Saving Fuel in Large-Bore Natural Gas Engines Using Cylinder-by-Cylinder Electronic Fuel Control: A Case Study

This paper describes the method used to retrofit a modern, computer-controlled fuel system to older, large-bore pipeline engines in order to improve the reliability of the engine, while also improving the fuel efficiency of the engine. In cases where the engines run in off-load condition (and many do), it is possible to improve fuel efficiency by from five to twenty-five percent, and the engine runs much smoother, reducing the mechanical stress on the engine. This system does not require expensive fuel valves that can withstand the heat and pressure of the combustion chamber, and thus is much more cost effective. With the developed software algorithms, the computer decides when, and how many, cylinders to disable, and when to reactivate. Of the approximately eight thousand low-speed, non-turbocharged stationary engines in pipeline service in North America, approximately half could benefit from this system, and will enable these engines to run for many more years in a much more efficient manner.