• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.15 no.4
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• pp.39-45
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• 2019

The operational conditions such as cooling tower water pump flow rate, cooling tower fan flow rate, and chiller capacity in heat source equipment, and supply air temperature and chilled water temperature in air conditioner are considered to study the effects on energy consumption for central cooling system by using TRNSYS program. As a result, the optimal values of supply air temperature and chilled water temperature for minimal total energy consumption are 12℃ and 8℃. And if maximum values of cooling tower water pump and fan flow rate is decreased from 100% to 40%, energy consumptions are increased 170MJ/day and 63.2MJ/day, respectively.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.233-238
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• 2006

A new district cooling system using ice slurry for the uncertain cooling load of the future is presented. The chilled water produced by the absorption chillers is used for the base cooling load. The temperature of the chilled water is reduced by mixing of ice slurry depending on increasing of the cooling load. Finally, IPF of the ice slurry is increased up to 10% at the peak load. The transporting mass flow rate is decreased down to 44.7%, and the diameter of the main pipe is decreased down to 66.7%, but the diameter of the branched pipe is designed as the same size of the chilled water.

• Journal of Environmental Science International
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• v.18 no.2
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• pp.187-195
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• 2009

This study was investigated to control the corrosion and scale at the cooling water system in steel works. Laboratory and field tests were performed for the indirect cooling water system of plate mill. Throughout the experiment, various factors such as leakage of pipes, heating rate and capacity, and the reaction between existing and substitute inhibitors were carefully monitored. The results showed that the harmful effect of high temperature could be minimized, and satisfactory corrosion/scale controls were effectively achieved using inhibitor, even at the increased temperature of $80^{\circ}C$. The batch and field tests in the gas scrubbing cooling water system of blast furnace and cooling water system of corex plant indicated that the new inhibitor was more effective for the prevention of corrosion and scale than the existing one.

• International journal of advanced smart convergence
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• v.9 no.2
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• pp.123-128
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• 2020

We constructed a cooling system for solar cells using convection phenomena and investigated its cooling performance. The cooling system didn't need any driving power or water resources. The convection cooler manufactured with a right-triangle shape of an air duct was attached to the rear of the solar cell to confirm that cooling was performed using convection phenomena. When the ratio of duct width to attachment surface width was 3:7, and the ratio of entrance height and exit height of duct was 5:1, it showed the best cooling performance. Comparative experiments with solar cells without convection cooler showed that cooling effects from 16.5℃ to 20.9℃ occurred after 40 minutes exposed to the 1300W Xenon lamp condition.

• Journal of Power System Engineering
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• v.19 no.4
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• pp.50-55
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• 2015

Recently, because of the deterioration of the nuclear generating station and increase of the cooler and heater, energy problem is increasing. To save the energy, the free cooling system is developed. The free cooling system is that cool the water to use cooled air in winter and is used in industrial process or data center. Yoon check the energy of free cooling system with dry cooler in korea. In this study, the value of the free cooling system with dry cooler is confirmed through using the NPV that is economic evaluation. when temperature degree of the cooled water is 10, in Chuncheon and Seoul the value is the most high. When temperature degree of the cooled water is 20, in Ulsan the value is the most high. As the result, because the using the temperature degree of the cooled water is high in the industrial process, the free cooling system is advantageous in korea.

• Journal of Power System Engineering
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• v.8 no.1
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• pp.41-47
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• 2004

Cooling towers are widely used not only for cooling products and equipment in manufacturing process but HVAC(Heating, Ventilation and Air Conditioning) system. As a cooling tower is the terminal apparatus which discharges heat from industrial process, the efficiency of heat exchange in the cooling tower greatly affects to the overall performance of a thermal system. In this paper, we constituted a new water cooling system by using a Latent heat of evaporation in an enclosed tank, and this system is consisted of an enclosed vacuum tank and water driven ejector system. Several experimental cases were carried out for improvement methods of high vacuum pressure and water cooling characteristics. The ejector performance was tested in case of water temperature variations that flows into the ejector. Based on the vacuum pressure by water driven ejector, the water cooling characteristics were investigated for the vaporized air condensing effects.

