Development of Next Generation Systems for Medium-Duty Natural Gas Engines

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Office of Heavy Vehicle Technologies

Enabling Technologies - Fuels & Systems

Development of Next Generation Systems for Medium-Duty Natural Gas Engines

Directing Organization:

Subcontractor:

National Renewable Energy Laboratory

Southwest Research Institute

1617 Cole Boulevard

6220 Culebra Road

Golden, CO 80401-3393

San Antonio, TX 78238

Technical Monitor:

Subcontract Number: YCI-8-17074-01

Keith Vertin

Telephone: (303) 275-4422

Subcontract Period: 10/97 - 2/99

Principal Investigator:

Daniel J. Podnar

Telephone: (210) 522-2564

DOE Project Manager:

NREL Business Team Administrator:

Steve Goguen

Kathleen Roqué

Telephone: (202) 586-8044

Telephone: (303) 275-3124

Objective: To design and develop next generation systems needed to increase the part load and full load efficiency of lean burn

spark-ignited natural gas engines. The program seeks to demonstrate diesel-like efficiency while retaining or improving upon

the emissions benefits already demonstrated on state-of-the-art natural gas engines.

Approach/Background:

This systems research work seeks to investigate the feasibility of unthrottled DING (direct

injection) and PING (port injection) fuel system designs for improving thermal efficiency. A lean stratified charge fueling strategy

will be used at low load. A homogeneous charge strategy is to be used at higher engine loads. New DING and PING fuel systems

are to be designed. Prototype hardware will be procured and tested on the end cylinder of a Deere 8.1 litre gas engine. System

performance and emissions testing will be carried out to assess unthrottled, stratified charge engine operation at part load. Control

strategies will be developed to meet performance and emissions objectives.

Status/Accomplishments:

The design of the DING/PING 500 psi fuel injection system is complete. Most prototype

hardware has been procured and fitted to the engine. The prototype engine has been used to perform preliminary testing of the

DING fuel system at part-load conditions. The design of the 500 psi fuel-injection system was completed and fitted to the prototype

engine. The end cylinder of the engine has been used to perform DING fuel system experiments at part-load conditions. Stratified

charge engine operation has been successfully demonstrated, and substantial fuel consumption improvements are apparent at part-

load. However, high hydrocarbon and NOx emissions have been measured due to the design limitations of the experimental fuel

injector. The wastegated and variable geometry turbocharger evaluations are complete, and significant improvements in part-load

efficiency have been quantified. The Phase I draft report has been delivered and is undergoing peer-review.

Future Direction: To be determined.

Major Project Reports (*=new): A poster of next-generation engine design concepts was presented at the DOE CCM

in October, 1997.

Document: c:\docs\quarter.rpt\FY98Q4.rpt