Parametric Analysis of Hybrid MCFC Micro Gas Turbine System

Author(s):  
Hongliang Hao ◽  
Huisheng Zhang ◽  
Shilie Weng ◽  
Ming Su

Fuel cells have been revealed to be a very attractive power generation system, promising highly efficient electricity generation and very low environmental impact. The integration of micro turbines and high-temperature fuel cells has been proposed in recent years as an extremely efficient solution for power generation. A molten carbonate fuel cell / micro gas turbine (MCFC/MGT) hybrid power system has theoretically demonstrated that it can achieve higher thermal efficiency than other conventional power generation systems. To understand operation characteristics of the MCFC/MGT hybrid power system, it is essential to analyze influence of operating and design parameters on its performance. Based on an existing 50KW MCFC stack, a steady-state thermodynamic model for MCFC/MGT hybrid power system is developed on the IPSEpro simulation platform and applied to a performance analysis. The characteristics under off-design and design condition for hybrid power system were also analyzed.

Author(s):  
Huisheng Zhang ◽  
Hongliang Hao ◽  
Shilie Weng ◽  
Ming Su

Molten carbonate fuel cells have been revealed to be very attractive power generation system, promising highly efficient electricity generation and very low environmental impact. The integration of micro gas turbine and molten carbonate fuel cells has been proposed in the last years as an extremely efficient solution for power generation. A steady-state thermodynamic exergetic model for MCFC/MGT hybrid power system is developed on the IPSEpro simulation platform, and applied to a performance analysis of exergy. The exergy method highlights irreversibility within the system components, and it is of particular interest in this paper. The simulation results show that the coupling of MGT with a MCFC reactor has shown a potential for an exergy efficiency of plant over 55% at design point and high efficiency at off-design point compared to other conventional power system.


Author(s):  
Ji Ho Ahn ◽  
Tong Seop Kim

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.


Author(s):  
Ji Ho Ahn ◽  
Tong Seop Kim

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.


Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2192 ◽  
Author(s):  
Chen Yang ◽  
Kangjie Deng ◽  
Hangxing He ◽  
Haochuang Wu ◽  
Kai Yao ◽  
...  

The research on the control strategy and dynamic characteristics of the Molten Carbonate Fuel Cell-Micro Gas Turbine (MCFC-MGT) hybrid power system has received much attention. The use of the Hardware-In-the-Loop Simulation (HILS) method to study the MCFC-MGT hybrid power system, where the MCFC is the model subsystem and the MGT is the physical subsystem, is an effective means to save development cost and time. The difficulty with developing the MCFC-MGT HILS system is the transfer of the mass, energy, and momentum between the physical subsystem and the model subsystem. Hence, a new Simulation–Stimulation (Sim–Stim) interface model of the MCFC-MGT HILS hybrid power system to achieve a consistent mass, energy, and momentum with the prototype system of the MCFC-MGT hybrid power system is proposed. In order to validate the Sim–Stim interface model before application in an actual system, both a real-time model of the MCFC-MGT hybrid power system and the MCFC-MGT HILS hybrid power system based on the Sim–Stim interface model were developed in the Advanced PROcess Simulation (APROS) platform. The step-up and step-down of the current density, which were strict for the Sim–Stim interface model, were studied in these two models. The results demonstrated that the Sim–Stim interface model developed for the MCFC-MGT HILS hybrid power system is rapid and reasonable.


Volume 3 ◽  
2004 ◽  
Author(s):  
Tae Won Song ◽  
Jeong L. Sohn ◽  
Jae Hwan Kim ◽  
Tong Seop Kim ◽  
Sung Tack Ro ◽  
...  

Performance of a solid oxide fuel cell (SOFC) can be enhanced by converting thermal energy of its high temperature exhaust gas to mechanical power using a micro gas turbine (MGT). A MGT plays also an important role to pressurize and warm up inlet gas streams of the SOFC. Performance behavior of the SOFC is sensitively influenced by internal constructions of the SOFC and related to design and operating parameters. In case of the SOFC/MGT hybrid power system, internal constructions of the SOFC influence not only on the performance of the SOFC but also on the whole hybrid system. In this study, influence of performance characteristics of the tubular SOFC and its internal reformer on the hybrid power system is discussed. For this purpose, detailed heat and mass transfer with reforming and electrochemical reactions in the SOFC are mathematically modeled and their results are reflected to the performance analysis. Effects of different internal constructions of the SOFC system and design parameters such as current density, recirculation ratio, fuel utilization factor, and catalyst density in internal reformer on the system performance are investigated and, as a result, some guidelines for the choice of those parameters for optimum operations of the SOFC/MGT hybrid power system are discussed.


