Flow control of combustible mixture into combustion chamber

Abstract

In a premix supply, for supplying a fuel and oxidizer gas into a combustion chamber for burning, the premix supply having a smaller diameter flow than the combustion chamber, the premix supply comprising at least one dielectric barrier discharge device (DBD) comprising two electrodes separated by a dielectric, improved flame stability limits may be provided for the adjacent combustor by the actuation of the DBD to induce ionic wind. Both electrodes may be provided in a single wall of the premix supply. The two electrodes may be arranged substantially upstream and downstream of each other. The electrodes may be arranged to generate an ionic wind preferentially directed in a direction of flow through the premix supply.

1 . A premix supply for supplying a fuel and oxidizer gas into a combustion chamber for burning, the premix supply having a smaller diameter flow than the combustion chamber, the premix supply comprising at least one dielectric barrier discharge device (DBD) comprising two electrodes separated by a dielectric, wherein both electrodes are provided in a single wall of the premix supply. 
     
     
         2 . The premix supply of  claim 1  wherein the at least one DBD is disposed symmetrically around the premix supply. 
     
     
         3 . The premix supply of  claim 1  wherein the at least one DBD is disposed on the premix supply adjacent a dump plane defined by the interface of the premix supply and the combustion chamber. 
     
     
         4 . The premix supply of  claim 1  wherein the electrodes are arranged to accelerate the fuel and oxidizer gas in a direction along the wall. 
     
     
         5 . The premix supply of  claim 1  wherein one of the two electrodes is partially upstream of the other of the two electrodes. 
     
     
         6 . The premix supply of  claim 1  wherein the electrodes are arranged to accelerate the fuel and oxidizer gas in a direction of the flow, with greater acceleration occurring closer to the wall of the premix supply, whereby a pipe-flow velocity profile of the fuel and oxidizer gas is modified to increase a velocity gradient the wall. 
     
     
         7 . The premix supply of  claim 1  wherein each of the at least one DBD is in a same wall, the wall defining an outer diameter of a flow of the fuel and oxidizer gas. 
     
     
         8 . The premix supply of  claim 1  assembled in a burner for fluid communication with a combustion chamber. 
     
     
         9 . A premix supply for supplying a fuel and oxidizer gas into a combustion chamber for burning, the premix supply having a smaller diameter flow than the combustion chamber, the premix supply comprising at least one dielectric barrier discharge device comprising two electrodes separated by a dielectric, wherein the electrodes are arranged to generate an ionic wind preferentially in a same direction as a flow through the premix supply. 
     
     
         10 . The premix supply of  claim 9  wherein the at least one DBD is disposed symmetrically around the premix supply. 
     
     
         11 . The premix supply of  claim 9  wherein the at least one DBD is disposed on the premix supply adjacent a dump plane defined by the interface of the premix supply and the combustion chamber. 
     
     
         12 . The premix supply of  claim 9  wherein the electrodes are both disposed in a same wall of the premix supply. 
     
     
         13 . The premix supply of  claim 9  wherein one of the two electrodes is partially upstream of the other. 
     
     
         14 . The premix supply of  claim 9  wherein the electrodes are arranged to accelerate the fuel and oxidizer gas, with greater acceleration occurring closer to the wall of the premix supply, whereby a velocity profile of the fuel and oxidizer gas is modified to increase a velocity gradient at the wall. 
     
     
         15 . The premix supply of  claim 9  wherein each of the at least one DBD is in a same wall, the wall defining an outer diameter of a flow of the fuel and oxidizer gas. 
     
     
         16 . The premix supply of  claim 9  assembled in a burner for fluid communication with a combustion chamber. 
     
     
         17 . A method for reducing flashback within a burner having a premix supply in fluid communication with a combustion chamber, the premix supply having a smaller diameter flow than the combustion chamber, comprising:
 providing in a wall of the premix supply at least one dielectric barrier discharge device having two electrodes separated by a dielectric; and   applying current to the dielectric barrier discharge device to generate an ionic wind preferentially in a same direction as a flow through the premix supply, at least when there is an elevated risk of flashback along the wall.