Go to the main menu
Skip to content
Go to bottom
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 14, Issue 12 - Dec 2002
Volume 14, Issue 11 - Nov 2002
Volume 14, Issue 10 - Oct 2002
Volume 14, Issue 9 - Sep 2002
Volume 14, Issue 8 - Aug 2002
Volume 14, Issue 7 - Jul 2002
Volume 14, Issue 6 - Jun 2002
Volume 14, Issue 5 - May 2002
Volume 14, Issue 4 - Apr 2002
Volume 14, Issue 3 - Mar 2002
Volume 14, Issue 2 - Feb 2002
Volume 14, Issue 1 - Jan 2002
Selecting the target year
Experiments on Thermal Response of Space Conditioned by a Pl-Controlled VAV System
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 91~97
The present study concerns an experiment on the supply-air control in variable air volume (VAV) system with a Pl control logic. A thermal chamber with a Pl control logic is constructed to verify the previously suggested multi-zone model. The stratified thermal model is adopted in the control logic for a thermal chamber cooling test. The effects of taler- mal parameters and control parameters such as supply air temperature and Pl control factor are investigated by implementing the thermal chamber cooling test. The experimental results obtained show that the transient behavior of the air-conditioned space temperature are in good agreement with the simulation results of the stratified thermal model
Benchmark Performance Analysis of Vapor Compression System with Capacity Modulation Compressor
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 98~107
The performance of a capacity controlled system, which are tandem, pole change, bypass and inverter driven compressor, has been compared with that of a con- ventional constant speed system. It has been found that capacity modulated system can offer more than 14 percent improvement in SEER over the conventional system. Comparative test results show that two compressor system can attain an improvement in SEER up to 42% over the conventional on/off system, and is feasible without additional investment.
A Study on the Interaction between Particles and Surrounding Fluid
;T.Kurihara;H. Monji;G. Matsui;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 108~115
The fundamental mechanism of a dispersed two-phase flow was investigated. Experiments were carried out to understand how the particles behaves under the influence of the particle size, shape, metamorphoses (bubble) and buoyancy of a single particle which is ascending from the standstill water. Two CCD cameras were employed for image processing of the behavior of the particles and the surrounding flow, which was interpreted with the technique of correlation PIV (Particle Image Velocimetry) and PTV (Particle Tracking Veloci- metry), respectively The experimental results showed that the large density difference bet- ween a particle and water caused high relative velocity and induced zigzag motion of the particle. Furthermore, the turbulence intensity of a bubble was about twice the case of the spherical solid particle of similar diameter.
Three Dimensional Analysis for the Performance of the Corrugated Louver Fin for a Vehicle Heat Exchanger
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 116~126
A three dimensional numerical analysis of the corrugated louver fin for a vehicle heat exchanger was performed. The heat transfer rate and the air pressure drop of the corrugated louver fins for a slim heater were compared with experimental results at the same operating conditions. As for the slim heater fin, we found an optimum fin pitch at certain operating conditions. As the fin pitch increased, the air pressure drop decreased. The vertical or flat top fin was superior to the common declined fin in the aspect of heat transfer performance. As the louver length increased, both the heat transfer rate and the air pressure drop increased.
Analysis of HGAX Cycle for Reducing the Generator Temperature and Enhancing the Hot-Water Temperature
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 127~133
The objectives of this paper are to develop an advanced GAX cycle named HGAX (Hybrid Generator Absorber heat exchanger) cycle, and to study the effect of key parameters on the cycle performance and the hot-water temperature from the condenser. New types of the HGAX cycle are developed by adding a compressor between the generator and the condenser- Type C (performance improvement and reduction of the generator temperature) and Type D (Hot-water temperature application). The solution temperature in the generator outlet is reduced to 168
with the COP improvement of 19% compared to the standard GAX cycle. The hot-water temperature from the condenser is raised to 106
for panel heating (Ondol heating) application.
A Study on Optimized Design Decision of Building Service Systems Based on a Life-Cycle Cost Analysis - A Case Study on Community Center and Congress Hall of a Local Government -
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 134~142
LCC (Life-Cycle Cost) analysis is a practical method and a guideline for evalua-ting the economic performance of building service systems. By using the LCC analysis, the most cost-effective design decision can be made, which has the lowest LCC during the project study period among the various design alternatives. The present case shows an example of appro-priate use of the LCC analysis, by demonstrating the procedures of decision making among at-tarnative building HVAC systems at community center and congress hall of a local government.
An Experimental Study for Evaluating Performance of Radiant Floor Cooling System Integrated with Dehumidification
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 143~152
It is critical for radiant floor cooling system using Ondol to cause condensation on a floor surface. To solve this problem, a radiant floor cooling system integrated with dehumidification was proposed and evaluated in terms of its applicability and prevention of condensation. Therresults show that the proposed system of radiant floor cooling integrated with dehumidification properly maintained the indoor setpoint temperatures and prevented the condensation on a floor surface. To achieve more stable indoor temperatures and humidity control, a further study for the operation of dehumidification panel will be needed.
