Power generation device dragged by steam turbine

Abstract

The invention relates to the technical field of steam turbine power generation, and discloses a steam turbine driven power generation device which comprises a steam boiler, a steam turbine, an asynchronous motor, a driven machine and an adjusting system. Steam output by the steam boiler is divided into two paths, one path enters the steam turbine to do work to drive the asynchronous motor and the fan to generate electricity and supply gas, and the steam after working enters the heat exchanger; and the other path enters the heat exchanger after passing through the temperature and pressure reducer. The asynchronous motor is connected with the turbine and the fan through the speed reducer, the overrun clutch and the coupler, and conversion between power generation and power receiving is achieved. A steam turbine rotor is a sleeved type flexible rotor, an impeller is of a rigid conical impeller structure, a partition plate body is made of alloy steel, and partition plate steam blades are in a shroud ring welding mode. The load of the asynchronous motor is changed through the adjusting system, gradient utilization of steam energy is achieved, and economic benefits of enterprises are improved.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbine power generation, in particular to a steam turbine driven power generation device. Background Art

[0002] A steam turbine, also known as a steam turbine engine, is a rotary steam power device. High-temperature and high-pressure steam passes through a fixed nozzle to become an accelerated airflow and is then sprayed onto the blades, causing the rotor with the blade rows to rotate and perform work externally. Steam turbines are the main equipment in modern thermal power plants and are also used in the metallurgical industry, chemical industry, and ship power plants.

[0003] In the process of using boiler steam, the boiler steam outputs energy to the operating equipment after passing through the temperature and pressure reducer. This is a direct steam output method and cannot achieve the cascade utilization of steam energy. At the same time, affected by the power consumption quota of the equipment, the boiler fan driving the boiler is subject to voltage limitations and other problems, resulting in abnormal operation of the boiler steam. Saving resources is a basic national policy of our country. We implement an energy development strategy that combines conservation and development and puts conservation first. Therefore, a turbine-driven power generation device is proposed. Summary of the invention

[0004] The present invention provides a steam turbine driven power generation device, which has the advantages of cascade utilization of steam energy and efficient power generation, and solves the problems raised by the above background technology.

[0005] The present invention provides the following technical solution: a steam turbine driven power generation device, comprising the following modules, a steam boiler, a steam turbine, an asynchronous motor, a driven machine and a regulating system;

[0006] Steam boiler: used to output working energy to the steam turbine to make it operate;

[0007] Steam turbine: used to utilize the working energy output by the steam boiler in a cascade manner, and to drive the driven machinery through the steam turbine, so that the mechanical equipment in the factory area can operate normally, and at the same time drive the asynchronous motor to generate electricity;

[0008] Asynchronous motor: When the steam turbine reaches the rated speed, it outputs the rated power. By placing the asynchronous motor between the critical point of power generation and power reception, and running the asynchronous motor and the reducer at the same speed, the asynchronous motor can generate electricity.

[0009] Dragged machinery: original equipment of the factory, used for production;

[0010] Regulation system: used to control the speed and power of the turbine.

[0011] Preferably, the steam output by the steam boiler is divided into two paths:

[0012] Route A: Steam enters the steam turbine through the steam pipeline, electric door, tee, reducer, electric door, and main steam valve to do work, driving the asynchronous motor and fan to generate electricity and supply air. The steam after doing work then enters the heat exchanger through the steam pipeline;

[0013] Route B: Enters the heat exchanger after passing through the temperature and pressure reducer.

[0014] Preferably, the asynchronous motor comprises: a reducer, an overrunning clutch and a coupling; the steam turbine is connected to the overrunning clutch via the reducer, the overrunning clutch is connected to the asynchronous motor, and the asynchronous motor is connected to the fan via the coupling.

