Thermal power frequency regulation system and method based on off-peak electricity heat storage compensation

Abstract

The present invention provides a thermal power frequency regulation system and method based on off-peak electricity heat storage compensation. The principle is to use off-peak electricity on the power grid at night to heat a heat storage medium, additionally provide an electric heating heat storage device, the heat storage medium, and a heat storage medium-condensate heat exchange device, provide the heat storage medium-condensate heat exchange device outside an original extracted steam-condensate shell-and-tube heat exchanger and connect same in parallel to the original shell-and-tube heat exchanger, and control the flow distribution of condensate on an extracted steam side and a heat storage medium side by means of valves on the two parallel pipelines. When a thermal power unit issues a frequency regulation instruction, by taking a low-frequency situation as an example, the opening of a valve of a condensate-low-pressure cylinder extracted steam heat exchange pipeline is reduced, so that the heat exchange amount between the condensate and the heat storage medium is increased, the heat exchange amount between the low-pressure cylinder extracted steam and the condensate is reduced, the temperature and pressure of an extracted steam inlet rise, and under the regenerative self-balancing effect, the extracted steam flow rate decreases, and the work output of a steam turbine rises. Thus, the present invention rapidly increases the thermal power load, has a longer duration compared with that of condensate throttling regulation, maintains unit stability, exhibits a high green electricity probability, and offers high economic efficiency.

Description

Thermal power frequency modulation system and method based on low valley electricity heat storage compensation TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, in particular to a thermal power frequency modulation system and method based on low valley electricity heat storage compensation. BACKGROUND

[0002] Under the double carbon development goal, with the increasing proportion of renewable energy, the frequency stability of the power system is under great pressure and challenge. Frequency is a key indicator of power grid operation. In an alternating current power system, frequency is a reflection of active power balance. On the one hand, new energy with power electronic interface does not have the rotational inertia and primary frequency modulation capability of traditional synchronous machines. Large-scale access leads to a decrease in system synchronous rotational inertia and primary frequency modulation capability, and a decrease in system power disturbance resistance. On the other hand, the randomness of renewable energy output is large, and the amplitude and frequency of power disturbance in system operation increase, resulting in an increase in the requirement for system frequency modulation capability.

[0003] The energy endowment of China determines that coal-fired thermal power will still be the adjustment resource in a long period of time in the future. The role of thermal power units in the power system will gradually change from providing long-term power supply as base load power supply to providing short-term power supply as adjustment power supply. In a double high power system, thermal power units will bear the main frequency modulation task, and providing primary frequency modulation capability will become one of the most important tasks of future thermal power plants. At present, the frequency modulation capability of thermal power is not enough, and the overall network capability is relatively insufficient compared with the increase in the amount of wind and solar power connected to the grid, and it is urgent to greatly improve the frequency modulation capability of thermal power units to provide power support for a higher proportion of wind and solar new energy connected to the grid.

[0004] At present, the frequency modulation optimization means of thermal power units includes internal and external strategies. The internal strategies mainly include main steam valve frequency modulation, condensate throttling frequency modulation, supplementary valve frequency modulation, heating butterfly valve frequency modulation, and feedwater bypass frequency modulation strategy. The external strategies mainly include battery energy storage combined frequency modulation and molten salt heat storage frequency modulation. However, the internal strategies usually need to excavate the energy storage of the unit itself, but after instantaneously releasing the energy storage to provide frequency modulation, the unit faces unstable operating parameters and even may exceed the safety boundary in the subsequent recovery stage. The battery energy storage of the external strategy has problems in cost and safety, and the molten salt heat storage is mostly high-temperature heat storage, which has a relatively high cost for frequency modulation.

[0005] In summary, the frequency modulation scheme provided by the prior art cannot meet the demand for low-cost stable operation. SUMMARY

[0006] The present application provides a thermal power frequency modulation system and method based on low valley electricity heat storage compensation, which can solve the problem that the prior art cannot meet the demand for low-cost stable operation, and realize thermal power frequency modulation with performance, safety and cost

