Dual zone automatic climate control algorithm utilizing heat flux analysis

• US 6,782,945 B1
• Filed: 02/26/2003
• Issued: 08/31/2004
• Est. Priority Date: 02/26/2003
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Technical Center North America Incorporated (Nissan Motor Co., Ltd.)
• Inventors: Eisenhour, Ronald S.
• Primary Examiner(s): WAYNER, WILLIAM E
• Application Number:
  US10/373,202
• Publication Number:
  US 20040164171A1
• Time in Patent Office: 552 Days
• Field of Search: 236/49.3, 236/91.C, 621/79, 454/258, 165/203
• US Class Current: 165/203
• CPC Class Codes: B60H 1/00064 for sending air streams of different temperatures into the passenger compartment
• CPC Class Codes: B60H 1/0075 the input being solar radiation
• CPC Class Codes: B60H 2001/00185 Distribution of conditionned air

Abstract

A method for automatically controlling the climate in a plurality of climate control zones of a cabin of an automobile comprising at least a driver zone and a passenger zone having a temperature sensor located in a driver side zone and at least one conditioned air outlet vent in each of the zones, the method comprising, obtaining various values indicative of internal and external climate, determining outlet temperatures and mass flow rates of at least one of a driver zone outlet and at least one of a passenger zone outlet based at least on the above obtained values and on other factors relating to the design of the automobile, including a zone air crossover influence factor, providing conditioned air to the cabin from at least one of the driver zone outlets and at least one of the passenger zone outlets at the determined outlet temperatures and mass flow rates.

Claims

1. A method for automatically controlling the climate in a plurality of climate control zones of a cabin of an automobile comprising at least a first zone and a second zone having a temperature sensor located in the first zone and a conditioned air outlet vent in each of the zones, the method comprising:

obtaining a target temperature value for the first zone and the second zone;

obtaining a first zone temperature value estimate from the sensor in the first zone;

obtaining an ambient air temperature value;

obtaining a sun load heat flux value for at least one of the first zone and the second zone;

obtaining a first zone gain factor value based at least on the first zone temperature value estimate;

automatically determining the outlet temperatures and mass flow rates of the first zone outlet and the second zone outlet based at least on the above obtained values and on a conduction/convection heat transfer coefficient between the cabin and ambient air, an effective glass area for solar load transmission, a zone air crossover influence factor, and predetermined constraints on the relationship of the outlet temperatures and air flow, wherein the zone air crossover influence factor is a factor based on blending of air in the cabin; and

providing conditioned air to the cabin from the first zone outlet and the second zone outlet at outlet temperatures and mass flow rates correlating to the determined outlet temperatures and mass flow rates.

2. The method of claim 1, wherein the zone air crossover influence factor is variable and depends on an air distribution mode.

3. The method of claim 1, further including calculating an error term and subtracting it from the second zone outlet temperature to establish a new second zone outlet temperature, the error term comprising a value based on the first zone target temperature value, the first zone temperature value estimate, the mass air flow rate of the second zone outlet, and a second zone gain factor value based at least on the first zone temperature value estimate, wherein the conditioned air provided to the second zone is at the new second zone outlet temperature.

4. The method of claim 3, wherein the first zone gain factor value and the second zone gain factor value are approximately equal when the first zone temperature estimate is between about 20°

C. and about 28°

C.

5. The method of claim 4, wherein the first zone gain factor value and the second zone gain factor value vary inversely in relation to changing first zone temperature estimates between at least the range from about 10°

C. to about 20°

C. and between at least the range from about 28°

C. to about 35°

C.

6. The method of claim 5, wherein the first zone gain factor value decreases with increasing first zone temperature estimates below about 20°

C. and increases with increasing first zone temperature estimates above about 28°

C.

7. The method of claim 1, further including calculating an overset value to be added to the second zone outlet temperature value, the overset value comprising a value based on the second zone target temperature value, the conduction/convection heat transfer coefficient between the cabin and the ambient air, and the mass air flow rate, as adjusted by a value that sets the strength of the overshoot.

8. The method of claim 1, wherein the mass flow rate of the conditioned air provided to the first zone is about the same as the mass flow rate of the conditioned air provided to the second zone.

9. The method of claim 8, further including calculating a minimum mass air flow rate based on the conduction/convection heat transfer coefficient between the cabin and the ambient air, the second zone target temperature value, the ambient air temperature value, the sun load heat flux value for the second zone, the effective glass area for solar load transmission, and a capacity temperature value selected from a group consisting of a constant cooling device temperature and a constant heating device temperature, and wherein the mass air flow rate of the conditioned air delivered to the cabin is based on the calculated minimum mass air flow rate.