[0015] Preferably, the turbine rotor adopts a sleeve-type flexible rotor, the impeller is a rigid conical impeller structure, the turning guide vane ring is divided into an upper and a lower half, both of which are cast with alloy cast steel, a balancing hole is provided on the turning guide vane ring, and a "hook" structure is used to fix it to the cylinder at the center dividing surface of the upper and lower halves.

[0016] Preferably, the turbine partition body is made of alloy steel, the partition blades are welded with circumferential belts, reinforcing ribs are cast on the partition at the inlet end of the blades, the partition is fixed in the cylinder partition groove, the lower half of the partition is connected to the cylinder at the horizontal center plane with a suspension pin, a round head key is installed between the bottom of the lower half of the partition and the cylinder, and radial sealing keys and cylindrical pins are installed on the horizontal center plane of the upper and lower halves of the partition.

[0017] Preferably, the regulating system has two DC24V power supplies. The regulating system accepts CCS remote control instructions or regulating instructions issued by the operator through the human-machine interface, collects speed and pressure signals from the site, and position feedback signals of the high-pressure valve or the steam extraction valve, performs closed-loop PID control, and adjusts the valve opening by changing the hydraulic pressure to achieve safe and stable operation of the unit.

[0018] Preferably, the regulation system also includes an electrical integrated cabinet, which allows the motor to generate overspeed power and send it to the electrical background for monitoring by setting comprehensive protection parameters.

[0019] Preferably, the rotor excitation of the asynchronous generator obtains induced excitation current from the power grid or factory power.

[0020] The present invention has the following beneficial effects:

[0021] 1. A steam turbine driven power generation device stabilizes the steam turbine load and changes the load provided by the steam turbine to the asynchronous motor through an adjustment system, and utilizes the reduction of the asynchronous motor load or the increase of steam in the steam boiler to make the asynchronous motor receive more work for power generation; when the asynchronous motor load increases to full load operation, the power generation of the asynchronous motor decreases accordingly, so that the steam boiler can achieve cascade utilization of steam energy through the steam turbine while meeting the process requirements.

[0022] 2. This steam turbine-driven power generation device adjusts the system device speed so that the speed of the asynchronous motor limited by the grid frequency is basically stabilized at about 3000r / min±4‰. When the fan load suddenly decreases, the overrunning clutch is used to prevent the steam turbine from having a "runaway" accident due to the load reduction. If the steam pressure at the turbine inlet decreases and the steam supply decreases, the work done by the steam turbine is insufficient to drive the fan. At this time, the asynchronous motor starts to work externally to drive the fan to operate normally, and the asynchronous motor switches from the power generation state to the external work state to ensure the normal speed of the fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the connection of the system of the present invention;

[0024] Figure 2 It is a schematic diagram of the asynchronous motor system of the present invention;

[0025] Figure 3 This is a schematic diagram of the power generation process of the present invention;

[0026] Figure 4 This is a diagram of the adjustment system of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] like Figure 1-Figure 4 As shown, a steam turbine driven power generation device includes the following modules: a steam boiler, a steam turbine, an asynchronous motor, a driven machine and a regulating system;

[0029] Steam boiler: used to output working energy to the steam turbine to make it operate;

[0030] Steam turbine: used to utilize the working energy output by the steam boiler in a cascade manner, and to drive the driven machinery through the steam turbine, so that the mechanical equipment in the factory area can operate normally, and at the same time drive the asynchronous motor to generate electricity;

[0031] Asynchronous motor: When the steam turbine reaches the rated speed, it outputs the rated power. By placing the asynchronous motor between the critical point of power generation and power reception, the asynchronous motor and the reducer run at the same speed, so that the asynchronous motor can generate electricity;

[0032] Dragged machinery: original equipment of the factory, used for production;

[0033] Regulation system: used to control the speed and power of the turbine.

