Three-time reheating steam turbine generator unit with double shafts

Abstract

The utility model belongs to the technical field of power generation, and discloses a three-time reheating steam turbine generator unit with double shafts. The double-shaft three-time reheating steam turbine generator unit comprises a boiler, a first shaft system, a second shaft system and a steam pipeline system, the boiler comprises a boiler body, a superheater and three reheaters, the superheater and the reheaters are arranged in the boiler body, and a header connecting area is arranged at the position, corresponding to a steam inlet and outlet header, of the boiler body; the first shaft system comprises an ultrahigh-pressure cylinder, a high-pressure cylinder, at least two first medium-pressure cylinders and a first generator, and the first shaft system is attached to the header connecting area; the second shaft system comprises at least two second medium-pressure cylinders, at least two low-pressure cylinders and a second generator; the steam pipeline system comprises a plurality of first steam pipelines and a plurality of second steam pipelines, the first steam pipelines are used for communicating the boiler with the first shaft system and the boiler with the second shaft system, and the second steam pipelines are used for communicating the second medium-pressure cylinder and the low-pressure cylinder. While the efficiency of the steam turbine generator unit is improved, the investment of the steam turbine generator unit is considered, and the marginal benefit is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to power generation technical field especially relates to a triple reheat steam turbine generator unit of double shaft arrangement. BACKGROUND

[0002] Increasing steam parameters and increasing reheat times are relatively effective means for improving the efficiency of thermal power generator units, in recent years, in order to continuously improve the efficiency of thermal power generator units, China is continuously developing 600 DEG C level and above high parameters and twice reheat units. However, the length of the high-temperature and high-pressure steam pipeline between the boiler and the steam turbine generator unit is thus increased, the pipeline pressure loss and heat loss are also increased, which not only increases the investment cost of the pipeline system, but also reduces the work capacity of the steam turbine, affects the economy of the unit, and has low marginal efficiency.

[0003] In the prior art, the high and low positions of the steam turbine generator unit can be arranged on separate shafts in order to shorten the length of the high-temperature and high-pressure steam pipeline. The high-position shaft system includes a high-pressure cylinder or includes a high-pressure cylinder and a medium-pressure cylinder. However, since the steam specific volume of the high-pressure cylinder and the medium-pressure cylinder is small, the cylinder volume is small, and thus the rotational inertia of the entire high-position shaft system is also small. In severe operating conditions, the shaft system of the unit may be unstable, which is not conducive to the safe and stable operation of the power grid. Since the rotational inertia of the high-position shaft system itself is low, the risk of load rejection overspeed under high load conditions is higher, which puts more stringent requirements on the adjustment control system. Moreover, under low rotational inertia, high-parameter steam is more likely to cause the generation of steam gap excitation, and the vibration of the steam turbine generator unit is thus increased, which further affects the safety of the operation of the high-position shaft system.

[0004] Therefore, the utility model provides a triple reheat steam turbine generator unit of double shaft arrangement, which can greatly improve the efficiency of the unit, and also takes into account the investment economy, safety and reliability, to solve the above problems. UTILITY MODEL CONTENTS

[0005] The utility model discloses a triple reheat steam turbine generator unit of double shaft arrangement, which can solve the problems caused by the increase of reheat times, such as the increase of the length of the high-temperature and high-pressure steam pipeline, which further leads to the increase of the pipeline pressure drop loss and heat loss, the increase of the investment cost, and the decrease of the economy of the unit. The utility model can also take advantage of triple reheat, which not only improves the efficiency of the steam turbine generator unit, but also takes into account the economy of the steam turbine generator unit, and has high marginal efficiency. Moreover, the rotational inertia of the first shaft system and the second shaft system can be greatly improved, which improves the transient stability of the steam turbine generator unit under the short-circuit fault of the power transmission line, reduces the rotor fly-up speed during load rejection, and also has a certain inhibitory effect on the steam gap excitation of the steam turbine, thereby reducing the vibration of the shaft system of the steam turbine generator unit, which is beneficial to the safe operation of the first shaft system and the second shaft system.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] A triple-reheat steam turbine generator unit of double-shaft arrangement, comprising:

