STEAM TURBINE PLANT

Description

[0001] The invention relates to a steam turbine system according to claim 1.

[0002] To operate a steam turbine at its optimal operating point, certain (optimal) steam parameters, particularly regarding mass flow, pressure, moisture content, and / or temperature, must be maintained. However, if process steam is used to operate the steam turbine or if the steam is supplied from renewable energy sources, the steam parameters can fluctuate significantly. In these cases, the steam parameters must be adjusted to the required values ​​before entering the steam turbine or along the expansion section; otherwise, efficiency may decrease or the steam turbine may be damaged.

[0003] An unpublished application by the applicant therefore provides for the generation of secondary steam, if required, by means of a secondary steam source. This secondary steam is then mixed with the primary steam if predefined limits for one or more steam parameters (in particular mass flow, pressure, temperature, and / or moisture content) of the primary steam are exceeded or fallen below. This results in a total steam product, generated from the primary and secondary steam, with steam parameters that lie within a predefined range. The secondary steam is generated by means of a secondary steam source, which reacts hydrogen and oxygen within a defined area or component, such as a combustion chamber, to produce the steam.

[0004] The combustion of oxygen with hydrogen allows for the rapid production of large quantities of steam with high steam parameters (especially high temperature and low or no moisture content). This enables the secondary steam to be supplied very quickly and blended with the primary steam as soon as one or more of the primary steam's parameters fall below or exceed predefined limits. By selectively blending secondary steam, a total steam output can be achieved that exhibits optimal steam parameters for operating the steam turbine system.

[0005] From US patent 3,276,203 A, a steam turbine system is known which comprises a first and a second turbine section, wherein the first turbine section is connectable to the second turbine section via at least one first coupling, and wherein the water-steam cycle further comprises a first primary steam source and a second secondary steam source. The first turbine section can be supplied with primary steam from the primary steam source, and the second turbine section can be supplied with primary steam from the primary steam source or a portion thereof and / or secondary steam from the secondary steam source.

[0006] However, generating secondary steam using hydrogen and oxygen is costly. Therefore, a decision must be made between operating the steam turbine at a lower output, risking damage through suboptimal operation, or accepting the higher costs. Ideally, a steam turbine system would be highly flexible and adaptable to changing needs at short notice.

[0007] The object of the invention is therefore to provide such a system that can be operated flexibly.

[0008] The problem is solved by the features of independent claim 1.

[0009] Further embodiments of the invention, which can be used individually or in combination with each other, are the subject of the exemplary embodiments.

[0010] The steam turbine system according to the invention comprises at least one water-steam cycle in which a steam turbine with at least one first and one second sub-turbine is arranged. The first sub-turbine and the second sub-turbine are connectable via at least one first coupling. Furthermore, the water-steam cycle comprises a first primary steam source and a second secondary steam source, wherein the first sub-turbine can be supplied with primary steam from the primary steam source, and the second sub-turbine can be supplied with primary steam from the primary steam source or a portion thereof and / or secondary steam (or a portion thereof) from the secondary steam source, and the secondary steam can be generated by means of a steam generator which is a component of the secondary steam source, wherein hydrogen and oxygen are reacted together to generate the steam.The first coupling is designed as a switchable coupling, and a second switchable coupling is arranged between the first and second turbine sections, which can be actuated independently of the first switchable coupling. A generator or machine is arranged between the first and second switchable couplings, which can be connected to the first and / or second turbine section depending on the switching position of the first or second switchable coupling.

[0011] For the purposes of this invention, primary steam is defined as the steam originating from the primary steam source; this may also be partially expanded steam or a portion of the original steam generated by the primary steam source.

[0012] A turbine section consists of at least one turbine casing. The combination of at least two turbine sections, which can be connected via a switchable coupling, and a secondary steam source that can generate steam using hydrogen and oxygen results in a highly flexible steam turbine system that can be adapted to rapidly changing conditions with regard to both steam supply and output demand (electrical energy or drive power of a connected consumer). For example, the first turbine section can be operated individually or together with the second turbine section, provided there is sufficient primary steam with the appropriate steam parameters, without additional secondary steam. If the primary steam parameters are insufficient, the second turbine section can be operated with a mixture of primary and secondary steam or with secondary steam alone.The steam turbine system according to the invention is therefore flexible, whereby the individual operating modes can be quickly adjusted and varied due to the coupling and the secondary steam available at short notice.

