Supercritical carbon dioxide cycle power generation system and thermoelectric decoupling operation method thereof

Abstract

A cold side outlet of a heat regenerator is connected with an inlet of a boiler, an outlet of the boiler is connected with the air inlet side of a carbon dioxide unit, and the exhaust side of the carbon dioxide unit is connected with a hot side inlet of the heat regenerator; a hot side outlet of the heat regenerator is connected with an inlet of the cooler, an outlet of the cooler is connected with an inlet of the gas storage tank, an outlet of the gas storage tank is connected with an inlet of the compressor, and an outlet of the compressor is connected with the inlet of the gas storage tank; a turbine inlet of the carbon dioxide unit is connected with a turbine outlet of the carbon dioxide unit; a heat side outlet of the heat regenerator is connected with an inlet of a heat supply network air pump, an outlet of the heat supply network air pump communicates with an inlet of an auxiliary air heat exchanger, an outlet of the auxiliary air heat exchanger communicates with an inlet of a main system cooler, and the system and method can flexibly adjust the generating capacity and the heat supply capacity according to the power grid requirement and the heat load change.

Description

Technical Field

[0001] The present invention belongs to the technical field of supercritical carbon dioxide cycle power generation, and relates to a supercritical carbon dioxide cycle power generation system and a method for thermoelectric decoupling operation thereof. Background Art

[0002] Centralized heating in the north has a long history. However, as a common thermal power plant, the traditional "electricity determined by heat" mode greatly restricts the heat supply and power supply of the thermal power plant. The existing systems usually have difficulty in effectively decoupling thermal energy and electrical energy, which limits the adaptability and efficiency of the system under different working conditions.

[0003] Supercritical carbon dioxide cycle power generation systems have attracted attention due to their high efficiency and compact equipment layout. However, in terms of heat supply, their excellent peak shaving ability and flexible thermoelectric decoupling ability have been overlooked for a long time. There is great potential for the construction, commissioning, and operation of related systems. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art, and provide a supercritical carbon dioxide cycle power generation system and a method for thermoelectric decoupling operation thereof. The system and method can flexibly adjust the power generation and heat supply according to the grid demand and heat load changes.

[0005] To achieve the above purpose, the present invention discloses a supercritical carbon dioxide cycle power generation system, including a compressor, a recuperator, a boiler, a carbon dioxide unit, a cooler, a gas storage tank, a heat network gas pump, and an auxiliary gas heat exchanger;

[0006] The outlet of the compressor is connected to the cold-side inlet of the recuperator, the cold-side outlet of the recuperator is connected to the inlet of the boiler, the outlet of the boiler is connected to the intake side of the carbon dioxide unit, the exhaust side of the carbon dioxide unit is connected to the hot-side inlet of the recuperator, the hot-side outlet of the recuperator is connected to the inlet of the cooler, the outlet of the cooler is connected to the inlet of the gas storage tank, the outlet of the gas storage tank is connected to the inlet of the compressor, and the outlet of the compressor is connected to the inlet of the gas storage tank; the turbine inlet of the carbon dioxide unit is connected to the turbine outlet of the carbon dioxide unit;

[0007] The hot-side outlet of the recuperator is connected to the inlet of the heat network gas pump, the outlet of the heat network gas pump is connected to the inlet of the auxiliary gas heat exchanger, and the outlet of the auxiliary gas heat exchanger is connected to the inlet of the main system cooler.

[0008] The further improvement of the supercritical carbon dioxide cycle power generation system of the present invention lies in:

[0009] Further, the outlet of the compressor is connected to the inlet of the gas storage tank through a compressor bypass.

[0010] Further, the turbine inlet of the carbon dioxide unit is connected to the turbine outlet of the carbon dioxide unit through a turbine bypass.

[0011] Further, the cold side of the cooler is connected to the cooling unit.

[0012] Further, the hot side outlet of the regenerator is connected to the inlet of the heat network gas pump through a branch pipeline and the main circuit to the heat network circuit valve.

