Dry gas sealing element of energy storage compressor

Abstract

The invention provides an energy storage compressor dry gas sealing element which comprises a movable ring mechanism, a static ring mechanism and an elastic supporting mechanism, and the movable ring mechanism is used for being installed on a rotating shaft; the elastic supporting mechanism is used for being installed in a compressor cavity, and the static ring mechanism is installed on the compressor cavity through the elastic supporting mechanism. The compressor cavity is provided with an air inlet channel and an exhaust channel. The static ring mechanism comprises a static ring body and a push ring, the push ring is L-shaped, a first mounting groove is formed in the push ring, and an elastic compensation piece is mounted in the first mounting groove; according to the dry gas sealing structure, in the actual using process, frequent starting and stopping can be resisted, the dry gas sealing structure adapts to large-range pressure changes, and the sealing effect is good.

Description

Technical Field

[0001] This invention relates to the field of dry gas sealing technology, specifically to a dry gas sealing component for an energy storage compressor. Background Technology

[0002] Compressed air energy storage technology boasts advantages such as high efficiency, environmental friendliness, and safety, and has broad development prospects. This technology utilizes electricity generated during off-peak hours to compress and store air, releasing the energy during peak hours to convert it into mechanical or electrical energy. This technology features high energy density, high-efficiency conversion, long lifespan, and high reliability, making it suitable for the energy storage needs of power systems.

[0003] The key equipment for compressed air energy storage is the centrifugal compressor and turbine. Due to their operating conditions, centrifugal compressors require repeated start-up and shutdown processes daily, with operating pressures varying from atmospheric pressure to tens of megapascals, and significant temperature variations. Conventional dry gas seals are unsuitable for the operating conditions of centrifugal compressors used in energy storage. Summary of the Invention

[0004] The purpose of this invention is to provide a dry gas seal for an energy storage compressor, which can withstand frequent start-stop cycles, adapt to a wide range of pressure changes, and has a good sealing effect during actual use.

[0005] The technical solution adopted in this invention is:

[0006] A dry gas seal for an energy storage compressor includes a dynamic ring mechanism, a static ring mechanism, and an elastic support mechanism, wherein the dynamic ring mechanism is used to be mounted on a rotating shaft;

[0007] The elastic support mechanism is used to be installed in the compressor cavity, and the stationary ring mechanism is installed on the compressor cavity through the elastic support mechanism; the compressor cavity is provided with an intake passage and an exhaust passage;

[0008] The stationary ring mechanism includes a stationary ring body and a push ring. The push ring is L-shaped and has a first mounting groove. An elastic compensation component is installed in the first mounting groove.

[0009] Preferably, the rotating ring mechanism includes a rotating ring body, a bushing, and a clamping sleeve. The rotating ring body is mounted on the bushing, and the clamping sleeve is mounted on the rotating shaft. A limiting area for limiting the bushing is formed between the clamping sleeve and the rotating shaft. The rotating ring body is provided with a plurality of spiral grooves.

[0010] Preferably, the elastic support mechanism includes a spring seat and a spring body, the spring seat is mounted on the compressor cavity, and the stationary ring body is connected to the spring seat through the spring body.

[0011] Preferably, a sealing element is installed on the compressor cavity, and the sealing element is provided with a plurality of sealing portions arranged in a comb-like pattern.

[0012] Preferably, the spiral groove is composed of several spiral unit grooves, and the groove depth of the spiral unit groove decreases in a stepped manner along the rotation direction of the moving ring body.

[0013] Preferably, the width of the spiral groove decreases from the high-pressure side to the low-pressure side.

[0014] Preferably, the bushing is provided with a second mounting groove, and the elastic compensation member is installed in the second mounting groove.

[0015] Preferably, a locking nut for limiting the position of the bushing is installed on the rotating shaft.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] In this invention, when the compressor is initially started, the rotational speed of the rotating shaft and the rotating ring mechanism mounted on the rotating shaft is low, and the dynamic pressure effect cannot form sufficient gas film stiffness to push the spring body support mechanism to compress. At this time, the elastic force released by the pre-compression of the elastic compensation component can act on the stationary ring body continuously and stably through the push ring, providing it with an initial and controllable closing force.

[0018] When the pressure fluctuation of the sealing gas causes a slight change in the opening force, the elastic compensation component can be quickly compressed or rebounded, and the push ring pushes the stationary ring body to make a slight axial displacement, thereby adjusting the balance between the closing force and the opening force in real time.

