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Hydrogen
Sensors Boost Hybrids; Today’s Models Losing Gas?
Transportation
Originating
Technology/ NASA Contribution
Advanced chemical sensors are used in aeronautic and
space applications to provide safety monitoring, emission
monitoring, and fire detection. In order to fully do
their jobs, these sensors must be able to operate in
a range of environments. NASA has developed sensor
technologies addressing these needs with the intent
of improving safety, optimizing combustion efficiencies,
and controlling emissions.
On the ground, the chemical sensors were developed
by NASA engineers to detect potential hydrogen leaks
during Space Shuttle launch operations. The Space Shuttle
uses a combination of hydrogen and oxygen as fuel for
its main engines. Liquid hydrogen is pumped to the
external tank from a storage tank located several hundred
feet away. Any hydrogen leak could potentially result
in a hydrogen fire, which is invisible to the naked
eye. It is important to detect the presence of a hydrogen
fire in order to prevent a major accident.
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The
image to the right shows what appear to be
three small holes in the liquid hydrogen tubes
inside the nozzle on Space Shuttle Main Engine
No. 3 (right-most engine), following the landing
of Space Shuttle Columbia (STS-93) on July
27, 1999. The smaller image above shows the
holes in greater detail. During the mission,
Columbia reached an orbit about 7 miles lower
than anticipated, due to premature main engine
cutoff that was traced to a hydrogen leak. |
In the air, the same hydrogen-leak dangers are
present. Stress and temperature changes can cause tiny
cracks or holes to form in the tubes that line the
Space Shuttle’s main engine nozzle. Such defects could
allow the hydrogen that is pumped through the nozzle
during firing
to escape.
Responding to the challenges associated with pinpointing
hydrogen leaks, NASA endeavored to improve propellant
leak-detection capabilities during assembly, pre-launch
operations, and flight. The objective was to reduce
the operational cost of assembling and maintaining
hydrogen delivery systems with automated detection
systems. In particular, efforts have been focused on
developing an automated hydrogen leak-detection system
using multiple, networked hydrogen sensors that are
operable in harsh conditions.
Partnership
In 1999, Glenn Research Center’s Technology Commercialization
Office awarded Makel
Engineering, Inc., with a Small
Business Technology Transfer (STTR) contract and additional
funding to commercialize NASA’s automated hydrogen-sensing
technology for aerospace, industry, and consumer applications.
Makel Engineering, based in Chico, California, worked
closely with Glenn throughout the technology’s commercial
development. Recognizing that the NASA sensors could
expedite the time-to-market for hydrogen-fueled transportation
vehicles, the company went on to partner with a top
U.S. automaker and supply its advanced hydrogen sensors
for hydrogen-powered internal combustion engine (H2ICE)
applications.
Product Outcome
The U.S. Government, auto manufacturers, and citizens
have all encouraged the use of hydrogen as a transportation
fuel. Transitioning to hydrogen would
provide several advantages, such as reducing dependence
on foreign oil and eliminating vehicle emissions. Before
this future is realized, however, two essential principles
must be addressed: the need to responsibly tackle overarching
fuel-safety concerns and the need for fast, reliable
hydrogen monitoring—integrating data collection, analysis,
and communication.
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Makel
Engineering, Inc.’s advanced hydrogen sensors
are built to operate in harsh conditions, for
aerospace, industrial, and commercial applications. |
Consequently, Makel Engineering is providing Ford Motor
Company with hydrogen leak-sensing systems for its
prototype H2ICE vehicles. The systems consist of four
hydrogen sensors, a control unit, and associated cabling.
The sensors are installed at various locations throughout
the vehicle and continuously monitored by the control
unit. In the event of a hydrogen gas leak, the sensors
will alert the control unit to the presence of hydrogen,
and the control unit can then initiate appropriate
actions.
Ford regards the H2ICE as a near-term, low-cost transition
or “bridging” strategy to stimulate the development
and maturation of the hydrogen infrastructure and related
hydrogen technologies, including on-board hydrogen
fuel storage, hydrogen fuel dispensing, and hydrogen
safety sensors. The engine has a laundry list of benefits
that rival its gasoline-powered predecessor. It possesses
all-weather capability with no cold-start issues, and
requires zero warm-up. It has high efficiency (52-percent
peak-indicated efficiency), as the vehicles it operates
can easily achieve California’s Super-Ultra-Low-Emission Vehicle (SULEV) standards
and more than
99-percent reduced carbon dioxide vehicle emissions. Even more, its performance—while
running comparable to gasoline—increases fuel economy by 25 percent, and up to
50 percent with an aggressive hybrid electric strategy.
The prototype version of the hydrogen-hybrid
powertrain was unveiled to the public in January 2003, in the Model U concept
vehicle at the North American International Auto Show (NAIAS) in Detroit. There,
Ford touted the Model U as “a model for
change for the next century” and “the Model T of the
21st century.”
The drivable version of the supercharged, intercooled hydrogen powertrain was
unveiled during the Ford Centennial celebration in June 2003. Scores of journalists
from around the world were able to experience driving the H2ICE-equipped prototype
vehicle firsthand during a media drive held in a Detroit-area park.
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Makel
Engineering, Inc., worked with Ford Motor Company’s research and development
team on a comprehensive hydrogen-monitoring system for the Model U prototype.
The system provides continuous leak monitoring throughout the vehicle
and has been demonstrated at car shows and other advanced automotive
technology events. |
Ford is moving to put the hydrogen-powered technology to work in a V-10 shuttle
bus engine, as well. The H2ICE E-450 chassis cab made its debut earlier this
year at the 2005 NAIAS. The E-450 shuttle bus seats up to 12 passengers, including
the driver, with room for luggage. The vehicle is equipped with a 5,000-psi hydrogen
fuel tank and emits only water as exhaust. The automaker expects the shuttle
bus to have a driving range of up to 150 miles, depending on conditions and vehicle
load.
Makel Engineering notes that, as the use of hydrogen as a transportation fuel
becomes more prevalent, numerous technological solutions for hydrogen generation,
storage, and utilization will be created—all having stringent safety requirements.
Furthermore, it asserts that, as hydrogen becomes a more practical and established
fuel source, the availability of safe hydrogen refueling sources will be fundamental
to public acceptance. Effective hydrogen sensors that respond accurately and
quickly to hydrogen gas leaks will be a prerequisite in the development of hydrogen-powered
vehicles and related infrastructure.
Makel Engineering’s development and delivery of a vehicle-safety sensor system
demonstrates acceptable levels of performance, reliability, and cost, and overcomes
a major commercialization barrier for transportation applications.
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