Medium-pressure main steam adjusting combined valve with fine adjusting function

Abstract

The invention discloses a medium-pressure main steam adjusting combined valve with a fine adjusting function, relates to a medium-pressure main steam adjusting combined valve of a steam turbine, and aims to solve the problems that when the steam extraction amount in front of a reheat valve is too large, the reheat steam pressure is reduced, and the heat supply steam extraction is lower than the pressure required by a user. One ends of two fine adjustment valves are simultaneously communicated with one end of a medium-pressure main steam valve through a first valve body, and the other end of the medium-pressure main steam valve is used for introducing reheated steam; the other ends of the two fine adjustment valves are respectively communicated with a first joint and a second joint of a three-way joint, and a third joint of the three-way joint is used for discharging reheated steam to a steam turbine; the first butterfly valve is arranged on a cavity channel of the fine adjustment valve; the fine adjustment valve is used for adjusting the reheat steam output of the fine adjustment valve; the second butterfly valve is arranged on a cavity channel of the medium-pressure main steam valve; the second butterfly valve is used for adjusting the steam inlet amount of the medium-pressure main steam valve. The device has the beneficial effects that the steam inlet amount and the upstream steam pressure can be accurately adjusted.

Description

Technical Field

[0001] The invention relates to a medium-pressure main steam regulating valve for a steam turbine. Background Art

[0002] With the development of economy and technology, the power industry has responded to the national requirements of energy conservation and environmental protection. The demand for high-parameter industrial steam extraction of large-power steam turbines in thermal power plants has become more and more diversified. In recent years, more and more industrial steam extractions are installed before the medium-pressure valve. The steam extraction volume before the medium-pressure main steam valve is large, the boiler pressure will be reduced, and the extraction pressure cannot be guaranteed. In this state, the medium-pressure main steam regulating combined valve needs to be adjusted to ensure the extraction pressure. The existing medium-pressure main steam regulating combined valve cannot achieve this function. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that when the extraction steam volume before the reheat valve is too large, the reheat steam pressure drops and the heating extraction steam is lower than the user's required pressure. A medium-pressure main steam regulating combined valve with fine adjustment function is proposed.

[0004] The medium-pressure main steam regulating combined valve with fine-tuning function described in the present invention comprises two fine-tuning regulating valves, a medium-pressure main steam valve, a first valve body, a three-way joint, a first butterfly valve and a second butterfly valve;

[0005] One end of the two fine adjustment valves is simultaneously connected to one end of the medium-pressure main steam valve through the first valve body, and the other end of the medium-pressure main steam valve is used to pass reheat steam;

[0006] The other ends of the two fine adjustment valves are respectively connected to the first joint and the second joint of the three-way joint, and the third joint of the three-way joint is used to introduce the reheated steam into the steam turbine;

[0007] The first butterfly valve is arranged on the chamber passage of the fine-adjusting regulating valve; the first butterfly valve is used to adjust the reheat steam outlet of the fine-adjusting regulating valve;

[0008] The second butterfly valve is arranged on the chamber passage of the medium-pressure main steam valve; the second butterfly valve is used to shut down the steam turbine in an emergency.

[0009] Furthermore, the combined valve also includes an elastic bracket;

[0010] There are three elastic supports, one of which is supported on the bottom of the medium-pressure main steam valve; and the other two elastic supports are supported on the sides of two fine-tuning regulating valves respectively.

[0011] Further, the fine adjustment regulating valve comprises a valve stem steam leakage pipe, a first valve stem, a first valve cover, a first sleeve, a second threaded ring and a second sleeve;

[0012] The first valve cover is arranged on the first valve body, and the first valve cover and the first valve body form an "L"-shaped chamber channel with steam entering axially of the valve body and exhausting steam in radial direction of the valve body; the outer end of the axial steam inlet channel of the valve body serves as the steam inlet of the chamber channel of the fine adjustment valve; the lowermost end of the radial steam exhaust channel of the valve body serves as the steam outlet of the chamber channel of the fine adjustment valve; the steam outlet of the chamber channel of the fine adjustment valve is used to communicate with the first joint or the second joint of the three-way joint;

