JPS61116031A - Gas turbine - Google Patents

Abstract

PURPOSE:To enable fetching of an output from both turbines, by a method wherein reduction gears respectively are connected to high and low pressure turbine, the reduction gears are intercoupled through a synchronous shaft for interlocking, and an output shaft is projected from the one reduction gear. CONSTITUTION:A high pressure compressor 3 is installed to a rotor shaft 2 of a high pressure turbine 1, and a low pressure compressor 7 is installed to a rotor shaft 6 of a low pressure turbine 5. The rotor shafts 2 and 6 are concentrically supported in series to a turbine casing 8, and reduction gears 9 and 10 are connected to the outer end sides of the rotor shafts 2 and 6, respectively. The reduction gears 9 and 10 are intercoupled through a synchronous shaft 11 for interlocking, and meanwhile, an output shaft 12, being located to the reduction gear 10, is connected to a load 13. This causes the rotor shafts 2 and 6 to reduce in a speed to a specified value and couple with each other, resulting in the possibility to fetch both outputs, generated by the rotor shafts 2 and 6, as the output of an engine through the output shaft 12.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to gas turbines.

(Prior art) (a) In a gas turbine, the main components are a compressor, a turbine, a combustor, a heat exchanger, etc., and there are many ways to arrange them. For example, "Gas turbine cycle theory"
, Sankaido, published July 25, 1971, P53-P
75 or "Gas Turbine", Corona Publishing, published June 10, 1980, pages 35 to 48, examples of their arrangement are described.

According to the conventional example, if the turbine has one stage, it is of course a single-shaft type (see Figure 6), but if there are two or more stages of turbines, including a radial turbine, it is a two-shaft free turbine type. (Refer to Fig. 7), there is no example of a single-shaft gas turbine with two or more stages of turbines, including a radial turbine.

On the other hand, as gas turbines for power generation, single-shaft gas turbines that have little frequency fluctuation during load fluctuations are common.

(c) Turbine types are broadly classified into radial turbines and axial flow turbines. Radial turbines have a simple and sturdy structure, and can have a higher allowable circumferential speed than axial flow turbines, so the unit flow rate is It has a higher output than an axial flow turbine and has high adiabatic efficiency. However, since a multi-stage structure becomes complicated, it is common to use a radial turbine for the single stage or high pressure stage and an axial flow turbine for the low pressure stage. As described above, the radial turbine has a simple structure, can be manufactured at low cost, and is suitable for small flow rates, so it is convenient for use in small gas turbines.

(d) In recent years, with the advent of new heat-resistant materials called ceramics, it has become possible to dramatically increase the turbine inlet temperature. As a result, it has become possible to achieve high thermal efficiency and miniaturize the engine.

However, ceramic rotors can still only be manufactured in small sizes. Therefore, it can be said that ceramics are suitable for rotors of radial turbines.

(Problem to be solved by the invention) When a ceramic rotor is used for the rotor of a radial turbine, the outlet temperature becomes low when a high load is applied even under a high inlet temperature, and a large-diameter low-pressure turbine is placed in its wake. Since the low-pressure turbine can be sustained by an uncooled rotor made of a heat-resistant alloy, it can be an economical and highly efficient engine.

In other words, in the past, the functions of the high-pressure turbine and low-pressure turbine were completely separate, with one for the gas generator and the other for output, but now output can be extracted from both the high-pressure turbine and the low-pressure turbine. In this way, an economical and highly efficient engine can be obtained.

For example, as a gas turbine for power generation, the rotor shaft of a high-pressure turbine using a ceramic radial rotor or an air-cooled radial rotor made of a heat-resistant alloy is mechanically connected to the rotor shaft of a low-pressure turbine using an uncooled rotor made of a heat-resistant alloy. If a single-shaft gas turbine can be obtained in this way, an economical and highly efficient engine can be obtained.

However, as explained in section (a) of the prior art,
There is still no single-shaft gas turbine with two or more turbine stages.

The reason is as follows.

■ Radial turbines have a large amount of work per stage, so they have high circumferential speeds, that is, high speed rotation, and it is necessary to match the rotational speed with the axial flow turbines from the second stage onwards.

Therefore, direct connection is difficult.

■ Radial turbines have high hub stresses as a result of their high circumferential speeds, so the hub is generally solid.

Therefore, no through shaft is provided. It is also very difficult to protrude the extension shaft from the hub. For this reason, it is mechanically very difficult to connect two concentric shafts with different rotational speeds at a constant speed ratio within the turbine casing using gears.

However, as mentioned above, in a gas turbine that has two or more stages of turbines, including a radial turbine, if a single-shaft gas turbine can be obtained, engine output can be obtained from both the high-pressure shaft and the low-pressure shaft. , can be made into an economical and highly efficient engine.

Therefore, an object of the present invention is to obtain a multi-stage l-axis gas turbine using a radial turbine in the high-pressure stage.

(Means for solving problems) In order to achieve the above object, the present invention has taken the following measures.

That is, the feature of the present invention is that reduction gears are connected to the rotor shaft of the high-pressure turbine and the rotor shaft of the low-pressure turbine, and both reduction gears are interlocked and connected by a synchronous shaft, and the output from one of the reduction gears is It is located at the point where the shaft protrudes.

