A radial clearance adjustment device for a turbine engine

Abstract

The present invention relates to a radial clearance adjustment device for a turbine engine, comprising: a housing, guide blades fixed inside the housing, and turbine blades installed at the center position inside the housing; wherein a guide groove is provided inside the housing, a guide ring is integrally arranged in the guide groove, and forms an air passage together with the turbine blades at the bottom of the housing, the guide ring comprises a positioning ring, a center ring integrally arranged at the center of the guide ring, and valve rings separately arranged on both sides of the center ring, a main passage is provided inside the center ring, and the main passage is connected to a cooling hole; a secondary passage and a valve passage are provided inside the valve ring, and the secondary passage is connected to the cooling hole. The radial clearance adjustment device for a turbine engine of the present invention uses the design of a graded guide ring so that the turbine can maintain sufficient radial clearance during the startup process, effectively reduce the amount of air leakage, and improve the working efficiency of the turbine, so as to solve the current technical problem of controlling the amount of air leakage of turbine blades.

Description

Technical Field

[0001] The present invention belongs to the field of engine structure design, and particularly relates to a radial clearance adjustment device for a turbine engine. Background Art

[0002] Turbines (such as centrifugal compressors, turbines, etc.) often operate at high temperatures, and both their rotor components and stator components undergo high-temperature expansion processes.

[0003] In a machine with a quick start, that is, a machine that executes a quick start program within a short period, the sealing gap between the sealing arrangement mounted on the stationary component and the rotating component must be designed such that during the quick start, the sealing arrangement does not contact the rotating component, which undergoes a rapid dimensional increase due to centrifugal and thermal radial growth in the radial direction.

[0004] To prevent seal damage during startup caused by the slower radial growth of the stator compared to the rotor, the diameter dimension of the sealing arrangement is designed to maintain a sufficient radial clearance even during a quick start. Therefore, when the steady-state operating conditions of the turbine are reached, the radial seal clearance is relatively large. However, a large radial clearance results in a decrease in the efficiency of the turbine. Therefore, improved control of the radial clearance of the sealing arrangement in turbines operating at high temperatures and having a quick start program is required.

[0005] To solve the current problem of controlling the air leakage amount of turbine blades, the present invention proposes a novel radial clearance adjustment device. Summary of the Invention

[0006] In view of the deficiencies in the related art, the present invention provides a radial clearance adjustment device for a turbine engine. Through the design of a stepped guide ring, the turbine can maintain a sufficient radial clearance during the startup process. After stable operation, the labyrinth channels formed by the stepped guide ring can not only maintain the radial clearance but also reduce the air leakage amount, greatly improving the working efficiency of the turbine to solve the current technical problem of controlling the air leakage amount of turbine blades.

[0007] The present invention provides a radial clearance adjustment device for a turbine engine, comprising:

[0008] A housing, which is integrally annular. A guide groove is provided inside the housing, and cooling holes for introducing a coolant are opened in the housing;

[0009] Guide vanes, which are fixed inside the housing and are arranged in multiple rows along the circumferential direction of the housing and multiple rows along the axial direction of the housing;

[0010] Turbine blades, which are of an axial flow type as a whole, and the turbine blades are installed at the central position inside the housing; and

[0011] A guide ring, which is integrally arranged in the guide groove and forms an air passage together with the turbine blades inside the housing;

[0012] Wherein, the guide ring further includes:

[0013] A positioning ring, which has a positioning surface and is arranged close to the guide groove through the positioning surface;

[0014] A central ring, which is integrally arranged at the center of the guide ring. There is a main passage inside the central ring, and the main passage is communicated with the cooling holes. By injecting a coolant into the cooling holes, the central ring is cooled; and

[0015] A valve ring, which is separately arranged on both sides of the central ring. There are a secondary passage and a valve passage inside the valve ring. The secondary passage and the valve passage are not communicated with each other. The secondary passage is communicated with the cooling holes. By injecting a coolant into the cooling holes, the valve ring is cooled, and the valve passage is communicated with the bottom of the main passage.

[0016] In some embodiments, the cooling holes are formed in the housing and extend vertically into the housing until they are communicated with the main passage and the secondary passage in the guide ring.

[0017] In some embodiments, the number of the cooling holes is one or more, and the coolant is cooling air or water.

