Combustor and gas turbine

Abstract

A combustor of the present disclosure includes: a mixing portion which is provided with a plurality of mixing passages passing through the mixing portion so as to be extended from an upstream end surface to a downstream end surface of the mixing portion intersecting an axis of the combustor, air being introduced to the plurality of the mixing passages from the upstream end surface of the mixing portion; and a fuel supply portion which is configured to supply the air introduced to the mixing passages with fuel to generate mixed fluid, wherein flow paths of the mixing passages have different pressure loss coefficients so that the differences in the flow velocity of the mixed fluid flowing through the mixing passages at the downstream end surface of the mixing portion are greater than those of a case where the mixing passages have the same flow path shape.

What is claimed is: 
     
         1 . A combustor comprising:
 a mixing portion which is provided with a plurality of mixing passages passing through the mixing portion so as to be extended from an upstream end surface to a downstream end surface of the mixing portion intersecting an axis of the combustor, air being introduced to the plurality of the mixing passages from the upstream end surface of the mixing portion; and   a fuel supply portion which is configured to supply the air introduced to the mixing passages with fuel to generate mixed fluid,   wherein flow paths of the mixing passages have different pressure loss coefficients so that the differences in the flow velocity of the mixed fluid flowing through the mixing passages at the downstream end surface of the mixing portion are greater than those of a case where the mixing passages have the same flow path shape.   
     
     
         2 . The combustor according to  claim 1 .
 wherein each of the mixing passages includes: 
 an inlet portion which is continuous to the upstream end surface of the mixing portion, and 
 a main portion which is extended from the inlet portion to the downstream end surface of the mixing portion and of which an inner diameter is constant throughout the entire of the main portion, and 
 wherein the inlet portions of the mixing passages have different flow path shapes. 
   
     
     
         3 . The combustor according to  claim 2 ,
 wherein the fuel supply portion has fuel nozzles, tips of which are inserted into the mixing passages from the upstream end surface of the mixing portion, supplying fuel into the mixing passages through the tips of the fuel nozzles, and   wherein the tips of the fuel nozzles have different outer diameters.   
     
     
         4 . The combustor according to  claim 3 . 
 wherein each of the inlet portions of the mixing passages has a bell mouth shape, an inner diameter increases toward the upstream end surface of the mixing portion.   
     
     
         5 . The combustor according to  claim 2 .
 wherein the fuel supply portion has fuel injection holes supplying fuel into the mixing passages from surroundings of the mixing passages, and   wherein the mixing portion includes: 
 a first mixing passage in which the inlet portion is continuous to the main portion, has a constant inner diameter and has a same inner diameter as the main portion, and 
 a second mixing passage in which the inlet portion has a bell mouth shape in which an inner diameter is increased toward the upstream end surface of the mixing portion. 
   
     
     
         6 . The combustor according to  claim 1 . 
 wherein the fuel supply portions and the mixing passages are combined such that the lower the pressure loss coefficient of the mixing passage, the higher the fuel supply rate of the fuel supply portion.   
     
     
         7 . A gas turbine comprising 
 a compressor which generates air;   the combustor according to  claim 1  generating a combustion gas by mixing a fuel with air compressed by the compressor and combusting the generated mixed fluid; and   a turbine being driven by the combustion gas.