CN112761743B - Gas turbine exhaust diffuser seal structure - Google Patents

Abstract

The invention provides a sealing structure of an exhaust diffuser of a gas turbine, which belongs to the field of gas turbines.A mounting groove is arranged on one of an inner ring of a front-section diffuser and an inner ring of a rear-section diffuser, the mounting groove is arranged on the matching surface of the inner ring of the front-section diffuser and the inner ring of the rear-section diffuser, the sealing ring is partially positioned in the mounting groove, a first spring is arranged on the side surface of the mounting groove, the first spring pushes the sealing ring out towards the pressure direction of gas generated to the sealing ring, a second spring is arranged at the bottom of the mounting groove, and the second spring pushes the sealing ring out of the mounting groove, so that the sealing ring is tightly pressed on the matching surface of the inner ring of the front-section diffuser and the inner ring of the rear-section diffuser and the side wall of the mounting groove; the stability of the sealing structure is further improved through structures such as the spring sleeve and the like; simple structure and low cost.

Description

A gas turbine exhaust diffuser sealing structure

technical field

The invention relates to the field of gas turbines, relates to a gas turbine exhaust diffuser, and in particular relates to a gas turbine exhaust diffuser sealing structure.

Background technique

In industrial gas turbines, the exhaust gas velocity of the turbine is high, which will make the loss of exhaust gas larger and affect the efficiency of the unit. In order to reduce this part of the loss, the exhaust gas velocity must be reduced, so a diffuser is installed on the exhaust side of the turbine, usually The diffuser is an annular channel composed of inner and outer rings, and the axial span is relatively large. In addition, the tangential support, oil pipe, air pipe, etc. must pass through the diffuser to the rear bearing seat, in order to facilitate installation and reduce the axial span , the diffuser will be designed into a two-section structure in the axial direction, and a sealing structure will be set at the connection part to prevent gas leakage. If gas leakage occurs at the inner ring position, the gas will directly reach the bearing seat. If the temperature of the bearing is increased, the bearing will be damaged. If there is lubricating oil seeping out, it will cause a fire. Therefore, the tightness of the connection between the front and rear sections of the diffuser should be strictly guaranteed.

FIG. 1 is a schematic structural diagram of a diffuser according to the prior art solution, and FIG. 2 is an enlarged view of part A of the prior art solution. Among them, the support plate 2 passes through the cylinder 1, the front diffuser outer ring 3 and the front diffuser inner ring 5 are connected with the bearing seat 7 to support the bearing of the gas turbine; the front diffuser outer ring 3 and the rear diffuser outer ring 4 The diffuser outer ring is formed, the front diffuser inner ring 5 and the rear diffuser inner ring 6 form the diffuser inner ring; the connection between the front diffuser inner ring 5 and the rear diffuser inner ring 6 is provided with a diffuser sealing structure, such as As shown in FIG. 2 , a sealing groove 8 is provided on the inner ring 5 of the front diffuser or the inner ring 6 of the rear diffuser, and a sealing ring 9 is installed in the sealing groove 8. The connection structure of the inner ring 6 of the diffuser is sealed to prevent the leakage of gas and lubricating oil from causing bearing damage.

However, the above-mentioned prior art solution has the following problems: compared with the cylinder 1, the wall of the diffuser is thinner, so when it is in a higher temperature environment, deformation is more likely to occur, and the deformation amount is larger than that of the cylinder. Due to the large diameter of the diffuser and the splicing structure of the front and the rear, when the circumferential heating is uneven, the amount of deformation will be different, which is easy to cause the displacement of the sealing ring, which may easily lead to the failure of the sealing structure. In addition, during the operation of the unit, due to the influence of vibration and other factors, it may also cause seal failure, resulting in gas leakage, affecting the safe operation of the unit.

In view of the above problems, the document CN109630218A discloses an exhaust member of a gas turbine, which is provided with an inner diffuser, which is formed in a cylindrical shape and is divided into a plurality of parts in the circumferential direction; The circumferential direction is integrally formed, and the front end portion is connected to the rear end portion of the inner diffuser; the second seal case is formed in a cylindrical shape and is integrally formed along the circumferential direction, and the front end portion is connected to the rear end portion of the first seal case; support connection The part supports the rear end part of the first seal case and the front end part of the second seal case so as to be movable in the axial direction. Therefore, it is easy to detach and install the casing, and it is possible to realize the improvement of the maintainability. However, its sealing structure can only cope with the axial movement between the first sealing casing and the second sealing casing, and when the two move radially, there is a certain risk of sealing failure.

