A method for adjusting the thermal deformation rate of a casing by changing the thermal capacity of the casing

Abstract

The present application belongs to the field of aircraft engine design, and particularly relates to a method for adjusting the thermal deformation rate of a casing by changing the thermal capacity of the casing. Including: when it is necessary to increase the deformation rate of the stator casing, locally thinning the stator casing; when it is necessary to slow down the deformation rate of the stator casing, locally thickening the stator casing. The method of adjusting the thermal deformation rate of the casing by changing the thermal capacity of the present application achieves the purpose of adjusting the deformation rate of the stator casing by locally adjusting the casing structure without replacing the material of the stator casing, and this adjustment is bidirectional, that is, it can be increased or decreased. Compared with replacing the material of the stator casing, the present application ensures that the steady-state rotor-stator clearance does not change while realizing the transitional rotor-stator clearance control. Compared with the use of a comb-tooth-honeycomb sealing structure, the present application will not be limited by the use environment.

Description

Technical Field

[0001] The present application belongs to the field of aero-engine design, and in particular relates to a method for adjusting the thermal deformation rate of a casing by changing the thermal capacity of the casing. Background Art

[0002] In the field of aero-engine design, the stator casing mechanism is widely used, mainly bearing load and supporting functions, and expanding and contracting with the change of ambient temperature under working conditions. Since the size of the rotor components will also change with the change of speed and temperature, and the size change process of the rotor and stator cannot be completely synchronized, the stator components are usually lagging behind, so the rotor-stator clearance changes with the relative movement of the rotor and stator before reaching a steady state. In a rotor-stator system working in a high-temperature environment, the rotor-stator clearance often deviates from the steady-state design value due to the mismatch of the transition state rotor-stator thermal deformation rate. When the rotor-stator clearance is reduced to a certain extent, the rotor-stator radial friction will occur. In order to alleviate the impact of the transition state rotor-stator friction, there are two commonly used methods: one is to use a material with a fast thermal response rate (larger linear expansion coefficient) for the stator casing, or to use a comb-tooth-honeycomb sealing structure, and use the hardness difference of the rotor and stator and the abradability of the honeycomb material to reduce the impact of friction.

[0003] However, the above two solutions have certain limitations in the specific application process. When using a material with a thermal response rate as the stator casing material, for the same cold-state rotor-stator gap, although the transition state rotor-stator gap can maintain a certain gap, the large linear expansion coefficient of the stator casing will cause the steady-state rotor-stator gap to be unable to maintain a small level, which is not conducive to maintaining the steady-state performance of the engine. If the steady-state gap is reduced by narrowing the cold-state assembly gap, it will bring greater difficulties to the assembly process control and production capacity. Therefore, the method of adjusting the rotor-stator deformation rate by replacing the stator casing material needs to seek a balance between the steady-state gap, transition state gap, assembly gap, production capacity, and assembly capacity. For the comb-tooth-honeycomb sealing structure, since the honeycomb requires a welding process, when the use environment reaches a certain temperature, the application of the sealing structure will be limited.

[0004] Therefore, it is desired to have a technical solution to overcome or at least alleviate at least one of the above-mentioned defects of the prior art. Summary of the invention

[0005] The purpose of the present application is to provide a method for adjusting the thermal deformation rate of a casing by changing the thermal capacity of the casing, so as to solve at least one problem existing in the prior art.

[0006] The technical solution of this application is:

[0007] A method for adjusting the thermal deformation rate of a casing by changing the thermal capacity of the casing, comprising:

[0008] When the deformation rate of the stator casing needs to be increased, the stator casing is locally thinned;

[0009] When it is necessary to slow down the deformation rate of the stator casing, the stator casing is locally thickened.

[0010] In at least one embodiment of the present application, the position where the stator case is locally thinned is located on the other side of the position where the stator case is opposite to the rotor.

[0011] In at least one embodiment of the present application, the position where the stator case is locally thickened is located on the other side of the position where the stator case is opposite to the rotor.

[0012] In at least one embodiment of the present application, a coating is provided on a portion of the stator casing close to a blade tip portion of the rotor.

[0013] The invention has at least the following beneficial technical effects:

[0014] The method of adjusting the thermal deformation rate of the casing by changing the thermal capacity of the casing in the present application, and the method of changing the thermal deformation rate by adjusting the thermal capacity of the casing, have the advantages of simplicity and strong adaptability compared with the existing transition state to stator friction improvement methods; compared with replacing the stator casing material, the adjustment of the thermal deformation rate in the present application is continuous and flexible, and the verification process is simpler; in addition, for any stator casing that wants to change the thermal response rate, it can be achieved by changing the thermal capacity, and it is highly applicable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of a typical rotor-stator structure of an implementation method of the prior art;

[0016] Figure 2 This is a schematic diagram of the structure of the stator casing after heat capacity adjustment according to an embodiment of the present application;

[0017] Figure 3 This is a schematic diagram comparing the transition state stator clearance before and after adjustment of an implementation mode of the present application;

[0018] Figure 4 It is a schematic diagram comparing the steady-state rotor-stator clearance before and after adjustment of an implementation mode of the present application.

