A deep peak regulation system and method for a thermal power unit based on intelligent cooperative control

Abstract

The application discloses a kind of based on intelligent collaborative control's thermal power generating unit deep peak shaving system and method, the system includes: steam turbine generator unit, steam compressor unit, cascade heating unit and intelligent collaborative control unit;Intelligent collaborative control unit is connected with regulating valve, steam compressor unit and the generator of steam turbine generator unit respectively;Intelligent collaborative control unit is configured as: obtaining heat supply network load demand and power grid deep peak shaving instruction;In response to heat supply network load demand and power grid deep peak shaving instruction, the power consumption of the regulating valve, steam compressor unit and the power generation of generator are controlled in the near-zero target value required by the deep peak shaving instruction by coordinated control unit net on-grid power of unit.This application can continuously and smoothly reduce unit net on-grid power from rated value to near zero, solve the problem that existing cylinder cutting technology is rigid and cannot continuously peak shaving, truly realize the independent decoupling of power generation and heat load.

Description

Technical Field

[0001] This invention belongs to the field of thermal power generation and combined heat and power technology, and particularly relates to a deep peak shaving system and method for thermal power units based on intelligent collaborative control. Background Technology

[0002] Cogeneration units, as crucial infrastructure for ensuring residential heating and industrial heat load, have long undertaken the dual tasks of baseload power supply and heating in the power system. However, with the large-scale grid connection of new energy sources such as wind power and photovoltaics, the power grid has placed higher demands on the regulation capabilities of traditional thermal power units. Cogeneration units not only need to meet peak electricity demand but also suppress demand during off-peak hours when new energy sources have surplus power. How to achieve a deep reduction in power generation while maintaining continuous heating has become a core technical bottleneck restricting the participation of cogeneration units in grid regulation.

[0003] To address these needs, the industry has explored various flexible retrofit technologies. One such technology, known as low-pressure cylinder zero-output technology, attempts to improve heating capacity by bypassing the intermediate-pressure cylinder and exhausting steam to the grid heater. However, this approach results in a sharp reduction in the steam intake of the low-pressure cylinder, causing the last-stage long blades to operate under low-flow "blowing" conditions for extended periods. This makes them highly susceptible to frictional heat generation, leading to excessive exhaust temperature and blade vibration, severely threatening rotor mechanical safety. Furthermore, the operating mode only switches between limited discrete states, failing to achieve continuous and smooth regulation of grid power. High back-pressure heating and optical shaft retrofit technologies represent the other extreme: the former sacrifices heating capacity by increasing exhaust pressure, resulting in a permanent decrease in power generation efficiency; the latter completely separates power generation from heating, ensuring heating but causing the unit to lose its grid regulation value—both at the expense of economic efficiency. Absorption heat pump technology, limited by the working fluid pair and thermodynamic cycle principle, suffers from limited outlet water temperature increase, system complexity, and large footprint. Moreover, its driving heat source still requires steam extraction for power generation, failing to fundamentally achieve thermoelectric decoupling.

[0004] Furthermore, some power plants are forced to adopt a two-shift start-stop system to meet the demand for deep peak shaving at night. Frequent start-stop cycles bring huge alternating thermal stress to main equipment such as boilers and turbines, significantly accelerating equipment fatigue and lifespan loss, and making operation complex and posing high safety risks. While configuring electrochemical energy storage can provide fast frequency regulation services, its investment cost is high when used for long-term, large-capacity deep peak shaving scenarios, and it still cannot change the safety boundary of the unit itself when operating at low load. It is an external compensation rather than an internal optimization.

[0005] It is evident that existing technological solutions either sacrifice safety, compromise economic efficiency, or have limited regulation capabilities, making it difficult to simultaneously meet the comprehensive requirements of new power systems for thermal power units in terms of safe operation, continuous heating, and deep regulation. Therefore, there is an urgent need to develop an innovative solution that can achieve continuous, smooth, and wide-range regulation of power generation from rated value to near-zero output, while ensuring the safety of the unit itself and guaranteeing continuous and stable heating. Summary of the Invention

[0006] The purpose of this invention is to provide a deep peak-shaving system and method for thermal power units based on intelligent collaborative control. This system can continuously and smoothly reduce the net on-grid power of the unit from the rated value to near zero, solving the problem of rigid adjustment and inability to continuously shave peak power in existing cylinder cutting technology, and truly realizing the independent decoupling of power generation and heat load.

