Turbine power generation system and method for supercritical carbon dioxide cycle combined heat and power generation

Abstract

The invention discloses a supercritical carbon dioxide cycle combined heat and power generation turbine power generation system and method. The system comprises a high-pressure turbine, a boiler, a low-pressure turbine, a high-temperature heat regenerator, a low-temperature heat regenerator, a main compressor, a re-compressor, a power generator and a heat supply network heater. In the system, a low-pressure turbine is connected with a generator, and a high-pressure turbine is connected with a main compressor and a re-compressor. And a heat supply network heater is connected between the low-temperature heat regenerator bypass loops. The cooler cold side is connected with the heating network heater cold side. The high-pressure turbine drives the main compressor and the re-compressor to rotate, so that the power generation efficiency can be improved; the temperature of heating cooling water is increased by recycling and circulating heat discharged to the outside through the cooler and utilizing heat of a bypass loop of the low-temperature heat regenerator, and the heating function is achieved synchronously. The efficiency of the heat regenerator is improved by reasonably distributing the flow distribution proportion of the main branch. According to the system, through an efficient rotating machine arrangement scheme and heat recovery and utilization, the comprehensive utilization rate of energy is increased, and good cogeneration performance is shown.

Description

Technical Field

[0001] The invention belongs to the technical field of waste heat recovery and power generation, and relates to a turbine power generation system and method for supercritical carbon dioxide cycle cogeneration. Background Art

[0002] As an important part of energy supply, coal-fired units play a key role in electricity production and heating services. By adjusting the power generation, these units can effectively cope with the fluctuations in energy demand in different periods, especially during the heating season, and can stably provide the necessary heat.

[0003] However, with the large-scale grid connection of renewable energy, the power system faces unprecedented scheduling challenges. Coal-fired cogeneration units not only need to maintain stable heat output, but also need to play a more active role in grid peak regulation. Traditional coal-fired cogeneration units mostly use steam Rankine cycle, which involves a complex phase change process, resulting in a slow response of the system to load changes, making it difficult to meet the current power system's needs for flexibility and rapid response capabilities.

[0004] In this context, the supercritical carbon dioxide Brayton cycle, as an innovative energy conversion system, has gradually attracted the attention of the industry. Unlike the steam Rankine cycle, the supercritical carbon dioxide Brayton cycle maintains a supercritical state throughout the entire working process, avoiding the phase change process, thereby significantly improving the response speed and regulation ability of the system. Therefore, this new cycle system is regarded as an ideal choice to replace the traditional steam Rankine cycle and realize the upgrade of the energy conversion system of coal-fired boilers.

[0005] Despite this, there are still many technical challenges in applying the supercritical carbon dioxide Brayton cycle to coal-fired cogeneration units. Due to the fundamental differences in the cycle fluid and cycle type, the existing system configuration and workflow of the cogeneration unit based on the steam Rankine cycle cannot be directly transplanted to the supercritical carbon dioxide cycle system. In addition, current research on supercritical carbon dioxide cycles mainly focuses on power generation systems, while there are relatively few studies on cogeneration systems that meet both heating needs and grid peak load requirements.

[0006] Therefore, developing a supercritical carbon dioxide cogeneration system that can adapt to complex scheduling requirements and provide stable heating output has become a technical problem that needs to be solved urgently. Summary of the invention

[0007] The purpose of the present invention is to solve the technical problem that the traditional coal-fired steam Rankine cycle cogeneration unit in the prior art is difficult to meet the user's heating and power grid peak load demand, and to provide a supercritical carbon dioxide cycle cogeneration turbine power generation system and method.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: The first aspect of the present invention provides a supercritical carbon dioxide cycle cogeneration turbine power generation system, comprising a high-pressure turbine, a boiler, a low-pressure turbine, a high-temperature regenerator, a low-temperature regenerator, a main compressor, a recompressor and a generator; The main gas outlet of the boiler is connected to the inlet of the high-pressure turbine; the outlet of the high-pressure turbine is connected to the reheat gas inlet of the boiler; the reheater outlet of the boiler is connected to the inlet of the low-pressure turbine; the outlet of the low-pressure turbine is connected to the hot side inlet of the high-temperature regenerator; the hot side outlet of the high-temperature regenerator is connected to the hot side inlet of the low-temperature regenerator, and the hot side outlet of the low-temperature regenerator is respectively connected to the inlet of the main compressor and the inlet of the recompressor; the outlet of the main compressor is connected to the cold side inlet of the low-temperature regenerator; the cold side outlet of the low-temperature regenerator is connected to the cold side inlet of the high-temperature regenerator, and the cold side outlet of the high-temperature regenerator is connected to the main gas inlet of the boiler; the low-pressure turbine is connected to the generator; the cold side inlet of the high-temperature regenerator is connected to the economizer of the boiler; the economizer of the boiler is connected to the main gas inlet of the boiler.