[0013] Further, the outlet of the heat network gas pump is divided into two paths. One path is connected to the inlet of the auxiliary gas heat exchanger through the heat network heat exchanger and the heat network heat exchanger regulating valve, and the other path is connected to the inlet of the auxiliary gas heat exchanger through the heat network heat exchanger bypass stop valve and the heat network heat exchanger bypass regulating valve.

[0014] Further, the outlet of the auxiliary gas heat exchanger is connected to the inlet of the main system cooler through the heat network circuit to the main circuit valve.

[0015] Further, a quick closing valve and a regulating valve are provided at the inlet of the carbon dioxide unit, and a check valve is provided at the outlet of the carbon dioxide unit.

[0016] Further, a circuit board type heat exchanger is selected for the cooler.

[0017] The present invention discloses a thermal electrolysis decoupling operation method for a supercritical carbon dioxide cycle power generation system, including the following steps:

[0018] The cold carbon dioxide output from the gas storage tank enters the compressor to be pressurized, and then enters the regenerator to be preheated and then enters the boiler to exchange heat and increase temperature;

[0019] The high-grade working medium after heat exchange output by the boiler enters the carbon dioxide unit to do work. The exhausted gas after work enters the hot side of the regenerator as a heat source to heat the working medium at the outlet of the compressor. The exhausted gas after heat exchange output by the regenerator is divided into two branches. One branch directly enters the cooler, and the other branch enters the heat network gas pump. The working medium output by the heat network gas pump enters the auxiliary gas heat exchanger through the heat network heat exchanger, and the working medium output by the auxiliary gas heat exchanger enters the cooler to be cooled, and then enters the gas storage tank to improve the efficiency and operation stability of the compressor.

[0020] The present invention has the following beneficial effects:

[0021] When the supercritical carbon dioxide cycle power generation system and its thermal-electric decoupling operation method of the present invention are specifically operated, when the electrical load demand increases and the thermal load demand decreases, the output of the compressor is increased, the inlet guide vane, the frequency converter frequency or the compressor bypass is adjusted according to the parameters of the compressor, the opening degree of the bypass regulating valve of the heat network heat exchanger is increased, and at the same time, the opening degree of the regulating valve of the heat network heat exchanger is decreased, and at the same time, the fuel quantity of the boiler is appropriately reduced; when the electrical load demand decreases and the thermal load demand increases, the compressor is made to reduce its output, the inlet guide vane, the frequency converter frequency or the compressor bypass is adjusted according to the parameters of the compressor, the compressor operates at its rated load and the compressor bypass is fully closed, realizing a thermal-electric decoupling operation mode different from the traditional "electricity determined by heat" in thermoelectricity, flexibly adjusting the power generation and heat supply according to the grid demand and the change of the thermal load, and improving the energy utilization efficiency and economy of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 It is a structural diagram of the present invention.

[0024] Among them, 1 is a compressor, 2 is a regenerator, 3 is a boiler, 4 is a carbon dioxide unit, 5 is a cooler, 6 is a gas storage tank, 7 is a cooling unit, 1by is a compressor bypass, 4by is a turbine bypass, 8 is a heat network gas pump, 9 is a heat network heat exchanger, 10 is an auxiliary gas heat exchanger 10, 8a is a main circuit to heat network circuit valve, 8b is a heat network circuit to main circuit valve, 9a is a regulating valve of the heat network heat exchanger, 9b is a bypass stop valve of the heat network heat exchanger, and 9c is a bypass regulating valve of the heat network heat exchanger. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] 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 some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "including" and "comprising" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0027] It should also be understood that the terms used in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the description of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0028] It should be further understood that the term "and / or" used in the description of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the preceding and following related objects.

[0029] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present invention to describe preset ranges, etc., these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0030] Depending on the context, the word "if" as used herein can be interpreted as "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detected (stated condition or event)" can be interpreted as "when determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)".

