scholarly journals An optimal coordinated proton exchange membrane fuel cell heat management method based on large-scale multi-agent deep reinforcement learning

2021 ◽  
Vol 7 ◽  
pp. 6054-6068
Author(s):  
Jiawen Li ◽  
Yaping Li ◽  
Tao Yu
Author(s):  
Shashank Sharma ◽  
Mayank Gupta ◽  
Shaswat Anand ◽  
Naveen Kumar

The high costs associated with fuel cell manufacturing have precluded its production on a large scale. The major emphasis of the present wok is to bring down the overall cost of an independent fuel cell unit. The manufacturing cost can be reduced using commonly available and corrosion resistant materials into the fuel cell assembly. Bipolar plates usually employed in proton exchange membrane fuel cells are fabricated from conducting graphite. Graphite owing to its conductivity, corrosion resistance and easy machinability, is the preferred material in static systems. However, due to its brittle characteristics and failure under bending loads, graphite is inferior in its mechanical properties as compared to metals and their alloys. Dimensional stability is also compromised due to wear and friction. In the present work, an attempt is made to assemble a fuel cell stack which would have durability and sustainability in dynamic conditions, where the setup would be able to withstand periodic shocks, vibrations, and fatigue loads. Instead of employing graphite as the bipolar plate which serves the dual purpose of a current collector and area for flow fields, graphite foil protected aluminum as the current collector and machined plastic slabs on which the flow fields are carved, have been employed. Both the substitutes are easily available owing to mass production and have a small processing cost associated with them. Further, the technique employed for processing of Nafion and hot pressing of the catalyst loaded gas diffusion layer onto the proton exchange membrane have been elaborated in the present paper along with the systematic approach followed by the research group eliminating various current collector candidates for fuel cell applications. The various stages attained towards the final fabrication of the foil protected lightweight current collector, has also been highlighted in the present work.


Author(s):  
Nana Zhao ◽  
Zhong Xie ◽  
Zhiqing Shi

Durability and cost are the two major factors limiting the large-scale implementation of fuel cell technology for use in commercial, residential, or transportation applications. The conditioning cost is usually negligible for making proton exchange membrane fuel cells (PEMFCs) at R&D or demo stage with several tens of stacks each year. However, with industry's focus shifting from component development to commercial high-volume manufacturing, the conditioning process requires significant additional capital investments and operating costs, thus becomes one of the bottlenecks for PEMFC manufacturing, particularly at a high production volume (>1000 stack/year). To understand the mechanisms behind PEMFC conditioning, and to potentially reduce conditioning time or even to eliminate the conditioning process, the conditioning behaviors of commercial Nafion™ XL100 and Nafion® NRE 211 membranes were studied. The potential effects of the membrane additive on fuel cell conditioning were diagnosed using in situ electrochemical impedance spectroscopy (EIS). It was found that the membrane additive led to the significant variation of the charge transfer resistance in EIS during conditioning, which affected the conditioning behavior of the membrane electrode assembly (MEA).


Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 366
Author(s):  
Mylène Robert ◽  
Assma El Kaddouri ◽  
Jean-Christophe Perrin ◽  
Kévin Mozet ◽  
Jérôme Dillet ◽  
...  

A proton-exchange membrane fuel cell (PEMFC) constitutes today one of the preferred technologies to promote hydrogen-based alternative energies. However, the large-scale deployment of PEMFCs is still hampered by insufficient durability and reliability. In particular, the degradation of the polyelectrolyte membrane, caused by harsh mechanical and chemical stresses experienced during fuel cell operation, has been identified as one of the main factors restricting the PEMFC lifetime. An innovative chemical-mechanical ex situ aging device was developed to simultaneously expose the membrane to mechanical fatigue and an oxidizing environment (i.e., free radicals) in order to reproduce conditions close to those encountered in fuel cell systems. A cyclic compressive stress of 5 or 10 MPa was applied during several hours while a degrading solution (H2O2 or a Fenton solution) was circulated in contact with the membrane. The results demonstrated that both composite Nafion™ XL and non-reinforced Nafion™ NR211 membranes are significantly degraded by the conjoint mechanical and chemical stress exposure. The fluoride emission rate (FER) was generally slightly lower with XL than with NR211, which could be attributed to the degradation mitigation strategies developed for composite XL, except when the pressure level or the aging duration were increased, suggesting a limitation of the improved durability of XL.


Author(s):  
Tiancai Ma ◽  
Zhaoli Zhang ◽  
Weikang Lin ◽  
Yanbo Yang ◽  
Naiyuan Yao

Abstract Reliability and durability are the main factors that hinder the large scale commercialization of proton exchange membrane fuel cell. Water management is the key to solve such problems, and water content is the measurement standard of water management. But it is very difficult to measure water content inside the fuel cell directly. Thus, water fault diagnosis is a basic and hots technology to monitor the water content indirectly based on the measurable parameters. In this paper, the water fault diagnosis of the proton exchange membrane fuel cell system has been summarized in four sections including the analytical model method, knowledge based method, signal processing method and electrochemical method from practical application, and part of them is from the perspective of vehicle application.


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