[0007] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a deep peak-shaving system for thermal power units based on intelligent collaborative control, comprising: A steam turbine generator set, comprising a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder connected in sequence, and a generator connected to the low-pressure cylinder; A steam compressor unit, the inlet of which is connected to the exhaust port of a low-pressure cylinder via a pipeline, for extracting and compressing exhaust steam; A stepped heating unit, wherein the stepped heating unit includes a base heater and a peak heater; The basic heater has a primary side and a secondary side; the primary side inlet is connected to a steam compressor unit to receive compressed exhaust steam; the secondary side inlet is connected to a primary heating network return water pipeline to introduce primary heating network return water and use the compressed exhaust steam to perform primary heat exchange with the primary heating network return water to obtain heating network return water after primary heat exchange. The peak heater has a first side and a second side; the inlet of the first side is connected to the steam extraction port of the intermediate pressure cylinder through a regulating valve, and is used to extract the exhaust steam of the intermediate pressure cylinder; the inlet of the second side is connected to the outlet of the secondary side, and is used to introduce the heat network return water after the first heat exchange, and to use the exhaust steam of the intermediate pressure cylinder to perform secondary heat exchange with the heat network return water after the first heat exchange to obtain the primary heat network water supply. The intelligent collaborative control unit is connected to the regulating valve, the steam compressor unit, and the generator respectively. The intelligent collaborative control unit is configured to: acquire the heating network load demand and the grid deep peak shaving command; and respond to the heating network load demand and the grid deep peak shaving command by coordinating and controlling the power consumption of the regulating valve, the steam compressor unit, and the power generation of the generator to control the net grid power of the unit to the near-zero target value required by the deep peak shaving command.

[0008] Optionally, the intelligent collaborative control unit is further configured to: in response to a deep peak shaving command, prioritize the execution of control operations to close or reduce the size of the regulating valve, so as to eliminate the impact of intermediate-pressure cylinder steam extraction on power generation.

[0009] Optionally, the intelligent collaborative control unit is further configured to: adjust the power consumption of the steam compressor unit while or after performing the control operation of closing or reducing the regulating valve, so that the steam compressor unit meets the load requirements of the heating network.

[0010] Optionally, the intelligent collaborative control unit is further configured to reduce the power generation of the generator in the steam turbine generator set to a preset value after the steam compressor unit meets the heating network load requirements.

[0011] Optionally, the intelligent collaborative control unit is further configured to: after the power generation drops to a preset value, further increase the power consumption of the steam compressor unit to exceed the power required to maintain the current heating network load, and synchronously adjust the power generation to control the net on-grid power at a near-zero target value.

[0012] Optionally, the steam compressor unit includes a steam compressor and a drive unit connected to the steam compressor; the drive unit is a variable frequency motor; the steam compressor is a centrifugal compressor, a screw compressor, or a positive displacement compressor.

[0013] Optionally, the steam compressor also has adjustable inlet guide vanes for fine adjustment of the compression ratio in conjunction with variable frequency speed control.

[0014] Optionally, the deep peak shaving system for thermal power units based on intelligent collaborative control further includes a condensate collection device, which is installed at the junction of the primary side outlet pipe and the first side outlet pipe to collect the water from the two outlets.

[0015] Optionally, the deep peak-shaving system for thermal power units based on intelligent collaborative control further includes a thermal storage unit, which includes a thermal storage device and a valve assembly; the valve assembly includes a first controlled valve, a second controlled valve, a main regulating valve, and an outlet regulating valve. The heat storage unit is located between the primary heating network return water pipe and the cascade heating unit, and includes a cold water inlet and a hot water inlet; The cold water inlet is connected to the primary heating network return water pipe via a first controlled valve; The hot water outlet is connected to the secondary outlet pipe of the basic heater via a second controlled valve; The main regulating valve is located downstream of the primary heating network return water pipe, and between the connection between the first controlled valve and the primary heating network return water pipe and the secondary side inlet. The outlet regulating valve is installed on the connecting pipe between the secondary side outlet and the second side inlet of the peak heater; The valve assembly is connected to the intelligent collaborative control unit and is used to collaboratively store the excess heat generated by the steam compressor unit in the deep peak shaving mode that exceeds the load demand of the heating network, and release the stored heat to assist in heating when needed.

