• Journal of Power System Engineering
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• v.13 no.6
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• pp.76-81
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• 2009

Thermal desorption systems are designed to remove organic compounds from solid matrices such as soils, sludges and filter cakes without thermally destroying them. It is a separation technology, not a destruction technology. Since it is a thermal process, there is a common belief that temperature is the only significant parameter to be monitored. While it is true that better removal efficiencies are usually achieved at higher temperatures, other factors must be considered. Since the process is governed by mass transfer, heating time and the amount of mixing are also key parameters in optimizing removal efficiency. Thermal desorption have been successfully used for just about every organic contaminant found to date. It has also been used to remove mercury. In the present study, the numerical simulation has been performed to investigate the characteristics of heat transfer of LTTD(low temperature thermal desorption). The commercial software, AMESIM was applied for analyzing the heat transfer process in the LTTD.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.4
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• pp.37-46
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• 2001

This study numerically investigates thermal comfort of a space cooled by a floor-supply air-conditioning system, in which three different combinations of supply and return locations, one floor-supply/ceiling-return and two floor-supply/floor-return, are treated. A complementary experiment is performed to validate the present numerical analysis, and the prediction agrees favorably with the measured data. In the numerical procedure, a simplified model mimicking the inlet flow through a diffuser is developed for efficient simulations. The calculated results show that the ceiling-return type is far better in terms of thermal comfort than the floor-return ones within the extent of this study, which seems to be caused by effective vertical penetration of the supply air against natural convection. It is also revealed that the arrangement of port locations in the floor-supply/floor-return system has insignificant effect on the cooling performance. For selecting a proper system, other characteristics including the heating performance should be accounted for simultaneously with the present considerations.

• 한국연소학회:학술대회논문집
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• 2000.12a
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• pp.17-23
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• 2000

Knock in SI engines causes physical damage to the piston and combustion chamber and lowers the thermal efficiency. The increase in compression ratio which can improve the thermal efficiency and engine performance has been limited by engine knock. So the need of making clear the knocking phenomenon has increased. This paper reviews the methods of knock detection, characterization and prediction of knock with the reduced chemical kinetic modeling.

• Journal of the Korean Society of Combustion
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• v.5 no.2
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• pp.29-35
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• 2000

Knock in SI engines causes physical damage to the piston and combustion chamber and lowers the thermal efficiency. The increase in compression ratio which can improve the thermal efficiency and engine performance has been limited by engine knock. So the need of making clear the knocking phenomenon has increased. This paper reviews the methods of knock detection, characterization and prediction of knock with the reduced chemical kinetic modeling.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.808-810
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• 2002

Higher current-rating and improved thermal performance are being sought for existing medium-voltage vacuum circuit breakers(VCB) in order to meet market needs which require to be compact and downsized. In this paper, thermal performance of medium voltage vacuum circuit breaker was investigated through experiments and numerical analysis. We changed several major parameters of current-rating and heat sink affecting on thermal behaviors in the breaker and observed the results. To predict the temperature distribution in complex three-dimensional (3-D) VCB components and gas, the commercial package was used to simulate conjugate heat transfer. Although some assumptions and simplifications were introduced to simulate the model, results from the computational model were in good agreement with actual temperature rise measurements obtained from experiments.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.144-149
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• 2011

This study aims to evaluate performance of ventilation and thermal about breathing wall by flowing air to indoor on appropriate conditions that is effective aperture area in the Central region(20, 50, $80cm^2/m^2$). The result is as follows : 1) Sectional temperature distribution of inflow and outflow out under the constant ventilation was reviewed. In the case of inflow, outside temperature increase effect was confirmed. 2) The more differences of temperature between outdoor and indraft of air was high, the more heat recovery was high.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.754-761
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• 2013

Thermal displacement is an important issue in machine tool systems. During the last several decades, thermal error compensation technology has significantly reduced thermal distortion error; this success has been attributed to the development of a precise, robust thermal error model. A major advantage of using the thermal error model is instant compensation for the control variables during the modeling process. However, successful application of thermal error modeling requires correct determination of the temperature sensor placement. In this paper, a procedure for predicting thermal-mode-based thermal error is introduced. Based on this thermal analysis, temperature sensors were positioned for multiple heat-source models. The performance of the sensors based on thermal-mode error analysis, was compared with conventional methods through simulation and experiments, for the case of a slide table in a transient state. Our results show that for predicting thermal error the proposed thermal model is more accurate than the conventional model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.1
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• pp.53-61
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• 2021

This paper is a preliminary study for the development of a drone for inspection inside a boiler in a thermal power plant, which is a high-temperature environment, and validated whether the drone can fly normally through a high-temperature environment simulation using AirSim. In a high-temperature flight environment, the aerodynamic characteristics of the air density and viscosity are different from room temperature, and the flight performance of the drone is also changed accordingly. Therefore, in order to confirm the change of the aerodynamic characteristics of the propeller according to the temperature change, the propeller analysis and thrust test through JBLADE, and the operation characteristics prediction through the electric propulsion system performance prediction model were performed. In addition, the analysis and performance prediction results were applied to AirSim for simulation, and the aircraft redesigned through the analysis of the results. As a result of the redesign, it was confirmed that about 65% of the maximum power used before the redesign was reduced to 52% to obtain the necessary thrust when hovering in an environment of 80℃.

• Solar Energy
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• v.7 no.1
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• pp.3-13
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• 1987

A batch type passive solar water systems, which perform the dual function of absorbing the solar energy and storing the heated water, have been designed and fabricated for the purpose of side-by-side testing at KIER. The test models included an A, B and C type batch systems which were classified according to the design of box and arrangement of tanks. The year-round performance tests show that B type batch system taken the step-wise tank arrangement indicates 55.7% yearly-average collection efficiency factor and 61% yearly-average maximum collection efficiency factor. Computer-aided-experimental results show that the sufficient hot water can be obtained in the early morning if the glazing is supplemented by a reflector/insulation cover. The thermal performance equation has been developed for the prediction of hourly variation of the water temperature in tank.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.3990-4002
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• 2021

CSPACE (Core meltdown, Safety and Performance Analysis CodE for nuclear power plants) for a simulation of severe accident progression in a Pressurized Water Reactor (PWR) is developed by coupling of verified system thermal hydraulic code of SPACE (Safety and Performance Analysis CodE for nuclear power plants) and core damage progression code of COMPASS (Core Meltdown Progression Accident Simulation Software). SPACE is responsible for the description of fluid state in nuclear system nodes, while COMPASS is responsible for the prediction of thermal and mechanical responses of core fuels and reactor vessel heat structures. New heat transfer models to each phase of the fluid, flow blockage, corium behavior in the lower head are added to COMPASS. Then, an interface module for the data transfer between two codes was developed to enable coupling. An implicit coupling scheme of wall heat transfer was applied to prevent fluid temperature oscillation. To validate the performance of newly developed code CSPACE, we analyzed typical severe accident scenarios for OPR1000 (Optimized Power Reactor 1000), which were initiated from large break loss of coolant accident, small break loss of coolant accident, and station black out accident. The results including thermal hydraulic behavior of RCS, core damage progression, hydrogen generation, corium behavior in the lower head, reactor vessel failure were reasonable and consistent. We demonstrate that CSPACE provides a good platform for the prediction of severe accident progression by detailed review of analysis results and a qualitative comparison with the results of previous MELCOR analysis.