• Journal of Power System Engineering
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• v.7 no.2
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• pp.17-22
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• 2003

As side-by-side refrigerators came into existence, there has been a growing concern about the free%ins-up of the vital equipment in a walk-in freezer. Due to a bad performance, customers are experiencing too much frustration. In order to minimize the freezing phenomena, the numerical simulation has been performed on the characteristics of cold air flow in a side-by-side refrigerator. The flow field has been simulated with a standard $k-\varepsilon$ turbulent model and a SIMPLE algorithm based on the finite volume method. Through the results of the analysis of the pattern of cold air flow, finally the shape of outlet for cold air flow was modified. The present model was compared with the modified model. The latter was better than the former in minimizing the freezing phenomena.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.341-348
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• 2000

Effects of different types of sub-freezing methods on quality of raw pork loin, beef loin and tuna were studied. Storage tests were undertaken as follows; the three different types of sub-freezing methods, such as regular cold chamber at $-1^{\circ}C$, air-blast sub-freezing at $-5^{\circ}C$ and sharp-plate sub-freezing at $-5^{\circ}C$, were evaluated for extending freshness of samples. Pork loin packed with polyethylene-film showed no significant differences (P<0.05) in physico-chemical properties among the above sub-freezing methods. Air-blast sub-freezing methods revealed faster evaporation of moisture from samples. The same sub-freezing method also showed increased VBN values of pork loin and tuna samples. Regular cold chamber resulted in increased TBA values and K values of beef loin and tuna, respectively. It appeared that sharp-plate freezing system kept the food samples with the least loss of freshness among the above three sub-freezing methods. These results indicated that freshness of raw pork, beef and tuna could be significantly extended by the sharp-plate sub-freezing method.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.344-351
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• 2019

In this work, the mechanism of contraction and expansion noise generation is investigated, and effective methods are proposed to reduce the occurrence frequency of noise during operation of the refrigerator. First, the frequency spectrum analysis was made by using the sound pressure signal measured in an anechoic chamber to investigate the characteristic of noise and the frequency of occurrence. Second, a thermal deformation analysis was conducted to predict the location of noise source. It is found from the analysis that the biggest thermal deformation occurs in the middle of the left inner case in the freezer room. Following the investigation made, a noise reduction method is proposed. The method is proposed to reduce the contraction and expansion noise by reducing the thermal deformation through increasing ABS (Acrylonitrile Butadiene Styrene) thickness in the center of refrigerator.

• Journal of the KSME
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• v.25 no.5
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• pp.400-405
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• 1985

펠티어효과가 10여년 전에 발견되었으나 이것을 공학분야에 응용되기 시작한 것은 반도체 재료가 개발되기 시작한 1950년경부터 실용화되기 시작하였다. 이러한 열전식 열펌프를 이용하여 냉 각시스템을 만들 경우 재래식인 기계식 냉동시스템과 비교해 볼 때 여러 가지 장점이 있다. 열전식 냉동방법은 전자가 한 반도체에서 다른 반도체로 이동하면서 그 주위의 열과 함께 이동 하는 원리를 이용한 것이기 때문에 기계식 냉동시스템의 중요한 구성품인 압축기, 증발기, 응 축기, 용매제와 같은 부품이 전혀 필요가 없다. 움직이는 부품이 없기 때문에 소음이 없고 신 뢰성이 높다. 100W 보다 적은 열출력에 대해서는 무게가 적고 부피가 적은 장점이 있다. 또한 습도 제어가 정확하고 전류의 방향만 바꾸워 주면 쉽게 냉동에서 가열로 전환이 된다. 작동습 도범위는 제품에 따라 다르지만 대개 +100.deg.C~ -125.deg. C까지 가능하다. 이러한 장점 때 문에 가장 많이 응용되고 있는 분야는 군사무기인 관성항법유도무기의 전자부품실을 냉각시켜 주는 데 사용되고 그 외에 용도는 다양하다. 본 고에서는 열전식 열펌프의 원리와 그 응용에 대해서 가능한 상세히 설명하여 앞으로 이 분야에 대한 연구에 보템이 되고저 한다.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.13-16
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• 1989

Attempts were made to fix acetaldehyde on base materials, which were selected from carbohydrates, by freeze drying. More acetaldehyde was fixed, in general, on combined base materials than single base materials, and mannitol+lactose were the best among the combined base materials tested. But the combination of mannitol and maltodextrin appeared to be more economical for the mass production. Loss of acetaldehyde during freeze drying was decreased as the concentration of the combined base material was increased, and it reached minimum at 40% of the base material. As dryer chamber pressure was reduced, loss of acetaldehyde during drying was decreased.

• Journal of Food Hygiene and Safety
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• v.38 no.5
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• pp.373-380
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• 2023

This study surveyed and compared the temperature distribution in domestic refrigerators and freezers used in Korea to determine whether temperature varied according to the location of food storage. We selected 50 people to collect temperature data; among them, 25 measured the temperature of refrigerators, while the remaining measured the temperature of freezers. Consequently, the lowest and highest temperatures measured in domestic refrigerators were found to be -8.2℃ and 15.8℃, respectively, with an average temperature of 3.73℃. The temperature distribution based on internal location was: 5.06±1.69℃ for the door storage compartment, 4.18±1.19℃ for the inside wall surface, and 3.41±1.36℃ for the inner storage box. Significant temperature differences between the top and bottom were only identified at the door storage compartment (P<0.01). Further, the minimum and maximum temperatures measured in the freezer was -30.3℃ and 0.7℃, respectively, with an average temperature of -17.95℃. The temperature distribution based on location was: -17.19±1.68℃ for the door storage compartment, -17.81±1.07℃ for the inside wall surface, and -18.78±1.72℃ for the inside storage box. The results were similar to that of the refrigerator, with the lowest temperature in the inside storage box, and a significant temperature difference between the top and bottom noted only at the door (P<0.01). The maximum temperature difference (between locations) within the refrigerator and freezer was found to be 2.18 and 2.02℃, respectively. In conclusion, the temperature in the entire space was not constant; there were significant deviations at different storage locations. Therefore, public authorities should actively advise customers on the recommended storage locations for each food type. People will benefit from awareness about storage management, including avoiding storage of temperature-sensitive foods in door compartment.

• Journal of the Korean Institute of Gas
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• v.20 no.3
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• pp.38-45
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• 2016

In this study, we found that the release and dispersion of ammonia can create hazardous atmospheres using FLACS software. In General, ventilation or gas detector installations are recommended as preventive measures to control explosion incidents. However, the ventilation installations cannot be applicable to the refrigeration facility that uses ammonia as refrigerating medium, because the freezing room should be sealed. From the accident investigation of the explosion case, we suggested that all electronic devices were needed to be switched by explosion proof devices, and communication facility was also needed to be installed to announce to all employees within a building in case alert condition like ammonia releases occurred.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2005.10a
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• pp.88-88
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• 2005

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.22 no.4
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• pp.245-250
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• 1993

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