[0034] Among them, the steam output by the steam boiler is divided into two paths:

[0035] Route A: Steam enters the steam turbine through the steam pipeline, electric door, tee, reducer, electric door, and main steam valve to do work, driving the asynchronous motor and fan to generate electricity and supply air. The steam after doing work then enters the heat exchanger through the steam pipeline;

[0036] Route B: After passing through the temperature and pressure reducer, it enters the heat exchanger, and the steam impulses the steam turbine to rotate. The steam turbine and the reducer are connected to the asynchronous motor through the overrunning clutch, driving the asynchronous motor to rotate. The rotation of the asynchronous motor drags the fan through the coupling to work normally. When the power of the steam turbine is greater than the power required by the fan, the motor generates electricity to provide electricity to other electrical equipment or to the Internet, thereby improving the economic benefits of the enterprise. At the same time, the steam is divided into two routes, so that the output of the steam boiler can be utilized in a cascade manner.

[0037] Among them, the asynchronous motor includes: a reducer, an overrunning clutch and a coupling; the steam turbine is connected to the overrunning clutch through the reducer, the overrunning clutch is connected to the asynchronous motor, and the asynchronous motor is connected to the fan through the coupling. When the steam volume is sufficient, the external work of the steam turbine is greater than the power required by the fan, and the motor generates electricity externally for use by other electrical equipment or for power supply to the Internet; when the steam volume is insufficient, the external work of the steam turbine is less than the power required by the feed water pump, which cannot meet the motor drive demand at this time, and the insufficient part is supplemented by the motor. The steam turbine rotates in the specified direction through the reducer and the motor to work. When the steam turbine reaches the rated speed, it outputs the rated power, and the motor is between the critical point of power generation and power reception. At this time, the motor power switch is connected, and the motor and the reducer run at the same speed. In order to enable the motor to achieve power generation operation, it is only necessary to adjust the steam turbine through the adjustment system and release the frequency converter to make it output a sufficient capacity of power generation load. At this time, the asynchronous motor will be pulled into synchronization to become a generator operation mode. The greater the output power of the steam turbine, the more active power the generator outputs. The current reaches the electrical integrated cabinet through the cable and then is sent to the power grid through the cable.

[0038] Among them, the turbine rotor adopts a set-type flexible rotor, the impeller is a rigid conical impeller structure, the turning guide vane ring is divided into upper and lower halves, both are cast with alloy cast steel, and a balancing hole is provided on the turning guide vane ring. A "hook" structure is used to fix it to the cylinder at the center dividing surface of the upper and lower halves. The steam turbine rotor adopts a set-type flexible rotor, and the impeller is a rigid conical impeller structure. The impellers are separated by a steam seal sleeve. When the set rotor is working, the gap between the moving and stationary blades can be adjusted with the steam seal sleeve. The impeller and the steam seal sleeve are mounted on the shaft with a certain interference fit, so that an axial flat key is installed between them and the shaft to withstand the torque; the steering guide vane ring is divided into an upper and a lower half, both of which are cast with alloy cast steel to reduce the axial thrust of the compound speed stage; a balancing hole is provided on the steering guide vane ring to deform the steering guide vane ring, and a "hook" structure is used to fix it to the cylinder at the center dividing surface of the upper and lower halves. At the same time, the "top" and "ground" are connected to the cylinder with a round head key. In order to reduce friction blast loss, a protective cover is installed on the uninflated part.

[0039] Among them, the turbine diaphragm body is made of alloy steel, the diaphragm steam blade adopts the belt welding type, the diaphragm at the inlet end of the steam blade is cast with reinforcing ribs, the diaphragm is fixed in the cylinder diaphragm groove, the lower half of the diaphragm is connected to the cylinder at the horizontal center plane with a hanging pin, a round head key is installed between the bottom of the lower diaphragm and the cylinder, and the upper and lower diaphragms are equipped with radial sealing keys and cylindrical pins at the horizontal center plane. The reinforcing ribs are cast on the diaphragm at the inlet end of the steam blade to increase the bending strength of the steam blade; the radial sealing keys and cylindrical pins are installed at the horizontal center plane of the upper and lower diaphragms to ensure the correct positioning of the upper and lower diaphragms, and there is enough gap between the diaphragm and the cylinder to allow the diaphragm to expand freely after heating. The diaphragm steam seal adopts a steel steam seal ring inlaid with steel sheets.

