• Journal of Institute of Convergence Technology
• /
• v.2 no.1
• /
• pp.1-6
• /
• 2012

The cold chain system in South-East Asia is requiring to maintain freshness of refrigerated or frozen food. In this study, Thermal storage system using Phase change material (PCM) was developed and evaluated its performance about temperature and cold keeping time. For various application of cold chain system, we developed portable cold box, cold roll container and freezing station. Keeping time on laboratory tests of portable cold box in case of refrigeration and freezing were 6 hours and 4 hours, respectively. Cold container was developed to 2.5 ton scale. Evaluation in Indonesia, it was showed to keep the setting temperature of $-10^{\circ}C$ over 40 hours at $30^{\circ}C$ of ambient air. Freezing station using PCM was kept over 24 hours under $-20^{\circ}C$.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.8 no.4
• /
• pp.576-582
• /
• 1996

This work studies qualitative thermal characteristics of PCM cold storage medium container and its surrounding streams. Experimental parameters are initial PCM temperature and cold water flow rate. A mathematical modeling was establised to estimate temperature distribution and the cooling process. We found that the phase-change temperatures of PCM varies from 6 to $8^{\circ}C$ which is constant for other materials and that the dominant heat transfer resistance is that on the container side taking about 3/4 of the total resistance. The one dimensional mathematical model predicts experimental data quit well.

• Journal of Biosystems Engineering
• /
• v.31 no.3 s.116
• /
• pp.161-167
• /
• 2006

The purpose of this study is to find the optimal conditions of PCM slurry manufacturing equipment for saving the marketing cost and keeping the original quality of products. In addition, the characteristics of the movable container for shipping or distributing products is analysed. The major results are as follows. 1. PCM thermal storage system is designed with the conditions of temperature($-5{\sim}10^{\circ}C$), cold chain time(30 minutes), and one time usage(50 liter). This system includes tank, freezer, circulating pump, cycle type heat exchanger, swelling tank, equipment of supplying PCM supplying unit includes cold tank, cycle type heat exchanger, suction unit and control equipments, etc. 2. After ability test of PCM thermal storage system, it shows that the required freezing time of PCM thermal storage system is less than one of the previous system. The reason is that churn (top and bottom) and compulsion circulation are occurred simultaneously and unit cooler type method is better than chiller type method. 3. By the experiment of transportation latent heat container, it is decided that the best container is $K_1$ with latent heat temperature($0{\sim}5^{\circ}C$) and density(0.15%). However, for $K_l\;and\;K_2$, it is necessary more studies on latent heat thermal conditions and conditions of making method.

• Korean Journal of Medicinal Crop Science
• /
• v.23 no.4
• /
• pp.305-310
• /
• 2015

This study was conducted to obtain the basic data related to seed characteristics and germination conditions of the Coriandrum sativum L. at different storage condition and temperature. The shape of fruit was oval with light brown color. Fruit was mericarp, biloculate, with one ovule in each locus. The length and width of seed were $1.37{\pm}0.067mm$ and $0.52{\pm}0.039mm$, respectively. Weight of 1,000 seeds was $6.55{\pm}0.15g$. Seeds which were stored at room ($15^{\circ}C$) and cold temperature ($4^{\circ}C$) in vinyl container showed the highest germination rate (93.3%) under the room temperature germination condition. Percentage of germination in cold and freeze temperature was 20% and 0%, respectively. Germination rate of room storage seeds with paper container increased to about 91.3%, however, decreased in cold ($4^{\circ}C$) and freeze storage ($-20^{\circ}C$) with paper container (76.7% and 78.0%, respectively). Germination rate of seed in vinyl stock container was better than that of paper stock container. Germination rate of seeds stored at room temperature for 4 years (2010 - 2013) ranged from 80.0% to 91.3%. Therefore, coriander seeds are expected to be stored at room temperature for increasing the germination rate and keeping a long term.

• Journal of Biosystems Engineering
• /
• v.28 no.1
• /
• pp.35-44
• /
• 2003

This study was conducted to develop proper model for cold storage facility that could of for uniform heat movement and air movement f3r green grocery and improve improper design of the existing container-type cold storage facility. For that reason, new model(dome-type) cold storage facility was developed using 3-D CFD(computational fluid dynamics) simulation. The size was 6m${\times}$6m${\times}$5m. Its size and configuration were same to simulation model. Unit cooler was designed to send cold air in 4 side ways. A dome-type cold storage facility showed uniform distributions of air temperature and velocity because cold air was forced to move down along the ceiling and the wall and then circulated to the unit cooler from the central part of the floor. Dome-type cold storage facility also showed by low wind velocity, below 1 m/s that could minimized cold damage and quality deterioration.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.29 no.3
• /
• pp.195-201
• /
• 2023