[0007] The application provides a thermal power frequency modulation system based on low-valley electricity heat storage compensation, which comprises a speed regulator, an electro-hydraulic servo mechanism, a regenerative heater module, an electric heating heat storage compensation module and a heat storage-condensate flow regulating valve control module; the speed regulator is used for calculating a power increment expected value and a heat storage-condensate flow regulating valve position instruction signal according to a power grid frequency difference signal; the heat storage-condensate flow regulating valve control module is used for formulating a control strategy according to the heat storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, obtaining a power control result obtained by executing the control strategy, and obtaining a frequency modulation result according to the power increment expected value and the power control result; the electro-hydraulic servo mechanism is used for adjusting the heat storage-condensate flow regulating valve according to the control strategy; the electric heating heat storage compensation module comprises a heat storage medium-condensate heat exchange device, an electric heating heat storage device and a heat storage medium, the electric heating heat storage device is connected with a power supply and is started only in a low-valley electricity price period, the electric heating heat storage device is used for converting electric energy of the power supply into heat energy and storing the heat energy into the heat storage medium; the regenerative heater module and the electric heating heat storage compensation module are used for heating condensate together, and the regenerative heater module and the electric heating heat storage compensation module are in series heat exchange, the electric heating heat storage compensation module is connected with a boiler of a thermal power unit through a heat storage-condensate heat exchange pipeline, and the heat storage-condensate flow regulating valve is arranged on the heat storage-condensate heat exchange pipeline.

[0008] According to the thermal power frequency modulation system based on low-valley electricity heat storage compensation provided by the application, the regenerative heater module comprises a plurality of low-pressure heaters; correspondingly, the heat storage medium and the plurality of low-pressure heaters are in series heat exchange; a difference between a highest heat storage temperature of the heat storage medium and a magnitude of condensate water temperature of a target low-pressure heater reaches a preset threshold value; wherein the target low-pressure heater is a nearest low-pressure heater before a deaerator of the thermal power unit.

[0009] According to the thermal power frequency modulation system based on low-valley electricity heat storage compensation provided by the application, the regenerative heater module is connected with a steam turbine of the thermal power unit through a steam-condensate heat exchange pipeline; correspondingly, the steam-condensate heat exchange pipeline and the heat storage-condensate heat exchange pipeline are in parallel.

[0010] According to the low valley electricity heat storage compensation-based thermal power frequency modulation system provided by the application, the control strategy is formulated according to the heat storage-condensate water flow regulating valve position instruction signal and the power grid frequency difference signal, and specifically includes: in the case that the power grid frequency difference is lower than a preset threshold, it is judged that the current disturbance belongs to a low-frequency event, and the control strategy is to increase the opening of the heat storage-condensate water flow regulating valve according to the heat storage-condensate water flow regulating valve position instruction signal; in the case that the power grid frequency difference is not lower than the preset threshold, it is judged that the current disturbance belongs to a high-frequency event, and the control strategy is to reduce the opening of the heat storage-condensate water flow regulating valve according to the heat storage-condensate water flow regulating valve position instruction signal.

[0011] The application further provides a low valley electricity heat storage compensation-based thermal power frequency modulation method, including: in response to the power grid frequency difference exceeding a dead zone, converting the power grid frequency difference signal into a power increment expected value and a heat storage-condensate water flow regulating valve position instruction signal based on the governor; formulating a control strategy according to the heat storage-condensate water flow regulating valve position instruction signal and the power grid frequency difference signal, adjusting the heat storage-condensate water flow regulating valve according to the control strategy to obtain a power control result; in the case that the power control result meets the condition of the power increment expected value, the frequency modulation is completed.

[0012] According to the low valley electricity heat storage compensation-based thermal power frequency modulation method provided by the application, the control strategy is formulated according to the heat storage-condensate water flow regulating valve position instruction signal and the power grid frequency difference signal, and the heat storage-condensate water flow regulating valve is adjusted according to the control strategy to obtain a power control result, and specifically includes: in the case that the power grid frequency difference is lower than a preset threshold, it is judged that the current disturbance belongs to a low-frequency event, and the opening of the heat storage-condensate water flow regulating valve is increased according to the heat storage-condensate water flow regulating valve position instruction signal, so that the steam turbine extraction flow is reduced, and a power control result of the power increase of the steam turbine is obtained.

[0013] According to the low valley electricity heat storage compensation-based thermal power frequency modulation method provided by the application, the control strategy is formulated according to the heat storage-condensate water flow regulating valve position instruction signal and the power grid frequency difference signal, and the heat storage-condensate water flow regulating valve is adjusted according to the control strategy to obtain a power control result, and specifically includes: in the case that the power grid frequency difference is not lower than a preset threshold, it is judged that the current disturbance belongs to a high-frequency event, and the opening of the heat storage-condensate water flow regulating valve is reduced according to the heat storage-condensate water flow regulating valve position instruction signal, so that the steam turbine extraction flow is increased, and a power control result of the power reduction of the steam turbine is obtained.

[0014] The application further provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for frequency modulation of thermal power based on low-valley power storage compensation according to any of the above.

[0015] The application further provides a non-transitory computer readable storage medium, which stores a computer program, wherein the computer program is executable by a processor to implement the method for frequency modulation of thermal power based on low-valley power storage compensation according to any of the above.

