http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
조용석(Y.S.Cho),이윤석(Y.S.Lee) 한국자동차공학회 1998 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1998 No.11_1
In order to satisfy the ULEV emissions regulation, fast light-off of a catalyst is essential for reduction of HC and CO emissions during the cold start. Cranking Exhaust Gas Ignition (CEGI) method developed in this study showed that the catalyst reaches the light-off temperature in a few seconds. The CEGI stops the ignition signal for a few seconds during the cranking period, so the unburned fuel-air mixture bypasses the combustion chamber and flows through the exhaust manifold. When the unburned mixture reaches two glow plugs installed upstream of the catalyst, it burns and releases the thermal energy to heat up the catalyst. In the FTP-75 vehicle tests, the CEGI showed that the exhaust emissions reduced by 47.7% for THC and by 88.6% for CO in the cold-transient phase of the test.<br/>
Close-Coupled Catalysic Converter 입구의 유동분포 측정 및 수치해석
조용석(Y.S.Cho),김창래(C.R.Kim),김득상(D.S.Kim),이윤석(Y.S.Lee),주영철(J.Y.Joo),한민섭(M.S.Han) 한국자동차공학회 1997 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1997 No.6_1
Results from an experimental study of flow distribution in a close-coupled catalytic converter (CCC) are presented. The experiments were carried out with a flow measurement system. Two cases were studied; steady flow condition and transient flow condition. The flow distribution at the exit of the first monolith of the CCC was measured with a pitot tube. Results from numerical analysis are also presented.<br/> Experimental results showed that the uniformity index of exhaust gas velocity decreases as Reynolds number increases. In steady flow conditions, the flow through each exhaust pipe makes the flow concentrate on a small region of the CCC inlet. On the other hand, the transient test results showed that the flow through each exhaust pipe in the engine firing order interacts with each other to make the flow distribution uniform. The results from numerical analysis support the experimental results, and help explain the flow in the entry region of the CCC.<br/>
조용석(Y.S.Cho),김득상(D.S.Kim),이윤석(Y.S.Lee),송대근(D.K.Song),주영철(Y.C.Joo),한민섭(M.S.Han) 한국자동차공학회 1998 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1998 No.11_1
Results from an experimental study to measure the conversion efficiency of a close-coupled catalytic converter (CCC) are presented. Exhaust gases upstream and downstream of the catalyst are sampled by a sampling probe, and analyzed by an exhaust gas analyzer. The distribution of the exhaust species and catalyst conversion efficiency over the catalyst face is compared with the velocity distribution in the catalytic converter.<br/> Results showed that the conversion efficiency is not strongly dependent on the velocity distribution, but the species concentration distribution correlates well with the velocity distribution. It was found that the non-uniform velocity distribution results in non -uniform species distribution over the catalyst face and speed up the aging process in a specific region of the catalyst.<br/>