Multistaged lean prevaporizing premixing fuel injector
A multistaged lean prevaporizing premixing fuel injector apparatus is provided. The fuel injector may be utilized with a turbogenerator. Preheated combustion air from the turbogenerator's recuperator may be utilized by the fuel injector to prevaporize liquid fuel. The injector may provide for premixing of multiple fuel streams and include multiple stages with a flow distributor plate separating adjacent stages. The injector may include multiple stages, with a pilot tube located in a final stage splitting the fuel stream into a premixed pilot stream and a premixed final fuel and air mixture stream.
1. A multistaged lean prevaporizing premixing fuel injector apparatus for mixing multiple fuels, comprising:
a preliminary prevaporizing premixing chamber having a central longitudinal axis and having an inlet end, and having a preliminary air inlet for introducing air into the preliminary prevaporizing premixing chamber;
an intermediate prevaporizong premixing chamber communicated with and downstream of the preliminary prevaporizing premixing chamber, and having an intermediate air inlet for introducing air into the intermediate prevaporizing premixing chamber;
a final prevaporizing premixing chamber communicated with and downstream of the intermediate prevaporizing premixing chamber, and having a final air inlet for introducing air into the final prevaporizing premixing chamber, the final prevaporizing premixing chamber having an outlet end;
a liquid fuel nozzle arranged to project a spray of a liquid first fuel into the preliminary prevaporizing premixing chamber;
a second fuel inlet communicated with the preliminary prevaporizing premixing chamber for introducing a second fuel into the preliminary prevaporizing premixing chamber;
a common air supply passage for communicating a common combustion air source to the preliminary air inlet, the intermediate air inlet, and the final air inlet at substantially the same temperature;
an intermediate flow distributor separating the preliminary and intermediate prevaporizing premixing chambers for distributing a first fuel-air mixture of the first and second fuels and air across a cross-section of the intermediate prevaporizing premixing chamber; and
a final flow distributor located upstream of the final prevaporizing premixing chamber separating the intermediate and final prevaporizing premixing chambers for distributing a second fuel-air mixture of the first and second fuels and air across a cross-section of the final prevaporizing premixing chamber.
2. The fuel injector apparatus of claim 1 , further comprising:
a pilot tube located in the final prevaporizing premixing chamber and dividing the second fuel-air mixture into a pilot flow stream and a final prevaporizing premixing flow stream, the pilot flow stream flowing to the outlet end of the final prevaporizing premixing chamber without being mixed with air from the final air inlet.
3. The fuel injector apparatus of claim 2 , further comprising:
an annular chamber wall concentric with the central longitudinal axis and defining the preliminary, intermediate, and final prevaporizing premixing chambers within the chamber wall;
wherein the pilot tube is located concentrically within the annular chamber wall; and
wherein the final flow distributor connects the pilot tube and the chamber wall and has a plurality of distribution openings through the final flow distributor for distributing the second fuel-air mixture into the final prevaporizing premixing flow stream.
4. The fuel injector apparatus of claim 1 , wherein:
the second fuel inlet is a gaseous fuel inlet and the second fuel is a gaseous second fuel.
5. The fuel injector apparatus of claim 1 , in combination with a microturbine having an inlet air compressor and having a recuperator for using microturbine exhaust gas to preheat compressed air from the compressor prior to directing the preheated compressed air to a combustor of the microturbine, wherein:
the common air supply passage is communicated with the recuperator to provide preheated compressed air from the recuperator to the preliminary air inlet, the intermediate air inlet, and the final air inlet at a temperature in the range of from about 900° F. to about 1300° F.
6. The fuel injector apparatus of claim 1 , wherein:
the common combustion air source comprises a recuperator outlet of a microturbine.
7. The fuel injector apparatus of claim 1 , wherein:
a cross-sectional area of the final prevaporizing premixing chamber adjacent the outlet end decreases toward the outlet end.
