Subcritical 300mw steam turbine reheat governing valve

Abstract

A reheat regulating valve for a subcritical 300MW steam turbine. This invention relates to the field of steam turbine technology. The invention addresses the common problems of poor tightness and poor adjustability in existing subcritical 300MW steam turbine reheat regulating valves. The invention includes a pre-opening valve, a locking nut, a valve stem, a medium-pressure regulating valve connecting sleeve, a valve disc, a valve cover, a valve seat, a valve body, and a bushing. The lower end of the valve stem is fixedly connected to the pre-opening valve, and the upper end of the pre-opening valve is fixedly connected to the locking nut. A connecting nut is located above the locking nut. The upper end of the pre-opening valve is equipped with a medium-pressure regulating valve connecting sleeve, which is inserted into the valve disc. A through hole is located in the middle of the lower end face of the valve disc, and the pre-opening valve is located inside the through hole. A circular sleeve is located at the lower end of the valve cover, and the circular sleeve is located within the valve body. The steam inlet end of the valve body is located on one side of the circular sleeve. A bushing is located on the inner circumferential side wall of the circular sleeve, and the upper end of the valve disc is inserted into the bushing. This invention is used in 300MW steam turbines.

Description

Technical Field

[0001] This invention relates to the field of steam turbine technology, and specifically to a reheat regulating valve for a subcritical 300MW steam turbine. Background Technology

[0002] With the rapid development of my country's industry and agriculture, the power industry is placing increasingly higher demands on the steam turbine manufacturing industry. Steam turbines are trending towards larger capacity, higher parameters, lower pollution, higher reliability, higher load adaptability, higher automation, safety, and economic development. Modern large steam turbines generally adopt a multi-stage, multi-cylinder, and multi-exhaust structure; the cylinders employ internal and external double-layer or multi-layer cylinder structures. Steam turbine design must select a reasonable thermodynamic cycle, and the flow path of the steam turbine should have good thermodynamic and aerodynamic characteristics. The main and auxiliary turbines and their main components should have satisfactory strength and vibration characteristics, good automatic adjustment performance, and reasonable manufacturing processes. However, currently, the reheat regulating valves of subcritical 300MW steam turbines in China generally suffer from poor tightness and poor adjustability. Summary of the Invention

[0003] This invention addresses the common problems of poor tightness and poor adjustability in existing subcritical 300MW turbine reheat regulating valves, and proposes a new subcritical 300MW turbine reheat regulating valve.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: The present invention includes a pre-opening valve, a locking nut, a valve stem, a medium-pressure regulating valve connecting sleeve, a valve disc, a valve cover, a valve seat, a valve body, and a bushing. The valve stem is vertically inserted into the end face of the valve cover. The lower end of the valve stem is fixedly connected to the pre-opening valve, and the upper end of the pre-opening valve is fixedly connected to the locking nut. A connecting nut is provided at the upper end of the locking nut. Both the locking nut and the connecting nut are located on the outer side of the lower end of the valve stem. The upper end of the pre-opening valve is provided with a medium-pressure regulating valve connecting sleeve, and the upper end of the medium-pressure regulating valve connecting sleeve is fitted onto the valve disc. On the outside of the rod, the lower end of the medium-pressure regulating valve connecting sleeve is fitted onto the outside of the connecting nut and the locking nut. The medium-pressure regulating valve connecting sleeve is inserted into the valve disc. A valve disc through hole is provided in the middle of the lower end face of the valve disc. The pre-opening valve is located on the inner end of the valve disc through hole. A circular ring is provided at the lower end of the valve cover. The circular ring is located in the valve body. The steam inlet end of the valve body is located on one side of the circular ring. A bushing is provided on the inner circumferential side wall of the circular ring. The upper end of the valve disc is inserted into the bushing. The lower end of the butterfly valve is located in the valve seat. The valve seat is fixed to the root of the inner side wall of the steam outlet end of the valve body.

