A steam turbine operation blowdown device

Abstract

The application discloses a steam turbine operation blowdown device, wherein the steam turbine comprises a cylinder, a blade row arranged in the cylinder and an air inlet pipe for conveying dry hot steam or wet hot steam, and the air inlet pipe is communicated with the cylinder; the blade row comprises alternatingly arranged static blade rows and dynamic blade rows, the static blade rows are connected with the inner wall of the cylinder, and the dynamic blade rows are connected with main shafts; the outer wall of the cylinder is provided with a vibrating member, a telescopic conducting rod is connected with the vibrating end of the vibrating member, and the conducting rod extends into the cylinder. When the air inlet pipe conveys the wet hot steam, the water carried in the steam itself has a certain scouring and cleaning effect, the vibrating member applies controllable micro-vibration to the static blade row through the conducting rod, the water film covering the surface of the blade produces disturbance and micro-explosion effect, the permeation and peeling capacity of the water to the scale layer are enhanced, meanwhile, the vibration energy generated by the vibrating member operation is transmitted to the inside of the cylinder through the conducting rod, and the adhered scale can be cleaned up under the condition that the steam turbine normally operates and the blade row continuously rotates.

Description

Technical Field

[0001] This invention relates to the field of steam turbine technology, and in particular to a steam turbine operation sewage discharge device. Background Technology

[0002] Steam turbines, as key equipment for converting steam thermal energy into mechanical work, are widely used in thermal power generation, nuclear power, and industrial drives. During long-term operation, the flow passages of steam turbines (especially the blade system) face severe problems of fouling and foreign matter deposition. Specifically, when steam turbines use dry or wet steam as the working fluid, trace minerals, corrosion products, and incompletely purified impurity particles carried in the steam gradually adhere to and deposit on the blade surfaces and within the flow channels as the steam flows through the stationary and moving blades.

[0003] This fouling phenomenon leads to a series of adverse effects. First, fouling alters the original blade profile, increasing steam flow resistance and reducing stage efficiency, ultimately resulting in a decrease in overall turbine output and economy. Second, uneven fouling deposition can disrupt rotor dynamic balance, causing increased unit vibration and, in severe cases, even threatening operational safety. Furthermore, if fouling flakes off and enters subsequent stages with the high-speed steam flow, it may cause erosion or mechanical damage to the blades.

[0004] To address the aforementioned issues, existing technologies typically employ two types of measures. One is to clean the blades manually or with high-pressure water during shutdown maintenance. However, this method requires unit shutdown, disrupting production continuity, and involves long cleaning cycles and high labor intensity. The second method is to use water spraying or sandblasting cleaning techniques during online operation. However, these techniques often require complex auxiliary systems, and the sprayed medium may cause thermal shock or erosion to the blades; improper control could exacerbate equipment damage.

[0005] Therefore, how to effectively and online remove scale buildup on the turbine blade system without affecting the normal operation of the turbine has become a pressing technical problem to be solved in this field. Summary of the Invention

[0006] In view of this, the present invention addresses the deficiencies of the prior art, and its main objective is to provide a steam turbine operation sewage discharge device that solves the aforementioned problems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a steam turbine operation sewage discharge device, wherein the steam turbine includes a cylinder body, blades disposed within the cylinder body, and an intake pipe for conveying dry hot steam or wet hot steam, and the intake pipe is connected to the cylinder body:

[0008] The blade rack includes alternating stationary blade racks and moving blade racks. The stationary blade racks are connected to the inner wall of the cylinder, and the moving blade racks are connected to the main shaft.

[0009] The outer wall of the cylinder is equipped with a vibrating element, and the vibrating end of the vibrating element is connected to a retractable transmission rod, which extends into the cylinder body.

[0010] Furthermore, the vibrating component is a piezoelectric exciter, and the transmission rod can abut against the stationary blade grid.

[0011] Furthermore, the stationary blade grid includes an outer ring and multiple stationary blades circumferentially disposed on the outer ring, and the transmission rod can abut against the outer ring.

[0012] Furthermore, the stationary vane grates are provided in multiple sets and distributed along the cylinder axial direction, with a vibrating element provided every three sets of stationary vane grates.

[0013] Furthermore, the stationary vane grates are provided in multiple sets and distributed along the cylinder axial direction, with a vibrating element provided every four sets of stationary vane grates.

[0014] Furthermore, a through-hole is provided on the cylinder body for the transmission rod to pass through, and a metal bellows is installed inside the through-hole and connected to the transmission rod; the outer wall of one end of the metal bellows is sealed to the inner wall of the through-hole, and the other end is sealed to the end of the transmission rod.

