A combined heat and power frequency modulation system and method of operation thereof

Abstract

This invention provides a combined heat and power (CHP) frequency regulation system and its operating method. The CHP frequency regulation system includes a CHP system, a steam ejector system, and a heat pump system. The CHP system includes a steam turbine, which is connected to a heating extraction valve, a thermal storage extraction valve, and a low-pressure extraction valve. The heating extraction valve is connected to the heat user. The steam ejector system includes a thermal storage tank and a steam ejector. The thermal storage extraction valve is connected to the thermal storage tank, which is connected to the high-pressure steam port of the steam ejector via a steam supply valve. The outlet of the steam ejector is connected to the heat user. The low-pressure extraction valve is connected to the heat pump system, and the low-pressure steam port of the steam ejector is connected to the heat pump system via a low-pressure steam valve. Thus, heat is supplied to the heat user through the combined heating extraction valve and steam ejector. The heat supply to the heat user can be adjusted according to the operating load of the CHP system, maintaining stable heat supply to the heat user and improving the frequency regulation performance of the CHP system.

Description

Technical Field

[0001] This invention relates to the technical field of combined heat and power (CHP) heating, specifically to a CHP frequency regulation system and its operating method. Background Technology

[0002] Currently, with the rapid development of new energy sources and the large-scale grid connection of wind and solar power units, the proportion of new energy power generation is increasing. However, due to the large daily fluctuations in the power supply of new energy sources over time, it is currently impossible to effectively predict the fluctuations in their output power. Therefore, the grid connection of new energy sources will cause fluctuations in the frequency of the power grid, affecting the power supply quality of the grid.

[0003] The power grid has put forward relevant requirements for thermal power units to participate in peak shaving and frequency regulation. Cogeneration units can supply electricity to electricity users and heat to heat users. Due to the "heat-determined electricity" characteristic of cogeneration units, their ability to participate in frequency regulation is limited. Therefore, it is urgent to improve the ability of cogeneration units to participate in frequency regulation while ensuring the stable supply of heat to heat users. Summary of the Invention

[0004] Therefore, in order to improve the frequency regulation performance of cogeneration units while ensuring a stable steam supply to heat users, this invention provides a cogeneration frequency regulation system and its operating method.

[0005] In a first aspect, the cogeneration frequency regulation system provided by the present invention includes:

[0006] A thermal power system, comprising a steam turbine connected to a heat supply extraction valve, a heat storage extraction valve, and a low-pressure extraction valve, wherein the heat supply extraction valve is connected to a heat user.

[0007] A steam ejector system includes a thermal storage tank and a steam ejector. The thermal storage extraction valve is connected to the inlet of the thermal storage tank, and a steam supply valve is connected to the outlet of the thermal storage tank. The steam supply valve is connected to the high-pressure steam port of the steam ejector, and a low-pressure steam valve is connected to the low-pressure steam port of the steam ejector. The outlet of the steam ejector is also connected to the heat user.

[0008] A heat pump system, wherein the low-pressure steam extraction valve is connected to the heat pump system, and the heat pump system is connected to the low-pressure steam valve.

[0009] Optionally, the thermoelectric system further includes: a condenser connected to the exhaust steam of the steam turbine, a condensate pump connected to the condenser outlet, a deaerator connected to the condensate pump, a feedwater pump connected to the deaerator, a high-pressure regenerative heater connected to the feedwater pump, and a boiler connected between the high-pressure regenerative heater and the steam turbine.

[0010] Optionally, the heat pump system includes:

[0011] The condenser has its heat exchanger steam inlet connected to the low-pressure extraction valve, and its heat exchanger steam outlet connected to a condensate pump.

[0012] The absorber has its heat exchanger steam inlet connected to the condenser via the condensate pump, and its heat exchanger steam outlet connected to the low-pressure steam valve.

[0013] The generator has its steam outlet connected to the steam inlet of the condenser, and its concentrated solution outlet connected to a solution pump.

[0014] The solution heat exchanger has its concentrated solution outlet connected to the concentrated solution inlet of the absorber, its concentrated solution inlet connected to the generator via the solution pump, its dilute solution inlet connected to the dilute solution outlet of the absorber, and its dilute solution outlet connected to a throttle valve, which is connected to the dilute solution inlet of the generator via the throttle valve.

