Water-hydrogen-cooled steam turbine generator suitable for replacing old steam turbine generator with complete steam turbine generator

Abstract

The invention discloses a water hydrogen cooling steam turbine generator suitable for replacing old complete machine, which comprises a stator, and the stator comprises a stator base which is constructed as a closed shell, and the two ends of the stator base are provided with sealing end covers; the hydrogen cooling devices are detachably arranged on the two sides of the top wall of the closed shell and communicate with the closed shell; the stator iron core is fixed in the stator base, and axial flow fans are arranged at the two ends of the stator iron core; the ventilation system is formed on the inner circumferential wall of the stator base in the circumferential direction of the stator core, and a plurality of air inlet areas and air outlet areas are formed in the axial direction of the stator core; the rotor comprises a rotor rotating shaft which is arranged in the stator iron core; and the front-end bearing and the rear-end bearing are respectively arranged on the fixed foundation, and the front-end bearing and the rear-end bearing are connected with the shaft end of the rotor rotating shaft. The water-hydrogen-cooled steam turbine generator can be better suitable for the hoisting capacity of an original workshop of the steam turbine generator, the position of a platform main supporting beam and the size of a platform hole.

Description

Technical Field

[0001] The embodiments of this invention relate to the field of steam turbine generator technology. More specifically, this invention relates to a water-hydrogen-cooled steam turbine generator suitable for complete replacement of outdated units. Background Technology

[0002] With the development of the national economy, my country's power industry has also developed rapidly. By 1987, the total installed capacity reached 100 million kilowatts, and by 1995, it reached 200 million kilowatts, with tens of thousands of large steam turbine generators installed. The design life of a generator is generally 30 years, meaning that the generator units installed during the period of rapid expansion of my country's total installed capacity in the 1980s and 1990s have either been decommissioned or are nearing decommissioning. The methods for handling decommissioned units include: direct scrapping; replacing smaller units with larger ones; extending the lifespan of units by replacing old components; and extending the lifespan of power plants by replacing the entire unit. Direct scrapping of units means shutting down the power plant, which is related to power grid layout issues. "Replacing smaller units with larger ones" does not involve power grid layout issues, but it requires rebuilding new generator units and their supporting facilities, which involves large investments, long cycles, and is only suitable for units with smaller original capacities. The lifespan extension method of replacing aging components limits the scope of modification to the generator's internal structure. This method requires the least initial investment and has the shortest timeframe. However, due to the complex internal structure and high dimensional precision of generators, coupled with the limited availability of computers and networks in the 1980s and 90s and the resulting outdated technical data management, original design drawings and even the original manufacturer's information are often unavailable. This can easily introduce hidden quality issues within the generator. Furthermore, partial modifications are unlikely to resolve inherent problems such as low efficiency or severe coil wear. In contrast, replacing the aging generator with a new one avoids internal generator issues. Even without design drawings, physical information can be obtained through direct measurement. This method also offers moderate investment and a reasonable construction period, making it a recommended approach for generator sets reaching the end of their lifespan.

[0003] In existing technologies, although generators used for complete replacement are new generators and do not involve internal generator issues, the replacement process still requires identifying and assessing all parameters and interfaces related to the power plant. For example, an existing 500MW water-hydrogen cooled generator, nearing the end of its service life, uses a water-hydrogen-hydrogen combination for cooling. The stator windings are internally water-cooled, the rotor windings are internally hydrogen-cooled via air gap intake, and the stator core uses a tangential ventilation system for hydrogen cooling. The generator stator uses a three-section frame, with the two end sections connected to the middle section horizontally via a clamping mechanism. The three sections are assembled as a single unit at the power plant. The hydrogen cooler is located within the end frame. The stator section employs a circumferential two-inlet, two-outlet ventilation system. The stator airflow structure design corresponding to the end and intermediate frames results in a large generator stator size. This leads to a foundation opening size of 9250mm x 4000mm and a bearing span of 10315mm. Furthermore, due to the three-section frame structure and separate hoisting, the maximum load capacity of the power plant's crane is only 250T. Therefore, although the existing generators are long overall, the three-section design limits the maximum crane load to 250T. This makes it difficult to replace the old generator with a conventional one, given the large overall size and limited lifting capacity. Consequently, incompatibility issues often arise between the new generator and the plant's parameters and interfaces, such as insufficient plant lifting capacity, inaccurate generator platform main support beam positioning, and incorrect generator platform opening dimensions. Summary of the Invention

