All-electric drive type steam turbine exhaust heat supply system and method

Abstract

The application discloses a full-electricity-driven steam turbine exhaust heat supply system and method. The system comprises: a steam source extraction unit, the inlet of which is connected to the high-pressure cylinder exhaust pipeline of a steam turbine for steam extraction; an electric steam compressor unit, the inlet of which is connected to the outlet of the steam source extraction unit for steam pressure lifting to a target heat supply pressure; an electric heating temperature rising unit, the inlet of which is connected to the outlet of the electric steam compressor unit for steam temperature heating to a target heat supply temperature; an integrated control unit connected to the electric steam compressor unit and the electric heating temperature rising unit for coordinated control of the pressure and temperature of the steam; and a power supply adjusting unit connected to the electric steam compressor unit and the electric heating temperature rising unit for power supply and power distribution optimization. The application can realize full-electricity-driven steam supply and modularity, and completely decouples the rigid coupling between the heat supply system and the heat cycle of the power generation host.

Description

Technical Field

[0001] This invention belongs to the field of energy and power engineering and thermal power technology, and particularly relates to a fully electric steam turbine exhaust heat supply system and method. Background Technology

[0002] Driven by the transformation of the energy structure, improving the comprehensive energy utilization efficiency and operational flexibility of traditional thermal power plants is crucial. For power plants equipped with supercritical, single-stage reheat, direct air-cooled condensing units such as the NZK660-24.2 / 566 / 566 type, their industrial heating demand (e.g., 4.1 MPa, 390℃) is limited by the high-pressure cylinder exhaust pressure (1.5~3.0 MPa), making direct utilization impossible. Therefore, traditional solutions face significant challenges in practice, primarily as follows: Traditional heating methods widely employ pressure matching systems, which match parameters by mixing reheat steam with main steam. However, internal regulating components, such as valve stems and nozzles, operate under high pressure differentials and high-frequency regulation conditions, commonly experiencing mechanical failures such as bending, detachment, cavitation, and internal noise. This leads to difficulties in regulating steam flow, making long-term stable operation impossible and requiring significant maintenance. Furthermore, in the event of pressure matching system failure, an emergency solution of "direct main steam pressure reduction" is often resorted to, reducing the high-grade main steam (14-24.2 MPa) to 4.1 MPa via a bypass valve. This process results in substantial loss of usable energy, a serious waste of energy quality, and consequently, high heating costs and extremely poor economic efficiency. Other options, such as the "back-pressure turbine solution," can generate electricity and recover some energy, but the main steam still needs to be depressurized to its safe inlet pressure, resulting in significant throttling losses. Moreover, the system is complex and the initial investment is high. The turbine body modification solution, such as adding a rotating baffle to the high-pressure cylinder for steam extraction, is extremely technically difficult, requires major modifications to the high-temperature and high-pressure cylinder, is extremely costly, and poses a significant risk to the safe operation of the main unit.

[0003] In addition, frequent maintenance has led to the existing steam supply pipelines approaching their material limit in terms of welding heat treatment times, resulting in significant risks to pipeline integrity. However, with the surge in the proportion of fluctuating renewable energy sources such as wind and solar power, the power grid's demand for rapidly adjustable and interruptible loads is becoming increasingly urgent. Traditional heating systems not only suffer from the aforementioned inherent problems but are also ill-suited to fulfilling their new role of supporting the stable operation of the power grid.

[0004] Therefore, although the industry has proposed the idea of ​​replacing steam with electricity, aiming to use electricity to directly improve the quality of steam, there is still a lack of mature solutions on how to systematically solve key technical problems such as electric compression of large-flow steam, efficient electric heating, and multi-energy flow coordinated control, and achieve friendly interaction with the power grid. Summary of the Invention

[0005] The purpose of this invention is to provide a fully electric steam turbine exhaust heating system and method, which can realize the complete electrification and modularization of steam supply, and completely decouple the rigid coupling between the heating system and the thermal cycle of the generator.

