• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.232-239
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• 1995

This study was carried out to get required torque data needed to design and develop a roll-up ventilation system in a pipe-constructed plastic film green-house. The results obtained from this study are as follows : 1. The required torques of a roll-up ventilation system in greenhouse are the functions of its length. The torques should multiplied by the conversion coefficients (2.0 in ceiling vent, 1.8 in side vent) in case of application. 2. In constructing pipe-constructed plastic film greenhouse, a shaft pipe is the largest essential element in roll - up shaft weight constitution which have an effect on the required torques. Therefore, the pipe should be light using nonferrous materials like aluminum alloy. 3. A planetary reduction ventilator of differential ring gear type is suitable for a roll-up ventilation system, because it can make high efficient reduction just using the first step shift.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.241-244
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• 2008

Recently, The high Air-Tightness and high heat insulation for building construction cause a ventilation air volume deficiency. Also, Worldwide high energy price is strongly urging to economize the air conditioning energy. Therefore Heat Recovery Ventilation is used for the satisfaction of ventilation air volume and building energy saving. Accordingly, this study dose the heat exchanger performance evaluation and economic efficiency evaluation of Heat Recovery Ventilation. And, we wish to make a basic study about HRV System application of HVAC System and Multi System Air-conditioning.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.496-500
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• 2010

Understanding train-wind is the best method to know how to optimize subway ventilation system. The capacity and efficiency of the subway ventilation system are known by pressure and velocity while train runs. Analysis of the internal flow in subway tunnel and around subway station are studied using numerical methods. Characteristics of internal flow and influence of subway ventilation system for the subway station with platform screen door and tunnel are analyzed by unsteady state analysis. Velocity and pressure of train wind transformation are compared at around subway ventilation system and the internal flow is investigated at the subway tunnel.

• Tunnel and Underground Space
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• v.29 no.6
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• pp.480-507
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• 2019

This paper aims at optimizing the auxiliary ventilation system in large-opening limestone mines with unducted fans. An extensive CFD and also site study were carried out for optimization at the blind entries. The fan location, operating mode, and layout are the parameters for optimization. Since the jet stream discharged from the auxiliary fan is flowing faster than 15 m/s in most of the cases, the stream collides with floor, sides or roof and even with the jet stream generated from the other fan placed upstream. Then, it is likely to lose a large portion of its inertial force and then its ventilation efficiency drops considerably. Therefore, the optimal fan installation interval is defined in this study as an interval that maximizes the uninterrupted flowing distance of the jet stream, while the cross-sectional installation location can be optimized to minimize the energy loss due to possible collision with the entry sides. Consequently, the optimization of the fan location will improve ventilation efficiency and subsequently the energy cost. A number of different three-dimensional computational domains representing a full-scale underground space were developed for the CFD study. The velocity profiles and the CO concentrations were studied to design and optimize the auxiliary ventilation system without duct and at the same time mine site experiments were carried out for comparison purposes. The ultimate goal is to optimize the auxiliary ventilation system without tubing to provide a reliable, low-cost and efficient solution to maintain the clean and safe work environment in local large-opening underground limestone mines.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.10
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• pp.695-702
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• 2007

In this paper, the ventilation efficiencies of an underground sewage disposal plant were investigated for ventilating system without fan, ventilating system with eleven cross flow fans and ventilating system with sixteen cross flow fans by numerical method. It has been found that the air change effectiveness of the system without fan was predicted 0.44. It means that an additional ventilating equipment is needed to maintain good indoor air quality. For the ventilating system with sixteen cross flow fans, the air change effectiveness was predicted 0.55. The air change effectiveness of the ventilating system with eleven cross flow fans was predicted 0.51. It is known that the air change effectiveness above 0.5 is enough to eliminate pollutant and bad smell in the indoor. Therefore, it is recommended to select the ventilating system with eleven cross flow fans for the underground sewage disposal plant in an economic point of view.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.754-757
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• 2008

To maintain the indoor air quality, many ventilation systems and technologies have been developed in the highly insulated and air tight buildings. In this study, a porous construction material, which is applicable to passive ventilation system, is developed and measured the performances of the permeability and the resistance of water vapor, and the dust collection efficiency. The average coefficient of water vapor permeability shows $3.6\;g/m^2{\cdot}h{\cdot}mmHg$, which is slightly higher than Hanji ($2.4{\sim}3.2\;g/m^2{\cdot}h{\cdot}mmHg$) and the average water vapor resistance factor shows $0.303\;g/m^2{\cdot}h{\cdot}mmHg/g$, which is slightly smaller than Hanji($0.309{\sim}0.315\;g/m^2{\cdot}h{\cdot}mmHg/g$). The pressure drop of the porous construction material is smaller than the HEPA filter and the minimum dust collection efficiency shows 82.8% in the range of $2{\sim}9\;cm/s$.

• Particle and aerosol research
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• v.19 no.2
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• pp.43-53
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• 2023

In this study, the ventilation system of the enclosed conveyor belt for coal transportation was evaluated, and the particle removal efficiency according to the ventilation conditions was identified using computational fluid dynamics and particle behavior analysis. The most effective way to remove dust generated inside the closed conveyor belt is to adjust the position of the exhaust port of the duct so that the air is exhausted around the rear of the conveyor belt. And this method seems to work for another narrow and long spaces where air enters in one direction. In addition, when the air flow rate of the each duct was less than 300 CMM, it was efficient to increase the flow rate of the duct located at the rear of the conveyor belt, and when the flow rate of the each duct was higher than 300 CMM, it was efficient to increase the flow rate of the duct located at the front of the conveyor belt.

• Journal of Animal Environmental Science
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• v.8 no.2
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• pp.73-78
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• 2002

The experiment was carried out to investigate the optimal air velocity for improving the ventilation efficiency of duct ventilation system used in Korean swine building. The results are followed ; In 2.2 m height of duct, the air velocity of hole was 5.0 m/s as the over level of recommendation. In different hole interval, the air velocity was various of 4.6${\sim}$11.6 m/s in narrow hole interval, 5.4${\sim}$10.9 m/s in broad hole interval. But the air velocity was 6.6${\sim}$7.7 m/s in duct system pierced hole with equal interval, and it was equal velocity in different parts of duct in this hole interval.

• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.466-471
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• 2014

It is important to develop the smart ventilation system in order to minimize a building energy consumption using ventilation. In this study, We evaluated the efficiency of the smart ventilation system being developed at the nursery. To evaluate the energy savings and carbon dioxide removal efficiency, two kinds of experimental conditions were compared. First, air conditioner and Smart HVAC system were operated. Second, air conditioner was operating and external air was put into the inside by rate of air circulation. It was more effective when working with air conditioning and ventilation system at the same time. If the Smart HVAC system is applied in a multi-use facility, indoor air quality will be comfortable and the social cost will be reduced.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.10
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• pp.705-710
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• 2012

This study aims to analyse changes of inner temperature of PVS(Passive ventilation skin) and heat recovery when it has ventilation of air through PVS using numerical simulation in the winter condition. Results are as follows. 1) In case of the air inflows through PVS, change of inner temperature of PVS is lower than in case of the air flows inner space to out space, by dynamic insulation. 2) It was identified that the temperature gradient of PVS were bigger by increases of ventilation amount. To reduce ventilation load, heat transfer efficiency at the inner side of PVS is important and what performance of insulation at the inner side of PVS secure helps to improve heat performance of all PVS.