[0004] To address one or more of the technical problems mentioned above, this invention provides a water-hydrogen-cooled steam turbine generator suitable for replacing old units, enabling it to better adapt to the original factory's hoisting capacity, the position of the main support beam of the generator platform, and the opening size of the generator platform.

[0005] This application provides a water-hydrogen-cooled steam turbine generator suitable for complete replacement, comprising: a stator, the stator including: a stator frame, which is constructed as a sealed shell, with sealed end caps at both ends of the stator frame; a hydrogen cooling device, which is detachably disposed on both sides of the top wall of the sealed shell and communicates with the sealed shell; a stator core, which is fixed inside the stator frame, with axial flow fans at both ends of the stator core; a ventilation system, which is formed on the inner peripheral wall of the stator frame along the circumference of the stator core and forms several air inlet and outlet zones along the axial direction of the stator core, the hydrogen cooling device, the stator frame, and the ventilation system forming a closed loop for hydrogen circulation through the axial flow fans; and a rotor, the rotor including: a rotor shaft, which is disposed inside the stator core, with both ends of the rotor shaft passing through the sealed end caps; a front bearing and a rear bearing, which are respectively disposed on a fixed base and connected to the shaft ends of the rotor shaft.

[0006] In some embodiments, the hydrogen cooling device includes: a sealed cooling housing detachably fixedly connected to the top of the stator frame, the sealed cooling housing having an air outlet and an air inlet; and a hydrogen cooler disposed within the sealed cooling housing; wherein the top wall of the stator frame has: an air inlet communicating with the air outlet, the air inlet being located on the air inlet side of the axial fan; and an air outlet communicating with the air inlet, the air outlet being located at a position on the stator frame communicating with the outlet of the ventilation system.

[0007] In some embodiments, the inner wall of the stator frame is provided with a plurality of annular partitions spaced along the axial direction. The plurality of annular partitions are used to support the stator core. An annular region is formed between adjacent annular partitions. The annular region is constructed as an air inlet area and an air outlet area. An air inlet channel for connecting each air inlet area and an air outlet channel for connecting each air outlet area are formed on the annular partitions.

[0008] In some embodiments, the ventilation system includes n air inlet zones and n+1 air outlet zones, with the air inlet zones and air outlet zones arranged alternately side by side.

[0009] In some embodiments, the stator core includes a plurality of stator laminations, the thickness of which ranges from 0.35 mm to 0.4 mm.

[0010] In some embodiments, a winding slot is formed on the stator core, and two layers of stator coils are disposed in the winding slot. The upper stator coil is located at the opening of the winding slot, and the lower stator coil is located at the bottom of the winding slot. End fixing structures are provided at both ends of the stator core for fixing the two ends of the stator coils.

[0011] In some embodiments, the end fixing structure includes: an insulating conical ring disposed on the outer circumference of the end of the lower stator coil; an insulating segmented pressure plate disposed on the inner circumference of the end of the upper stator coil, the insulating segmented pressure plate being fixedly connected to the insulating conical ring; a first insulating spacer block and a second insulating spacer block, the first insulating spacer block being disposed between each coil at the involute termination of the stator coil and fixed to the insulating segmented pressure plate and the insulating conical ring; the second insulating spacer block being disposed between each coil at the involute beginning of the stator coil and located between the insulating segmented pressure plate and the insulating conical ring. The insulating conical ring, the insulating segmented pressure plate, the first insulating spacer block, the second insulating spacer block, and the spacer block together form a sealed space filled with insulating material.

