• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.144-150
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• 2008

This research aims to develop parts for advanced fuel/oil filtering re-circulation applicable to this kind of regulation proof engines. These parts can playa role of converting traditional air emission type crankcase into recovery type crankcase so that the engine can deal with environmental regulations, which do not allow minimal amount of toxic gas discharge. For the experiment, test method and specially made testing equipment are prepared. The results showed that oil separation efficiency of the cone type CCV(Crank Case Ventilation) system was higher than one of cylinder type both in bench test and in engine.

• Journal of Power System Engineering
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• v.10 no.2
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• pp.68-74
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• 2006

In the development of new automobiles, the efforts to reduce environmental problems like air pollution have been risen. Blowby gas consists of about $20{\sim}35%$ of total amount of Hydrocarbon (HC), one of dangerous pollutants issuing from automobiles. A PCV valve is a very small component in an automotive engine but it is a very important part. Because that a PCV valve is used to control blowby gas and to recirculate it into a manifold automatically. Although it has very simple operating principle, designing a PCV valve is so difficult due to interaction between fluid and solid. In this study, our purpose is to develop a design program for a PCV valve and to verify its efficiency. Both Bernoulli equation and 4th order Runge-Kutta method were adopted to predict spool displacements and flow patterns. Comparing with experiments, it was found that both spool diameters and displacements were predicted well, however, flow rates showed a little differences because of the assumption of non viscous flow.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.174-178
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• 2011

This paper deals with the free cooling system of express bus using natural energy source in order to improve the room air quality and save cooling energy. In an express bus, there are may passengers in unit area, requiring the improvement of air quality and giving higher energy saving efficiency. Particularly, the express buses running fast make it easy to take in outdoor air at a flow rate controllable with a damper mechanism. This paper proposes the analysis on the air flow achieved by a damper controlled vertically and horizontally in order not to deteriorate the ride comfort of the passengers.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.923-924
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• 2007

due to the modification of ventilation system for variable speed high efficiency PMSM, the ventilation structure is analyzed in this part. First, a cooling structure was proposed for the variable speed PMSM. Through the contrast result of whole stress and speed distribution in the cooling channel by fluid field, the fans setting fashion is confirmed. By the studying of cooling structure for improved PMSM, the position of the cooling hole in the rotor is optimized by the finite element method. At last, the thermal field distribution of the motor is calculated by FEM. The calculated thermal rise is in accord with measured value, which provides effective basement for the design and safety operation of PMSM.

• Korean Institute of Interior Design Journal
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• v.13 no.4
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• pp.118-126
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• 2004

This study started from the premise that the future elementary school should be designed based on ecological approach in order to restore the emotionality of children. This study aimed at providing a guideline for designing the interior of elementary schools based on ecological approach. Through literature review, the characteristics of ecological architecture and the regulations for green buildings were explored. Also 7 elementary schools which were evaluated as good school design through renowned books representing the ecological characteristics were chosen and analyzed. The results revealed that the school design included natural lighting by roof lighting, natural ventilation, greening, and use of natural materials. This study suggested three categories as a the guideline for the interior space of eco-school design; energy efficiency, greening and sustainability, which included natural lighting, natural ventilation, heating and cooling, planting, materials and water recycling.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.7
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• pp.84-91
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• 2012

In this paper, design by magnetic analysis software and proportional control of solenoid for pressure valve for electric pressure cooker is described. The validation of design was proved by 3D finite element analysis results. Also the efficiency of an air ventilation mechanism was considered when pressure was happened by fluid analysis results. The linear proportional control system by AVR was manufactured and its validation was proved by pressure control of solenoid.

• Journal of computational fluids engineering
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• v.14 no.2
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• pp.39-45
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• 2009

In engine room, proper enclosure system is preferable for reducing noise level but the enclosure system in the engine room causes bad influence on cooling performance due to poor ventilation. Cooling efficiency of the enclosure system can be improved by varying fan speed and proper flow path for ventilation. In this study, numerical analysis is performed to assess cooling effect of the enclosure system using finite volume method. The RNG k-$\varepsilon$ model is adopted for turbulence model along with heat exchanger model and porous media model for heat exchanger analysis, and moving reference frame model for rotational fan. Verification result shows reasonable agreement with experimental data. Analysis results show direct effect of velocity and temperature distribution on cooling ability in the enclosure system. Enclosure system of case B shows high heat transfer coefficient and has the smallest area ratio of opened flow passages which is good for noise level reduction.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.6
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• pp.524-531
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• 2001

The temperature and humidity distribution in a dry room are studied numerically by using standard$\kappa-\varepsilon$ turbulence model. In order to evaluate effective heat and moisture ventilation characteristics inside the room, the heat removal capacity and moisture exhaust efficiency are introduced. An effective ventilation control is analyzed by evaluating quantitatively temperature and humidity distributions. It was found that the mean absolute humidity inside the room was almost constant with approximately 0.1905g/kg air regardless of the models and the heat generation rates. This was believed that the moisture generation by workers was relatively small. 40% improvement of the critical decay time was achieved, through the modifications of design variables.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2989-2994
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• 2008

The shopping center in underground passage for efficient space utilization is increased in urban area. This study describes operation characteristics of HVAC systems with ventilation and individual heating and cooling unit for shopping center in underground passage. In order to compare energy saving, thermal environment and installation space, etc., an integrated simulator with heat production and distribution system was designed and constructed. Energy delivery efficiency is improved over 20%, and energy saving of the hybrid system is calculated as over 30% compared to conventional all air type in the case of heating. And also the results showed that humidity decreased about $5{\sim}6%$, also characteristics of thermal control is improved over 34%.

• Journal of Bio-Environment Control
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• v.14 no.1
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• pp.29-37
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• 2005

In order to provide fundamental data on utilization of dehumidifier in greenhouses, a condensing type dehumidifier using ground water as a coolant was developed and tested dehumidification performance. The developed dehumidifier was applied to greenhouse with fog cooling system and effect of dehumidification on improvement of evaporative cooling efficiency was analyzed. Results of the dehumidifier performance test showed that dehumidification using ground water as a coolant was sufficiently possible in fog cooling greenhouse. When the set point temperature of greenhouse cooling was $32^{\circ}C$ and as temperatures of ground water rose from $15^{\circ}C\;to\;18^{\circ}C,\;21^{\circ}C\;and\;24^{\circ}C$, dehumidification rates decreased by $17.7\%,\;35.4\%\;and\;52.8\%$, respectively. As flow rates of ground water reduced to $75\%\;and\;50\%$, dehumidification rates decreased by $12.1\%\;and\;30.5\%$, respectively. Cooling efficiency of greenhouse equipped with fog system was distinctly improved by artificial dehumidification. When the ventilation rate was 0.7 air exchanges per minute, dehumidification rates of the fog cooling greenhouse caused by natural ventilation were 53.9%-74.4% and they rose up to 75.4%-95.9% by operating the dehumidifier. In case of using the ground water of $18^{\circ}C$ and flow rate of design condition, it was analyzed that whole fog spraying water can be dehumidified even if the ventilation rate is 0.36 exchanges per minute. As a utilization of dehumidifier, it is possible to improve cooling efficiency of fog system in naturally ventilated greenhouses.