Document CN104040148A discloses a gas turbine, which includes a strut, which penetrates the outer diffuser and the inner diffuser to connect the exhaust chamber wall and the bearing box; a strut cover, which covers the strut along the extending direction of the strut; a partition wall, which is arranged in the Between the radially inner side of the inner diffuser and the radially outer side of the bearing housing, the upstream side portion and the bearing housing are sealed, and the downstream side portion and the inner diffuser are sealed. The pillar through-hole; the hole sealing member is fixed to the pillar through-hole of the partition wall so as to be relatively movable in the extending direction with respect to the pillar, and closes the gap between the pillar through-hole and the pillar. This document describes a sealing member, which uses a spring to press the sealing body against the inner wall of the inner diffuser, so as to ensure that when the gas turbine is running, when the equipment is thermally expanded due to the cooling gas, the shaft will occur. The seal can still be maintained during lateral and radial displacement. However, in the above technical solution, the axial movement is handled by the sealing body sliding on the inner diffusion wall. When sliding, the sealing body moves between the two side walls of the groove where it is located, and cannot be pressed against the side walls, which is easy to make The gas enters the space near the bearing housing from the gap between the seal body and the groove in which it is located, and there is a risk of seal failure.

SUMMARY OF THE INVENTION

Aiming at the problem that the sealing structure in the prior art is easy to cause sealing failure when sliding, the present invention provides a sealing structure for a gas turbine exhaust diffuser.

In order to achieve the above purpose, the technical solution adopted in the present invention is as follows: a gas turbine exhaust diffuser sealing structure, including a front diffuser inner ring, a rear diffuser inner ring, a sealing ring, a first spring, and a second spring, so The front diffuser inner ring is matched with the rear diffuser inner ring, and is characterized in that one of the front diffuser inner ring and the rear diffuser inner ring is provided with an installation groove, and the installation groove It is arranged on the mating surface of the inner ring of the front diffuser and the inner ring of the rear diffuser, the sealing ring is partially located in the installation groove, and the first spring is provided on the side of the installation groove, The first spring pushes the sealing ring out in the direction of the pressure generated by the gas on the sealing ring, and the second spring is provided at the bottom of the installation groove, and the second spring pushes the sealing ring to the top out of the mounting slot.

Preferably, the sealing ring is provided with a first hole for accommodating the first spring and a second hole for accommodating the second spring, and both the first hole and the second hole are blind holes.

Preferably, the first holes and the second holes on the sealing ring are arranged in a staggered manner.

Preferably, spring sleeves are respectively sleeved on the side of the first spring away from the first hole and the side of the second spring away from the second hole.

Preferably, the opening side part of the spring sleeve sleeved on the first spring is located in the first hole, and the opening side part of the spring sleeve sleeved on the second spring is located in the first hole in the second hole.

Preferably, a through hole is drilled at the bottom of the spring sleeve, an opening is provided on the side of the spring sleeve, and the opening communicates with the through hole.

Preferably, the sealing ring is a combination of a plurality of identical sealing rings.

Preferably, both ends of the sealing ring unit are respectively machined with a first sealing extension section and a second sealing extension section, and the first sealing extension section of the adjacent sealing ring unit and the The second sealing protrusions are overlapped in sequence.

Preferably, the sealing structure further comprises a sealing groove and a sealing ring, the cross-section of the sealing groove is a trapezoid with the width of the bottom of the groove smaller than the width of the groove, and the cross-section of the sealing ring is a trapezoid matching the sealing groove.

Preferably, the number of the sealing grooves is multiple, the sealing grooves are spaced apart, and the number of the sealing rings is the same as the number of the sealing grooves.

The invention has the following beneficial effects: the first spring and the second spring press the sealing ring against the side wall of the sealing groove and the mating surface, so that the sealing ring can still be pressed against the contact surface when sliding between the sealing ring and its contact surface , reducing the risk of sealing structure failure when the sealing structure slides relative to the contact surface; the exhaust diffuser sealing structure of the present invention is simple and easy to implement, and the front-end diffuser inner ring is installed by installing a sealing ring on the rear diffuser. . The sealing of the inner ring of the rear diffuser reduces the improvement cost of the existing equipment, and at the same time can effectively reduce the leakage and ensure the safe operation of the unit; it is easy to disassemble and assemble and improve the maintainability of the unit.

Description of drawings

FIG. 1 is a schematic structural diagram of an exhaust diffuser according to the prior art solution.

