Steam guide fin structure for preventing impact on valve stem

Abstract

The application discloses a steam inlet guide rib structure of an anti-impact valve rod and relates to the field of steam turbine valve rods. In the design of the diameter of a valve rod of a regulating valve, a large safety coefficient has to be adopted, the diameter of the valve rod is limited by design conditions, and the air leakage of the valve rod is increased correspondingly. Therefore, the steam inlet guide rib structure of the anti-impact valve rod is provided. The steam inlet guide rib structure of the anti-impact valve rod comprises a steam inlet channel of a steam turbine, a valve rod of a regulating valve and a valve chamber, the steam inlet channel of the steam turbine is connected with the valve chamber, the valve rod of the regulating valve is installed in the valve chamber, guide ribs are arranged in the steam inlet channel of the steam turbine in an equal cross-section longitudinal direction, the guide ribs are arranged at the longitudinal center line position of the steam inlet channel of the steam turbine, the guide ribs in the steam inlet channel of the steam turbine divide the steam inlet channel of the steam turbine into two airflow ports which are left-right symmetrical, the guide ribs are integrally connected with the inner pipe of the steam inlet channel of the steam turbine, and the guide ribs prevent the airflow in the steam inlet channel of the steam turbine from directly impacting the valve rod in the valve chamber. The steam inlet guide rib structure of the anti-impact valve rod is applied to the field of steam turbine valve rods.

Description

Technical Field

[0001] This invention relates to the field of steam turbine valve stems, and more specifically to an anti-impact valve stem inlet guide rib structure. Background Technology

[0002] Due to space constraints, marine steam turbines require a compact design. The main steam valve is arranged side-by-side with the cylinder, horizontally connected via an inlet flange. The regulating valve chamber and inlet passage are adjacent to each other at the cylinder head. High-parameter steam enters the regulating valve chamber through a short inlet passage, directly impacting the valve stem. Instability in the high-parameter steam flow rate can cause valve stem vibration. Significant fluctuations in steam pressure or frequent, uneven flow rate changes result in constantly shifting forces on the valve disc, leading to valve stem vibration. This phenomenon is particularly likely to occur during steam supply system malfunctions or sudden turbine load changes. Long-term operation and the impact of high-parameter steam on the valve stem can cause deformation and cracks.

[0003] Therefore, in order to overcome the safety hazards of valve stem deformation and cracking, a larger safety factor must be adopted in the design of valve stem diameter. Increasing the valve stem diameter will also be subject to design constraints and will correspondingly increase the valve stem leakage. Summary of the Invention

[0004] In order to address the problem that the design of existing regulating valve stem diameters necessitates the use of a large safety factor, and that increasing the valve stem diameter is also subject to design limitations and correspondingly increases valve stem leakage, this invention provides an inlet guide rib structure for an anti-impact valve stem.

[0005] The technical solution of this invention is:

[0006] An anti-impact valve stem inlet guide rib structure comprises a steam turbine inlet passage, a regulating valve stem, and a regulating valve chamber. The steam turbine inlet passage and the regulating valve chamber are fixedly connected and are horizontally arranged together at the cylinder head. The regulating valve stem is installed in the regulating valve chamber. High-pressure, high-speed steam enters the steam turbine inlet passage through the main steam valve. Guide ribs with equal cross-sections are arranged longitudinally within the steam turbine inlet passage. The guide ribs are located at the longitudinal centerline of the steam turbine inlet passage and divide the steam turbine inlet passage into two symmetrical airflow ports. The steam turbine inlet passage and the guide ribs are integrally connected.

[0007] The top of the guide rib is integrally connected to the top wall of the inner tube of the turbine inlet passage, and the top of the guide rib is integrally connected to the bottom wall of the inner tube of the turbine inlet passage. The middle part of the guide rib is a streamlined guide rib with double tail fins. The guide rib prevents the airflow in the turbine inlet passage from directly impacting the valve stem in the regulating valve chamber.

