Carnot battery energy storage system

Abstract

The invention relates to a Carnot battery energy storage system. The Carnot battery energy storage system comprises a heat pump unit, a heat storage unit and an organic Rankine cycle unit. The organic Rankine cycle unit comprises an organic Rankine cycle evaporator, an organic Rankine cycle turbine, an organic Rankine cycle regenerator, an organic Rankine cycle condenser, a pump and a regenerator assembly; the heat storage working medium side of the organic Rankine cycle evaporator is connected in series in the heat storage unit, and the outlet of the organic Rankine cycle side of the organic Rankine cycle evaporator communicates with the inlet of the heat release side of the organic Rankine cycle regenerator through the organic Rankine cycle turbine; an outlet of the heat release side of the organic Rankine cycle regenerator communicates with an inlet of the heat absorption side of the organic Rankine cycle regenerator through an organic Rankine cycle condenser and a pump. An outlet of the heat absorption side of the organic Rankine cycle heat regenerator communicates with an inlet of the organic Rankine cycle side of the organic Rankine cycle evaporator through the heat absorption side of the heat regenerator assembly. The Carnot battery energy storage system is high in overall energy storage efficiency.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a Carnot battery energy storage system. Background Art

[0002] With the rapid development of renewable energy, such as wind and solar power, the utilization of resources has become a widespread choice. However, the intermittent and unstable nature of renewable energy poses certain challenges to existing power grids. To address this mismatch and meet society's continuous demand for electricity, a long-term, large-capacity energy storage system is needed. Currently, various technological approaches are competing, such as lithium batteries, pumped hydropower storage, and compressed air energy storage, but each has its limitations. For example, lithium batteries are expensive and pose safety concerns, making them unsuitable for long-term, large-capacity energy storage. While pumped hydropower storage is mature, it has geographical requirements and a maximum capacity limit. Compressed air energy storage is just beginning and also has geographical requirements. In this context, Carnot battery technology, which is free of geographical restrictions and offers relatively reasonable investment, has attracted widespread attention. Existing research has primarily focused on Carnot batteries using steam Rankine cycle heat pumps and organic Rankine cycles. However, these Carnot batteries suffer from low overall energy storage efficiency. Summary of the Invention

[0003] Based on this, it is necessary to provide a Carnot battery energy storage system with higher overall energy storage efficiency.

[0004] The present application provides a Carnot battery energy storage system, comprising a heat pump unit, a heat storage unit, and an organic Rankine cycle unit; the heat pump unit is used to absorb heat energy from a waste heat source, transfer it to the heat storage unit, and store it;

[0005] The organic Rankine cycle unit includes: an organic Rankine cycle evaporator, an organic Rankine cycle turbine, an organic Rankine cycle regenerator, an organic Rankine cycle condenser, a pump, and a regenerator assembly;

[0006] The heat storage working medium side of the organic Rankine cycle evaporator is connected in series to the heat storage unit. The outlet of the organic Rankine cycle side of the organic Rankine cycle evaporator is connected to the inlet of the heat release side of the organic Rankine cycle regenerator through the organic Rankine cycle turbine. The outlet of the heat release side of the organic Rankine cycle regenerator is connected to the inlet of the heat absorption side of the organic Rankine cycle regenerator through the organic Rankine cycle condenser and pump. The outlet of the heat absorption side of the organic Rankine cycle regenerator is connected to the inlet of the organic Rankine cycle side of the organic Rankine cycle evaporator through the heat absorption side of the regenerator assembly.

[0007] The middle section of the organic Rankine cycle turbine is in communication with the heat release side of the regenerator assembly.

[0008] In one embodiment, the regenerator assembly includes a first regenerator, a second regenerator, and a first compressor, wherein the heat absorption side of the first regenerator and the heat absorption side of the second regenerator are sequentially connected in series between the outlet of the heat absorption side of the organic Rankine cycle regenerator and the inlet of the organic Rankine cycle side of the organic Rankine cycle evaporator;

[0009] The heat release side of the first regenerator and the heat release side of the second regenerator are connected in series between the middle section of the organic Rankine cycle turbine and the inlet of the first compressor. The outlet of the first compressor is connected to the inlet of the heat absorption side of the second regenerator.

[0010] In one embodiment, the outlet of the heat absorption side of the first regenerator and the inlet of the heat absorption side of the second regenerator are connected in series via a connecting pipe, and the outlet of the first compressor is connected to the connecting pipe.

