A nozzle ring with a pressure balance hole and a turbine having the same

Abstract

The present invention discloses a nozzle ring with a pressure balance hole and a turbine having the same. The nozzle ring includes an annular base body, guide vanes, and a pressure balance hole. The base body has a central opening for accommodating an impeller. The guide vanes are arranged at intervals along the circumferential direction of the nozzle ring on the base body. The pressure balance hole penetrates through the base body and the guide vanes along the axial direction of the nozzle ring. According to the nozzle ring of the present invention, the pressure balance hole can reduce or eliminate the axial force, has a simple structure, improves the efficiency, avoids axial movement of the impeller, reduces rubbing of the impeller, ensures that the blade strength of the impeller is not affected, and reduces vibration and noise.

Description

Technical Field

[0001] The present invention relates to the technical field of turbomachinery, and more particularly to a nozzle ring having pressure balance holes and a turbine having the same. Background Art

[0002] During the rotation of the impeller, the fluid pressures on the front and back surfaces of the impeller disk are different, resulting in an axial force on the rotor that varies with the operating state. This can easily cause the impeller to move axially, leading to impeller rubbing, damage to the seal, vibration and noise. In severe cases, it may even cause the bearing connected to the impeller to burn out and the shaft to break.

[0003] Therefore, it is necessary to provide a nozzle ring having pressure balance holes and a turbine having the same to at least partially solve the above problems. Summary of the Invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further elaborated in the Detailed Description section. The Summary of the Invention section of the present invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0005] To at least partially solve the above problems, according to a first aspect of the present invention, there is provided a nozzle ring having pressure balance holes, the nozzle ring comprising:

[0006] A ring-shaped base body having a central opening for receiving an impeller;

[0007] Guide vanes spaced circumferentially along the nozzle ring to the base body; and

[0008] Pressure balance holes extending axially through the base body and the guide vanes along the nozzle ring.

[0009] According to the nozzle ring of the present invention, the nozzle ring includes a ring-shaped base body, guide vanes and pressure balance holes. The base body has a central opening for receiving an impeller, the guide vanes are spaced circumferentially along the nozzle ring to the base body, and the pressure balance holes extend axially through the base body and the guide vanes along the nozzle ring. In this way, the pressure balance holes can reduce or eliminate the axial force, have a simple structure, improve efficiency, prevent the impeller from axially moving, reduce impeller rubbing, ensure that the blade strength of the impeller is not affected, and reduce vibration and noise.

[0010] , optionally, the guide vane includes a leading edge and a flow guiding portion connected to the leading edge, the leading edge having a part of the pressure balance hole, and the flow guiding portion extending obliquely in a direction towards the central opening along the radial direction of the nozzle ring.

[0011] Optionally, the dimension of the leading edge in the width direction of the guide vane is greater than that of the flow guiding portion, and the width of the flow guiding portion gradually decreases in the direction towards the central opening.

[0012] Optionally, the pressure balance hole includes a large-diameter portion and a small-diameter portion that are connected. The large-diameter portion penetrates through a part of the base body, and the small-diameter portion penetrates through another part of the base body and the guide vane.

[0013] Optionally, it includes a first base body and a second base body. The first base body and the second base body are arranged opposite to each other in the axial direction. The guide vane is located between the first base body and the second base body, and the pressure balance hole penetrates through the first base body and the second base body.

[0014] Optionally, the pressure balance hole includes a large-diameter portion and a small-diameter portion that are connected. The large-diameter portion penetrates through a part of the first base body, and the small-diameter portion penetrates through another part of the first base body, the guide vane, and the second base body.

[0015] Optionally, it includes a plurality of guide vanes, and a part of the plurality of guide vanes is provided with the pressure balance hole.

[0016] Optionally, it further includes a connection hole that penetrates through the guide vane, and the connection hole and the pressure balance hole are arranged at intervals in the circumferential direction.

[0017] The present invention also provides a turbine, which includes an impeller and the above-mentioned nozzle ring. There is a gap between the impeller and the nozzle ring in the radial direction of the nozzle ring, and the gap communicates with the pressure balance hole.

