SBIR-STTR Award

The author is one of the original members of an engineering team that developed the first production intensified common rail injection system (CAT-Navistar HEUI), and we are therefore very familiar with this technology. We (AFT) have developed a 450-500 bar (6500-7250 psi) common rail pump that is used in our prototype DME fuel system. Although this pump was designed to pump DME, with minor modifications it can very easily pump engine lubricating oil. Since both the CAT HEUI and Navistar''s Electro-Hydraulic injectors use lube oil driven 7:1 hydraulic intensifed injectors, by applying our very high pressure common rail pump will easily allow us to achieve the requested injection pressures (40,000 psi). Considering compressibility losses, etc, we can possibly achieve >45,000 psi. We propose to make design modifications to our DME inlet throttled wobble plate pump, build a prototype and, using a production Navistar injector, demonstrate successful operation on a specially built test bench. We envision that the demonstration will include performance mapping the fuel system at various rail pressures and pulse widths (Injection durations). In phase 1, multiple injections will not be demonstrated because the cost of electronics can not be contained within the program cost limitations. Phase II would include demonstration of multiple injections, as well as injector durability and performance development.

Keywords:
Intensified Injectors, Common Rail Pump, High Injection Pressure

The Army uses intensified fuel injection systems on a number of their diesel powered vehicles. These systems are currently limited to injection pressures of about 20,000 psi. In an effort to increase thermal efficiiency (fuel economy), raise power output and operate on a variety of heavy hydrocarbon fuels, the army desires to develop an ultra-high pressure (>40,000 psi)intensified fuel injection system. In Phase 1, we are developing and will demonstrate a single injector system that will meet the Army's criteria. To reach the pressure goals we are using a COTS injector but are developing a higher pressure common rail pump and a common rail that can withstand the ultra-high pressure. In Phase 2, we will develop a full 6 cylinder system, including electronics, that will "bolt onto" an Army COTS diesel engine.

Keywords:
Diesel Fuel Injection, Intensified Fuel Injector, Common Rail, Ultra-High Pressure Injection.