This book focuses on water content estimation and control of the PEM fuel cell stack and the individual cell in vehicle. Firstly, the mathematical connection between polarization curve and equivalent circuit model proves importance of MEA and its feasibility to study water content. Optimizing structure of MEA realizes the internal water content recirculation of a fuel cell and improves its performance under middle or lower current density. The influence of water content on performance of MEA is quantified, and variation of equivalent circuit model is an excellent indicator of water content. Secondly, the comprehensive online AC impedance measurement method is put forward, including current excitation method, weak voltage and current signal processing method, and method for analyzing measurement error, and experiment validates measurement accuracy. The high-frequency impedance and statistical characteristic are proposed as indicator of water content. Finally, the dynamic model of the air supply system of a fuel cell engine is established and the closed-loop control of the air supply system and the water content estimation are decoupled. The experiment on a fuel cell system validates the proposed method for searching optimized operating conditions and the water management strategy.

Sliding-mode Control of PEM Fuel Cells demonstrates the application of higher-order sliding-mode control to PEMFC dynamics showing the advantages of sliding modes. The book introduces the theory of fuel cells and sliding-mode control. It contextualises PEMFCs both in terms of their development and within the hydrogen economy and today’s energy production situation as a whole. It then discusses fuel-cell operation principles, the mathematical background of high-order sliding-mode control and to a feasibility study for the use of sliding modes in the control of an automotive fuel stack. Part II presents experimental results of sliding-mode-control application to laboratory fuel cells and deals with subsystem-based modelling, detailed design, and observability and controllability. Simulation results are contrasted with empirical data and performance, robustness and implementation issues are treated in depth. Possibilities for future research are also laid out.

Water and Thermal Management of Proton Exchange Membrane Fuel Cells introduces the main research methods and latest advances in the water and thermal management of PEMFCs. The book introduces the transport mechanism of each component, including modeling methods at different scales, along with practical exercises. Topics include PEMFC fundamentals, working principles and transport mechanisms, characterization tests and diagnostic analysis, the simulation of multiphase transport and electrode kinetics, cell-scale modeling, stack-scale modeling, and system-scale modeling. This volume offers a practical handbook for researchers, students and engineers in the fields of proton exchange membrane fuel cells. Proton exchange membrane fuel cells (PEMFCs) are high-efficiency and low-emission electrochemical energy conversion devices. Inside the PEMFC complex, physical and chemical processes take place, such as electrochemical reaction, multiphase flow and heat transfer. This book explores these topics, and more. - Introduces the transport mechanism for each component of PEMFCs - Presents modeling methods at different scales, including component, cell, stack and system scales - Provides exercises in PEMFC modeling, along with examples of necessary codes - Covers the latest advances in PEMFCs in a convenient and structured manner - Offers a solution to researchers, students and engineers working on proton exchange membrane fuel cells

The fuel cell is a potential candidate for energy storage and conversion in our future energy mix. It is able to directly convert the chemical energy stored in fuel (e.g. hydrogen) into electricity, without undergoing different intermediary conversion steps. In the field of mobile and stationary applications, it is considered to be one of the future energy solutions. Among the different fuel cell types, the proton exchange membrane (PEM) fuel cell has shown great potential in mobile applications, due to its low operating temperature, solid-state electrolyte and compactness. This book presents a detailed state of art of PEM fuel cell modeling, with very detailed physical phenomena equations in different physical domains. Examples and a fully coupled multi-physical 1.2 kW PEMFC model are given help the reader better understand how to use the equations.

