Supercritical carbon dioxide cycle recompression heat and power dual supply system and operating method

Abstract

The application belongs to the technical field of power generation, and discloses a supercritical carbon dioxide cycle recompression heat and electricity double supply system and an operation method. The system comprises a main compressor, a regenerative unit, a boiler, a turbine unit, a precooler, a recompression compressor, a heat supply compressor and a heater unit. The outlet of the main compressor is in communication with the regenerative unit, the outlet of the regenerative unit is connected to the boiler, the boiler is connected to the turbine unit, and the outlet of the turbine unit is connected to the regenerative unit. The precooler is connected to the regenerative unit, and the outlet of the precooler is in communication with the inlet of the main compressor. The recompression compressor and the heat supply compressor are both connected to the regenerative unit, and the heater unit is arranged between the heat supply compressor and the main compressor and between the regenerative unit and the main compressor. The working medium after being heated is used to heat the primary network water, so that the temperature of the primary network water supply meets the design requirements, and the working medium after heat release returns to the system, thereby reducing the disturbance of the regenerative system and ensuring the safe and stable operation of the system.

Description

Technical Field

[0001] This invention relates to the field of power generation technology, and in particular to a supercritical carbon dioxide recycle recompression thermoelectric dual-power system and its operation method. Background Technology

[0002] In recent years, supercritical carbon dioxide power cycles have attracted widespread attention from academia and industry due to their advantages of high efficiency, flexibility, and compactness. This technology has developed rapidly, moving from theoretical research to experimental verification, marking a significant step closer to industrial application. It has broad application prospects in coal-fired power generation, nuclear power, solar thermal power generation, and waste heat power generation. However, users such as residents, hospitals, office buildings, and industrial parks not only have electricity needs but also require other energy sources such as heat. Therefore, the single-function electricity production of supercritical carbon dioxide power generation technology cannot meet the diversified energy demands of users. Further research is needed on multi-energy production technologies for supercritical carbon dioxide power cycles, including electricity and heat, to meet user needs. Generally, the working fluid temperature at the cold end of a supercritical carbon dioxide power cycle is relatively high, reaching above 90℃, indicating potential for heat supply. However, the design temperature of the primary supply and return water in heating networks is around 120 / 70℃, while the working fluid at the cold end of the supercritical carbon dioxide cycle is too low to heat the network water to the design temperature, requiring additional peak-load heaters. Furthermore, the usable temperature range is relatively small, limiting the available heat capacity. Among the existing supercritical carbon dioxide power cycle cogeneration technologies, one method uses a heat pump to upgrade the heat of circulating water before supplying heat, which requires the construction of an additional heat pump heating system, making the system complex and requiring a large investment; the other method uses high-temperature exhaust gas from the turbine for heating, which significantly reduces the amount of heat recovery and the boiler inlet temperature, thus affecting the safe and stable operation of the boiler. Summary of the Invention

[0003] The purpose of this invention is to provide a supercritical carbon dioxide recirculation and recompression dual-power system and its operation method, in order to solve the problems of existing systems being complex, requiring large investments, and having significantly reduced heat recovery and boiler inlet temperature, which affect the safe and stable operation of the boiler.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] In a first aspect, the present invention provides a supercritical carbon dioxide recompression thermoelectric dual-supply system, comprising a main compressor, a regenerator unit, a boiler, a turbine unit, a precooler, a recompressor, a heating compressor, and a heater unit; the outlet of the main compressor is connected to the regenerator unit, the outlet of the regenerator unit is connected to the boiler, the boiler is connected to the turbine unit, and the outlet of the turbine unit is connected to the regenerator unit; the precooler is connected to the regenerator unit, and the outlet of the precooler is connected to the inlet of the main compressor; both the recompressor and the heating compressor are connected to the regenerator unit, and heater units are provided between the heating compressor and the main compressor, and between the regenerator unit and the main compressor.

[0006] Furthermore, the regenerative unit includes a low-temperature regenerator and a high-temperature regenerator. 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 boiler feed gas inlet. 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 connected to the precooler inlet.

