A plant-level combined heat and power unit combined heat supply system and an operation method thereof

Abstract

The present application belongs to the technical field of combined heat and power generation, and discloses a plant-level combined heat and power generation unit combined heat supply system and an operation method thereof. The plant-level combined heat and power generation unit combined heat supply system comprises a first ejector, a second ejector, a heat storage heat exchanger, a heat storage device, a first ejector heater, an absorption heat pump, a peak heater, a compression heat pump and a basic heater group. In the present application, the heat network water is heated in the basic heater group, the first ejector heater, the absorption heat pump and the peak heater in stages, and then supplied to the outside, so that the heat exchange loss is reduced, the energy utilization efficiency is improved; by adopting the series connection of the basic heater group, the ejector and the heat pump, the low-temperature waste heat is fully utilized, the consumption of high-grade steam is reduced, and the heat supply cost is reduced; by adopting the heat storage technology and the compression heat pump auxiliary heat supply, the heat supply demand can still be met when the power plant participates in the grid peak regulation, and the heat supply capacity and the heat supply flexibility of the power plant are improved.

Description

Technical Field

[0001] This invention belongs to the field of combined heat and power technology, and specifically relates to a plant-level combined heat and power unit combined heating system and its operation method. Background Technology

[0002] Currently, with the high proportion and large-scale grid connection of renewable energy sources such as wind and solar power, traditional thermal power plants urgently need to undertake tasks such as peak shaving and frequency regulation to ensure the stable operation of the power grid. Thermal power is gradually transforming from a primary energy source to a basic energy source. At the same time, with the continuous advancement of industrialization and urbanization, the demand for centralized heating such as residential heating is growing rapidly, forcing thermal power units to develop towards a high heat-to-power ratio and high flexibility.

[0003] Given the above, the new challenge for cogeneration technology is to ensure heating demand while meeting the grid's peak-shaving needs. However, existing cogeneration technologies have low energy efficiency and poor heating flexibility, so developing a new cogeneration solution to improve the power plant's ability to participate in grid peak-shaving is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a plant-level combined heat and power (CHP) unit combined heating system and its operation method to solve one or more of the aforementioned technical problems. The technical solution provided by this invention can fully recover low-temperature waste heat from the system, ensuring heating demand while meeting the grid's peak-shaving requirements, and also possesses high energy utilization efficiency and good heating flexibility.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a combined heating system for a plant-level cogeneration unit, comprising: a No. 1 ejector, a No. 2 ejector, a heat exchanger, a heat storage device, a No. 1 ejector heater, an absorption heat pump, a peak heater, a compression heat pump, and a basic heater assembly; wherein...

[0007] Each heater in the basic heater group is used to connect to the exhaust port of multiple heating units; the cold-side fluid outlet of the basic heater group is divided into two paths, one path is connected to the cold-side fluid inlet of the No. 1 ejector heater, and the other path is connected to the cold-side fluid inlet of the compression heat pump.

[0008] The ejector fluid inlet of the No. 1 ejector, the evaporator low-temperature heat source end inlet of the absorption heat pump, and the evaporator low-temperature heat source end inlet of the compression heat pump are respectively used to connect to the exhaust steam header of the multiple heating units.

[0009] The power fluid inlet of the No. 1 ejector, the power fluid inlet of the No. 2 ejector, the hot-side fluid inlet of the peak heater, and the hot-side fluid inlet of the heat storage heat exchanger are respectively used to connect to the heating extraction steam header of the multiple heating units.

[0010] The outlet of the first ejector is divided into two paths: one path is connected to the steam inlet of the first ejector heater, and the other path is connected to the ejector fluid inlet of the second ejector; the outlet of the second ejector is connected to the driving steam inlet of the absorption heat pump; the cold-side fluid outlet of the first ejector heater is connected to the cold-side fluid inlet of the absorption heat pump, and the cold-side fluid outlet of the absorption heat pump is connected to the cold-side fluid inlet of the peak heater; the cold-side fluid outlet of the compression heat pump is connected to the cold-side fluid inlet of the peak heater.

