• Journal of Environmental Impact Assessment
• /
• v.9 no.4
• /
• pp.323-338
• /
• 2000

A Korean air dispersion modeling software, AirMaster, was developed on a basis of dispersion theories adopted in U.S. EPA's ISC3 (Industrial Source Complex - version 3) model to assess the air quality impact from the stacks. Key characteristics of AirMaster are as follows: 1) The building downwash effect can be easily simulated; 2) The screen, long term, and short term models can be run independently; 3) The input data to run the model such as meteorological and terrain data are supplied automatically from the databases in AirMaster; and 4) The modeling procedure is easy and simple under the GUI window environment. In order to validate AirMaster, comparisons with ISC3 model and Indianapolis tracer experiment were carried out. It was shown that AirMaster was identical to ISCST3 and ISCLT3 models in predicting the 1 hr to annual concentrations from the stack under various stack emission and meteorological conditions. The 1 hr concentrations predicted by AirMaster also showed a good agreement with the Indianapolis tracer measurements.

• Fire Science and Engineering
• /
• v.23 no.6
• /
• pp.91-97
• /
• 2009

The mass flow rates and performance of natural smoke ventilators in high-rise buildings with 40, 80, 120 stories were evaluated using CONTAMW tool. The results showed that only limited part of smoke ventilators can have positive exhaust flow in high-rise buildings due to stack effect and wind velocities. In the higher story buildings larger stack effect can overcome outside strong wind effect to give more ventilation performance. The air tightness of the building have strong effect on the exhaust performance of the ventilators to give lower performance with loose air tightness of the exterior walls.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.33 no.12
• /
• pp.32-38
• /
• 2004

초고층건물의 건설이 증가되고 있지만 건물외파와 출입문의 기밀도가 낮게 유지될 때, 이러한 누설면적과 층별로 구획할 수없는 수직샤프트(계단실 등)와 직렬로 배치될 경우, 필연적으로 발생하게 되는 굴뚝 현상(stack effect)의 발생원인과 차압크기 산정하는 방법 및 예방대책을 소개하고자 한다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.9 no.3
• /
• pp.170-183
• /
• 1980

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.9 no.4
• /
• pp.250-265
• /
• 1980

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 1999.10a
• /
• pp.250-251
• /
• 1999

미국 산업환기 매뉴얼에서 빗물을 가장 효과적으로 방지하는 굴뚝으로 권장하고 있는 이중 굴뚝(Vertical Discharge Stack)을 우리의 기상조건에서 검증하여 그 사용가능성을 검토하고 기존에 우리 나라에서 가장 많이 사용되고 있는 삿갓모양과 "ㄱ" 모양 굴뚝의 불합리성을 지적할 뿐만 아니라 아울러 빗물 유입 방지나 배기저항을 최소화하고 배기확산에도 효과적인 새로운 모양의 굴뚝을 연구해 보고자 한다. (Clarke, J. H, 1965 ; Hama, G. M., 1963 ; ACGIH, 1998)(중략)

• 한국전기화학회:학술대회논문집
• /
• 2005.07a
• /
• pp.103-110
• /
• 2005

Fuel cell systems are consisted of various parts, for example fuel cell stack, fuel supplier, electrical converters, controllers and so on. Each components of system should have appropriate specification for their applications as well as simplicity. Because thermal load can be managed simply by using fans without any water cooling system, the air-cooled PEMFC is widely used in sub kW and around 1kW systems. The performance of an air-cooled system is highly dependent on ambient temperature and humidity. In this paper, the air-cooled PEMFC systems are developed and investigated to study the operating characteristics in the aspect of the thermal and water coupled management by the control of the axial fans and compressors. Various experiments were also conducted to get the cell voltage distribution, the relative humidity of the reactant gas and the thermal management by axial cooling fans, which cannot be observed in single cell experiment. After then, as practical applications, portable fuel cell system and a hybrid electric cart were successfully integrated and operated by using this air-cooled stack.

• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.7
• /
• pp.765-772
• /
• 2015

In this research, the characteristics of SOFC/GT (Solid Oxide Fuel Cell/Gas Turbine) system temperature, stack power and system efficiency for flow rates of air, CH4 and water supplied to SOFC stack have been investigated. The temperature of the gas supplied to cathode and anode of SOFC stack in the SOFC/GT system are maintained by utilizing exhaust gas without the addition of external heat source. As a result, within the scope of this study, temperatures of gas supplied to cathode and anode of SOFC stack were maintained at 1000 (K) by utilizing the exhaust gas of the SOFC/GT system without the addition of external heat source. The system efficiency is increased with increase of air flow rate supplied to the stack and with decrease of $CH_4$ flow rate supplied to the stack. In addition, it can be found that the flow rate of the exhaust gas supplied to the turbine had a significant effect on the system efficiency. And the efficiencies of SOFC stack and SOFC/GT system depending upon various operating conditions of the SOFC/GT system is 51~57% and 57~73%, respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.7 no.2
• /
• pp.329-340
• /
• 1995

Basic refrigeration effect and efficiency of a thermoacoustic refrigerator is studied. The refrigerator model for numerical simulation is composed of half wavelength resonator and appropriate stack of plate. Theoretical model for thermoacoustic refrigeration suggested by Swift et. al is adapted for numerical calculation. The model contains arbitrary viscosity effect of the gas filled in the resonator. The wave equation is integrated by using 4-th order Runge-Kutta algorithm to give pressure distribution along the stack of plate. Heat flux and COP are also calculated based on the energy flux equation. By analyzing the numerical simulation results, optimum values of design parameters for thermoacoustic refrigerator are obtained.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.137-140
• /
• 2007

We consider the optimum air flow channel design for DMFC's in the present study. The effect of pressure drop across the inlet and outlet of a stack on the performance of a DMFC is the optimization of such geometric parameters is crucial to minimize the parasitic power usage by the auxiliary devices such as fuel pumps and blowers. In this paper, we present how the pressure drop control can optimize the driving point of a DMFC stack. Further, we show how the optimal fuel utilization ratio can be achieved, not degrading the performance of DMFC stacks. Overall, we discuss how the flow channel design affects the selection of balance of plant(BOP) components, the design of DMFC systems and the system efficiency.