[0018] According to the turbine of the present invention, the turbine includes an impeller and the above-mentioned nozzle ring. The nozzle ring includes a ring-shaped base body, guide vanes, and a pressure balance hole. The base body has a central opening for accommodating the impeller. The guide vanes are arranged at intervals along the circumferential direction of the nozzle ring to the base body. The pressure balance hole penetrates through the base body and the guide vanes in the axial direction of the nozzle ring. There is a gap between the impeller and the nozzle ring in the radial direction of the nozzle ring, and the gap communicates with the pressure balance hole. In this way, the pressure balance hole can reduce or eliminate the axial force, has a simple structure, improves the efficiency, avoids the axial movement of the impeller, reduces the rubbing of the impeller, ensures that the blade strength of the impeller is not affected, and reduces vibration and noise.

[0019] Optionally, the impeller includes a wheel disc and a plurality of blades connected to the wheel disc. The plurality of blades are spaced apart in the circumferential direction to form a channel for fluid flow. Description of the Drawings

[0020] The following drawings of the present invention are hereby incorporated as part of the present invention for understanding the present invention. The embodiments of the present invention shown in the drawings and their descriptions are used to explain the device and principle of the present invention. In the drawings,

[0021] Figure 1 is a partial cross-sectional perspective view of a nozzle ring according to a preferred embodiment of the present invention;

[0022] Figure 2 is a partial cross-sectional view of a turbine according to a preferred embodiment of the present invention;

[0023] Figure 3 is a partial cross-sectional perspective view of a nozzle ring according to another preferred embodiment of the present invention.

[0024] Explanation of reference numerals:

[0025] 100: nozzle ring 110: base

[0026] 111: central opening 112: first base

[0027] 113: second base 120: guide vane

[0028] 121: leading edge 122: flow guiding portion

[0029] 130: pressure balance hole 131: first large diameter portion

[0030] 132: first small diameter portion 140: connecting hole

[0031] 141: second large diameter portion 142: second small diameter portion

[0032] 200: turbine 201: impeller

[0033] 202: blade 203: disk

[0034] 204: back of the wheel 205: sealing structure

[0035] 206: first side wall 207: second side wall

[0036] 208: flow guiding channel 211: first gap

[0037] 212: second gap 213: third gap Detailed embodiments

[0038] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the present invention.

[0039] To thoroughly understand the present invention, detailed structures will be presented in the following description to illustrate the present invention. Obviously, the implementation of the present invention is not limited to the specific details familiar to those skilled in the art of this technology. The preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may have other embodiments and should not be construed as limited to the embodiments presented herein.

[0040] It should be understood that the purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present invention. The singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. When the terms "comprising" and / or "including" are used in this specification, they specify the presence of the stated features, wholes, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or combinations thereof. The terms "upper", "lower", "front", "rear", "left", "right", and similar expressions used in the present invention are for illustrative purposes only and not limitations.

[0041] The ordinal numbers such as "first" and "second" cited in the present invention are merely identifiers and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" does not imply the existence of a "second component" by itself, and the term "second component" does not imply the existence of a "first component" by itself.

[0042] Hereinafter, specific embodiments of the present invention will be described in more detail with reference to the accompanying drawings, which show representative embodiments of the present invention and do not limit the present invention.

[0043] Figure 1 A nozzle ring 100 showing a preferred embodiment of the present invention is presented.

[0044] As Figure 1 and Figure 2 shown, the present invention provides a nozzle ring 100 having a pressure balance hole 130. The nozzle ring 100 is for an impeller 201 and facilitates adjusting the pressure of the fluid affecting the back surface of the impeller 201. The nozzle ring 100 can accommodate the impeller 201. The axis of the impeller 201 coincides with the axis of the nozzle ring 100.

[0045] The impeller 201 is rotatable relative to the nozzle ring 100 about the central axis A of the impeller 201. The nozzle ring 100 can be used in a centripetal turbine, and fluid can be guided through the nozzle ring 100 to the blades 202 of the impeller 201. The nozzle ring 100 can also be used in a centrifugal turbine, and fluid can also be guided through the impeller 201 into the nozzle ring 100. The pressure of the fluid in the impeller 201 is less than the pressure of the fluid in the nozzle ring 100.

[0046] The nozzle ring 100 includes a base body 110, guide vanes 120, and pressure balance holes 130. The base body 110 can be configured as a ring. Optionally, the base body 110 can be configured as a circular ring. The axis of the base body 110 coincides with the axis of the impeller 201. The base body 110 has a central opening 111 for accommodating the impeller 201. The axis of the central opening 111 coincides with the axis of the impeller 201.