[0005] The beneficial effects of this invention are:

[0006] This invention proposes a reheat regulating valve for a subcritical 300MW steam turbine, which improves both the tightness and adjustability of the reheat regulating valve. This ensures the effective operation of the steam turbine, improves its efficiency, and extends the service life of the turbine unit. Attached Figure Description

[0007] Figure 1 This is a front sectional view of the overall structure of the present invention. Detailed Implementation

[0008] Specific implementation method one: Combining Figure 1 The subcritical 300MW steam turbine reheat regulating valve described in this embodiment includes a pre-opening valve 1, a locking nut 4, a valve stem 5, a medium-pressure regulating valve connecting sleeve 6, a valve disc 11, a valve cover 12, a valve seat 13, a valve body 14, and a bushing 15. The valve stem 5 is vertically inserted into the end face of the valve cover 12. The lower end of the valve stem 5 is fixedly connected to the pre-opening valve 1, and the upper end of the pre-opening valve 1 is fixedly connected to the locking nut 4. The upper end of the locking nut 4 is provided with a connecting nut 7. Both the locking nut 4 and the connecting nut 7 are located on the outer side of the lower end of the valve stem 5. The upper end of the pre-opening valve 1 is provided with a medium-pressure regulating valve connecting sleeve 6, and the upper end of the medium-pressure regulating valve connecting sleeve 6 is fitted with... On the outside of valve stem 5, the lower end of medium-pressure regulating valve connecting sleeve 6 is fitted onto the outside of connecting nut 7 and locking nut 4. Medium-pressure regulating valve connecting sleeve 6 is inserted into valve disc 11. Valve disc through hole is provided in the middle of the lower end face of valve disc 11. Pre-opening valve 1 is provided on the inner end of valve disc through hole. Circular sleeve is provided at the lower end of valve cover 12. Circular sleeve is provided in valve body 14. Steam inlet end of valve body 14 is provided on one side of circular sleeve. Bushing 15 is provided on the inner circumferential side wall of circular sleeve. Upper end of valve disc 11 is inserted into bushing 15. Lower end of butterfly valve 11 is provided in valve seat 13. Valve seat 13 is fixed to the root of the inner side wall of steam outlet end of valve body 14.

[0009] In this embodiment, the pre-opening valve 1 and the locking nut 4 enclose the valve stem 5 and tighten it with threads. The pin 9 locks the pre-opening valve 1 and the locking nut 4 to prevent rotation. The connecting nut 7 is tightened onto the valve stem 5 with threads. The medium-pressure regulating valve connecting sleeve 6 passes through the valve stem 5 from top to bottom and is tightened onto the valve disc 11 with the outer diameter thread and then locked with pin 3. The bushing 15 and the valve cover 12 are fixed with pin 10. After the mounting sleeve 2 and the valve cover 12 are fitted together, they are fixed with a converging joint. The valve seat 13 is fixed to the valve body 14 with a converging joint. After the valve stem 5 passes through the mounting sleeve 2 from bottom to top, the valve cover 12 is tightened onto the valve body 14 with bolts.

[0010] Specific Implementation Method Two: Combining Figure 1 Note that, in this embodiment, the outer circumferential sidewall of the lower end of the medium-pressure regulating valve connecting sleeve 6 extends outward, and the outer circumferential sidewall of the extension section is fixedly connected to the inner sidewall of the valve disc 11. Other components and connection methods are the same as in specific embodiment one.

[0011] Specific implementation method three: Combining Figure 1 Note that, in this embodiment, the extension section is provided with multiple connecting sleeve through holes evenly distributed along the circumferential direction. Other components and connection methods are the same as in specific embodiment two.

[0012] Specific implementation method four: Combination Figure 1 In this embodiment, the annular sleeve has multiple annular sleeve through holes evenly distributed along the circumferential direction on its sidewall, and the bushing 15 has multiple bushing through holes evenly distributed along the circumferential direction on its sidewall. Each bushing through hole corresponds to one annular sleeve through hole. A gap is provided between the bushing 15 and the valve disc 11. Other components and connection methods are the same as in specific embodiments one, two, or three.

[0013] Specific Implementation Method Five: Combining Figure 1 Note that, in this embodiment, the inner wall of the connecting sleeve 6 of the medium-pressure regulating valve has a movable cavity along the height direction. The connecting nut 7 and the locking nut 4 are disposed in the movable cavity and can move along the height direction of the movable cavity. Other components and connection methods are the same as in specific embodiment four.

[0014] Specific Implementation Method Six: Combination Figure 1 Note that in this embodiment, a gap is provided between the connecting sleeve 6 of the medium-pressure regulating valve and the connecting nut 7 and locking nut 4. Other components and connection methods are the same as in specific embodiment five.

