A peak-shaving and frequency-regulating system and method for an electrically started steam heating device of a thermal power unit

Abstract

The present invention discloses a peak-shaving and frequency-regulating system and method for an electric-start steam heating device of a thermal power generation unit. The system includes an electric-start steam heating device, a peak-shaving and frequency-regulating control module, and a power transmission and power supply module. The electric-start steam heating device is used to provide steam for the thermal power generation unit during the startup phase. The peak-shaving and frequency-regulating control module is used to receive peak-shaving and frequency-regulating instructions from the power grid dispatching center, transmit power transformation and power supply instructions to the power transmission and power supply module, and transmit power generation instructions to the thermal power generation unit. The power transmission and power supply module is used to control the amount of power output and on / off of the thermal power generation unit to the electric-start steam heating device, as well as the amount of power output to the power grid by the thermal power generation unit. The thermal power generation unit generates power and provides the operating power of the electric-start steam heating device, as well as transmits power to the power grid. During the cold start phase, the thermal power generation unit uses steam from the electric-start steam heating device for startup. Providing the electric-start steam heating device can reduce pollution emissions.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal power generation peak regulation and frequency modulation, and in particular relates to a peak regulation and frequency modulation system and method for an electrically started steam heating device of a thermal power unit. Background Art

[0002] A thermal power plant uses combustible materials (such as coal) as fuel to produce electricity. The basic process is as follows: When the fuel is burned, it heats water to generate steam, converting the fuel's chemical energy into heat. The steam pressure then drives the turbine, converting the heat into mechanical energy. The turbine then drives the generator, converting the mechanical energy into electricity. The steam-water system of a thermal power plant consists of a boiler, steam turbine, condenser, high- and low-pressure heaters, condensate pumps, and feedwater pumps. It includes a steam-water circulation system, chemical water treatment, and cooling systems. Water is heated in the boiler to steam, which is then further heated in the heater to become superheated steam, which then enters the turbine through the main steam line. As the steam continues to expand, the high-speed flow of steam drives the turbine blades, thereby driving the generator.

[0003] At present, most of the startup steam boilers installed in thermal power plants are oil-fired boilers, and a few power plants use coal-fired or gas-fired startup boilers. As local environmental protection departments have increased their environmental protection requirements for thermal power plants, although oil-fired or coal-fired startup boilers have a short operating time, their flue gas pollution emissions are also the focus of environmental protection bureaus. Many thermal power plants have been subject to environmental inspections and penalties for this. Summary of the Invention

[0004] The purpose of the present invention is to provide a peak-shaving and frequency-regulating system and method for an electrically started steam heating device of a thermal power unit, so as to solve the problem of flue gas pollution emission in thermal power plants in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A first aspect of an embodiment of the present invention provides a peak-shaving and frequency-regulating system for an electrically started steam heating device of a thermal power generation unit, comprising an electrically started steam heating device, a peak-shaving and frequency-regulating control module, a power transmission and transformation and power supply module, a thermal power generation unit, a power grid dispatching center, and a power grid;

[0007] The steam output end of the electric starting steam heating device is connected to the starting steam input end of the thermal power unit through a starting steam pipeline, so as to provide starting steam for the thermal power unit;

[0008] The peak-shaving and frequency-regulating control module is used to receive the peak-shaving and frequency-regulating instructions from the power grid dispatching center, send power transformation and power supply instructions to the power transmission and transformation and power supply module, and send power generation instructions to the thermal power generation unit;

[0009] The power transmission and transformation and power supply module is used to receive instructions from the peak-shaving and frequency-regulating control module, and control the amount of power outputted by the thermal power generation unit to the electric start steam heating device and the amount of power outputted by the thermal power generation unit to the power grid;

[0010] The thermal power generation unit is used to generate electricity and provide working electricity for the electric starting steam heating device, as well as transmit electricity to the power grid; the thermal power generation unit uses the steam from the electric starting steam heating device to start during the cold start phase.