[0016] The application further provides a computer program product, which includes a computer program, wherein the computer program is executable by a processor to implement the method for frequency modulation of thermal power based on low-valley power storage compensation according to any of the above.

[0017] The application provides a system and a method for frequency modulation of thermal power based on low-valley power storage compensation, wherein the system includes a speed governor, an electro-hydraulic servo mechanism, a regenerative heater module, an electric heating storage compensation module, and a storage-condensate flow regulating valve control module; the speed governor is used to calculate a power increment expected value and a storage-condensate flow regulating valve position instruction signal according to a power grid frequency difference signal; the storage-condensate flow regulating valve control module is used to formulate a control strategy according to the storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, and obtain a power control result obtained by executing the control strategy, and obtain a frequency modulation result according to the power increment expected value and the power control result; the electro-hydraulic servo mechanism is used to adjust the storage-condensate flow regulating valve according to the control strategy; the electric heating storage compensation module includes a storage medium-condensate heat exchange device, an electric heating storage device, and a storage medium, the electric heating storage device is connected with a power source and is started only during a low-valley power price period, and is used to convert electric energy of the power source into heat energy and store the heat energy into the storage medium; the regenerative heater module and the electric heating storage compensation module are used to heat condensate water together, and the regenerative heater module and the electric heating storage compensation module are in series heat exchange, the electric heating storage compensation module is connected with a boiler of a thermal power unit through a storage-condensate heat exchange pipeline, and the storage-condensate flow regulating valve is arranged on the storage-condensate heat exchange pipeline. The application compensates the regenerative heater by using the storage medium heated by low-valley power on the power grid at night, and formulates a control strategy by using the storage-condensate flow regulating valve control module to control the frequency modulation mode, so that the low-temperature storage compensation is used to compensate for the decrease of feed water temperature caused by steam extraction, and the stability of the unit is not affected, the electric energy consumed by the storage is also taken from the low-valley period at night, the probability of green power is high, the storage loss is also less than that of high-temperature storage, and the economy is high. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to make the technical solutions in the present application or prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0019] Fig. 1 is a structural schematic diagram of a thermal power frequency modulation system based on low-valley electricity heat storage compensation provided by the present application; Fig. 2 is a structural schematic diagram of a thermal power frequency modulation system based on low-valley electricity heat storage compensation provided by the present application; Fig. 3 is a flow schematic diagram of a thermal power frequency modulation method based on low-valley electricity heat storage compensation provided by the present application;

[0020] Fig. 1 is a structural schematic diagram of a thermal power frequency modulation system based on low-valley electricity heat storage compensation provided by the present application; DETAILED DESCRIPTION

[0021] In order to make the technical solutions in the present application or prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0022] The thermal power frequency modulation system based on low-valley electricity heat storage compensation provided by the present application will be described below in combination with Figs. 1-2. As shown in Fig. 1, the system comprises a speed governor 110, an electro-hydraulic servo mechanism 120, a regenerative heater module 130, an electric heating heat storage compensation module 140 and a heat storage-condensate flow regulating valve control module 150.

[0023] The speed governor 110 is used to calculate a power increment expected value and a heat storage-condensate flow regulating valve position instruction signal according to a power grid frequency difference signal. Specifically, the speed governor converts the frequency difference into the power increment and the heat storage-condensate flow regulating valve position instruction signal in sequence after receiving a signal that the frequency difference exceeds a dead zone.

[0024] The heat storage-condensate flow regulating valve control module 150 is configured to formulate a control strategy according to the heat storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, and obtain a power control result obtained by executing the control strategy, and obtain a frequency modulation result according to the power increment expected value and the power control result. Specifically, the control strategy includes how to adjust the heat storage-condensate flow regulating valve position instruction signal under what event. The power control result includes the adjustment of the steam turbine power, and can also include the adjustment of the power of the thermal power generating unit. The power control result and the power increment expected value are compared, if the power control result meets the requirement of the power increment expected value, a frequency modulation completion result is obtained, otherwise, a frequency modulation failure result is obtained. The control strategy and the related power control result will be further explained in the subsequent embodiments.

[0025] Further, the electro-hydraulic servo mechanism 120 is configured to adjust the heat storage-condensate flow regulating valve according to the control strategy. Specifically, the heat storage-condensate flow regulating valve reaches a specified valve position under the action of the electro-hydraulic servo mechanism 120 according to the control strategy.

[0026] The electric heating heat storage compensation module 140 includes a heat storage medium-condensate heat exchange device, an electric heating heat storage device, and a heat storage medium. The electric heating heat storage device is connected with a power supply and is started only during a low-valley electricity price period. The electric heating heat storage device is configured to convert the electric energy of the power supply into heat energy and store the heat energy into the heat storage medium.

