High-speed ceramic turbine rotor structure with active cooling function

Abstract

The invention relates to a high-speed ceramic turbine rotor structure with an active cooling function. The high-speed ceramic turbine rotor structure comprises a turbine rotating shaft, a ceramic turbine impeller and a cooling oil injection ring. The ceramic turbine impeller and the turbine rotating shaft are assembled together to form the ceramic turbine rotor, and when the ceramic turbine rotor works, cooling lubricating oil enters through an inlet in the cooling oil spraying ring in the radial direction and is sprayed out through an outlet of the cooling oil spraying ring in the axial direction. Then cooling lubricating oil enters the snake-shaped active cooling channel of the turbine rotating shaft in the axial direction through a cooling lubricating oil inlet of the active cooling channel of the turbine rotating shaft, and is thrown out from a cooling lubricating oil outlet of the active cooling channel of the turbine rotating shaft in the radial direction after a shaft sleeve of the turbine rotating shaft is cooled; and the lubricating oil flows back to the lubricating oil main loop for cooling and pressurizing and then enters the circulation again. The structure can realize effective cooling of the connecting part in the working process of the ceramic turbine rotor, and the strength and the working reliability of the ceramic turbine rotor are improved.

Description

Technical Field

[0001] The invention belongs to the field of radial flow turbine structure design, and in particular relates to a high-speed ceramic turbine rotor structure with active cooling. Background Art

[0002] As the core component of the radial turbine system, the high-speed turbine rotor is one of the most complex and severe components in the turbine. When the turbine is working, the turbine rotor is in a high-speed rotation state under the action of high-temperature gas working fluid, and its speed can reach tens of thousands of revolutions per minute, and some rotors even reach hundreds of thousands of revolutions per minute. Once the turbine rotor structure fails, not only will the turbine fail to work normally and fail to convert thermal energy into mechanical energy, but it will also cause damage to other structures in the system. Therefore, a reasonable design of the turbine rotor structure is crucial to ensure the structural reliability of the turbine system.

[0003] In order to meet the high efficiency and other performance requirements of the turbine system, the inlet temperature of the turbine continues to increase, and the turbine impeller uses high-temperature resistant ceramic materials instead of high-temperature alloy materials. The turbine rotor consists of a turbine impeller and a shaft structure. The shaft is made of high-strength alloy steel. For turbine impellers made of high-temperature alloys, friction welding, electron beam and other processes can be used to achieve a reliable connection between the turbine impeller and the alloy steel shaft. For turbine impellers made of ceramic materials, it is difficult to use friction welding, electron beam and other welding processes to achieve a reliable connection between the ceramic turbine impeller and the alloy steel shaft.

[0004] In view of the high performance and high reliability requirements of the turbine system, the turbine rotor is required to be able to work reliably under high temperature and high speed conditions. The turbine rotor must not only be able to work reliably under high temperature conditions, but also have good aerodynamic performance and low weight. To this end, based on the structural characteristics of high-temperature and high-speed ceramic turbine rotors, the structure of the turbine rotor is reasonably designed to meet the performance and reliability requirements of the high-speed turbine rotor, and achieve the goal of efficient and reliable operation of the turbine system under high temperature conditions. Summary of the invention

[0005] Aiming at the reliability design requirements of high-speed radial flow ceramic turbine rotor structure, the present invention proposes a high-speed ceramic turbine rotor structure with active cooling. The turbine rotor includes a turbine shaft, a ceramic turbine impeller and a cooling oil spray ring. The ceramic turbine impeller is assembled with the turbine shaft to form a ceramic turbine rotor. When the ceramic turbine rotor is working, the cooling lubricating oil enters radially through the inlet of the cooling oil spray ring and is sprayed axially through its outlet. Then, the cooling lubricating oil enters the serpentine active cooling channel of the turbine shaft axially through the cooling lubricating oil inlet of the active cooling channel of the turbine shaft. After the cooling of the sleeve of the turbine shaft is completed, it is radially thrown out from the cooling lubricating oil outlet of the active cooling channel of the turbine shaft, and flows back to the main lubricating oil circuit for cooling and pressurization before entering the circulation again. In this way, effective cooling of the connection parts during the operation of the ceramic turbine rotor is achieved, and the strength of the ceramic turbine rotor connection structure and the working reliability are ensured.

