Leakage-proof device of air preheater

Abstract

The utility model provides a leakage-proof device of an air preheater. The leakage-proof device comprises a driving mechanism; one end of the transmission shaft is connected to the output end of the driving mechanism; one side of the sealing box rotates relatively and is arranged on the transmission shaft in a sealing and sleeving manner, and the part of the wall surface of the sealing box is separated from the transmission shaft; the fan is used for enabling cold air to flow to waste heat according to a preset direction, the fan is connected to the other end of the transmission shaft so as to be driven by the driving mechanism to rotate, and the other side of the sealing box is connected to the back face of the fan in a sealing mode; the negative pressure device is used for forming a negative pressure space, and the negative pressure device is communicated with the sealing box; wherein the sealed space is used for accommodating dust. Compared with the prior art, the utility model adopts the mode of active collection and negative pressure discharge, so that the requirement on sealing performance can be reduced, the technical complexity and cost of equipment can be further reduced, and meanwhile, the dust cannot fly away at will to cause pollution and sanitation problems.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of thermal power generation equipment, especially to an air preheater leakage prevention device. BACKGROUND

[0002] The air preheater is a heat exchange device for heating the cold air entering the combustion-supporting boiler by using the hot flue gas discharged from the tail of the combustion boiler in the thermal power plant.

[0003] In the existing air preheater, the sealing of the cold and hot ends of the central cylinder against air leakage and powder leakage (dust) is a common problem. Air leakage and powder leakage can cause serious hygiene and environmental problems. At the same time, the power plant has to invest a large amount of manpower and money to control and remove the leaked dust.

[0004] To solve this technical problem, some leakage-preventing end covers are designed, and the design concept is to solve the leakage problem by strengthening the sealing. However, such a solution cannot balance the sealing effect and the cost of the sealing device, and is difficult to popularize. SUMMARY

[0005] In view of the deficiencies of the existing technology mentioned in the background section, the utility model provides an air preheater leakage prevention device, which uses a positive leakage prevention device to significantly improve the leakage prevention effect without excessively increasing the cost, and is convenient for popularization and promotion.

[0006] The air preheater leakage prevention device provided by the first aspect of the utility model embodiment comprises: a driving mechanism; a transmission shaft, one end of which is connected to the output end of the driving mechanism; a sealing box, one side of which is rotatably and sealingly sleeved on the transmission shaft, and part of the wall surface of the sealing box is spaced apart from the transmission shaft to form a sealing space between the transmission shaft and the sealing box; a fan for making cold air flow to the waste heat device in a preset direction, the fan being connected to the other end of the transmission shaft to be driven to rotate by the driving mechanism, the other side of the sealing box being sealingly connected to the back of the fan; and a negative pressure device for forming a negative pressure space, the negative pressure device being in communication with the sealing box; wherein the sealing space is used for accommodating dust.

[0007] In a possible implementation, the negative pressure device comprises: a flue, the inside of which forms a negative pressure space; a dust removal device, which is in communication with the flue; and a pipeline, which is connected between the flue and the sealing box, wherein the dust in the sealing space flows to the dust removal device along the pipeline and the flue under the action of negative pressure and is collected by the dust removal device.

[0008] In a possible implementation, the negative pressure device comprises a one-way valve arranged on the pipeline and configured to open when the pressure in the flue is less than a threshold value of the sealing box and to close when the pressure in the flue is greater than or equal to the threshold value of the sealing box.

[0009] In a possible implementation, the negative pressure device comprises a vibration device arranged inside or outside the pipeline and configured to vibrate the pipeline.

[0010] In a possible implementation, a controller is further included and electrically connected to the vibration device, and the controller is configured to determine whether the one-way valve is open when a vibration instruction is received, and to control the vibration device to vibrate the pipeline in a state where the one-way valve is open.

[0011] In a possible implementation, the one-way valve comprises an elastic member and a plug body connected to an end of the elastic member, the plug body is configured to block the pipeline in an extended state of the elastic member, and the plug body is configured to at least partially open the pipeline in a retracted state of the elastic member.

[0012] In a possible implementation, the pipeline is provided with a blocking portion defining a throat portion in the pipeline, the blocking portion is configured to make the throat portion horizontal, the elastic member is configured to extend and retract in the horizontal direction, and the plug body is configured to open and block the throat portion under the action of the elastic member.