[0015] Optionally, a heat source steam supply valve is connected to the outlet of the heat storage tank, and the heat source steam supply valve is connected to the heat exchanger inlet of the generator.

[0016] Optionally, the heat exchanger outlet of the generator is connected to the deaerator.

[0017] Optionally, the heat users include medium-pressure heat users and low-pressure heat users;

[0018] The heating steam extraction valve includes a medium-pressure heating steam extraction valve and a low-pressure heating steam extraction valve. The medium-pressure heating steam extraction valve is connected to the medium-pressure heat user, and the low-pressure heating steam extraction valve is connected to the low-pressure heat user.

[0019] The thermal storage tank includes a high-pressure thermal storage tank and a medium-pressure thermal storage tank; the steam supply valve includes a high-pressure steam supply valve connected to the high-pressure thermal storage tank and a medium-pressure steam supply valve connected to the medium-pressure thermal storage tank; the low-pressure steam valve includes a first low-pressure steam valve and a second low-pressure steam valve connected in parallel on the absorber.

[0020] The steam ejector includes a first steam ejector and a second steam ejector. The outlet of the first steam ejector is connected to the medium-pressure heat user, and the outlet of the second steam ejector is connected to the low-pressure heat user. The high-pressure steam supply valve is connected to the high-pressure steam port of the first steam ejector, and the first low-pressure steam valve is connected to the low-pressure steam port of the first steam ejector. The medium-pressure steam supply valve is connected to the high-pressure steam port of the second steam ejector, and the second low-pressure steam valve is connected to the low-pressure steam port of the second steam ejector.

[0021] Optionally, the heat source steam supply valve is connected to the high-pressure heat storage tank and is arranged in parallel with the high-pressure steam supply valve.

[0022] On the other hand, the operating method of the cogeneration frequency regulation system provided by the present invention includes the following steps:

[0023] Open the thermal storage steam extraction valve to supply steam into the thermal storage tank, and close the thermal storage steam extraction valve after the thermal storage tank is full;

[0024] When the steam turbine unit is operating at increased load, the heating extraction valve is adjusted to reduce the heat supply to the heat users, while the steam supply valve, low-pressure extraction valve and low-pressure steam valve are adjusted to increase the heat supply to the heat users by the steam ejector.

[0025] When the turbine unit is operating at reduced load, the heating extraction valve is widened to increase the heat supply to the heat users; while the steam supply valve, low-pressure extraction valve and low-pressure steam valve are narrowed to reduce the heat supply to the heat users by the first steam ejector and the second steam ejector.

[0026] Optionally, the working method further includes: adjusting the opening size of the low-pressure extraction valve to keep the flow rate entering the heat pump system stable.

[0027] The technical solution of this invention has the following advantages:

[0028] 1. The cogeneration frequency regulation system provided by the present invention, by setting up a heat storage tank, can store hot steam in the heat storage tank after opening the heat storage extraction valve. The steam in the heat storage tank is used as the high-pressure steam source of the steam ejector. A low-pressure extraction valve is set up and connected to the heat pump system. The low-pressure steam in the steam turbine is heated by the heat pump system and sent to the low-pressure steam port of the steam ejector as the low-pressure gas source of the steam ejector. Thus, the steam ejector can supply heat to the heat user together with the heating extraction valve. In this way, when the cogeneration system is operating at increased load, the heating extraction valve can be reduced to decrease the heat supply to users, allowing more steam to enter the turbine to perform work and increasing the power of the cogeneration system. At the same time, the low-pressure extraction valve and the supply valve can be increased to improve the heat supply from the steam ejector to users, ensuring stable heating for users. Conversely, when the cogeneration system is operating at reduced load, the heating extraction valve can be increased to improve the heat supply to users, reducing the power of the cogeneration system. At the same time, the low-pressure extraction valve and the supply valve can be reduced to decrease the heat supply from the steam ejector to users, ensuring stable heating for users.

[0029] 2. The cogeneration frequency regulation system provided by the present invention, in the heat pump system, reduces the temperature difference between the high-pressure steam and the low-pressure steam on both sides of the steam ejector by having the low-pressure steam extracted by the low-pressure extraction valve undergo two stages of preheating through the condenser and absorber, and uses the heat storage tank as the heat source of the generator to achieve cascade utilization of energy and improve energy utilization efficiency.