[0007] Furthermore, the turbine unit includes a high-pressure turbine and a low-pressure turbine; the boiler main gas outlet is connected to the high-pressure turbine inlet, the high-pressure turbine outlet is connected to the boiler reheat inlet, the boiler reheat outlet is connected to the low-pressure turbine inlet, and the low-pressure turbine outlet is connected to the hot-side inlet of the high-temperature regenerator.

[0008] Furthermore, the hot-side outlet of the low-temperature regenerator is connected to the inlet of the recompressor, and the outlet of the recompressor is connected to the cold-side outlet of the low-temperature regenerator; the hot-side outlet of the low-temperature regenerator is connected to the inlet of the heating compressor.

[0009] Furthermore, the outlet of the re-compressor is connected to the inlet of the buffer tank, the outlet of the heating compressor is connected to the inlet of the buffer tank, and the outlet of the buffer tank is connected to the heater unit.

[0010] Furthermore, the heater unit includes a high-temperature heating network heater and a low-temperature heating network heater; the outlet of the buffer tank is connected to the hot-side inlet of the high-temperature heating network heater, and the hot-side outlet of the high-temperature heating network heater is connected to the outlet of the main compressor; the hot-side outlet of the low-temperature regenerator is connected to the hot-side inlet of the low-temperature heating network heater, and the hot-side outlet of the low-temperature heating network heater is connected to the inlet of the precooler; the cold-side outlet of the low-temperature heating network heater is connected to the cold-side inlet of the high-temperature heating network heater.

[0011] Furthermore, the primary network return water temperature at the cold side inlet of the low-temperature heating network heater is 45–85℃; the primary network supply water temperature at the cold side outlet of the high-temperature heating network heater is 100–130℃.

[0012] Furthermore, the system's circulating working fluid is supercritical carbon dioxide.

[0013] Furthermore, the outlet temperature of the heating compressor is 200–300°C, and the flow split ratio of the heating compressor is 0–51%.

[0014] Secondly, the present invention provides an operation method for a supercritical carbon dioxide cycle recompression thermoelectric dual-power system, comprising the following steps:

[0015] During the non-heating season, heating compressors, low-temperature heating network heaters, high-temperature heating network heaters, and buffer tanks are shut down, and their pipelines are closed. The supercritical carbon dioxide circulating working fluid, after being compressed by the main compressor, flows through the cold side of the low-temperature regenerator to absorb heat. At the cold side outlet of the low-temperature regenerator, it merges with the working fluid from the re-compressor outlet, and then flows sequentially through the cold side of the high-temperature regenerator and the boiler to absorb heat, becoming a high-temperature, high-pressure working fluid. It then enters the high-pressure turbine to do work, and the exhaust gas from the high-pressure turbine re-enters the boiler to absorb heat again. After being heated again, it enters the low-pressure turbine to do work, and the exhaust gas from the low-pressure turbine flows sequentially through the hot side of the high-temperature regenerator and the hot side of the low-temperature regenerator to release heat. The working fluid at the hot side outlet of the low-temperature regenerator is divided into two paths. One path of the working fluid is cooled by the precooler and enters the main compressor to start the recirculation. The other path of the working fluid is compressed by the re-compressor and merges with the working fluid at the cold side outlet of the low-temperature regenerator before entering the system. Part of the output power from the high-pressure turbine and the low-pressure turbine drives the main compressor and the re-compressor, and the remainder is used for power generation.

