PARTIAL AIR INLET CONTROL STRATEGY FOR AIR CONDITIONING SYSTEM

• US 20120009859A1
• Filed: 07/07/2010
• Published: 01/12/2012
• Est. Priority Date: 07/07/2010
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Wijaya, Halim, Madhavan, Ranganathan, Koberstein, Manfred, Jones, Curtis M.
• Granted Patent: US 10,639,961 B2
• Time in Patent Office: Days
• US Class Current: 454/75
• CPC Class Codes: B60H 1/00764 the input being a vehicle driving condition, e.g. speed B60H1/00828, B60H1/00864 take precedence
• CPC Class Codes: B60H 1/00785 by the detection of humidity or frost
• CPC Class Codes: B60H 1/00849 for selectively commanding the induction of outside or inside air B60H1/00842 takes precedence

Abstract

A system and method of selecting air intake between 100% fresh air mode and 100% recirculated air mode for optimum heating/cooling performance, fuel economy and/or high voltage (HV) battery power consumption is disclosed. The system and method includes a partial recirculation control strategy in which the air inlet door is moved progressively to any position by taking into account cooling/heating loads and cabin fogging probability. As cooling/heating loads increase the air inlet door moves toward 100% recirculation mode. As fogging probability increases the air inlet door moves toward 100% fresh air mode. By selectively choosing a position between 100% recirculation and 100% fresh air, fuel economy and/or HV battery power consumption is optimized without compromising passenger comfort or causing fogging on interior glass surfaces. In cooling applications the compressor load is minimized and air conditioning performance is improved due to the reduced evaporator cooling load. The direct result of this improvement is increased fuel economy in the case of the internal combustion vehicle, reduced engine on time in the case of the hybrid electric vehicle (due to reduced HV battery power consumption), and reduced HV battery power consumption in the case of the hybrid electric vehicle (HEV) and the electric vehicle (EV). In heating applications, as the heating load is reduced the fuel economy of the internal combustion (IC) engine will be improved, the engine on time is reduced in the case of the HEV, and HV battery power consumption is reduced in the case of the EV.

Claims

1. A system for economically controlling a heating, ventilation and air conditioning (HVAC) system for a vehicle having an interior and an exterior comprising:

a fresh air opening;

a recirculated air opening;

a conditioner for heating or cooling air from said fresh air opening or recirculated air from said recirculated air opening;

a movable air inlet mechanism operatively associated with at least one of said openings;

a controller for controlling said air inlet mechanism;

a humidity level/dew point sensor associated with the interior of the vehicle;

a controller to which said sensors are connected and to which said air inlet mechanism is connected, said controller including an algorithm programmed to cause said controller to selectively move said mechanism up to and including a position in which 100% of conditioned air in the vehicle is fresh air and up to and including a position in which 100% of conditioned air in the vehicle is recirculated air and to any position there between in response to fogging probability based upon information from said sensor.

2. The system of claim 1 further including a temperature sensor wherein said fogging probability is based additionally upon information from said temperature sensor.

3. The system of claim 2 wherein said temperature sensor is selected from the group consisting of an outside ambient temperature sensor associated with the outside of the vehicle and a glass temperature sensor associated with one or more of the vehicle'"'"'s windows.

4. The system of claim 1 further including a vehicle speed sensor and a blower speed sensor and in which said controller is programmed to select the position of said movable air flow regulator based on a combination of the speed of the vehicle, the blower speed, and the probability of fogging.

5. The system of claim 1 further including a vehicle speed sensor and in which said controller is programmed to select the position of said movable air flow regulator based on the speed of the vehicle and the probability of fogging.

6. The system of claim 1 further including a blower speed sensor and in which said controller is programmed to select the position of said movable air flow regulator based on the blower speed and the probability of fogging.

7. The system of claim 1 in which said controller is programmed to select the position of said movable air flow regulator based on the probability of fogging alone.

