Nuclear turbine welding rotor capable of realizing rapid temperature equalization

Abstract

The invention is suitable for the field of nuclear turbines, and discloses a nuclear turbine welding rotor capable of achieving rapid temperature equalization. A plurality of cavities are formed in the welding rotor, a plurality of connecting holes used for being communicated with the cavities, a plurality of air inlets formed in the welding rotor and communicated with the cavities and a plurality of air outlets formed in the welding rotor and communicated with the cavities are formed among the cavities, and the cavities where the air inlets are located are different from the cavities where the air outlets are located. In the starting process of the nuclear turbine, a small part of steam in the turbine can flow in all the cavities after entering the rotor from the air inlet, the effect of synchronously heating the inner walls of the cavities is achieved, and then the steam flows out from the air outlet, so that the overall average temperature of the rotor can be effectively increased, the stress concentration phenomenon of the rotor is weakened, and thermal stress is reduced.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power steam turbines, and in particular to a nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization. Background Art

[0002] Nuclear power generation, due to its advantages of cleanliness, efficiency, and stability, is increasingly occupying a larger proportion of my country's power structure. With the rapid integration of large-scale renewable energy, the new power system has placed higher demands on the load response capabilities of nuclear power units.

[0003] Currently, nuclear power is increasingly involved in grid peak regulation, becoming a key safety guarantor for the highly flexible new power system. Nuclear steam turbines are essential equipment for nuclear power plants, and welded rotors are key components within them. Welded rotors are large and complex, resulting in complex internal thermal stresses during cooling and difficulty in achieving rapid temperature uniformity. This presents both a key and challenging challenge in achieving rapid startup and shutdown of the unit. During peak regulation, nuclear steam turbines experience thermal stress concentration in the welded rotors during startup, impacting both unit safety and the economic benefits of the power plant. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a nuclear power steam turbine welding rotor that can achieve rapid temperature equalization.

[0005] The technical solution adopted by the present invention to solve its technical problems is: constructing a nuclear power turbine welding rotor that can achieve rapid temperature equalization, including: a plurality of cavities are provided inside the welding rotor, a plurality of connecting holes for connecting the cavities are provided between the plurality of cavities, a plurality of air inlets are provided on the welding rotor and connected to the cavities, and a plurality of air outlets are provided on the welding rotor and connected to the cavities, and the cavity where the air inlet is located is different from the cavity where the air outlet is located.

[0006] In some embodiments, a speed switch assembly is provided at the air outlet. When the speed of the welding rotor is zero, the opening of the speed switch assembly is 100%, and air can freely enter and exit the air outlet. When the speed of the welding rotor gradually increases, the opening of the speed switch assembly gradually decreases from 100% to 0%, and air cannot enter or exit the air outlet.

[0007] In some embodiments, the speed switch assembly includes a valve body, a ball disposed in the valve body, an adjusting rod threadedly connected to the valve body and abutting against the ball, and a spring with two ends respectively abutting against the valve body and the ball.

[0008] In some embodiments, the air inlet areas of the plurality of air inlets are smaller than or equal to the air outlet areas of the plurality of air outlets.

[0009] In some embodiments, the number of the cavities is greater than or equal to three, and a number of connection holes located on both sides of the same cavity are not concentric with each other.

[0010] In some embodiments, when there is one connecting hole on one axial side of the cavity, the connecting hole is arranged at the center of the cavity.

[0011] In some embodiments, when the number of the connection holes on one axial side of the cavity is greater than or equal to two, the connection holes are evenly distributed on the side surface of the cavity around the central axis of the welded rotor.

[0012] In some embodiments, the cavity is cylindrical.

[0013] In some embodiments, the direction of the air inlet is offset from the central axis of the cavity.

[0014] In some embodiments, the welding rotor is provided with a wheel disc, and the cavity is provided at the center of the wheel disc.

