Abstract
The hybridization of gas turbine technology with high temperature fuel cells represents an ultra-high efficiency, ultra-low emission, fuel flexible power generation platform. The performance of past prototypes has been limited by marginal compatibility of the two primary sub-systems. This paper addresses the challenge of selecting compatible hardware by presenting a simple and robust method for bespoke hybrid system design and off-the-shelf component integration. This is the first application of detailed, spatially resolved, physical models capable of resolving off-design performance to the integration analysis of FC–GT hybrids. Static maps are produced for both turbine and fuel cell sub-systems that readily evaluate the compatibility and hybrid performance. Molten carbonate and solid oxide fuel cells are considered for hybridization with recuperated micro-turbines and larger axial flow gas turbine systems. Current state-of-the-art molten carbonate technology is shown to pair well with present micro-turbine technology in an FC bottoming cycle design achieving 74.4% LHV efficiency. Solid oxide technology demonstrates remarkable potential for integration with larger scale axial turbo-machinery to achieve greater than 75% LHV efficiency. This performance map technique closely matches results from detailed integrated hybrid system analyses, and enables quick determination of performance requirements for balance of plant design and optimization.
Highlights
Integration of fuel cell and gas turbine technologies into a single symbiotic hybrid system has been shown to produce systems with high fuel-to-electricity conversion efficiency [1e4]
Note the 10e15% improvement of Fuel cellegas turbine hybrids (FCeGT) technology compared to both fuel cells and heat engines alone, and the minimal loss of hybrid system efficiency when 80% fuel utilization is applied
This paper presented a novel methodology for pre-determining hardware compatibility for FCeGT hybridization that employs offdesign performance maps generated from detailed, spatially resolved, physical component models
Summary
Integration of fuel cell and gas turbine technologies into a single symbiotic hybrid system has been shown to produce systems with high fuel-to-electricity conversion efficiency [1e4]. A fuel cell extracts work directly from the chemical energy of a fuel, producing much less entropy than a combustion process This allows efficient electrical generation, but electrochemical losses, internal resistance and post-anode fuel oxidation generate substantial amounts of high temperature heat that is capable of powering a wide range of bottoming cycle engines such as gas turbines, steam turbines and Stirling engines. This topping-cycle design introduces the need for a pressure vessel and increases the potential for compressor stall/ surge In both topping and bottoming cycles the turbine can provide a substantial portion of the air pre-heating requirement for the fuel cell, either through compression, recuperation, or recirculation. The methodology is applied to demonstrate the estimation of hybrid efficiency for two well-defined sub-systems, and to demonstrate how performance criteria can be established for a purpose designed or bespoke turbine that would meet the requirements of existing SOFC or MCFC equipment and provide for a large operating envelope
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
