Effects of Working Fluids on the Performance of a Roots Pump for Hydrogen Recirculation in a PEM Fuel Cell System

In this paper, the performance of a Roots pump for hydrogen recirculation in proton exchange membrane (PEM) fuel cell system is simulated based on CFD modeling. The Roots pump is in a three-lobe configuration with helical rotors, and it is developed specifically for fuel cell systems between 60 to 110 kW. A three-dimensional model of the Roots pump is established to predict the pump performance, including the flow rate and power consumption under various operating conditions. Extensive simulations were conducted and then verified experimentally by operating with working fluids of air and helium. Based on the validated CFD model, the contents of water vapor and nitrogen in the hydrogen recirculated are taken into account to evaluate the Roots pump performance numerically according to the actual conditions of the recirculating hydrogen at the stack outlet. It is shown that the volumetric efficiency and isentropic efficiency are improved with the increase fraction of water vapor and nitrogen. It is found that the performance of the Roots pump integrated in the PEM fuel cell system is between the performance of the pump working with air and helium. Finally, correlations of volumetric efficiency and isentropic efficiency are given based on the CFD results to show the general pattern of this kind of hydrogen pump. It is believed that these equations are very helpful to the design and operation control of the PEM fuel cell system.

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Theoretical Analysis on the Autothermal Reforming Process of Ethanol as Fuel for a Proton Exchange Membrane Fuel Cell System

Journal of Fuel Cell Science and Technology ◽

10.1115/1.2756844 ◽

2006 ◽

Vol 4 (4) ◽

pp. 468-473 ◽

Cited By ~ 11

Author(s):

Alessandra Perna

Keyword(s):

Fuel Cell ◽

Proton Exchange Membrane ◽

Pem Fuel Cell ◽

Cell System ◽

Autothermal Reforming ◽

Proton Exchange ◽

Operating Conditions ◽

Hydrogen Yield ◽

Fuel Cell System ◽

Exchange Membrane

The purpose of this work is to investigate, by a thermodynamic analysis, the effects of the process variables on the performance of an autothermal reforming (ATR)-based fuel processor, operating on ethanol as fuel, integrated into an overall proton exchange membrane (PEM) fuel cell system. This analysis has been carried out finding the better operating conditions to maximize hydrogen yield and to minimize CO carbon monoxide production. In order to evaluate the overall efficiency of the system, PEM fuel cell operations have been analyzed by an available parametric model.

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Optimization of a PEM Fuel Cell System for Low-Speed Hybrid Electric Vehicles

Volume 1: 32nd Design Automation Conference, Parts A and B ◽

10.1115/detc2006-99606 ◽

2006 ◽

Cited By ~ 2

Author(s):

Jeffrey D. Wishart ◽

Zuomin Dong ◽

Marc M. Secanell

Keyword(s):

Fuel Cell ◽

Pem Fuel Cell ◽

Load Cycle ◽

Cell System ◽

Operating Conditions ◽

System Model ◽

Fuel Cell System ◽

Vehicle Model ◽

Low Speed ◽

Stack Model

Design optimization is performed by presenting a systematic method to obtain the optimal operating conditions of a Proton Exchange Membrane (PEM) fuel cell system targeted towards a vehicular application. The fuel cell stack model is a modified version of the semi-empirical model introduced by researchers at the Royal Military College of Canada and one that is widely used by industry. Empirical data obtained from tests of PEM fuel cell stacks are used to determine the empirical parameters of the fuel cell performance model. Based on this stack model, a fuel cell system model is built in MATLAB. Included in the system model are heat transfer and gas flow considerations and the associated Balance of Plant (BOP) components. The modified ADVISOR vehicle simulation tool is used to integrate the New York City Cycle (NYCC) drive cycle and vehicle model to determine the power requirements and hence the load cycle of the fuel cell system for a low-speed fuel cell hybrid electric vehicle (LSFCHEV). The optimization of the powerplant of this vehicle type is unique. The vehicle model has been developed in the work to describe the characteristics and performance of an electric scooter, a simple low-speed vehicle (LSV). The net output power and system exergetic efficiency of the system are maximized for various system operating conditions using the weighted objective function based on the load cycle requirement. The method is based on the coupling of the fuel cell system model with three optimization algorithms (a) sequential quadratic programming (SQP); (b) simulated annealing (SA); and (c) genetic algorithm (GA). The results of the optimization provide useful information that will be used in future study on control algorithms for LSFCHEVs. This study facilitates research on more complex fuel cell system modeling and optimization, and provides a basis for experimentation to verify the fuel cell system model.