[0018] In some embodiments, the cross-section of the guide groove is a T-shaped structure, and the T-shaped structure includes a horizontal part and a vertical part. The horizontal part is integrally arranged at the middle position inside the housing, and the vertical part is arranged below the horizontal part and extends to the bottom of the housing.

[0019] In some embodiments, two positioning rings are provided, which are separately arranged on both sides of the valve ring. The axial positions of the two positioning rings do not correspond to those of the turbine blades, so that there is no scratching between the turbine blades and the positioning rings;

[0020] The cross-section of the positioning ring is an inverted L structure, and the inverted L structure includes a positioning ring body arranged vertically and a positioning surface arranged horizontally at the top of the positioning ring body. Through the horizontal positioning surface, the positioning ring is inserted into the horizontal part of the guide groove, and finally the two positioning rings are arranged close to the guide groove.

[0021] In some of these embodiments, the main channel is entirely disposed inside the central ring. The main channel includes a first main channel and a second main channel disposed below the first main channel. The first main channel is disposed in the vertical direction and is in communication with the cooling holes. The second main channel is disposed in the horizontal direction and the second main channel is in communication with the first channel. The first main channel and the second main channel are both in an annular structure as a whole. By injecting a coolant into the cooling holes, the coolant flows through the first main channel and the second main channel to cool the central ring;

[0022] The secondary channel is in an inverted L-shaped structure as a whole. The inverted L-shaped structure includes a horizontal channel and a vertical channel disposed below the horizontal channel. The horizontal channel is in communication with the cooling holes. The vertical channel extends straight down inside the valve ring. By injecting a coolant into the cooling holes, the coolant flows through the horizontal channel and the vertical channel in sequence to cool the valve ring;

[0023] The valve channel is disposed below the secondary channel and is not in communication with the secondary channel. A check valve is provided inside the valve channel and is in communication with the second main channel in the main channel to regulate the flow of the coolant between the valve channel and the main channel.

[0024] In some of these embodiments, the ratio of the amount of coolant flowing inside the valve channel to that flowing inside the main channel is (0.1 - 0.3):1.

[0025] In some of these embodiments, a plurality of turbine blades are provided. The plurality of turbine blades are installed on the rotating shaft at the central position of the bottom of the housing and are located between two rows of guide vanes and are supported by bearings. The plurality of turbine blades rotate together with the rotating shaft to form a rotating swept edge.

[0026] In some of these embodiments, an insulating layer is further provided between the guide ring and the housing. The insulating layer makes the guide ring in an adiabatic state relative to the housing, so that the housing will not shrink towards the blade direction.

[0027] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0028] 1. The radial clearance adjustment device for a turbine engine proposed by the present invention, through the design of the stepped guide ring, enables the turbine to maintain a sufficient radial clearance during the startup process. After stable operation, the labyrinth channels formed by the stepped guide ring can not only maintain the radial clearance but also reduce the air leakage amount, greatly improving the working efficiency of the turbine to solve the technical problem of controlling the air leakage amount of the current turbine blades;

[0029] 2. The radial clearance adjustment device for a turbine engine proposed by the present invention realizes the effective control of the air leakage amount of the turbine blades and further improves the working efficiency of the turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and shall not unduly limit the present invention. In the drawings:

[0031] Figure 1 is a schematic overall cross-sectional view of an embodiment of a radial clearance adjustment device for a turbine engine according to the present invention;

[0032] Figure 2 is a cross-sectional view of an embodiment of a radial clearance adjustment device for a turbine engine according to the present invention when the turbine just starts;

[0033] Figure 3 is a cross-sectional view of an embodiment of a radial clearance adjustment device for a turbine engine according to the present invention when the turbine just operates stably.

[0034] In the above figures:

[0035] 1. Housing; 2. Guide groove; 3. Cooling hole; 4. Guide vane; 5. Turbine blade; 6. Positioning ring; 7. Central ring; 8. Valve ring; 9. First main channel; 10. Second main channel; 11. Secondary channel; 12. Valve channel; 13. Thermal insulation layer; 14. Check valve; 15. Positioning surface; 16. Air channel;

[0036] 41. Leading edge; 42. Trailing edge. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "transverse", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0039] The terms "first", "second", and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", and "third" may explicitly or implicitly include one or more of such features.

