Combined energy storage coupled thermal grid frequency modulation auxiliary thermal power unit system and method

Abstract

The present application relates to the field of power grid frequency modulation, and particularly relates to a combined energy storage coupled with a heat network frequency modulation auxiliary thermal power generating unit system and method. The system comprises a dispatching control platform, a steam turbine generator unit, one end of the steam turbine generator unit being connected with the dispatching control platform, and the other end being connected with a steam supply main pipe, and a molten salt heat storage unit, one end of the molten salt heat storage unit being connected with the dispatching control platform, and the other end being connected with the steam supply main pipe. The present application combines the molten salt energy storage with the heat network for frequency modulation, on the one hand, without the need to set double molten salt electric heaters for frequency modulation power, the electric heaters can participate in the adjustment at full power, reducing the engineering cost of the molten salt heat storage unit, and on the other hand, solving the problem of energy efficiency reduction of the electric heaters in long-term intermediate load operation. When the heat network is frequency modulated, the steam self-balancing supplement of the molten salt heat storage unit improves the steam supply stability when the heat network is frequency modulated, so that it will not cause steam supply pressure fluctuation, solving the disadvantages of the heat network being unable to store energy and generating overheated steam.

Description

Technical Field

[0001] This invention relates to the field of power grid frequency regulation, specifically to a combined energy storage coupled heating network frequency regulation auxiliary thermal power unit system and method. Background Technology

[0002] Since electricity is difficult to store on a large scale, the power grid dispatch center needs to maintain the generation load within the grid equal to the consumption load at all times. When the generation load in the grid is greater than the consumption load, the grid frequency increases, and vice versa. Therefore, the process by which the power grid adjusts the generation load according to the consumption load is also called "frequency regulation".

[0003] There are many methods for frequency regulation in the existing technology. For example, Chinese Patent Application No. 201210304745.8 discloses a method for improving the primary frequency regulation capability of heating units by utilizing heat storage in heating network pipelines. Specifically, it discloses using a nonlinear filter to decompose the unit load command into two parts: a slowly changing steady-state load command and a rapidly changing transient load command. The steady-state load command is sent to the original unit coordination control system, and the transient load command is divided into two paths. One path passes through a first-order inertial element and is superimposed on the opening command of the heating extraction steam regulating butterfly valve. The other path passes through the transfer function of the regulating butterfly valve opening on the unit's power generation load and is then superimposed in reverse on the unit's power generation load signal. The superimposed signal is then used as the power generation load feedback signal of the original coordination control system. The problems with the above-mentioned patents are that frequency regulation using the thermal hysteresis of the heating network requires a large-scale heating network, which is not applicable to small-scale thermal power units. In addition, the adjustment range of the heating network butterfly valve is limited, and excessive adjustment of the steam supply flow will lead to severe fluctuations in the heat consumption of heat users. Furthermore, the regulation dead zone of this technology is during the grid down-regulation process, that is, when the heating network is supplying steam at full load, the butterfly valve cannot be opened further, which makes it impossible to achieve grid down-regulation.

[0004] For example, Chinese patent application number 202410345140.6 discloses a frequency regulation method and system for molten salt energy storage coupled with thermal power units. Specifically, it discloses that the frequency regulation response requirements of the power grid are decomposed using the VMD algorithm to obtain residual components and multiple modal components; the degree of aliasing between adjacent modal components is calculated, and high-frequency modal component groups and low-frequency modal component groups are divided based on the minimum value of adjacent aliasing; if the high-frequency modal component group includes only one modal component, the residual components and multiple modal components are divided into high-frequency groups and low-frequency groups according to the center frequency; multiple fusion methods are used for the modal components in the high-frequency group to obtain different fused components; the ratio of each fused component to the frequency regulation response requirements of the power grid is calculated to obtain the target ratio group and the target fused component; the modal components in the high-frequency group corresponding to the target fused component constitute the high-frequency component, and the low-frequency group and the remaining modal components in the high-frequency group constitute the low-frequency component; so as to control the molten salt energy storage equipment and thermal power units to respond according to the high and low frequency components respectively. The aforementioned patent utilizes molten salt energy storage for frequency regulation of thermal power units. However, the electric heaters in molten salt energy storage need to operate continuously at intermediate load levels, leading to a long-term phenomenon of high-quality steam being underutilized, resulting in reduced energy efficiency. Furthermore, the electric heater power of molten salt energy storage requires a load twice the frequency regulation capacity to meet the regulation requirements, resulting in significant investment. Additionally, if this technology does not operate at intermediate load levels, its regulation dead zone occurs during grid-based regulation; that is, when the electric heater power is zero, the system lacks the ability to release energy, making grid-based regulation impossible. Summary of the Invention