[0031] To make the objectives, 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 accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Generally, the components in the drawings described and shown in the embodiments of the present invention can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0032] Various structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0033] Embodiment 1

[0034] Reference Figure 1 , the supercritical carbon dioxide cycle power generation system according to the present invention includes a compressor 1, a recuperator 2, a boiler 3, a carbon dioxide unit 4, a cooler 5, a gas storage tank 6, a cooling unit 7, a compressor bypass 1by, a turbine bypass 4by, a heat network gas pump 8, a heat network heat exchanger 9, an auxiliary gas heat exchanger 10, a main circuit to heat network circuit valve 8a, a heat network circuit to main circuit valve 8b, a heat network heat exchanger regulating valve 9a, a heat network heat exchanger bypass stop valve 9b, and a heat network heat exchanger bypass regulating valve 9c;

[0035] The outlet of the compressor 1 is connected to the cold-side inlet of the recuperator 2, the cold-side outlet of the recuperator 2 is connected to the inlet of the boiler 3, the outlet of the boiler 3 is connected to the intake side of the carbon dioxide unit 4, the exhaust side of the carbon dioxide unit 4 is connected to the hot-side inlet of the recuperator 2, the hot-side outlet of the recuperator 2 is connected to the inlet of the cooler 5, the outlet of the cooler 5 is connected to the inlet of the gas storage tank 6, and the outlet of the gas storage tank 6 is connected to the inlet of the compressor 1. The outlet of the compressor 1 is connected to the inlet of the gas storage tank 6 through the compressor bypass 1by; the turbine inlet and the turbine outlet of the carbon dioxide unit 4 are connected through the turbine bypass 4by, and the cold side of the cooler 5 is connected to the cooling unit 7.

[0036] The hot-side outlet of the recuperator 2 is connected to the inlet of the heat network gas pump 8 through a branch pipeline and the main circuit to heat network circuit valve 8a. The outlet of the heat network gas pump 8 is divided into two paths. Among them, one path is connected to the inlet of the auxiliary gas heat exchanger 10 through the heat network heat exchanger 9 and the heat network heat exchanger regulating valve 9a, and the other path is connected to the inlet of the auxiliary gas heat exchanger 10 through the heat network heat exchanger bypass stop valve 9b and the heat network heat exchanger bypass regulating valve 9c. The outlet of the auxiliary gas heat exchanger 10 is connected to the inlet of the main system cooler 5 through the heat network circuit to main circuit valve 8b.

[0037] In this embodiment, the main compressor 1 only needs to meet the variable condition regulation ability, which can be achieved by forms such as but not limited to frequency converters and outlet guide vanes.

[0038] In this embodiment, the recuperator 2 selects a circuit board type heat exchanger with high adaptability to carbon dioxide and liquid metal.

[0039] In this embodiment, the form, layout, number of reheats, and type of fuel of the boiler 3 are determined according to the actual situation.

[0040] In this embodiment, a quick closing valve and a regulating valve are provided at the inlet of the carbon dioxide unit 4, and a check valve is provided at the outlet of the carbon dioxide unit 4; the sealing method is dry gas sealing.

[0041] In this embodiment, the cooler 5 is selected as a circuit board type heat exchanger; the selection of the cold source can be determined according to the actual situation.

[0042] In this embodiment, the gas storage tank 6 is selected as a closed pressure vessel with model parameters sufficient to meet the working pressure boundary of the system.

[0043] In this embodiment, the hot network gas pump 8 is selected as an axial flow compressor 1 capable of accommodating a large flow rate. It is recommended to select a frequency converter to increase the adjustment margin to meet the simultaneous adjustment of the total circulation flow rate on the hot network side and the pressure before the cooler 5 in the hot network loop.

[0044] In this embodiment, there are no special requirements for the models and heat exchange methods of the hot network heat exchanger 9 and the auxiliary gas heat exchanger 10, and only the basic heat exchange requirements need to be met. Regarding issues such as their quantity, layout, and whether to introduce an auxiliary gas system, etc., they can be determined according to the actual situation.