[0006] The technical solution of the present invention:

[0007] A high-speed ceramic turbine rotor structure with active cooling comprises a turbine shaft, a ceramic turbine impeller and a cooling oil injection ring.

[0008] The turbine shaft is located on the back side of the ceramic turbine impeller. The end of the turbine shaft close to the ceramic turbine impeller is provided with a sleeve for mounting the turbine impeller. The center of the sleeve of the turbine shaft is provided with a stepped blind hole assembled with the stepped shaft of the back of the ceramic turbine impeller. The stepped blind hole of the turbine shaft and the stepped shaft of the back of the ceramic turbine impeller are interference fitted. An active cooling channel is provided on the outer side of the stepped blind hole of the turbine shaft. The active cooling channel of the turbine shaft is a serpentine channel uniformly distributed along the circumference of the stepped blind hole. Lubricating oil flows through the cooling channel. The cooling lubricating oil inlet of the active cooling channel of the turbine shaft is evenly distributed along the axial direction on the annular end surface of the sleeve away from the ceramic turbine impeller. The cooling lubricating oil outlet of the active cooling channel of the turbine shaft is evenly distributed along the radial direction on the cylindrical surface of the sleeve of the turbine shaft away from the turbine impeller. An oil collecting ring groove is provided at the cooling lubricating oil outlet of the active cooling channel of the turbine shaft. Sealing comb teeth and piston ring sealing grooves are provided on the outer cylindrical surface of the sleeve of the turbine shaft in sequence from the end surface close to the back of the ceramic turbine impeller.

[0009] The ceramic turbine impeller is a radial flow integral impeller structure, and is made of high-strength silicon nitride ceramic material. A stepped shaft is provided on the back of the wheel of the ceramic turbine impeller to be assembled with the stepped blind hole of the turbine shaft. The stepped shaft of the ceramic turbine impeller and the stepped blind hole of the turbine shaft are assembled by interference fit.

[0010] The cooling oil spray ring is an annular structure and is a stationary component installed on the bearing body. The cooling oil spray ring is close to the cooling and lubricating oil inlet side of the active cooling channel of the turbine shaft. The cooling and lubricating oil inlet is evenly distributed radially on the outer cylindrical surface of the cooling oil spray ring. The cooling and lubricating oil outlet is evenly distributed axially on the annular end surface of the cooling oil spray ring on the side of the cooling and lubricating oil inlet of the active cooling channel of the turbine shaft. The cooling and lubricating oil outlet of the cooling oil spray ring is opposite to the cooling and lubricating oil inlet of the active cooling channel of the turbine shaft.

[0011] The ceramic turbine impeller is assembled together with the turbine shaft to form a ceramic turbine rotor. When the ceramic turbine rotor is working, the cooling lubricating oil enters radially through the inlet of the cooling oil injection ring and is ejected axially through its outlet. Then, the cooling lubricating oil enters axially into the serpentine active cooling channel of the turbine shaft through the cooling lubricating oil inlet of the active cooling channel of the turbine shaft. After cooling the sleeve of the turbine shaft, the cooling lubricating oil is radially thrown out from the cooling lubricating oil outlet of the active cooling channel of the turbine shaft, and flows back to the main lubricating oil circuit for cooling and pressurization before entering the circulation again.

[0012] The beneficial effects of the present invention are:

[0013] The present invention proposes a high-speed ceramic turbine rotor structure with active cooling, wherein the stepped blind hole of the turbine shaft and the stepped shaft of the wheel back of the turbine impeller are fitted with interference fit, and an active cooling channel is provided on the outer side of the stepped blind hole of the turbine shaft, which can prevent the turbine rotor from expanding and loosening under the action of high-temperature and high-pressure gas when working, and ensure the connection reliability between the turbine shaft and the turbine impeller. The cooling lubricating oil inlet of the active cooling channel of the turbine shaft is evenly distributed along the axial direction on the annular end surface of the sleeve away from the turbine impeller, and the cooling lubricating oil outlet is evenly distributed along the radial direction on the cylindrical surface of the sleeve of the turbine shaft away from the turbine impeller. Such a setting can form a pumping effect on the cooling lubricating oil in the serpentine channel when the turbine shaft rotates, thereby improving the active cooling effect of the turbine shaft. The outer cylindrical surface of the sleeve of the turbine shaft is provided with sealing comb teeth and piston ring sealing grooves in sequence from the end surface close to the wheel back of the turbine impeller, which can prevent the cooling lubricating oil from flowing from one side of the shaft to the end of the turbine impeller, and can also prevent the high-temperature gas in the turbine impeller from entering one side of the turbine shaft. The cooling lubricating oil outlet of the active cooling channel of the turbine shaft is provided with an annular groove to prevent the cooling lubricating oil at the outlet of the active cooling channel from mixing with the cooling lubricating oil at the inlet. The cooling oil spray ring is a stationary component installed on the bearing body, which can conveniently introduce the lubricating oil used to cool the bearing into the active cooling channel of the turbine shaft. The setting of these structural features can achieve effective cooling of the high-speed ceramic turbine rotor connection structure and improve the strength and working reliability of the ceramic turbine rotor connection structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of a high-speed ceramic turbine rotor with active cooling.

