WO2021249184A1

WO2021249184A1 - Two-duct turbojet engine with bearing cooling function

Info

Publication number: WO2021249184A1
Application number: PCT/CN2021/095916
Authority: WO
Inventors: 赵景山; 张家悦
Original assignee: 清华大学
Priority date: 2020-06-08
Filing date: 2021-05-26
Publication date: 2021-12-16
Also published as: CN111636975A; CN111636975B

Abstract

A two-duct turbojet engine, comprising ducts, an air inlet mechanism (1) arranged at an air inlet end of the ducts and an exhaust nozzle (5) arranged at an air outlet end of the ducts, wherein the ducts comprise an outer duct (3) and an inner duct (2) located in the outer duct, the outer duct and the inner duct respectively communicate with the exhaust nozzle, and the outer duct and the inner duct respectively communicate with the air inlet mechanism. The engine reduces the temperature of a bearing working area when the engine is working, reduces cost of the engine, prolongs the service life of the engine, and improves the performance of the engine.

Description

Two-ducted turbojet engine with bearing cooling function

Technical field

The invention relates to the technical field of engines, in particular to a two-ducted turbojet engine with a bearing cooling function.

Background technique

In 1903, the Wright brothers successfully tested a controlled fixed-wing aircraft for the first time. In the following century, aviation aircraft brought earth-shaking changes to human society. Countries around the world have invested a lot of scientific research efforts to develop aviation aircraft technology, and the most critical technology in aviation aircraft technology is aviation engine technology.

Before the 1940s, most airplanes used piston engines. This kind of engine can only output torque and cannot directly generate pull or thrust, so it is often used with propellers. The propeller rotates under the drive of the engine to generate tension on the blades. As the flight speed of the aircraft increases, the linear velocity of the airflow at the end of the blades greatly increases, which greatly reduces the efficiency of the engine, thus greatly restricting the flight speed. After the 1940s, some Western countries began to develop and use turbojet engines. The turbojet engine is composed of five parts: air intake device, compressor turbine, combustion chamber, turbine, and tail nozzle. Compared with a piston engine, the intake, combustion, expansion, work, exhaust and other processes of a turbojet engine are completed by different components at the same time, which improves work efficiency. At the same time, under the action of the compressor at the front end of the turbojet engine, the intake air volume of the turbojet engine far exceeds that of the piston engine, so its operating power has also been greatly improved compared to the piston engine. However, when the engine is running, the temperature at the turbine behind the combustion chamber is extremely high, about 500°C to 700°C. Extremely high working temperature is undoubtedly a huge challenge for key components such as bearings. On the one hand, the existing lubricants are difficult to effectively lubricate at such high temperatures. On the other hand, the working life of rotating parts at high temperatures is extremely short. In recent years, scientists and engineers have invested a lot of time, energy and money in the development of bearings that can work effectively at high temperatures. If the temperature of the bearing working area can be reduced to a reasonable range, the cost of the engine will be greatly reduced, the life of the engine will be prolonged, and the performance of the engine will be improved.

Therefore, providing a two-ducted turbojet engine with a bearing cooling function to reduce engine cost, extend engine life, and improve engine performance is a technical problem that needs to be solved urgently in this field.

Summary of the invention

The purpose of the present invention is to provide a two-ducted turbojet engine with bearing cooling function to solve the above-mentioned problems in the prior art, reduce the temperature of the bearing working area when the engine is working, reduce the cost of the engine, extend the life of the engine, and improve Engine performance.

In order to achieve the above objectives, the present invention provides the following solutions:

The present invention provides a two-ducted turbojet engine with a bearing cooling function, comprising a duct, an air intake mechanism arranged at the intake end of the duct, and a tail nozzle arranged at the air outlet end of the duct, The duct includes an outer duct and an inner duct located in the outer duct, the outer duct and the inner duct are respectively connected with the exhaust nozzle, and the outer duct and the inner duct are respectively connected with The air intake mechanism is in communication.

