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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 22, Issue 12 - Dec 2010
Volume 22, Issue 11 - Nov 2010
Volume 22, Issue 10 - Oct 2010
Volume 22, Issue 9 - Sep 2010
Volume 22, Issue 8 - Aug 2010
Volume 22, Issue 7 - Jul 2010
Volume 22, Issue 6 - Jun 2010
Volume 22, Issue 5 - May 2010
Volume 22, Issue 4 - Apr 2010
Volume 22, Issue 3 - Mar 2010
Volume 22, Issue 2 - Feb 2010
Volume 22, Issue 1 - Jan 2010
Selecting the target year
Performance Characteristics of Thermoelectric Generator Modules For Parallel and Serial Electrical Circuits
Kim, Yun-Ho ; Kim, Myung-Kee ; Kim, Seo-Young ; Rhee, Gwang-Hoon ; Um, Suk-Kee ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 259~267
An experiment has been performed in order to investigate the characteristics of multiple thermoelectric modules (TEMs) with electrical circuits. The open circuit voltage of TEM connected parallel circuit is equal to the sum of individual TEMs. In contrast, the open circuit voltage is equal to the average of that individual TEM for a series circuit. The power output and conversion efficiency of TEM for both parallel and series circuits increase as the operating temperature conditions for individual TEMs becomes identical. Comparing parallel with series circuits, the power generation performance is more excellent for series circuit than parallel circuit. This result is attributed to the power loss from the TEM with better power generation performance.
An Experimental Study on the Optimization of the Performance Characteristics of a Refrigeration System Using R-600a and R-134a
Jang, Eui-Sung ; Yoon, Won-Jae ; Chung, Hyun-Joon ; Jung, Hae-Won ; Kim, Yong-Chan ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 268~274
Because both R-134a and R-600a are used as a refrigerant of a household refrigerator in the global market, the home-appliance industry needs an optimized cycle for both refrigerants. The objective of this study is to provide the design guideline on the optimization of a refrigeration system using both refrigerants. For both refrigerants, the performance characteristics of the refrigeration system were tested by varying refrigerant charge amount, capillary tube length, suction diameter and SLHX length. The tested refrigeration system was optimized at the refrigerant charge of 60 g and the capillary tube length of 3600 mm with R-134a, and the refrigerant charge of 34 g and the capillary tube length of 3900 mm with R-600a. The COP increased from 1.63 to 1.68 for R-134a and increased from 1.37 to 1.48 for R-600a, respectively, by applying the suction diameter expansion. In addition, the COP of the R-134a and R-600a system decreased by 2.3~2.4% as the SLHX length decreased by 300 mm.
A Basic Study on Control Algorithm for Car HVAC
Shin, Young-Gy ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 275~281
Car HVAC is one of main factors influencing a potential customer's first impression. It should be fault-free, which requires the most stable control performance. So, the control algorithm consists of a proportional feedback only, not with an integral action needed for elimination of steady-state errors. To reduce the errors and make the response faster, feedforward algorithm based on predicted thermal load is added. To evaluate the performance, car HVAC is dynamically modelled and its control logic is simulated. The results shows that the proportional feedback leads to about
of steady-state error. When the feedback is combined with the feedforward algorithm and with a set value update based on disturbances, it predicts less than
of control error and improved thermal comfort.
Surface Characteristics of Polymer Material Treated by Atmospheric Pressure Plasma
Seo, Seung-Ho ; Chang, Sung-Hwan ; Yoo, Yeong-Eun ; Chung, Jae-Dong ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 282~288
Experiment on the surface characteristics of polymer films treated by atmospheric pressure plasma has been conducted. We chose the process parameters as frequency, gas flow, treatment time, and scrutinized the effects of the process parameters on the surface characteristics of polymer materials by measuring the contact angle and examining SEM. As the result, the surface characteristics highly depends on frequency, reaction gas and treatment time. In the case of PC substrate, the contact angle was changed from
(before plasma treatment) to
(after plasma treatment) at 30 kHz, CDA 0.6%, and number of repeat 7. In the case of PET substrate, the contact angle change was found from
at 20 kHz, CDA 0.6%, and number of repeat 7. In the case of EVA substrate, it shows from
at 30 kHz, CDA 0.6%, and number of repeat 7.
