Gasoline-electrical tri-source powertrain with permanent magnet coupler arranged in different axes and its working method

Abstract

The invention discloses a steam-electric-electric three-source power assembly with permanent magnet couplers arranged in different axes and a working method thereof. The output shaft of the steam turbine is connected to the first input shaft of the reducer through a first speed-regulating permanent magnet coupler, the output shaft of the electric motor is connected to the second input shaft of the reducer through a second speed-regulating permanent magnet coupler, the output shaft of the pneumatic motor is connected to the third input shaft of the reducer through a third speed-regulating permanent magnet coupler, and the output shaft of the reducer is connected to external rotating machinery; a control system is connected to the steam turbine, the first speed-regulating permanent magnet coupler, the electric motor, the second speed-regulating permanent magnet coupler, the pneumatic motor and the third speed-regulating permanent magnet coupler. The power assembly and the working method thereof have the characteristics of saving electric energy, simple start-up and shutdown operations, and short time consumption.

Description

Technical Field

[0001] The invention relates to a three-source power assembly of a gas, an electric and a gas and a working method thereof, and in particular to a three-source power assembly of a gas, an electric and a gas and a gas and a working method thereof with a permanent magnet coupler arranged in different axes. Background Art

[0002] The power production process of coal-fired power plants determines that the power plants need to be equipped with a large number of fans, pumps and various rotating machinery. Usually, these fans or pumps are driven by electric motors. The motor drive mode has the advantages of fast start and stop, stability and reliability, but as the energy consumption index assessment of thermal power units becomes more stringent, reducing the power consumption rate has become an issue that many thermal power plants have to consider.

[0003] Using small steam turbines instead of electric motors to drive equipment with high power such as induced draft fans and water pumps can significantly reduce the power consumption of equipment in the plant. It has been widely used in power plants. Steam-driven equipment uses the steam produced by the unit boiler as an energy source, which can effectively improve the energy consumption level of the unit, but it also has the following disadvantages:

[0004] 1. The startup process is cumbersome and time-consuming, which affects the speed of the unit to connect to the grid and carry load. The startup process of a small steam turbine requires turning, warming up the pipes, running, warming up, and constant speed, until the fan and water pump reach the normal operating speed, which often takes 4-5 hours. Compared with the electric equipment switch closing, the equipment can be started within a few minutes, which is obviously time-consuming and troublesome, and slows down the speed of the unit startup and grid connection.

[0005] 2. The shutdown process is cumbersome and time-consuming. An additional turbine cranking motor is required. After the normal shutdown or accident shutdown of the steam-powered equipment, in order to ensure that the turbine main shaft is not damaged, it is necessary to maintain the shaft seal and put the cranking device into use to maintain the main shaft speed. It will take 2-3 hours to completely shut down. The entire shutdown process takes a long time.

[0006] Permanent magnet coupler is also called magnetic coupling and permanent magnet transmission device. It is mainly composed of three parts: conductor rotor, magnetic rotor and controller. Generally, the conductor rotor is connected to the motor shaft, the permanent magnet rotor is connected to the shaft of the working machine, there is an air gap (called air gap) between the conductor rotor and the permanent magnet rotor, and there is no mechanical connection to transmit torque. In this way, a soft (magnetic) connection is formed between the motor and the working machine, and the change of torque and speed of the working machine shaft is achieved by adjusting the air gap. Due to the different air gap adjustment methods, permanent magnet eddy current transmission devices are divided into standard type, delayed type, speed regulating type, speed regulating type and other different types.

[0007] The permanent magnetic coupler integrates non-contact and super elastic (soft) transmission, which can greatly reduce impact and vibration and reduce the starting current of the equipment. At the same time, it has high transmission efficiency and long service life.

[0008] How to effectively combine the power-saving advantages of pneumatic equipment and the speed characteristics of electric equipment to give full play to the strengths of both is a problem worth studying. Summary of the invention

[0009] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a three-source powertrain with permanent magnet couplers arranged in different axes and a working method thereof. The powertrain and its working method have the characteristics of saving electric energy, simple start-up and shutdown operations, and short time consumption.

[0010] To achieve the above-mentioned purpose, the steam-electric three-source power assembly with a permanent magnet coupler arranged in different axes of the present invention comprises a control system, a steam turbine, a first speed-regulating permanent magnet coupler, an electric motor, a second speed-regulating permanent magnet coupler, a pneumatic motor and a third speed-regulating permanent magnet coupler;

[0011] The output shaft of the steam turbine is connected to the first input shaft of the reducer through the first speed-regulating permanent magnetic coupler, the output shaft of the electric motor is connected to the second input shaft of the reducer through the second speed-regulating permanent magnetic coupler, the output shaft of the pneumatic motor is connected to the third input shaft of the reducer through the third speed-regulating permanent magnetic coupler, and the output shaft of the reducer is connected to an external rotating machine;

[0012] The control system is connected with the steam turbine, the first speed regulating permanent magnet coupler, the electric motor, the second speed regulating permanent magnet coupler, the pneumatic motor and the third speed regulating permanent magnet coupler.