[0008] A boiler, comprising a furnace body and superheaters and three groups of reheaters arranged in the furnace body, the superheaters and the reheaters each having steam inlet and outlet and forming a steam inlet and outlet header, the furnace body having a header connecting area corresponding to the steam inlet and outlet header;

[0009] A first shaft system, comprising an ultra-high pressure cylinder, a high pressure cylinder, at least two first intermediate pressure cylinders and a first generator, the first shaft system being attached to the header connecting area;

[0010] A second shaft system, comprising at least two second intermediate pressure cylinders, at least two low pressure cylinders and a second generator;

[0011] A steam pipe system, comprising a plurality of first steam pipes and a plurality of second steam pipes, the first steam pipes being used to connect the boiler with the first shaft system and the boiler with the second shaft system, and the second steam pipes being used to connect the at least two second intermediate pressure cylinders and the at least two low pressure cylinders;

[0012] The central axis of the first shaft system and the central axis of the second shaft system are both perpendicular to the axis of the left and right walls of the boiler and are both consistent with the axis of the front and back walls of the boiler.

[0013] Preferably, the triple-reheat steam turbine generator unit of double-shaft arrangement further comprises:

[0014] An exhaust pipe and a condenser, the exhaust pipe connecting the low pressure cylinders with the condenser.

[0015] Preferably, along the Z-axis direction, the first shaft system and the second shaft system are at the same height.

[0016] Preferably, along the Z-axis direction, the first shaft system and the second shaft system have a height difference, and the second shaft system is attached to the header connecting area.

[0017] Preferably, along the Z-axis direction, the first shaft system and the second shaft system have a height difference, and the second shaft system is arranged close to the condenser.

[0018] Preferably, the material of the exhaust pipe is carbon steel.

[0019] As preferred, the three groups of reheaters are a primary reheater, a secondary reheater and a tertiary reheater, the super-high pressure cylinder is communicated with the superheater and the primary reheater through the first steam pipeline, the high pressure cylinder is communicated with the primary reheater and the secondary reheater through the first steam pipeline, at least two first intermediate pressure cylinders are communicated with the secondary reheater and the tertiary reheater through the first steam pipeline, and at least two second intermediate pressure cylinders are communicated with the tertiary reheater through the first steam pipeline.

[0020] As preferred, the number of the first intermediate pressure cylinders is two.

[0021] As preferred, the number of the second intermediate pressure cylinders is two.

[0022] As preferred, the number of the low pressure cylinders is two or three.

[0023] The utility model discloses the beneficial effect:

[0024] The triple reheated steam turbine generator unit of double-shaft arrangement includes a boiler, a first shaft system, a second shaft system and a steam pipeline system, the boiler includes a furnace body and a superheater and three groups of reheaters arranged in the furnace body, the superheater and reheater have steam import and export respectively and form steam import and export header, and the furnace body is the header connection area at the steam import and export header corresponding place;The first shaft system includes a super-high pressure cylinder, a high pressure cylinder, at least two first intermediate pressure cylinders and a first generator, and the first shaft system is attached to the header connection area;The second shaft system includes at least two second intermediate pressure cylinders, at least two low pressure cylinders and a second generator;Among them, the central axis of the first shaft system and the central axis of the second shaft system are perpendicular to the axis of the left and right wall of the boiler, and the central axis of the first shaft system and the central axis of the second shaft system are consistent with the axis of the front and back wall of the boiler;The steam pipeline system includes a plurality of first steam pipelines and a plurality of second steam pipelines, a plurality of first steam pipelines are used to connect the boiler and the first shaft system, the boiler and the second shaft system, and a plurality of second steam pipelines are used to connect at least two second intermediate pressure cylinders and at least two low pressure cylinders.

