Power distribution system for balance generator of double-machine regenerative backpressure air extraction type steam turbine

Abstract

The utility model discloses a power distribution system for a double-machine regenerative backpressure air extraction type turbine equipped with a balanced generator, which comprises a double-machine regenerative system equipped with a balanced generator, a converter subsystem, a dry-type rectifier transformer, a damping cabinet and a plurality of medium-voltage switch cabinets which are electrically connected in sequence, the damping cabinet and the medium-voltage switch cabinet are electrically connected through a pouring bus. According to the utility model, an oil-immersed rectifier transformer is replaced by the high-efficiency and energy-saving rectifier dry-type transformer, and the dry-type transformer has no fire spreading danger even if a short-circuit fault occurs, so that after the dry-type rectifier transformer is adopted, the rectifier transformer can be arranged in a power distribution room which is in a main power house and is closer to a converter and auxiliary power equipment; not only can the arrangement outside the steam engine room be simplified, but also the construction cost and arrangement workload of connecting cables can be reduced; after the rectifier transformer is arranged in the main power house, one oil-immersed rectifier transformer is omitted for each machine outside the main power house, so that the arrangement outside the main power house can be simplified.

Description

Technical Field

[0001] The utility model relates to the electrical field, in particular to a double-machine heat recovery back-pressure extraction type steam turbine with a balanced generator power distribution system. Background Art

[0002] For large thermal power units, a single reheat or double reheat system is conventionally used. The extraction steam after reheating has a high superheat degree and directly enters the high-pressure heater to heat the feed water. The heat exchange temperature difference is large and the irreversible loss is large. In order to reduce this irreversible loss, a dual-machine heat recovery system can be adopted, and the feed water pump turbine provides extraction steam with a lower temperature to avoid the overheating of the extraction steam. The traditional small steam turbine speed regulation is achieved by adjusting the opening of the small steam turbine steam inlet valve. The dual-machine heat recovery system is equipped with a balanced generator to keep the small steam turbine steam inlet valve fully open when the unit is started or peak-shaving, simplifying the operation and maintenance workload, improving the unit stability, and improving the unit efficiency.

[0003] At present, when a dual-machine heat recovery system is used to configure a balanced generator, the phase-shifting transformer is arranged outside the main plant building using an oil-immersed transformer, while the converter and plant power equipment are arranged inside the main plant building. This causes the connecting conductor between the phase-shifting transformer and the plant power and converter to become longer, the cost increases, and the layout in the main plant building becomes more difficult.

[0004] In addition, in the existing dual-machine heat recovery system with a balanced generator solution, the converter system and the factory power system are connected by cables. The total amount of cables is large, which causes the cable channel (cable tray) to occupy a larger area and is difficult to arrange. At the same time, arranging them on the cable tray will interfere with the control cables on the tray, and the control signal will malfunction when the converter system is started.

[0005] Therefore, it is urgent to propose a new solution to solve the above problems. Summary of the invention

[0006] The utility model provides a dual-machine heat recovery back-pressure extraction steam turbine with a balanced generator power distribution system, which solves the problem that the existing oil-immersed rectifier transformer is arranged outside the main plant and the converter system and the plant power system are connected by cables, resulting in excessive costs and interference with the control system.

[0007] The utility model provides a dual-machine heat recovery back-pressure extraction steam turbine with a balanced generator power distribution system, comprising a dual-machine heat recovery system configured with a balanced generator, a converter subsystem, a dry-type rectifier transformer, a damping cabinet and a plurality of medium-voltage switch cabinets which are electrically connected in sequence, wherein the dry-type rectifier transformer is arranged in a main plant, and the damping cabinet and the medium-voltage switch cabinet are electrically connected by casting a busbar.

[0008] Furthermore, the dual-machine heat recovery system is configured with a balanced generator including a base, a bearing, an exciter and a main outlet box, the bearing is arranged on the base, and the exciter is connected through the bearing.