[0030] 3. The cogeneration frequency regulation system provided by the present invention connects the heat exchanger outlet of the generator to the deaerator water level, thereby controlling the flow rate into the condenser by adjusting the low-pressure extraction steam valve, and correspondingly adjusting the water level in the deaerator to ensure the stability of the water level in the deaerator.

[0031] 4. The operating method of the cogeneration frequency regulation system provided by the present invention adapts the heat supply steam extraction valve and steam ejector to the heat users based on the operating load of the cogeneration system, thereby improving the frequency regulation performance of the cogeneration system while maintaining stable heat supply to the heat users. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a cogeneration frequency regulation system provided in an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached drawings: 1. Boiler; 2. Steam turbine; 3. Condenser; 4. Condensate pump; 5. Deaerator; 6. Feedwater pump; 7. High-pressure regenerative heater; 8. High-pressure thermal storage extraction valve; 9. Medium-pressure thermal storage extraction valve; 10. Medium-pressure heating extraction valve; 11. Low-pressure heating extraction valve; 12. Low-pressure extraction valve; 13. Condenser; 14. Absorber; 15. Generator; 16. Condensate pump; 17. Solution heat exchanger; 18. Solution pump; 19. Throttling valve; 20. High-pressure thermal storage tank; 21. High-pressure steam supply valve; 22. First steam ejector; 23. First low-pressure steam valve; 24. Heat source steam supply valve; 25. Medium-pressure thermal storage tank; 26. Medium-pressure steam supply valve; 27. Second steam ejector; 28. Second low-pressure steam valve. Detailed Implementation

[0035] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] This embodiment provides a combined heat and power frequency regulation system, such as Figure 1 As shown, it includes: a thermoelectric system, a steam ejection system, and a heat pump system.

[0040] The thermal power system includes: boiler 1, steam turbine 2, condenser 3, deaerator 5, feedwater pump 6, and high-pressure regenerator.

[0041] Condenser 3 is connected to the exhaust steam of turbine 2 to condense and recover the water vapor discharged from turbine 2; condensate pump 4 is connected to the outlet of condenser 3 and is connected to the inlet of deaerator 5 through condensate pump 4; deaerator 5 is connected to feedwater pump 6 through feedwater pump 6 and is connected to high-pressure regenerative heater 7 through feedwater pump 6; high-pressure regenerative heater 7 is connected to boiler 1 through boiler 1 and is connected back to turbine 2.

[0042] The turbine 2 is equipped with a heat storage extraction valve, a heat supply extraction valve, and a low-pressure extraction valve 12. The heat supply extraction valve is connected to the heat user, so that some of the steam in the turbine 2 is sent to the heat user for heating. The heat storage extraction valve is connected to the steam ejection system, and the low-pressure extraction valve 12 is connected to the heat pump system.

[0043] The steam ejector system includes a thermal storage tank and a steam ejector. A thermal storage extraction valve is connected to the inlet of the thermal storage tank, storing steam from turbine 2 into the tank. The steam ejector has a high-pressure steam port, a low-pressure steam port, and an outlet. A steam supply valve is connected to the outlet of the thermal storage tank, and this valve is connected to the high-pressure steam port of the steam ejector. The steam supply valve controls the flow of steam from the thermal storage tank into the high-pressure steam port of the steam ejector, serving as the high-pressure steam source for the ejector. A low-pressure steam valve is connected to the low-pressure steam port of the steam ejector, and this valve is also connected to the heat pump system. This allows the low-pressure steam extracted by the low-pressure extraction valve 12 to be heated by the heat pump system before entering the low-pressure steam port of the steam ejector, serving as the low-pressure steam source for the ejector. The outlet of the steam ejector is also connected to the heat user, enabling heat to be supplied to the user through the coordinated operation of the heat supply extraction valve and the steam ejector.

[0044] The heat pump system includes: condenser 13, absorber 14, generator 15, solution heat exchanger 17, solution pump 18 and throttle valve 19. The heat pump system contains a heating low-pressure steam circuit and a heat pump working fluid circulation circuit.

[0045] In the heating low-pressure steam circuit, the heat exchanger steam inlet of condenser 13 is connected to low-pressure extraction valve 12, the heat exchanger steam outlet of condenser 13 is connected to heat exchanger steam inlet of absorber 14, and the heat exchanger steam outlet of absorber 14 is connected to a low-pressure steam valve, which is connected to the low-pressure steam port of the steam ejector, so that the low-pressure steam extracted from the low-pressure extraction valve 12 passes through condenser 13 and absorber 14 in sequence and then enters the steam ejector.

