Integrated waste heat and shaft work assisted gas turbine-carnot cell combined system and operation method

Abstract

The application discloses a combined system of a gas turbine and a Carnot cell with auxiliary waste heat and shaft power and an operation method, and belongs to the field of thermal power engineering. The combined system comprises a gas turbine unit, a Carnot cell unit, a coaxial coupling and switching device, a flue gas waste heat deep utilization unit and a control system. The gas turbine unit is used for gas power generation, and the exhaust gas thereof enters the flue gas waste heat deep utilization unit. The Carnot cell unit is used for charging or discharging of the system. The coaxial coupling and switching device is used for connection or disconnection of the shaft system of the gas turbine unit and the energy storage compressor rotor shaft and the energy release expander rotor shaft in the Carnot cell unit. The flue gas waste heat deep utilization unit is used for recovery of flue gas heat energy of the gas turbine unit. The control system is used for operation regulation and control of the system. The application not only innovatively realizes full-period step-by-step efficient recovery of flue gas waste heat, but also realizes power flow between the gas turbine and the Carnot cell unit through the coaxial coupling and switching device from the mechanical level.

Description

Technical Field

[0001] This invention belongs to the field of thermal power engineering, specifically relating to a gas turbine-Carnot battery integrated system and its operation method that combines waste heat and shaft power assistance. Background Technology

[0002] Due to the strong intermittency and volatility of wind and solar power generation, large-scale renewable energy bases face challenges in power consumption. To address this issue, the "electricity-hydrogen-electricity" model (utilizing surplus electricity from wind and solar power generation to electrolyze water to produce hydrogen, which is then used to generate electricity via gas turbines) is an effective approach to achieving both efficient renewable energy consumption and flexible grid peak shaving.

[0003] The "electricity-hydrogen-electricity" model in large-scale new energy bases suffers from significant efficiency losses and faces dual regulation requirements: grid power regulation and hydrogen energy consumption regulation. Traditional hydrogen-fired / hydrogen-blended gas turbine power generation systems struggle to achieve bidirectional regulation of both electricity and hydrogen energy consumption (i.e., when the grid is in a downturn and cannot continue absorbing hydrogen), and their power regulation rate is limited by thermal inertia, making it difficult to match the demands of rapid power frequency regulation. Therefore, there is an urgent need for a flexible regulation resource that can efficiently complement hydrogen energy systems and possess rapid response capabilities to enhance the bidirectional regulation capabilities of hydrogen-fired / hydrogen-blended gas turbine power generation systems. Summary of the Invention

[0004] This invention aims to overcome the shortcomings of existing technologies and provide a gas turbine-Carnot battery integrated commissioning system and operation method that combines waste heat and shaft power assistance. This invention not only innovatively achieves efficient, cascaded recovery of exhaust waste heat throughout all time periods, but also, through coaxial coupling and switching devices, mechanically connects the power flow between the gas turbine and the Carnot battery unit. This allows the system to flexibly and quickly switch between various modes such as energy storage, peak power generation, and black start, making it suitable for large-scale new energy bases in remote desert areas. On the one hand, the system can utilize the exhaust waste heat from the gas turbines within the base (which can be modified to operate on hydrogen fuel or with hydrogen blending) to further improve its own efficiency; on the other hand, it possesses rapid charge and discharge response and direct shaft power assistance capabilities, improving load conditions and response capabilities.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The gas turbine-Carnot battery integrated system for waste heat and shaft power assistance includes a gas turbine unit, a Carnot battery unit, a coaxial coupling and switching device, a deep utilization unit for flue gas waste heat, and a control system. The gas turbine unit is used for gas-fired power generation, and its exhaust gas enters the flue gas waste heat deep utilization unit. Carnot battery cells are used for charging or discharging the system. Coaxial coupling and switching device for connecting or disconnecting the shaft system of the gas turbine unit from the rotor shaft of the energy storage compressor and the rotor shaft of the energy release expander in the Carnot battery unit; The flue gas waste heat deep utilization unit is used for the recovery of heat energy from the flue gas of the gas turbine unit; Control system, used for the operation and regulation of the system.

