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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
Influence of the Secondary Fluid Flow Rate on the Performance of a GSHP System
Lee, Jun-Yub ; Chung, Jin-Taek ; Woo, Jung-Son ; Choi, Jong-Min ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 649~656
The aim of this study is to investigate the influence of the secondary fluid flow rate through GLHX on a GSHP system with vertical single U-tube type GLHXs. The COP of a GSHP system with large flow rate was lower than it with small flow rate due to large power consumption of ground loop circulating pump. It is suggested that the heat pump unit with high COP and low flow rate through the GLHX have to be selected in order to enhance the performance of the system and reduce the length of GLHX.
Comparison of Performance Characteristics with Heat Exchanger Type in
Bae, Kyung-Jin ; Cho, Hong-Hyun ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 657~664
The theoretical analysis of performance characteristics in a
cycle with the heat exchanger type was carried out. The size and performance of the fin-tube and microchannel heat exchanger were compared with operating conditions. As a result, the performance of the fin-tube gascooler and evaporator were more sensitive to the variation of operating condition compared to that of the microchannel gascooler and evaporator. Beside, the sizes of microchannel gascooler and evaporator could be decreased by 73% and 76%, respectively, compared to those of the fin-tube type gascooler and evaporator with the similar capacity. The COP and reliability of the
system can be increased by using a microchannel heat exchanger.
The 1D-3D Simulation for Smoke Ventilation in a Rescue Station of a Railroad Tunnel under the Fire
Jung, Jae-Hyuk ; Hur, Nahm-Keon ; Lee, Jung-Pyo ; Kim, Jin-Kon ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 665~671
In the present study a 1D-3D numerical simulation was performed to analyze the fire safety in a rescue station of a long railroad tunnel equipped with a mechanical ventilation. The behavior of hot air was studied for the emergency operation mode of ventilation system in case of fire in the rescue station. The 1D simulation was carried out for entire tunnel region. Detailed 3D CFD simulation was performed for the rescue station area in the central region of the tunnel by using the result of the 1D simulation as the boundary condition of the 3D simulation. Various type of cross passage installation were evaluated for the prevention of smoke diffusion to suggest the optimized interval of the cross passages in the rescue tunnel.
A Container Stacking System for the Mobile Harbor
Kim, In-Su ; Kim, Kwang-Hoon ; Son, Kwon ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 672~678
The purpose of this study is to develop a stacking guidance system (SGS) of containers in the mobile harbor (MH). A mobile harbor is a floating structure especially designed for loading and unloading containers from and to a large container ship. A novel stacking guidance system was proposed for unloading the container in an effective way against possible vibrations of the floating body. The guidance system works as an aid for loading containers with a wider opening for easier stacking of a container into a moving storage cell due to waves. In order to determine the most effective inclination angle of the cell-guide, this study performed the dynamic analysis of the SGS equipped in the MH subject to fluctuations of the sea. The motions of the guidance system and a container loaded were calculated using ADAMS. The simulation results of the contact force between the two rigid bodies showed that a desirable angle of the cell-guide should be around 20 degrees from the vertical. This proposed SGS can considerably reduce the loading and unloading time, and will enhance the performance of the MH.
Long-Term Thermal Conductivity Prediction of Polyurethane Foam Applying Precision Mass Spectrometer for Cell Gas Analysis
Kim, Jin-Seok ; Chun, Jong-Han ; Lee, Jin-Bok ; Lee, Hyo-Jin ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 679~686
A proprietary device is adopted to break out the membrane of cell in the rigid polyurethane foam. As it is known, the membrane of cell is hardly tearing-off thoroughly in a mechanical way due to both its elastic characteristic and micro sized pores. In this study, a novel experimental approach is introduced to burst out all gases inside the cells of the rigid polyurethane foam by abrasively grinding micro-cells completely into fine powder. The biggest advantage of this approach is to be capable of releasing all gases out from the cell even in the micro pores. As clearly reflected from the repeatability, the accuracy of the result is highly improved and high confidence in the data sets as well. For the measurements of not only gas composition but partial pressure for each gas simultaneously as well, a precision gas mass spectrometer is used in-line directly to the abrasive grinding device. To control the starting point of the polyurethane foam, all samples were prepared on site in the laboratory. Manufactured time is one of the most critical factors in characterization of cell gas composition because it is known that one of gas composition, especially, carbon dioxide, is diffused out dramatically in a short period of time as soon as it is foamed.
