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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 24, Issue 12 - Dec 2012
Volume 24, Issue 11 - Nov 2012
Volume 24, Issue 10 - Oct 2012
Volume 24, Issue 9 - Sep 2012
Volume 24, Issue 8 - Aug 2012
Volume 24, Issue 7 - Jul 2012
Volume 24, Issue 6 - Jun 2012
Volume 24, Issue 5 - May 2012
Volume 24, Issue 4 - Apr 2012
Volume 24, Issue 3 - Mar 2012
Volume 24, Issue 2 - Feb 2012
Volume 24, Issue 1 - Jan 2012
Selecting the target year
Energy Efficiency Evaluation of Heating and Cooling Systems as Space Program in Renovated Library
Park, Kang-Hyun ; Cha, Jung-Hoon ; Kim, Su-Min ; Park, Kyung-Won ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 205~211
DOI : 10.6110/KJACR.2012.24.3.205
Unlike the previous approaches, we analyzed for economic efficiency of renewed heating and cooling systems as the characteristics of space. The purpose of this study is to analysis the energy consumption and economical efficiency of absorption chillers and EHP systems in renovated library. It is important that equipment selection should be considering energy cost as well as space program. In recently, many EHP systems were installed in the building for reducing the energy cost and for seeking the convenience of individual control. In contrast, though absorption chillers have the disadvantage of a central control, absorption chillers are appropriate for the conditions of the library that needs simultaneous operation. The results by payback period method, show that selection of heating and cooling systems should be consider for space program and the characteristics of space.
Power and Heat Load of IT Equipment Projections for New Data Center`s HVAC System Design
Cho, Jin-Kyun ; Shin, Seung-Ho ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 212~217
DOI : 10.6110/KJACR.2012.24.3.212
The cooling of data centers has emerged as a significant challenge as the density of IT equipment increased. With the rapid increasing of heat load and cooling system, predictions for electronics power trends have been closely watched. A data center power density projection is needed so that IT organizations can develop data centers with adequate cooling for reasonable lifetimes. This paper will discuss the need for something more than processor and equipment power trend projections which have overestimated the required infrastructure for customers. This projection will use data from a survey of actual enterprise data centers and the ASHRAE projections to formulate a data center server heat load trend projection.
Characteristic of Thermal Output of Thermally Activated Building System During the Heating Operation According to FDM Analysis
Lim, Jae-Han ; Song, Jin-Hee ; Koo, Bo-Kyoung ; Song, Seung-Yeong ; Senog, Yoon-Bok ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 218~223
DOI : 10.6110/KJACR.2012.24.3.218
This study is focused on the evaluation of thermal output of TABS (Thermally Activated Building System). The aim of this study is to evaluate TABS in terms of the temperature difference between heating medium supply temperature (
) and return temperature (
), thermal output and the surface temperature distribution according to the design flow rate and the design flow temperature. Through the transient heat transfer simulation using temperature calculation using Crank-Nicolson FDM using Physibel Voltra 6.0 W, the temperature difference between
, thermal output and the surface temperature distribution of specific TABS was calculated and evaluated. The results show that specific thermal output and temperature difference at
of supply water temperature were about 162
A Study on The Performance of a Heat Recovery Ventilator According to the Properties of Spacers
Lim, Tae-Kun ; Jeon, Byung-Heon ; Kim, Jong-Won ; Jung, Sung-Hak ; Lee, Seung-Kap ; Ahn, Young-Chull ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 224~229
DOI : 10.6110/KJACR.2012.24.3.224
The importance of ventilation system is being emphasized by interest of indoor air quality. Especially, heat recovery ventilation system has attracted attention as most effective ventilation plan. Because it can reduce hazardous construction materials, indoor air pollutions, and also can reduce air conditioning energy cost. In heat recovery ventilator, the element core is the most important part. The element core is composed of liner and spacer. And liner and spacer are stacked alternately. On the Liner, heat and humidity transfer are made between supply and exhaust air. And spacer plays a role as a tunnel of exhaust and supply. In this study, we investigated and analyzed the efficiency of a heat recovery ventilator, when the spacer`s properties are changed. As a result, difference spacer`s properties affect an efficiency of heat recovery ventilator.
Performance Analysis of Ground-Coupled Heat Pump System with Slinky-Type Horizontal Ground Heat Exchanger
Sohn, Byong-Hu ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 230~239
DOI : 10.6110/KJACR.2012.24.3.230
Ground-coupled heat pump (GCHP) systems utilize the immense renewable storage capacity of the ground as a heat source or sink to provide space heating, cooling, and domestic hot water. The main objective of the present study is to investigate the cooling and heating performance of a small scale GCHP system with horizontal ground heat exchanger (HGHE). In order to evaluate the performance, a water-to-air ground-source heat pump unit connected to a test room with a net floor area of 18.4 m2 and a volume of 64.4 m3 in the Korea Institute of Construction Technology (
) was designed and constructed. This GCHP system mainly consisted of slinky-type HGHE with a total length of 400 m, indoor heat pump, and measuring devices. The peak cooling and heating loads of the test room were 5.07 kW and 4.12 kW, respectively. The experimental results were obtained from March 15, 2011 to August 31, 2011 and the performance coefficients of the system were determined from the measured data. The overall seasonal performance factor (SPF) for cooling was 3.31 while the system delivered heating at a daily average performance coefficients of 2.82.