[0025] By setting the central axis of the first shaft system and the central axis of the second shaft system to be perpendicular to the axis of the left and right wall direction of the boiler, and setting the central axis of the first shaft system and the central axis of the second shaft system to be consistent with the axis of the front and back wall direction of the boiler, when arranging the first steam pipeline, the first steam pipeline can be symmetrically arranged according to the central axis of the first shaft system or the central axis of the second shaft system, so that the steam turbine equipment can avoid the torsional thrust generated by the asymmetric arrangement of the first steam pipeline according to the central axis of the first shaft system or the central axis of the second shaft system. That is, the first shaft system and the second shaft system are vertically and directly arranged opposite to the boiler, so that the first steam pipeline can be symmetrically arranged according to the central axis of the first shaft system or the central axis of the second shaft system, thereby eliminating the asymmetric torsional thrust of the steam turbine on both sides.

[0026] Through three reheat, the efficiency of the steam turbine generator set is greatly improved. The plurality of cylinders of the super-high pressure cylinder, the high pressure cylinder, the first medium pressure cylinder, the second medium pressure cylinder and the low pressure cylinder are respectively arranged to be connected as the first shaft system and the second shaft system, the first shaft system is arranged at the header connection area, and the first shaft system and the second shaft system are vertically and directly arranged opposite to the boiler, so that the length of the first steam pipeline is greatly shortened, the asymmetric torsional thrust of the steam turbine on both sides is eliminated, the investment cost of the steam pipeline is greatly reduced, the economy of the unit is greatly improved, and the operation safety of the steam turbine is improved. At the same time, since the length of the first steam pipeline is shortened, the pressure of the high pressure steam and the heat loss are reduced, thereby improving the efficiency of the steam turbine generator set; and the steam stored in the pipeline system is also reduced, so that the regulation inertia of the steam turbine generator set is greatly improved.

[0027] Compared with the prior art, the first shaft system of the steam turbine generator set includes at least four cylinders, i.e. a super-high pressure cylinder, a high pressure cylinder and at least two first medium pressure cylinders, and the second shaft system also includes at least four cylinders, i.e. at least two second medium pressure cylinders and at least two low pressure cylinders. By optimizing the cylinder configuration of the first shaft system and the second shaft system, the moment of inertia of the first shaft system and the second shaft system is greatly improved, the transient stability of the steam turbine generator set under short-circuit fault of the power transmission line is improved, the rotor overspeed during load rejection is reduced, the steam gap excitation of the steam turbine is inhibited to some extent, thereby reducing the vibration of the shaft system of the steam turbine generator set, which is beneficial to the operation safety of the first shaft system and the second shaft system. While greatly improving the economy of the steam turbine generator set, the moment of inertia of the first shaft system and the second shaft system is improved, and the safety and stability of the first shaft system and the second shaft system are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic view of a tower furnace in a double-shaft arranged three-reheat steam turbine generator set according to an embodiment one of the present application;

[0029] Figure 2 isFigure 1 Figure 2 is a top view of the first shaft system and the boiler in the embodiment one of the present application;

[0030] Figure 3 Figure 4 is a schematic diagram of the tower furnace in the triple-reheat steam turbine generator unit with double-shaft arrangement provided in the embodiment two of the present application;

[0031] Figure 4 Figure 5 is a top view of the first shaft system and the boiler in the embodiment two of the present application; Figure 3

[0032] Figure 6 is a top view of the second shaft system and the boiler in the embodiment two of the present application; Figure 5 Figure 3 Figure 7 is a schematic diagram of the π-type furnace in the triple-reheat steam turbine generator unit with double-shaft arrangement provided in the embodiment three of the present application;

[0033] Figure 6 Figure 8 is a top view of the first shaft system and the boiler in the embodiment three of the present application;

[0034] Figure 7 Figure 6 Figure 9 is a top view of the second shaft system and the boiler in the embodiment three of the present application;

[0035] Figure 8 Figure 10 is a schematic diagram of the π-type furnace in the triple-reheat steam turbine generator unit with double-shaft arrangement provided in the embodiment four of the present application; Figure 6

[0036] Figure 11 is a top view of the first shaft system and the boiler in the embodiment four of the present application; Figure 9

[0037] Figure 12 is a top view of the second shaft system and the boiler in the embodiment four of the present application. Figure 10 Figure 9 Figure 13 is a schematic diagram of the tower furnace in the triple-reheat steam turbine generator unit with double-shaft arrangement provided in the embodiment five of the present application;

[0038] Figure 11 Figure 9 Figure 14 is a top view of the first shaft system and the boiler in the embodiment five of the present application.

