Integrated control system and method

• US 8,567,355 B2
• Filed: 12/22/2010
• Issued: 10/29/2013
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Baldwin, Darryl, Wang, Paul Sai Keat, Kim, Myoungjin
• Primary Examiner(s): Low, Lindsay
• Assistant Examiner(s): BRAUCH, CHARLES JOSEPH
• Application Number:
  US12/976,811
• Publication Number:
  US 20120160191A1
• Time in Patent Office: 1,042 Days
• Field of Search: None
• US Class Current: 123/3
• CPC Class Codes: F02B 43/08 Plants characterised by the engines using gaseous fuel generated in the plant from solid fuel, e.g. wood
• CPC Class Codes: F02D 19/023 to adjust the fuel mass or volume flow
• CPC Class Codes: F02D 19/027 Determining the fuel pressure, temperature or volume flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02D 41/0027 the fuel being gaseous non-electrical control F02D19/02
• CPC Class Codes: F02M 21/0215 Mixtures of gaseous fuels; Natural gas; Biogas; Mine gas; Landfill gas
• CPC Class Codes: F02M 21/0227 Means to treat or clean gaseous fuels or fuel systems, e.g. removal of tar, cracking, reforming or enriching
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

An integrated control system for use with an engine connected to a generator providing electrical power to a switchgear is disclosed. The engine receives gas produced by a gasifier. The control system includes an electronic controller associated with the gasifier, engine, generator, and switchgear. A gas flow sensor monitors a gas flow from the gasifier to the engine through an engine gas control valve and provides a gas flow signal to the electronic controller. A gas oversupply sensor monitors a gas oversupply from the gasifier and provides an oversupply signal indicative of gas not provided to the engine. A power output sensor monitors a power output of the switchgear and provide a power output signal. The electronic controller changes gas production of the gasifier and the power output rating of the switchgear based on the gas flow signal, the oversupply signal, and the power output signal.

Claims

1. An integrated control system for use with an engine connected to a generator, the generator providing electrical power to a switchgear, the engine operating using a gas produced by a gasifier that is associated with the engine as a fuel source, the integrated control system comprising:

an electronic controller operably associated with the gasifier, the engine, the generator, and the switchgear, wherein the electronic controller includes a gasifier programmable logic controller, an engine electronic control module, and a switchgear controller that are adapted to exchange information with one another in a coordinated fashion;

a gas flow sensor disposed to monitor a gas flow from the gasifier to the engine through an engine gas control valve and provide a gas flow signal indicative of the gas flow to the electronic controller;

a gas oversupply sensor disposed to monitor a gas oversupply from the gasifier and provide an oversupply signal indicative of the gas oversupply to the electronic controller, wherein the gas oversupply is a portion of the gas flow from the gasifier that is not provided to the engine;

a power output sensor disposed to monitor a power output of the switchgear and provide a power output signal indicative of the power output to the electronic controller;

wherein the electronic controller is disposed to change a gas production of the gasifier and change a power output rating of the switchgear based on the gas flow signal, the oversupply signal, and the power output signal.

2. The integrated control system of claim 1, wherein the gas flow sensor includes a position sensor providing a position signal to the electronic controller indicative of an extent of opening of an engine gas supply valve supplying gas from the gasifier to the engine, and a pressure sensor disposed to monitor a pressure of gas accumulated in an accumulator disposed to receive gas from the gasifier and provide gas to the engine via the engine gas control valve, the pressure sensor being disposed to provide a pressure signal indicative of the pressure of gas to the electronic controller, and wherein the gas flow signal is calculated by the electronic controller based on the position signal and the pressure signal.

3. The integrated control system of claim 1, wherein the gas oversupply sensor includes at least one of a flame sensor and a pressure relief valve activation sensor.

4. The integrated control system of claim 1, wherein the electronic controller is further disposed to cause a reduction in gas production at the gasifier when the oversupply signal indicates that an oversupply of gas is present and is above a threshold value and when the power output signal is below a corresponding threshold value.

5. The integrated control system of claim 1, wherein the electronic controller is further disposed to increase an output rating of the switchgear when the oversupply signal indicates that an oversupply of gas is present and the power output signal is below a corresponding threshold value.

6. The integrated control system of claim 1, wherein the electronic controller is further disposed to decrease an output rating of the switchgear for a predetermined period when the oversupply signal indicates that there is no oversupply of gas, the power output signal indicates that that power output is at a desired level, and the gas flow signal is below a threshold value.

7. The integrated control system of claim 1, wherein the electronic controller is further disposed to decrease an output rating of the switchgear when the oversupply signal indicates that there is no oversupply of gas, the power output signal is below a threshold value, and the gas flow signal is above a threshold value.

8. The integrated control system of claim 1, wherein the electronic controller is further disposed to cause an increase in gas production at the gasifier when the oversupply signal indicates that there is no oversupply of gas, the power output signal is below a threshold value, and the gas flow signal is below a threshold value.

9. The integrated control system of claim 1, wherein the electronic controller further comprises a watchdog function configured to allow the changes to the output rating of the switchgear while a maximum derate condition has not been reached.

10. The integrated control system of claim 1, wherein the electronic controller is further disposed to monitor for an engine knocking condition and retard engine ignition timing when the engine knocking condition is detected.

11. The integrated control system of claim 10, further including a knock sensor configured to provide an engine knock signal to the electronic controller, the engine knock signal being indicative of a presence of an engine knocking condition, wherein the electronic controller is further disposed to analyze the engine knock signal and detect the engine knocking condition.

12. The integrated control system of claim 11, wherein the electronic controller is further disposed to retard engine timing by a predetermined amount when the engine knocking condition is present, and to re-advance engine timing while the engine knocking condition does not persist.

13. A method for the coordinated control of a system including a gasifier connected to an engine, the engine driving a generator connected to a switchgear that provides electrical power to a grid, the engine being configured to operate using a fuel provided to the engine in gaseous phase from the gasifier, the method comprising:

monitoring a gas flow from the gasifier to the engine through an engine gas control valve to provide a gas flow signal indicative of the gas flow;

monitoring a gas oversupply from the gasifier to provide an oversupply signal indicative of the gas oversupply, wherein the gas oversupply is a portion of the gas flow from the gasifier that is not provided to the engine;

monitoring a power output of the switchgear to provide a power output signal indicative of the power output;

changing, independently, a gas production of the gasifier and a power output rating of the switchgear based on the gas flow signal, the oversupply signal, and the power output signal.

14. The method of claim 13, further comprising reducing gas production at the gasifier when the engine operates at a steady state, the oversupply signal indicates that an oversupply of gas is present and is above a threshold value, and when the power output signal is below a corresponding threshold value.

15. The method of claim 13, further comprising increasing an output rating of the switchgear when the oversupply signal indicates that an oversupply of gas is present and the power output signal is below a corresponding threshold value.

16. The method of claim 13, further comprising decreasing an output rating of the switchgear for a predetermined period when the oversupply signal indicates that there is no oversupply of gas, the power output signal indicates that that power output is at a desired level, and the gas flow signal is below a threshold value.

17. The method of claim 13, further comprising decreasing an output rating of the switchgear when the oversupply signal indicates that there is no oversupply of gas, the power output signal is below a threshold value, and the gas flow signal is above a threshold value.

18. The method of claim 13, further comprising increasing gas production at the gasifier when the oversupply signal indicates that there is no oversupply of gas, the power output signal is below a threshold value, and the gas flow signal is below a threshold value.

19. The method of claim 13, further comprising allowing changes to the output rating of the switchgear while a maximum derate condition has not been reached.