[0016] During the heating season, when the heating load demand is low, the heating compressor does not operate. The primary network return water is first heated by a portion of the working fluid diverted from the hot side outlet of the low-temperature regenerator in the low-temperature network heater. Then, it is further heated to the design parameters by a portion of the working fluid diverted from the recompressor outlet in the high-temperature network heater and supplied to the outside. The working fluid diverted from the hot side outlet of the low-temperature regenerator for heating releases heat in the low-temperature network heater and flows into the inlet of the precooler. The working fluid diverted from the recompressor outlet for heating releases heat in the high-temperature network heater and flows into the outlet of the main compressor, returning to the system. As the heating load increases, the flow rate of the working fluid diverted from the recompressor outlet for heating continuously increases until it is entirely diverted for heating. When the heating load continues to increase, the heating compressor starts, compresses and heats the working fluid at the hot side outlet of the low-temperature regenerator, and then mixes it with the working fluid at the recompressor outlet in the buffer tank before entering the high-temperature network heater to heat the network water for heating. After releasing heat, the working fluid flows into the outlet of the main compressor.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] This invention provides a supercritical carbon dioxide recirculation and recompression thermoelectric dual-supply system and its operation method. The system increases the temperature of the carbon dioxide working fluid at the cold end of the system by compressing it, and then uses the heated working fluid to heat the primary heat network water, thereby ensuring that the primary heat network water supply temperature meets the design requirements. The working fluid, after releasing heat, returns to the system, reducing disturbances in the regenerative system and ensuring safe and stable system operation. At the same time, the return water temperature of the primary heat network is relatively low, which can first absorb the waste heat at the cold end, thereby reducing energy loss and improving the system's energy utilization efficiency.

[0019] This invention reduces waste heat loss at the cold end of the system and improves energy utilization efficiency through combined heat and power generation.

[0020] This invention utilizes a low-temperature heating network heater to recover some of the waste heat from the cold end for heating, thereby reducing energy loss and improving energy utilization efficiency.

[0021] This invention utilizes a compressor to compress the working fluid and raise its temperature for heating, which can reduce the disturbance of the regenerative system and the boiler inlet temperature, and ensure the safe and stable operation of the system.

[0022] This invention achieves a diversified energy supply through dual heat and power generation, which can better meet users' needs for multiple energy sources.

[0023] This invention requires fewer heating devices, has a simpler system, and is safer, more reliable, and more flexible in operation, with lower investment costs. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a supercritical carbon dioxide recirculation and recompression thermoelectric dual-power system according to the present invention.

[0025] in:

[0026] 1-Main compressor, 2-Low-temperature regenerator, 3-High-temperature regenerator, 4-Boiler, 5-High-pressure turbine, 6-Low-pressure turbine, 7-Precooler, 8-Recompressor, 9-Heating compressor, 10-Low-temperature heating network heater, 11-High-temperature heating network heater, 12-Buffer tank. Detailed Implementation

[0027] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Example 1, please refer to Figure 1 A supercritical carbon dioxide recirculation and recompression dual-supply thermoelectric system includes a main compressor 1, a regenerator unit, a boiler 4, a turbine unit, a precooler 7, a recompressor 8, a heating compressor 9, and a heater unit. The outlet of the main compressor 1 is connected to the regenerator unit, the outlet of the regenerator unit is connected to the boiler 4, the boiler 4 is connected to the turbine unit, and the outlet of the turbine unit is connected to the regenerator unit. The precooler 7 is connected to the regenerator unit, and the outlet of the precooler 7 is connected to the inlet of the main compressor 1. The recompressor 8 and the heating compressor 9 are both connected to the regenerator unit. A heater unit is provided between the heating compressor 9 and the main compressor 1, and between the regenerator unit and the main compressor 1.

[0031] By compressing the carbon dioxide working fluid at the cold end of the system to raise its temperature, the heated working fluid is then used to heat the primary heat network water, thereby ensuring that the primary network water supply temperature meets the design requirements. The working fluid, after releasing heat, returns to the system, reducing disturbances in the regenerative system and ensuring the safe and stable operation of the system. At the same time, the return water temperature of the primary heat network is relatively low, which can first absorb the waste heat at the cold end, thereby reducing energy loss and improving the system's energy utilization efficiency.

[0032] Example 2: The present invention provides a supercritical carbon dioxide recompression thermoelectric dual-supply system, including a main compressor 1, a low-temperature regenerator 2, a high-temperature regenerator 3, a boiler 4, a high-pressure turbine 5, a low-pressure turbine 6, a precooler 7, a recompressor 8, a heating compressor 9, a low-temperature heating network heater 10, a high-temperature heating network heater 11, and a buffer tank 12.