[0005] To address the problems mentioned in the prior art, this invention proposes a combined energy storage coupled with heating network frequency regulation auxiliary thermal power unit system. It adopts a frequency regulation method that combines molten salt energy storage with heating network, and utilizes the fact that the dead zones of heating network frequency regulation and molten salt frequency regulation are exactly opposite to achieve coupled frequency regulation.

[0006] The present invention relates to a combined energy storage coupled heating network frequency regulation auxiliary thermal power unit system, comprising:

[0007] Dispatch and control platform;

[0008] The steam turbine generator set is connected at one end to the dispatch control platform and at the other end to the steam supply main pipe.

[0009] The molten salt thermal storage unit is connected to the dispatch control platform at one end and to the steam supply main pipe at the other end.

[0010] Preferably, the molten salt thermal storage unit includes a water supply system, a phase change thermal storage unit connected to the water supply system, a high-temperature molten salt tank, a steam drum, and a superheater;

[0011] The phase change thermal storage unit is connected to a high-temperature molten salt tank;

[0012] One end of the steam drum is connected to the superheater, and the other end is connected to the phase change heat storage unit;

[0013] The superheater is connected to the phase change heat storage unit and also to the high-temperature molten salt tank.

[0014] Preferably, both the phase change thermal storage unit and the high-temperature molten salt tank are equipped with heating components.

[0015] Preferably, a forced circulation pump is provided between the steam drum and the water supply system.

[0016] Preferably, a water flow regulating valve is provided between the water supply system and the phase change thermal storage unit.

[0017] Preferably, a pressure self-balancing check valve and a steam supply valve are installed sequentially between the superheater and the steam supply header in the direction of steam flow.

[0018] Preferably, the scheduling and control platform includes an instruction receiving module, an analysis module, a calculation module, a dispatch control module, and a pressure analysis module.

[0019] A method for a combined energy storage coupled heating network-assisted thermal power unit system includes:

[0020] When the demand for grid frequency regulation increases, the dispatch control platform analyzes the grid dispatch instructions and calls the heating network for frequency regulation. According to the grid dispatch instructions, it controls the opening and closing of the heating network regulating valve. During the opening and closing of the heating network regulating valve, the molten salt thermal storage unit is used to supplement steam to achieve stable steam supply.

[0021] When the grid frequency regulation demand decreases, the steam supply valve is opened, the dispatch control platform analyzes the grid dispatch instructions and starts the phase change thermal storage and heat transfer unit electric heating and load increase. When the grid frequency regulation demand decreases further, the phase change thermal storage and heat transfer unit electric heating power decreases, and at the same time, steam is supplemented to the molten salt thermal storage unit to compensate for steam fluctuations when the grid frequency regulation demand increases.

[0022] Preferably, the steam replenishment process is as follows: when steam fluctuations occur in the heating network header, the steam stored in the steam drum is heated by the heater and sent to the heating network header for steam replenishment, thereby stabilizing the steam supply.

[0023] Preferably, when the steam in the steam drum is insufficient, the feedwater system is started, and saturated steam is generated after being heated by the phase change heat storage unit and sent to the steam drum for storage; the high-temperature molten salt storage tank provides a heat source for the superheater.