[0013] The second sleeve is cylindrical; and the second sleeve vertically covers the chamber channel interface of the "L"-shaped chamber channel valve body for radial exhaust of steam;

[0014] The first valve disc is located inside the second sleeve;

[0015] The bottom end of the first valve stem is arranged in the first valve disc, and the first valve stem and the first valve disc are fixed by a second threaded ring; as the first valve stem rises, the first valve stem drives the first butterfly valve to rise at the same time, thereby increasing the steam inlet area of ​​the second sleeve, and the steam inlet amount of the fine adjustment valve increases accordingly;

[0016] The top end of the first valve stem passes through the first valve cover;

[0017] The first sleeve is interference-fitted with the first valve cover, and a steam leakage port is provided on the outer periphery of the first sleeve;

[0018] One end of the valve stem steam leakage pipe is connected to the steam leakage port, and the other end of the valve stem steam leakage pipe is connected to the external leakage steam collection.

[0019] Further, the fine adjustment regulating valve further comprises a first threaded ring;

[0020] The first sleeve is fixed to the first valve cover by a first threaded ring.

[0021] Further, the medium-pressure main steam valve includes a connecting pipeline, a pipeline control valve, a second valve cover, a fixing nut, a rocker arm, a second valve stem and a second valve body;

[0022] The first valve cover is arranged on the second valve body, and the first valve cover and the second valve body form a "Y"-shaped chamber channel; the "Y"-shaped chamber channel includes a steam inlet channel and two steam outlet channels; the outermost end of the steam inlet channel serves as the steam inlet of the medium-pressure main steam valve chamber channel, and the outermost ends of the two steam outlet channels serve as the two steam inlets of the medium-pressure main steam valve chamber channel, wherein the two steam outlet channels are respectively connected with the inlets of the two fine-adjusting regulating valve chamber channels through the first valve body;

[0023] The second butterfly valve is in the shape of a disc, and the second butterfly valve vertically blocks a steam inlet channel of the "Y"-shaped chamber channel; and the second butterfly valve is fixed to the rocker arm by a fixing nut;

[0024] One end of the rocker arm is axially connected to the second valve stem; the second valve stem is rotated to make the rocker arm move in an arc with the second valve stem as the center, so that the second butterfly valve is transformed from a vertical state to a state parallel to the axial direction of the steam inlet channel, and the "Y"-shaped chamber channel is opened;

[0025] The communication pipe is connected between the front and rear chambers of the second butterfly valve;

[0026] The pipeline control valve is arranged on the communicating pipeline.

[0027] Furthermore, a limiting boss is provided on the second valve cover;

[0028] The limiting boss is used to limit the rotation angle of the rocker arm.

[0029] Furthermore, a temperature reduction device is provided on the steam extraction pipeline before the medium-pressure main steam valve.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The combined valve described in the present invention can meet the precise regulation of any steam inlet amount from 0 to full flow of the unit flow, and can accurately adjust the steam inlet amount by changing the opening of the second butterfly valve; the steam pressure before the valve can be accurately adjusted by matching the opening of the first butterfly valve; it is a good solution to the problem that when the steam extraction amount before the reheat valve is too large, the reheat steam pressure drops, and the heating steam extraction pressure is lower than the user's required pressure; and the second butterfly valve is a shut-off valve, located in front of the regulating valve, and is used to cut off the steam entering the turbine in an emergency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A top view of a medium-pressure main steam regulating combined valve with a fine adjustment function as described in the first specific implementation mode;

[0033] Figure 2 for Figure 1 A side view;

[0034] Figure 3 for Figure 1 B-direction lateral view;

[0035] Figure 4 It is a cross-sectional view of the internal structure of the fine adjustment valve in the third specific implementation mode;

[0036] Figure 5 It is an enlarged structural schematic diagram of the interference fit between the first sleeve and the first valve cover in the third specific implementation mode;

[0037] Figure 6 It is a cross-sectional view of the internal structure of the medium-pressure main steam valve in the fifth specific implementation mode.

