• Journal of the Korean Society for Precision Engineering
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• v.28 no.1
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• pp.96-101
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• 2011

Under extreme test or operation condition, refrigerator endures complicated stresses state and thermal bowing deformation arises on the sidewall. Shelf rails designed in the inner case provide increased surface area to permit expansion without bowing, and also increase structural rigidity to resist bowing. In this study, we designed six different shelf patterns of refrigerator model and studied the bead on refrigerator deformation using finite element method (FEM). Analysis result shows that increasing the numbers of beads properly in refrigerator is more helpful to reduce thermal bowing deformation. In addition, the beads would decrease stress on refrigerator sidewall. However, vertical beads have no effect to reduce thermal deformation of the bowing.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.7
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• pp.971-980
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• 2010

In this paper, an artificial neural network (ANN) was employed to build a predicting model for refrigerator structure. The predicting model includes three input variables of the plaque depth (D), width (W) and interval distance(S) on the inner wall. Finite element method was utilized to obtain the data, which would be necessary for the ANN training process. Finally, a genetic algorithm (GA) was applied to find the optimal parameters that leaded to the minimum inner case deformation under operating condition. The optimal combination found is the depth(D) of 2.63mm, the width(W) of 19.24mm and the interval distance(S) of 49.38mm which leaded to the smallest deformation of 1.88mm for the given refrigerator model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.427-428
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• 2009

In the manufacture process of refrigerator cabinet, polyurethane(PU) liquid firstly is injected between outer plate and inner case in high temperature about $40^{\circ}C$, and PU foam is generated and solidified to the room temperature. There will be great residual stress in the PU foam, especially at the corners after the whole refrigerator is completely assembled. The stress condition will become more complicated under operating condition because of the large temperature difference between the freezing room and outer plate. And also, there are great differences of properties for plastic and steel which would cause different deformation under temperature gradient. The steel outer plate would expand compared to the PU foam or ABS material under operation condition, which induces a thermally bowing deformation in the refrigerator cabinet. The objective of this paper is to design an optimum bead structure or to use reinforcement in the refrigerator except for improving material properties in order to decrease the deformation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.5
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• pp.505-511
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• 2016

The aim of this study is to investigate the thermoforming characteristics of an inner case with three refrigerator cavities using three-dimensional(3D) thermoforming analyses. We perform fundamental formability analyses using a 3D model of the mould for the inner case. We carry out tensile tests at the elevated temperature to examine the properties and characteristics of the thermoformed material. Then, we design sub-processes of the thermoforming process for the inner case. In addition, we develop suitable finite-element models for different sub-processes. We investigate the deformed shapes and thickness distributions of the inner case for different sub-processes using the results of the thermoforming analysis. Finally, we discuss the formability and thermoforming characteristics of the inner case with three cavities.

• Proceedings of the Korean Society of Rheology Conference
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• 2002.05a
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• pp.77-80
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• 2002

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.3
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• pp.196-202
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• 2003

Two dimensional modeling was carried out to find the safety distance between the defrost heater and the plastic inner wall of domestic refrigerator Estimation was processed for the three cases; the estimation of plastic wall temperature (1) without any protection, (2) with an aluminum foil attached on a wall, and (3) with an aluminum shield installed between heater and wall. The former two cases are found to be dangerous during defrosting process, because the temperatures of inner wall reach above 80'C , which is the upper temperature limit of the wall material. The case with an aluminum shield is considered to be safe by maintaining the temperature of the wall in the range of 6$0^{\circ}C$ during defrosting process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.4
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• pp.391-396
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• 2015

When the temperature of a flange in a refrigerator is reduced to the dew point, condensation is generated on the flange. Generally, hot lines, having a temperature of $35^{\circ}C$, are located near the flange to increase its surface temperature above the dew point. Hot lines are installed in close contact with the flange in order to increase the heat transfer from the hot lines to the flange surface. Through this work, the effects of the hot line shape and installation conditions, including a gap between the hot line and flange, and the function of a spacer in the inner case of the refrigerator were investigated. Additionally, an optimal shape of the inner case for easy assembling is proposed considering the contact between the hot line and flange.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1605-1610
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• 2015

The present study has been accomplished to elucidate the effect of radiation heat transfer in the heat transfer analysis of refrigerator gasket, which has near 30% of refrigerator heat loss. The numerical heat transfer analysis has been conducted with the simplified modeling of refrigerator gasket. From the present CFD analysis, heat loss at the gasket is $25.6W/m^2$ for the case without radiation effect and that for the case with radiation effect is $55.0W/m^2$, which is 2.2 times greater heat loss. The radiation protection layers were installed in the gasket from 0 to 7 and the case with 7 layers has 33% reduction effect of heat loss compared with the case without any radiation protection layer. Additionally, it is better effect of radiation heat loss reduction that the radiation protection layers would be placed to the outer or inner side of gasket rather than placing to the center of gasket.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.457-463
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• 2012

Current refrigerators are designed to have thin doors and walls to facilitate user convenience and increase inner storage space. However, the thin doors and walls gives rise to the problem of dew generation on the outer surface of a refrigerator due to a large critical temperature difference between the outer wall and the room air; So far, an electric heater is commonly used for making the dew to evaporate; in this case, the heater inevitably requires additional electrical power. We propose a new approach to reduce the dew generation in a refrigerator by redesigning the gasket and varying the thickness of the inner case of the refrigerator. The results of simulations performed in this study indicate that the surface temperature in the region where dew was generated was increased by approximately $0.39{\sim}3.07^{\circ}C$ without the use of a heater.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.11
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• pp.1228-1235
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• 2012

A refrigerator has many components which are made from diverse materials such as metal, polymer, plastic, and rubber. So, it generally requires much time and efforts to build up an analysis model in finite element analysis. In this work, to reduce the computational time and efforts a simplified modeling method was proposed for the analysis of a refrigerator. Occasionally, a stick-slip noise occurs in a refrigerator due to relative slip between shelf and inner-case. When we solve the problem by a FE analysis, we should model the structures with detail for considering the contact conditions; by this reason, too many efforts are consumed in the conventional analysis method. Through this work, we shows the concept of simplifying approach and a good agreement with the results of a real model analysis. And also, the evaluation of the proposed method and the application of contact analysis using the simplified model are discussed.