[0011] Optionally, the electric-start steam heating device includes an electric-start steam boiler and an electric superheater, the water inlet of the electric-start steam boiler is connected to a water supply pipe, and the steam outlet of the electric-start steam boiler passes through the electric superheater and is connected to the thermal power unit through a starting steam pipe.

[0012] Optionally, the steam outlet of the electric steam boiler is also connected to an external industrial steam user through an industrial steam pipeline.

[0013] Optionally, the industrial steam users include: any one or more of industrial park steam users, beverage steam users, tobacco steam users, papermaking steam users, ship steam users, feed steam users, hospital steam users, beer steam users, grease steam users, tire steam users, hotel steam users, dairy steam users, and chemical steam users.

[0014] Optionally, the electric start steam boiler is any one of an electrode steam boiler, an electric heating tube steam boiler, an electromagnetic induction steam boiler, a solid heat storage electric steam boiler, and a molten salt heat storage electric steam boiler.

[0015] Optionally, the electric superheater is used to heat the saturated steam generated by the electric starting steam boiler to a temperature that reaches the superheat temperature requirement of the starting steam required for warming up or starting the turbine in the thermal power unit.

[0016] Optionally, the startup steam pipeline is connected to the outlet of the electric superheater and the turbine startup warm-up or impulse steam pipeline.

[0017] Optionally, the industrial steam pipeline is connected to the electric steam boiler or electric superheater to inject the generated steam into the industrial steam pipeline, and steam energy storage is achieved by using a long-distance industrial steam pipeline network.

[0018] Optionally, the electrically started steam heating device is configured to be used in parallel in multiple units.

[0019] A second aspect of the embodiments of the present invention provides a method for peak-shaving and frequency-regulating an electrically started steam heating device of a thermal power generation unit, based on the aforementioned system for peak-shaving and frequency-regulating an electrically started steam heating device of a thermal power generation unit, comprising the following steps:

[0020] When the power plant is not in peak load or frequency regulation state, it starts from cold state. At this time, the electric starting steam heating device is used to heat water to generate superheated steam to meet the starting steam demand of the power plant in cold state.

[0021] In the peak-shaving and frequency-regulating state, the initial thermal power unit is in a normal operating state, and the heating power of the electric-start steam heating device is 50% of the full power with a fluctuation of 20%; according to the peak-shaving and frequency-regulating load requirements of the power grid, the peak-shaving and frequency-regulating control module sends instructions to the power transmission and transformation and power supply module, and the power transmission and transformation and power supply module controls the change of the electric heating power of the electric-start steam heating device to meet the peak-shaving and frequency-regulating load requirements of the power grid; when the power grid requires a reduction in the amount of online power, industrial steam in the thermal power unit is extracted for steam heat storage, the power transmission and transformation and power supply module increases the electric heating power of the electric-start steam heating device, stores the generated steam for heat storage, and the peak-shaving and frequency-regulating control module controls the reduction of the power generation power of the thermal power unit; when the power grid requires an increase in the amount of online power, the peak-shaving and frequency-regulating control module controls the increase of the power generation power of the thermal power unit, the power transmission and transformation and power supply module reduces the electric heating power of the electric-start steam heating device, and stores the generated steam for heat storage.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] The peak-shaving and frequency-regulating system of the electric-start steam heating device of the thermal power unit provided in the embodiment of the present invention can not only cleanly replace the original oil-fired and coal-fired starting boilers to reduce pollution emissions by setting the electric-start steam heating device, but also replace the existing oil-fired or coal-fired starting boilers that emit pollution, so that the pollution emissions of the whole process of the thermal power plant meet the standards; and the electric-start steam heating device can serve as an important element for converting electrical energy into thermal energy for peak-shaving and frequency regulation of the thermal power plant, and can partially realize the thermoelectric decoupling and emergency peak-shaving and frequency regulation requirements of the thermal power unit, and can partially realize thermoelectric decoupling, becoming an important equipment for flexible emergency peak-shaving and frequency regulation of thermal power.