[0012] In some embodiments, the axial length of the stator core is less than 5000 mm, the outer diameter of the stator core is less than 2700 mm, and the ratio of the effective length to the outer diameter of the stator core is less than 1.7.

[0013] In some embodiments, the stator frame further includes stator feet, which are detachably and fixedly connected to the bottom of the stator frame.

[0014] In some embodiments, the stator frame further includes a plurality of stator hangers, which are detachably fixed to both sides of the stator frame in a horizontal direction, wherein the length of the stator hangers extends to the outside of the stator base.

[0015] The water-hydrogen-cooled turbine generator described above integrates the hydrogen cooling device, front bearing, and rear bearing with a detachable connection, all independent of the stator. This allows the generator to maintain the overall length and width of the stator without increasing its size, and in fact, to reduce them compared to existing technologies. Furthermore, the multi-section structure directly reduces the stator's weight during hoisting. The ventilation system, integrated within the stator frame, ensures effective cooling of the stator core and rotor without increasing the stator's overall size or weight. This allows the water-hydrogen-cooled turbine generator to be directly compatible with the factory's hoisting capacity and the stator's foundation opening dimensions when replacing older, less-used generators. This allows for complete replacement based on the original generator's design and foundation. Additionally, the stator frame provides multiple paths for circulating hydrogen cooling throughout the generator, effectively cooling it while the fully enclosed structure prevents contaminants and moisture from entering. Attached Figure Description

[0016] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0017] Figure 1 This is a schematic diagram of the structure of a water-hydrogen cooled steam turbine generator according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 The diagram shown is a side view of the water-hydrogen cooled steam turbine generator.

[0019] Figure 3 This is a schematic diagram of the internal structure of a water-hydrogen cooled steam turbine generator according to an embodiment of the present invention;

[0020] Figure 4 for Figure 3 The diagram shows the structure of the water-hydrogen cooled steam turbine generator along the AA direction;

[0021] Figure 5 for Figure 3The diagram shows the structure of the water-hydrogen cooled steam turbine generator along the BB direction;

[0022] Figure 6 This is a schematic diagram of the end fixing structure according to an embodiment of the present invention;

[0023] Figure 7 for Figure 6 A schematic diagram of the end fixing structure along the CC direction;

[0024] Figure 8 for Figure 6 The diagram shows the end fixing structure along the DD direction. Detailed Implementation

[0025] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0026] Figure 1 The structure of a water-hydrogen cooled steam turbine generator 100 according to an embodiment of the present invention is shown. Figure 2 A side view of a water-hydrogen-cooled steam turbine generator 100 is shown. Figure 3 The internal structure of a water-hydrogen-cooled steam turbine generator 100 according to an embodiment of the present invention is shown. (Combined with...) Figures 1 to 3 As shown, the water-hydrogen-cooled steam turbine generator 100, suitable for complete replacement of old units, includes a stator 1. The stator 1 includes: a stator frame 11, which is constructed as a sealed shell, and sealing end caps 111 are provided at both ends of the stator frame 11; a hydrogen cooling device 2, which is detachably installed on both sides of the top wall of the sealed shell and communicates with the sealed shell; a stator core 12, which is fixed inside the stator frame 11, and axial flow fans 13 are provided at both ends of the stator core 12; and a ventilation system 14, which is formed along the circumference of the stator core 12 on the inner peripheral wall of the stator frame 11 and along the... The stator core 12 forms several air inlet zones 143 and air outlet zones 144 along its axial direction. The hydrogen cooling device 2, stator frame 11, and ventilation system 14 form a closed loop for hydrogen circulation through the axial flow fan 13. The rotor 3 includes: a rotor shaft, which is disposed inside the stator core 12, with both ends of the rotor shaft passing through a sealing end cover 111; a front bearing 31 and a rear bearing 31, which are respectively disposed on a fixed foundation and connected to the shaft ends of the rotor shaft.

