Design method of oil supply device for sliding bearing tile of gas turbine capable of reversing

Abstract

The invention provides a design method of a backing gas turbine sliding bearing tile oil supply device. The design method comprises the following steps that S1, design input is given; s2, the number n of oil supply pipes is determined; s3, the diameter phi of the oil supply pipe is determined; s4, determining the positioning size L and alpha of the nozzle; s5, the nozzle diameter d and the distance LK are determined; s6, the lubricating oil flow is calculated; and S7, the designed oil supply device of the sliding bearing tile of the gas turbine capable of reversing is machined. The design method is reasonable in scheme, clear in design process and high in guidance, and the efficiency of the sliding bearing tile oil supply device of the reversing gas turbine is greatly improved. The method is summarized in the domestic design of the sliding bearing of the backing-up gas turbine in the first use process, and has very important reference value in the design of the sliding bearing of the gas turbine in the future.

Description

Technical Field

[0001] The invention belongs to the field of gas turbines and aero engines, and in particular relates to a design method for a reversible gas turbine sliding bearing pad oil supply device. Background Art

[0002] Compared with rolling bearings, sliding bearings are more suitable for working environments with large thrust loads and high speeds; and sliding bearings are less sensitive to damage from water, dust and impurities; sliding bearings tend to wear gradually and have a long service life. Even if the sliding bearing fails, the machine can continue to work for a period of time to avoid accidents caused by sudden shutdowns. The manufacturing accuracy, difficulty and cost of sliding bearings are all superior to rolling bearings. In theory, sliding bearings are more suitable for the high-speed and high-thrust working environment of gas turbines. However, there are few sliding bearings in gas turbines at home and abroad. This is mainly based on the following reasons: on the one hand, the structure of gas turbines is very compact and the working temperature is extremely high. The working temperature environment in the bearing area is very harsh, and sliding bearings are easily damaged at high temperatures; on the other hand, gas turbines are used on ships, and the working load environment is harsh. They are often affected by ocean waves, resulting in complex operating environments such as pitch, roll, bow swing, sway, sway, heave, etc., which make the bearings bear complex alternating loads and cause them to fail. In a reversible gas turbine, the sliding bearings not only need to operate under high temperature, high speed and high load conditions, but also need to operate stably under forward and reverse conditions, which increases the difficulty of sliding bearing design. As a result, the design of sliding bearings has become one of the bottlenecks in the design of reversible gas turbines. The following problems and difficulties have arisen in the design and application of sliding bearings for reversible gas turbines:

[0003] Conventional sliding bearings used in steam turbines and various common machines have a small load, usually not exceeding 10 tons. However, the axial thrust of the turbine rotor of a gas turbine power plant cannot usually be balanced and eliminated inside the machine, so the thrust of the sliding bearing is very large. The thrust of a medium-sized gas turbine is basically in the order of more than 20 tons, or even up to 40 tons. On the other hand, gas turbines have high power and compact structure, and work at high temperatures and high speeds. The working environment of sliding bearings is very harsh, above 100°C, up to 120°C, or even higher. Therefore, the design of sliding bearings in reversible gas turbines is relatively difficult.

[0004] Improvement of existing technology: In the design of gas turbine bearings, mature tilting pad sliding bearings are usually selected in China, and babbitt alloy pads are used. The working temperature of babbitt alloy is usually lower than 80℃, and it will melt and fail when working at 100℃. Improvements have also been made to the pad materials, using materials such as lead bronze to increase the working temperature of the pads.

[0005] One of the deficiencies of the existing technology is that by selecting the common tilting pad sliding bearing forms and structures at home and abroad, the common sliding bearings often wear out in the edge area of ​​the pad under the high temperature, high speed and high thrust of the gas turbine, and gradually extend to the entire pad, resulting in the failure of the bearing. The main reason is that the conventional bearing uses a nozzle or pad to supply oil, and the oil supply area can only cover the middle position of the pad, such as Figure 1 As shown, the edge area often lacks oil, causing wear at the edge. Summary of the invention

[0006] The object of the present invention is to provide a design method for a reversible gas turbine sliding bearing pad oil supply device.