[0006] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a fully electric-driven steam turbine exhaust heating system, comprising: a steam source extraction unit, an electric steam compressor unit, an electric heat rise unit, a power supply regulation unit, and an integrated control unit; the inlet of the steam source extraction unit is connected to the exhaust pipe of the high-pressure cylinder of the steam turbine for extracting steam and measuring the initial pressure signal and the initial temperature signal; The integrated control unit is connected to the steam source extraction unit and is used to calculate and output the initial speed command and the initial power command based on the preset target heating pressure and target heating temperature, as well as the initial pressure signal and the initial temperature signal. The electric steam compressor unit is connected to the steam source extraction unit and the integrated control unit. It is used to receive the initial speed command, compress the steam to obtain compressed steam, and measure the compressed steam to obtain the first pressure signal. The electric heating unit is connected to the electric steam compressor unit and the integrated control unit. It is used to receive the initial power command, heat the compressed steam to obtain output steam, and measure the output steam to obtain the first temperature signal. The integrated control unit is also used to adjust the speed of the variable frequency motor and the input power of the high-pressure electric heater in the electric steam compressor unit in a closed loop based on the feedback of the first pressure signal and the first temperature signal, as well as the preset target heating pressure and target heating temperature, so as to achieve stable output of steam at the target heating pressure and target heating temperature. The power supply regulation unit is connected to the electric steam compressor unit and the electric heating unit to provide power and optimize power distribution.

[0007] Optionally, the steam source extraction unit includes an isolation valve, a steam filter, and a first pressure and temperature measuring device connected in sequence along the steam flow direction.

[0008] Optionally, the electric steam compressor unit includes a variable frequency motor, a steam compressor driven by the variable frequency motor, a safety valve located at the outlet of the steam compressor, and a second pressure and temperature measuring device connected to the safety valve; the inlet of the steam compressor is used to receive steam that has been measured by the first pressure and temperature measuring device.

[0009] Optionally, the electric heating unit includes a high-pressure electric heater, a temperature control cabinet, and a third pressure and temperature measuring device; the inlet of the high-pressure electric heater is used to connect steam that has been measured by the second pressure and temperature measuring device; the temperature control cabinet is connected to the high-pressure electric heater and is used to adjust the input power of the high-pressure electric heater; the third pressure and temperature measuring device is located at the outlet of the high-pressure electric heater.

[0010] Optionally, the heating element of the high-pressure electric heater is in contact with the steam flow channel and is a tubular resistance type, flange type, or electromagnetic induction type heater; the high-pressure electric heater adopts a multi-section or multi-group independent structure design, and the power of each section or group is independently controlled by the temperature control cabinet.

[0011] Optionally, the power supply regulation unit includes: a power intelligent distribution module, a plant power access bus, and a renewable energy grid connection interface; one end of the plant power access bus is connected to the power intelligent distribution module, and the other end is connected to the power plant's plant power system; one end of the renewable energy grid connection interface is connected to the power intelligent distribution module, and the other end is connected to the photovoltaic and wind power generation systems; the power intelligent distribution module is used to dynamically allocate the power supplied to the electric steam compressor unit and the electric heating unit according to grid dispatch instructions, real-time electricity prices, or renewable energy output.

[0012] Optionally, the integrated control unit is connected to the first pressure and temperature measuring device to receive the initial pressure signal and initial temperature signal measured by the first pressure and temperature measuring device, calculate the initial speed and initial power according to the preset target heating pressure and target heating temperature, and output the initial speed command of the variable frequency motor and the initial power command of the high-voltage electric heater. The integrated control unit is connected to the second pressure and temperature measuring device to receive the first pressure signal fed back by the second pressure and temperature measuring device, and to adjust the speed of the variable frequency motor in a closed loop according to the first pressure signal and the target heating pressure. The integrated control unit is connected to the third pressure and temperature measuring device to receive the first temperature signal fed back by the third pressure and temperature measuring device, and to adjust the input power of the high-pressure electric heater in a closed loop according to the first temperature signal and the target heating temperature.

[0013] Optionally, the all-electric-driven steam turbine exhaust heating system further includes a compression heat recovery unit, which includes a water spray desuperheating device installed at the outlet of the electric steam compressor unit, used to spray demineralized water to cool the outlet when the outlet temperature of the electric steam compressor unit exceeds a set threshold.