[0027] According to an embodiment of the present invention, the hydrogen cooling device 2 of the water-hydrogen-cooled turbine generator 100 is independently and detachably mounted above the stator frame 11. The stator frame 11 is constructed as a sealed shell, allowing multiple paths within the stator frame 11 to circulate and cool hydrogen throughout the generator after the hydrogen cooling device 2 is connected to it. The hydrogen cooling device 2, stator frame 11, and ventilation system 14 form a closed-loop hydrogen circulation circuit via an axial fan 13, enabling effective hydrogen cooling of the stator core 12 and rotor 3. In this application, during the replacement and hoisting process of the water-hydrogen-cooled turbine generator 100, the hydrogen cooling device 2, front bearing 31, and rear bearing 31 are first disassembled from the stator frame 11. After the stator 1 is hoisted to its basic target position using a crane, jacks are used to support the stator frame 11 (on which a stator lifting bracket 19 is mounted) to lower the stator 1 to the ground. Then, other related components, such as the stator base 18, are assembled. Adjust the height of the jacks to allow stator 1 to be placed on the ground via stator feet 18. Remove the load-bearing jacks and use the jacks to fine-tune the front-back and left-right positions of stator 1 by adjusting the distance between stator 1 and the ground anchor. Then, use the load-bearing jacks again to adjust the vertical height of stator 1 to complete its positioning. After the stator 1 is installed, use a crane to lift the hydrogen cooling device 2, front bearing 31, and rear bearing 31. Install the hydrogen cooling device 2 at the preset position on the top of the stator base 11. Then, assemble the rotor 3 with stator 1 and install the front bearing 31 and rear bearing 31 at the preset positions on the fixed foundation, thus completing the replacement of the old generator.

[0028] Based on existing technology, the current 500MW water-hydrogen-cooled generator, which has reached the end of its service life, has a stator with a three-section frame. The two end sections are connected to the middle section horizontally using a clamping method, and the three sections are installed as a whole at the power plant. The hydrogen cooler is located in the end sections. The middle section of the stator uses a circumferential two-inlet, two-outlet ventilation system. The stator airflow structure design of the end and middle sections results in a large stator size, with the foundation opening for accommodating the stator reaching 9250mm in length and 4000mm in width, and the bearing span reaching 10315mm. Furthermore, due to the three-section frame structure, the maximum load capacity of the crane equipped at the power plant is only 250T.

[0029] In this application, through the above-described configuration, the water-hydrogen-cooled turbine generator 100 according to the embodiment of the present invention has the hydrogen cooling device 2, the front bearing 31, and the rear bearing 31 detachably connected to the stator 1 independently, thus constructing the water-hydrogen-cooled turbine generator 100 according to the embodiment of the present invention as a multi-segment structure. Simultaneously, the stator frame 11 provides multiple paths for circulating and cooling hydrogen throughout the generator. These configurations allow the water-hydrogen-cooled turbine generator 100 of the embodiment of the present invention to achieve this without additionally increasing the overall length and width of the stator 1, and even to reduce the overall length and width of the stator 1 compared to the prior art. Furthermore, the multi-segment structure directly reduces the weight of the stator 1 during hoisting. Furthermore, the ventilation system 14, formed within the stator frame 11, ensures effective cooling of the stator core 12 and rotor 3 without increasing the overall size and weight of the stator 1. This allows the water-hydrogen-cooled turbine generator 100 of this embodiment to be directly compatible with the factory hoisting capacity and stator foundation opening dimensions when replacing an aging generator. This allows for complete replacement while maintaining the original generator's design and mounting foundation. Additionally, the stator frame 11 provides multiple paths for circulating hydrogen cooling throughout the generator, effectively cooling it while the fully enclosed structure prevents contaminants and humid gases from entering.