[0011] The inlet of the thermal storage medium of the thermal storage device is connected to the cold-side fluid outlet of the thermal storage heat exchanger, and the outlet of the thermal storage medium of the thermal storage device is connected to the cold-side fluid inlet of the thermal storage heat exchanger; the cold-side fluid outlet of the thermal storage device is divided into three paths: the first path is connected to the power fluid inlet of the first ejector, the second path is connected to the power fluid inlet of the second ejector, and the third path is connected to the hot-side fluid inlet of the peak heater.

[0012] A further improvement of the present invention is that, in the basic heater group, each heater is connected in series according to the magnitude of the inlet steam pressure from small to large.

[0013] A further improvement of the present invention is that it also includes: multiple heating units;

[0014] The steam extracted from the heating units is fed into the heating extraction steam header, and the exhaust steam from the heating units is fed into the exhaust steam header.

[0015] A further improvement of the present invention is that,

[0016] The No. 1 injector is connected to the heating steam extraction main pipe by a No. 1 valve.

[0017] The No. 2 injector is connected to the heating steam extraction main pipe by a No. 2 valve.

[0018] A valve number three is installed on the connecting pipeline between the heat storage device and the second injector;

[0019] A fourth valve is installed on the connecting pipeline between the heat storage device and the peak heater;

[0020] The peak heater is equipped with valve number five on the pipeline that connects to the heating extraction steam main pipe;

[0021] A valve number six is ​​installed on the connecting pipeline between the basic heater group and the No. 1 injector heater;

[0022] A valve No. 7 is installed on the connecting pipeline between the basic heater group and the compression heat pump;

[0023] The heat storage device is connected to the No. 1 ejector by a valve No. 8.

[0024] A valve No. 9 is installed on the connecting pipe of the hot-side fluid inlet of the heat storage heat exchanger.

[0025] A further improvement of the present invention is that the cold-side fluid inlet of the heat storage device is used to connect to the makeup water pipeline of the multiple heating units.

[0026] A further improvement of the present invention is that the condensates of the basic heater group, the heat storage heat exchanger, the first ejector heater, the absorption heat pump, the peak heater, and the compression heat pump are used to flow into the condensers of the multiple heating units.

[0027] A further improvement of the present invention is that the absorption heat pump is a first type of absorption heat pump.

[0028] This invention provides an operation method for the above-mentioned plant-level cogeneration unit combined heating system. In the plant-level cogeneration unit combined heating system, a valve is installed on the pipeline connecting the No. 1 ejector to the heating extraction steam main pipe; a valve is installed on the pipeline connecting the No. 2 ejector to the heating extraction steam main pipe; a valve is installed on the pipeline connecting the thermal storage device to the No. 2 ejector; a valve is installed on the pipeline connecting the thermal storage device to the peak heater; a valve is installed on the pipeline connecting the peak heater to the heating extraction steam main pipe; a valve is installed on the pipeline connecting the basic heater group to the No. 1 ejector heater; a valve is installed on the pipeline connecting the basic heater group to the compression heat pump; a valve is installed on the pipeline connecting the thermal storage device to the No. 1 ejector; and a valve is installed on the pipeline connecting the hot-side fluid inlet of the thermal storage heat exchanger.

[0029] The operating method includes the following steps: When the outlet steam flow rate of the heating extraction steam header meets the requirements of ejector No. 1, ejector No. 2, peak heater and heat storage heat exchanger, valves No. 1, No. 2, No. 5, No. 9 and No. 6 are opened. The outlet steam of the heating extraction steam header enters ejector No. 1, ejector No. 2, peak heater and heat storage heat exchanger. The outlet steam of the exhaust steam header is injected into ejector No. 1 heater through ejector No. 1 to release heat. The outlet steam of ejector No. 1 is injected into absorption heat pump through ejector No. 2 to release heat. The return water of the heating network enters each heater of the basic heater group in sequence to be heated in stages, and is then exchanged in ejector No. 1 heater, absorption heat pump and peak heater in sequence before being supplied to the outside. The outlet steam from the heating extraction steam header enters heat storage heat exchanger to release heat, and the heat storage device stores heat.