10. The method of claim 9, wherein the mass air flow rate of the air delivered to the cabin is limited to a predetermined maximum mass air flow rate above a variable mass flow rate based on predetermined constraints.

11. The method of claim 10, wherein the variable mass flow rate based on predetermined constraints is substantially correlated to various blower voltages, the maximum mass air flow rate is substantially correlated to the blower voltage, and wherein the maximum mass air flow rate is limited to an equivalent blower voltage that is no greater than about 2 volts above the equivalent voltage of the mass air flow rate based on predetermined constraints.

12. The method of claim 1, wherein the conditioned air provided to the cabin from the first zone outlet and the second zone outlet at outlet temperatures and mass flow rates is equal to the determined outlet temperatures and mass flow rates, respectively.

13. The method of claim 1, wherein the first zone is a driver zone and the second zone is the passenger zone.

14. A method for automatically controlling the climate in a plurality of climate control zones of a cabin of an automobile comprising at least a first zone and a second zone having a temperature sensor located in a first zone and an conditioned air outlet vent in each of the zones, the method comprising at least utilizing an algorithm relating to at least equations

15. The method of claim 14, wherein

16. The method of claim 15, wherein Ge and Ge′

are approximately equal when the first zone temperature estimate is between about 20°

C. and about 28°

C.

17. The method of claim 16, wherein Ge and Ge′

vary inversely in relation to changing first zone temperature estimates between at least the range from about 10°

C. to about 20°

C. and between at least the range from about 28°

C. to about 35°

C.

18. The method of claim 17, wherein Ge decreases with increasing first zone temperature estimates below about 20°

C. and increases with increasing first zone temperature estimates above about 28°

C.

19. The method of claim 14, wherein

20. The method of claim 14, further including calculating a minimum mass air flow rate from the equation:

21. The method of claim 20, wherein the mass air flow rate of the air delivered to the cabin is limited to a predetermined maximum mass air flow rate above a variable mass flow rate based on predetermined constraints.

22. The method of claim 21, wherein the variable mass flow rate based on predetermined constraints is substantially correlated to various blower voltages, the maximum mass air flow rate is substantially correlated to the blower voltage, and wherein the maximum mass air flow rate is limited to an equivalent blower voltage that is no greater than about 2 volts above an equivalent voltage of the mass air flow rate based on predetermined constraints.

23. The method of claim 14, wherein the conditioned air provided to the cabin from the first zone outlet and the second zone outlet at outlet temperatures and mass flow rates is equal to the determined outlet temperatures and mass flow rates, respectively.

24. An automobile having an automatic climate control system according to claim 23.

25. The method of claim 14, wherein the constraints include human constraint factors that modify thermodynamic constraint factors in the relationship of air flow and the outlet temperatures, and wherein the method further includes repeatedly addressing the constraints in response to incremental changes in variables in the equations to effect a change that will result in a modification of the outlet temperatures.

26. The method of claim 14, wherein the first zone is a driver zone and the second zone is the passenger zone.

27. An automatic climate control apparatus for automatically controlling climate in a plurality of climate control zones of a cabin of an automobile comprising at least a first zone and a second zone, comprising:

an air blower adapted to blow conditioned air into the cabin;

an air outlet vent in the first zone in fluid communication with the air blower;

an air outlet vent in the second zone in fluid communication with the air blower;

an air cooling device and an air heating device in fluid communication with the air blower, the first zone vent, and the second zone vent;

a temperature sensor located in the first zone adapted to provide a temperature value estimate of the first zone;

an electronic processor device comprising a processor and a memory, wherein the memory is adapted to store a plurality of equations, the plurality of equations including equations for the air outlet temperatures and mass flow rates of the first zone outlet and the second zone outlet, the equations being based on variables including;

a target temperature value for the first zone and the second zone;

a first zone temperature value estimate;

an ambient air temperature value;

a sun load heat flux value for at least one of the first zone and the second zone;

a first zone gain factor value based at least on the first zone temperature value estimate;

a conduction/convection heat transfer coefficient between the cabin and the ambient air;

an effective glass area for solar load transmission; and

a zone air crossover influence factor, wherein the zone air crossover influence factor is a factor based on blending of air in the cabin;

wherein

the electronic processor is adapted to automatically control and adjust mass flow rate and temperature of the air being blown from the vents based on the equations as constrained by predetermined constraints on the relationship of the outlet temperatures and air flow.