[0008] Furthermore, the streamlined guide rib portion of the double tail fin in the middle of the guide rib has an R1 leading edge arc surface, an R2 arc-shaped tail fin surface, an R3 guide surface, and an R4 tail edge arc surface.

[0009] The leading edge arc surface of R1 and the guide surface of R3 form the airflow intake arc surface in the steam turbine intake channel.

[0010] Furthermore, the R1 leading edge arc surface of the guide rib is set at the steam inlet of the steam turbine inlet channel, and the airflow is divided into two parts when passing through the R1 leading edge arc surface of the guide rib.

[0011] Furthermore, the R3 guide surface of the guide rib guides the airflow from the turbine inlet passage into the regulating valve chamber along the R3 guide surface.

[0012] Furthermore, the R2 arc-shaped tail fin surface and the R4 trailing edge arc surface of the guide rib are integrally formed to form the tail arc surface, so that the trailing edge portion formed by the R2 arc-shaped tail fin surface and the R4 trailing edge arc surface has a small curvature structure, which reduces airflow separation.

[0013] Furthermore, the valve stem is installed into the regulating valve chamber, and the valve stem and the guide rib are arranged on the same axis;

[0014] The width of the tail fin of the guide rib covers the valve stem diameter and is arranged longitudinally along the steam turbine inlet passage so that the guide rib covers the valve stem.

[0015] Furthermore, the longitudinal section of the guide rib is a double-tail wing structure, and the width of the tail wing is greater than or equal to 1.5 times the valve stem diameter, so that the valve stem avoids direct impact from the high-pressure and high-speed airflow entering the regulating valve chamber.

[0016] Furthermore, the steam turbine inlet passage has a tubular structure, and the inner diameter of the steam turbine inlet passage is the same as the overall length of the guide rib.

[0017] Furthermore, the steam inlet section of the turbine inlet channel and the guide ribs are integrally cast structures.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] This invention relates to a design method for adding guide ribs to the steam inlet passage of a steam turbine. The guide ribs are designed and arranged on the same axis as the regulating valve stem. The streamlined head design ensures smooth airflow, and the width of the guide rib tail fin is required to cover the diameter of the regulating valve stem. The guide ribs are arranged longitudinally along the steam inlet passage of the steam turbine to ensure that the regulating valve stem avoids direct impact from the incoming steam in both the radial and vertical directions.

[0020] The invention adds a flow guide rib structure, which effectively avoids direct impact of the steam inlet on the regulating valve stem, and solves the hidden dangers of vibration, deformation and cracking of the regulating valve stem caused by airflow impact, thereby improving the stability and safety reliability of the steam turbine under long-term operation.

[0021] This invention employs a method of installing built-in streamlined guide ribs within the steam turbine inlet passage. The cross-section of the guide ribs is often longitudinally arranged with a double-tail streamlined cross-section, which effectively enhances the rigidity of the steam inlet passage, achieving two goals at once. It also features a simple structure, ease of implementation, and does not occupy external space of the steam turbine.

[0022] During the startup and operation of the steam turbine, high-pressure, high-speed steam enters the steam inlet channel through the main steam valve. The airflow is divided into two parts by the leading edge arc surface of the guide rib R1 and enters the regulating valve steam chamber along the guide surface R3. The guide rib cross section is designed with double tail wings, and the tail wing width is designed to be greater than or equal to 1.5 times the valve stem diameter. The regulating valve stem effectively avoids direct impact from the high-speed airflow. The trailing edge arc surface R4 adopts a small curvature design to reduce airflow separation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention;

[0024] Figure 2 This is a cross-sectional view of the middle section of the guide rib;