FIG. 2 is an enlarged view of part A of the prior art solution.

FIG. 3 is a schematic diagram of the exhaust diffuser sealing structure of a gas turbine exhaust diffuser sealing structure.

FIG. 4 is an enlarged view of part B of a gas turbine exhaust diffuser sealing structure.

FIG. 5 is a front view of a spring cover of a gas turbine exhaust diffuser sealing structure.

Figure 6 is a C-C sectional view of the spring cover.

FIG. 7 is a schematic diagram of a single structure of a sealing ring of a sealing structure of a gas turbine exhaust diffuser.

FIG. 8 is a schematic diagram of the assembly of a sealing ring of a gas turbine exhaust diffuser sealing structure.

In the figure: 1 is the cylinder, 2 is the support plate, 3 is the outer ring of the front diffuser, 4 is the outer ring of the rear diffuser, 5 is the inner ring of the front diffuser, 6 is the inner ring of the rear diffuser, 7 is the bearing seat , 8 is the sealing groove, 9 is the sealing ring, 10 is the first hole, 11 is the first spring, 12 is the spring sleeve, 1201 is the first spring sleeve, 1202 is the second spring sleeve, 13 is the second hole, 14 is the The second spring, 15 is the installation groove, 16 is the sealing ring, 17 is the sealing ring unit, 17a is the first sealing ring unit, 17b is the second sealing ring unit, 18 is the first sealing extension section, 19 is the first sealing ring unit The second seal extension.

Detailed ways

Hereinafter, the present invention will be further described with reference to the specific embodiments of the drawings. The content of the present invention is only directed to the sealing structure of the end of the diffuser, and does not involve the structure and installation and fixation of the diffuser.

In the description of the present invention, it should be noted that terms indicating orientation or positional relationship such as "upper", "lower", "left" and "right" are based on the orientation or positional relationship shown in the drawings, and are only for simplification It is described, rather than indicated or implied, that the referred device or element must have a particular orientation, particular orientation configuration, or operation, and therefore should not be construed as limiting the invention. In addition, under the premise of no conflict, the various embodiments or technical features described below can be combined arbitrarily to form new embodiments.

In the description of the present invention, the axial direction refers to the left and right directions in the figure; the radial direction refers to the upper and lower directions in the figure. In addition, the drawings only schematically illustrate the sealing structure at the end of the exhaust diffuser and its location, but this does not constitute a limitation on the sealing structure scheme of the exhaust diffuser of the gas turbine.

As shown in Figures 3 and 4, a gas turbine exhaust diffuser sealing structure includes a front diffuser inner ring 5, a rear diffuser inner ring 6, a sealing ring 16, a first spring 11, a second spring 14, and a front diffuser inner ring 5. The diffuser inner ring 5 is matched with the rear diffuser inner ring 6, and is characterized in that one of the front diffuser inner ring 5 and the rear diffuser inner ring 6 is provided with an installation groove 15, and the installation groove 15 is arranged in the front diffuser. On the mating surface of the inner ring 5 of the diffuser and the inner ring 6 of the rear diffuser, the sealing ring 16 is partially located in the installation groove 15, and a first spring 11 is arranged on the side of the installation groove 15. To push the sealing ring 16 out in the direction of the pressure, the bottom of the installation groove 15 is provided with a second spring 14 , and the second spring 14 pushes the sealing ring 16 out of the installation groove 15 . In this embodiment, the installation groove 15 is arranged on the inner ring 6 of the rear diffuser, and the first spring 11 pushes the sealing ring 16 toward the bearing, so that the sealing ring 16 is pressed against the side of the installation groove 15 close to the bearing, The second spring 14 pushes the sealing ring 16 out of the installation groove 15 and presses the sealing ring 16 against the inner ring 5 of the front diffuser.