[0024] The peak-shaving and frequency-regulating system of the electric-start steam heating device of a thermal power unit provided in an embodiment of the present invention can not only increase the external heat supply by setting up an industrial steam pipeline in combination with an external industrial steam heating system, but also utilize the long-distance industrial steam pipeline as a carrier for steam heat storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 A simplified structural diagram of the peak-shaving and frequency-regulating system of the electrically started steam heating device of a thermal power unit provided in an embodiment of the present invention.

[0027] Figure 2 This is a simplified structural diagram of a peak-shaving and frequency-regulating system for an electrically started steam heating device of a thermal power unit provided in another embodiment of the present invention.

[0028] Figure 3 This is a simplified structural diagram of a peak-shaving and frequency-regulating system for an electrically started steam heating device of a thermal power unit provided in another embodiment of the present invention.

[0029] Figure 4 A flow chart of a method for peak and frequency regulation of an electrically started steam heating device of a thermal power unit provided by an embodiment of the present invention.

[0030] Among them: 1. Electric-start steam heating device; 2. Peak-shaving and frequency-regulating control module; 3. Power transmission and transformation and power supply module; 4. Starting steam pipeline; 5. Industrial steam pipeline; 6. Water supply pipeline; 7. Electric-start steam boiler; 8. Electric superheater; 9. Thermal power unit; 10. Power grid dispatching center; 11. Power grid; 12. Industrial steam users. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0032] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise indicated, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0033] like Figure 1As shown, the first aspect of the embodiment of the present invention provides a peak-shaving and frequency-regulating system for an electric-start steam heating device of a thermal power unit, comprising an electric-start steam heating device 1, a peak-shaving and frequency-regulating control module 2, a power transmission and transformation and power supply module 3, a thermal power unit 9, a power grid dispatching center 10 and a power grid 11; the steam output end of the electric-start steam heating device 1 is connected to the startup steam input end of the thermal power unit 9 through a startup steam pipeline 4, so as to provide startup steam for the thermal power unit 9; the peak-shaving and frequency-regulating control module 2 is used to receive the peak-shaving and frequency-regulating instructions of the power grid dispatching center 10, and to send the power transmission and transformation and power supply module 3 to the thermal power unit 9, the power grid dispatching center 10 and the power grid 11; the steam output end of the electric-start steam heating device 1 is connected to the startup steam input end of the thermal power unit 9 through the ... and to provide startup steam for the thermal power unit 9; the peak-shaving and frequency-regulating control module 2 is used to receive the peak-shaving and frequency-regulating instructions of the power grid dispatching center 10, and to send the power transmission and transformation and power supply module 3 to the thermal power unit 9, the power grid dispatching center 10 and power grid 11; the steam output end of the electric-start steam heating device 1 is connected to the startup steam input end The power and power supply module 3 sends power transformation and power supply instructions, and sends power generation instructions to the thermal power unit 9; the power transmission and transformation and power supply module 3 is used to receive instructions from the peak-shaving and frequency regulation control module 2, and control the amount of power output and on-off of the thermal power unit 9 to the electric start steam heating device 1, and control the amount of power output and on-off of the thermal power unit 9 to the power grid 11; the thermal power unit 9 is used to generate electricity and provide the working power of the electric start steam heating device 1, and transmit electricity to the power grid 11; the thermal power unit 9 uses the steam of the electric start steam heating device 1 to start during the cold start stage. The peak-shaving and frequency-regulating system of the electric-start steam heating device of the thermal power unit provided in the embodiment of the present invention can not only cleanly replace the original oil-fired and coal-fired starting boilers to reduce pollution emissions by setting the electric-start steam heating device, but also replace the existing oil-fired or coal-fired starting boilers that emit pollution, so that the pollution emissions of the whole process of the thermal power plant meet the standards; and the electric-start steam heating device can serve as an important element for converting electrical energy into thermal energy for peak-shaving and frequency regulation of the thermal power plant, and can partially realize the thermoelectric decoupling and emergency peak-shaving and frequency regulation requirements of the thermal power unit, and can partially realize thermoelectric decoupling, becoming an important equipment for flexible emergency peak-shaving and frequency regulation of thermal power.

