Power plant heat supply system based on wind curtailment and electricity curtailment and control method

Abstract

The invention provides a power plant heat supply system and method based on wind curtailment and electricity curtailment. The system comprises a high-voltage electrode steam boiler, a steam overheating module, a steam distribution module and an intelligent control module. The high-voltage electrode steam boiler is used for converting abandoned wind and abandoned light electric energy into saturated steam heat energy; the steam superheating module heats the saturated steam into superheated steam meeting the starting requirement of the steam turbine; the steam distribution module distributes saturated steam to a factory area heating system, a family member area heat supply system or the steam overheating module; the intelligent control module monitors the wind and light abandoning power and the unit operation state and controls the boiler operation power and the steam distribution flow direction. The system has three operation modes of abandoned power consumption, emergency heat supply and unit starting, unification of efficient consumption of clean energy and heat supply safety guarantee is achieved, the equipment utilization rate is increased, and the investment and operation cost is reduced.

Description

TECHNICAL FIELD

[0001] The present document relates to the technical field of power plant heating, and particularly relates to a power plant heating system based on abandoned wind and abandoned electricity and a control method. BACKGROUND

[0002] With the transformation of energy structure, the proportion of new energy power generation such as wind power and photovoltaic is increasing. However, due to the inherent intermittency and volatility of new energy power generation, when the power grid consumption capacity is insufficient, a large amount of abandoned wind and abandoned light often occurs, resulting in serious waste of clean energy. At the same time, in the cold northern region, urban heating is a basic demand related to people's livelihood, and the safety and reliability of heating are crucial.

[0003] At present, the heating system of many regional thermal power plants generally faces the following outstanding problems: after the unit expansion or the retirement of old units of some thermal power plants, the actual state in the heating season is single large-capacity unit operation. This single-machine supply mode has extremely high operation risk. Once the only unit is out of service due to failure, it will cause large-area and long-time interruption in the heating area, which not only may cause freezing damage of user-side heating equipment and production facilities, but also may cause serious livelihood problems, and the social impact is extremely bad. Although some power plants are equipped with start-up boilers as required, the design function is single, the steam output is limited, and it is only used for local steam such as shaft seal during unit start-up, and cannot bear the huge emergency heating load required by the whole plant area and living area when the main unit fails.

[0004] Secondly, the problem of waste of clean energy is significant. Many power plants have built wind farms and photovoltaic power stations near them to develop new energy comprehensively. However, the abandoned wind and abandoned light power generated by these new energy power stations lacks stable and efficient local consumption channels.

[0005] The existing technology has obvious limitations in solving the above single problem. For example, some schemes propose to build independent electric boiler systems to specifically consume abandoned electricity. However, such systems are usually only used as a supplementary heating means for economic operation, and their capacity configuration and system access reliability are not designed according to the highest standard of emergency backup heat source, so they cannot bear the supply mission when the main unit fails, and the investment benefit is relatively low. Another idea is to enhance the capacity of the start-up boiler, but its original design is to meet the specific and short-time small-flow steam parameter demand, which is not matched with the large-flow and continuous stable heating parameter required by heating, and the system is difficult to be compatible.

[0006] In summary, the skilled in the art has long been faced with a technical dilemma: how to create an integrated solution that can organically and reliably integrate the emergency guarantee function of ensuring heating safety, the steam supply function of meeting the unit start-up and the abandoned power consumption function of realizing economic benefits in the same system without repeated investment and complex system modification. This is the core technical problem that the present application aims to solve. SUMMARY

[0007] The present application provides a power plant heating system and control method based on abandoned wind and abandoned electricity, aiming to solve the above problems.

[0008] According to the present application, a power plant heating system based on abandoned wind and abandoned electricity is provided, comprising: a high-voltage electrode steam boiler, a steam superheating module, a steam distribution module and an intelligent control module; The high-voltage electrode steam boiler module is used to convert the input abandoned wind and abandoned light power into saturated steam heat energy, and its steam output end is connected to the steam distribution module, and the power input end is connected to the power plant special bus; The steam superheating module is used to heat the saturated steam into superheated steam that meets the requirements of the steam turbine start-up, and the inlet end of the steam superheating module is connected to the main steam output pipeline of the high-voltage electrode steam boiler module, and the outlet end is connected to the steam turbine shaft seal system; The steam distribution module is used to distribute the saturated steam to different heating circuits according to the demand, and the steam distribution module input end is connected to the steam output end of the high-voltage electrode steam boiler module, and the first output end of the steam distribution module is connected to the plant heating system, and the second output end is connected to the steam-water heat exchanger of the staff area heating system; The intelligent control module is connected to the control ends of the high-voltage electrode steam boiler module and the steam distribution module, and is used to monitor the abandoned wind and abandoned light power and the unit operation state, control the operation power of the high-voltage electrode steam boiler module and the steam flow direction of the steam distribution module.