28. The apparatus of claim 27, further including a device adapted to vary the amount of air entering the cabin that has passed through or around the air heating device.

29. The apparatus of claim 27, wherein the conditioned air provided to the cabin from the first zone outlet and the second zone outlet at outlet temperatures and mass flow rates is equal to the determined outlet temperatures and mass flow rates, respectively.

30. The apparatus of claim 27, wherein the first zone is a driver zone and the second zone is the passenger zone.

31. A climate control device for controlling at least one component of a climate control system that controls climate in a plurality of climate control zones of a cabin of an automobile comprising at least a first zone and a second zone, comprising:

a device adapted to receive a signal representing mass flow rate of conditioned air being blown into the cabin;

a device adapted to output a signal to control heating and cooling of air being blown into the cabin;

a device adapted to output a signal to control the mass flow rate of air being blown into the cabin;

a device adapted to receive a signal representative of a sensed temperature inside the cabin;

a device storing an algorithm based on at least a plurality of equations, the plurality of equations including equations for air outlet temperatures and mass flow rates of first zone outlet and second zone outlet, the equations being based on variables including;

a target temperature value for the first zone and the second zone;

a first zone temperature value estimate;

an ambient air temperature value;

a sun load heat flux value for at least one of the first zone and the second zone;

a first zone gain factor value based at least on the first zone temperature value estimate;

a conduction/convection heat transfer coefficient between the cabin and ambient air;

an effective glass area for solar load transmission; and

a zone air crossover influence factor, wherein the zone air crossover influence factor is a factor based on blending of air in the cabin; and

a device storing a plurality of predetermined constraints on a relationship of the first zone and second zone outlet temperatures and air flow;

wherein

the control device is adapted to automatically output a signal to control and adjust the mass flow rate and temperature of air being blown from the vents based on the equations as constrained by the predetermined constraints on the relationship of the outlet temperatures and air flows.

32. The apparatus of claim 31, wherein the first zone is a driver zone and the second zone is the passenger zone.

33. A method for automatically controlling climate in a plurality of climate control zones of a cabin of an automobile comprising at least a first zone and a second zone having a temperature sensor located in the first zone and a temperature sensor located in the second zone and an conditioned air outlet vent in each of the zones, the method comprising:

obtaining a target temperature value for the first zone and the second zone;

obtaining temperature value estimates for the first zone and the second zone from the first zone temperature sensor and the second zone temperature sensor respectively;

obtaining an ambient air temperature value;

obtaining a sun load heat flux value for at least one of the first zone and the second zone;

obtaining at least one of a gain factor value based the first zone temperature value estimate and a gain factor value based on the second zone temperature value estimate;

automatically determining outlet temperatures and mass flow rates of the first zone outlet and the second zone outlet based at least on the above obtained values and on a conduction/convection heat transfer coefficient between the cabin and ambient air, an effective glass area for solar load transmission, a zone air crossover influence factor, and predetermined constraints on a relationship of the outlet temperatures and air flow;

wherein the zone air crossover influence factor is a factor based on blending of air in the cabin; and

,

providing conditioned air to the cabin from the first zone outlet and the second zone outlet at outlet temperatures and mass flow rates correlating to the determined outlet temperatures and mass flow rates.

34. The method of claim 33, wherein the zone air crossover influence factor is variable and depends on an air distribution mode.

35. The method of claim 33, wherein the mass flow rate of the conditioned air provided to the first zone is about the same as the mass flow rate of the conditioned air provided to the second zone.

36. The method of claim 35, further including calculating a minimum mass air flow rate based on the conduction/convection heat transfer coefficient between the cabin and the ambient air, the second zone target temperature value, the ambient air temperature value, the sun load heat flux value for the second zone, the effective glass area for solar load transmission, and a capacity temperature value selected from a group consisting of a constant cooling device temperature and a constant heating device temperature, wherein the mass air flow rate of the conditioned air delivered to the cabin is based on the calculated minimum mass air flow rate.

37. The method of claim 36, wherein the mass air flow rate of the air delivered to the cabin is limited to a predetermined maximum mass air flow rate above a variable mass flow rate based on predetermined constraints.