[0038] Among them, 1 is a fine-tuning regulating valve; 2 is a medium-pressure main steam valve; 3 is a first valve body; 4 is a valve stem steam leakage pipe; 5 is an elastic bracket; 6 is a three-way joint; 7 is a connecting pipeline; 8 is a first valve stem; 9 is a first valve cover; 10 is a first sleeve; 11 is a first threaded ring; 12 is a second threaded ring; 13 is a first valve disc; 14 is a second sleeve; 15 is a pipeline control valve; 16 is a second valve cover; 17 is a fixing nut; 18 is a rocker arm; 19 is a second butterfly valve; 20 is a second valve stem; 21 is a second valve body. DETAILED DESCRIPTION

[0039] Specific implementation method 1. Combination Figures 1 to 3 The present embodiment is described as a medium-pressure main steam regulating combined valve with a fine adjustment function, wherein the combined valve comprises two fine adjustment regulating valves 1, a medium-pressure main steam valve 2, a first valve body 3, a three-way joint 6, a first butterfly valve 14 and a second butterfly valve 19;

[0040] One end of the two fine adjustment valves 1 is simultaneously connected to one end of the medium-pressure main steam valve 2 through the first valve body 3, and the other end of the medium-pressure main steam valve 2 is used to pass reheat steam;

[0041] The other ends of the two fine adjustment valves 1 are respectively connected to the first joint and the second joint of the three-way joint 6, and the third joint of the three-way joint 6 is used to introduce the reheated steam into the steam turbine;

[0042] The first butterfly valve 13 is arranged on the chamber passage of the fine-tuning regulating valve 1; the first butterfly valve 13 is used to adjust the reheat steam outlet of the fine-tuning regulating valve 1; and then realize the function of maintaining the reheat pressure without decreasing;

[0043] The second butterfly valve 19 is arranged on the chamber passage of the medium-pressure main steam valve 2; the second butterfly valve 19 is used to close the medium-pressure main steam valve 2 in an emergency.

[0044] In this embodiment, the reheated steam from the boiler reheater passes through the medium-pressure main steam valve 2, enters the two fine-adjusting regulating valves 1, and after being adjusted, they are connected through the three-way joint 6 and then enter the steam turbine; when the extraction system before the medium-pressure main steam valve 2 is put into operation, the medium-pressure main steam valve 2 is fully opened, and the two fine-adjusting regulating valves 1 match the opening according to the calculated flow rate to achieve the function of extracting steam to keep the reheating pressure from decreasing. After the opening of the first butterfly valve 13 is accurately calculated, it can not only meet the steam inlet regulation during normal operation, but also meet the precise and micro-adjustment during the warm-up, start-up and extraction regulation process; the combined valve can meet the precise regulation of any steam inlet amount from 0 to full flow of the unit flow, and the steam inlet amount can be accurately adjusted by changing the opening of the first butterfly valve; the steam pressure before the valve can be accurately adjusted by the opening of the first butterfly valve; it is very good to solve the problem that when the steam extraction before the reheat valve is too large, the reheat steam pressure drops, and the heating extraction steam is lower than the user's required pressure; and the second butterfly valve is a shut-off valve, located before the regulating valve, used to cut off the steam entering the steam turbine in an emergency.

[0045] Specific implementation method 2: This implementation method further defines the medium-pressure main steam regulating combined valve with fine adjustment function described in specific implementation method 1. In this implementation method, the combined valve further includes an elastic bracket 5;

[0046] There are three elastic supports 5 , one of which is supported on the bottom of the medium-pressure main steam valve 2 ; and the other two elastic supports 5 are supported on the bottoms of two fine-adjusting control valves 1 , respectively.

[0047] In this embodiment, the elastic support 5 is set as three-point support. The three-point elastic support 5 can absorb thermal compensation and thermal displacement of the unit valve under various working conditions, reduce vibration caused by operation and variable working conditions, and adapt to the variable working condition operation of the valve steam extraction.