[0013] The reducer is a spiral bevel reducer or a helical gear reducer.

[0014] The working method of the three-source powertrain of the gas-electric powertrain with the permanent magnet coupler arranged in different axes of the present invention comprises the following steps:

[0015] At the initial start-up, the load on the rotating machinery is relatively light, requiring the output of the rotating machinery to be no more than 30% of its rated output. In this stage, the electric motor is used as the power source.

[0016] During the normal operation stage, the output of the rotating machinery is required to be within the range of 30%-100% of the rated output and be able to be adjusted continuously. During this stage, the steam turbine is used as the power source;

[0017] During the shutdown phase, the load on the rotating machinery is 0. At this time, the equipment is only required to rotate at a low speed and ensure that the turbine can rotate normally. During this phase, the pneumatic motor is used as the power source.

[0018] The specific steps include:

[0019] The air gap between the conductor disk and the magnet disk in the first speed-regulating permanent magnetic coupler, the second speed-regulating permanent magnetic coupler and the third speed-regulating permanent magnetic coupler is at the maximum position, and the torque transmission between the steam turbine, the electric motor and the pneumatic motor and the reducer is 0;

[0020] Start the motor and gradually reduce the air gap between the conductor disk and the magnet disk in the second speed-regulating permanent magnetic coupler, so that the torque transmitted between the motor and the reducer gradually increases from zero to the rated value. At this time, the output of the rotating machinery is continuously adjusted within the range of 0-30% of the rated output to meet the initial start-up requirements. At the same time, the steam turbine is warmed up and started. After the steam turbine runs smoothly, request to switch the power source to the steam turbine, and use the steam turbine as the power source;

[0021] In the normal operation stage, when the steam turbine trips due to a fault, the motor is started and the air gap between the conductor disk and the magnet disk in the second speed regulating permanent magnetic coupler is directly adjusted to the minimum value to transmit the maximum torque;

[0022] During the shutdown stage, when the motor is working, the air gap between the conductor disk and the magnet disk in the second speed-regulating permanent magnet coupler is increased to release the elastic connection between the motor and the reducer; when the steam turbine is working, the turbine is gradually stopped, and at the same time, the pneumatic motor starts to start gradually. During this period, according to the required turning speed, the air gap between the conductor disk and the magnet disk in the first speed-regulating permanent magnet coupler and the third speed-regulating permanent magnet coupler is adjusted to ensure that the steam turbine can maintain a normal turning speed.

[0023] The present invention has the following beneficial effects:

[0024] The steam-electric three-source power assembly with off-axis arrangement of permanent magnet couplers and its working method described in the present invention utilizes steam turbine, electric motor and pneumatic motor as power sources in different stages during specific operation, that is, the electric motor is used as the power source in the initial startup stage, the steam turbine is used as the power source in the normal operation stage, and the pneumatic motor is used as the power source in the shutdown stage. It can give full play to the advantages of fast start and stop of electric motor drive and the advantage of low factory power consumption rate of steam turbine drive, has significantly excellent comprehensive efficiency and saves electricity. At the same time, three speed-regulating permanent magnet couplers are used to realize the complete intervention and exit of steam turbine, electric motor and pneumatic motor. Compared with the existing steam-electric dual-drive equipment, the startup process is smoother and the switching process has less disturbance. At the same time, the operation is simpler and the time consumption is shorter.

[0025] Furthermore, when the steam turbine fails and trips, the electric motor is started, which has the function of switching from steam-driven to electric-driven under accident conditions, greatly improving the availability and reliability of the equipment.

[0026] Furthermore, using a pneumatic motor as a turbine shutdown turning device has obvious energy-saving and cost advantages compared to setting up an independent small motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention.

