https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1131&context=usdoepub

A review of polymer electrolyte membrane fuel cells: Technology, applications,and needs on fundamental research

This paper reviews the development of clean vehicles, including pure electric vehicles (EVs), hybrid electric vehicles (HEVs) and fuel cell electric vehicles (FCEVs), and high energy power batteries, such as nickel metal hydride (Ni-MH), lithium-ion (Li-ion) and proton exchange membrane fuel cells (PEMFCs). The mathematical models and thermal behavior of the batteries are described. Details of various thermal management techniques, especially the PCMs battery thermal management system and the materials thermal conductivity, are discussed and compared. It is concluded that the EVs, HEVs and FCEVs are effective to reduce GHG and pollutants emission and save energy. At stressful and abuse conditions, especially at high discharge rates and at high operating or ambient temperatures, traditional battery thermal energy management systems, such as air and liquid, may be not meeting the requirements. Pulsating heat pipe may be more effective but needs to be well designed. In addition, progress in developing new high temperature material is very difficult. PCM for battery thermal management is a better selection than others. Nevertheless, thermal conductivity of the PCMs such as paraffin is low and some methods are adopted to enhance the heat transfer of the PCMs. The performance and thermo-mechanical behaviors of the improved PCMs in the battery thermal management system need to be investigated experimentally. And the possibility of the heat collection and recycling needs to be discussed in terms of energy saving and efficient.

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A review of power battery thermal energy management

Water transport in polymer electrolyte membrane fuel cells

Spark ignition natural gas engines—A review

Background There are wide variations in the clinical use of cryotherapy, and guidelines continue to be made on an empirical basis. Study Design Systematic review assessing the evidence base for cryotherapy in the treatment of acute soft-tissue injuries. Methods A computerized literature search, citation tracking, and hand searching were carried out up to April 2002. Eligible studies were randomized-controlled trials describing human subjects recovering from acute soft-tissue injuries and employing a cryotherapy treatment in isolation or in combination with other therapies. Two reviewers independently assessed the validity of included trials using the Physiotherapy Evidence Database (PEDro) scale. Results Twenty-two trials met the inclusion criteria. There was a mean PEDro score of 3.4 out of of 10. There was marginal evidence that ice plus exercise is most effective, after ankle sprain and postsurgery. There was little evidence to suggest that the addition of ice to compression had any significant effect, but this was restricted to treatment of hospital inpatients. Few studies assessed the effectiveness of ice on closed soft-tissue injury, and there was no evidence of an optimal mode or duration of treatment. Conclusion Many more high-quality trials are needed to provide evidence-based guidelines in the treatment of acute soft-tissue injuries.

The use of ice in the treatment of acute soft tissue injury: A systematic review of randomized controlled trials.

Water behavior in serpentine micro-channel for proton exchange membrane fuel cell cathode

Water and thermal management for Ballard PEM fuel cell stack

Characteristics and structure of nominally non-premixed flames of natural gas are investigated using a burner that employs simultaneously two distinct features: fuel and oxidiser direct injection, and inverse fuel and oxidiser delivery. At low exit velocities, the result is an inverse diffusion flame that has been noted in the past for its low NOx emissions, soot luminosity, and narrow stability limits. The present study aimed at extending the burner operating range, and it demonstrated that the inverse flame exhibits a varying degree of partial premixing dependent on the discharge nozzle conditions and the ratio of inner air jet and outer fuel jet velocities. These two variables affect the flame length, temperature distributions, and stability limits. Temperature measurements and Schlieren visualisation show areas of enhanced turbulent mixing in the shear region and the presence of a well-mixed reaction zone on the flame centreline. This reaction zone is enveloped by an outer diffusion flame, yielding a unique double-flame structure. As the fuel–air equivalence ratio is decreasing with an increase in the inner jet velocity, the well-mixed reaction zone extends considerably. These findings suggest a method for establishing a flame of uniform high temperature by optimising the coaxial nozzle geometry and flow conditions. The normalised flame length is decreasing exponentially with the air/fuel velocity ratio. Measurements demonstrate that the inverse flame stability limits change qualitatively with varying degree of partial premixing. At the low premixing level, the flame blow-out is a function of the inner and outer jet velocities and the nozzle conditions. The flame blow-out at high degree of partial premixing occurs abruptly at a single value of the inner air jet velocity, regardless of the fuel jet velocity and almost independent of the discharge nozzle conditions.

Andrzej Sobiesiak

Papers

Water behavior in serpentine micro-channel for proton exchange membrane fuel cell cathode

Water and thermal management for Ballard PEM fuel cell stack

Characteristics and structure of inverse flames of natural gas

Water and thermal management in a single PEM fuel cell with non-uniform stack temperature

Water and pressure effects on a single PEM fuel cell