[0030] Please continue to refer to this. Figure 1 The hydrogen cooling device 2 may include: a sealed cooling housing 21, which is detachably and fixedly connected to the top of the stator frame 11, and the sealed cooling housing 21 has an air outlet and an air inlet; and a hydrogen cooler 22, which is disposed inside the sealed cooling housing 21. The top wall of the stator frame 11 has: an air inlet communicating with the air outlet, located on the air inlet side of the axial fan 13; and an air outlet communicating with the air inlet, located at the position of the stator frame 11 that communicates with the outlet of the ventilation system 14.

[0031] In this application, the hydrogen cooling device 2 is detachably connected to the stator base 11 via the sealed cooling housing 21, specifically, it can be detachably connected via bolts. This design allows it to be removed from the stator base 11 during hoisting, reducing its weight during hoisting, and it can be installed after the stator 1 is placed. This makes the hydrogen cooling device 2 of the hydrogen cooling source of the water-hydrogen cooled turbine generator 100 of this embodiment easy to install and remove, facilitating hoisting and installation by on-site personnel when replacing the entire generator when it reaches the end of its service life.

[0032] Please refer to Figure 3The inner wall of the stator frame 11 is provided with a number of annular partitions at intervals along the axial direction. The annular partitions are used to support the stator core 12. Annular regions are formed between adjacent annular partitions. The annular regions are constructed as air inlet regions 143 and air outlet regions 144. Air inlet channels 141 for connecting each air inlet region 143 and air outlet channels 142 for connecting each air outlet region 144 are formed on the annular partitions.

[0033] In this application, the stator frame 11 can be constructed as a housing made of welded steel plates. The function of the stator frame 11 is to accommodate and support the stator core 12 and the stator windings, and to provide multiple paths for circulating cooling hydrogen throughout the generator. The axially arranged annular baffles inside the stator frame 11 not only enhance the rigidity of the stator frame 11 to more stably support the stator core 12, but also prevent resonance. At the same time, multiple annular areas are provided between the stator core 12 and the stator frame 11. By rationally designing the ventilation holes, air inlet channels 141, and air outlet channels 142 on the annular baffles of the stator frame 11, cooling gas can flow in and out from these areas, thereby effectively cooling the generator without increasing the structural dimensions of the stator frame 11.

[0034] Please refer to Figure 4 and Figure 5 In some embodiments, the air inlet channel 141 is located below the stator frame 11 in the axial direction, and the air outlet channel 142 is located above the stator frame 11 in the axial direction.

[0035] In this application, the air inlet channel 141 is located at a 45° angle to the side below the middle section of the stator frame 11 (viewed axially), and hydrogen gas flows in from the axial fan 13 through the end of the stator frame 11. The air outlet channel 142 is located at a 45° angle to the side above the middle section of the stator frame 11 (viewed axially), and is connected to the hydrogen cooling device 2 through an opening above the end of the stator frame 11. With this arrangement, the cooling gas flows from bottom to top, passing through each air inlet zone 143 and air outlet zone 144, and is finally discharged into the hydrogen cooling device 2. This effectively improves the cooling efficiency, ensuring that the cooling effect is improved while maintaining the length of the stator 1.

[0036] Please continue to refer to Figure 3 The ventilation system 14 may include n air inlet zones 143 and n+1 air outlet zones 144, with the air inlet zones 143 and air outlet zones 144 arranged alternately in parallel.

[0037] In this application, n=4 is preferred, that is, the ventilation system 14 can preferably have 4 air inlet zones 143 and 5 air outlet zones 144, for a total of 9 air zones.

[0038] In existing technologies, the 500MW water-hydrogen-cooled generators that have reached the end of their service life employ a circumferential two-inlet, two-outlet ventilation system in the middle section of the stator, meaning there are only two air inlet zones and two air outlet zones. The stator airflow structure design corresponding to the end and middle frames results in a large generator stator size, causing the foundation opening size to reach 9250mm in length and 4000mm in width, and the bearing span to reach 10315mm.