[0033] The main compressor 1 outlet is connected to the cold-side inlet of the low-temperature regenerator 2; the cold-side outlet of the low-temperature regenerator 2 is connected to the cold-side inlet of the high-temperature regenerator 3; the cold-side outlet of the high-temperature regenerator 3 is connected to the boiler 4 feed gas inlet; the boiler 4 main gas outlet is connected to the high-pressure turbine 5 inlet; the high-pressure turbine 5 outlet is connected to the boiler 4 reheat inlet; the boiler 4 reheat outlet is connected to the low-pressure turbine 6 inlet; the low-pressure turbine 6 outlet is connected to the high-temperature regenerator 3 hot-side inlet; the high-temperature regenerator 3 hot-side outlet is connected to the low-temperature regenerator 2 hot-side inlet; the low-temperature regenerator 2 hot-side outlet is connected to the precooler 7 inlet; and the precooler 7 outlet is connected to the main compressor 1 inlet. The low-temperature regenerator 2 hot-side outlet is connected to the reheat inlet. The inlet of compressor 8 is connected to the main compressor 1; the outlet of recompressor 8 is connected to the cold side outlet of low-temperature regenerator 2; the outlet of recompressor 8 is connected to the inlet of buffer tank 12; the hot side outlet of low-temperature regenerator 2 is connected to the inlet of heating compressor 9; the outlet of heating compressor 9 is connected to the inlet of buffer tank 12; the outlet of buffer tank 12 is connected to the hot side inlet of high-temperature heating network heater 11; the hot side outlet of high-temperature heating network heater 11 is connected to the outlet of main compressor 1; the hot side outlet of low-temperature regenerator 2 is connected to the hot side inlet of low-temperature heating network heater 10; the hot side outlet of low-temperature heating network heater 10 is connected to the inlet of precooler 7; the cold side outlet of low-temperature heating network heater 10 is connected to the cold side inlet of high-temperature heating network heater 11.

[0034] The circulating working fluid of the system is supercritical carbon dioxide.

[0035] The outlet temperature of the heating compressor 9 is 200–300°C;

[0036] The cold-side inlet primary network return water temperature of the low-temperature heating network heater 10 is 45-85℃.

[0037] The primary water supply temperature at the cold side outlet of the high-temperature heating network heater 11 is 100-130℃.

[0038] The flow split ratio of the heating compressor 9 is 0-51%.

[0039] This invention uses supercritical carbon dioxide as the circulating working fluid, which has the characteristics of high thermal efficiency, low energy consumption, and environmental friendliness. In the system, carbon dioxide is recycled multiple times, heated and reheated through different regenerators and boilers, achieving efficient energy conversion and utilization.

[0040] The system of this invention can not only generate electricity but also provide heat for heating. By adjusting the operating status of the main compressor, re-compressor, and heating compressor, as well as the heat distribution of each regenerator and heater, the system can provide electricity and heat simultaneously or separately as needed.

[0041] The heating compressor, low-temperature heating network heater, and high-temperature heating network heater in this invention system can be flexibly adjusted according to changes in heating load. The flow split ratio of the heating compressor can be set within a range of 0–51%, allowing for precise flow control based on actual needs to meet different heating requirements.

[0042] This invention, by incorporating a buffer tank, allows the system to balance flow fluctuations to a certain extent, ensuring system stability. Furthermore, the system's design and layout consider the coordination and cooperation between its components, enabling the entire system to operate efficiently and stably.

[0043] This invention uses supercritical carbon dioxide as the circulating working fluid, which results in lower carbon emissions and environmental pollution compared to traditional fossil fuels. Furthermore, the system's dual-power (thermal and electrical) capability helps improve overall energy utilization efficiency, reduce energy waste, and aligns with the requirements of sustainable development.