[0009] Furthermore, the dry-type rectifier transformer includes a primary high-voltage wire outlet hole, a secondary high-voltage wire outlet hole and a heat dissipation exhaust fan.

[0010] Furthermore, the medium voltage switchgear is a 10kV switchgear.

[0011] Furthermore, the medium voltage switch cabinet comprises a first medium voltage switch cabinet and a second medium voltage switch cabinet which are arranged in parallel.

[0012] Furthermore, the cast busbar and the medium-voltage switch cabinet are electrically connected via a first cast busbar phase expansion box, and the cast busbar and the damping cabinet are electrically connected via a second cast busbar phase expansion box.

[0013] Furthermore, the converter subsystem includes a converter machine-side high-opening cabinet, a first converter power unit cabinet, a second converter power unit cabinet and a third converter power unit cabinet, wherein the first converter power unit cabinet, the second converter power unit cabinet and the third converter power unit cabinet are respectively connected to the dry-type rectifier transformer through three sets of connecting cables.

[0014] Furthermore, the dual-machine heat recovery system is configured such that the balancing generator is connected to the converter subsystem via a connecting cable, and the dry-type rectifier transformer is connected to the damping cabinet via a connecting cable.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1. The utility model replaces the oil-immersed rectifier transformer with an efficient and energy-saving rectifier dry-type transformer. One of the advantages of the dry-type transformer is that it does not self-ignite. Even if a short-circuit fault occurs, there is no danger of fire spreading. Therefore, after the dry-type rectifier transformer is adopted, it can be arranged in the main plant, which can not only simplify the layout outside the main plant, but also reduce the cost and layout workload of the connecting conductor; after the rectifier transformer is arranged in the main plant, each machine outside the main plant will reduce one oil-immersed rectifier transformer, which can simplify the layout outside the main plant;

[0017] 2. The utility model changes the cable connection into a cast busbar connection. Since the cast busbar occupies a small area and has flexible layout, it can solve the problem of many pipelines in the main plant and difficulty in arranging the cable bridge. The cast busbar and the bridge are arranged separately, which can completely solve the interference problem of the power cable on the control cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the connection of the power distribution system of the back-pressure extraction steam turbine equipped with a balanced generator of the utility model;

[0019] Figure numerals: 1. Dual-machine heat recovery system equipped with balanced generator; 12. Main outlet box; 13. Exciter; 14. Bearing; 15. Base; 2. Converter subsystem; 21. Converter machine side high-opening cabinet; 22. First converter power unit cabinet; 23. Second converter power unit cabinet; 24. Third converter power unit cabinet; 3. Dry-type rectifier transformer; 31. Primary high-voltage outlet hole; 32. Secondary high-voltage outlet hole; 33. Cooling exhaust fan; 4. Damping cabinet; 5. Medium-voltage switch cabinet; 51. First medium-voltage switch cabinet; 52. Second medium-voltage switch cabinet; 6. Cast bus; 7. Connecting cable; 81. First cast bus phase expansion box; 82. Second cast bus phase expansion box. DETAILED DESCRIPTION

[0020] In order to further understand the content, features and functions of the utility model, the following embodiments are given, together with the attached Figure 1 The detailed instructions are as follows.

[0021] like Figure 1 As shown, this embodiment discloses a dual-machine heat recovery back-pressure extraction steam turbine with balanced generator power distribution system, including a dual-machine heat recovery system with balanced generator 1, a converter subsystem 2, a dry-type rectifier transformer 3, a damping cabinet 4 and two medium-voltage switch cabinets 5 electrically connected in sequence, the damping cabinet 4 provides resistance for the loop, the above-mentioned dry-type rectifier transformer 3 is arranged in the main plant, and the damping cabinet 4 and the medium-voltage switch cabinet 5 are electrically connected by a cast busbar 6.

