A high temperature metal sealing ring for a small gas turbine

Abstract

The present invention relates to a high-temperature metal sealing ring for a small gas turbine, comprising: a sealing ring, a sealing mating surface and a stress relief groove; the sealing mating surface comprises a mating surface 1 and a mating surface 2, and the stress relief groove is arranged on the inner side of the sealing ring. The beneficial effects of the present invention are: a stress relief groove is provided to absorb the high-temperature expansion, and when the temperature changes from low temperature to high temperature, the expansion direction will point to the direction of reducing the stress relief groove, which effectively solves the stress concentration caused by high-temperature expansion and improves the service life of the metal sealing ring under high temperature conditions; the width of the stress relief groove is set to the ring expansion of the sealing ring at the working temperature of the sealing ring, and the stress relief groove is just closed during normal operation, which effectively improves the sealing effect under high temperature environment; there are sealing mating surfaces on both sides with a surface roughness not greater than Ra0.8, and the free spacing is 1.005 to 1.01 times the width of the sealing groove, so as to ensure plane sealing during use, and use the pressure difference to achieve sealing, thereby improving the sealing effect.

Description

Technical Field

[0001] The invention belongs to the field of sealing devices, and in particular relates to a high-temperature metal sealing ring of a small gas turbine. Background Art

[0002] As an internal combustion power machine that uses continuous flowing gas as a working fluid to drive the impeller to rotate and convert chemical energy into work, a gas turbine consists of three core components: a compressor, a combustion chamber, and a gas turbine. The blades of the gas turbine are installed on the turbine disk. The turbine disk of a small gas turbine is generally connected by end face teeth, and the end face tooth gap is large, which will cause a large flow leakage at the top and bottom of the tooth. In addition, as the turbine disk is a high-temperature component, this leakage will cause uncontrollable cooling gas distribution, so the sealing of this part needs to be considered separately. At the same time, there should not be a large gap between the sealing ring and the sealing groove to leave a margin for expansion, otherwise it will bring hidden dangers such as vibration during high-speed rotation. However, if the gap is not enough, the metal sealing ring will be squeezed with the sealing groove when it expands due to heat, resulting in obvious stress concentration, which will affect the life of the metal sealing ring and may damage the sealed parts such as the turbine disk, thereby affecting their life.

[0003] Sealing is generally performed by installing a sealing ring. CN112780772A discloses a U-shaped metal sealing ring; CN213775537U discloses a metal sealing ring used between the valve seat and the valve body opening, which cannot be used for sealing between gas turbine disks, and cannot be used in situations where the temperature is high and reaches above 500°C. CN213775537U discloses a metal sealing ring with a special-shaped cross section, but does not describe how it can be used for sealing on the turbine side, or for high-temperature applications.

[0004] In summary, existing sealing rings have the problem that they cannot be used for sealing between gas turbine disks and cannot be used in situations where the temperature is as high as 500°C or above. Summary of the invention

[0005] The object of the present invention is to overcome the deficiencies in the prior art and provide a high-temperature metal sealing ring for a small gas turbine.

[0006] The high-temperature metal sealing ring of this small gas turbine includes a sealing ring, a sealing mating surface and a stress relief groove; the sealing mating surface includes a mating surface one and a mating surface two, the mating surface one and the mating surface two are respectively arranged on the upper and lower surfaces of the sealing ring, and the ring cross-section of the sealing ring between the mating surface one and the mating surface two is an arc concave toward the center of the sealing ring; the stress relief groove is arranged on the inner side of the sealing ring, the depth direction of the stress relief groove is perpendicular to the ring, and the deepest surface of the stress relief groove is in the shape of an arc.

[0007] Preferably, a plurality of stress relief grooves are provided on the sealing ring, and the number of the stress relief grooves should be less than or equal to 4.

[0008] Preferably, the width L of the stress relief groove is determined by the diameter expansion of the sealing ring when working at high temperature, and the sum of the widths L of all stress relief grooves should be equal to or smaller than the diameter expansion of the sealing ring.

[0009] Preferably, the sealing ring is made of high temperature alloy; the surface roughness of the first and second mating surfaces is not greater than Ra0.8, and the free distance between the first and second mating surfaces is 1.005 to 1.01 times the width of the sealing groove.

[0010] As a preference: the surfaces of the first mating surface and the second mating surface are provided with lead-in chamfers.

[0011] Preferably, the sealing ring is made by integral machining.