[0027] The regenerative heater module 130 and the electric heating heat storage compensation module 140 are used together to heat the condensate water, and the regenerative heater module 130 and the electric heating heat storage compensation module 140 are in series heat exchange. The electric heating heat storage compensation module 140 is connected with the boiler of the thermal power generating unit through a heat storage-condensate heat exchange pipeline. The heat storage-condensate flow regulating valve is arranged on the heat storage-condensate heat exchange pipeline.

[0028] It should be noted that the thermal power frequency modulation system and method based on low-valley electricity storage compensation provided by the present application takes a coal-fired thermal power generating unit as an application object, proposes a heat storage compensation heating technology for a low-pressure heater, sets an electric heating heat storage compensation module 140 to assist a regenerative heater module 130 to heat the condensate water, and the electric heating heat storage compensation module 140 and the regenerative heater module 130 are in series heat exchange.

[0029] It can be understood that, in general, the regenerative heater module includes a plurality of high-pressure heaters and / or a plurality of low-pressure heaters.

[0030] In a specific embodiment, the regenerative heater module 130 includes three high-pressure heaters and four low-pressure heaters.

[0031] Further, the thermal power generating unit also comprises a first deaerator.

[0032] Based on the above embodiment, the heat storage medium and the multi-stage low-pressure heater are in series heat exchange. Specifically, in order to reduce the loss of heat exchange between the sensible heat storage medium and the condensate water, the heat storage medium and the condensate water in the shell side of the multi-stage low-pressure heater are sequentially exchanged, aiming to realize the cascade utilization of heat. On this basis, the multi-stage extraction steam flow of the low-pressure cylinder can also be adjusted according to the control strategy to realize more heat storage capacity release. The present application will be further explained in subsequent embodiments.

[0033] In a specific embodiment, as shown in FIG. 2, the upper part is the heat storage medium, and the lower part is a four-stage low-pressure heater. Among them, the four-stage low-pressure heater is No. 5, No. 6, No. 7, and No. 8 low-pressure heater from right to left. On this basis, according to the principle of cascade utilization of heat, the heat storage medium is sequentially exchanged with No. 5, No. 6, No. 7, and No. 8 low-pressure heater in series

[0034] Further, the electric heating heat storage compensation module 140 referred to in the embodiment of the present application comprises an electric heating heat storage device, a heat storage medium, and a heat storage medium-condensate water heat exchange device. It should be pointed out that the present application does not reform the high-pressure heater and deaerator of the original thermal power generating unit, but compensates the heat supply of the low-pressure heater through the added electric heating heat storage device, heat storage medium, and heat storage medium-condensate water heat exchange device.

[0035] Among them, the heat storage medium in the electric heating heat storage compensation module 140 is heated by using the off-peak electricity on the network at night, that is, the electric heating heat storage device connected to the power supply (or power system) converts electric energy into heat energy by using off-peak electricity and stores it in the heat storage medium. The purpose of setting the electric heating heat storage compensation module is to compensate the heat supply of the heat recovery heater by using low-temperature heat storage with off-peak electricity, so as to heat the condensate water with the low-pressure cylinder extraction steam together, which has the effect of absorbing low new energy. At the same time, the heat storage cost is relatively low, and the heat loss is also relatively small, which has strong economic efficiency.

[0036] In some embodiments, the energy storage mode of the heat storage medium is sensible heat storage. It can be understood that sensible heat storage is a technology that uses the heat absorbed or released by a substance when its temperature changes to store energy.

[0037] Based on the above embodiment, in some embodiments, a heat storage medium with a boiling point above 200℃ and a melting point below 80℃ is used to form the electric heating heat storage compensation module 140.

[0038] Based on the above embodiment, the difference between the order of magnitude of the maximum heat storage temperature of the heat storage medium and the order of magnitude of the condensate water temperature of the target low-pressure heater reaches a preset threshold value; wherein the target low-pressure heater is the nearest low-pressure heater before the deaerator.

[0039] Specifically, in the case of the 4th low-pressure heater being the 5th, 6th, 7th, and 8th low-pressure heater, respectively, the maximum heat storage temperature of the heat storage medium is in the same order of magnitude as the condensate water temperature before the first low-pressure heater (5th) of the deaerator, thereby having a small impact on the water level and temperature of the deaerator, and achieving the purpose of having a small impact on the operation of the unit.

