Theoretical analysis and optimum integration strategy of the PEM fuel cell and internal combustion engine hybrid system for vehicle applications

2015 ◽  
pp. n/a-n/a ◽  
Author(s):  
Xiuqin Zhang ◽  
Meng Ni ◽  
Wei He ◽  
Feifei Dong
Keyword(s):  
Fuel Cell ◽  
Theoretical Analysis ◽  
Internal Combustion Engine ◽  
Hybrid System ◽  
Combustion Engine ◽  
Pem Fuel Cell ◽  
Internal Combustion ◽  
Integration Strategy

Comparative analysis between a PEM fuel cell and an internal combustion engine driving an electricity generator: Technical, economical and ecological aspects

2014 ◽  
Vol 63 (1) ◽  
pp. 354-361 ◽  
Author(s):  
Lúcia Bollini Braga ◽  
Jose Luz Silveira ◽  
Marcio Evaristo da Silva ◽  
Einara Blanco Machin ◽  
Daniel Travieso Pedroso ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Fuel Cell ◽  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Pem Fuel Cell ◽  
Internal Combustion ◽  
Ecological Aspects

Part Load Efficiency Enhancement of an Automotive Engine Via a Direct Methanol Fuel Cell-Internal Combustion Engine Hybrid System

2013 ◽  
Vol 10 (3) ◽  
Author(s):  
Osman Sinan Suslu ◽  
Ipek Becerik
Keyword(s):  
Fuel Cell ◽  
Internal Combustion Engine ◽  
Hybrid System ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Fuel Saving ◽  
System Efficiency ◽  
Product Gas ◽  
Direct Methanol ◽  
A Cell

The operation of a direct methanol fuel cell with an internal combustion engine in a hybrid system is investigated in terms of fuel efficiency. The following work shows a potential for fuel saving because the engine's waste heat is utilized in preconditioning of methanol for the fuel cell and in postconditioning of the cell's anode exhaust for the engine. The low activity of methanol oxidation catalysts and methanol crossover are the main drawbacks of direct methanol fuel cells. H3PO4-doped polybenzimidazole membranes have lower methanol crossover, and allow a higher operational temperature and methanol concentration compared to Nafion membranes. The operation of the cell at higher temperature with polybenzimidazole membranes improves catalyst activity and mass transfer increasing cell efficiency. But the fuel feed to this type of membrane must be in vapor phase. Methanol solution can be evaporated by the engine coolant. Unutilized methanol in the anode exhaust is converted to H2 rich product gas in a reactor before feeding into the engine. The endothermic reaction enthalpy for this conversion is recovered from engine's exhaust gas. The system efficiency increases with the cell's fuel utilization, as long as the cell's efficiency is higher than the engine's efficiency. In order to increase the system efficiency with load, the current density of the fuel cell should not be increased beyond the point where the cell and engine efficiency meet. Beyond that, the product gas should be substituted with liquid methanol to meet the rest of the load because the engine charge's energy density can be increased with liquid methanol injection into the engine. If the engine charge is comprised of fuel cell exhaust only and the engine's indicated efficiency is 20%, the efficiency of the hybrid system will be 25.5% at a cell voltage of 0.4 V and a cell fuel utilization of 40%. This corresponds to a fuel saving of 28% compared to the internal combustion engine. The hybrid system efficiency will increase to 28.5% at this operating point, if the fuel cell's anode exhaust is further decomposed in a reactor prior to combustion in the engine. The addition of the reactor to the hybrid system corresponds to a fuel saving of 43% compared to the engine and a fuel saving of 12% compared to the hybrid system without the reactor.