[0039] Figure 1 is a schematic diagram of the triple-reheat steam turbine generator unit with double-shaft arrangement provided in the embodiment one of the present application;

[0040] 1, boiler; 11, superheater; 12, first reheater; 13, second reheater; 14, third reheater; 15, header connection area;

[0041] 2, first shaft system; 21, super-high pressure cylinder; 22, high pressure cylinder; 23, first intermediate pressure cylinder; 24, first generator;

[0042] 3, second shaft system; 31, second intermediate pressure cylinder; 32, low pressure cylinder; 33, second generator;

[0043] 41, main steam pipe; 42, first cold reheat pipe; 43, first hot reheat pipe; 44, second cold reheat pipe; 45, second hot reheat pipe; 46, third cold reheat pipe; 47, third hot reheat pipe;​​​​

[0044] 5. Second steam pipe;

[0045] 6. Exhaust steam pipe;

[0046] 7. Condenser. DETAILED DESCRIPTION

[0047] The utility model will be described in further detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the utility model, and not to limit the utility model. In addition, it should be noted that only the parts related to the utility model are shown in the drawings for ease of description, not all the structures.

[0048] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0049] In the utility model, unless otherwise explicitly specified and limited, the first feature "on" or "below" the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0050] In the description of the embodiment, the terms "up", "down", "left", "right", "vertical", "horizontal", "inner", "outer" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the utility model. In addition, the terms "first" and "second" are only used to distinguish in description, and have no special meaning.

[0051] Embodiment one

[0052] In the prior art, in order to improve the economy, high and low shaft arrangement of the steam turbine generator set can be used to shorten the length of the high-temperature and high-pressure steam pipeline. The high shaft system includes a high-pressure cylinder or a high-pressure cylinder and a medium-pressure cylinder. However, due to the small steam specific volume and small cylinder volume of the high-pressure cylinder and the medium-pressure cylinder, the moment of inertia of the entire high shaft system is small, and the shaft system of the unit may be unstable under severe working conditions, which is not conducive to the safe and stable operation of the power grid. Due to the low moment of inertia of the high shaft system, the risk of load rejection overspeed under high load conditions is higher, which puts higher requirements on the adjustment control system, and the high-parameter steam under low moment of inertia is more likely to cause the generation of air gap excitation, and the vibration of the steam turbine generator set will increase, thereby affecting the safety of the operation of the high shaft system.

[0053] In order to solve the above problems, as shown in Figure 1 、 Figure 2 The embodiment provides a double-shaft arrangement triple-reheat steam turbine generator set, which comprises a boiler 1, a first shaft system 2, a second shaft system 3 and a steam pipeline system. The boiler 1 comprises a furnace body, a superheater 11 and three groups of reheaters arranged in the furnace body. The superheater 11 and the reheaters each have steam inlets and outlets and form steam inlet and outlet headers. The furnace body has a header connection area 15 corresponding to the steam inlet and outlet headers. The first shaft system 2 comprises an ultra-high-pressure cylinder 21, a high-pressure cylinder 22, at least two first medium-pressure cylinders 23 and a first generator 24. The first shaft system 2 is attached to the header connection area 15. The second shaft system 3 comprises at least two second medium-pressure cylinders 31, at least two low-pressure cylinders 32 and a second generator 33. The central axis of the first shaft system 2 and the central axis of the second shaft system 3 are perpendicular to the axis of the left and right walls of the boiler 1, and the central axis of the first shaft system 2 and the central axis of the second shaft system 3 are consistent with the axis of the front and back walls of the boiler 1. The steam pipeline system comprises a plurality of first steam pipelines and a plurality of second steam pipelines 5. The plurality of first steam pipelines are used to connect the boiler 1, the first shaft system 2 and the second shaft system 3. The plurality of second steam pipelines 5 are used to connect the at least two second medium-pressure cylinders 31 and the at least two low-pressure cylinders 32.