[0025] In the diagram: 1. Steam inlet passage of the steam turbine, 2. Guide rib, 3. Regulating valve stem, 4. Regulating valve chamber, 5. Airflow outlet. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0027] Specific implementation method one: Combining Figure 1 and Figure 2This embodiment describes an anti-impact valve stem steam inlet guide rib structure, comprising a steam turbine inlet passage 1, a regulating valve stem 3, and a regulating valve chamber 4. The steam turbine inlet passage 1 and the regulating valve chamber 4 are fixedly connected and are horizontally arranged together at the cylinder head. The regulating valve stem 3 is installed inside the regulating valve chamber 4. High-pressure, high-speed steam enters the steam turbine inlet passage 1 through the main steam valve. The steam turbine inlet passage 1 has longitudinally arranged guide ribs 2 with equal cross-sections. The guide ribs 2 are located at the longitudinal centerline of the steam turbine inlet passage 1. The guide ribs 2 divide the steam turbine inlet passage 1 into two symmetrical airflow ports 5. The steam turbine inlet passage 1 and the guide ribs 2 are integrally connected.

[0028] The top of the guide rib 2 is integrally connected to the top wall of the inner tube of the turbine inlet passage 1, and the top of the guide rib 2 is integrally connected to the bottom wall of the inner tube of the turbine inlet passage 1. The middle part of the guide rib 2 is a streamlined guide rib with double tail fins. The guide rib 2 prevents the airflow in the turbine inlet passage 1 from directly impacting the regulating valve stem 3 in the regulating valve chamber 4.

[0029] This effectively prevents direct airflow impact on the regulating valve stem 3. The streamlined cross-section of the guide rib 2 extends longitudinally through the turbine inlet passage 1, effectively strengthening its rigidity. This prevents the regulating valve stem 3 from direct impact from the inlet steam, thus avoiding deformation and cracking, and preventing vibration of the regulating valve stem 3 caused by airflow, ensuring the stability and safety of the turbine, even under continuous long-term turbine operation.

[0030] The turbine inlet passage 1 and the regulating valve chamber 4 are arranged horizontally together at the cylinder head, and the main steam valve is connected at the vertical flange.

[0031] The guide ribs are streamlined guide ribs with built-in double tail fins, arranged longitudinally with equal cross-sections between the steam turbine inlet passage 1 and the regulating valve chamber 4.

[0032] Specific Implementation Method Two: Combining Figure 1 and Figure 2 This embodiment describes an anti-impact valve stem steam inlet guide rib structure. The streamlined guide rib portion of the double tail fin in the middle of the guide rib 2 has an R1 leading edge arc surface, an R2 arc-shaped tail fin surface, an R3 guide surface, and an R4 tail edge arc surface.

[0033] The leading edge arc surface of R1 and the guide surface of R3 form the airflow intake arc surface in the steam turbine intake channel 1.

[0034] The present invention provides a design method for adding guide ribs to the steam inlet channel 1 of a steam turbine. The guide ribs are designed and arranged on the same axis as the regulating valve stem 3. The streamlined head design ensures smooth airflow, and the width of the tail fin of the guide rib is required to cover the diameter of the regulating valve stem 3. The guide ribs are arranged longitudinally along the steam inlet channel 1 of the steam turbine to ensure that the regulating valve stem 3 avoids direct impact from the incoming steam in both the radial and vertical directions.

[0035] Specific implementation method three: Combining Figure 1 and Figure 2 This embodiment describes an anti-impact valve stem steam inlet guide rib structure, wherein the R1 leading edge arc surface of the guide rib 2 is disposed at the steam inlet of the steam turbine steam inlet channel 1;

[0036] During turbine startup and operation, high-pressure, high-speed steam enters the turbine inlet passage 1 through the main steam valve. As it passes through the leading edge arc surface R1 of the guide rib 2, the airflow splits into two parts.

[0037] Specific implementation method four: Combination Figure 1 and Figure 2 This embodiment describes an anti-impact valve stem steam inlet guide rib structure. The R3 guide surface of the guide rib 2 guides the airflow from the turbine steam inlet passage 1 into the regulating valve steam chamber 4 along the R3 guide surface.

