Optimal operation region of super-high-speed electrical air compressor in fuel cell system for working stability under multiple-time scale excitation

Author(s):  
Donghai Hu ◽  
Wenshuo Hou ◽  
Leli Hu ◽  
Lei Yang ◽  
Qingqing Yang ◽  
...  
2021 ◽  
pp. 29-38
Author(s):  
Nabeel Ahsan ◽  
Mahrukh Mehmood ◽  
Asad A. Zaidi

This paper discusses different air management technologies for fuel cell systems. Two different types of compressors are analyzed for Proton-exchange membrane fuel cells (PEMFC). Some important criteria are analyzed thoroughly for the selection of turbo compressor among different types of compressors illustrated with the help of matrix representations. The impacts of various input parameters for Fuel Cell (FC) are also explained thoroughly. Later the numerical modeling of an automobile fuel cell system using a high speed turbo-compressor for air supply is explained. The numerical model incorporates the important input parameters related with air and hydrogen. It also performed energy and mass balances across different components such as pump, fan, heat-exchanger, air compressor and also keeps in consideration the pressure drop across the flow pipes and various mechanical parts. The model is solved to obtain the characteristics of the FC system at different operating conditions. Therefore, it can be concluded that the high speed turbo compressor with a turbo-expander can have significant effects on the overall system power and efficiency.


2001 ◽  
Author(s):  
Daisie D. Boettner ◽  
Gino Paganelli ◽  
Yann G. Guezennec ◽  
Giorgio Rizzoni ◽  
Michael J. Moran

Abstract This paper describes a Proton Exchange Membrane (PEM) fuel cell system model for automotive applications that includes an air compressor, cooling system, and other auxiliaries. The fuel cell system model has been integrated into a vehicle performance simulator that determines fuel economy and allows consideration of control strategies. Significant fuel cell system efficiency improvements may be possible through control of the air compressor and other auxiliaries. Fuel cell system efficiency results are presented for two limiting air compressor cases: ideal control and no control. Extension of the present analysis to hybrid configurations consisting of a fuel cell system and battery is currently under study.


Author(s):  
Anthony N. Zinn ◽  
Todd H. Gardner ◽  
David A. Berry ◽  
Robert E. James ◽  
Dushyant Shekhawat

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.


2010 ◽  
Vol 26-28 ◽  
pp. 1019-1026
Author(s):  
Dong Ji Xuan ◽  
Zhen Zhe Li ◽  
Tai Hong Cheng ◽  
Yun De Shen

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.


Author(s):  
Linfen Xing ◽  
Jianmei Feng ◽  
Zhilong He ◽  
Xueyuan Peng

The air compressor is a key component in the polymer electrolyte membrane (PEM) fuel cell system and its performance has great impact on the electric power output from the system. Here, analysis was conducted firstly on the Roots-type compressor with fixed internal compression based on the volume reduction created by helical rotors. The built-in volume ratio variations with the wrap angle and the lobe numbers were calculated and discussed. Then a prototype of the Roots-type air compressor with 6 lobes was developed according to the outcomes of the research. The volumetric and isentropic efficiency of the prototype were measured under the discharge pressures from 0.11 MPa to 0.25 MPa while the rotation speeds from 10000 to 14000 rpm. Under the design conditions, the volumetric efficiency and isentropic efficiency of the Roots-type air compressor were 75.8% and 53.9% respectively. It was concluded that this kind of Roots-type air compressor is especially suitable for the fuel cell systems applied in the range extended electric vehicles.


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