• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.04a
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• pp.24-24
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• 1999

This study addresses the effectiveness of TEC(Thermoelectric cooler) application for spacecraft thermal control. The required radiator area and power consumption characteristics of active thermal control using TEC are compared with the passive control at BOL and EOL through unsteady thermal analyses by calculating external heat fluxes. When the component operating temperature is low enough in TEC active control, the required radiator area can be smaller than the passive thermal control. TEC also needs less power consumption than the passive control under the condition that the temperature of cooling pars is low enough and/or the design temperature margin of the components is narrow enough.

• Journal of the Korean housing association
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• v.22 no.3
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• pp.113-122
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• 2011

This study aimed to develop AI- (Artificial Intelligence) based thermal control logics and test their performance for identifying the optimal thermal control method in buildings. For this objective, a conventional Two-Position On/Off logic and two AI-based variable logics, which applied ANN (Artificial Neural Network) and ANFIS (Adaptive Neuro-Fuzzy Inference System), have developed. Performance of each logic was tested in a typical two-story residential building in U.S.A. using the computer simulation incorporating MATLAB and IBPT (International Building Physics Toolbox). In the analysis of the test results, AI-based control logic presented the advanced thermal comfort with stability compared to the conventional logic while they did not show significant energy saving effects. In conclusion, the predictive and adaptive AI-based control logics have a potential to maintain interior air temperature more comfortably, and the findings in this study could be a solid foundation for identifying the optimal thermal control method in buildings.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.5
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• pp.113-119
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• 2015

The technical development of electric vehicles has been actively proceeding because of the reduction of oil resources and need for eco-friendly vehicle technology. In particular, an electronic control unit is an important element in the technology of electric vehicles due to the motor drive system. This paper concerns an experimental study on the thermal analysis of the steering control ECU structure for an electric vehicle. The ECU unit is designed for eight heat sinks for the thermal analysis of the ECU structure. The thermal analysis characteristics of the ECU structure are evaluated by the temperature distribution, heat flow, von Mises stress, total translation, and external surface temperature measurement of the ECU unit.

• International Journal of Air-Conditioning and Refrigeration
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• v.14 no.4
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• pp.125-130
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• 2006

This study has been performed to investigate the thermal performance of variable conductance heat pipe (VCHP) with screen meshed wick. The active length of condenser section in a VCHP is varied by non-condensible gas, which controls the operating temperature, and the heat capacity of VCHP is controlled by the operating temperature. In this study, numerical analysis of the VCHP based on the diffusion model of non-condensible gas is done for the thermal control performance of VCHP. Water is used as a working fluid and nitrogen as a control non-condensible gas in the copper tube. As a result, the thermal conductance of VCHP has been compared with that of constant conductance heat pipe (CCHP) corresponding to the variation of operating temperature.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.91-101
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• 2006

Lately, massive concrete structures are increasingly built. In such massive structures, the heat of hydration of mass concrete causes thermal cracks. To avoid thermal crack, methods widely acceptable for practical use are pre-cooling, pipe cooling and control of placing height. Thermal stress analysis is performed to find the way of controlling the thermal crack of pier footing mat in this paper. The footing mat model for the analysis is $12m{\times}14m$area and 3m height. The analysis results are compared with method of control of lift height and method of pipe cooling. The analysis results show that thermal crack can be removed by method of placing control and pipe cooling at footing mat placed on the ground.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.1
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• pp.50-56
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• 2015

Korea district heating systems have mainly used setting temperature control and outdoor reset control. Different from such conventional normal methods, a thermal-load control proposed in Sweden can decrease the return temperature and reduce pump power consumptions because the control is able to provide the appropriate amount of required heat. In this study, further improved predictive optimal control in addition to the conventional controls were simulated in order to verify its effect in district heating system using TRNSYS 17. $200m^2$ apartment housing which accounts for 25% in Korea and is used as a calculation model;. the number of households in the simulation was 9. As a result, a higher temperature difference and decreasing flow rate at primary loop were shown when using thermal-load control.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.2
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• pp.103-114
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• 2012

Nowadays membrane material is widely used for large indoor spaces and long spaces such as traditional market. Thermal insulation and sound field control performance is considered as a main properties for design of such buildings. In this paper sound absorption and thermal insulation properties of membrane material was investigated. Firstly, normal incidence sound absorption coefficient of 10 kinds of glass wool textiles showed that sound absorption coefficient was increased in proportion of thickness and surface density of textile. Sound absorption coefficient of 4 kinds of sound absorptive inner membrane with outer membrane was tested in the reverberation chamber. Sound absorption coefficient of mid frequency range was about 0.4 ~ 0.6. Also, sound absorption coefficient was changed by the air space behind the membrane material. Secondly, sound field control performance was investigated using mock-up space. By the installation of sound absorption membrane material, reverberation time was decreased and speech intelligibility was increased. Finally, thermal resistance and room temperature in two kinds of mock-up rooms were tested, simultaneously. Results of thermal properties showed thermal insulation properties ware increased by adding inner membrane material underneath the outer membrane.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.369-376
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• 2001

As many studies have performed to reduce thermal cracking in mass concrete, it is already prepared against thermal cracking, we can find many plans against thermal cracking in several reference book. But it needs practical guidelines to be available in construction site. In this study to establish control method of thermal cracking in mass concrete, tests which have factors of placing thickness and curing method of concrete are performed.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.210-215
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• 2004

: A DNA analysis system based on fluorescence analysis has to have a DNA amplifying thermal cycle system. DNA amplification is executed by the temperature control. Accuracy of fluorescence analysis is influenced by the temperature control technology. For that reason, the temperature control is core technology in developing the DNA analysis system. Therefore, the objective of this paper is to develop the hardware to apply thermoelectric module to the DNA amplifying thermal cycle system. In order to verify the developed hardware for controlling the temperature of thermoelectric module, a DNA amplifying thermal cycle test was performed. From the test, the developed hardware controlled the temperature of thermoelectric module successfully. Therefore, it is expected that the developed hardware can be applied to the DNA amplifying thermal cycle system.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2304-2308
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• 2003

Ocean thermal energy conversion (OTEC) is an effective method of power generation, which has a small impact on the environment and can be utilized semi-permanently. This paper describes a dynamic model for a pilot OTEC plant built by the Institute of Ocean Energy, Saga University, Japan. This plant is based on Uehara cycle, in which binary mixtures of ammonia and water is used as the working fluid. Some simulation results attained by this model and the analysis of the results are presented. The developed computer simulation can be used to actual practice effectively, such as stable control in a steady operation, optimal determination of the plant specifications for a higher thermal efficiency and evaluation of the economic prospects and off-line training for the operators of OTEC plant.