Steam extraction quick-closing non-return system for steam turbine

Abstract

A steam extraction quick-closing check system for a steam turbine comprises a hydraulic mechanism and a steam valve body which are sequentially connected with a check valve in series, and further comprises a hydraulic valve connected with the hydraulic mechanism. By means of reasonable arrangement of component structures and switching of a pressure oil way through the hydraulic valve, the function of rapidly closing the check valve is achieved, the check valve can be rapidly closed smaller than 0.5 S, meanwhile, the production cost is reduced, a steam turbine is rapidly separated, and the steam turbine or a steam extraction system is protected.

Description

Technical Field

[0001] The utility model belongs to the technical field of steam turbines, and in particular relates to a steam extraction fast-closing and non-return system for steam turbines. Background Art

[0002] The extraction quick-closing check valve is used in the extraction system of power plants or thermal power plants, or in the steam and water and other non-corrosive media pipelines of other systems to prevent the sudden drop in the pressure inside the turbine when the turbine unit is suddenly unloaded, and the steam in the extraction pipe flows back into the turbine, causing the turbine blades to be broken and the turbine generator to be damaged, so as to protect the safe operation of the turbine.

[0003] Existing quick-closing check valves for steam extraction open when pressurized oil is introduced into the lower cylinder. When the oil is shut off, the valve closes due to the spring force that overcomes the buoyancy of the steam. Due to the interaction between the buoyancy of the steam, the pressure generated by the pressurized oil, and the spring force, achieving rapid and complete closure with this type of quick-closing check valve requires a larger spring and a larger hydraulic cylinder, which is costly. Summary of the Invention

[0004] In view of the above problems, the purpose of the present invention is to provide a steam extraction fast closing and check system for a steam turbine, which solves the fast closing and cost problems of existing valves by rationally arranging the component structure.

[0005] To achieve the above-mentioned purpose, the technical solutions adopted by the present invention include:

[0006] A steam extraction quick-closing check system for a steam turbine comprises a check valve, a hydraulic mechanism and a steam valve body connected in series, and also comprises a hydraulic valve connected to the hydraulic mechanism.

[0007] Preferably, the hydraulic mechanism includes a coaxially arranged hydraulic cylinder, a piston, a valve stem and a spring. The piston is located in the hydraulic cylinder and divides the hydraulic cylinder into an S chamber and an X chamber. The valve stem is passed through the hydraulic cylinder and is connected to the piston, and both ends of the valve stem are respectively connected to the steam valve body and the check valve. The spring is sleeved on the extension section of the valve stem close to the check valve; the B port of the hydraulic valve is connected to the X chamber, and the A port of the hydraulic valve is connected to the S chamber.

[0008] Preferably, two oil circuits are connected between the A port of the hydraulic valve and the S chamber, and an unloading valve is provided on one of the oil circuits.

[0009] Compared with the prior art, the advantages of the present invention are:

[0010] The utility model discloses a steam turbine extraction quick-closing check valve system. By rationally arranging the component structure, the hydraulic valve switches the pressure oil circuit to achieve the effect of quickly closing the check valve, so that the check valve can be quickly closed in less than 0.5 seconds, while reducing production costs, quickly isolating the steam turbine, and protecting the steam turbine or the steam extraction system. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0012] Figure 1 This is a schematic diagram of the startup state of the steam extraction quick-closing and check system for the steam turbine of the present utility model;

[0013] Figure 2 This is a schematic diagram of the quick-closing state of the steam turbine extraction quick-closing and check system of the utility model;

[0014] The numbers in the figure represent:

[0015] 0-check valve, 1-steam valve body; 2-hydraulic mechanism, 200-hydraulic cylinder, 201-piston, 202-valve stem, 203-spring; 4-unloading valve; 5-hydraulic valve. DETAILED DESCRIPTION

[0016] The utility model is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the utility model.

[0017] It should be noted that the directional terms mentioned in this article are consistent with the specific directions on the paper in the drawings of the specification or the corresponding directions in the space shown in the drawings; all components and equipment in this utility model, unless otherwise specified, are all components and equipment known in the prior art.

[0018] Example

[0019] This embodiment discloses a steam extraction quick-closing check valve system for a steam turbine, comprising a check valve 0, a hydraulic mechanism 2, and a steam valve body 1 connected in series, and also comprising a hydraulic valve 5 connected to the hydraulic mechanism;

[0020] Its function is to switch the pressure oil circuit through the hydraulic valve to quickly close the check valve 0, so that the check valve can be quickly closed in less than 0.5S, while reducing production costs, quickly isolating the turbine, and protecting the turbine or steam extraction system.