Cogeneration of Heat and Electricity: A Comparison of Gas Turbine, Internal Combustion Engine, and MCFC/GT Hybrid System Alternatives

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
S. Bargigli ◽  
V. Cigolotti ◽  
D. Pierini ◽  
A. Moreno ◽  
F. Iacobone ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Internal Combustion Engine ◽  
Gas Turbine ◽  
Hybrid System ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Individual Performance ◽  
Exergy Efficiency ◽  
Embodied Energy ◽  
Molten Carbonate

The purpose of this paper is to present the results of a feasibility study of the supply of electricity and heat to a large user (i.e., a public hospital in Northern Italy) by means of a molten carbonate fuel cell (MCFC) hybrid system in comparison with other technologies. The study investigated three alternative options in order to meet the user’s demand: internal combustion engine, gas turbine, and a hybrid system (molten carbonate fuel cells and gas turbine, MCFC-HS), which is currently under development by Ansaldo Fuel Cell Ltd. and ENEA. The user requirement was the yearly supplies of 6.65 GWhe/year and 21.64 GWhth/year. Due to demand fluctuations over the year, integration by electric grid and/or additional thermal boilers was also required and investigated. The approach integrates the usual mass balance with large scale material flow accounting, embodied energy analysis, exergy efficiency, and emergy synthesis, within a LCA perspective. Results show that the best performance from the point of view of energy and exergy efficiency is shown by the MCFC-hybrid system. The latter is also characterized by the lowest embodied energy demand and cumulative material demand as well as by the lowest requirement for direct and indirect environmental support (emergy method). However, the small thermal energy supply of the MCFC-HS compared with the large thermal needs of the hospital calls for a larger use of the additional boiler. The latter device worsens the local-scale emissions of the system, compared with the other alternatives investigated. Results point out that a proper choice cannot only be based on the individual performance of an even well performing technological device, but also needs to be tailored on the system’s characteristics and dynamics, in order to adequately match supply and demand.

Integrated Anaerobic Digester and Fuel Cell Power Generation System for Community Use

2015 ◽  
Author(s):  
Ryan Falkenstein-Smith ◽  
Kang Wang ◽  
Ryan Milcarek ◽  
Jeongmin Ahn
Keyword(s):  
Fuel Cell ◽  
Waste Management ◽  
Power System ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Energy Content ◽  
New York State ◽  
Internal Combustion ◽  
Optimal Performance

New York State is expected to experience future population growth that is increasingly concentrated in urban areas, where there is already a heavy burden on the existing energy, water and waste management infrastructure. To meet aggressive environmental standards (such as that established by the State’s “80x50” goal), future electrical power capacity must produce substantially fewer greenhouse gas emissions than currently generated by coal- or natural gas-fired power plants. Currently, biogas is combusted to produce heat and electricity via an internal combustion engine generator set. A conventional internal combustion engine generator set is 22–45 % efficient in converting methane to electricity, thus wasting 65–78 % of the biogas energy content unless the lower temperature heat can be recovered. Fuel cells, on the other hand, are 40–60 % efficient in converting methane to electrical energy, and 80–90 % efficient for cogeneration if heat (> 400 °C) is recovered and utilized for heating and cooling in the community power system. This current research studies the feasibility of a community biomass-to-electricity power system which offers significant environmental, economic and resilience improvements over centrally-generated energy, with the additional benefit of reducing or eliminating disposal costs associated with landfills and publicly-owned treatment works (POTWs). Flame Fuel Cell (FFC) performance was investigated while modifying biogas content and fuel flow rate. A maximum power density peak at 748 mWcm-2 and an OCV of 0.856 V was achieved. It should be noted that the performance obtained with the model biofuel is comparable to the performances of direct methane fueled DC-SOFC and SC-SOFC. The common trends also concluded an acceptable range for optimal performance. Although the methane to CO2 ratios of 3:7 and 2:8 produced power, they are not the strongest ratios to have optimal performance, meaning that operation should stay between the 6:4/4:6 ratio range. Lastly, the amount of air added to the biogas mixture is crucial to achieving the optimal performance of the cell. The data obtained confirmed the feasibility of a biofuel driven fuel cell CHP device capable of achieving higher efficiency than existing technologies. The significant power output produced from the sustainable biogas composition is competitive with current hydrocarbon fuel sources. This idea can be expanded for a community waste management infrastructure.

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