[0013] The advantages of the invention are explained below using various exemplary embodiments. These will show: Fig. 1 : The basic structure of a first embodiment of a steam turbine plant with a switchable coupling. Fig. 2 : A first operating mode of the in Fig. 1 steam turbine system shown. Fig. 3 : A second operating mode of the in Fig. 1 steam turbine system shown. Fig. 4 : A third operating mode of the in Fig. 1 steam turbine system shown. Fig. 5 : A fourth operating mode of the in Fig. 1 steam turbine system shown. Fig. 6 : The basic structure of a first embodiment of a steam turbine system according to the invention with two switchable couplings. Fig. 7 : A first operating mode of the in Fig. 6 steam turbine system shown. Fig. 8 : A second operating mode of the in Fig. 6 steam turbine system shown. Fig. 9 : A third operating mode of the in Fig. 6 steam turbine system shown. Fig. 10 : A fourth operating mode of the in Fig. 6 steam turbine system shown. Fig. 11 : A fifth operating mode of the in Fig. 6 steam turbine system shown.

[0014] The figures each show a simplified, schematic view of the invention, in which essentially only the components necessary for the invention are depicted. Components that are self-evident to those skilled in the art and necessary for the operation of any steam turbine system, such as valves, throttles, any gearboxes, and any condenser, are not shown for the sake of clarity. Identical or functionally equivalent components are identified by the same reference numerals across all figures. Fig. 1 shows a steam turbine system with a switchable clutch and the associated Fg. 2 to 5 different operating modes of the in Fig. 1 described steam turbine plant.

[0015] Fig. 6 shows a steam turbine system according to the invention, and Fig. 7 bis 11 Various operating modes of the steam turbine system according to the invention. In the illustrations ( Fig. 2 bis 5 and 7 bis 11 ) The areas of the water-steam cycle (e.g., pipelines) that are not required for the respective operating mode or are not traversed are not shown for the sake of clarity.

[0016] Fig. 1 Figure 1 shows the basic structure of a steam turbine system with a switchable coupling. The steam turbine system comprises a water-steam cycle 1 in which a steam turbine 2 is arranged. The steam turbine 2 comprises a first partial turbine 2' and a second partial turbine 2". The two partial turbines 2' and 2" are connected in series and can be connected via a switchable coupling 3, so that when the coupling 3 is closed, they can drive a common output shaft 8. The steam turbine system also includes a primary steam source 4. The primary steam supplied by the primary steam source 4 can have fluctuating steam parameters, which can prevent continuous operation of the steam turbine system, or at least its operation at an optimal operating point. The primary steam source 4 could be, for example, a waste incineration plant or a renewable energy power plant (e.g., a solar thermal power plant).To ensure continuous operation of the steam turbine system, or to adjust the steam parameters before and / or along the expansion section, a secondary steam source 5 is provided. The secondary steam source 5 obtains its steam by reacting hydrogen and oxygen in a controlled manner. This process yields large quantities of steam at high temperatures. Water (liquid or vapor) can be added to the secondary steam to condition it. The primary and secondary steam sources 4 and 5 are arranged within the water-steam cycle 1 such that the first turbine section 2' is supplied with the primary steam from the primary steam source 4, and the second turbine section 2" is supplied with the primary steam from the primary steam source 4, the partially expanded primary steam (after expansion in turbine section 2'), and / or a portion thereof, and / or a secondary mass flow from the secondary steam source 5.The operating mode used depends primarily on the steam parameters, in particular the mass flow rate, pressure, wetness, and / or temperature of the primary steam. The optimal operating mode can be set by preferably continuously acquiring the necessary measurement data and comparing it with the target values, e.g., using appropriate characteristic curves. The measuring and control equipment required for this is not shown.

[0017] The following will be discussed in Fig. 2 bis 5 Various operating modes are shown, which are connected to the steam turbine system. Fig. 1 can be driven.

[0018] Fig. 2 shows a first operating mode of the in Fig. 1 The steam turbine system shown is operated exclusively with primary steam supplied by primary steam source 4. A typical application scenario would be when sufficient primary steam with steam parameters is available to operate the steam turbine system at its optimal operating point. In such a case, the addition of secondary steam is unnecessary. The primary steam supplied by primary steam source 4 is first fed to the steam inlet 9 of the first turbine section 2', where it undergoes initial expansion. The partially expanded primary steam then exits the first turbine section 2' via steam outlet 10 and is fed through corresponding lines of the water-steam cycle 1 to the steam inlet 11 of the second turbine section 2''. There, it expands further and exits the second turbine section 2'' via steam outlet 12.The switchable clutch 3 is closed, so that all the power provided by the partial turbines 2', 2" can be transmitted to the common output shaft 8.

