Gas turbine size optimization in a hybrid system considering SOFC degradation

Abstract

The coupling of a pressurized solid oxide fuel cell (SOFC) and a gas turbine has been proven to result in extremely high efficiency and reduced emissions. The presence of the gas turbine can improve system durability compared to a standalone SOFC, because the turbomachinery can supply additional power as the fuel cell degrades to meet the power request. Since performance degradation is an obstacles to SOFC systems commercialization, the optimization of the hybrid system to mitigate SOFC degradation effects is of great interest. In this work, an optimization approach was used to innovatively study the effect of gas turbine size on system durability for a 400 kW fuel cell stack. A larger turbine allowed a bigger reduction in SOFC power before replacing the stack, but increased the initial capital investment and decreased the initial turbine efficiency. Thus, the power ratio between SOFC and gas turbine significantly influenced system economic results.

A Study of Anode-Supported Solid Oxide Fuel Cell Modeling and Optimization Using Neural Network and Multi-Armed Bandit Algorithm

“…[11] Many studies have been conducted to optimize the design variables of fuel cells. Of the optimization theories, genetic algorithm (GA) has been mostly used to find the optimal parameters of the fuel cells [18][19][20][21]. The GA has a mechanism to avoid local optimal, but there are many variables that need to be determined, so the result is very dependent on the variables.…”

Cyber-Physical System of a Solid Oxide Fuel Cell/Micro Gas Turbine Hybrid Power Plant

“…NOx emissions below 10 ppm and CO emissions below 20 ppm have been demonstrated for this type of system [3] and the high-temperature exhaust gases can be useful for cogeneration [4]. As a consequence, hybrid SOFC/MGT concepts have been extensively studied [5][6][7]. However, as a result of the high capital cost required to build hybrid demonstrators, only few studies include experimental data where measured efficiencies are usually lower than expected [5][6][7][8][9][10][11].…”

“…As a consequence, hybrid SOFC/MGT concepts have been extensively studied [5][6][7]. However, as a result of the high capital cost required to build hybrid demonstrators, only few studies include experimental data where measured efficiencies are usually lower than expected [5][6][7][8][9][10][11]. Only Mitsubishi Hitachi Power Systems, Ltd. (MHPS) has commissioned hybrid power plant demonstrators [12,13]; however, no experimental data has been reported.…”

Robust Design of a Hybrid Energy System

“…SOFCs are a very attractive fuel cell technology for energy conversion, as they can guarantee high electrical efficiencies, low emissions, possibility of cogeneration and modularity [3]. High temperature fuel cell exhaust gases can also be used to drive a bottoming thermodynamic cycle, raising the overall hybrid cycle efficiency to more than 70% [4], resulting in a particularly interesting application for hybrid system integration [3,5].…”