[0046] In the heat pump working fluid circulation loop, the steam outlet and concentrated solution outlet of generator 15 are connected to the steam inlet of condenser 13 and the inlet of solution pump 18, respectively. The outlet of solution pump 18 is connected to the concentrated solution inlet of solution heat exchanger 17, the concentrated solution outlet of solution heat exchanger 17 is connected to the concentrated solution inlet of absorber 14, the dilute solution outlet of absorber 14 is connected to the dilute solution inlet of solution heat exchanger 17, the dilute solution outlet of solution heat exchanger 17 is connected to the inlet of throttle valve 19, and the outlet of throttle valve 19 is connected to the dilute solution inlet of generator 15. A heat source steam supply valve 24 is also connected to the outlet of the heat storage tank, which is connected to the heat exchanger inlet of generator 15. The heat exchanger outlet of generator 15 is connected to deaerator 5.

[0047] The aforementioned heat pump system heats the dilute solution in generator 15 by introducing steam from the heat storage tank through the heat source steam supply valve 24. This steam evaporates the water in the dilute solution, which then enters condenser 13. The remaining concentrated solution is pumped by solution pump 18 into a solution heat exchanger, and then into absorber 14. The steam entering condenser 13 first heats the low-pressure steam in the heating low-pressure steam circuit and is condensed. It is then pumped by condensate pump 16 into absorber 14, where it mixes with the concentrated solution to form a dilute solution. This mixture releases heat, further heating the low-pressure steam in absorber 14. The dilute solution then passes through solution heat exchanger 17 and is returned to generator. This process achieves two-stage heating of the low-pressure steam before it enters the low-pressure steam port of the steam ejector.

[0048] By employing the aforementioned cogeneration frequency regulation system, during turbine 2 operation, the heating extraction valve is opened to fill the thermal storage tank with steam before closing it. When turbine 2 is operating at increased load, the heating extraction valve is closed to allow more steam to enter turbine 2 and perform work, thus increasing the unit's power output. Simultaneously, the steam supply valve is opened to allow more steam from the thermal storage tank to be supplied to heat users via the steam ejector. Conversely, when turbine 2 is operating at reduced load, the heating extraction valve is opened to reduce the amount of steam entering turbine 2 to perform work, allowing more steam to be delivered to heat users through the heating pipeline. The steam supply valve is then closed to reduce the heat supply from the steam ejector to heat users, and steam is appropriately replenished to the thermal storage tank. Thus, by adjusting the heat supply from the heating pipeline and the steam ejector to heat users, the total heat delivered to heat users is kept stable.

[0049] Furthermore, during the aforementioned adjustment process, since the amount of steam entering turbine 2 to perform work varies, the opening size of the low-pressure extraction valve 12 can be adjusted accordingly to maintain a stable flow rate into condenser 13 and to keep the water level in deaerator 5 stable, in order to avoid significant fluctuations in the condensate flow rate. In the heat pump system, the low-pressure steam is preheated in stages by condenser 13 and absorber 14, which reduces the temperature difference between the high-pressure steam and the low-pressure steam on both sides of the steam ejector, thus avoiding energy loss due to excessive temperature difference.

[0050] like Figure 1 As shown, in this embodiment, based on the heating pressure of different heat users, heat users include medium-pressure heat users and low-pressure heat users.

[0051] Correspondingly, the heating steam extraction valve includes a medium-pressure heating steam extraction valve 10 and a low-pressure heating steam extraction valve 11. The medium-pressure heating steam extraction valve 10 is connected to the medium-pressure heat user, and the low-pressure heating steam extraction valve 11 is connected to the low-pressure heat user.

[0052] The thermal storage tank includes a high-pressure thermal storage tank 20 and a medium-pressure thermal storage tank 25. The thermal storage extraction valves include a high-pressure thermal storage extraction valve 8 and a medium-pressure thermal storage extraction valve 9. The high-pressure thermal storage extraction valve 8 is connected to the high-pressure thermal storage tank 20 to store the high-pressure steam in the turbine 2 into the high-pressure thermal storage tank 20. The medium-pressure thermal storage extraction valve 9 is connected to the medium-pressure thermal storage tank 25 to store the medium-pressure steam in the turbine 2 into the medium-pressure thermal storage tank 25.