[0019] Fig. 3 shows a second operating mode of the in Fig. 1 The steam turbine system shown is operated exclusively with secondary steam supplied by the secondary steam source 5. A typical application would be, for example, if the primary steam source in a solar thermal power plant were operated using solar energy and there were a prolonged period of darkness or shading, e.g., due to dense clouds. The secondary steam supplied by the secondary source 5 is fed to the steam inlet 11 of the second turbine section 2", expands within the second turbine section 2", and then exits the second turbine section 2" via the steam outlet 12. The work performed during expansion is transmitted to the output shaft 8. The switchable clutch 3 is open, so that the first turbine section 2' is not engaged.

[0020] Fig. 4 shows a third operating mode of the in Fig. 1 The steam turbine system shown in the diagram operates with primary steam, to which secondary steam is added during the expansion phase. A typical application would be, for example, if the steam parameters of the primary steam are still within the permissible limits at the beginning of the expansion phase, but fall below and / or exceed the operating ranges during expansion, for example, if the temperature at the steam outlet 10 from the first turbine section 2' is too low. The primary steam supplied by the primary steam source 4 is initially fed to the steam inlet 9 of the first turbine section 2', and an initial expansion of the primary steam occurs. The partially expanded primary steam leaves the first turbine section 2' via the steam outlet 10 and is then fed via corresponding lines of the water-steam cycle 1 to the steam inlet 11 of the second turbine section 2".To adjust the steam parameters before entering the second turbine section 2", secondary steam, supplied by the secondary steam source 5, is mixed with the partially expanded primary steam. The steam parameters of the mixed secondary steam are determined by the steam parameters of the partially expanded primary steam downstream of the steam outlet 10 (which can also be indirectly determined from the power output and / or rotational speed, as well as other steam parameters along the expansion section). The required parameters are measured using appropriate sensors, and a downstream control unit uses these measurements to determine the steam parameters of the secondary steam to be mixed in order to achieve a total steam mixture whose parameters are within permissible and predefined limits. The measuring and control unit is not explicitly shown in any of the figures.After the partially expanded primary steam is mixed with the secondary steam, the total steam formed from the partially expanded primary and secondary steam is fed to the second turbine section 2" via the steam inlet 11, expanded, and discharged from the second turbine section 2" via the steam outlet 12. The coupling 3 is engaged in this operating mode, allowing both turbine sections 2' and 2" to transmit work to the output shaft 8.

[0021] Fig. 5 shows a fourth operating mode of the in Fig. 1 The steam turbine system shown is operated with primary and secondary steam, whereby the first turbine section 2' is not supplied with steam and performs no work. The primary steam, supplied by the primary steam source 4, is mixed with secondary steam, supplied by the secondary steam source 5, before entering the second turbine section 2". In contrast to the operating mode according to Fig. 4 When the coupling 3 is not engaged, the total steam formed from primary and secondary steam is directed through the steam inlet 11 into the second turbine section 2", where it expands and is discharged through the steam outlet 12 from the second turbine section 2". The work performed by the second turbine section 2" is transmitted to the output shaft 8.

[0022] Fig. 6 Figure 1 shows the basic structure of a first embodiment of a steam turbine system according to the invention. The essential difference between the one described in Figure 2 is that the turbine system described in Figure 3 is... Fig. 1 The described steam turbine system consists in that each turbine section has its own output shaft 8', 8" which can be connected to a generator or a driven machine 7 via switchable couplings 3', 3" . Each output shaft 8', 8" is connected to a switchable coupling 3', 3" through which the respective output shaft 8', 8" can be connected to a generator or driven machine 7 located between the two output shafts 8', 8" . Furthermore, both output shafts 8', 8" can perform work at different speeds. The remaining structure and the components used in the steam turbine system are essentially identical to the structure described in [reference to relevant document]. Fig. 1 Reference is made to its description. Likewise, the previously described operating modes 1-4 are related to the steam turbine system according to Fig. 6 This is feasible, whereby, depending on the operating mode, either the first, the second, or both partial turbines 2', 2'' drive the generator or the working machine 7. Without going into the operating modes in detail again—reference is again made to the previous explanations of the individual operating modes—the position of the individual couplings 3', 3" and the functions resulting from their position are briefly described below.