[0028] Among them, 1 is a steam turbine, 2 is a first speed-regulating permanent magnet coupler, 3 is an electric motor, 4 is a second speed-regulating permanent magnet coupler, 5 is a speed reducer, 6 is a third speed-regulating permanent magnet coupler, and 7 is a pneumatic motor. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0030] refer to Figure 1 The steam-electric three-source power assembly with different-axis arrangement of permanent magnet couplers described in the present invention includes a control system, a steam turbine 1, a first speed-regulating permanent magnet coupler 2, a motor 3, a second speed-regulating permanent magnet coupler 4, a pneumatic motor 7 and a third speed-regulating permanent magnet coupler 6; the output shaft of the steam turbine 1 is connected to the first input shaft of the reducer 5 through the first speed-regulating permanent magnet coupler 2, the output shaft of the motor 3 is connected to the second input shaft of the reducer 5 through the second speed-regulating permanent magnet coupler 4, the output shaft of the pneumatic motor 7 is connected to the third input shaft of the reducer 5 through the third speed-regulating permanent magnet coupler 6, and the output shaft of the reducer 5 is connected to the external rotating machinery; the control system is connected to the steam turbine 1, the first speed-regulating permanent magnet coupler 2, the motor 3, the second speed-regulating permanent magnet coupler 4, the pneumatic motor 7 and the third speed-regulating permanent magnet coupler 6, and preferably, the reducer 5 is a spiral bevel reducer or a helical gear reducer.

[0031] The working method of the three-source powertrain of the gas-electric powertrain with the permanent magnet coupler arranged in different axes of the present invention comprises the following steps:

[0032] The steam turbine 1 uses the steam produced by the boiler as an energy source to drive the impeller to rotate to generate power, and then finally drives the rotating machinery to work through the first speed-regulating permanent magnetic coupler 2 and the reducer 5. The working principle of the first speed-regulating permanent magnetic coupler 2 is: the torque transmitted to the reducer 5 by the steam turbine 1 is adjusted by adjusting the size of the air gap between the conductor disk and the magnet disk, wherein the torque changes continuously within the range of 0-rated value to achieve smooth intervention and smooth exit of the power source.

[0033] The motor 3 is connected to the reducer 5 through the second speed-regulating permanent magnet coupler 4. The main function of the second speed-regulating permanent magnet coupler 4 is to reduce the large torque impact at the moment of starting, reduce the starting current of the equipment, and realize the smooth intervention and exit of the power source.

[0034] The pneumatic motor 7 uses compressed air as a power source, and then uses high-pressure compressed air to drive the internal impeller to rotate, and then transmits power to the reducer 5 through the output shaft and the third speed-regulating permanent magnet coupler 6, and finally drives the rotating machinery to rotate at a low speed, while driving the low-speed cranking of the turbine 1.

[0035] The specific working process of the present invention is:

[0036] When working, it is divided into the initial startup stage, normal operation stage and shutdown stage;

[0037] At the initial start-up, the load carried by the rotating machinery is relatively light, requiring the output of the rotating machinery not to exceed 30% of its rated output. In this stage, a low-power electric motor 3 is used as a power source.

[0038] During the normal operation stage, the output of the rotating machinery is required to be within the range of 30% to 100% of the rated output and be able to be adjusted continuously. In this stage, the steam turbine 1 is used as the power source.

[0039] During the shutdown phase, the load on the rotating machinery is 0. At this time, the equipment is only required to rotate at a low speed and ensure that the steam turbine 1 can rotate normally. In this phase, the pneumatic motor 7 is used as the power source.

[0040] The specific application process is:

[0041] 1) The air gap between the conductor disk and the magnet disk in the first speed-regulating permanent magnetic coupler 2, the second speed-regulating permanent magnetic coupler 4 and the third speed-regulating permanent magnetic coupler 6 is at the maximum position, and the torque transmission between the steam turbine 1, the electric motor 3 and the pneumatic motor 7 and the reducer 5 is 0;

[0042] 2) Start the motor 3, gradually reduce the air gap between the conductor disk and the magnet disk in the second speed-regulating permanent magnet coupler 4, so that the torque transmitted between the motor 3 and the reducer 5 gradually increases from zero to the rated value. At this time, the output of the rotating machinery is continuously adjusted within the range of 0-30% of the rated output to meet the requirements of the initial start-up. At the same time, the steam turbine 1 is warmed up and rushed. After the steam turbine 1 runs smoothly, it is requested to switch the power source. The switching process is: first, the speed of the steam turbine 1 is increased to 10r / min-20r / min higher than the speed of the motor 3, and then the air gap between the conductor disk and the magnet disk in the first speed-regulating permanent magnet coupler 2 is gradually reduced. The power of the steam turbine 1 begins to intervene. When the speed of the rotating machinery begins to increase, the motor 3 is stopped, and the air gap between the conductor disk and the magnet disk in the second speed-regulating permanent magnet coupler 4 is increased, so that the motor 3 is completely withdrawn. At this time, the power source of the rotating machinery is switched from the motor 3 to the steam turbine 1 without disturbance.