[0040] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] As shown in the Figure 1 accompanying drawings, in a schematic embodiment of the radial clearance adjustment device for a turbine engine according to the present invention, the radial clearance adjustment device for a turbine engine mainly includes: a housing 1, a guide groove 2 provided inside the housing 1, a guide ring integrally disposed in the guide groove 2, a guide vane 4 fixed to the bottom of the housing 1, and a turbine blade 5 mounted at the central position of the bottom of the housing 1, etc. The following will detail these key components:

[0042] Combined with the accompanying Figure 1, the housing 1 is generally annular in shape. Inside the housing 1, guide vanes 4 are fixed. A plurality of guide vanes 4 are arranged circumferentially inside the housing 1 and multiple rows are arranged axially along the housing 1. Specifically, the guide vane 4 includes a leading edge 41 and a trailing edge 42 through which the working medium flows. The turbine blade 5 is generally axial-flow type. A plurality of turbine blades 5 are provided. The plurality of turbine blades 5 are installed on a rotating shaft (not shown in the figure) at the central position inside the housing 1 and are supported by bearings (not shown in the figure). The plurality of turbine blades 5 rotate together with the rotating shaft, thus having a rotating swept edge. In addition, in some other embodiments, the plurality of turbine blades 5 can also be connected to the rotating shaft through a balance drum (not shown in the figure). Inside the housing 1, a guide groove 2 is provided. The guide ring is generally arranged in the guide groove 2 and together with the turbine blades 5 inside the housing 1 forms an air passage 16. Specifically, the cross-section of the guide groove 2 is a T-shaped structure. The T-shaped structure includes a horizontal part and a vertical part. The horizontal part is generally arranged at the middle position inside the housing 1, and the vertical part is arranged below the horizontal part and extends all the way to the bottom of the housing 1. A cooling hole 3 for introducing a coolant is opened at the top of the housing 1. The cooling hole 3 extends vertically all the way into the housing 1 until it communicates with a plurality of channels in the guide ring. The number of the cooling holes 3 can be set to one or more, and the coolant used is cooling air or water. In addition, in the present invention, an insulating layer 13 (such as a thermal barrier coating or the like) is also provided between the guide ring and the housing 1. The insulating layer 13 makes the guide ring in an adiabatic state relative to the housing 1, so that the housing 1 will not shrink towards the blade direction.

[0043] Next, the guide ring further includes a central ring 7, a valve ring 8, and a positioning ring 6 which are made of the same material and are in close contact. Referring to the attached Figure 1 It can be seen that the above-mentioned several rings are arranged in the order of the positioning ring 6, the valve ring 8, and the central ring 7 from upstream to downstream. Among them, two positioning rings 6 are provided and are respectively arranged on both sides of the valve ring 8. The axial positions of the two positioning rings 6 do not correspond to those of the turbine blades 5, so that no scratching occurs between the turbine blades 5 and the positioning rings 6. Each positioning ring 6 has a positioning surface 15. Through the positioning surface 15, the positioning ring 6 can be closely arranged against the guide groove 2. The following further explains the actual function of the positioning surface 15 in combination with the cross-sectional structure of the positioning ring 6. The cross-section of the positioning ring 6 is an inverted L structure. The inverted L structure includes a positioning ring 6 body arranged in the vertical direction and a positioning surface 15 arranged horizontally on the top of the positioning ring 6 body. Through the horizontally arranged positioning surface 15, the positioning ring 5 is inserted into the horizontal part of the guide groove 2. Finally, the two positioning rings 6 are closely arranged against the guide groove 2 to achieve accurate positioning of the positioning ring 6.

[0044] There are two valve rings 8, which are respectively arranged on both sides of the central ring 7. Inside the valve ring 8, there are a secondary channel 11 and a valve channel 12. The secondary channel 11 and the valve channel 12 are not connected to each other. The secondary channel 11 is connected to the cooling hole 3. By injecting coolant into the cooling hole 3, the valve ring 8 is cooled. The valve channel 12 is connected to the bottom of the main channel inside the central ring 8. Specifically, the secondary channel 11 is integrally in an inverted L-shaped structure, which includes a horizontal channel and a vertical channel arranged below the horizontal channel. The horizontal channel is connected to the cooling hole 3, and the vertical channel extends downward in the valve ring 8. By injecting coolant into the cooling hole 3, the coolant flows through the horizontal channel and the vertical channel in sequence, for cooling the valve ring 8; the valve channel 12 is arranged below the secondary channel 11 and is not connected to the secondary channel 11. A check valve 14 is arranged inside the valve channel 12, and it is connected to the second main channel 10 in the main channel inside the central ring 8, for regulating the flow of coolant between the valve channel 12 and the main channel.

