Climate Thermal Load Based Minimum Flow Rate Water Pump Control

• US 20130094972A1
• Filed: 10/18/2011
• Published: 04/18/2013
• Est. Priority Date: 10/18/2011
• Status: Abandoned Application

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Smith, Mark G., Jackson, Kenneth J., Thompson, Scott James, Abihana, Osama A.
• Application Number:
  US13/275,360
• Publication Number:
  US 20130094972A1
• Time in Patent Office: Days
• US Class Current: 417/32
• CPC Class Codes: F01P 2025/13 Ambient temperature
• CPC Class Codes: F01P 7/164 by varying pump speed
• CPC Class Codes: F04B 49/065 and making use of computers

Abstract

A control system for minimizing the flow rate and energy consumption of a water pump in a vehicle. The control system and method correlate a climate thermal load value with the temperature of the coolant in a climate control cooling circuit. A correlation is performed by mapping the inputs to a desired pump flow rate that is determined to be necessary at a minimum to provide adequate cooling for the engine and for air conditioning or heating the vehicle.

Claims

1. A system for controlling a water pump in a vehicle comprising:

an electric motor operating the water pump;

a controller generating a heater core flow request signal as a function of a climate thermal load and a heater coolant temperature; and

providing a signal to the motor to set the pump flow rate to satisfy the heater core flow request.

2. The system of claim 1 wherein the determining step includes selecting a pump flow rate based upon a table of values corresponding to a plurality of climate thermal load values and a plurality of heater coolant temperature values.

3. The system of claim 1 wherein the climate thermal load value is based upon the cabin temperature set point, and ambient air temperature.

4. The system of claim 1 wherein the heater coolant temperature is obtained from a thermal sensor that senses the temperature of the coolant at an inlet to a heater core.

5. The system of claim 1 wherein the pump flow rate is selected to minimize power consumption by the electric motor and increase fuel economy.

6. The system of claim 1 wherein the controller determines whether a heating ventilation and air conditioning (HVAC) selector is set to a maximum defrost setting and wherein the pump flow rate is at a maximum value.

7. The system of claim 1 wherein the controller determines whether an HVAC selector is requesting cabin temperature change.

8. The system of claim 1 wherein the climate thermal load value is obtained from a vehicle bus.

9. A method of controlling a water pump in a vehicle comprising:

setting the water pump at maximum flow if a maximum defrost input is actuated;

if the maximum defrost input is not actuated, setting the water pump to no flow if the HVAC input is not actuated;

if the HVAC input is actuated, integrating a climate thermal load value and a heater coolant temperature value using a multiple variable table to select a heater core flow rate, and if the heater core flow rate is greater than a threshold value, providing a signal to an electric motor that controls the flow rate of the water pump.

10. The method of claim 9 wherein the threshold value is zero.

11. The method of claim 9 wherein the HVAC input includes a thermistor and a variable temperature selector switch for controlling the temperature of a passenger compartment.

12. The method of claim 9 wherein the integrating step includes selecting a heater core flow rate based upon a table of values corresponding to a plurality of climate thermal load values and a plurality of heater coolant temperature values.

13. The method of claim 9 wherein the climate thermal load value is based upon the cabin temperature set point, and ambient air temperature.

14. The method of claim 9 wherein the heater core flow rate is selected to minimize power consumption by the electric motor and increase fuel economy.

15. A heating ventilation and air conditioning (HVAC) system for a vehicle having an electric motor driven water pump, the system comprising:

a heater core;

an HVAC selector having a heat request setting, an air cooling request setting and a maximum defrost setting;

a climate module that provides a thermal load value;

a coolant temperature sensor that determines the temperature of a coolant;

a controller that provides a coolant flow request value to the water pump, wherein the coolant flow request is set to a maximum if the maximum defrost setting is actuated, wherein the coolant flow request is set at zero if the heat request setting is off, and a heater core flow rate is set based upon the thermal load value and coolant temperature value; and

wherein if the heater core flow rate is greater than zero, the heater core flow is mapped to the water pump speed.

16. The system of claim 15 wherein the controller selects the coolant flow request based upon a table of values corresponding to a plurality of climate thermal load values and a plurality of coolant temperature values.

17. The system of claim 15 wherein the heat request setting and the air cooling request setting is compared to a passenger compartment temperature signal for controlling the temperature of a passenger compartment.

18. The system of claim 15 wherein the controller integrates a table of values corresponding to a plurality of climate thermal load values and a plurality of heater coolant temperature values.

19. The system of claim 15 wherein the coolant temperature sensor is a cylinder head temperature sensor from which the temperature of the coolant is inferred.

20. The system of claim 15 wherein the thermal load value is based upon a cabin temperature sensor signal, a cabin temperature set point, an ambient temperature signal, and a sun load sensor signal.