[0022] On the one hand, the utility model replaces the oil-immersed rectifier transformer with a high-efficiency and energy-saving rectifier dry-type transformer. One of the advantages of the dry-type transformer is that it does not self-ignite. Even if a short-circuit fault occurs, there is no danger of fire spreading. Therefore, after the dry-type rectifier transformer is adopted, it can be arranged in the main factory building, which can not only simplify the arrangement outside the main factory building, but also reduce the cost and arrangement workload of the connecting conductor; after the rectifier transformer is arranged in the main factory building, each machine outside the main factory building will reduce one oil-immersed rectifier transformer, which can simplify the arrangement outside the main factory building; on the other hand, the cable connection is changed to a cast busbar connection. Since the cast busbar occupies a small area and has flexible arrangement, it can solve the problem of many pipelines in the main factory building and the difficulty in arranging the cable bridge. Moreover, the cast busbar and the bridge are arranged separately, which can completely solve the interference problem of the power cable on the control cable.

[0023] In this embodiment, Figure 1 As shown, the dual-machine heat recovery system configuration balanced generator 1 includes a base 15, a bearing 14, an exciter 13 and a main outlet box 12, the bearing 14 is arranged on the base 15, and the exciter 13 is connected through the bearing 14.

[0024] In this embodiment, Figure 1As shown, the dry-type rectifier transformer 3 includes a primary high-voltage outlet hole 31 , a secondary high-voltage outlet hole 32 and a heat dissipation fan 33 , and the heat dissipation fan 33 is used to dissipate heat for the dry-type rectifier transformer 3 .

[0025] In this embodiment, the medium voltage switch cabinet 5 is a 10 kV switch cabinet, and other voltage levels can also be selected according to actual conditions.

[0026] In this embodiment, Figure 1 As shown, there are two medium-voltage switch cabinets 5 , including a first medium-voltage switch cabinet 51 and a second medium-voltage switch cabinet 52 .

[0027] In this embodiment, Figure 1 As shown, the cast busbar 6 and the medium-voltage switch cabinet 5 are electrically connected through the first cast busbar phase expansion box 81, and the cast busbar 6 and the damping cabinet 4 are electrically connected through the second cast busbar phase expansion box 82, wherein the first cast busbar phase expansion box 81 and the second cast busbar phase expansion box 82 are used for later inspection and maintenance.

[0028] In this embodiment, Figure 1 As shown, the converter subsystem 2 includes a converter machine side high-opening cabinet 21, a first converter power unit cabinet 22, a second converter power unit cabinet 23 and a third converter power unit cabinet 24, wherein the converter machine side high-opening cabinet 21 is respectively connected to the first converter power unit cabinet 22, the second converter power unit cabinet 23 and the third converter power unit cabinet 24 through three internal cables, and the first converter power unit cabinet 22, the second converter power unit cabinet 23 and the third converter power unit cabinet 24 are respectively connected to the dry-type rectifier transformer 3 through three groups of connecting cables 7.

[0029] In this embodiment, Figure 1 As shown, the dual-machine heat recovery system is configured with a balancing generator 1 connected to a converter subsystem 2 via a connecting cable 7 , and a dry-type rectifier transformer 3 connected to a damping cabinet 4 via a connecting cable 7 .

[0030] In this embodiment, Figure 1As shown, the generator room where the balanced generator 1 of the dual-machine heat recovery system is located is arranged on the operating floor of the main plant, with an elevation of 17 meters; the high-opening cabinet 21 on the converter side, the first converter power unit cabinet 22, the second converter power unit cabinet 23 and the third converter power unit cabinet 24 are arranged in the converter room; the dry-type rectifier transformer 3 and the damping cabinet 4 are arranged in the phase-shifting transformer and distribution room; the first medium-voltage switch cabinet 51 and the second medium-voltage switch cabinet 52 are arranged in the medium-voltage distribution room. The main plant includes the 0-meter layer, the middle layer and the operating layer, and the generator room, converter room, phase-shifting transformer and distribution room and medium-voltage distribution room are all arranged in the main plant. This arrangement concentrates the entire dual-machine heat recovery back-pressure extraction steam turbine with balanced generator distribution system in the main plant, which can reduce the cost of the internal connecting conductors of the system. Since large dry-type transformers have large heat dissipation problems and heavy loads, the phase-shifting transformer distribution room is arranged on the 0-meter floor of the main plant, and the converter room is arranged on the middle floor, with an elevation of 8.6 meters. The medium-voltage distribution room is arranged in a large thermal power plant, and its layout is basically fixed on the overhead floor of the middle floor of the main plant, with an elevation of 11.6 meters. There are many cables in the medium-voltage distribution room, and the bridge layout in the cable mezzanine of the medium-voltage distribution room is complex. Using cast busbar 6 instead of conventional cable connection can simplify the layout of the cable channel and avoid the problem that the power cables in the dual-machine heat recovery back-pressure extraction steam turbine balanced generator distribution system interfere with the control circuits in and near the distribution room.

