Recirculating valve of boiler feed pump

Abstract

The utility model relates to the technical field of flow regulating valves, in particular to a boiler feed pump recirculation valve which comprises a recirculation valve body and an anti-backflow buffer mechanism. The recirculation valve body comprises a valve element and a shell, and a medium channel is formed between the valve element and the shell. The direction, facing the second valve cage, of the first valve cage is set as a preset direction; the anti-backflow buffer mechanism is arranged in the second valve cage; the anti-backflow buffer mechanism comprises a medium buffer frame; the medium buffering frame is arranged in the second valve cage, and a buffering gap is formed between the medium buffering frame and the second valve cage; the medium buffer frame can be communicated with or separated from the medium channel; a plurality of medium outflow holes are formed in the bottom wall of the second valve cage. The boiler feed pump recirculation valve is ingenious in structural design, high-pressure water can be prevented from flowing back from the deaerator when flowing back to the deaerator from the pump outlet, meanwhile, the boiler feed pump recirculation valve can buffer media at the outlet of the valve cage, the flow speed of the media at the outlet of the valve cage is further reduced, and the service life of the boiler feed pump is prolonged. And the erosion resistance is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of flow regulating valves, in particular to a boiler feed water pump recirculation valve. Background Art

[0002] The minimum flow regulating valve, also known as the boiler feedwater pump recirculation valve, is installed at the feedwater pump outlet in a power plant, connecting it to the deaerator. The boiler feedwater pump draws water from the deaerator to the boiler. To prevent overheating and cavitation, the feedwater pump flow rate must always be at least a specified safety flow rate, also known as the minimum flow rate. When the required boiler feedwater flow rate is very low, such as when a turbine trips, the minimum flow valve must be opened promptly to recirculate some high-pressure water from the pump outlet back to the deaerator to ensure safe operation of the feedwater pump.

[0003] When some high-temperature and high-pressure media flow through common flow valves, they will cause erosion to the flow valves, thereby shortening the service life of the flow valves. Utility Model Content

[0004] The purpose of the present utility model includes providing a boiler feed water pump recirculation valve, which has an ingenious structural design and can prevent high-pressure water from flowing back from the deaerator when returning high-pressure water from the pump outlet to the deaerator. At the same time, the boiler feed water pump recirculation valve can buffer the medium at the valve cage outlet, further slow down the medium flow rate at the valve cage outlet, and further improve the anti-erosion ability.

[0005] In order to achieve the above purpose, the preferred solution adopted by the present invention is:

[0006] A boiler feed water pump recirculation valve comprises a recirculation valve body and an anti-backflow buffer mechanism; the recirculation valve body comprises a valve core and an outer shell, the outer shell comprises a first valve cage, a plurality of regulating valve seats, a sealing valve seat and a second valve cage connected in sequence from top to bottom; a medium channel is provided between the valve core and the outer shell; the direction of the first valve cage toward the second valve cage is set to a preset direction; the anti-backflow buffer mechanism is provided in the second valve cage; the anti-backflow buffer mechanism comprises a medium buffer frame; the medium buffer frame is provided in the second valve cage, and a buffer gap is provided between the medium buffer frame and the second valve cage; the medium buffer frame can be connected to or separated from the medium channel; the medium buffer frame is provided with a connecting hole, and the medium buffer frame can move in a preset direction; when the medium buffer frame moves toward the bottom wall of the second valve cage, the connecting hole can be connected to the buffer gap; when the medium buffer frame moves away from the bottom wall of the second valve cage, the connecting hole can be separated from the buffer gap; the bottom wall of the second valve cage is provided with a plurality of medium outflow holes.

[0007] Further, in the preferred embodiment of the utility model, the anti-backflow buffering mechanism further comprises a guide column; one end of the guide column is connected to the inner side of the bottom wall, and the other end extends towards the first valve cage; a limiting groove is recessed in the bottom of the medium buffering frame, and the limiting groove extends towards the first valve cage; the communication hole is arranged in the side wall of the limiting groove; the limiting groove is arranged on the guide column; the end of the guide column away from the bottom wall is elastically connected with the groove bottom wall of the limiting groove; the side wall of the guide column is recessed with a communication groove; the communication groove can be communicated with or separated from the communication hole.

