BNSF Railway, a Fort Worth, Texas company, is one of North America’s leading freight transportation companies. The company has a rail network of 32,000 route miles in 28 U.S. states and two Canadian provinces.
Traditional rail transportation is highly efficient and uses significantly less fuel than highway alternatives. BNSF intends to improve upon that efficiency and has been experimenting with a hydrogen fueled fuel cell locomotive for the past several years.
Recently the U.S. Patent and Trademark Office granted BNSF’s patent covering fuel cell locomotives.
U.S. Patent Number 8,117,969, entitled “Hydrogen Fuel Cell Hybrid Locomotives” describes a locomotive including a set of batteries for driving a plurality of electric traction motors for moving the locomotive and a fuel cell power plant for charging the batteries and driving the electric traction motors.
The hydrogen hybrid locomotive is based on a commercially available diesel-hybrid donor platform. The locomotive design uses a cab section (101), which houses the control systems used by the controller, a center section (102), which contains the batteries and hydrogen storage tanks, a rear section (103) containing the hydrogen fuel cell power plant, and an adjustable ballast section (104) located under the chassis.
Ballast is needed because the locomotive does not carry heavy diesel fuel, which means the weight is significantly under the weight needed to maximize the traction of the wheels on the rails.
In the embodiment disclosed in the patent and shown in Figure 2 above, hydrogen is provided to two fuel cell power plants based on two power stack modules (201a – 201b). The fuel cells are proton exchange membrane cells and (in the preferred embodiment) are Ballard Power Systems, Inc Mk903 PEM fuel cell stacks.
Hydrogen is provided to the power modules from 14 carbon-fiber composite tanks (204). Power from the fuel cell is delivered to a DC converter (203) and to the locomotive systems including the traction motors (209a – 209d). The power output of the fuel cell stacks can be varied depending on demand by adjusting the flow of air through the system.
BNSF has an operational fuel cell locomotive prototype serving in a demonstration project in Los Angeles. Funding for the locomotive came from BNSF and the Department of Defense. The prototype is a switch locomotive, which moves freight cars within rail yards and rail stations during train assembly and disassembly.
The prototype was unveiled in Topeka, Kansas in January 2009. It then traveled to Colorado for additional testing and was sent to California in 2010. It was tested in the Los Angeles rail yards in Commerce and Hobart through 2010 and 2011.
Use of hydrogen fuel cells in locomotives can reduce the amount of particulate pollution around rail lines and reduce the amount of greenhouse gases expelled into the atmosphere. Hydrogen fuel cell locomotives can also reduce railroad dependency on fossil fuels. Additionally, fuel cell locomotives can also act as mobile electricity sources, for example in disaster recovery scenarios.
Article by David Gibbs, appearing courtesy Green Patent Blog.