[0030] A further improvement of the present invention is that the operating method further includes the following steps:

[0031] When the power plant participates in grid peak shaving and the steam flow rate at the outlet of the heating extraction steam header cannot meet the needs of No. 1 ejector, No. 2 ejector, and peak heater, valves No. 9, No. 8, No. 3, and No. 4 are opened to allow supplementary water to enter the thermal storage device for heating and to replenish the steam demand of No. 1 ejector, No. 2 ejector, and peak heater. When the heat stored in the thermal storage device cannot meet the heating demand, valve No. 7 is opened, and part of the outlet fluid of the basic heater group enters the compression heat pump to absorb heat, and then enters the peak heater to absorb heat to meet the external heating demand.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The plant-level combined heat and power (CHP) unit combined heating system provided by this invention organically combines CHP units with thermal storage technology, ejectors, and heat pump technology. It can fully recover low-temperature waste heat from the system, ensuring heating demand while meeting grid peak-shaving requirements, and possesses high energy utilization efficiency and good heating flexibility. Specifically, in this invention, the heating network water is heated in stages through the basic heater group, the No. 1 ejector heater, the absorption heat pump, and the peak heater before being supplied externally. This reduces heat exchange losses at each heat exchange stage and improves energy utilization efficiency. By employing a series-connected basic heater group, ejectors, and heat pump, this invention fully utilizes the low-temperature waste heat in the system, reducing the consumption of high-grade steam and lowering heating costs. Furthermore, by using thermal storage technology and compression heat pumps for auxiliary heating, this invention can still meet heating demands when the power plant participates in grid peak-shaving, improving the power plant's heating capacity and flexibility, and promoting the consumption of renewable energy. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below; obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of a combined heat and power (CHP) system for a plant-level cogeneration unit, provided in an embodiment of the present invention.

[0036] Figure 1 The annotations in the accompanying drawings are explained as follows:

[0037] 1. No. 1 ejector; 2. No. 2 ejector; 3. Heat exchanger; 4. Heat storage device; 5. No. 1 ejector heater; 6. Absorption heat pump; 7. Peak heater; 8. Compression heat pump;

[0038] 9. Valve No. 1; 10. Valve No. 2; 11. Valve No. 3; 12. Valve No. 4; 13. Valve No. 5; 14. Valve No. 6; 15. Valve No. 7; 16. Valve No. 8; 17. Valve No. 9;

[0039] 18. Basic heater assembly. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] The present invention will now be described in further detail with reference to the accompanying drawings:

[0043] Please see Figure 1 The present invention provides a plant-level combined heat and power (CHP) unit combined heating system, specifically comprising: a No. 1 ejector 1, a No. 2 ejector 2, a heat exchanger 3, a heat storage device 4, a No. 1 ejector heater 5, an absorption heat pump 6, a peak heater 7, a compression heat pump 8, and a basic heater group 18; wherein,

[0044] Each heater in the basic heater group 18 is used to connect to the exhaust port of multiple heating units; a further preferred embodiment is that the heaters in the basic heater group 18 are connected in series according to the inlet steam pressure from small to large.

[0045] The cold-side fluid outlet of the basic heater group 18 is divided into two paths: one path is connected to the cold-side fluid inlet of the first ejector heater 5, and the other path is connected to the cold-side fluid inlet of the compression heat pump 8.

[0046] The ejector fluid inlet of the first ejector 1, the evaporator low-temperature heat source end inlet of the absorption heat pump 6, and the evaporator low-temperature heat source end inlet of the compression heat pump 8 are respectively used to connect to the exhaust steam header of the multiple heating units; the power fluid inlet of the first ejector 1, the power fluid inlet of the second ejector 2, the hot-side fluid inlet of the peak heater 7, and the hot-side fluid inlet of the heat storage heat exchanger 3 are respectively used to connect to the heating extraction steam header of the multiple heating units.

