Galip Guvelioglu - Academia.edu (original) (raw)

Galip Guvelioglu

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Papers by Galip Guvelioglu

Research paper thumbnail of Flow rate and humidification effects on a PEM fuel cell performance and operation

Journal of Power Sources, 2007

A new algorithm is presented to integrate component balances along polymer electrolyte membrane f... more A new algorithm is presented to integrate component balances along polymer electrolyte membrane fuel cell (PEMFC) channels to obtain three-dimensional results from a detailed two-dimensional finite element model. The analysis studies the cell performance at various hydrogen flow rates, air flow rates and humidification levels. This analysis shows that hydrogen and air flow rates and their relative humidity are critical to current density, membrane dry-out, and electrode flooding. Uniform current densities along the channels are known to be critical for thermal management and fuel cell life. This approach, of integrating a detailed two-dimensional across-the-channel model, is a promising method for fuel cell design due to its low computational cost compared to three-dimensional computational fluid dynamics models, its applicability to a wide range of fuel cell designs, and its ease of extending to fuel cell stack models.

Research paper thumbnail of Oxygen supply for oxyfuel CO2 capture

International Journal of Greenhouse Gas Control, 2011

This paper presents the results of a study to develop Air Products' air separation unit (ASU) off... more This paper presents the results of a study to develop Air Products' air separation unit (ASU) offerings for oxyfuel coal CO 2 capture projects. A scalable "reference plant" concept is described to match particular sizes of power generation equipment, taking into account factors such as safety, reliability, operating flexibility, efficiency, and low capital cost. We describe the selection of a process cycle to exploit the low purity requirements, as well as the options for compression machinery and drivers as the scale of the plant increases and the sizes of referenced equipment limit the possibilities. We also explore integration with other elements of the system, such as preheating condensate or heating and expanding pressurised nitrogen. In addition, we consider how the ASU affects the flexibility of the oxyfuel system and discuss how its power consumption can be reduced during periods of high power demand. Finally, the advantages and disadvantages of different execution strategies for air separation unit projects are discussed, as well as alternative commercial models for the supply of oxygen. (P. Higginbotham). commercial plants both in technology selection and execution strategy to provide the most benefit to future projects.

Research paper thumbnail of Flow rate and humidification effects on a PEM fuel cell performance and operation

Journal of Power Sources, 2007

A new algorithm is presented to integrate component balances along polymer electrolyte membrane f... more A new algorithm is presented to integrate component balances along polymer electrolyte membrane fuel cell (PEMFC) channels to obtain three-dimensional results from a detailed two-dimensional finite element model. The analysis studies the cell performance at various hydrogen flow rates, air flow rates and humidification levels. This analysis shows that hydrogen and air flow rates and their relative humidity are critical to current density, membrane dry-out, and electrode flooding. Uniform current densities along the channels are known to be critical for thermal management and fuel cell life. This approach, of integrating a detailed two-dimensional across-the-channel model, is a promising method for fuel cell design due to its low computational cost compared to three-dimensional computational fluid dynamics models, its applicability to a wide range of fuel cell designs, and its ease of extending to fuel cell stack models.

Research paper thumbnail of Oxygen supply for oxyfuel CO2 capture

International Journal of Greenhouse Gas Control, 2011

This paper presents the results of a study to develop Air Products' air separation unit (ASU) off... more This paper presents the results of a study to develop Air Products' air separation unit (ASU) offerings for oxyfuel coal CO 2 capture projects. A scalable "reference plant" concept is described to match particular sizes of power generation equipment, taking into account factors such as safety, reliability, operating flexibility, efficiency, and low capital cost. We describe the selection of a process cycle to exploit the low purity requirements, as well as the options for compression machinery and drivers as the scale of the plant increases and the sizes of referenced equipment limit the possibilities. We also explore integration with other elements of the system, such as preheating condensate or heating and expanding pressurised nitrogen. In addition, we consider how the ASU affects the flexibility of the oxyfuel system and discuss how its power consumption can be reduced during periods of high power demand. Finally, the advantages and disadvantages of different execution strategies for air separation unit projects are discussed, as well as alternative commercial models for the supply of oxygen. (P. Higginbotham). commercial plants both in technology selection and execution strategy to provide the most benefit to future projects.

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