Method and system for compressor outlet temperature regulation

Patent metadata

Field	Value
Publication number	US-10858987-B2
Application number	US-201916355589-A
Country	US
Kind code	B2
Filing date	Mar 15, 2019
Priority date	Apr 15, 2016
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

Methods and systems are provided for controlling a boosted engine system, having a turbocharger and a charge air cooler, to limit overheating of a compressor outlet. In one example, a method includes predicting an engine torque profile based on current and future engine operating conditions. The method then models a compressor outlet temperature profile and reduces engine torque output to limit overheating of the compressor outlet.

First claim

The invention claimed is:

1. A method for an engine coupled to a vehicle, comprising:
adjusting an engine torque output based on a future compressor outlet temperature profile to maintain an actual compressor outlet temperature below a threshold, the future compressor outlet temperature profile based on current and predicted engine operating conditions estimated based on inputs from external vehicle communications.

2. The method of claim 1 , wherein the future compressor outlet temperature profile includes predicted compressor outlet temperatures over a future horizon of vehicle operation.

3. The method of claim 2 , wherein the predicted compressor outlet temperatures are based on a predicted engine torque required over the future horizon of vehicle operation.

4. The method of claim 2 , wherein the adjusting includes limiting the engine torque output to below a threshold torque responsive to a duration over which the predicted compressor outlet temperatures are above a threshold temperature, a torque level to which engine torque is limited being reduced as the duration increases.

5. The method of claim 4 , wherein the threshold temperature is based on a material property of a tubing coupling an intake compressor outlet to a downstream intercooler.

6. The method of claim 4 , wherein the torque level to which the engine torque output is limited is further reduced responsive to a degree beyond which a peak predicted temperature of the future compressor outlet temperature profile is above the threshold temperature, the torque level reduced further as the degree increases.

7. The method of claim 4 , wherein limiting the engine torque includes reducing an opening of an intake throttle to reduce an intake air flow to the engine.

8. The method of claim 7 , wherein limiting the engine torque further includes one or more of increasing an opening of an exhaust wastegate valve, increasing an opening of an EGR valve, and retarding spark timing.

9. The method of claim 2 , further comprising estimating the future compressor outlet temperature profile based on the current and predicted engine operating conditions, the estimating including estimating an initial future compressor outlet temperature based on the current and predicted engine operating conditions, and filtering the initial future compressor outlet temperature over the future horizon via one or more of a low-pass filter and a moving average filter, a bandpass of the filter based on a material property of tubing between a turbocharger compressor and an intercooler, and a duration of the future horizon.

10. The method of claim 9 , wherein estimating the future compressor outlet temperature profile includes:
estimating an engine torque over the future horizon based on the current and predicted engine operating conditions;
estimating an engine air mass-flow rate over the future horizon based on the estimated engine torque;
estimating an exhaust back-pressure based on each of the estimated engine air mass-flow rate and barometric pressure;
mapping each of an intake manifold pressure and a throttle inlet pressure based on the exhaust back-pressure;
estimating a compressor pressure ratio based on each of the estimated engine air mass-flow rate, the throttle inlet pressure, and the exhaust back-pressure;
estimating a compressor efficiency based on each of the estimated engine air mass-flow rate, the compressor pressure ratio, and an inlet air temperature; and
estimating the initial future compressor outlet temperature based on each of the estimated compressor efficiency, the inlet air temperature, and the compressor pressure ratio.

11. The method of claim 1 , wherein the inputs from external vehicle communications include inputs from one or more of a navigation system and a wireless communication unit communicatively coupled to the engine, wherein the inputs include one or more of vehicle data, navigation data, location data, map data, terrain data, and weather data, and wherein the current and predicted engine operating conditions include each of a vehicle weight, an engine size, a vehicle speed, an engine torque, an engine load, barometric pressure, exhaust pressure, MAP, inlet air temperature, a compressor pressure ratio, compressor efficiency, throttle inlet pressure, and an intake mass airflow rate.

12. The method of claim 1 , wherein the engine is a turbocharged engine system and wherein the actual compressor outlet temperature includes a temperature of boosted intake gasses included between a turbocharger compressor and an intercooler.

13. A vehicle system, comprising:
an engine including an intake manifold;
an intake throttle coupled to the intake manifold;
an intake compressor coupled upstream of the intake throttle for providing a boosted aircharge to the intake manifold;
an intercooler coupled downstream of the intake compressor via a tubing;
a navigation system communicatively coupled to a network, the navigation system configured to retrieve one or more inputs including vehicle data, navigation data, location data, map data, terrain data, and weather data from the network; and
a controller with computer readable instructions stored on non-transitory memory for:
estimating actual and predicted engine operating conditions for an upcoming segment of vehicle travel based on the one or more inputs retrieved at the navigation system;
calculating a compressor outlet temperature profile for the upcoming segment of vehicle travel based on the estimated actual and predicted engine operating conditions; and
maintaining an actual compressor outlet temperature below a threshold temperature via adjustments to the intake throttle, the adjustments responsive to the calculated compressor outlet temperature profile.

14. The system of claim 13 , wherein the maintaining includes reducing an engine torque below a threshold torque by reducing an opening of the intake throttle responsive to a predicted temperature of the calculated compressor outlet temperature profile exceeding a threshold temperature, the threshold torque based at least on a driver torque demand, the threshold temperature based at least on a material property of the tubing.

15. The system of claim 13 , wherein the calculating includes:
estimating an engine torque for the upcoming segment of vehicle travel based on the estimated actual and predicted engine operating conditions;
converting the estimated engine torque into an estimated engine air mass-flow rate;
estimating an exhaust back-pressure based on each of the estimated engine air mass-flow rate and barometric pressure;
mapping each of an intake manifold pressure and a throttle inlet pressure based on the exhaust back-pressure;
estimating a compressor pressure ratio based on each of the estimated engine air mass-flow rate, the throttle inlet pressure, and the exhaust back-pressure;
estimating a compressor efficiency based on each of the estimated engine air mass-flow rate, the compressor pressure ratio, and an inlet air temperature; and
predicting the compressor outlet temperature profile based on each of the estimated compressor efficiency, the inlet air temperature, and the compressor pressure ratio.

Assignees

• Ford Global Tech Llc

Inventors

• Santillo Mario Anthony
• Hellstrom John Erik Mikael
• Ossareh Hamid-Reza
• Xiao Baitao

Classifications

• F02D23/00

  Controlling engines characterised by their being supercharged · CPC title

• F02D2009/0227

  Atmospheric pressure · CPC title

• F02D41/0007 Primary

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

• F02B37/12 Primary

  Control of the pumps · CPC title

• F02D41/18

  by measuring intake air flow · CPC title