Stack Engineering

Doyon J etal, 2003, The DirectFuel Cell stack engineering./owmit/ of Power Sources, 118, 8-13. 

Upgrade Blowdown Stacks Engineering complexity Regulatory requirements No emission banking Benzene exposure reduction... 

Correspondingly, in state-of-the-art PEFC stacks, the poly(PFSA) membranes employed are typically 20-50 pm thick and, while requiring more care in handling and in stack engineering, such very thin... 

A mathematical model will generally be required to interpret activation and concentration polarization data and translate it into data useful for stack engineers. 

Much of the single-cell data presented and published is taken at finite utilization. While useful for qualitative comparisons between cells, this data is generally not usable for further stack engineering. 

For MEA designers or fuel cell stack engineers, a polarization curve is an immensely useful practical analysis tool. It allows for a comparative assessment of sources of voltage losses in the cell, fuel cell failure modes, critical or limiting current densities, as well as impacts of degradation and water management. For materials scientists, the polarization curve entails useful information on performance effects... 

Doyon, J., Farooque, M. and Mara, H. The Direct FuelCell Stack Engineering , Journal of Power Sources, 5195 (2003) 1-6. 

The literature does not comprise many experimental data to test first the relevance of the assumptions, and then calibrate the models. Despite the importance of confidentiality issues in electrode and stack engineering, massive efforts on such tasks are needed to propose general modelling frameworks. 

Siemens AG has been involved in R D on PFFCs, and Vickers Shipbuilding Engineering Ltd. (United Kingdom) is evaluating PFFCs from Ballard Power Systems for power generation. A 35-ceU stack was successfully tested for more than 300 h. Plans are under way to test a 20-kW PEFC. 

R. S. Saltzman, Challenges in Stack Sulfur Emissions Measurements, paper presented at 30th Annual Petroleum Mechanical Engineering Conference, Tulsa, OHa., Sept. 21-25,1975. 

H. G. Rigo, A. J. Chandler, and W. S. Lanier, The Relationship Between Chlorine in Waste Streams and Dioxin Emissions From Waste Combustor Stacks, The American Society of Mechanical Engineers, New York, 1995. 

Kister, H. Z., K. F. Larson and T. Yanagi, How Do Trays and Packing Stack Up Chemical Engineering Progress, February 1994. 

Mists and Sprays - There are numerous industrial chemical operations which involve liquid-in-gas dispersions. These operations generate mists and sprays that consist of particles in diameter ranges of 0.1 to 5,000 fim. Engineers most commonly encounter spray droplets which are particles often formed unintentionally in chemical plant operations. For example, vapors or fumes may condense onto piping, ducts, or stack walls. Under such conditions liquid films form. 

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