[0034] like Figure 2 As shown, in some other embodiments, the steam outlet of the electric steam boiler 7 is also connected to an external industrial steam user 12 via an industrial steam pipeline 5. The industrial steam pipeline 5 is connected to the electric steam boiler 7 or the electric superheater 8, enabling steam generated by the electric steam heating device to be injected into the industrial steam pipeline, thereby achieving steam energy storage using a long-distance industrial steam pipeline network. In some other embodiments, the industrial steam pipeline 5 is also connected to the external industrial steam extraction pipeline of the steam turbine power generation link in the thermal power unit 9, extracting steam externally when reducing the power generation of the thermal power unit.

[0035] like Figure 3As shown, in an embodiment of the present invention, an electric-start steam heating device 1 includes an electric-start steam boiler 7 and an electric superheater 8. The water inlet of the electric-start steam boiler 7 is connected to a water supply pipe 6. The steam outlet of the electric-start steam boiler 7 passes through the electric superheater 8 and is then connected to a thermal power unit 9 via a starting steam pipe 4. The electric-start steam boiler 7 is used to generate saturated starting steam required for starting the thermal power unit 9. The electric superheater 8 is used to heat the saturated steam generated by the electric-start steam boiler 7 to a temperature that meets the superheating requirements for starting steam required for warming up or starting the turbine in the thermal power unit 9. The power transmission and power supply module 3 is connected to the electric-start steam boiler 7 and the electric superheater 8 via cables, respectively. The electric-start steam boiler 7 and the electric superheater 8 are powered by grid electricity or power generated by the thermal power unit. The water supply pipe 6 is connected to the electric-start steam boiler 7, the starting steam pipe 4, and the steam turbine in sequence, heating the feed water through the electric-start steam boiler 7 to generate steam.

[0036] As an example of an embodiment of the present invention, the electric start steam boiler 7 is any one of an electrode steam boiler, an electric heating tube steam boiler, an electromagnetic induction steam boiler, a solid heat storage electric steam boiler, and a molten salt heat storage electric steam boiler.

[0037] As a specific embodiment of the present invention, the starting steam pipeline 4 is connected to the outlet of the electric superheater 8 and the turbine starting warm-up or impulse steam pipeline in the thermal power unit 9.

[0038] As an example of an embodiment of the present invention, the industrial steam users 12 include: any one or more of industrial park steam users, beverage steam users, tobacco steam users, papermaking steam users, ship steam users, feed steam users, hospital steam users, beer steam users, grease steam users, tire steam users, hotel steam users, dairy steam users, and chemical steam users.

[0039] In some other embodiments, a plurality of electrically started steam heating devices 1 are configured to be used in parallel.

[0040] In some other embodiments, the electric-start steam boiler 7 and the electric superheater 8 are respectively connected to any one or more of the power plant pulverized coal boiler, deaerator, steam-driven feed water pump, industrial steam network, turbine shaft seal and turbine cylinder warming or flushing pipeline. Under the fully cold state, the saturated or superheated steam generated by the electric-start steam boiler 7 and the electric superheater 8 meets any one or more of the steam requirements for boiler cleaning, pipe blowing, deaerator heating, steam-driven feed water pump, external steam supply, turbine shaft seal, and turbine cylinder warming.

[0041] like Figure 4 As shown, a second aspect of the embodiment of the present invention provides a peak-shaving and frequency-regulating method for an electrically started steam heating device of a thermal power generation unit, based on the above-mentioned peak-shaving and frequency-regulating system for an electrically started steam heating device of a thermal power generation unit, comprising the following steps:

[0042] In the non-peak frequency regulation state, the thermal power unit 9 is started from a cold state. At this time, the electric starting steam heating device 1 is used to heat water to generate superheated steam to meet the starting steam demand of the steam turbine in the thermal power unit 9 in the cold state.