[0047] The guide vanes 120 can be arranged at intervals along the circumferential direction of the nozzle ring 100 on the base body 110. Specifically, the guide vanes 120 are evenly distributed on the base body 110 around the central axis of the nozzle ring 100. The central axis of the nozzle ring 100 coincides with the central axis A of the impeller 201. The nozzle ring 100 can be integrally formed, or the base body 110 and the guide vanes 120 are connected together by welding. Preferably, there is a chamfer between the guide vanes 120 and the base body 110, and they are connected by an arc transition, so as to reduce the stress on the guide vanes 120 and prevent stress concentration.

[0048] The nozzle ring 100 includes a plurality of guide vanes 120, and the plurality of guide vanes 120 are arranged at intervals along the circumferential direction of the nozzle ring 100 on the base body 110. Preferably, Figure 1 The shown nozzle ring 100 can include 17 guide vanes 120, and the 17 guide vanes 120 are evenly distributed on the base body 110 along the circumferential direction of the nozzle ring 100. Of course, according to the actual situation, the number of the guide vanes 120 can be adjusted, and this embodiment does not intend to limit this.

[0049] Fluid can be guided through the nozzle ring 100 to the blades 202 of the impeller 201, and fluid can also be guided through the impeller 201 into the nozzle ring 100. This embodiment does not intend to limit this. For example, the nozzle ring 100 can be used in an exhaust gas turbine, and the fluid can be exhaust gas. The exhaust gas does work in the turbine 200. The energy of the exhaust gas is used to drive the impeller 201 of the turbine 200. The nozzle ring 100 can specifically guide the exhaust gas to the impeller 201 to ensure reliable operation. The nozzle ring 100 can be held in place between the turbine housing and the bearing housing.

[0050] As Figure 2As shown, the housing may include a first side wall 206 and a second side wall 207 that are opposite to each other in the axial direction of the nozzle ring 100. The nozzle ring 100 and the impeller 201 are located between the first side wall 206 and the second side wall 207. The nozzle ring 100 is spaced apart from the impeller 201 in the radial direction of the nozzle ring 100. There is a first gap 211 between the nozzle ring 100 and the impeller 201 in the radial direction of the nozzle ring 100. There is a second gap 212 between the nozzle ring 100 and the first side wall 206. The impeller 201 includes blades 202 and a disk 203. The disk 203 is closer to the first side wall 206 than the blades 202 in the axial direction of the impeller 201. There is a third gap 213 between the first side wall 206 and the disk 203. The second side wall 207 may include an arc section to conform to the shape of the blades 202.

[0051] The disk 203 includes a back 204. In the present embodiment, the "back 204 of the impeller 201" refers to the surface of the impeller 201 facing away from the blades 202, that is, the back surface of the disk 203. There is a third gap 213 between the back 204 of the impeller 201 and the first side wall 206.

[0052] When the fluid flows into the third gap 213 through the first gap 211, it will generate a force on the impeller 201 in the axial direction of the impeller 201, affecting the rotation of the impeller 201. The fluid flowing through the first gap 211 will also flow into the second gap 212. The pressure balance hole 130 penetrates through the base 110 and the guide vane 120 in the axial direction of the nozzle ring 100. In this way, the pressure balance hole 130 can discharge the fluid in the second gap 212.

[0053] The pressure balance hole 130 penetrates through the entire nozzle ring 100 in the axial direction of the nozzle ring 100. In particular, the pressure balance hole 130 penetrates through the guide vane 120 and the base 110 in the axial direction of the nozzle ring 100, thereby forming a pressure relief channel for the fluid. The pressure balance hole 130 can reduce the amount of fluid entering the third gap 213, thereby reducing the axial force of the fluid on the impeller 201, avoiding the axial movement and rubbing of the impeller 201, reducing vibration and noise, and avoiding the burning of the bearing connected to the impeller 201 and the occurrence of shaft breakage.

[0054] The base 110 is closer to the first side wall 206 than the guide vane 120 in the axial direction of the nozzle ring 100. There is a second gap 212 between the base 110 and the first side wall 206. The first gap 211 is in communication with both the second gap 212 and the third gap 213.

[0055] For example, in a centripetal turbine, fluid can be guided to the blades 202 of the impeller 201 via the nozzle ring 100. The high-pressure fluid is depressurized to medium-pressure fluid via the guide vane 120, and the medium-pressure fluid is located in the first gap 211. The medium-pressure fluid in the first gap 211 is depressurized to low-pressure fluid via the blades 202 of the impeller 201. Alternatively, in a centrifugal turbine, the fluid can also be guided to the nozzle ring 100 via the impeller 201. The low-pressure fluid is pressurized to medium-pressure fluid via the blades 202, and the medium-pressure fluid is located in the first gap 211. The medium-pressure fluid in the first gap 211 is pressurized to high-pressure fluid via the guide vane 120. The pressure of the fluid in the nozzle ring 100 is greater than the pressure of the fluid in the impeller 201.