[0012] The high temperature metal sealing ring of the small gas turbine comprises the following steps:

[0013] Step 1: Meshing turbine discs: meshing turbine disc 1 and turbine disc 2 with each other through end face teeth;

[0014] Step 1: Install the sealing ring: install the sealing ring in the sealing groove between the turbine disk 1 and the turbine disk 2, and press the mating surface 1 and the mating surface 2 against both sides of the sealing groove respectively;

[0015] Steps, gas turbine operation: The high-temperature combustion gas generated by the small gas turbine is located above the turbine disk 1 and the turbine disk 2 to push the blades to do work, and the cooling air path is located below the turbine disk 1 and the turbine disk 2. The air pressure P1 of the cooling air below is higher than the air pressure P2 of the high-temperature combustion gas above, and the mating surface 1 and the mating surface 2 are closer to the surface of the sealing groove; and the metal sealing ring expands as the temperature increases, and the width L of the stress relief groove becomes narrower.

[0016] The beneficial effects of the present invention are:

[0017] 1) The present invention is provided with a stress relief groove to absorb high-temperature expansion. When the temperature of the metal sealing ring changes from low temperature to high temperature, its expansion direction will point to the direction of shrinking the stress relief groove, which effectively solves the problem of stress concentration caused by high-temperature expansion of the metal sealing ring and improves the service life of the metal sealing ring under high temperature conditions.

[0018] 2) The present invention sets the width of the stress relief groove to the ring expansion amount of the sealing ring at the working temperature of the sealing ring, so that during normal operation, the sealing ring will just close the stress relief groove due to thermal expansion, thereby achieving a leak-free seal and effectively improving the sealing effect in a high temperature environment.

[0019] 3) The present invention is provided with sealing mating surfaces on both sides, and the surface roughness is not greater than Ra0.8, and the free spacing between the two mating surfaces is 1.005 to 1.01 times the width of the sealing groove, thereby ensuring that the sealing ring is in a compressed state during use and achieving plane sealing, achieving sealing by utilizing pressure difference, and improving the sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the overall schematic diagram of the high temperature metal sealing ring;

[0021] Figure 2 It is a schematic diagram of the cross section of a high temperature metal sealing ring;

[0022] Figure 3 for Figure 1 Schematic diagram of the stress relief groove of the high temperature metal sealing ring at position A in the middle;

[0023] Figure 4 Schematic diagram of the application scenario of high-temperature metal sealing rings.

[0024] Explanation of the reference numerals: sealing mating surface 1, mating surface one 2, mating surface two 3, stress relief groove 4, turbine disk one 5, turbine disk two 6, end face tooth 7. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0026] Embodiment 1

[0027] As an example, Figures 1 to 3 As shown: a high-temperature metal sealing ring of a small gas turbine, the high-temperature metal sealing ring is made of high-temperature alloy material through integral machining, including a sealing ring, a sealing mating surface 1 and a stress relief groove 4; the sealing mating surface 1 requires high precision, and the surface roughness is not greater than Ra0.8; the sealing mating surface 1 includes a mating surface 1 2 and a mating surface 2 3, the mating surface 1 2 and the mating surface 2 3 are respectively arranged on the upper and lower surfaces of the sealing ring and are provided with an introduction chamfer, which is convenient for installation; the free spacing between the mating surface 1 2 and the mating surface 2 3 is 1.005 to 1.01 times the width of the sealing groove, and the ring cross section of the sealing ring is an arc concave toward the center of the sealing ring;

[0028] No more than four stress relief grooves 4 are arranged on the inner side of the sealing ring, the depth direction of the stress relief groove 4 is perpendicular to the ring, and the deepest surface of the stress relief groove 4 is arc-shaped; the width L of the stress relief groove is set based on the temperature of the position during normal operation of the small gas turbine, and is determined by the diameter expansion of the sealing ring during high-temperature operation, and the sum of the widths L of all stress relief grooves 4 should be equal to or slightly smaller than the diameter expansion of the sealing ring, so that the sealing ring can just close the stress relief groove due to thermal expansion during normal operation, thereby achieving a leak-free seal.

[0029] During use, if Figure 2 and Figure 3 The left side of the sealing ring, i.e. the inner side of the sealing ring, is subjected to the pressure P1 of the cooling gas, and the right side of the sealing ring, i.e. the outer side of the sealing ring, is subjected to the pressure of the high-temperature fuel gas or the pressure P2 of the cooling gas after passing through the throttling gas path; the pressure P1 must be greater than the pressure P2, so that the two sealing surfaces set will fit the sealing component more closely under the action of the pressure difference, effectively improving the sealing efficiency of the sealing ring.