[0044] The design parameters (such as temperature and flow rate) of each component in this invention system have a certain adjustable range, which can be adjusted and optimized according to actual needs. Furthermore, the system can also be expanded and upgraded as needed to adapt to greater energy demands and higher operating efficiency requirements.

[0045] Example 3: This invention provides an operation method for a supercritical carbon dioxide cycle recompression thermoelectric dual-power system.

[0046] During the non-heating season, the heating compressor 9, low-temperature heating network heater 10, high-temperature heating network heater 11, and buffer tank 12 are shut down, and their pipelines are closed. The supercritical carbon dioxide circulating working fluid is compressed by the main compressor 1 and flows through the cold side of the low-temperature regenerator 2 to absorb heat. At the cold side outlet of the low-temperature regenerator 2, it merges with the working fluid at the outlet of the re-compressor 8. It then flows through the cold side of the high-temperature regenerator 3 and the boiler 4 to absorb heat, becoming a high-temperature and high-pressure working fluid. It then enters the high-pressure turbine 5 to do work. The exhaust gas from the high-pressure turbine 5 enters the boiler 4 again to absorb heat. After being heated again, it enters the low-pressure turbine 6 to do work. The exhaust gas from the low-pressure turbine 6 flows through the hot side of the high-temperature regenerator 3 and the hot side of the low-temperature regenerator 2 to release heat. The working fluid at the hot side outlet of the low-temperature regenerator 2 is divided into two paths. One path is cooled by the precooler 7 and enters the main compressor 1 to start the recirculation. The other path is compressed by the re-compressor 8 and merges with the working fluid at the cold side outlet of the low-temperature regenerator 2 before entering the system. The output power of the high-pressure turbine 5 and the low-pressure turbine 6 is used to drive the main compressor 1 and the re-compressor 8, and the rest is used to generate electricity.

[0047] During the heating season, when the heating load demand is low, the heating compressor 9 does not operate. The primary network return water is first heated in the low-temperature heating network heater 10 by a portion of the working fluid diverted from the hot side outlet of the low-temperature regenerator 2. Then, in the high-temperature heating network heater 11, it is further heated to the design parameters by a portion of the working fluid diverted from the outlet of the recompressor 8 and supplied to the outside. The working fluid diverted from the hot side outlet of the low-temperature regenerator 2 for heating releases heat in the low-temperature heating network heater 10 and flows into the inlet of the precooler 7. The working fluid diverted from the outlet of the recompressor 8 for heating releases heat in the high-temperature heating network heater 11 and flows into the outlet of the main compressor 1, returning to the system. As the heating load increases, the flow rate of the working fluid diverted from the outlet of the recompressor 8 for heating continuously increases until it is entirely diverted for heating. When the heating load continues to increase, the heating compressor 9 starts, compresses and heats the working fluid at the hot side outlet of the low-temperature regenerator 2, and then mixes it with the working fluid at the outlet of the re-compressor 8 into the buffer tank 12, and then enters the high-temperature heating network heater 11 to heat the heating network water for heating; after releasing heat, the working fluid flows into the outlet of the main compressor 1.

[0048] The present invention compresses the working fluid through the main compressor 1, and after multi-stage heating (low-temperature regenerator 2, high-temperature regenerator 3 and boiler 4), the working fluid does work in the high-pressure turbine 5 and low-pressure turbine 6, realizing the conversion of thermal energy into mechanical energy, and then driving the generator to generate electricity.

[0049] Part of the system's output power is used to drive the main compressor 1 and the re-compressor 8, realizing the recycling of energy and improving system efficiency.

[0050] During the heating season, the system can flexibly adjust the heating strategy according to the heating load demand. When the heating load is low, heating is provided only by utilizing a portion of the working fluid diverted from the system through the low-temperature heating network heater 10 and the high-temperature heating network heater 11.

[0051] With the increase in heating load, the start-up of heating compressor 9 and the introduction of buffer tank 12 enable the system to provide more stable and higher temperature heating water to meet greater heating demand.