[0054] By setting the central axis of the first shaft system 2 and the central axis of the second shaft system 3 to be perpendicular to the axis of the left and right wall of the boiler 1, and setting the central axis of the first shaft system 2 and the central axis of the second shaft system 3 to be consistent with the axis of the front and back wall of the boiler 1, the first steam pipeline can be symmetrically arranged according to the central axis of the first shaft system 2 or the central axis of the second shaft system 3 when the first steam pipeline is arranged, so as to avoid the turbine equipment from bearing the torsional thrust caused by the asymmetric arrangement of the first steam pipeline according to the central axis of the first shaft system 2 or the central axis of the second shaft system 3. That is, the first shaft system 2 and the second shaft system 3 are both vertically and directly arranged with the boiler, so that the first steam pipeline can be symmetrically arranged according to the central axis of the first shaft system 2 or the central axis of the second shaft system 3, thereby eliminating the asymmetric torsional thrust of the interfaces on both sides of the turbine.

[0055] The efficiency of the steam turbine generator set is greatly improved through three reheatings. The plurality of cylinders of the super-high-pressure cylinder 21, the high-pressure cylinder 22, the first intermediate-pressure cylinder 23, the second intermediate-pressure cylinder 31 and the low-pressure cylinder 32 are respectively connected to the first shaft system 2 and the second shaft system 3, the first shaft system 2 is arranged at the header connection area 15, and the first shaft system 2 and the second shaft system 3 are both vertically and directly arranged with the boiler, so that the length of the first steam pipeline is greatly shortened, the asymmetric torsional thrust of the interfaces on both sides of the turbine is eliminated, the investment cost of the steam pipeline is greatly reduced, the economy of the unit is greatly improved, and the operation safety of the turbine is improved. At the same time, since the length of the first steam pipeline is shortened, the pressure of the high-pressure steam and the heat loss are reduced, thereby improving the efficiency of the steam turbine generator set; and the steam amount stored in the pipeline system is also reduced, which greatly improves the regulation inertia of the steam turbine generator set.

[0056] Compared with the prior art, the first shaft system 2 of the steam turbine generator set includes at least four cylinders, i.e., the super-high-pressure cylinder 21, the high-pressure cylinder 22 and at least two first intermediate-pressure cylinders 21, and the second shaft system 3 also includes at least four cylinders, i.e., at least two second intermediate-pressure cylinders 31 and at least two low-pressure cylinders 32. By optimizing the cylinder configuration of the first shaft system 2 and the second shaft system 3, the rotational inertia of the first shaft system 2 and the second shaft system 3 is greatly improved, the transient stability of the steam turbine generator set under the short-circuit fault of the power transmission line is improved, the rotor overspeed during load rejection is reduced, the steam gap excitation of the turbine is inhibited to some extent, thereby reducing the vibration of the shaft system of the steam turbine generator set, which is beneficial to the operation safety of the first shaft system 2 and the second shaft system 3. While greatly improving the economy of the steam turbine generator set, the rotational inertia of the first shaft system 2 and the second shaft system 3 is improved, and the safety and stability of the first shaft system 2 and the second shaft system 3 are ensured.

[0057] In the embodiment, the boiler 1 is a tower furnace, which is a common boiler structure in the art. The specific structure of the boiler 1 is not described herein.