[0053] The steam ejector includes a first steam ejector 22 and a second steam ejector 27. The steam supply valves include a high-pressure steam supply valve 21 and a medium-pressure steam supply valve 26. The high-pressure steam port of the first steam ejector 22 is connected to the high-pressure heat storage tank 20 via the high-pressure steam supply valve 21, and the outlet of the first steam ejector 22 is connected to the medium-pressure heat user, making the steam in the high-pressure heat storage tank 20 the high-pressure steam source for the first steam ejector 22. The high-pressure steam port of the second steam ejector 27 is connected to the medium-pressure heat storage tank 25 via the medium-pressure steam supply valve 26, and the outlet of the second steam ejector 27 is connected to the low-pressure heat user, making the steam in the medium-pressure heat storage tank 25 the high-pressure steam source for the second steam ejector 27. The heat source steam supply valve 24 is connected to the high-pressure heat storage tank 20, meaning that the heat from the high-pressure heat storage tank 20 is used as the heat source for the generator 15.

[0054] The low-pressure steam valve includes a first low-pressure steam valve 23 and a second low-pressure steam valve 28. The first low-pressure steam valve 23 and the second low-pressure steam valve 28 are connected in parallel at the heat exchanger outlet of the absorber 14. The first low-pressure steam valve 23 is connected to the low-pressure steam port of the first steam ejector 22, and the second low-pressure steam valve 28 is connected to the low-pressure steam port of the second steam ejector 27, thereby sending low-pressure steam into the first steam ejector 22 and the second steam ejector 27 respectively.

[0055] Based on the cogeneration frequency regulation system described above, this embodiment also provides a method for operating the cogeneration frequency regulation system, the method comprising the following steps:

[0056] Open the high-pressure thermal storage extraction valve 8 and the medium-pressure thermal storage extraction valve 9 to supply high-pressure steam and medium-pressure steam to the high-pressure thermal storage tank 20 and the medium-pressure thermal storage tank 25 respectively. After the high-pressure thermal storage tank 20 and the medium-pressure thermal storage tank 25 are full, close the high-pressure thermal storage extraction valve 8 and the medium-pressure thermal storage extraction valve 9.

[0057] During the load increase process of turbine unit 2, the intermediate-pressure heating extraction valve 10 and the low-pressure heating extraction valve 11 are reduced to decrease the heat supply to the heat users, allowing more steam to enter turbine 2 to perform work; and the first high-pressure steam supply valve 21, the second high-pressure steam supply valve 21, the intermediate-pressure steam supply valve 26, the low-pressure extraction valve 12, the first low-pressure steam valve 23, and the second low-pressure steam valve 28 are increased to improve the heat supply to the heat users by the first steam ejector 22 and the second steam ejector 27.

[0058] During the load reduction process of turbine unit 2, the medium-pressure heating extraction valve 10 and the low-pressure heating extraction valve 11 are increased to improve the heat supply to heat users; while the first high-pressure steam supply valve 21, the second high-pressure steam supply valve 21, the medium-pressure steam supply valve 26, the low-pressure extraction valve 12, the first low-pressure steam valve 23, and the second low-pressure steam valve 28 are decreased to reduce the heat supply to heat users by the first steam ejector 22 and the second steam ejector 27.

[0059] During the adjustment process, the opening size of the low-pressure extraction valve 12 is adjusted appropriately to keep the flow rate entering the condenser 13 stable.