Characteristics of Carbon Nano Fluid Added PVP
Seo, Hyang-Min ; Park, Sung-Seek ; Kim, Nam-Jin ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 289~295
In this study, the enhancement of the thermal conductivity of water in the presence of multi-walled carbon nanotubes, MWCNT, was investigated. Sodium Dodecyl Sulfate, SDS, and Polyvinylpyrrolidone, PVP, were employed as the dispersant. SDS or PVP was added in pure water. And then, MWCNT of 0.0005, 0.001, 0.002, 0.003, 0.004, 0.005, 0.01, and 0.02 vol% was dispersed respectively. The thermal conductivity and the viscosity were measured with a transient hot-wire instrument built for this study and the DV II+ Pro viscometer. The results showed that PVP had good thermal conductivity at 300 wt% and this was better than that of SDS 100 wt%, also, the viscosity of nano fluid added PVP rapidly increased until 0.02 vol%.
Study on the Performance Characteristics of Hybrid Solar Heating System during Spring Season
Pyo, Jong-Hyun ; Kim, Won-Seok ; Cho, Hong-Hyun ; Park, Cha-Sik ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 296~303
An experimental study was carried out to investigate performance characteristics of the hybrid solar system during spring season. The system operating condition, each load, and heat pump performance were analyzed with the cloud cover. As a results, the collector heat, solar fraction, and hot water load were decreased with a rise of the cloud. The heating load was considerably effected by the ambient temperature regardless of the cloud cover. Besides, the temperature of hot water increased with the solar radiation. The COP of the heat pump was significantly influenced by the ambient temperature, that was 2.09~2.46 for gray day and 1.94~2.71 for fair day, respectively.
Evaluation Methods for Chemical Emissions from TV Products and Establishing Criteria for the Perceived Indoor Air Quality
Kang, Hyo-Seok ; Yoon, Dong-Won ; Lee, Yoon-Gyu ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 304~313
During recent years, various studies have demonstrated that indoor chemical pollution causes health problem and also negatively affect the performance of work by occupants. Building materials have been concerned as indoor chemical sources. Some of guidelines and certification system has been developed and resulted as dramatic decrease of harmful indoor chemicals such as formaldehyde and volatile organic compounds. Also, Home furniture and electrical devices has been concerned as one the primary influence the indoor chemical concentration in residential spaces. It is found that various kinds of electric home appliances have a significant source of chemical emission in indoor environments. In this study, the methodologies of detecting harmful chemicals from various kinds of products has been developed with large chamber measurement system and suggest some of the evaluation method for the chemicals from the home appliances as TV sets.
Influence of the Variations of Functional-Interior Factors on Study-rooms in Apartment
Kim, Sang-Min ; Kim, Soo-Young ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 314~321
This study examines the influence of functional interior factors on the variation of indoor environment to propose proper elements for planning studyrooms. Several factors that should be included in planning stages of the rooms are discussed to apply appropriate conditions for a pilot study. Field measurements and survey were performed in actual apartment buildings. The influence of lighting, thermal and acoustical conditions on comfort levels were examined.
Heat Transfer Performance of the Duct with Various Cross Section in Heat Exchanger
Kim, Eung-Bok ; Han, Min-Sub ; Kim, Nae-Hyun ; Won, Tae-Yeon ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 322~327
It is a critical task to keep the ventilation system working in a proper and efficient manner in large multi-storey buildings, and the enthalpy exchanger is becoming an increasingly important part of the ventilation system by playing the function of channeling heat and moisture. We present a computational study on the heat transfer performance of the cross-flow enthalpy exchanger, which is in large use for residential buildings. The ducts are considered whose cross-sectional shapes resemble triangle and longitudinal centerline a cosine wave. It is shown that, as the cross-sectional shape departs from triangle, the heat transfer performance of the duct tends to deteriorate. Also, applying the wave-like shape to the longitudinal centerline of the duct increases the rate of heat transfer and the applied pressure-gradient at the same time. The origin of the performance variations in the cases considered are quantitatively analyzed and discussed.
Effects of Performance Analysis of a Desiccant Cooling System with a Direct Evaporative Cooler in the Inlet of Regeneration Process
Dash, Ulziiutas ; Sung, Sang-Chul ; Oh, Myung-Do ; Lee, Dae-Young ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 5, 2010, Pages 328~335
The purpose of this study is to make an analysis of influence on the cooling capacity and COP of a desiccant cooling system with a regenerative evaporative cooler when a direct evaporative cooler was applied to the inlet of regeneration process of this system. We used cycle simulation in order to analyze the performance of this system. From the cycle simulation, we knew that the optimal rotation time of desiccant rotor was between 160s and 220s and hardly ever affected cooling capacity of desiccant cooling system when this system was operated at the outdoor air condition of
and 40% RH and low regeneration temperature of
. Also there was optimal area ratio of regeneration to dehumidification between 0.7 and 1.0. Our results showed that it had a small effect on the system’s cooling capacity to install direct evaporative cooler at the inlet of regeneration process.