• Food Engineering Progress
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• v.23 no.4
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• pp.270-277
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• 2019

Commercial direct refrigerators have good energy efficiency, but are difficult to use for supercooled storage due to their large temperature deviation. Placing insulators and conductors inside the refrigerator could reduce these temperature deviations to within 0.3 degrees, allowing for the supercooled storage. The supercooled storage of salted Chinese cabbages during ten weeks was progressed to compare the other low temperature storages. The nucleation temperatures of salted Chinese cabbage were around -2.5℃ and the freezing points were around -0.4℃, so -2℃ was selected for the supercooled storage. The growth rate of lactic acid bacteria and yeast at -2℃ storage was lower than that at 2℃ storage. The reducing sugar was maintained higher due to the growth rate of lactic acid bacteria. The supercooled storage had an effect of delaying the fermentation of the salted Chinese cabbage, which may have the effect of delaying the fermentation of kimchi. This enhancement method of the direct refrigerator was effective for the supercooled storage and would be promising for commercial use.

• Food Science of Animal Resources
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• v.42 no.3
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• pp.467-485
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• 2022

Supercooling storage refers to lowering the product temperature below its freezing point without phase transition and has the potential to extend shelf life. Nevertheless, supercooled objects are in a thermodynamically unstable state, and nucleation can occur spontaneously. To achieve supercooling storage, slow cooling and insulation are essential. Hence, a stepwise algorithm for the supercooling storage of pork loins was designed and validated in this study. Pork loins were stored at 3℃, -18℃, and -3℃ (freezing), and supercooled for 16 days. All samples remained in a supercooled state and were unfrozen at the end of storage. Supercooled pork loins were superior in terms of drip loss, cooking loss, and water-holding capacity compared to frozen samples. Additionally, supercooling treatment prevented discoloration, increase of volatile basic nitrogen, and microbial growth. Thus, supercooling of pork loin was achieved using a stepwise program and was effective to maintain meat quality.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.12
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• pp.850-856
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• 2007

In a supercooled or capsule type ice storage system, aqueous solution (or water) may have trouble with non-uniform dissolution though the system contributes to the simplicity of system and ecological improvement. The non-uniform dissolution increases the instability of the system because it may cause an ice blockage in pipe or cooling part. In order to observe the supercooled state, a cooling experiment was performed with pressurization to an ethylene glycol(EG) 3 mass% solution in stationary state. Also, the effect of the pressurization from 101 to 505 kPa to the dissolution of supercooled aqueous solution was measured with the dissolution time of the supercooled aqueous solution at a fixed cooling rate of brine. At results, the dissolution of supercooled point decreased as the pressure of the aqueous solution in the vessel increased. Moreover, the dissolution point increased as the heat flux for cooling increased.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.578-584
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• 2013

Ice slurry that is a mixture of fine ice crystals and liquid water is a widely used working fluid in the ice thermal energy storage system due to its flowability and large latent heat of fusion. Generally ice slurry is made from supercooled water. But the excessive supercooling causes the water to freeze even worse to block the pipe. Additionally large degree of supercooling of water degrades the efficiency of the ice thermal energy storage system. Therefore the effective method to control the phase change from supercooled water to ice slurry is needed. In this paper we experimentally studied a novel method to generate the ice slurry from the supercooled water using the ultrasonic vibration. It was found that the cavitation impact of supercooled water by ultrasonic vibration can help the generation of ice slurry.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.9
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• pp.647-653
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• 2007

In dynamic ice storage system(DISS), ice slurry is formed not only from solution freezing by mechanical removing parts but also supercooled solution. However, in order to perform continuous ice formation in the system without mechanical moving parts, supercooled aqueous solution should be formed stable through cooling heat exchanger and be dissolved uniformly in storage tank. In previous study, the time of ice slurry increased as the pressure of the cooling heat exchanger(PHX) increased. In this study, a cooling experiment of an ethylene glycol 7mass% solution was performed with various inlet temperature of the PHX, which has constant brine inlet temperature of $-7^{\circ}C$. The temperature in the storage tank maintained to freezing point of the solution. At results, the time of ice slurry formation increased as the supercooling degree decreased and the cooling rate increased.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.138-143
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• 2006