[0009] Furthermore, a cooler is provided between the hot side outlet of the low-temperature regenerator and the inlet of the main compressor.

[0010] Furthermore, the hot side inlet of the cooler is connected to the hot side outlet of the low-temperature regenerator, and the hot side outlet of the cooler is connected to the inlet of the main compressor.

[0011] Furthermore, the outlet of the main compressor is also connected to a heat network heater; the outlet of the main compressor is connected to the hot side outlet of the heat network heater; the hot side inlet of the heat network heater is connected to the economizer inlet of the boiler; the economizer outlet of the boiler is connected to the cold side outlet of the high-temperature regenerator.

[0012] Furthermore, the hot side inlet of the heat network heater is also connected to the cold side inlet of the high temperature regenerator.

[0013] Furthermore, the cold side of the heating network heater is connected to the heating network.

[0014] Furthermore, the outlet of the recompressor is connected to the cold side inlet of the high-temperature regenerator.

[0015] Furthermore, the high-pressure turbine is coaxially connected to the main compressor and the re-compressor.

[0016] Furthermore, the low-pressure turbine is coaxially connected to the generator.

[0017] A second aspect of the present invention provides a supercritical carbon dioxide cycle cogeneration turbine power generation method, comprising the following steps: The high-temperature flue gas generated by the boiler transfers heat to the supercritical carbon dioxide to obtain high-temperature and high-pressure supercritical carbon dioxide; The high-temperature and high-pressure supercritical carbon dioxide enters the high-pressure turbine to perform work and then enters the boiler for reheating; the reheated supercritical carbon dioxide enters the low-pressure turbine to perform work and then enters the high-temperature regenerator and the low-temperature regenerator to release heat; After releasing heat, part of the supercritical carbon dioxide is cooled by the cooler and then enters the main compressor for compression and cooling, while the other part enters the re-compressor for compression and cooling; After being compressed and cooled by the main compressor, the supercritical carbon dioxide enters the low-temperature regenerator to absorb heat and increase its temperature; The supercritical carbon dioxide after absorbing heat and heating in the low-temperature regenerator is combined with the supercritical carbon dioxide after compression and cooling in the compressor and then divided into two streams. One stream enters the high-temperature regenerator to absorb heat and heat up, one stream enters the economizer of the boiler to absorb heat and heat up, and one stream enters the heating network heater to release heat and cool down. The gas that has been heated up by the high-temperature regenerator and the boiler economizer enters the boiler; The gas after being cooled down by the heat network heater enters the low-temperature regenerator to absorb heat and heat up; The cooling water passes through the cooler and the heat network heater in turn to absorb heat and increase its temperature.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a turbine power generation system for supercritical carbon dioxide cycle cogeneration, which uses supercritical carbon dioxide as a working medium, has excellent thermophysical properties under high pressure and high temperature conditions, and can effectively improve the cycle thermal efficiency. The high-pressure turbine and the low-pressure turbine respectively use the energy of high-temperature, high-pressure and medium-pressure exhaust steam to perform work, thereby realizing multi-stage utilization of energy and improving the energy conversion efficiency of the overall system. The high-temperature regenerator and the low-temperature regenerator are set up to effectively recover the exhaust steam heat discharged after the turbine performs work, which is used to preheat the carbon dioxide before entering the boiler, and at the same time precool the carbon dioxide before entering the main compressor and the recompressor, thereby reducing energy loss. The connection between the economizer and the cold side inlet of the high-temperature regenerator further utilizes the system waste heat, preheats the boiler feed gas, and improves the thermal efficiency of the boiler. The high-pressure turbine in the system drives the main compressor and the recompressor to rotate, thereby reducing external power consumption and mechanical energy loss, thereby not only improving the thermal efficiency of the system, but also improving the self-sufficiency of the system. The low-pressure turbine is directly connected to the generator, thereby enhancing the flexibility of the system.

[0019] Furthermore, the cooler not only reduces the compressor inlet temperature, but also provides additional heat recovery opportunities by discharging heat to the outside through the hot side. This part of heat can be used for the heating system, further improving the comprehensive utilization rate of energy. The high-temperature regenerator and low-temperature regenerator in the system work together to form a complete heat recovery and reuse system with the cooler, ensuring the maximum utilization of system energy.