[0016] Secondly, the present invention provides a deep peak shaving method for thermal power units based on intelligent cooperative control, employing the deep peak shaving system for thermal power units based on intelligent cooperative control as described in the first aspect, characterized in that it includes: Obtain deep peak shaving instructions and heating network load demand; In response to the deep peak shaving command, the control operation of closing or reducing the control valve is performed first to eliminate the impact of steam extraction from the intermediate pressure cylinder on the power generation. Adjust the power consumption of the steam compressor unit so that the steam compressor unit meets the load requirements of the heating network; Reduce the power output of the generator in the steam turbine generator set to a preset value; Increase the power consumption of the steam compressor unit to exceed the power required to maintain the current heating network load, and simultaneously adjust the power generation to control the net on-grid power at a near-zero target value.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention provides a deep peak-shaving system and method for thermal power units based on intelligent collaborative control. By introducing a steam compression unit and cooperating with an intelligent collaborative control unit, it prioritizes closing the intermediate-pressure cylinder extraction steam regulating valve under deep peak-shaving conditions, cutting off the physical link of heat-driven power generation. This completely transfers the heating task to the electric compressor, thoroughly freeing the turbine generator unit from the heating load. Subsequently, through collaborative control, it reduces power generation and actively increases the compressor's power consumption, making the compressor a giant controllable load. This allows the unit's net on-grid power to be continuously and smoothly reduced from its rated value to near zero, solving the problem of rigid regulation and inability to continuously shave peak loads in existing cylinder-cutting technologies, and truly achieving independent decoupling of power generation and heat load.

[0018] The present invention provides a deep peak-shaving system and method for thermal power units based on intelligent collaborative control. However, this invention does not completely cut off the steam intake to the low-pressure cylinder during the deep peak-shaving process. After shutting off the steam extraction from the intermediate-pressure cylinder, all the steam originally intended for heating enters the low-pressure cylinder, maintaining the minimum cooling flow rate. At this time, the low-pressure cylinder is in a normal flow state. However, due to insufficient steam intake, serious problems arise, such as "blowing" and overheating of the last-stage long blades, excessive exhaust temperature, and airflow vibration, which severely threaten the mechanical safety of the rotor.

[0019] The present invention provides a deep peak-shaving system and method for thermal power units based on intelligent collaborative control, enabling the thermal power units to maintain continuous grid-connected operation throughout the heating season. During off-peak hours at night, the system switches to a "near-zero grid connection" mode, utilizing compressor power consumption to ensure heating and achieve deep peak shaving. During daytime peak hours, it exits this mode, resuming high-power generation and using extracted steam for auxiliary heating. This operating mode completely replaces the traditional "two-shift" daily start-up and shutdown system, avoiding the enormous alternating thermal stress and lifespan loss of boilers and turbines caused by frequent start-ups and shutdowns. It significantly reduces the operational intensity and safety risks for operators, and substantially improves the unit's availability and economy. Attached Figure Description

[0020] Figure 1 The diagram shown is a process flow chart of a deep peak-shaving system for thermal power units based on intelligent collaborative control in one embodiment of the present invention. In the diagram: 1-Boiler; 2-High-pressure cylinder; 3-Medium-pressure cylinder; 4-Low-pressure cylinder; 5-Condenser; 6-Steam compressor; 7-Basic heater; 8-Peak heater; 9-Primary heating network supply pipe; 10-Primary heating network return pipe; 11-Regulating valve; 12-Generator; 13-Intelligent collaborative control unit; 14-Power grid deep peak shaving command interface; 15-Heating network load demand signal interface; 16-Drain collection device; 17-Three-way valve; 18-First shut-off valve; 19-Second shut-off valve; 20-Heat storage device; 21-First controlled valve; 22-Second controlled valve; 23-Main regulating valve; 24-Outlet regulating valve. Detailed Implementation

[0021] 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.

[0022] Example 1

[0023] like Figure 1 As shown in the figure, this embodiment of the invention introduces a deep peak-shaving system for thermal power units based on intelligent collaborative control, including: a steam turbine generator set, a steam compressor unit, a cascade heating unit, and an intelligent collaborative control unit; In this embodiment, the steam turbine generator set includes a high-pressure cylinder 2, an intermediate-pressure cylinder 3, and a low-pressure cylinder 4 connected in sequence, and a generator 12 connected to the low-pressure cylinder 4. The high-pressure cylinder 2 first receives high-temperature, high-pressure steam, and its carefully designed blade stage causes the steam to initially expand and do work, driving the rotor to rotate. Subsequently, the steam enters the intermediate-pressure cylinder 3, continuing to release energy to drive the rotor to rotate. The low-pressure cylinder 4 receives the exhaust steam from the intermediate-pressure cylinder 3, allowing the steam to further expand within a larger volume, converting more thermal energy into mechanical energy, which is then transferred to the generator through a coupling. The generator, with its advanced electromagnetic design, efficiently converts mechanical energy into electrical energy output.