[0039] Compared with the prior art, in this application, the water-hydrogen-cooled steam turbine generator 100 can effectively improve the cooling effect on the stator core 12 and rotor 3 by increasing the air zone of the hydrogen cooling cycle, while maintaining the overall size of the stator frame 11. Thus, the cooling effect of the water-hydrogen-cooled steam turbine generator 100 after the replacement of the old machine according to the embodiment of the present invention is better than that of the prior art.

[0040] In some preferred embodiments, the stator core 12 may include a plurality of stator laminations, the thickness of which ranges from 0.35 mm to 0.4 mm.

[0041] In this application, the stator laminations are preferably made of 0.35mm thick, and low-loss oriented silicon steel sheets are used. This design, using high-permeability, low-loss stator laminations, effectively improves the generator's power generation efficiency while further reducing the weight of the stator core 12. This allows the water-hydrogen cooled turbine generator 100 according to this embodiment of the invention to better meet the on-site lifting conditions when replacing an aging generator.

[0042] Please refer to Figures 6 to 8 In some embodiments, a winding groove 15 is formed on the stator core 12, and two layers of stator coils 16 are arranged in the winding groove 15. The upper stator coil 161 is located at the opening of the winding groove 15, and the lower stator coil 162 is located at the bottom of the winding groove 15. End fixing structures 17 are provided at both ends of the stator core 12, and the end fixing structures 17 are used to fix the two ends of the stator coils 16.

[0043] In the prior art, large synchronous generators conventionally use 42 or 48 slots. Compared with the prior art, in this application, two layers of stator coils 16 are arranged in layers within the winding slot 15, making the winding slot 15 a multi-slot compact design. This directly reduces the axial length of the stator core 12, lowers the weight of the stator 1, and meets the requirements for on-site lifting. At the same time, it can also correspondingly reduce the span of the rotor 3, thereby improving the rigidity of the rotor 3 and enhancing the stability of the rotor 3's shaft system. In addition, this application can provide 54 winding slots within the stator core 12 to ensure that the voltage of the water-hydrogen cooled steam turbine generator 100 of this embodiment can reach the design value while shortening the length of the stator core 12.

[0044] Please continue to refer to Figures 6 to 8 In some embodiments, the end fixing structure 17 may include: an insulating conical ring 171 disposed on the outer circumference of the end of the lower stator coil 162; an insulating segmented pressure plate 172 disposed on the inner circumference of the end of the upper stator coil 161, the insulating segmented pressure plate 172 being fixedly connected to the insulating conical ring 171; a first insulating spacer 173 and a second insulating spacer 174, the first insulating spacer 173 being disposed between each coil at the involute termination of the stator coil 16 and fixed to the insulating segmented pressure plate 172 and the insulating conical ring 171; the second insulating spacer 174 being disposed between each coil at the involute beginning of the stator coil 16 and located between the insulating segmented pressure plate 172 and the insulating conical ring 171. The insulating conical ring 171, the insulating segmented pressure plate 172, the first insulating spacer 173 and the second insulating spacer 174, and the stator coil 16 form a sealed space filled with insulating material.

[0045] In this application, the first screw 175 passes through one end of the insulating block pressure plate 172 and the first insulating spacer 173, and is threadedly connected and fixed to the insulating conical ring 171. The second screw 176 passes through the other end of the insulating block pressure plate 172, passes through the bypass of the second insulating spacer 174, and is threadedly connected and fixed to the insulating conical ring 171. The first insulating spacer 173, the second insulating spacer 174, the stator coil 16, the insulating block pressure plate 172, and the insulating conical ring 171 are fitted together. In this application, the involute of the stator coil 16 should be understood as the trajectory of any point on the bar in the stator coil 16 as it rolls along the base circle of the stator coil 16, which is called an involute of the stator coil 16. In this application, the starting point and the ending point of the involute of the stator coil 16 are the two ends of the axial direction of the stator coil 16. In this application, a first insulating spacer 173 is provided between each slotted bar at the involute termination of the stator coil 16. The first insulating spacer 173 is in close contact with the bar or in close contact through a conformal insulating material 177. In this application, the insulating material 177 may be an infused insulating epoxy resin.