Garlic (Allium sativum)is a major crop in most Asian countries, and its consumption in Asia-Pacific countries exceeds 90% of the global consumption. It contains beneficial ingredients and numerous essential nutrients, such as manganese, vitamin B6, and vitamin B1. Garlic demand is rising not only in Asian countries but also around the world. Particularly, garlic demand has been steadily increasing in European countries, such as Spain, France, Italy, and the American continent. In South Korea, 331,671 tons and 387,671 tons of garlic was produced in 2018 and 2019, respectively, making the country the fifth ranking garlic producer in the world, and the production has been increasing every year. In this study, the study on temperature distribution in cold storage of Korean garlic in folding wire mesh pallet container using CFD (Computational Fluid Dynamics) analysis was performed and Computations were based a commercial simulation software (ANSYS Workbenh Ver. 18.0). Considering the respiration heat of garlic, the decreasing rate of temperature in the area in contact with the cold air was fast due to the inflow of cold air inside, while the decreasing rate of temperature in the center of the pallet was very low. In order to maintain a uniform temperature distribution inside the agricultural product storage pallet in a low-temperature warehouse, it is considered desirable to install an air passageway to allow low-temperature air to flow into the wire mesh pallet.

• Food Science and Preservation
• /
• v.22 no.6
• /
• pp.788-795
• /
• 2015

The efficacy of an experimentally designed cold chain container and a currently used styrofoam container was investigated with respect to important factors affecting the quality of fresh beef during storage under different conditions. The temperature in the TEPP-1 container was maintained at $5^{\circ}C$ using a phase change material (PCM) during transport and delivery. During storage in the TEPP-1 container, no significant difference was observed in pH of beef, but color decreased slightly, which does not affect the desire to purchase. After storage for 7 days, the rate of VBN and TBA in the TEPP-1 container, was lower than that in the TEPP-2 container. Drip loss was lower in the TEPP-1 container (0.87%) than in the TEPP-2 container (1.78%). No significant changes were observed in microbal count until 4 days in either of the containers, but after storage for 7 days, the count increased significantly. Microbial count in TEPP-1 was 6.65 log CFU/mL and that in TEPP-2 was 7.62 log CFU/mL. The results of sensory evaluations indicated that the overall acceptability of beef after storage for 7 days was better in the TEPP-1 container than in the TEPP-2 container. The EPS container was inferior in comparison with TEPP-1 and TEPP-2. It was impossible to continue the experiment using the EPS container after 3 days. These results suggest that the experimentally designed TEPP-1 container can be used for beef transport and delivery for 7 days without significantly affecting the quality of beef.

• Food Science and Preservation
• /
• v.8 no.1
• /
• pp.23-29
• /
• 2001

To extend the freshness of late autumn Chinese cabbage, the packaging and loading effects on the quality were investigated during cold storage. Judging from overall quality during storage period, late autumn Chinese cabbage could be stored by 3 months at 0$\^{C}$ cold storage. However, late autumn Chinese cabbage was not acceptable for long-term storage because of its marketability and the storage cost. Among 3 packaging methods(PP-net, carton and plastic container) for stored Chinese cabbage, plastic container and carton were more effective than PP-net packaging for the freshness prolongation. Gas composition in the plastic bags during storage was not significantly different among packaging conditions and O$_2$ and CO$_2$ concentrations were 13∼18% and 0.75∼7.48%, respectively, MAP with plastic film was effective for the quality retention because of low oxygen composition and high humidity condition in the bags.

• Food Science and Biotechnology
• /
• v.18 no.6
• /
• pp.1392-1397
• /
• 2009

This study was aimed at developing a low cost cold storage system for agricultural products. Three kinds of slurries: $K_1$, $K_2$, and $K_3$ slurries were developed using phase change materials (PCMs) such as tetradecane, octadecane, and sodium polyacrylate to maintain the desired temperature ranges. The slurries were manufactured by in-situ polymerization. Tetradecane and octadecane were capsulated in a core with melamine at the surface. The thermodynamic characteristics of the slurries were measured and analyzed. The latent heats of the $K_1$, $K_2$, and $K_3$ slurries at the melting points were 206.41, 186.88, and 147.91 kJ/kg, respectively. A transportable cold storage container was built to investigate the performance of the slurries as thermal storage media. The temperatures at the insides of the container could be maintained in the ranges of 0-5, 5-10, and $10-15^{\circ}C$ for more than 23, 27, and 60 hr with the $K_1$, $K_2$, and $K_3$ slurries, respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.1
• /
• pp.153-160
• /
• 2018

A pressure vessel consists of an inner tank and the outer tank; the material of the inner tank is austenite stainless steel, and the outer tank is general carbon steel. As the storage amount increase, the size of the inner tank for LNG also increases, which eventually increases the weight of the LNG storage tank. The Cold Stretch method can transport and store the LNG in a larger amount than the conventional pressure container, and the weight of the pressure vessel can also be reduced at 50 70% due to the reduction of the thickness, which is excellent from an economic and energy consumption perspective. Although the Cold Stretch method has these advantages, the domestic situation has not developed any related legislation. In this study, the actual production of pressure vessels using the Cold Stretch method will be processed and the volume expansion after the Cold Stretch will be checked and compared with the mechanical properties.