[0021] The hydraulic mechanism 2 disclosed in this embodiment includes a coaxially arranged hydraulic cylinder 20000, a piston 201, a valve stem 202 and a spring 203. The piston 201 is located in the hydraulic cylinder 20000 and divides the hydraulic cylinder 20000 into an S chamber and an X chamber. The valve stem 202 is inserted into the hydraulic cylinder 20000 and is connected to the piston 201. The two ends of the valve stem 202 are respectively connected to the steam valve body 1 and the check valve 0. The spring 203 is sleeved on the extension section of the valve stem 202 close to the check valve 0; the hydraulic valve 5B port is connected to the X chamber, and the hydraulic valve 5A port is connected to the S chamber; two oil circuits are connected between the hydraulic valve 5A port and the S chamber, and an unloading valve 4 is provided on one of the oil circuits.

[0022] The principle of the opening process of the extraction steam quick-closing check valve in this embodiment is as follows:

[0023] like Figure 1 As shown, under normal operating conditions, the quick-closing oil is introduced and the hydraulic valve 5 oil circuit is switched to Figure 1 In the valve position shown, pressurized oil flows through the PB line of hydraulic valve 5 into the X chamber of hydraulic cylinder 200. This pressure acts on piston 201, generating an upward force P1. The pressure in the S chamber of hydraulic cylinder 200 is unloaded via the unloading valve 4 and the AT line of hydraulic valve 5. This pressure acts on piston 201, generating a downward force P2 = 0. Simultaneously, spring 3 generates a downward spring force P3. The upward force P1 generated by the pressure in the X chamber of hydraulic cylinder 200 and the buoyancy P4 generated in the steam valve body 1 work together to overcome the spring force P3. Piston 201 in hydraulic cylinder 200 drives valve stem 202 upward, opening the valve pointer to the travel switch position H, thus opening check valve 0.

[0024] The principle of the quick closing process of the extraction steam quick closing check valve in this embodiment is as follows:

[0025] When the steam turbine does not need to extract steam, remove the quick-closing oil and switch the hydraulic valve 5 oil circuit to Figure 2 In the valve position shown, pressurized oil flows through the PA line of hydraulic valve 5 into the S chamber of hydraulic cylinder 200. This pressure acts on piston 201, generating a downward force P2. The pressure in the X chamber of hydraulic cylinder 200 is unloaded via the unloading valve 4 and the BT line of hydraulic valve 5. This pressure acts on piston 201, generating an upward force P1 = 0. Simultaneously, spring 3 generates a downward spring force P3. The downward force P2 generated by the pressurized oil in the S chamber of hydraulic cylinder 200 and the spring force P3 overcome the buoyancy P4 generated by the steam in valve body 1. The valve stem 202 in hydraulic cylinder 200 drives piston 201 downward, rapidly closing the indicator to the travel switch position L, effectively closing the check valve 0.

[0026] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0027] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0028] In addition, the various different implementation methods disclosed in this solution can also be arbitrarily combined, as long as they do not violate the ideas of this disclosure, they should also be regarded as the contents of the invention of this disclosure.

Claims

1. A steam turbine extraction quick-close check system, characterized in that: The invention comprises a check valve (0), a hydraulic mechanism (2) and a steam valve body (1) which are sequentially connected in series, and also comprises a hydraulic valve (5) connected to the hydraulic mechanism (2).

2. The steam turbine extraction quick-closing check system according to claim 1, characterized in that: The hydraulic mechanism (2) comprises a coaxially arranged hydraulic cylinder (200), a piston (201), a valve stem (202) and a spring (203); the piston (201) is located in the hydraulic cylinder (200) and divides the hydraulic cylinder (200) into an S chamber and an X chamber; the valve stem (202) is inserted into the hydraulic cylinder (200) and connected to the piston (201); and both ends of the valve stem (202) are respectively connected to the steam valve body (1) and the check valve (0); and the spring (203) is sleeved on an extension section of the valve stem (202) close to the check valve (0); The B port of the hydraulic valve (5) is connected to the X cavity, and the A port of the hydraulic valve (5) is connected to the S cavity.

3. The steam turbine extraction quick-close check system according to any one of claims 1 or 2, characterized in that: Two oil circuits are connected between the A port of the hydraulic valve (5) and the S chamber, and an unloading valve (4) is provided on one of the oil circuits.

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