[0008] Further, in the preferred embodiment of the utility model, the communication groove extends along the preset direction.

[0009] Further, in the preferred embodiment of the utility model, the anti-backflow buffering mechanism further comprises a plurality of first elastic members; the first elastic members are arranged and connected between the groove bottom wall and the guide column.

[0010] Further, in the preferred embodiment of the utility model, the side wall of the medium buffering frame is in contact with the side wall of the second valve cage; the upper edge of the medium buffering frame can be in abutment with the lower edge of the sealing valve seat.

[0011] Further, in the preferred embodiment of the utility model, the anti-backflow buffering mechanism further comprises a plurality of first elastic members; the first elastic members are arranged and connected between the groove bottom wall and the guide column.

[0012] Further, in the preferred embodiment of the utility model, the plurality of limiting assemblies are arranged on the center line in a circumferential interval with the center line of the valve core as the center line.

[0013] Further, in the preferred embodiment of the utility model, the first elastic member is a spring.

[0014] Further, in the preferred embodiment of the utility model, the second elastic member is a spring.

[0015] Further, in the preferred embodiment of the utility model, along the preset direction, the outer side wall of the valve core in the first valve cage is sleeved with a plurality of sealing rings, and the sealing rings are in contact with the inner side wall of the first valve cage.

[0016] The boiler feed water pump recirculation valve provided by the utility model has the beneficial effects that:

[0017] The utility model provides a boiler feedwater pump recirculation valve, comprising a recirculation valve body and an anti-backflow buffer mechanism. Based on the respective structural designs of the recirculation valve body and the anti-backflow buffer mechanism, as well as the design of the connection between them, the resulting boiler feedwater pump recirculation valve can achieve the following:

[0018] (1) When returning high-pressure water from the pump outlet to the deaerator, avoid backflow of high-pressure water from the deaerator;

[0019] (2) It can buffer the medium at the cage outlet, further slow down the medium flow rate at the cage outlet, and further improve the anti-erosion ability;

[0020] (3) A limiting mechanism is provided on the inner side wall where the sealing valve seat and the valve core come into contact, and the limiting mechanism can further improve the sealing performance of the recirculation valve;

[0021] (4) When the valve core of the recirculation valve moves upward to open, the limit mechanism can help to quickly open the boiler feed water pump recirculation valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic cross-sectional view of a boiler feed water pump recirculation valve in a closed state provided by an embodiment of the present utility model;

[0024] Figure 2 A schematic cross-sectional view of a boiler feed water pump recirculation valve in an open state provided by an embodiment of the present utility model;

[0025] Figure 3 for Figure 1 A magnified view of area A;

[0026] Figure 4 for Figure 1 A magnified view of area B;

[0027] Icon: 10-boiler feed water pump recirculation valve, 100-recirculation valve body, 200-anti-backflow buffer mechanism, 300-limiting assembly, 400-buffer gap, 110-valve core, 120-housing, 130-medium channel, 140-sealing ring, 121-first valve cage, 122-adjusting valve seat, 123-sealing valve seat, 124-second valve cage, 125-medium outflow hole, 210-medium buffer frame, 220-guide column, 230-first elastic part, 211-connecting hole, 212-limiting groove, 221-connecting groove, 111-sealing groove, 310-second elastic part, 320-sealing block. DETAILED DESCRIPTION

[0028] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. Example 1

[0031] The following is combined with Figures 1-4 The utility model is further described as follows:

[0032] The utility model provides a boiler feed water pump recirculation valve 10, please refer to Figures 1-4 The boiler feed water pump recirculation valve 10 includes a recirculation valve body 100, an anti-backflow buffer mechanism 200 and a limit mechanism (not marked in the figure).

[0033] The recirculation valve body 100 includes a valve core 110 and a housing 120. The housing 120 includes a first valve cage 121, a plurality of regulating valve seats 122, a sealing valve seat 123, and a second valve cage 124 connected in sequence from top to bottom. A medium channel 130 is defined between the valve core 110 and the housing 120.