[0019] When the compressor is about to stop, the rotational speed of the rotating shaft decreases and the gas film opening force gradually decreases. At this time, the push ring can drive the stationary ring body to approach the end face of the moving ring mechanism at a relatively gentle speed and force under the action of the elastic compensation component until the sealing end face of the stationary ring body and the moving ring mechanism are in contact. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] Figure 2 For the present invention Figure 1 A magnified view of a portion of point A in the middle.

[0023] Figure 3 This is a schematic diagram of the structure of the moving ring body in this invention.

[0024] The attached diagram lists the components represented by each number as follows:

[0025] 101-Dynamic ring mechanism, 102-Static ring mechanism, 103-Elastic support mechanism, 104-Rotating shaft, 105-Compressor cavity, 106-Static ring body, 107-Push ring, 108-First mounting groove, 109-Elastic compensation component, 110-Dynamic ring body, 111-Shaft sleeve, 112-Pressure sleeve, 113-Spring seat, 114-Spring body, 115-Seal, 116-Sealing part, 114-Spiral unit groove, 118-Second mounting groove, 119-Locking nut. Detailed Implementation

[0026] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0027] In the description of the embodiments of the present invention, it should be understood that the terms "length", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In this embodiment of the invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention according to the specific circumstances.

[0030] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] The following disclosure provides many different implementations or examples for carrying out different structures of the embodiments of the present invention. To simplify the disclosure of the embodiments of the present invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of the present invention; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0032] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0033] Example 1

[0034] See Figures 1-3 This embodiment discloses a dry gas sealing device for sealing the sealing end face, specifically a dry gas sealing component 115 for an energy storage compressor, including a dynamic ring mechanism 101, a static ring mechanism 102 and an elastic support mechanism 103, wherein the dynamic ring mechanism 101 is used to be installed on the rotating shaft 104.

[0035] The elastic support mechanism 103 is used to be installed inside the compressor cavity 105, and the stationary ring mechanism 102 is installed on the compressor cavity 105 through the elastic support mechanism 103; the compressor cavity 105 is provided with an air intake passage and an exhaust passage.

[0036] The stationary ring mechanism 102 includes a stationary ring body 106 and a push ring 107. The push ring 107 is L-shaped and has a first mounting groove 108. An elastic compensation member 109 is installed in the first mounting groove 108.

[0037] In this embodiment, a drive device for driving the rotating shaft 104 to rotate is installed inside the compressor cavity 105. The drive device is a conventional drive device in the prior art. The output end of the drive device is fixedly connected to the rotating shaft 104, and its structure and function will not be described in detail here. When the compressor is initially started, the rotating shaft 104 and the rotating ring mechanism 101 mounted on the rotating shaft 104 rotate at a low speed, and the dynamic pressure effect cannot form sufficient gas film stiffness to push the spring body 114 support mechanism to compress. At this time, the elastic force released by the pre-compression of the elastic compensation element 109 can continuously and stably act on the stationary ring body 106 through the push ring 107, providing it with an initial and controllable closure. The force ensures a very small gap between the stationary ring end face and the rotating ring mechanism 101 end face, limiting short-circuit leakage of the sealing gas. Furthermore, as the rotational speed of the rotating shaft 104 and the rotating ring mechanism 101 increases, the clean sealing gas entering between the stationary ring end face and the rotating ring mechanism 101 end face through the air intake channel can quickly and effectively accumulate in the gap formed between them, laying a solid foundation for the rapid and stable establishment of the dynamic pressure sealing gas film between them. As the rotating ring mechanism 101 rotates at high speed with the rotating shaft 104, the dynamic pressure gas film continuously provides an opening force opposite to the closing force, pushing the spring body 114 to support it. The mechanism compresses; when the pressure fluctuation of the sealing gas causes a slight change in the opening force, the elastic compensation element 109 can be quickly further compressed or rebounded, pushing the stationary ring body 106 to make a slight axial displacement through the push ring 107, adjusting the balance between the closing force and the opening force in real time, thereby maintaining a stable sealing gap; when the compressor is about to stop, the rotation speed of the rotating shaft 104 decreases, and the gas film opening force gradually decreases; at this time, the push ring 107 can drive the stationary ring body 106 at a relatively gentle speed and force under the action of the elastic compensation element 109 to approach the end face of the moving ring mechanism 101 until the sealing end face of the stationary ring body 106 and the moving ring mechanism 101 are in contact, reducing the impact on the sealing end face at the moment of each stop under frequent start-stop conditions. The impact wear caused by the surface significantly extends the service life of the sealing pair and improves the reliability of the seal throughout its lifespan. The elastic support mechanism 103 is used to ensure that the stationary ring mechanism 102 remains in the correct position after shutdown, preparing for the next start-up. During the input of the clean sealing gas through the air inlet channel, a small amount of sealing gas in the gap between the sealing end faces and the process gas that may leak slightly are introduced into the compressor cavity 105 through the exhaust channel, ensuring the pressure in the sealing cavity is stable and avoiding abnormal pressure rise caused by gas accumulation. The exhaust channel is connected to a vent pipe, and the wear between the stationary ring end face and the end face of the moving ring mechanism 101 can be monitored by detecting the flow rate of the process gas in the vent pipe.