[0047] The outlet of the first ejector 1 is divided into two paths: one path is connected to the steam inlet of the first ejector heater 5, and the other path is connected to the ejector fluid inlet of the second ejector 2; the outlet of the second ejector 2 is connected to the driving steam inlet of the absorption heat pump 6; the cold-side fluid outlet of the first ejector heater 5 is connected to the cold-side fluid inlet of the absorption heat pump 6, and the cold-side fluid outlet of the absorption heat pump 6 is connected to the cold-side fluid inlet of the peak heater 7; the cold-side fluid outlet of the compression heat pump 8 is connected to the cold-side fluid inlet of the peak heater 7.

[0048] The heat storage medium inlet of the heat storage device 4 is connected to the cold-side fluid outlet of the heat storage heat exchanger 3, and the heat storage medium outlet of the heat storage device 4 is connected to the cold-side fluid inlet of the heat storage heat exchanger 3; the cold-side fluid outlet of the heat storage device 4 is divided into three paths, one path is connected to the power fluid inlet of the first ejector 1, one path is connected to the power fluid inlet of the second ejector 2, and one path is connected to the hot-side fluid inlet of the peak heater 7.

[0049] In the above-described technical solution of this invention, the heating network water is heated in stages through the basic heater group, the No. 1 ejector heater, the absorption heat pump, and the peak heater before being supplied to the outside. This reduces heat exchange losses in each heat exchange stage and improves energy utilization efficiency. In addition, by using the basic heater group, ejector, and heat pump in series, the low-temperature waste heat in the system is fully utilized, reducing the consumption of high-grade steam and lowering heating costs. This invention employs thermal storage technology and compression heat pump-assisted heating, which can still meet heating needs when the power plant participates in grid peak shaving, improving the power plant's heating capacity and flexibility, and promoting the consumption of renewable energy.

[0050] Please see Figure 1 In a further preferred embodiment of the present invention, the invention further includes: multiple heating units;

[0051] The steam extracted from the multiple heating units is fed into the heating steam extraction header A, and the exhaust steam from the multiple heating units is fed into the exhaust steam header C; wherein...

[0052] The heating extraction steam header A is divided into four paths: one path is connected to the power fluid inlet of the first ejector 1, one path is connected to the power fluid inlet of the second ejector 2, one path is connected to the hot-side fluid inlet of the peak heater 7, and one path is connected to the hot-side fluid inlet of the heat storage heat exchanger 3.

[0053] The outlet of the exhaust header C is divided into three paths: one path is connected to the ejector fluid inlet of the first ejector 1, one path is connected to the low-temperature heat source inlet of the evaporator of the absorption heat pump 6, and one path is connected to the low-temperature heat source inlet of the evaporator of the compression heat pump 8.

[0054] Furthermore, when the steam extracted from the multiple heating units meets the pressure requirements of the peak heater 7, it is fed into the steam extraction header A.

[0055] In a further optional technical solution of this invention embodiment, a valve 9 is provided on the connecting pipeline between the heating extraction steam main pipe A and the first ejector 1; a valve 10 is provided on the connecting pipeline between the heating extraction steam main pipe A and the second ejector 2; a valve 13 is provided on the connecting pipeline between the heating extraction steam main pipe A and the peak heater 7; a valve 17 is provided on the connecting pipeline with the heat storage heat exchanger 3; a valve 16 is provided on the connecting pipeline between the heat storage device 4 and the first ejector 1; a valve 11 is provided on the connecting pipeline with the second ejector 2; a valve 12 is provided on the connecting pipeline with the peak heater 7; a valve 14 is provided on the connecting pipeline between the basic heater group 18 and the first ejector heater 5; and a valve 15 is provided on the connecting pipeline with the compression heat pump 8.