[0015] Furthermore, the vibrating components are distributed along the axial direction of the cylinder body, and adjacent vibrating components are circumferentially offset in the cylinder body.

[0016] Furthermore, the moving blade grating has multiple moving blades, which are arranged circumferentially on the main shaft, and a tie rod is provided between each pair of adjacent moving blades.

[0017] Furthermore, the moving blade cascade has multiple sets, and these multiple sets of moving blade cascade are arranged along the axial direction of the main shaft in descending order of flow size.

[0018] Furthermore, the number of tie rods on the moving blades in the moving blade cascade increases with the increase of the moving blade size.

[0019] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution, when the intake pipe is transporting hot and humid steam, the moisture carried in the steam itself has a certain flushing and cleaning effect. The vibrating component applies controllable micro-amplitude vibration to the stationary blade through the transmission rod, causing the water film covering the blade surface to generate disturbance and micro-explosion effect, which enhances the ability of moisture to penetrate and peel off the scale layer. At the same time, the vibration energy generated by the operation of the vibrating component is transmitted to the inside of the cylinder through the transmission rod, which can help remove the attached scale while the steam turbine is running normally and the blade is rotating continuously.

[0020] To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0021] Figure 1 This is a plan view of Embodiment 1 of the present invention.

[0022] Figure 2 This is Embodiment 1 of the present invention. Figure 1 Enlarged view of point A.

[0023] Figure 3 This is Embodiment 1 of the present invention. Figure 1 Enlarged view of point B.

[0024] Figure 4 This is Embodiment 1 of the present invention. Figure 3 Enlarged view of point C.

[0025] Explanation of reference numerals in the attached diagram:

[0026] Cylinder block 10, port 11, metal bellows 12;

[0027] Blade cascade 20, stationary blade cascade 21, outer ring 211, stationary blade 212, moving blade cascade 22, moving blade 221, tie rod 222;

[0028] Intake pipe 30;

[0029] Spindle 40;

[0030] Vibrating component 50, transmission rod 51. Detailed Implementation

[0031] Please refer to Figure 1-4 As shown, it illustrates the specific structure of a preferred first embodiment of the present invention, which is a steam turbine operation sewage discharge device, wherein the steam turbine includes a cylinder 10, blades 20 disposed within the cylinder 10, and an intake pipe 30 for conveying dry hot steam or wet hot steam, and the intake pipe 30 is connected to the cylinder 10:

[0032] The blade cascade 20 includes alternating stationary blade cascade 21 and moving blade cascade 22. The stationary blade cascade 21 is connected to the inner wall of the cylinder block 10, and the moving blade cascade 22 is connected to the main shaft 40.

[0033] A vibrating element 50 is provided on the outer wall of the cylinder body 10. The vibrating end of the vibrating element 50 is connected to a retractable transmission rod 51, which extends into the cylinder body 10. When the intake pipe 30 delivers hot humid steam, the moisture carried in the steam itself has a certain scouring and cleaning effect. The vibrating element 50 applies controllable micro-amplitude vibration to the stationary blade 21 through the transmission rod 51, causing disturbance and micro-explosion effects on the water film covering the blade surface, enhancing the ability of moisture to penetrate and peel off the scale layer. At the same time, the vibration energy generated by the operation of the vibrating element 50 is transmitted to the interior of the cylinder body 10 through the transmission rod 51, which can assist in removing the attached scale while the turbine is running normally and the blade 20 is continuously rotating.

[0034] It should be noted that when the intake pipe 30 delivers hot and humid steam, the moisture carried in the steam itself has a certain scouring and cleaning effect. The vibrating element 50 applies controllable micro-amplitude vibration to the stationary blade grid 21 through the transmission rod 51, causing the water film covering the blade surface to generate disturbance and micro-explosion effect, thereby enhancing the ability of moisture to penetrate and peel off the scale layer.

[0035] For example, the vibrating element 50 is a piezoelectric vibrator, and the transmission rod 51 can abut against the stationary blade 21. The piezoelectric vibrator utilizes the inverse piezoelectric effect of piezoelectric ceramics, that is, by applying voltage to control its deformation, vibration is generated. Therefore, the vibration frequency can be precisely adjusted according to the working conditions, which can avoid the natural frequencies of the blades and rotor to avoid resonance damage, and find the frequency window most conducive to scale removal.

