Part Load Strategies of a Multi-MW Molten Carbonate Fuel Cell Gas Turbine Hybrid System

2007 ◽  
Author(s):  
Georgia C. Karvountzi ◽  
Paul F. Duby
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Cell Voltage ◽  
Combined Cycle ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Part Load ◽  
Full Load ◽  
Carbonate Fuel Cell

The goal of this study is to define the operating envelope of a 20MW molten carbonate fuel cell (MCFC)-gas turbine hybrid system, under part load conditions. The first part of the paper reviews our baseline fuel cell hybrid system model that predicts overall system LHV efficiency around 69% at full load. The second part of the paper consider several strategies: 1/ run fuel cell at full load and bypass gas turbine; 2 /run fuel cell at full load and gas turbine at part load; 3/ run fuel cell at OCV and gas turbine at full load; 4/ run fuel cell at part load and gas turbine at full load; and 5/run both fuel cell and gas turbine at part load. The best system part-load performance was achieved when the fuel cell operates at part load while the gas turbine is at full load. The highest operational flexibility is achieved when we part load both the fuel cell and the gas turbine. Depending on system targets and deliverables such as fuel cell voltage and fuel utilization or gas turbine firing temperature some of these modes may not be economical. A comparison with the performance of a conventional combined cycle 20MW power plant under part load was performed. The MCFC hybrid system showed better efficiency and better cost of electricity (COE) under part load operation than the gas turbine combined cycle part loaded.

Part-Load Performance Analysis of Pressurized Molten Carbonate Fuel Cell/Micro-Gas Turbine Hybrid System Using a Commercially Available Micro-Gas Turbine

2009 ◽  
Author(s):  
Ai-guo Liu ◽  
Yi-wu Weng
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Control Strategies ◽  
Molten Carbonate Fuel Cell ◽  
Inlet Temperature ◽  
Molten Carbonate ◽  
Part Load ◽  
Micro Gas Turbine ◽  
Carbonate Fuel Cell

This paper presented the work on the design and part-load operation of a power generation system composed of a pressurized molten carbonate fuel cell and a micro-gas turbine (MCFC/MGT). The gas turbine was based on the commercially available one and the MCFC was assumed to be newly designed for the hybrid system. The effect of different control strategies on the performance of system during part-load operation has been analyzed. Performance of system and gas turbine was compared at the same part-load considering the different control strategies. The results show that the system efficiency is lower compared with the same systems analyzed by the other authors. The system has good performance when both the turbine inlet temperature and cell temperature are maintained close to the design-point condition, but it is difficult for gas turbine to obtain the original power.

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.

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.

Performance Enhancement of a Molten Carbonate Fuel Cell/Micro Gas Turbine Hybrid System With Carbon Capture by Off-Gas Recirculation

2018 ◽  
Author(s):  
Ji Ho Ahn ◽  
Ji Hun Jeong ◽  
Tong Seop Kim
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Carbon Capture ◽  
Molten Carbonate Fuel Cell ◽  
Human Society ◽  
Molten Carbonate ◽  
Micro Gas Turbine ◽  
Gas Recirculation ◽  
Carbonate Fuel Cell

The demand for clean energy continues to increase as the human society becomes more aware of environmental challenges such as global warming. Various power systems based on high-temperature fuel cells have been proposed, especially hybrid systems combining a fuel cell with a gas turbine, and research on carbon capture and storage technology to prevent the emission of greenhouse gases is already underway. This study suggests a new method to innovatively enhance the efficiency of a molten carbonate fuel cell/micro gas turbine hybrid system including carbon capture. The key technology adopted to improve the net cycle efficiency is off-gas recirculation. The hybrid system incorporating oxy-combustion capture was devised, and its performance was compared with that of a post-combustion system based on a hybrid system. A molten carbonate fuel cell system based on a commercial unit was modeled. Externally supplied water for reforming was not needed as a result of the presence of the water vapor in the recirculated anode off-gas. The analyses confirmed that the thermal efficiencies of all the systems (MCFC stand-alone, hybrid, hybrid with oxy-combustion capture, hybrid with post-combustion capture) were significantly improved by introducing the off-gas recirculation. In particular, the largest efficiency improvement was observed for the oxy-combustion hybrid system. Its efficiency is over 57% and is even higher than that of the post-combustion hybrid system.

