Significant improvements in efficiency for electricity generation from coal can be achieved by cycles that employ a high-temperature, highly recuperative gas turbine topping cycle. The principal difficulty of employing a gas turbine in a coal-fired power generation system is the possible erosion and corrosion of the high-temperature rotating gas turbine components caused by the coal’s inorganic and organically bound constituents (ash, sulfur, and alkali metals). One route to overcome this problem is the development of an externally fired gas turbine system employing a coal fired heat exchanger. The solution discussed in this paper is the design of a Radiatively Enhanced, Aerodynamically Cleaned Heat-Exchanger (REACH-Exchanger). The REACH-Exchanger is fired by radiative and convective heat transfer from a moderately clean fuel stream and radiative heat transfer from the flame of a much larger uncleaned fuel stream, which supplies most of the heat. The approach is to utilize the best ceramic technology available for high-temperature parts of the REACH-Exchanger and to shield the high-temperature surfaces from interaction with coal minerals by employing clean combustion gases that sweep the tube surface exposed to the coal flame. This paper presents a combined experimental/computational study to assess the viability of the REACH-Exchanger concept. Experimental results indicated that the REACH-Exchanger can be effectively fired using radiation from the coal flame. Both computation and experiments indicate that the ceramic heat exchanger can be aerodynamically protected by a tertiary stream with an acceptably low flow rate.

1.
Zabolotny, E. R., Vivenzio, T. A., and LeHaye, P., Proceedings of the American Power Conference, 52nd Annual Meeting, Chicago, IL, Apr. 23–25, 1990.
2.
LeHaye
P. G.
, and
Zabolotny
E.
,
Proc. IGTI
, Vol.
4
,
1989
, p.
263
263
.
3.
Foster Wheeler Development Corporation, “Development of a High-Performance Coal-Fired Power Generating System With Pyrolysis Gas and Char-Fired High Temperature Furnace (HITAF),” Quarterly Progress Report (3), for U.S. DoE/PETC Contract No. DE-AC22-91PC1154, 1992.
4.
United Technologies Research Center, “Coal-Fired High Performance Power Generating System,” Quarterly Progress Report, for U.S. DoE/PETC Contract No. DE-AC22-92PC91155, July 1–Sept. 30, 1992.
5.
Solomon, P. R., Bates, S. C., Carangelo, R. M., and Hamblen, D. G., “Coal Fired Heating Apparatus and Method,” patent application, 1991.
6.
Solomon, P. R., Serio, M. A., Cosgrove, J. E., Pines, D. S., and Zhang, Y., “An Advanced Coal Fired Heat Exchanger/Gas Turbine Topping Cycle for a High Efficiency Power Plan,” Final Report for U.S. Department of Energy, Contract No. DE-FG05-92ER81323, May, 1993.
7.
Advanced Fuel Research, Inc., “Feasibility Study for an Advanced Coal Fired Heat-Exchanger/Gas Turbine Topping Cycle for a High Efficiency Power Plant,” DoE Contract #DE-AC22-92PC92196.
8.
Solomon, P. R., Best, P. E., Chien, P. L., and Goodman, R. M., “A Laboratory Combustion Facility for Evaluation of CWF,” 6th International Workshop on Coal-Liquid and Alternate Fuels Technology, Halifax, Canada, 1986.
9.
Solomon, P. R., Chien, P. L., and Best, P. E., “Measurement and Optimization of Combustion Performance of Coal Water Fuels,” US DOE Contract No. DE-AC01-85ER80320 Final Report, 1986.
10.
Markham
J. R.
,
Solomon
P. R.
, and
Best
P. E.
, “
A FT-IR Based Instrument for Measuring Spectral Emittance of Material at High Temperature
,”
Review of Scientific Instruments
, Vol.
61
,
1991
, p.
3700
3700
.
11.
Markham
J. R.
,
Best
P. E.
,
Solomon
P. R.
, and
Yu
Z. Z.
, “
Measurement of Radiative Properties of Ash and Slag by FT-IR Emission and Reflection Spectroscopy
,”
ASME Journal of Heat Transfer
, Vol.
114
,
1992
, p.
458
458
.
12.
Markham, J. R., Kinsella, K., Carangelo, R. M., Brouillette, C. R., Carangelo, M. D., Best, P. E., and Solomon, P. R., “A Bench Top FT-IR Instrument for Simultaneously Measuring Surface Spectral Emittance and Temperature,” Review of Scientific Instrument, in press, 1993.
13.
Solomon, P. R., Markham, J. R., Zhang, Y. P., Carangelo, R. M., Brewster, B. S., and Smoot, L. D., “The Study of a Coal Flame by FT-IR Emission/Transmission Tomography and Comprehensive Modeling,” Sci-Mix Poster Session, ACS Meeting, Washington, DC, 1990.
14.
Solomon, P. R., Chien, P. L., Carangelo, R. M., Best, P. E., and Markham, J. R., Proc. The 22nd Symposium (Int.) on Combustion, The Combustion Institute, Pittsburgh, PA, 1988, p. 211.
15.
Markham, J. R., Zhang, Y. P., Carangelo, R. M., and Solomon, P. R., FTIR Emission/Transmission Tomography of a Coal Flame, The 23rd Symposium (Int) on Combustion, The Combustion Institute, 1990, pp. 1869–1875.
16.
Smith, P. J., Smoot, L. D., and Fletcher, T. H., “User’s Manual for a Computer Program for 2-Dimensional Coal Gasification of Combustion (PCGC-2),” Interim Report Vol. II prepared for U.S. DoE/METC Contract No. DE-AC21-81MC16518, Combustion Laboratory, Brigham Young University, Oct. 1983; see also Smoot, L. D., and Brewster, B. S., “User’s Manual for 1990 Version of Pulverized Coal Gasification and Combustion 2-Dimensional (87-PCGC-2),” rev., ACERC, Brigham Young University, July 1991.
17.
Sabnis, J. S., de Jong, F. J., and Gibeling, H. J., “Calculation of Particle Trajectories in Solid-Rocket Motors With Arbitrary Acceleration,” J. Prop. Power, Vol. 8, Sept.–Oct., 1992.
18.
Sabnis, J. S., Choi, S. K., Buggeln, R. C., and Gibeling, H. J., “Computation of Two-Phase Shear Layer Flow Using an Eulerian–Lagrangian Analysis,” AIAA Paper No. 88-3202, 1988.
19.
Sabnis, J. S., and de Jong, F. J., “Calculation of the Two-Phase Flow in an Evaporating Spray Using an Eulerian–Lagrangian Analysis,” AIAA Paper No. 90-0447, 1990.
This content is only available via PDF.
You do not currently have access to this content.