[0024] In this embodiment, the inlet of the steam compressor unit is connected to the exhaust port of the low-pressure cylinder 4 via a pipeline for extracting and compressing exhaust steam. The steam compressor unit includes a steam compressor 6 and a drive unit connected to the steam compressor 6. The drive unit is a variable frequency motor. In this embodiment, the steam compressor can be a centrifugal compressor, a screw compressor, or a positive displacement compressor, and it has adjustable inlet guide vanes for fine adjustment of the compression ratio in conjunction with variable frequency speed control. The steam compressor is specifically configured as follows: It can handle saturated wet steam with an absolute pressure of 3-15 kPa; Its compression ratio can be continuously varied within a set range according to the command, thereby compressing the intake steam to any desired target pressure and temperature within the range of absolute pressure 40-200kPa; Its variable frequency motor power is continuously adjustable. This makes the steam compressor not only a heat pump, but also a giant flexible plant power load with continuously adjustable power.

[0025] In this embodiment, a control valve assembly is added to the pipeline from the low-pressure cylinder 4 to the condenser 5. The control valve assembly includes a three-way valve 17, a first shut-off valve 18, and a second shut-off valve 19. The first port of the three-way valve 17 is connected to the low-pressure cylinder 4, and the second port is connected to the condenser 5 via the first shut-off valve 18. The third port is connected to the exhaust steam recovery pipeline via the second shut-off valve 19, which in turn connects to a high-power variable frequency speed-regulating steam compressor 6. The control valve assembly is controlled by an intelligent collaborative control unit and is used to open when deep peak shaving is required, introducing some of the low-pressure cylinder exhaust steam into the compressor; and to close when not needed, restoring the original operating mode.

[0026] In this embodiment, the cascade heating unit includes a base heater 7 and a peak heater 8 arranged in series; Furthermore, the base heater 7 employs a shell-and-tube heat exchanger. Its shell side, serving as the primary side, is connected to the steam compressor 6 for inputting compressed exhaust steam. The tube side, serving as the secondary side, is connected to the primary heating network return water pipe 10 via a pipeline to introduce primary heating network return water. The compressed exhaust steam and the primary heating network return water undergo a primary heat exchange to obtain primary heating network return water. In this embodiment, the primary heating network return water is driven by a heating network circulation pump to enter the tube side of the base heater 7, where it undergoes a first heat exchange with the compressed exhaust steam flowing in the shell side. After the heat exchange, the compressed exhaust steam releases its latent heat of vaporization and condenses into condensate, which is discharged through the base heater 7's bottom, i.e., the primary side outlet, connected to the base heater condensate drain pipe. The primary heating network return water is heated to obtain primary heating network return water, which flows out from the tube side (secondary side) outlet of the base heater 7.

[0027] Furthermore, the peak heater 8 also employs a shell-and-tube heat exchanger. Its shell side, serving as the first side, is connected to the extraction port of the intermediate-pressure cylinder 3 via a regulating valve 11 to introduce exhaust steam from the intermediate-pressure cylinder. Its tube side, serving as the second side, is connected to the tube-side outlet of the base heater 7 via a pipeline to introduce the return water from the heating network after the first heat exchange in the base heater 7. Inside the peak heater 8, the exhaust steam from the intermediate-pressure cylinder undergoes a second heat exchange with the return water from the heating network after the first heat exchange, heating it to the primary heating network supply water temperature that meets the heating requirements. Subsequently, the water flows through the tube-side outlet of the peak heater 8 into the primary heating network supply pipe 9 and is output to the heating network.

[0028] After heat exchange, the exhaust steam from the intermediate-pressure cylinder condenses into condensate, which is discharged through the peak heating condensate pipe connected to the bottom of the peak heater 8. Both the basic heating condensate pipe and the peak heating condensate pipe are connected to the condensate collection device 16. After the two condensates are mixed, they are returned to the feedwater system through the condensate collection device 16 to achieve working fluid recovery.