[0020] Furthermore, a portion of the gas heated up by the low-temperature regenerator and the recompressor enters the heating network heater to heat the heating water preheated by the cooler, further increasing the temperature of the heating steam. By adjusting the flow distribution ratio of the gas after merging to the heating network heater, high-temperature regenerator, and economizer, the outlet temperature of the heating steam can be reasonably adjusted, and the heat exchange efficiency of the low-temperature regenerator and the high-temperature regenerator can be improved.

[0021] Furthermore, the present invention discloses a turbine power generation method for supercritical carbon dioxide cycle cogeneration, which utilizes the high-temperature flue gas generated by the boiler to transfer heat to the supercritical carbon dioxide to make it reach a high-temperature and high-pressure state. This process effectively utilizes the heat energy generated by the boiler and improves the energy conversion efficiency. The high-temperature and high-pressure supercritical carbon dioxide works in the high-pressure turbine and the low-pressure turbine, converts the heat energy into mechanical energy, and then drives the compressor to rotate and the generator to generate electricity, thereby realizing efficient energy conversion. After the reheated supercritical carbon dioxide enters the low-pressure turbine to work, it recovers heat through the high-temperature regenerator and the low-temperature regenerator, thereby reducing energy loss. The supercritical carbon dioxide after heat release enters the main compressor and the recompressor for compression and cooling respectively. This process not only provides conditions for subsequent heat absorption and heating, but also further improves the overall efficiency of the system through energy conversion during the compression process. The supercritical carbon dioxide after compression and cooling by the main compressor enters the low-temperature regenerator for heat absorption and heating, and merges with the supercritical carbon dioxide after compression and cooling by the recompressor and then splits, one part enters the high-temperature regenerator for heat absorption and heating, one part enters the economizer of the boiler for heat absorption and heating, and one part enters the heating network heater to heat the heating water. This design enables the heat to be flexibly distributed and utilized in the system, thus improving the adaptability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 This is a structural diagram of the turbine power generation system for supercritical carbon dioxide cycle cogeneration of the present invention.

[0024] Among them: 1-high pressure turbine; 2-boiler; 3-low pressure turbine; 4-high temperature regenerator; 5-low temperature regenerator; 6-cooler; 7-main compressor; 8-recompressor; 9-generator; 10-heat network heater. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention described and marked in the drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0028] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0029] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings: See also Figure 1The present invention provides a supercritical carbon dioxide cycle cogeneration turbine power generation system, including a high-pressure turbine 1, a boiler 2, a low-pressure turbine 3, a high-temperature regenerator 4, a low-temperature regenerator 5, a cooler 6, a main compressor 7, a recompressor 8, a generator 9 and a heat network heater 10.

[0032] As one of the power sources of the system, the high-pressure turbine 1 has its inlet connected to the main gas outlet of the boiler 2, receiving high-temperature and high-pressure supercritical carbon dioxide gas for expansion and work. The outlet of the high-pressure turbine 1 is connected to the reheat gas inlet of the boiler 2, and the carbon dioxide gas after work is sent back to the boiler 2 for reheating.

[0033] The boiler 2 is used to heat and reheat the supercritical carbon dioxide gas to make it reach a state suitable for turbine expansion to do work. The main gas outlet of the boiler 2 is connected to the inlet of the high-pressure turbine 1, and the reheated gas outlet is connected to the inlet of the low-pressure turbine 3.

[0034] The low-pressure turbine 3 is used as a power generation turbine, receiving the supercritical carbon dioxide gas reheated by the boiler 2 to expand and perform work, thereby driving the generator 9 to generate electricity. The outlet of the low-pressure turbine 3 is connected to the hot side inlet of the high-temperature regenerator 4.

[0035] The high-temperature regenerator 4 is used to recover the heat of the carbon dioxide gas at the outlet of the low-pressure turbine 3 and preheat the carbon dioxide gas entering the boiler 2. Its hot side inlet is connected to the outlet of the low-pressure turbine 3, and its hot side outlet is connected to the hot side inlet of the low-temperature regenerator 5. The cold side inlet is connected to the outlet of the recompressor 8 and the carbon dioxide working medium outlet of the economizer of the boiler 2, and the cold side outlet is connected to the main gas inlet of the boiler 2.

