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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 16, Issue 12 - Dec 2004
Volume 16, Issue 11 - Nov 2004
Volume 16, Issue 10 - Oct 2004
Volume 16, Issue 9 - Sep 2004
Volume 16, Issue 8 - Aug 2004
Volume 16, Issue 7 - Jul 2004
Volume 16, Issue 6 - Jun 2004
Volume 16, Issue 5 - May 2004
Volume 16, Issue 4 - Apr 2004
Volume 16, Issue 3 - Mar 2004
Volume 16, Issue 2 - Feb 2004
Volume 16, Issue 1 - Jan 2004
Selecting the target year
Performance Characteristics Analysis of Gas Turbine-Pressurized SOFC Hybrid Systems
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 16, issue 7, 2004, Pages 615~622
Recently, the hybrid system combining fuel cell and gas turbine has drawn much attention owing to its high efficiency and ultra low emission. It is now on the verge of world wide development and various system configurations have been proposed. A national project funded by Korean government has also been initiated to develop a pressurized hybrid system. This work aims at presenting design performance analysis for various possible system configurations as an initial step for the system development. Study focuses are given to major design options including the power ratio between gas turbine and fuel cell, reforming method (internal or external), reforming heat source (reforming burner, cathode hot air, fuel cell heat release) and steam supply method for reformer (anode gas recirculation, external steam generator). A wide variation in performance among different configurations has been predicted.
Experiments on the Heat Transfer and Pressure Drop Characteristics of a Channel with Pin-Fin Array
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 16, issue 7, 2004, Pages 623~629
Rapid development of electronic technology requires small size, high density packaging and high power of electronic devices, which result in more heat generation by the electronic system. Present cooling technology may not be adequate for the thermal management in the current state-of-the-art electronic equipment. Forced convective heat transfer in a channel filled with pin-fin array is studied experimentally in this paper as an alternative cool-ing scheme for a high heat-dissipating equipment. Various configurations of the pin-fin array are selected in order to find out the effect of spacing and diameter of the pin-fin on the heat transfer and pressure drop characteristics. In the low porosity region, interfacial heat transfer and pressure drop seem to show different trend compared to the conventional heat transfer process.
Study on the Performance Characteristics with the Height of a Regenerator and Dehumidifier for Liquid Desiccant Dehumidification System
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 16, issue 7, 2004, Pages 630~638
Liquid desiccant dehumidification systems have the ability to provide efficient humidity and temperature control while saving the electrical energy requirement for air conditioning as compared to a conventional system. The dehumidifier and the regenerator form the heart of this system. The latent part of the cooling load is overcome using liquid desiccant. The model regenerator has been designed to study the absorption characteristic of the aqueous triethylene glycol (TEG) solution which is in the flow range from 20 to 50 LPM. Also, this system designed that was able to change the height of the regenerator and dehumidifier. Because the effect of performance have different result according the height. The effect of performance factors of the regenerator with inlet solution flow rate, air flow rate, solution concentration, solution temperature, brine temperature, air temperature and inlet air relative humidity have been analyzed. Data obtained are useful for design guidance and performance analysis of the hybrid air conditioning system.
Condensing Heat Transfer Characteristics of Propylene Refrigerant
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 16, issue 7, 2004, Pages 639~644
This paper deals with the heat transfer characteristics of R-1270 (Propylene), R-600a (Iso-butane) and R-290 (Propane) as an environment friendly refrigerant and R-22 for condensing. The experimental apparatus has been set-up as a conventional vapor compression type heat pump system. The test section is a horizontal double pipe heat exchanger. A tube diameter of 12.70 mm with 1.32 mm wall thickness is used for this investigation. The test results showed that the local condensing heat transfer coefficients of hydrocarbon refrigerants were higher than that of R-22. The average condensing heat transfer coefficient was obtained with the maximum value in R-1270 and the minimum one in R-22. Comparing the heat transfer coefficient of experimental results with that of other correlations, the presented results had a good agreement with the Cavallini-Zecchin's correlation. It reveals that the natural refrigerants can be used as substitute for R-22.
Performance Analysis of Fin-tube Evaporator for Carbon Dioxide
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 16, issue 7, 2004, Pages 645~651
Fin-tube evaporator for carbon dioxide has been investigated both by experiment and simulation. Inside refrigerant heat transfer and outside heat and mass transfer of a wet surface heat exchanger were modeled using appropriate correlations. The results estimated by the calculation were in good agreement with the experimental results. The simulation errors were less than 7.9% for estimating capacity, 0.6
for air exit temperature, 1.2% for air exit humidity and 17% for
exit pressure. The simulation program was used to study the effect of air flow direction, number of rows and refrigerant circuits. For a 2-row evaporator, parallel flow showed better performance for low air velocity but for high air velocity, counter-flow was better. Refrigerant circuits, however, showed insignificant effect on the performance.
Estimation of Train-Induced Wind Generated by Train Operation in Subway Tunnels
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 16, issue 7, 2004, Pages 652~657
Development of underground space in urban area has a huge amount of potential to ease the limitations on the land use and the efficiency especially in urban area. Considering public transportation in urban area, subway system could be one of the most efficient and practical approaches. Subsequently this leads the public to have more chances to experience the indoor air quality (IAQ) in subway systems. In this study, it was aimed to produce useful data for the IAQ control in subway environments, Specifically the train-induced wind has been investigated by means of field survey and analysis. The recent updates including the quantified characteristics of train-induced wind are presented in this paper.
An Approach to Model Ground-Coupled Building Foundation for Energy Simulation
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 16, issue 7, 2004, Pages 658~666
In this paper, a two-dimensional transient ground-coupled numerical model for slab-on-grade foundation is developed and integrated into EnergyPlus. A validation analysis is first presented to ensure that for the developed building foundation heat transfer module is properly implemented within EnergyPlus. Then, the predictions from the developed model are compared to those obtained from the simplified building foundation model currently used in EnergyPlus. The results show that the developed foundation heat transfer module accounts better for the effects of the ground thermal mass attributed to the ground than the simplified foundation model currently used in EnergyPlus.
Frosting Behavior on the Plate of Thermally Conductive Plastic
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 16, issue 7, 2004, Pages 667~672
An experimental study has been carried out to investigate the frosting behavior on the plate of thermally conductive plastic (PBT based resin) by comparing it with those of aluminum and some plastic test specimens (PTFE based resin). It is found that the frosting behavior of plastic specimens with 1 mm thickness shows similar trend to that of aluminum except PTFE. The properties of frost formed on the specimens are found to be affected by both thermal conductivity and surface characteristics of the materials. The results indicate that the heat and mass transfer rates of PBT resin are almost equivalent to those of aluminum.
Cost Accounting of Electricity and Heat on Combined Cycle Cogeneration
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 16, issue 7, 2004, Pages 673~682
The cost accounting of products on energy system is important for evaluating the economical efficiency and deciding the reasonable sale price. In the present, the suggested OECOPC method was applied to a combined cycle cogeneration, and each unit cost of electricity and heat products was calculated. In addition, the previous thermoeconomic methods were applied and calculated to equal system. As a result of comparing various methods, the unit costs by OECOPC method were calculated in the middle value of those. This result tells that OECOPC methods are most moderate. The suggested OECOPC method can apply any energy system. Hence this method is expected to make contribution to cost accounting on energy System.