[0006] A further improvement of the present invention is that the gas turbine unit includes a compressor, a combustion chamber and a gas turbine connected in sequence via a main shaft, and the exhaust port of the gas turbine is connected to the flue gas side inlet of the flue gas waste heat deep utilization unit.

[0007] A further improvement of the present invention is that the waste heat utilization unit of the flue gas includes a primary flue gas heat exchanger and a secondary flue gas heat exchanger arranged in series along the flue gas flow direction.

[0008] A further improvement of the present invention is that the Carnot battery cell includes a physically isolated energy storage circuit and an energy release circuit; the energy storage circuit includes an energy storage compressor, a first heat storage heat exchanger, and a first connecting pipeline disposed between the working fluid side of the energy storage circuit and the first-stage flue gas heat exchanger; the energy release circuit includes an energy release expander, a second heat storage heat exchanger, a condenser, a working fluid pump, and a second connecting pipeline disposed between the working fluid side of the energy release circuit and the second-stage flue gas heat exchanger; the system also includes a high-temperature heat storage tank and a low-temperature heat storage tank connected to the first heat storage heat exchanger and the second heat storage heat exchanger via working fluid pipelines.

[0009] A further improvement of the present invention is that the coaxial coupling and switching device is mechanically connected between the main shaft of the gas turbine unit, the rotor shaft of the energy storage compressor, and the rotor shaft of the energy release expander; the coaxial coupling and switching device is configured to controllably enable the energy storage compressor and / or the energy release expander to selectively mechanically couple or disconnect with the main shaft of the gas turbine unit.

[0010] A further improvement of the present invention is that the control system is connected to the coaxial coupling and switching device, as well as the valve signals on the first and second connecting pipelines.

[0011] A further improvement of the present invention is that the coaxial coupling and switching device includes a clutch assembly and / or a gear mechanism to achieve the selective mechanical coupling.

[0012] A further improvement of the present invention is that the heat storage medium stored in the high-temperature heat storage tank and the low-temperature heat storage tank is molten salt.

[0013] A further improvement of the present invention is that the energy storage circuit constitutes a heat pump cycle, the working fluid of which is carbon dioxide, air or nitrogen; the energy release circuit constitutes an organic Rankine cycle, the working fluid of which is R245fa, R1336mzz(Z) or pentane. The energy release circuit also includes a second generator coaxially connected to the energy release expander.

[0014] The operation method of the gas turbine-Carnot battery integrated commissioning system with waste heat and shaft power assistance is configured to have at least a first operation configuration and a second operation configuration. Under the first running configuration: The coaxial coupling and switching device couples the energy storage compressor to the gas turbine main shaft and disconnects the energy release expander from the gas turbine main shaft. The valve on the first connecting pipeline is open, and the valve on the second connecting pipeline is closed; The outlet of the high-temperature heat storage tank, the heat storage working fluid side of the first heat storage heat exchanger, and the inlet of the low-temperature heat storage tank are sequentially connected to form a first heat storage working fluid circuit, and the working fluid pipeline between the high-temperature heat storage tank and the second heat storage heat exchanger is closed. Under the second running configuration: The coaxial coupling and switching device couples the energy release expander to the gas turbine main shaft and disconnects the energy storage compressor from the gas turbine main shaft. The valve on the second connecting pipeline is opened, and the valve on the first connecting pipeline is closed; The outlet of the high-temperature heat storage tank, the heat storage working fluid side of the second heat storage heat exchanger, and the inlet of the low-temperature heat storage tank are sequentially connected to form a second heat storage working fluid circuit, and the working fluid pipeline between the high-temperature heat storage tank and the first heat storage heat exchanger is closed. The control system is configured to receive grid dispatch instructions and / or real-time electricity price signals, and based on the thermal storage status of the high-temperature thermal storage tank and the low-temperature thermal storage tank, automatically control the switching of the coaxial coupling and switching device and the opening and closing of valves on the first and second connecting pipelines, so that the system can switch between energy storage mode, peak power generation mode and black start standby mode.