[0043] In the peak-shaving and frequency-regulating state, the initial thermal power unit 9 is in the normal operating state, and the heating power of the electric-start steam heating device 1 is in the middle gear: 50% of the full power with a fluctuation of 20%; according to the peak-shaving and frequency-regulating load requirements of the power grid 11, the peak-shaving and frequency-regulating control module 2 in the centralized control system sends instructions to the power transmission and transformation and power supply module 3, and the power transmission and transformation and power supply module 3 controls the electric heating power change of the electric-start steam heating device 1 to meet the peak-shaving and frequency-regulating load requirements of the power grid; when the power grid 11 requires to reduce the amount of power on the grid, the industrial steam in the thermal power unit 9 is extracted for steaming. Steam heat storage, the power transmission and transformation and power supply module 3 increases the electric heating power of the electric-start steam heating device 1, injects the generated steam into the industrial steam heating network, and uses the industrial steam pipeline to store heat. The peak-shaving and frequency-regulating control module 2 controls to reduce the power generation power of the thermal power unit 9; when the power grid requires an increase in the amount of online electricity, the peak-shaving and frequency-regulating control module 2 controls to increase the power generation power of the thermal power unit 9, the power transmission and transformation and power supply module 3 reduces the electric heating power of the electric-start steam heating device 1, injects the generated steam into the industrial steam heating network, and uses the industrial steam pipeline to store heat.

[0044] Embodiments of the present invention provide a peak-shaving and frequency-regulating system and method for an electric-start steam heating device in a thermal power plant. By installing an electric-start steam heating device, not only can it cleanly replace existing oil- and coal-fired starting boilers to reduce pollution emissions, but the electric-start steam heating device can also serve as a key component for converting electrical energy into thermal energy for peak-shaving and frequency-regulating purposes in thermal power plants, partially achieving thermal-electric decoupling and emergency peak-shaving and frequency-regulating requirements for thermal power plants. The peak-shaving and frequency-regulating system for an electric-start steam heating device in a thermal power plant provided by embodiments of the present invention utilizes a high-voltage electric-start steam boiler, a new, efficient and clean electric boiler imported from abroad. This boiler was previously used in nuclear power plants as a steam turbine startup steam boiler and is a good alternative to oil- and coal-fired starting boilers in domestic thermal power plants. Compared to oil-fired boilers, electric-start steam boilers are not only cleaner but also equipped with electric superheaters. The entire system can not only replace oil- and coal-fired boilers but also, under special conditions, respond to power grid peak-shaving and frequency-regulating auxiliary service signals. By activating the electric-start steam boiler, the system can respond to the power grid's emergency peak-shaving and frequency-regulating auxiliary service needs for thermal power plants.

[0045] It is understood from common technical knowledge that the present invention may be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the embodiments disclosed above are, in all respects, merely illustrative and not exclusive. All modifications within the scope of the present invention or equivalent to the scope of the present invention are intended to be encompassed by the present invention.

