Supercritical steam turbine reheating main control valve shell

Abstract

The utility model provides a supercritical steam turbine reheating main control valve casing which comprises a valve casing, an inner valve cover, a valve rod and a lining, the inner valve cover is arranged in the valve casing, a center hole is formed in the inner valve cover, the lining fixedly connected with the center hole is arranged in the center hole, the valve rod is inserted in the lining inner hole and connected with the lining inner hole in a sliding mode, and the valve cover is arranged in the valve casing. And a graphene coating is arranged on the inner side wall of the lining. The graphene coating is arranged on the inner side wall of the lining, the sealing performance and corrosion resistance of the valve are improved, the abrasion resistance of the lining and the valve rod is improved, the service life of the valve and valve shell parts can be effectively prolonged, and the use cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of supercritical steam turbine valves, in particular to a reheat main control valve housing of a supercritical steam turbine. Background Technique

[0002] At present, the main power generation methods in various countries in the world are thermal power generation, hydropower generation and nuclear power generation. Among them, thermal power generation accounts for more than 70% of the total power generation, occupying a large share. However, with the aggravation of the global greenhouse effect, the society pays increasing attention to environmental problems, and requires power plants to reduce the emissions of carbon dioxide, nitrogen oxides, sulfur dioxide, etc. to meet strict environmental protection requirements. In addition, the increasing shortage of fossil fuels such as coal makes it an urgent problem for power plants to further improve the coal-fired power generation efficiency.

[0003] The key to solving these problems is to develop clean coal power generation technology. One is to use high-efficiency power generation technology with clean emissions, such as using gas turbine units; the other is to improve the steam parameters and thermal efficiency of the units, that is, supercriticalization. Supercritical steam turbines are core equipment in the fields of power generation and drive, known as the pearls of the equipment manufacturing industry, and have excellent thermal performance, high reliability, high efficiency and high stability.

[0004] The development of domestic supercritical steam turbine units started relatively late. Since the late 1980s, 300MW and 600MW subcritical units have been introduced from abroad, and the first supercritical unit was put into operation at Shanghai Shidongkou No. 2 Power Plant in 1992. It took nearly 20 years for domestic to fully digest and absorb. It only took three years for domestic supercritical power generation technology to develop from research and development to commercial operation. This leapfrog development is exactly the inevitable result of the common progress and development of the power generation industry and the power station equipment manufacturing industry. With the research and development and application of supercritical coal-fired power generation technology, the overall level of China's power generation industry and power station equipment manufacturing industry has reached a new level.

[0005] Traditional valve parts mostly adopt integral stainless steel or alloy steel materials, but extremely high requirements are imposed on the valve sealing part. The sealing surface requires relatively high hardness, corrosion resistance and wear resistance. However, after the unit runs for a long time, the wear resistance and hardness of stainless steel and alloy steel cannot meet the sealing requirements, affecting the sealing performance and service life of the valve. Content of the Utility Model

[0006] The utility model aims to provide a reheat main control valve housing of a supercritical steam turbine to overcome the deficiencies existing in the prior art.

[0007] To solve the above technical problems, the technical solution of the present utility model is: a reheat main control valve housing of a supercritical steam turbine, including a valve housing, an inner valve cover, a valve rod, and a bushing. An inner valve cover is provided inside the valve housing. A central hole is provided inside the inner valve cover. A bushing fixedly connected thereto is provided in the central hole. The valve rod is inserted into the inner hole of the bushing and is slidably connected to the inner hole of the bushing. And a graphene coating is provided on the inner side wall of the bushing.

[0008] Further, for the reheat main control valve housing of the above-mentioned supercritical steam turbine, a threaded ring threadedly connected thereto is further provided inside the valve housing. The threaded ring abuts against the end of one end of the inner valve cover. And a step is provided on the outer side of the inner valve cover. The step abuts against the stepped surface inside the valve housing. The inner valve cover is restricted from axial displacement through the cooperation of the threaded ring and the step.

[0009] Further, for the reheat main control valve housing of the above-mentioned supercritical steam turbine, an outer valve cover is further provided at the end of one side of the valve housing. The outer valve cover is fixed to the end of the valve housing through fasteners. The threaded ring is located between the outer valve cover and the inner valve cover.

[0010] Further, for the reheat main control valve housing of the above-mentioned supercritical steam turbine, the bushing is a combined component, including an outer bushing, a middle bushing, and an inner bushing arranged in sequence from outside to inside. And a plurality of the middle bushings are provided, located between the outer bushing and the inner bushing, and arranged axially along the bushing.

