阅读说明：本技术 多转子微型燃气轮机及其启动方法 (Multi-rotor micro gas turbine and starting method thereof ) 是由 靳普 于 2020-11-18 设计创作，主要内容包括：本申请公开了一种多转子微型燃气轮机及其启动方法,通过对燃气轮机的启动结构及启动方法进行改进,大大缩短了核心机转子转轴的长度,降低了设备加工难度,减小了设备震动。(The application discloses miniature gas turbine of many rotors and start-up method thereof through improving the start-up structure and the start-up method to gas turbine, has shortened the length of core machine rotor pivot greatly, has reduced the equipment processing degree of difficulty, has reduced equipment vibrations.)

1. A multi-rotor micro gas turbine comprises a core machine and a free machine, wherein the core machine comprises a gas compressor, a turbine, a rotating shaft, an air inlet channel and a combustion chamber; the gas compressor and the turbine are respectively sleeved at the front end and the tail end of the rotating shaft, the front end of the gas compressor is encircled into the gas inlet channel by a shell which is covered around, the outlet of the gas compressor is communicated with the combustion chamber through the gas outlet channel, the rim of the turbine is arranged in the exhaust channel of the combustion chamber, and high-temperature and high-pressure gas sprayed out of the exhaust channel of the combustion chamber is sprayed on the end surface of the turbine to push the turbine to rotate to do work; the rotating shaft is supported in the stator through a radial bearing; each bearing is arranged on a shaft section of a rotating shaft between the compressor and the turbine, a bearing cavity is formed between the gas outlet channel and the stator, the gas seal is arranged on the gas back surface of the compressor to prevent gas on the gas back surface of the compressor from leaking into the bearing cavity, and the gas seal is arranged on the front side of the turbine to prevent gas from leaking into the bearing cavity from a gap between the turbine and the combustion chamber;

the free machine comprises a free casing, a free turbine, a motor, a free rotor system and a smoke gas chamber, wherein the free turbine, the motor and the free rotor system are arranged in the free casing, and the free turbine and the motor are sequentially and coaxially arranged on the free rotor system;

the free turbine wheel rim is arranged in the exhaust passage of the combustion chamber, the high-temperature high-pressure gas at the front section of the exhaust passage of the combustion chamber is sprayed on the end surface of the turbine to push the turbine to rotate to do work, and the high-temperature high-pressure gas at the rear section of the exhaust passage of the combustion chamber is sprayed on the end surface of the free turbine to push the free turbine to rotate to do work; the outlet of the flue gas chamber is communicated with the outside.

2. The multiple rotor micro gas turbine as claimed in claim 1, wherein: the gas firstly enters the gas compressor, is pressurized by the gas compressor and then enters the combustion chamber for combustion, and hot combustion products are ejected from the outlet of the combustion chamber through the exhaust passage; the edge of the turbine of the core machine extends into the front section of the exhaust passage, the edge of the free turbine extends into the rear section of the exhaust passage and is coaxial with the turbine of the core machine, at the moment, the high-temperature gas can push the turbine of the core machine to rotate, drive the compressor which is coaxially connected with the turbine of the core machine through the rotating shaft to rotate, and can push the free turbine to rotate, so that the high-temperature gas does work to drive the motor to generate power, and the redundant high-temperature gas.

3. The multiple rotor micro gas turbine as claimed in claim 1, wherein: and the outlet of the flue gas chamber is communicated with a waste heat recovery device arranged outside.

4. The multiple rotor micro gas turbine as claimed in claim 3, wherein: the waste heat recovery device comprises a boiler, a radiator and a heat exchanger.

5. Method for starting up a multiple rotor micro gas turbine according to any one of claims 1 to 4, characterized in that it comprises the following steps:

1) starting a motor to drive a free rotor system to rotate so as to drive a free turbine to rotate, wherein airflow vortex is generated when the free turbine rotates to drive a core machine turbine in front of the free turbine to rotate; the turbine of the core machine drives the coaxial compressor impeller to rotate;

2) determining that the micro gas turbine meets an ignition condition, and starting an igniter to execute an ignition operation;

3) after the ignition operation is successful, fuel is combusted, so that the speed of the rotor of the core engine of the micro gas turbine is continuously increased until the rotor stably rotates, and the motor is disconnected; after combustion, high-temperature and high-pressure gas is sprayed out to push a turbine of the core machine and a free turbine to rotate, the turbine drives a coaxial compressor impeller to rotate at a high speed, and the whole machine continuously operates; the free turbine drives the motor to generate electricity.

