Control system and method for controlling a gas generating system

• US 6,051,192 A
• Filed: 04/15/1997
• Issued: 04/18/2000
• Est. Priority Date: 04/15/1997
• Status: Expired due to Fees

• Current Assignee: International Fuel Cells Corporation (Doosan Corporation)
• Original Assignee: International Fuel Cells Corporation (Doosan Corporation)
• Inventors: Grubb, Paul A., VanDine, Leslie L., Maston, Valerie A., Smith, Raymond M., Malinowski, Theodore S., Sederquist, Richard A.
• Primary Examiner(s): Tran, Hien
• Assistant Examiner(s): KENNEDY, JAMES C
• Application Number:
  US08/838,119
• Time in Patent Office: 1,099 Days
• Field of Search: 422/110, 422/111, 422/105, 422/182, 423/418.2, 423/245.3, 48/85, 429/23, 429/22, 429/24, 364/528.09
• US Class Current: 422/110
• CPC Class Codes: B01J 19/0006 Controlling or regulating processes controlling or regulating in general G05
• CPC Class Codes: B01J 8/001 Controlling catalytic processes B01J8/1809 takes precedence
• CPC Class Codes: C01B 3/32 by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
• CPC Class Codes: H01M 8/0612 from carbon-containing material
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A control system and method for controlling a fuel processing system operational to produce a gas for a downstream process from a fuel, wherein the fuel processing system uses a plurality of fuel processing elements, a fuel input and a waste gas input, each of the fuel processing elements having an individual output and the plurality of fuel processing elements having a collective output, and wherein the downstream process has a waste gas output and a dynamic gas load demand. The control system includes a device for receiving communication from the downstream process indicative of the dynamic load demand and a device for controlling the collective output level of the gas in response to the dynamic load demand. The device for controlling is operative to at least one of substantially equally distribute the dynamic load demand among the plurality of fuel processing elements such that the individual outputs from each of the fuel processing elements are substantially equal to each other for forming the collective output and most efficiently distribute the dynamic load among the plurality of fuel processing elements such that at least one of the individual outputs contributes to the collective output.

Claims

1. A control system for controlling a fuel processing system operational to produce a gas for a downstream process from a fuel, wherein said fuel processing system uses a plurality of fuel processing elements, a fuel input and a waste gas input, each of said fuel processing elements having an individual output and said plurality of fuel processing elements having a collective output, and wherein the downstream process has a waste gas output and a dynamic load demand, comprising:

means for receiving communication from said downstream process indicative of said dynamic load demand; and

means for controlling the collective output level of said gas in response to said dynamic load demand, wherein said means for controlling includes at least one of;

means for substantially equally distributing said dynamic load demand among said plurality of fuel processing elements such that said individual outputs from each of said fuel processing elements are substantially equal to each other for forming said collective output, and

means for most efficiently distributing said dynamic load among said plurality of fuel processing elements such that at least one of said individual outputs contributes to said collective output wherein said means for most efficiently distributing includes means for determining the most efficient combination of said individual fuel processing elements for forming said collective output in response to said dynamic load demand.

2. The control system according to claim 1, wherein said means for controlling further comprises:

means for sensing temperature within each of said plurality of fuel processing elements,

means for increasing, decreasing and maintaining flow level of said fuel into each of said plurality of fuel processing elements as required by said load demand,

means for increasing, decreasing and maintaining flow of waste gas into each of said fuel processing elements for processing said fuel to produce said gas, wherein as said flow level of said fuel is increased into said fuel input, said temperature is increased within a temperature range by increasing flow of said waste gas into said waste gas input, and

means for determining the sufficiency of said waste gas for reaching and maintaining said temperature as required to process said fuel at said collective output level mandated by said load demand;

wherein if said waste gas is sufficient for reaching and maintaining said temperature as required to process said fuel at said flow level responsive to said load demand, said means for controlling further for maintaining said fuel flow level if said waste gas is insufficient for reaching and maintaining said temperature as required to process said fuel at said flow level responsive to said load demand, said means for controlling further for one of reducing said flow level of said fuel to another flow level at which said waste gas is sufficient and causing the retrieval of additional waste gas from another source for maintaining said temperature for supporting said fuel flow level.

3. The control system, according to claim 2, wherein said means for increasing, decreasing, and maintaining fuel flow level and flow of waste gas comprise flow control elements.

