SU7500A1 - Steam turbine, working with high pressure steam and crushed steam, or the corresponding medium pressure steam - Google Patents

Description

Typically, turbines for operating with two pressures of steam are designed in such a way that, while simultaneously supplying both pressures with steam, the steam coming from the high pressure stages, together with the external steam supplied, is supplied through one or more valves to the low pressure portion of the turbine , wherein these valves in the mixing space maintain approximately atmospheric pressure. Such a device suffers from the disadvantage that, when operating exclusively with ground steam, the high-pressure stages continuously rotate, without performing work, in a stationary pair with atmospheric pressure, as a result of which considerable ventilation losses occur; the heat generated by this ventilation can only be discharged to an insignificant degree

heat-conducting and radiating parts of the machine, so that these steps very quickly acquire an unacceptably high temperature.

Alternatively, the crumpled steam expands separately in several stages and is mixed with steam coming from the high pressure stages only in a common steam discharge nipple. The disadvantage of this device lies in the large number of stages, in which the turbine takes up a lot of space and costs, is much more expensive.

The present invention aims to eliminate these disadvantages.

In FIG. 1 and FIG. 2 depicts longitudinal sections of two turbines. The steam through the nozzles and enters the impeller of the stage of medium pressure, through the other nozzles of this stage flows fresh steam from the stage of high pressure, and the mixing

occurs only after passage through the impeller of the stage of average pressure in the space b. In this space, even in the highest possible amount of m of that pair, there should be a vacuum, since the supply of moth of vapor at atmospheric pressure is impossible. As a result, when operating exclusively with steam steam, the high pressure stage rotates in the steam under vacuum, which should greatly reduce the friction of the impeller.

In some cases, when the number of that pair entering the work is too large, so that steam cannot pass through nozzles installed on the part of the circumference of the average pressure stage, it is possible to sum up the crumpled steam around the entire circumference of the average pressure stage. This makes it impossible to pass the medium pressure stage through the impeller Fresh steam coming from the high pressure stage. This steam must, by the middle level

pressure, together with the steam flow from the medium pressure stage, to the next low pressure stage, as shown in FIG. 2. In both cases, the individual pressure stages may have wheels with one or several rims of blades.

The subject of the patent.

A steam turbine operating as high-pressure steam and crushed steam or the corresponding medium-pressure steam, with the supply of mist steam or a corresponding steam of medium pressure through special nozzles to the middle stage, characterized by the fact that only the ground or corresponding steam acts on the blades. medium pressure, while the steam from the high pressure stages is bypassed by the middle stage to the low pressure stage that follows it, together with the vapor that has passed the middle stage.