[0056] In the technical solution provided by the embodiments of the present invention, one path of the heat network return water passes sequentially through the basic heater group 18, the first ejector heater 5, the absorption heat pump 6, and the peak heater 7, while the other path is connected to the basic heater group 18, the compression heat pump 8, and the peak heater 7 in sequence through pipelines.

[0057] In a further optional embodiment of the present invention, the cold-side fluid inlet of the heat storage device 4 is connected to the makeup water pipeline of multiple heating units.

[0058] In a further optional embodiment of the present invention, the condensate from the basic heater group 18, the heat storage heat exchanger 3, the first ejector heater 5, the absorption heat pump 6, the peak heater 7, and the compression heat pump 8 is finely treated and then fed into the condenser of multiple heating units.

[0059] In a further optional embodiment of the present invention, the number of the plurality of heating units is ≥2.

[0060] In a further optional embodiment of the present invention, the absorption heat pump 6 is a first type of absorption heat pump.

[0061] An operation method for the above-mentioned plant-level combined heat and power unit combined heating system provided by the embodiments of the present invention specifically includes the following steps:

[0062] When the outlet steam flow of the heating extraction steam header A meets the requirements of No. 1 ejector 1, No. 2 ejector 2, peak heater 7 and heat storage heat exchanger 3, valves No. 1 9, No. 2 10, No. 5 13, No. 9 17 and No. 6 14 are opened. The outlet steam of the heating extraction steam header A enters No. 1 ejector 1, No. 2 ejector 2, peak heater 7 and heat storage heat exchanger 3. The outlet steam of the exhaust steam header C is injected into No. 1 ejector heater 5 through No. 1 ejector 1 to release heat. The outlet steam of No. 1 ejector 1 is injected into absorption heat pump 6 through No. 2 ejector 2 to release heat. The return water of the heating network enters each heater of the basic heater group 18 in sequence to be heated in stages, and absorbs heat in No. 1 ejector heater 5, absorption heat pump 6 and peak heater 7 in sequence before supplying heat to the outside. The outlet steam from the heating extraction steam header A enters the heat storage heat exchanger 3 to release heat, and the heat storage device 4 stores heat.

[0063] When the power plant participates in grid peak shaving and the steam flow at the outlet of the heating extraction steam header A cannot meet the needs of ejector 1, ejector 2, and peak heater 7, valves 17 (9), 16 (8), 11 (3), and 12 (4) are opened. Makeup water enters the thermal storage device 4, is heated, and then replenishes the steam demand of ejector 1, ejector 2, and peak heater 7. When the heat stored in the thermal storage device 4 cannot meet the heating demand, valve 15 (7) is opened. Part of the fluid at the outlet of the basic heater group 18 enters the compression heat pump 8 to absorb heat, and then enters the peak heater to absorb heat to meet the external heating demand. This system can improve the heating flexibility of the unit and cooperate with grid peak shaving.

