Swirl burner for ammonia combustion

Abstract

Disclosed herein are methods and systems for burning gaseous ammonia, including receiving a oxidizer gas into a chamber body such that the oxidizer gas generally flows in direction that extends along a longitudinal axis of the chamber body; introducing gaseous ammonia into the chamber body such that swirl is introduced into the gaseous ammonia; mixing the oxidizer gas and the gaseous ammonia to form a combustion mixture; igniting the combustion mixture; and combusting the combustion mixture for a duration such that the gaseous ammonia is converted to combustion products.

What is claimed is: 
     
         1 . A method of burning gaseous ammonia, comprising:
 receiving an oxidizer gas into a chamber body such that the oxidizer gas flows in the chamber body;   introducing gaseous ammonia into the chamber body such that swirl is induced in the gaseous ammonia;   mixing the oxidizer gas and the gaseous ammonia to form a combustion mixture;   igniting the combustion mixture; and   combusting the combustion mixture for a duration such that the gaseous ammonia is converted to combustion products.   
     
     
         2 . The method of  claim 1 , wherein at least 98% of the gaseous ammonia is converted to combustion products. 
     
     
         3 . The method of  claim 2 , wherein at least 99.9% of the gaseous ammonia is converted to combustion products. 
     
     
         4 . The method of  claim 1 , wherein combusting the combustion mixture for the duration produces a resultant level of NO X  that is below a threshold value of 10 ppm. 
     
     
         5 . The method of  claim 4 , wherein the threshold value is 2.5 ppm. 
     
     
         6 . The method of  claim 1 , wherein igniting the combustion mixture comprises igniting the combustion mixture at a gas pressure in a range from 10 PSI to 20 PSI. 
     
     
         7 . The method of  claim 1 , further comprising introducing, during introducing gaseous ammonia, a flow of gaseous hydrogen into the chamber body at less than 25% v/v to the gaseous ammonia. 
     
     
         8 . The method of  claim 1 , wherein the gaseous ammonia is introduced into the chamber body in a direction normal to the longitudinal axis. 
     
     
         9 . An ammonia combustion system, comprising
 a plurality of ammonia burners, each ammonia burner comprising:
 a chamber body; 
 an intake conduit having a first end for receiving oxidizer gas and a second end coupled to one open end of the chamber body and the second end defining an opening having a cross-sectional area that is larger than a maximum cross-sectional area of the chamber body; 
 a nozzle connected to an end of the chamber body opposing the oxidizer gas intake, the nozzle having an inlet opening and an outlet opening, wherein the outlet opening is enlarged or reduced in size relative to the inlet opening; 
 a plurality of inlets extending through a sidewall of the chamber body, configured to receive gaseous ammonia at an angle relative to a central axis of the chamber body such that when oxidizer gas passes through the chamber body, swirl is induced in the gaseous ammonia; 
 a flame holder surrounding the outlet opening of the nozzle and configured to confine a flame exiting the outlet opening; and 
   a fuel manifold configured to receive pressurized gaseous ammonia and deliver gaseous ammonia to the plurality of inlets of each of the plurality of burners.   
     
     
         10 . The system of  claim 9 , wherein the plurality of ammonia burners are configured to receive pressurized gaseous ammonia from the fuel manifold, or substantially unpressurized gaseous ammonia, from the fuel manifold. 
     
     
         11 . The system of  claim 9 , wherein the fuel manifold encloses the chamber body of each of the plurality of burners. 
     
     
         12 . The system of  claim 9 , wherein the fuel manifold is configured to deliver the gaseous ammonia at a plurality of pressures to the plurality of burners. 
     
     
         13 . The system of  claim 9 , wherein the plurality of inlets extend through the sidewall of the chamber body at an angle relative to a longitudinal axis, and an acute angle with respect to an inner wall of the chamber body, and wherein the inlets are configured to achieve a swirl number of at least 0.5. 
     
     
         14 . The system of  claim 9 , wherein the oxidizer gas scoop, chamber body, and nozzle are a unitary body. 
     
     
         15 . The system of  claim 9 , wherein the nozzle has an opening angle in a range from −20 to 20 degrees, and wherein a distance the nozzle extends into the flame holder is configured to induce toroidal reburn in uncombusted ammonia exiting the flame. 
     
     
         16 . The system of  claim 9 , wherein the flame holder is configured such that a flame exiting the outlet opening of the nozzle impinges an inner wall of the flame holder at a distance such that at least 50% of ammonia present in the flame is combusted. 
     
     
         17 . The system of  claim 9 , wherein the flame holder defines an internal volume configured to combust the gaseous ammonia and is configured to confine a flame exiting the outlet opening, wherein an inner dimension of the flame holder is proportional to the opening angle of the nozzle. 
     
     
         18 . The system of  claim 9 , wherein the flame holder comprises a metal or a ceramic material, and wherein a sidewall of the flame holder defines a plurality of perforations. 
     
     
         19 . The system of  claim 9 , wherein the chamber body includes a static turbine comprising a plurality of vanes, and wherein each vane of the static turbine is shaped such that an edge nearest the oxidizer gas intake forms a 0 degree angle with respect to the central axis of the chamber body and an edge nearest the nozzles forms a 60 degree angle with respect to the central axis of the chamber body. 
     
     
         20 . The system of  claim 9 , wherein the flame holder has a cross-sectional area that is larger than the maximum cross-sectional area of the chamber body.