6. The starting method according to claim 5, wherein in step 2), the micro gas turbine is determined to satisfy the ignition condition, and the starting of the igniter to perform the ignition operation comprises:

determining that the rotation speed of a rotor driven by the rotation of an impeller of the gas compressor reaches an ignition speed;

the rotor is maintained at the ignition speed, and the fuel pump is started to supply fuel;

the igniter is turned on to perform ignition operation.

Technical Field

The scheme relates to the field of starting modes of gas turbines, in particular to a multi-rotor micro gas turbine and a starting method thereof.

Background

The industrial gas turbine mainly comprises three parts of a compressor, a combustion chamber and a turbine. After entering the compressor, the air is compressed into high-temperature and high-pressure air, then the air is supplied to a combustion chamber for fuel combustion, and the generated high-temperature and high-pressure gas expands in a turbine to do work.

The single-rotor gas turbine has the advantages that the whole structure is only provided with one shaft, the gas compressor and the turbine are all arranged on the shaft, the structure is simple, and the economy is good. Theoretically, the compressor of the micro gas turbine with the single-rotor structure can be made into any number of stages to achieve a certain pressure increase ratio. However, the structural limitation of the single rotor causes all parts to be arranged on the same main shaft, when the rotating speed of the single rotor suddenly drops, the high-pressure part of the compressor can seriously drop in efficiency because the rotating speed cannot be enough, and simultaneously, the load of the low-pressure part of the compressor can sharply rise. Surging occurs when the low pressure compressor is partially overloaded, and in normal operation, surging is not allowed. To solve this problem, guide vanes are usually added before the compressor or bleed air is used in the middle stage of the compressor, i.e. a part of the pressurized air is bled to reduce the load of the low-pressure part of the compressor. The method has obvious defects, not only can greatly reduce the efficiency, but also has not very obvious effect on the compressor with high pressure ratio.

In order to improve the working efficiency of the compressor and reduce surge, multiple rotors are thought to solve the problem. For example, the low-pressure compressor and the high-pressure compressor of a micro gas turbine are operated at different rotational speeds. The low-pressure compressor and the low-pressure turbine are linked to form a low-pressure rotor, and the high-pressure compressor and the high-pressure turbine are linked to form a high-pressure rotor. The low pressure spool rotates at a relatively low speed. The air temperature in the compressor is increased due to the compression effect, and the sound speed is increased along with the increase of the air temperature, so that the upper limit of the rotating speed of the high-pressure rotor can be increased, and the diameter of the high-pressure rotor can be reduced. The high-pressure rotor of the double-rotor micro gas turbine is light in weight and small in starting inertia, so that the high-pressure rotor can be driven by a starting motor.

However, in the micro gas turbine with the dual-rotor structure, because the fan is linked with the low-pressure compressor, the centrifugal force and the tip speed born by the fan with a relatively large diameter are also large, the huge centrifugal force requires that the weight of the fan cannot be too large, the length of the blade cannot be too long, the improvement of the bypass ratio is limited, and the higher the bypass ratio is, the higher the thrust is, and the oil is relatively saved. The low-pressure compressor has to reduce the number of revolutions for linkage with the fan, the single-stage pressure ratio is reduced, and the number of stages of the compressor fan has to be increased for achieving the total pressure ratio. Thus, the weight of the compressor is difficult to reduce.

In summary, the conventional mechanical single rotor has many functional limitations, while the conventional multi-rotor system has great engineering complexity and uncertainty. For example, the core engine of the conventional multi-rotor gas turbine is started by using a motor, and the length of a rotor rotating shaft is greatly increased by using the motor, so that a series of problems are caused, such as high processing difficulty, difficulty in ensuring coaxiality, serious vibration and large mass.

Disclosure of Invention

The invention aims to provide a multi-rotor micro gas turbine and a starting method thereof aiming at the defects in the prior art.

In order to achieve the purpose, the invention adopts the following scheme:

a multi-rotor micro gas turbine comprises a core machine and a free machine, wherein the core machine comprises a gas compressor 1, a turbine 2, a rotating shaft 3, an air inlet channel 4 and a combustion chamber 5; the gas compressor 1 and the turbine 2 are respectively sleeved at the front end and the tail end of the rotating shaft 3, the front end of the gas compressor 1 surrounds a covered shell to form the gas inlet channel 4, the outlet of the gas compressor 1 is communicated with the combustion chamber 5 through the gas outlet channel 6, the rim of the turbine 2 is arranged in the exhaust channel 7 of the combustion chamber 5, and high-temperature and high-pressure gas sprayed out of the exhaust channel 7 of the combustion chamber 5 is sprayed on the end surface of the turbine 2 to push the turbine 2 to rotate to do work; the rotating shaft 3 is supported in the stator through a radial bearing 8; each bearing is arranged on a shaft section of a rotating shaft between the compressor 1 and the turbine 2, a bearing cavity 9 is formed between the gas outlet channel and the stator, a gas seal 10 is arranged on the back gas surface of the compressor 1 to prevent gas on the back gas surface of the compressor 1 from leaking into the bearing cavity 9, and a gas seal 10 is arranged on the front side of the turbine 2 to prevent gas from leaking into the bearing cavity 9 from a gap between the turbine 2 and the combustion chamber 5;