[0038] During turbine startup and operation, high-pressure, high-speed steam enters the turbine inlet passage 1 through the main steam valve, and the airflow enters the regulating valve chamber 4 along the guide surface R3.

[0039] Specific Implementation Method Five: Combining Figure 1 and Figure 2 This embodiment describes an anti-impact valve stem inlet guide rib structure. The R2 arc-shaped tail fin surface and the R4 tail edge arc surface of the guide rib 2 are integrally formed to form a tail arc surface, so that the tail edge portion formed by the R2 arc-shaped tail fin surface and the R4 tail edge arc surface has a small curvature structure, which reduces airflow separation.

[0040] During turbine startup and operation, high-pressure, high-speed steam enters turbine inlet passage 1 through main steam valve. The small curvature design of the arc-shaped tail fin and the R4 trailing edge arc surface reduces airflow separation.

[0041] Specific Implementation Method Six: Combination Figure 1 and Figure 2 This embodiment describes an anti-impact valve stem steam inlet guide rib structure, wherein the regulating valve stem 3 is installed in the regulating valve steam chamber 4, and the regulating valve stem 3 and the guide rib 2 are arranged on the same axis.

[0042] The width of the tail fin of the guide rib 2 covers the diameter of the valve stem 6 and is arranged longitudinally along the steam inlet passage 1 of the turbine, so that the guide rib 2 covers the valve stem 3 of the regulating valve.

[0043] Specific implementation method seven: Combining Figure 1 and Figure 2 This embodiment describes an anti-impact valve stem inlet guide rib structure. The longitudinal section of the guide rib 2 is a double tail wing structure, and the width of the tail wing is greater than or equal to 1.5 times the diameter of the regulating valve stem 3, so that the regulating valve stem 3 avoids direct impact from the high-pressure and high-speed airflow entering the regulating valve steam chamber 4.

[0044] The addition of the guide rib 2 in this invention effectively prevents the steam inlet from directly impacting the regulating valve stem 3, thus resolving the potential risks of vibration, deformation, and cracking of the regulating valve stem 3 caused by airflow impact. This improves the stability and reliability of the steam turbine under long-term operation.

[0045] Specific implementation method eight: Combination Figure 1 and Figure 2 This embodiment describes an anti-impact valve stem steam inlet guide rib structure, wherein the steam turbine steam inlet channel 1 is a tubular structure, and the inner diameter length of the steam turbine steam inlet channel 1 is the same as the overall length of the guide rib 2.

[0046] This invention employs a method of installing built-in streamlined guide ribs 2 inside the steam inlet channel 1 of a steam turbine. The cross-section of the guide ribs 2 is often arranged longitudinally with a double-tail streamlined cross-section, which effectively enhances the rigidity of the steam inlet channel, achieving two goals at once. It also features simple structure, easy implementation, and does not occupy external space of the steam turbine.

[0047] Specific Implementation Method Nine: Combining Figure 1 and Figure 2 This embodiment describes an anti-impact valve stem steam inlet guide rib structure, wherein the steam inlet portion of the steam turbine steam inlet channel 1 and the guide rib 2 are integrally cast structures.

[0048] This invention adopts a relatively simple built-in structure, which is integrally cast with the steam inlet of the cylinder. Its service life is basically the same as that of the cylinder, ensuring that it remains effective throughout the life cycle of the steam turbine. There is no operational risk here.

[0049] Design the required cross-sectional area of ​​the steam turbine inlet passage 1 based on steam parameters and flow velocity;

[0050] Based on the relative position of the steam turbine inlet passage 1 and the regulating valve, as well as the diameter and length of the regulating valve stem 3, the steam flow state is analyzed.