[0014] Optionally, the all-electric turbine exhaust heating system further includes a bypass pipeline for emergency heating during system failure or maintenance. The bypass pipeline includes a bypass valve and a desuperheating and pressure reducing device. One end of the bypass valve is connected to the main steam pipeline, and the other end is connected to the inlet of the desuperheating and pressure reducing device. The outlet of the desuperheating and pressure reducing device is connected to the outlet of the high-pressure electric heater.

[0015] In a second aspect, the present invention provides a fully electric-driven steam turbine exhaust heat supply method, employing the fully electric-driven steam turbine exhaust heat supply system as described in the first aspect, comprising: The steam source extraction unit continuously extracts steam from the exhaust pipe of the high-pressure cylinder of the steam turbine and measures the initial pressure signal and the initial temperature signal. The integrated control unit calculates and outputs the initial speed command and initial power command based on the preset target heating pressure and target heating temperature, as well as the initial pressure signal and initial temperature signal. The electric steam compressor unit receives the initial speed command, compresses the steam to obtain compressed steam, and measures the compressed steam to obtain the first pressure signal; The electric heating unit receives the initial power command, heats the compressed steam to obtain output steam, and measures the output steam to obtain the first temperature signal. Based on the feedback of the first pressure signal and the first temperature signal, as well as the preset target heating pressure and target heating temperature, the integrated control unit adjusts the speed of the variable frequency motor and the input power of the high-pressure electric heater in the electric steam compressor unit in a closed loop to achieve a stable output of steam at the target heating pressure and target heating temperature. The power supply regulation unit responds to grid demands or optimizes economic operation by providing power to the electric steam compressor unit and the electric heating unit and optimizing power distribution.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The all-electric-driven steam turbine exhaust heating system provided by this invention, by integrating an electric steam compression unit and an electric heating unit, fundamentally eliminates the dependence on high-grade heat sources such as boiler reheat steam. It can operate independently simply by drawing steam from the high-pressure exhaust pipe and connecting to a power source, thus completely achieving thermoelectric decoupling. This allows the planning, layout, and operation of the heating system to be entirely autonomous from the generator set. It not only solves the long-standing problem of "heat-driven power generation" that has constrained the flexibility of power plants, greatly releasing the peak-shaving potential of the unit, but also significantly simplifies the system structure and improves operational reliability. In terms of control performance, based on the millisecond-level rapid response capability of the electric compressor speed and electric heater power, combined with the advanced decoupling control algorithm in the integrated control unit, the system can achieve extremely high precision and high stability regulation of the outlet steam pressure and temperature. Its steam supply quality far exceeds that of traditional fluid mechanical regulation methods, sufficient to meet the stringent requirements of high-end precision industrial users for steam parameters. Attached Figure Description

[0017] Figure 1 The diagram shown is a process flow chart of a fully electric-driven steam turbine exhaust heating system according to one embodiment of the present invention. In the diagram: 100, Steam source unit; 101, Isolation valve; 102, Steam filter; 103, First pressure and temperature measuring device; 200, Electric steam compressor unit; 201, Steam compressor; 202, Variable frequency motor; 203, Safety valve; 204, Second pressure and temperature measuring device; 600, Electric heating unit; 601, High-pressure electric heater; 602, Temperature control cabinet; 603, Third pressure and temperature measuring device; 700, Integrated control unit; 800, Power supply regulation unit; 802, Plant power busbar; 803, Renewable energy interface; 801, Power distribution module; 900, Compression heat recovery unit; 901, Water spray desuperheating device; 500, Bypass pipeline; 501, Bypass valve; 502, Desuperheating and pressure reducing device. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0019] Example 1

