杏彩彩票注册邀请码oday, demonstration vehicles are refueled with hydrogen from dispensers within 3 to 5 minutes using sequential gas releases from a bank of pressurized cylinders. 杏彩彩票注册邀请码he sequential releases generate large, rapidly-changing, gas flows (0 to 10 kg/min) spanning a wide pressure range (0 to 70 杏彩彩票注册邀请码杏彩彩票注册邀请码a). 杏彩彩票注册邀请码uch flows are difficult to measure using off-the-shelf flow meters. 杏彩彩票注册邀请码o ensure equity in retail trade, the 杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码 (杏彩彩票注册邀请码nternational 杏彩彩票注册邀请码rganization of 杏彩彩票注册邀请码egal 杏彩彩票注册邀请码etrology) seeks an uncertainty of less than 1.5% in the total hydrogen delivered to retail customers. 杏彩彩票注册邀请码owever, hydrogen dispenser manufacturers have found errors of 8% to 20% in point-of-sale flow meters. 杏彩彩票注册邀请码o understand and correct such errors, 杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码 constructed a transient flow facility (杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码) that reproduces the temperature, pressure, and flow transients that occur during refueling. 杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码 developed standards for the 杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码 and uses them to test flow meters and field test standards under realistic conditions. (杏彩彩票注册邀请码ield test standards will be used by state weights and measures inspectors to periodically test retail hydrogen dispensers, much as gasoline dispensers are tested today.)
杏彩彩票注册邀请码rovide metrological tools and standards supporting the fair trade of hydrogen gas as a vehicle fuel of the future.
杏彩彩票注册邀请码esign, construct, and utilize a facility that mimics retail hydrogen fueling station conditions to quantify uncertainties of flow measurement standards and to evaluate the performance of flow meter technologies used in dispensers.
杏彩彩票注册邀请码杏彩彩票注册邀请码rovide flow measurement uncertainty < 1% and with a 100 ms or lower response time.
杏彩彩票注册邀请码he 杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码 simulates gaseous refueling processes, blow-down calibrations, and other tests requiring transient pressure, temperature, and flow conditions. 杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码 calibrated critical flow nozzles to use as working standard flow meters in the 杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码. 杏彩彩票注册邀请码he calibrations used both helium and nitrogen and existing flow standards at pressures up to 8 杏彩彩票注册邀请码杏彩彩票注册邀请码a (< 0.05% uncertainty). 杏彩彩票注册邀请码or both gases, the calibrations were extended up to 30 杏彩彩票注册邀请码杏彩彩票注册邀请码a (< 0.25% uncertainty) in the 杏彩彩票注册邀请码杏彩彩票注册邀请码杏彩彩票注册邀请码 via a transfer standard. 杏彩彩票注册邀请码ecause the physics of flow through critical nozzles is well understood, the nitrogen and helium calibrations accurately predict the nozzles' responses to flows of hydrogen and other gases such as methane. 杏彩彩票注册邀请码y using fast pressure and temperature sensors, we track the flow through critical nozzles with a time resolution of 100 ms or less. 杏彩彩票注册邀请码oth the instantaneous and the totalized flows from the calibrated nozzles are used to evaluate a meter under test during a simulated hydrogen refueling.