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

Patent metadata

Field	Value
Publication number	US-9518516-B2
Application number	US-201514595993-A
Country	US
Kind code	B2
Filing date	Jan 13, 2015
Priority date	Jan 13, 2015
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

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.

First claim

What is claimed is:

1. A method of controlling the amount of diesel fuel delivered to a dual-fuel internal combustion engine, the engine being fueled with both gaseous fuel and diesel fuel, comprising:
receiving a signal from the operator of the engine representing a desired torque;
determining a desired intake manifold pressure and a desired intake manifold oxygen fraction, based on the desired torque;
controlling flow actuators for at least the intake air flow and the intake gaseous fuel such that the desired intake manifold pressure and the desired intake manifold oxygen fraction will occur;
receiving sensor data from which the engine speed and a current in-cylinder state can be measured or estimated;
wherein the current in-cylinder state comprises at least an in-cylinder amount of gaseous fuel and an in-cylinder amount of oxygen;
determining a current amount of diesel fuel based at least on the desired torque, the engine speed and the current in-cylinder state; and
generating a diesel fueling command representing the current amount of diesel fuel.

2. The method of claim 1 , wherein the receiving step is performed by receiving an accelerator pedal position signal.

3. The method of claim 1 , wherein the desired intake manifold state comprises at least an intake manifold pressure value.

4. The method of claim 1 , wherein the engine has a throttle, and the controlling flow actuators step is performed by controlling at least the throttle.

5. The method of claim 1 , wherein the engine has a gaseous fuel intake valve, and the controlling flow actuators step is performed by controlling at least the gaseous fuel intake valve.

6. The method of claim 1 , wherein the engine has a compressor and compressor by-pass valve, and the controlling flow actuators step is performed by controlling at least the compressor bypass valve.

7. The method of claim 1 , wherein the gaseous fuel is natural gas.

8. A controller for controlling the amount of diesel fuel delivered to a dual-fuel internal combustion engine, the engine being fueled with both gaseous fuel and diesel fuel, and the engine having a conventional engine control unit, comprising:
a processor and memory system programmed to perform the following tasks: to receive a signal from the operator of the engine representing a desired torque; to determine a desired intake manifold pressure and a desired intake manifold oxygen fraction, based on the desired torque; to control flow actuators for at least the intake air flow and the intake gaseous fuel such that the desired intake manifold pressure and desired intake manifold oxygen fraction will occur; to receive sensor data from which the engine speed and a current in-cylinder state can be measured or estimated; wherein the current in-cylinder state comprises at least an in-cylinder amount of gaseous fuel and an in-cylinder amount of oxygen; to determine a current amount of diesel fuel based at least on the desired torque, the engine speed and the current in-cylinder state; and to generate a diesel fueling command representing the current amount of diesel fuel.

9. The controller of claim 8 , wherein the controller receives an accelerator pedal position signal representing desired torque.

10. The controller of claim 8 , wherein the desired intake manifold state comprises at least an intake manifold pressure value.

11. The controller of claim 8 , wherein the engine has a throttle, and the controlling step is performed by controlling at least the throttle.

12. The controller of claim 8 , wherein the engine has a gaseous fuel intake valve, and the controlling step is performed by controlling at least the gaseous fuel intake valve.

13. The controller of claim 8 , wherein the engine has a compressor and compressor by-pass valve, and the controlling step is performed by controlling at least the compressor bypass valve.

14. The controller of claim 8 , wherein the gaseous fuel is natural gas.

Assignees

• Southwest Res Inst

Inventors

• Roecker Ryan C
• Sarlashkar Jayant V
• Branyon David P
• Callahan Timothy J

Classifications

• F02D19/0647

  the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME] · CPC title

• F02D41/1458

  with determination means using an estimation · CPC title

• F02D2041/1415

  using a state feedback or a state space representation · CPC title

• F02D41/0007

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D19/10

  peculiar to compression-ignition engines in which the main fuel is gaseous · CPC title