[0036] The low-temperature regenerator 5 further recovers the heat of the carbon dioxide gas at the outlet of the high-temperature regenerator 4, and preheats the carbon dioxide gas and heating water entering the system. Its hot side inlet is connected to the hot side outlet of the high-temperature regenerator 4, and the hot side outlet is also connected to the hot side inlet of the cooler 6 and the inlet of the recompressor 8. The cold side inlet is connected to the outlet of the main compressor 7 and the hot side outlet of the heating network heater 10, and the cold side outlet is connected to the hot side inlet of the heating network heater 10, the cold side inlet of the high-temperature regenerator 4 and the carbon dioxide working medium inlet of the economizer of the boiler 2.

[0037] The cooler 6 is used to cool the carbon dioxide gas at the hot side outlet of the low temperature regenerator 5 to a temperature suitable for the inlet of the main compressor 7. Its hot side inlet is connected to the hot side outlet of the low temperature regenerator 5, and the hot side outlet is connected to the inlet of the main compressor 7. The cold side is connected to the cooling water inlet, and the cooling water outlet is connected to the cold side inlet of the heating network heater 10.

[0038] The main compressor 7 is used to compress the cooled carbon dioxide gas to a pressure suitable for the inlet of the boiler 2. Its inlet is connected to the hot side outlet of the cooler 6, and its outlet is connected to the hot side outlet of the heating network heater 10 and the cold side inlet of the low-temperature regenerator 5.

[0039] The recompressor 8 is used to further compress the carbon dioxide gas at the hot side outlet of the low temperature regenerator 5 to a pressure suitable for the cold side inlet of the high temperature regenerator 4. Its inlet is connected to the hot side outlet of the low temperature regenerator 5, and its outlet is connected to the cold side outlet of the low temperature regenerator 5.

[0040] The generator 9 is coaxially driven by the low-pressure turbine 3 and converts the mechanical energy generated by the turbine expansion work into electrical energy output.

[0041] The heating network heater 10 uses the heat of the carbon dioxide gas at the cold side inlet of the high temperature regenerator 4 to heat the heating water, realizing cogeneration of heat and power. Its hot side inlet is connected to the cold side inlet of the high temperature regenerator 4, and its hot side outlet is connected to the cold side inlet of the low temperature regenerator 5, that is, the heating network heater is distributed in the middle of the side branch loop on the cold side of the low temperature regenerator. The cold side inlet is connected to the cold side outlet of the cooler 6, and the cold side outlet is connected to the heating user end.

[0042] The working process / working principle of the present invention is as follows: The boiler working medium side is preheated by the flue gas heat release process after the combustion of gas / coal in the boiler 2, so that the supercritical carbon dioxide gas reaches a state suitable for turbine expansion to do work.

[0043] The supercritical carbon dioxide gas is heated to a high temperature and high pressure state in the boiler 2, and then enters the high pressure turbine 1 to expand and work, driving the main compressor 7 and the re-compressor 8. The carbon dioxide gas after work is reheated in the boiler 2, and then enters the low pressure turbine 3 to further expand and work, driving the generator 9 to generate electricity. The expanded carbon dioxide gas is successively passed through the high temperature regenerator 4 and the low temperature regenerator 5 for heat recovery, and finally divided into two paths, one path is cooled in the cooler 6 and then enters the main compressor 7 for compression, and the other path enters the re-compressor 8 for compression; the gas compressed by the main compressor 7 enters the low temperature regenerator 5 to absorb heat and heat up, and then merges with the gas compressed by the re-compressor 8; at the cold side outlet of the low temperature regenerator 5, the merged working fluid is split again, one enters the cold side of the high temperature regenerator 4 to absorb heat, one enters the hot side of the heat network heater 10 to release heat, and another enters the economizer of the boiler 2 to absorb heat. The carbon dioxide working fluid that releases heat through the heat network heater merges with the carbon dioxide working fluid compressed by the main compressor, and then enters the cold side inlet of the low temperature regenerator together. After the carbon dioxide working medium that has absorbed heat from the cold side of the high-temperature regenerator 4 and the economizer of the boiler 2 is combined, it enters the inlet of the main gas equipment of the boiler 2 together to complete a cycle.

[0044] In the heat network heater 10, the heat of the combined gas of the carbon dioxide at the cold side outlet of the low-temperature regenerator 5 and the carbon dioxide at the outlet of the recompressor 8 is used to heat the heating water, thereby realizing cogeneration of heat and power. After the heating water is heated by the heat network heater 10, it provides heat energy to the building through the heating user end.