[0052] This invention achieves cascaded energy utilization through the design of the low-temperature regenerator 2 and the high-temperature regenerator 3. During the exhaust process of the high-pressure turbine 5 and the low-pressure turbine 6, the heat of the working fluid is recovered and used to preheat the working fluid entering the system, reducing energy loss and improving the overall system efficiency.

[0053] The present invention uses supercritical carbon dioxide as the circulating working fluid, which has high thermophysical properties, such as low critical temperature and pressure, enabling the system to operate at lower temperatures and pressures, thereby reducing energy consumption and carbon emissions.

[0054] The recovery and reuse of heat in the system further reduces energy consumption and environmental pollution.

[0055] This invention takes into account the different needs of the non-heating season and the heating season, and achieves efficient and stable operation of the system by adjusting the operating status of the equipment and the opening and closing of the pipeline.

[0056] The introduction of equipment such as heating compressor 9, low-temperature heating network heater 10, high-temperature heating network heater 11 and buffer tank 12 enhances the system's regulation capability and stability.

[0057] In summary, this supercritical carbon dioxide recycle recompression cogeneration system achieves efficient, stable, and environmentally friendly operation of cogeneration through its high efficiency, flexible heating strategies, cascaded energy utilization, environmental protection and energy conservation, as well as high reliability and stability.

[0058] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A supercritical carbon dioxide recompression thermoelectric dual-power system, characterized in that, It includes a main compressor (1), a regenerating unit, a boiler (4), a turbine unit, a precooler (7), a re-compressor (8), a heating compressor (9), and a heater unit; the outlet of the main compressor (1) is connected to the regenerating unit, the outlet of the regenerating unit is connected to the boiler (4), the boiler (4) is connected to the turbine unit, and the outlet of the turbine unit is connected to the regenerating unit; the precooler (7) is connected to the regenerating unit, and the outlet of the precooler (7) is connected to the inlet of the main compressor (1); the re-compressor (8) and the heating compressor (9) are both connected to the regenerating unit, and a heater unit is provided between the heating compressor (9) and the main compressor (1), and between the regenerating unit and the main compressor (1); The regeneration unit includes a low-temperature regenerator (2) and a high-temperature regenerator (3). The outlet of the main compressor (1) is connected to the cold-side inlet of the low-temperature regenerator (2), the cold-side outlet of the low-temperature regenerator (2) is connected to the cold-side inlet of the high-temperature regenerator (3), and the cold-side outlet of the high-temperature regenerator (3) is connected to the gas inlet of the boiler (4). The hot-side outlet of the high-temperature regenerator (3) is connected to the hot-side inlet of the low-temperature regenerator (2), and the hot-side outlet of the low-temperature regenerator (2) is connected to the inlet of the precooler (7). The hot side outlet of the low-temperature regenerator (2) is connected to the inlet of the recompressor (8), and the outlet of the recompressor (8) is connected to the cold side outlet of the low-temperature regenerator (2); the hot side outlet of the low-temperature regenerator (2) is connected to the inlet of the heating compressor (9); The outlet of the recompressor (8) is connected to the inlet of the buffer tank (12), the outlet of the heating compressor (9) is connected to the inlet of the buffer tank (12), and the outlet of the buffer tank (12) is connected to the heater unit. The heater unit includes a high-temperature heating network heater (11) and a low-temperature heating network heater (10); the outlet of the buffer tank (12) is connected to the hot side inlet of the high-temperature heating network heater (11), and the hot side outlet of the high-temperature heating network heater (11) is connected to the outlet of the main compressor (1); the hot side outlet of the low-temperature regenerator (2) is connected to the hot side inlet of the low-temperature heating network heater (10), and the hot side outlet of the low-temperature heating network heater (10) is connected to the inlet of the precooler (7); the cold side outlet of the low-temperature heating network heater (10) is connected to the cold side inlet of the high-temperature heating network heater (11).