[0007] A design method for a reversible gas turbine sliding bearing pad oil supply device comprises the following steps:

[0008] S1, given design input;

[0009] S2, determine the number of oil supply pipes n;

[0010] S3, determine the oil supply pipe diameter φ;

[0011] S4, determine the nozzle positioning size L and α;

[0012] S5, determine the nozzle diameter d and spacing L K ;

[0013] S6, calculate the lubricating oil flow rate;

[0014] S7, process the oil supply device of the reversible gas turbine sliding bearing pad that meets the design.

[0015] Furthermore, in S1, the maximum outer diameter D0 of the retainer of the pad oil supply device and the minimum inner diameter D0 of the large nut are given according to the spatial arrangement of the gas turbine sliding bearing and the size of the main shaft of the gas turbine. i .

[0016] Furthermore, in S2, according to the structural characteristics of the oil supply device, the number of oil supply pipes is equal to the number of sliding bearing pads.

[0017] Furthermore, the oil supply pipe diameter in S3 is constrained by the following parameters:

[0018] According to the wrap angle of the sliding bearing design parameters, the spacing L0 between the two tiles is determined. There is the following relationship between the spacing between the tiles and the width B of the oil supply pipe:

[0019] L0=B+2δ (1)

[0020] φ=B-2t (2)

[0021] Where δ is the gap between the cage and the tile, usually 0.3mm≤δ≤0.5mm. This gap can ensure that the tile can swing freely in the cage and that the lubricating oil between the tiles can be discharged in time.

[0022] t is the wall thickness of the oil supply pipe, usually 3mm or more to ensure sufficient strength of the retainer.

[0023] Furthermore, according to the working principle of the oil supply device in S4, the diameter direction of the orifice should face the edge plates on the oil inlet and oil outlet sides of the tile. The use of three-dimensional model positioning in the design can accurately and quickly determine the position and angle dimensions of the orifice.

[0024] Furthermore, in order to ensure the spraying effect of the nozzle in S5, the diameter of the nozzle hole K is 0.7mm≤d≤3mm.

[0025] The working angle of the hole injection is greater than 60°. In order to ensure that the tile can be evenly and fully lubricated along the oil inlet edge, the nozzle spacing has the following relationship.

[0026] L L ≤2*S*tan30° (3)

[0027] Where S is the distance from the nozzle to the edge of the tile.

[0028] Furthermore, in S6, the lubricating oil flow rate is adjusted by adjusting the nozzle aperture and the distance between the oil injection holes, so as to meet the design requirements of the sliding bearing.

[0029] Furthermore, during the processing in S7, the aperture d should be processed according to the design minimum value or the reserve value, and the lubricating oil flow test measurement should be carried out before installation, and the nozzle aperture d should be adjusted to meet the design requirements.

[0030] The beneficial effects of the present invention are:

[0031] 1. The oil supply device designed in the present invention has a simple structure and is easy to process. On the premise of being able to realize the complex oil supply function, it greatly saves the processing cost.

[0032] 2. Compared with the traditional oil supply device, the oil supply device designed in the present invention can prevent the bearing failure caused by insufficient oil supply to the edge of the tile and wear of the edge of the tile, and improve the formation of the oil film on the tile during operation and the cooling effect of the tile, thereby reducing the tile problem and improving the applicability of the bearing. At the same time, the present invention can adapt to the stable oil supply of the sliding bearing under the forward and reverse conditions of the reversible gas turbine.

[0033] 3. The design method of the present invention is reasonable, the design process is clear, and the guidance is strong, which greatly improves the efficiency of the oil supply device of the reversible gas turbine sliding bearing block.

[0034] 4. The present invention is summarized during the first use in the design of reversible gas turbine sliding bearings in China, and has very important reference value in the design of gas turbine sliding bearings in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a map of the area where the prior art tile slots are used for oil supply and the nozzles are not able to supply oil sufficiently;

[0036] Figure 2 This is an overall structural diagram of the oil supply device for the sliding bearing pad of a gas turbine of the present invention;

[0037] Figure 3 A cross-sectional view of the oil supply device for the sliding bearing pad of a gas turbine according to the present invention;

[0038] Figure 4 A three-dimensional model diagram of the tile oil supply device of the present invention;

[0039] Figure 5 It is the oil supply route map of the present invention;

[0040] Figure 6 This is a structural diagram of the fuel injection port of the present invention;

[0041] Figure 7 This is a structural diagram of the oil supply isolation ring nozzle of the present invention;

[0042] Figure 8 This is a diagram of the coverage of the nozzle oil injection of the present invention;

[0043] Fig. 9 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with the accompanying drawings.