[0013] In a possible implementation, the sealing box comprises a pressing plate and a box body with an open side, the pressing plate is integrally formed on a back surface of the fan, the pressing plate is provided with an annular groove, the box body is sleeved on the transmission shaft, the open side of the box body faces the pressing plate and the edge of the box body extends into the annular groove, and a sealing ring is clamped between the edge and the annular groove.

[0014] In a possible implementation, the driving mechanism comprises a motor, a coupling and a speed reducer connected in sequence, and the transmission shaft is connected to the output end of the speed reducer.

[0015] In a possible implementation, the box body comprises a first sub-box body and a second sub-box body, the first sub-box body and the second sub-box body are each provided with a groove adapted to the surface of the transmission shaft, the groove is configured to clamp the transmission shaft from both sides by the first sub-box body and the second sub-box body, and the groove completely surrounds the transmission shaft.

[0016] The air preheater leakage prevention device provided by the embodiment of the application discards the leakage prevention method mainly by plugging in the prior art, and instead collects the leaked dust in a sealing box with a sealing space, and then uses a negative pressure device connected with the sealing box to suck away the collected dust. Compared with the passive leakage prevention in the prior art, the active collection and negative pressure discharge method can reduce the requirement for sealing performance, and thus can reduce the technical complexity and cost of the equipment, but the dust will not be randomly scattered to cause pollution and health problems. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the application and the prior art, the drawings needed to be used in the embodiments and the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only embodiments of the application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0018] Figure 1 The structural schematic diagram of the air preheater leakage prevention device provided by one embodiment in the application;

[0019] Figure 2 The structural sectional view schematic diagram of the air preheater leakage prevention device provided by one embodiment in the application;

[0020] Figure 3 The schematic diagram of the sealing box body in one embodiment in the application, the left side Figure 3-1 is the right view, the right side Figure 3-2 is the sectional view;

[0021] Figure 4 The schematic diagram of the sealing box pressing plate in one embodiment in the application, the left side Figure 4-1 is the sectional view, the right side Figure 4-2 is the left view.

[0022] Among them: 100-air preheater leakage prevention device, 10-driving mechanism, 20-transmission shaft, 30-sealing box, 31-pressing plate, 311-annular groove, 32-box body, 322-first sub-box body, 324-second sub-box body, 326-groove, 40-fan, 50-negative pressure device, 51-flue, 52-dust removal device, 53-pipe, 531-throat, 532-plugging part, 54-one-way valve, 541-elastic member, 542-plug body. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0027] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0028] like Figure 1 The diagram shown is a structural schematic of an air preheater leak-proof device 100 provided in one embodiment of this application. The air preheater leak-proof device 100 includes a drive mechanism 10, a transmission shaft 20, a sealing box 30, a fan 40, and a negative pressure device 50. Specifically, the drive mechanism 10 includes a transmission shaft 20, one end of which is connected to the output end of the drive mechanism 10; a sealing box 30, one side of which is rotatably and sealingly mounted on the transmission shaft 20, with a portion of the wall of the sealing box 30 spaced apart from the transmission shaft 20 to form a sealed space between the transmission shaft 20 and the sealing box 30; a fan 40, used to direct cold air towards the waste heat device in a preset direction, the fan 40 being connected to the other end of the transmission shaft and driven to rotate by the drive mechanism 10, the other side of the sealing box 30 being sealingly connected to the back of the fan 40; and a negative pressure device 50, used to form a negative pressure space, the negative pressure device 50 communicating with the sealing box 30; wherein the sealed space is used to contain dust.

[0029] The waste heat device in the present application can be a heat generating device or a heat dissipating device in a power plant, such as a boiler, a pipe, etc., which constitutes part of an air preheater system (especially a heat exchange device). The cold air flows to the waste heat device under the driving of the fan 40 and exchanges heat with the waste heat device, and the temperature of the cold air is increased and then the cold air is guided into the combustion chamber, thereby achieving the purpose of reusing waste heat and reducing energy consumption.

[0030] In the technical scheme provided by the embodiment of the present application, the dust is first collected in the sealed space of the sealed box 30, and then under the action of the negative pressure device 50, the dust flows from the sealed space to the negative pressure device under the action of the negative pressure, and due to the action of the negative pressure, the dust cannot flow back into the sealed box 30 or the environment, thereby avoiding pollution and hygiene problems. The air preheater leakage prevention device 100 provided by the embodiment of the present application discards the leakage prevention means mainly by "plugging" in the prior art, but sets the sealed box 30 with a sealed space, first collects the leaked dust in the sealed box 30, and then uses the negative pressure device 50 connected with the sealed box 30 to suck away the collected dust. Compared with the passive leakage prevention in the prior art, the present application adopts an active collection and negative pressure removal mode, which can reduce the requirement for sealing performance, and thus can reduce the technical complexity and cost of the equipment.