Taking this embodiment as an example, the principle of the present invention will be explained: when the exhaust diffuser is working, the gas flows from the front diffuser to the rear diffuser through the annular channel between the diffuser outer ring and the diffuser inner ring, At this time, the gas pressure in the annular channel is relatively large, and the pressure in the direction of the bearing is generated on the sealing ring 16 through the gap between the inner ring 5 of the front diffuser and the inner ring 6 of the rear diffuser. Since the second spring 14 presses the sealing ring 16 on the inner ring 5 of the front diffuser, the gas in the annular channel is prevented from entering the space near the bearing seat 7; the first spring 11 presses the sealing ring 16 against the side of the installation groove 15 On the wall, the gas in the annular channel is prevented from entering the space near the bearing seat 7 from the side wall of the installation groove 15; at the same time, since the gas pressure and the pressure generated by the first spring 11 are both directed toward the bearing, the sealing ring 16 is further compressed. It is installed on the side wall of the groove 15 , thereby improving the sealing effect of the sealing ring 16 . When there is an axial displacement between the front diffuser inner ring 5 and the rear diffuser inner ring 6, under the elastic force of the first spring 11, the sealing ring 16 is still pressed against the front diffuser inner ring 5, so that the The sealing ring 17 can still seal. When radial displacement occurs between the inner ring 5 of the front diffuser and the inner ring 6 of the rear diffuser, under the elastic force of the second spring 14, the sealing ring 16 is still pressed against the side wall of the installation groove 15, so that The sealing ring 16 remains sealed. When the sealing structure is affected by the vibration of the front diffuser inner ring 5 and the rear diffuser inner ring 6, the sealing structure is always pressed against the side wall of the installation groove 15 and the front diffuser by the elastic force of the first spring 11 and the second spring 14. On the inner ring 5 of the device, sealing is achieved. Through the above method, the sealing structure can still maintain the sealing when the axial and radial displacement and vibration occur between the front diffuser inner ring 5 and the rear diffuser inner ring 6, and the radial sealing and the axial sealing are realized. At the same time, when sliding occurs between the sealing ring 16 and its contact surface, the sealing ring 16 is kept in a pressed state with the contact surface, so as to avoid the failure of the sealing structure during sliding.

As shown in FIG. 4 , the sealing ring 16 is provided with a first hole 10 for accommodating the first spring 11 and a second hole 13 for accommodating the second spring 14 , the first hole 10 and the second hole 13 are both blind holes. The first spring 11 and the second spring 14 are accommodated through the first hole 10 and the second hole 13 , so as to facilitate the installation of the sealing ring 16 .

As shown in FIG. 7 , the first holes 10 and the second holes 13 on the sealing ring 16 are arranged in a staggered manner. By staggering the arrangement of the first holes 10 and the second holes 13, the partial structure of the sealing ring unit 17 is avoided.

As shown in FIG. 4 , the side of the first spring 11 away from the first hole 10 and the side of the second spring 14 away from the second hole 13 are respectively sleeved with a spring sleeve 12 . In this embodiment, a first spring cover 1201 is provided on the side of the first spring 11 away from the first hole 10 , and a second spring cover 1202 is provided on the side of the second spring 14 away from the second hole 13 . By wrapping the first spring 11 and the second spring 14 in the first spring sleeve 1201 and the second spring sleeve 1202 respectively, the spring can be prevented from being skewed and the influence of the high-heat and high-pressure gas in the annular channel on the performance of the spring can be reduced, thereby preventing the spring from being skewed. failure, improve the stability of the sealing structure.

As shown in FIG. 4 , the opening side part of the spring sleeve 12 sleeved on the first spring 11 is located in the first hole 10 , and the opening side part of the spring sleeve 12 sleeved on the second spring 14 is located in the second hole 13 Inside. In this embodiment, the opening side part of the first spring cover 1201 is located in the first hole 10 , and the opening side part of the second spring cover 1202 is located in the second hole 13 . By extending the spring cover 12 into the first hole 10 or the second hole 13 , the stability of the installation structure of the spring cover 12 is improved.

As shown in FIGS. 5 and 6 , a through hole is drilled at the bottom of the spring sleeve 12 , an opening is provided on the side of the spring sleeve 12 , and the opening is communicated with the through hole. Through the through holes and openings, the gas inside the spring cover is communicated with the gas outside, so that the pressing force of the spring on the sealing ring 16 is not affected by the gas pressure in the spring cover. In addition, the installation of the spring cover 12 into the first hole 10 or the second hole 13 can be facilitated by providing the opening.

As shown in FIGS. 7 and 8 , the seal ring 16 is formed by combining a plurality of identical seal ring units 17 . In this way, the disassembly and assembly of the seal ring 16 can be facilitated.

As shown in FIG. 7, both ends of the sealing ring unit 17 are respectively machined with a first sealing extension 18 and a second sealing extension 19, and the first sealing extension 18 of the adjacent sealing ring unit 17 is The second sealing projections 19 overlap in sequence. As shown in FIG. 5 , the sealing ring unit 17a is adjacent to the sealing ring unit 17b, and the first extension section 18 of the first sealing ring unit 17a overlaps the second extension section 19 of the second sealing ring unit 17b , because both the first sealing ring unit 17a and the second sealing ring unit 17b are pressed into the installation groove 15, and the sealing ring 16 is subjected to axial pressure when the exhaust diffuser is in use, so that the first sealing ring 16 is pressed in the axial direction. The sealing protruding section 18 is pressed against the second sealing protruding section 19 so as to achieve radial sealing.