[0009] According to the present application, a heating and abandoned power consumption collaborative control method is provided, characterized in that it comprises: Based on the real-time monitoring of the abandoned wind and abandoned light power signals and the power plant unit fault state signals, mode determination is performed; According to the determined mode, the energy input and output of the high-voltage electrode steam boiler module are coordinated and controlled; According to the determined mode, the steam distribution module is controlled to distribute the steam generated by the high-voltage electrode steam boiler module to one or more target systems; The mode includes: abandoned power consumption mode, emergency heating mode and unit start-up mode.

[0010] With the embodiment of the present application, the following beneficial effects are achieved: through a set of high-voltage electrode steam boiler system, three functions of emergency heating, unit startup steam supply and abandoned wind and light consumption are realized at the same time, the problem of needing multiple independent systems in the traditional scheme is solved, the equipment utilization is improved, and the investment cost is reduced. The system has an emergency heating mode and enjoys the highest priority in the control logic, can be quickly put into operation when the main unit fails, effectively prevents heating interruption, and ensures the heating safety of the power plant itself and the family area. The system can convert unstable abandoned wind and light electricity into stable heat for heating, realizes local efficient consumption of clean energy, and reduces the heating cost and carbon emission of the power plant. Through the intelligent control module, automatic judgment and smooth switching of the three modes of abandoned electricity consumption, emergency heating and unit startup are realized, the system responds quickly, and is stable and reliable in operation. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the one or more embodiments of the present specification or the prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present specification, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0012] Figure 1 FIG. 1 is a schematic diagram of a power plant heating system based on abandoned wind and electricity according to an embodiment of the present application. Figure 2 FIG. 2 is a flowchart of a power plant heating control method based on abandoned wind and electricity according to an embodiment of the present application. DETAILED DESCRIPTION

[0013] In order to make the person skilled in the art better understand the technical solutions in the one or more embodiments of the present specification, the technical solutions in the one or more embodiments of the present specification will be clearly and completely described below in conjunction with the drawings in the one or more embodiments of the present specification. Obviously, the described embodiments are only some embodiments of the present specification, not all embodiments. Based on the one or more embodiments of the present specification, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present document.

[0014] SYSTEM EMBODIMENT According to the embodiment of the present application, a schematic diagram of a power plant heating system based on abandoned wind and electricity is provided, Figure 1 FIG. 1 is a schematic diagram of a power plant heating system based on abandoned wind and electricity according to an embodiment of the present application. Figure 1 As shown in FIG. 1, the power plant heating system based on abandoned wind and electricity according to the embodiment of the present application specifically includes: A high-voltage electrode steam boiler, a steam superheating module, a steam distribution module, and an intelligent control module; The high-voltage electrode steam boiler module is used for converting the inputted abandoned wind and light electric energy into saturated steam heat energy, and has a steam output end connected with the steam distribution module and a power input end connected with a power plant special bus. The rated power of the high-voltage electrode steam boiler module is not less than the sum of the maximum heat load of the power plant residential area and the production plant in extreme weather, and the power regulating system of the high-voltage electrode steam boiler module is communicatively connected with the power limiting monitoring system of the wind power field and the photovoltaic power station, and can adjust the output power in a stepless following manner of wind and light.

[0015] The steam superheating module is used for heating the saturated steam into superheated steam meeting the starting requirements of a steam turbine, and has an inlet end connected with the main steam output pipeline of the high-voltage electrode steam boiler module and an outlet end connected with a steam turbine shaft seal system. The steam distribution module is used for distributing the saturated steam to different heat supply circuits according to requirements, and has an input end connected with the steam output end of the high-voltage electrode steam boiler module, a first output end connected with a plant area heating system, and a second output end connected with a steam-water heat exchanger of a residential area heat supply system. The steam distribution module comprises a first steam branch, a second steam branch, and a third steam branch connected with the steam superheating module. The first steam branch is provided with a first regulating valve for controlling the steam flow to the plant area heating system. The second steam branch is provided with a second regulating valve for controlling the steam flow to the residential area heat supply system. The third steam branch is provided with a shut-off valve for being opened to supply steam to the steam superheating module in a unit starting mode.

[0016] The intelligent control module is connected with the control ends of the high-voltage electrode steam boiler module and the steam distribution module, and is used for monitoring the abandoned wind and light power and the unit operation state, controlling the operation power of the high-voltage electrode steam boiler module and the steam flow direction of the steam distribution module.

