Honda R&D installs hydrogen refueling station for field validation of new MC Fill dynamic fast-fill protocol
|MC Method control diagram, from a 2013 DOE-hosted webinar on hydrogen refueling. MC Fill allows dynamic control of refueling based on gas temperature. Click to enlarge.|
Preparing for the 2015 introduction of the next Honda fuel cell-electric vehicle (FCEV), Honda R&D Americas has installed an advanced hydrogen refueling station on its Torrance, California campus to serve as a platform for demonstrating and validating its MC Fill hydrogen fueling protocol. Honda, which is also participating in the SAE J2601 work on a standardized light-duty vehicle hydrogen fueling protocol, will make the new research station available to other automakers to further validate the MC Fill protocol’s performance and functionality.
As with the J2601 protocol, which is due to be published soon (likely in April), the MC Fill fast-fill protocol is designed for fuel systems that store hydrogen at a pressure of up to 700 bar (70MPa or 10,000 psi). The primary differentiator between the current J2601 approach and Honda’s MC Fill is that Honda offers dynamic control of the refueling rate based on the measured gas temperature rather than a lookup table to control the pressure ramp rate, said Steve Mathison, Senior Engineer at Honda R&D Americas.
|Honda’s fueling station. Click to enlarge.|
The result would be a filling time optimized for the ambient conditions at the refueling station. Honda says that its fueling protocol can reduce 700-bar fueling times by up to 45% versus comparable fueling protocols, and can complete most fills in less than three minutes under normal temperature conditions.
The MC Fill more precisely monitors the dispenser outlet temperature and uses this information to calculate the shortest fueling time possible; the intelligence is in the dispenser controller. This dynamic, fast-fill control allows the dispenser continuously to adjust to current temperature and other conditions which normally affect the refueling time.
Derived from two key values in a heat transfer equation—“M” for mass and “C” for specific heat—the MC Fill name refers to the heat capacity of the hydrogen storage system and represents the capability of the system to absorb the heat that is generated during fueling. The MC Fill protocol utilizes this value, as well as the dispenser outlet gas temperature and pressure, in its fill control logic.
In order to meet customer expectations, hydrogen fuel cell-powered vehicles need driving ranges and fueling times comparable to conventional gasoline vehicles. This new fueling protocol will allow FCEV customers everywhere to realize short fueling times over a wide range of temperatures.—Steve Mathison
MC Fill is at this point a non-normative, development protocol from the point of view of J2601; however, noted Mathison, Honda is hoping that future revisions of the protocol will include MC Fill.
Honda has put MC Fill through a number of computer simulations and testing; the field validation at the Torrance R&D center is the final step of showing real world use of the protocol, he added.
Honda has spent nearly two decades in the development and deployment of fuel cell technology including extensive real world testing, including the first government fleet deployment and retail customer lease programs in the United States.
Honda has also made significant technological advancements in fuel cell operation in both hot and sub-freezing temperatures and safety regulations, since the introduction of its first generation fuel cell vehicle, the FCX, in 2002.
Honda launched its current fuel cell-electric vehicle, the FCX Clarity, in July 2008 as a real technological breakthrough in the areas of design, sedan packaging, assembly line manufacturing, and fuel cell stack size and efficiency.
In November 2013, the new Honda FCEV Concept debuted at the Los Angeles International Auto Show, pointing the way to an all-new Honda fuel cell car launching in the US and Japan in 2015 and later in Europe. (Earlier post.) Honda’s next-generation fuel cell-electric vehicle will feature a fuel cell powertrain packaged completely in the engine room of the vehicle, allowing for efficiencies in cabin space as well as flexibility in the potential application of FC technology to multiple vehicle types in the future. The next-generation Honda FCEV is anticipated to have a driving range of more than 300 miles.
In July 2013, General Motors and Honda announced a long-term, definitive master agreement to co-develop next-generation fuel cell system and hydrogen storage technologies, aiming for the 2020 time frame. (Earlier post.)