Systems and methods for compensating airflow determinations for air compressor bleed

Patent metadata

Field	Value
Publication number	US-9297325-B2
Application number	US-201213648434-A
Country	US
Kind code	B2
Filing date	Oct 10, 2012
Priority date	Jan 31, 2012
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

Systems and methods are disclosed for compensating a mass airflow (MAF) sensor reading to account for the bleeding or diversion of intake airflow for compressor operation in determining fresh air flow into an engine. The engine is downstream from the compressor diversion.

First claim

What is claimed is:

1. A method of operating an internal combustion engine and an air compressor operably connected to one another, each receiving a portion of pressurized air from a pressure source, the internal combustion engine including a controller with instructions encoded on a non-transitory computer readable medium to execute:
interpreting, with the controller, an operational status of the air compressor;
in response to the operational status of the air compressor being active to indicate a diversion of the portion of pressurized air from the pressure source to the air compressor, determining, with the controller, a compressor flow value of the portion of pressurized air received from the pressure source by the air compressor, and further comprising determining, with the controller, a fresh airflow value to the internal combustion engine in response to the compressor flow value and a flow value for the pressurized air from the pressure source from a mass airflow sensor operably coupled to the controller; and
adjusting, with the controller, a combustion parameter for the internal combustion engine in response to the fresh airflow value to the internal combustion engine to compensate for the diversion of the portion of pressurized air from the pressure source to the air compressor.

2. The method of claim 1 , wherein determining the compressor flow value further includes utilizing a flow estimation model.

3. The method of claim 2 , wherein utilizing the flow estimation model further includes selecting at least one model from the group of models consisting of compressor efficiency table based, air-tank pressure based, virtual air-tank pressure based, and mass-momentum conservation based models.

4. The method of claim 2 , further including introducing an exhaust gas produced by the internal combustion engine into the portion of pressurized air received by the internal combustion engine for recirculation of the exhaust gas to the internal combustion engine.

5. The method of claim 4 , further including determining a charge flow of the internal combustion engine, and determining an exhaust gas recirculation flow into the internal combustion engine in response to the charge flow and the fresh airflow to the internal combustion engine.

6. The method of claim 1 , wherein determining the operational status of the air compressor further comprises interpreting an engine operational condition.

7. An engine driven compressor apparatus, comprising:
an internal combustion engine and an air compressor driven by the internal combustion engine, the internal combustion engine including an air intake system;
a mass airflow (MAF) sensor in the intake system in communication with a controller, the MAF sensor located upstream of a pressure source;
an air compressor inlet located downstream of the pressure source and upstream of the internal combustion engine; and
a controller operably connected to the MAF sensor, the internal combustion engine, and the air compressor, wherein the controller includes a non-transitory computer readable medium with instructions executable to:
determine an airflow from the intake system into the air compressor during operation of the air compressor in response to a flow parameter determined by the MAF sensor and a flow estimation model associated with the air compressor;
determine a fresh airflow into the internal combustion engine from the flow parameter determined by the MAF and the airflow into the air compressor; and
adjust a combustion parameter of the internal combustion engine in response to the fresh airflow.

8. The engine driven compressor apparatus of claim 7 , wherein the instructions are executable to determine an operational status of the air compressor in response to a signal from a pressure sensor associated with the air compressor.

9. An internal combustion engine system, comprising:
a first airflow bound for a source of pressurization;
a first flowpath operably coupled to receive a first portion of a pressurized airflow from the source of pressurization and structured to provide the first portion of the pressurized airflow to an air compressor;
a second flowpath operably coupled to receive a second portion of the pressurized airflow from the source of pressurization and structured to provide the second portion of the pressurized airflow to an internal combustion engine; and
a controller operably connected to the internal combustion engine and the air compressor, the controller including a non-transitory computer readable medium with instructions executable to:
interpret an operational status of the air compressor, a flow estimation model having been stored in a memory of the controller, and a flow parameter of the first airflow measured by an airflow sensor and provided to the controller;
determine a fresh airflow value of the second flowpath in response to the operational status of the air compressor being active, the flow estimation model providing a compressor flow value as the air compressor being active, and a difference between the flow parameter of the first airflow and the compressor flow value; and
adjust a combustion parameter of the internal combustion engine in response to the fresh airflow value that compensates for a reduction in the fresh airflow value to the internal combustion engine indicated by the compressor flow value.

10. The internal combustion engine system of claim 9 , wherein the controller further comprising executable instructions to interpret at least one of an engine operating condition in response to at least one sensor associated with the engine and an air compressor pressure differential value in response to at least one pressure sensor associated with the air compressor, and to determine the operational status of the air compressor is active in response to the at least one of the engine operating condition indicating a changed engine operating condition and the air compressor pressure differential value indicating a change in pressure.

11. The internal combustion engine system of claim 9 , further including an exhaust gas recirculation (EGR) system connected to the internal combustion engine and to the second flowpath at a location downstream of the first flowpath.

12. The internal combustion engine system of claim 11 , wherein the controller further comprising executable instructions to interpret a charge flow value of the internal combustion engine in response to one or more operating conditions of the engine, and to determine an EGR flow value in response to a difference between the charge flow value and, the fresh airflow value.

13. The internal combustion engine system of claim 9 , wherein the internal combustion engine is a diesel engine.

14. The internal combustion engine system of claim 13 , wherein the air compressor is a positive displacement air compressor.

Assignees

• Cummins Inc

Inventors

• Sujan Vivek A
• Vyas Ashwin

Classifications

• F02D41/0007

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

• F02D41/18 Primary

  by measuring intake air flow · CPC title

• Y02T10/144

  Cross-Sectional Technologies · mapped topic

• Y02T10/12

  Improving ICE efficiencies · CPC title