[0036] For example, the stator blade cascade 21 includes an outer ring 211 and a plurality of stator blades 212 circumferentially disposed on the outer ring 211, and the transmission rod 51 can abut against the outer ring 211. The outer ring 211, as an integral annular frame connecting all the stator blades 212, is the most rigid structure in the stator blade cascade 21. Applying vibration to the outer ring 211 is equivalent to pushing the entire stator blade cascade 21 as a rigid body. The vibration energy can be transmitted without loss to the root of each stator blade 212 through the outer ring 211, realizing efficient excitation of the blades on the outer ring 211.

[0037] For example, multiple sets of stationary vane grids 21 are provided and distributed along the axial direction of the cylinder body 10, with a vibrating element 50 provided every three sets of stationary vane grids 21. By providing a vibrating element 50 every three sets of stationary vane grids 21, each section of steam flow area has its own vibration source coverage, ensuring that all stages from the high-pressure cylinder to the low-pressure cylinder can obtain sufficient and uniform excitation intensity, avoiding the occurrence of excessive vibration at the near end and ineffective vibration at the far end.

[0038] For example, the stationary vane 21 is provided in multiple sets and distributed along the axial direction of the cylinder body 10, and a vibrating element 50 is provided every four sets of stationary vane 21. Compared with three sets, four sets make the vibration energy field distribution of the entire unit more balanced and complementary, avoiding the risk of accidental resonance in some areas due to excessive vibration sources.

[0039] For example, the cylinder body 10 has a through-hole 11 for the transmission rod 51 to pass through, and a metal bellows 12 connected to the transmission rod 51 is disposed in the through-hole 11; the outer wall of one end of the metal bellows 12 is sealed to the inner wall of the through-hole 11, and the other end is sealed to the end of the transmission rod 51. The metal bellows 12 is made of heat-resistant alloys such as stainless steel, which can fully withstand the operating temperature of the steam turbine, and has excellent corrosion resistance and fatigue resistance. At the same time, because the metal bellows 12 is a flexible element, it can freely expand and contract in the axial direction (following the movement of the transmission rod 51), and its pipe wall itself is completely sealed.

[0040] For example, the vibrating elements 50 are distributed along the axial direction of the cylinder 10, and adjacent vibrating elements 50 are circumferentially offset in the cylinder 10. It should be noted that the adjacent vibrating elements 50 are circumferentially offset in the cylinder 10 to form a three-dimensional excitation network. For example, the first group of vibrating elements acts on the top of the cylinder, the second group acts on the side, and the third group acts on the bottom. Through the spatially offset layout, the vibration waves enter the flow area from multiple angles, complement each other, and interweave to form a network, cleaning the entire ring of stationary blades from multiple angles (360 degrees). In addition, the vibration waves generated by the offset vibrating elements 50 have different phases and propagation paths in space. They interfere with each other and cancel each other out, avoiding the risk of superposition of resonance at the same frequency.

[0041] For example, the moving blade grid 22 has multiple moving blades 221, which are arranged circumferentially on the main shaft 40, and a tie rod 222 is provided between each two adjacent moving blades 221. The tie rod 222 connects adjacent moving blades 221 so that each blade will not vibrate independently at its own natural frequency under the action of steam excitation force or externally transmitted vibration.

[0042] For example, the moving blade cascade 22 has multiple sets, and these multiple sets of moving blade cascade 22 are arranged in descending order of flow size along the axial direction of the main shaft 40. The "descending order of flow size" is actually an "increasing" arrangement from the high-pressure side to the low-pressure side (the high-pressure stage blades are short, and the low-pressure stage blades are long). This ensures that the annular flow area of ​​each stage of the moving blade cascade 22 is proportional to the volumetric flow rate of the steam flowing through that stage, so that the steam velocity is always maintained within the reasonable range of the design. This achieves the optimal matching of the velocity triangles of each stage within the stage group, thereby ensuring the high-efficiency energy conversion of the entire machine.

[0043] For example, the number of tie rods 222 on the moving blade 221 in the moving blade cascade 22 increases with the size of the moving blade. As a cantilever beam structure, the stiffness of the moving blade 221 is inversely proportional to the cube of its size—the longer the blade, the more significant the decrease in stiffness. Under the external excitation environment introduced by the vibrating component 50, long blades with insufficient stiffness are more prone to large deformations, leading to tip rubbing or root stress exceeding limits. By increasing the number of tie rods 222, multiple support points are added in the middle or top of the long blade, transforming the single cantilever beam into a multi-point supported truss structure. The stiffness is improved, ensuring that the deformation of the long blade under external excitation environment is strictly limited within the design allowable range, thus ensuring the safe operation of the moving blade cascade 22.