[0040] Further, in some embodiments, the heat storage medium-condensate water heat exchange device is placed outside the extraction-condensate water shell-and-tube heat exchanger of the original thermal power unit and is connected in parallel with the original shell-and-tube heat exchanger to facilitate the heat exchange between the heat storage medium and the condensate water on the shell side of the multi-stage low-pressure heater.

[0041] On this basis, in some embodiments, the regenerative heater module 130 is connected to the steam turbine of the thermal power unit through an extraction-condensate water heat exchange pipeline; correspondingly, the extraction-condensate water heat exchange pipeline is connected in parallel with the heat storage-condensate water heat exchange pipeline.

[0042] Specifically, the pipeline for heat storage and condensate water heat exchange (heat storage-condensate water heat exchange pipeline) and the extraction-condensate water heat exchange pipeline are connected in parallel, and a heat storage-condensate water flow regulating valve is arranged on the heat storage-condensate water heat exchange pipeline, and the opening degree of the valve determines the flow distribution of the condensate water to the heat storage and extraction heat exchange.

[0043] Further, in some embodiments, the control strategy is formulated according to the heat storage-condensate water flow regulating valve position instruction signal and the power grid frequency difference signal, specifically including: in the case where the power grid frequency difference is lower than a preset threshold, it is judged that the current disturbance belongs to a low-frequency event, and the control strategy is to increase the opening degree of the heat storage-condensate water flow regulating valve according to the heat storage-condensate water flow regulating valve position instruction signal; in the case where the power grid frequency difference is not lower than the preset threshold, it is judged that the current disturbance belongs to a high-frequency event, and the control strategy is to decrease the opening degree of the heat storage-condensate water flow regulating valve according to the heat storage-condensate water flow regulating valve position instruction signal. 。

[0044] It can be understood that the power grid frequency difference refers to the deviation between the frequency of the power grid and the standard frequency. In China, the standard frequency is 50 Hz 。 High-frequency event and low-frequency event refer to a series of phenomena occurring when the power grid frequency deviation exceeds a certain threshold. Generally, according to the power grid frequency difference, these events can be divided into the following categories: high-frequency event: when the power grid frequency deviation exceeds 0.2 Hz, it can be determined as a high-frequency event. High-frequency event is usually caused by a sudden decrease in load in the power grid, resulting in an increase in generator speed and frequency. High-frequency event can cause problems such as generator stall and wind turbine disconnection from the power grid.

[0045] Low frequency event: when the grid frequency deviation is less than 0.2Hz, it can be determined as a low frequency event 。 Low frequency event is usually caused by sudden increase of load in the grid, which leads to the decrease of generator speed and frequency. Low frequency event can cause the generator to overspeed, and when the frequency decreases to below 49.5Hz, it can cause the generator to trip, wind turbine to fail to start, etc.

[0046] Under high frequency event, the control strategy is to reduce the opening of the heat storage-condensate flow regulating valve, so that more condensate enters the extraction- condensate heat exchange pipeline, the extraction flow of the steam turbine increases, and the output of the steam turbine decreases; under low frequency event, the control strategy is to increase the opening of the heat storage-condensate flow regulating valve, so that less condensate enters the extraction- condensate heat exchange pipeline, the extraction flow of the steam turbine decreases, and the output of the steam turbine increases.

[0047] In actual implementation process, in response to the grid frequency deviation exceeding the dead zone, the thermal power unit issues a primary frequency modulation or AGC secondary frequency modulation instruction, at which time the frequency modulation is started. Under low frequency event, the opening of the heat storage-condensate flow regulating valve is increased, the heat exchange amount between the condensate and the heat storage medium is increased, the extraction- condensate heat exchange of the low-pressure cylinder is reduced, the extraction inlet temperature and pressure are increased, and under the self-balancing action of the regenerative heat, the extraction flow is reduced, and the work of the steam turbine is increased. This method can quickly increase the thermal power load, and uses low-temperature heat storage to compensate for the decrease of extraction, reduces the disturbance to the deaerator, boiler and other equipment, reduces the increase of coal consumption caused by the disturbance, has longer frequency modulation capacity and duration, does not affect the stability of the unit, the electric energy consumed by the heat storage is taken from the night valley period, and the probability of green electricity is high. The heat storage loss is also less than that of high-temperature heat storage, and the economy is higher.

[0048] Further, an extraction- condensate flow regulating valve can also be provided, that is, an extraction- condensate flow regulating valve is provided on the extraction- condensate heat exchange pipeline.

[0049] The provision of the heat storage- condensate flow regulating valve and the extraction- condensate flow regulating valve can control the condensate flow in the heat storage- condensate heat exchange pipeline and the extraction- condensate heat exchange pipeline respectively, so that the valve opening of the two pipelines determines the flow distribution of the condensate to the sensible heat storage and the extraction heat exchange.