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Machine Learning Approach for Modeling and Control of a Commercial Heliocentris FC50 PEM Fuel Cell System

Mathematics ◽

10.3390/math9172068 ◽

2021 ◽

Vol 9 (17) ◽

pp. 2068

Author(s):

Mohamed Derbeli ◽

Cristian Napole ◽

Oscar Barambones

Keyword(s):

Machine Learning ◽

Fuel Cell ◽

Pem Fuel Cell ◽

Cell System ◽

Operating Conditions ◽

Effect Of Temperature ◽

Fuel Cell System ◽

Wide Range ◽

Temperature And Humidity ◽

Predicted Model

In recent years, machine learning (ML) has received growing attention and it has been used in a wide range of applications. However, the ML application in renewable energies systems such as fuel cells is still limited. In this paper, a prognostic framework based on artificial neural network (ANN) is designed to predict the performance of proton exchange membrane (PEM) fuel cell system, aiming to investigate the effect of temperature and humidity on the stack characteristics and on tracking control improvements. A large part of the experimental database for various operating conditions has been used in the training operation to achieve an accurate model. Extensive tests with various ANN parameters such as number of neurons, number of hidden layers, selection of training dataset, etc., are performed to obtain the best fit in terms of prediction accuracy. The effect of temperature and humidity based on the predicted model are investigated and compared to the ones obtained from real-time experiments. The control design based on the predicted model is performed to keep the stack operating point at an adequate power stage with high-performance tracking. Experimental results have demonstrated the effectiveness of the proposed model for performance improvements of PEM fuel cell system.

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Numerical investigation into effects of ejector geometry and operating conditions on hydrogen recirculation ratio in 80 kW PEM fuel cell system

Energy ◽

10.1016/j.energy.2021.121100 ◽

2021 ◽

pp. 121100

Author(s):

Jenn-Kun Kuo ◽

Chun-Yao Hsieh

Keyword(s):

Fuel Cell ◽

Numerical Investigation ◽

Pem Fuel Cell ◽

Cell System ◽

Operating Conditions ◽

Fuel Cell System

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PEM Fuel Cell Electrodes Surface Defects Impact on the System Performance

Volume 8: Energy ◽

10.1115/imece2020-23920 ◽

2020 ◽

Author(s):

Victor M. Fontalvo ◽

Danny Illera ◽

Marco E. Sanjuan ◽

Humberto A. Gomez

Keyword(s):

Fuel Cell ◽

Dynamic System ◽

Pem Fuel Cell ◽

Gas Diffusion ◽

Cell System ◽

Operating Conditions ◽

System Response ◽

Fuel Cell System ◽

Free Process ◽

The Impact

Abstract Fuel cell system manufacturing process is not a defect-free process, therefore, the impact of typical defects in the electrodes (i.e. Gas Diffusion Layer (GDL)) surface has to be taken into consideration when the fuel cell system is being designed. To assess the impact of the defect on the performance, two approaches were taken into consideration. Initially, the fuel cell system was simulated using a unidimensional (1D) dynamic model which took into consideration mass transfer, heat transfer, and electrochemical phenomena. The second approach was experimental, using a 5 sq.cm PEM fuel cell, the impact of the GDL porosity on the fuel cell system was studied. Also, the system response under different load changes was investigated. After that, experimental results are presented to give a better insight into the phenomena analyzed, mainly on the dynamic system response. Cracks and catalyst clusters were the main defects analyzed, both of them were observed in new membranes assemblies. To control the defects, new membranes assemblies were tested, and after that, defects were induced using Nafion solution and catalyst powder to emulate the presence of catalyst clusters. For the cracks, some fibers in the GDL cloth were cut to emulate the defect. Membranes now with defects were tested again to compare its performance and detect any performance loss due to the physical changes in the electrodes. Results indicate a strong correlation between the porosity and the supply air pressure and the system time constants. Also, the impact of the defects was evidenced in the dynamic system response, after step changes in the operating conditions.

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