[0056] The pressure of the medium-pressure fluid is greater than the pressure of the low-pressure fluid in the impeller 201. Therefore, the medium-pressure fluid located between the back of the wheel 204 and the first side wall 206 exerts a force on the impeller 201 towards the second side wall 207, which easily causes axial movement of the impeller. The present invention provides a nozzle ring 100, which includes a pressure balance hole 130. The pressure balance hole 130 can discharge the medium-pressure fluid in the second gap 212, so that most of the medium-pressure fluid in the first gap 211 is discharged through the pressure balance hole 130, reducing the amount of fluid entering between the wheel disc 203 and the first side wall 206.

[0057] The axial direction of the pressure balance hole 130 is substantially parallel to the axial direction of the nozzle ring 100. The second side wall 207 may be provided with a first through hole, and the first through hole may correspond to the pressure balance hole 130 along the axial direction of the nozzle ring 100. The medium-pressure fluid can be discharged via the pressure balance hole 130 and the first through hole. Optionally, the pressure balance hole 130 may be communicated with the diversion channel 208, and the fluid in the pressure balance hole 130 enters the diversion channel 208. The second side wall 207 may also be provided with a second through hole, and the second through hole can communicate the diversion channel 208 and the low-pressure region of the impeller 201. In this way, the medium-pressure fluid leaked from the back of the wheel 204 is drained to the low-pressure region of the impeller 201 through the pressure balance hole 130, which plays a role in reducing the pressure of the back of the wheel 204. The diversion channel can be constructed as a tubular structure, or can be constructed as a hole on the wall surface or a cavity formed between components.

[0058] Thus, the pressure balance hole 130 can reduce the amount of fluid between the impeller 201 and the first side wall 206, reduce the pressure exerted by the fluid on the back of the wheel 204 of the impeller 201, prevent the impeller 201 from moving towards the direction of the second side wall 207, avoid axial movement and rubbing of the impeller 201, reduce vibration and noise, and avoid burning of the bearing connected to the impeller 201 and the phenomenon of broken shaft.

[0059] Preferably, the wheel disc 203 can also be in sealing cooperation with the first side wall 206 to further reduce the amount of fluid entering the third gap 213. A sealing structure 205 can be provided between the wheel disc 203 and the first side wall 206, and the sealing structure 205 can block the flow of fluid. In particular, a sealing structure 205 is provided between the back 204 of the wheel disc 203 and the first side wall 206, and the sealing structure 205 can be configured as a serrated labyrinth structure to reduce the amount of fluid entering the third gap 213. Preferably, the number and diameter of the pressure balance holes 130 are matched with the sealing structure 205 to achieve better sealing and pressure balance effects.

[0060] According to the nozzle ring of the present invention, the nozzle ring includes an annular base body, guide vanes and pressure balance holes. The base body has a central opening for accommodating the impeller. The guide vanes are spaced along the circumferential direction of the nozzle ring to the base body, and the pressure balance holes penetrate the base body and the guide vanes along the axial direction of the nozzle ring. In this way, the pressure balance holes can reduce or eliminate the axial force, have a simple structure, improve the efficiency, avoid the axial movement of the impeller, reduce the rubbing of the impeller, ensure that the blade strength of the impeller is not affected, and reduce vibration and noise.

[0061] Preferably, as Figure 1 shown, the guide vane 120 includes a leading edge 121 and a flow guiding portion 122, and the flow guiding portion 122 is connected to the leading edge 121. The leading edge 121 has a part of the pressure balance hole 130, and the pressure balance hole 130 penetrates the base body 110 and the leading edge 121 along the axial direction of the nozzle ring 100. The flow guiding portion 122 extends obliquely in the direction towards the central opening 111 along the radial direction of the nozzle ring 100 to form an inclined flow channel for the fluid. In this way, part of the guide vane 120 blocks the flow of the fluid along the radial direction of the nozzle ring 100, and the fluid does not directly act on the impeller 201 along the radial direction of the nozzle ring 100, so that the pressure of the fluid can be changed.