[0046] Through the above arrangement, the insulating conical ring 171, the insulating segmented pressure plate 172, the first insulating spacer 173 and the second insulating spacer 174, and the stator coil 16 tightly attached to the first insulating spacer 173 and the second insulating spacer 174 together form a sealed space surrounding the involute portion of the stator coil 16. Insulating epoxy resin is poured into this sealed space to form an integral, fixed, additional insulating structure at the ends of the stator coil 16. This strengthens the insulation and reliability between the ends of the stator coil 16, effectively solving the problem of weakened insulation caused by the small distance between the ends of adjacent stator coils 16 due to the increased number of winding slots 15 in the stator core 12. Furthermore, the epoxy resin filling makes the ends of the stator coil 16 form a single unit, providing good rigidity in both radial and tangential directions, and eliminating vibration and wear issues.

[0047] In some embodiments, the axial length of the stator core 12 is less than 5000 mm, the outer diameter of the stator core 12 is less than 2700 mm, and the ratio of the effective length to the outer diameter of the stator core 12 is less than 1.7.

[0048] Through the above settings, the water-hydrogen-cooled steam turbine generator 100 of the present invention can further effectively limit the overall size of the water-hydrogen-cooled steam turbine generator 100 by limiting the size of the stator core 12, thereby enabling the water-hydrogen-cooled steam turbine generator 100 of the present invention to be better suited for the replacement of old generators that have reached the end of their service life in the prior art.

[0049] Please continue to refer to Figure 1 In some embodiments, the stator frame 11 may further include a stator base 18, which is detachably fixedly connected to the bottom of the stator frame 11.

[0050] In this application, the stator base 18 is independent of the stator frame 11, which allows it to be removed from the stator frame 11 during hoisting, reducing hoisting weight and further making the water-hydrogen cooled turbine generator 100 of this embodiment more suitable for replacement of old units. Furthermore, direct installation and fixation are achieved through bolted connections. This connection method makes the installation and removal of the stator base 18 more convenient and rapid.

[0051] Please refer to Figure 2 In some embodiments, the stator frame 11 may further include a plurality of stator hangers 19, which are detachably fixed to both sides of the stator frame 11 in the horizontal direction, wherein the length of the stator hangers 19 extends to the outside of the stator base 18.

[0052] In this application, the stator lifting arm 19 can be made of alloy steel forging to improve its strength during use. In this application, the stator lifting arm 19 is bolted to the side wall of the stator base 11 to facilitate lifting by a crane. The stator lifting arm 19 is removed after the stator base 11 is fixed to the foundation.

[0053] In the foregoing description of this application, unless otherwise expressly specified and limited, the terms "fixed," "installed," "connected," or "linked" should be interpreted broadly. For example, the term "linked" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can refer to the internal communication of two components or the interaction between two components. Therefore, unless otherwise expressly limited in this application, those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] Based on the above description of this application, those skilled in the art will also understand that the terms used, such as "upper," "lower," "front," "rear," "left," "right," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "center," "longitudinal," "transverse," "clockwise," or "counterclockwise," are based on the orientation or positional relationship shown in the accompanying drawings of this application. They are only for the purpose of facilitating the explanation of the present invention and simplifying the description, and do not explicitly or implicitly suggest that the device or element involved must have the specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as a limitation on the present invention.

[0055] Furthermore, the terms "first" or "second," etc., used in this application to refer to numbers or ordinal numbers are for descriptive purposes only and should not be construed as explicitly or implicitly indicating relative importance or specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, or more, unless otherwise explicitly specified.