[0044] In summary, the key design focus of this invention is;

[0045] 1.1 When the steam turbine switches to or operates in a condition that transports hot, humid steam, the control system, integrated into the equipment, can identify this state. Since the hot, humid steam contains moisture, this creates conditions for online cleaning using the physical properties of moisture. The control system then activates the vibration-assisted drainage function accordingly.

[0046] 1.2 The control system sends commands to the piezoelectric vibrator 50, which is arranged on the outer wall of the cylinder 10. The vibrator 50, according to preset parameters, begins to generate controllable micro-amplitude high-frequency vibrations. The vibration energy generated by the vibrator 50 is directly transmitted to the outer ring 211 of the stationary blade grating 21, which it contacts, through the retractable transmission rod 51 connected to it. Since the outer ring 211 is the rigidest integral structure, the vibration energy is transmitted almost without loss to the root of each stationary blade 212 of that stage of the stationary blade grating, achieving uniform excitation of the entire stationary blade grating.

[0047] 1.3 When hot, moist steam flows over the surface of the vibrating stator blade 212, the moisture carried in the steam forms a water film on the blade surface. Simultaneously with the micro-vibration of the stator blade 212, the water film covering its surface is strongly disturbed. The energy of the vibration is transmitted into the interior of the water film, causing rapid changes in local pressure and temperature, resulting in numerous micro-scale cavitation and micro-explosion phenomena. This micro-explosion effect greatly enhances the permeability of moisture to the scale layer, allowing it to penetrate deep into the tiny cracks within the scale layer. Under the combined action of the mechanical force of vibration, the scouring force of the water film, and the impact force generated by the micro-explosion, the originally hardened scale structure is destroyed, loosened, and ultimately peeled off from the blade surface.

[0048] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A steam turbine operation sewage discharge device, wherein the steam turbine includes a cylinder block (10), blades (20) disposed within the cylinder block (10), and an intake pipe (30) for conveying dry hot steam or wet hot steam, and the intake pipe (30) is connected to the cylinder block (10), characterized in that: The blade cascade (20) includes alternating stationary blade cascade (21) and moving blade cascade (22), wherein the stationary blade cascade (21) is connected to the inner wall of the cylinder body (10), and the moving blade cascade (22) is connected to the main shaft (40). The cylinder body (10) has a vibrating element (50) on its outer wall. The vibrating end of the vibrating element (50) is connected to a retractable transmission rod (51), and the transmission rod (51) extends into the cylinder body (10).

2. The steam turbine operation sewage discharge device according to claim 1, characterized in that: The vibrating element (50) is a piezoelectric exciter, and the transmission rod (51) can abut against the stationary leaf grid (21).

3. A steam turbine operation sewage discharge device according to claim 1 or 2, characterized in that: The stationary blade grid (21) includes an outer ring (211) and a plurality of stationary blades (212) circumferentially disposed on the outer ring (211), and the transmission rod (51) can abut against the outer ring (211).

4. The steam turbine operation sewage discharge device according to claim 3, characterized in that: The stationary blades (21) are provided in multiple sets and distributed along the cylinder body (10) axially, and a vibrating element (50) is provided every three sets of stationary blades (21).

5. A steam turbine operation sewage discharge device according to claim 3, characterized in that: The stationary blades (21) are provided in multiple sets and distributed along the cylinder body (10) axially, and a vibrating element (50) is provided every four sets of stationary blades (21).

6. The steam turbine operation sewage discharge device according to claim 1, characterized in that: The cylinder body (10) has an opening (11) through which the guide rod (51) passes. A metal bellows (12) is installed in the opening (11) and is connected to the guide rod (51). The outer wall of one end of the metal bellows (12) is sealed to the inner wall of the opening (11), and the other end is sealed to the end of the guide rod (51).

7. A steam turbine operation sewage discharge device according to claim 5, characterized in that: Multiple vibrating elements (50) are distributed along the axial direction of the cylinder (10), and adjacent vibrating elements (50) are circumferentially misaligned on the cylinder (10).

8. The steam turbine operation sewage discharge device according to claim 1, characterized in that: The moving blade grid (22) has multiple moving blades (221), which are arranged circumferentially on the main shaft (40), and a tie rod (222) is provided between each two adjacent moving blades (221).

9. A steam turbine operation sewage discharge device according to claim 8, characterized in that: The moving blade grating (22) has multiple sets, and the multiple sets of the moving blade grating (22) are arranged in descending order of flow size along the axial direction of the main shaft (40).

10. A steam turbine operation sewage discharge device according to claim 9, characterized in that: The number of tie rods (222) on the moving blades (221) in each set of moving blade grids (22) increases as the size of the moving blades increases.

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