WO1998015719A1

WO1998015719A1 - Steam turbine

Info

Publication number: WO1998015719A1
Application number: PCT/EP1997/005491
Authority: WO
Inventors: Armin Drosdziok; Andreas FELDMÜLLER
Original assignee: Siemens Aktiengesellschaft
Priority date: 1996-10-08
Filing date: 1997-10-07
Publication date: 1998-04-16
Also published as: TW355727B

Abstract

A steam turbine includes a low-pressure portion, which can be set up flush to the ground or in a low construction and can be connected to a condenser that can likewise be set up flush to the ground. The outer housing has an outward-bulging side surface for forming a compensation chamber and a side opening opposite to the side surface for connection of a condenser.

Description

STEAM TURBINE

Background of the Invention: Field of the Invention: The invention relates to a steam turbine system having a low- pressure portion.

In a steam turbine plant, typically a steam turbine combined with a condenser to make a steam turbine system is disposed in a machine house or turbine hall. The condenser may be connected on the downstream side axially or radially to the steam turbine. In an axial configuration, the condenser is placed longitudinally of the turbine shaft, while conversely in a radial configuration it is mounted in a position oriented at right angles to the longitudinal direction of the turbine shaft.

In order to utilize gravity to reinforce mass transport from the turbine to the condenser in the radial mode of construction, the condenser is typically disposed below the steam turbine. Such a construction of the steam turbine, which is also called a high construction, entails considerable structural and engineering expense, especially because of the large number of structural components. Moreover, the expense of assembly in setting up such a steam turbine system is particularly high, especially since the steam turbine located above the condenser requires an expensive and complicated supporting construction.

Summary of the Invention:

It is accordingly an object of the invention to provide a steam turbine, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type, which can be set up flush to the ground or in a low construction and which can be connected to a condenser that can likewise be set up flush to the ground.

With the foregoing and other objects in view there is provided, in accordance with the invention, a steam turbine, comprising a low-pressure portion having an outer housing, the outer housing having an outward-bulging side surface defining a compensation chamber, and the outer housing having a side opening opposite the side surface for connection of a condenser.

The invention takes as its point of departure the concept that steam leaving the steam turbine and to be supplied to the condenser should be suitably guided, for a low construction of the steam turbine. In order to assure a sufficiently large flow cross section for steam guidance, so that the flow loss is only slight, a space suitable for that purpose should be available inside the steam turbine housing. The steam that has collected there should be suitably deflected for delivery to the condenser.

In accordance with a concomitant feature of the invention, there is provided a bled steam line passed through the outward-bulging side surface of the low-pressure portion. This is done in order to make it possible to draw bled steam from the steam turbine for feeding a component of a steam power plant, such as a preheater unit.

The advantages attainable with the invention are in particular that because of the compensation chamber created by the outward-bulging side surface, steam from the steam turbine, even when the steam turbine is set up flush to the ground, can be supplied to a condenser that is directly connected radially to the steam turbine on the downstream O 98/15719

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side and that is itself set up flush to the ground. Since the steam turbine and the condenser are set up flush to the ground, a complicated and costly support construction is unnecessary. The overall result is a compact, space-saving kind of construction, and only especially slight demands are made in terms of statics and of the size of the turbine hall.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in a steam turbine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims .

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings .

Brief Description of the Drawings : Fig. 1 is a diagrammatic, top-plan view of one exemplary embodiment of a steam turbine system according to the inven ion;

Fig. 2 is a side-elevational view of the steam turbine system of Fig. 1, as seen along a line II-II of Fig. 1, in the direction of the arrows;

Fig. 3 is a longitudinal-sectional view of a low-pressure portion of a steam turbine; and Fig. 4 is a cross-sectional view of the low-pressure portion of Fig. 3.

Description of the Preferred Embodiments: Referring now in detail to the figures of the drawings, m which identical parts are identified by the same reference numerals, and first, particularly, to Fig. 1 thereof, there is seen a steam turbine system 1 which includes a steam turbine 2 with a high-pressure and medium-pressure portion 2a and a low-pressure portion 2b, to which a condenser 4 is connected radially on the downstream side. A preheater unit 6 is disposed on a side of the steam turbine 2 facing the condenser 4. A generator 8 which is located m the vicinity of the steam turbine 2 can be driven through a steam turbine shaft 7.