[0038] The elastic compensating member 109 is a C-ring structure, made of a metal material such as stainless steel or a polymer material such as polytetrafluoroethylene. The structural coefficient S of the elastic compensating member 109 can be calculated as follows:

[0039]

[0040] E is the elastic modulus (unit: Pa) of the elastic compensator 109 material; Ac is the cross-sectional area (unit: m²) of the elastic compensator 109 material. 2 Lc is the effective length (in meters) of the elastic compensator 109. In this embodiment, the average perimeter of the elastic compensator 109 is taken as the effective length. The elastic modulus E ranges from 0.1 to 200 GPa, preferably 5 GPa. The cross-sectional area Ac is generally designed to be 0.1 to 10 mm² according to the sealing conditions. 2 .

[0041] To optimize the dynamic response of the sealing system, the structural coefficient □ of the elastic compensation component 109 should match the gas film stiffness Kgas, where S = Kgas; the gas film stiffness is the rate of change of the gas film opening force with respect to the gas film thickness, reflecting the stability of the sealing gas film under dynamic conditions.

[0042]

[0043] C is a coefficient reflecting the effect of the spiral groove geometry on the gas film pressure enhancement effect. In this embodiment, the value ranges from 0.5 to 2, with a preferred value of 1.25; A is the sealing area (unit: m²). 2 ) The R0 and R i These are the outer and inner radii of the sealing ring, respectively; the P in Here, μ is the intake pressure (in Pa), μ is the dynamic viscosity of the sealing gas (in Pa·s), ω is the angular velocity of the rotating shaft (in rad / s), and L is the characteristic length (in m). The average radius of the sealing end face is taken as L = (R0 + R...). i ) / 2;

[0044] The relationship between the structural coefficient of the elastic compensation component and the sealing gas parameters is obtained as follows:

[0045]

[0046] The relationship between the structural coefficient of the elastic compensator 109 and the sealing gas parameters allows for the direct calculation of the parameters of the elastic compensator 109 based on the sealing conditions, thereby improving the reliability and lifespan of the sealing system under frequent start-stop and pressure fluctuations. For high-pressure and high-speed conditions, it is necessary to select an elastic compensator 109 with a higher elastic modulus E or a larger cross-sectional area Ac to provide sufficient stiffness.

[0047] In a further optimization, the moving ring mechanism 101 includes a moving ring body 110, a bushing 111, and a clamping sleeve 112. The moving ring body 110 is mounted on the bushing 111, and the clamping sleeve 112 is mounted on the rotating shaft 104. A limiting area for limiting the bushing 111 is formed between the clamping sleeve 112 and the rotating shaft 104. The moving ring body 110 is provided with a plurality of spiral grooves. When the rotating ring body 110 rotates at high speed, the spiral groove on the rotating ring body 110 can pump the sealing gas introduced through the air intake channel into the space between the sealing end faces, converting the kinetic energy of the fluid into pressure energy, thereby forming a dynamic pressure sealing gas film that separates the two end faces. In this embodiment, the bushing 111 and the clamping sleeve 112 are fixedly installed on the rotating shaft 104. The bushing 111 serves as the mounting base for the rotating ring body 110, achieving precise alignment and reliable torque transmission between the rotating ring and the rotating shaft 104. The limiting area formed between the clamping sleeve 112 and the rotating shaft 104 provides precise axial positioning and rigid limiting for the bushing 111.