[0015] 1 Turbine shaft 2 Cooling oil injection ring 3 Turbine impeller 4 Oil collecting ring groove 5 Piston ring sealing groove 6 Sealing grate teeth DETAILED DESCRIPTION

[0016] A high-speed ceramic turbine rotor structure with active cooling comprises a turbine shaft 1, a ceramic turbine impeller 3 and a cooling oil injection ring 2.

[0017] The turbine shaft 1 is located on the back side of the ceramic turbine impeller 3. The end of the turbine shaft 1 close to the ceramic turbine impeller 3 is provided with a sleeve for mounting the turbine impeller. The central part of the sleeve of the turbine shaft 1 is provided with a stepped blind hole assembled with the stepped shaft of the back of the ceramic turbine impeller 3. The stepped blind hole of the turbine shaft 1 and the stepped shaft of the back of the ceramic turbine impeller 3 are interference fitted. An active cooling channel is provided on the outer side of the stepped blind hole of the turbine shaft 1. The active cooling channel of the turbine shaft 1 is a serpentine channel uniformly distributed along the circumference of the stepped blind hole. Lubricating oil flows through the active cooling channel. The cooling lubricating oil inlet of the active cooling channel of the turbine shaft 1 is evenly distributed along the axial direction on the annular end surface of the sleeve away from the ceramic turbine impeller 3. The cooling lubricating oil outlet of the active cooling channel of the turbine shaft 1 is evenly distributed along the radial direction on the cylindrical surface of the sleeve of the turbine shaft 1 away from the turbine impeller. An oil collecting ring groove 4 is provided at the cooling lubricating oil outlet of the active cooling channel of the turbine shaft 1. Sealing comb teeth 6 and piston ring sealing grooves 5 are sequentially provided on the outer cylindrical surface of the sleeve of the turbine shaft 1 from the end surface close to the back side of the ceramic turbine impeller 3.

[0018] The ceramic turbine impeller 3 is a radial integral impeller structure. The ceramic turbine impeller 3 is made of high-strength silicon nitride ceramic material. A stepped shaft is provided on the back of the wheel of the ceramic turbine impeller 3 to be assembled with the stepped blind hole of the turbine shaft 1. The stepped shaft of the ceramic turbine impeller 3 is fitted with the stepped blind hole of the turbine shaft 1 by interference fit.

[0019] The cooling oil spray ring 2 is an annular structure. The cooling oil spray ring 2 is a stationary component installed on the bearing body. The cooling oil spray ring 2 is close to the cooling lubricating oil inlet side of the active cooling channel of the turbine shaft 1. The cooling lubricating oil inlet is evenly distributed radially on the outer cylindrical surface of the cooling oil spray ring 2. The cooling oil spray ring 2 is close to the cooling lubricating oil inlet of the active cooling channel of the turbine shaft 1. The annular end surface is provided with cooling lubricating oil outlets evenly distributed along the axial direction. The cooling lubricating oil outlet of the cooling oil spray ring 2 is opposite to the cooling lubricating oil inlet of the active cooling channel of the turbine shaft 1.

[0020] The ceramic turbine impeller 3 is assembled together with the turbine shaft 1 to form a ceramic turbine rotor. When the ceramic turbine rotor is working, the cooling lubricating oil enters radially through the inlet of the cooling oil injection ring 2 and is ejected axially through its outlet. Then, the cooling lubricating oil enters axially into the serpentine active cooling channel of the turbine shaft 1 through the cooling lubricating oil inlet of the active cooling channel of the turbine shaft 1. After cooling the sleeve of the turbine shaft 1, it is radially thrown out from the cooling lubricating oil outlet of the active cooling channel of the turbine shaft 1, and flows back to the main lubricating oil circuit for cooling and pressurization before entering the circulation again.

