Oxygen-fuel combuster and method for injecting oxygen and fuel

Abstract

An oxygen-fuel combustor and a method for injecting oxygen and fuel. The oxygen-fuel combustor includes a discharge head unit coupled to a heating furnace and a central supply unit in which, among fuel and primary oxygen, at least the fuel is supplied to the heating furnace. An oxygen supply unit supplies secondary oxygen to the heating furnace. The fuel is injected through a central nozzle unit. Secondary oxygen supplied from the oxygen supply unit is injected through an oxygen nozzle unit. The oxygen nozzle unit includes an accommodation cone part is recessed to decrease in diameter from an entrance. An inclined injection hole part passes through at an incline from the accommodation cone part toward an exit such that the injection direction of the fuel and injection direction of the secondary oxygen cross each other in front of the discharge head unit.

1 . An oxygen-fuel combustor comprising:
 a discharge head unit coupled to a heating furnace to supply a fuel and oxygen to the heating furnace, the discharge head unit comprising a discharge body exposed to an inside of the heating furnace to supply the fuel and the oxygen, a center through-portion formed in a center of the discharge body, oxygen through-portions formed in the discharge body so as to be spaced apart from each other in a circumferential direction of an imaginary circle centered on the center through-portion, and a coupling flange provided on an outer peripheral surface of the discharge body for coupling with the heating furnace;   a center supply unit coupled to the center through-portion to supply at least the fuel, among the fuel and primary oxygen, to the heating furnace;   an oxygen supply unit coupled to the oxygen through-portions to supply secondary oxygen to the heating furnace;   a center nozzle unit coupled to the center supply unit or the center through-portion so as to be exposed to the inside of the heating furnace from the center through-portion, the center nozzle unit being configured to inject at least the fuel among the fuel and the primary oxygen supplied from the center supply unit; and   an oxygen nozzle unit coupled to the oxygen supply unit or the oxygen through-portions so as to be exposed to an inside of the heating furnace from the oxygen through-portions, the oxygen nozzle unit being configured to inject the secondary oxygen supplied from the oxygen supply unit,   wherein the oxygen nozzle unit comprises: a conical accommodating portion recessed so as to have a smaller diameter with increasing distance from an inlet of the conical accommodating portion; and an inclined injection hole formed obliquely from the conical accommodating portion toward an outlet of the inclined injection a hole so that an injection direction of the fuel and an injection direction of the secondary oxygen cross each other in front of the discharge head unit.   
     
     
         2 . The oxygen-fuel combustor according to  claim 1 , wherein the oxygen nozzle unit further comprises an inclination indicator provided at the outlet of the inclination indicator to indicate a direction in which the injection hole is inclined. 
     
     
         3 . The oxygen-fuel combustor according to  claim 1 , wherein an injection angle of the oxygen injected from the inclined injection hole is not less than 2.5 degrees and not more than 30 degrees. 
     
     
         4 . The oxygen-fuel combustor according to  claim 1 , wherein the oxygen through-portions comprise: a first oxygen through-portions formed so as to be spaced apart from each other in a circumferential direction of a first imaginary circle centered on the center through-portion; and second oxygen through-portions formed so as to be spaced apart from each other in a circumferential direction of a second imaginary circle that is larger than the first imaginary circle,
 wherein the oxygen supply unit comprises: a first oxygen supply unit coupled to the first oxygen through-portions; and a second oxygen supply unit coupled to the second oxygen through-portions, and   wherein the oxygen nozzle unit comprises: a first oxygen nozzle unit coupled to the first oxygen supply unit or the first oxygen through-portions so as to be exposed to the inside of the heating furnace from the first oxygen through-portions; and a second oxygen nozzle unit coupled to the second oxygen supply unit or the second oxygen through-portions so as to be exposed to the inside of the heating furnace from the second oxygen through-portions.   
     
     
         5 . The oxygen-fuel combustor according to  claim 1 , wherein an amount of an exhaust gas to be introduced into a flame is adjusted according to at least any one of an injection interval of the secondary oxygen, an injection angle of the secondary oxygen, and a collision point of the fuel and the secondary oxygen. 
     