[0064] In summary, this invention discloses a plant-level combined heat and power (CHP) unit combined heating system and its operation method. The system comprises multiple heating units, a No. 1 ejector, a No. 2 ejector, a thermal storage heat exchanger, a thermal storage device, a No. 1 ejector heater, an absorption heat pump, a peak heater, a compression heat pump, a basic heater group, a heating extraction steam header A, and an exhaust steam header C. The No. 1 and No. 2 ejectors are connected in series to extract exhaust steam from multiple heating units. The steam from the No. 2 ejector outlet drives the absorption heat pump. The heating network water is heated in stages in the various heaters of the basic heater group, the No. 1 ejector heater, the absorption heat pump, and the peak heater before being supplied externally, fully recovering the low-temperature waste heat in the system and reducing heating costs. Simultaneously, this invention employs thermal storage technology and a compression heat pump for auxiliary heating, which can assist the system in grid peak shaving, improving the power plant's heating capacity and flexibility, and promoting the consumption of renewable energy. This invention organically combines cogeneration units with thermal storage technology, ejectors, and heat pump technology, enabling full recovery of low-temperature waste heat from the system. It can meet the grid's peak-shaving requirements while ensuring heating demand, and boasts high energy efficiency and good heating flexibility. This invention can deeply explore the energy-saving potential of cogeneration power plants and improve their heating flexibility, which is of great significance for reducing cogeneration costs and enhancing the power plant's ability to participate in grid peak-shaving.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A combined heating system for a plant-level cogeneration unit, characterized in that, include: Ejector No. 1 (1), Ejector No. 2 (2), Heat exchanger (3), Heat storage device (4), Heater for Ejector No. 1 (5), Absorption heat pump (6), Peak heater (7), Compression heat pump (8), and basic heater group (18); among which, Each heater in the basic heater group (18) is used to connect to the exhaust port of multiple heating units; the cold side fluid outlet of the basic heater group (18) is divided into two paths, one path is connected to the cold side fluid inlet of the No. 1 ejector heater (5), and the other path is connected to the cold side fluid inlet of the compression heat pump (8). The ejector fluid inlet of the No. 1 ejector (1), the evaporator low-temperature heat source end inlet of the absorption heat pump (6), and the evaporator low-temperature heat source end inlet of the compression heat pump (8) are respectively used to connect to the exhaust steam header of the multiple heating units. The power fluid inlet of the first injector (1), the power fluid inlet of the second injector (2), the hot-side fluid inlet of the peak heater (7), and the hot-side fluid inlet of the heat storage heat exchanger (3) are respectively used to connect to the heating extraction steam header of the multiple heating units. The outlet of the first ejector (1) is divided into two paths: one path is connected to the steam inlet of the first ejector heater (5), and the other path is connected to the ejector fluid inlet of the second ejector (2); the outlet of the second ejector (2) is connected to the driving steam inlet of the absorption heat pump (6); the cold-side fluid outlet of the first ejector heater (5) is connected to the cold-side fluid inlet of the absorption heat pump (6), the cold-side fluid outlet of the absorption heat pump (6) is connected to the cold-side fluid inlet of the peak heater (7); the cold-side fluid outlet of the compression heat pump (8) is connected to the cold-side fluid inlet of the peak heater (7). The heat storage medium inlet of the heat storage device (4) is connected to the cold-side fluid outlet of the heat storage heat exchanger (3), and the heat storage medium outlet of the heat storage device (4) is connected to the cold-side fluid inlet of the heat storage heat exchanger (3); the cold-side fluid outlet of the heat storage device (4) is divided into three paths, the first path is connected to the power fluid inlet of the first ejector (1), the second path is connected to the power fluid inlet of the second ejector (2), and the third path is connected to the hot-side fluid inlet of the peak heater (7).

2. The combined heating system for a plant-level cogeneration unit according to claim 1, characterized in that, In the basic heater group (18), each heater is connected in series according to the inlet steam pressure from small to large.

3. The combined heating system for a plant-level cogeneration unit according to claim 1, characterized in that, Also includes: Multiple heating units; The steam extracted from the heating units is fed into the heating extraction steam header, and the exhaust steam from the heating units is fed into the exhaust steam header.

4. The combined heating system for a plant-level cogeneration unit according to claim 1, characterized in that, The No. 1 injector (1) is used to install a No. 1 valve (9) on the pipeline connected to the heating steam extraction main pipe; The second injector (2) is used to connect to the heating steam extraction main pipe and a second valve (10) is installed on the pipeline; A valve (11) is installed on the connecting pipeline between the heat storage device (4) and the second ejector (2); A fourth valve (12) is installed on the connecting pipeline between the heat storage device (4) and the peak heater (7); The peak heater (7) is equipped with valve No. 5 (13) on the pipeline connected to the heating extraction steam main pipe; A valve (14) is provided on the connecting pipeline between the basic heater group (18) and the first injector heater (5); A valve (15) No. 7 is provided on the connecting pipeline between the basic heater group (18) and the compression heat pump (8); The heat storage device (4) is connected to the No. 1 ejector (1) by a No. 8 valve (16); A valve (17) is installed on the connecting pipe of the hot side fluid inlet of the heat storage heat exchanger (3).

