• Progress in Superconductivity and Cryogenics
• /
• v.17 no.3
• /
• pp.41-46
• /
• 2015

Recently, the development of the HTS power cable is actively promoted. As the length of HTS power cable increases, there have been many efforts to develop large capacity cryocooler. Among the various cryocooler, the Brayton refrigerator is the most competitive for HTS power cable. The Brayton refrigerator is composed of recuperative heat exchangers, a compressor, and a cryogenic turbo expander. In these components, the cryogenic turbo expander is a part to decrease the temperature and it is the most significant component that is closely related with overall system efficiency. It rotates with high speed using a high-pressure helium or neon gas at cryogenic temperature. This paper describes the design of a 10 kW class Brayton refrigeration cycle and the cryogenic turbo expander. Flow and structural analysis are performed for the rotating impeller and nozzle to verify the efficiency and the design performance.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.15 no.4
• /
• pp.312-317
• /
• 2003

This paper describes an experimental study on small-scale sorption refrigerator. Silica gel (type A) as an adsorbent, HFC-l34a as a refrigerant were selected for a sorption refrigerator The focus of the design was to reduce the cycle time of the sorption refrigerator. Through the experiment, pressure and temperature variations in the adsorber were measured and the performance of refrigerator was predicted. In this paper, the small-scale sorption refrigerator operates with the cycle time of 4805. Its predicted cooling capacity is 25 W at -15$^{\circ}C$ and COP is 0.23.

• Journal of Power System Engineering
• /
• v.15 no.5
• /
• pp.37-42
• /
• 2011

The normal cooling system of a refrigerator is applied to indirect a cooling methods. But the Kimchi refrigerator is applied to direct the cooling method. Recently when the model was applied to both direct and indirect the cooling methods, the improvement was considerable. With the development of the living standards in Korea, there has been more sensitive dissatisfaction about the taste and the smell of Kimchi. In order to solve these kinds, there is a need to systematic and scientific approach. Based on these, the purpose of this study is to optimize design for improve the storage period of Kimchi refrigerator. In this research, we concentrate on the temperature change and heat transfer characteristics of interior parts of the Kimchi refrigerator due to control cycle of temperature and flow phenomenon of cooling air.

• Archives of design research
• /
• v.14
• /
• pp.1-7
• /
• 1996

Designers often hesitate to decide the shape, size, and layout of a product. Though ergonomic principles and data are absolutely needed in this process, they don have enough guidelines to refer. For the refrigerator designers, they also are not convinced of their decision: the vertical position of the freezing and refrigerating rooms, the height of shelves, the shape of door-handle, etc. To support the refrigerator design, we applied several ergonomic methods to the evaluation of refrigerator. EMG was measured to evaluate the load of users lumbar muscle. Based upon the experimental EMG data, we developed a model to estimate the relative load corresponding to the height of refrigerator shelves. Two different layouts of a refrigerator, R/F and F/R styles, were compared with the model. A three-dimensional motion analysis method was used to evaluate the users motion of using a refrigerator. Ten door-handles with the different shapes and positions were evaluated by tracking the rotations of the users arm. Video protocol analysis was used to evaluate the user interface of a control panel in a refrigerator. Finally, we suggested several ergonomic design guidelines based on the facts found in this research and the anthropometric data of the Korean adults. The results of this study can be applied to the ergonomic design of refrigerators

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.6 no.1
• /
• pp.11-19
• /
• 1994

An optimal design for Gifford-McMahon/Joule-Thomson(GM-JT) refrigerators was performed by a numerical method. The design goal was to meet the cooling requirement for MRI systems, which was 3 Watt at 4 K. A general cycle analysis program was written to calculate the cooling capacity of the GM-JT refrigerators for the givenstage GM refrigerator. The program was executed for a specific refrigerator with various design parameters. The optimal values for the maximum cooling were found for the sizes of the heat exchangers, the mass flow rate of helium, and the compression pressure.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.5
• /
• pp.470-476
• /
• 2010

In this work, the mechanism of structure-borne noise resulting from vibration of a compressor for a refrigerator is experimentally analyzed and an effective method is proposed to reduce the noise. Firstly, the emission noise, when the compressor is turned on and off, is measured and analyzed to identify the generation mechanism of structure-borne noise. And the acceleration on the outer wall of the refrigerator is also analyzed to identify the distribution of vibration. Secondly, an effective design method to reduce the noise is suggested by using the finite element analysis and Taguchi method. Consequently an optimal design of the refrigerator, which has lower noise, is obtained and then its performance and validity are verified through the analysis and test.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2003.05a
• /
• pp.90-93
• /
• 2003

This study aims to validate the effectiveness of VE system with an arm-master in the evaluation of virtual prototype. A virtual kitchen with a refrigerator was presented in a CAVE system. Subjects put in and pull out virtual objects by using the arm-master. Twelve subjects participated in six experimental conditions: three types of refrigerator door grips and two reaction forces. After each trial, subjects evaluated a virtual refrigerator in terms of easiness of operation, similarity in force, presence etc. The results show the subjects preferred vertical grip than horizontal grip and light reaction force than heavy one. The VE system with the arm-master will be very helpful in the design evaluation of virtual prototypes.

• Progress in Superconductivity and Cryogenics
• /
• v.10 no.1
• /
• pp.67-70
• /
• 2008

Performance of integral type Stirling refrigerator used for cooling infrared detector is affected by principal factors such as design factors and operating factors. Operating factors include charging pressure and operating frequency. The purpose of this paper is to examine the basic design analysis on the integral type Stirling refrigerator and the changes in performance through experiments on operating factors.

• Korean Journal of Computational Design and Engineering
• /
• v.22 no.1
• /
• pp.59-69
• /
• 2017

Internal capacity of a refrigerator is an important indicator for design and purchasing criteria. The components facing the internal space may have holes or gaps between parts. In traditional way, design engineers manually remodeled the parts to fill the holes and the gaps for enclosed boundary of the internal space. Then they calculated internal volume by subtracting the assembly of parts from its enclosing volume. However, filling holes and gaps is not an automated process requiring a plenty of labor and time. In this research, we have developed a voxel-based method to estimate the internal volume of a refrigerator automatically. It starts transforming all components facing the interior space into voxels and fills all holes and gaps automatically by the developed hole-filling algorithm to form a completely closed boundary of the assembly. Then, it identifies the boundary voxels that are facing to the internal voxels with any part of the component. After getting the intersection points between the boundary voxels and the surfaces of components, it generates the boundary surface of triangular facets with the intersection points. Finally, it estimates the internal volume by adding volume of each tetrahedron composed of a triangle of boundary surface and an arbitrary point.

• Progress in Superconductivity and Cryogenics
• /
• v.6 no.1
• /
• pp.53-58
• /
• 2004

A Miniature inertance pulse tube refrigerator was designed and tested with a 10 W compressor. Erperiments were carried out for different pulse tube length and inertance tube length. An adiabatic model which considered the pressure drop in the regenerator was used to analyze the performance of the pulse tube refrigerator. Among various design parameters which should be optimized, the pulse tube length and the inertance tube length were optimized. PdV work and several different loss mechanism were included in the analysis to simulate more accurately the physical phenomena in the pulse tube refrigerator. Nevertheless, the simulation program could not completely predict the porformance of the refrigerator. The possible reason for the difference of the optimal point between the simulation and the experiment was explained.