• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.517-532
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• 2017

The transverse ventilation system, commonly applied to urban tunnel, is necessary to be distributed with airflow uniformly. In this study, we developed a program that can optimize the opening ratio of ports to ensure ventilation performance of design criteria through a uniform airflow distribution even though ventilation interval becomes longer. And program's prediction performance was verified by comparison with TUNVEN DUCT program. For comparison, Semi-transverse ventilation system was applied. Both programs predicted a similar port size and air flow distribution, and the variation range of the calculated values was 11.71% and 1.36%, respectively. This program is very useful for port optimization design of transverse and semi-transverse ventilation system, because it is possible to analyze various tunnel lengths and supply/exhaust port installation conditions.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.701-705
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• 2009

After revision of law of architecture in 2006, all houses which have more 100 households must has ventilation unit for the indoor air quality. Optimal design of the natural and the mechanical ventilation has being considered. In this paper, it is carried out about optimal design for airflow distribution of total heat exchanger in houses using CFD. As the result, first design of ventilation has some problem in porch area. Adding diffusers in porch area and changing diffuser schedule make more efficient ventilation than original design.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.10
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• pp.545-552
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• 2009

It is common to design the duct branches where to supply the required air flow for individual room in residential apartment house. And TAB process is applied to control the designed air volume with adjusting volume dampers and/or supply diffusers after fully installing the ventilation system. This process has been resulted increasing the initial cost for the residential ventilation system because of man-hour and accessories such as volume control damper or diffuser. However it is difficult to adjust the air volume adequately in small air duct branches in residential ventilation system. The purpose of this study is to figure out the performance of Multidrop chamber coupling system for the residential ventilation system.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.589-593
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• 2007

In the mechanical ventilation system, it is a fundamental condition to distribute the air equally to the each room. In this study, distribution performance of the air distributor which generally connected to a circular duct was investigated by simulation and experiment. In the first CFD analysis, maximum air flow rate deviation was an 63% in the air distributor model. After numbers of model modification and simulation, maximum flow rate deviation was reduced to 19% in the final simulation model. An air distributor which used in the experiment was produced by using data obtained from the final analysis. When experimental result was compared with analysis result, there was a deviation difference as much as 9%.

• KIEAE Journal
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• v.9 no.4
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• pp.17-22
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• 2009

It is common to design the duct branches where to supply the required air flow for individual room in residential apartment house. However it is difficult to adjust the air volume adequately in small air duct branches in residential ventilation system. The purpose of this study is to figure out the performance of Multidrop chamber coupling system for the residential ventilation system. The experiments were designed to simulate apartment of $84m^2$ and established multidrop chamber duct and general duct on the ceiling of the apartment. Distribution performance of air supply rate were evaluated in this experiments. As a result, distribution performance of air supply rate in the general duct is different from designed air supply rate by about 35% ~ 50% and about 10% in the multidrop chamber system. In additional the sound insulation performance of the multidrop chamber system decreased about 20% compared with general duct system. Therefore, the multidrop chamber system is considered to satisfy proper air supply rate of each room and to improve the sound insulation performance in apartment Houses.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.9
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• pp.622-629
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• 2007

Compact semi-center type automotive air handling system(AHS) is developed in this study and it's performance is compared with the conventional 3-pieces type air hand-ling system. The pressure drop is measured at component level and system level, and air flow rate and air distribution of discharge air through each ducts from air handling system are measured. System level characteristics of pressure drop at face and windshield discharge mode and air flow rate are investigated, and also temperature control linearities are tested. The volume of the air handling system package is reduced about 20%. And air flow rate increase about 5 to 20% compared to the conventional 3-pieces type air handling system at each discharge mode with significantly improved air pressure drop both component and system level. Also, air distribution and temperature controllability meet to evaluation criteria.

• 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.