Thermo-Economic Optimization of a Solid Oxide Fuel Cell, Gas Turbine Hybrid System

[+] Author and Article Information
N. Autissier1

 Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Industrial Energy Systems (LENI), CH-1015 Lausanne, Switzerlandnordahl.autissier@epfl.ch

F. Palazzi, F. Marechal, J. van Herle, D. Favrat

 Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Industrial Energy Systems (LENI), CH-1015 Lausanne, Switzerland


Corresponding author.

J. Fuel Cell Sci. Technol 4(2), 123-129 (Jun 15, 2006) (7 pages) doi:10.1115/1.2714564 History: Received December 07, 2005; Revised June 15, 2006

Large scale power production benefits from the high efficiency of gas-steam combined cycles. In the lower power range, fuel cells are a good candidate to combine with gas turbines. Such systems can achieve efficiencies exceeding 60%. High-temperature solid oxide fuel cells (SOFC) offer good opportunities for this coupling. In this paper, a systematic method to select a design according to user specifications is presented. The most attractive configurations of this technology coupling are identified using a thermo-economic multi-objective optimization approach. The SOFC model includes detailed computation of losses of the electrodes and thermal management. The system is integrated using pinch based methods. A thermo-economic approach is then used to compute the integrated system performances, size, and cost. This allows to perform the optimization of the system with regard to two objectives: minimize the specific cost and maximize the efficiency. Optimization results prove the existence of designs with costs from 2400$kW for a 44% efficiency to 6700$kW for a 70% efficiency. Several design options are analyzed regarding, among others, fuel processing, pressure ratio, or turbine inlet temperature. The model of a pressurized SOFC–μGT hybrid cycle combines a state-of-the-art planar SOFC with a high-speed micro-gas turbine sustained by air bearings.

Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 1

System model structure

Grahic Jump Location
Figure 2

System flowsheet with decision variables used for optimization

Grahic Jump Location
Figure 3

nsds diagram for single stage compressor from Balje (13)

Grahic Jump Location
Figure 4

Hot and cold composite curve

Grahic Jump Location
Figure 5

Efficiency versus system cost

Grahic Jump Location
Figure 6

Efficiency versus fuel utilization

Grahic Jump Location
Figure 7

Efficiency versus steam to carbon ratio

Grahic Jump Location
Figure 8

Efficiency versus current density

Grahic Jump Location
Figure 9

Efficiency versus cell potential

Grahic Jump Location
Figure 10

Efficiency versus electricity from mechanical power

Grahic Jump Location
Figure 11

Efficiency versus air excess ratio

Grahic Jump Location
Figure 12

Efficiency versus heat exchanger cost

Grahic Jump Location
Figure 13

Composite curves cluster 3 η=70%, corrected by minimum ΔT

Grahic Jump Location
Figure 14

Composite curves cluster 1 η=69%, corrected by minimum ΔT



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In