[0015] Compared with the prior art, the present invention has at least the following beneficial technical effects: 1. Compared with traditional hydrogen-fired / hydrogen-blended gas turbine power generation systems, this invention has multiple operating modes that can be flexibly switched, improving the system's ability to quickly adjust power load and the depth of adjustment. 2. This invention features bidirectional regulation of electricity and hydrogen energy consumption, meaning that when the power grid is in a downturn, the system can still continue to consume hydrogen produced from green electricity; when the hydrogen produced from green electricity is insufficient, the system can still generate electricity through thermal storage. This greatly improves the stability and flexibility of hydrogen and electricity regulation in the "Shagolan" base.

[0016] 3. The series-connected flue gas waste heat utilization unit used in this invention improves energy utilization efficiency.

[0017] 4. The "Shagohuang" base has a harsh environment and is far from the main power grid, resulting in a high risk of power grid failure. This system is equipped with black start and off-grid support modes, providing guaranteed start-up power. When the power grid is completely lost, the system can disconnect from the main grid and generate electricity independently using thermal storage to quickly restore power to critical loads within the plant, greatly improving the stability and reliability of the energy base under extreme conditions. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a structural block diagram of the gas turbine-Carnot battery integrated system for waste heat and shaft power assistance according to the present invention.

[0020] Explanation of reference numerals in the attached figures: 100. Gas turbine unit; 101. Compressor; 102. Combustion chamber; 103. Gas turbine; 104. First generator; 200. Carnot battery cell; 201a. Energy storage compressor; 201b. Energy release expander; 202. Second generator; 203. Condenser; 300. Coaxial coupling and switching device; 400. Deep utilization unit for waste heat from flue gas; 401. Primary flue gas heat exchanger; 402. Secondary flue gas heat exchanger; 500. Control system; 600, Energy storage module; 601, High-temperature thermal storage tank; 602, Low-temperature thermal storage tank; 603, First thermal storage heat exchanger; 604, Second thermal storage heat exchanger; 605, First molten salt pump; 606, Second molten salt pump. Detailed Implementation

[0021] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0029] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] Example 1: like Figure 1 As shown, the integrated waste heat and shaft power assisted gas turbine-Carnot battery joint regulation system provided by the present invention includes a gas turbine unit 100, a Carnot battery unit 200, a coaxial coupling and switching device 300, a flue gas waste heat deep utilization unit 400, and a control system 500. Gas turbine unit 100 is used for gas-fired power generation, and its exhaust gas enters flue gas waste heat deep utilization unit 400; The Carnot battery cell 200 is used for charging or discharging the system. The coaxial coupling and switching device 300 is used to connect or disconnect the shaft system of the gas turbine unit 100 from the rotor shaft of the energy storage compressor 201a and the rotor shaft of the energy release expander 201b in the Carnot battery unit 200. The flue gas waste heat deep utilization unit 400 is used for the recovery of flue gas heat energy from the gas turbine unit 100; The control system 500 is used for system operation and regulation.

[0031] In this embodiment, the gas turbine unit 100 includes a compressor 101, a combustion chamber 102 and a gas turbine 103 connected in sequence via a main shaft, and the exhaust port of the gas turbine 103 is connected to the flue gas side inlet of the flue gas waste heat utilization unit 400.

[0032] In this embodiment, the waste heat utilization unit 400 includes a primary flue gas heat exchanger 401 and a secondary flue gas heat exchanger 402 arranged in series along the flue gas flow direction.

[0033] In this embodiment, the Carnot battery unit 200 includes a physically isolated energy storage circuit and an energy release circuit; the energy storage circuit includes an energy storage compressor 201a, a first heat storage heat exchanger 603, and a first connecting pipe disposed between the working fluid side of the energy storage circuit and the first-stage flue gas heat exchanger 401; the energy release circuit includes an energy release expander 201b, a second heat storage heat exchanger 604, a condenser 203, a working fluid pump 204, and a second connecting pipe disposed between the working fluid side of the energy release circuit and the second-stage flue gas heat exchanger 402; the system also includes a high-temperature heat storage tank 601 and a low-temperature heat storage tank 602 connected to the first heat storage heat exchanger 603 and the second heat storage heat exchanger 604 via working fluid pipes.