[0011] In one embodiment, the middle section of the organic Rankine cycle turbine is connected to the inlet of the heat release side of the second regenerator via a pipeline, and a flow control valve is provided on the pipeline.

[0012] In one embodiment, the organic Rankine cycle turbine is further connected to an organic Rankine cycle generator.

[0013] In one embodiment, the heat pump unit is configured as a Brayton heat pump unit, and the working fluid circulating in the heat pump unit is a gaseous working fluid.

[0014] In one embodiment, the heat pump unit includes: a first evaporator, a heat pump regenerator, a heat pump compressor, a first condenser, and a pressure reducing device;

[0015] The heat release side of the first evaporator is connected to the waste heat source, and the outlet of the heat absorption side of the first evaporator is connected to the inlet of the heat absorption side of the heat pump regenerator; the outlet of the heat absorption side of the heat pump regenerator is connected to the inlet of the heat release side of the first condenser through the heat pump compressor; the outlet of the heat release side of the first condenser is connected to the inlet of the heat release side of the heat pump regenerator; the outlet of the heat release side of the heat pump regenerator is connected to the inlet of the heat absorption side of the first evaporator through the pressure reducing device.

[0016] In one embodiment, the pressure reducing device is a turbine;

[0017] The pressure reducing device is further connected to a first generator, which is used to supply power to the heat pump compressor.

[0018] In one embodiment, the heat storage unit includes a first heat storage tank and a second heat storage tank;

[0019] The outlet of the first heat storage tank is connected to the inlet of the heat storage working fluid side of the first condenser; the outlet of the heat storage working fluid side of the first condenser is connected to the inlet of the second heat storage tank; the outlet of the second heat storage tank is connected to the inlet of the heat storage working fluid side of the organic Rankine cycle evaporator; the outlet of the heat storage working fluid side of the organic Rankine cycle evaporator is connected to the inlet of the first heat storage tank.

[0020] In one embodiment, a switch valve is provided on the pipeline between the outlet of the first heat storage tank and the inlet of the heat storage working medium side of the first condenser; and / or

[0021] A switch valve is provided on the pipeline between the outlet of the heat storage medium side of the first condenser and the inlet of the second heat storage tank; and / or

[0022] A switch valve is provided on the pipeline between the outlet of the second heat storage tank and the inlet of the heat storage working medium side of the organic Rankine cycle evaporator; and / or

[0023] A switch valve is provided on the pipeline between the outlet of the heat storage working medium side of the organic Rankine cycle evaporator and the inlet of the first heat storage tank.

[0024] The beneficial effects of the above-mentioned Carnot battery energy storage system are:

[0025] Because the outlet of the organic Rankine cycle regenerator's heat absorption side communicates with the inlet of the organic Rankine cycle evaporator's organic Rankine cycle side via the regenerator assembly's heat absorption side, the working fluid flowing out of the organic Rankine cycle regenerator's heat absorption side outlet is reheated by the regenerator assembly before entering the organic Rankine cycle evaporator. This further elevates the temperature of the working fluid flowing out of the organic Rankine cycle evaporator and entering the organic Rankine cycle turbine, thereby improving the power generation efficiency of the organic Rankine cycle turbine after work is performed. Furthermore, because the midsection of the organic Rankine cycle turbine communicates with the heat release side of the regenerator assembly, it can serve as a heat source for the regenerator assembly's heat absorption side. The regenerator assembly can efficiently utilize the temperature of the working fluid during the operation of the organic Rankine cycle turbine, thereby increasing the temperature of the working fluid entering the organic Rankine cycle evaporator and correspondingly reducing the amount of heat absorbed from the heat storage unit, thereby improving the power generation efficiency of the heat stored in the heat storage unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a system block diagram of the Carnot battery energy storage system provided in an embodiment of the present application.

[0027] Description of Figure Numbers:

[0028] 100. Carnot battery energy storage system;

[0029] 10. Heat pump unit; 1. First evaporator; 2. Heat pump regenerator; 3. Heat pump compressor; 4. First condenser; 5. Pressure reducing device;

[0030] 20. Heat storage unit; 21. First heat storage tank; 22. Second heat storage tank;

[0031] 30. Organic Rankine cycle unit; 31. Organic Rankine cycle evaporator; 32. Organic Rankine cycle turbine; 33. Organic Rankine cycle generator; 34. Organic Rankine cycle regenerator; 35. Organic Rankine cycle condenser; 36. Pump; 37. Regenerator assembly; 371. First regenerator; 372. Second regenerator; 373. Connecting pipes; 39. First compressor. DETAILED DESCRIPTION

[0032] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0035] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0036] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0037] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0038] Figure 1 This is a system block diagram of the Carnot battery energy storage system provided in an embodiment of the present application.

