Engine cooling system and method

Patent metadata

Field	Value
Publication number	US-10450941-B2
Application number	US-201815885346-A
Country	US
Kind code	B2
Filing date	Jan 31, 2018
Priority date	Jan 31, 2018
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

Methods and systems are provided for expediting engine cooling while reducing the overall energy consumption of the engine cooling system's components. A first circulation pump is used to pump coolant through an engine block as a function of engine output while a second radiator pump is selectively operated when a thermostat valve is open to pump coolant through a radiator and the engine block to effect the engine coolant temperature. Operation of the second pump is coordinated with the operation of a radiator cooling fan and grille shutters to improve radiator performance.

First claim

The invention claimed is:

1. An engine coolant system, comprising:
a first pump coupled between a thermostat and a cylinder head;
a second pump coupled between the thermostat and a radiator fan;
grille shutters;
a first temperature sensor for sensing coolant temperature at a radiator outlet; and
a second temperature sensor for sensing the coolant temperature at a radiator inlet.

2. The system of claim 1 , further comprising a controller including computer-readable instructions stored on non-transitory memory for:
adjusting an output of the first pump based on engine power, the first pump operated independent of a state of the thermostat; and
selectively operating the second pump responsive to the thermostat being open.

3. The system of claim 2 , further comprising an engine coolant temperature (ECT) sensor and a cylinder head temperature (CHT) sensor, and wherein adjusting the output of the first pump based on engine power includes adjusting the output of the first pump as a difference between sensed engine temperature and target engine temperature increases, the sensed engine temperature including sensed ECT or sensed CHT.

4. The system of claim 3 , wherein the controller includes further instructions for adjusting the target engine temperature as a function of each of intake air temperature, engine power, and feedback knock from a knock sensor.

5. The system of claim 4 , wherein the target engine temperature is lowered as the intake air temperature decreases, the engine power increases, or the feedback knock increases.

6. The system of claim 3 , wherein the output of the first pump is increased monotonically as the difference between the sensed engine temperature and the target engine temperature increases.

7. The system of claim 2 , wherein adjusting the output of the first pump includes adjusting one or more of pump speed, pump flow rate, and pump output pressure.

8. The system of claim 3 , wherein adjusting the output of the first pump based on engine power includes increasing the output of the first pump until sensed engine temperature is at the target engine temperature.

9. The system of claim 1 , wherein selectively operating the second pump responsive to the thermostat being open includes when the thermostat is open, adjusting an output of the second pump as a function of a difference between sensed radiator inlet temperature (RIT) and sensed radiator outlet temperature (ROT).

10. The system of claim 9 , wherein the output of the second pump is increased as the difference between sensed RIT and sensed ROT decreases.

11. The system of claim 3 , wherein an opening temperature of the thermostat is set to be lower than the target engine temperature.

12. The system of claim 1 , wherein the controller includes further instructions for:
while operating the second pump, adjusting a speed of the radiator fan and a degree of opening of the grill shutters to maintain a threshold difference between temperature at the radiator inlet and the radiator outlet.

13. A method, comprising:
circulating coolant through a cylinder head via a first pump, independent of a state of a thermostat valve, as a function of engine temperature; and
circulating coolant through the cylinder head via a second pump, based on the state of the thermostat valve, as a function of the engine temperature.

14. The method of claim 13 , wherein the first pump is coupled in an engine coolant line between the thermostat and the cylinder head and the second pump is coupled in the engine coolant line between the thermostat and a radiator fan.

15. The method of claim 13 , wherein the circulating via the first pump includes increasing an output of the first pump monotonically as the engine temperature exceeds a target temperature, the target temperature selected as a function of intake air temperature, feedback knock, and engine load.

16. The method of claim 15 , further comprising opening the thermostat responsive to the engine temperature being within a threshold of the target temperature, and wherein the circulating via the second pump includes enabling the pump responsive to the thermostat being open, and adjusting an output of the second pump as the engine temperature exceeds the target temperature.

17. The method of claim 16 , further comprising, while the thermostat is open, adjusting each of a radiator fan speed and a grille shutter opening responsive to a sensed radiator inlet temperature and a sensed radiator inlet temperature to maintain a larger than threshold temperature difference across the radiator.

18. A method for an engine, comprising:
while a thermostat of a coolant line is closed, maintaining engine temperature at or below a target temperature via a first coolant pump; and
while the thermostat is open, maintaining the engine temperature below the target temperature via each of the first coolant pump and a second coolant pump, the second pump coupled upstream of the first pump in the coolant line.

19. The method of claim 18 , further comprising, while the thermostat is open, adjusting each of a radiator fan speed and a grille shutter opening to maintain a threshold difference between a sensed radiator inlet temperature and a sensed radiator outlet temperature.

20. The method of claim 18 , further comprising, opening the thermostat valve responsive to the engine temperature being within a threshold of the target temperature, the target temperature selected as a function of intake air temperature, feedback knock, and engine load, the target temperature lowered as the intake air temperature decreases, feedback knock increases, or engine load increases.

Assignees

• Ford Global Tech Llc

Inventors

• Cunningham Ralph
• Ulrey Joseph
• Pursifull Ross

Classifications

• F01P2005/105

  Using two or more pumps · CPC title

• F01P7/165

  characterised by systems with two or more loops · CPC title

• F01P7/164 Primary

  by varying pump speed · CPC title

• F01P7/16

  by thermostatic control · CPC title

• F01P7/04

  by varying pump speed, e.g. by changing pump-drive gear ratio · CPC title