Fault Detection and Diagnosis Simulation for CAV AHU System
Han, Dong-Won ; Chang, Young-Soo ; Kim, Seo-Young ; Kim, Yong-Chan ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 687~696
In this study, FDD algorithm was developed using the normalized distance method and general pattern classifier method that can be applied to constant air volume air handling unit(CAV AHU) system. The simulation model using TRNSYS and EES was developed in order to obtain characteristic data of CAV AHU system under the normal and the faulty operation. Sensitivity analysis of fault detection was carried out with respect to fault progress. When differential pressure of mixed air filter increased by more than about 105 pascal, FDD algorithm was able to detect the fault. The return air temperature is very important measurement parameter controlling cooling capacity. Therefore, it is important to detect measurement error of the return air temperature. Measurement error of the return air temperature sensor can be detected at below
by FDD algorithm. FDD algorithm developed in this study was found to indicate each failure modes accurately.
Numerical Analysis on Energy Reduction of an Exhaust-Air-Heat-Recovery Type Air Washer System for Semiconductor Manufacturing Clean Rooms
Song, Gen-Soo ; Kim, Hyung-Tae ; Yoo, Kyung-Hoon ; Son, Seung-Woo ; Shin, Dae-Kun ; Kim, Young-Il ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 697~703
In recent semiconductor manufacturing clean rooms, air washers are used to remove airborne gaseous contaminants from the outdoor air introduced into a clean room. Meanwhile, there is a large amount of exhaust air from a clean room. From an energy conservation point of view, heat recovery is useful for reducing the outdoor air conditioning load required to maintain a clean room. Therefore it is desirable to recover heat from the exhaust air and use it to cool or heat the outdoor air. In the present study, numerical analysis was conducted to evaluate the recovered heat of an exhaust air heat recovery type air washer system, which is the key part of an energy saving outdoor air conditioning system for semiconductor clean rooms. The present numerical results showed relatively good agreement with the available experimental data.
Flow Boiling of R-123/Oil Mixture in a Plain Tube Bundle
Lee, Jin-Wook ; Lee, Jae-Ho ; Kim, Nae-Hyun ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 704~709
The effect of oil on flow boiling of R-123 in a plain tube bundles was experimentally investigated for a range of quality and heat flux. It is shown that the heat transfer coefficient decreased as the oil concentration increased. Comparison with the previous pool boiling data reveals that the reduction of heat transfer coefficient by oil is more pronounced in pool boiling, and the difference increased with the increase of oil concentration and heat flux. Within the experimental range, the variation of mass flux or quality has negligible effect on the heat transfer coefficient.
A Numerical Study on R410A Charge Amount in an Air Cooled Mini-Channel Condenser
Park, Chang-Yong ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 710~718
A numerical study was performed to predict refrigerant charge amount in a mini-channel condenser for a R410A residential air-conditioning system. Multi-channel flat tubes with 12 mini-channels of 1.17 mm average hydraulic diameter for each tube were applied to the condenser. The condenser consisted of 3 passes, and the first, second, and third pass had 44, 19, and 11 tubes, respectively. Each pass was connected by a vertical header. In this study, the condenser was divided into 410 finite volumes, and analyzed by an
-NTU method. With thermophysical properties and void fraction models for each volume element, the R410A amount distribution and a total charge amount in the condenser were calculated. The predicted total charge amount was compared with the experimentally measured charge amount under a standard ARI A condition. The developed model could predict the charge amount in the mini-channel condenser within prediction errors from -23.9% to -3.0%. Air velocity distribution at the condenser face was considered as non-uniform and uniform by the simulation model, and its results showed that the air velocity distribution could significantly influence the charge amount and vapor phase distribution in the condenser.
Consideration of Appropriate Thermal Storage Time of Air-Conditioning System with Slab Thermal Storage in an Office Building by Use of Measurement Value
Jung, Jae-Hoon ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 22, issue 10, 2010, Pages 719~726
In this paper, the appropriate thermal storage time of an air-conditioning system with slab thermal storage was considered by use of summer measurement values. Two standards of heat extraction rate and criterion function were established as the standard that evaluates appropriateness. When heat extraction rate was a standard, zero hour and seven hours were obtained as appropriate thermal storage time, in the case of evaluation by energy consumption and running cost individually. Also, when criterion function was a standard, the difference between energy consumption and running cost was small, it was because the weight function to room air temperature deviation was much bigger than heat extraction rate.