Exhaust channel of microturbine engine

Abstract

An exhaust channel of a microturbine engine, characterized by a tapering pipe for reducing the speed at which a high-temperature gas is discharged from the turbine and ensuring that the high-temperature gas induced into a recuperator produces a uniform, low-speed flow field, with a view to preventing any noticeable vortex region from developing in the channel, minimizing the pressure loss in the channel, and enhancing the heat exchange efficiency of the recuperator.

What is claimed is: 
     
         1 . An exhaust channel of a microturbine engine, comprising:
 an expanding segment being a tapering pipe and having an expanding segment outlet and an expanding segment inlet of a smaller diameter than the expanding segment outlet;   A bending segment being a U-shaped curved tube and having a bending segment outlet and a bending segment inlet in communication with the expanding segment outlet;   a heat exchange segment being a pipe and having a heat exchange segment outlet and a heat exchange segment inlet in communication with the bending segment outlet, wherein the heat exchange segment contains cooling fins; and   A rear exhaust segment being a pipe, being in communication with the heat exchange segment outlet, and being of a larger diameter than the heat exchange segment.   
     
     
         2 . The exhaust channel of a microturbine engine of  claim 1 , wherein the expanding segment has a tapering angle no greater than 7°. 
     
     
         3 . The exhaust channel of a microturbine engine of  claim 1 , wherein a rate of change in cross-sectional area of the bending segment is expressed by 0.1<(ΔA/ΔL)<0.2, where cross-sectional area and length of the bending segment are denoted by ΔA and ΔL, respectively. 
     
     
         4 . The exhaust channel of a microturbine engine of  claim 1 , wherein an included angle between the bending segment outlet and the heat exchange segment inlet is no greater than 5°. 
     
     
         5 . The exhaust channel of a microturbine engine of  claim 1 , wherein the rear exhaust segment has a larger internal volume than the heat exchange segment. 
     
     
         6 . The exhaust channel of a microturbine engine of  claim 1 , wherein the expanding segment, the bending segment, the heat exchange segment and the rear exhaust segment are each made of sheet metal and then welded together. 
     
     
         7 . The exhaust channel of a microturbine engine of  claim 1 , wherein the expanding segment, the bending segment, the heat exchange segment and the rear exhaust segment are integrated.