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effect of pulsing the oxidant flow on PEM fuel cell performance
Title
The effect of pulsing the oxidant flow on PEM fuel cell performance.
Creator
Fuchs, Michel., Florida Atlantic University, Abtahi, Homayoon
Abstract/Description
Verification of a numerical model, used to describe the processes within a PEM Fuel Cell, revealed interesting results in the fuel cell's performance. To verify the transient response of the model, the oxidant supplied to the fuel cell was pulsed at various frequencies, which led to improvements in performance. In addition two novel methods to help determine the operating conditions within a PEM Fuel Cell were developed. The first method utilized several thermocouples, evenly spaced over the...
Show moreVerification of a numerical model, used to describe the processes within a PEM Fuel Cell, revealed interesting results in the fuel cell's performance. To verify the transient response of the model, the oxidant supplied to the fuel cell was pulsed at various frequencies, which led to improvements in performance. In addition two novel methods to help determine the operating conditions within a PEM Fuel Cell were developed. The first method utilized several thermocouples, evenly spaced over the site of reaction to monitor regional temperatures, while the second method utilized a special sensor to detect regional moisture conditions. All aspects of the verification process met with limited success, since the proper level of humidification to the fuel cell was not achieved.
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Date Issued
1998
PURL
http://purl.flvc.org/fcla/dt/15595
Subject Headings
Fuel cells
Format
Document (PDF)
Study of high temperature PEM fuel cell (HT-PEMFC) waste heat recovery through ejector based refrigeration
Title
Study of high temperature PEM fuel cell (HT-PEMFC) waste heat recovery through ejector based refrigeration.
Creator
Fuchs, Michel., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The incorporation of an ejector refrigeration cycle with a high temperature PEM fuel cell (HT-PEMFC) presents a novel approach to combined heat and power (CHP) applications. An ejector refrigeration system (ERS) can enhance the flexibility of a CHP system by providing an additional means of utilizing the fuel cell waste heat besides domestic hot water (DHW) heating. This study looks into the performance gains that can be attained by incorporating ejector refrigeration with HT-PEMFC micro-CHP ...
Show moreThe incorporation of an ejector refrigeration cycle with a high temperature PEM fuel cell (HT-PEMFC) presents a novel approach to combined heat and power (CHP) applications. An ejector refrigeration system (ERS) can enhance the flexibility of a CHP system by providing an additional means of utilizing the fuel cell waste heat besides domestic hot water (DHW) heating. This study looks into the performance gains that can be attained by incorporating ejector refrigeration with HT-PEMFC micro-CHP (mCHP) systems (1 to 5kWe). The effectiveness of the ERS in utilizing fuel cell waste heat is studied as is the relulting enhancement to overall system efficiency. A test rig specially constructed to evaluate an ERS under simulated HT-PEMFC conditions is used to test the concept and verify modeling predictions. In addition, two separate analytical models were constructed to simulate the ERS test rig and a HT-PEMFC/ERS mCHP system. The ERS test rig was simulated using a Matlab based model, while two residential sized HT-PEMFC/ERS mCHP systems were simulated using a Simulink model. Using U.S. Energy Information Administration (EIA) air conditioning and DHW load profiles, as well as data collected from a large residential monitoring study in Florida, the Simulink model provides the results in system efficiency gain associated with supporting residential space cooling and water heating loads. It was found that incorporation of an ERS increased the efficiency of a HT-PEMFC mCHP system by 8 t0 10 percentage points over just using the fuel cell waste heat for DHW. In addition, results from the Matlab ERS test rig model were shown to match well with experimental results.
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Date Issued
2012
PURL
http://purl.flvc.org/FAU/3355557
Subject Headings
Proton exchange membrane fuel cells, Fuel cells, Mathematical models, Heat exchangers, Design and construction, Renewable energy sources
Format
Document (PDF)