SU1502850A1 - Partial turbine stage - Google Patents

Abstract

The invention relates to turbine engineering and allows an increase in the efficiency of a partial turbine degree. In protective plates 5-7, located on the inactive part of the arc of circumference of the impeller 2 on both sides of the rotor blades (RL) 3 and 4, the channels (K) 8 are made in the form of half a torus. The input 9 of the channel 8 is located at the periphery 10, and the output 11 - at the root of 12 RL 3 and 4. The ventilated working fluid flow from the periphery of 10 RL 3 and 4 gets into K 8, where it smoothly turns and with minimal losses is directed to the root of 12 RL 3 and 4. Limiting the value of the ventilated flow with increasing its specific amount of momentum leads to a decrease in ventilation moment, and after ovatelno and power costs for the fan tion. 3 il.

Description

one

(21) 4385984 / 24-06

(22) 12.12.87

(46) 08.23.89. Bul No. 31

(71) Leningrad Shipbuilding Institute

(72) V.Ye.Petrovsky, Yu.M.Pogodin, V.L.Rakov and A.V.Serov

(53) 621.165 (088.8)

(56) Truhniy A.D., Losev S.M. Stationary steam turbines. - M .: Energoizdat, 1981, p. 292, 318.

(54) PARTIAL TURBINE STAGE

(57) The invention relates to a turbine structure and makes it possible to increase the efficiency of the partial turbine stage. In protective flaps 5-7, located 10 J

// / 2

On the inactive part of the arc of the circumference of the impeller 2 on both sides of the working blades (XR) 3 and 4, the channels (K) 8 are made in the form of half a torus. The input 9 of the channel 8 is located at the periphery 10, and the output 11 is located at the root 12 of the RL 3 and 4. The ventilated working fluid flow from the periphery of 10 RL 3 and 4 falls into K 8, where it smoothly turns and with minimal loss is directed to the root 12 of the RL 3 and 4. Limiting the value of the ventilated flow while increasing its specific moment of movement reduced ventilation moment and, consequently, costly ti on gate tion. 3 il.

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The invention relates to power engineering, namely turbine construction.

The purpose of the invention is to increase the efficiency of the stage operation by improving the organization of the ventilated flow on the inactive part of the wheel circumference arc.

Figure 1 shows the active part of a step with two speed steps, a longitudinal section; in FIG. 2, the inactive part of step j in FIG. 3 is a part of the protective shield with a channel.

The partial turbine stage contains a nozzle apparatus 1 and an impeller 2, on both sides of the working loops 3 and 4 of which protective shields 5-7 are installed on the inactive part of the circular arc. The protective flaps 5-7 are made in the form of a half torus located in the circumferential direction of the channel 8, the entrance 9 of which is located at the periphery 10, the output 11 - at the root of 12 blades 3 and 4. The channels 8 are formed in the protective flaps 5-7 placed in them the central body 13. Between the working blades 3 and 4 is located the guiding apparatus 14,

In order to allow placement of the channels 8 with the central body 13 in a limited thickness of the protective flaps 5-7, the forming surfaces 15 of the channels 8 may have an ellitic or semi-circumferential shape. The flow area of the channels 8 remains approximately constant along the movement of the working medium. The size of the flow area, as well as the specific profile of the channels 8, is expediently selected using

Data from experimental design testing under specific conditions.

When the turbine stage is working (rotation of the impeller 2), the working medium is ventilated in the inactive part by the action of centrifugal forces is thrown to the periphery of the 10 blades 3 and 4 and enters the inlet 9 of the channel 8, in which it smoothly turns and passes through the outlet 11 to the root 12 (to the root part) of the working blades 3 and 4 practically with preservation of the moment of momentum. The presence in the channels 8 of the central body 13 makes it possible to limit the magnitude of the ventilated flow. An increase in the specific moment of the amount of movement of the ventilated medium at the inlet to the root 12 (in the root part) of the impeller 2 at a limited amount of consumption leads to a decrease in the ventilation moment, and consequently, the power consumption for ventilation.

Formula

and 3

gaining

A partial turbine stage containing a nozzle apparatus and an impeller, on both sides of the blades of which protective plates are installed on the inactive part of the circular arc, characterized in that, in order to improve efficiency, the channels located in the circumferential direction are made in the form of a half torus, whose entrance is located at the periphery, and the exit is at the root of the blades.

figure 1

Claims (1)

Claim Partial turbine stage 30 containing a nozzle apparatus and an impeller, on both sides of the working blades of which protective shields are installed on the inactive part of the circular arc, distinguishing them by the fact that, in order to increase efficiency, the channels in the circumferential direction are made in the form of half torus whose entrance is located 40 at the periphery, and the exit at the root of the working blades. g