[0062] Optionally, the flow guiding portion 122 can be closer to the central opening 111 than the leading edge 121 along the radial direction. The guide vane 120 guides the flow of the fluid along the radial direction of the nozzle ring 100. The dimension of the leading edge 121 in the width direction of the guide vane 120 is larger than the dimension of the flow guiding portion 122. In this way, the guide vane 120 has sufficient structural strength to prevent being damaged by the impact of the fluid, and also reduces the influence of the pressure balance hole 130 on the profile and strength of the guide vane 120 (flow guiding portion 122).

[0063] The width direction of the guide vane 120 is substantially parallel to the circumferential direction of the nozzle ring 100. There can be a certain angle between the length direction of the guide vane 120 and the radial direction of the nozzle ring 100. For example, the angle between the length direction of the guide vane 120 and the radial direction of the nozzle ring 100 can be an acute angle to provide an inclined flow channel for the fluid.

[0064] The width of the flow guiding portion 122 in the direction towards the central opening 111 gradually decreases. The width of the flow guiding portion 122 away from the central opening 111 is greater than the width of the flow guiding portion 122 close to the central opening 111. The width of the flow guiding portion 122 connected to the leading edge 121 can be greater than the width of the free end of the flow guiding portion 122 close to the central opening 111. Thus, the resistance of the flow guiding portion 122 to fluid flow is reduced.

[0065] Furthermore, the pressure balance hole 130 includes a first large-diameter portion 131 and a first small-diameter portion 132, and the first large-diameter portion 131 and the first small-diameter portion 132 are in communication. The dimension of the first large-diameter portion 131 in the radial direction of the nozzle ring 1 OO is greater than the dimension of the first small-diameter portion 132. The first large-diameter portion 131 penetrates through a part of the base body 110. The dimension of the first large-diameter portion 131 in the axial direction of the nozzle ring 100 is smaller than the dimension of the base body 110. The first small-diameter portion 132 penetrates through another part of the base body 110 and the guide vane 120. In this way, the length of the first small-diameter portion 132 in the axial direction of the nozzle ring 100 is reduced, and the processing difficulty is lowered. When machining the pressure balance hole 130, the first large-diameter portion 131 can be machined first, and then the first small-diameter portion 132 can be further machined.

[0066] The nozzle ring 100 may include a plurality of pressure balance holes 130, and the plurality of pressure balance holes 130 are arranged at intervals in the circumferential direction of the nozzle ring 100. Further, a part of the plurality of guide vanes 120 is provided with the pressure balance holes 130. The plurality of pressure balance holes 130 are uniformly distributed on the plurality of guide vanes 120 in the circumferential direction of the nozzle ring 100 to ensure the uniformity of flow and the overall structural strength of the nozzle ring 100.

[0067] The nozzle ring 100 further includes connection holes 140, and the connection holes 140 are used to connect to the guide vane 120 and the second side wall 207, so as to fixedly connect the nozzle ring 100 to the housing. The nozzle ring 100 may include a plurality of connection holes 140, and the plurality of connection holes 140 are arranged at intervals in the circumferential direction of the nozzle ring 100. The connection holes 140 and the pressure balance holes 130 are arranged at intervals in the circumferential direction of the nozzle ring 100. Thus, it is convenient for pressure relief and enables the nozzle ring 100 to be stably connected to the housing. Some of the guide vanes 120 may be neither provided with the pressure balance holes 130 nor provided with the connection holes 140.

[0068] Preferably, the nozzle ring 100 may include four pressure balance holes 130 and four connection holes 140, and the four pressure balance holes 130 and the four connection holes 140 are arranged at intervals in the circumferential direction of the nozzle ring 100 to ensure the stable flow of the fluid.

[0069] The connecting hole 140 penetrates through the guide vane 120. The connecting hole 140 may include a second large-diameter portion 141 and a second small-diameter portion 142, and the second large-diameter portion 141 and the second small-diameter portion 142 are in communication. The dimension of the second large-diameter portion 141 in the radial direction of the nozzle ring 100 is larger than that of the second small-diameter portion 142. The second large-diameter portion 141 penetrates through a part of the base body 110. The dimension of the second large-diameter portion 141 in the axial direction of the nozzle ring 100 is smaller than that of the base body 110. The second small-diameter portion 142 penetrates through another part of the base body 110 and the guide vane 120. In this way, the length of the second small-diameter portion 142 in the axial direction of the nozzle ring 100 is reduced, and the machining accuracy is lowered.

