Fuel injector

Patent metadata

Field	Value
Publication number	US-2016178206-A1
Application number	US-201314910462-A
Country	US
Kind code	A1
Filing date	Oct 18, 2013
Priority date	Oct 18, 2013
Publication date	Jun 23, 2016
Grant date	—

Abstract

An injector includes: an upstream support plate ( 11 ) into which a fuel gas (F) is introduced and which has the shape of a tapered cylinder whose diameter gradually enlarges; a downstream support plate ( 12 ) that defines a plenum at an inner side along with the upstream support plate ( 11 ); and premixing tubes ( 13 ), each of which is supported by the upstream and downstream supporting plates ( 11 and 12 ) and introduces air. The plurality of premixing tubes ( 13 ) are disposed in a plurality of circular rows at equal intervals in a circumferential direction, and portions of the premixing tubes ( 13 ) which are located in the plenum are formed with fuel introducing holes ( 13 a ).

First claim

1 . A fuel injector comprising:
an upstream support plate configured to introduce a fuel gas from a first end side into an inner side in a direction of an axis and having a shape of a tapered cylinder whose diameter gradually enlarges toward a second end side in the direction of the axis; a downstream support plate provided to intersect the axis, disposed at the second end side of the upstream support plate in the direction of the axis, and configured to define a plenum at an inner side along with the upstream support plate; and a plurality of premixing tubes provided to extend in the direction of the axis to be supported on the upstream and downstream support plates and configured to introduce air from the first end side in the direction of the axis, wherein the plurality of premixing tubes are disposed in rows shaped as a plurality of circles whose radial dimensions centered on the axis are different from each other, the neighboring premixing tubes disposed in the same row are disposed equidistantly from each other in a circumferential direction, portions of the premixing tubes which are located in the plenum are formed with fuel introduction holes penetrating the premixing tubes from outside to inside, and
the fuel gas supplied from the plenum into the premixing tubes via the fuel introduction holes is mixed with the air in the premixing tubes and is injected from second end sides of the premixing tubes in the direction of the axis.

2 . The fuel injector according to claim 1 , wherein a length of the plenum in each row in the direction of the axis is set such that a flow velocity of the fuel gas circulating in circumferential spaces between the plurality of premixing tubes in a radial direction is constant.

3 . The fuel injector according to claim 2 , wherein, when the row at an innermost side in a radial direction is set as a first row, the length of the plenum in an a-th row in the direction of the axis is defined as La, the number of premixing tubes in the a-th row is defined as Na, and a volume flow rate of the fuel gas in the a-th row is defined as Ga, the upstream support plate is configured such that the length (La) of the plenum in the a-th row in the direction of the axis is represented by the following formula:
La=L 1× Ga/G 1× N 1/ Na
where L1: the length of the plenum in a first row in the direction of the axis, G1: the volume flow rate of the fuel gas in the first row N1: the number of premixing tubes in the first row.

4 . The fuel injector according to claim 1 , wherein the premixing tubes protrude toward an outer side of the plenum relative to at least one of the upstream support plate and the downstream support plate in the direction of the axis.

5 . The fuel injector according to claim 1 , wherein the fuel injector includes a fuel guide having a tapered surface whose center is the axis and whose diameter is gradually enlarged from the first end side in the direction of the axis to the second end side in the direction of the axis and fixing to a surface of the first end side of the downstream support plate in the plenum in the direction of the axis.

6 . A combustor comprising the fuel injector according to claim 1 .

7 . A gas turbine comprising the fuel injector according to claim 1 .

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Yoshino Ryo
• Saito Keijiro

Classifications

• F23R3/286 Primary

  having fuel-air premixing devices (F23R3/30 takes precedence) · CPC title

• F23D14/62

  Mixing devices; Mixing tubes · CPC title

• F23R3/10

  for primary air (F23R3/06, F23R3/045 take precedence) · CPC title

• F23D14/64

  with injectors · CPC title

• F23R3/32

  being tubular · CPC title