[0031] As shown in Figure 2 Fig. 1 is a structural cross-sectional view of an air preheater leakage prevention device 100 provided by an embodiment of the present application.

[0032] In a possible implementation, the negative pressure device 50 includes: a flue 51, which has a negative pressure space formed inside; a dust removal device 52, which is in communication with the flue 51; and a pipeline 53, which is connected between the flue 51 and the sealed box 30. In the sealed space, the dust flows to the dust removal device 52 along the pipeline 53 and the flue 51 under the action of the negative pressure and is collected by the dust removal device 52.

[0033] The flue 51 is a device that exists in a thermal power plant itself, and its function is to discharge flue gas containing dust. Because of the flow of gas, the internal pressure of the flue 51 is also less than the external environmental pressure, that is, it is a negative pressure space. In the embodiment of the present application, the negative pressure device 50 is configured as the flue 51, so that it is not necessary to additionally arrange the negative pressure device 50, which does not increase the cost and does not additionally arrange the equipment space, and is flexible and convenient and does not excessively increase the cost. In addition, the dust removal device 52 is also an existing device in the thermal power plant, and its original function is to adsorb dust in the flue gas. In the embodiment of the present application, the dust removal device 52 also adsorbs the dust flowing into the flue 51 from the sealed box 30, so that one device has multiple functions to reduce the cost and further avoid pollution and hygiene problems caused by random scattering of dust.

[0034] In other possible embodiments, the negative pressure device 50 can be formed by other means such as a negative pressure pump, which is also within the scope of the present application.

[0035] In a specific embodiment, the dust removal device 52 is configured as an electric dust removal device 52. In other variants, the specific type of the dust removal device 52 can also be selected.

[0036] In a possible embodiment, the negative pressure device 50 comprises a one-way valve 54 arranged on the pipeline 53 and configured to be opened when the pressure in the flue 51 is less than a threshold value of the sealed box 30, and closed when the pressure in the flue 51 is greater than or equal to the aforementioned threshold value of the sealed box 30.

[0037] By configuring the one-way valve 54 as described above, when the negative pressure device 50 is working, the one-way valve 54 is opened, and the dust flows from the sealed box 30 into the negative pressure device; when the negative pressure device 50 is not working, the one-way valve 54 is closed, although the dust cannot flow from the sealed box 30 into the negative pressure device 50, but also avoids the airflow from the negative pressure device 50 flowing reversely into the sealed box 30, which blows away the collected dust.

[0038] In a possible embodiment, the one-way valve 54 comprises an elastic member 541 and a plug body 542 connected to the end of the elastic member 541, and in the stretched state of the elastic member 541, the plug body 542 blocks the pipeline 53, and in the contracted state of the elastic member 541, the plug body 542 at least partially opens the pipeline 53.

[0039] The air preheater leakage prevention device 100 with the one-way valve 54 as described above has a simple structure and is easy to implement, and will not frequently malfunction in harsh working conditions, and most importantly, it does not need manual operation, and only relies on pressure difference to achieve opening and closing.

[0040] In a possible embodiment, as shown in Figure 2 the pipeline 53 is provided with a blocking portion 532 defining a throat portion 531 in the pipeline 53, and the blocking portion 532 is configured to make the throat portion 531 horizontal; the elastic member 541 is configured to stretch and contract in the horizontal direction, and the plug body 542 is used to open and block the throat portion 531 under the action of the elastic member 541.

[0041] In the present embodiment, by the above arrangement, the one-way valve 54 realizes the opening and closing in the horizontal direction, and the influence of the gravity of the elastic member 541 and the plug body 542 is reduced, and the sensitivity of the one-way valve 54 is higher.

[0042] In a possible embodiment, the negative pressure device 50 comprises a vibration device 55 arranged inside or outside the pipeline 53, for generating vibration of the pipeline 53.

[0043] The vibration device 55 can vibrate the pipeline 53, so that the dust attached to the pipeline wall flows into the sealed box 30 or the negative pressure device 50 along with the air flow, avoiding the pipeline 53 from being blocked after long-term use and causing the device to fail.

