Determination of optimal operation plans of fuel cell system in residential house with PV system

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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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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