[0070] The nozzle ring 100 can be connected to the housing through a connecting member to position and fix the nozzle ring 100. For example, the nozzle ring 100 is connected to the second side wall 207 through bolts and nuts. The dimension and shape of the second large-diameter portion 141 can match the shape of the nut. For example, the dimension and shape of the second large-diameter portion 141 can match the dimension and shape of a hexagonal nut. In this way, the nut can be completely located in the second large-diameter portion 141, and the nut does not protrude from the second large-diameter portion 141 in the axial direction of the nozzle ring 100, so as to prevent the bolt from protruding and interfering with the assembly of other components.

[0071] Figure 3 The nozzle ring 100 showing another preferred embodiment of the present invention is illustrated.

[0072] Figure 3 The structure of the shown nozzle ring is the same as Figure 1 the structure of the shown nozzle ring is similar, Figure 1 the shown nozzle ring can be an open nozzle ring, Figure 3 the shown nozzle ring can be a closed nozzle ring. The differences will be described below, and the similarities will not be elaborated. Figure 3 The shown nozzle ring 100 includes two base bodies (a first base body 112 and a second base body 113), and the first base body 112 and the second base body 113 are arranged opposite to each other in the axial direction of the nozzle ring 100. The guide vane 120 is located between the first base body 112 and the second base body 113 and is connected to both the first base body 112 and the second base body 113. In this way, it is convenient to guide the flow of the fluid.

[0073] The guide vane 120 is integrally formed with both the first base body 112 and the second base body 113, or the guide vane 120 is connected to both the first base body 112 and the second base body 113 by welding. The first base body 112 includes a first inner surface, the second base body 113 includes a second inner surface opposite to the first inner surface, and the first inner surface, the second inner surface and the surface of the guide vane 120 together form a channel for fluid flow.

[0074] Preferably, a chamfer may be provided between the guide vane 120 and the first base body 112, and they are connected together by an arc transition, so as to reduce the stress on the guide vane 120 and prevent stress concentration. Preferably, a chamfer may be provided between the guide vane 120 and the second base body 113, and they are connected together by an arc transition, so as to reduce the stress on the guide vane 120 and prevent stress concentration.

[0075] The pressure balance hole 130 may penetrate through the first base body 112 and the second base body 113. In this way, the fluid can be discharged through the first base body 112 and the second base body 113. The pressure balance hole 130 penetrates through the entire nozzle ring 100 along the axial direction of the nozzle ring 100. In particular, the pressure balance hole 130 penetrates through the guide vane 120, the first base body 112 and the second base body 113 along the axial direction of the nozzle ring 100, thereby forming a pressure relief channel for the fluid.

[0076] The pressure balance hole 130 includes a first large-diameter portion 131 and a first small-diameter portion 132 that are communicated. The dimension of the first large-diameter portion 131 along the radial direction of the nozzle ring 100 is larger than that of the first small-diameter portion 132. The first large-diameter portion 131 penetrates through a part of the first base body 112. The dimension of the first large-diameter portion 131 along the axial direction of the nozzle ring 100 is smaller than that of the first base body 112. The first small-diameter portion 132 penetrates through another part of the first base body 112, the guide vane 120 and the second base body 113. In this way, the length of the first small-diameter portion 132 along the axial direction of the nozzle ring 100 is reduced, and the processing difficulty is lowered.

[0077] Preferably, Figure 3 The shown nozzle ring 100 may include 17 guide vanes 120, and the 17 guide vanes 120 are evenly distributed between the first base body 112 and the second base body 113 along the circumferential direction of the nozzle ring 100. Of course, according to the actual situation, the number of the guide vanes 120 can be adjusted, and this embodiment does not intend to limit this.

[0078] According to the nozzle ring of the present invention, the nozzle ring includes a pressure balance hole, and the pressure balance hole can reduce the amount of fluid on the back of the impeller, reduce the acting force exerted by the fluid on the back of the impeller, weaken the influence of the fluid discharged from the pressure balance hole on the operation of the impeller, without the need to provide holes on the impeller, without damaging the chamfer of the impeller, without affecting the flow of the fluid, ensuring the efficiency of the impeller in doing work, and avoiding the burning of the bearing connected to the impeller and the occurrence of shaft breakage. The pressure balance hole penetrates through the base body and the guide vane, which can reduce the length of the pressure balance hole along the axial direction of the nozzle ring and avoid the situation of delay and hysteresis in the dynamic working condition.

