Articles & Issues

Language: korean

Conflict of Interest: In relation to this article, we declare that there is no conflict of interest.

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

All issues

삼상순환유동층에서 내부열원과 층간의 열전달특성

Immersed Heater-to-Bed Heat Transfer Characteristics in Three-Phase Circulating Fluidized Beds

조용준 남석희 강용^† 김상돈¹

Yong-Jun Cho Seok-Hee Nam Yong Kang^† Sang-Done Kim¹

충남대학교 화학공학과, 대전 305-764 ¹한국과학기술원 화학공학과, 대전 305-701

Department of Chemical Engineering, Chungnam National University, Daeduk Science Town, Teajon 305-764, Korea ¹Department of Chemical Engineering, Korea Advanced Institute of Science and Technology, Teajon 305-701, Korea

HWAHAK KONGHAK, December 2000, 38(6), 877-881(5), NONE

Download PDF

Abstract

직경이 0.102 m, 높이 3.5 m인 삼상순환유동층의 상승관(riser)에서 내부열원과 유동층간의 열전달 특성을 고찰하였다. 기체유속(0.01-0.07 m/s), 액체유속(0-0.31 m/s) 그리고 고체순환속도(2-8 kg/m²s) 등을 변수로 선정하였으며 이들 변수들이 열원과 유동층간의 온도차와 열전달계수에 미치는 영향을 고찰하였다. 각 실험조건에서 열전달특성 규명을 위하여 온도차요동신호를 측정하였으며 측정된 온도차요동신호의 표준편차를 구하였다. 삼상순환유동층의 상승관에서 열원과 유동층간의 온도차요동의 표준편차는 기체유속과 고체순환속도가 증가하면 증가하였으나, 액체유속의 증가에 따라서는 감소하는 경향을 나타내었다. 상승관에서 내부열원과 유동층간의 열전달계수는 기체유속과 고체순환속도가 증가함에 따라서 증가하였으나 액체의 유속에 따라서는 거의 변화가 없었다. 상승관에서의 열전달 계수는 기체와 액체의 유속 그리고 고체순환속도의 상관식으로 나타낼 수 있었다.

Heat transfer characteristics between the immersed heater and the fluidized bed have been investigated in the riser of a three-phase circulation fluidized bed (0.102 m ID 3.5 m in height). Effects of gas (0.01-0.07 m/s) and liquid velocities (0-0.31 m/s) and solid circulating rate (2-8 kg/m(2)s) on the temperature difference fluctuations between the immersed heater and the bed, and thus on the heat transfer coefficients have been examined. The temperature difference fluctuation signals have been measured at a steady state and interpreted in terms of the standard deviation. The heat transfer coefficient and standard deviation of temperature fluctuations have increased with increasing gas velocity or solid circulating rate, however, the standard deviation has decreased while the heat transfer coefficient has not changed considerably, with increasing liquid velocity. The heat transfer coefficient has been well correlated in terms of gas and liquid velocities and solid circulation rate.

Keywords

Three-Phase Circulating Fluidized Bed Heat Transfer Immersed Heater-to-Bed Temperature Fluctuations

References

Kim SD, Kang Y, "Mixed Flow Hydrodynamics. Advances in Engineering Fluid Mechanics Series," N.P. Cheremisinoff edn., Gulf Houston, 845 (1996)
Kim SD, Kang Y, Chem. Eng. Sci., 52(21-22), 3639 (1997)
Han S, Zhou J, Jin Y, Loh KC, Wang Z, Chem. Eng. J., 70(1), 9 (1998)
Liang W, Wu Q, Yu Z, Jin Y, Wang Z, Can. J. Chem. Eng., 73(5), 656 (1995)
Liang WG, Wu QW, Yu ZQ, Jin Y, Bi HT, AIChE J., 41(2), 267 (1995)
Cho YJ, Song PS, Kim SH, Kang Y, Kim SD, J. Chem. Eng. Jpn., 34(2), 254 (2001)
Kim SH, Cho YJ, Song PS, Kang Y, Kim Sd, HWAHAK KONGHAK, 37(6), 916 (1999)
Wang T, Lin ZT, Zhu CM, Liu DC, Saxena SC, AIChE J., 39, 1406 (1993)
Kang Y, Kim SD, Korean J. Chem. Eng., 5(2), 154 (1988)
Kang Y, Fan LT, Kim SD, AIChE J., 37, 1101 (1991)
Kang Y, Suh IS, Kim SD, Chem. Eng. Commun., 34, 1 (1985)
Chiu TM, Ziegler EN, AIChE J., 29, 677 (1983)
Kumar S, Kusakabe K, Fan LS, Chem. Eng. Sci., 48, 2407 (1993)
Muroyama K, Fukuma M, Yasunishi A, Can. J. Chem. Eng., 64, 409 (1986)
Briens CL, Del Pozo M, Trudell C, Wild G, Chem. Eng. Sci., 54(6), 731 (1999)