     
         6 . The oxygen-fuel combustor according to  claim 1 , wherein the center supply unit comprises:
 a first center supply unit configured to supply one of the fuel and the primary oxygen to the heating furnace and comprising a first center supply pipe through which the one of the fuel and the primary oxygen to be supplied to the heating furnace is delivered; and   a second center supply unit coupled to the center through-portion to supply a remaining one of the fuel and the primary oxygen to the heating furnace and comprising a second center supply pipe through which the remaining one of the fuel and the primary oxygen to be supplied to the heating furnace is delivered in a state in which the first center supply pipe is inserted into the second center supply pipe, and
 wherein the center nozzle unit comprises a center nozzle coupled to the first center supply pipe and having a first injection hole formed therein, from which a fluid delivered from the first center supply pipe is injected; and a nozzle flange protruding from an outer peripheral surface of the center nozzle and coupled to the second center supply pipe, the nozzle flange having a second injection hole formed therein, from which a fluid delivered from the second center supply pipe is injected. 
   
     
     
         7 . The oxygen-fuel combustor according to  claim 6 , wherein the second injection hole is obliquely formed in the nozzle flange so that an injection direction of the fluid delivered from the second center supply pipe and an injection direction of the fluid delivered from the first center supply pipe cross each other. 
     
     
         8 . The oxygen-fuel combustor according to  claim 1 , wherein the center supply unit comprises:
 a first center supply unit configured to supply a primary fuel to the heating furnace and comprising a first center supply pipe through which the primary fuel to be supplied to the heating furnace is delivered; and   a second center supply unit coupled to the center through-portion to supply a secondary fuel to the heating furnace and comprising a second center supply pipe through which the secondary fuel to be supplied to the heating furnace is delivered in a state in which the first center supply pipe is inserted into the second center supply pipe, and   wherein the center nozzle unit comprises: a center nozzle coupled to the first center supply pipe and having a first injection hole formed therein, from which the primary fuel delivered from the first center supply pipe is injected; and a nozzle flange protruding from an outer peripheral surface of the center nozzle and coupled to the second center supply pipe, the nozzle flange having a second injection hole formed therein, from which the secondary fuel delivered from the second center supply pipe is injected.   
     
     
         9 . The oxygen-fuel combustor according to  claim 8 , wherein the second injection hole is obliquely formed in the nozzle flange so that an injection direction of the secondary fuel delivered from the second center supply pipe and an injection direction of the oxygen supplied from the oxygen supply unit cross each other. 
     
     
         10 . The oxygen-fuel combustor according to  claim 1 , wherein the oxygen through-portions include two to four oxygen through-portions spaced apart from each other in the circumferential direction. 
     
     
         11 . A method of injecting oxygen and a fuel, the method comprising:
 measuring an internal temperature of a heating furnace;   comparing the internal temperature of the heating furnace, measured in the measuring, with a predetermined auto-ignition temperature;   forming a first flame by injecting primary oxygen and secondary oxygen to the fuel when a result of the comparing is that the internal temperature of the heating furnace is less than the predetermined auto-ignition temperature; and   forming a second flame by injecting only the secondary oxygen to the fuel when the result of the comparing is that the internal temperature of the heating furnace is equal to or greater than the predetermined auto-ignition temperature,
 wherein, in the forming the first flame, an injection amount of the primary oxygen is 30% or less of a total injection amount of oxygen, and an injection amount of the secondary oxygen is 70% or more of the total injection amount of oxygen. 
   
     
     
         12 . The method according to  claim 11 , wherein the forming the first flame comprises:
 injecting the fuel forward of a discharge head unit via a center nozzle unit provided at a center of the discharge head unit;   injecting the primary oxygen forward of the discharge head unit via the center nozzle unit so as to form a fuel thickening region in which the primary oxygen and the fuel are injected in directions crossing each other and react with each other in front of the discharge head unit; and   injecting the secondary oxygen forward of the discharge head unit via an oxygen nozzle unit, provided in the discharge head unit so as to be spaced apart from the center nozzle unit, so as to form an oxygen reaction region in which the secondary oxygen and the fuel are injected in directions crossing each other and react with each other in front of the discharge head unit, the oxygen reaction region being formed at a location farther from the discharge head unit than the fuel thickening region.   
     