[0031] The utility model described above only expresses the implementation method of the utility model embodiment, and cannot be understood as limiting the scope of the utility model patent, nor is it any form of limitation on the structure of the utility model embodiment. It should be pointed out that for ordinary technicians in this field, several changes and improvements can be made without departing from the concept of the utility model embodiment, which all belong to the protection scope of the utility model embodiment.

Claims

1. Dual heat recovery back pressure extraction steam turbine with balanced generator power distribution system, characterized by: The invention comprises a dual-machine heat recovery system configuration including a balanced generator (1), a converter subsystem (2), a dry-type rectifier transformer (3), a damping cabinet (4) and a plurality of medium-voltage switch cabinets (5) which are electrically connected in sequence, wherein the dry-type rectifier transformer (3) is arranged in a main plant, and the damping cabinet (4) and the medium-voltage switch cabinet (5) are electrically connected via a cast busbar (6).

2. The dual-machine heat recovery back pressure extraction steam turbine with balanced generator power distribution system according to claim 1 is characterized in that: The dual-machine heat recovery system configuration balanced generator (1) comprises a base (15), a bearing (14), an exciter (13) and a main outlet box (12); the bearing (14) is arranged on the base (15), and the exciter (13) is connected via the bearing (14).

3. The dual-machine heat recovery back pressure extraction steam turbine with balanced generator power distribution system according to claim 1 is characterized in that: The dry-type rectifier transformer (3) comprises a primary high-voltage wire outlet hole (31), a secondary high-voltage wire outlet hole (32) and a heat dissipation fan (33).

4. The dual-machine heat recovery back pressure extraction steam turbine with balanced generator power distribution system according to claim 1 is characterized in that: The medium voltage switch cabinet (5) is a 10 kV switch cabinet.

5. The dual-machine heat recovery back pressure extraction steam turbine with balanced generator power distribution system according to claim 1 is characterized in that: The medium-voltage switch cabinet (5) comprises a first medium-voltage switch cabinet (51) and a second medium-voltage switch cabinet (52) which are arranged in parallel.

6. The dual-unit heat recovery back pressure extraction steam turbine with balanced generator power distribution system according to claim 5 is characterized in that: The cast busbar (6) and the medium-voltage switch cabinet (5) are electrically connected via a first cast busbar phase expansion box (81), and the cast busbar (6) and the damping cabinet (4) are electrically connected via a second cast busbar phase expansion box (82).

7. The dual-machine heat recovery back pressure extraction steam turbine with balanced generator power distribution system according to claim 1, characterized in that: The converter subsystem (2) comprises a converter machine-side high-opening cabinet (21), a first converter power unit cabinet (22), a second converter power unit cabinet (23) and a third converter power unit cabinet (24), wherein the first converter power unit cabinet (22), the second converter power unit cabinet (23) and the third converter power unit cabinet (24) are respectively connected to the dry-type rectifier transformer (3) via three sets of connection cables (7).

8. The dual-machine heat recovery back pressure extraction steam turbine with balanced generator power distribution system according to claim 1, characterized in that: The dual-machine heat recovery system is configured such that the balancing generator (1) is connected to the converter subsystem (2) via a connecting cable (7), and the dry-type rectifier transformer (3) is connected to the damping cabinet (4) via a connecting cable (7).

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