[0039] Reference Figure 1 The Carnot battery energy storage system 100 provided in an embodiment of the present application includes a heat pump unit 10, a heat storage unit 20, and an organic Rankine cycle unit 30. The heat pump unit 10 is used to absorb heat energy from a waste heat source and transfer and store it in the heat storage unit 20. The organic Rankine cycle unit 30 includes an organic Rankine cycle evaporator 31, an organic Rankine cycle turbine 32, an organic Rankine cycle regenerator 34, an organic Rankine cycle condenser 35, a pump 36, and a regenerator assembly 37.

[0040] The heat storage working medium side of the organic Rankine cycle evaporator 31 is connected in series to the heat storage unit 20. The outlet of the organic Rankine cycle side of the organic Rankine cycle evaporator 31 is connected to the inlet of the heat release side of the organic Rankine cycle regenerator 34 through the organic Rankine cycle turbine 32. The outlet of the heat release side of the organic Rankine cycle regenerator 34 is connected to the inlet of the heat absorption side of the organic Rankine cycle regenerator 34 through the organic Rankine cycle condenser 35 and pump 36. The outlet of the heat absorption side of the organic Rankine cycle regenerator 34 is connected to the inlet of the organic Rankine cycle side of the organic Rankine cycle evaporator 31 through the heat absorption side of the regenerator assembly 37. The middle section of the organic Rankine cycle turbine 32 is connected to the heat release side of the regenerator assembly 37.

[0041] The Carnot battery energy storage system 100 includes a heat pump unit 10, a heat storage unit 20 and an organic Rankine cycle unit 30. The heat pump unit 10 is used to absorb the heat energy of the waste heat source, transfer and store it in the heat storage unit 20. The heat pump unit 10 can store the heat energy of the waste heat source in the heat storage unit 20.

[0042] In the organic Rankine cycle unit 30, the heat storage working medium side of the organic Rankine cycle evaporator 31 is connected in series to the heat storage unit 20. The outlet of the organic Rankine cycle side of the organic Rankine cycle evaporator 31 is connected to the inlet of the heat release side of the organic Rankine cycle regenerator 34 through the organic Rankine cycle turbine 32. The outlet of the heat release side of the organic Rankine cycle regenerator 34 is connected to the inlet of the heat absorption side of the organic Rankine cycle regenerator 34 through the organic Rankine cycle condenser 35 and the pump 36. The outlet of the heat absorption side of the organic Rankine cycle regenerator 34 is connected to the inlet of the organic Rankine cycle side of the organic Rankine cycle evaporator 31 through the heat absorption side of the regenerator assembly 37.

[0043] In this way, the heat stored in the heat storage unit 20 can be dissipated by the heat storage medium in the organic Rankine cycle evaporator 31, absorbed by the working medium flowing in the organic Rankine cycle side of the organic Rankine cycle evaporator 31, and then enter the organic Rankine cycle turbine 32 to generate power. The organic Rankine cycle unit 30 converts the thermal energy stored in the heat storage unit 20 into electrical energy and releases it. Thus, the heat pump unit 10, the heat storage unit 20, and the organic Rankine cycle unit 30 work together to store electrical energy and heat energy from waste heat sources in the form of thermal energy, and convert this thermal energy into electrical energy when needed.

[0044] Furthermore, since the outlet of the heat absorption side of the organic Rankine cycle regenerator 34 is connected to the inlet of the organic Rankine cycle side of the organic Rankine cycle evaporator 31 through the heat absorption side of the regenerator assembly 37, the working fluid flowing out of the outlet of the heat absorption side of the organic Rankine cycle regenerator 34 will enter the organic Rankine cycle evaporator 31 only after being reheated by the regenerator assembly 37. The temperature of the working fluid flowing out of the organic Rankine cycle evaporator 31 and entering the organic Rankine cycle turbine 32 is further increased, which can improve the power generation efficiency of the organic Rankine cycle turbine 32 after performing work. Furthermore, since the middle section of the organic Rankine cycle turbine 32 is connected to the heat release side of the regenerator assembly 37 and can serve as a heat source for the heat absorption side of the regenerator assembly 37, the regenerator assembly 37 can efficiently utilize the temperature of the working fluid during the operation of the organic Rankine cycle turbine 32, thereby increasing the temperature of the working fluid entering the organic Rankine cycle evaporator 31, and correspondingly reducing the amount of heat absorbed from the heat storage unit 20, thereby improving the power generation efficiency of the heat stored in the heat storage unit 20.