[0030] Embodiment 2

[0031] like Figures 1 to 4 As shown, another embodiment of the high-temperature metal sealing ring of the small gas turbine is as follows: the turbine disk 1 5 and the turbine disk 2 6 are aligned and meshed with each other through the end face teeth 7; in a high-temperature environment, the high-temperature combustion gas generated by the small gas turbine is above the turbine disk 1 5 and the turbine disk 2 6 to drive the blades to work, and the cooling gas is below the turbine disk 1 5 and the turbine disk 2 6;

[0032] When in use, the sealing ring is installed in the sealing groove between the turbine disk 1 5 and the turbine disk 2 6. After normal installation, the sealing mating surface 1 presses the sealing groove, thereby achieving plane sealing.

[0033] After the turbine is running, the high-temperature combustion gas generated by the small gas turbine on the outside of the meshing position of the turbine disk 1 5 and the turbine disk 2 6 drives the blades to do work. The air pressure on the outside of the sealing ring is P2, and the inside of the sealing ring is the air path for the cooling gas, and the air pressure is P1. Due to the different temperatures inside and outside the sealing ring, the air pressure P1 of the cooling gas on the inside of the sealing ring is higher than the air pressure P2 of the high-temperature combustion gas on the outside of the sealing ring, and a pressure difference is formed inside and outside the sealing ring, so that the matching surface 1 2 and the matching surface 2 3 are squeezed and more closely fit the surface of the sealing groove. At the same time, the metal sealing ring expands and becomes larger as the temperature rises, squeezing the stress relief groove 4, narrowing the width L of the stress relief groove 4, thereby achieving a leak-free seal and eliminating the problem of stress concentration caused by the high-temperature expansion of the metal sealing ring, thereby effectively improving the service life of the sealing ring.

Claims

1. A high temperature metal sealing ring for a small gas turbine, characterized in that: include: A sealing ring, a sealing mating surface (1) and a stress relief groove (4); the sealing mating surface (1) comprises a mating surface 1 (2) and a mating surface 2 (3), the mating surface 1 (2) and the mating surface 2 (3) are respectively arranged on the upper and lower surfaces of the sealing ring, and the ring cross section of the sealing ring between the mating surface 1 (2) and the mating surface 2 (3) is an arc shape concave toward the center of the sealing ring; the stress relief groove (4) is arranged on the inner side of the sealing ring, the depth direction of the stress relief groove (4) is perpendicular to the ring shape, and the deepest surface of the stress relief groove (4) is in the shape of an arc.

2. The high temperature metal sealing ring of a small gas turbine according to claim 1, characterized in that: A plurality of stress relief grooves (4) are arranged on the sealing ring, and the number of the stress relief grooves (4) should be less than or equal to 4.

3. The high temperature metal sealing ring of a small gas turbine according to claim 2, characterized in that: The width L of the stress relief groove (4) is determined by the diameter expansion of the sealing ring when working at high temperature, and the sum of the widths L of all stress relief grooves (4) should be less than or equal to the diameter expansion of the sealing ring.

4. The high temperature metal sealing ring of a small gas turbine according to claim 1, characterized in that: The sealing ring is made of high temperature alloy.

5. The high temperature metal sealing ring of a small gas turbine according to claim 1, characterized in that: The surface roughness of the mating surface 1 (2) and the mating surface 2 (3) is not greater than Ra0.

8.

6. The high temperature metal sealing ring of a small gas turbine according to claim 1, characterized in that: The free distance between the first mating surface (2) and the second mating surface (3) is 1.005 to 1.01 times the width of the sealing groove.

7. The high temperature metal sealing ring of a small gas turbine according to claim 1, characterized in that: The surfaces of the first mating surface (2) and the second mating surface (3) are provided with lead-in chamfers.

8. The high temperature metal sealing ring of a small gas turbine according to claim 1, characterized in that: The sealing ring is made by one-piece machining.

9. The high temperature metal sealing ring according to claim 1, characterized in that: The method of use includes the following steps: Step 1, meshing the turbine discs: meshing the turbine disc 1 (5) and the turbine disc 2 (6) with each other through the end face teeth (7); Step 2, installing the sealing ring: installing the sealing ring in the sealing groove between the turbine disk 1 (5) and the turbine disk 2 (6), with the mating surface 1 (2) and the mating surface 2 (3) respectively pressing the two sides of the sealing groove; Step 3, gas turbine operation: the high-temperature combustion gas generated by the small gas turbine is located on the outside of the sealing ring to push the blades to work, and the inside of the sealing ring is the air path for cooling gas. The pressure P1 of the cooling gas on the inside is higher than the pressure P2 of the high-temperature combustion gas on the outside, so that the first mating surface (2) and the second mating surface (3) are more closely attached to the surface of the sealing groove; and the metal sealing ring expands and becomes larger as the temperature rises, and the width L of the stress relief groove (4) becomes narrower.

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