[0034] In this embodiment, to clarify the positional relationships of various components, the direction from the first cage 121 toward the second cage 124 is set as a predetermined direction. Along the predetermined direction, multiple sealing rings 140 are sleeved around the outer wall of the valve core 110 within the first cage 121. The sealing rings 140 contact the inner wall of the first cage 121.

[0035] In this embodiment, the backflow prevention buffer mechanism 200 is disposed in the second cage 124. The backflow prevention buffer mechanism 200 includes a medium buffer frame 210, a guide post 220, and a plurality of first elastic members 230. In this embodiment, the first elastic members 230 are springs.

[0036] The media buffer frame 210 is disposed within the second cage 124, with a buffer gap 400 defined between the media buffer frame 210 and the second cage 124. The media buffer frame 210 can be in communication with or separated from the media channel 130. Specifically, the sidewalls of the media buffer frame 210 contact the sidewalls of the second cage 124, and the upper edge of the media buffer frame 210 abuts the lower edge of the sealing valve seat 123.

[0037] In this embodiment, the media buffer frame 210 is provided with a connecting hole 211, allowing the media buffer frame 210 to move in a predetermined direction. Specifically, in this embodiment, one end of a guide post 220 is connected to the inner side of the bottom wall, and the other end extends toward the first valve cage 121. A retaining groove 212 is recessed in the bottom of the media buffer frame 210, extending toward the first valve cage 121. The connecting hole 211 is formed in the sidewall of the retaining groove 212. The retaining groove 212 covers the guide post 220. The end of the guide post 220 away from the bottom wall is elastically connected to the bottom wall of the retaining groove 212 via a first elastic member 230.

[0038] A connecting groove 221 is recessed into the sidewall of the guide post 220 and extends in a predetermined direction. The connecting groove 221 can be connected to or separated from the connecting hole 211. When the media buffer frame 210 moves toward the bottom wall of the second valve cage 124, the connecting hole 211 can connect to the buffer gap 400. When the media buffer frame 210 moves away from the bottom wall of the second valve cage 124, the connecting hole 211 can be separated from the buffer gap 400. The bottom wall of the second valve cage 124 is formed with a plurality of media outflow holes 125.

[0039] In this embodiment, the limiting mechanism is provided on the inner wall where the sealing valve seat 123 abuts against the valve core 110. A plurality of sealing grooves 111 are formed in the abutment area between the valve core 110 and the sealing valve seat 123.

[0040] The limiting mechanism includes multiple limiting assemblies 300. These limiting assemblies 300 are circumferentially spaced about the centerline of the valve core 110. The limiting assemblies 300 include a second elastic member 310 and a sealing block 320. The second elastic member 310 is a spring. One end of the second elastic member 310 is connected to the inner sidewall, and the other end is connected to the sealing block 320. When the sealing valve seat 123 abuts the valve core 110, the sealing block 320 is embedded in the sealing groove 111, and the second elastic member 310 is compressed.

[0041] The boiler feed water pump recirculation valve 10 provided in this embodiment works as follows: when the boiler feed water pump recirculation valve 10 is closed, the first elastic member 230 is in a telescopic state, the medium buffer frame 210 is separated from the buffer gap 400, thereby isolating it from the outside world, and high-pressure water cannot flow back; at this time, the second elastic member 310 is in a compressed state, and the sealing block 320 is embedded in the sealing groove 111, further improving the sealing performance of the boiler feed water pump recirculation valve 10.

[0042] When the boiler feed water pump recirculation valve 10 is opened, the valve core 110 moves upward. At this time, the second elastic member 310 of the limiting mechanism exerts an upward thrust on the valve core 110 under its own elastic force, thereby accelerating the upward movement of the valve core 110. When the valve core 110 moves upward, high-pressure water enters the medium buffer frame 210 through the medium channel 130. Under the action of the gravity of the high-pressure water, the medium buffer frame 210 moves downward along the guide column 220. The first elastic member 230 is squeezed, the limiting groove 212 moves downward, and the connecting hole 211 is connected to the connecting groove 221. The high-pressure water flows from the medium buffer frame 210 through the connecting hole 211 and the connecting groove 221 into the buffer gap 400 and then flows out through the medium outflow hole 125. At this time, the flow rate of the high-pressure water is buffered, further improving the anti-erosion capability.