[0015] The implementation of the present invention to achieve a nuclear power steam turbine welded rotor with rapid temperature equalization has the following beneficial effects: during the startup of the nuclear power steam turbine, a very small portion of the steam in the steam turbine enters the interior of the rotor from the air inlet, flows in each cavity, and plays a role in synchronously heating the inner wall of the cavity, and then flows out from the air outlet, which can effectively increase the average temperature of the entire rotor, weaken the rotor stress concentration phenomenon, and reduce thermal stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can derive other relevant drawings based on these drawings without inventive effort. In the drawings:

[0017] Figure 1 This is an overall diagram of a nuclear power steam turbine welded rotor capable of achieving rapid temperature equalization in one embodiment of the present invention;

[0018] Figure 2 This is a diagram of a cavity structure of a nuclear power steam turbine welded rotor capable of achieving rapid temperature uniformity in one embodiment of the present invention;

[0019] Figure 3 This is a perspective view of a speed switch assembly for a nuclear power steam turbine welded rotor capable of achieving rapid temperature equalization in one embodiment of the present invention;

[0020] Figure 4This is a cross-sectional view of a speed switch assembly for a nuclear power steam turbine welded rotor capable of achieving rapid temperature equalization in one embodiment of the present invention;

[0021] Figure 5 This is a graph showing average temperature variation of a welded rotor of a nuclear power steam turbine capable of achieving rapid temperature equalization in one embodiment of the present invention;

[0022] Figure 6 The present invention is a rotor stress variation curve diagram of a nuclear power steam turbine welded rotor capable of achieving rapid temperature equalization in one embodiment of the present invention.

[0023] Reference numerals

[0024] 100, welded rotor; 200, cavity; 300, air inlet; 400, connecting hole; 500, air outlet; 600, speed switch assembly; 610, valve body; 620, sphere; 630, spring; 640, adjusting rod. DETAILED DESCRIPTION

[0025] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by "upper," "inner," and "outer," etc., are based on the orientations or positional relationships shown in the accompanying drawings and are constructed and operated in specific orientations. These are merely for the purpose of facilitating the description of the present technical solution and do not necessarily require the device or component to have a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0026] It should also be noted that, unless otherwise clearly specified and limited, terms such as "installation", "connection", "fixation", and "setting" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intervening elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of such features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0027] Figures 1 to 6A nuclear power steam turbine welding rotor 100 capable of achieving rapid temperature equalization in an embodiment of the present invention is shown. The nuclear power steam turbine welding rotor 100 capable of achieving rapid temperature equalization can be used for rapid temperature equalization of welding rotors 100 of steam turbines inside nuclear power plants. The welding rotor 100 may include a plurality of cavities 200 provided inside the welding rotor 100, a plurality of connection holes 400 for connecting the cavities 200 between the plurality of cavities 200, a plurality of air inlets 300 provided on the welding rotor 100 and connected to the cavities 200, and a plurality of air outlets 500 provided on the welding rotor 100 and connected to the cavities 200. The cavity 200 where the air inlet 300 is located is different from the cavity 200 where the air outlet 500 is located.

[0028] During the startup of a nuclear power steam turbine, a very small portion of the steam in the steam turbine enters the rotor from the air inlet 300, flows in each cavity 200, and plays a role in synchronously heating the inner wall of the cavity 200, and then flows out from the air outlet 500, which can effectively increase the average temperature of the entire rotor, weaken the rotor stress concentration phenomenon, and reduce thermal stress.

[0029] Figure 5 The figure shows the average rotor temperature change curve before and after steam is introduced into the rotor. During actual unit startup, the average temperature of the welded rotor 100 with cavity 200 is higher than that of the welded rotor 100 without cavity 200. This is because the inner wall of the welded rotor 100 with cavity 200 undergoes convective heat exchange with the small amount of steam within cavity 200, achieving simultaneous heating of the inside and outside of the welded rotor 100. During the unit's initial load ramp-up, the average temperature rise rate of the welded rotor 100 with cavity 200 increased from 5.30°C / h to 6.33°C / h, a change of 19.43%.

[0030] Figure 6 The data show that during the actual unit startup process, the maximum stress change trends of the welded rotor 100 with and without the cavity 200 are basically the same. Due to the synchronous heating effect of steam, the temperature gradient on the inner and outer surfaces of the welded rotor 100 is reduced, causing the maximum stress of the welded rotor 100 with the cavity 200 to decrease from 199.25 MPa of the welded rotor 100 without the cavity 200 to 196.69 MPa, with a change rate of 1.3%.

[0031] It can be understood that due to the large size of the welded rotor 100, the welded rotor 100 is not formed in one piece. The welded rotor 100 is welded by several rotor segments. The cavity 200 is set at the welding surface of two adjacent rotor segments. Part of the cavity 200 is set on the welding surface of the rotor segment, and another part of the cavity 200 is set on the welding surface of the other rotor. When the two rotors are combined, a complete cavity 200 is formed. The cavity 200 is processed before welding, which can greatly reduce the processing difficulty.