[0024] Compared with the prior art, the present invention achieves the following technical effects:

[0025] This invention combines molten salt energy storage with a heating network for frequency regulation, overcoming the shortcomings of separate frequency regulation of the heating network and molten salt energy storage in traditional technologies. Compared to traditional separate heating network frequency regulation, this invention is applicable to thermal power units of any size, offering strong adaptability and versatility. Secondly, while traditional heating network frequency regulation cannot store energy, this invention can store energy simultaneously with heating, using the stored thermal energy to heat steam at a suitable temperature, thus preventing equipment damage caused by overheated steam. Furthermore, the molten salt thermal storage unit in this invention can replenish steam in real time during frequency regulation, achieving steam self-balancing and improving the steam supply stability during heating network frequency regulation. This reduces steam pressure fluctuations caused by insufficient stability in traditional heating network frequency regulation, further enhancing the heating experience for users.

[0026] Compared with traditional standalone molten salt energy storage frequency regulation, this invention eliminates the need for a double load on the electric heater. This is because the invention utilizes a steam turbine generator set to compensate for the frequency regulation dead zone and frequency regulation requirements. Thus, the electric heater does not need to be doubled for the frequency regulation capacity, effectively reducing engineering costs. On the other hand, it allows the electric heater to participate in regulation at full power, avoiding the problem of reduced energy efficiency when the electric heater operates at intermediate load for a long time in traditional molten salt energy storage frequency regulation. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the invention;

[0029] Figure 3 This is a schematic diagram of the method of the present invention.

[0030] Reference numerals in the attached diagram: 1. Molten salt thermal storage unit; 2. Heat network regulating valve; 3. Steam supply header; 4. Steam turbine generator set; 5. Dispatch and control platform; 6. Phase change thermal storage unit; 7. High-temperature molten salt tank; 8. Superheater; 9. Steam drum; 10. Feedwater system; 11. Pressure self-balancing check valve; 12. Steam supply valve; 13. Forced circulation pump; 14. Water flow regulating valve. Detailed Implementation

[0031] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Rather, the embodiments of this application include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0032] like Figure 1As shown, the combined energy storage coupled heating network frequency regulation auxiliary thermal power unit system of the present invention includes: a dispatch control platform 5; a steam turbine generator set 4, one end of which is connected to the dispatch control platform 5 and the other end of which is connected to the steam supply main pipe 3; and a molten salt thermal storage unit 1, one end of which is connected to the dispatch control platform 5 and the other end of which is connected to the steam supply main pipe 3.

[0033] In existing technologies, frequency regulation using the thermal hysteresis of heating networks requires a large-scale heating network, making it unsuitable for small-scale thermal power units. Furthermore, the adjustable range of the heating network butterfly valve is limited, and excessive adjustment of the steam supply flow can lead to severe fluctuations in heat consumption for users. In addition, the regulation dead zone of this technology occurs during the grid down-regulation process, i.e., when the heating network is supplying steam at full load, the butterfly valve cannot be opened further, thus failing to achieve grid down-regulation.

[0034] Using molten salt energy storage for frequency regulation of thermal power units requires the electric heaters of the molten salt energy storage to operate continuously in the intermediate load range. This leads to a long-term phenomenon of high-quality steam being underutilized, resulting in reduced energy efficiency. Furthermore, the electric heater power of molten salt energy storage requires a load with twice the frequency regulation capacity to meet the regulation requirements, resulting in significant investment. In addition, if this technology does not operate in the intermediate load range, its regulation dead zone occurs during grid-based regulation; that is, when the electric heater power is zero, the system lacks the ability to release energy, making grid-based regulation impossible.

[0035] This invention combines molten salt energy storage with a heating network for frequency regulation. On one hand, it eliminates the need for double the molten salt electric heaters for the frequency regulation power, allowing the electric heaters to participate in regulation at full power, thus reducing the engineering cost of the molten salt thermal storage unit. On the other hand, it solves the problem of reduced energy efficiency of electric heaters during long-term operation at intermediate loads. During heating network frequency regulation, the invention improves steam supply stability through the steam self-balancing replenishment of the molten salt thermal storage unit, preventing steam pressure fluctuations and overcoming the drawbacks of heating networks being unable to store energy and generating superheated steam.