[0040] Among them, the regulation system has two DC24V power supplies. The regulation system accepts CCS remote control commands or regulation commands issued by operators through the human-machine interface, collects speed and pressure signals from the site, and the position feedback signals of the high-pressure valve or the steam extraction (steam supplement) valve, and performs closed-loop PID control. By changing the hydraulic pressure, the valve opening is adjusted to achieve safe and stable operation of the unit. The redundant power supply design can effectively prevent the controller from shutting down due to the loss of one power supply, thereby enhancing the system reliability. During the speed increase process of the unit, the regulation system controls the actual speed of the unit through the speed regulation loop. Under this loop, the regulator receives the speed signal of the on-site steam turbine, and after three-out-of-two logic optimization, it is used as the speed feedback signal. This signal is compared with the speed set value, and after PID regulation, the opening signal of the oil motor is output, which is compared with the on-site LVDT oil motor. The unit position feedback signal is compared and the control signal is output to the electro-hydraulic servo valve to control the opening of the oil motor, that is, to control the opening of the regulating valve, thereby controlling the unit speed. When increasing the speed, the operator can set the target speed and the speed increase rate. After the unit is connected to the grid, the DEH control system switches to the power control loop, and the steam turbine speed is used as a primary frequency modulation signal to participate in the control. The regulator allows the unit to immediately carry the initial load as needed, and the measured power and unit speed are used as feedback signals. The speed deviation is used as a primary frequency modulation signal to correct the given power. After the power setting is compared with the power feedback, after PID calculation and power amplification, the throttle opening is controlled by the electro-hydraulic converter and the oil motor to eliminate the deviation signal, and the unit power is adjusted without difference. If there is no power feedback, it will operate in valve position control mode, that is, by increasing the speed setting, opening the regulating steam valve, and increasing the steam intake to achieve the purpose of increasing the load.

[0041] The regulation system also includes an electrical integrated cabinet, which allows the motor to generate power at overspeed and sends it to the electrical background for monitoring by setting the comprehensive protection parameters. An electrical integrated cabinet is added to reduce the starting current when the motor starts. By setting the comprehensive protection parameters, the motor is allowed to generate power at overspeed and sends it to the electrical background for monitoring, ensuring that the motor can be converted from the generating state to the motor state in time when the turbine output is insufficient or shut down.

[0042] Among them, the rotor excitation of the asynchronous generator obtains the induced excitation current from the power grid or the factory power. The rotor excitation of the asynchronous generator obtains the induced excitation current from the power grid or the factory power, and there is no need to set up a special excitation device and excitation adjustment device, so there is no loss of step phenomenon. During operation, it is only necessary to match the load according to the unit capacity; at the same time, the rotor structure is simple, the thermal capacity is large, and the resistance to high-order harmonic loads is strong. From the perspective of economic efficiency, the asynchronous generator has no DC excitation system and no collector ring brushes, so the generator has high efficiency, simple operation, high grid-connected safety, and low operation and maintenance costs.