[0020] like Figure 1 As shown in the figure, an embodiment of the present invention introduces a fully electric-driven steam turbine exhaust heat supply system, comprising: Steam source extraction unit 100, the inlet of which is connected to the high-pressure cylinder exhaust pipe of the steam turbine, is used to extract steam and measure the initial pressure signal and the initial temperature signal. The integrated control unit 700 is connected to the steam source extraction unit 100 and is used to calculate and output the initial speed command and the initial power command based on the preset target heating pressure and target heating temperature, as well as the initial pressure signal and the initial temperature signal. The electric steam compressor unit 200 is connected to the steam source extraction unit 100 and the integrated control unit 700. It is used to receive the initial speed command, compress the steam to obtain compressed steam, and measure the compressed steam to obtain the first pressure signal. The electric heating unit 600 is connected to the electric steam compressor unit 200 and the integrated control unit 700. It is used to receive the initial power command, heat the compressed steam to obtain output steam, and measure the output steam to obtain the first temperature signal. The integrated control unit 700 is also used to adjust the speed of the variable frequency motor 202 and the input power of the high-pressure electric heater 601 in the electric steam compressor unit 200 in a closed loop based on the feedback of the first pressure signal and the first temperature signal, as well as the preset target heating pressure and target heating temperature, so as to achieve stable output of steam at the target heating pressure and target heating temperature. The power supply regulation unit 800 is connected to the electric steam compressor unit 200 and the electric heating unit 600 to provide power and optimize power distribution.

[0021] The all-electrically driven steam turbine exhaust heating system provided in this invention completely achieves thermoelectric decoupling, resulting in a highly autonomous system. It completely eliminates reliance on high-grade heat sources such as main boiler steam and reheat steam, requiring only a single high-pressure cylinder exhaust pipe steam interface and a single power supply interface. This allows the planning, layout, and operation of the heating system to be completely independent of the generator set, solving the long-standing problem of "heat-driven power generation" in power plants, releasing the unit's peak-shaving capacity, simplifying the system structure, and improving reliability.

[0022] In this embodiment, the steam source intake unit 100 serves as the system's raw material inlet, connected via a pipe flange to the cold reheat steam pipeline after the exhaust port of the high-pressure cylinder of the steam turbine. The steam source intake unit 100 includes an isolation valve 101, a steam filter 102, and a first pressure and temperature measuring device 103 connected sequentially along the steam flow direction. The isolation valve 101 is used for system activation and deactivation, the steam filter 102 is used to protect downstream precision equipment, and the first pressure and temperature measuring device 103 is used to monitor the steam source status in real time, i.e., the initial temperature and initial pressure, providing feedforward signals to the integrated control unit 700.

[0023] In this embodiment, the integrated control unit 700 is connected to the first pressure and temperature measuring device 103, and is used to receive the initial pressure signal and initial temperature signal measured by the first pressure and temperature measuring device 103, and to calculate the initial speed according to the preset target heating pressure and initial pressure signal, and to calculate the initial power according to the target heating temperature and initial temperature signal, so as to obtain the initial speed command and initial power command, which are respectively sent to the variable frequency motor 202 and the high-voltage electric heater 601.

[0024] In this embodiment, the electric steam compressor unit 200 serves as the system's pressure engine. Its core is a multi-stage centrifugal or axial-flow high-pressure steam compressor 201 driven by a variable frequency motor 202. Specifically, the electric steam compressor unit 200 includes a variable frequency motor 202, a steam compressor 201 driven by the variable frequency motor 202, a safety valve 203 located at the outlet of the steam compressor 201, and a second pressure and temperature measuring device 204 connected to the safety valve 203. The inlet of the steam compressor 201 is used to receive steam that has been measured by the first pressure and temperature measuring device 103. Specifically, the electric steam compressor unit 200 receives low-to-medium parameter steam (e.g., 1.5-3 MPa, 300-350℃) from the steam source extraction unit 100 and an initial speed command from the integrated control unit 700, and inputs the initial speed command into the steam compressor 201, causing it to consume electrical energy to continuously increase its pressure to / approach the target heating pressure.

[0025] It should be noted that after compression by the steam compressor 201, the steam parameters may only be infinitely close to the target heating pressure. Therefore, a second pressure and temperature measuring device 204 is installed in the electric steam compressor unit 200 to provide feedback on the first pressure signal of the compressed steam. This signal, combined with the closed-loop adjustment of the variable frequency motor 202 in the electric steam compressor unit 200 by the integrated control unit 700, stabilizes the compressed steam output by the electric steam compressor unit 200 to the target heating pressure. This variable frequency speed control technology enables pressure regulation to have millisecond-level response capability and a wide load adaptability range. The safety valve 203 is installed to ensure overpressure safety.

