Transport Properties of Hydrogen-Water Vapor Mixture in Fuel Cell Systems

摘要

Knowledge of the transport property of viscosity and thermal conductivity of a hydrogen-water vapor mixture is very important in solving today's engineering problems in fuel cell applications. The properties may be conveniently represented as a function of the quantity of moisture by weight in grams of water per kilogram of dry hydrogen. Values of viscosity and thermal conductivity are calculated for constant pressures of 0.1 MPa, 0.5 MPa and 1 MPa, respectively, on the basis of the equations of state of real gases in the temperature range from 340 K to 500 K and in the range of water vapor concentrations from 10 g H_2O/kg dry hydrogen to 10~5 g H_2O/kg dry hydrogen. Useful information obtained indicates that accurate humidity measurements and control are required for the thermal conductivity decreases significantly at a temperature above 120 °C and a pressure above 0.1 MPa as water vapor concentration increases.