Preferably, the inner tube includes an inner tube shell, a main shaft rotatably connected with the inner tube shell through a bearing, and an impeller and a turbine fixedly connected to the main shaft. The impeller is close to the air intake mechanism. The turbine is close to the tail nozzle.

Preferably, the air intake mechanism includes an air inlet and a diffuser fixedly connected to the air inlet, and the diffuser and the impeller form a compressor turbine.

Preferably, the inner tube shell is provided with a baffle plate at one end close to the turbine, and the baffle plate is fixedly connected to the inner tube shell.

Preferably, the outer duct includes an outer duct housing, the air intake mechanism and the inner duct are both located in the outer duct housing, and a turbine stator is also arranged in the outer duct housing, and The turbine stator is combined with the turbine to form a turbine.

Preferably, a combustion chamber is further provided in the outer duct shell, and the combustion chamber is located between the compressor turbine and the turbine.

Preferably, the diameter of the tail nozzle gradually decreases from the inlet end to the outlet end.

Compared with the prior art, the present invention has achieved the following technical effects:

The two-ducted turbojet engine with bearing cooling function provided by the present invention reduces the temperature of the bearing working area when the engine is working, reduces the engine cost, prolongs the engine life, and improves the engine performance. In the working process, the air passes through the air intake mechanism and is divided into two parts, which enter the inner duct and the outer duct respectively; the air entering the inner duct flows along the inner duct, cools the key rotating parts such as the main shaft and the bearing, and is sprayed from the exhaust by the turbine. Exhaust from the pipe; the air entering the outer duct flows into the combustion chamber, mixes with the fuel and burns, pushes the turbine, and is discharged from the tail nozzle at high speed. The two-ducted turbojet engine with bearing cooling function provided by the present invention can control the temperature of the bearing located near the turbine at 300 DEG C to 400 DEG C, and meet the operating temperature range of ordinary bearings. The continuous inflow of low-temperature air into the inner channel cools down key rotating parts such as bearings, reduces the operating temperature of key rotating parts such as bearings, avoids the failure of lubricating fluid at high temperatures, and improves the service life of key rotating parts such as bearings. Improved engine performance and extended engine life. Aeroengine is the core component of aviation aircraft, and improving its working performance is conducive to improving the flight performance of aviation aircraft, which has important economic, environmental and social significance.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, without creative work, other drawings can be obtained based on these drawings.

Fig. 1 is a structural schematic diagram 1 of a two-ducted turbojet engine with bearing cooling function according to the present invention;

Figure 2 is the second structural diagram of the two-ducted turbojet engine with bearing cooling function according to the present invention;

Among them: 1- intake mechanism; 2- inner duct; 3- outer duct; 4- turbine; 5- tail nozzle; 6-turbine; 7- deflector; 8- bearing; 9- main shaft; 10- combustion Chamber; 11-diffuser; 12-impeller; 13-inlet.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide a two-ducted turbojet engine with a bearing cooling function to reduce the temperature of the bearing working area when the engine is working, reduce engine costs, extend engine life, and improve engine performance.

In order to make the above objectives, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1 to 2: The two-ducted turbojet engine with bearing cooling function in this embodiment includes a duct, an intake mechanism 1 arranged at the intake end of the duct, and a tail injection arranged at the outlet end of the duct Tube 5.

Among them, the duct includes an outer duct 3 and an inner duct 2 located in the outer duct 3. The outer duct 3 and the inner duct 2 are respectively connected with the exhaust nozzle 5, and the outer duct 3 and the inner duct 2 are respectively connected with the intake mechanism 1 Connected. The inner tube 2 includes an inner tube shell, a main shaft 9 rotatably connected with the inner tube shell through a bearing 8 and a turbine 6 fixedly connected to the main shaft 9. The turbine 6 is close to the exhaust nozzle 5, and the diameter of the exhaust nozzle 5 is along the intake The direction from the end to the outlet end gradually decreases, which has good aerodynamic characteristics.

