• Journal of Power System Engineering
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• v.21 no.2
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• pp.77-82
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• 2017

In the fishing boat, freshwater ice is loaded on the fishroom in advance and it is used for storage of fishes. However, it causes degradation of catches' freshness. Therefore, seawater ice machine on board is necessary for the fishing industry. In this study, seawater ice machine with drum type evaporator was manufactured, and the system was tested under various operating conditions having an influence on the COP and amount of ice produced. The main results are as follow : The COP of the system gets larger when the evaporation temperature and rotation speed of the drum in the evaporator increases. The most effective refrigerant is R22 and the value of the COP was 1.43 times higher than that of R404A. The amount of produced ice increases with respect to increment of the evaporation temperature, while that decreases with respect to increment of the evaporator drum rotation speed.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.298-303
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• 2001

A fundamental study on the under water harvest-type ice storage system and its temperature characteristics in ice storage system was performed experimentally. The experiments were conducted by changing the inlet refrigerant temperature of an evaporator to analyzing the thermal fluid motion inside the ice storage tank. From the experimental results, the cold storage characteristics were investigated by measuring the axial and radial temperature variations inside the ice storage tank with respect to the inlet and outlet refrigerant temperatures of an evaporator. In case of the under water harvest-type ice storage system, thermal fluid. motion inside the ice storage tank was shown differently in comparison with that of other ice storage systems. During the cooling storage process, there was no supercooling phenomenon in the ice storage tank. These results show the characteristic of this system and the possibility of application to other fields.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.210-215
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• 2000

A fundamental study on the under water harvest-type ice storage system and its temperature characteristics in ice storage system was performed experimentally. The experiments were conducted by changing the inlet refrigerant temperature of an evaporator to analyzing the thermal fluid motion inside the ice storage tank. From the experimental results, the cold storage characteristics were investigated by measuring the axial and radial temperature variations inside the ice storage tank with respect to the inlet and outlet refrigerant temperatures of an evaporator. In case of the under water harvest-type ice storage system, thermal fluid motion inside the ice storage tank was shown differently in comparison with that of other ice storage systems. During the cooling storage process, there was no supercooling phenomenon in the ice storage tank. These results show the characteristic of this system and the possibility of application to other fields.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.5
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• pp.653-659
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• 2001

This paper is concerned with the development of a new method for making and separating ice in-water and saving floated ice by installing an evaporation panel in an ice storage tank. The new method shows very good heat transfer efficiency than that of the convectional method. It is because the evaporation panel is directly contacted with water in the storage tank. The experiments were performed by varying inlet and outlet refrigerant temperatures of its evaporator. From the experimental results, the operating characteristics of in-water harvest-type ice storage system were investigated by measuring temperature and pressure at each point of the ice storage system and power required to operating compressor respect to the changes of the inlet and outlet refrigerant temperature of evaporator. It can be think that defrost frequency decreased and heavy ice created as the refrigerant temperature of evaporator outlet and defrost setting temperature is low so gotten result can effect to release efficiency. Also, consumption power, condensing heat quantity, refrigerating capacity and performance efficiency decreased as time goes by. Therefore, these results provide the basic data for system optimization, performance improvement and the possibility of application to other fields.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.558-564
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• 2021

The water purifier market has increased rapidly in recent years. The welding technology of the evaporator is a key component that determines the level of ice production and the cold water performance of an ice purifier. The finger type evaporator of an ice purifier can remove ice and is divided largely into an instant heat method and a hot gas method. In the hot gas type evaporator, particularly during the production process, the pinhole phenomenon inside the copper pipe and clogging problems occur intermittently when welding high-pressure pipes due to the high-temperature oxygen welding. Its use in a water purifier can cause a problem in that ice and cold water do not form, and repairs cannot be made on site. To solve this problem, in this study, a cap jig was applied to improve the welding defect of the hot gas evaporator. In addition, the oxygen welding flame size was adjusted so that the heat source could be well supplied to the cap jig, and the effectiveness was confirmed through a wave pressure test, a test, and a thermal shock test.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.3 no.2
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• pp.87-96
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• 1991

A two-phase closed thermosyphon is applied to an ice storage system. The thermosyphon is used to freeze the water in a storage tank. The experiment has been performed to investigate the effects of the important parameters such as the quantity of the fluid filled with, the ratio of the length of the evaporator to the condenser, and the temperature and the mass flow rate of the brine. It is found that the higher thermal performance of the thermosyphon is obtained as the ratio of the length of the evaporator section to that of the condenser section is decreased and the temperature of the brine is lowered. The increase of the quantity of the working fluid also favors the performance of the system. The experimental data can be utilized for the basic design of ice storage systems with thermosyphons.

