• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.11
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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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.9
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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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1095-1103
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• 2014

A packaging and distribution system for transferring individual live squids at low temperature was developed and compared to a conventional bulk container system. Ten live squids in individual packages were stored in a large container at low temperature ($0{\sim}10^{\circ}C$). Live squids in individual packages at $6^{\circ}C$ showed a survival rate of 84% up to 72 hours, after which the survival rate decreased. However, the survival rate remained at 60% up to 120 hours. Further, the squids survived up to a maximum of 7 days. Optimum temperature was $5^{\circ}C$, and the survival rate of the packages was 70% when stored at $5^{\circ}C$ for 96 hours. A distribution test was carried out using a refrigerator truck at $5^{\circ}C$, and the results showed a 100% survival rate up to 16 hours and over 90% survival rate after 20 hours. A rectangular container was the most favorable when loading the container into the refrigerator truck. In testing the required volume of supplied seawater, 100% survival rate was observed over 15 hours with 20 L of sea water or more. Therefore, a single squid needed 2 L of seawater. After refrigerator truck transportation, optimum temperature for fish tank storage was $5^{\circ}C$, at which the survival rate was over 90% up to 72 hours. Using a refrigerator truck at $5^{\circ}C$, live squids survived up to 7 days, maintaining marketability.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.8 no.2
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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.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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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.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.9 no.1
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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).