[0048] Further optimized, the elastic support mechanism 103 includes a spring seat 113 and a spring body 114. The spring seat 113 is mounted on the compressor cavity 105, and the stationary ring body 106 is connected to the spring seat 113 via the spring body 114. Before the compressor starts, the preload of the spring body 114 is applied to the sealing end face through the spring seat 113 and the stationary ring body 106, forming an initial closing force. During the compressor's start-up, shutdown, acceleration, and deceleration, the rotating shaft 104 will experience axial movement due to changes in temperature and force. One end of the spring body 114 is fixedly connected to the spring seat 113, and the other end of the spring body 114 is fixedly connected to the stationary ring body 106. The spring body 114 in the elastic support mechanism 103 is used to compensate for macroscopic axial displacement, and the elastic compensation component 109 is used to compensate for high-frequency, small-amplitude end face force changes caused by pressure fluctuations. This approach simultaneously ensures the reliability of large displacement compensation and the high precision of micro-gap control.

[0049] Further optimization involves installing a seal 115 on the compressor cavity 105, with a plurality of sealing portions 116 arranged in a comb-like pattern. These sealing portions 116 form a multi-stage seal, effectively preventing solid particles, droplets, or tar-like substances that may be present in the untreated process gas within the compressor cavity 105 from directly impacting or entering the sealing end faces between the stationary ring body 106 and the rotating ring body 110.

[0050] Further optimization involves the spiral groove being composed of several spiral unit grooves 117, the depth of which decreases in a stepped manner along the rotation direction of the moving ring body 110. When gas flows in the spiral unit grooves 117 with stepped decreasing depth, the gas pressure can achieve a discrete, discontinuous increase along the flow path. Compared to the spiral grooves with continuously varying depths in the prior art, the spiral unit grooves 117 with stepped decreasing depths can form a gas film with higher pressure while maintaining a constant rotational speed of the rotating shaft 104. This allows the sealing end face to generate an effective opening force at a lower rotational speed, shortening the time required from startup to the formation of a stable non-contact seal.

[0051] Further optimization involves decreasing the width of the spiral groove from the high-pressure side to the low-pressure side. As gas flows from the high-pressure side to the low-pressure side, the gas flow velocity increases accordingly as the groove width decreases, allowing the gas kinetic energy to be converted into pressure energy more effectively, thus enhancing the throttling effect. The groove width structure creates a continuously varying flow area on the sealing end faces of the moving ring body 110 and the stationary ring body 106, avoiding sudden pressure changes. The narrower groove width on the low-pressure side increases the flow resistance, effectively limiting the amount of gas leakage through the sealing end face.

[0052] Further optimization involves providing a second mounting groove 118 on the bushing 111, within which the elastic compensation member 109 is installed. The second mounting groove 118 is located on the side of the bushing 111 closest to the rotating shaft 104. The elastic compensation member 109 installed within the second mounting groove 118 provides simultaneous axial and radial elastic compensation, allowing the gravel bushing 111 to make minor adaptive adjustments. This improves the fit of the end face of the rotating ring body 110 and enhances operational stability under complex working conditions.

[0053] Further optimization involves installing a locking nut 119 on the rotating shaft 104 to limit the position of the bushing 111. The clamping sleeve 112 provides an axial reference surface, and the locking nut 119 applies a preload. The locking nut 119 and the clamping sleeve 112 together form a bidirectional limiting structure to fix the axial position of the bushing 111, preventing axial movement of the bushing 111 during operation, while maintaining the normal working condition of the elastic compensation component 109.

[0054] Example 2

[0055] See Figures 1-3 This embodiment is a further optimization based on Embodiment 1. This embodiment provides a design calculation method for the spiral groove described in Embodiment 1, the method specifically including:

[0056] The spiral groove is equally divided into n spiral unit grooves 117 along the rotation direction, and the groove depth of each spiral unit groove 117 is h. i Decreasing in a stepwise manner

[0057] h i =h0-(i-1)ζΔh

[0058] Where h0 is the initial value of the high-pressure side groove depth, which ranges from 10 to 50 μm, and is preferably 30 μm in this embodiment; i is the spiral unit groove number (1-i, where i is 8-24);

[0059]

[0060] The k t , where k is the groove depth reduction coefficient, ranging from 0.01 to 0.05. In this embodiment, k is preferred. t The value is 0.03; h0 is the minimum groove depth on the low-pressure side, ranging from 2 to 10 μm, and in this embodiment, h0 is preferably 6 μm. In this embodiment, by optimizing the groove depth gradient and distribution, the gas film performance can be directly improved, the gas film establishment time can be shortened, and the working conditions of repeated daily start-stop of the energy storage compressor can be adapted to reduce the end face contact friction during the start-up phase; and the groove depth, through the coefficient C of the gas film pressure enhancement effect of the correlation reaction spiral groove geometric parameters, further realizes the quantitative matching of the gas film stiffness and the stiffness of the elastic compensation component 109.