[0029] This embodiment employs a tiered heating unit. First, an electric compressor recovers the waste heat from the low-grade exhaust steam originally destined for the condenser, providing basic heating to the return water of the heating network. Then, depending on demand, steam is extracted from the intermediate-pressure cylinder for peak heating. This tiered utilization method offers higher overall energy efficiency compared to directly using high back-pressure heating or simply extracting steam for heating. Especially under deep peak-shaving conditions, the heat converted from the excess power consumption of the steam compressor can be stored in the heating network water or in a thermal storage device, achieving spatial and temporal energy transfer and avoiding energy waste.

[0030] To further enhance the system's regulation capability and heating safety, this embodiment also includes a heat storage unit, which comprises a heat storage device 20 and a valve assembly. The valve assembly includes a first controlled valve 21, a second controlled valve 22, a main regulating valve 23, and an outlet regulating valve 24. The heat storage unit is located between the primary heating network return water pipe 10 and the cascade heating unit, and includes a cold water inlet and a hot water inlet. The cold water inlet is connected to the primary heating network return water pipe 10 via the first controlled valve 21, and the hot water inlet is connected to the secondary outlet pipe of the base heater via the second controlled valve. The main regulating valve 23 is located downstream of the primary heating network return water pipe 10, and between the connection between the first controlled valve 21 and the primary heating network return water pipe 10 and the secondary side inlet; the outlet regulating valve 24 is located on the connecting pipeline between the secondary side outlet and the second side inlet of the peak heater 8; the valve assembly is connected to the intelligent collaborative control unit 13, and is used to collaboratively store the excess heat generated by the steam compressor unit in the deep peak shaving mode that exceeds the heating network load demand in the heat storage device 20, and release the stored heat to assist heating when needed.

[0031] Specifically, under normal heating mode: the main regulating valve 23 is fully open to ensure that the primary heating return water enters the base heater 7, the outlet regulating valve 24 is fully open, and the hot water at the secondary side outlet flows normally to the peak heater 8, while the first controlled valve 21 and the second controlled valve 22 are closed.

[0032] In thermal storage mode: When excess heat needs to be stored, the intelligent collaborative control unit 13 closes the outlet regulating valve 24 to block the flow of hot water from the secondary side outlet to the peak heater 8, closes the main regulating valve 23 to block the direct entry of primary heating return water into the base heater 7, and simultaneously opens the first controlled valve 21 and the second controlled valve 22. Because the outlet regulating valve 24 is closed, the hot water at the secondary side outlet of the base heater 7 cannot flow to the peak heater 8 and is forced to enter the thermal storage device 20 through the hot water outlet via the second controlled valve 22. Simultaneously, because the main regulating valve 23 is closed, the flow of primary heating network return water in the primary heating network return water pipe 10 is obstructed. This process continues until the thermal storage device 20 is filled with hot water from the secondary side outlet, completing the heat storage.

[0033] In heat release mode: When heat needs to be released, the intelligent collaborative control unit 13 selects one of the following two modes based on the available heat of the heat storage device 20 and the current heat load demand: Shutdown mode: If the heat storage is sufficient, the steam compressor 6 is completely shut down, and the heat load is borne entirely by the heat storage device 20; Combined heating mode: If the heat storage capacity is limited or it is necessary to maintain the minimum operating load of the compressor, the output of the steam compressor 6 is appropriately reduced, and the heat load is shared by the steam compressor 6 and the heat storage device 20.

[0034] After determining the status of the steam compressor, the intelligent collaborative control unit 13 fully opens the main regulating valve 23 (ensuring normal return water flow) and fully opens the outlet regulating valve 24 to provide a path for hot water discharge. Simultaneously, the first controlled valve 21 and the second controlled valve 22 are opened. Hot water stored in the secondary side outlet of the thermal storage device 20, driven by the return water pressure provided by the heating network circulation pump, is discharged from the hot water outlet through the second controlled valve 22 and flows into the inlet of the peak heater 8 through the fully open outlet regulating valve 24. Simultaneously, due to the displacement effect caused by the hot water discharge, the primary heating network return water in the primary heating network return water pipe 10 is automatically replenished into the thermal storage device 20 from the cold water outlet through the opened first controlled valve 21, maintaining pressure balance within the device. This process continues until the heat in the thermal storage device 20 is completely released or the heat load demand changes.