[0026] In this embodiment, the electric heating unit 600 includes a high-pressure electric heater 601, a temperature control cabinet 602, and a third pressure and temperature measuring device 603. The inlet of the high-pressure electric heater 601 is used to receive steam that has been measured by the second pressure and temperature measuring device 204. The temperature control cabinet 602 is connected to the high-pressure electric heater 601 and is used to adjust the input power of the high-pressure electric heater 601. The third pressure and temperature measuring device 603 is located at the outlet of the high-pressure electric heater 601. Specifically, the electric heating unit 600 serves as the core of the system's temperature precision control. Its core equipment is a specially designed high-pressure electric heater 601, which can be mineral-insulated (MI) armored resistance type, flange type, or electromagnetic induction type. Specifically, the electric heating unit 600 receives compressed steam from the electric steam compressor unit 200 and initial power commands from the integrated control unit 700, and inputs the initial power commands into the high-pressure electric heater 601 to continuously raise its temperature to / close to the target heating pressure.

[0027] It should be noted that after being heated by the high-pressure electric heater 601, the steam parameters may be only infinitely close to the target heating temperature. Therefore, a third pressure and temperature measuring device 603 is set in the electric heating unit 600 to feed back the temperature of the compressed steam, i.e., the first temperature signal. Specifically, the heating element inside the high-pressure electric heater 601 is directly immersed in or surrounds the steam flow channel, resulting in high electro-thermal conversion efficiency. The accompanying temperature control cabinet 602 embeds multiple sets of high-power solid-state relays (SSRs) or silicon controlled rectifiers (SCRs) power adjustment modules. These modules, combined with the first temperature signal output from the integrated control unit 700, can steplessly or precisely adjust the total power and the power of each zone of the high-pressure electric heater 601 according to the first temperature signal, thereby heating the steam from its compressed temperature to the target temperature.

[0028] Specifically, in this embodiment, the first pressure and temperature measuring device 103, the second pressure and temperature measuring device 204, and the third pressure and temperature measuring device 603 all include pressure transmitters and temperature elements for continuously measuring the steam pressure and temperature inside the pipeline.

[0029] In this embodiment, the integrated control unit 700 is connected to the second pressure and temperature measuring device 204 of the electric steam compressor unit 200, and is used to receive the first pressure signal fed back by the second pressure and temperature measuring device 204, and control the speed of the variable frequency motor 202 according to the first pressure signal; the integrated control unit 700 is connected to the third pressure and temperature measuring device 603 of the electric heating unit 600, and is used to receive the first temperature signal fed back by the third pressure and temperature measuring device 603, and control the output power of the temperature control cabinet 602, i.e. the input power of the high-pressure electric heater 601, according to the first temperature signal.

[0030] Specifically, the integrated control unit 700 employs a high-performance PLC or industrial computer, running advanced control algorithms (such as decoupled PID and model predictive control). The integrated control unit 700 receives real-time data from the first, second, and third pressure and temperature measuring devices 103, 204, and 603, and executes the core control strategy (calculation of initial speed and initial power, and closed-loop regulation of the variable frequency motor speed and the input power of the high-pressure electric heater): establishing two independent and coordinated closed-loop control loops—one controlling the speed of the steam compressor 201 with the first pressure signal, and the other controlling the input power of the high-pressure electric heater 601 with the first temperature signal. This achieves decoupled control of pressure and temperature, ensuring that the steam supply parameters remain highly stable (pressure deviation ±0.05 MPa, temperature deviation ±2℃) even when the steam source fluctuates or the heat load changes.

[0031] Specifically, the core control strategy of the integrated control unit 700 is a control technology known to those skilled in the art, and will not be described in detail here.

[0032] The all-electrically driven steam turbine exhaust heating system provided in this invention achieves unparalleled control performance, with both the steam compressor (speed control) and the high-pressure electric heater (power control) possessing extremely fast response speeds in the millisecond to second range. Combined with the advanced decoupling control algorithm of the integrated control unit, the system's regulation accuracy, stability, and anti-interference capability for outlet pressure and temperature far exceed those of traditional solutions based on fluid mechanical regulation, meeting the stringent requirements of high-end precision industrial users for steam parameters.

