Transient turbine exhaust temperature control for a turbogenerator

• US 6,612,112 B2
• Filed: 11/05/2001
• Issued: 09/02/2003
• Est. Priority Date: 12/08/1998
• Status: Expired due to Term

• Current Assignee: Capstone Turbine Corp.
• Original Assignee: Capstone Turbine Corp.
• Inventors: Gilbreth, Mark, Edelman, Ed, Wacknov, Joel, Wall, Simon
• Primary Examiner(s): Casaregola, Louis J.
• Application Number:
  US10/012,770
• Publication Number:
  US 20020121091A1
• Time in Patent Office: 666 Days
• Field of Search: 60/392.81, 607/73
• US Class Current: 60/773
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F02C 7/08 Heating air supply before combustion, e.g. by exhaust gases
• CPC Class Codes: F02C 9/26 Control of fuel supply F02C9/48 takes precedence; fuel valves F02C7/232
• CPC Class Codes: F02C 9/32 characterised by throttling of fuel F02C9/38 takes precedence
• CPC Class Codes: F05D 2270/02 to control rotational speed (n)
• CPC Class Codes: F05D 2270/053 Explicitly mentioned power
• CPC Class Codes: F05D 2270/06 to match engine to driven device
• CPC Class Codes: F05D 2270/093 of one engine in a multi-engine system
• CPC Class Codes: F05D 2270/303 Temperature
• CPC Class Codes: F05D 2270/304 Spool rotational speed

Abstract

A turbogenerator is controlled by a temperature loop that provides fuel to the combustor to maintain a desired turbine exhaust temperature, and by a speed control loop that controls the speed of the turbogenerator to provide a desired power output. When the desired power output is reduced, the turbogenerator speed is reduced accordingly, and the desired turbine exhaust temperature is increased temporarily to maintain sufficient fuel flow to the combustor to prevent combustor flame-out.

Claims

1. A method for controlling a turbogenerator, comprising:

operating the turbogenerator at a selected speed to provide a selected amount of power;

providing fuel to the turbogenerator to maintain a turbine exhaust temperature at a first selected value;

reducing the turbogenerator speed to provide a reduced amount of power;

providing fuel to the turbogenerator to maintain the turbine exhaust temperature at a second selected value higher than the first selected value for a selected period of time; and

gradually increasing the amount of fuel provided to the turbogenerator over the selected period of time to maintain the turbine exhaust temperature at the second selected value.

2. The method of claim 1, wherein reducing the turbogenerator speed comprises:

reducing the turbogenerator speed to provide a reduced amount of power in response to a reduction in power demand.

3. The method of claim 2, wherein reducing the turbogenerator speed comprises:

reducing the turbogenerator speed to provide a reduced amount of power in response to a specified reduction in the power demand.

4. A method for controlling a turbogenerator, comprising:

operating the turbogenerator at a selected speed to provide a selected amount of power;

providing fuel to the turbogenerator to maintain a turbine exhaust temperature at a first selected value;

reducing the turbogenerator speed to provide a reduced amount of power, wherein reducing the turbogenerator speed comprises reducing the turbogenerator speed to provide a reduced amount of power in response to a reduction in power demand;

providing fuel to the turbogenerator to maintain the turbine exhaust temperature at a second selected value higher than the first selected value for a selected period of time; and

prior to reducing the turbogenerator speed, allowing a specified period of time to lapse after the reduction in the power demand.

5. The method of claim 4, wherein reducing the turbogenerator speed comprises:

reducing the turbogenerator speed to provide a reduced amount of power in response to a specified reduction in the power demand.

6. A method for controlling a turbogenerator, comprising:

operating the turbogenerator at a selected speed to provide a selected amount of power;

providing fuel to the turbogenerator to maintain a turbine exhaust temperature at a first selected value;

reducing the turbo generator speed to provide a reduced amount of power; and

providing fuel to the turbogenerator to maintain the turbine exhaust temperature at a second selected value higher than the first selected value for a selected period of time,

wherein the period of time is selected in accordance with characteristics of a heat recuperator associated with the turbogenerator.