[0050] Further, since the sensible heat storage medium is in series heat release in each stage of the low-pressure heater, the heat exchange amount of each stage of the heater can also be adjusted by the heat storage- condensate flow regulating valve. Therefore, the overall effect is that the low-temperature sensible heat storage driven by off-peak electricity can realize flexible adjustment of the extraction flow of each stage and the total amount.

[0051] Under high frequency events, the control strategy is to reduce the opening of the heat storage- condensate flow regulating valve and / or increase the opening of the extraction- condensate flow regulating valve, so that more condensate enters the extraction- condensate heat exchange pipeline and less condensate enters the heat storage- condensate heat exchange pipeline, so that the steam turbine extraction flow increases and the steam turbine output decreases.

[0052] Under low frequency events, the control strategy is the opposite, that is, to increase the opening of the heat storage- condensate flow regulating valve and / or reduce the opening of the extraction- condensate flow regulating valve, so that less condensate enters the extraction- condensate heat exchange pipeline and more condensate enters the heat storage- condensate heat exchange pipeline, so that the steam turbine extraction flow decreases and the steam turbine output increases.

[0053] Further, after the electric power service mechanism 120 completes the control of the regulating valve, the heat storage- condensate flow regulating valve control module 150 obtains the power control result obtained by executing the control strategy. Specifically, the steam turbine extraction flow decreases, and the power control result of the steam turbine power increase is obtained. The steam turbine extraction flow increases, and the power control result of the steam turbine power decrease is obtained.

[0054] The application provides a thermal power frequency modulation system based on low-valley power heat storage compensation, which comprises a speed regulator, an electro-hydraulic servo mechanism, a regenerative heater module, an electric heating heat storage compensation module and a heat storage-condensate flow regulating valve control module; the speed regulator is used for calculating a power increment expected value and a heat storage-condensate flow regulating valve position instruction signal according to a power grid frequency difference signal; the heat storage-condensate flow regulating valve control module is used for formulating a control strategy according to the heat storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, obtaining a power control result obtained by executing the control strategy, and obtaining a frequency modulation result according to the power increment expected value and the power control result; the electro-hydraulic servo mechanism is used for adjusting the heat storage-condensate flow regulating valve according to the control strategy; the electric heating heat storage compensation module comprises a heat storage medium-condensate heat exchange device, an electric heating heat storage device and a heat storage medium, the electric heating heat storage device is connected with a power supply and is started only during a low-valley power price period, and the electric heating heat storage device is used for converting electric energy of the power supply into heat energy and storing the heat energy into the heat storage medium; the regenerative heater module and the electric heating heat storage compensation module are used for heating condensate together, and the regenerative heater module and the electric heating heat storage compensation module are in series heat exchange, the electric heating heat storage compensation module is connected with a boiler of a thermal power unit through a heat storage-condensate heat exchange pipeline, and the heat storage-condensate flow regulating valve is arranged on the heat storage-condensate heat exchange pipeline. The application compensates the regenerative heater by using a heat storage medium heated by low-valley power on the network at night. The control strategy is formulated by using the heat storage-condensate flow regulating valve control module to control the frequency modulation mode, so that the low-temperature heat storage is used to compensate for the decrease of feed water temperature caused by steam extraction, the stability of the unit is not affected, the electric energy consumed by the heat storage is taken from the low-valley period at night, the probability of green power is high, the heat storage loss is less than that of high-temperature heat storage, and the economy is high.

[0055] The application provides a thermal power frequency modulation method based on low-valley power heat storage compensation, and the following description can be referred to in combination with the above description of the thermal power frequency modulation system based on low-valley power heat storage compensation. As shown in FIG. 3, the method comprises the following steps: step 310: in response to the fact that the power grid frequency difference exceeds a dead zone, converting the power grid frequency difference signal into a power increment expected value and a heat storage-condensate flow regulating valve position instruction signal based on the speed regulator; step 320: formulating a control strategy according to the heat storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, adjusting the heat storage-condensate flow regulating valve according to the control strategy, and obtaining a power control result; and step 330: under the condition that the power control result meets the power increment expected value, completing frequency modulation.

[0056] According to the power frequency regulation method based on low-valley electricity heat storage compensation provided by the application, the control strategy is formulated according to the heat storage-condensate water flow regulating valve position instruction signal and the power grid frequency difference signal, the heat storage-condensate water flow regulating valve is adjusted according to the control strategy, and the power control result is obtained, and specifically, the opening of the heat storage-condensate water flow regulating valve is increased according to the heat storage-condensate water flow regulating valve position instruction signal when the power grid frequency difference is lower than a preset threshold value, the steam turbine extraction flow is reduced, and the power control result of the power increase of the steam turbine is obtained.