[0045] The cooling water enters the cooler 6 through the cold side inlet of the cooler 6, absorbs the heat of the carbon dioxide gas discharged by the supercritical carbon dioxide cycle, enters the cold side of the heat network heater 10 through the cold side outlet of the cooler 6, further absorbs heat, and returns to the cold side inlet of the cooler 6 through the return water system at the heating user end, forming a cooling water cycle.

[0046] An embodiment of the present invention provides a turbine power generation method for supercritical carbon dioxide cycle cogeneration: the high-temperature flue gas in the boiler 2 transfers heat to the supercritical carbon dioxide, and then the high-temperature and high-pressure supercritical carbon dioxide enters the high-pressure turbine 1 to perform work; the medium-pressure exhaust steam discharged from the outlet of the high-pressure turbine 1 enters the boiler 2 again to absorb heat to the highest temperature and enters the low-pressure turbine 3 to perform work, and the exhaust gas after doing work enters the hot side of the high-temperature regenerator 4 and the hot side of the low-temperature regenerator 5 to release heat, and then splits, one stream is cooled on the hot side of the cooler 6 and enters the main compressor 7 for compression and cooling, the compressed fluid merges with a part of the fluid from the hot side of the heat network heater 10 After cooling, enters the cold side of the low-temperature regenerator 5 to absorb heat and heat up, and the other stream is directly compressed and cooled through the re-compressor 8, the two streams merge at the cold side outlet of the low-temperature regenerator 5 and are split again before entering the cold side inlet of the high-temperature regenerator 4, the first stream passes through the cold side of the high-temperature regenerator 4 to absorb heat and heat up, the second stream enters the economizer of the boiler 2 to absorb heat and heat up, and the third stream passes through the hot side of the heat network heater 10 to release heat and cool down. The first gas stream and the second gas stream meet at the hot side outlet of the high-temperature regenerator 4 and enter the main gas equipment inlet of the boiler 2 together.

[0047] Since the inlet temperature of the hot side of the cooler 6 is about 90°C, the waste heat discharged to the cold side of the cooler 6 by recycling the supercritical carbon dioxide cycle alone cannot heat the cooling water into steam at about 130°C. Therefore, the present invention adds a heat network heater 10 to achieve the heating steam temperature target. In order to improve the heat transfer efficiency of the heat network heater 10, it is considered to use the pipe section with the smallest temperature difference with the heating steam to provide heat for the heat network heater 10. The temperature difference between the gas after the working fluid at the cold side outlet of the low-temperature regenerator 5 and the working fluid at the outlet of the recompressor is combined and the heating steam is the smallest. Therefore, the working fluid at the cold side outlet of the low-temperature regenerator 5 is diverted, and one of the streams is used to release heat to the heat network heat exchanger 10 to change the water phase into steam and raise its temperature to the required temperature.

[0048] The cooling water enters the cold side of the cooler 6 and the cold side of the heating network heater 10 in turn, absorbs heat and becomes steam at about 130°C, which is then sent to the heating pipe. The hot side of the cooler 6 is used to release heat to preheat the cooling water, which recycles the waste heat discharged by the power generation system to the external environment and improves the comprehensive utilization efficiency of energy. The preheated cooling water is heated by the re-divided flow stream of the cold side bypass of the low-temperature regenerator, which can effectively increase its temperature to the steam temperature required for heating.

[0049] A high-pressure turbine 1 is used to drive the main compressor 7 and the re-compressor 8 to rotate, and a low-pressure turbine 3 is used to drive the generator 9 to generate electricity. This method can reduce the power consumption when the compressor is directly driven by an electric motor by dragging the turbine to drive the compressor, thereby improving the power generation efficiency.

[0050] The present invention can redistribute the flow rates on the hot and cold sides of the regenerator by reasonably adjusting the distribution ratio of each flow stream during gas diversion, thereby reducing the temperature difference between the hot and cold ends of the regenerator and improving the efficiency of the regenerator, so that the cogeneration system can maximize the power generation efficiency while ensuring heat supply and achieve efficient use of energy.

