exchanger.
A Prediction of VOCs Emission Rate with Temperature Variation in Floor Heating Space by Numerical Analysis
Kang, Dong-Hwa ; Choi, Dong-Hee ; Kim, Sun-Sook ; Kim, Young-Don ; Yeo, Myoung-Souk ; Kim, Kwang-Woo ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 18, issue 6, 2006, Pages 468~476
The paper deals with the numerical analysis of contaminants emission from the material affected by temperature variation in floor heating system. Considering mass transfer and heat transfer theories, a computer program for the analysis of VOCs emission was made. To demonstrate the accuracy of the numerical solution, the prediction results and the measured data were compared. Using this program, emission rates of the materials in the bakeout space and the no bake-out space were compared to estimate the variation of emission rate.
Frost Prevention of Fin-Tube Heat Exchanger by Spreading Antifreezing Solution
Oh, Sang-Youp ; Chang, Young-Soo ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 18, issue 6, 2006, Pages 477~485
A study on frost prevention of fin-tube heat exchanger is experimently performed by spreading antifreezing solution on heat exchanger surface. It is desirable that the antifreezing solution spreads completely on the surface forming thin liquid film to prevent frost nucleation and crystal growth and to reduce the thermal resistance across the liquid film. A small amount of antifreezing solution falls in drops on heat exchanger surface using two types of supplying devices, and a porous layer coating technique is adopted to enhance the wettedness of antifreezing solution on the surface. It is observed that the antifreezing solution liquid film prevents fin-tube heat exchanger from frosting, and heat transfer performance does not degrade through the frosting tests. The concentration of supplied antifreezing solution can be determined by heat transfer analysis of the first row of heat exchanger to avoid antifreezing solution freezing due to dilution by moisture absorption.
Characteristics of VOCs Emission According Interior Finish Materials and Working Phases of New Apartments
Pang, Seung-Ki ; Cho, Woo-Jin ; Sohn, Jang-Yeul ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 18, issue 6, 2006, Pages 486~492
In this research, IAQ is measured to evaluate the emission performance of VOCs in three new apartment houses finished by totally EFMs (Environmental Friendly Material), partially installed EFMs and general materials. Among various VOCs, Target pollutants for the IAQ measurement are benzene, ethylbenzene, toluene, xylene, 1,4-Dichlorobenzene and formaldehyde. The measurement is conducted one day after each interior finishing material is worked over by construction schedule. The result of this research concluded that (1) Except toluene, the concentration levels of each pollutant did not exceed the national IAQ standards in all test residences, (2) As the interior finishing work schedule, A toluene level peaked when the furniture installing was ended. (3) The toluene concentration level of the house installed general interior materials as the non-EFMs furniture was one and half higher than other houses. Consequently, installing. the furniture made by EFMs is one of effective methods to improve the IAQ for new apartment houses.
Thermal Conductivity Measurement of Grouting Materials for Ground Heat Exchanger Borehole
Sohn, Byong-Hu ; Shin, Hyun-Joon ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 18, issue 6, 2006, Pages 493~500
This paper concerns the measurement of thermal conductivity of grouting materials for ground loop heat exchanger. A thermal conductivity meter, QTM-500 based on modified transient hot wire method was used to measure the thermal conductivity of neat bentonite and mixtures of bentonite and various additives. Relative to the total mixture mass, as the percent additive was increased the mixture thermal conductivity increased. For the bentonite-silica sand mixtures, the higher density of the sand particles resulted in much higher mixture thermal conductivity. The quartzite and silica sands produced the largest increases in mixture thermal conductivity, while common masonry and limestone sands produced lower thermal conductivity increases.
Simulation of Refrigeration System with MPCM Slurry as Secondary Fluid
Choi, Jong-Min ; Kim, Yong-Chan ; Cheon, Deok-Woo ; Kang, Hoon ; Yoon, Joon-Sang ; Cho, Han-Ho ; Kim, Young-Bae ; Lee, Ho-Seong ; Choi, Kwang-Min ; Kang, Yong-Hwa ; Jeon, Jong-Ug ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 18, issue 6, 2006, Pages 501~508
MPCM (Microencapsulated Phase Change Material) slurries show several advantages over the sensible heat transportation system. In this study, a numerical model for a vapor compression refrigeration system using MPCM slurries as a secondary fluid through an evaporator was developed, and the system performance was compared with that using water. Generally, the MPCM system showed higher performance than the water system. The COP of the MPCM system was higher by 16.6 to 18.6% than that of the water system at all conditions. The MPCM slurry yields better performance in the aspect of heat transfer and heat transportation comparing to the sensible heat transfer medium such as water.
Cooling Characteristics on the Forced Convection of an Array of Electronic Components in Channel Flow (II) - The Effect of the Reynolds Number (without the Heat Sink) -
Kim, Kwang-Soo ; Yang, Jang-Sik ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 18, issue 6, 2006, Pages 509~517
Present study is concerned with an experimental study on the cooling characteristics of heat-generating components arranged in channels which are made by printed circuit boards. To estimate the thermal performance of the heat-generating components arranged by
in channel flow, three variables are used: the inlet velocity, the height of channel, and row number of the component. The cooling characteristics of the heat-generating components such as the surface temperature rise, the adiabatic temperature rise, the adiabatic heat transfer coefficient, and the effect of thermal wake are compared with the result of the experiment and the numerical analysis. The experimental result is in a good agreement with the numerical analysis. The heat transfer coefficient increases as the Reynolds number increases, while the thermal wake function calculated for each row decreases as the Reynolds number increases. In addition, it is found that Nu-Re correlation equation is Identical to the previous studies, and the empirical correlation equation between the thermal wake function and Re is presented.
Heat Transfer Characteristics of Micro-encapsulated Phase-Change-Material Slurry
Kim, Myoung-Jun ; Park, Ki-Won ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 18, issue 6, 2006, Pages 518~525
The present experiments have been performed for obtaining the melting heat transfer characteristics of micro-encapsulated solid-liquid phase-change material and water mixture slurry flow in a circular tube heated with constant wall heat flux. The phase change material having a low melting point was selected for a domestic cooling system in the present study. The governing parameters were found to be latent heat material concentration, heat flux, and the slurry velocity. The experimental results revealed that the increase of tube wall temperature of latent microcapsule slurry was lower than that of water caused by the heat absorption of fusion.
Prediction of Heat-Up Time of the Glass Plate by IR Heaters in an LCD-Panel Cleaning Process
Kim, Yun-Ho ; Ji, Tae-Ho ; Kim, Seo-Young ; Rhee, Gwang-Hoon ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 18, issue 6, 2006, Pages 526~533
The prediction of heat-up time of an LCD glass plate in LCD glass pre-treatment process has been implemented in the present study. Firstly, the analytical solution for one-dimensional radiation heat transfer from IR heaters to a LCD glass plate is obtained. When the surface temperature of the IR heaters is set at 473 K, the heat-up time of LCD glass to averaged temperature of 383K is 28 seconds. In addition, a three dimensional full CFD analysis using STAR-CD is implemented in an effort to consider the effect of 3-D heat loss through the furnace walls. From the results of the 3-D CFB analysis, the heat-up time increases up to 32.5 seconds under the same conditions. When the IR heater temperature in creases up to 573 K, the heat-up time decreases to 12 seconds for the one-dimensional analytical solution and to 13.5 seconds for the 3-D CFD analysis, respectively.