[0044] The vibration device 55 can realize the vibration action through a pendulum device or a motor-driven device, and the specific implementation can refer to the prior art, which will not be described in detail in the present application. The vibration can be realized through a mechanical spring device or an electric control device, and the vibration frequency can be adjusted or controlled to achieve the desired effect.

[0045] In an embodiment not shown in the drawings, a controller is further included and electrically connected to the vibration device 55. The controller is used to determine whether the one-way valve 54 is open when receiving a vibration instruction. In the state that the one-way valve 54 is open, the vibration device 55 is controlled to vibrate the pipeline 53.

[0046] The one-way valve 54 can be configured as an electric control valve, such as a solenoid valve, an electric control plug valve, etc. The vibration device 55 can also be configured as an electric control device, such as a motor-driven vibration device. The controller can determine the opening state of the one-way valve 54 before controlling the vibration. Only when it is determined that the one-way valve 54 is in the closed state, the vibration device is controlled to work. In this way, it can be ensured that the dust shaken off directly flows from the pipeline 53 along the flue 51 to the dust removal device 52, and will not flow into the sealed box 30.

[0047] In a possible implementation, the driving mechanism 10 includes a motor 11, a shaft coupling 12, and a speed reducer 13 connected in sequence, and a transmission shaft 20 connected to the output end of the speed reducer 13.

[0048] As shown in FIG. 1, it is a schematic view of the sealed box 30 in an embodiment of the present application. The left side is a front view, the right side is a rear view, and the middle is a sectional view. Figure 3 As shown in FIG. 1, it is a schematic view of the sealed box 30 in an embodiment of the present application. The left side is a front view, the right side is a rear view, and the middle is a sectional view. Figure 3-1 As shown in FIG. 1, it is a schematic view of the sealed box 30 in an embodiment of the present application. The left side is a front view, the right side is a rear view, and the middle is a sectional view. Figure 3-2 As shown in FIG. 1, it is a schematic view of the sealed box 30 in an embodiment of the present application. The left side is a front view, the right side is a rear view, and the middle is a sectional view. Figure 4 As shown in FIG. 1, it is a schematic view of the sealed box 30 in an embodiment of the present application. The left side is a front view, the right side is a rear view, and the middle is a sectional view. Figure 4-1 As shown in FIG. 1, it is a schematic view of the sealed box 30 in an embodiment of the present application. The left side is a front view, the right side is a rear view, and the middle is a sectional view. Figure 4-2 As shown in FIG. 1, it is a schematic view of the sealed box 30 in an embodiment of the present application. The left side is a front view, the right side is a rear view, and the middle is a sectional view.

[0049] In the illustrated embodiment, the sealed box 30 includes a pressing plate 31 and a box body 32 with one open side. The pressing plate 31 is integrally formed on the back of the fan 40, and the ring-shaped groove 311 is formed on the pressing plate 31. The box body 32 is sleeved on the transmission shaft 20, and the open side thereof faces the pressing plate 31 and the edge 321 thereof extends into the ring-shaped groove 311. The sealing ring 33 is clamped between the edge 321 and the ring-shaped groove 311.

[0050] Through the embedded cooperation structure of the edge 321 of the box body 32 and the annular groove 311, the good sealing of the sealing box 30 and the fan 40 is realized, and the possibility of dust leakage from the sealing box 30 can be effectively reduced.

[0051] In the illustrated embodiment, the box body 32 comprises a first sub-box body 322 and a second sub-box body 324, and the first sub-box body 322 and the second sub-box body 324 are both formed with a groove 326 suitable for the surface adaptation of the transmission shaft 20, and the groove 326 is configured to clamp the transmission shaft 20 from both sides, and the groove 326 completely surrounds the transmission shaft 20.

[0052] The prior art baffle structure is integrally formed with a hole at the center position, and is sleeved on the transmission shaft 20 through the hole. The deficiency is that there must be a certain gap between the hole and the outer wall of the transmission shaft 20, otherwise it is difficult to install, but this will lead to poor sealing performance. In the embodiment of the application, the box body 32 is designed in a split form, and is sleeved on the transmission shaft 20 by clamping from both sides, and the gap between the box 32 and the wall surface can be smaller or even non-existent, and the overall sealing effect is better.

[0053] Further, with reference to the accompanying drawings Figure 2 At one end of the pipeline 53 close to the flue 51, a stop valve is arranged, which can facilitate maintenance after failure. The distance between the stop valve and the flue 51 can be adaptively sleeved according to the need, and the operation is convenient.