[0043] In the normal operation stage, when the steam turbine 1 trips due to a fault, the motor 3 is started, and the air gap between the conductor disk and the magnet disk in the second speed regulating permanent magnetic coupler 4 is directly adjusted to the minimum value to transmit the maximum torque;

[0044] When the equipment needs to shut down, when the motor 3 is working at this time, the air gap between the conductor disk and the magnet disk in the second speed-regulating permanent magnet coupler 4 is increased to disengage the elastic connection between the motor 3 and the reducer 5. When the steam turbine 1 is working at this time, since it involves the cranking after shutdown, the pneumatic motor 7 is started when the steam turbine 1 begins to shut down gradually. During this period, according to the required speed of the cranking, the air gap between the conductor disk and the magnet disk in the first speed-regulating permanent magnet coupler 2 and the third speed-regulating permanent magnet coupler 6 is adjusted to ensure that the steam turbine 1 can maintain a normal cranking speed.

Claims

1. A working method of a three-source powertrain with a permanent magnet coupler arranged in different axes, characterized in that: The steam-electric-electric three-source power assembly with the permanent magnet coupler arranged in different axes comprises a control system, a steam turbine (1), a first speed-regulating permanent magnet coupler (2), an electric motor (3), a second speed-regulating permanent magnet coupler (4), a pneumatic motor (7) and a third speed-regulating permanent magnet coupler (6); The output shaft of the steam turbine (1) is connected to the first input shaft of the reducer (5) through a first speed-regulating permanent magnetic coupler (2), the output shaft of the electric motor (3) is connected to the second input shaft of the reducer (5) through a second speed-regulating permanent magnetic coupler (4), the output shaft of the pneumatic motor (7) is connected to the third input shaft of the reducer (5) through a third speed-regulating permanent magnetic coupler (6), and the output shaft of the reducer (5) is connected to an external rotating machine; The control system is connected to the steam turbine (1), the first speed regulating permanent magnet coupler (2), the electric motor (3), the second speed regulating permanent magnet coupler (4), the pneumatic motor (7) and the third speed regulating permanent magnet coupler (6); The reducer (5) is a spiral bevel reducer or a helical gear reducer; The following steps are involved: At the initial start-up stage, the load carried by the rotating machinery is relatively light, and the output of the rotating machinery is required to be no more than 30% of its rated output. In this stage, the electric motor (3) is used as the power source; During the normal operation stage, the output of the rotating machinery is required to be within the range of 30%-100% of the rated output and be able to be adjusted continuously. During this stage, the steam turbine (1) is used as the power source; During the shutdown phase, the load on the rotating machinery is zero. At this time, the equipment is only required to rotate at a low speed and ensure that the steam turbine (1) can rotate normally. During this phase, the pneumatic motor (7) is used as the power source. The specific steps include: The air gap between the conductor disk and the magnet disk in the first speed-regulating permanent magnet coupler (2), the second speed-regulating permanent magnet coupler (4) and the third speed-regulating permanent magnet coupler (6) is at the maximum position, and the torque transmission between the steam turbine (1), the electric motor (3) and the pneumatic motor (7) and the reducer (5) is 0; The motor (3) is started, and the air gap between the conductor disk and the magnet disk in the second speed-regulating permanent magnetic coupler (4) is gradually reduced, so that the torque transmitted between the motor (3) and the reducer (5) gradually increases from zero to a rated value. At this time, the output of the rotating machine is continuously adjusted within a range of 0-30% of the rated output to meet the requirements of the initial start-up. At the same time, the steam turbine (1) is warmed up and started. After the steam turbine (1) runs smoothly, a request is made to switch the power source to the steam turbine (1), and the steam turbine (1) is used as the power source; In the normal operation stage, when the steam turbine (1) trips due to a fault, the motor (3) is started and the air gap between the conductor disk and the magnet disk in the second speed regulating permanent magnetic coupler (4) is directly adjusted to a minimum value to transmit maximum torque; During the shutdown phase, when the motor (3) is working, the air gap between the conductor disk and the magnet disk in the second speed-regulating permanent magnet coupler (4) is increased to disconnect the elastic connection between the motor (3) and the reducer (5); when the steam turbine (1) is working, the steam turbine (1) is gradually stopped, and at the same time, the pneumatic motor (7) starts to start gradually. During this period, according to the required turning speed, the air gap between the conductor disk and the magnet disk in the first speed-regulating permanent magnet coupler (2) and the third speed-regulating permanent magnet coupler (6) is adjusted to ensure that the steam turbine (1) can maintain a normal turning speed.

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