Triple-Layer Control System for Molten Carbonate Fuel Cell–Gas Turbine Hybrid System

2015 ◽  
Vol 12 (4) ◽  
Author(s):  
Jarosław Milewski ◽  
Piotr Biczel ◽  
Mariusz Kłos
Keyword(s):  
Control System ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Control Strategy ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Wide Range ◽  
Electric Equipment ◽  
Carbonate Fuel Cell

The control system of molten carbonate fuel cell (MCFC) coupled with a gas turbine (GT) should be based on the multilayer structure (two- or three-layers), wherein the third layer is connected with the power output from the system and can be considered separately. Simulation model of the MCFC–GT hybrid system (HS) was built. The simulator is based on a zero-dimensional modeling of the individual elements of the system. The simulator was used for mapping the main components behavior (MCFC and GT separately). On the basis of the obtained maps of the performances and adopted restrictions on technical–operational nature, the operation line for the first line of the control strategy was obtained. The control system which realizes the obtained control strategy was built in reality. Then, the hardware-based models of the main elements were created based on the electric equipment. The hardware–software model was connected to the control system and adequate simulations were performed. The presented results indicate that the analyzed MCFC–GT HS possesses a high operation and control flexibility while at the same time maintaining stable thermal efficiency. Operation of the system is possible over a wide range of parameter changes.

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.

The control strategy for a molten carbonate fuel cell hybrid system

2010 ◽  
Vol 35 (7) ◽  
pp. 2997-3000 ◽  
Author(s):  
Jarosław Milewski ◽  
Tomasz Świercz ◽  
Krzysztof Badyda ◽  
Andrzej Miller ◽  
Antoni Dmowski ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Hybrid System ◽  
Control Strategy ◽  
Cell Hybrid ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Carbonate Fuel Cell ◽  
Fuel Cell Hybrid

scholarly journals Triple-layer based control strategy for molten carbonate fuel cell – hybrid system

2012 ◽  
Vol 33 (3) ◽  
pp. 445-461 ◽  
Author(s):  
Jarosław Milewski ◽  
Andrzej Miller
Keyword(s):  
Fuel Cell ◽  
Hybrid System ◽  
Control Strategy ◽  
Cell Hybrid ◽  
Molten Carbonate Fuel Cell ◽  
Maximum Efficiency ◽  
Molten Carbonate ◽  
Independent Parameters ◽  
Carbonate Fuel Cell ◽  
Fuel Cell Hybrid

Abstract Based on mathematical modelling and numerical simulations, a control strategy for a Molten Carbonate Fuel Cell Hybrid System (MCFC-HS) is presented. Adequate maps of performances with three independent parameters are shown. The independent parameters are as follows: stack current, fuel mass flow and compressor outlet pressure. Those parameters can be controlled by external load, fuel valve and turbine-compressor shaft speed, respectively. The control system is purposed to meet many constraints: e.g. stack temperature, steam-to-carbon ratio, compressor surge limitation, etc. The aim is to achieve maximum efficiency of power generated within these constraints. Governing equations of MCFC-HS modelling are given. An operational line of the MCFC-GT system is presented which fulfils several constraints (temperature difference, cell temperature, etc.) The system is able to achieve efficiency of more than 62% even in part-load operation.

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.

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.

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