[0034] In this embodiment, the coaxial coupling and switching device 300 is mechanically connected between the main shaft of the gas turbine unit 100, the rotor shaft of the energy storage compressor 201a, and the rotor shaft of the energy release expander 201b; the coaxial coupling and switching device 300 is configured to controllably enable the energy storage compressor 201a and / or the energy release expander 201b to selectively mechanically couple or disconnect from the main shaft of the gas turbine unit 100.

[0035] In this embodiment, the control system 500 is connected to the coaxial coupling and switching device 300, as well as the valve signals on the first and second connecting pipelines.

[0036] In this embodiment, the coaxial coupling and switching device 300 includes a clutch assembly and / or a gear mechanism to achieve the selective mechanical coupling.

[0037] In this embodiment, the heat storage medium stored in the high-temperature heat storage tank 601 and the low-temperature heat storage tank 602 is molten salt.

[0038] In this embodiment, the energy storage circuit constitutes a heat pump cycle, and its working fluid is carbon dioxide, air or nitrogen; the energy release circuit constitutes an organic Rankine cycle, and its working fluid is R245fa, R1336mzz(Z) or pentane. The energy release circuit also includes a second generator 202 coaxially connected to the energy release expander 201b.

[0039] Example 2: like Figure 1As shown, the present invention provides a gas turbine-Carnot battery integrated system that combines waste heat and shaft power assistance. The system mainly includes a gas turbine unit 100, a Carnot battery unit 200, a coaxial coupling and switching device 300, a flue gas waste heat deep utilization unit 400, and a control system 500.

[0040] The gas turbine unit 100 employs the gas turbine portion of a conventional simple cycle or combined cycle system, comprising a compressor 101, a gas turbine 103, and a first generator 104 mechanically connected sequentially via a main shaft. The combustion chamber 102 is located between the outlet of the compressor 101 and the inlet of the gas turbine 103. The high-temperature exhaust gas (flue gas) from the gas turbine 103 after it has performed work is discharged from its exhaust port and transported via a flue to the flue gas side inlet of the flue gas waste heat utilization unit 400.

[0041] The waste heat utilization unit 400 includes a primary flue gas heat exchanger 401 and a secondary flue gas heat exchanger 402 arranged in series along the flue gas flow direction (i.e., from the gas turbine 103 towards the chimney). The waste heat of this flue gas will be extracted and utilized in stages and in succession in the two heat exchangers.

[0042] The Carnot battery unit 200 is the core of the system for energy storage and release, and it includes energy storage circuits and energy release circuits that are physically and cyclically isolated from each other.

[0043] Energy storage loop: This constitutes a heat pump cycle. Its core working component is the energy storage compressor 201a. The loop also includes a first heat storage heat exchanger 603. The outlet on the working fluid side of the energy storage loop is connected to the working fluid side inlet of the first-stage flue gas heat exchanger 401 via a first connecting pipe (equipped with a controllable valve), thus using the first-stage flue gas heat exchanger 401 as the evaporator of this heat pump cycle. In the cycle, the working fluid (e.g., carbon dioxide) absorbs waste heat from the flue gas and evaporates in the first-stage flue gas heat exchanger 401. It is then compressed and heated by the energy storage compressor 201a, then releases heat to the working fluid and condenses in the first heat storage heat exchanger 603, finally returning to the first-stage flue gas heat exchanger 401 to complete the cycle.

