Novel In-Situ Laser Based Diagnostics for Measurement of Water Vapor and Carbon Dioxide Concentrations in the Gas Distribution Channels of a PEM Fuel Cell

Author(s):  
Derek E. Lambe ◽  
Kyle Seleski ◽  
Ranganathan Kumar ◽  
Saptarshi Basu

A novel method has been implemented for measuring the concentration of various gas species (water vapor, carbon dioxide) within fuel cell gas channels and other minichannel applications in a non-invasive manner through the use of tunable diode laser absorption spectroscopy (TDLAS). An optically accessible test cell has been designed to allow for the passage of 1–0.5 millimeter diameter laser beams along 12 mm-12 cm long flow paths, while also allowing for visual observation of the channels in order to detect the formation of liquid water. Concentrations of water vapor and carbon dioxide have been measured in situ within the test cell with a temporal resolution of 0.5 secs and 2.5 secs respectively. The technique is portable to high aspect ratio channels yielding concentration measurements of species over 1 mm long passages with an experimental uncertainty of 5%.

Author(s):  
Ritobrata Sur ◽  
Thomas J. Boucher ◽  
Michael W. Renfro ◽  
Baki M. Cetegen

A robust, accurate and fast in-situ sensor was developed for detection of water vapor partial pressure and temperature simultaneously at the anode and cathode channels of a PEM fuel cell. Tunable diode laser absorption spectroscopy (TDLAS) utilizing wavelength modulation (WMS) was employed for these measurements. This method determines the ratio of the second and first harmonics (2f/1f) of the spectroscopic absorption profile of water vapor by the aid of a software lock-in amplifier. Measurements were taken using a diode laser emitting around a wavelength of 1471 nm where the water vapor absorption exhibits significant sensitivity to partial pressure and temperature. Measurements of water vapor concentration and temperature in were taken at steady and dynamic operating conditions in the anode and cathode gas channels near the inlet and outlet ports of a serpentine channel PEM fuel cell with Nafion membrane of active area 50 cm2. Different load and inlet humidity conditions were tested to characterize the operation at different conditions. The partial pressure of water vapor increases towards the exit of both the gas channels, but the increase is found to be more significant on the cathode side. The dynamic operation of the fuel cell was also examined in this study as well as the simultaneous measurements at the anode and cathode gas channels.


2018 ◽  
pp. 193-206
Author(s):  
John R. B. Lighton

All analyzers have strengths and limitations that vary with the technology used, and directly affect their suitability for different types of metabolic rate measurement. It is important for researchers to become familiar with the characteristics of the analyzer(s) they are using. This chapter discusses the chief technologies utilized in aerial gas analyzers for O2, CO2, and water vapor, and their advantages, disadvantages, and operating characteristics. For oxygen analyzers, the single channel and differential heated zirconia cell, single channel and differential fuel cell, and paramagnetic types are described. For carbon dioxide analyzers, the single-wavelength and dual-wavelength nondispersive infrared types are discussed. For water vapor analyzers, the chilled-mirror, infrared and capacitive types are considered.


2007 ◽  
Vol 96 (7) ◽  
pp. 1776-1793 ◽  
Author(s):  
Henning Gieseler ◽  
William J. Kessler ◽  
Michael Finson ◽  
Steven J. Davis ◽  
Phillip A. Mulhall ◽  
...  

2020 ◽  
pp. 103114
Author(s):  
Shruti Ghanekar ◽  
Rajavasanth Rajasegar ◽  
Nicholas Traina ◽  
Constandinos Mitsingas ◽  
Richard M. Kesler ◽  
...  

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