38. The method of claim 37, wherein the variable mass flow rate based on predetermined constraints is substantially correlated to various blower voltages, the maximum mass air flow rate is substantially correlated to the blower voltage, and wherein the maximum mass air flow rate is limited to an equivalent blower voltage that is no greater than about 2 volts above the equivalent voltage of the mass air flow rate based on predetermined constraints.

39. The method of claim 33, wherein the conditioned air provided to the cabin from the first zone outlet and the second zone outlet at outlet temperatures and mass flow rates is equal to the determined outlet temperatures and mass flow rates, respectively.

40. The method of claim 38, wherein the first zone is a driver zone and the second zone is the passenger zone.

41. A method for automatically controlling climate in a plurality of climate control zones of a cabin of an automobile comprising at least a first zone and a second zone and having a temperature sensor located in the first zone and a temperature sensor located in the second zone and an air outlet vent in each of the zones, the method comprising at least utilizing an algorithm relating to at least equations:

42. The method of claim 41, wherein the conditioned air provided to the cabin from the first zone outlet and the second zone outlet at outlet temperatures and mass flow rates is equal to the determined outlet temperatures and mass flow rates, respectively.

43. The method of claim 42, wherein GA_(D) is equal to or about equal to GA_(P).

44. The method of claim 42, wherein Ge_(D) is equal to or about equal to Ge_(P).

45. The method of claim 43, further including calculating a minimum mass air flow rate from the equation:

 

GA_(D/P)=K·

(TGT(P)−

Ta−

q_s(P)·

GL/K)/(Capacity Temperature−

TGT(P))

where Capacity Temperature is a value selected from a group consisting of a constant cooling device temperature and a constant heating device temperature, and wherein the mass air flow rate of the conditioned air delivered to the cabin is based on the calculated minimum mass air flow rate.

46. The method of claim 45, wherein the mass air flow rate of the air delivered to the cabin is limited to a predetermined maximum mass air flow rate above a variable mass flow rate based on predetermined constraints.

47. The method of claim 45, wherein the variable mass flow rate based on predetermined constraints is substantially correlated to various blower voltages, the maximum mass air flow rate is substantially correlated to the blower voltage, and wherein the maximum mass air flow rate is limited to an equivalent blower voltage that is no greater than about 2 volts above the equivalent voltage of the mass air flow rate based on predetermined constraints.

48. The method of claim 41, wherein the first zone is a driver zone and the second zone is the passenger zone.

49. An automatic climate control apparatus for automatically controlling climate in a plurality of climate control zones of a cabin of an automobile comprising at least a first zone and a second zone, comprising:

an air blower adapted to blow conditioned air into the cabin;

an air outlet vent in the first zone in fluid communication with the air blower;

an air outlet vent in the second zone in fluid communication with the air blower;

an air cooling device and an air heating device in fluid communication with the air blower, the first zone vent, and the second zone vent;

a temperature sensor located in the first zone adapted to provide a temperature value estimate of the first zone;

an electronic processor device comprising a processor and a memory, wherein the memory is adapted to store a plurality of equations, the plurality of equations including equations for the air outlet temperatures and mass flow rates of the first zone outlet and the second zone outlet, the equations being based on variables including;

a target temperature value for the first zone and the second zone;

a first zone temperature value estimate;

an ambient air temperature value;

a sun load heat flux value for at least one of the first zone and the second zone;

a first zone gain factor value based at least on the first zone temperature value estimate;

a conduction/convection heat transfer coefficient between the cabin and ambient air;

an effective glass area for solar load transmission; and

a zone air crossover influence factor, wherein the zone air crossover influence factor is a factor based on blending of air in the cabin;

wherein

the electronic processor is adapted to automatically control and adjust the mass flow rate and the temperature of the air being blown from the vents based on the equations as constrained by predetermined constraints on the relationship of the outlet temperatures and air flow.

50. The apparatus of claim 49, wherein the first zone is a driver zone and the second zone is the passenger zone.

51. A method for automatically controlling the climate in a plurality of climate control zones of a cabin of an automobile comprising at least a first zone and a second zone having a temperature sensor located in a first zone and an conditioned air outlet vent in each of the zones, the method comprising at least utilizing an algorithm relating to at least equations

52. A method for automatically controlling climate in a plurality of climate control zones of a cabin of an automobile comprising at least a first zone and a second zone and having a temperature sensor located in the first zone and a temperature sensor located in the second zone and an air outlet vent in each of the zones, the method comprising at least utilizing an algorithm relating to at least equations: