Cooking appliance and method for limiting cooking utensil temperatures using time-to-target criteria

• US 10,260,755 B2
• Filed: 07/11/2016
• Issued: 04/16/2019
• Est. Priority Date: 07/11/2016
• Status: Active Grant

• Current Assignee: Haier US Appliance Solutions, Inc. DBA GE Appliances (Haier Group Company)
• Original Assignee: Haier US Appliance Solutions, Inc. DBA GE Appliances (Haier Group Company)
• Inventors: Bach, James Carter
• Primary Examiner(s): Paschall, Mark H
• Application Number:
  US15/206,400
• Publication Number:
  US 20180010805A1
• Time in Patent Office: 1,009 Days
• Field of Search: 219491, 219492, 219497, 219506, 219702, 219710, 219719
• CPC Class Codes: F24C 7/087 of electric circuits regulating heat
• CPC Class Codes: F24C 7/088 on stoves
• CPC Class Codes: H05B 1/0261 of food
• CPC Class Codes: H05B 3/748 Resistive heating elements, i.e. heating elements exposed to the air, e.g. coil wire heater H05B3/742 takes precedence
• CPC Class Codes: H05B 6/062 for cooking plates or the like

Abstract

Cooking appliances and methods for operating cooking appliances are provided. In one exemplary embodiment, a method for operating a cooking appliance is provided. The method includes providing power to the heating source according to a first control mode; determining whether to transition from the first control mode to a second control mode and, if so, then providing power to the heating source according to the second control mode. The method further includes determining whether to transition from the second control mode to a third control mode and, if so, then providing power to the heating source according to the third control mode. The cooking appliances and methods include features for limiting cooking utensil temperatures using time-to-target criteria.

Claims

1. A method for operating a cooking appliance, the method comprising:

providing power to the heating source according to a first control mode, the first control mode comprising calculating a time interval t_limit for a temperature of a cooking utensil positioned on the heating source to reach a target temperature limit T_limit;

determining whether the time interval t_limit to reach the target temperature limit T_limit is less than or equal to a predetermined time interval limit t_{turn_off} and, if so, then

providing power to the heating source according to a second control mode, the second control mode comprising reducing the heating source power to a minimum power level P_min and incrementing a timer t_off;

determining whether the timer t_off has surpassed a threshold time t_thr and, if so, then

providing power to the heating source according to a third control mode,

wherein power is provided to the heating source in the third control mode using a proportional-integral or proportional-integral-derivative control algorithm.

2. The method of claim 1, wherein the first control mode comprises

providing power to the heating source based on a power level input.

3. The method of claim 1, wherein a temperature sensor contacts a bottom surface of the cooking utensil to sense the temperature of the cooking utensil.

4. The method of claim 1, further comprising, if the time interval t_limit to reach the target temperature limit T_limit is greater than the predetermined time interval limit t_{turn_off},

determining whether the temperature of the cooking utensil is at least equal to the target temperature limit T_limit and, if so, then

proceeding to providing power to the heating source according to the second control mode.

5. The method of claim 4, further comprising, if the temperature of the cooking utensil is less than the target temperature limit T_limit,

continuing to provide power to the heating source according to the first control mode.

6. The method of claim 1, further comprising, if the time interval t_limit to reach the target temperature limit T_limit is less than or equal to the predetermined time interval limit t_{turn_off},

determining whether the temperature of the cooking utensil is at least equal to an enabling threshold temperature T_thr before proceeding to providing power to the heating source according to the second control mode.

7. The method of claim 1, further comprising, if the timer t_off has not surpassed the threshold time t_thr,

determining whether a temperature of a cooking utensil positioned on the heating source is at least equal to the target temperature limit T_limit and, if so, then

proceeding to providing power to the heating source according to the third control mode.

8. The method of claim 7, further comprising, if the temperature of the cooking utensil is less than the target temperature limit T_limit,

determining whether the temperature of the cooking utensil is less than or equal to a disabling threshold temperature T_resume and, if so, then

returning to providing power to the heating source according to the first control mode.

9. The method of claim 1, further comprising determining whether to transition from the second control mode to the first control mode and, if so, then

returning to providing power to the heating source according to the first control mode.

10. The method of claim 9, wherein determining whether to transition from the second control mode to the first control mode comprises comparing a temperature of a cooking utensil positioned on the heating source to a disabling threshold temperature T_resume.