[0015] Specific implementation method seven: Combination Figure 1 In this embodiment, a mounting sleeve 2 is provided between the valve stem 5 and the valve cover 12. The outer side wall of the mounting sleeve 2 is inserted into the middle of the upper end face of the valve cover 12, and the inner side wall of the mounting sleeve 2 is fitted onto the outer side of the valve stem 5. Other components and connection methods are the same as in specific embodiments one, two, three, five, or six.

[0016] Specific implementation method eight: Combination Figure 1 Note that, in this embodiment, the outer circumferential sidewall of the upper end of the valve stem 5 is threaded. Other components and connection methods are the same as in specific embodiment seven.

[0017] In this embodiment, the thread on the valve stem 5 extends to the inner side of the mounting sleeve 2. The middle part of the outer wall of the mounting sleeve 2 is provided with an annular groove in the circumferential direction. The middle part of the inner side of the valve cover 12 is provided with a leakage channel in the horizontal direction. The leakage channel communicates with the annular groove of the mounting sleeve 2. The thread on the valve stem 5 can ensure the stability of the valve stem 5 when the regulating valve is working and will not shake. At the same time, it ensures that the airflow flows out through the leakage channel of the valve cover 12 and will not cause interference to the inside of the regulating valve.

[0018] Specific Implementation Method Nine: Combining Figure 1 Note that, in this embodiment, a filter screen is fixedly connected to the inner side of the valve body 14, and the filter screen is fitted onto the outer side of the annular sleeve. Other components and connection methods are the same as in specific embodiment one.

[0019] Specific Implementation Method Ten: Combining Figure 1Note that in this embodiment, the connecting nut 7 and the valve stem 5 are fixedly connected by screws 8. Other components and connection methods are the same as in specific embodiments one, two, three, five, six, eight, or nine.

[0020] Working principle

[0021] After the reheat main steam valve, steam enters through the steam inlet end on one side of the valve body 14, passes through the filter screen, and enters the regulating valve chamber. Steam enters through the annular sleeve through hole of the valve cover 12 and the bushing through hole of the bushing 15, flowing upward into the valve disc 11 through the gap between the bushing 15 and the valve disc 11. Then, steam enters through the connecting sleeve through hole on the connecting sleeve 6 of the intermediate pressure regulating valve. The pre-opening valve chamber is formed in the area enclosed by the lower end face of the extension section of the intermediate pressure regulating valve connecting sleeve 6, the inner side wall of the valve disc 11, the upper end of the lower end face of the valve disc 11, and the outer side wall of the pre-opening valve 1. Steam enters the pre-opening valve chamber through the connecting sleeve through hole. When the valve stem 5 is pulled upward, the pre-opening valve 1, the locking nut 4, and the connecting nut 7 move vertically upward together with the valve stem 5. The pre-opening valve 1 and the valve disc through hole on the lower end face of the valve disc 11... When the gap is separated, the pre-opening valve 1 opens, and steam flows out of the reheat regulating valve through the valve disc through hole. When the valve stem 5 is pulled up further, the pre-opening valve 1, the locking nut 4, and the connecting nut 7 continue to move vertically upward with the valve stem 5. When the connecting nut 7 reaches the highest point of the movable cavity, the valve stem 5 is pulled up further, and the connecting nut 7 lifts the medium-pressure regulating valve connecting sleeve 6. The valve disc 11 moves upward and separates from the valve seat 13, and the valve disc 11 opens. After the reheat main steam valve, the steam is directly discharged from the reheat regulating valve through the steam outlet at the lower end of the valve body 14. This two-stage opening method improves the adjustability of the reheat regulating valve. When the valve stem 5 is pressed down, the lower end face of the pre-opening valve 1 abuts against the inner end of the valve disc through hole. When the valve disc 11 abuts against the valve seat 13, the pre-opening valve 1 and the valve disc 11 close, and steam cannot flow, ensuring the tightness of the valve.