[0036] Figure 1 As shown, the molten salt thermal storage unit 1 includes a water supply system 10, a phase change thermal storage unit 6 connected to the water supply system 10, a high-temperature molten salt tank 7, a steam drum 9, and a superheater 8. In this embodiment, the phase change thermal storage unit 6 is an energy storage device based on phase change energy storage materials. It utilizes the characteristic of substances absorbing or releasing a large amount of latent heat during phase change to store and release heat. The heating component in the phase change thermal storage unit 6 can heat the incoming water. After being heated by the phase change thermal storage unit 6, the incoming water generates high-temperature steam, which is then sent to the steam drum 9 for storage. In this embodiment, the heating component is an electric heater.

[0037] In this embodiment, the phase change material of the phase change heat storage unit 6 is preferably solid molten salt. Solid molten salt has high energy storage density and good thermal stability. The solid molten salt is a low-temperature salt in the phase change heat storage unit 6. At this time, the low-temperature salt is heated by the heating component. Due to the difference in density, the liquid molten salt will rise and the solid molten salt will sink and expand in volume. The expanded liquid molten salt flows into the high-temperature molten salt tank 7 through the pipeline (using a pump). It is stored in the high-temperature molten salt tank 7. The high-temperature molten salt tank 7 can heat the superheater 8. After the superheater 8 releases heat, the high-temperature molten salt becomes low-temperature molten salt and is sent into the phase change heat storage unit 6 for storage, realizing the circulation of molten salt between the phase change heat storage unit 6 and the high-temperature molten salt tank 7.

[0038] In this embodiment, the purpose of the superheater 8 is to allow high-temperature and high-pressure steam to pass through the superheater 8 and exchange heat with it, thereby further increasing the temperature of the steam. The superheater 8 is preferably a convection superheater 8, which uses the high-temperature molten salt tank 7 to provide a heat source, so that the steam temperature is raised to meet the quality requirements of the steam supply header 3 and sent into the steam supply header 3 to achieve stable steam supply pressure fluctuations.

[0039] In this embodiment, a pressure self-balancing check valve 11 and a steam supply valve 12 are sequentially arranged between the superheater 8 and the steam supply header 3 according to the steam flow direction. To ensure the safety, efficiency, and stability of steam during transmission, valves are arranged at the connection between the superheater 8 and the steam supply header 3, with the pressure self-balancing check valve 11 and the steam supply valve 12 arranged sequentially according to the natural steam flow direction. The pressure self-balancing check valve 11 automatically adjusts the steam flow direction and provides additional safety assurance under specific conditions (such as pressure fluctuations). Specifically, when the pressure in the steam supply header 3 drops instantaneously, the valve can quickly sense this change and automatically open after detecting the pressure difference, allowing saturated steam from the steam drum 9 to pass through quickly after being heated by the superheater 8. This process effectively alleviates the problem of unstable steam supply that may be caused by pressure drop in the steam supply header 3, and can respond quickly to sudden situations such as pressure fluctuations. By automatically adjusting the steam flow direction and heating process, it ensures the stability and reliability of the steam supply parameters.

[0040] according to Figure 2 As shown, the steam supply valve 12 and the heating network regulating valve 2 are configured to switch between heating network frequency regulation and molten salt thermal storage frequency regulation based on the grid frequency regulation demand. When the grid frequency regulation demand increases, heating network frequency regulation is used, and the grid load is rapidly regulated by adjusting the opening of the heating network regulating valve 2. When the grid frequency regulation demand decreases, molten salt thermal storage frequency regulation is used, utilizing the high heat storage density and stability of molten salt to store thermal energy during periods of low grid load, while also compensating for steam fluctuations during heating network frequency regulation.