[0033] In this embodiment, the power supply regulation unit 800 includes: a power intelligent allocation module 801, a plant auxiliary power access bus 802, and a renewable energy grid connection interface 803; one end of the plant auxiliary power access bus 802 is connected to the power intelligent allocation module 801, and the other end is connected to the power plant auxiliary power system; one end of the renewable energy grid connection interface 803 is connected to the power intelligent allocation module 801, and the other end is connected to the photovoltaic and wind power generation systems; the power intelligent allocation module 801 is used to dynamically allocate the power supplied to the electric steam compressor unit 200 and the electric heating unit 600 according to grid dispatch instructions, real-time electricity prices, or renewable energy output. Specifically, the power supply regulation unit 800 not only obtains basic power from the power plant auxiliary power bus 804, but also connects to distributed power sources such as photovoltaic and wind power within the plant through a dedicated renewable energy grid connection interface 803. The intelligent power allocation module 803 performs optimized calculations based on multiple signals (such as grid AGC commands, real-time electricity prices, and predicted green electricity output) to dynamically determine the total operating power of the system and intelligently allocate it to the steam compressor 201 and the high-pressure electric heater 601. For example, during periods of high photovoltaic power generation and when the grid needs to absorb the excess power, the system can be instructed to operate at full load or even overload, converting excess green electricity into heat energy stored in steam. The dynamic allocation method of the intelligent power allocation module 801 in the power supply regulation unit 800 is a technique well-known to those skilled in the art and will not be described in detail in this embodiment.

[0034] The all-electric turbine exhaust heating system provided in this invention has a power supply regulation unit that can be precisely controlled to absorb fluctuating renewable energy, achieving "green electricity" to produce "green steam." It can respond to grid dispatch commands, rapidly adjusting load to participate in frequency regulation, peak shaving, and valley filling, providing ancillary services and generating revenue. Furthermore, it can optimize energy consumption internally through a power distribution module, achieving economic dispatch. This transforms power plants from simple energy producers into comprehensive energy service providers. In addition, the all-electric turbine exhaust heating system provided in this invention offers significant energy efficiency and environmental benefits. Although it increases plant power consumption, from a system-wide perspective, it avoids the huge losses from directly reducing the value of ultra-high-parameter main steam. In renewable energy scenarios, it can achieve near-zero carbon steam supply. Its role as a peak-shaving resource brings significant social value in improving overall grid efficiency and reducing emissions.

[0035] Furthermore, in this embodiment, the all-electrically driven steam turbine exhaust heating system also includes a compression heat recovery unit 900. The compression heat recovery unit 900 includes a water spray desuperheating device 901 located at the outlet of the electric steam compressor unit 200. This device sprays demineralized water to cool the outlet when the outlet temperature of the electric steam compressor unit 200 exceeds a set threshold. Specifically, when the water spray desuperheating device 901 detects that the outlet temperature of the steam compressor 201 exceeds a set threshold (e.g., 375°C) due to high back pressure or high pressure ratio operation in summer, it automatically sprays a small amount of high-pressure demineralized water for evaporative cooling. This recovers excess heat from the compression process, avoiding energy waste; it also provides the necessary temperature rise adjustment margin for the subsequent high-pressure electric heater, enhancing the system's control robustness under all operating conditions.

[0036] Furthermore, in this embodiment, the all-electrically driven turbine exhaust heating system also includes a bypass pipeline 500. The bypass pipeline includes a bypass valve 501 and a desuperheating and pressure-reducing device 502. One end of the bypass valve 501 is connected to the main steam pipeline, and the other end is connected to the inlet of the desuperheating and pressure-reducing device 502. The outlet of the desuperheating and pressure-reducing device 502 is connected to the outlet of the high-pressure electric heater 601, used for emergency heating during system failures or maintenance. Specifically, when the main system equipment (electric steam compressor unit 200) is under maintenance or experiences a sudden failure, the system can switch to bypass operation, supplying steam after simple pressure reduction. Although the steam parameters are reduced, uninterrupted heating is ensured, greatly improving system availability.

