Exergy Analysis of a Hybrid Micro Gas Turbine Fuel Cell System Based on Existing Components

2012 ◽  
Author(s):  
D. P. Bakalis ◽  
A. G. Stamatis
Keyword(s):  
Fuel Cell ◽  
Hybrid System ◽  
Exergy Analysis ◽  
Cell System ◽  
System Component ◽  
Utilization Factor ◽  
Fuel Cell Stack ◽  
Micro Gas Turbine ◽  
Partial Load ◽  
Set Up

A hybrid system based on an existing recuperated microturbine and a pre-commercially available high temperature tubular solid oxide fuel cell is modeled in order to study its performance. Individual models are developed for the microturbine and fuel cell generator and merged into a single one in order to set up the hybrid system. The model utilizes performance maps for the compressor and turbine components for the part load operation. The full and partial load exergetic performance is studied and the amounts of exergy destruction and efficiency of each hybrid system component are presented, in order to evaluate the irreversibilities and thermodynamic inefficiencies. Moreover, the effects of various performance parameters such as fuel cell stack temperature and fuel utilization factor are investigated. Based on the available results, suggestions are given in order to reduce the overall system irreversibility. Finally, the environmental impact of the hybrid system operation is evaluated.

Off-Design Performance Analysis of a Hybrid System Based on an Existing Molten Fuel Cell Stack

2003 ◽  
Vol 125 (4) ◽  
pp. 986-993 ◽  
Author(s):  
P. Bedont ◽  
O. Grillo ◽  
A. F. Massardo
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Load Condition ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Utilization Factor ◽  
Micro Gas Turbine ◽  
Fixed Design ◽  
Stack Model

This paper addresses the off-design analysis of a hybrid system (HS) based on the coupling of an existing Ansaldo Fuel Cells (formerly Ansaldo Ricerche) molten carbonate fuel cell (MCFC) stack (100 kW) and a micro gas turbine. The MCFC stack model at fixed design conditions has previously been presented by the authors. The present work refers to an off-design stack model, taking into account the influence of the reactor layout, current density, air and fuel utilization factor, CO2 recycle loop, cell operating temperature, etc. Finally, the design and off-design model of the whole hybrid system is presented. Efficiency at part load condition is presented and discussed, taking into account all the constraints for the stack and the micro gas turbine, with particular emphasis on CO2 recycle control.

Performance Simulation of a Hybrid Micro Gas Turbine Fuel Cell System Based on Existing Components

2011 ◽  
Author(s):  
D. P. Bakalis ◽  
A. G. Stamatis
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
System Performance ◽  
Cell System ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Utilization Factor ◽  
Micro Gas Turbine ◽  
Wide Range ◽  
Using Data

The objective of this work is the development of a simulation model for a hybrid Solid Oxide Fuel Cell (SOFC)/Micro Gas Turbine (MGT) system, flexible and robust enough, capable to predict the system performance under various operating conditions. The hybrid system consists of a high temperature SOFC, based on a tubular configuration developed by Siemens Power Generation Inc, and a recuperated small gas turbine (GT) validated using data for the Capstone C30. The design and off-design performance of the system is examined by means of performance maps. Moreover, operating parameters such as fuel utilization factor, steam to carbon ratio and current density are varied over a wide range and the influence on system performance is studied. The optimum operating conditions are discussed with regard to overall system performance under part load operation. The results show that high electrical efficiencies can be achieved making these systems appropriate for distributed generation applications.

Performance Evaluation of a Molten Carbonate Fuel Cell/Micro Gas Turbine Hybrid System With Oxy-Combustion Carbon Capture

2017 ◽  
Author(s):  
Ji Ho Ahn ◽  
Tong Seop Kim
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Carbon Capture ◽  
Molten Carbonate Fuel Cell ◽  
Design Parameters ◽  
Molten Carbonate ◽  
Micro Gas Turbine ◽  
Carbonate Fuel Cell

Owing to the increasing consumption of fossil fuels and emission of greenhouse gases, interests in highly efficient and low carbon emitting power systems are growing fast. Several research groups have been suggesting advanced systems based on fuel cells and have also been applying carbon capture and storage technology to satisfy the demand for clean energy. In this study, the performance of a hybrid system, which is a combination of a molten carbonate fuel cell (MCFC) with oxy-combustion carbon capture and an indirectly fired micro gas turbine (MGT) was predicted. A 2.5MW MCFC system that is used in commercial applications was used as the reference system so that the results of the study could be applicable to practical situations. The ambient pressure type hybrid system was modeled by referring to the design parameters of an MGT that is currently being developed. A semi-closed type design characterized by flow recirculation was adopted for this hybrid system. A part of the recirculating gas is converted into liquefied carbon dioxide and captured for storage at the carbon separation unit. Almost 100% carbon dioxide capture is possible with this system. In these systems, the output power of the fuel cell is larger than in the normal hybrid system without carbon capture because the partial pressure of carbon dioxide increases. The increased cell power partially compensates for the power loss due to the carbon capture and MGT power reduction. The dependence of net system efficiency of the oxy-hybrid on compressor pressure ratio is marginal, especially beyond an optimal value.

scholarly journals Design, Construction, and Testing of a Gasifier-Specific Solid Oxide Fuel Cell System

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1985 ◽  
Author(s):  
Alvaro Fernandes ◽  
Joerg Brabandt ◽  
Oliver Posdziech ◽  
Ali Saadabadi ◽  
Mayra Recalde ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Exergy Analysis ◽  
Thermodynamic Simulation ◽  
Cell System ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell System ◽  
Simulation Results ◽  
Design Construction

This paper describes the steps involved in the design, construction, and testing of a gasifier-specific solid oxide fuel cell (SOFC) system. The design choices are based on reported thermodynamic simulation results for the entire gasifier- gas cleanup-SOFC system. The constructed SOFC system is tested and the measured parameters are compared with those given by a system simulation. Furthermore, a detailed exergy analysis is performed to determine the components responsible for poor efficiency. It is concluded that the SOFC system demonstrates reasonable agreement with the simulated results. Furthermore, based on the exergy results, the components causing major irreversible performance losses are identified.

