|The HPDI LNG system with engine, injectors, tank module, fuel conditioners, and pumps. Click to enlarge.|
The Board of the California South Coast Air Quality Management District (SCAQMD) has approved US$2.9 million for the immediate acquisition and deployment of 20 Westport high pressure direct injection (HPDI) liquefied natural gas (LNG) heavy-duty trucks at the Port of Los Angeles (POLA) and Port of Long Beach (POLB).
Under the terms of the agreement with SCAQMD, Total Transportation Services Inc. (TTSI) of Los Angeles will replace 20 of its pre-1990 trucks with the 2006 CARB and EPA certified Westport LNG systems installed in Kenworth T800 trucks. The funding support for TTSI’s LNG vehicle acquisition represents US$144,000 per truck.
The Westport HPDI system uses natural gas as the primary fuel, along with a small amount of diesel as an ignition source or “liquid spark plug”. The system uses a patented injector with a dual-concentric needle which allows for small quantities of diesel fuel and large quantities of natural gas to be delivered at high pressure to the combustion chamber. (Earlier post.)
|HPDI: The diesel fuel is delivered just prior to top-dead-center, followed by the main fuel quantity of natural gas.|
Natural gas has a higher ignition temperature than diesel and will not easily ignite at the temperatures and pressures in the combustion chamber of a normal diesel engine. To assist with the ignition of natural gas, a small amount of diesel fuel is injected into the engine cylinder using a dual-concentric needle injector the same injector followed by the main natural gas fuel injection. The diesel fuel is delivered just prior to top-dead-center, followed by the main fuel quantity of natural gas.
HPDI gives the engine the efficiency and low-speed torque advantages of compression ignition while using natural gas as the primary fuel. With HPDI engines, approximately 95% of the diesel fuel (by energy) consumed in a diesel engine is displaced with natural gas with no compromises on engine torque, power, fuel economy, or driveability while at the same time reducing NOxby 50% and CO2 by up to 20%.
On February 1, 2007, SCAQMD, POLA, and POLB released a joint request for proposals for US$22 million to solicit LNG truck projects. On February 3, 2006, the Board of SCAQMD set aside US$6 million to replace older heavy-duty diesel trucks at the POLA and the POLB with new LNG trucks. The ports contributed US$8 million each towards this project.
Six applications to the RFP were received for 170 trucks for a total funding request of US$24.5 million. The San Pedro Bay Ports Clean Air Action Plan (earlier post), approved in November 2006, sets out a plan to replace approximately 5,300 diesel trucks with LNG trucks by 2011.
The SCAQMD is the air pollution control agency for all of Orange County and the urban portions of Los Angeles, Riverside and San Bernardino counties. This area of 10,743 square miles is home to over 16 million people—about half the population of the whole state of California. It is the second most populated urban area in the United States and one of the smoggiest.