[0011] Further, for the reheat main control valve housing of the above-mentioned supercritical steam turbine, the outer bushing is provided at the end of one end of the inner valve cover. One end of it is inserted into the central hole of the inner valve cover. The other end is provided with a flange plate protruding from the central hole and abutting against the end of the inner valve cover. The outer bushing is fixedly connected to the inner valve cover through fasteners provided on the flange plate.

[0012] Further, for the reheat main control valve housing of the above-mentioned supercritical steam turbine, a locking ring abutting against it is provided at the inner side end of the inner bushing. The locking ring is threadedly connected to the inner valve cover.

[0013] Further, for the reheat main control valve housing of the above-mentioned supercritical steam turbine, a temperature measuring hole is further provided on the outer side of the valve housing.

[0014] Further, for the reheat main control valve housing of the above-mentioned supercritical steam turbine, the valve rod is made of a high-temperature alloy.

[0015] Compared with the prior art, the beneficial effects of the present utility model are: a graphene coating is provided on the inner side wall of the bushing of the present utility model, that is, a graphene coating is formed on the valve sealing surface, which improves the sealing performance and corrosion resistance of the valve, improves the wear resistance between the bushing and the valve rod, can reduce the leakage of the valve, and can effectively improve the service life of the valve and valve housing parts and reduce the use cost. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of the reheat main regulating valve housing of the supercritical steam turbine of the present invention;

[0018] Figure 2 is Figure 1 a partial enlarged schematic diagram of A in

[0019] In the figure: 1. Valve housing; 2. Inner valve cover; 21. Step; 3. Valve stem; 4. Bushing; 41. Outer bushing; 42. Middle bushing; 43. Inner bushing; 5. Graphene coating; 6. Threaded ring; 7. Outer valve cover; 8. Locking ring; 9. Temperature measuring hole; 10. Valve seat. Detailed implementation manners

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0021] Embodiment 1

[0022] As Figure 1 , 2 shown, a reheat main regulating valve housing of a supercritical steam turbine includes a valve housing 1, an inner valve cover 2, a valve stem 3, and a bushing 4. An inner valve cover 2 is provided inside the valve housing 1. A central hole is provided inside the inner valve cover 2. A bushing 4 fixedly connected thereto is provided in the central hole. The valve stem 3 is inserted into the inner hole of the bushing 4 and is slidably connected to the inner hole of the bushing 4. And a graphene coating 5 is provided on the inner side wall of the bushing 4. In addition, a valve seat 10 is further provided inside one end of the valve housing 1 that is in steam communication. The flow rate of the valve can be controlled by adjusting the distance between the valve stem 3 and the valve seat 10.

[0023] Graphene coating is an allotrope of carbon and is one of the materials with the highest known strength. At the same time, the fracture strength of graphene reaches 130 GPa, which is hundreds of times higher than that of steel, and has excellent combined properties such as high hardness, high temperature resistance, and corrosion resistance, and can significantly improve the wear resistance and scratch resistance of materials.

[0024] The supercritical steam turbine bears pressures far exceeding those of other types of steam turbines and steam at temperatures above 600 °C. A graphene coating is provided on the inner side wall of the bushing 4, that is, a graphene coating 5 is formed on the valve sealing surface, which can improve the sealing performance and corrosion resistance of the valve, enhance the wear resistance between the bushing and the valve stem, reduce the leakage of the valve, effectively extend the service life of valve and valve housing parts, and reduce the use cost.

[0025] In the above structure, as Figure 1 , 2 shown, the bushing 4 is a composite component, including an outer bushing 41, a middle bushing 42, and an inner bushing 43 arranged in sequence from outside to inside. A plurality of middle bushings 42 are provided between the outer bushing 41 and the inner bushing 43 and are arranged axially along the bushing 4. The number of middle bushings 42 is set according to the actual situation. In this embodiment, 3 middle bushings 42 are provided. Setting the bushing 4 as a composite component not only facilitates processing and can reduce the manufacturing cost, but also when local wear of graphene occurs, only the local part needs to be replaced, which is convenient for maintenance and saves costs.