[0051] Based on the above calculation and analysis results, guide ribs 2 are set at the corresponding positions of the steam turbine inlet channel 1, and the cross-sectional profile is designed to change the steam inlet flow trajectory to prevent the airflow from directly regulating the valve stem 3.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A steam inlet guide rib structure for an anti-impact valve stem, comprising a steam turbine inlet passage (1), a regulating valve stem (3), and a regulating valve chamber (4), wherein the steam turbine inlet passage (1) is fixedly connected to the regulating valve chamber (4), and the steam turbine inlet passage (1) and the regulating valve chamber (4) are horizontally arranged together at the cylinder head, the regulating valve stem (3) is installed in the regulating valve chamber (4), and high-pressure, high-speed steam enters the steam turbine inlet passage (1) through the main steam valve, characterized in that, The turbine inlet passage (1) has longitudinally arranged guide ribs (2) with equal cross-section. The guide ribs (2) are located at the longitudinal centerline of the turbine inlet passage (1). The guide ribs (2) in the turbine inlet passage (1) divide the turbine inlet passage (1) into two symmetrical airflow ports (5). The turbine inlet passage (1) and the guide ribs (2) are integrally connected. The top of the guide rib (2) is integrally connected to the top wall of the inner tube of the steam turbine inlet passage (1), and the top of the guide rib (2) is integrally connected to the bottom wall of the inner tube of the steam turbine inlet passage (1). The middle part of the guide rib (2) is a streamlined guide rib with double tail wings. The guide rib (2) prevents the airflow in the steam turbine inlet passage (1) from directly impacting the regulating valve stem (3) in the regulating valve chamber (4). The streamlined guide rib of the double tail fin in the middle of the guide rib (2) has an R1 leading edge arc surface, an R2 arc tail fin surface, an R3 guide surface and an R4 trailing edge arc surface; The leading edge arc surface of R1 and the guide surface of R3 form the airflow intake arc surface in the steam turbine intake channel (1); The R2 arc-shaped tail fin surface and the R4 trailing edge arc surface of the guide rib (2) are integrally formed to form the tail arc surface, so that the trailing edge part formed by the R2 arc-shaped tail fin surface and the R4 trailing edge arc surface passes through a small curvature structure, reducing airflow separation.

2. The steam inlet guide rib structure of the anti-impact valve stem according to claim 1, characterized in that, The R1 leading edge arc surface of the guide rib (2) is set at the steam inlet of the steam turbine inlet channel (1), and the airflow is divided into two parts when passing through the R1 leading edge arc surface of the guide rib (2).

3. The steam inlet guide rib structure of the anti-impact valve stem according to claim 2, characterized in that, The R3 guide surface of the guide rib (2) guides the airflow of the turbine inlet passage (1) into the regulating valve chamber (4) along the R3 guide surface.

4. The steam inlet guide rib structure of the anti-impact valve stem according to claim 1, characterized in that, The regulating valve stem (3) is installed in the regulating valve steam chamber (4), and the regulating valve stem (3) and the guide rib (2) are arranged on the same axis; The width of the tail fin of the guide rib (2) covers the diameter of the valve stem (6) and is arranged longitudinally along the steam turbine inlet passage (1) so that the guide rib (2) covers the regulating valve stem (3).

5. The steam inlet guide rib structure of the anti-impact valve stem according to claim 4, characterized in that, The longitudinal section of the guide rib (2) is a double tail wing structure, and the width of the tail wing is greater than or equal to 1.5 times the diameter of the regulating valve stem (3), so that the regulating valve stem (3) avoids direct impact from the high-pressure and high-speed airflow entering the regulating valve steam chamber (4).

6. The steam inlet guide rib structure of the anti-impact valve stem according to claim 4, characterized in that, The steam turbine inlet passage (1) has a tubular structure, and the inner diameter of the steam turbine inlet passage (1) is the same as the overall length of the guide rib (2).

7. The steam inlet guide rib structure of the anti-impact valve stem according to claim 6, characterized in that, The steam inlet section of the steam turbine inlet channel (1) and the guide rib (2) are integrally cast structures.

Images