[0058] Specifically, the first steam pipeline is a high-temperature and high-pressure steam pipeline, and the second steam pipeline 5 is a common steam pipeline; wherein, the first steam pipeline comprises a main steam pipeline 41, a first cold reheat pipeline 42, a first hot reheat pipeline 43, a second cold reheat pipeline 44, a second hot reheat pipeline 45, a third cold reheat pipeline 46 and a third hot reheat pipeline 47. The three groups of reheaters are a first reheater 12, a second reheater 13 and a third reheater 14. The super-high-pressure cylinder 21 is connected with the superheater 11 through the main steam pipeline 41, and the super-high-pressure cylinder 21 is connected with the first reheater 12 through the first cold reheat pipeline 42; the high-pressure cylinder 22 is connected with the first reheater 12 through the first hot reheat pipeline 43, and the high-pressure cylinder 22 is connected with the second reheater 13 through the second cold reheat pipeline 44; the first intermediate-pressure cylinder 23 is connected with the second reheater 13 through the second hot reheat pipeline 45, and the first intermediate-pressure cylinder 23 is connected with the third reheater 14 through the third cold reheat pipeline 46; the second intermediate-pressure cylinder 31 is connected with the third reheater 14 through the third hot reheat pipeline 47, and the second intermediate-pressure cylinder 31 is connected with the low-pressure cylinder 32 through the second steam pipeline 5. That is, the main steam generated by the superheater 11 does work in the super-high-pressure cylinder 21, the exhaust steam of the super-high-pressure cylinder 21 is heated in the first reheater 12 and then does work in the high-pressure cylinder 22, the exhaust steam of the high-pressure cylinder 22 is heated in the second reheater 13 and then does work in the first intermediate-pressure cylinder 23, the exhaust steam of the first intermediate-pressure cylinder 23 is heated in the third reheater 14 and then does work in the second intermediate-pressure cylinder 31, and the exhaust steam of the second intermediate-pressure cylinder 31 does work in the low-pressure cylinder 32.

[0059] By setting the first shafting 2 close to the header connection area 15, the length of the main steam pipeline 41 from the superheater 11 to the super-high-pressure cylinder 21 can be greatly shortened, and the lengths of the first hot reheat pipeline 43 and the second hot reheat pipeline 45 can also be greatly shortened, which greatly reduces the investment cost of the high-temperature and high-pressure steam pipeline of the steam turbine generator unit and reduces the pressure and heat loss of the high-pressure steam in the high-temperature and high-pressure steam pipeline.

[0060] It should be noted that the main steam pipeline 41, the first hot reheat pipeline 43, the second hot reheat pipeline 45 and the third hot reheat pipeline 47 all need to be made of high-temperature alloy steel of 600℃ grade.

[0061] In the embodiment, the main steam pressure is set to 30-33 MPa, the first reheat pressure is set to 12-14 MPa, the second reheat pressure is set to 6-9 MPa, and the third reheat pressure is set to 2-3 MPa. It should be noted that, since the secondary reheat steam pressure is low and the specific volume is large, at least two first intermediate-pressure cylinders 23 are needed to adapt to the large steam volume flow. Similarly, since the tertiary reheat steam pressure is low and the specific volume is large, at least two second intermediate-pressure cylinders 31 are needed. The specific number of the first intermediate-pressure cylinders 23 and the second intermediate-pressure cylinders 31 and the low-pressure cylinders 32 is not limited in the embodiment, and can be designed according to actual needs. For example, the number of the first intermediate-pressure cylinders 23 and the second intermediate-pressure cylinders 31 in the embodiment is both two.

[0062] In the embodiment, the number of the low-pressure cylinders 32 is two or three.

[0063] Specifically, as shown in Figure 1 , the steam turbine generator unit further includes a steam exhaust pipe 6 and a condenser 7, and the steam exhaust pipe 6 is connected between the low-pressure cylinders 32 and the condenser 7. The steam exhaust pipe 6 is made of carbon steel, and the manufacturing cost of the steam exhaust pipe 6 is much lower than that of the high-temperature and high-pressure steam pipe.