[0035] In this embodiment, the intelligent collaborative control unit 13 is connected to the regulating valve 11, the steam compressor unit, and the generator 12, respectively. The intelligent collaborative control unit 13 is configured to: acquire the heating network load demand and the grid deep peak shaving command; and, in response to the heating network load demand and the grid deep peak shaving command, coordinate and control the power consumption of the regulating valve 11, the steam compressor unit, and the power generation of the generator 12 to control the net grid power of the unit to the near-zero target value required by the deep peak shaving command.

[0036] Furthermore, the intelligent collaborative control unit is also configured as follows: In response to the deep peak shaving command, the control operation of closing or reducing the size of the regulating valve is performed first to eliminate the impact of steam extraction from the intermediate pressure cylinder on the power generation.

[0037] While performing the control operation of closing or reducing the regulating valve, or afterward, the power consumption of the steam compressor unit is adjusted so that the steam compressor unit meets the load requirements of the heating network.

[0038] After the steam compressor unit meets the heating network load requirements, the power generation of the generator in the steam turbine generator set is reduced to a preset value.

[0039] After the power generation drops to the preset value, the power consumption of the steam compressor unit is further increased to exceed the power required to maintain the current heating network load, and the power generation is adjusted synchronously to control the net on-grid power at a near-zero target value.

[0040] Specifically, the intelligent collaborative control unit 13 adopts a distributed control system or a programmable logic controller, and is connected to the power grid deep peak shaving command interface 14, the heating network load demand signal interface 15, the regulating valve 11, the variable frequency motor, the actuator of the inlet guide vane of the steam compressor 6, the excitation regulator of the generator 12, and the main control system of the boiler 1, respectively. The intelligent collaborative control unit 13 has a built-in multivariate coordinated optimization control algorithm, which can generate control commands based on the power grid deep peak shaving command obtained through the power grid deep peak shaving command interface 14, the heating network load demand obtained through the heating network load demand signal interface 15, and the unit operating parameters (including main steam pressure / flow, generator power, steam compressor power, heating network supply and return water temperature, etc.).

[0041] The working process of this embodiment will be explained in detail below with reference to specific operating conditions.

[0042] During peak wind power generation at night, the power grid requires generating units to reduce their net on-grid power to near zero, while the heating network still needs to maintain a stable heating load. Upon receiving the grid's deep peak-shaving command and the heating network load demand, the intelligent collaborative control unit 13 automatically executes the following control steps: S1, Decoupling operation: The intelligent collaborative control unit 13 first sends a command to the regulating valve 11 to slowly close / shut off the valve, gradually reducing the steam extraction volume from the intermediate-pressure cylinder. Simultaneously, it sends an opening command to the second shut-off valve 19 at the inlet of the steam compressor 6 and a start command to the variable frequency motor, initiating the operation of the steam compressor 6. The intelligent collaborative control unit 13 calculates the required compressor heat output based on the heating network load demand and initially sets the compressor speed and inlet guide vane opening, gradually increasing the power consumption and heat output of the steam compressor 6 to compensate for the reduced steam extraction for heating. This process maintains a stable heating network water supply temperature.

[0043] S2, Independent heating: When regulating valve 11 is fully closed, the steam extraction for heating from the intermediate-pressure cylinder is completely cut off, and the heat network load is entirely borne by steam compressor 6. At this time, the turbine generator set is decoupled from the heat load, and the power generation of generator 12 is no longer limited by the heat supply.

[0044] S3, Reduce power generation: The intelligent collaborative control unit 13 sends instructions to the boiler main control system to gradually reduce the main steam flow, causing the generator 12's power output to gradually decrease from 300MW. Considering the boiler's minimum stable combustion load, the power output eventually drops to the technically permissible minimum value, 90MW (preset value). During this process, the intelligent collaborative control unit 13 continuously monitors safety parameters such as the exhaust temperature and vibration of the low-pressure cylinder 4 to ensure that the low-pressure cylinder has sufficient cooling steam.

[0045] S4. Active power consumption and net power regulation: At this point, the power generation capacity is 90MW, while the power consumption of steam compressor 6 to meet the 150MWth heat load is approximately 50MW. Assuming the heat pump coefficient of performance (COP) is 3 and other plant power consumption is approximately 10MW, the net on-grid power is 90-50-10=30MW, which has not yet reached the near-zero target. To achieve a net on-grid power close to zero, the intelligent collaborative control unit 13 further increases the power consumption of steam compressor 6: by increasing the frequency of the variable frequency motor and adjusting the inlet guide vanes, the compressor power is increased from 50MW to 80MW. The extra 30MW of electrical energy is converted into additional heat energy, which is handled in one of the following two ways: Method A: Directly transfer heat to the heating network water to increase the temperature of the primary heating network water supply and temporarily store the heat using the huge heat capacity of the heating network pipe network.