[0037] The all-electrically driven steam turbine exhaust heating system provided in this invention allows each unit to be designed in a standardized and modular manner, enabling rapid integration and installation like building blocks. The retrofit project does not require modification of the main equipment, has a short construction period, low risk, and requires significantly less investment than large-scale retrofit projects such as back-pressure turbines, making it easy to implement on a large scale in existing thermal power plants.

[0038] Example 2

[0039] This invention provides a fully electric-driven steam turbine exhaust heat supply method, employing the fully electric-driven steam turbine exhaust heat supply system described in Embodiment 1, comprising: The steam source extraction unit continuously extracts steam from the exhaust pipe of the high-pressure cylinder of the steam turbine and measures the initial pressure signal and the initial temperature signal. The integrated control unit calculates and outputs the initial speed command and initial power command based on the preset target heating pressure and target heating temperature, as well as the initial pressure signal and initial temperature signal. The electric steam compressor unit receives the initial speed command, compresses the steam to obtain compressed steam, and measures the compressed steam to obtain the first pressure signal; The electric heating unit receives the initial power command, heats the compressed steam to obtain output steam, and measures the output steam to obtain the first temperature signal. Based on the feedback of the first pressure signal and the first temperature signal, as well as the preset target heating pressure and target heating temperature, the integrated control unit adjusts the speed of the variable frequency motor and the input power of the high-pressure electric heater in the electric steam compressor unit in a closed loop to achieve a stable output of steam at the target heating pressure and target heating temperature. The power supply regulation unit responds to grid demands or optimizes economic operation by providing power to the electric steam compressor unit and the electric heating unit and optimizing power distribution.

[0040] Example 3

[0041] This invention provides a thermal power plant equipped with a fully electric turbine exhaust heating system as described in Embodiment 1.

[0042] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0043] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0044] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0045] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A fully electric-driven steam turbine exhaust heat supply system, characterized in that, include: Steam source extraction unit, electric steam compressor unit, electric heating unit, power supply regulation unit, and integrated control unit; The inlet of the steam source extraction unit is connected to the high-pressure cylinder exhaust pipe of the steam turbine for extracting steam and measuring the initial pressure and initial temperature signals. The integrated control unit is connected to the steam source extraction unit and is used to calculate and output the initial speed command and the initial power command based on the preset target heating pressure and target heating temperature, as well as the initial pressure signal and the initial temperature signal. The electric steam compressor unit is connected to the steam source extraction unit and the integrated control unit. It is used to receive the initial speed command, compress the steam to obtain compressed steam, and measure the compressed steam to obtain the first pressure signal. The electric heating unit is connected to the electric steam compressor unit and the integrated control unit. It is used to receive the initial power command, heat the compressed steam to obtain output steam, and measure the output steam to obtain the first temperature signal. The integrated control unit is also used to adjust the speed of the variable frequency motor and the input power of the high-pressure electric heater in the electric steam compressor unit in a closed loop based on the feedback of the first pressure signal and the first temperature signal, as well as the preset target heating pressure and target heating temperature, so as to achieve stable output of steam at the target heating pressure and target heating temperature. The power supply regulation unit is connected to the electric steam compressor unit and the electric heating unit to provide power and optimize power distribution.

2. The all-electric drive steam turbine exhaust heating system according to claim 1, characterized in that, The steam source extraction unit includes an isolation valve, a steam filter, and a first pressure and temperature measuring device connected in sequence along the steam flow direction.

3. The all-electrically driven steam turbine exhaust heating system according to claim 2, characterized in that, The electric steam compressor unit includes a variable frequency motor, a steam compressor driven by the variable frequency motor, a safety valve located at the outlet of the steam compressor, and a second pressure and temperature measuring device connected to the safety valve; the inlet of the steam compressor is used to receive steam that has been measured by the first pressure and temperature measuring device.

4. The all-electric drive steam turbine exhaust heating system according to claim 3, characterized in that, The electric heating unit includes a high-pressure electric heater, a temperature control cabinet, and a third pressure and temperature measuring device; the inlet of the high-pressure electric heater is used to receive steam that has been measured by the second pressure and temperature measuring device; the temperature control cabinet is connected to the high-pressure electric heater and is used to adjust the input power of the high-pressure electric heater; the third pressure and temperature measuring device is located at the outlet of the high-pressure electric heater.