[0032] In a specific embodiment, the spacing between the cavities 200 is determined after thermal analysis of the welded rotor 100 , and thus the spacing between the cavities 200 is different.

[0033] It can be understood that the connection hole 400 , the air inlet 300 and the air outlet 500 are all processed before the rotor segments are welded, which can reduce the difficulty of processing.

[0034] In a specific embodiment, the air inlets 300 are all arranged on the same rotor segment, and there will not be one air inlet 300 on one rotor segment and another air inlet 300 on another rotor segment, which is conducive to achieving dynamic balance of the rotor.

[0035] In a specific embodiment, the air outlets 500 are all arranged on the same rotor segment, and there will not be a situation where one air outlet 500 is on one rotor segment and another air outlet 500 is on another rotor segment, which is conducive to achieving dynamic balance of the rotor.

[0036] In a specific embodiment, the central axes of the plurality of cavities 200 are concentric, which can ensure the dynamic balance of the welded rotor 100 .

[0037] Figure 1 、 Figure 2 and Figure 5 It is shown that the air outlet 500 may include a speed switch assembly 600 at the air outlet 500 in one embodiment. When the speed of the welding rotor 100 is zero, the opening of the speed switch assembly 600 is 100%, and air can freely enter and exit the air outlet 500. When the speed of the welding rotor 100 gradually increases, the opening of the speed switch assembly 600 gradually decreases from 100% to 0%, and air cannot enter or exit the air outlet 500. When the speed of the welding rotor 100 is zero.

[0038] Understandably, during the turbine startup process, utilizing the cavity 200 structure within the welded rotor 100, a very small amount of steam from the main steam enters the welded rotor 100. Due to the relatively low rotational speed of the welded rotor 100, the exhaust port's speed switch assembly 600 is in an open state, allowing the steam entering the cavity 200 to flow, thereby simultaneously heating the inner wall of the cavity 200. This effectively raises the average temperature of the rotor as a whole, weakens rotor stress concentration, and reduces thermal stress. As the turbine speed increases and the rotor reaches a uniform temperature, the exhaust port's speed switch assembly 600 opens to zero under the influence of the enormous centrifugal force, blocking the exhaust port. At this point, the speed switch assembly 600 is closed, preventing steam from flowing within the rotor cavity 200.

[0039] Figure 1 、 Figure 2 and Figure 5 The speed switch assembly 600, in one embodiment, may include a valve body 610, a ball 620 disposed within the valve body 610, an adjusting rod 640 threadedly connected to the valve body 610 and abutting the ball 620, and a spring 630 with its ends abutting the valve body 610 and the ball 620, respectively. Because the welded rotor 100 rotates at a relatively low speed, the speed switch assembly 600 structure at the gas outlet 500 is in an open state, allowing steam entering the cavity 200 to flow, thereby simultaneously heating the inner wall of the cavity 200. This effectively raises the average temperature of the rotor as a whole, reduces rotor stress concentration, and reduces thermal stress. As the turbine speed increases and the rotor reaches a uniform temperature, the spring 630 of the speed switch assembly 600 is compressed under the action of the enormous centrifugal force, causing the ball 620 connected to the spring 630 to move outward, thereby blocking the exhaust port. At this point, the speed switch assembly 600 is in a closed state, preventing steam from flowing within the rotor cavity 200.

[0040] Figure 1 、 Figure 2 and Figure 5 The air inlet 300 may include, in one embodiment, a plurality of air inlets 300 whose air inlet area is less than or equal to the air outlet area of ​​a plurality of air outlets 500 , thereby ensuring that the air inlet flow rate inside the welding rotor 100 is not greater than the air outlet flow rate, and that no pressure difference is formed inside, thereby making the air temperature inside the welding rotor 100 more balanced.

[0041] Figure 1 、 Figure 2 It is shown that in one embodiment, the first shielding unit may include three or more cavities 200, and several connecting holes 400 located on both sides of the same cavity 200 are not concentric with each other. The central axis of the connecting hole 400 on one axial side of the cavity 200 will not be aligned with the central axis of the connecting hole 400 on the other side, thereby preventing external high-temperature steam from flowing out directly from the two connecting holes 400. The non-concentricity of the connecting holes 400 allows steam to flow to other places in the cavity 200, thereby increasing the temperature of other parts of the cavity 200.

