Fuel-air pre-mixer with prefilmer

Patent metadata

Field	Value
Publication number	US-9441836-B2
Application number	US-201213545418-A
Country	US
Kind code	B2
Filing date	Jul 10, 2012
Priority date	Jul 10, 2012
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A fuel-air premixer for a combustor of a gas turbine engine includes a central passage disposed along an axis and operable to communicate a first airflow and an outer annular passage about the axis operable to communicate a second airflow. The fuel-air premixer further includes an inner annular passage about the axis and between the central passage and the outer annular passage for communicating fuel flow. The inner annular passage including an inner exit angled for directing fuel flow toward the axis into a mixer passage downstream of the outer and inner exits for mixing the fuel flow with the first and second airflows.

First claim

What is claimed is:

1. A fuel-air premixer for a combustor of a gas turbine engine comprising:
a central passage disposed along an axis for a first airflow;
an outer annular passage disposed about the central passage and operable to communicate a second airflow through an outer exit into the central passage, wherein at least one of the first and second airflows is non-swirled;
an inner annular passage disposed between the central passage and the outer annular passage and operable for communicating a fuel flow into the central passage, the inner annular passage including an inner exit angled for directing fuel flow toward the axis, wherein the outer exit is axially forward of the inner exit;
a first heat shield disposed between the inner annular passage and the outer annular passage and a second heat shield between the central passage and the inner annular passage; and
a mixer passage downstream of the outer exit and the inner exit for mixing the fuel flow with the first and second airflows.

2. A fuel-air premixer for a combustor of a gas turbine engine comprising:
a central passage disposed along an axis for a first airflow;
an outer annular passage disposed about the central passage and operable to communicate a second airflow through an outer exit into the central passage, wherein at least one of the first and second airflows is non-swirled;
an inner annular passage disposed between the central passage and the outer annular passage and operable for communicating a fuel flow into the central passage, the inner annular passage including an inner exit angled for directing fuel flow toward the axis;
opening passages communicating fuel to the inner annular passage, the opening passages angled relative to the axis to induce a swirl into fuel flow through the inner annular passage and exiting through the inner exit; and
a mixer passage downstream of the outer exit and the inner exit for mixing the fuel flow with the first and second airflows.

3. The fuel-air premixer as recited in claim 2 , wherein the angle of the opening passages relative to the axis induces a tangential swirl to the fuel flow exiting through the inner exit.

4. The fuel-air premixer as recited in claim 3 , wherein the inner annular passage comprises a baffle for spreading fuel flow exiting through the inner exit.

5. The fuel-air premixer as recited in claim 1 , wherein the outer annular passage includes an outer exit angled for directing the second airflow radially inward toward the axis.

6. The fuel-air premixer as recited in claim 5 , wherein the outer annular passage is configured to provide the second airflow as an unswirled airflow.

7. The fuel-air premixer as recited in claim 1 , wherein the central passage is configured to provide the first airflow as an unswirled airflow.

8. The fuel-air premixer as recited in claim 1 , wherein the mixing passage defines a mixing length forward of the inner exit, wherein the mixing length comprises a length for mixing the first and second airflows and the fuel flows to a desired level at a desired fuel flow rate.

9. A combustor assembly for a gas turbine engine comprising:
a combustion chamber; and
a fuel-air mixer in communication with the combustion chamber, the fuel-air mixer including:
a central passage disposed along an axis and operable to communicate a first airflow,
an outer annular passage disposed about the central passage and operable to communicate a second airflow through an outer exit into the central passage, wherein at least one of the first and second airflows is non-swirled,
an inner annular passage disposed between the central passage and the outer annular passage operable for communicating fuel flow into the central passage, the inner annular passage including an inner exit angled for directing fuel flow toward the axis, wherein the outer exit is axially forward of the inner exit;
a baffle within the inner annular passage for spreading fuel flow exiting through the inner exit; and
a mixer passage downstream of the outer and inner exits for mixing the fuel flow with the first and second airflows.

10. The combustor assembly as recited in claim 9 , wherein the mixer includes a length spacing the outer and inner exits from the combustion chamber, wherein the length defines a mixing length where fuel from the inner exits mixes with the first and second airflows.

11. A combustor assembly for a gas turbine engine comprising:
a combustion chamber; and
a fuel-air mixer in communication with the combustion chamber, the fuel-air mixer including:
a central passage disposed along an axis and operable to communicate a first airflow,
an outer annular passage disposed about the central passage and operable to communicate a second airflow through an outer exit into the central passage, wherein at least one of the first and second airflows is non-swirled, wherein the other annular passage includes an outer exit angled for directing the second airflow radially inward toward the axis,
an inner annular passage disposed between the central passage and the outer annular passage operable for communicating fuel flow into the central passage, the inner annular passage including an inner exit angled for directing fuel flow toward the axis,
opening passages communicating fuel to the inner annular passage, the opening passages angled relative to the axis to induce swirl into fuel flow through the inner annular passage and the inner exit, and
a mixer passage downstream of the outer and inner exits for mixing the fuel flow with the first and second airflows.

12. The combustor assembly as recited in claim 11 , wherein the inner annular passage includes a baffle for spreading fuel flow exiting through the inner exit.

13. A gas turbine engine assembly comprising:
a fan including a plurality of fan blades rotatable about an axis;
a compressor section
a combustor in fluid communication with the compressor section, the combustor including a combustion chamber and fuel-air mixer including a central passage disposed along an axis for a first airflow, an outer annular passage disposed about the central passage and operable to communicate a second airflow through an outer exit into the central passage, an inner annular passage disposed between the central passage and the outer annular passage that is operable for communicating fuel flow into the central passage, the inner annular passage including an inner exit angled for directing fuel flow toward the axis and a baffle for spreading fuel flow exiting through the inner exit, wherein the outer exit is axially forward of the inner exit and angled for directing the second airflow inward toward the axis and at least one of the first airflow and the second airflow is non-swirled, and a mixer passage downstream of the outer and inner exits for mixing the fuel flow with the first and second airflows;
a turbine section in fluid communication with the combustor, the turbine section driving the compressor section; and
a geared architecture driven by the turbine section for rotating the fan about the axis.

14. The gas turbine engine assembly as recited in claim 13 , wherein the mixer includes a length spacing the outer and inner exits from the combustion chamber, wherein the length defines a mixing length where fuel from the inner exits mixes with the first and second airflows.

15. A gas turbine engine assembly comprising:
a fan including a plurality of fan blades rotatable about an axis;
a compressor section
a combustor in fluid communication with the compressor section, the combustor including a combustion chamber and fuel-air mixer including a central pass

Assignees

• Cohen Jeffrey M
• Dai Zhongtao
• Green Kevin E
• United Technologies Corp

Inventors

• Cohen Jeffrey M
• Dai Zhongtao
• Green Kevin E

Classifications

• F23R3/28 Primary

  characterised by the fuel supply (burners F23D) · CPC title

• F23D2900/11101

  Pulverising gas flow impinging on fuel from pre-filming surface, e.g. lip atomizers · CPC title