[0044] The energy release loop constitutes an Organic Rankine Cycle (ORC). Its core working component is the energy release expander 201b, whose output shaft is coaxially connected to the second generator 202. The loop also includes a second heat storage heat exchanger 604 and a condenser 203. The outlet on the working fluid side of the energy release loop is connected to the working fluid side inlet of the secondary flue gas heat exchanger 402 via a second connecting pipe (equipped with a controllable valve), thus using the secondary flue gas heat exchanger 402 as a preheater for this ORC cycle. In the cycle, the working fluid (e.g., R245fa) first absorbs waste heat from the flue gas in the secondary flue gas heat exchanger 402 for preheating, then absorbs heat from the high-temperature heat storage tank 601 in the second heat storage heat exchanger 604 and evaporates and becomes superheated. It then enters the energy release expander 201b to expand and do work, driving the second generator 202 to generate electricity. The exhaust gas after doing work releases heat to the environment (such as cooling water or air) and condenses in the condenser 203. Finally, it is pressurized by the working fluid pump 204 and returned to the secondary flue gas heat exchanger 402 to complete the cycle.

[0045] The system also includes a thermal storage subsystem, the core of which is a high-temperature thermal storage tank 601 and a low-temperature thermal storage tank 602. The high-temperature thermal storage tank 601 and the low-temperature thermal storage tank 602 can selectively form a circulation loop with the thermal storage working fluid side of the first thermal storage heat exchanger 603 or the second thermal storage heat exchanger 604 via working fluid pipelines and a first molten salt pump 605 and a second molten salt pump 606. The thermal storage working fluid is preferably a molten salt, such as a binary nitrate.

[0046] The core innovative component of this invention lies in the coaxial coupling and switching device 300. This coaxial coupling and switching device 300 is mechanically connected between the main shaft of the gas turbine unit 100 (specifically, the extended shaft of the compressor 101 or gas turbine 103), the rotor shaft of the energy storage compressor 201a, and the rotor shaft of the energy release expander 201b. In a preferred embodiment, the coaxial coupling and switching device 300 includes a clutch group consisting of multiple sets of electromagnetic clutches or hydraulic clutches, and can be integrated with a transmission gearbox to adapt to different speeds.

[0047] The control system 500 can achieve one or more of the following connection states by sending commands to these clutches: coupling the energy storage compressor 201a separately to the gas turbine main shaft; coupling the energy release expander 201b separately to the gas turbine main shaft; coupling both to the gas turbine main shaft simultaneously; or disconnecting both from the gas turbine main shaft. This design enables flexible distribution and coupling of mechanical power flow.

[0048] The control system 500, for example, is a distributed control system (DCS) or a programmable logic controller (PLC), and is connected to the coaxial coupling and switching device 300, the control valves on the first and second connecting pipelines, the pumps, the power grid dispatching system, and the temperature / level sensor of the thermal storage tank.

[0049] Example 3: First operating configuration (waste heat power enhancement and energy storage mode) This embodiment describes the specific workflow of the system under the first operating configuration. This mode is suitable for peak shaving during periods of low grid load, where the system converts electrical energy and waste heat into thermal energy for storage.

[0050] 1. Mode Activation and Configuration: The control system 500 receives the energy storage command and automatically performs the following operations: 1) Control the coaxial coupling and switching device 300 to activate the clutch, firmly coupling the rotor shaft of the energy storage compressor 201a with the main shaft of the gas turbine unit 100, while ensuring that the rotor shaft of the energy release expander 201b is completely disconnected from the main shaft of the gas turbine.

[0051] 2) Open the valve on the first connecting pipeline and close the valve on the second connecting pipeline.

[0052] 3) Open the pipeline valves between the high-temperature heat storage tank 601 and the first heat storage heat exchanger 603, and between the first heat storage heat exchanger 603 and the low-temperature heat storage tank 602, and start the corresponding molten salt pump 605 to form the first heat storage working fluid circuit. At the same time, close the pipeline valve between the high-temperature heat storage tank 601 and the second heat storage heat exchanger 604.

[0053] 2. System operation process: 1) The gas turbine unit 100 generates electricity during normal operation. The high-temperature flue gas produced flows sequentially through the primary flue gas heat exchanger 401 and the secondary flue gas heat exchanger 402 before being discharged to the chimney. In the primary flue gas heat exchanger 401, the flue gas transfers heat to the working fluid in the energy storage loop.