[0021] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-speed ceramic turbine rotor structure with active cooling, characterized in that: It comprises a turbine shaft (1), a ceramic turbine impeller (3) and a cooling oil injection ring (2); The turbine shaft (1) is located on the back side of the ceramic turbine impeller (3); one end of the turbine shaft (1) close to the ceramic turbine impeller (3) is provided with a sleeve for mounting the turbine impeller; the center of the sleeve of the turbine shaft (1) is provided with a stepped blind hole for fitting with the stepped shaft on the back of the ceramic turbine impeller (3); the stepped blind hole of the turbine shaft (1) and the stepped shaft on the back of the ceramic turbine impeller (3) are fitted with interference fit; the outer side of the stepped blind hole of the turbine shaft (1) is provided with an active cooling The active cooling channel of the turbine shaft (1) has lubricating oil flowing therein, the cooling lubricating oil inlet of the active cooling channel of the turbine shaft (1) is evenly distributed along the axial direction on the annular end surface of the shaft sleeve away from the ceramic turbine impeller (3), the cooling lubricating oil outlet of the active cooling channel of the turbine shaft (1) is evenly distributed along the radial direction on the cylindrical surface of the shaft sleeve of the turbine shaft (1) away from the turbine impeller, and the cooling lubricating oil outlet of the active cooling channel of the turbine shaft (1) is provided with an oil collecting ring groove (4); The ceramic turbine impeller (3) is a radial flow integral impeller structure, and a stepped shaft is provided at the wheel back of the ceramic turbine impeller (3) to be assembled with the stepped blind hole of the turbine shaft (1), and the stepped shaft of the ceramic turbine impeller (3) and the stepped blind hole of the turbine shaft (1) are assembled by interference fit; The cooling oil injection ring (2) is an annular structure. The cooling oil injection ring (2) is a stationary component installed on the bearing body. The cooling oil injection ring (2) is close to the cooling lubricating oil inlet side of the active cooling channel of the turbine shaft (1). The cooling lubricating oil inlet is evenly distributed in the radial direction on the outer cylindrical surface of the cooling oil injection ring (2). The cooling lubricating oil outlet is evenly distributed in the axial direction on the annular end surface of the cooling oil injection ring (2) on the side of the cooling lubricating oil inlet of the active cooling channel of the turbine shaft (1). The ceramic turbine impeller (3) is assembled with the turbine shaft (1) to form a ceramic turbine rotor. When the ceramic turbine rotor is working, the cooling lubricating oil enters radially through the inlet of the cooling oil injection ring (2) and is ejected axially through its outlet. Then, the cooling lubricating oil enters axially into the serpentine active cooling channel of the turbine shaft (1) through the cooling lubricating oil inlet of the active cooling channel of the turbine shaft (1). After the cooling of the shaft sleeve of the turbine shaft (1) is completed, the cooling lubricating oil is ejected radially from the cooling lubricating oil outlet of the active cooling channel of the turbine shaft (1), and flows back to the main lubricating oil circuit for cooling and pressurization before entering the next cycle.

2. A high-speed ceramic turbine rotor structure with active cooling according to claim 1, characterized in that: The active cooling channel of the turbine shaft (1) is a serpentine channel evenly distributed along the circumference of the stepped blind hole ring.

3. A high-speed ceramic turbine rotor structure with active cooling according to claim 1, characterized in that: The outer cylindrical surface of the shaft sleeve of the turbine shaft (1) is provided with sealing grate teeth (6) and a piston ring sealing groove (5) in sequence starting from the end surface close to the wheel back side of the ceramic turbine impeller (3).

4. A high-speed ceramic turbine rotor structure with active cooling according to claim 1, characterized in that: The ceramic turbine impeller (3) is made of high-strength silicon nitride ceramic material.

5. A high-speed ceramic turbine rotor structure with active cooling according to claim 1, characterized in that: The cooling lubricating oil outlet of the cooling oil spray ring (2) is opposite to the cooling lubricating oil inlet of the active cooling channel of the turbine shaft (1).

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