The peculiarity of ice slurry, such as liquidity, high heat transfer rate and easy storage can also find to supercooled type dynamic ice storage system(DISS) which is one of the DISS. However, in order to accomplish continuous ice formation in the system without mechanical moving parts, supercooled aqueous solutionshould be formed stable through cooling heat exchanger and be dissoluted in storage tank. In previous research, the time of ice slurry increased as the pressure of the cooling heat exchanger(PHX) increased. In this study, a cooling experiment of an ethylene glycol 7mass% solution was performed with various inlet temperature of the PHX, which has constant brine inlet temperature of $-7^{\circ}C$. The temperature in the storage tank maintained to freezing point of the solution. At results, the time of ice slurry formation increased as the supercooling degree decreased and the cooling rate increased.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.7
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• pp.862-872
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• 1997

Ice formation in a horizontal circular cylinder has been studied numerically. From the numerical analysis results, it was found that there were three types of freezing pattern and that freezing phenomenon was affected largely by density inversion and cooling rate. The type of freezing pattern largely depends on the secondary flow which is generated by density inversion. When supercooling energy is released before the development of the secondary flow, the annular ice layer grows. If the energy is released when the secondary flow is considerably developed and the supercooled region is removed to the upper half part of the cylinder, an asymmetric ice layer grows. And if the energy is released after perfect development of the secondary flow, instantaneous dendritic ice formation over the full region occurs. Furthermore, this secondary flow was found to have an effect on heat transfer characteristics. The heat transfer rate becomes small at the instant when the secondary flow is generated, but becomes large with the development of the flow. It's concluded that for the facilitation of heat transfer it is desirable to keep water in liquid phase until the secondary flow is perfectly developed. This study gave an instruction of performance improvement of capsule type ice storage tank.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.1
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• pp.25-31
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• 2009

Supercooled type ice storage system with aqueous solution (or water) may have trouble with non-uniform release of supercooling even though it contributes to the simplicity of system and ecological improvement. The non-uniform release increases the instability of the system because it may cause an ice blockage in pipe or cooling part. In order to suppress the release of the supercooling, a cooling experiment was tried to an ethylene glycol(EG) 3 mass% solution corresponding with pressurization. Also, the frequency ratio of the release of the supercooling was measured to the pressurization from 101 to 505 kPa. At results, the frequency ratio of supercooling release tends to decrease as the pressure of the aqueous solution increased in each cooling rate. Moreover, it tends to decrease as the cooling rate of the solution decreased in each pressure.

• Journal of Veterinary Science
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• v.24 no.6
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• pp.79.1-79.16
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• 2023

Background: The need for a storage method capable of preserving the intrinsic properties of bones without using toxic substances has always been raised. Supercooling is a relatively recently introduced preservation method that meets this need. Supercooling refers to the phenomenon of liquid in which the temperature drops below its freezing point without solidifying or crystallizing. Objectives: The purpose of this study was to identify the preservation efficiency and applicability of the supercooling technique as a cortical bone allograft storage modality. Methods: The biomechanical effects of various storage methods, including deep freezing, cryopreservation, lyophilization, glycerol preservation, and supercooling, were evaluated with the three-point banding test, axial compression test, and electron microscopy. Additionally, cortical bone allografts were applied to the radial bone defect in New Zealand White rabbits to determine the biological effects. The degree of bone union was assessed with postoperative clinical signs, radiography, micro-computed tomography, and biomechanical analysis. Results: The biomechanical properties of cortical bone grafts preserved using glycerol and supercooling method were found to be comparable to those of normal bone while also significantly stronger than deep-frozen, cryopreserved, and lyophilized bone grafts. Preclinical research performed in rabbit radial defect models revealed that supercooled and glycerol-preserved bone allografts exhibited significantly better bone union than other groups. Conclusions: Considering the biomechanical and biological superiority, the supercooling technique could be one of the optimal preservation methods for cortical bone allografts. This study will form the basis for a novel application of supercooling as a bone material preservation technique.

• Journal of Energy Engineering
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• v.16 no.4
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• pp.164-169
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• 2007

The decrease in the summer peak electric load in our country is very important. The government has arranged and implemented a lot of support policies and statutes to decrease the peak electric load. And the ice-thermal-energy-storage system is known as one of the alternatives. The purpose of this paper is to evaluate the performance and the total efficiency of its storage tank, conducting the charging operation, the parallel operation and the single operation of a storage tank. The thermal energy density stored and discharging efficiency of a storage tank and the efficiency of total energy utilization of system are $18.4\;USRT-h/m^3$, 96.2% and 2028.7 kcal/kWh under the operation of design condition. When the storage tank is supplied more ice thermal energy than design condition, it is estimated that the efficiency of system are lower than the design condition by the supercooled effect.