[0048] Specific implementation method 3: Combination Figures 4 to 5 This embodiment is described. This embodiment further defines a medium-pressure main steam regulating combined valve with a fine adjustment function described in the first embodiment. In this embodiment, the fine adjustment regulating valve 1 includes a valve stem steam leakage pipe 4, a first valve stem 8, a first valve cover 9, a first sleeve 10, a second threaded ring 12 and a second sleeve 14;

[0049] The first valve cover 9 is arranged on the first valve body 3, and the first valve cover 9 and the first valve body 3 form an "L"-shaped chamber channel with steam entering axially of the valve body and exhausting steam in radial direction of the valve body; the outer end of the axial steam inlet channel of the valve body serves as the steam inlet of the chamber channel of the fine adjustment valve 1; the lowermost end of the radial steam exhaust channel of the valve body serves as the steam outlet of the chamber channel of the fine adjustment valve 1; the steam outlet of the chamber channel of the fine adjustment valve 1 is used to communicate with the first joint or the second joint of the three-way joint 6;

[0050] The second sleeve 14 is cylindrical; and the second sleeve 14 vertically covers the chamber channel interface of the "L"-shaped chamber channel valve body for radial exhaust of steam;

[0051] The first valve disc 13 is located inside the second sleeve 14;

[0052] The bottom end of the first valve stem 8 is arranged in a valve disc 13, and the first valve stem 8 and the first valve disc 13 are fixed by the second threaded ring 12; as the first valve stem 8 rises, the first valve stem 8 drives the first butterfly valve 13 to rise at the same time, thereby making the first butterfly valve 13 away from the first valve body 3, the steam inlet area of ​​the second valve body 14 increases, and the steam inlet amount of the fine adjustment valve 1 increases accordingly;

[0053] The top end of the first valve stem 8 passes through the first valve cover 9;

[0054] The first sleeve 10 is interference fit with the first valve cover 9, and a steam leakage port is provided on the outer periphery of the first sleeve 10;

[0055] One end of the valve stem steam leakage pipe 4 is connected to the leakage port, and the other end of the valve stem steam leakage pipe 4 is connected to the external leakage steam collection terminal.

[0056] In this embodiment, the interference fit between the first sleeve 10 and the first valve cover 9 is to ensure the airtightness of the cavity; the other end of the valve stem steam leakage pipe 4 is connected to the corresponding collection equipment to reduce energy loss; compared with the conventional thermal power unit regulating valve, when the combined valve described in this embodiment is put into operation under the rated parameters of the valve front industrial steam extraction, the fine adjustment regulating valve 1 cannot achieve self-sealing, and the valve stem steam leakage pipe 4 is a long-term operating condition with high parameters and large flow. The conventional valve stem steam leakage system can no longer meet the requirements. The valve stem steam leakage pipe 4 selects the valve stem steam leakage quantity and the steam leakage terminal according to the unit thermal calculation, which is used to timely recover the high-parameter and large-flow valve stem steam leakage energy loss when the regulating valve is partially opened, and avoid the high-parameter valve stem steam leakage from leaking into the factory building and causing danger.

[0057] Specific embodiment 4: This embodiment further defines the medium-pressure main steam regulating combined valve with fine adjustment function described in specific embodiment 3. In this embodiment, the fine adjustment regulating valve 1 further includes a first threaded ring 11;

[0058] The first sleeve 10 may also be fixed on the first valve cover 9 by a first threaded ring 11 .

[0059] In this embodiment, the first threaded ring 11 is used to increase the fixing firmness of the first sleeve 10 and the first valve cover 9, so that the first sleeve 10 and the first valve cover 9 have better sealing performance.

[0060] Specific implementation method V. Combination Figure 6This embodiment is described. This embodiment further defines a medium-pressure main steam regulating combined valve with a fine adjustment function described in the first embodiment. In this embodiment, the medium-pressure main steam valve 2 includes a connecting pipe 7, a pipe control valve 15, a second valve cover 16, a fixing nut 17, a rocker arm 18, a second valve stem 20 and a second valve body 21;

[0061] The first valve cover 16 is arranged on the second valve body 21, and the first valve cover 16 and the second valve body 21 form a "Y"-shaped chamber channel; the "Y"-shaped chamber channel includes a steam inlet channel and two steam outlet channels; the outermost end of the steam inlet channel serves as the steam inlet of the chamber channel of the medium-pressure main steam valve 2, and the outermost ends of the two steam outlet channels serve as two steam outlets of the chamber channel of the medium-pressure main steam valve 2, wherein the two steam outlet channels are respectively connected to the two chamber channel inlets of the fine adjustment valve 1 through the first valve body 3;