[0045] The central ring 7 is integrally arranged at the center of the guide ring. Inside the central ring 7, there is a main channel, and the main channel is connected to the cooling hole 3. By injecting coolant into the cooling hole 3, the central ring 7 is cooled. Specifically, the main channel is integrally arranged inside the central ring 7. The main channel further includes a first main channel 9 and a second main channel 10 arranged below the first main channel 9. The first main channel 9 is arranged in the vertical direction and is connected to the cooling hole 3. The second main channel 10 is arranged in the horizontal direction, and the second main channel 10 is connected to the first channel 9. The first main channel 9 and the second main channel 10 are both integrally in a ring structure. By injecting coolant into the cooling hole 3, the coolant flows through the first main channel 9 and the second main channel 10, for cooling the central ring 7. In addition, the ratio of the amount of coolant flowing inside the valve channel 12 to that flowing inside the main channel is (0.1 - 0.3):1. Specifically, 0.1:1, 0.2:1, 0.3:1 or any value within the above-defined range all fall within the protection scope of the present invention.

[0046] The following combines the attached Figures 2-3 Describe the working process of an embodiment of the radial clearance adjustment device for a turbine engine of the present invention:

[0047] As shown in the attached Figure 2As shown, the turbine engine is in a hot start state at this time. The centrifugal forces acting on the turbine blades 5 and the housing 1 cause an increase in the radial dimension, resulting in a narrowing of the air passage 16 between the turbine blades 5 and the guide ring, a reduction in the radial clearance, and possible scratching between the turbine blades 5 and the guide ring. Therefore, in this case, coolant is injected from the cooling holes 3. The coolant flows through the first main passage 9 and the second main passage 10 of the central ring 7 to cool the central ring 7. At the same time, the coolant enters the secondary passage 11 of the valve ring 8 to cool the valve ring 8. By reasonably designing the opening pressure of the check valve 14, the check valve 14 cannot be in an open state at this time, the valve passage 12 is closed, and the cooling air cannot flow from the main passage into the valve passage 12. Control the cooling air volume of the main passage and the secondary passage 11 to cause the central ring 7 and the valve rings 8 on both sides to contract by the same amount, so as to ensure that there is no unnecessary scratching between the turbine blades 5 and the guide ring in the hot start state.

[0048] As shown in the Figure 3 attachment, the turbine engine is in a stable operating state at this time. After reaching the standard opening pressure of the check valve 14, the check valve 14 opens, and at this time, coolant is allowed to flow from the main passage into the valve passage 12. Typically, the ratio of the coolant volume in the valve passage 12 to that in the main passage is 0.1 - 0.3. At this time, since part of the coolant in the main passage flows into the valve passage 12, the coolant volume for cooling in the main passage decreases, and the coolant volume for cooling in the valve passage 12 increases. At this time, the central ring 7 grows radially relative to the hot start state, and the valve ring 8 contracts radially relative to the hot start state. The guide ring forms a labyrinth edge on the outside, optimizing the sealing effect at this time. On the basis of ensuring a reasonable radial clearance, the leakage of the blades at this time is further reduced, and the operating efficiency of the turbine engine is optimized.

[0049] Through the description of multiple embodiments of the radial clearance adjustment device for a turbine engine according to the present invention, it can be seen that the embodiments of the radial clearance adjustment device for a turbine engine according to the present invention have at least one or more of the following advantages:

[0050] 1. Effectively control the leakage of the turbine blades and reduce the leakage. The radial clearance adjustment device for a turbine engine proposed by the present invention, through the design of the stepped guide ring, enables the turbine to maintain a sufficient radial clearance during the startup process. After stable operation, the labyrinth channels formed by the stepped guide ring can also reduce the leakage on the basis of maintaining the radial clearance, greatly improving the operating efficiency of the turbine and solving the current technical problem of controlling the leakage of the turbine blades.

