CN112004996B

CN112004996B - Steam turbine assembly

Info

Publication number: CN112004996B
Application number: CN201980027985.8A
Authority: CN
Inventors: S·黑克尔; L·霍迈尔; N·皮珀; R·昆科茨; M·韦克松
Original assignee: Siemens Energy Global GmbH and Co KG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2018-04-26
Filing date: 2019-04-04
Publication date: 2022-10-21
Anticipated expiration: 2039-04-04
Also published as: EP3561238A1; CN112004996A; WO2019206597A1

Abstract

The invention relates to an assembly comprising a steam turbine (2) and two additional steam lines to the steam turbine (2), wherein a diaphragm (10, 11) is arranged in each steam supply line in order to thereby minimize undesirable rotor vibrations.

Description

Steam turbine assembly

Technical Field

The invention relates to an assembly comprising a steam turbine, a steam supply line which is fluidically connected to an inflow region of the steam turbine, and a steam valve which is arranged in the steam supply line, wherein the inflow region is fluidically connected to a flow channel, furthermore comprising an additional steam line which is fluidically connected to an additional inflow region of the steam turbine, and an additional steam valve which is arranged in the additional steam line, wherein the additional inflow region is arranged downstream of the flow channel.

Background

Steam turbines generally include a plurality of turbine sections, for example divided into a high pressure turbine section, an intermediate pressure turbine section, and a low pressure turbine section. Some steam turbine embodiments include multiple turbine sections and have a common shaft. The length of the shaft is relatively long here. Fresh steam is generated in the steam generator. The live steam reaches the high-pressure turbine section via a live steam line and a live steam valve. The live steam generally flows into an inflow region of the high-pressure turbine section, wherein the inflow region opens into a flow channel characterized by guide vanes and rotor blades. The heat energy of the steam is converted into rotational energy of the shaft in the flow channel.

In addition to the main valve through which the live steam flows, there are also embodiments in which an additional steam mass flow flows into the steam turbine in order to increase the power. The additional steam mass flow merges downstream into the flow channel. However, the introduction of the additional steam mass flow may lead to conditions acting on the rotor, which risks exciting rotor vibrations.

In order to keep the forces acting on the rotor due to the introduction of the additional steam mass flow small, the additional steam mass flow can be distributed to the two lines after the steam valve, which can be an additional steam valve. The flow field in the region distributed to the two ducts may have a significantly unstable nature, so that periodic disturbances may be induced in the two ducts downstream, which may lead to undesirable rotor vibrations.

Disclosure of Invention

It is an object of the invention to provide a feasible solution for minimizing the risk of rotor vibrations while introducing an additional mass flow.

This object is achieved by an assembly comprising a steam turbine, a steam supply line which is fluidically connected to an inflow region of the steam turbine, and a steam valve which is arranged in the steam supply line, wherein the inflow region is fluidically connected to a flow channel, furthermore comprising an additional steam line which is fluidically connected to an additional inflow region of the steam turbine, an additional steam valve which is arranged in the additional steam line, wherein the additional inflow region is arranged downstream of the flow channel, wherein a device for increasing the pressure loss is arranged in the additional steam line, wherein the additional steam line is divided after the additional steam valve into a first additional steam line and a second additional steam line, wherein the first additional steam line opens into a first additional inflow region in the flow channel, and the second additional steam line opens into a further second additional inflow region in the flow channel, wherein a first device for reducing the pressure is arranged in the first additional steam line, and a second device for reducing the pressure is arranged in the second additional steam line.

The invention therefore consists in intentionally increasing the pressure loss in the additional steam line in order to attenuate possible disturbances from the steam valve.

Thereby, flow disturbances and consequent rotor vibrations are significantly mitigated with this solution.

Advantageous refinements are given below.

In an advantageous first refinement, the device is designed as a valve.

Here, the valve is set in a position where the pressure loss is optimal for the application. Further adjustments to the position are generally not required.

In a further advantageous development, the device is designed as a diaphragm. This is a particularly advantageous embodiment. Here, a single-hole membrane or a porous membrane is arranged in the additional steam line. The pressure loss of the additional throttle element should in operation be at least 5% of the pressure drop of the additional steam valve. The diaphragm is designed accordingly.

The fact that the additional steam mass flow is distributed to both conduits will be taken into account. These lines each open into an additional inflow region in the flow channel. The first additional inflow region may be arranged, for example, at the 3 o 'clock position, and the second additional inflow region may be arranged, for example, at the 9 o' clock position. The steam flowing in through the first and second additional steam lines may cause vibrations of the rotor, which are minimized in that means designed for pressure reduction are arranged in each of the first and second additional steam lines. It is thus proposed to arrange a first device, which may be a valve, a membrane or a single-or multi-hole membrane, in the first additional steam line. It is also proposed that the second device arranged in the second additional steam line is designed as a valve, a diaphragm, a single-hole diaphragm or a porous diaphragm. Here, the pressure loss in each pipe may be set to be symmetrical or asymmetrical. This means that in the case of an asymmetrical arrangement, the pressure loss generated by the first device in the first additional steam line differs from the pressure loss of the second device in the second additional steam line. In a symmetrical arrangement, the pressure losses generated by the first means and by the second means are the same. In this configuration, the static forces acting on the rotor are minimal. The more the flow is damped, the lower the risk of rotor vibrations.