[0017] In an abandoned power consumption mode, the intelligent control module opens the first regulating valve and / or the second regulating valve, and dynamically adjusts the output power of the high-voltage electrode steam boiler module according to the real-time abandoned wind and light power. In an emergency heat supply mode, the intelligent control module controls the high-voltage electrode steam boiler module to operate at a rated power, and fully opens the first regulating valve and the second regulating valve. In a unit starting mode, the intelligent control module opens the shut-off valve, starts the steam superheating module, and adjusts the opening degrees of the first regulating valve and the second regulating valve to distribute the remaining steam under the premise of ensuring the shaft seal steam supply.

[0018] The intelligent control module, as the control core of the system, adopts an industrial programmable logic controller (PLC) or a distributed control system (DCS) as its hardware basis. The module establishes a data connection with the monitoring system of the wind farm and photovoltaic power station and the distributed control system (DCS) of the power plant unit through an industrial communication network, such as the Modbus TCP / IP protocol, to collect the abandoned wind and light power signals and the unit operation state signals in real time. At the same time, the module also acquires the operating parameters of the high-pressure electrode steam boiler and the valve position feedback signals of the valves in the steam distribution module in real time.

[0019] The intelligent control module is internally preset with mode determination logic. When it is monitored that there is abandoned wind and light power greater than zero and the main unit is in a normal operating state, the system automatically enters the abandoned power consumption mode. When a fault shutdown signal of the main unit is monitored, the system immediately and unconditionally switches to the emergency heating mode with the highest priority. When a start request signal from the unit DCS is received and shaft seal steam is needed, the system enters the unit start mode with a higher priority than the abandoned power consumption mode.

[0020] After determining the operating mode, the intelligent control module executes the corresponding control strategy.

[0021] In the abandoned power consumption mode, the module sends a power adjustment instruction to the high-pressure electrode steam boiler, so that the output power of the boiler dynamically tracks the real-time abandoned wind and light power value, realizing stepless adjustment of the power. At the same time, the module calculates and controls the opening degrees of the first regulating valve and the second regulating valve in the steam distribution module according to the actual heat load demand of the plant area and the staff area, and distributes the generated saturated steam to the heating system.

[0022] In the emergency heating mode, the module instructs the high-pressure electrode steam boiler to operate stably at the rated power, and at the same time instructs the steam distribution module to open the first regulating valve and the second regulating valve to 100% to maximize the heating flow.

[0023] In the unit start mode, the module first instructs to open the shut-off valve on the third steam branch and start the steam superheating module to ensure that the steam parameters supplied to the shaft seal of the steam turbine meet the requirements. Then, under the premise of ensuring the steam flow required by the shaft seal, the module calculates the remaining steam amount and adjusts the opening degrees of the first regulating valve and the second regulating valve according to the remaining steam amount, and distributes the remaining steam to the heating system.

[0024] Through the above technical means, the intelligent control module realizes automatic judgment and collaborative control of the three core functions, ensuring that the system can reliably and efficiently operate under different operating conditions.

[0025] The system further comprises a thermal deaerating subsystem, which comprises a thermal deaerator and a boiler feed water pump. The inlet pipe of the thermal deaerator is connected to the plant's softened water system. Its steam source is saturated steam generated by the high-pressure electrode steam boiler module. Its outlet is connected to the feed port of the high-pressure electrode steam boiler module through the boiler feed pump, forming a closed-loop heat recovery circuit.

[0026] The embodiments of this invention offer the following advantages: A single high-pressure electrode steam boiler system simultaneously achieves three functions: emergency heating, unit startup steam supply, and wind and solar power curtailment, solving the problem of requiring multiple independent systems in traditional solutions, improving equipment utilization, and reducing investment costs. The system features an emergency heating mode with the highest priority in the control logic, enabling rapid activation in case of main unit failure, effectively preventing heating interruptions and ensuring heating safety for the power plant and its residential areas. The system can convert unstable wind and solar power curtailment into stable thermal energy for heating, achieving efficient on-site utilization of clean energy and reducing the power plant's heating costs and carbon emissions. The intelligent control module enables automatic judgment and smooth switching between the three modes of curtailment utilization, emergency heating, and unit startup, resulting in rapid system response and stable and reliable operation.