the free machine comprises a free casing 17, a free turbine 18, a motor 19, a free rotor system 20 and a flue gas chamber 21, wherein the free turbine 18, the motor 19 and the free rotor system 20 are arranged in the free casing 17, and the free turbine 18 and the motor 19 are sequentially and coaxially arranged on the free rotor system 20;

the rim of the free turbine 18 is arranged in the exhaust passage 7 of the combustion chamber 5, the high-temperature high-pressure gas at the front section of the exhaust passage 7 of the combustion chamber 5 is sprayed on the end surface of the turbine 2 to push the turbine 2 to rotate to do work, and the high-temperature high-pressure gas at the rear section of the exhaust passage 7 of the combustion chamber 5 is sprayed on the end surface of the free turbine 18 to push the free turbine 18 to rotate to do work; the outlet of the flue gas chamber 21 is communicated with the outside.

The gas firstly enters the gas compressor 1, is pressurized by the gas compressor 1 and then enters the combustion chamber 5 for combustion, and hot combustion products are ejected from the outlet of the combustion chamber 5 through the exhaust passage 7; the edge of the core turbine 2 extends into the front section of the exhaust passage 7, the edge of the free turbine 18 extends into the rear section of the exhaust passage 7 and is coaxial with the core turbine 2, at the moment, the high-temperature gas can push the core turbine 2 to rotate, the compressor 1 which is coaxially connected with the core turbine 2 through the rotating shaft 3 is driven to rotate, the free turbine 18 can be pushed to rotate, therefore, the work is done to drive the motor 19 to generate electricity, and the redundant high-temperature gas is discharged from the exhaust passage 7.

And the outlet of the flue gas chamber is communicated with a waste heat recovery device arranged outside.

The waste heat recovery device comprises a boiler, a radiator and a heat exchanger.

A method for starting a multi-rotor micro gas turbine comprises the following steps:

1) starting the motor 19 to drive the free rotor system 20 to rotate so as to drive the free turbine 18 to rotate, and generating airflow vortex when the free turbine 18 rotates so as to drive the core turbine 2 in front of the free turbine 18 to rotate; the core turbine 2 drives a coaxial compressor 1 impeller to rotate;

2) determining that the micro gas turbine meets an ignition condition, and starting an igniter to execute an ignition operation;

3) after the ignition operation is successful, fuel is combusted, so that the speed of the rotor of the core engine of the micro gas turbine is continuously increased until the rotor stably rotates, and the motor 19 is disconnected; after combustion, high-temperature and high-pressure gas is sprayed out to push a core turbine 2 and a free turbine 18 to rotate, the turbine 2 drives a coaxial compressor 1 impeller to rotate at a high speed, and the whole machine continuously operates; the free turbine 18 drives the electric motor 19 to generate electricity.

Further, in step 2), the determining that the micro gas turbine satisfies the ignition condition, and turning on the igniter to perform the ignition operation includes:

determining that the rotation speed of the rotor driven by the rotation of the impeller of the gas compressor 1 reaches the ignition speed;

the rotor is maintained at the ignition speed, and the fuel pump is started to supply fuel;

the igniter is turned on to perform ignition operation.

Advantageous effects

The core machine is started in a free machine turbine self-absorption mode instead of a motor, so that the length of a rotating shaft of a rotor of the core machine is greatly shortened, and a series of advantages such as low processing difficulty, easiness in ensuring coaxiality, small vibration and light weight are brought.

Drawings

FIG. 1 is a block diagram of a multi-rotor micro gas turbine in an embodiment

Reference numerals: the gas turbine engine comprises a gas compressor 1, a turbine 2, a rotating shaft 3, a gas inlet channel 4, a combustion chamber 5, a gas outlet channel 6, a gas exhaust channel 7, a radial bearing 8, a bearing cavity 9, a gas seal 10, a thrust disc 11, a thrust bearing 12, a gas pipe 14, an electric ducted fan 15, a branch 16, a free casing 17, a free turbine 18, a motor 19, a free rotor system 20 and a gas flue chamber 21.