[0054] 2) The energy storage compressor 201a is directly driven by the gas turbine main shaft via coaxial coupling (consuming part of the gas turbine shaft power). After absorbing heat in the first-stage flue gas heat exchanger 401, the working fluid in the energy storage circuit enters the energy storage compressor 201a, where it is compressed and heated to become a high-temperature, high-pressure gas.

[0055] 3) The high-temperature, high-pressure working fluid then enters the first heat exchanger 603, where it releases its high-temperature heat energy to the low-temperature molten salt pumped from the low-temperature heat storage tank 602. The working fluid, after releasing heat, returns to the cycle starting point.

[0056] 4) After absorbing heat in the first heat exchanger 603, the low-temperature molten salt rises in temperature and becomes high-temperature molten salt, which is then stored in the high-temperature heat storage tank 601. Thus, a portion of the shaft power and waste heat from the gas turbine are synergistically converted into high-temperature thermal energy and stored.

[0057] In this mode, the energy release circuit and its second generator 202 are in hot standby or shutdown state.

[0058] Example 4: Second operating configuration (waste heat co-generation peak power generation mode) This embodiment describes the specific workflow of the system under the second operating configuration described in claim 6. This mode is suitable for peak grid load periods when the units need to provide maximum output, where the system releases stored thermal energy and utilizes real-time flue gas waste heat to additionally increase power generation.

[0059] 1. Mode Activation and Configuration: After receiving the peak power generation command and confirming that the high-temperature thermal storage tank 601 has sufficient thermal storage, the control system 500 automatically performs the following operations: 1) Control the coaxial coupling and switching device 300 to activate the clutch, firmly coupling the rotor shaft of the energy release expander 201b with the main shaft of the gas turbine unit 100, while ensuring that the rotor shaft of the energy storage compressor 201a is completely disconnected from the main shaft of the gas turbine.

[0060] 2) Open the valve on the second connecting pipeline and close the valve on the first connecting pipeline.

[0061] 3) Open the pipeline valves between the high-temperature heat storage tank 601 and the second heat storage heat exchanger 604, and between the second heat storage heat exchanger 604 and the low-temperature heat storage tank 602, and start the corresponding molten salt pump 606 to form the second heat storage working fluid circuit. At the same time, close the pipeline valve between the high-temperature heat storage tank 601 and the first heat storage heat exchanger 603.

[0062] 4) The control system 500 will synchronously connect the second generator 202 to the grid.

[0063] 2. System operation process: 1) The gas turbine unit 100 operates at a high load, and its high-temperature flue gas also flows through two-stage flue gas heat exchangers. At this time, the heat of the flue gas is mainly utilized by the secondary flue gas heat exchanger 402.

[0064] 2) The working fluid from the energy release loop of the condenser 203 first enters the secondary flue gas heat exchanger 402, where it absorbs the waste heat of the medium-temperature flue gas for preheating, thereby improving its own quality.

[0065] 3) The preheated working fluid then enters the second heat exchanger 604, where it exchanges heat with the high-temperature molten salt flowing out of the high-temperature heat storage tank 601, absorbs the stored high-grade heat energy, evaporates and is superheated into high-temperature and high-pressure steam.

[0066] 4) The high-temperature, high-pressure working fluid drives the energy-releasing expander 201b to perform work. At this time, the mechanical work output by the energy-releasing expander 201b is directly transmitted to the main shaft of the gas turbine through a coaxial coupling device. This additional shaft work directly assists in driving the compressor 101, thereby reducing the load on the gas turbine 103 used to drive the compressor 101. The technical effect is that, with the fuel input to the combustion chamber remaining constant (or slightly increased), the gas turbine 103 has more surplus work available to drive the first generator to generate electricity, which is equivalent to increasing the peak output capacity of the gas turbine unit. Simultaneously, the electrical energy generated by the second generator 202 driven by the energy-releasing expander 201b is also connected to the power grid, providing additional electrical power output. The exhaust gas after performing work is condensed in the condenser 203.

