• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.95-98
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• 2008

Temperature difference energy is a good energy source replacing the fossil fuels. In the study, we classified the temperature difference energy as 4 types by the source & using method. For the understanding economic property of temperature difference energy, we tried simle economic analysis. As the result, Pay back period of 4 case of the temperature difference energy are from 1.23 to 12.65 years. Major factors influenced economic effect are operation time and energy user distance from the temperature difference energy source. If we can select optimal capacity and look for more effient energy users, Temperature difference energy play a important role of replacing fossil energy. So, for dess emination of temperature difference energy, we suggest that temperature difference energy must be included in renewable energy. Applying the effective methods among various promotion program of renewable energy policy, utilization of temperature difference energy could be activated.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.170.2-170.2
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• 2010

The amount of the heating and cooling energy of water source heat pump using the raw water from the Paldang water intake station is investigated in the study. The Han river water is conveyed in the large-size shallowly buried pipe. Averaged water temperature at the position, 27 km from the Paldang water intake station, is increased by $1.11^{\circ}C$ due to the geothermal energy transfer under the ground, therefore the raw water has more thermal energy than the river water. To estimate of the thermal energy for the raw water, it is assumed that the water source heat pump is used for the heating and cooling ventilation. When $5.0^{\circ}C$ temperature difference energy of the raw water is used in the heat pump system all the year except for the January and February in which $3.0^{\circ}C$ temperature difference energy is used. It is predicted that total 5,766.3 Tcal could be used in the metropolitan area a year, which is about 3.0% of the river water unutilized energy resources.

• Journal of Hydrogen and New Energy
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• v.26 no.6
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• pp.590-599
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• 2015

In this paper a performance analysis is carried out based on the first and second laws of thermodynamics for heat exchanger in organic Rankine cycle (ORC) for the recovery of low-temperature finite thermal energy source. In the analysis, effects of the selection of working fluid and pinch temperature difference are investigated on the performance of the heat exchanger including the effectiveness of the heat exchanger, exergy destruction, second-law efficiency, number of transfer unit (NTU), and pinch point. The temperature distribution are shown depending on the working fluids and the pinch temperature difference. The results show that the performance of the heat exchanger depends on the pinch temperature difference sensitively. As the pinch temperature increases, the exergy destruction in the evaporator increases but the effectiveness, second law efficiency and NTU decreases.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.663-664
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• 2016

Temperature difference power generation using sea water is a method repeatedly closed liquefaction and gasification by using the ammonia (refrigerant) of the deep sea water and surface water with a temperature difference between turning the turbine. The larger the temperature difference between the nature of the temperature characteristic energy generation development, the better. This is the story that the surface waters of the deep-water temperature difference is large. But the winter is not large temperature difference between surface water and deep water has lowered energy efficiency. And desalination technologies accounted for 97% of the earth, but we can not eat the technology to convert sea water into fresh water, fresh water produced by the desalination technology that is available for various industries such as irrigation, drinking water in the vessel.In this paper, LNG transport vessels, based on the LNG transport ship to the temperature difference power generation using cold energy of thermal energy and LNG marine diesel engines, which use the existing order to improve the temperature of the surface waters of the season that is the current problem we propose that a complex development of desalination and desalination of seawater freezing research into hybrid research and utilizing the cold energy of the engine.

• Journal of Hydrogen and New Energy
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• v.33 no.4
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• pp.419-429
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• 2022

Effects of operating variables on temperature profile and performance of 3 MWth chemical looping combustion system were estimated by mass and energy balance analysis based on configuration and dimension of the system determined by design tool. Air reactor gas velocity, fuel reactor gas velocity, solid circulation rate, and solid input percentage to fluidized bed heat exchanger were considered as representative operating variables. Overall heat output and oxygen concentration in the exhaust gas from the air reactor increased but temperature difference decreased as air reactor gas velocity increased. Overall heat output, required solid circulation rate, and temperature difference increased as fuel reactor gas velocity increased. However, overall heat output and temperature difference decreased as solid circulation rate increased. Temperature difference decreased as solid circulation rate through the fluidized bed heat exchanger increased. Effect of each variables on temperature profile and performance can be determined and these results will be helpful to determine operating range of each variable.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.17 no.4
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• pp.36-45
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• 2021

In this study, to improve the indoor thermal environment of the radiant floor heating system, a study was conducted on the temperature change characteristics and energy consumption according to the change of the indoor air set temperature, the supply hot water temperature and the outdoor temperature. As for the control method, the on/off control and the thermal difference proportional control method proposed through previous studies were applied. In addition, in consideration of field applicability, numerical analysis was performed for the case where the indoor air temperature sensor was affected by the wall temperature. As a result, it was found that the temperature difference proportional control method is more effective for thermal comfort and energy saving than on/off control.