4. The control system according to claim 3, further including means for increasing and decreasing flow of air and steam into said fuel processing elements, wherein said flow of said air and steam increases with an increase in the flow of said waste gas and fuel flow level and decreases with a decrease in the flow of said waste gas and fuel flow level.

5. The control system according to claim 2, wherein said means for determining comprises means for sensing the quantity and content of said waste gas, wherein if said quantity and content are sufficient for reaching and maintaining said temperature as required to process said fuel at said flow level responsive to said load demand, said means for controlling maintains said fuel flow level and if one of said quantity and content is insufficient for reaching and maintaining said temperature as required to process said fuel at said level responsive to said load demand, said means for controlling one of decreases said flow level to another level at which said quantity and content are sufficient and causes the retrieval of additional waste gas from another source for reaching and maintaining said temperature.

6. The control system according to claim 1, wherein each of said fuel processing elements has an operating range, said means for controlling the collective output level further including means for causing each of said elements to operate at substantially equivalent individual operating levels for producing a cumulative operating level and a cumulative output of said gas responsive to said dynamic gas load demand.

7. The control system according to claim 1, wherein said means for controlling includes means for interfacing with said means for receiving for acquiring commands indicative of the collective output level required by said load demand.

8. The control system according to claim 1, wherein said means for receiving comprises a central command control unit.

9. A method for controlling a fuel processing system operational to produce a gas for a downstream process from a fuel, wherein said system uses a plurality of fuel processing elements, a fuel input and a waste gas input, each of said fuel processing elements having an individual output and said plurality of fuel processing elements having a collective output, and wherein the downstream process has a waste gas output and a dynamic gas load demand, comprising:

receiving communication from said downstream process indicative of said load demand;

controlling the collective output level of said gas in response to said communication, wherein said step of controlling includes at least one of;

substantially equally distributing said dynamic load demand among said plurality of fuel processing elements such that said individual outputs from each of said fuel processing elements are substantially equal to each other for forming said collective output, and

most efficiently distributing said dynamic load among said plurality of fuel processing elements such that at least one of said individual outputs contributes to said collective output wherein said step of most efficiently distributing includes the step of determining the most efficient combination of said individual fuel processing elements or forming said collective output in response to said dynamic load demand.

10. The method according to claim 9, wherein said step of controlling further comprises the steps of:

sensing temperature within each of said plurality of fuel processing elements,

at least one of increasing, decreasing, and maintaining said flow level of said fuel into each of said plurality of fuel processing elements,

at least one of increasing, decreasing, and maintaining flow of said waste gas into each of said fuel processing elements for processing said fuel to produce said gas, wherein as said fuel flow level is increased into said fuel input, said temperature is increased by increasing flow of said waste gas into said waste gas input,

determining the sufficiency of said waste gas for reaching and maintaining said temperature as required to process said fuel at a level of said flow mandated by said load demand;

wherein if said waste gas is sufficient for reaching and maintaining said temperature as required to process said fuel flowing at said level responsive to said load demand, further comprising the step of maintaining said fuel flow level; and

wherein if said waste gas is insufficient for reaching and maintaining said temperature as required to process said fuel flowing at said flow level responsive to said load demand, further comprising at least one of reducing said flow level to another level at which said waste gas is sufficient and retrieving additional waste gas from another source for reaching and maintaining said temperature as required to process said fuel as determined by said collective output level in response to said load demand.

11. The method according to claim 10, further including the step of at least one of increasing, decreasing, and maintaining flow of air and steam into said fuel processing elements, wherein said flow of said air and steam increases with the increase of the flow of said waste gas and fuel flow level and decreases with the decrease of the flow of said waste gas and fuel flow level.

12. The method according to claim 10, wherein said step of determining comprises the step of sensing the quantity and content of said waste gas, wherein if said quantity and content are sufficient for reaching and maintaining said temperature as required to process said fuel at said flow level responsive to said load demand, further comprising the step of maintaining said fuel flow level and if one of said quantity and content is insufficient for reaching and maintaining said temperature as required to process said fuel at said level responsive to said load demand, further comprising one of decreasing said flow level to another level at which said quantity and content are sufficient and retrieving additional waste gas from another source for reaching and maintaining said temperature.

13. The method according to claim 9, wherein each of said fuel processing elements has an operating range, said step of controlling the collective output level further including the step of causing each of said elements to operate at substantially equivalent individual operating levels for producing a cumulative operating level and a cumulative output of said gas responsive to said dynamic gas load demand.

14. The method according to claim 9, further including the step of controlling the collective output level in response to said communication by commanding said means for controlling to change said collective output levels.