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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 21, Issue 12 - Dec 2009
Volume 21, Issue 11 - Nov 2009
Volume 21, Issue 10 - Oct 2009
Volume 21, Issue 9 - Sep 2009
Volume 21, Issue 8 - Aug 2009
Volume 21, Issue 7 - Jul 2009
Volume 21, Issue 6 - Jun 2009
Volume 21, Issue 5 - May 2009
Volume 21, Issue 4 - Apr 2009
Volume 21, Issue 3 - Mar 2009
Volume 21, Issue 2 - Feb 2009
Volume 21, Issue 1 - Jan 2009
Selecting the target year
Energy and Economic Analysis of Heat Recovery Cogeneration Loop Integrated with Heat Pump System by Detailed Building Energy Simulation
Seo, Dong-Hyun ; Koh, Jae-Yoon ; Park, Yool ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 21, issue 2, 2009, Pages 71~78
Up until recently, the energy and the economic analysis of a cogeneration system have been implemented by a manual calculation that is based on monthly thermal loads of buildings. In this study, a cogeneration system modeling validation with a detail building energy simulation, eQUEST, for a building energy and cost prediction has been implemented. By analyzing the hourly building electricity and thermal loads, it enables users to decide proper cogeneration system capacity and to estimate more accurate building energy consumption. eQUEST also verified the energy analysis when the heat pump system is integrated with the cogeneration system. The mechanical system configuration benefits from the high efficiency heat pump system while avoiding the building electricity demand increase. Economic analysis such as LCC (Life Cycle Cost) method is carried out to verify economical benefits of the system by applying actual utility rates of KEPCO(Korea Electricity Power COmpany) and KOGAS(KOrea GAS company).
Experimental Study on the Performance Change of the Fin and Tube Type Heat Exchanger by the Frosting
Kim, Jung-Kuk ; Koyama, Shigeru ; Kuwahara, Ken ; Park, Byung-Duck ; Kim, Dong-Hwi ; Sa, Yong-Cheol ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 21, issue 2, 2009, Pages 79~86
The present study was investigates the effect of the parameters on the frost formation and heat transfer performance such as fin shape, air temperature and air velocity. Heat transfer rate and pressure drop by frost were experimentally investigated. Effect of the wet blub temperature and air velocity on the heat transfer performance has been also investigated. The heat transfer performance of the louver fin and tube type heat exchanger was higher by maximum of 0.85% than the corrugate fin type at the air temperature of
. As the wet blub temperature of air were increased, the heat transfer rate, pressure drop and mass of frost of three test models were increased. Especially, the maximum heat transfer rate and maximum pressure drop were shown for the Type B louver fin heat exchanger. As an experimental result, the enhancement factor(EF) of louver fin and tube type heat exchanger was only
due to the high pressure drop.
Slim Air-Conditioner with Parallel Flow Heat Exchangers for Cooling of Telecommunication Cabinet
Cho, J.P. ; Kim, N.H. ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 21, issue 2, 2009, Pages 87~93
Slim telecommunication cabinet cooler, equipped with parallel flow heat exchangers and operating with R-22, is developed. The performance is compared with imported one, equipped with fin-tube heat exchangers and operating with R-134a. Test results show that the newly-developed cooler increases the cooling capacity by 6% and EER by 33%. The refrigerant charge for the developed cooler is 500g compared with 1250g for the imported one. The adoption of parallel flow heat exchanger appears to have reduced the refrigerant charge. In addition, it is shown that the reduced air flow rates through parallel heat exchangers as compared with those through fin-tube heat exchangers are beneficial to the reduction of the equipment noise.
Applicability of Scroll Expander-compressor for Stirling Engine
Kim, Seong-Jun ; Kim, Hyun-Jin ; Kim, Young-Min ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 21, issue 2, 2009, Pages 94~102
Conceptual design of scroll expander and scroll compressor for 10kW-class Stirling engine utilizing solar energy as heat source has been carried out to estimate the applicability of scroll mechanism for Stirling cycle. CO2 was chosen as working fluid, since it has lower expansion index and higher density among probably usable gases. Gas temperature at the expander inlet was set at
, and that at the compressor inlet was at
. System efficiency reached maximum at the pressure ratio of about 2.5, and the peak efficiency increased with increasing high side pressure. Due to safety concern, the pressure condition of 6 MPa/2.5 MPa was chosen as design condition. Orbiting scroll members for the expander and compressor were designed to have double-sided structure in order to reduce the overall scroll size and to cancel out the axial gas forces acting on the orbiting scroll base plate. By parametric study on the scroll profile, smaller possible size for the scroll members was obtained. With the shaft speed of 3600rpm, the shaft output of the designed scroll expander was calculated to be 45.4kW, while input power for the scroll compressor was 34.5kW, yielding 10.9kW for the output power of the Stirling engine. System efficiency was estimated to be about 7.3%, and overall efficiencies of the scroll expander and compressor were around 84.1% and 88.3%, respectively.