8. A multistaged lean prevaporizing premixing fuel injector apparatus, comprising:
a preliminary prevaporizing premixing chamber having a central longitudinal axis and having an inlet end, and having a preliminary air inlet for introducing air into the preliminary prevaporizing premixing chamber transversely to the longitudinal axis;
an intermediate prevaporizing premixing chamber downstream of the preliminary prevaporizing premixing chamber, and having an intermediate air inlet for introducing air into the intermediate prevaporizing premixing chamber;
a final prevaporizing premixing chamber downstream of the intermediate prevaporizing premixing chamber, and having a final air inlet for introducing air into the final prevaporizing premixing chamber, the final prevaporizing premixing chamber having an outlet end;
a liquid fuel nozzle arranged to project a spray of liquid fuel into the preliminary prevaporizing premixing chamber upstream of the preliminary air inlet;
a common air supply passage for communicating a common combustion air source to the preliminary air inlet, the intermediate air inlet, and the final air inlet at substantially the same temperature;
an intermediate flow distributor located between the preliminary and intermediate prevaporizing premixing chambers for distributing fuel-air mixture from the preliminary prevaporizing premixing chamber across a cross-section of the intermediate prevaporizing premixing chamber; and
a final flow distributor located between the intermediate and final prevaporizing premixing chambers for distributing fuel-air mixture from the intermediate prevaporizing premixing chamber into a final prevaporizing premixing flow stream.
9. The fuel injector apparatus of claim 8 , in combination with a microturbine having an inlet air compressor and having a recuperator for using microturbine exhaust gas to preheat compressed air from the compressor prior to directing the preheated compressed air to a combustor of the microturbine, wherein:
the common air supply passage is communicated with the recuperator to provide the preheated compressed air from the recuperator to the preliminary air inlet, the intermediate air inlet, and the final air inlet at a temperature in the range of from about 900° F. to about 1300° F.
10. The fuel injector apparatus of claim 8 , wherein:
the common combustion air source comprises a recuperator outlet of a microturbine.
11. The fuel injector apparatus of claim 8 , further comprising:
an annular preliminary chamber wall defining the preliminary prevaporizing premixing chamber within the chamber wall;
wherein the preliminary air inlet is one of a plurality of preliminary air inlets defined by a plurality of openings in the preliminary chamber wall downstream of the liquid fuel nozzle.
12. The fuel injector apparatus of claim 11 , further comprising:
an annular outer wall concentrically disposed about the annular preliminary chamber wall so that an annular passage is defined between the annular outer wall and the annular preliminary chamber wall, the annular passage comprising at least a portion of the common air supply passage.
13. The fuel injector apparatus of claim 8 , further comprising:
a pilot tube located in the final prevaporizing premixing chamber and dividing a the fuel-air mixture from the intermediate prevaporizing premixing chamber entering the final prevaporizing premixing chamber into a pilot flow stream and the final prevaporizing premixing flow stream, the pilot flow stream flowing to the outlet end of the final prevaporizing premixing chamber without being mixed with air from the final air inlet.
14. The fuel injector apparatus of claim 13 , further comprising:
a bluff body connected to the pilot tube adjacent the outlet end of the final prevaporizing premixing chamber, the bluff body reducing a cross-sectional area of the final prevaporizing premixing chamber at the outlet end.
15. The fuel injector apparatus of claim 13 , further comprising:
an annular chamber wall concentric with the central longitudinal axis and defining the preliminary, intermediate, and final prevaporizing premixing chambers within the chamber wall;
wherein the pilot tube is located concentrically within the annular chamber wall; and
the flow distributor connecting the pilot tube and the chamber wall and having a plurality of distribution openings through the final flow distributor for distributing flow of the fuel-air mixture into the final prevaporizing premixing flow stream.
16. The fuel injector apparatus of claim 8 , further comprising:
one or more gaseous fuel inlets communicated with the preliminary prevaporizing premixing chamber.
17. The fuel injector apparatus of claim 8 , wherein:
a cross-sectional area of the final prevaporizing premixing chamber adjacent the outlet end decreases toward the outlet end.