[0019] in:

[0020] 1-Typical stator casing; 2-Rotor; 3-Adjusted stator casing. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the embodiment of this application will be described in more detail below in conjunction with the drawings in the embodiment of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be construed as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0022] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 understood as limiting the scope of protection of the present application.

[0023] The following is combined with Figures 1 to 4 This application is described in further detail.

[0024] The present application provides a method for adjusting the thermal deformation rate of a casing by changing the thermal capacity of the casing, comprising:

[0025] When the deformation rate of the stator casing needs to be increased, the stator casing is locally thinned;

[0026] When it is necessary to slow down the deformation rate of the stator casing, the stator casing is locally thickened.

[0027] The method of adjusting the thermal deformation rate of the casing by changing the thermal capacity of the casing of the present application partially adjusts the structure of the stator casing 1 to change the thermal response rate of the stator casing 1, and realizes the control of the transition state to the stator clearance under the premise of ensuring that the steady-state to stator clearance remains unchanged. It should be made clear that the inclusiveness requirement must be met during the adjustment of the thermal response rate of the stator casing 1.

[0028] The method of adjusting the thermal deformation rate of the casing by changing the thermal capacity of the casing of the present application can adjust the thermal deformation rate of the casing by adjusting the local structure of the stator casing 1. This adjustment is bidirectional: it can be accelerated or slowed down. By adjusting the thermal deformation rate of the stator casing 1, the control of the rotor-stator clearance in the transition state is achieved, and the influence of abnormal friction of the rotor-stator in the transition state on the safety, reliability, structural stability and maintenance cost of the engine is avoided.

[0029] In the preferred embodiment of the present application, taking accelerating the deformation rate of the stator casing as an example, an introduction is made:

[0030] The typical rotor-stator matching structures commonly seen at present are as follows: Figure 1 As shown in the figure, in the parts with higher working temperature, the sealing form of the rotor and stator is usually the matching form of blade tip (rotor)-coating (stator). There will be a certain gap between the rotor and stator in the assembled state and working state. If the thermal deformation matching degree of the rotor and stator is not good, when the engine state changes and stabilizes again, the rotor and stator may be deformed in an uncoordinated manner. Figure 3 The collision and friction conditions shown in the figure may cause structural damage to engine components in severe cases, affecting engine safety and reliability and increasing subsequent repair costs.

[0031] In this embodiment, a typical adjusted stator casing structure is provided, such as Figure 2 By locally thinning the stator casing, the adjusted stator casing 3 is obtained to reduce the casing heat capacity, increase its thermal response rate, and improve the control ability of the transition state rotor-stator clearance without affecting the steady-state rotor-stator clearance. The comparison of the transition state and steady-state rotor-stator clearance before and after adjustment is shown in Figure 3 , Figure 4 As shown, the deformation matching degree between the stator casing and the rotor can be improved after the heat capacity is adjusted, and there is no difference in the steady-state rotor-stator gap.

[0032] In addition, the method of changing the heat capacity of the casing is not limited to Figure 2 The local thinning shown. If the deformation rate of the stator casing needs to be slowed down, the stator casing can also be adaptively thickened locally to achieve this. According to specific application requirements, the stator casing can also be partially or completely improved in structure to speed up or slow down the deformation rate of the stator casing. It should be noted that during the adjustment of the thermal capacity of the stator casing, the casing containment requirements must be met.

[0033] In a preferred embodiment of the present application, the location where the stator casing is locally thinned is located on the other side of the position where the stator casing is opposite to the rotor, see Figure 2 The location where the stator casing is locally thickened is also located on the other side of the location where the stator casing is opposite to the rotor. Advantageously, in this embodiment, a coating is also provided at a location of the stator casing near the blade tip of the rotor.

[0034] The method of adjusting the thermal deformation rate of the casing by changing the thermal capacity of the casing in the present application achieves the purpose of adjusting the deformation rate of the stator casing by locally adjusting the casing structure without replacing the material of the stator casing, and this adjustment is bidirectional, that is, it can be increased or decreased. Compared with replacing the material of the stator casing, the present application ensures that the steady-state rotor-stator gap does not change while realizing the control of the rotor-stator gap in the transition state. Compared with the use of a comb-tooth-honeycomb sealing structure, the present application will not be limited by the use environment.

[0035] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for adjusting the thermal deformation rate of a casing by changing the thermal capacity of the casing, characterized in that: include: When the deformation rate of the stator casing needs to be increased, the stator casing is locally thinned; When the deformation rate of the stator casing needs to be slowed down, the stator casing is locally thickened; The position where the stator casing is locally thinned is located on the other side of the position where the stator casing is opposite to the rotor; The position where the stator casing is locally thickened is located on the other side of the position where the stator casing is opposite to the rotor.

2. The method for adjusting the thermal deformation rate of a casing by changing the thermal capacity of the casing according to claim 1, characterized in that: A coating is provided at a portion of the stator casing close to a blade tip portion of the rotor.

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