[0064] It should be noted that, the first shaft system 2 and the second shaft system 3 can be supported by a support platform to ensure the safety of the overall structure, or the first shaft system 2 and the second shaft system 3 can be hoisted in a suspended manner, which is not limited in the embodiment.

[0065] In the embodiment, as shown in Figure 1 , along the Z-axis direction, the first shaft system 2 and the second shaft system 3 are at the same height, which can shorten the length of the third heat re-pipe 47 at the same time, further reduce the cost of the high-temperature and high-pressure steam pipe, and since the manufacturing cost of the steam exhaust pipe 6 is much lower than that of the third heat re-pipe 47, even if the length of the steam exhaust pipe 6 is longer, the overall cost of the steam turbine generator unit can still be reduced.

[0066] Embodiment Two

[0067] As shown in Figures 3-5 , the embodiment provides a triple-reheat steam turbine generator unit with a double-shaft arrangement, which is basically the same as the triple-reheat steam turbine generator unit with a double-shaft arrangement provided in the embodiment one, except that the arrangement of the first shaft system 2 and the second shaft system 3 is different.

[0068] In this embodiment, there is a height difference between the first shaft system 2 and the second shaft system 3 along the Z-axis, and the second shaft system 3 is located close to the header connection area 15. This arrangement significantly shortens the length of the third reheat pipe 47 from the tertiary reheater 14 to the second intermediate-pressure cylinder 31, further reducing the cost of the high-temperature, high-pressure steam pipe. Furthermore, since the manufacturing cost of the exhaust pipe 6 is much lower than that of the third reheat pipe 47, even with a longer exhaust pipe 6, the overall cost of the turbine generator set can still be reduced. Moreover, the distribution of the first shaft system 2 and the second shaft system 3 along the Z-axis facilitates the symmetrical distribution and stress balance of the steam pipe systems on both sides of the first shaft system 2 and the second shaft system 3.

[0069] Example 3

[0070] like Figures 6-8 As shown, this embodiment provides a dual-shaft arrangement triple reheat steam turbine generator set, which has a structure that is basically the same as the dual-shaft arrangement triple reheat steam turbine generator set provided in Embodiment 1. The difference is that the arrangement of the first shaft system 2 and the second shaft system 3 is different.

[0071] In this embodiment, there is a height difference between the first shaft system 2 and the second shaft system 3 along the Z-axis, and the second shaft system 3 is located close to the condenser 7. That is, by setting the first shaft system 2 close to the header connection area 15, the length of the main steam pipe 41 from the superheater 11 to the ultra-high pressure cylinder 21 is greatly shortened. Similarly, the lengths of the first heat reheat pipe 43 and the second heat reheat pipe 45 are also greatly shortened, thereby reducing the cost of the high-temperature and high-pressure steam pipes of the turbine generator set. The second shaft system 3 is set according to the conventional arrangement in the prior art. Compared with Embodiment 1 and Embodiment 2, the length of the third heat reheat pipe 47 is longer at this time, but the low-pressure cylinder 32 can directly exhaust steam to the condenser 7 without the need to set a long exhaust pipe 6.

[0072] Example 4

[0073] like Figures 9-11 As shown, this embodiment provides a dual-shaft arrangement triple reheat steam turbine generator set, which has a structure that is basically the same as the dual-shaft arrangement triple reheat steam turbine generator set provided in Embodiment 2. The difference is that the boiler 1 in this embodiment is a π-type boiler.

[0074] It should be noted that the π-type furnace is a commonly used boiler structure in this field, and its specific structure will not be described in detail in this embodiment.

[0075] In the embodiment, since the header connection area 15 of the π-shaped furnace is located at the top of the π-shaped furnace, the first shafting 2 is directly arranged on the top platform of the boiler 1, the second shafting 3 is arranged in front of the boiler 1 and close to the header connection area 15. By this layout, the length of the main steam pipeline 41 from the superheater 11 to the ultra-high pressure cylinder 21 is greatly shortened, and the lengths of the first, second and third heat re-pipelines 43, 45 and 47 are also greatly shortened, so as to reduce the cost of the high-temperature and high-pressure steam pipeline of the steam turbine generator unit; and the first shafting 2 can be directly supported by the top platform of the boiler 1, so as to further reduce the installation cost of the steam turbine generator unit.