[0057] According to the power frequency regulation method based on low-valley electricity heat storage compensation provided by the application, the control strategy is formulated according to the heat storage-condensate water flow regulating valve position instruction signal and the power grid frequency difference signal, the heat storage-condensate water flow regulating valve is adjusted according to the control strategy, and the power control result is obtained, and specifically, the opening of the heat storage-condensate water flow regulating valve is increased according to the heat storage-condensate water flow regulating valve position instruction signal when the power grid frequency difference is lower than a preset threshold value, the steam turbine extraction flow is reduced, and the power control result of the power increase of the steam turbine is obtained.

[0058] The power frequency regulation method based on low-valley electricity heat storage compensation provided by the application is used for compensating the regenerative heater by using the heat storage medium heated by the low-valley electricity on the network at night, and the control strategy is formulated by using the heat storage-condensate water flow regulating valve control module to control the frequency regulation mode, so that the low-temperature heat storage is used for compensating the reduction of the feedwater temperature caused by the extraction reduction, the stability of the unit is not affected, the electric energy consumed by the heat storage is taken from the low-valley period at night, the green electricity probability is high, the heat storage loss is less than that of the high-temperature heat storage, and the economy is high.

[0059] Fig. 4 shows an example of an entity structure diagram of an electronic device, as shown in Fig. 4, the electronic device can include: a processor 410, a communications interface 420, a memory 430 and a communications bus 440, wherein the processor 410, the communications interface 420, the memory 430 complete the communication among each other through the communications bus 440. The processor 410 can call the logic instructions in the memory 430 to execute the low valley power storage compensation based thermal power frequency modulation method, the method comprises: in response to the grid frequency difference exceeding the dead zone, converting the grid frequency difference signal into a power increment expected value and a heat storage-condensate flow regulating valve position instruction signal based on the speed governor; formulating a control strategy according to the heat storage-condensate flow regulating valve position instruction signal and the grid frequency difference signal, adjusting the heat storage-condensate flow regulating valve according to the control strategy to obtain a power control result; under the condition that the power control result meets the power increment expected value, the frequency modulation is completed.

[0060] In addition, the logic instructions in the memory 430 described above can be realized in the form of a software function unit and sold or used as an independent product, which can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, which is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0061] On the other hand, the present application also provides a computer program product, the computer program product includes a computer program, the computer program can be stored on a non-transitory computer readable storage medium, when the computer program is executed by a processor, the computer can execute the low valley power storage compensation based thermal power frequency modulation method provided by the above-mentioned method, the method comprises: in response to the grid frequency difference exceeding the dead zone, converting the grid frequency difference signal into a power increment expected value and a heat storage-condensate flow regulating valve position instruction signal based on the speed governor; formulating a control strategy according to the heat storage-condensate flow regulating valve position instruction signal and the grid frequency difference signal, adjusting the heat storage-condensate flow regulating valve according to the control strategy to obtain a power control result; under the condition that the power control result meets the power increment expected value, the frequency modulation is completed.

[0062] In yet another aspect, the present application also provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the method for low-valley power heat storage compensation based frequency modulation of thermal power provided by the above method, the method comprising: in response to the grid frequency difference exceeding a dead zone, converting the grid frequency difference signal into a power increment expected value and a heat storage-condensate flow regulating valve position instruction signal based on the speed governor; formulating a control strategy according to the heat storage-condensate flow regulating valve position instruction signal and the grid frequency difference signal, adjusting the heat storage-condensate flow regulating valve according to the control strategy to obtain a power control result; and under the condition that the power control result meets the power increment expected value, completing frequency modulation. The above-described device embodiments are merely illustrative, and the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place or distributed on multiple network units. Some or all of the modules can be selected to achieve the purpose of the present embodiment according to actual needs. Those skilled in the art can understand and implement it without creative labor.