[0022] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A reheat regulating valve for a subcritical 300MW steam turbine, characterized in that: The subcritical 300MW steam turbine reheat regulating valve includes a pre-start valve (1), a locking nut (4), a valve stem (5), a medium-pressure regulating valve connecting sleeve (6), a valve disc (11), a valve cover (12), a valve seat (13), a valve body (14), and a bushing (15). The valve stem (5) is vertically inserted into the end face of the valve cover (12). The lower end of the valve stem (5) is fixedly connected to the pre-start valve (1), and the upper end of the pre-start valve (1) is fixedly connected to the locking nut (4). The upper end of the locking nut (4) is provided with a connecting nut (7). Both the locking nut (4) and the connecting nut (7) are located on the outer side of the lower end of the valve stem (5). The upper end of the pre-start valve (1) is provided with a medium-pressure regulating valve connecting sleeve (6), and the upper end of the medium-pressure regulating valve connecting sleeve (6) is fitted with a bushing. The lower end of the medium-pressure regulating valve connecting sleeve (6) is fitted on the outside of the valve stem (5), and the connecting nut (7) and locking nut (4) are fitted on the outside of the medium-pressure regulating valve connecting sleeve (6). The medium-pressure regulating valve connecting sleeve (6) is inserted into the valve disc (11). The valve disc through hole is provided in the middle of the lower end face of the valve disc (11). The pre-opening valve (1) is set on the inner end of the valve disc through hole. The lower end of the valve cover (12) is provided with a ring sleeve. The ring sleeve is set in the valve body (14). The steam inlet end of the valve body (14) is set on one side of the ring sleeve. The inner circumferential side wall of the ring sleeve is provided with a bushing (15). The upper end of the valve disc (11) is inserted into the bushing (15). The lower end of the valve disc (11) is set in the valve seat (13). The valve seat (13) is fixed to the root of the inner side wall of the steam outlet end of the valve body (14). The outer circumferential sidewall of the lower end of the medium pressure regulating valve connecting sleeve (6) is provided with an extension section extending outward, and the outer circumferential sidewall of the extension section is fixedly connected to the inner sidewall of the valve disc (11). The extension section is provided with multiple connecting sleeve through holes evenly distributed along the circumferential direction. The side wall of the ring sleeve is provided with a plurality of ring sleeve through holes evenly distributed along the circumferential direction, and the side wall of the bushing (15) is provided with a plurality of bushing through holes evenly distributed along the circumferential direction. Each bushing through hole is respectively set to correspond one-to-one with a ring sleeve through hole. A gap is provided between the bushing (15) and the valve disc (11). The valve stem (5) has a thread on the outer circumferential side wall at the upper end; the thread on the valve stem (5) extends to the inner side of the mounting sleeve (2); the middle part of the outer side wall of the mounting sleeve (2) has an annular groove along the circumferential direction; the middle part of the inner side of the valve cover (12) has a leakage channel along the horizontal direction; the leakage channel is connected to the annular groove of the mounting sleeve (2). The pre-opening valve chamber is formed within the enclosed area between the lower end face of the extension section of the medium-pressure regulating valve connecting sleeve (6), the inner wall of the valve disc (11), the upper end of the lower end face of the valve disc (11), and the outer wall of the pre-opening valve (1). Steam enters through the steam inlet end on one side of the valve body (14). Steam enters through the annular sleeve through hole of the valve cover (12) and the bushing through hole of the bushing (15) and flows upward into the valve disc (11) through the gap between the bushing (15) and the valve disc (11). Then, steam enters through the connecting sleeve through hole on the medium pressure regulating valve connecting sleeve (6) and enters the pre-opening valve chamber through the connecting sleeve through hole.

2. The subcritical 300MW steam turbine reheat regulating valve according to claim 1, characterized in that: The inner wall of the connecting sleeve (6) of the medium pressure regulating valve is provided with a movable cavity along the height direction. The connecting nut (7) and the locking nut (4) are set in the movable cavity and can move along the height direction of the movable cavity.

3. The subcritical 300MW steam turbine reheat regulating valve according to claim 2, characterized in that: There is a gap between the connecting sleeve (6) of the medium pressure regulating valve and the connecting nut (7) and the locking nut (4).

4. A subcritical 300MW steam turbine reheat regulating valve according to claim 1, 2, or 3, characterized in that: An installation sleeve (2) is provided between the valve stem (5) and the valve cover (12). The outer side wall of the installation sleeve (2) is inserted into the middle of the upper end face of the valve cover (12), and the inner side wall of the installation sleeve (2) is fitted onto the outer side of the valve stem (5).

5. The reheat regulating valve for a subcritical 300MW steam turbine according to claim 1, characterized in that: A filter screen is fixed to the inner side of the valve body (14), and the filter screen is fitted on the outer side of the annular sleeve.

6. A subcritical 300MW steam turbine reheat regulating valve according to claim 1, 2, 3 or 5, characterized in that: The connecting nut (7) and the valve stem (5) are fixedly connected by screws (8).

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