[0051] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A supercritical carbon dioxide cycle cogeneration turbine power generation system, characterized in that: It includes a high-pressure turbine (1), a boiler (2), a low-pressure turbine (3), a high-temperature regenerator (4), a low-temperature regenerator (5), a main compressor (7), a recompressor (8), a generator (9) and a heating network heater (10); The main gas outlet of the boiler (2) is connected to the inlet of the high-pressure turbine (1); the high-pressure turbine (1) is connected to the reheat gas inlet of the boiler (2); the reheat outlet of the boiler (2) is connected to the inlet of the low-pressure turbine (3); the outlet of the low-pressure turbine (3) is connected to the hot side inlet of the high-temperature regenerator (4); the hot side outlet of the high-temperature regenerator (4) is connected to the hot side inlet of the low-temperature regenerator (5), and the hot side outlet of the low-temperature regenerator (5) is connected to the inlet of the main compressor (7) and the inlet of the recompressor (8) respectively. ) inlet; the outlet of the main compressor (7) is connected to the cold side inlet of the low-temperature regenerator (5); the cold side outlet of the low-temperature regenerator (5) is connected to the cold side inlet of the high-temperature regenerator (4), and the cold side outlet of the high-temperature regenerator (4) is connected to the main gas inlet of the boiler (2); the low-pressure turbine (3) is connected to the generator (9); the cold side inlet of the high-temperature regenerator (4) is connected to the economizer of the boiler (2); and the economizer of the boiler (2) is connected to the main gas inlet of the boiler (2).

2. The supercritical carbon dioxide cycle cogeneration turbine power generation system according to claim 1, characterized in that: A cooler (6) is provided between the hot side outlet of the low-temperature regenerator (5) and the inlet of the main compressor (7).

3. The supercritical carbon dioxide cycle cogeneration turbine power generation system according to claim 2, characterized in that: The hot side inlet of the cooler (6) is connected to the hot side outlet of the low-temperature regenerator (5), and the hot side outlet of the cooler (6) is connected to the inlet of the main compressor (7).

4. The supercritical carbon dioxide cycle cogeneration turbine power generation system according to claim 1, characterized in that: The outlet of the main compressor (7) is also connected to a heat network heater (10); the outlet of the main compressor (7) is connected to the hot side outlet of the heat network heater (10); and the hot side inlet of the heat network heater (10) is connected to the economizer inlet of the boiler (2).

5. The supercritical carbon dioxide cycle cogeneration turbine power generation system according to claim 4, characterized in that: The hot side inlet of the heating network heater (10) is also connected to the cold side inlet of the high temperature regenerator (4).

6. The supercritical carbon dioxide cycle cogeneration turbine power generation system according to claim 4, characterized in that: The cold side of the heating network heater (10) is connected to the heating network.

7. The supercritical carbon dioxide cycle cogeneration turbine power generation system according to claim 1, characterized in that: The outlet of the recompressor (8) is connected to the cold side inlet of the high-temperature regenerator (4).

8. The supercritical carbon dioxide cycle cogeneration turbine power generation system according to claim 1, characterized in that: The high-pressure turbine (1) is coaxially connected to the main compressor (7) and the recompressor (8).

9. The supercritical carbon dioxide cycle cogeneration turbine power generation system according to claim 1, characterized in that: The low-pressure turbine (3) is coaxially connected to the generator (9).

10. A supercritical carbon dioxide cycle cogeneration turbine power generation method, characterized in that: The following steps are involved: The high-temperature flue gas generated by the boiler (2) transfers heat to the supercritical carbon dioxide to obtain high-temperature and high-pressure supercritical carbon dioxide; The high-temperature and high-pressure supercritical carbon dioxide enters the high-pressure turbine (1) to perform work and then enters the boiler (2) for reheating; the reheated supercritical carbon dioxide enters the low-pressure turbine (3) to perform work and then enters the high-temperature regenerator (4) and the low-temperature regenerator (5) for heat release; After releasing heat, part of the supercritical carbon dioxide enters the main compressor (7) for compression and cooling, and the other part enters the re-compressor (8) for compression and cooling; The supercritical carbon dioxide compressed and cooled by the main compressor (7) enters the low-temperature regenerator (5) to absorb heat and increase its temperature; The supercritical carbon dioxide after absorbing heat and increasing in temperature in the low-temperature regenerator (5) is combined with the supercritical carbon dioxide after being compressed and cooled in the recompressor (8) and then divided into two streams, one of which enters the high-temperature regenerator (4) to absorb heat and increase in temperature, one of which enters the economizer of the boiler (2) to absorb heat and increase in temperature, and one of which enters the heating network heater (10) to release heat and decrease in temperature; The gas that has been heated by the high-temperature regenerator (4) and the economizer of the boiler (2) enters the boiler (2); The gas after being cooled down by the heating network heater (10) enters the low-temperature regenerator (5) to absorb heat and increase its temperature; The cooling water, after absorbing heat and rising in temperature through the cooler (6) and the heating network heater (10), changes into heating steam.

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