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강승규,윤준용,이도형,Kang, Seung-Kyu,Yoon, Joon-Yong,Lee, Do-Hyung 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.6
A numerical analysis of turbulent gas-particle two-phase flow is performed in conjunction with the experiments of Fackrell & Robins and Raupach & Legg that considered ground-level source and/or elevated source flat plate flow. K-$\omega$ turbulence model is used in order to analyze fully turbulent flow field and the concentration equation with settling velocity is adopted for the concentration field. The model of Einstein and Chien is applied that couples the velocity field and the concentration field. Turbulent eddy viscosity is re-evaluated in this model. The present numerical results have good agreement between the simulation and the experimental data for the mean flow velocities and particle concentrations. While the previous study shows about 27% error in the vicinity of the source of particle concentration, the .present study allows about 14% error. A new turbulent gas-particle flow model developed by this study is able to cut down error by 13% at a near source.
강승규(Seung-Kyu Kang),최경석(Kyung-Suhk Choi),윤준용(Joon-Yong Yoon) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
Carbon Monoxide(CO) poisoning accident is higher than any other gas accident in the rate of deaths/incidents. In the last five years, 36 people died and 104 were wounded because of carbon monoxide poisoning accident. Most of these CO poisoning accidents were caused by defective exhaust tube in the old gas boiler and multi-use facility. In this study, the spread of incomplete combustion gas(CO) released from leakage hole of exhaust tube was analyzed by computational flow modeling and concentration measuring test. CO gas leaked form exhaust tube in a building was highest concentrated near the ceiling and formed the circular currents along the walls. Through these experiments and simulation, the reasonable installation location of carbon monoxide alarm was made certain and suggested.
수치해법을 이용한 2단 열교환기 장착 가정용 보일러 연소실의 연소 및 열전달 특성 해석
강승규(Seung-Kyu Kang),최경석(Kyoung-Suhk Choi),권정락(Jeong-Rack Kwon) 한국가스학회 2010 한국가스학회지 Vol.14 No.5
본 연구는 가정용 보일러의 연소실 전산유동해석을 통해 연소실 내부의 온도분포 및 유동형태를 해석하였다. 전산해석을 통해 연소실의 열교환기 구조변화에 따른 효율향상 및 배기가스 발생 특성을 예측하였다. 2단 열교환기 장착시 연소실 내부의 온도를 하강시킴으로서 연소가스의 고온영역 체류시간 감소로 Thermal NOx의 생성이 억제되어 NOx의 발생량이 감소할 것으로 예측되었다. 효율면에서는 2단 열교환기 장착 시 1단 열교환기에 비해 약 24%의 효율이 상승하였다. 반면에 2단 열교환기 장착 시 약 10%의 압력손실이 증가하는 것으로 확인되었다. In this work, a numerical investigation is performed for the combustion chamber of domestic gas boiler with 1-stage and 2-stage heat exchangers. The fluid flow and heat transfer performance is simulated with a structure change of heat exchanger. The numerical solution shows that the heat transfer of the 2-stage heat exchanger is about 24% higher than that of the 1-stage heat exchanger, while the pressure loss of the 2-stage heat exchanger increases. The temperature of combustion chamber with 2-stage heat exchanger is lower than that of 1-stage. This effect reduces thermal NOx with decrease of high temperature staying time of the combustion gas.