     
         13 . The method according to  claim 12 , wherein the injecting the secondary oxygen comprises, at least one of:
 injecting the secondary oxygen forward of the discharge head unit via a first oxygen nozzle unit, provided in the discharge head unit so as to be spaced apart from the center nozzle unit, so as to form a first oxygen reaction region in which the secondary oxygen and the fuel are injected in directions crossing each other and react with each other in front of the discharge head unit, the first oxygen reaction region being formed at a location farther from the discharge head unit than the fuel thickening region; and   injecting the secondary oxygen forward of the discharge head unit via a second oxygen nozzle unit, provided in the discharge head unit so as to be spaced apart from the center nozzle unit, so as to form a second oxygen reaction region in which the secondary oxygen and the fuel are injected in directions crossing each other and react with each other in front of the discharge head unit, the second oxygen reaction region being formed at a location farther from the discharge head unit than the fuel thickening region,
 wherein the first oxygen reaction region is formed in front of the discharge head unit at a location closer to the discharge head unit than the second oxygen reaction region, and 
 wherein the first oxygen nozzle unit is closer to the center nozzle unit than the second oxygen nozzle unit. 
   
     
     
         14 . The method according to  claim 12 , wherein the forming the second flame comprises the injecting the fuel and the injecting the secondary oxygen, without the injecting the primary oxygen, compared to the forming the first flame. 
     
     
         15 . A method of injecting oxygen and a fuel, the method comprising:
 measuring an internal temperature of a heating furnace;   comparing the internal temperature of the heating furnace, measured in the measuring, with a predetermined auto-ignition temperature;   forming a first flame by injecting at least one of a primary fuel and a secondary fuel to the oxygen when a result of the comparing is that the internal temperature of the heating furnace is less than the predetermined auto-ignition temperature; and   forming a second flame by injecting at least one of the primary fuel and the secondary fuel to the oxygen when the result of the comparing is that the internal temperature of the heating furnace is equal to or greater than the predetermined auto-ignition temperature,
 wherein, in at least one of the forming the first flame and the forming the second flame, at least one of an oxygen reaction region in which the primary fuel and the oxygen are injected in directions crossing each other and react with each other in front of a discharge head unit and two or more additional reaction regions in which the secondary fuel and the oxygen are injected in directions crossing each other and react with each other between the discharge head unit and the oxygen reaction region is formed. 
   
     
     
         16 . The method according to  claim 15 , wherein the forming the first flame comprises:
 injecting the oxygen forward of the discharge head unit via an oxygen nozzle unit, provided in the discharge head unit so as to be spaced apart from a center nozzle unit provided at a center of the discharge head unit, so as to form at least one of the oxygen reaction region in which the primary fuel and the oxygen are injected in directions crossing each other and react with each other in front of the discharge head unit and the additional reaction regions in which the secondary fuel and the oxygen are injected in directions crossing each other and react with each other, and   at least one of:
 injecting the primary fuel to the oxygen reaction region via the center nozzle unit; and 
 injecting the secondary fuel to the additional reaction regions via the center nozzle unit. 
   
     
     
         17 . The method according to  claim 16 , wherein the injecting the oxygen comprises:
 injecting the oxygen forward of the discharge head unit via a first oxygen nozzle unit, provided in the discharge head unit so as to be spaced apart from the center nozzle unit, so as to form a first oxygen reaction region in which the primary fuel and the oxygen are injected in directions crossing each other and react with each other in front of the discharge head unit; and   injecting the oxygen forward of the discharge head unit via a second oxygen nozzle unit, provided in the discharge head unit so as to be spaced apart from the center nozzle unit, so as to form a second oxygen reaction region in which the primary fuel and the oxygen are injected in directions crossing each other and react with each other in front of the discharge head unit,
 wherein the first oxygen reaction region is formed in front of the discharge head unit at a location closer to the discharge head unit than the second oxygen reaction region, and 
 wherein the first oxygen nozzle unit is closer to the center nozzle unit than the second oxygen nozzle unit. 
   
     
     
         18 . The method according to  claim 16 , wherein the forming the second flame comprises:
 injecting the primary fuel to the oxygen reaction region or injecting the secondary fuel to the additional reaction regions via the center nozzle unit; and   injecting the oxygen to at least one of the oxygen reaction region or the additional reaction regions according to a type of the fuel injected in the injecting the primary fuel or the secondary fuel.   
     
     
         19 . The method according to  claim 11 , wherein, when the fuel and the oxygen are injected in at least one of the forming the first flame and the forming the second flame, an injection speed of the fuel injected forward of the discharge head unit from the center nozzle unit is equal to or less than 50% of an injection speed of the oxygen injected from the oxygen nozzle unit. 
     
     
         20 . The method according to  claim 11 , wherein, when the fuel and the oxygen are injected in at least one of the forming the first flame and the forming the second flame, an injection speed of the oxygen injected from the oxygen nozzle unit ranges from 100 m/s to 400 m/s.