[0045] In the embodiment of the present application, the organic Rankine cycle unit 30 is a supercritical organic Rankine cycle, which has a higher power generation efficiency than a subcritical organic Rankine cycle.

[0046] In specific implementation, the regenerator assembly 37 includes a first regenerator 371, a second regenerator 372 and a first compressor 39. The heat absorption side of the first regenerator 371 and the heat absorption side of the second regenerator 372 are connected in series between the outlet of the heat absorption side of the organic Rankine cycle regenerator 34 and the inlet of the organic Rankine cycle side of the organic Rankine cycle evaporator 31.

[0047] like Figure 1 As shown by the dotted line, the heat release side of the first regenerator 371 and the heat release side of the second regenerator 38 are connected in series between the middle section of the organic Rankine cycle turbine 32 and the inlet of the first compressor 39, and the outlet of the first compressor 39 is connected to the inlet of the heat absorption side of the second regenerator 372.

[0048] In this way, the medium-temperature and medium-pressure medium flowing out from the middle section of the organic Rankine cycle turbine 32 heats the medium in the heat absorption side of the second regenerator 372 when flowing through the heat release side of the second regenerator 372, and then heats the medium in the heat absorption side of the first regenerator 371 when flowing through the heat release side of the first regenerator 371. In this way, the working fluid flowing out from the outlet of the heat absorption side of the organic Rankine cycle regenerator 34 will be heated twice by the first regenerator 371 and the second regenerator 372.

[0049] In the embodiment of the present application, the outlet of the heat absorption side of the first regenerator 371 and the inlet of the heat absorption side of the second regenerator 372 are connected in series via a connecting pipe 373, and the outlet of the first compressor 39 is connected to the connecting pipe 373. Thus, after being compressed by the first compressor 39, the working fluid, which has both increased pressure and temperature, mixes with the working fluid flowing from the heat absorption side of the first regenerator 371. The provision of the first compressor 39 further increases the pressure and temperature of the working fluid exiting the middle section of the organic Rankine cycle turbine 32, reaching a level comparable to that of the working fluid flowing out of the heat absorption side outlet of the first regenerator 371.

[0050] In this embodiment, a pipe connects the middle section of the organic Rankine cycle turbine 32 to the heat release inlet of the second regenerator 372. A flow control valve (not shown) is installed on the pipe. This allows the amount of working fluid flowing from the organic Rankine cycle turbine 32 into the second regenerator 372 to be adjusted as needed.

[0051] In the embodiment of the present application, the organic Rankine cycle turbine 32 is also connected to the organic Rankine cycle generator 33 to convert the expansion work into electrical energy.

[0052] Furthermore, the heat pump unit 10 is configured as a Brayton heat pump unit, and the working fluid circulating in the heat pump unit is a gaseous working fluid, which can be well adapted to the waste heat source and the organic Rankine cycle unit 30.

[0053] The heat pump unit in the related art uses a steam Rankine cycle heat pump, whose heat absorption and release processes are primarily isothermal. This heat exchange process with existing waste heat sources is a variable temperature process. This mismatch in the heat exchange process results in significant energy loss and large temperature differences, which can affect the life of the heat exchanger. In contrast, the heat pump unit in the present embodiment is a Brayton heat pump unit. The Brayton cycle heat pump primarily circulates in the gaseous region, avoiding isothermal heat exchange and significantly improving waste heat matching. This solves the waste heat source matching problem faced by Carnot battery energy storage systems in the energy storage field.

[0054] In the embodiment of the present application, the heat pump unit 10 includes: a first evaporator 1 , a heat pump regenerator 2 , a heat pump compressor 3 , a first condenser 4 and a pressure reducing device 5 .

[0055] The heat release side of the first evaporator 1 is connected to the waste heat source, and the heat absorption side outlet of the first evaporator 1 is connected to the heat absorption side inlet of the heat pump regenerator 2. The heat absorption side outlet of the heat pump regenerator 2 is connected to the heat release side inlet of the first condenser 4 through the heat pump compressor 3. The heat release side outlet of the first condenser 4 is connected to the heat release side inlet of the heat pump regenerator 2. The heat release side outlet of the heat pump regenerator 2 is connected to the heat absorption side inlet of the first evaporator 1 through the pressure reducing device 5.