[0046] Method B: If the system is equipped with a heat storage device, the intelligent collaborative control unit 13 opens the first and second controlled valves to introduce part of the heat network return water into the heat storage device, store the excess heat in the heat storage tank, and release it when needed.

[0047] While increasing the power of the steam compressor 6, the intelligent collaborative control unit 13 fine-tunes the power generation, ensuring that the net grid-connected power is precisely stabilized at the preset near-zero target value. At this point, the system enters a deep peak-shaving steady state, achieving near-zero grid connection.

[0048] Furthermore, thermal storage devices play a crucial role during extreme winter weather or periods of significant heat load fluctuation. For instance, when the heat load suddenly increases while the steam compressor is already at maximum output, the intelligent collaborative control unit 13 can open the second controlled valve of the thermal storage device, releasing the stored heat into the return water of the heating network to quickly fill the heating gap. Conversely, when the heat load decreases but the compressor still needs to maintain a high power consumption to meet peak demand, excess heat can be stored in the thermal storage device. The introduction of thermal storage devices further enhances the system's regulatory flexibility and heating security.

[0049] In this embodiment, the core algorithm of the intelligent collaborative control unit 13 adopts a multivariate coordination strategy based on model predictive control. The algorithm uses net grid power as the objective function, with regulating valve opening, compressor speed / guide vane opening, and boiler main control commands as operating variables, and grid supply water temperature, low-pressure cylinder exhaust temperature, and compressor surge margin as constraints. Through online rolling optimization, the optimal control command is calculated in real time and sent to each actuator. Simultaneously, the algorithm includes a feedforward compensation stage, enabling it to respond in advance to changes in heat load and grid commands, overcoming the hysteresis effect of the boiler's large inertia, and achieving rapid and smooth power regulation. The specific algorithm process will not be described in detail here.

[0050] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0051] Example 2

[0052] This invention provides a deep peak shaving method for thermal power units based on intelligent cooperative control, employing the deep peak shaving system for thermal power units based on intelligent cooperative control described in Embodiment 1, comprising: Obtain deep peak shaving instructions and heating network load demand; In response to the deep peak shaving command, the control operation of closing or reducing the control valve is performed first to eliminate the impact of steam extraction from the intermediate pressure cylinder on the power generation. Adjust the power consumption of the steam compressor unit so that the steam compressor unit meets the load requirements of the heating network; Reduce the power output of the generator in the steam turbine generator set to a preset value; Increase the power consumption of the steam compressor unit to exceed the power required to maintain the current heating network load, and simultaneously adjust the power generation to control the net on-grid power at a near-zero target value.

[0053] Example 3

[0054] This embodiment provides a computer-readable storage medium storing a computer program that, when executed, implements the deep peak shaving method for thermal power units based on intelligent collaborative control as described in Embodiment 2.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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 deep peak-shaving system for thermal power units based on intelligent collaborative control, characterized in that, include: A steam turbine generator set, comprising a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder connected in sequence, and a generator connected to the low-pressure cylinder; A steam compressor unit, the inlet of which is connected to the exhaust port of a low-pressure cylinder via a pipeline, for extracting and compressing exhaust steam; A stepped heating unit, wherein the stepped heating unit includes a base heater and a peak heater; The basic heater has a primary side and a secondary side; the primary side inlet is connected to a steam compressor unit to receive compressed exhaust steam; the secondary side inlet is connected to a primary heating network return water pipeline to introduce primary heating network return water and use the compressed exhaust steam to perform primary heat exchange with the primary heating network return water to obtain heating network return water after primary heat exchange. The peak heater has a first side and a second side; the inlet of the first side is connected to the steam extraction port of the intermediate pressure cylinder through a regulating valve, and is used to extract the exhaust steam of the intermediate pressure cylinder; the inlet of the second side is connected to the outlet of the secondary side, and is used to introduce the heat network return water after the first heat exchange, and to use the exhaust steam of the intermediate pressure cylinder to perform secondary heat exchange with the heat network return water after the first heat exchange to obtain the primary heat network water supply. The intelligent collaborative control unit is connected to the regulating valve, the steam compressor unit, and the generator respectively. The intelligent collaborative control unit is configured to: acquire the heating network load demand and the grid deep peak shaving command; and respond to the heating network load demand and the grid deep peak shaving command by coordinating and controlling the power consumption of the regulating valve, the steam compressor unit, and the power generation of the generator to control the net grid power of the unit to the near-zero target value required by the deep peak shaving command.