[0079] The present invention also provides a turbine 200, which includes an impeller 201 and the above-mentioned nozzle ring 100. There is a first gap 211 between the impeller 201 and the nozzle ring 100 in the radial direction of the nozzle ring 100, and the first gap 211 communicates with the pressure balance hole 130. In this way, the fluid in the first gap 211 can be discharged through the pressure balance hole 130, and the pressure balance hole 130 can play a role in relieving pressure, reducing the axial force exerted on the impeller 201 by the fluid pressure.

[0080] For the turbine according to the present invention, the turbine includes an impeller and the above-mentioned nozzle ring. The nozzle ring includes a ring-shaped base body, guide vanes and a pressure balance hole. The base body has a central opening for accommodating the impeller. The guide vanes are arranged at intervals along the circumferential direction of the nozzle ring on the base body. The pressure balance hole penetrates the base body and the guide vanes along the axial direction of the nozzle ring. There is a gap between the impeller and the nozzle ring in the radial direction of the nozzle ring, and the gap communicates with the pressure balance hole. In this way, the pressure balance hole can reduce or eliminate the axial force, has a simple structure, improves the efficiency, avoids the axial displacement of the impeller, reduces the rubbing of the impeller, ensures that the blade strength of the impeller is not affected, and reduces vibration and noise.

[0081] Further, as described above, the impeller 201 includes a wheel disc 203 and a plurality of blades 202, and the plurality of blades 202 are all connected to the wheel disc 203. The axial direction of the impeller 201 is parallel to the axial direction of the nozzle ring 100. The housing includes a first side wall 206 and a second side wall 207 arranged opposite to each other along the axial direction of the nozzle ring 100. The wheel disc 203 is closer to the first side wall 206 than the blades 202 in the axial direction of the impeller 201. There is a third gap between the first side wall 206 and the wheel disc 203. The second side wall 207 may include an arc section to fit the shape of the blades 202.

[0082] The base body 110 is closer to the first side wall 206 than the guide vanes 120 in the axial direction of the nozzle ring 100. There is a second gap 212 between the base body 110 and the first side wall 206. The first gap 211 communicates with both the second gap 212 and the third gap 213.

[0083] Multiple blades 202 may also be spaced circumferentially around the nozzle ring 100 to form channels for fluid flow. The fluid may be guided into the first gap 211 by the guide vanes 120 of the nozzle ring 100, and then into the second gap 212 and the third gap 213, respectively. Alternatively, the fluid may be guided into the first gap 211 by the blades 202 of the impeller 201, and then into the second gap 212 and the third gap 213, respectively. The pressure of the fluid in the nozzle ring 100 is greater than the pressure of the fluid in the impeller 201. The fluid in the nozzle ring 100 may be a high-pressure fluid, the fluid in the first gap 211 may be a medium-pressure fluid, and the fluid in the impeller 201 may be a low-pressure fluid. The medium-pressure fluid in the first gap 211 may enter both the second gap 212 and the third gap 213.

[0084] The intermediate-pressure fluid between the impeller 203 and the first sidewall 206 exerts a force on the impeller 201 toward the second sidewall 207. Therefore, the pressure balance hole 130 can discharge the intermediate-pressure fluid in the second slit 212, so that most of the intermediate-pressure fluid in the first slit 211 is discharged through the pressure balance hole 130, thereby reducing the amount of fluid entering between the impeller 203 and the first sidewall 206.

[0085] The axial direction of the pressure balance hole 130 is substantially parallel to the axial direction of the nozzle ring 100. The second sidewall 207 may be provided with a first through hole, and the second through hole may correspond to the pressure balance hole 130 along the axial direction of the nozzle ring 100. Medium-pressure fluid may be discharged through the pressure balance hole 130 and the through hole. Optionally, the pressure balance hole 130 may be connected to the guide channel 208, and the fluid in the pressure balance hole 130 may enter the guide channel 208. The second sidewall 207 may also be provided with a second through hole, which may connect the guide channel 208 and the low-pressure area of the impeller 201. In this way, the medium-pressure fluid leaking from the wheel back 204 is guided to the low-pressure area of the impeller 201 through the pressure balance hole 130, thereby reducing the pressure on the wheel back 204.

[0086] Therefore, the pressure balance hole 130 can reduce the amount of fluid between the impeller 201 and the first side wall 206, reducing the pressure exerted by the fluid on the wheel back 204 of the impeller 201, so that the impeller 201 does not move toward the second side wall 207, avoiding the impeller 201 from moving and rubbing, reducing vibration and noise, and avoiding the burning of the bearings connected to the impeller 201 and the occurrence of broken shafts.