2020 ◽  
Vol 8 (2) ◽  
pp. 74 ◽  
Author(s):  
Hyeonmin Jeon ◽  
Kido Park ◽  
Jongsu Kim

In order to secure the safe operation of the ship, it is crucial to closely examine the suitability from the design stage of the ship, and to set up a preliminary review and countermeasures for failures and defects that may occur during the construction process. In shipyards, the failure mode and effects analysis (FMEA) evaluation method using risk priority number (RPN) is used in the shipbuilding process. In the case of the conventional RPN method, evaluation items and criteria are ambiguous, and subjective factors such as evaluator’s experience and understanding of the system operate a lot on the same contents, resulting in differences in evaluation results. Therefore, this study aims to evaluate the safety and reliability for ship application of the reliability-enhanced fuel cell-based hybrid power system by applying the re-established FMEA technique. Experts formed an FMEA team to redefine reliable assessment criteria for the RPN assessment factors severity (S), occurrence (O), and detection (D). Analyze potential failures of each function of the molten-carbonate fuel cell (MCFC) system, battery system, and diesel engine components of the fuel cell-based hybrid power system set as evaluation targets to redefine the evaluation criteria, and the evaluation criteria were derived by identifying the effects of potential failures. In order to confirm the reliability of the derived criteria, the reliability of individual evaluation items was verified by using the significance probability used in statistics and the coincidence coefficient of Kendall. The evaluation was conducted to the external evaluators using the reestablished evaluation criteria. As a result of analyzing the correspondence according to the results of the evaluation items, the severity was 0.906, the incidence 0.844, and the detection degree 0.861. Improved agreement was obtained, which is a significant result to confirm the reliability of the reestablished evaluation results.


Author(s):  
Daniele Chiappini ◽  
Luca Andreassi ◽  
Elio Jannelli ◽  
Stefano Ubertini

The application of high temperature fuel cells in stationary power generation seems to be one of the possible solutions to the problem related to the environment preservation and to the growing interest for distributed electric power generation. Great expectations have been placed on both simple and hybrid fuel cell plants, thus making necessary the evolution of analysis strategies to evaluate thermodynamic performance, design improvements, and acceleration of new developments. This paper investigates the thermodynamic potential of combining traditional internal combustion energy systems (i.e., gas turbine and internal combustion engine) with a molten carbonate fuel cell for medium- and low-scale electrical power productions with low CO2 emissions. The coupling is performed by placing the fuel cell at the exhaust of the thermal engine. As in molten carbonate fuel cells the oxygen-charge carrier in the electrolyte is the carbonate ion, part of the CO2 in the gas turbine flue gas is moved to the anode and then separated by steam condensation. Plant performance is evaluated in function of different parameters to identify optimal solutions. The results show that the proposed power system can be conveniently used as a source of power generation.


Author(s):  
Ma Shixi ◽  
Dengji Zhou ◽  
Huisheng Zhang ◽  
Zhenhua Lu

Hybrid power systems are becoming popular for remote areas due to lower operating cost and green gas emission. Most of these systems are used in remote or harsh environments, so the effect of ambient conditions on system operation is an important factor that should not be ignored. In this paper, the system referred is a domestic hybrid power system including a renewable energy conversion device (Photovoltaic, PV), a traditional energy conversion device (Micro Gas Turbine, MGT) and an electrochemical energy storage unit (batteries). A numerical model, which considers the effect of ambient conditions on the whole system, has been developed. Model Predictive Control (MPC) strategy has been applied to the analysis of power management. The control strategy includes the objective of minimizing system costs, while considering real operational constraints of the plants. Performances attainable with the MPC strategy have been evaluated in comparison with a standard Rule Based Control logic (RBC), by means of costs and efficiency parameters of the system. The effects of ambient conditions on system operation based on MPC-based strategy are evaluated. The simulation has been carried out for the summer and winter periods in four places with different climate in China. Results show that a lower cost of primary fossil energy is found by using the MPC strategy. This is mainly due to the increased use of renewable energy sources by considering the future load. An obvious effect of ambient conditions on control process is observed. A significant improvement for the whole year in efficiency of the system, especially in high latitude cold regions with larger temperature difference from the design condition, is achieved by considering the ambient conditions. The highest reduction of fuel consumption reaches to 4% during the winter. As a result, the effect of the ambient conditions in some areas must be taken into account for control system design.


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