Claims

1. A method for peak-shaving and frequency-regulating an electrically started steam heating device of a thermal power unit, which is implemented based on a peak-shaving and frequency-regulating system of an electrically started steam heating device of a thermal power unit, and is characterized in that: A peak-shaving and frequency-regulating system for an electrically started steam heating device of a thermal power generation unit, comprising an electrically started steam heating device (1), a peak-shaving and frequency-regulating control module (2), a power transmission and distribution and power supply module (3), a thermal power generation unit (9), a power grid dispatching center (10), and a power grid (11); The steam output end of the electric starting steam heating device (1) is connected to the starting steam input end of the thermal power unit (9) through a starting steam pipeline (4), so as to provide starting steam for the thermal power unit (9); The peak-shaving and frequency-regulating control module (2) is used to receive the peak-shaving and frequency-regulating instructions from the power grid dispatching center (10), send power transformation and power supply instructions to the power transmission and power supply module (3), and send power generation instructions to the thermal power generation unit (9); The power transmission and power supply module (3) is used to receive instructions from the peak-shaving and frequency-regulating control module (2), and to control the amount of power outputted by the thermal power generation unit (9) to the electric start steam heating device (1) and the on-off switching, as well as the amount of power outputted by the thermal power generation unit (9) to the power grid (11). The thermal power generation unit (9) is used to generate electricity and provide working electricity for the electric starting steam heating device (1), and transmit electricity to the power grid (11); the thermal power generation unit (9) is started by using the steam of the electric starting steam heating device (1) during the cold start phase; The electric start steam heating device (1) comprises an electric start steam boiler (7) and an electric superheater (8); the water inlet of the electric start steam boiler (7) is connected to a water supply pipe (6); the steam outlet of the electric start steam boiler (7) passes through the electric superheater (8) and is connected to the thermal power unit (9) through a starting steam pipe (4); The steam outlet of the electric steam boiler (7) is also connected to an external industrial steam user (12) through an industrial steam pipeline (5); The electric superheater (8) is used to heat the saturated steam generated by the electric starting steam boiler (7) to a temperature that reaches the superheated temperature requirement of the starting steam required for warming up or starting the turbine in the thermal power unit (9); The starting steam pipeline (4) is connected to the outlet of the electric superheater (8) and the turbine starting warm-up or impulse steam pipeline; The industrial steam pipeline (5) is connected to the electric steam boiler (7) or the electric superheater (8), and the generated steam is injected into the industrial steam pipeline, thereby realizing steam energy storage by utilizing the long-distance industrial steam pipeline network; The electrically started steam heating device (1) is arranged to be used in parallel in a plurality of ways; The method comprises the following steps: In the non-peak frequency regulation state, the thermal power generation unit (9) is started from a cold state, and at this time, the electric starting steam heating device (1) is used to heat water to generate superheated steam to meet the starting steam demand of the thermal power generation unit (9) in the cold state; In the peak-shaving and frequency-regulating state, the initial thermal power unit (9) is in a normal operating state, and the heating power of the electric-start steam heating device (1) is 50% of the full power with a fluctuation of 20%; according to the peak-shaving and frequency-regulating load requirements of the power grid (11), the peak-shaving and frequency-regulating control module (2) sends an instruction to the power transmission and transformation and power supply module (3), and the power transmission and transformation and power supply module (3) controls the electric heating power change of the electric-start steam heating device (1) to meet the peak-shaving and frequency-regulating load requirements of the power grid; when the power grid (11) requires to reduce the amount of power on the grid, the thermal power unit (9) is drawn The industrial steam in the group (9) is subjected to steam heat storage, the power transmission and power supply module (3) increases the electric heating power of the electric start steam heating device (1), stores the generated steam for heat storage, and the peak-shaving and frequency regulation control module (2) controls to reduce the power generation power of the thermal power generation group (9); when the power grid requires an increase in the amount of electricity connected to the grid, the peak-shaving and frequency regulation control module (2) controls to increase the power generation power of the thermal power generation group (9), the power transmission and power supply module (3) reduces the electric heating power of the electric start steam heating device (1), and stores the generated steam for heat storage.

2. The peak-shaving and frequency-modulating method for an electrically started steam heating device of a thermal power plant according to claim 1, characterized in that: The industrial steam users (12) include any one or more of industrial park steam users, beverage steam users, tobacco steam users, papermaking steam users, ship steam users, feed steam users, hospital steam users, beer steam users, grease steam users, tire steam users, hotel steam users, dairy steam users, and chemical steam users.

3. The peak-shaving and frequency-modulating method for an electrically started steam heating device of a thermal power plant according to claim 1, characterized in that: The electric start steam boiler (7) is any one of an electrode steam boiler, an electric heating tube steam boiler, an electromagnetic induction steam boiler, a solid heat storage electric steam boiler, and a molten salt heat storage electric steam boiler.

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