[0063] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on such understanding, the above technical solutions, essentially or in terms of contribution to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0064] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A thermal power frequency modulation system based on low valley electricity heat storage compensation, characterized in that, The speed governor, the electro-hydraulic servo mechanism, the regenerative heater module, the electric heating heat storage compensation module and the heat storage-condensate flow regulating valve control module are included. The speed governor is used to calculate a power increment expected value and a heat storage-condensate flow regulating valve position instruction signal according to a power grid frequency difference signal; the heat storage-condensate flow regulating valve control module is used to formulate a control strategy according to the heat storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, and obtain a power control result obtained by executing the control strategy, and obtain a frequency modulation result according to the power increment expected value and the power control result; the electro-hydraulic servo mechanism is used to adjust the heat storage-condensate flow regulating valve according to the control strategy. The electric heating heat storage compensation module includes a heat storage medium-condensate heat exchange device, an electric heating heat storage device and a heat storage medium, the electric heating heat storage device is connected with a power supply and is started only in a low-valley electricity price period, the electric heating heat storage device is used to convert electric energy of the power supply into heat energy and store the heat energy into the heat storage medium; the regenerative heater module and the electric heating heat storage compensation module are used to heat condensate water together, and the regenerative heater module and the electric heating heat storage compensation module are in series heat exchange, the electric heating heat storage compensation module is connected with a boiler of a thermal power unit through a heat storage-condensate heat exchange pipeline, and the heat storage-condensate flow regulating valve is arranged on the heat storage-condensate heat exchange pipeline.

2. The low-valley power storage heat compensation-based thermal power frequency modulation system according to claim 1, characterized in that, The regenerative heater module includes a plurality of low-pressure heaters. Correspondingly, the heat storage medium and the plurality of low-pressure heaters are in series heat exchange. A difference between a magnitude of a highest heat storage temperature of the heat storage medium and a magnitude of a condensate water temperature of a target low-pressure heater reaches a preset threshold value; wherein the target low-pressure heater is a nearest low-pressure heater before a deaerator of the thermal power unit.

3. The low-valley power storage heat compensation-based thermal power frequency modulation system according to claim 1, characterized in that, The regenerative heater module is connected with a steam turbine of the thermal power unit through a steam-condensate heat exchange pipeline. Correspondingly, the steam-condensate heat exchange pipeline is connected with the heat storage-condensate heat exchange pipeline in parallel.

4. The low-valley power storage heat compensation-based thermal power frequency modulation system according to claim 1, characterized in that, The control strategy is formulated according to the heat storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, and specifically includes: In a case where the power grid frequency difference is lower than a preset threshold value, it is judged that a current disturbance belongs to a low-frequency event, and the control strategy is to increase an opening degree of the heat storage-condensate flow regulating valve according to the heat storage-condensate flow regulating valve position instruction signal; In a case where the power grid frequency difference is not lower than the preset threshold value, it is judged that the current disturbance belongs to a high-frequency event, and the control strategy is to decrease the opening degree of the heat storage-condensate flow regulating valve according to the heat storage-condensate flow regulating valve position instruction signal.

5. A thermal power frequency modulation method based on low valley electricity heat storage compensation, characterized in that, The method is executed by using the thermal power frequency modulation system based on low-valley electricity storage compensation according to any one of claims 1 to 4, and the method includes: In response to the power grid frequency difference exceeding a dead zone, the power grid frequency difference signal is converted into a power increment expected value and a heat storage-condensate flow regulating valve position instruction signal based on the speed governor. According to the heat storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, a control strategy is formulated, the heat storage-condensate flow regulating valve is adjusted according to the control strategy, and a power control result is obtained. In the power control result, if the power increment expected value is met, the frequency modulation is completed.

6. The method for thermal power frequency modulation based on low valley electricity heat storage compensation according to claim 5, characterized in that, The control strategy is formulated according to the heat storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, the heat storage-condensate flow regulating valve is adjusted according to the control strategy, and a power control result is obtained, and specifically includes: If the power grid frequency difference is lower than a preset threshold, it is judged that the current disturbance belongs to a low-frequency event, the opening of the heat storage-condensate flow regulating valve is increased according to the heat storage-condensate flow regulating valve position instruction signal, the steam turbine extraction flow is reduced, and a power control result of increasing the steam turbine power is obtained.

7. The method for thermal power frequency modulation based on low valley electricity heat storage compensation according to claim 5, characterized in that, The control strategy is formulated according to the heat storage-condensate flow regulating valve position instruction signal and the power grid frequency difference signal, the heat storage-condensate flow regulating valve is adjusted according to the control strategy, and a power control result is obtained, and specifically includes: If the power grid frequency difference is not lower than a preset threshold, it is judged that the current disturbance belongs to a high-frequency event, the opening of the heat storage-condensate flow regulating valve is reduced according to the heat storage-condensate flow regulating valve position instruction signal, the steam turbine extraction flow is increased, and a power control result of reducing the steam turbine power is obtained.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the thermal power frequency modulation method based on low-valley electricity heat storage compensation according to any one of claims 5 to 7. 9.A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the thermal power frequency modulation method based on low-valley electricity heat storage compensation according to any one of claims 5 to 7.

10. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the thermal power frequency modulation method based on low-valley electricity heat storage compensation according to any one of claims 5 to 7.

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