J. of Thermal Science Vol.7, No.2 ~ - - 7 rr "- / JT" Mathematical Modeling of Flow Field in Ceramic Candle Filter Taewon Seo Heuy-Dong Kim School of Mechanical Eng., Andong National Univ., 388 Songchun-Dong, Andong, Korea Joo-Hong Choi Depart. of Chemical Eng., Gyeongsang National Univ., 900 Gajwa-Dong, Chinju, Korea Jae Hwa Chung Korea Electric Power Research Institute, Taejon, Korea Integrated gasification combined cycle (IGCC) is one of the candidates to achieve stringent environ- mental regulation among the clean coal technologies. Advancing the technology of the hot gas cleanup systems is the most critical component in the development of the IGCC. Thus tile aim of this study is to understand the flow field in the ceramic filter and the influence of ceramic filter in removal of the particles contained in the hot gas flow. The numerical model based on the Reynolds stress turbulence model with the Darcy's law in the porous region is adopted. It is found that the effect of the porosity in the flowfield is negligibly small while the effect of the filter length is significant. It is also found as the permeability decreases, the reattachment point due to the flow separation moves upstream. This is because the fluid is sucked into the filter region due to the pressure drop before the flow separation occurs. The particle follows well with the fluid stream and the particle is directly sucked into the filter due to the pressure drop even in the flow separation region. Keywords: IGCC, ceramic candle filter, permeability, porosity, Reynolds stress model. INTRODUCTION According to EPRI report[ 1] the electricity require- ment in the world is predicted as approximately 600 GW in the year 2,000. It is expected that about 60% of the total required electricity in year 2,000 will be supplied from the new coal-based power technologies such as Clean Coal Technology (CCT). It has been ob- served that the Integrated Gasification Combined Cy- cle (IGCC) and Pressurized Fluidized-bed Combustor (PFBC) will play an important role in CCT[2,31. IGCC and PFBC are emerging technologies to meet Received, 1998. the stringent environment restrictions and to increase the efficiency of the coal-based power plant, Advanc- ing the technology of the hot gas cleanup systems is the most critical component in the development of the IGCC and PFBC. Increasing attention has been paid to IGCC as the clean coal power plant system to mini- mize the environmental contamination and to increase thermal performance. The removal of the particulate contained in the hot gas is important to protect the gas turbine. The particulate produced in the gasi- fication process of IGCC have been moved away by ceramic candle filter, To increase the performance of the filtering process is of importance to get uniform