An Experimental Study on Performance of Paper Heat Exchangers for Exhaust Heat Recovery Ventilation System
Chung, Min-Ho ; Oh, Byung-Kil ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 240~246
DOI : 10.6110/KJACR.2012.24.3.240
The supply and use of exhaust heat recovery ventilation system as effective energy saving equipment has been increasing steadily. The exhaust heat recovery ventilation system can be installed at ceiling of balcony or emergency space. However, ventilation system can not be installed at emergency space because where have to remain as empty space by law. Therefore, the proper installation space of ventilation system is needed. In this study, to install heat recovery ventilation system in the light weight wall, thickness of heat exchanger was assembled below 140 mm. One or two paper heat exchangers were installed in the ventilation system. The efficiency of heat recovery was analyzed through performance experiment on case of cooling and heating mode.
A Numerical Study of Natural Convection in a Square Enclosure with two Hot Circular Cylinders
Park, Seong-Hyun ; Park, Yong-Gap ; Ha, Man-Yeong ; Yoon, Hyun-Sik ; Son, Chang-Min ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 247~255
DOI : 10.6110/KJACR.2012.24.3.247
Numerical calculations are carried out for the natural convection in a square enclosure with two hot cylinders induced by temperature difference between a cold outer rectangular cylinder and two hot circular cylinders. A two-dimensional solution for unsteady natural convection is obtained, using the immersed boundary method (IBM) to model two inner circular cylinders based on finite volume method, for different Rayleigh numbers varying over the range of
. The study goes further to investigate the effect of the location of two cylinders on the heat transfer and fluid flow. The location of inner circular cylinders is changed vertically along the center-line of square enclosure. The changes of heat transfer quantities have been presented.
Design of a Micro-Channel Heat Exchanger for Heat Pump Using Approximate Optimization Method
Seo, Seok-Won ; Ye, Huee-Youl ; Lee, Kwan-Soo ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 256~264
DOI : 10.6110/KJACR.2012.24.3.256
A general procedure for the optimal design of a micro-channel heat exchanger for heat pump systems is presented. For this design, a performance analysis program that can reflect the various geometric variables of the micro-channel heat exchanger was developed. The deviation between simulated and experiment results of previous research was within 4% for the heat transfer rate. To prove the feasibility of the optimal design process, the performance of the reference heat exchanger was compared to that of the optimized heat exchanger. The
and PECv of the optimized heat exchanger were enhanced by 14% and 26%, respectively.
Heat Transfer Characteristics of Heat Exchange Module for a Water Tube Type Modular Boiler
Ahn, Joon ; Kim, Jong-Jin ; Kang, Sae-Byul ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 265~270
DOI : 10.6110/KJACR.2012.24.3.265
A finned tube type heat exchange module has been proposed for a multi-burner water tube boiler. Fin density and length increase in streamwise direction to equalize the evaporation for each module, which makes it difficult to apply conventional bulk design procedure. The design program has been improved by updating data for every row of tubes along the flow. A numerical simulation has been also conducted to evaluate the effect of inlet conditions and validated with experiment. The heat transfer of the first row has been underpredicted by the conventional Zhukauskas correlation, since the acceleration of the flow due to the blockage is not fully inflected. The fin tip temperature is also underpredicted by Bessel solution, because of the interaction with neighboring fins.
Analyses on Satisfaction and Perception for Space according to Experiencing Interactive Media in Exhibition Halls
Song, Yoo-Young ; Lee, Ji-Hyun ; Kim, Soo-Young ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 271~280
DOI : 10.6110/KJACR.2012.24.3.271
This study examines the influence of experiencing interactive media in exhibition halls on the satisfaction and perception for the exhibition space. Field measurements and surveys were performed in two exhibition halls where various interactive media were exhibited. Results imply that experiencing interactive media was important to enhance understanding the information provided by them. In order to improve satisfaction for the exhibition halls, the layout of space need to be organized effectively in a way that visitors easily feel interest in the contents and information exhibited in the space. Also, in order to keep better perception for exhibition space, the information provided in the space should be organized clearly and open to visitors easily. The flow of visitors` traffic in the exhibition space should be perceived easily by the visitors. Multiple linear regression indicated that the space should be organized effectively with good visual composition that surrounds the exhibits in order to improve satisfaction level for the exhibition hall. In addition, various information provided by the media contributed to improve perception for the exhibition hall.
A Study on the Oxide Scale of the Long Term Serviced 12%Cr Boiler Tube Steel
Kim, Beom-Soo ; Min, Taek-Ki ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 24, issue 3, 2012, Pages 281~287
DOI : 10.6110/KJACR.2012.24.3.281
The internal oxide scale of twelve superheater and reheater tubes were tested which were serviced for 30,000~120,000 hours in thermal power plants. The oxide scale was formed in three layers. The Cr-rich area was observed beneath the original metal surface. The hematite (
) phase was formed on the outer surface. The intermediate layer was magnetite (
). The thickness of Cr-rich layer was about half of the total scale. All layers grew during the operation hour of the plant. The thickness of thickest scale was 0.2mm in superheater tubes. This can increase the tube metal temperature about
more than initial state.
tube metal temperature can reduce tube life about 30%, but the boiler tube`s design margin is big enough therefore it has been analyzed that it would not effect on the life span.