Moisture is a crucial factor in the durability and performance of proton exchange membrane fuel cells, frequently managed with external humidification of reactant gases. Membrane humidifiers have been utilized to maintain proper water content levels of cathode air in vehicular fuel cell systems, avoiding fuel cell operation limits, especially in high temperature conditions.
Since the precise measurement of hollow fiber membrane performance ensures the design capability of the shell-tube membrane humidifier, it is necessary to understand the measurement uncertainty of vapor transport through the hollow fiber membrane. In this study, the uncertainty of the water vapor transport rate is analyzed with experimental data. Parametric investigation of vapor transport was carried out with isothermal conditions and variation of operating parameters including temperature, pressure, and inlet relative humidity. The vapor transport is presented by the vapor transfer rate from the wet air to the dry air through the membrane, which is affected by the sensitivity of the foregoing operating parameters and the reliability of sensors. The reliable data of humidifier performance is of vital importance in fuel cell system optimization. Therefore, the uncertainty analysis of individual parameters and the vapor transfer rate was conducted to confirm the reliability of vapor transport experiments.