Compact inward-firing premix fuel combustion system, and fluid heating system and packaged burner system including the same

Abstract

An inward-firing combustion burner, includes a burner casing configured to receive a fuel-air mixture at a burner inlet and to provide hot combustion gas at a burner output, a combustion substrate disposed within the burner casing, the substrate having a shape comprising at least a semi-cone or a flat surface or equivalent shape, having a substrate porosity defined by a plurality of pores, and having a substrate inner surface and a substrate outer surface, the substrate configured to receive the fuel-air mixture at the outer surface of the substrate, the fuel-air mixture passing through the pores at a mixture flow rate from the substrate outer surface toward the substrate inner surface, and the burner configured such that, in operation, the fuel-air mixture ignites near the plurality of pores to form a respective plurality of flamelets, each flamelet corresponding to one of the pores.

What is claimed is: 
     
         1 . A combustion burner, comprising:
 a burner casing configured to receive a fuel-air mixture at a burner inlet and to provide hot combustion gas at a burner output;   a combustion substrate disposed within the burner casing, the substrate having a shape that is substantially flat, having a substrate porosity defined by a plurality of pores, the pores having a 3D shape comprising a predetermined thickness, and having a substrate inner surface and a substrate outer surface;   the substrate configured to receive the fuel-air mixture at the outer surface of the substrate, the fuel-air mixture passing through the pores at a mixture flow rate from the substrate outer surface toward the substrate inner surface;   the burner configured such that, in operation, the fuel-air mixture ignites in a reaction zone inside a combustion cavity near the plurality of pores to form a respective plurality of flamelets, each flamelet corresponding to one of the pores, wherein the plurality of flamelets exhibits suspended flame combustion (SF combustion); and   wherein the porosity is set such that a flame equilibrium ratio (ρ) causes the reaction zone, for 1<ρ<100, to be approximately stationary and inside the combustion cavity.   
     
     
         2 . The burner of  claim 1 , wherein the 3-dimensional structure of the pores are set such that the mixture rate is substantially uniform along a length of the substrate and the plurality of flamelets forms a stable substantially uniform flame front along the inner surface of the substrate. 
     
     
         3 . The combustion burner of  claim 1  wherein at least one of the pores comprises a 3-D shape of a nozzle. 
     
     
         4 . The combustion burner of  claim 1 , wherein the thickness of at least one of the pores is the thickness of 20 GA steel (about 0.9525 mm). 
     
     
         5 . The burner of  claim 1 , wherein the 3-dimensional structure of the pores is set such that the plurality of flamelets exhibits stable suspended flame combustion (SF combustion). 
     
     
         6 . The burner of  claim 1 , wherein the 3-dimensional structure of the pores are set such that the mixture rate is substantially uniform along a length of the substrate and the plurality of flamelets forms a stable substantially uniform flame front along the inner surface of the substrate. 
     
     
         7 . The burner of  claim 1 , further comprising a mesh disposed on the substrate, and wherein the thickness of the pores is determined by a combined thickness of the mesh and the substrate. 
     
     
         8 . The burner of  claim 1 , wherein the 3-dimensional structure of the pores have a shape comprising at least one of: circular, rectangular, symmetrical shape, and asymmetrical shape, and having the predetermined thickness. 
     
     
         9 . The burner of  claim 1 , wherein the shape of at least one pore is an approximately circular shape having a maximum diameter between about 0.5 millimeters and about 2 millimeters and the predetermined thickness is at least 0.9525 mm. 
     
     
         10 . The burner of  claim 1 , wherein the shape of at least one of the pores is an approximately slot shape with width between about 0.5 millimeters and about 2 millimeters and length between about 2 millimeters and about 15 millimeters and the predetermined thickness is at least 0.9525 mm.