[0054] The above description is only the preferred embodiment of the present application and the explanation of the applied technical principles, and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. The utility model scope involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above utility model concept. For example, the technical solutions formed by the mutual replacement of the above features and the technical features disclosed in the present application (but not limited to) having similar functions.

Claims

1. An air preheater leak prevention device, characterized by, The utility model relates to a kind of exhaust heat device, comprising: Driving mechanism (10);Transmission shaft (20), one end is connected in the output of the driving mechanism (10); Sealing box (30), one side is relative rotation and sealingly encased in the transmission shaft (20), part of the wall surface of the sealing box (30) is spaced apart from the transmission shaft (20), to form sealed space between the transmission shaft (20) and the sealing box (30); Fan (40) for making cold air flow to waste heat device according to preset direction, the fan (40) is connected on the other end of the transmission shaft to be driven to rotate by the driving mechanism (10), the other side of the sealing box (30) is sealingly connected in the back of the fan (40);And, negative pressure device (50) for forming negative pressure space, the negative pressure device (50) is communicated with the sealing box (30);Wherein, the sealed space is used to accommodate dust.

2. The air preheater leak prevention apparatus of claim 1, wherein, The negative pressure device (50) includes: flue (51), negative pressure space is formed in the inside;Dust removal device (52) is communicated with the flue (51);Pipeline (53), the pipeline (53) is connected between the flue (51) and the sealing box (30), wherein, dust in the sealed space flows to the dust removal device (52) along the pipeline (53) and the flue (51) under the action of negative pressure, is collected by the dust removal device (52).

3. The air preheater leak prevention apparatus of claim 2, wherein, The negative pressure device (50) includes: check valve (54), is arranged on the pipeline (53), is configured to open when the pressure in the flue (51) is less than a threshold value of the sealing box (30), and close when the pressure in the flue (51) is greater than or equal to the threshold value of the sealing box (30).

4. The air preheater leak prevention apparatus of claim 3, wherein, The negative pressure device (50) includes: vibration device (55), is arranged inside or outside the pipeline (53), for making the pipeline (53) vibrate.

5. The air preheater leak prevention apparatus of claim 4, wherein, Also include controller, is electrically connected to the vibration device (55), the controller is used to judge whether the check valve (54) is opened when receiving vibration instruction, controls the vibration device (55) and strikes the pipeline (53) in the state that the check valve (54) is opened.

6. The air preheater leak prevention apparatus of claim 3, wherein, The check valve (54) includes: elastic member (541) and plug body (542) connected in the end of the elastic member (541), the plug body (542) is blocked in the elastic member (541) stretch state The pipeline (53), and the plug body (542) at least partially opens the pipeline (53) in the elastic member (541) contraction state.

7. The air preheater leak prevention apparatus of claim 6, wherein, The pipeline (53) is provided with the blocking part (532) in the pipeline (53) and defines throat (531), the blocking part (532) is configured to make the throat (531) be horizontal direction;The elastic member (541) is configured to stretch and contract in horizontal direction, and the plug body (542) is used to open and block the throat (531) under the action of the elastic member (541).

8. The air preheater leak prevention apparatus of claim 1, wherein, The sealing box (30) comprises a pressing plate (31) and a box body (32) with one side open; the pressing plate (31) is integrally formed on the back of the fan (40), and a ring-shaped groove (311) is formed on the pressing plate (31); the box body (32) is sleeved on the transmission shaft (20), the open side thereof faces the pressing plate (31), and the edge (321) thereof extends into the ring-shaped groove (311), and a sealing ring (33) is clamped between the edge (321) and the ring-shaped groove (311).

9. The air preheater leak prevention apparatus of claim 1, wherein, The driving mechanism (10) comprises a motor (11), a shaft coupling (12) and a speed reducer (13) connected in sequence, and the transmission shaft (20) is connected to the output end of the speed reducer (13).

10. The air preheater leak prevention apparatus of claim 8, wherein, The box body (32) comprises a first sub-box body (322) and a second sub-box body (324), the first sub-box body (322) and the second sub-box body (324) are both formed with a groove (326) suitable for the surface of the transmission shaft (20), the groove (326) is configured to clamp the transmission shaft (20) from both sides by the first sub-box body (322) and the second sub-box body (324), and the groove (326) completely surrounds the transmission shaft (20).

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