5. The all-electric drive steam turbine exhaust heating system according to claim 4, characterized in that, The heating element of the high-pressure electric heater is in contact with the steam flow channel and is a tubular resistance type, flange type, or electromagnetic induction heater; the high-pressure electric heater adopts a multi-section or multi-group independent structure design, and the power of each section or group is independently controlled by the temperature control cabinet.

6. The all-electric drive steam turbine exhaust heating system according to claim 4, characterized in that, The power supply regulation unit includes: a power intelligent allocation module, a plant power access bus, and a renewable energy grid connection interface; one end of the plant power access bus is connected to the power intelligent allocation module, and the other end is connected to the power plant's plant power system; one end of the renewable energy grid connection interface is connected to the power intelligent allocation module, and the other end is connected to the photovoltaic and wind power generation systems; the power intelligent allocation module is used to dynamically allocate the power supplied to the electric steam compressor unit and the electric heating unit according to grid dispatch instructions, real-time electricity prices, or renewable energy output.

7. The all-electrically driven steam turbine exhaust heating system according to claim 6, characterized in that, The integrated control unit is connected to the first pressure and temperature measuring device and is used to receive the initial pressure signal and initial temperature signal measured by the first pressure and temperature measuring device, calculate the initial speed and initial power according to the preset target heating pressure and target heating temperature, and output the initial speed command of the variable frequency motor and the initial power command of the high-voltage electric heater. The integrated control unit is connected to the second pressure and temperature measuring device to receive the first pressure signal fed back by the second pressure and temperature measuring device, and to adjust the speed of the variable frequency motor in a closed loop according to the first pressure signal and the target heating pressure. The integrated control unit is connected to the third pressure and temperature measuring device to receive the first temperature signal fed back by the third pressure and temperature measuring device, and to adjust the input power of the high-pressure electric heater in a closed loop according to the first temperature signal and the target heating temperature.

8. The all-electric drive steam turbine exhaust heating system according to claim 7, characterized in that, It also includes a compression heat recovery unit, which includes a water spray de-cooling device installed at the outlet of the electric steam compressor unit, used to spray demineralized water to cool down when the outlet temperature of the electric steam compressor unit exceeds a set threshold.

9. The all-electric drive steam turbine exhaust heating system according to claim 8, characterized in that, It also includes a bypass pipeline for emergency heating in case of system failure or maintenance. The bypass pipeline includes a bypass valve and a desuperheating and pressure reducing device. One end of the bypass valve is connected to the main steam pipeline, and the other end is connected to the inlet of the desuperheating and pressure reducing device. The outlet of the desuperheating and pressure reducing device is connected to the outlet of the high-pressure electric heater.

10. A fully electric-driven steam turbine exhaust heat supply method, employing the fully electric-driven steam turbine exhaust heat supply system as described in any one of claims 1-9, characterized in that, include: The steam source extraction unit continuously extracts steam from the exhaust pipe of the high-pressure cylinder of the steam turbine and measures the initial pressure signal and the initial temperature signal. The integrated control unit calculates and outputs the initial speed command and initial power command based on the preset target heating pressure and target heating temperature, as well as the initial pressure signal and initial temperature signal. The electric steam compressor unit receives the initial speed command, compresses the steam to obtain compressed steam, and measures the compressed steam to obtain the first pressure signal; The electric heating unit receives the initial power command, heats the compressed steam to obtain output steam, and measures the output steam to obtain the first temperature signal. Based on the feedback of the first pressure signal and the first temperature signal, as well as the preset target heating pressure and target heating temperature, the integrated control unit adjusts the speed of the variable frequency motor and the input power of the high-pressure electric heater in the electric steam compressor unit in a closed loop to achieve a stable output of steam at the target heating pressure and target heating temperature. The power supply regulation unit responds to grid demands or optimizes economic operation by providing power to the electric steam compressor unit and the electric heating unit and optimizing power distribution.

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