As shown in FIG. 4 , the sealing structure also includes a sealing groove 8 and a sealing ring 9 . The trapezoidal cross-section facilitates the installation and cooperation of the sealing ring 9 and the sealing groove 8, and the sealing ring 9 is pressed against the side of the sealing groove 8, so that the sealing ring 9 can also be pressed on the side of the sealing groove 8. Seal, improve the sealing effect.

As shown in FIG. 4 , the number of the sealing grooves 8 is plural, the sealing grooves 8 are spaced apart, and the number of the sealing rings 9 is the same as the number of the sealing grooves 8 . Multi-level sealing is performed by setting multiple sealing grooves 8 and sealing rings 9, and by setting intervals, it is avoided that the setting of sealing grooves 8 and sealing rings 9 are too concentrated at the same time, so that the force of the structural member where the sealing groove 8 is located is more uniform, Thereby, the sealing performance and the reliability of the sealing structure are improved.

The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect, and non-essential technical features can be increased or decreased according to actual needs to meet the needs of different situations.

Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than limiting the protection scope of the present invention. It deviates from the essence and scope of the technical solution of the present invention.

Claims (10)

1. The utility model provides a gas turbine exhaust diffuser seal structure, includes anterior segment diffuser inner ring, back end diffuser inner ring, sealing ring, first spring, second spring, anterior segment diffuser inner ring with back end diffuser inner ring cooperatees, its characterized in that: the gas-gas burner is characterized in that one of the front-section diffuser inner ring and the rear-section diffuser inner ring is provided with a mounting groove, the mounting groove is formed in the matching surface of the front-section diffuser inner ring and the rear-section diffuser inner ring, the sealing ring is partially located in the mounting groove, the side face of the mounting groove is provided with the first spring, the first spring enables the sealing ring to eject gas in the direction of pressure generated by the sealing ring, the bottom of the mounting groove is provided with the second spring, and the second spring enables the sealing ring to eject out of the mounting groove.

2. The gas turbine exhaust diffuser seal arrangement of claim 1, wherein: and a first hole for accommodating the first spring and a second hole for accommodating the second spring are arranged on the sealing ring, and the first hole and the second hole are blind holes.

3. A gas turbine exhaust diffuser seal construction as set forth in claim 2 wherein: the first holes and the second holes on the sealing ring are arranged in a staggered mode.

4. A gas turbine exhaust diffuser seal construction as set forth in claim 2 wherein: one side of the first spring, which is far away from the first hole, and one side of the second spring, which is far away from the second hole, are respectively sleeved with a spring sleeve.

5. The gas turbine exhaust diffuser seal arrangement of claim 4, wherein: the part, sleeved on one side of the opening of the spring sleeve of the first spring, is positioned in the first hole, and the part, sleeved on one side of the opening of the spring sleeve of the second spring, is positioned in the second hole.

6. The gas turbine exhaust diffuser seal arrangement of claim 4, wherein: the spring sleeve is characterized in that a through hole is drilled at the bottom of the spring sleeve, an opening is formed in the side face of the spring sleeve, and the opening is communicated with the through hole.

7. The gas turbine exhaust diffuser seal arrangement of claim 1, wherein: the sealing ring is formed by combining a plurality of identical sealing ring monomers.

8. The gas turbine exhaust diffuser seal arrangement of claim 7, wherein: the free both ends of sealing ring have processed first sealed section of stretching out and the sealed section of stretching out of second respectively, and is adjacent the free sealing ring first sealed section of stretching out with the sealed section of stretching out of second is overlap joint in proper order.

9. The gas turbine exhaust diffuser seal arrangement of claim 1, wherein: the sealing structure further comprises a sealing groove and a sealing ring, the cross section of the sealing groove is trapezoidal, the width of the groove bottom is smaller than that of the groove opening, and the cross section of the sealing ring is trapezoidal matched with the sealing groove.

10. The gas turbine exhaust diffuser seal arrangement of claim 9, wherein: the number of seal grooves is a plurality of, leave the interval between the seal groove, the quantity of sealing washer with the number of seal groove is the same.

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