[0045] In this embodiment, the compressor bypass 1by and the turbine bypass 4by need to meet an adjustable range of 100% and have the ability to act quickly.

[0046] Embodiment 2

[0047] The present invention discloses a method for thermoelectric decoupling operation of a supercritical carbon dioxide cycle power generation system. The supercritical carbon dioxide cycle power generation system includes a compressor 1, a regenerator 2, a boiler 3, a carbon dioxide unit 4, a cooler 5, a gas storage tank 6, a cooling unit 7, a compressor bypass 1by, a turbine bypass 4by, a hot network gas pump 8, a hot network heat exchanger 9, an auxiliary gas heat exchanger 10, a main circuit to hot network circuit valve 8a, a hot network circuit to main circuit valve 8b, a hot network heat exchanger regulating valve 9a, a hot network heat exchanger bypass stop valve 9b, and a hot network heat exchanger bypass regulating valve 9c;

[0048] The method for thermoelectric decoupling operation of the supercritical carbon dioxide cycle power generation system includes the following steps:

[0049] During the system preparation stage, the external working fluid output by the gas storage tank 6 fills the main system through a pipeline. At this time, the turbine bypass 4by remains fully open, the main circuit to the heat network circuit valve 8a and the heat network circuit to the main circuit valve 8b are kept open according to the heating requirements, the heat network heat exchanger bypass stop valve 9b and the heat network heat exchanger bypass regulating valve 9c are kept open; the heat network heat exchanger regulating valve 9a is closed after the pressurization is completed.

[0050] Under the rated operating mode, the cold carbon dioxide output by the gas storage tank 6 (the working fluid parameters should be kept above the critical point, that is, the temperature is higher than 31.05 °C and the pressure is higher than 7.38 MPa) enters the compressor 1 to be pressurized, then enters the regenerator 2 to be preheated and then enters the boiler 3 for heat exchange and temperature rise. The heat source of the boiler 3 can be coal, natural gas or nuclear energy.

[0051] The high-grade working fluid after heat exchange output by the boiler 3 enters the carbon dioxide unit 4 to do work. The exhausted gas after work enters the hot side of the regenerator 2 as a heat source to heat the working fluid at the outlet of the compressor 1. The exhausted gas after heat exchange output by the regenerator 2 is divided into two branches. One branch directly enters the cooler 5, and the other branch enters the heat network gas pump 8 through the main circuit to the heat network circuit valve 8a. The working fluid output by the heat network gas pump 8 enters the auxiliary gas heat exchanger 10 through the heat network heat exchanger 9 and the heat network heat exchanger regulating valve 9a, or can also enter the auxiliary gas heat exchanger 10 through the heat network heat exchanger bypass stop valve 9b and the heat network heat exchanger bypass regulating valve 9c, serving as the heat source of the auxiliary steam system. The working fluid output by the auxiliary gas heat exchanger 10 enters the cooler 5 through the main circuit to the heat network circuit valve 8a to be cooled, and then enters the gas storage tank 6 to improve the efficiency and operating stability of the compressor 1.

[0052] When the power supply demand and the heating demand increase simultaneously, there is not much difference from the traditional thermal power generation in increasing the load. At this time, the output of the compressor 1 is increased, and at the same time, the fuel quantity of the boiler 3 is increased. The inlet working fluid parameters (temperature, pressure) of the carbon dioxide unit 4 increase, so the electric load and the heat load increase synchronously. On the contrary, when the power supply demand and the heating demand decrease simultaneously, the fuel quantity of the boiler 3 and the output of the compressor 1 are appropriately reduced, and the electric load and the heat load decrease synchronously.

