Development of a Hydrogen Flow Meter With High Accuracy at Low Flow Rates to Measure Fuel Consumption for Fuel Cell Vehicles

With the increasing prevalence of fuel cell vehicles, hydrogen consumption during fuel economy certification needs to be measured in an accurate and convenient manner. Typically, consumption is measured by weighing hydrogen cylinders before and after testing and calculating the amount of depleted hydrogen by the difference in weight. This method is theoretically highly accurate but time-consuming. This paper describes a new method developed to measure hydrogen consumption using a flow meter system. With a flow meter input pressure of 2MPa, and a minimum flow rate of 4NL/min, this new system achieves a level of error that is within 0.5% of the weight measurement method, but is far simpler and reduces the measuring time by approximately 130 minutes.