[0027] Method Implementation Examples According to embodiments of the present invention, a power plant heating control method based on wind and electricity curtailment is provided. Figure 2 This is a flowchart of a power plant heating control method based on wind and electricity curtailment according to an embodiment of the present invention. Figure 2 As shown, an embodiment of the present invention provides a power plant heating method based on wind and electricity curtailment, specifically including: S1. Based on the real-time monitoring of wind and solar power curtailment signals and power plant unit fault status signals, a mode determination is performed; the modes include: curtailment consumption mode, emergency heating mode, and unit start-up mode.

[0028] The mode determination process also incorporates pre-judgment based on predicted signals: the intelligent control module receives wind power and solar power prediction data for the next 4-8 hours through the scheduling data network interface. When it is predicted that the curtailed power will continuously exceed the boiler's minimum stable combustion power for more than 1 hour, the module sets a preparatory curtailment flag in advance and outputs a command to preheat the boiler to a ready state. Simultaneously, the module receives the unit's planned shutdown signal, marks that time period as a high-probability emergency period, and optimizes control parameters accordingly.

[0029] S2. Based on the determined mode, coordinate the energy input and output of the high-pressure electrode steam boiler module; S2 specifically includes: In the curtailment and absorption mode, the output power of the high-pressure electrode steam boiler module is controlled to track the curtailed wind and solar power. The high-pressure electrode steam boiler module dynamically adjusts its output power based on real-time curtailed wind and solar power in this mode, ensuring the output power does not exceed 20MW of its rated power, thus achieving stepless tracking of wind and solar power. Specifically, a power tracking algorithm with heating network inertia compensation is adopted: this algorithm uses real-time curtailed power P... abandon As a feedforward mechanism, the deviation between the measured temperature values ​​T_actual and the setpoint T_set at multiple key nodes in the heating network is used as feedback to calculate the power compensation amount ΔP through a PID controller. Ultimately, the boiler's power command P... cmd =P abandon + ΔP. This method utilizes the thermal inertia of the heating network as virtual energy storage to smooth boiler output commands and more fully track power curtailment fluctuations while ensuring heating quality.

[0030] In emergency heating or unit start-up mode, the high-pressure electrode steam boiler module is controlled to operate at its rated power or a set power that meets the corresponding load demand. In emergency heating mode, the high-pressure electrode steam boiler operates at a rated power of 20MW to meet the emergency heating demand of the residential area and production plant, which has a maximum heat load of 19.945MW. In unit start-up mode, the high-pressure electrode steam boiler provides steam parameters of 1.0MPa, 300℃, and 10t / h to meet the shaft seal steam supply requirements, with a start-up time of approximately 15 hours. In the curtailment and consumption mode, the output power of the high-pressure electrode steam boiler module is controlled to dynamically adjust based on the real-time curtailment of wind and solar power, and the output power does not exceed the rated power of the high-pressure electrode steam boiler module.

[0031] S3. Based on the determined mode, control the steam distribution module to distribute the steam generated by the high-pressure electrode steam boiler module to one or more target systems; S3 specifically includes: in the power curtailment and emergency heating modes, controlling the steam distribution module to distribute steam to the plant heating or residential heating system; in the power curtailment mode, the opening degree of the first and second electric regulating valves is independently controlled by a PID controller based on heat load demand; in the emergency heating mode, the conventional control logic directly outputs a 100% opening command to the first and second electric regulating valves.

[0032] In unit start-up mode, the steam distribution module is controlled to prioritize the steam flow to the steam superheating module to meet the shaft seal steam supply requirements, and distribute the remaining steam to the plant heating and residential heating systems. Specifically, priority control is achieved through a high-priority selector: the output of the shaft seal steam supply pressure regulating loop serves as the master command signal for opening the third branch shut-off valve and starting / stopping the steam superheating module. Simultaneously, this signal is also sent to the steam distribution calculation unit, which subtracts the shaft seal steam consumption from the total boiler steam production to obtain the remaining steam quantity, which is then proportionally distributed to the first and second branches.