[0087] Preferably, the wheel disc 203 can be in sealing cooperation with the first side wall 206 to further reduce the amount of fluid entering the third gap 213. A sealing structure 205 can be provided between the wheel disc 203 and the first side wall 206, and the sealing structure 205 can block the flow of fluid. In particular, a sealing structure 205 is provided between the back 204 of the wheel disc 203 and the first side wall 206, and the sealing structure 205 can be configured as a serrated labyrinth structure to reduce the amount of fluid entering the third gap 213. Preferably, the number and diameter of the pressure balance holes 130 are matched with the sealing structure 205 to achieve better sealing and pressure balance effects.

[0088] According to the nozzle ring of the present invention, the nozzle ring includes pressure balance holes, and the pressure balance holes can cooperate with the sealing structure between the back of the impeller and the housing (or the transmission shaft), which can effectively reduce the pressure exerted on the back of the impeller, play a role in axial force balance, and can avoid the influence of the pressure balance holes on the internal flow field, enhancing the operation reliability and efficiency of the turbine.

[0089] Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the technical field of the present invention. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. Terms such as "part" and "component" as used herein can represent both a single part and a combination of multiple parts. Terms such as "mounted" and "arranged" as used herein can represent both a component being directly attached to another component and a component being attached to another component through an intermediate member. Features described in one embodiment herein can be applied to another embodiment alone or in combination with other features, unless the feature is not applicable or otherwise stated in that other embodiment.

[0090] The present invention has been described through the above embodiments, but it should be understood that the above embodiments are only for the purpose of illustration and example, and are not intended to limit the present invention within the scope of the described embodiments. In addition, those skilled in the art can understand that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of protection required by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalent scope.

Claims

1. A turbine, characterized in that, The turbine includes an impeller and a nozzle ring. There is a gap between the impeller and the nozzle ring in the radial direction of the nozzle ring. The nozzle ring includes: A ring-shaped base body having a central opening for accommodating the impeller; Guide vanes spaced along the circumferential direction of the nozzle ring to the base body; and Pressure balance holes penetrating the base body and the guide vanes in the axial direction of the nozzle ring. The gap is communicated with the pressure balance holes. The turbine further includes a housing, which includes a first side wall and a second side wall opposite to each other in the axial direction of the nozzle ring. The nozzle ring and the impeller are located between the first side wall and the second side wall. The nozzle ring is spaced from the impeller in the radial direction of the nozzle ring. There is a first gap between the nozzle ring and the impeller in the radial direction of the nozzle ring, and a second gap between the nozzle ring and the first side wall. The impeller includes blades and a wheel disc. The wheel disc is closer to the first side wall than the blades in the axial direction of the impeller. There is a third gap between the first side wall and the wheel disc.

2. The turbine according to claim 1, wherein The guide vane includes a leading edge and a flow guiding portion connected to the leading edge. The leading edge has a part of the pressure balance hole. The flow guiding portion extends obliquely in the radial direction of the nozzle ring towards the direction of the central opening.

3. The turbine according to claim 2, wherein The dimension of the leading edge in the width direction of the guide vane is larger than that of the flow guiding portion. The width of the flow guiding portion gradually decreases towards the direction of the central opening.

4. The turbine according to claim 1, wherein, The pressure balance hole includes a connected large-diameter portion and a small-diameter portion. The large-diameter portion penetrates a part of the base body, and the small-diameter portion penetrates another part of the base body and the guide vane.

5. The turbine according to claim 1, characterized in that, The nozzle ring includes a first base body and a second base body arranged opposite to each other in the axial direction. The guide vanes are located between the first base body and the second base body. The pressure balance hole penetrates the first base body and the second base body.

6. The turbine according to claim 5, characterized in that, The pressure balance hole includes a connected large-diameter portion and a small-diameter portion. The large-diameter portion penetrates a part of the first base body, and the small-diameter portion penetrates another part of the first base body, the guide vane and the second base body.

7. The turbine according to any one of claims 1-6, characterized in that, The nozzle ring includes a plurality of guide vanes, and a part of the plurality of guide vanes is provided with the pressure balance holes.

8. The turbine according to claim 7, characterized in that, The nozzle ring further includes connection holes penetrating the guide vanes, and the connection holes and the pressure balance holes are spaced along the circumferential direction.

9. The turbine according to claim 1, characterized in that, The impeller includes a plurality of blades connected to the wheel disc. The plurality of blades are spaced apart along the circumferential direction to form a channel for fluid flow.

Images