11. The method of claim 1, further comprising determining whether to transition from the third control mode to the first control mode and, if so, then

returning to providing power to the heating source according to the first control mode.

12. The method of claim 11, wherein determining whether to transition from the third control mode to the first control mode comprises comparing a temperature of a cooking utensil positioned on the heating source to a disabling threshold temperature T_resume.

13. A cooking appliance, comprising:

a heating source;

a temperature sensor, the temperature sensor positioned to sense the temperature of a bottom surface of a cooking utensil when the cooking utensil is placed on or adjacent to the heating source;

an energy control device for modulating the power provided to the heating source;

a controller, the controller in operative communication with the temperature sensor and the energy control device, the controller configured for

providing power to the heating source according to a first control mode, the first control mode comprising calculating a time interval t_limit for a temperature of a cooking utensil positioned on the heating source to reach a target temperature limit T_limit;

determining whether the time interval t_limit to reach the target temperature limit T_limit is less than or equal to a predetermined time interval limit t_{turn_off} and, if so, then

providing power to the heating source according to a second control mode, the second control mode comprising reducing the heating source power to a minimum power level P_min and incrementing a timer t_off;

determining whether the timer t_off has surpassed a threshold time t_thr and, if so, then

providing power to the heating source according to a third control mode,

wherein power is provided to the heating source in the third control mode using a proportional-integral or proportional-integral-derivative control algorithm.

14. The cooking appliance of claim 13, wherein the temperature sensor is a spring-loaded temperature sensor.

15. The cooking appliance of claim 13, further comprising a shield extending circumferentially around the temperature sensor.

16. A cooking appliance, comprising:

a heating source;

a temperature sensor, the temperature sensor positioned to sense the temperature T_sensed of a bottom surface of a cooking utensil when the cooking utensil is placed on or adjacent to the heating source;

an energy control device for modulating the power provided to the heating source;

a controller, the controller in operative communication with the temperature sensor and the energy control device, the controller configured for

providing power to the heating source according to a first control mode, the first control mode comprising calculating a time interval t_limit for a temperature of a cooking utensil positioned on the heating source to reach a target temperature limit T_limit;

determining whether the time interval t_limit to reach the target temperature limit T_limit is less than or equal to a predetermined time interval limit t_{turn_off} and, if so, then

providing power to the heating source according to a second control mode, the second control mode comprising reducing the heating source power to a minimum power level P_min and incrementing a timer t_off;

determining whether the timer t_off has surpassed a threshold time t_thr and, if so, then

providing power to the heating source according to a third control mode;

comparing the temperature T_sensed sensed by the temperature sensor to a disabling threshold temperature T_resume to determine if the temperature T_sensed of the cooking utensil is less than the disabling threshold temperature T_resume and, if so, then

 

providing power to the heating source according to the first control mode,

 

wherein power is provided to the heating source in the third control mode using a proportional-integral or proportional-integral-derivative control algorithm.

17. The cooking appliance of claim 16, wherein the controller is further configure for, if the time interval t_limit to reach the target temperature limit T_limit is greater than the predetermined time interval limit t_{turn_off},

determining whether the temperature of the cooking utensil is at least equal to the target temperature limit T_limit and, if so, then proceeding to providing power to the heating source according to the second control mode but, if not, then continuing to provide power to the heating source according to the first control mode.

18. The cooking appliance of claim 16, wherein the controller is further configured for, if the timer t_off has not surpassed the threshold time t_thr,

determining whether a temperature of a cooking utensil positioned on the heating source is at least equal to the target temperature limit T_limit and, if so, then proceeding to providing power to the heating source according to the third control mode, but if the temperature of the cooking utensil is less than the target temperature limit T_limit,

determining whether the temperature of the cooking utensil is less than or equal to the disabling threshold temperature T_resume and, if so, then

returning to providing power to the heating source according to the first control mode.

19. The cooking appliance of claim 16, wherein power is provided to the heating source in the third control mode using a proportional-integral control algorithm wherein the power provided to the heating source equals the sum of an integral term I and the product of a proportional gain factor K_p and a temperature error T_err.

20. The cooking appliance of claim 16, wherein the time interval t_limit is calculated as a difference between the target temperature limit T_limit and a current cooking utensil temperature T_sensed(0), divided by a rate of change Δ

T of the temperature T_sensed sensed by the temperature sensor.