Fuel Cells as Naval Prime Movers: Feasibility, Advances and Implications

Pending or recently enacted greenhouse gas regulations and mandates are leading to the need for current and feasible GHG reduction solutions including combined heat and power (CHP). Distributed generation using advanced reciprocating engines, gas turbines, microturbines and fuel cells has been shown to reduce greenhouse gases (GHG) compared to the U.S. electrical generation mix due to the use of natural gas and high electrical generation efficiencies of these prime movers. Many of these prime movers are also well suited for use in CHP systems which recover heat generated during combustion or energy conversion. CHP increases the total efficiency of the prime mover by recovering waste heat for generating electricity, replacing process steam, hot water for buildings or even cooling via absorption chilling. The increased efficiency of CHP systems further reduces GHG emissions compared to systems which do not recover waste thermal energy. Current GHG mandates within the U.S Federal sector and looming GHG legislation for states puts an emphasis on understanding the GHG reduction potential of such systems. This study compares the GHG savings from various state-of-the-art prime movers. GHG reductions from commercially available prime movers in the 1–5 MW class including, various industrial fuel cells, large and small gas turbines, micro turbines and reciprocating gas engines with and without CHP are compared to centralized electricity generation including the U.S. mix and the best available technology with natural gas combined cycle power plants. The findings show significant GHG saving potential with the use of CHP. Also provided is an exploration of the accounting methodology for GHG reductions with CHP and the sensitivity of such analyses to electrical generation efficiency, emissions factors and most importantly recoverable heat and thermal recovery efficiency from the CHP system.

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The Integration of Atmospheric Molten Carbonate Fuel Cells With Gas Turbine and Steam Cycles

Volume 2: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations ◽

10.1115/2001-gt-0382 ◽

2001 ◽

Cited By ~ 2

Author(s):

Stefano Campanari ◽

Ennio Macchi

Keyword(s):

Fuel Cells ◽

Fuel Cell ◽

Gas Turbine ◽

Atmospheric Pressure ◽

Fossil Fuel Combustion ◽

Molten Carbonate ◽

Molten Carbonate Fuel Cells ◽

Prime Movers ◽

Working Parameters ◽

Energy Balances

The exploitation of the high-temperature-fuel-cell technology, actually being developed by many companies involved in the gas turbine market, could allow outperforming performance of conventional prime movers based upon fossil fuel combustion. This paper investigates the integration of molten carbonate fuel cells (MCFCs) working at atmospheric pressure with some representative cycle configurations based either on steam and gas turbine cycles. Detailed energy balances of the most promising cycle configurations are presented; fuel cell and conventional components working parameters and technological issues are described and discussed. It is shown that efficiencies well above 60% can be achieved by combining MCFCs either with recuperative gas turbine or steam cycles.

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