Axial flow turbine with small blade structure

Abstract

The invention provides an axial flow type turbine with a small blade structure. The axial flow type turbine comprises a hub, a plurality of main blades and a plurality of small blades, wherein the hub is provided with a front end surface and a circumferential surface; the plurality of main blades are evenly arranged on the circumferential surface of the hub and are provided with pressure surfaces, force absorbing surfaces and main blade connecting surfaces, and the main blade connecting surfaces are provided with first front edges; and the small blades and the main blades are alternately arranged, the small blades are provided with small blade connecting surfaces, and the small blade connecting surfaces are provided with second front edges. The radial height of the small blades is h, the radial height of the main blades is H, and h / H is 0.05-0.3. The axial chord length of the small blade connecting surfaces is L1, the axial chord length of the main blade connecting surfaces is L2, and L1 / L2 is 0.2-0.6. The axial length from the second front edges of the small blade connecting surfaces to the first front edges of the main blade connecting surfaces is m, and m / L is 0-0.4. The circumferential angle between the first front edges of the two adjacent main blade connecting surfaces is theta1, the circumferential angle between the first front edges of the main blade connecting surfaces and the second front edges, corresponding to the force absorbing surfaces, of the small blade connecting surfaces is theta2, and theta2 / theta1 is 0.3-0.8.

Description

technical field [0001] The invention relates to the field of turbomachinery, in particular to an axial-flow turbine with a small blade structure. Background technique [0002] The turbine is a blade-type machine that converts the energy of the fluid working medium into mechanical energy for output. The fluid working medium expands in the turbine and drives the turbine to rotate, and outputs mechanical work to the outside. In an axial flow turbine, the fluid working fluid enters the turbine at a nearly axial angle and exits axially. Axial-flow turbines are used in gas turbines, turbo-piston combined engines, and turbo-compound internal combustion engines. [0003] Since the linear velocity of the axial-flow turbine rotor blade changes with the radius, the relative inlet flow angle of the rotor changes along the direction of the blade height, so the blade shape design of the rotor needs to change with the blade height. At the tip of the rotor blade, the relative airflow angl...

AI Technical Summary

Problems solved by technology

The uneven distribution of the fluid in the radial direction causes the load at the rotor blade root to become larger, so the flow separation phenomenon near the blade root is more likely to occur, and the separation scale is larger, resulting in a decrease in turbine performance

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