[0062] The second butterfly valve 19 is disc-shaped and vertically blocks the steam inlet passage of the "Y"-shaped chamber passage; and the second butterfly valve 19 is fixed to the rocker arm 18 by a fixing nut 17;

[0063] One end of the rocker arm 18 is axially connected to the second valve stem 20; the second valve stem 20 is rotated to make the rocker arm 18 move in an arc around the second valve stem 20, so that the second butterfly valve 19 is transformed from a vertical state to a state parallel to the axial direction of the steam inlet channel, and the "Y"-shaped chamber channel is opened;

[0064] The communication pipe 7 is connected between the front and rear chambers of the second butterfly valve 19;

[0065] The pipeline control valve 15 is arranged on the communication pipeline 7 .

[0066] In this embodiment, the "Y"-shaped chamber channel has one steam inlet channel and two steam outlet channels; the steam inlet channel and the steam outlet channel are both cylindrical; the second butterfly valve 19 vertically blocks the steam inlet channel of the "Y"-shaped chamber channel, which means that the second butterfly valve 19 is perpendicular to the central axis of the steam inlet channel; the pipeline control valve 15 is used to adjust the stroke of the connecting pipeline 7. The purpose of setting the connecting pipeline 7 is to make the air pressure in the front and rear chambers of the second butterfly valve 19 in a balanced state, reduce the pressure difference before and after the second valve disc 19, and make the second valve disc 19 open smoothly; the medium-pressure main steam valve 2 is used as a safety measure to cut off the steam entering the turbine in an emergency state to prevent the turbine rotor speed from rising and causing an accident.

[0067] Specific implementation method 6: This implementation method further defines the medium-pressure main steam regulating combined valve with fine adjustment function described in specific implementation method 5. In this implementation method, a limiting boss is provided on the second valve cover 16;

[0068] The limiting boss is used to limit the rotation angle of the rocker arm 18 .

[0069] In this embodiment, a limiting boss is disposed on the lower surface of the second valve cover 16, and the limiting boss prevents the second valve disc 19 from over-opening.

[0070] Specific embodiment seven: This embodiment further limits the medium-pressure main steam regulating combined valve with fine adjustment function described in specific embodiment five. In this embodiment, a cooling device is provided on the steam extraction pipeline before the main steam valve 2 to adjust the steam extraction temperature before the valve.

[0071] In this embodiment, if the extraction steam temperature is required to be lower than the actual extraction steam temperature, a temperature reduction device may be provided on the extraction steam pipeline before the main steam valve 2 to achieve this function.

[0072] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A medium-pressure main steam regulating combined valve with fine adjustment function, characterized in that: The combined valve comprises two fine-adjusting control valves (1), a medium-pressure main steam valve (2), a first valve body (3), a three-way connector (6), a first butterfly valve (13) and a second butterfly valve (19); One end of the two fine-adjusting control valves (1) is simultaneously connected to one end of the medium-pressure main steam valve (2) through the first valve body (3), and the other end of the medium-pressure main steam valve (2) is used to pass reheat steam; The other ends of the two fine adjustment valves (1) are respectively connected to a first joint and a second joint of a three-way joint (6); the third joint of the three-way joint (6) is used to introduce reheated steam into the steam turbine; The first butterfly valve (13) is arranged on the chamber channel of the fine-adjusting regulating valve (1); the first butterfly valve (13) is used to adjust the reheat steam outlet volume of the fine-adjusting regulating valve (1); The second butterfly valve (19) is arranged on the chamber channel of the medium-pressure main steam valve (2); the second butterfly valve (19) is used to close the medium-pressure main steam valve (2) in an emergency.

2. A medium-pressure main steam regulating combined valve with fine adjustment function according to claim 1, characterized in that: The combined valve further comprises an elastic support (5); There are three elastic supports (5), one elastic support (5) is supported on the bottom of the medium-pressure main steam valve (2); and the other two elastic supports (5) are respectively supported on the sides of two fine-adjusting control valves (1).