Detailed Description

Examples

As shown in fig. 1, a multi-rotor micro gas turbine comprises a core machine and a free machine, wherein the core machine comprises a compressor 1, a turbine 2, a rotating shaft 3, an air inlet channel 4 and a combustion chamber 5; the gas compressor 1 and the turbine 2 are respectively sleeved at the front end and the tail end of the rotating shaft 3, the front end of the gas compressor 1 surrounds a covered shell to form the gas inlet channel 4, the outlet of the gas compressor 1 is communicated with the combustion chamber 5 through the gas outlet channel 6, the rim of the turbine 2 is arranged in the exhaust channel 7 of the combustion chamber 5, and high-temperature and high-pressure gas sprayed out of the exhaust channel 7 of the combustion chamber 5 is sprayed on the end surface of the turbine 2 to push the turbine 2 to rotate to do work; the rotating shaft 3 is supported in the stator through a radial bearing 8; each bearing is arranged on a shaft section of a rotating shaft between the compressor 1 and the turbine 2, a bearing cavity 9 is formed between the gas outlet channel 6 and the stator, a gas seal 10 is arranged on the back gas surface of the compressor 1 to prevent gas on the back gas surface of the compressor 1 from leaking into the bearing cavity 9, and a gas seal 10 is arranged on the front side of the turbine 2 to prevent gas from leaking into the bearing cavity 9 from a gap between the turbine 2 and the combustion chamber 5;

the free machine comprises a free casing 17, a free turbine 18, a motor 19, a free rotor system 20 and a flue gas chamber 21, wherein the free turbine 18, the motor 19 and the free rotor system 20 are arranged in the free casing 17, and the free turbine 18 and the motor 19 are sequentially and coaxially arranged on the free rotor system 20;

the rim of the free turbine 18 is arranged in the exhaust passage 7 of the combustion chamber 5, the high-temperature high-pressure gas at the front section of the exhaust passage 7 of the combustion chamber 5 is sprayed on the end surface of the turbine 2 to push the turbine 2 to rotate to do work, and the high-temperature high-pressure gas at the rear section of the exhaust passage 7 of the combustion chamber 5 is sprayed on the end surface of the free turbine 18 to push the free turbine 18 to rotate to do work; the outlet of the flue gas chamber 21 is communicated with the outside.

The gas firstly enters the gas compressor 1, is pressurized by the gas compressor 1 and then enters the combustion chamber 5 for combustion, and hot combustion products are ejected from the outlet of the combustion chamber 5 through the exhaust passage 7; the edge of the core turbine 2 extends into the front section of the exhaust passage 7, the edge of the free turbine 18 extends into the rear section of the exhaust passage 7 and is coaxial with the core turbine 2, at the moment, the high-temperature gas can push the core turbine 2 to rotate, the compressor 1 which is coaxially connected with the core turbine 2 through the rotating shaft 3 is driven to rotate, the free turbine 18 can be pushed to rotate, therefore, the work is done to drive the motor 19 to generate electricity, and the redundant high-temperature gas is discharged from the exhaust passage 7.

And the outlet of the flue gas chamber is communicated with a waste heat recovery device arranged outside.

The waste heat recovery device comprises a boiler, a radiator and a heat exchanger, and is used for further recycling the superheated flue gas discharged from the outlet of the flue gas chamber, such as heating the boiler by the superheated flue gas, heating the radiator or providing a heat source for the heat exchanger.

The starting method of the multi-rotor micro gas turbine comprises the following steps:

1) starting the motor 19 to drive the free rotor system 20 to rotate so as to drive the free turbine 18 to rotate, and generating airflow vortex when the free turbine 18 rotates so as to drive the core turbine 2 in front of the free turbine 18 to rotate; the core turbine 2 drives a coaxial compressor 1 impeller to rotate;

2) determining that the micro gas turbine meets an ignition condition, and starting an igniter to execute an ignition operation;

3) after the ignition operation is successful, fuel is combusted, so that the speed of the rotor of the core engine of the micro gas turbine is continuously increased until the rotor stably rotates, and the motor 19 is disconnected; after combustion, high-temperature and high-pressure gas is sprayed out to push a core turbine 2 and a free turbine 18 to rotate, the turbine 2 drives a coaxial compressor 1 impeller to rotate at a high speed, and the whole machine continuously operates; the free turbine 18 drives the electric motor 19 to generate electricity.

Further, in step 2), the determining that the micro gas turbine satisfies the ignition condition, and turning on the igniter to perform the ignition operation includes:

determining that the rotation speed of the rotor driven by the rotation of the impeller of the gas compressor 1 reaches the ignition speed;

the rotor is maintained at the ignition speed, and the fuel pump is started to supply fuel;

the igniter is turned on to perform ignition operation.

The above embodiments are preferred embodiments of the present invention, and those skilled in the art can make variations and modifications to the above embodiments, therefore, the present invention is not limited to the above embodiments, and any obvious improvements, substitutions or modifications made by those skilled in the art based on the present invention are within the protection scope of the present invention.