[0041] In this embodiment, a forced circulation pump 13 is provided between the steam drum 9 and the water supply system 10. The purpose is to ensure that the steam water level in the steam drum 9 can be stably maintained within a predetermined normal range. This is because the water level in the steam drum 9 is directly related to the safe operation and efficiency of the entire system. If the water level is too high, it may cause water to be carried in the steam, thereby affecting the steam quality and damaging the equipment. If the water level is too low, it may cause dry burning, resulting in equipment damage or even safety accidents. Therefore, the forced circulation pump 13 is introduced. Its main function is to actively regulate the water level in the steam drum 9 by increasing the flow rate and power of the water circulation. Specifically, when the dispatch control platform 5 detects that the water level in the steam drum 9 exceeds the set upper limit, it will start the forced circulation pump 13 to control the water level.

[0042] In this embodiment, a water flow regulating valve 14 is provided between the water supply system 10 and the phase change heat storage unit 6. The water flow regulating valve 14 is a component connecting the water supply system 10 and the phase change heat storage unit 6. Its main function is to dynamically adjust and control the water flow rate according to the requirements of the scheduling and control platform 5 or preset conditions, so as to realize precise water flow control between the water supply system 10 and the phase change heat storage unit 6, thereby improving the heat storage efficiency and system stability.

[0043] Implementation, for example Figure 1 As shown, the turbine generator set 4 converts the thermal energy of steam into mechanical energy, which in turn drives the generator to generate electrical energy, providing power support for the heating network. In this embodiment, when heating network frequency regulation is adopted, the dispatch control platform 5 calculates the amount of power that needs to be adjusted according to the grid dispatch instructions, and then changes the flow and resistance characteristics of the heating network by adjusting the opening of the heating network regulating valve 2, thereby affecting the energy consumption of the heating equipment in the heating network, so as to achieve the purpose of frequency regulation.

[0044] In this embodiment, the dispatch control platform 5 includes an instruction receiving module, an analysis module, a calculation module, a dispatch control module, and a pressure analysis module. The instruction receiving module is used to receive power grid dispatch instructions.

[0045] Analysis module: Analyzes the status of the electric heating in the heating network regulating valve 2 and the molten salt thermal storage unit 1 in the system, and analyzes whether the system is in a state of increased or decreased grid frequency regulation demand, or is in the process of decreasing grid frequency regulation demand.

[0046] The calculation module analyzes the amplitude that the calculation system needs to adjust and converts the frequency-modulated power signal into an executable valve opening degree and electric heater load signal.

[0047] Transportation control module: It achieves the tracking of target values ​​through invocation and control.

[0048] Pressure analysis module: Real-time detection of heating network pressure fluctuations, automatic stabilization of the heating network using molten salt thermal storage unit 1, and activation of the feedwater system 10 in molten salt thermal storage unit 1 to generate new steam when the steam volume in steam drum 9 is insufficient.

[0049] When using, Figure 3 As shown, when the grid frequency regulation demand increases, the dispatch control platform 5 analyzes the grid dispatch instructions and calls the heating network for frequency regulation. The heating network regulating valve 2 is used to track the grid dispatch instructions. When the grid needs to increase further, the heating network regulating valve 2 is closed. When the grid demand decreases, the heating network regulating valve 2 is fully opened. The steam supply fluctuations during the opening and closing of the heating network regulating valve 2 are self-stabilized by the molten salt thermal storage unit 1 to maintain stable steam supply.

[0050] When the grid frequency regulation demand decreases, the steam supply valve 12 is opened. The dispatch control platform 5 analyzes the grid dispatch instructions and calls the electric heaters in the phase change thermal storage unit 6 and the high-temperature molten salt tank 7 to start and increase the load. When the grid frequency regulation demand decreases further, the power of the electric heaters decreases. During this process, the molten salt thermal storage unit 1 can be charged at the same time. When steam fluctuations occur in the steam supply header 3, the steam stored in the steam drum 9 is heated to the required steam quality by the superheater 8 and then sent to the steam supply header 3 for steam supply, so as to achieve self-stabilization of the steam supply fluctuation pressure. When the steam stored in the steam drum 9 is insufficient, the feedwater system 10 is started. After being heated by the phase change thermal storage unit 6, saturated steam is generated and sent to the steam drum 9 for storage. The heat source of the superheater 8 comes from the high-temperature molten salt tank. After releasing heat, the low-temperature salt in the high-temperature molten salt tank is sent to the phase change thermal storage unit 6 for storage.

