Apparatus and method for optimizing operation of sugar dryers

• US 8,108,074 B2
• Filed: 02/12/2008
• Issued: 01/31/2012
• Est. Priority Date: 02/12/2008
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Boder, Howard M.
• Primary Examiner(s): DeCady, Albert
• Assistant Examiner(s): Lopez Alvarez, Olvin
• Application Number:
  US12/029,587
• Publication Number:
  US 20090204246A1
• Time in Patent Office: 1,449 Days
• Field of Search: 700/36, 700/208, 700/275, 700/103, 700/31, 700/29, 700/53, 34445-447, 344/83, 344/11, 34/68
• US Class Current: 700/274
• CPC Class Codes: G05B 13/048 using a predictor

Abstract

A method includes determining how to adjust one or more manipulated variables using at least one model. The one or more manipulated variables are associated with a sugar dryer. The method also includes generating one or more control signals to control one or more controlled variables associated with the sugar dryer. The one or more controlled variables include an outfall temperature associated with the sugar dryer, and the one or more manipulated variables include a rate at which wet material is provided to the sugar dryer. The sugar dryer could include multiple sugar dryers. At least two of the sugar dryers could operate using different fuels. The one or more control signals could be generated to control the rates at which the wet material is provided to the multiple sugar dryers based on costs associated with the different fuels.

Claims

1. An apparatus comprising:

at least one memory configured to store at least one model, the at least one model associated with manipulated variables and controlled variables, the manipulated variables and the controlled variables associated with multiple sugar dryers that operate using different fuels and that operate in parallel such that each sugar dryer can process wet material independent of one or more other sugar dryers; and

at least one processor configured to determine how to adjust the manipulated variables using the at least one model;

wherein the controlled variables include outfall temperatures associated with the sugar dryers;

wherein the manipulated variables include rates at which the wet material is provided to the sugar dryers;

wherein the at least one processor is configured to control the outfall temperature of each sugar dryer based on the rate at which the wet material is provided to that sugar dryer; and

wherein the at least one processor is configured to use an economic optimization to control the rates at which the wet material is provided to the sugar dryers based on different costs associated with the different fuels.

2. The apparatus of claim 1, wherein the at least one processor is configured to use the economic optimization in order to utilize the multiple sugar dryers to different extents based on the different costs associated with the different fuels.

3. The apparatus of claim 2, wherein the at least one processor is configured to use the economic optimization in order to maximize production of dried material using the sugar dryer associated with a cheaper fuel.

4. The apparatus of claim 1, wherein the controlled variables further include at least one of:

a moisture content associated with dried material leaving at least one of the sugar dryers, a flow of fuel used to produce a hot gas for at least one of the sugar dryers, a temperature associated with the hot gas, a pressure associated with the hot gas, and a quantity of the wet material provided to at least one of the sugar dryers.

5. The apparatus of claim 1, wherein the manipulated variables further include a temperature setpoint associated with a hot gas for at least one of the sugar dryers.

6. The apparatus of claim 1, wherein the at least one model is further associated with one or more disturbance variables, the one or more disturbance variables including at least one of:

a moisture content associated with the wet material, and an ambient temperature.

7. The apparatus of claim 1, wherein the economic optimization comprises one of:

a linear program economic optimization and a quadratic program economic optimization.

8. The apparatus of claim 1, wherein the at least one processor is further configured to generate a user interface for presentation to a user and to receive input from the user, the input associated with a change to at least one of:

a low limit value, a high limit value, and a setpoint associated with one of the controlled and manipulated variables.

9. A method comprising:

determining how to adjust manipulated variables using at least one model, the manipulated variables associated with multiple sugar dryers that operate using different fuels and that operate in parallel such that each sugar dryer can process wet material independent of one or more other sugar dryers; and

generating control signals to control controlled variables associated with the sugar dryers;

wherein the controlled variables include outfall temperatures associated with the sugar dryers;

wherein the manipulated variables include rates at which the wet material is provided to the sugar dryers;

wherein determining how to adjust the manipulated variables comprises determining how to control the outfall temperature of each sugar dryer based on the rate at which the wet material is provided to that sugar dryer; and

wherein determining how to adjust the manipulated variables further comprises using an economic optimization to control the rates at which the wet material is provided to the sugar dryers based on different costs associated with the different fuels.

10. The method of claim 9, wherein using the economic optimization to control the sugar dryers comprises using the economic optimization in order to utilize the multiple sugar dryers to different extents based on the different costs associated with the different fuels.

11. The method of claim 10, wherein using the economic optimization in order to utilize the multiple sugar dryers to different extents comprises using the economic optimization in order to maximize production of dried material using the sugar dryer associated with a cheaper fuel.

12. The method of claim 9, wherein the controlled variables further include at least one of:

a moisture content associated with dried material leaving at least one of the sugar dryers, a flow of fuel used to produce a hot gas for at least one of the sugar dryers, a temperature associated with the hot gas, a pressure associated with the hot gas, and a quantity of the wet material provided to at least one of the sugar dryers.

13. The method of claim 9, wherein the manipulated variables further include a temperature setpoint associated with a hot gas for at least one of the sugar dryers.

14. The method of claim 9, wherein the at least one model is further associated with one or more disturbance variables, the one or more disturbance variables including at least one of:

a moisture content associated with the wet material, and an ambient temperature.

15. The method of claim 9, wherein the economic optimization comprises one of:

a linear program economic optimization and a quadratic program economic optimization.

16. The method of claim 9, further comprising:

presenting a user interface to a user; and

receiving input from the user, the input associated with a change to at least one of;

a low limit value, a high limit value, and a setpoint associated with one of the controlled and manipulated variables;

wherein generating the control signals comprises generating the control signals based on at least one of;

the low limit value, the high limit value, and the setpoint.

17. The method of claim 9, further comprising outputting the control signals to the sugar dryers.

21. The method of claim 9, wherein determining how to adjust the manipulated variables further comprises determining how to control the outfall temperature each of sugar dryer based on (ii) a pressure setpoint associated with a bull ring coupling a gas burner or a coal fluidized bed to that sugar dryer.

18. A non-transitory computer readable medium embodying a computer program, to be executed by a sugar dryer controller, the computer program comprising:

computer readable program code for determining how to adjust manipulated variables using at least one model, the manipulated variables associated with multiple sugar dryers that operate using different fuels and that operate in parallel such that each sugar dryer can process wet material independent of one or more other sugar dryers; and

computer readable program code for generating control signals to control controlled variables associated with the sugar dryers;

wherein the controlled variables include outfall temperatures associated with the sugar dryers;

wherein the manipulated variables include rates at which the wet material is provided to the sugar dryers;

wherein the computer readable program code for determining how to adjust the manipulated variables comprises computer readable program code for determining how to control the outfall temperature of each sugar dryer based on the rate at which the wet material is provided to that sugar dryer; and

wherein the computer readable program code for determining how to adjust the manipulated variables further comprises computer readable program code for using an economic optimization to control the rates at which the wet material is provided to the sugar dryers based on different costs associated with the different fuels.

19. The computer readable medium of claim 18, wherein the computer readable program code for using the economic optimization to control the sugar dryers comprises computer readable program code for using the economic optimization in order to utilize the multiple sugar dryers to different extents based on the different costs associated with the different fuels.

20. The computer readable medium of claim 19, wherein the computer readable program code for using the economic optimization to utilize the multiple sugar dryers to different extents comprises computer readable program code for using the economic optimization in order to maximize production of dried material using the sugar dryer associated with a cheaper fuel.