Development of Fuel Consumption Measurement Methods for Hydrogen Fuel Cell Vehicles 2006-01-0217

Japan Automobile Research Institute has devised and evaluated the various fuel consumption measurement methods for fuel cell vehicles (FCVs). The examination covers the methods based on measurement of electrical current, hydrogen pressure/temperature, weight and flow rate that are expected to be the same accuracy and convenience as conventional measurement methods such as carbon balance method or fuel flow measurement method. As a result of examining the measurement accuracy for each method with a sonic nozzle used as a standard, it is found that both the pressure method and the weight method fulfill the target accuracy of ±1% and that the flow method is able to improve the accuracy by means of calibration with hydrogen. Also, as a result of applying each method to the fuel consumption test of FCVs, the relative error between the pressure method and weight method is within ±1%. The measurements are repeatable regardless of the number of tests and test vehicles; the accuracy and practicability were verified. Those fruits are utilized for the groundwork of establishing the criteria and standards. They have been reflected even in the committee drafts of ISO/TC22/SC21 WG2.