Efficiency Analyses of a Coal Gasification Molten Carbonate Fuel Cell With a Gas Turbine Combined Cycle Including CO2 Recovery

2008 ◽  
Author(s):  
F. Yoshiba ◽  
E. Koda
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Coal Gas ◽  
Co2 Recovery ◽  
And Storage ◽  
Carbonate Fuel Cell

The efficiency of an integrated coal gasification system equipped with a molten carbonate fuel cell, a gas turbine and a steam turbine (IG/MCFC) is calculated. Coal is conveyed to a gasifier furnace by CO2 and changed to coal gas by adding oxygen; a methyldiethanolamine (MDEA) method is applied to initiate a cleanup procedure of the coal gas. A water-gas shift converter is employed to heat up the coal gas. The cathode gas of the MCFC is composed of CO2 and O2 with a composition of 66.7/33.3 (noble cathode gas composition). The magnitude of the system’s electrical power output is assumed to be that of a 300 MW class. The calculated net efficiency of the 2.2 MPa pressurised system reached a 60.1% high heating value (HHV) without CO2 recovery. The 2.2 MPa pressurised system, however, has a short lifetime limited by the shortening of electrodes. For this reason, a further 0.15 MPa pressurised system (low pressurised system) efficiency is recorded which has a more promising shortening time of the electrodes. The net efficiency of the low pressurised system is 51.9% HHV without CO2recovery. Since the coal is gasified using oxygen and the cathode gas of the MCFC is composed of CO2/O2, the system’s exhaust gas only includes CO2, thus the system is ready for the recovery and storage of carbon dioxide (Carbon Capture and Storage ready, CCS ready). For the purpose of estimating the net efficiency with CO2 recovery, a liquid form of CO2 with a pressure of 10MPa is assumed. Using the 2.2 MPa pressurised system, the net efficiency including the consumption of CO2 compression and liquefaction is evaluated at 58.2% HHV. Another simple CO2 closed system configuration without gas turbine is proposed; the net efficiencies of the 2.2 MPa and the 0.15 MPa system including the consumption of CO2 liquefaction are determined at 56.4% and 50.3% HHV, respectively. According to the calculation results, a high efficiency system with CO2 recovery is possible by applying the noble cathode gas in the IG/MCFC systems.

Molten Carbonate Fuel Cell Gas Turbine Combined Cycle for Marine Propulsion: Part B — Part Load Operation

2002 ◽  
Author(s):  
Maria-Teresa Basurto ◽  
Pericles Pilidis ◽  
Richard Hales
Keyword(s):  
Fuel Cell ◽  
Power Systems ◽  
Gas Turbine ◽  
Combined Cycle ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Hybrid Power Systems ◽  
Hybrid Power ◽  
Marine Propulsion ◽  
Carbonate Fuel Cell

Molten Carbonate Fuel Cell/Gas Turbine (MCFC/GT) hybrid power systems represent a modern, efficient and clean alternative to the currently used marine propulsion systems. The objective of this paper is to present the results found from the application of MCFC/GT hybrid power systems to marine propulsion, and in particular to present the results of the off-design performance of a COGAFC system (Combined Gas Turbine and Fuel Cell System). The results presented are subjected to the current uncertainties on MCFC power systems derived from its early stage of development. It is, then, the interest of the authors to summarise the results of the research work done, providing to the lectors the understanding and a general view of which are the concerns, the benefits, and which should be the next steps on the implementation of these systems. The study is summarised into two papers: “Molten Carbonate Fuel Cell Gas Turbine Combined Cycle for Marine Propulsion. Part A: Design Point Operation” (Basurto et al., 2002), that describes the selection of the design point, and “Molten Carbonate Fuel Cell Gas Turbine Combined Cycle for Marine Propulsion. Part B: Part Load Operation”, that describes the off-design performance of the system. The study is based on previous work published by the authors on the integration of MCFCs with gas turbines (Basurto et al., 2001).

Sign in / Sign up

Export Citation Format

Share Document