• Journal of the Korea Concrete Institute
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• v.12 no.3
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• pp.95-102
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• 2000

Crack control due to temperature is an important factor for the mass concrete structure. Pre-cooling is the effective system to reduce the highest temperature of mass concrete. In this study, for pre-cooling, cooling water, cooling water with ics flake are used. The results of a series of experimental studies indicate that the changes in properties of fresh concrete after cooling are of low degree, and compressive strength of concrete is changed very little by cooling. The adiabatic temperature rise is also measured with pre-cooling concrete specimens. It is shown that hydration heat characteristics of cement and concrete were largely affected by pre-cooling.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1099-1104
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• 2008

Recent year, mean energy consumptions of a people are higher than other country. And international oil price became over 120 dollar. This energy environment as well as energy war. Maybe, the Meteorological Administration is going to enforce scorching heatwave special report system from that come summer. Besides, 2008 summer, maximum demand power is expected by 64,240,000kW. The electric power equipment reserve rate appeared in to keep 12.5% level. Chilled water storage system witch is one of electric load administration system. Heat pump system used cooling tower heat recovery is advantage that use is possible to summer in small a public bath building. In this paper, we suggest that heat pump system by heat recovery using cooling tower when it is heating operation of ambient air temperature. To apply cooling tower heat recovery heat pump to chilled water heat storage type and achieved performance evaluation about operation. As a result, performance of heat pump system that about 121% in cooling mode, 138% in heating mode higher than KEPCO standard. And heating operation possible to ambient air temperature about $23^{\circ}C$, which of appear cooling tower outlet temperature about $13^{\circ}C$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.3
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• pp.367-373
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• 2003

The present study investigates the fire suppression characteristics using a water mist fire suppression system. The fire extinguishing times are measured for various fire sources, fuel types, and different total flooding rates of water mist. Pool fire with hydrocabon fuel is successfully extinguished within a minute under the operating conditions of the water mist system. Two different regimes of the smoke layer cooling are observed, such as rapid and slow cooling processes. The regimes are divided by threshold time which is calculated with auto-correlation function. The threshold time for the initial cooling decreases with increasing water flow-rates and fire sources. These initial cooling effects play an important role in preventing the occurance of flashover fire by the initial fire suppression.

• Agricultural and Biosystems Engineering
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• v.6 no.1
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• pp.27-33
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• 2005

Soy protein meat analog was produced using a twin-screw extruder attached with a cooling die. Heat transfer analysis was performed for cooling dies with various die sizes at the four different moisture contents of feed during extrusion process. The experimental design consisted of two cooling die widths (30 and 60 mm), three cooling die lengths (100, 200, and 300 mm), four product moisture contents (71.2, 67.0, 61.6 and 55.8%), and water and water plus ethylene glycol as cooling material. When water was used as cooling medium, the values of equivalent overall heat transfer coefficient $(U_e)$ for each die width of 30 and 60 mm were in the range of 187.0 - 341.4 and $358.5-191.6W/m^2^{\circ}C$ depending on the size of die length. Convective heat transfer coefficients between cooling water and inside die wall of cooling channel $(h_c)$ for both die widths of 30 and 60 mm were 588.5, 416.1, and $339.8W/m^2^{\circ}C$ for each die length of 100, 200, and 300 mm. Convective heat transfer coefficients between product and inside die wall of product channel $(h_p)$ for each die width of 30 and 60 mm were in the range of $434.6-888.1W/m^2^{\circ}C$ and $460.7-1014.5W/m^2^{\circ}C$ depending on the size of die length. When water plus ethylene glycol was used as cooling medium, the values of $U_e$ were in the range of $143.9-319.6W/m^2^{\circ}C$ and $177.8-332.7W/m^2^{\circ}C$ for each die width of 30 and 60 mm depending on the size of die length.