[0053] Considering that most heat supply units adopt the "heat-determined power generation" mode in winter, in this context, when the heat supply demand is adjusted within a small range (below 10% of the rated load), the focus of operation should be concentrated on the opening relationship between the regulating valve 9a of the heat exchanger in the heat network loop and the bypass regulating valve 9c of the heat exchanger in the heat network. At this time, the adjustment of the two should be based on the valve characteristic curve, and according to the required heat supply, the opening ratio of the two should be adjusted. During the adjustment process, the main system may be disturbed by the instantaneous small-range pressure fluctuation in terms of electrical load or the rotational speed of the turbine in the carbon dioxide unit 4. The operator should strengthen the monitoring and intervention of relevant parameters. When necessary, an auxiliary gas system can be introduced to buffer the disturbance of the enthalpy value change in the heat network loop through the auxiliary gas heat exchanger 10.

[0054] When the power grid dispatching or heat network dispatching needs to adjust the power supply and heat supply output within a large range, it is necessary to reconstruct the "thermal power" balance of the system.

[0055] When the electrical load demand increases and the heat load demand decreases, the output of the compressor 1 is increased, and the inlet guide vane, frequency converter frequency or the compressor bypass 1by is adjusted according to the parameters of the compressor 1. The opening of the bypass regulating valve 9c of the heat exchanger in the heat network is increased, while the opening of the regulating valve 9a of the heat exchanger in the heat network is decreased, and at the same time, the fuel quantity of the boiler 3 is appropriately reduced. For this operating condition requirement, by adjusting the cooling capacity of the cooler 5, while reducing the disturbance of the working medium parameters at the inlet of the compressor 1, the operating point of the compressor 1 is made closer to the carbon dioxide critical point (31.05 °C, 7.38 MPa). According to the physical properties of carbon dioxide: approaching the critical point is equivalent to increasing the output power of the compressor 1.

[0056] On the contrary, when the electrical load demand decreases and the heat load demand increases, the system should preferably refer to the following adjustment method: reduce the output of the compressor 1, adjust the inlet guide vane, frequency converter frequency or the compressor bypass 1by according to the parameters of the compressor 1, and the circulating flow rate of the main system should be continuously monitored during the adjustment. When adjusting the compressor bypass 1by, consider the valve characteristic curve. When the compressor 1 is operating at the rated load and the compressor bypass 1by is fully closed, it is not recommended to reduce the output of the compressor 1 by opening the compressor bypass 1by, which is likely to cause overpressure at the inlet of the compressor 1, resulting in too high exhaust gas pressure and sudden drop of electrical load.

[0057] For the heat network loop, reduce the opening of the bypass regulating valve 9c of the heat exchanger in the heat network and increase the opening of the regulating valve 9a of the heat exchanger in the heat network. This method is only applicable to lower heat supply operating conditions.

[0058] Meanwhile, for the main system loop, the fuel quantity of the boiler 3 is moderately increased; for the changing working conditions, while reducing the disturbance of the heat network loop to the main system, especially the working medium parameters at the inlet of the compressor 1, by adjusting the cooling capacity of the cooler 5, the operating point of the compressor 1 is adjusted to deviate upward from the carbon dioxide critical point (31.05 °C, 7.38 MPa). According to the physical properties of carbon dioxide: being far from the critical point is equivalent to reducing the output power of the compressor 1.

[0059] It should be noted that when reconstructing the "thermal power" balance of the system, it is not recommended to adjust the output of the heat network air pump 8 over a large range to avoid affecting the change of the heat network water enthalpy value; avoid affecting the pressure after the valve 8b from the heat network loop to the main loop, avoid affecting the inlet pressure of the compressor 1 and even the load of the carbon dioxide unit 4 and the steady state of the entire system.

[0060] The adjustment of different auxiliary machines should be carried out separately to avoid over-adjustment leading to the system overpressure trip of the protection setting value. In addition, for the change of the working medium parameters at the inlet of the compressor 1 during the heat load adjustment, by default, in the supercritical carbon dioxide cycle power generation system, its parameters should be above the carbon dioxide critical point (31.05 °C, 7.38 MPa).

