Device for injecting dihydrogen and air

Abstract

A longitudinal-axis (X) dihydrogen injection device is configured to be mounted on an annular bottom of an annular combustion chamber of a turbomachine. The injection device includes an inner channel for dihydrogen circulation and an outer annular channel for circulation of a mixture of at least air. The inner channel and the outer annular channel are coaxial. An inner swirler is housed in the inner channel and an outer swirler is housed in the outer annular channel. A downstream end of the inner channel is arranged upstream, at a distance r, from a downstream end of the outer annular channel. With this dihydrogen combustion, polluting carbon emissions such as carbon monoxide, unburned hydrocarbons or even fine and smoke particles can be eliminated.

1 . A longitudinal-axis dihydrogen injection device configured to be mounted on an annular bottom of an annular combustion chamber of a turbomachine, the injection device comprising an inner channel configured to circulate dihydrogen and an outer annular channel configured to circulate a mixture comprising at least air, wherein the inner channel and the outer annular channel are coaxial, an inner swirler is housed in the inner channel and an outer swirler is housed in the outer annular channel, and wherein a downstream end of the inner channel is arranged upstream, at a distance r, from a downstream end of the outer annular channel. 
     
     
         2 . The injection device according to  claim 1 , wherein the inner channel is a central tubular channel. 
     
     
         3 . The injection device according to  claim 1 , wherein the inner swirler has a helical shape. 
     
     
         4 . The injection device according to  claim 1 , wherein the inner swirler is arranged along the longitudinal axis downstream from the outer swirler. 
     
     
         5 . The injection device according to  claim 1 , wherein a rotation rate S generated by the inner swirler, is defined as a ratio between a tangential velocity and the discharge velocity along the longitudinal axis of a flow of dihydrogen leaving the inner swirler, and wherein the rotation rate S is greater than or equal to 0.6. 
     
     
         6 . The injection device according to  claim 1 , wherein the inner swirler is arranged upstream, at a distance l, from a downstream end of the inner channel. 
     
     
         7 . The injection device according to  claim 1 , wherein a thickness of the wall e of the inner channel and an inner diameter d of the inner channel are such that a ratio e/d is between 0.05 and 0.7. 
     
     
         8 . The injection device according to  claim 1 , wherein the inner channel has an inner diameter d, and the outer annular channel has an inner diameter D such that a ratio D/d is between 3 and 10. 
     
     
         9 . The injection device according to claim  16 , wherein a ratio l/d is between 1 and 3. 
     
     
         10 . The injection device according to  claim 8  wherein the distance r is between 0.05D and 0.5D. 
     
     
         11 . The injection device according to  claim 1 , wherein the outer swirler is arranged near an upstream end of said outer annular channel at a distance L from the downstream end of the outer annular channel. 
     
     
         12 . The injection device according to  claim 11 , wherein the inner channel has an inner diameter d, and the outer annular channel has an inner diameter D such that a ratio D/d is between 3 and 10, and the distance L is between 1D and 5D. 
     
     
         13 . The injection device according to  claim 5 , wherein the rotation rate S is greater than 0.6; where a dihydrogen discharge velocity u i  in the inner channel is greater than a critical value u i.c.  and satisfies the following relationship: 
       
         
           
             
               
                 
                   u 
                   
                     i 
                     , 
                     c 
                   
                 
                 
                   u 
                   
                     i 
                     , 
                     
                       c 
                       ⁢ 
                       0 
                     
                   
                 
               
               = 
               
                 
                   
                     ( 
                     
                       
                         S 
                         0 
                       
                       S 
                     
                     ) 
                   
                   β 
                 
                 ⁢ 
                 
                   P 
                   
                     P 
                     0 
                   
                 
                 ⁢ 
                 
                   
                     ( 
                     
                       
                         T 
                         a 
                       
                       
                         T 
                         
                           a 
                           ⁢ 
                           0 
                         
                       
                     
                     ) 
                   
                   0.8 
                 
               
             
           
         
         wherein: 
         P is a pressure in the annular combustion chamber; 
         T a  is an air temperature in Kelvin in the outer channel; 
         β is between 1 and 1.5 and is a factor dependent on a used swirler type; and 
         S 0 =0.6, P 0 =1 bar, T a0 =300 K and u i,c0 =18 m/s. 
       
     
     
         14 . The injection device according to  claim 1 , wherein the mixture is air. 
     
     
         15 . An assembly comprising the injection device according to  claim 1 , wherein the inner channel is fluidly connected to dihydrogen supply means, the inner swirler is configured to rotate said dihydrogen, the outer annular channel is fluidly connected to air supply means, and the outer swirler is configured to rotate said air. 
     
     
         16 . The injection device according to  claim 6 , wherein a thickness of the wall e of the inner channel and an inner diameter d of the inner channel are such that a ratio e/d is between 0.05 and 0.7.