[0043] In summary, the boiler feed water pump recirculation valve 10 provided in this embodiment has an ingenious structural design and can prevent high-pressure water from flowing back from the deaerator when returning high-pressure water from the pump outlet to the deaerator. At the same time, the boiler feed water pump recirculation valve 10 can buffer the medium at the valve cage outlet, further slow down the medium flow rate at the valve cage outlet, and further improve the anti-erosion ability.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A boiler feed water pump recirculation valve, characterized in that: It includes a recirculation valve body and an anti-backflow buffer mechanism; The recirculation valve body includes a valve core and a housing. The housing includes a first valve cage, a plurality of regulating valve seats, a sealing valve seat, and a second valve cage connected in sequence from top to bottom. A medium passage is defined between the valve core and the housing. The direction of the first valve cage toward the second valve cage is set to a preset direction. The anti-backflow buffer mechanism is disposed in the second valve cage. The anti-backflow buffer mechanism includes a medium buffer frame; the medium buffer frame is disposed in the second valve cage, and a buffer gap is defined between the medium buffer frame and the second valve cage; the medium buffer frame can be in communication with or separated from the medium channel; The medium buffer frame is provided with a connecting hole, and the medium buffer frame can move along the preset direction; when the medium buffer frame moves toward the bottom wall of the second valve cage, the connecting hole can be connected with the buffer gap; when the medium buffer frame moves away from the bottom wall of the second valve cage, the connecting hole can be separated from the buffer gap; the bottom wall of the second valve cage is provided with multiple medium outflow holes.

2. The boiler feed water pump recirculation valve according to claim 1, characterized in that: The anti-backflow buffer mechanism further includes a guide post; one end of the guide post is connected to the inner side of the bottom wall, and the other end extends toward the first valve cage; A limiting groove is recessed at the bottom of the medium buffer frame, and the limiting groove extends toward the first valve cage; the communicating hole is opened on the side wall of the limiting groove; the limiting groove cover is provided on the guide column; the end of the guide column away from the bottom wall is elastically connected to the bottom wall of the limiting groove; a communicating groove is recessed on the side wall of the guide column; the communicating groove can be connected to or separated from the communicating hole.

3. The boiler feed water pump recirculation valve according to claim 2, characterized in that: The communicating groove extends along the preset direction.

4. The boiler feed water pump recirculation valve according to claim 2, characterized in that: The anti-backflow buffer mechanism further includes a plurality of first elastic members; the first elastic members are arranged and connected between the bottom wall of the groove and the guide column.

5. The boiler feed water pump recirculation valve according to claim 1, characterized in that: The side wall of the medium buffer frame contacts the side wall of the second valve cage; the upper edge of the medium buffer frame can abut against the lower edge of the sealing valve seat.

6. The boiler feed water pump recirculation valve according to claim 1, characterized in that: It also includes a limiting mechanism; the limiting mechanism is arranged on the inner side wall when the sealing valve seat and the valve core abut against each other; a plurality of sealing grooves are concavely provided at the abutment point between the valve core and the sealing valve seat; The limiting mechanism includes multiple groups of limiting components; the limiting components include a second elastic member and a sealing block; one end of the second elastic member is connected to the inner wall, and the other end is connected to the sealing block; when the sealing valve seat abuts the valve core, the sealing block is embedded in the sealing groove and the second elastic member is compressed.

7. The boiler feed water pump recirculation valve according to claim 6, characterized in that: A plurality of groups of the limit assemblies are arranged at intervals in the circumferential direction on the center line with the axis of the valve core as the center line.

8. The boiler feed water pump recirculation valve according to claim 4, characterized in that: The first elastic member is a spring.

9. The boiler feed water pump recirculation valve according to claim 6, characterized in that: The second elastic member is a spring.

10. The boiler feed water pump recirculation valve according to claim 1, characterized in that: Along the preset direction, a plurality of sealing rings are sleeved on an outer side wall of the valve core located in the first valve cage, and the sealing rings are in contact with an inner side wall of the first valve cage.

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