System, apparatus, and method for controlling an engine system to account for varying fuel quality
AssigneeCaterpillar Inc.
InventorsGeetika DILAWARI, Shawn M. DAMM, Shivangi WAGLE, Hannes MARSCHEIDER
Life of this patent
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Abstract
A system, apparatus, and method for controlling an engine system can provide fuel reactivity compensation control for an engine of the engine system. Pilot fuel quantity supplied to the engine can be controlled using a nitrous oxide (NOx) error. Likewise, air-to-fuel ratio (AFR) for the engine can be controlled using the NOx error. Each of a pilot fuel offset and an AFR control trim can be generated using the NOx error. The pilot fuel offset and the AFR control trim can be used to control the pilot fuel quantity and the AFR, respectively.
Claims20
An engine control system for a dual fuel engine comprising:
- a nitrous oxide (NOx) sensor configured to sense NOx generated from operation of the dual fuel engine;
- and
- an engine control module (ECM) configured to control, in real time, pilot fuel quantity and air-to-fuel ratio (AFR) for the operation of the dual fuel engine based on NOx sensed by the NOx sensor, wherein the ECM includes a NOx controller to perform fuel reactivity compensation, the NOx controller being configured to:
- generate, according to closed-loop control, a NOx error signal based on a comparison of an actual NOx signal from the NOx sensor and a desired NOx signal generated from a mapping operation of the NOx controller,
- generate an additive pilot fuel offset signal using the NOx error signal,
- receive an intake manifold air pressure (IMAP) error signal,
- receive either an exhaust temperature signal or an exhaust temperature error signal, and
- generate a multiplicative AFR control trim signal using the NOx error signal, the IMAP error signal, and either the actual exhaust temperature signal or the exhaust temperature error signal, and
- wherein the ECM is configured to output, at the same time, a pilot fuel quantity control signal generated from additive trimming according to the generated additive pilot fuel offset signal and an AFR control signal generated from multiplicative trimming according to the generated multiplicative AFR control trim signal to decrease the NOx error signal and maintain an actual exhaust temperature of the dual fuel engine within a predetermined, load-dependent exhaust temperature range.
A method of providing fuel reactivity compensation control for a dual fuel engine comprising:
- controlling, using control circuitry, pilot fuel quantity supplied to the dual fuel engine for operation of the dual fuel engine responsive to a nitrous oxide (NOx) error value generated from an actual NOx value from a NOx sensor;
- and
- controlling, using the control circuitry, air-to-fuel ratio (AFR) for the operation of the dual fuel engine responsive to the NOx error value,
- wherein the NOx error value is generated from a comparison of the actual NOx value from the NOx sensor and a desired NOx value,
- wherein said controlling the pilot fuel quantity includes generating a pilot fuel offset value using the NOx error value, and
- wherein said controlling the AFR includes generating an AFR command trim value using the NOx error value.
A non-transitory computer-readable storage medium having stored thereon instructions that, when executed by one or more processors, cause the one or more processors to perform an engine control method comprising:
- controlling pilot fuel quantity supplied to an engine using a nitrous oxide (NOx) error;
- and
- controlling air-to-fuel ratio (AFR) for the engine using the NOx error,
- wherein said controlling the pilot fuel quantity includes generating a pilot fuel offset using the NOx error, and
- wherein said controlling the AFR includes generating an AFR command trim using the NOx error.
Dependencies are inferred from the claim text.