Evaluation of Cathode Air Flow Transients in a SOFC/GT Hybrid System Using Hardware in the Loop Simulation

2014 ◽  
Author(s):  
Nana Zhou ◽  
Chen Yang ◽  
David Tucker
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Mass Flow ◽  
Cell System ◽  
Department Of Energy ◽  
Dynamic Responses ◽  
Partial Recovery ◽  
Fuel Cell System ◽  
Air Mass

Thermal management in the fuel cell component of a direct fired solid oxide fuel cell gas turbine (SOFC/GT) hybrid power system, especially during an imposed load transient, can be improved by effective management and control of the cathode air mass flow. The response of gas turbine hardware system and the fuel cell stack to the cathode air mass flow transient was evaluated using a hardware-based simulation facility designed and built by the U.S. Department of Energy, National Energy Technology Laboratory (NETL). The disturbances of the cathode air mass flow were accomplished by diverting air around the fuel cell system through the manipulation of a hot-air bypass valve in open loop experiments. The dynamic responses of the SOFC/GT hybrid system were studied in this paper. The evaluation included distributed temperatures, current densities, heat generation and losses along the fuel cell over the course of the transient along with localized temperature gradients. The reduction of cathode air mass flow resulted in a sharp decrease and partial recovery of the thermal effluent from the fuel cell system in the first 10 seconds. In contrast, the turbine rotational speed did not exhibit a similar trend. The collection of distributed fuel cell and turbine trends obtained will be used in the development of controls to mitigate failure and extend life during operational transients.

Performance Evaluation of a Molten Carbonate Fuel Cell/Micro Gas Turbine Hybrid System With Oxy-Combustion Carbon Capture

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Ji Ho Ahn ◽  
Tong Seop Kim
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Carbon Capture ◽  
Molten Carbonate Fuel Cell ◽  
Design Parameters ◽  
Molten Carbonate ◽  
Micro Gas Turbine ◽  
Carbonate Fuel Cell

Owing to the increasing consumption of fossil fuels and emission of greenhouse gases, interests in highly efficient and low carbon emitting power systems are growing fast. Several research groups have been suggesting advanced systems based on fuel cells and have also been applying carbon capture and storage technology to satisfy the demand for clean energy. In this study, the performance of a hybrid system, which is a combination of a molten carbonate fuel cell (MCFC) with oxy-combustion carbon capture and an indirectly fired micro gas turbine (MGT), was predicted. A 2.5 MW MCFC system that is used in commercial applications was used as the reference system so that the results of the study could be applied to practical situations. The ambient pressure type hybrid system was modeled by referring to the design parameters of an MGT that is currently being developed. A semi-closed type design characterized by flow recirculation was adopted for this hybrid system. A part of the recirculating gas is converted into liquefied carbon dioxide and captured for storage at the carbon separation unit (CSU). Almost 100% carbon dioxide capture is possible with this system. In these systems, the output power of the fuel cell is larger than in the normal hybrid system without carbon capture because the partial pressure of carbon dioxide increases. The increased cell power partially compensates for the power loss due to the carbon capture and MGT power reduction. The dependence of net system efficiency of the oxy-hybrid on compressor pressure ratio is marginal, especially beyond an optimal value.

scholarly journals Overcoming the Challenges for a Mass Manufacturing Machine for the Assembly of PEMFC Stacks

Machines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 66 ◽  
Author(s):  
Porstmann ◽  
Wannemacher ◽  
Richter
Keyword(s):  
Fuel Cell ◽  
Economies Of Scale ◽  
Polymer Electrolyte Membrane ◽  
Cell System ◽  
Active Components ◽  
Fuel Cell Stack ◽  
Electrolyte Membrane ◽  
Modular Concept ◽  
A Cell ◽  
Manufacturing Machine

One of the major obstacles standing in the way of a break-through in fuel cell technology is its relatively high costs compared to well established fossil-based technologies. The reasons for these high costs predominantly lie in the use of non-standardized components, complex system components, and non-automated production of fuel cells. This problem can be identified at multiple levels, for example, the electrochemically active components of the fuel cell stack, peripheral components of the fuel cell system, and eventually on the level of stack and system assembly. This article focused on the industrialization of polymer electrolyte membrane fuel cell (PEMFC) stack components and assembly. To achieve this, the first step is the formulation of the requirement specifications for the automated PEMFC stack production. The developed mass manufacturing machine (MMM) enables a reduction of the assembly time of a cell fuel cell stack to 15 minutes. Furthermore the targeted automation level is theoretically capable of producing up to 10,000 fuel cell stacks per year. This will result in a ~50% stack cost reduction through economies of scale and increased automation. The modular concept is scalable to meet increasing future demand which is essential for the market ramp-up and success of this technology.

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