Characteristics of Heat Transfer for Hydrogen and Wall During Filling Hydrogen Into Actual Tank at High Pressure

An experiment has been made to measure the rise in temperature of hydrogen and tank wall during filling of actual tanks to 35 and 70 MPa. Three different tank configurations are used, having volumes of 205, 130 and 39 liters. The filling time is 5 to 20 minutes. A governing equation for the filling process is proposed, which includes unknown values for heat transfer coefficients between the hydrogen and the wall and the wall and surrounding air. The values are tentatively assumed to be 500 W/(m2 K) during filling and 250 W/(m2 K) after filling for the inside tank wall and 4.5 W/(m2 K) for the outside tank wall. The measured temperatures of the hydrogen gas and the wall are in good agreement with the calculated ones.Copyright © 2007 by ASME