Southwest Research Institute

Timothy Joseph Callahan

David Pratt Branyon

Ryan C Roecker

Charles Edward Roberts, Jr

Jayant V Sarlashkar

Rudolf Hermann Stanglmaier

Thomas W Ryan, Iii

John Craig Hedrick

Robert Wayne Burrahm

Garrett L Anderson

Lee Gene Dodge

Jeremy D Eubanks

John Thomas Kubesh

Daniel William Stewart

James Corwin Snyder

A method, used with dual-fuel engine, of controlling the amount of gaseous fuel delivered to the engine. At operating conditions that result in an equivalence ratio below a predetermined threshold (which typically occur at mid or part loads), it is determined whether better performance and/or lower emissions can be achieved by reducing gaseous fuel to some cylinders and increasing gaseous fuel to others. Typically, the gaseous fuel is reduced to zero to a number of cylinders and increased to others, with the increase resulting in an equivalence ratio that will provide improved emissions and efficiency and the desired engine output.

Dual-fuel diesel engine with cylinder fueling control of gaseous fueling at less than full loads

A method, used with dual-fuel engine, of controlling the amount of diesel fuel delivered to the engine. The method compensates for the poor transient response of gaseous fueling. A controller receives a signal from the operator of the engine representing a desired torque, and based on this signal, determines a desired intake manifold state. It generates commands to various actuators to control the intake air and the intake gaseous fuel such that the desired intake manifold state will occur. The controller also receives sensor data from which the current in-cylinder state can be measured or estimated. It determines a current amount of diesel fuel based on the desired torque, the engine speed and the current in-cylinder state, and generates a diesel fueling command.

State-based diesel fueling for improved transient response in dual-fuel engine

A heavy-duty flame propagation engine has control systems and exhaust aftertreatment systems adapted to provide ultra-low emissions relative to Diesel engines while achieving comparable fuel consumption at reduced emission levels. The control systems include exhaust gas circulation, variable valve actuation, cylinder deactivation, pilot fuel injection, high energy ignition systems and combinations thereof to provide substantially stoichiometric combustion conditions over an entire load range of the engine. In one embodiment, the engine has direct in-cylinder fuel injection, is adapted for lean air-fuel mixture operation, and includes an oxidation catalyst and a lean NOx adsorber.

High-efficiency, low emission gasoline engines for heavy-duty applications

Growing community of inventors

San Antonio, TX, United States of America

Timothy Joseph Callahan