Fuel cell gas turbine hybrid design, control, and performance

The modern green revolution charges forward under a banner of global climate change. The heart of this revolution rests upon a realization that more can be done with less when resources are used wisely. The United States has long been a world leader in the valuable commodities of energy and technology. Solutions to 21st century energy and environment related issues require leadership, vision, and expertise across multiple disciplines. Cooperation must develop between scientists and politicians, neighborhoods and communities to deploy integrated solutions to energy, water, waste treatment, other service providers, and the environment. Fuel cell gas turbine hybrid technology presents a game-changing platform for electricity production and environmental sensitivity. This work presents a streamlined design methodology for optimizing hybrid systems and testing dynamic control strategies. Detailed component modeling is paramount to accurate systems analysis. This study developed unique, first principle, models, including a novel fuel cell model able to simulate and spatially resolve transient temperature, pressure and species distributions for a simulated fuel cell stack in a computationally efficient manner. The novel model accounts for internal manifolding of fuel and oxidant streams and predicts two dimensional fields associated with the dynamic operation of a single high temperature fuel cell. The MatLab-SimulinkRTM model calculates dynamic performance for both solid oxide and molten carbonate fuel cell types that utilize both direct and indirect internal reforming. The dynamic models utilized in this work are robust and scalable for application to distributed generation and central plant design studies. The turbomachinery modeling utilizes a novel method for stable compressor and turbine map interpolation. The controls design demonstrates the capability for stack temperature management during perturbations and turndown for both synchronous and asynchronous generator plants. The design study of FC-GT hybrids undertaken presents a methodology for determining optimal hybridization of a fuel cell with a gas turbine device, and ascertaining the performance requirements of the balance of plant. The integrated system methodology developed can determine system performance, operating limits, and possible dynamic instabilities. The control scenarios presented herein offer different balances between operational range, performance, and stability with varying degrees of complexity in the control implementation.