[0026] Among them, as Figure 1 shown, the outer bushing 41 is provided at one end of the inner valve cover 2. One end of it is inserted into the central hole of the inner valve cover 2, and the other end is provided with a flange plate protruding from the central hole and abutting against the end of the inner valve cover 2. The outer bushing 41 is fixedly connected to the inner valve cover 2 through fasteners provided on the flange plate. In addition, a locking ring 8 is provided at the inner side end of the inner bushing 43 and abuts against it. The locking ring 8 is threadedly connected to the inner valve cover 2. The outer bushing 41 is completely fixed through the fixed connection of the flange plate to the valve housing 1, and one axial end of the bushing 4 is restricted. Then, the other end of the bushing 4 is positioned through the locking ring 8, so that the middle bushing 42 located between the outer bushing 41 and the inner bushing 43 is completely fixed. The installation is simple and the replacement and maintenance are convenient.

[0027] Embodiment 2

[0028] Based on the structure of Embodiment 1, as Figure 1 shown, a threaded ring 6 threadedly connected to it is further provided in the valve housing 1. The threaded ring 6 abuts against one end of the inner valve cover 2. A step 21 is provided on the outer side of the inner valve cover 2, and the step 21 abuts against the step surface inside the valve housing 1. The inner valve cover 2 restricts the axial displacement through the cooperation of the threaded ring 6 and the step 21. In addition, an outer valve cover 7 is provided at one end of the valve housing 1. The outer valve cover 7 is fixed to the end of the valve housing 1 through fasteners. The threaded ring 6 is located between the outer valve cover 7 and the inner valve cover 2. The opening diameter of the end of the supercritical steam turbine valve housing where the outer valve cover is installed is 1 - 2 meters. The setting of this double valve cover can minimize steam loss and improve the thermal efficiency of the steam turbine unit.

[0029] In addition, as Figure 1As shown, a temperature measuring hole 9 is also provided on the outer side of the valve housing, which is convenient for monitoring the temperature inside the valve housing.

[0030] In addition, the valve stem 3 is made of a high-temperature alloy, such as NiCr20Ti, which has good high-temperature strength and corrosion resistance, improves the wear resistance of the valve stem, and thus reduces the leakage of the valve.

[0031] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above-described exemplary embodiments, and the present utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present utility model. Any reference signs in the claims should not be construed as limiting the claimed rights.

[0032] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A reheat main control valve housing for a supercritical steam turbine, characterized in that: It includes a valve housing, an inner valve cover, a valve stem, and a bushing. An inner valve cover is provided inside the valve housing. A central hole is provided inside the inner valve cover. A bushing fixedly connected thereto is provided in the central hole. The valve stem is inserted into the inner hole of the bushing and is slidably connected to the inner hole of the bushing. And a graphene coating is provided on the inner side wall of the bushing.

2. The reheat main control valve housing of the supercritical steam turbine according to claim 1, wherein: A threaded ring threadedly connected to the valve housing is further provided inside the valve housing. The threaded ring abuts against the end of one end of the inner valve cover. And a step is provided on the outer side of the inner valve cover. The step abuts against the step surface inside the valve housing. The axial displacement of the inner valve cover is restricted by the cooperation of the threaded ring and the step.

3. The reheat main control valve housing of the supercritical steam turbine according to claim 2, characterized in that: An outer valve cover is further provided at the end of one side of the valve housing. The outer valve cover is fixed to the end of the valve housing by fasteners. The threaded ring is located between the outer valve cover and the inner valve cover.

4. The reheat main control valve housing of the supercritical steam turbine according to claim 1, characterized in that: The bushing is a composite part, including an outer bushing, a middle bushing, and an inner bushing arranged in sequence from outside to inside. And a plurality of middle bushings are provided, located between the outer bushing and the inner bushing, and arranged axially along the bushing.

5. The reheat main control valve housing of the supercritical steam turbine according to claim 4, characterized in that: The outer bushing is provided at the end of one end of the inner valve cover. One end of it is inserted into the central hole of the inner valve cover. The other end is provided with a flange plate protruding from the central hole and abutting against the end of the inner valve cover. The outer bushing is fixedly connected to the inner valve cover by fasteners provided on the flange plate.

6. The reheat main control valve housing of the supercritical steam turbine according to claim 5, characterized in that: A locking ring abutting against it is provided at the inner side end of the inner bushing. The locking ring is threadedly connected to the inner valve cover.

7. The reheat main control valve housing of the supercritical steam turbine according to claim 1, wherein: A temperature measuring hole is further provided on the outer side of the valve housing.

8. The reheat main control valve housing of the supercritical steam turbine according to claim 1, characterized in that: The valve stem is made of a superalloy.

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