Study on the Control Performance Evaluation of the Exhaust Stack used in High Riser Public House
Kwon, Yong-Il ; Ahn, Jung-Hun ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 21, issue 2, 2009, Pages 103~108
Local exhaust system used in toilet and cooking place of low-rise public house installed roof ventilator at terminal of stack. There are many high riser public houses in Korea. These buildings were not viewed as being major contributors to exhaust pollutants producted in indoor. It was because many engineers thought that exhaust in high riser public house depends on stack effect. But Neutral pressure level represents in a terminal of stack with air tightness for the best exhaust efficiency. Thereby, lower floors have the worst indoor air quality. This paper focuses mainly on the exhaust efficiency improved by roof fan with motor installed in high riser public house. It is observed there is higher exhaust efficiency than the existing natural roof ventilator.
Performance of R430A on Refrigeration System of Domestic Water Purifiers
Park, Ki-Jung ; Lee, Yo-Han ; Jung, Dong-Soo ; Kim, Kyoung-Kee ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 21, issue 2, 2009, Pages 109~117
In this study, thermodynamic performance of R430A is examined both numerically and experimentally in an effort to replace HFC134a used in the refrigeration system of domestic water purifiers. Even though HFC134a is used predominantly in such a system these days, it needs to be phased out in the near future in Europe and most of the developed countries due to its high global warming potential. To solve this problem, cycle simulation and experimental measurements are carried out with a new refrigerant mixture of 76%R152a124% R600a using actual domestic water purifiers. This mixture is numbered and listed as R430A by ASHRAE recently. Test results show that the system performance with R430A is greatly influenced by the amount of charge due to the small internal volume of the refrigeration system of the domestic water purifiers. With the optimum amount of charge of 21 to 22 grams, about 50% of HFC134a, the energy consumption of R430A is 13.4% lower than that of HFC 134a. The compressor dome and discharge temperatures and condenser center temperature of R430A are very similar to those of HFC134a at the optimum charge. Overall, R430A, a new long term environmentally safe refrigerant, is a good alternative for HFC134a requiring little change in the refrigeration system of the domestic water purifiers.
Evaluation of the Alternatives to Minimize Stack Effect Problems with Elevators in Tall Complex Buildings
Yu, Jung-Yeon ; Song, Kyoo-Dong ; Cho, Dong-Woo ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 21, issue 2, 2009, Pages 118~125
The purpose of this study is to evaluate the stack effect reduction alternatives in tall complex buildings in cold climates. The main problems in tall buildings occur in elevators. Such problems as elevator doors that do not close and exhaust airflows result in excessive pressure differences across elevator doors due to stack effect. Under the expected conditions causing these pressure differences, Field measurements are performed in three tall buildings. Each result of the measurements is analyzed in architectural design aspects. With these analysis, building design guidelines are proposed and analyzed by field measurements and computer simulations.
Analysis of Combustion Oscillation and its Suppression in a Silo Type Gas Turbine Combustor
Seo, Seok-Bin ; Ahn, Dal-Hong ; Cha, Dong-Jin ; Park, Jong-Ho ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 21, issue 2, 2009, Pages 126~130
The present study describes an investigation into the characteristics of combustion oscillation and its suppression instability of a silo type gas turbine combustor in commercial power plant. Combustion oscillation is occurred the combustor in near full load during operation. As a result of FFT analysis of the combustion dynamics, the frequency of the oscillation is analyzed as the 1'st longitudinal mode of acoustic resonance of the combustor. For suppress of the instability, combustion tuning with adjust of fuel valve schedule is carried out, which changes equivalent ratio of each burners. As the result, the oscillation is successfully reduced with meeting the level of NOx emission regulation.