# US 2023/0057599 A1 · Start-up sequence for gaseous fuel engine

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- Number: US 2023/0057599 A1
- Document ID: US20230057599A1
- Status: Published application
- Kind: A1
- Application number: 17/406,655
- Filed: 2021-08-19
- Published: 2023-02-23
- Earliest claimed: 2021-08-19
- Applicants: Pratt & Whitney Canada Corp.
- Inventors: Thomas DILLON; Todd MILLER
- Web page: https://patentgrep.com/patent/US20230057599A1

## CPC

- F02C 7/264: Ignition
- F02C 9/00: Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants (controlling air intakes F02C7/057; controlling turbines F01D; controlling compressors F04D27/00; controlling in general G05)
- F01D 19/00: Starting of machines or engines; Regulating, controlling, or safety means in connection therewith (warming-up before starting F01D25/10; turning or inching gear F01D25/34)
- F02C 7/22: Fuel supply systems
- F05D 2220/32: in gas turbines
- F05D 2240/35: Combustors or associated equipment
- F05D 2260/85: Starting
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

Methods and systems for starting an engine are described. The method comprises a manifold purging phase where the at least one fuel manifold is filled with an inert gas; a manifold fuel filling phase, where fuel flows into the at least one manifold and blends with the inert gas as the engine rotates, and the inert gas is subsequently turned off; and an ignition phase, where the fuel flowing from the at least one manifold into the combustor is ignited and light-up is detected.

## Claims

### Claim 1

A method for starting an engine coupled to a fuel system having at least one fuel manifold configured to supply fuel to a combustor of the engine, the method comprising:
a manifold purging phase where the at least one fuel manifold is filled with an inert gas;
a manifold fuel filling phase, where the fuel flows into the at least one manifold and blends with the inert gas as the engine rotates, the inert gas and the fuel allowed to flow into the at east on fuel manifold during the manifold fuel filling phase, and the inert gas is subsequently turned off; and
an ignition phase, where the fuel flowing from the at least one manifold into the combustor is ignited and light-up is detected.

### Claim 2 (depends on 1)

The method of claim 1, wherein the fuel is a gaseous fuel.

### Claim 3 (depends on 1)

The method of claim 1, wherein the fuel system is a dual fuel system for gaseous fuel and liquid fuel.

### Claim 4 (depends on 1)

The method of claim 1, wherein the inert gas is turned off by switching a common flow-diverter valve from the inert gas to the fuel.

### Claim 5 (depends on 1)

The method of claim 1, wherein the at least one manifold comprises a first manifold and a second manifold, and wherein the manifold purging phase comprises filling the first manifold and the second manifold with the inert gas.

### Claim 6 (depends on 5)

The method of claim 5, wherein the manifold fuel filling phase comprises flowing the fuel into the first manifold and isolating the second manifold from the fuel, and wherein the ignition phase comprises allowing the fuel to flow into the second manifold post-light-up.

### Claim 7

(canceled)

### Claim 8 (depends on 1)

The method of claim 1, wherein the at least one manifold comprises a plurality of manifolds, and the plurality of manifolds are filled with the inert gas concurrently.

### Claim 9 (depends on 1)

The method of claim 1, further comprising determining that one or more conditions for an inert gas manifold purge are met prior to initiating the manifold purging phase.

### Claim 10 (depends on 1)

The method of claim 1, wherein the manifold fuel filling phase comprises reducing a flow rate of the fuel flow prior to igniting the fuel in the combustor.

### Claim 11

A system for starting an engine coupled to a fuel system having at least one fuel manifold configured to supply fuel to a combustor of the engine, the system comprising:
a processor; and
a non-transitory computer-readable medium having stored thereon program code executable by the processor for:
a manifold purging phase where the at least one fuel manifold is filled with an inert gas;
a manifold fuel filling phase, where the fuel flows into the at least one manifold and blends with the inert gas as the engine rotates, the inert gas and the fuel allowed to flow into the at least one fuel manifold during the manifold fuel filling phase, and the inert gas is subsequently turned off; and
an ignition phase, where the fuel flowing from the at least one manifold into the combustor is ignited and light-up is detected.

### Claim 12 (depends on 11)

The system of claim 11, wherein the fuel is a gaseous fuel.

### Claim 13 (depends on 11)

The system of claim 11, wherein the fuel system is a dual fuel system for gaseous fuel and liquid fuel.

### Claim 14 (depends on 11)

The system of claim 11, wherein the inert gas is turned off by switching a common flow-diverter valve from the inert gas to the fuel.

### Claim 15 (depends on 11)

The system of claim 11, wherein the at least one manifold comprises a first manifold and a second manifold, and wherein the manifold purging phase comprises filling the first manifold and the second manifold with the inert gas.

### Claim 16 (depends on 15)

The system of claim 15, wherein the manifold fuel filling phase comprises flowing the fuel into the first manifold and isolating the second manifold from the fuel, and wherein the ignition phase comprises allowing the fuel to flow into the second manifold post-light-up.

### Claim 17

(canceled)

### Claim 18 (depends on 11)

The system of claim 11, wherein the at least one manifold comprises a plurality of manifolds, and the plurality of manifolds are filled with the inert gas concurrently.

### Claim 19 (depends on 11)

The system of claim 11, wherein the program code is further executable for determining that one or more conditions for an inert gas manifold purge are met prior to initiating the manifold purging phase.

### Claim 20 (depends on 11)

The system of claim 11, wherein the manifold fuel filling phase comprises reducing a flow rate of the fuel flow prior to igniting the fuel in the combustor.

### Claim 21 (depends on 1)

The method of claim 1, wherein the engine is an aircraft engine.

### Claim 22 (depends on 11)

The system of claim 11, wherein the engine is an aircraft engine.