SU1318700A2 - Axial-flow turbine stage - Google Patents

Abstract

The invention relates to the turbine industry and allows to increase the efficiency of the stage by reducing losses from the leakage of the working fluid. The end flaps 11 are installed at the inlet of the discharge openings (PO) 4 and increase the passage area of the channel 12, which increases the throughput of PO 4. The possibility of moving the shutters 11 in the circumferential direction reduces the PO 4 throughput required when repairing diaphragm seals or skidding workers shovels salt. 3 il. f (S (L with 00 Fig. 2

Description

The invention relates to turbine construction, in particular to axial steam turbines, and is an improvement of the invention according to the author. St. No. 1044798.

The purpose of the invention is to increase the efficiency of the stage by reducing losses due to leakage of the working fluid.

FIG. 1 shows an axial turbine stage; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a view B in FIG. I.

The axial turbine stage comprises an impeller 1 having a disk 2 with vanes 3 and discharge openings 4 and a fixed diaphragm 5 located with a gap 6 relative to the shaft 7 of the turbine. The disk 2 is provided with end flaps 8 installed at the exit of the holes 4 with the possibility of circumferential mixing. Each flap 8 is located relative to the end surface of the disk 2 to form a channel 9 open on the side opposite to the direction of impeller impeller 1. The disk 2 is provided with an annular groove 10 and the flap 8 is installed in the latter with the formation of a dovetail-type movable joint in it. The disk 2 is provided with additional end flaps 11 installed at the inlet of the discharge openings 4 with the possibility of circumferential movement and positioned relative to the end surface of the disk 2 with the formation of channels 12 open in the direction of rotation of disk 2.

Stage axial turbine operates as follows.

Through the gap 6 passes the working fluid (diaphragm leakage) and enters the chamber 13. The leakage flow flows in relative motion to the discharge openings 4 at an angle. The end guides 11 installed at the inlet of the discharge openings 4 increase the passage area of the channel 12 as compared to the area of the flow area without

end guides 11. This increases the capacity of the discharge openings, which allows the entire diaphragm leakage to flow through the discharge openings 4, reducing the flow of suction into the flow part of the turbine stage to zero, and thus increasing the efficiency of the stage.

Channel section 11

0

the inlet of the discharge openings 4 is selected from the condition of maximum leakage through the discharge openings 4, determined, for example, by the possible wear of the diaphragm seals.

However, after repairing the diaphragm

5 seals or when the rotor blades drift when the diaphragm leakage decreases or the stage’s reactivity increases, it becomes necessary to reduce the flow capacity of the discharge openings to prevent the turbine stage from flowing through the root gap 15 into chamber 13, which determined values reduces the efficiency of the stage.

5 A reduction in the capacity of the discharge openings 4 is ensured by the installation at the entrance of the end guides 11 with the possibility of movement in the circumferential direction.

thirty

Claims (1)

Invention Formula Axial turbine stage according to aut. St. No. 1044798, characterized in that, in order to increase efficiency, the disk is provided with additional end flaps installed at the entrance of the discharge openings with the possibility of circumferential movement and positioned relative to the disk face surface with the formation of channels opened in the direction of rotation disk. V ////////////////////.: - at //. b. shm ttm U /// 7 ////////// A Fig, 1