Westport introduces advanced LNG tank system for natural gas trucks; unsaturated LNG for large SI engines
Westport Innovations Inc. is introducing a new on-board liquefied natural gas (LNG) storage solution that supports the use of cold (unsaturated) LNG fuel for large SI-engine vehicles that would have earlier required warm (saturated) LNG. By carrying fuel as cold LNG, the Westport LNG Tank System can increase fuel storage times and improve vehicle range by up to 10%.
There are two standards for dispensing LNG: saturated (“green” or “warm”) LNG (8 bar and ‐130 °C) or unsaturated (“blue” or “cold”) LNG (3 bar and ‐150 °C). Each type of LNG fuel is optimized for a different engine technology; saturated LNG, with its warmer temperature, creates a vapor pressure in the tank that helps deliver fuel to the engine.
For example, vehicles equipped with Cummins Westport engines require saturated LNG as there is no fuel pump involved. Vehicles equipped with the Westport Innovations HD engine system can operate on either saturated or unsaturated LNG, although vehicle range is better using the unsaturated form.
Current industry standard systems require two LNG tanks to operate effectively with larger SI engines and require saturated LNG. The Westport LNG Tank System is optimized for trucks running even the largest SI engines, reducing the overall fuel system costs and weight with the single-tank option.
With the new tank system, fleets with a combination of SI and Westport HPDI trucks canuse the same LNG refueling infrastructure due to the system’s fuel-flexible capabilities.
Compared to existing compressed natural gas (CNG) options, a single 150-gallon (568-liter) Westport LNG Tank System takes the place of three standard CNG tanks, lowering fuel storage costs and reducing overall vehicle weight by approximately 600 lbs (272 kg).
The 120-gallon (454-liter) or 150-gallon single-tank systems can run for approximately 350 to 450 miles (563 to 724 km), respectively, on cold LNG. Those ranges double for dual-tank configurations.
The new system offers fuel-flexibility with the ability to carry both cold and warm LNG; universal system design allows for any original equipment manufacturer (OEM) to integrate the tanks.
The Westport Active System Management features proprietary control algorithms and connects with standard engine controllers to allow fuel delivery to match driving patterns.
An advanced driver display that indicates not only the LNG fuel levels, but also status and diagnostic information about the tank and integrated pumps.
The new Westport LNG Tank System will be available in 120- and 150-gallon capacities, is optimized for spark ignited (SI) engines and begins shipping by mid-2013. Customers receive a two year / 250,000 mile warranty along with access to field service from Westport-trained personnel.
Our early production systems tested with the Cummins Westport ISX12 G in a Peterbilt 384 truck have proven to have excellent performance characteristics and superior operating results on a single tank. We believe this is the only on-board fuel system for LNG-fueled engines that can operate on a single tank using range-extending cold LNG.—Steve Anderson, Westport HD Vice President of Business Development