[0076] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present application. Here, it is unnecessary and impossible to enumerate all the embodiments. Any modification, equivalent substitution and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A double shaft arrangement triple reheat steam turbine generator unit characterized in that, include: The boiler (1) includes a boiler body and a superheater (11) and three sets of reheaters disposed in the boiler body. The superheater (11) and the reheaters have steam inlet and outlet and form a steam inlet and outlet header. The boiler body is a header connection area (15) corresponding to the steam inlet and outlet header. The first shaft system (2) includes an ultra-high pressure cylinder (21), a high pressure cylinder (22), at least two first intermediate pressure cylinders (23) and a first generator (24), and the first shaft system (2) is attached to the header connection area (15); The second shaft system (3) includes at least two second intermediate pressure cylinders (31), at least two low pressure cylinders (32) and a second generator (33); A steam pipeline system comprising a plurality of first steam pipelines and a plurality of second steam pipelines (5), wherein the plurality of first steam pipelines are used to connect the boiler (1) with the first shaft system (2) and the boiler (1) with the second shaft system (3), and the plurality of second steam pipelines (5) are used to connect at least two second intermediate pressure cylinders (31) and at least two low pressure cylinders (32); The central axis of the first shaft system (2) and the central axis of the second shaft system (3) are both perpendicular to the axis of the left and right walls of the boiler (1), and the central axis of the first shaft system (2) and the central axis of the second shaft system (3) are both consistent with the axis of the front and rear walls of the boiler (1).

2. The double shaft arranged triple reheat steam turbine generator unit as claimed in claim 1 wherein, The dual-shaft triple reheat turbine generator set also includes: The exhaust pipe (6) and the condenser (7) are connected, wherein the exhaust pipe (6) connects the low-pressure cylinder (32) and the condenser (7).

3. The double shaft arranged triple reheat steam turbine generator unit as claimed in claim 1 wherein, Along the Z-axis, the first axis system (2) and the second axis system (3) are at the same height.

4. The double shaft arranged triple reheat steam turbine generator unit as claimed in claim 1 wherein, Along the Z-axis, there is a height difference between the first shaft system (2) and the second shaft system (3), and the second shaft system (3) is attached to the header connection area (15).

5. The double shaft arranged triple reheat steam turbine generator unit as claimed in claim 2 wherein, Along the Z-axis, there is a height difference between the first shaft system (2) and the second shaft system (3), and the second shaft system (3) is located close to the condenser (7).

6. The double shaft arranged triple reheat steam turbine generator unit as claimed in claim 2 wherein, The exhaust pipe is made of carbon steel.

7. The double shaft arranged triple reheat steam turbine generator unit as claimed in claim 1 wherein, The three sets of reheaters are a primary reheater (12), a secondary reheater (13), and a tertiary reheater (14). The ultra-high pressure cylinder (21) is connected to the superheater (11) and the primary reheater (12) through the first steam pipe. The high pressure cylinder (22) is connected to the primary reheater (12) and the secondary reheater (13) through the first steam pipe. At least two of the first intermediate pressure cylinders (23) are connected to the secondary reheater (13) and the tertiary reheater (14) through the first steam pipe. At least two of the second intermediate pressure cylinders (31) are connected to the tertiary reheater (14) through the first steam pipe.

8. The double-shaft arranged triple reheat steam turbine generator unit as claimed in claim 1, characterized in that, The number of the first intermediate pressure cylinder (23) is two.

9. The double-shaft arranged triple reheat steam turbine generator unit as claimed in claim 1, wherein, The number of the second intermediate pressure cylinder (31) is two.

10. The double-shaft arranged triple reheat steam turbine generator unit as claimed in claim 1, characterized in that, The number of low-pressure cylinders (32) is two or three.

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