• Journal of the Korean Society of Food Culture
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• v.17 no.5
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• pp.638-645
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• 2002

The purpose of this study is to evaluate the quality characteristics and consumer acceptance of the Kimchi affected by the storage method and the duration. The characteristics of Kimchi fermented and stored in the traditional method, such as cave facility or pit storage on the shore were compared to the Kimchi which was stored in the Kimchi refrigerator using the physicochemical and sensory evaluation. The quality of Kimchi stored by the Kimchi refrigerator was most acceptable with 3 month storage, while that of Kimchi stored by the storage facility under the ground on the shore was 1 month storage. Shelf life of Kimchi was extended up to 5 month stored by Kimchi refrigerator, and 3 month for the Kimchi stored under the ground on the shore.

• Progress in Superconductivity and Cryogenics
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• v.4 no.2
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• pp.58-62
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• 2002

The purpose of this study is to analyze the charging gas effect on the resonance and performance characteristics of the linear compressor for small scale FPFD Stirling refrigerator. To ensure high performance of FPFD type Stirling refrigerator, the operating frequency of the refrigerator should be around the natural frequency of compressor. The gas spring effect which is induced from Pressure change in cylinder due to motion of pistons has significant effect on the natural frequency of the compressor. The numerical results show the linear compressor has high natural frequency when the charging pressure of working fluid is high and the stroke of compressor, current, input power and efficiency of compressor were shown with different operating conditions.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.10
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• pp.817-824
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• 2002

A diffusion absorption refrigerator is a heat-generated refrigeration system. It uses a three-component working fluid consisting of the refrigerant (ammonia), the absorbent (water) and the auxiliary gas (typically hydrogen). This system has no moving parts and the associated noise and vibration. In this study, the operating characteristics of diffusion absorption refrigerator are investigated through cycle modeling and simulation. System parameters considered in this study are the charged concentration of ammonia aqueous solution, the concentration difference between absorber inlet and outlet and the system pressure determined by the amount of auxiliary gas charged. It was found that there exists a critical value of concentration difference that maximizes the refrigerating capacity. And the lower the system pressure, the higher the refrigerating capacity.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.6
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• pp.319-325
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• 2009

The purpose of this study is to investigate the performance characteristics of a bypass two-circuit refrigerator. A bench scale refrigeration system was designed and constructed to estimate possible performance improvement of the bypass two-circuit refrigerator. The experiments were conducted in the bench scale refrigeration system by varying capacity of the condenser and refrigerant charge amount with an adoption of a refrigerant storage vessel. The COPs of the bypass two-circuit refrigeration system in the refrigerator and freezer (RF)-mode and freezer(F) only-mode were increased by 10% and 17%, respectively, with increasing the capacity of the condenser. Besides, the COP of the system in the F only-mode was increased by 10% by adopting the refrigerant storage vessel.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.10
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• pp.925-931
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• 2000

Refrigerating ability of vapor compression refrigerator is decided by the harmonic work of it's components such as compressor, condenser, evaporator, expansion device, and so on. In this study, choosing refrigerant injectors as a new one of expansion device, temperature change of the cold room, ice freezing ability, and power consumption on flowrate of injector and refrigerant charging condition are evaluated experimentally. As the results of this study, it is verified that the spray injection type refrigeration system has some merits according to the flowrate and spray pattern of injector and charging quantum of refrigerant. And there are some design factors such as spray pattern and shape of spray chamber to utilize and fabricate this refrigerant injection type refrigerator.

• International Journal of Air-Conditioning and Refrigeration
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• v.8 no.2
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• pp.29-38
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• 2000

Air side heat transfer and pressure drop for f 9.52 fin-tube heat exchanger with various types of slit and louver fins were measured, and compared with wave-slit fin. Longitudinal and transverse tube spacings of the heat exchangers are 21.65 mm and 25mm respectively. Actual heat exchanger was tested using water, and the tests were performed for 2 row heat exchangers with 3 different fin spacings, 1.3, 1.5 and 1.7 mm. The overall performance of the enhanced fins was evaluated by comparing heat transfer coefficient with respect to fan power

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.46
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• pp.159-166
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• 1998

Estimating the temperature distribution of a refrigerator-room is important for preventing the over-refrigeration and improving its operating efficiency. It is also necessary in the realization process of the concentrated refrigeration function which has been provided recently as a generalized function in many refrigerator models. In this paper, we investigate the estimation problem of temperature in refrigerator-room and propose a fuzzy adaptive model. The model is unique in that it employs the concept of the fuzzy dead zone in order to improve the accuracy of estimation. The obtained results are then used for determining the optimal position of a temperature sensor.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.489-495
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• 2003

A high performance and low noise refrigerator fan has been developed in order to satisfy the customer's high quality needs, that is, luxury, big size and low noise. In this study, the characteristics of a new developed fan and a current fan was calculated and compared by using numerical simulation. Rotation of a fan makes cold air circulation inside a refrigerator. A numerical simulation of air flow shows distribution and local flow regime of a cold air flow circulation, and revealed a cause of low noise as well. Optimization of a duct shape also decreased noise level.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.3
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• pp.267-272
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• 2004

In this paper a new intelligent diagnostic system for a refrigerator used for a cold-storage of farm produce was propose. It is verified that the developed system is useful for the fault observation and diagnose of a refrigerator by experimental implementation. The basic idea of the proposed system in that the temperature of major pipes at fault status differs from those at normal status. In order to realize the proposed system, the temperature measuring system and diagnostic program were developed.

• 연구논문집
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• s.31
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• pp.15-21
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• 2001

A thermoacoustic refrigerator has not only considerable feasibility but also commercial usability, because it has high reliability, lower vibration, no moving part. and easy construction. In the present study, the resonant characteristics of a thermoacoustic refrigerator, varying the length of resonant tube from 400mm to 850mm, were investigated to improve performance. In order to determine the optimum position of the stack in the resonant tube and the optimum frequency, the simple open-tube-type thermoacoustic refrigerator was constructed. Air was used as a coolant. In the fifth harmonic, the largest $\DeltaT$ was $52.6^{\circ}C$ at 827Hz, tube length of 400mm, and stack length of 40mm.