• Journal of the Korean Solar Energy Society
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• v.22 no.2
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• pp.11-17
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• 2002

This paper is concerned with the development of a new method for making, separating ice and storage floated ice by installing an evaporation plate at under-water within a storage tank. In a conventional harvest-type ice storage system, a tank saves ice by separating an ice from an installed evaporation plate, which is located above an ice storage tank as an ice storage system. Developed new harvest-type method shows good heat transfer efficiency than a convectional method. It is because the evaporation panel is directly contacted with water in a storage tank. Also, at a conventional system a circulating pump, a circulating water distributor and a piping are installed, however these components are not necessary in a new method. In this study ice storage systems are experimentally investigated to study the charge and discharge of thermal energy. The results show the applicable possibility and performance enhancement of a new type.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.3 no.2
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• pp.142-151
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• 1991

In the present investigation, it has been proposed to utilize a direct contact heat exchanger as an evaporator to solve the difficulties such as scaling, corrosion and law thermal efficiencies, associated with the conventional evaporator. Liquified nitrozen was utilized as a working fluid to investigate basic natures of bubble dynamics in the evaporator, and spray nozzles were adopted to inject liquified nitrozen into the spray column with varying flow rates of dispersed phase fluids. Experimentations were carried out in the range of $6.54{\times}10^{-4}kg/s$ - 0.030 kg/s for dispersed phase flow rates with one, three and five nozzle holes. Observing the bubble dynamics for the evaporator the feasibility of utilizing a direct contact heat exchanger as a LNG evaporator has been evaluated. The results show that no eruption phenomena was observed in the present investigation with $LN_2$ and the interface between $N_2$ bubbles and water was fully turbulent. It is believed that the high injection velocity of $LN_2$ through the spray nozzles provide good mixing effects for both heat and mass transfers between water and $N_2$ bubbles. Ice was formed on the surface of the spray nozzle for higher $LN_2$ flow rates. However, even in this case, it is observed that the ice was detached as soon as it was formed. Under the present experimental conditions, the shapes of $LN_2$ bubbles were in the spherical-cap region according to the Clift, Grace and Weber Graphs. The height of foam region caused by the breakup of larger bubbles keeps increasing with high injection velocities until it reaches it's maximum height.

• Journal of Power System Engineering
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• v.14 no.5
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• pp.76-82
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• 2010

This paper investigates the optimum operating conditions to construct total automatic control system with high energy efficiency of a newly developed seawater ice machine. The machine has an electronic expansion valve(EEV) and a variable speed rotating drum with an evaporator installed inside. The coefficient of performance(COP) was used as an index to evaluate energy efficiency of the machine. At first, the opening angle of EEV was adjusted to obtain COP of the machine at a constant speed of the drum. Then, we checked seawater ice product versus opening angles of the EEV. Finally, effect of drum's rotating speed in response to product of seawater ice and seawater ice temperature were considered.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.8
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• pp.437-445
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• 2017

Because of improvement of living standards and increased use of ice at home, built-in ice makers are of interest. In this study, refrigeration cycle of a unitary ice maker for residential usage was optimized using R-404A. Optimization was achieved through a search for proper refrigerant charge amount. For the present ice maker producing ice for 24 cups, the optimum charge amount was 200 g. In this configuration, the ice making cycle time was 17 minutes 53 seconds, ice production was 1.27 kg/h and COP was 0.310. After initial start-up, condensation and evaporation temperatures gradually decreased with time. As ice builds in the cup, heat transfer performance of the evaporator decreases, that results in decrease of evaporation and condensation temperatures. Replacement of existing slit nozzles with individual circular hole nozzles improved ice production capacity by 10 percent. Through visualization of ice formation in the ice cup, growth rate of the ice in the cup was relatively uniform.