In an advantageous development, the steam turbine is designed as a high-pressure turbine section. Other types of turbine sections are not excluded, such as a combined medium-high pressure turbine, a medium pressure turbine, a combined medium-low pressure turbine or a low pressure turbine.

The above features, characteristics and advantages of the present invention and its implementation will become more apparent and more easily understood in conjunction with the following description of the embodiments, which will be set forth in detail in conjunction with the accompanying drawings.

Drawings

Embodiments of the present invention are described below with reference to the drawings. The drawings are not intended to be exhaustive of the embodiments, but are shown in schematic and/or slightly modified form for illustration. For a theoretical addition which can be seen directly in the figures, reference is made to the relevant prior art. Wherein:

fig. 1 shows a schematic view of an assembly according to the invention.

Fig. 2 shows another schematic view of an assembly according to the invention.

Detailed Description

Fig. 1 shows an assembly 1 comprising a steam turbine 2. The steam turbine 2 has an outer casing (not shown in detail), an inner casing and a rotor. The steam generated in the steam generator flows into the steam turbine 2 via the live steam line 12. In the live steam line 12, a control valve 13 and a quick-closing valve 14 are arranged in each case. The steam flows into the live steam region 15 in the steam turbine. Here, the thermal energy of the steam is converted into mechanical rotational energy of the rotor. The additional steam mass flow flows through an additional steam line 3 via an additional steam valve 4. After the additional steam valve, the steam flows to the splitter 5. The steam is split at the splitter 5 and flows into a first additional steam line 6 and a second additional steam line 7. The first additional steam line 6 opens here into a first additional inflow region 8, the first additional inflow region 8 opening into a flow channel, not shown in detail.

The additional steam line 3 can form a branch 15 from the live steam line 12.

The second additional steam line 7 opens into a further second additional inflow region 9, the second additional inflow region 9 opening into a flow channel not shown in detail.

In the first additional steam line 6, a first device 10 for reducing the pressure is arranged. In the second additional steam line a second device 11 is arranged. The first device may be a valve, a diaphragm, a single-hole diaphragm, or a porous diaphragm.

The second device 11 may be a valve, a diaphragm, a single-hole diaphragm, or a porous diaphragm.

The value of the pressure reduction produced by the first means in the first additional steam line 6 can be different from the value of the pressure reduction achieved by the second means in the second additional steam line 7 (asymmetric setting of the pressure loss).

Fig. 2 is a further schematic illustration of the assembly according to the invention, wherein in fig. 2 the live steam line 12 is not shown, but only the arrangement of the additional steam line 3 and the subsequent distribution in the first additional steam line 6 and the second additional steam line 7.

In an alternative embodiment, the values of the pressure reduction achieved by the first and second means may be the same (symmetrical arrangement of pressure losses).

Although the invention has been illustrated and described in detail in the context of preferred embodiments, the invention is not limited to the examples disclosed and other variants can be derived therefrom by the person skilled in the art without departing from the scope of protection of the invention.

Claims

1. An assembly (1) of a steam turbine, comprising:

a steam turbine (2) is provided,

a steam supply line which is fluidically connected to an inflow region of the steam turbine, wherein the inflow region is fluidically connected to a flow channel, an

A steam valve arranged in the steam supply line,

the assembly (1) further comprises:

an additional steam line (3), the additional steam line (3) being fluidically connected to an additional inflow region (8, 9) of the steam turbine (2),

an additional steam valve (4), the additional steam valve (4) being arranged in the additional steam line (3),

it is characterized in that the preparation method is characterized in that,

the additional steam line (3) is divided into a first additional steam line (6) and a second additional steam line (7) after the additional steam valve (4),

wherein the first additional steam line (6) opens into a first additional inflow region (8) in the flow channel, and

the second additional steam line (7) opens into a further second additional inflow region (9) in the flow channel,

wherein a first device (10) for reducing the pressure is arranged in the first additional steam line (6) and a second device (11) for reducing the pressure is arranged in the second additional steam line (7).

2. The assembly according to claim 1, wherein said first means (10) is a valve and said second means (11) is a valve.

3. The assembly according to claim 1, wherein said first means (10) is a membrane and said second means (11) is a membrane.

4. The assembly according to claim 1, wherein said first means (10) is a single-pore membrane or a porous membrane and said second means (11) is a single-pore membrane or a porous membrane.

5. Assembly according to any one of claims 1 to 4, wherein the value of the pressure loss achieved by the first means (10) is different from the value of the pressure loss achieved by the second means (11).

6. Assembly according to one of claims 1 to 4, wherein the first device (10) is designed such that in operation the pressure loss immediately after the additional steam valve (4) or before the first additional inflow region (8) is at least 5% of the pressure drop of the additional steam valve (4).

7. Assembly according to one of claims 1 to 4, wherein the second device (11) is designed such that in operation the pressure loss immediately after the additional steam valve (4) or before the second additional inflow region (9) is at least 5% of the pressure drop of the additional steam valve (4).

8. An assembly according to any one of claims 1 to 4, in which the steam turbine (2) is designed as a high-pressure turbine section.

9. The assembly according to any one of claims 1 to 4, wherein the steam turbine (2) is designed as a combined medium-high pressure turbine, a medium-pressure turbine, a combined medium-low pressure turbine or a low-pressure turbine.