[0067] 5) After the high-temperature molten salt releases heat in the second heat exchanger 604, it cools down to become low-temperature molten salt and flows back to the low-temperature heat storage tank 602.

[0068] This mode achieves triple synergy of thermal energy storage power generation, real-time flue gas waste heat enhancement, and direct mechanical shaft power assistance, significantly improving the system's peak power generation capacity and overall efficiency.

[0069] Example 5: System Mode Switching The control system 500 has a built-in mode decision algorithm, whose input signals include: AGC instructions from the power grid dispatch center, time-of-use electricity price curves, and real-time temperature and liquid level of high-temperature thermal storage tank 601 and low-temperature thermal storage tank 602 (used to calculate available heat storage).

[0070] 1) When the grid load is low, but the gas turbine is needed to continue to consume fuel (such as green hydrogen in the new energy base), the system preferably switches to the energy storage mode of Example 2.

[0071] 2) When the power grid requires peak power generation or when the electricity price is at its peak and the thermal storage is sufficient, the system preferably switches to the peak power generation mode of Example 3.

[0072] 3) When thermal storage is insufficient or the Carnot battery unit is under maintenance, the system can switch to conventional gas turbine-only power generation mode, and the Carnot battery unit will be shut down.

[0073] 4) Black Start Backup Mode: When the power grid is completely de-energized, the control system 500 can switch to off-grid mode. At this time, the coaxial coupling and switching device 300 completely disconnects the mechanical connection between the Carnot battery and the gas turbine. The system utilizes the thermal energy stored in the thermal storage tank to independently operate the energy release circuit of the Carnot battery (like an independent ORC power station), driving the second generator 202 to generate electricity. This provides power to the power plant's critical safety loads (such as control power, lubricating oil pumps, turning gear) and the starter motor and ignition system of the gas turbine unit 100, thus enabling black start capability and greatly enhancing the power plant's own operational reliability.

[0074] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0075] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. An integrated waste heat and shaft work assisted gas turbine-Carnot cell co-optimized system, characterized in that, It includes a gas turbine unit (100), a Carnot battery unit (200), a coaxial coupling and switching device (300), a flue gas waste heat deep utilization unit (400), and a control system (500). The gas turbine unit (100) is used for gas-fired power generation, and its exhaust gas enters the flue gas waste heat deep utilization unit (400). Carnot battery cell (200) is used for charging or discharging the system; Coaxial coupling and switching device (300) for connecting or disconnecting the shaft system of the gas turbine unit (100) from the rotor shaft of the energy storage compressor (201a) and the rotor shaft of the energy release expander (201b) in the Carnot battery unit (200); A deep utilization unit for waste heat from flue gas (400) is used for the recovery of heat energy from the flue gas of the gas turbine unit (100); The control system (500) is used for the operation and regulation of the system.

2. The integrated waste heat and shaft work assisted gas turbine-Carnot battery co-optimized system of claim 1, wherein, The gas turbine unit (100) includes a compressor (101), a combustion chamber (102) and a gas turbine (103) connected in sequence via a main shaft. The exhaust port of the gas turbine (103) is connected to the flue gas side inlet of the flue gas waste heat deep utilization unit (400).

3. The integrated waste heat and shaft work assisted gas turbine-Carnot battery co-optimized system of claim 2, wherein, The waste heat utilization unit (400) includes a primary flue gas heat exchanger (401) and a secondary flue gas heat exchanger (402) arranged in series along the flue gas flow direction.