[0051] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present invention or make equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A radial clearance adjustment device for a turbine engine, characterized in that, it includes: A housing, which is annular as a whole. A guide groove is provided inside the housing, and cooling holes for introducing coolant are opened in the housing; Guide vanes, which are fixed inside the housing, and a plurality of them are arranged circumferentially along the housing, and multiple rows are arranged axially along the housing; Turbine blades, which are axially-flow type as a whole, and the turbine blades are installed at the central position inside the housing; and A guide ring, which is integrally arranged in the guide groove and forms an air passage together with the turbine blades inside the housing; Wherein, the guide ring further includes: A positioning ring, which has a positioning surface, and the positioning ring is closely attached to the guide groove through the positioning surface; A central ring, which is integrally arranged at the center of the guide ring. A main passage is provided inside the central ring, and the main passage is communicated with the cooling holes. By injecting coolant into the cooling holes, the central ring is cooled; and A valve ring, which is separately arranged on both sides of the central ring. A secondary passage and a valve passage are provided inside the valve ring. The secondary passage and the valve passage are not communicated with each other. The secondary passage is communicated with the cooling holes. By injecting coolant into the cooling holes, the valve ring is cooled, and the valve passage is communicated with the bottom of the main passage.

2. The radial clearance adjustment device for a turbine engine according to claim 1, characterized in that, The cooling holes are opened in the housing and extend vertically into the housing until they are communicated with the main passage and the secondary passage in the guide ring.

3. The radial clearance adjustment device for a turbine engine according to claim 2, characterized in that, The number of the cooling holes is one or more, and the coolant is cooling air or water.

4. The radial clearance adjustment device for a turbine engine according to claim 1, characterized in that, The cross-section of the guide groove is a T-shaped structure, and the T-shaped structure includes a horizontal part and a vertical part. The horizontal part is integrally arranged at the middle position inside the housing, and the vertical part is arranged below the horizontal part and extends to the bottom of the housing.

5. The radial clearance adjustment device for a turbine engine according to claim 4, characterized in that, Two positioning rings are provided in total, which are separately arranged on both sides of the valve ring. The axial positions of the two positioning rings do not correspond to those of the turbine blades, so that no scratching occurs between the turbine blades and the positioning rings; The cross-section of the positioning ring is an inverted L structure, and the inverted L structure includes a positioning ring body arranged vertically and a positioning surface arranged horizontally at the top of the positioning ring body. Through the horizontal positioning surface, the positioning ring is inserted into the horizontal part of the guide groove, and finally the two positioning rings are closely attached to the guide groove.

6. The radial clearance adjustment device for a turbine engine according to claim 1, characterized in that, The main channel is integrally disposed inside the central ring. The main channel includes a first main channel and a second main channel disposed below the first main channel. The first main channel is disposed in the vertical direction and is in communication with the cooling holes. The second main channel is disposed in the horizontal direction and the second main channel is in communication with the first main channel. The first main channel and the second main channel are both integrally in a ring structure. By injecting a coolant into the cooling holes, the coolant flows through the first main channel and the second main channel to cool the central ring; The secondary channel is integrally in an inverted L-shaped structure. The inverted L-shaped structure includes a horizontal channel and a vertical channel disposed below the horizontal channel. The horizontal channel is in communication with the cooling holes. The vertical channel extends straight down inside the valve ring. By injecting a coolant into the cooling holes, the coolant flows through the horizontal channel and the vertical channel in sequence to cool the valve ring; The valve channel is disposed below the secondary channel and is not in communication with the secondary channel. A check valve is provided inside the valve channel and is in communication with the second main channel in the main channel to regulate the flow of the coolant between the valve channel and the main channel.

7. The radial clearance adjustment device for a turbine engine according to claim 6, characterized in that the ratio of the coolant flow rate in the valve channel to that in the main channel is (0.1 - 0.3):

1.

8. The radial clearance adjustment device for a turbine engine according to claim 1, characterized in that a plurality of turbine blades are provided. The plurality of turbine blades are mounted on a rotating shaft at the central position at the bottom of the housing, and are located between two rows of the guide vanes and are supported by bearings. The plurality of turbine blades rotate together with the rotating shaft to form a rotating swept edge.

9. The radial clearance adjustment device for a turbine engine according to claim 1, characterized in that a heat insulation layer is further provided between the guide ring and the housing. The heat insulation layer insulates the guide ring from the housing so that the housing does not contract towards the blade direction.

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