8. The system of claim 1 including one or more additional sensors selected from the group consisting of an in-car temperature sensor, a blower speed sensor, an air delivery mode sensor, an air intake flow regulator position sensor, a discharge air temperature sensor, an engine coolant temperature sensor, a gear selector sensor, a vehicle speed sensor, a wiper position sensor, a windshield temperature sensor, and a rear window temperature sensor.

9. A system for economically controlling a heating, ventilation and air conditioning (HVAC) system for a vehicle having an interior and an exterior comprising:

a fresh air opening;

a recirculated air opening;

a conditioner for heating or cooling air from said fresh air opening or recirculated air from said recirculated air opening;

a movable air inlet mechanism operatively associated with at least one of said openings;

a controller for controlling said air inlet mechanism;

at least one sensor used to determine fogging probability;

a vehicle speed sensor;

a blower speed sensor;

a controller to which said sensors are connected and to which said air inlet mechanism is connected, said controller including an algorithm programmed to cause said controller to selectively move said mechanism up to and including a position in which 100% of conditioned air in the vehicle is fresh air and up to and including a position in which 100% of conditioned air in the vehicle is recirculated air and to any position there between in response to information from the group consisting of data from a combination of said at least one sensor, said vehicle speed sensor, and said blower speed sensor, data from said at least one sensor and said vehicle speed sensor, data from said at least one sensor and said blower speed sensor, and data alone from said at least one sensor.

10. The system of claim 9 wherein said at least one sensor used to determine fogging probability is selected from the group consisting of a humidity level/dew point sensor associated with the interior of the vehicle and a temperature sensor associated with the outside of the vehicle.

11. The system of claim 10 wherein said temperature sensor is selected from the group consisting of an outside ambient temperature sensor and a glass temperature sensor associated with one or more of the vehicle'"'"'s windows.

12. The system of claim 10 including one or more additional sensors selected from the group consisting of an in-car temperature sensor, an air delivery mode sensor, an air intake flow regulator position sensor, a discharge air temperature sensor, an engine coolant temperature sensor, a gear selector sensor, a wiper position sensor, a windshield temperature sensor, and a rear window temperature sensor.

13. A method for economically controlling a heating, ventilation and air conditioning (HVAC) system of a vehicle which discharges a flow of air to a passenger cabin of the vehicle, the method comprising the steps of:

forming an HVAC system comprising a recirculation door and associated ducts capable of being moved between a full fresh air position, a full recirculated air position, and a partial re-circulated air position in response to at least one sensor comprising a humidity/dewpoint sensor;

calculating the fogging probability based upon information received from said humidity/dewpoint sensor; and

adjusting the position of said recirculation door in response to the calculated fogging probability.

14. The method of claim 13 wherein said HVAC system includes a temperature sensor.

15. The method of claim 14 wherein said temperature sensor is selected from the group consisting of an outside ambient temperature sensor associated with the outside of the vehicle and a glass temperature sensor associated with one or more of the vehicle'"'"'s windows.

16. The method of claim 13 including the step of minimizing or preventing air spillage due to the partial recirculation door position.

17. The method of claim 13 including the step of minimizing or preventing noise, vibration and harshness due to the partial recirculation door position.

18. The method of claim 13 including the step of minimizing or preventing air spillage as a function of vehicle speed.

19. The method of claim 13 including the step of minimizing or preventing noise, vibration and harshness as a function of vehicle speed.

20. The method of claim 13 including the step of inhibiting of partial recirculation control by any condition of the group consisting of defrost mode when the vehicle is not in the neutral or park position, engine coolant temperature upon reaching a specified value, and selection by the vehicle operator of any one of a heated windshield, a rear glass defroster, or a wiper after the engine is on for a predetermined time.

21. The method of claim 13 including the step of enabling the operation of the air conditioning system in the event of a high fogging risk.

22. The method of claim 13 including the step of forming a fogging probability lookup table.

23. The method of claim 22 wherein said calculation of fogging probability is based on the formula (100*(% RH+Fog Ctrl Band−

Fog Lookup Table)/Fog Ctrl Band)+Fog Constant.