Method for turbocharger key-off cooling control based on engine load, and engine system implementing the same

Patent metadata

Field	Value
Publication number	US-10844743-B2
Application number	US-201816194829-A
Country	US
Kind code	B2
Filing date	Nov 19, 2018
Priority date	Dec 18, 2017
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

A method for turbocharger key-off cooling control may include performing turbocharger key-off cooling control based on engine load for circulating engine coolant to a turbocharger cooling line when high cooling performance of a vehicle is checked by a coolant temperature and an oil temperature at which a turbocharger controller does not require operation of an auxiliary electric water pump when an engine is stopped.

First claim

What is claimed is:

1. A method for a turbocharger key-off cooling control in a turbocharged engine system including an engine, a turbocharger for supplying turbocharged air to the engine for discharging exhaust gas from the engine, a turbocharger cooling system with a turbocharger cooling circuit, an auxiliary electric water pump (EWP) positioned upstream of the turbocharger, an electric water pump (EWP) positioned upstream of the engine, and an oil cooler, the method comprising:
controlling the turbocharger key-off cooling control based on engine load with a turbocharger controller when the engine is stopped by key-off immediately after the engine has been running;
determining, by the turbocharger controller, an auxiliary electric water pump (EWP) operation time A of the coolant temperature and an oil temperature of the oil cooler and an EWP operation time B of the coolant temperature and a fuel consumption; and
operating, by the turbocharger controller, the auxiliary electric water pump to circulate engine coolant to the turbocharger cooling circuit based on a final operation time selected as a maximum value between the auxiliary EWP operation time and the EWP operation time in a time map.

2. The method of claim 1 , wherein, with the turbocharger key-off cooling control based on engine load being carried out by a circulation flow through a coolant inlet pipe, a coolant feed pipe and a coolant outlet pipe with the engine coolant driven by the auxiliary electric water pump, the method further comprising:
determining a high cooling performance performed by vehicle cooling performance distinction control by the turbocharger controller; and
operating the auxiliary electric water pump to reach the high cooling performance vehicle control in which the final operation time is calculated by the turbocharger controller.

3. The method of claim 2 , wherein the vehicle cooling performance distinction control comprises:
checking an engine load driving condition before the engine is stopped by the turbocharger controller;
respectively setting a detection value of the coolant temperature and a detection value of the oil temperature as the coolant temperature when the engine is operated and the oil temperature when the engine is operated by the turbocharger controller;
checking key-off for the stopping of the engine by the turbocharger controller; and
checking the high cooling performance by measuring the coolant temperature when the engine is operated and measuring the oil temperature when the engine is operated by the turbocharger controller,
wherein the coolant temperature when the engine is operated and the oil temperature when the engine is operated are respectively compared to a predetermined coolant temperature and a predetermined oil temperature as thresholds to check the high cooling performance.

4. The method of claim 2 , wherein the high cooling performance vehicle control comprises:
respectively setting a measurement value of the coolant temperature and a measurement value of the oil temperature as the coolant temperature when the engine is stopped and the oil temperature when the engine is stopped by the turbocharger controller;
calculating a temperature-based operation time according to the coolant temperature and the oil temperature and a fuel-based operation time according to the coolant temperature and the fuel consumption by the turbocharger controller; and
defining the temperature-based operation time as the first EWP operation time A and the fuel-based operation time B as the second EWP operation time, and then selecting the final operation time as the maximum value between the first EWP operation time and the second EWP operation time by the turbocharger controller.

5. The method of claim 4 , wherein the coolant temperature when the engine is stopped and the oil temperature when the engine is stopped are respectively used as thresholds of a predetermined coolant temperature and a predetermined oil temperature, and a condition less than the thresholds is calculated as the temperature-based operation time.

6. The method of claim 4 , wherein an average fuel consumption is used as a threshold of a predetermined fuel consumption, and a condition equal to or more than the threshold is used as the fuel-based operation time.

7. The method of claim 1 , wherein during the turbocharger key-off cooling control, the engine coolant circulates in the turbocharger cooling line.

8. The method of claim 7 , wherein the turbocharger key-off cooling control comprises:
respectively setting a measurement value of the coolant temperature and a measurement value of the oil temperature as the coolant temperature when the engine is stopped and the oil temperature when the engine is stopped by the turbocharger controller;
calculating a temperature-based operation time based on the coolant temperature when the engine is stopped and the oil temperature when the engine is stopped by the turbocharger controller;
using a final operation time by application of an outside air temperature weight according to a measurement value of the outside air temperature for the temperature-based operation time by the turbocharger controller; and
circulating the engine coolant by operating the auxiliary electric water pump for the final operation time by the turbocharger controller.

9. An engine system comprising:
an engine;
a turbocharger for supplying turbocharged air to the engine for discharging exhaust gas from the engine;
a turbocharger cooling system including a turbocharger cooling circuit, an auxiliary electric water pump (EWP) positioned upstream of the turbocharger, an electric water pump (EWP) positioned upstream of the engine, and an oil cooler; and
a turbocharger controller,
wherein the turbocharger controller further includes executable program instructions stored in a non-transitory processor to:
receive an engine RPM, ignition on or off, a coolant temperature, an oil temperature, and an outside air temperature from a data input unit when the engine is stopped by an engine key-off immediately after the engine has been running;
determine an auxiliary electric water pump (EWP) operation time A of the coolant temperature and an oil temperature of the oil cooler and an EWP operation time B of the coolant temperature and a fuel consumption, and
operate the auxiliary electric water pump circulating the engine coolant to the turbocharger cooling circuit based on a final operation time selected as a maximum value between the auxiliary electric EWP operation time and the EWP operation time in a time map.

10. The engine system of claim 9 , wherein the turbocharger controller further includes executable program instructions to:
receive an accelerator pedal pressing amount, a vehicle speed during operation of the engine, the turbocharger, the auxiliary electric water pump, and the electric water pump.

11. The engine system of claim 9 , wherein the turbocharger controller further includes executable program instructions to:
generate a time map based on engine load;
generate a time map based on engine temperature;
generate a matching table for a cooling fan operation time of the auxiliary electric water pump for the engine load; and
generate an outside air temperature weight map provided with an operation time weight table for the cooling fan operation time of the auxiliary electric water pump,
wherein the operation time weight table multiplies a reference mapping value based on the coolant temperature and a weight value of the outside air temperature.

12. The engine system of claim 11 , wherein the time map based on engine load is based on a matching table for an average fuel co

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Lee Su-Ho
• Choi Jae-Seok
• Kwon Min-Young
• Lee Jun-Ho
• Kim Yong-Hoon
• Lee Yang-Geol

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02B39/16

  Other safety measures for, or other control of, pumps · CPC title

• F02B39/005 Primary

  Cooling of pump drives · CPC title

• F01P2060/12

  Turbo charger · CPC title

• F01P7/14 Primary

  the coolant being liquid · CPC title