• Journal of the Korean Solar Energy Society
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• v.28 no.6
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• pp.48-57
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• 2008

The research analyzed the distribution of the indoor temperatures of a radiant floor cooling system through mock-up experiments. It investigated the temperature difference of feed water, the vertical temperature difference of indoor air, the temperature difference of floor surface, and so on. The following is the results of the research. First, the research shows that the difference between indoor temperature and outside temperature was the smallest when the temperature of feed water was set at 16$^{\circ}C$. In addition, the temperature changes according to indoor positions (wall, room, floor, and ceiling) were the most uniform. Thus, the research found that the cold water temperature of 16$^{\circ}C$ is the most proper. In addition, it confirmed that the feed water temperature of 18$^{\circ}C$ is effective because the temperature can lower the temperature of a room to 13.55$^{\circ}C$, which is lower than the temperature of a non-cooling mode. Second, an investigation on the temperature distribution of vertical air in indoor space shows that the temperature distribution had a difference of 0.2 to 1.9$^{\circ}C$ on the average, which satisfies the range of 3.0$^{\circ}C$ in the standard of ISO.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.12 no.4
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• pp.21-26
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• 2016

In this study, the control strategies of indoor air temperature in floor radiant heating system were researched by computer simulation. The temperature difference based time control method using the difference of indoor set temperature and indoor temperature is compared with the existing On-Off control one for heating control performances. As a result, the temperature difference based time control method shows better thermal environmental characteristics in case of selected operational conditions in comparison with existing control one.

• Science of Emotion and Sensibility
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• v.16 no.1
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• pp.125-132
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• 2013

Recently, the consciousness of energy crisis is rapidly growing and sustainable eco-friendly energy sources are becoming issue. Therefore the portable electronic device requires new energy sources for providing continuous power supply and the power energy harvesting system of the human body that enables the power-harvesting research requests anytime, anywhere. One of the sources for energy harvesting is heat energy, which is the difference in temperature of the body and the surrounding environment. We tried to analyze the temperature difference between the environmental temperature and the temperature inside clothing according to the structure of the closed portion. And we examined the temperature difference between the environmental temperature and the temperature inside clothing according to the material of the clothing. The analysis showed that we have been able to get different results at parts of the body in the temperature inside clothing according to the structure of clothing. In upper torso of the chest and back, the temperature inside clothing of 'closed structure' was higher than the temperature inside clothing of 'opened structure'. In the section of arm and leg, it was reduced the difference of temperature inside clothing between 'closed structure' and 'opened structure'. It was particularly noticeable in the section of leg. The results of analysis of the difference between the environmental temperature and the temperature inside clothing according to the material of the clothing, in both cases of the two materials, 'closed structure' was higher than the 'opened structure' in the difference value between the environmental temperature and the temperature inside clothing. There was a difference according to the material in the section of leg. In this study, we outlined the basic guidelines for developing heat energy harvesting clothing by exploring the structure and material of clothing suitable for the heat energy harvesting.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.19 no.2
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• pp.1-7
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• 2023

In this study, in order to reduce the amount of infiltration generated from windows among the heat loss generated in the building, energy shutters were installed on the windows to conduct experiments on the change in internal temperature and amount of infiltration due to the pressure difference between the environmental chamber and the pressure box. As a result of the experiment, when the pressure difference was 0Pa, the initial temperature of the pressure box of window was higher than that of the pressure box of the energy shutter, but when the pressure difference occurred, the internal temperature of the pressure box of the energy shutter was higher. In addition, the amount of infiltration of the energy shutter was lower than that of the windows in all experimental conditions, and it was concluded that the reduction rate of the infiltration load (of the energy shutters) could be reduced by 53.3% compared to that of the windows.