4. The integrated waste heat and shaft work assisted gas turbine-Carnot battery co-optimized system of claim 3, wherein, The Carnot battery unit (200) includes a physically isolated energy storage circuit and an energy release circuit; the energy storage circuit includes an energy storage compressor (201a), a first heat storage heat exchanger (603), and a first connecting pipeline disposed between the working fluid side of the energy storage circuit and the first-stage flue gas heat exchanger (401); the energy release circuit includes an energy release expander (201b), a second heat storage heat exchanger (604), a condenser (203), a working fluid pump (204), and a second connecting pipeline disposed between the working fluid side of the energy release circuit and the second-stage flue gas heat exchanger (402); the system also includes a high-temperature heat storage tank (601) and a low-temperature heat storage tank (602) connected to the first heat storage heat exchanger (603) and the second heat storage heat exchanger (604) through a working fluid pipeline.

5. The integrated waste heat and shaft work assisted gas turbine-Carnot battery co-optimized system of claim 4, wherein, The coaxial coupling and switching device (300) is mechanically connected between the main shaft of the gas turbine unit (100), the rotor shaft of the energy storage compressor (201a), and the rotor shaft of the energy release expander (201b); the coaxial coupling and switching device (300) is configured to controllably enable the energy storage compressor (201a) and / or the energy release expander (201b) to selectively couple or disconnect mechanically with the main shaft of the gas turbine unit (100).

6. The integrated waste heat and shaft work assisted gas turbine-Carnot battery co-optimized system of claim 5, wherein, The control system (500) is connected to the coaxial coupling and switching device (300) and the valve signals on the first and second connecting pipelines.

7. The integrated waste heat and shaft work assisted combined gas turbine- Carnot cell co-optimized system of claim 6, wherein, The coaxial coupling and switching device (300) includes a clutch assembly and / or a gear mechanism to achieve the selective mechanical coupling.

8. The integrated waste heat and shaft work assisted gas turbine-Carnot battery co-optimized system of claim 6, wherein, The heat storage medium stored in the high-temperature heat storage tank (601) and the low-temperature heat storage tank (602) is molten salt.

9. The integrated waste heat and shaft work assisted gas turbine-Carnot battery co-optimized system of claim 6, wherein, The energy storage circuit constitutes a heat pump cycle, with carbon dioxide, air, or nitrogen as the working fluid; the energy release circuit constitutes an organic Rankine cycle, with R245fa, R1336mzz(Z), or pentane as the working fluid. The energy release circuit also includes a second generator (202) coaxially connected to the energy release expander (201b).

10. The operation method of the gas turbine-Carnot battery integrated commissioning system with waste heat and shaft power assistance as described in any one of claims 6 to 9, characterized in that, The method is configured to have at least a first running configuration and a second running configuration; Under the first running configuration: The coaxial coupling and switching device (300) couples the energy storage compressor (201a) to the gas turbine main shaft and disconnects the energy release expander (201b) from the gas turbine main shaft; The valve on the first connecting pipeline is open, and the valve on the second connecting pipeline is closed; The outlet of the high-temperature heat storage tank (601), the heat storage working fluid side of the first heat storage heat exchanger (603), and the inlet of the low-temperature heat storage tank (602) are sequentially connected to form a first heat storage working fluid circuit, and the working fluid pipeline between the high-temperature heat storage tank (601) and the second heat storage heat exchanger (604) is closed. Under the second running configuration: The coaxial coupling and switching device (300) couples the energy release expander (201b) to the gas turbine main shaft and disconnects the energy storage compressor (201a) from the gas turbine main shaft; The valve on the second connecting pipeline is opened, and the valve on the first connecting pipeline is closed; The outlet of the high-temperature heat storage tank (601), the heat storage working fluid side of the second heat storage heat exchanger (604), and the inlet of the low-temperature heat storage tank (602) are sequentially connected to form a second heat storage working fluid circuit, and the working fluid pipeline between the high-temperature heat storage tank (601) and the first heat storage heat exchanger (603) is closed. The control system (500) is configured to receive grid dispatch instructions and / or real-time electricity price signals, and based on the thermal storage status of the high-temperature thermal storage tank (601) and the low-temperature thermal storage tank (602), automatically control the switching of the coaxial coupling and switching device (300) and the opening and closing of valves on the first and second connecting pipelines, so that the system can switch between energy storage mode, peak power generation mode and black start standby mode.

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