[0043] When the present invention is in operation, when the boiler is started, the motor is first started to drive the fan, and then the steam turbine is started. When the steam turbine is started, when the steam turbine speed reaches the rated speed of the motor, the clutch is engaged, and the steam turbine begins to carry load. When the steam turbine power reaches the rated power of the fan, the motor is in a no-load operation state. At this time, the steam turbine speed is slowly increased. After exceeding the synchronous speed, the motor enters the power generation state, and the speed is continuously increased until the motor is in a full power state. During the steam turbine startup process, the motor high-voltage switch is in a closed state, and the fan air volume is adjusted by the air door. The steam turbine can drive the fan simultaneously with the asynchronous motor. When the steam turbine power exceeds the fan power, the asynchronous motor can be driven to generate electricity at the same time, and the generated electricity is incorporated into the power grid in the factory to reduce the factory power consumption; the exhaust steam of the steam turbine is used for the waste heat recovery unit or the heat network heater or the heat user; when the steam turbine fails or stops, the regulating system controls the overrunning clutch to automatically disengage, and the fan is driven by the asynchronous motor alone, and the original temperature reduction and pressure reduction device is started at the same time, and the new steam is sent to the waste heat recovery unit or the heat network heater for use through the temperature reduction and pressure reduction device.

[0044] It should be noted that, in this specification, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0045] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A steam turbine driven power generation device, characterized in that: It includes: A steam boiler used to output working energy to the steam turbine to operate the steam turbine; A steam turbine is used to utilize the working energy output by the steam boiler in a cascade manner, driving the driven machinery through the steam turbine, so that the factory equipment can operate normally, and at the same time, driving the asynchronous motor to generate electricity; When the steam turbine reaches the rated speed, it outputs the rated power. By inserting the asynchronous motor into the critical point of power generation and power reception, the asynchronous motor and the reducer run at the same speed, so that the asynchronous motor can generate electricity. Towed machinery used for work production; A regulating system used to control the speed and power of a steam turbine.

2. A steam turbine driven power generation device according to claim 1, characterized in that: The steam output by the steam boiler is divided into two paths: Route A: Steam enters the steam turbine through the steam pipeline, electric door, tee, reducer, electric door, and main steam valve to do work, driving the asynchronous motor and fan to generate electricity and supply air. The steam after doing work then enters the heat exchanger through the steam pipeline; Route B: Enters the heat exchanger after passing through the temperature and pressure reducer.

3. A steam turbine driven power generation device according to claim 1, characterized in that: The asynchronous motor comprises a reducer, an overrunning clutch and a coupling; the steam turbine is connected to the overrunning clutch via the reducer, the overrunning clutch is connected to the asynchronous motor, and the asynchronous motor is connected to the fan via the coupling.

4. A steam turbine driven power generation device according to claim 1, characterized in that: The turbine rotor adopts a set-type flexible rotor, the impeller is a rigid conical impeller structure, the steering guide vane ring is divided into an upper and a lower half, both of which are cast with alloy cast steel, a balancing hole is provided on the steering guide vane ring, and a "hook" structure is used to fix it to the cylinder at the center dividing surface of the upper and lower halves.

5. The steam turbine driven power generation device according to claim 1, characterized in that: The turbine partition body is made of alloy steel, the partition steam blades are welded with circumferential belts, reinforcing ribs are cast on the partition at the inlet end of the steam blades, the partition is fixed in the cylinder partition groove, the lower half of the partition is connected to the cylinder at the horizontal center plane with a hanging pin, a round head key is installed between the bottom of the lower half of the partition and the cylinder, and radial sealing keys and cylindrical pins are installed on the horizontal center plane of the upper and lower halves of the partition.

6. A steam turbine driven power generation device according to claim 1, characterized in that: The regulating system has two DC24V power supplies. The regulating system accepts CCS remote control instructions or adjustment instructions issued by operators through the human-machine interface, collects speed and pressure signals from the site, and position feedback signals of high-pressure valves or steam extraction valves, performs closed-loop PID control, and adjusts the valve opening by changing the hydraulic pressure to achieve safe and stable operation of the unit.

7. A steam turbine driven power generation device according to claim 1, characterized in that: The regulating system also includes an electrical integrated cabinet, which allows the motor to generate overspeed power and send it to the electrical background for monitoring by setting the comprehensive protection parameters.

8. The steam turbine driven power generation device according to claim 3, characterized in that: The rotor excitation of the asynchronous generator obtains the induced excitation current from the power grid or the factory power.

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