• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.206-212
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• 2004

It is necessary to consider the stability, economic environmental-friendly problems by the development of the road, supply of the automobile, environmental problem as designing the exhaust system. To reduce the noise and the vibration of the automobile, it is needed to consider the pulsation noise, air current noise, vibration of air pipe which generate the intake and exhaust noise of the automobile. Moreover, the discharge sounds, intake sound, radiation sound, transmitted sound are occurred. To reduce this influence, the variable valve is needed and to control these factors, path transformation muffler and active type muffler are needed. While engine efficiency could be reduced with this transformationand resistance by the pressure, thermal property. In this study, how to design exhaust systems yielding higher condversion efficiency, lower backpressure and optimize the performance. this study is recommended for exhaust system and designers and engineers involved in SI engine exhaust system and it will furnish information for you to design more efficient.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4047-4051
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• 2014

Modern apartment houses are constructed to be relatively airtight with a high heat insulation system to increase the energy efficiency. Such a system has a range of deleterious effects due to the insufficient ventilation. In this study, the ondol system, which is used as a heat source typical of winter in Korea, was set as the default system to evaluate the indoor heat environment according to the ventilation method, the factors of energy reduction by the ventilation system was analyzed. The experimental apparatus was used to simulate the ambient conditions for a certain constant temperature and humidity chamber. The experimental results showed that the supply water temperature higher air volume decreases with increasing supply air temperature in the following order: floor supply/exhaust > total heat exchange supply/exhaust > forced supply/exhaust. Through this study, the applicability of various ventilations could be examined.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.7
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• pp.578-584
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• 2012

In this study, the analysis on the distribution of indoor airflow velocity and temperature by using numerical simulation has carried out to make fundamental data for establishing the optimum design of laboratory animal facilities. From the results, it was found that replacement of cage lacks, air supply and exhaust system, supply air temperature, supply air velocity affect to the optimum design of laboratory animal facilities as a important element.

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.131-131
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• 2004

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.3
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• pp.240-246
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• 2012

The supply and use of exhaust heat recovery ventilation system as effective energy saving equipment has been increasing steadily. The exhaust heat recovery ventilation system can be installed at ceiling of balcony or emergency space. However, ventilation system can not be installed at emergency space because where have to remain as empty space by law. Therefore, the proper installation space of ventilation system is needed. In this study, to install heat recovery ventilation system in the light weight wall, thickness of heat exchanger was assembled below 140 mm. One or two paper heat exchangers were installed in the ventilation system. The efficiency of heat recovery was analyzed through performance experiment on case of cooling and heating mode.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.177-188
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• 2019

The purpose of the optimization of the installation of supply/exhaust ports for tunnels with transverse ventilation system is to supply fresh air from outside to inside of tunnels uniformly and exhaust pollutant from tunnels properly for creating safe and clean environment for tunnel users. For this purpose, a ventilation port area optimization program was developed to obtain a uniform supply or exhaust air volume inside a great depth double deck tunnel with transverse ventilation system. In order to area optimize the developed port sizing program, the wind velocity was measured in the duct of the currently operated tunnel with semi-transverse ventilation. Also 3D cfd was performed on the same tunnel and cfd results were compared to the measured value. As a result, the error rate between the predicted value from the program and measured value was 6.72%, while the error rate between the predicted value from the program and 3D cfd analysis value was 4.86%. Both of comparison results show less than 10% of error rate. Thus It is expected that supply/exhaust port optimization design of transverse ventilation tunnel can be possible with using this large exhaust port area optimization program.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.23-28
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• 2002

As the interest on the air pollution is gradually rising up at home and abroad, automotive industries have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative aftertreatment systems, and using clean fuels. Methanol, ethanol, LNG, LPG, H2, reformulated gasoline are generally recognized as the clean fuel. Since the low price policy of government on LPG has expanded its vehicle market recently, there is concern of the exhaust emission of LPG vehicle. In this paper, we studied the value of LPG fuel as a clean fuel by comparing the results of the exhaust emission from LPG and Gasoline fueled vehicles, and discussed its limitation of LPG vehicle with mixer type as a fuel supply system. FTIR was used to understand the difference of exhaust emission components of LPG and Gasoline fueled vehicles.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.305-315
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• 2018

In this study, the ventilation characteristics and the relationships between the required ventilation flow rate and the ventilation system flow rate was investigated by numerical method for the optimum design of the transverse ventilation and semi-transverse ventilation system in road tunnels. The following results were obtained. In supply exhaust transverse ventilation system, the system supply-exhaust air flow rate is theoretically equal to the difference between the required ventilation flow rate and natural ventilation flow rate. However, it is shown that it increases by about 10% in the analysis results. And, in the case of the longitudinal air flow rate is increased by installed jet fans, ventilation system air flow rate is reduced. However, as the longitudinal air flow rate increases, the concentration of pollutants in the tunnel decreases, so the exhaust effect of pollutants decreases, and the effect of reducing the system air flow rate is decreased. In case of semi-transverse with only air supply, ventilation system air flow rate is equal to required ventilation air flow rate when tunnel inlet velocity is negative, but results is shown it is increased within about 13.3%. Also, it was found that ventilation effect can not be expected even if the jet fans are increased when the tunnel inlet velocity is negative.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.6
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• pp.372-380
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• 2008

In order to control indoor air quality and save energy, it is needed to install a suitable ventilation system equipped with heat exchanger for heat recovery. Paper heat exchanger can recover $50{\sim}70%$ of the enthalpy difference between supply and exhaust air. The purpose of this research is to obtain the experimental correlations for the friction factor, heat transfer coefficient, mass transfer coefficient and permeance of paper heat exchanger, which can be used to predict the performance of the paper heat exchanger. Pressure drops at various velocities, and sensible and latent heat transfer rates at various dry-bulb temperatures, relative humidities and specific humidities are measured to derive experimental correlations. The results of prediction using correlations show fairly good agreement with the experimental data obtained in the actual operating conditions.

• Korean Institute of Interior Design Journal
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• v.18 no.3
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• pp.102-113
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• 2009

The SARS virus began to appear and spread in North America and Southeast Asia in the early 2000' s, infecting and harming many people. In the process of examining the causes for the virus, studies on the airborne SARS virus and the way it spread were carried out mainly in the medical field. In the field of architecture, studies were done on the diffusion of air pollutants in buildings using gases such as $CO_2$, $N_2O$, or $SF_6$, but research on virus diffusion was limited. There were also explanations of only the diffusion process without accurate information and discussion on virus characteristics. The aim of this study is to analyze the physical characteristics of airborne virus, consider the possibility of using coupled analysis model and tracer gas for analyzing virus diffusion in building space and, based on reports of how the infection spread in a hospital where SARS patients were discovered, analyze infection risk using tracer gas density and also diffusion patterns according to the location, shape, and volume of supply diffusers and exhaust grilles. This paper can provide standards and logical principles for evaluating various alternatives for making decisions on vertical or horizontal ward placement, air supply and exhaust installation and air volumes in medium or high story medical facilities.