[0060] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A cogeneration frequency regulation system, characterized in that, include: A thermal power system, comprising a steam turbine (2) connected to a heating extraction valve, a heat storage extraction valve and a low-pressure extraction valve (12), wherein the heating extraction valve is connected to a heat user; A steam ejector system includes a thermal storage tank and a steam ejector. The thermal storage extraction valve is connected to the inlet of the thermal storage tank, and a steam supply valve is connected to the outlet of the thermal storage tank. The steam supply valve is connected to the high-pressure steam port of the steam ejector, and a low-pressure steam valve is connected to the low-pressure steam port of the steam ejector. The outlet of the steam ejector is also connected to the heat user. A heat pump system, wherein the low-pressure extraction valve (12) is connected to the heat pump system, and the heat pump system is connected to the low-pressure steam valve; The heat pump system includes: The condenser (13) has its heat exchanger steam inlet connected to the low-pressure extraction valve (12); The heat exchanger steam outlet of the absorber (14) and condenser (13) is connected to the heat exchanger steam inlet of the absorber (14), and the heat exchanger steam outlet of the absorber (14) is connected to the low-pressure steam valve. The generator (15) has its steam outlet connected to the steam inlet of the condenser (13), and its concentrated solution outlet is connected to a solution pump (18). The solution heat exchanger (17) has its concentrated solution outlet connected to the concentrated solution inlet of the absorber (14), its concentrated solution inlet connected to the generator (15) via the solution pump (18), its dilute solution inlet connected to the dilute solution outlet of the absorber (14), its dilute solution outlet connected to a throttle valve (19), and connected to the dilute solution inlet of the generator (15) via the throttle valve (19); The heat users include medium-pressure heat users and low-pressure heat users; The heating steam extraction valve includes a medium-pressure heating steam extraction valve (10) and a low-pressure heating steam extraction valve (11). The medium-pressure heating steam extraction valve (10) is connected to the medium-pressure heat user, and the low-pressure heating steam extraction valve (11) is connected to the low-pressure heat user. The heat storage tank includes a high-pressure heat storage tank (20) and a medium-pressure heat storage tank (25). The steam supply valve includes a high-pressure steam supply valve (21) connected to the high-pressure heat storage tank (20) and a medium-pressure steam supply valve (26) connected to the medium-pressure heat storage tank (25). The low-pressure steam valve includes a first low-pressure steam valve (23) and a second low-pressure steam valve (28) connected in parallel at the heat exchanger outlet of the absorber (14). The steam ejector includes a first steam ejector (22) and a second steam ejector (27). The outlet of the first steam ejector (22) is connected to the medium-pressure heat user, and the outlet of the second steam ejector (27) is connected to the low-pressure heat user. The high-pressure steam supply valve (21) is connected to the high-pressure steam port of the first steam ejector (22), and the first low-pressure steam valve (23) is connected to the low-pressure steam port of the first steam ejector (22). The medium-pressure steam supply valve (26) is connected to the high-pressure steam port of the second steam ejector (27), and the second low-pressure steam valve (28) is connected to the low-pressure steam port of the second steam ejector (27).

2. The cogeneration frequency regulation system according to claim 1, characterized in that, The cogeneration frequency regulation system further includes: a condenser (3) connected to the exhaust steam of the turbine (2), a condensate pump (4) connected to the outlet of the condenser (3), a deaerator (5) connected to the condensate pump (4), a feed water pump (6) connected to the deaerator (5), a high-pressure regenerative heater (7) connected to the feed water pump (6), and a boiler (1) connected between the high-pressure regenerative heater (7) and the turbine (2).

3. The cogeneration frequency regulation system according to claim 2, characterized in that, A heat source steam supply valve (24) is connected to the outlet of the heat storage tank, and the heat source steam supply valve (24) is connected to the heat exchanger inlet of the generator (15).

4. The cogeneration frequency regulation system according to claim 3, characterized in that, The heat exchanger outlet of the generator (15) is connected to the deaerator (5).

5. The cogeneration frequency regulation system according to claim 3, characterized in that, The heat source steam supply valve (24) is connected to the high-pressure heat storage tank (20) and is arranged in parallel with the high-pressure steam supply valve (21).

6. A method for operating a cogeneration frequency regulation system based on any one of claims 1-5, characterized in that, The working method includes the following steps: Open the thermal storage steam extraction valve to supply steam into the thermal storage tank, and close the thermal storage steam extraction valve after the thermal storage tank is full; When the turbine (2) unit is operating at increased load, reduce the heating extraction valve to decrease the heat supply to the heat user, and increase the steam supply valve, low-pressure extraction valve (12) and low-pressure steam valve to increase the heat supply to the heat user by the steam ejector. When the turbine (2) unit is operating at reduced load, the heating extraction valve is increased to improve the heat supply to the heat user; and the steam supply valve, low-pressure extraction valve (12) and low-pressure steam valve are decreased to reduce the heat supply to the heat user by the first steam ejector (22) and the second steam ejector (27).

7. The operating method of the cogeneration frequency regulation system according to claim 6, characterized in that, The working method further includes: adjusting the opening size of the low-pressure extraction valve (12) to keep the flow rate entering the heat pump system stable.

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