[0061] Further optimization is achieved by calculating the coefficient C, which reflects the effect of the spiral groove geometry on the enhancement of film pressure, as follows:

[0062]

[0063] Wherein, n is the total number of spiral unit slots; n 0.3 The value of C indicates that the more unit slots there are (the greater the step density), the more significant the pressure increment superposition effect, and the larger the value of C. The exponent of 0.3 is used to reflect that when n>25, the growth of C slows down, which is consistent with the actual situation in engineering where too many unit slots will increase the processing difficulty and the pressure gain is limited. The value of γ is used to reflect the total variation of the slot depth.

[0064]

[0065] h n h represents the final groove depth at the spiral groove outlet (near the low-pressure side). avg Used for average tank depth in reaction:

[0066]

[0067] In this embodiment, the coefficient 0.85 is obtained by fitting a large amount of engineering test data on the dry gas seal of an energy storage compressor. The gas film stiffness and elastic compensation component can achieve precise matching, significantly reducing start-stop impact, reducing leakage, and extending seal life.

[0068] Table 1 below compares the sealing performance of Example 2 with that of Example 1 (based on typical operating conditions: inlet pressure Pin = 1 MPa, angular velocity ω = 1000 rad / s, sealing gas dynamic viscosity μ = 1.8 × 10⁻⁶). -5 Pa·s):

[0069]

[0070]

[0071] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dry gas seal (115) for an energy storage compressor, characterized in that: It includes a moving ring mechanism (101), a stationary ring mechanism (102), and an elastic support mechanism (103), wherein the moving ring mechanism (101) is used to be mounted on a rotating shaft (104); The elastic support mechanism (103) is used to be installed inside the compressor cavity (105), and the stationary ring mechanism (102) is installed on the compressor cavity (105) through the elastic support mechanism (103); the compressor cavity (105) is provided with an intake passage and an exhaust passage; The stationary ring mechanism (102) includes a stationary ring body (106) and a push ring (107). The push ring (107) is L-shaped and has a first mounting groove (108). An elastic compensation member (109) is installed in the first mounting groove (108).

2. The dry gas seal (115) for an energy storage compressor according to claim 1, characterized in that: The moving ring mechanism (101) includes a moving ring body (110), a bushing (111), and a clamping sleeve (112). The moving ring body (110) is mounted on the bushing (111), and the clamping sleeve (112) is mounted on the rotating shaft (104). A limiting area for limiting the bushing (111) is formed between the clamping sleeve (112) and the rotating shaft (104). The moving ring body (110) is provided with a plurality of spiral grooves.

3. The dry gas seal (115) for an energy storage compressor according to claim 1, characterized in that: The elastic support mechanism (103) includes a spring seat (113) and a spring body (114). The spring seat (113) is mounted on the compressor cavity (105), and the stationary ring body (106) is connected to the spring seat (113) through the spring body (114).

4. The dry gas seal (115) for an energy storage compressor according to claim 3, characterized in that: A sealing element (115) is installed on the compressor cavity (105), and the sealing element (115) is provided with a plurality of sealing parts (116) arranged in a comb-like pattern.

5. The dry gas seal (115) for an energy storage compressor according to claim 2, characterized in that: The spiral groove is composed of several spiral unit grooves (117), and the groove depth of the spiral unit grooves (117) decreases in a stepped manner along the rotation direction of the moving ring body (110).

6. The dry gas seal (115) for an energy storage compressor according to claim 5, characterized in that: The width of the spiral groove decreases from the high-pressure side to the low-pressure side.

7. The dry gas seal (115) for an energy storage compressor according to claim 2, characterized in that: The bushing (111) is provided with a second mounting groove (118), and the elastic compensation member (109) is installed in the second mounting groove (118).

8. The dry gas seal (115) for an energy storage compressor according to claim 2, characterized in that: A locking nut (119) for limiting the bushing (111) is installed on the rotating shaft (104).

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