[0045] The present invention firstly realizes its function through its unique structural form, adopting an oil supply isolation ring structure, such as Figure 2-Figure 4 As shown in the figure, it is mainly composed of four parts: a cage, a large nut, a pin and a plug. By controlling the oil supply to the tile, the tile can be lubricated more fully and the working temperature of the tile can be significantly reduced. The device has a simple structure and is easy to process. It can also form a complex oil supply circuit and has a perfect oil supply function.

[0046] Secondly, a reversible gas turbine sliding bearing pad oil supply device, the working oil supply principle is as follows Figure 5 As shown in FIG. 6 , the lubricating oil first enters the first oil supply pipe of the isolation ring through the oil inlet of the oil supply isolation ring, and then enters the annular oil cavity of the inner ring through the first oil supply pipe. The lubricating oil enters the remaining 7 oil supply pipes through the annular cavity. Oil injection ports are evenly arranged on both sides of each oil supply pipe along the radial direction, as shown in FIG. 6 . By adjusting the angle of the oil injection port and adjusting the angle α and position size L of the oil injection holes on both sides of the oil supply pipe, as shown in FIG. Figure 7 As shown, the lubricating oil on one side is directly sprayed into the oil inlet side of the tile, directly participating in the formation of the tile oil film, which greatly improves the film formation stability of the tile under start-stop and complex alternating load working environments; the lubricating oil coming out of the oil injection port on the other side is just sprayed to the edge of the tile and the oil film position of the oil outlet, which is the position with the highest temperature of each tile and the oil film, which greatly improves the cooling effect of the tile and greatly reduces the working temperature of the tile of the gas turbine sliding bearing. When the gas turbine reverses, the holes on the oil inlet side and the oil outlet side of the tile surface interchange, ensuring the uniform oil supply and sufficient cooling of the sliding bearing when the gas turbine is reversed. The common oil supply methods such as nozzles and tile slots in sliding bearings only set nozzles or oil inlets in the middle of the tile oil inlet, resulting in insufficient lubricating oil supply at the corners of the tile edge, which is easy to wear. The wear of the tile edge causes damage to the entire tile casting and leads to failure. Compared with the traditional oil supply structure, the oil inlet of the tile is provided with oil spraying ports along the radial direction, which makes the oil film formation of the tile more stable and reliable. At the same time, the oil outlet of the tile is also provided with cooling oil direct spraying along the radial direction, which greatly improves the cooling effect of the tile and significantly reduces the working temperature of the tile. Thus, it can adapt to the high temperature working environment of the gas turbine and the working requirements of forward and reverse rotation.

[0047] Finally, a design method for a reversible gas turbine sliding bearing pad oil supply device is implemented by the following steps:

[0048] S1: Given the design input. According to the spatial arrangement of the gas turbine sliding bearing and the size of the main shaft of the gas turbine, the maximum outer diameter D of the retainer of the pad oil supply device is given. O and the minimum inner diameter D of the large nut i .

[0049] S2: Determine the number n of oil supply pipes. According to the structural characteristics of the oil supply device, the number of oil supply pipes is equal to the number of sliding bearing pads;

[0050] S3: Determine the oil supply pipe diameter φ. In order to ensure the flow resistance in the lubricating oil pipeline, the oil supply pipe diameter φ should be as large as possible in theory, but the oil supply pipe diameter is constrained by the following parameters.

[0051] According to the wrap angle of the sliding bearing design parameters, the spacing L0 between the two tiles can be determined. There is the following relationship between the spacing between the tiles and the width B of the oil supply pipe:

[0052] L0=B+2δ (1)

[0053] φ=B-2t (2)

[0054] Among them, δ is the gap between the retainer and the tile, usually 0.3mm≤δ≤0.5mm. This gap can ensure that the tile can swing freely in the retainer and that the lubricating oil between the tiles can be discharged in time.

[0055] t is the wall thickness of the oil supply pipe, usually 3mm or more to ensure sufficient strength of the retainer.

[0056] S4: Determine the nozzle positioning dimensions L and α. According to the working principle of the oil supply device, theoretically, the diameter direction of the orifice should face the edge plate on the oil inlet and oil outlet sides of the tile. Using the three-dimensional model positioning in the design can accurately and quickly determine the position and angle dimensions of the orifice.