[0042] Figure 1 、 Figure 2 It is shown that in one embodiment, the first shielding unit may include: when there is one connecting hole 400 on one axial side of the cavity 200 , the connecting hole 400 is arranged at the center of the cavity 200 , which is convenient for processing and conducive to achieving dynamic balance of the welded rotor 100 .

[0043] Figure 1 、 Figure 2It is shown that in one embodiment, the connecting holes 400 may include connecting holes 400 on one axial side of the cavity 200. When the number of connecting holes 400 is greater than or equal to two, the multiple connecting holes 400 are evenly distributed on the side of the cavity 200 with the central axis of the welding rotor 100 as the axis, which is conducive to achieving dynamic balance of the welding rotor 100.

[0044] Figure 1 、 Figure 2 The cavity 200 is shown to include a cylindrical shape in one embodiment. The cylindrical shape of the cavity 200 is the same as that of the welding rotor 100. The wall thickness between the cavity 200 and the welding rotor 100 is uniform, the heating is more uniform, the thermal stress generated is relatively small, and the cylindrical cavity 200 is easier to process.

[0045] Figure 1 、 Figure 2 The air inlet 300 may include an embodiment in which the direction of the air inlet 300 is staggered from the central axis of the cavity 200 to prevent steam from entering the air inlet 300 from colliding with each other. The staggered setting of the air inlet 300 allows the steam to be blown to other parts of the cavity 200.

[0046] In a specific embodiment, the outer edges of the cavity 200 are all rounded, because sharp angles are prone to generate stress when processed, and sharp angles are prone to generate thermal stress after high-temperature heating. Rounded corners can greatly reduce stress generation.

[0047] Figure 1 、 Figure 2 and Figure 5 The welded rotor 100 may include a wheel disc in one embodiment. The cavity 200 is located at the center of the wheel disc. Since the wheel disc is connected to blades, the wheel disc is subjected to the largest force and internal stress, and requires rapid temperature equalization.

[0048] It is understandable that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A nuclear power steam turbine welding rotor capable of achieving rapid temperature uniformity, characterized in that: include: A plurality of cavities (200) are provided inside the welding rotor (100), a plurality of connection holes (400) for communicating with the cavities (200) are provided between the plurality of cavities (200), a plurality of air inlets (300) are provided on the welding rotor (100) and are connected to the cavities (200), and a plurality of air outlets (500) are provided on the welding rotor (100) and are connected to the cavities (200), wherein the cavities (200) where the air inlets (300) are located are different from the cavities (200) where the air outlets (500) are located.

2. A nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization according to claim 1, characterized in that: The air outlet (500) is provided with a speed switch assembly (600). When the speed of the welding rotor (100) is zero, the opening of the speed switch assembly (600) is 100%, and air can freely enter and exit the air outlet (500). When the speed of the welding rotor (100) gradually increases, the opening of the speed switch assembly (600) gradually decreases from 100% to 0%, and air cannot enter or exit the air outlet (500).

3. A nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization according to claim 2, characterized in that: The speed switch assembly (600) includes a valve body (610), a sphere (620) disposed in the valve body (610), an adjustment rod (640) threadedly connected to the valve body (610) and abutting against the sphere (620), and a spring (630) with two ends respectively abutting against the valve body (610) and the sphere (620).

4. The nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization according to claim 1, characterized in that: The air inlet areas of the plurality of air inlets (300) are smaller than or equal to the air outlet areas of the plurality of air outlets (500).

5. The nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization according to claim 1, characterized in that: The number of the cavities (200) is greater than or equal to three, and a plurality of connecting holes (400) located on both axial sides of the same cavity (200) are not concentric with each other.

6. The nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization according to claim 5, characterized in that: When there is only one connecting hole (400) on one axial side of the cavity (200), the connecting hole (400) is arranged at the center of the cavity (200).

7. The nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization according to claim 5, characterized in that: When the number of the connecting holes (400) on one axial side of the cavity (200) is greater than or equal to two, the connecting holes (400) are evenly distributed on the axial side of the cavity (200) with the central axis of the welding rotor (100) as the circumference.

8. The nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization according to claim 1, characterized in that: The cavity (200) is cylindrical.

9. A nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization according to claim 8, characterized in that: The direction of the air inlet (300) is offset from the central axis of the cavity (200).

10. The nuclear power steam turbine welding rotor capable of achieving rapid temperature equalization according to claim 1, characterized in that: The welding rotor (100) is provided with a wheel disc, and the cavity (200) is arranged at the center of the wheel disc.

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