2. The supercritical carbon dioxide recompression thermoelectric dual-power system according to claim 1, characterized in that, The turbine unit includes a high-pressure turbine (5) and a low-pressure turbine (6); the main gas outlet of the boiler (4) is connected to the inlet of the high-pressure turbine (5), the outlet of the high-pressure turbine (5) is connected to the reheat inlet of the boiler (4), the reheat outlet of the boiler (4) is connected to the inlet of the low-pressure turbine (6), and the outlet of the low-pressure turbine (6) is connected to the hot side inlet of the high-temperature regenerator (3).

3. The supercritical carbon dioxide recompression thermoelectric dual-power system according to claim 1, characterized in that, The cold side inlet of the low-temperature heating network heater (10) has a primary network return water temperature of 45~85℃; the cold side outlet of the high-temperature heating network heater (11) has a primary network supply water temperature of 100~130℃.

4. The supercritical carbon dioxide recompression thermoelectric dual-power system according to claim 1, characterized in that, The system's circulating working fluid is supercritical carbon dioxide.

5. A supercritical carbon dioxide recompression thermoelectric dual-power system according to claim 1, characterized in that, The outlet temperature of the heating compressor (9) is 200~300℃, and the flow split ratio of the heating compressor (9) is 0~51%.

6. A method for operating a supercritical carbon dioxide recompression thermoelectric dual-power system, characterized in that, The supercritical carbon dioxide cycle recompression thermoelectric dual-power system according to any one of claims 1 to 5 includes the following steps: During the non-heating season, the heating compressor (9), low-temperature heating network heater (10), high-temperature heating network heater (11), and buffer tank (12) are shut down, and their pipelines are closed. The supercritical carbon dioxide circulating working fluid is compressed by the main compressor (1), flows through the cold side of the low-temperature regenerator (2) to absorb heat, and merges with the working fluid at the outlet of the re-compressor (8) at the cold side outlet of the low-temperature regenerator (2). It then flows through the cold side of the high-temperature regenerator (3) and the boiler (4) to absorb heat, becoming a high-temperature and high-pressure working fluid. It then enters the high-pressure turbine (5) to do work, and the exhaust gas from the high-pressure turbine (5) enters the boiler (4) again to absorb heat. After being heated again, the heat enters the low-pressure turbine (6) to do work. The exhaust gas from the low-pressure turbine (6) flows sequentially through the hot side of the high-temperature regenerator (3) and the hot side of the low-temperature regenerator (2) to release heat. The working fluid at the hot side outlet of the low-temperature regenerator (2) is divided into two paths. One path of the working fluid is cooled by the precooler (7) and then enters the main compressor (1) to start the recirculation. The other path of the working fluid is compressed by the recompressor (8) and then merges with the working fluid at the cold side outlet of the low-temperature regenerator (2) and enters the system. Part of the output power from the high-pressure turbine (5) and the low-pressure turbine (6) drives the main compressor (1) and the recompressor (8), and the rest is used for power generation. During the heating season, when the heating load demand is low, the heating compressor (9) does not operate. The primary network return water is first heated in the low-temperature heating network heater (10) by a portion of the working fluid diverted from the hot side outlet of the low-temperature regenerator (2), and then further heated to the design parameters in the high-temperature heating network heater (11) by a portion of the working fluid diverted from the outlet of the re-compressor (8), and then supplied to the outside for heating. The working fluid diverted from the hot side outlet of the low-temperature regenerator (2) for heating releases heat in the low-temperature heating network heater (10) and then flows into the inlet of the precooler (7). The working fluid diverted from the outlet of the re-compressor (8) for heating is then... After the heat is released in the high-temperature heat network heater (11), it flows into the outlet of the main compressor (1) and returns to the system. As the heating load increases, the flow rate of the working fluid diverted for heating at the outlet of the recompressor (8) continues to increase until it is all diverted for heating. When the heating load continues to increase, the heating compressor (9) starts up, compresses and heats the working fluid at the hot side outlet of the low-temperature regenerator (2), and then mixes it with the working fluid at the outlet of the recompressor (8) in the buffer tank (12) and enters the high-temperature heat network heater (11) to heat the heat network water for heating. After the heat is released, the working fluid flows into the outlet of the main compressor (1).

Images