Model based bump-less transfer between passive and active mode operation of three-way check valve for liquid fuel delivery in gas turbine systems

Patent metadata

Field	Value
Publication number	US-10443510-B2
Application number	US-201615210382-A
Country	US
Kind code	B2
Filing date	Jul 14, 2016
Priority date	Jul 14, 2016
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

A method using an inverse three-way valve model with feed-forward fuel flow control is provided for controlling liquid fuel flow in a turbine power generation system to achieve a bump-less driven watts (dwatt) power output during fuel mode transitions between passive mode and active mode operations of a three-way check valve that delivers liquid fuel to the turbine combustor nozzles. The method utilizes an inverse fluid flow model for a three-way check valve which is based upon a valve position surrogate for the three-way check valve to develop a calculated estimate of a fuel spike/dwatt oscillation likely to occur during mode transitions of the three-way check valve and to produce a feed-forward control used to modulate a fuel path bypass valve within the turbine fuel supply circulation system that provides the liquid fuel to the three-way valve during transfers of valve operation between passive and active mode operations.

First claim

What is claimed is:

1. A method for controlling liquid fuel flow to one or more three-way check valves used for delivering fuel to a turbine combustor in a turbine power generation system during transfers between passive and active modes of check valve operation, the turbine power generation system including a combustor fuel delivery three-way check valve and a bypass valve, the method comprising:
producing a fuel flow spike signal based on an inverse operational model of the three-way check valve, the fuel flow spike signal indicative of an inverse of a fuel flow spike occurring during mode transfers of a fuel delivery three-way check valve between passive and active modes;
wherein the inverse operational model is developed by:
calculating a stroke of a three-way check valve delivering fuel to a combustor as a function of a measured pressure differential between a purge air pressure for the valve and a liquid fuel pressure that initiates a mode transfer process;
calculating a fluid flow resistance across the three-way check valve as a function of the calculated stroke of the three-way check valve;
calculating a fluid flow through the three-way check valve as a function of the calculated fluid flow resistance and a measured pressure difference existing between upstream and downstream sides of the three-way check valve;
calculating a fuel flow spike likely to occur as a result of the transfer of the valve between modes as a function of a difference in the calculated fluid flow and a known steady state flow for the three-way check valve; and
determining an inverse of the calculated fuel flow spike;

generating a bypass valve position command based on the fuel flow spike signal; and
providing the bypass valve position command to the bypass valve during transfers between passive and active modes of the three-way check valve operation in a feed-forward control manner that counteracts or mitigates a fuel flow spike associated with such mode transfers.

2. The method of claim 1 wherein the inverse operational model utilizes input data indicative of liquid fuel pressures existing upstream and downstream of the three-way check valve.

3. The method of claim 1 wherein the inverse operational model utilizes input data indicative of purge air pressure at the three-way check valve.

4. The method of claim 1 wherein the inverse operational model produces analytic output data indicative of a valve position for the three-way check valve.

5. The method of claim 1 wherein the bypass valve position command is developed from a fuel flow feedback signal indicative of liquid fuel flow through the three-way valve augmented by the fuel flow spike signal.

6. The method of claim 1 wherein the bypass valve position command is developed based on a fuel flow reference signal and a fuel flow feedback signal augmented by the fuel flow spike signal.

7. The method of claim 1 wherein the generating of the bypass valve position command includes determining an augmented fuel flow feedback signal as a function of the fuel flow spike signal.

8. The method of claim 1 wherein the inverse operational model further includes a model tuning algorithm configured to periodically check steady state error between a calculated fuel flow for the three-way check valve and a measured fuel flow through the three-way check valve, and make incremental changes to a calculated valve stroke value and/or a calculated flow resistance value and/or a value indicative of a calculated fluid flow through the three-way check valve.

9. A turbine power generation control system for controlling liquid fuel flow to a fuel delivery three-way check valve used for providing liquid fuel to a turbine combustor, comprising:
a fuel delivery three-way check valve;
a fuel bypass valve; and
a turbine system controller, the turbine system controller including a hardware processor configured to operate as an inverse operational model of the three-way check valve and to produce a fuel flow spike signal indicative of an inverse of a fuel flow spike which occurs during mode transitions of the three-way check valve between passive and active operational modes; and
a bypass valve controller, the bypass valve controller generating a bypass valve position command based on the fuel flow spike signal and providing the bypass valve position command to the fuel bypass valve during transfers of the three-way check valve operation between passive and active modes, wherein fuel flow spikes and output power oscillations resulting from transitions between operational modes for the three-way check valve operation are mitigated;
wherein the processor is configured to implement the inverse operational model by performing operations comprising:
calculating a stroke of the three-way check valve delivering fuel to a combustor as a function of a measured pressure differential between a purge air pressure for the valve and a liquid fuel pressure that initiates a mode transfer process;
calculating a fluid flow resistance across the three-way check valve as a function of the valve stroke of the three-way check valve;
calculating a fluid flow through the three-way check valve as a function of the calculated fluid flow resistance and a measured pressure difference existing between upstream and downstream sides of the three-way check valve;
calculating a fuel flow spike likely to occur as a result of the transfer of the valve between modes as a function of a difference in the calculated fluid flow and a known steady state flow for the three-way check valve; and
determining an inverse of the calculated fuel flow spike.

10. The system of claim 9 wherein the processor produces analytic output data indicative of a valve position for the three-way check valve based on the inverse operational model.

11. The system of claim 9 further comprising a signal augmenter which augments a fuel flow feedback signal indicative of liquid fuel flow through the three-way check valve with the fuel flow spike estimation signal.

12. The system of claim 9 wherein the bypass valve controller generates the valve position command based on a fuel flow feedback signal indicative of liquid fuel flow through the three-way check valve augmented by the fuel flow spike signal.

13. The system of claim 12 wherein the bypass valve position command is developed from a fuel flow feedback signal augmented by the fuel flow spike.

14. The system of claim 12 wherein the bypass valve position command is developed based on a fuel flow reference signal and a fuel flow feedback signal augmented by the fuel flow spike signal.

Assignees

• Gen Electric

Inventors

• Pobbati Omprakash
• Unnikrishnan Sunil
• Vavilala Pradeep Kumar
• Den Outer James Frederick

Classifications

• F02C9/263

  by means of fuel metering valves · CPC title

• F05D2270/71

  synthesized, i.e. parameter computed by a mathematical model · CPC title

• F02C7/232

  Fuel valves {(control of fuel supply by means of fuel metering valves F02C9/263)}; Draining valves or systems (valves in general F16K) · CPC title

• F02C9/32 Primary

  characterised by throttling of fuel (F02C9/38 takes precedence) · CPC title

• F05D2270/44

  active, predictive, or anticipative · CPC title