The air intake mechanism 1 includes an air inlet 13 and a diffuser 11 fixedly connected to the air inlet 13, and the impeller 12 is fixedly connected to the main shaft 9 in the inner duct 2. The impeller 12 and the diffuser 11 constitute a compressor turbine. The inner tube shell is provided with a baffle plate 7 at one end close to the turbine 4, and the baffle plate 7 is fixedly connected with the inner tube shell.

The outer duct 3 includes an outer duct housing. The air intake mechanism 1 and the inner duct 2 are both located in the outer duct housing. A turbine stator is also arranged in the outer duct housing. The turbine stator and the turbine 6 are combined to form a turbine 4. A combustion chamber 10 is also provided in the outer duct shell, and the combustion chamber 10 is located between the compressor turbine and the turbine 4.

The working process of the two-ducted turbojet engine with bearing cooling function in this embodiment is as follows:

After passing through the air intake mechanism 1, the air is divided into two parts, which enter the inner duct 2 and the outer duct 3 respectively; the air entering the inner duct 2 flows along the inner duct 2, and passes through the turbine 6 after cooling key rotating parts such as the main shaft 9 and the bearing 8 It is discharged from the tail nozzle 5, which reduces the working temperature of key rotating parts such as the bearing 8, avoids the failure of the lubricating fluid at high temperature, and improves the service life of the key rotating parts such as the bearing 8, thereby improving engine performance and extending engine life. The air entering the outer duct 3 enters the combustion chamber 10, is fully mixed with fuel, and burns, pushes the turbine 6, and is discharged at a high speed by the tail nozzle 5. The rotation of the turbine 6 drives the rotation of the compressor 11, which runs in a cycle.

In this specification, specific examples are used to describe the principle and implementation of the present invention. The description of the above examples is only used to help understand the method and core idea of the present invention; at the same time, for those of ordinary skill in the art, according to this The idea of the invention will change in the specific implementation and the scope of application. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

A two-ducted turbojet engine with bearing cooling function, which is characterized in that it comprises a duct, an air intake mechanism arranged at the intake end of the duct, and a tail nozzle arranged at the air outlet end of the duct, The duct includes an outer duct and an inner duct located in the outer duct, the outer duct and the inner duct are respectively connected with the exhaust nozzle, and the outer duct and the inner duct are respectively connected with The air intake mechanism is in communication.
The two ducted turbojet engine with bearing cooling function according to claim 1, characterized in that: the inner duct includes an inner duct shell, a main shaft and a fixed connection that are rotatably connected to the inner duct shell through a bearing An impeller and a turbine on the main shaft, the impeller is close to the air intake mechanism, and the turbine is close to the tail nozzle.
The two-ducted turbojet engine with bearing cooling function according to claim 2, characterized in that: the intake mechanism includes an intake duct and a diffuser fixedly connected in the intake duct, and the diffuser The compressor and the impeller form a compressor turbine.
The two ducted turbojet engine with bearing cooling function according to claim 3, characterized in that: the inner duct shell is provided with a deflector at one end close to the turbine, and the deflector is connected to the The inner shell is fixedly connected.
The two ducted turbojet engine with bearing cooling function according to claim 4, characterized in that: the outer duct includes an outer duct shell, and the air intake mechanism and the inner duct are both located in the In the outer duct housing, a turbine stator is also arranged in the outer duct housing, and the turbine stator and the turbine rotor are combined to form a turbine.
The two-ducted turbojet engine with bearing cooling function according to claim 5, characterized in that: the outer duct shell is also provided with a combustion chamber, and the combustion chamber is located between the compressor turbine and the turbine between.
The two-ducted turbojet engine with bearing cooling function according to claim 1, wherein the diameter of the tail nozzle gradually decreases from the inlet end to the outlet end.