[0033] The mode determination process follows a predetermined priority strategy, wherein the emergency heating mode and the unit startup mode have higher priority than the power curtailment and consumption mode. When a high-priority mode trigger condition exists, the system unconditionally switches to the corresponding high-priority mode. The priority strategy is implemented automatically and smoothly by the DCS system, with a system response time of ≤0.4S, ensuring heating safety and unit startup reliability.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power plant heating system based on wind and electricity curtailment, characterized in that... include: High-pressure electrode steam boiler, steam superheating module, steam distribution module and intelligent control module; The high-pressure electrode steam boiler module is used to convert the incoming curtailed wind and solar power into saturated steam thermal energy. Its steam output end is connected to the steam distribution module, and its power input end is connected to the power plant's dedicated bus. The steam superheating module is used to heat saturated steam into superheated steam that meets the turbine start-up requirements. The inlet end of the steam superheating module is connected to the main steam output pipeline of the high-pressure electrode steam boiler module, and the outlet end is connected to the turbine shaft sealing system. The steam distribution module is used to distribute saturated steam to different heating circuits as needed. The input end of the steam distribution module is connected to the steam output end of the high-pressure electrode steam boiler module. The first output end of the steam distribution module is connected to the plant heating system, and the second output end is connected to the steam-water heat exchanger of the residential area heating system. The intelligent control module is connected to the control terminals of the high-pressure electrode steam boiler module and the steam distribution module, and is used to monitor the power curtailment of wind and solar power and the operating status of the unit, and control the operating power of the high-pressure electrode steam boiler module and the steam flow direction of the steam distribution module.

2. The system according to claim 1, characterized in that, The steam distribution module includes a first steam branch and a second steam branch arranged in parallel, and a third steam branch connected to the steam superheating module; The first steam branch is equipped with a first regulating valve to control the steam flow to the plant heating system; A second regulating valve is provided on the second steam branch to control the steam flow to the heating system for the residential area; The third steam branch is equipped with a shut-off valve, which is used to open during unit startup mode to supply steam to the steam superheating module.

3. The system according to claim 2, characterized in that, In the curtailment mode, the intelligent control module opens the first regulating valve and / or the second regulating valve, and dynamically adjusts the output power of the high-pressure electrode steam boiler module according to the real-time curtailment power of wind and solar power. In emergency heating mode, the high-pressure electrode steam boiler module is controlled to operate at rated power, and the first and second regulating valves are fully opened; In the unit startup mode, the shut-off valve is opened, the steam superheating module is started, and the opening of the first regulating valve and the second regulating valve are adjusted to distribute the remaining steam while ensuring the supply of steam to the shaft seal.

4. The system according to claim 1, characterized in that, The rated power of the high-pressure electrode steam boiler module is not less than the sum of the maximum heat load of the power plant's residential area and production plant under extreme weather conditions, and its power regulation system is connected to the power curtailment monitoring system of the wind farm and photovoltaic power station, enabling it to adjust the output in a stepless wind-solar following manner.

5. The system according to claim 1, characterized in that, The system also includes a thermal deaeration subsystem, which includes a thermal deaerator and a boiler feedwater pump; The inlet pipe of the thermal deaerator is connected to the plant's softened water system. Its steam source is saturated steam generated by the high-pressure electrode steam boiler module. Its outlet is connected to the feed port of the high-pressure electrode steam boiler module through the boiler feed pump, forming a closed-loop heat recovery circuit.

6. A control method for a power plant heating system based on wind and electricity curtailment as described in claim 1, characterized in that: Mode determination is performed based on real-time monitored wind and solar power curtailment signals and power plant unit fault status signals; Based on the determined pattern, the energy input and output of the high-pressure electrode steam boiler module are coordinated and controlled. Based on the determined pattern, the steam distribution module is controlled to distribute the steam generated by the high-pressure electrode steam boiler module to one or more target systems; The modes include: power curtailment mode, emergency heating mode, and unit start-up mode.

7. The method according to claim 6, characterized in that, Based on the determined pattern, the coordinated control of the energy input and output of the high-pressure electrode steam boiler module specifically includes: In the curtailment and consumption mode, the output power of the high-pressure electrode steam boiler module is controlled to track the curtailed wind and solar power. In emergency heating or unit start-up mode, the high-pressure electrode steam boiler module is controlled to operate at rated power or a set power that meets the corresponding load requirements.

8. The method according to claim 7, characterized in that, In the curtailment and consumption mode, the output power of the high-pressure electrode steam boiler module is controlled to dynamically adjust based on the real-time curtailment of wind and solar power, and the output power does not exceed the rated power of the high-pressure electrode steam boiler module.

9. The method according to claim 6, characterized in that, The control steam distribution module distributes steam to one or more target systems, specifically including: In the power curtailment and emergency heating modes, the steam distribution module is controlled to distribute steam to the heating system of the plant area or the residential area. In the unit start-up mode, the steam distribution module is controlled to prioritize the steam flow to the steam superheating module to meet the steam supply requirements of the shaft seal, and the remaining steam is distributed to the plant heating and residential heating systems.

10. The method according to claim 6, characterized in that, The mode determination process follows a predetermined priority strategy, wherein the emergency heating mode and the unit start-up mode have higher priority than the power curtailment mode. When there is a triggering condition for a high-priority mode, the system unconditionally switches to the corresponding high-priority mode.

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