(Function) According to the present invention, the rotor shaft of the high-pressure turbine and the rotor shaft of the low-pressure turbine are reduced to a certain constant speed by their respective reducers, and are interconnected by a synchronous shaft. Both rotor shafts are mechanically connected, and both outputs generated at both rotor shafts can be taken out from the output shaft as engine output.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

What is shown in FIG. 1 is a layout diagram of a gas turbine according to the present invention, and FIG. 2 shows its actual structural diagram.

In the figure, reference numeral 1 denotes a high-pressure turbine, which is a radial turbine and is composed of a ceramic radial rotor. A high-pressure compressor 3 is provided on a rotor shaft 2 of this high-pressure turbine 1 . Compressed air discharged from the high-pressure compressor 3 is supplied to the high-pressure turbine 1 via the combustor 4.

Reference numeral 5 denotes a low-pressure turbine, which is an axial flow turbine, and whose rotor is an uncooled rotor made of a heat-resistant alloy. A low-pressure compressor 7 is provided on the rotor shaft 6 of the low-pressure turbine 5, and air discharged from the low-pressure compressor 7 is supplied to the high-pressure compressor 3 described above.

Further, combustion gas discharged from the high pressure turbine 1 is supplied to a low pressure turbine 5.

The rotor shaft 2 of the high-pressure turbine 1 and the rotor shaft 6 of the low-pressure turbine 5 are supported by a turbine casing 8 concentrically and in series. Both turbines 1.5 are arranged close to each other so that the exhaust gas from the high-pressure turbine 1 flows into the low-pressure turbine 5 with little loss (pressure loss, heat loss). Both rotor shafts 2 and 6 are not mechanically connected within the turbine casing 8 and are mutually free.

Reduction gears 9° and 10 are provided on the outer end sides of each of the rotor shafts 2 and 6, respectively.
is connected. Both reducers 9 and 10 are connected to the synchronous shaft 11.
are linked and linked. This synchronous shaft 11 is installed outside the turbine casing 8, and both rotor shafts 2, 6 .
is placed parallel to.

Output shaft 1 is connected to one reducer 1o of the reducers 9 and 10 mentioned above.
2 is provided. A load 13 is connected to this output shaft 12 .

Note that the power transmitted by the synchronous shaft 11 is connected to each rotor shaft 2 so that it does not become zero even in harsh operating conditions.
, 6 (because the transmission has backlash, this effect is to be eliminated).

According to the embodiment of the present invention, when the outlet pressure of the high-pressure turbine 1 is increased, the density of the working fluid is increased, and the weight and flow rate can be increased for the high-pressure turbine rotor 1 having a constant size. In other words, the output can be increased.

Since the integrally molded ceramic rotor 1 is subject to dimensional restrictions, a large output can be obtained by installing the large gas turbine 5 downstream of the high pressure turbine 1 as in the above embodiment.

Further, according to the above embodiment, since the synchronizing shaft 11 is installed outside the engine, there are fewer restrictions on the dimensions of the synchronizing shaft 11 (and maintenance is also easy).

Furthermore, since the space between the high-pressure turbine rotor shaft 2 and the low-pressure turbine rotor shaft 6 becomes free when the synchronous shaft 11 is removed,
There is no need to pay close attention to disassembling and reassembling, and disassembling and reassembling becomes easy.

Furthermore, since the high-pressure turbine rotor shaft 2 and the low-pressure turbine rotor shaft 6 have independent shaft systems, an optimal design can be achieved in terms of structure and aerodynamics.

3 to 5 show other embodiments of the present invention, and in the one shown in FIG. 3, two-stage compressors 3 and 7 are provided on the rotor shaft 2 of the high-pressure turbine 1.

In the one shown in FIG. 4, the low pressure compressor 7 is double.

In the one shown in FIG. 5, an intercooler 14 is placed between the low-pressure/high-pressure compressor 7.3, and the discharge air of the high-pressure compressor 1 and the exhaust air of the low-pressure turbine 5 are exchanged through a heat exchanger 15. It is to be exchanged.

Note that the present invention is not limited to the above embodiments,
For example, the low-pressure turbine 5 may be a radial turbine, and the arrangement of the turbine, compressor, combustor, cooler, etc. may be arbitrary. In short, it is sufficient to mechanically connect the high-pressure rotor shaft and the low-pressure rotor shaft via a reduction gear and a synchronous shaft, and to extract output from both rotor shafts.

(Effects of the Invention) According to the present invention, output can be extracted from both the low-pressure rotor shaft and the high-pressure rotor shaft, so that an economical and highly efficient engine can be obtained.

[Brief explanation of drawings]

FIG. 1 is a layout diagram of a gas turbine showing an embodiment of the present invention;
Figure 2 is a cross-sectional view of the actual machine based on the layout in Figure 1, and Figure 3-
FIG. 5 is a layout diagram of various gas turbines showing another embodiment of the present invention, and FIGS. 6 and 7 are layout diagrams of a gas turbine showing a conventional example. DESCRIPTION OF SYMBOLS 1... High pressure turbine, 2... Rotor shaft, 5... Low pressure turbine, 6... Rotor shaft, 9, 1o... Reduction gear, 11... Synchronous shaft, 12... Output shaft . Patent applicant: Kobe Steel, Ltd. @ 6 Figure R□59. 9-1〉7th
Figure 1 Figure 3 Figure 4 ρ1 131

Claims (1)

[Claims] 1. A reduction gear is connected to the rotor shaft of the high-pressure turbine and the rotor shaft of the low-pressure turbine, and both reduction gears are interlocked and connected by a synchronous shaft, and the output shaft is made to protrude from one of the reduction gears. gas turbine.