5. A plant-level combined heat and power unit combined heating system according to claim 1, characterized in that, The cold-side fluid inlet of the heat storage device (4) is used to connect to the makeup water pipeline of the multiple heating units.

6. The combined heating system for a plant-level cogeneration unit according to claim 1, characterized in that, The condensate drains from the basic heater group (18), the heat storage heat exchanger (3), the first ejector heater (5), the absorption heat pump (6), the peak heater (7), and the compression heat pump (8) are used to drain into the condensers of the multiple heating units.

7. The combined heating system for a plant-level cogeneration unit according to claim 1, characterized in that, The absorption heat pump (6) is a first-class absorption heat pump.

8. A method for operating a plant-level combined heat and power unit combined heating system as described in claim 1, characterized in that, In the combined heating system of the plant-level cogeneration unit, valve 9 is installed on the pipeline connecting the No. 1 ejector (1) to the heating extraction steam main pipe; valve 10 is installed on the pipeline connecting the No. 2 ejector (2) to the heating extraction steam main pipe; valve 11 is installed on the pipeline connecting the heat storage device (4) to the No. 2 ejector (2); valve 12 is installed on the pipeline connecting the heat storage device (4) to the peak heater (7); the peak heater (7) is used to connect with the heating extraction steam main pipe. A valve (13) is installed on the pipeline connecting the hot extraction steam header; a valve (14) is installed on the pipeline connecting the basic heater group (18) and the first ejector heater (5); a valve (15) is installed on the pipeline connecting the basic heater group (18) and the compression heat pump (8); a valve (16) is installed on the pipeline connecting the heat storage device (4) and the first ejector (1); a valve (17) is installed on the pipeline connecting the hot side fluid inlet of the heat storage heat exchanger (3). The operating method includes the following steps: When the outlet steam flow rate of the heating extraction steam header meets the requirements of ejector No. 1 (1), ejector No. 2 (2), peak heater (7), and heat storage heat exchanger (3), valves No. 1 (9), No. 2 (10), No. 5 (13), No. 9 (17), and No. 6 (14) are opened, and the outlet steam of the heating extraction steam header enters ejector No. 1 (1), ejector No. 2 (2), peak heater (7), and heat storage heat exchanger (3). The outlet steam of the exhaust steam header passes through a... The No. 1 ejector (1) is injected into the No. 1 ejector heater (5) to release heat. The outlet steam of the No. 1 ejector (1) is injected into the absorption heat pump (6) through the No. 2 ejector (2) to release heat. The return water of the heating network enters each heater of the basic heater group (18) in sequence to be heated in stages, and is then exchanged in the No. 1 ejector heater (5), absorption heat pump (6), and peak heater (7) in sequence before being supplied to the outside. The outlet steam from the heating extraction steam header enters the heat storage heat exchanger (3) to release heat, and the heat storage device (4) stores heat.

9. The operating method according to claim 8, characterized in that, It also includes the following steps: When the power plant participates in grid peak shaving and the steam flow rate at the outlet of the heating extraction steam header cannot meet the needs of No. 1 ejector (1), No. 2 ejector (2), and peak heater (7), valves No. 9 (17), No. 8 (16), No. 3 (11), and No. 4 (12) are opened to supplement water into the heat storage device (4) for heating and to supplement the steam demand of No. 1 ejector (1), No. 2 ejector (2), and peak heater (7); when the heat stored in the heat storage device (4) cannot meet the heating demand, valve No. 7 (15) is opened and some of the fluid at the outlet of the basic heater group (18) enters the compression heat pump (8) to absorb heat, and then enters the peak heater (7) to absorb heat to meet the external heating demand.

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