[0061] Those skilled in the art will readily conceive of other embodiments of the present invention upon considering the specification and the disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include known common knowledge or conventional technical means in the technical field not disclosed by the present invention. The specification and the embodiments are only regarded as exemplary, and the true scope and spirit of the present invention are pointed out by the following claims.

[0062] It should be understood that the present invention is not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

[0063] The above are only the preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent structural changes made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A supercritical carbon dioxide cycle power generation system, characterized in that: It comprises a compressor (1), a regenerator (2), a boiler (3), a carbon dioxide unit (4), a cooler (5), a gas storage tank (6), a heat network air pump (8) and an auxiliary gas heat exchanger (10); The outlet of the compressor (1) is connected to the cold side inlet of the regenerator (2), the cold side outlet of the regenerator (2) is connected to the inlet of the boiler (3), the outlet of the boiler (3) is connected to the air intake side of the carbon dioxide unit (4), the exhaust side of the carbon dioxide unit (4) is connected to the hot side inlet of the regenerator (2), the hot side outlet of the regenerator (2) is connected to the inlet of the cooler (5), the outlet of the cooler (5) is connected to the inlet of the gas storage tank (6), the outlet of the gas storage tank (6) is connected to the inlet of the compressor (1), and the outlet of the compressor (1) is connected to the inlet of the gas storage tank (6); the turbine inlet of the carbon dioxide unit (4) is connected to the turbine outlet of the carbon dioxide unit (4); The hot side outlet of the regenerator (2) is connected to the inlet of the heat network air pump (8), the outlet of the heat network air pump (8) is connected to the inlet of the auxiliary gas heat exchanger (10), and the outlet of the auxiliary gas heat exchanger (10) is connected to the inlet of the main system cooler (5).

2. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The outlet of the compressor (1) is connected to the inlet of the gas storage tank (6) through a compressor bypass (1by).

3. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The turbine inlet of the carbon dioxide unit (4) and the turbine outlet of the carbon dioxide unit (4) are connected via a turbine bypass (4by).

4. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The cold side of the cooler (5) is connected to a cooling unit (7).

5. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The hot side outlet of the regenerator (2) is connected to the inlet of the heat network air pump (8) via a branch pipeline and a main circuit to a heat network circuit valve (8a).

6. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The outlet of the heat network air pump (8) is divided into two paths, one of which is connected to the inlet of the auxiliary gas heat exchanger (10) via the heat network heat exchanger (9) and the heat network heat exchanger regulating valve (9a), and the other is connected to the inlet of the auxiliary gas heat exchanger (10) via the heat network heat exchanger bypass stop valve (9b) and the heat network heat exchanger bypass regulating valve (9c).

7. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The outlet of the auxiliary gas heat exchanger (10) is connected to the inlet of the main system cooler (5) through the heat network circuit to the main circuit valve (8b).

8. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The inlet of the carbon dioxide unit (4) is provided with a quick-closing valve and a regulating valve, and the outlet of the carbon dioxide unit (4) is provided with a check valve.

9. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The cooler (5) is a printed circuit board heat exchanger.

10. A method for thermoelectric decoupling operation of the supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The following steps are involved: The cold carbon dioxide output from the gas storage tank (6) enters the compressor (1) to increase the pressure, then enters the regenerator (2) to be preheated, and then enters the boiler (3) to exchange heat and increase the temperature; The high-quality working fluid after heat exchange outputted from the boiler (3) enters the carbon dioxide unit (4) to perform work, and the exhaust gas after the work enters the hot side of the regenerator (2) as a heat source to heat the outlet working fluid of the compressor (1). The exhaust gas after heat exchange outputted from the regenerator (2) is divided into two branches, one branch directly enters the cooler (5), and the other branch enters the heat network air pump (8). The working fluid outputted from the heat network air pump (8) enters the auxiliary gas heat exchanger (10) through the heat network heat exchanger (9). The working fluid outputted from the auxiliary gas heat exchanger (10) enters the cooler (5) to be cooled, and then enters the gas storage tank (6) to improve the efficiency and operation stability of the compressor (1).

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