[0051] The specific example uses a 2x330MW coal-fired power plant unit as an example. The turbines are 17.75 / 540 / 540 type subcritical, single-stage reheat, three-cylinder, two-exhaust condensing turbines. After heating system modification, steam can be extracted from the cold and hot sections of the turbines to supply heat externally, with a total designed heating steam capacity of 140T / h for both units. The regulation capacity of the two units is only 1%Pe / min, that is, a total regulation capacity of 6.6MW / min. By coupling the combined energy storage coupled heating network frequency regulation auxiliary power plant unit system and method of this invention, the regulation capacity is increased by nearly 2.5 times after the total capacity reaches 10MW.

[0052] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0053] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

[0056] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Rather, the embodiments of this application include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0057] Examples of this application are described in detail below, with examples shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The examples described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

Claims

1. A method for a combined energy storage coupled with a heating network frequency regulation auxiliary thermal power unit system, characterized in that, include: The dispatch control platform includes an instruction receiving module, an analysis module, a calculation module, a dispatch control module, and a pressure analysis module. The steam turbine generator set is connected at one end to the dispatch control platform and at the other end to the steam supply main pipe. The molten salt thermal storage unit is connected to the dispatch control platform at one end and to the steam supply header at the other end. The molten salt thermal storage unit includes a feedwater system, a phase change thermal storage unit connected to the feedwater system, a high-temperature molten salt tank, a steam drum, and a superheater. The phase change thermal storage unit is connected to the high-temperature molten salt tank. One end of the steam drum is connected to the superheater, and the other end is connected to the phase change thermal storage unit. The superheater is connected to the phase change thermal storage unit and also to the high-temperature molten salt tank. A pressure self-balancing check valve and a steam supply valve are installed sequentially between the superheater and the steam supply header in the direction of steam flow. When the demand for grid frequency regulation increases, the dispatch control platform analyzes the grid dispatch instructions and calls the heating network for frequency regulation. According to the grid dispatch instructions, it controls the opening and closing of the heating network regulating valve. During the opening and closing of the heating network regulating valve, the molten salt thermal storage unit is used to supplement steam to achieve stable steam supply. When the grid frequency regulation demand decreases, the steam supply valve is opened, the dispatch control platform analyzes the grid dispatch instructions and starts the phase change thermal storage and heat transfer unit electric heating and load increase. When the grid frequency regulation demand decreases further, the phase change thermal storage and heat transfer unit electric heating power decreases, and at the same time, steam is supplemented to the molten salt thermal storage unit to compensate for steam fluctuations when the grid frequency regulation demand increases.

2. The method for a combined energy storage coupled heating network frequency regulation auxiliary thermal power unit system according to claim 1, characterized in that, Heating components are provided in both the phase change thermal storage unit and the high-temperature molten salt tank.

3. The method for a combined energy storage coupled heating network frequency regulation auxiliary thermal power unit system according to claim 2, characterized in that, A forced circulation pump is installed between the steam drum and the water supply system.

4. The method for a combined energy storage coupled heating network frequency regulation auxiliary thermal power unit system according to claim 1, characterized in that, A water flow regulating valve is installed between the water supply system and the phase change thermal storage unit.

5. The method for a combined energy storage coupled heating network frequency regulation auxiliary thermal power unit system according to claim 1, characterized in that, The steam replenishment process is as follows: when steam fluctuations occur in the main heating network pipe, the steam stored in the steam drum is heated by the heat exchanger and sent to the main heating network pipe for steam replenishment to achieve stable steam supply.

6. The method for a combined energy storage coupled heating network frequency regulation auxiliary thermal power unit system according to claim 1, characterized in that, When the steam in the steam drum is insufficient, the feedwater system is started, and the saturated steam generated by the phase change heat storage unit is sent to the steam drum for storage; the high-temperature molten salt storage tank provides a heat source for the superheater.

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