Verification Experiment and Calculation of Heating Load for a Test Space
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 153~160
As a way to assess the reliability of programs for building energy analysis, verification experiment and calculation of heating load are simultaneously conducted for a well-defined test space. Experimental conditions are carefully set to minimize uncertainties associated with radiation heating, air change, infiltration, and room-to-room interaction. Dyna- mic load calculations using TRNSYS, which are performed for two different computation domains, rely on the energy rate control that represents inherent load characteristics of a space. The predicted instantaneous heating load favorably simulates the overall behavior the measured one, though the latter fluctuates much more rapidly than the former Comparison of the accumulative load between the experiment and calculations shows a close agreement within an engineering tolerance, regardless of the computation model. It is deduced from such findings that the present experimental results along with weather information can serve as a set of reference data for validating load calculation softwares from the users'standpoint. In order to enhance the completeness of this work, a complementary study on the cooling load for the same test space is highly recommended.
Condensation Heat Transfer Coefficients of Binary Refrigerant Mixtures on Enhanced Tubes
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 161~167
In this study, external condensation heat transfer coefficients (HTCs) of two non-azeotropic refrigerant mixtures of HFC32/HFC134a and HF0134a/HCF0123 at various compositions were measured on both low fin and Turbo-C enhanced tubes of 19.0 mm outside diameter All data were taken at the vapor temperature of 39
with a wall subcooling of 3- 8 K. Test results showed that HTCs of the tested mixtures on the enhanced tubes were much lower than the ideal values calculated by the mass fraction weighting of the pure compo- nents'HTCs. Also the reduction of HTCs due to the diffusion vapor film was much larger than that of a plain tube. Unlike HTCs of pure fluids, HTCs of the mixtures measured on enhanced tubes increased as the wall subcooling increased, which was due to the sudden break up of the vapor diffusion film with an increase in wall subcooling. Finally, heat transfer enhancement ratios for mixtures were found to be much lower than those of pure fluids.
Phase-change Temperature of Micro-encapsulated Phase-change Material
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 168~174
In order to obtain a new heat transfer fluid having a high thermal capacity, micro-capsules of a phase-change material can be a successful candidate to be added into water. In this study, 25, 50, 100, and $200\mu$m diameter micro-encapsulated Lauric acids were tested by a differential scanning calorimeter. The Lauric acid itself had a single freezing curve, but the micro-encapsulated Lauric acid had double freezing curves. The second freezing dominated for $25\mu$m diameter Lauric acids. But the first freeing energy became big as the size of the capsule increased.
Flow Condensation Heat Transfer Coefficients of Pure Refrigerants
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 175~183
Flow Condensation heat transfer coefficients (HTCs) of Rl2, R22, R32, Rl23, Rl25, R134a, R142b were measured experimentally on a horizontal plain tube. The experi- mental apparatus was composed of three main parts; a refrigerant loop, a water loop and a water-glycol loop. The test section in a refrigerant loop was made of a copper tube of 8.8 mm inner diameter and 1000 mm length respectively. The refrigerant was cooled by passing cold water through an annulus surrounding the test section. All tests were performed at a filed refrigerant saturation temperature of 4
with mass fluxes of 100, 200, 300 kg/
s. The experimental result showed that flow condensation HTCs increase as the quality, mass flux, and latent heat of condensation increase. At the same mass flux, the HTCs of R32 and R142b were higher than those of R22 by 35~45% and 7~14% respectively while HTCs of R134a and Rl23 were similar to those of R22. On the other hand, HTCs of Rl25 and Rl2 were lower than those of R22 by 28 ~30% and 15 ~25% respectively Finally, a new correlation for flow condensation HTCs was developed by modifying Dobson and Chato's correlation with the latent heat of condensation considered. The correlaton showed an average deviation of 13.1% for all pure fluids data indicating an excellent agreement.
Study on the Performance Evaluation of the Air-tightened Exhibition Case in the Museum
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 14, issue 2, 2002, Pages 184~190
This study was undertaken to judge the quality of air-tightened exhibition cases. Exhibition cases for artifacts display provide a layer of protection between the interior conditions in the exhibition case and the exterior fluctuating conditions of temperature and relative humidity in the museum environment. An infiltration model of the exhibition case was developed through the experimental measurements to calculate the number of air change rate in the exhibition case undergoing in a day, which represents the airtightness of the exhibition case. The results indicate that tighter exhibition cases provide greater protection against the fluctuating conditions of temperature and humidity outside. When the temperature and humi- dity difference between the exhibition case in-and-out is larger, some absorption materials should be applied to control the environmental conditions in the exhibition case.