[0023] Fig. 7 shows a first operating mode of a steam turbine plant according to the invention. Fig. 6 , analogous to the first operating mode of the steam turbine plant after Fig. 2 The steam turbine system operates exclusively with primary steam, which is supplied by the primary steam source 4 and subsequently expanded first in the first turbine section 2' and then in the second turbine section 2". The two couplings 3' and 3" are engaged, so that the work performed by the two turbine sections 2', 2" can be transmitted to the generator 7 via the respective output shafts 8', 8".

[0024] Fig. 8 shows a second operating mode of a steam turbine system according to the invention. Fig. 6 , analogous to the second operating mode of the steam turbine plant according to Fig. 3 In this operation, the steam turbine system is powered exclusively by secondary steam supplied by the secondary steam source 5. The secondary steam is expanded by means of the second turbine section 2", and the work performed is transmitted to the generator 7 via the second output shaft 8". For this purpose, the second coupling 3" is engaged. The first turbine section 2' is not supplied with steam in this mode and therefore performs no work. The first coupling 3' is disengaged, thus decoupling the first turbine section 2' from the generator 7 and consequently also from the second turbine section 2".

[0025] Fig. 9 shows a third operating mode of a steam turbine system according to the invention. Fig. 6 , analogous to the third operating mode of the steam turbine plant according to Fig. 4 The steam turbine system operates with primary steam from primary steam source 4, to which secondary steam from secondary steam source 5 is added during the expansion phase to adjust the steam parameters. For details, please refer to the description at [link to description]. Fig 4 referred to. In this operating mode, both the first and second couplings 3',3" are engaged to transmit the work performed during the expansion of the steam in the respective sub-turbines 2',2" via the respective output shafts 8',8", to the generator 7.

[0026] Fig. 10 shows a fourth operating mode of a steam turbine plant according to the invention. Fig. 6 , analogous to the fourth operating mode of the steam turbine plant according to Fig. 5 In this operation, the steam turbine system is powered by primary steam supplied by primary steam source 4, which is mixed with secondary steam supplied by secondary steam source 5 before entering the second turbine section 2". In this operating mode, the second coupling 3 is engaged to transmit the work performed during the expansion of the total steam mass flow in the second turbine section 2" to the generator 7 via the second output shaft 8". The first turbine section 2' is not supplied with primary steam and performs no work in this operating mode; consequently, the first coupling 3' is not engaged. The first output shaft 8' is therefore decoupled from the generator 7.

[0027] Fig. 11 shows a fifth operating mode of a steam turbine plant according to the invention. Fig. 6 In this operating mode, the steam turbine system operates exclusively with primary steam, which is supplied by the primary steam source 4 and is expanded solely in the first turbine section 2'. The work performed is transferred to the generator 7 via the first output shaft 8'. For this purpose, the first clutch 3' is engaged. The second turbine section 2" performs no work, and consequently, the second clutch 3" is not engaged. The second output shaft 8" is thus decoupled from the generator 7. Such an operating mode is possible due to the design of a steam turbine system according to the [reference to be added]. Fig. 1The embodiment shown is possible but not practical. In this case, the second turbine section 2" would be dragged along by the first turbine section 2' due to the design without a second switchable coupling, which would lead to a lower output of the generator 7 as a result of losses; furthermore, any ventilation of the second turbine section 2" due to the lack of steam supply could lead to damage to the steam turbine system.

Claims

1. A steam turbine plant, comprising at least one water-steam circuit (1), wherein the water-steam circuit (1) comprises at least one steam turbine (2) having at least one first and one second turbine section (2', 2"), wherein the first turbine section (2') is connectable indirectly or directly to the second turbine section (2") via at least one first coupling (3), wherein the water-steam circuit (1) further comprises a first primary steam source (4) and a second secondary steam source (5), wherein the first turbine section (2') is suppliable with primary steam of the primary steam source (4) and the second turbine section (2") is suppliable with the primary steam of the primary steam source (4) or a part thereof and / or secondary steam of the secondary steam source (5), and the secondary steam is generable through a steam generator which is a component of the secondary steam source (5) which, for steam generation, makes hydrogen and oxygen react with one another, characterised in that the first coupling (3) is formed as a switchable coupling and a second switchable coupling (3"), which is operable independently of the first switchable coupling (3'), is arranged between the first and second turbine sections (2', 2"), and wherein between the first and second switchable couplings (3', 3"), a generator or machine (7) is arranged which, depending on the switching position of the first and second switchable couplings (3', 3"), is connectable to the first and / or second turbine section(s) (2', 2"), respectively.