Both the high-pressure and medium-pressure portion 2a and the low-pressure portion 2b of the steam turbine 2 as well as the condenser 4 and the preheater unit 6 and the generator 8 are each constructed as a module and are moreover disposed flush with the ground. The term "module" should be understood m this case to mean a connectable, transportable component that can be pre-assembled. Each of the aforementioned modules is mounted on a sledlike structure or skid m a non-illustrated manner and can thus be shifted about especially easily.

The steam turbine system 1 is part of a non-illustrated coal- fired steam power plant having a high-pressure preheater, m the form of a module 9, that is likewise disposed flush with the ground on the side of the steam turbine 2 facing the condenser 4. The steam turbine system 1 is connected to a once-through steam generator of the steam power plant m a non-illustrated manner. One such once-through steam generator is described, for instance, m co-pendmg U.S. Patent Application Serial No. (Attorney's Docket No. 5796) entitled "Modular Boiler", filed concurrently with the instant application and having the same assignee. The steam turbine 2, the condenser 4, the preheater unit 6, the generator 8 and the module 9 are disposed in a common power house or turbine hall 10.

The generator 8 is connected through a supply line system 11, into which a switch system 12 is incorporated, to a generator transformer 13 which is disposed outside the turbine hall 10 and serves to transform electrical voltage furnished by the generator 8 to a higher level .

Fig. 2 is a side view of the turbine hall 10, showing the disposition of the steam turbine 2, the condenser 4 and the preheater unit 6 flush with the floor. The condenser 4 is radially connected to the steam turbine 2 on the downstream side. The condenser 4, which is constructed as a module, includes a first condenser element 4a and a second condenser element 4b located above the first. An especially space- saving, compact construction is thus achieved.

The preheater unit 6, which is also constructed as a module, includes a number of preheater elements 15 disposed in a common support stand or heater rig 14. Each preheater element 15 can be acted upon with bled steam A from the steam turbine 2 through a bled steam duct system 16. The pressure and temperature of the bled steam A are functions of the location, wherever it is, at which the steam turbine 2 is bled. Each preheater element 15 is constructed for a specific pressure range of the bled steam A. Locating the preheater elements 15 in the common heater rig 14 makes it possible to prefabricate the preheater unit 6 as a module. This makes the effort and expense of on-site assembly especially low. In order to facilitate assembly of the steam turbine system 1 even further, the module 9 is also mounted on a sled structure or skid.

As is shown in a longitudinal section in Fig. 3, the low- pressure portion 2b of the steam turbine 2 is constructed in dual-flow fashion. An outer housing 20 of the low-pressure portion 2b encloses an inner housing 22, in which the turbine shaft 7 is disposed with a set of low-pressure blades 24. The low-pressure portion 2b has a steam inlet region 26, to which steam from the high-pressure and medium-pressure portion 2a of the steam turbine 2 can be delivered through an overflow line 28. Steam that has expanded, producing work, in the low-pressure blades 24 of the low-pressure portion 2b, can be removed through a steam outlet region 30 and a number of steam passageway surfaces 32.

In order to form a compensation chamber 36 for the steam removed from the low-pressure blades 24, one side surface 38 of the outer housing 20 of the low-pressure portion 2b is curved outward, as is shown in Fig. 4. The steam entering the compensation chamber 36 can thus be deflected by simple provisions and then delivered to the condenser 4 with only especially slight flow losses. In order to provide a connection to the condenser 4, the outer housing 20 of the low-pressure portion 2b has a side opening 40 opposite the outward-curved side surface 38.

A bled steam adapter or connector 42 is provided in order to supply bled steam A to the bled steam line system 16. This element 42 is passed laterally through the inner housing 22. Alternatively, however, a vertically guided, bled steam adapter which is bent at an angle can be provided. The bled steam adapter 42 is connected to a bled steam line 46, which is passed through the outward-facing side surface 38 and which can be connected to the bled steam system 16.

The compensation chamber 36 formed by the outward-bulging side surface 38 assures that the condenser 4 can be radially laterally connected on the downstream side to the low- pressure portion 2b of the steam turbine 2 by especially simple provisions. This makes it possible to set up both the steam turbine 2 and the condenser 4 flush to the ground.

Claims

We claim :

1. A steam turbine, comprising:

a low-pressure portion having an outer housing, said outer housing having an outward-bulging side surface defining a compensation chamber, and said outer housing having a side opening opposite said side surface for connection of a condenser .

2. The steam turbine according to claim 1, including a bled steam line passing through said outward-bulging side surface.