2. The deep peak-shaving system for thermal power units based on intelligent collaborative control according to claim 1, characterized in that, The intelligent collaborative control unit is also configured to: in response to a deep peak shaving command, prioritize the execution of control operations to close or reduce the size of the regulating valve, so as to eliminate the impact of steam extraction from the intermediate pressure cylinder on power generation.

3. The deep peak-shaving system for thermal power units based on intelligent collaborative control according to claim 2, characterized in that, The intelligent collaborative control unit is also configured to adjust the power consumption of the steam compressor unit while or after performing the control operation of closing or reducing the regulating valve, so that the steam compressor unit meets the load requirements of the heating network.

4. The deep peak-shaving system for thermal power units based on intelligent collaborative control according to claim 3, characterized in that, The intelligent collaborative control unit is also configured to reduce the power generation of the generator in the steam turbine generator set to a preset value after the steam compressor unit meets the heating network load requirements.

5. The deep peak-shaving system for thermal power units based on intelligent collaborative control according to claim 4, characterized in that, The intelligent collaborative control unit is also configured to: after the power generation drops to a preset value, further increase the power consumption of the steam compressor unit to exceed the power required to maintain the current heating network load, and synchronously adjust the power generation to control the net on-grid power at a near-zero target value.

6. The deep peak-shaving system for thermal power units based on intelligent collaborative control according to claim 5, wherein the steam compressor unit includes a steam compressor and a drive component connected to the steam compressor; the drive component is a variable frequency motor; and the steam compressor is a centrifugal compressor, a screw compressor, or a positive displacement compressor.

7. The deep peak-shaving system for thermal power units based on intelligent collaborative control according to claim 6, characterized in that, The steam compressor also has adjustable inlet guide vanes, which are used in conjunction with frequency converter speed regulation to achieve fine adjustment of the compression ratio.

8. The deep peak-shaving system for thermal power units based on intelligent collaborative control according to claim 7, characterized in that, It also includes a drainage collection device, which is installed at the junction of the primary outlet pipe and the first outlet pipe to collect the water from the two outlets.

9. The deep peak-shaving system for thermal power units based on intelligent collaborative control according to claim 8, characterized in that, It also includes a thermal storage unit, which includes a thermal storage device and a valve assembly; the valve assembly includes a first controlled valve, a second controlled valve, a main regulating valve, and an outlet regulating valve; The heat storage unit is located between the primary heating network return water pipe and the cascade heating unit, and includes a cold water inlet and a hot water inlet; The cold water inlet is connected to the primary heating network return water pipe via a first controlled valve; The hot water outlet is connected to the secondary outlet pipe of the basic heater via a second controlled valve; The main regulating valve is located downstream of the primary heating network return water pipe, and between the connection between the first controlled valve and the primary heating network return water pipe and the secondary side inlet. The outlet regulating valve is installed on the connecting pipe between the secondary side outlet and the second side inlet of the peak heater; The valve assembly is connected to the intelligent collaborative control unit and is used to collaboratively store the excess heat generated by the steam compressor unit in the deep peak shaving mode that exceeds the load demand of the heating network, and release the stored heat to assist in heating when needed.

10. A method for deep peak shaving of thermal power units based on intelligent collaborative control, employing the deep peak shaving system for thermal power units based on intelligent collaborative control as described in any one of claims 1-9, characterized in that, include: Obtain deep peak shaving instructions and heating network load demand; In response to the deep peak shaving command, the control operation of closing or reducing the control valve is performed first to eliminate the impact of steam extraction from the intermediate pressure cylinder on the power generation. Adjust the power consumption of the steam compressor unit so that the steam compressor unit meets the load requirements of the heating network; Reduce the power output of the generator in the steam turbine generator set to a preset value; Increase the power consumption of the steam compressor unit to exceed the power required to maintain the current heating network load, and simultaneously adjust the power generation to control the net on-grid power at a near-zero target value.

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