3. The medium-pressure main steam regulating combined valve with fine adjustment function according to claim 1 is characterized in that: The fine adjustment regulating valve (1) comprises a valve stem steam leakage pipe (4), a first valve stem (8), a first valve cover (9), a first sleeve (10), a second threaded ring (12) and a second sleeve (14); The first valve cover (9) is arranged on the first valve body (3), and the first valve cover (9) and the first valve body (3) form an "L"-shaped chamber channel with steam entering axially of the valve body and exhausting steam in radial direction of the valve body; the outer end of the axial steam inlet channel of the valve body (3) serves as a steam inlet of the chamber channel of the fine adjustment valve (1); the lowermost end of the radial steam exhaust channel of the valve body (3) serves as a steam outlet of the chamber channel of the fine adjustment valve (1); the steam outlet of the chamber channel of the fine adjustment valve (1) is used to communicate with the first joint or the second joint of the three-way joint (6); The second sleeve (14) is cylindrical; and the second sleeve (14) vertically covers the chamber channel interface of the "L"-shaped chamber channel valve body for radial exhaust of steam; The first valve disc (13) is located inside the second sleeve (14); The bottom end of the first valve stem (8) is arranged in the first valve disc (13), and the first valve stem (8) and the first valve disc (13) are fixed by a second threaded ring (12); as the first valve stem (8) rises, the first valve stem (8) drives the first butterfly valve (13) to rise at the same time, thereby causing the first butterfly valve (13) to move away from the first valve body (3), increasing the steam inlet area of ​​the second sleeve (14), and increasing the steam inlet amount of the fine adjustment valve (1); The top end of the first valve stem (8) passes through the first valve cover (9); The first sleeve (10) and the first valve cover (9) are interference fit, and a steam leakage port is provided on the outer periphery of the first sleeve (10); One end of the valve stem steam leakage pipe (4) is connected to the steam leakage port, and the other end of the valve stem steam leakage pipe (4) is connected to an external steam leakage collection terminal.

4. A medium-pressure main steam regulating combined valve with fine adjustment function according to claim 3, characterized in that: The fine adjustment valve (1) may further comprise a first threaded ring (11); The first sleeve (10) can be fixed on the first valve cover (9) by a first threaded ring (11).

5. The medium-pressure main steam regulating combined valve with fine adjustment function according to claim 1 is characterized in that: The medium-pressure main steam valve (2) comprises a connecting pipeline (7), a pipeline control valve (15), a second valve cover (16), a fixing nut (17), a rocker arm (18), a second valve stem (20) and a second valve body (21); The first valve cover (16) is arranged on the second valve body (21), and the first valve cover (16) and the second valve body (21) form a "Y"-shaped chamber channel; the "Y"-shaped chamber channel includes a steam inlet channel and two steam outlet channels; the outermost end of the steam inlet channel serves as a steam inlet of the chamber channel of the medium-pressure main steam valve (2), and the outermost ends of the two steam outlet channels serve as two steam outlets of the chamber channel of the medium-pressure main steam valve (2), wherein the two steam outlet channels are respectively connected to the chamber channel inlets of the two fine-adjusting regulating valves (1) through the first valve body (3); The second butterfly valve (19) is disc-shaped, and the second butterfly valve (19) vertically blocks the steam inlet channel of the "Y"-shaped chamber channel; and the second butterfly valve (19) is fixed to the rocker arm (18) through a fixing nut (17); One end of the rocker arm (18) is axially connected to the second valve stem (20); the second valve stem (20) is rotated to make the rocker arm (18) move in an arc with the second valve stem (20) as the center, so that the second butterfly valve (19) is transformed from a vertical state to a state parallel to the axial direction of the steam inlet channel, thereby opening the "Y"-shaped chamber channel; The communication pipe (7) is connected between the front and rear chambers of the second butterfly valve (19); The pipeline control valve (15) is arranged on the connecting pipeline (7).

6. A medium-pressure main steam regulating combined valve with fine adjustment function according to claim 5, characterized in that: The second valve cover (16) is provided with a limiting boss; The limiting boss is used to limit the rotation angle of the rocker arm (18).

7. The medium-pressure main steam regulating combined valve with fine adjustment function according to claim 1 is characterized in that: A temperature reducing device may be provided on the steam extraction pipeline before the medium-pressure main steam valve (2) to adjust the steam temperature.

Images