• 한국자동차공학회논문집
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• 제19권6호
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• pp.119-125
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• 2011

The analysis of performance characteristics in a refrigerator truck using R404A and R744 was carried out by using theoretical method, and each performance was compared with a variation of operating conditions. The components and cycle simulation model were developed by using EES program. To investigate the performance characteristics with operating conditions, the performance of both systems was simulated according to indoor temperature, outdoor temperature, outdoor air velocity and compressor speed. As a result, the R744 system had a better COP than R404A system for given operating condition. The cooling capacity was not increased over the outdoor air velocity of 3 m/s. Besides, the performance of R404A system was more sensitive to operating conditions compared to that of R744 system.

• 설비공학논문집
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• 제23권11호
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• pp.733-740
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• 2011

To analyze the cooling performance in the refrigerator truck according to frost growth, the analytical model of refrigeration system was developed under frost and non-frost condition using EES. The system performance was analyzed with outdoor temperature, storage temperature, outdoor front air velocity and compressor speed in order to investigate the system performance characteristics with operating conditions. Besides, the system performance under frost condition was compared with that under non-frost condition. As a result, the frost thickness was 0.9 mm when the refrigerating capacity of frost condition was decreased by 30%. The maximum of the system COP was shown at compressor speed of 1500 rpm for non-frost and frost condition, simultaneously. The performance under frost condition was more sensitive to the operating condition compared to that under non-frost condition.

• 설비공학논문집
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• 제25권9호
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• pp.499-505
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• 2013

R744 has been appropriated for substitute refrigerant, because of its high stability, and environment-friendly nature as a natural refrigerant. To analyze the cooling performance of a refrigeration system in a refrigerator truck using R744 according to the blocking ratio, an analytical model of the refrigeration system was developed under frost conditions, using EES. The performance of the refrigeration system was predicted with the indoor and outdoor air temperature, outdoor air velocity, and compressor speed. As a result, the system performance decreased, with the increase of frost growth. When the blocking ratio was 40.4% in the basic condition, the refrigeration capacity was decreased by 27.1%, compared to the non-frost condition.

• 한국식품영양과학회지
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• 제43권7호
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• pp.1095-1103
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• 2014

본 연구에서는 오징어 개별 포장체를 개발하여 포장하지 않은 오징어와 저온 저장에서의 생존율을 비교함으로써 개별포장체를 활용한 유통시스템을 개발하고자 하였다. 개별 포장체를 이용한 활오징어는 저온 저장($10^{\circ}C$, $8^{\circ}C$, $6^{\circ}C$, $4^{\circ}C$, $2^{\circ}C$, $0^{\circ}C$) 조건 하에서 각 10마리씩 저장하였다. $6^{\circ}C$에서 격리 포장된 활오징어는 72시간까지 84%의 우수한 생존율을 나타내었고 이후 생존율이 감소하다 120시간까지 60% 이상의 생존율을 나타내었다. 또한 최대 7일까지 생존하는 것을 관찰하였다. 최적 온도는 $5^{\circ}C$였으며 $5^{\circ}C$에서 96시간 저장했을 때 70% 우수한 생존율을 나타내었고 최대 7일까지 생존이 가능하였다. 냉장트럭을 이용한 유통 실험에서 $5^{\circ}C$ 저온에서 16시간까지 100%의 우수한 생존율을 나타내었고 저장 20시간 이후에도 90% 이상의 우수한 생존율을 보였다. 냉장트럭에 적재할 용기 실험에서는 사각형의 저장용기가 유리하였다. 상자에 공급하는 최소 해수량 실험에서는 20 L 이상의 해수량에서 15시간 이상, 100% 생존하는 것을 확인하였다. 따라서 오징어 한 마리당 2 L의 해수가 필요한 것으로 판단되었다. 냉장트럭 운송 후 보관 수조의 최적 온도는 $5^{\circ}C$였으며 $5^{\circ}C$에서 저장 72시간까지 90% 이상의 생존율을 나타내었고 최대 7일까지 생존이 가능하였다. 따라서 본 연구 결과, 활오징어의 유통 시 개별 포장체를 사용하여 사각용기에 2 L의 해수를 같이 담아 $5^{\circ}C$의 냉장트럭으로 유통하는 것이 가장 바람직한 것으로 나타났다.

• 한국지열·수열에너지학회논문집
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• 제8권2호
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• pp.48-54
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• 2012

To analyze the cooling performance of fin-tube evaporator in the refrigerator truck using R744 according to frost growth, the analytical model of evaporator was developed under frost and non-frost conditions. The performance of fin-tube evaporator was investigated with frost thickness and indoor temperature. Besides, the performance of evaporator under frost condition was compared to that under non-frost condition. As a result, area of air passage and system performance were decreased as the frost thickness increased. The cooling capacity was reduced by 10%, 20%, 30% when the frost thickness was 0.7 mm, 1.1 mm, and 1.6 mm respectively. At these conditions, the block ratio was 31%, 48%, and 71%. In addition, the outlet quality of refrigerant was not over 1 when the frost thickness was 1.6 mm in spite of high indoor air temperature.

• 한국포장학회지
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• 제23권3호
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• pp.183-190
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• 2017

Carton clamp truck is widely perceived as the high-efficient handling equipment of factory premises and warehouse by its capability of palletless handling. Therefore, the significance of a lab-based handling simulation is becoming higher with the growth of clamp truck usage. In this study, preliminary FEA and design of handling test courses for the lab-based simulation of carton clamp truck handling were performed, and the PSD analyses were performed for the modified one for the test course proposed by Park et al. (2017) as well as ASTM D 6055 and ISTA 3B standards. For the vibration in all directions, the vibration energy intensity analyzed by ISTA 3B standard showed higher than that by the other two cases. A FEA was performed for the handling operation of the sudden stop of the clamps after lifting the target HCP (heavyweight refrigerator corrugated package, w=180 kgf) up to the specified height. The slip distance between the clamp arm and the target HCP was 0.85 mm. The simulation result of 0.85 mm was 3.7 times lower than the experimental result (3.2 mm) obtained by Park et al. (2017), and it was estimated that the deviation comes from both the experimental error by weight imbalance of target HCP, and excessive simplification during the FE modelling of target HCP.

• 한국포장학회지
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• 제9권1호
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• pp.7-10
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• 2003

This study was carried out to investigate vibration shock of electric appliances during transport. Microwave oven, TV, washing machine and refrigerator were singled out as the study items. Transport courses were selected as follow ; an expressway between Kumi and Seoul for TV, an expressway between Kwangju and Seoul for microwave oven and washing machine, a national road between Inchon and Seoul for refrigerator. the values of vibration shock were measured to be ${\sim}3G$ on the national road and 1G on the expressway for up and down direction, ${\sim}0.5G$ on the national road and expressway for back and forth direction and ${\sim}0.8G$ on the national road and expressway for right and left direction. There was no damage during transport. These values were corresponding to grade II of KS A 1026 (General Rules of Performance Testing for Packaged Freights).