Optimal Operation of Residential Fuel Cell System with Rapidly Fluctuating Energy Demand

A novel reciprocating compression device has been investigated as a non-catalytic natural gas reformer for solid oxide fuel cell systems. The reciprocating compression reformer is a potential improvement over current reforming technology for select applications due to its high degree of heat integration, its homogenous gas phase reaction environment, and its ability to co-produce shaft work. Performance modeling of the system was conducted to understand component integration and operational characteristics. The reformer was modeled by utilizing GRI mech. in tandem with CHEMKIN. The fuel cell was modeled as an equilibrium reactor assuming constant fuel utilization. The effect on the reformer and the reformer – fuel cell system efficiencies and exit gas concentrations was examined over a range of relative air-to-fuel ratios, 0.2 to 1.0, and at compression ratios of 50 and 100. Results from this study indicate that the reformer – fuel cell system could approach 50% efficiency, if run at low relative air-to-fuel ratios (0.3 to 0.5). With higher air-to-fuel ratios, system efficiencies were shown to continuously decline due to a decrease in the quality of synthesis gas provided to the fuel cell (i.e. more power being produced by the reformer). Optimal operation of the system has been shown to occur at a relative air-to-fuel ratio of approximately 0.775 and to be nearly independent of the compression ratio in the reciprocating compression reformer. Higher efficiencies may be obtained at lower relative air-to-fuel ratios; however, operation below this point may lead to excessive carbon formation as determined from an equilibrium carbon formation analysis.

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A Grid-Tied Fuel Cell Multilevel Inverter with Low Harmonic Distortions

Energies ◽

10.3390/en14030688 ◽

2021 ◽

Vol 14 (3) ◽

pp. 688

Author(s):

Khlid Ben Hamad ◽

Doudou N. Luta ◽

Atanda K. Raji

Keyword(s):

Fuel Cells ◽

Fuel Cell ◽

Energy Demand ◽

Fossil Fuels ◽

Clean Energy ◽

Energy System ◽

Cell System ◽

Proton Exchange ◽

Fuel Cell System ◽

Harmonic Distortions

As a result of global energy demand increase, concerns over global warming, and rapid exhaustion of fossil fuels, there is a growing interest in energy system dependence on clean and sustainable energy resources. Attractive power technologies include photovoltaic panels, wind turbines, and biomass power. Fuel cells are also clean energy units that substitute power generators based on fossil fuels. They are employed in various applications, including transportation, stationary power, and small portable power. Fuel cell connections to utility grids require that the power conditioning units, interfacing the fuel cells and the grids, operate accordingly (by complying with the grid requirements). This study aims to model a centralised, single-stage grid-tied three-level diode clamped inverter interfacing a multi-stack fuel cell system. The inverter is expected to produce harmonic distortions of less than 0.5% and achieve an efficiency of 85%. Besides the grid, the system consists of a 1.54 MW/1400 V DC proton exchange membrane fuel cell, a 1.3 MW three-level diode clamped inverter with a nominal voltage of 600 V, and an inductance-capacitance-inductance (LCL) filter. Two case studies based on the load conditions are considered to assess the developed system’s performance further. In case 1, the fuel cell system generates enough power to fully meet this load and exports the excess to the grid. In the other case, a load of 2.5 MW was connected at the grid-tied fuel cell inverter’s output terminals. The system imports the grid’s power to meet the 2.5 MW load since the fuel cell can only produce 1.54 MW. It is demonstrated that the system can supply and also receive power from the grid. The results show the developed system’s good performance with a low total harmonic distortion of about 0.12% for the voltage and 0.07% for the current. The results also reveal that the fuel cell inverter voltage and the frequency at the point of common coupling comply with the grid requirements.

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Optimization of PEM Fuel Cell System Using Dynamic Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.26-28.1019 ◽

2010 ◽

Vol 26-28 ◽

pp. 1019-1026

Author(s):

Dong Ji Xuan ◽

Zhen Zhe Li ◽

Tai Hong Cheng ◽

Yun De Shen

Keyword(s):

Fuel Cell ◽

Dynamic Model ◽

Output Power ◽

Power Efficiency ◽

Cell System ◽

Optimal Operation ◽

Maximum Output ◽

Fuel Cell System ◽

Operation Condition ◽

Stack Model

The output power efficiency of the fuel cell system depends on the anode pressure, cathode pressure, temperature, demanded current, air and hydrogen humidity. Thus, it is necessary to determine the optimal operation condition for maximum power efficiency. In this paper, we developed a dynamic model of fuel cell system which contains mass flow model, membrane hydration and electro-chemistry model. Experiments have been performed to evaluate the dynamical Polymer Electrolyte Membrane Fuel Cell (PEMFC) stack model. In order to determine the maximum output power and minimum use of hydrogen in a certain condition, response surface methodology optimization based on the proposed PEMFC stack model is presented. The results provide an effective method to optimize the operation condition under varied situations.

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Robust Optimal Operation of Two-Chamber Microbial Fuel Cell System Under Uncertainty: A Stochastic Simulation Based Multi-Objective Genetic Algorithm Approach

Fuel Cells ◽

10.1002/fuce.201200196 ◽

2013 ◽

Vol 13 (3) ◽

pp. 321-335 ◽

Cited By ~ 9

Author(s):

Y.-J. He ◽

Z.-F. Ma

Keyword(s):

Genetic Algorithm ◽

Fuel Cell ◽

Microbial Fuel Cell ◽

Stochastic Simulation ◽

Cell System ◽

Optimal Operation ◽

Fuel Cell System ◽

Multi Objective Genetic Algorithm ◽

Simulation Based ◽

Genetic Algorithm Approach

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Load Response Characteristics of the Proton Exchange Membrane Fuel Cell for Individual Cold-Region Houses

Journal of Fuel Cell Science and Technology ◽

10.1115/1.2744054 ◽

2008 ◽

Vol 5 (1) ◽

Author(s):

Shin’ya Obara

Keyword(s):

Fuel Cell ◽

Transient Response ◽

Energy Demand ◽

Cell System ◽

Proton Exchange ◽

Fuel Cell System ◽

Cold Region ◽

Response Characteristics ◽

Load Fluctuation ◽

Power Load

The power load pattern of an individual house is a set of loads that fluctuate rapidly. If it is controlled to follow a system at rapid load fluctuation, depending on the response characteristics of the system, the equipment may have poor power quality (voltage and frequency). When introducing a fuel cell system into a house, it is necessary to consider two transient response characteristics: electric power and heat power. Then, the details of the transient response characteristics of the fuel cell system composed from a reformer, a fuel cell, an inverter, a system interconnection device, etc., are investigated by experiment and numerical analysis. As a result, the control variables of the controllers and the relation to the response characteristics of the fuel cell system were clarified. Furthermore, the response characteristics of the system when accompanied by a load fluctuation of power were also clarified. The response characteristics when introducing the energy demand pattern of an individual cold-region house into a fuel cell system geothermal heat pump were analyzed. From this analysis result, the details of operation, including each auxiliary machine of the fuel cell system, were clarified.

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