[0057] S5: Determine the nozzle diameter d and spacing L K To ensure the spraying effect of the nozzle, the nozzle hole K usually has a diameter of 0.7mm≤d≤3mm.

[0058] Generally, the working angle of the hole injection is greater than 60°. In order to ensure that the tile can be evenly and fully lubricated along the oil inlet edge, the nozzle spacing has the following relationship: Figure 8 shown.

[0059] L L ≤2*S*tan30° (3)

[0060] Where S is the distance from the nozzle to the edge of the tile.

[0061] S6: A reversible gas turbine sliding bearing pad oil supply device After completing the above design, the lubricating oil flow rate is calculated. The lubricating oil flow rate is adjusted by adjusting the nozzle aperture and the spacing between the oil injection holes to meet the design requirements of the sliding bearing.

[0062] S7: When processing a reversible gas turbine sliding bearing pad oil supply device, the aperture d should be processed according to the design minimum value or a reserve value, and a lubricating oil flow test measurement should be carried out before installation, and the nozzle aperture d should be adjusted to meet the design requirements.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A design method for a reversible gas turbine sliding bearing pad oil supply device, characterized in that: The following steps are involved: S1, given design input; S2, determine the number of oil supply pipes n; S3, determine the oil supply pipe diameter φ; S4, determine the nozzle positioning size L and α; S5, determine the nozzle diameter d and spacing L K ; S6, calculate the lubricating oil flow rate; S7, process the oil supply device of the reversible gas turbine sliding bearing pad that meets the design.

2. The design method of a reversible gas turbine sliding bearing pad oil supply device according to claim 1, characterized in that: In S1, the maximum outer diameter D of the retainer of the pad oil supply device is given according to the spatial arrangement of the gas turbine sliding bearing and the size of the main shaft of the gas turbine. o and the minimum inner diameter D of the large nut i .

3. The design method of a reversible gas turbine sliding bearing pad oil supply device according to claim 1, characterized in that: In S2, according to the structural characteristics of the oil supply device, the number of oil supply pipes is equal to the number of sliding bearing pads.

4. The design method of a reversible gas turbine sliding bearing pad oil supply device according to claim 1, characterized in that: The oil supply pipe diameter in S3 is constrained by the following parameters: According to the wrap angle of the sliding bearing design parameters, the spacing L0 between the two tiles is determined. There is the following relationship between the spacing between the tiles and the width B of the oil supply pipe: L0=B+2δ (1) φ=B-2t (2) Where δ is the gap between the cage and the tile, usually 0.3mm≤δ≤0.5mm. This gap can ensure that the tile can swing freely in the cage and that the lubricating oil between the tiles can be discharged in time. t is the wall thickness of the oil supply pipe, usually 3mm or more to ensure sufficient strength of the retainer.

5. The method for designing a reversible gas turbine sliding bearing pad oil supply device according to claim 1, characterized in that: According to the working principle of the oil supply device in S4, the diameter direction of the orifice should face the edge plates on the oil inlet and oil outlet sides of the tile. The position and angle dimensions of the orifice can be accurately and quickly determined by using a three-dimensional model for positioning in the design.

6. The method for designing a reversible gas turbine sliding bearing pad oil supply device according to claim 1, characterized in that: In the above S5, in order to ensure the spraying effect of the nozzle, the diameter of the nozzle hole K is 0.7mm≤d≤3mm. The working angle of the hole injection is greater than 60°. In order to ensure that the tile can be evenly and fully lubricated along the oil inlet edge, the nozzle spacing has the following relationship. L L ≤2*S*tan30° (3) Where S is the distance from the nozzle to the edge of the tile.

7. The method for designing a reversible gas turbine sliding bearing pad oil supply device according to claim 1, characterized in that: In S6, the oil flow rate is adjusted by adjusting the nozzle aperture and the distance between the oil injection holes, so as to meet the design requirements of the sliding bearing.

8. The method for designing a reversible gas turbine sliding bearing pad oil supply device according to claim 1, characterized in that: During the processing of S7, the aperture d should be processed according to the design minimum value or with a reserve. The lubricating oil flow rate test measurement should be carried out before installation, and the nozzle aperture d should be adjusted to meet the design requirements.

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