[0056] While numerous embodiments of the invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of the invention. The appended claims are intended to define the scope of protection of the invention and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A water-hydrogen-cooled steam turbine generator suitable for complete replacement of old units, characterized in that, include: The stator includes: a stator frame, which is a sealed housing, with sealing end caps at both ends of the stator frame; a hydrogen cooling device, detachably mounted on both sides of the top wall of the sealed housing and connected to the sealed housing; a stator core, fixed inside the stator frame, with axial flow fans at both ends of the stator core; a ventilation system, formed along the circumference of the stator core on the inner circumferential wall of the stator frame, and forming several air inlet and outlet zones along the axial direction of the stator core; the hydrogen cooling device, the stator frame, and the ventilation system form a closed-loop hydrogen circulation circuit through the axial flow fans; and... The rotor includes: a rotor shaft disposed within the stator core, with both ends of the rotor shaft extending through the sealing end caps; a front bearing and a rear bearing respectively disposed on a fixed foundation, the front bearing and the rear bearing being connected to the shaft ends of the rotor shaft.

2. The water-hydrogen cooled steam turbine generator according to claim 1, characterized in that, The hydrogen cooling device includes: A sealed cooling housing, detachably and fixedly connected to the top of the stator base, wherein the sealed cooling housing has an air outlet and an air inlet; and, A hydrogen cooler, which is disposed within the sealed cooling housing; The stator frame has the following features on its top wall: an air inlet connected to the air outlet, the air inlet being located on the air inlet side of the axial fan; and an air outlet connected to the air inlet, the air outlet being located on the stator frame at a position connected to the outlet of the ventilation system.

3. The water-hydrogen cooled steam turbine generator according to claim 1, characterized in that, The inner wall of the stator base is provided with a plurality of annular partitions spaced along the axial direction. The plurality of annular partitions are used to support the stator core. An annular region is formed between adjacent annular partitions. The annular region is constructed as the air inlet area and the air outlet area. An air inlet channel for connecting each air inlet area and an air outlet channel for connecting each air outlet area are formed on the annular partition.

4. The water-hydrogen cooled steam turbine generator according to claim 3, characterized in that, The ventilation system includes n air inlet zones and n+1 air outlet zones, which are arranged alternately side by side.

5. The water-hydrogen-cooled steam turbine generator according to any one of claims 1-4, characterized in that, The stator core includes a plurality of stator laminations, the thickness of which ranges from 0.35mm to 0.4mm.

6. The water-hydrogen-cooled steam turbine generator according to any one of claims 1-4, characterized in that, The stator core has a winding groove, and two layers of stator coils are arranged in the winding groove. The upper stator coil is located at the opening of the winding groove, and the lower stator coil is located at the bottom of the winding groove. The stator core has end fixing structures at both ends, which are used to fix the two ends of the stator coils.

7. The water-hydrogen cooled steam turbine generator according to claim 6, characterized in that, The end fixing structure includes: An insulating conical ring is disposed on the outer circumference of the end of the lower stator coil; An insulating segmented pressure plate is disposed on the inner circle side of the end of the upper stator coil, and the insulating segmented pressure plate is fixedly connected to the insulating conical ring; A first insulating spacer block and a second insulating spacer block are provided. The first insulating spacer block is disposed between each coil at the end of the involute of the stator coil and is fixed to the insulating block pressure plate and the insulating cone ring. The second insulating spacer block is disposed between each coil at the beginning of the involute of the stator coil and is located between the insulating block pressure plate and the insulating cone ring. The insulating conical ring, the insulating block pressure plate, the first insulating spacer, the second insulating spacer, and the stator coil form a sealed space, which is filled with insulating material.

8. The water-hydrogen-cooled steam turbine generator according to any one of claims 1-4, characterized in that, The axial length of the stator core is less than 5000mm, the outer diameter of the stator core is less than 2700mm, and the ratio of the effective length to the outer diameter of the stator core is less than 1.

7.

9. The water-hydrogen-cooled steam turbine generator according to any one of claims 1-4, characterized in that, The stator base also includes stator feet, which are detachably and fixedly connected to the bottom of the stator base.

10. The water-hydrogen cooled steam turbine generator according to claim 5, characterized in that, The stator frame also includes several stator hangers, which are detachably fixed to both sides of the stator frame in the horizontal direction, wherein the length of the stator hangers extends to the outside of the stator base.

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