Polymer Electrolyte Membrane (PEM) fuel cells convert chemical energy in hydrogen into electrical energy with water as the only by-product. Thus, PEM fuel cells hold great promise to reduce both pollutant emissions and dependency on fossil fuels, especially for transportation—passenger cars, utility vehicles, and buses—and small-scale stationary and portable power generators. But one of the greatest challenges to realizing the high efficiency and zero emissions potential of PEM fuel cells technology is heat and water management. This book provides an introduction to the essential concepts for effective thermal and water management in PEM fuel cells and an assessment on the current status of fundamental research in this field. The book offers you: • An overview of current energy and environmental challenges and their imperatives for the development of renewable energy resources, including discussion of the role of PEM fuel cells in addressing these issues; • Reviews of basic principles pertaining to PEM fuel cells, including thermodynamics, electrochemical reaction kinetics, flow, heat and mass transfer; and • Descriptions and discussions of water transport and management within a PEM fuel cell, including vapor- and liquid-phase water removal from the electrodes, the effects of two-phase flow, and solid water or ice dynamics and removal, particularly the specialized case of starting a PEM fuel cell at sub-freezing temperatures (cold start) and the various processes related to ice formation.

Publishes theoretical and applied original papers in dynamic systems. Theoretical papers present new theoretical developments and knowledge for controls of dynamical systems together with clear engineering motivation for the new theory. Applied papers include modeling, simulation, and corroboration of theory with emphasis on demonstrated practicality.

Understand, Select, and Design Sensors for Hydrogen-Based Applications The use of hydrogen generated from renewable energy sources is expected to become an essential component of a low-carbon, environmentally friendly energy supply, spurring the worldwide development of hydrogen technologies. Sensors for Safety and Process Control in Hydrogen Technologies provides practical, expert-driven information on modern sensors for hydrogen and other gases as well as physical parameters essential for safety and process control in hydrogen technologies. It illustrates how sensing technologies can ensure the safe and efficient implementation of the emerging global hydrogen market. The book explains the various facets of sensor technologies, including practical aspects relevant in hydrogen technologies. It presents a comprehensive and up-to-date account of the theory (physical and chemical principles), design, and implementations of sensors in hydrogen technologies. The authors also offer guidance on the development of new sensors based on the analysis of the capabilities and limitations of existing sensors with respect to current performance requirements. Suitable for both technical and non-technical personnel, the book provides a balance between detailed descriptions and simple explanations. It gives invaluable insight into the role sensors play as key enabling devices for both control and safety in established and emerging hydrogen technologies.

Demand for fuel cell technology is growing rapidly. Fuel cells are being commercialized to provide power to buildings like hospitals and schools, to replace batteries in portable electronic devices, and as replacements for internal combustion engines in vehicles. PEM (Proton Exchange Membrane) fuel cells are lighter, smaller, and more efficient than other types of fuel cell. As a result, over 80% of fuel cells being produced today are PEM cells. This new edition of Dr. Barbir's groundbreaking book still lays the groundwork for engineers, technicians and students better than any other resource, covering fundamentals of design, electrochemistry, heat and mass transport, as well as providing the context of system design and applications. Yet it now also provides invaluable information on the latest advances in modeling, diagnostics, materials, and components, along with an updated chapter on the evolving applications areas wherein PEM cells are being deployed. Comprehensive guide covers all aspects of PEM fuel cells, from theory and fundamentals to practical applications Provides solutions to heat and water management problems engineers must face when designing and implementing PEM fuel cells in systems Hundreds of original illustrations, real-life engineering examples, and end-of-chapter problems help clarify, contextualize, and aid understanding

Proper water management is vital to guarantee achieving maximum performance and durability of proton exchange membrane (PEM) fuel cell. Therefore, how to maintain the delicate balance between membrane hydration and avoid water flooding has become principle goal to develop strategies for proper water management. Two methods of water management were introduced in this work, which including of operational control and sequential exhaust control. These methods of water management have been already performed in the conventional PEM fuel cell stack. However, there was less report of using them for the strip cell stack configuration. Since there are many advantages of direct visualization technique and also the strip cell stack in this work was assembled in the transparent configuration. The interesting phenomena inside the stack cell on both anode and cathode side can be revealed, directly. Therefore, this book will provide the additional informantion of the fundamental knowledge of water management and also be critical to understand for the water dynamic behavior inside the PEM fuel cell stack.