Premixed direct injection disk

A fuel/air mixing disk for use in a fuel/air premixing combustor assembly comprising:

• a plurality of adjacent, pie-shaped sectors, each sector having a first face, a second face, and an annular wall coupling the first and second faces together and separating the first and second faces to provide at least one fuel plenum disposed between the first and second faces and bounded by the annular wall and adapted to be in fluid communication with a fuel flow passage extending from an end cover of the combustor assembly transverse to the first face and intersecting the first face at a central position of at least one sector of the disk away from the annular wall;
• and
• a plurality of fuel/air mixing tubes extending through each sector between the first face and the second face, each mixing tube including an outer tube wall extending axially along a tube axis between an inlet end and an exit end and in fluid communication with the at least one fuel plenum, and an inner tube surface having an inner diameter,
• each of the plurality of fuel/air mixing tubes further including at least one fuel injection hole having a fuel injection hole diameter extending through said outer tube wall, said at least one fuel injection hole having an injection angle relative to said tube axis, said inner diameter of said inner tube surface being from 2 to 20 times greater than said fuel injection hole diameter, and
• wherein a recession distance between said fuel injection hole and said exit end along said tube axis is about 1 to 100 times greater than said fuel injection hole diameter.

A method of mixing high-hydrogen or synthetic gas fuel in a premixed direct injection disk for a turbine combustor, said method comprising;

• providing a plurality of adjacent, pie-shaped sectors, each sector having a first face, a second face, and an annular wall coupling the first and second faces together and separating the first and second faces to provide at least one fuel plenum disposed between the first and second faces and bounded by the annular wall and adapted to be in fluid communication with a fuel flow passage extending from an end cover of the combustor assembly transverse to the first face and intersecting the first face at a central position of at least one sector of the disk away from the annular wall;
• wherein each sector further comprises fuel/air mixing tubes extending between the first face and the second face, each of said plurality of mixing tubes extending axially along a flow path between an inlet end and an exit end and having at least one injection hole in fluid communication with the at least one fuel plenum, said at least one injection hole being oriented at an angle in the range of 20 to 90 degrees relative to a tube axis, each of said plurality of tubes including an outer tube wall extending axially along a tube axis between said inlet end and said exit end;
• injecting a first fluid into said plurality of mixing tubes at said inlet end;
• providing a gaseous high-hydrogen fuel or a gaseous synthetic fuel into said at least one fuel plenum;
• injecting the high-hydrogen fuel or synthetic fuel from the at least one fuel plenum into said mixing tubes through the plurality of injection holes;
• and
• mixing said first fluid and said high hydrogen fuel or synthetic fuel to a mixedness of greater than 50% fuel and first fluid mixture at said exit end of said tubes.