[0056] By providing a heat pump regenerator 2, the working fluid flowing out of the first evaporator 1 is heated before entering the heat pump compressor 3, further increasing the inlet temperature of the heat pump compressor 3. This improves the power generation efficiency of the power generation side while maintaining the same pressure ratio of the heat pump compressor 3, with little impact on the COP of the heat pump compressor 3. Furthermore, the temperature of the working fluid entering the heat release side of the first condenser 4 is increased, further increasing the temperature of the heat storage working fluid stored in the second heat storage tank 22 of the heat storage unit 20, which is beneficial to the overall energy storage efficiency of the Carnot battery energy storage system 100.

[0057] In this embodiment of the present application, the pressure reducing device 5 can be a turbine. The pressure reducing device 5 is also connected to a first generator, which is used to power the heat pump compressor 3. In this way, the expansion work of the pressure reducing device 5 generates electrical energy, which can be used to power the heat pump compressor 3, reducing power consumption.

[0058] In the present application, continue to refer to Figure 1 , the heat storage unit 20 includes a first heat storage tank 21 and a second heat storage tank 22. It is understandable that Figure 1 In order to simplify the diagram, the pipes connected to the inlet and outlet of the first heat storage tank 21 can be omitted and merged into one channel, and the pipes connected to the inlet and outlet of the second heat storage tank 22 can be omitted and merged into one channel. However, the connection relationship still follows the following description.

[0059] That is, the outlet of the first heat storage tank 21 is connected to the inlet of the heat storage medium side of the first condenser 4, and the outlet of the heat storage medium side of the first condenser 4 is connected to the inlet of the second heat storage tank 22. The outlet of the second heat storage tank 22 is connected to the inlet of the heat storage medium side of the organic Rankine cycle evaporator 31. The outlet of the heat storage medium side of the organic Rankine cycle evaporator 31 is connected to the inlet of the first heat storage tank 21.

[0060] In this way, when the heat storage working fluid flows from the first heat storage tank 21 through the heat storage working fluid side of the first condenser 4, it absorbs heat from the heat release side of the first condenser 4, increasing its temperature before flowing into the second heat storage tank 22. When the heat storage working fluid flowing out of the second heat storage tank 22 flows through the heat storage working fluid side of the organic Rankine cycle evaporator 31, it dissipates heat to the organic Rankine cycle side of the organic Rankine cycle evaporator 31 and transfers heat to the working fluid on the organic Rankine cycle side of the organic Rankine cycle evaporator 31. The temperature of the heat storage working fluid flowing out of the heat storage working fluid side of the organic Rankine cycle evaporator 31 decreases before entering the first heat storage tank 21. As a result, the temperature of the heat storage working fluid in the first heat storage tank 21 is lower than that of the heat storage working fluid in the second heat storage tank 22.

[0061] In this embodiment of the present application, an on-off valve is provided on the pipe between the outlet of the first heat storage tank 21 and the inlet of the heat storage medium side of the first condenser 4. Furthermore, an on-off valve is provided on the pipe between the outlet of the heat storage medium side of the first condenser 4 and the inlet of the second heat storage tank 22. Furthermore, an on-off valve is provided on the pipe between the outlet of the second heat storage tank 22 and the inlet of the heat storage medium side of the organic Rankine cycle evaporator 31. Furthermore, an on-off valve is provided on the pipe between the outlet of the heat storage medium side of the organic Rankine cycle evaporator 31 and the inlet of the first heat storage tank 21.

[0062] The following combination Figure 1 , detailing the operating principle of the Carnot battery energy storage system of this application.

[0063] The heat pump unit 10 uses electric energy to absorb the heat energy of the waste heat source and increase the temperature of the working fluid of the heat pump unit. The increased working fluid transfers the heat to the heat storage unit 20 for storage through the first condenser 4. The organic Rankine cycle unit 30 absorbs the heat in the heat storage unit 20 to perform work.

[0064] In the heat pump unit 10, after absorbing heat in the first evaporator 1 and the heat pump regenerator 2, the working fluid enters the heat pump compressor 3 for compression. The compressed working fluid then enters the heat release side of the first condenser 4, transferring heat to the heat storage unit 2. The first condenser 4 is connected to the heat release side of the heat pump regenerator 2, which is in turn connected to the pressure reducing device 5 (turbine). The working fluid on the heat release side of the first condenser 4 passes through the heat pump regenerator 2 and then enters the turbine for expansion and temperature reduction before returning to the first evaporator 1.

[0065] The working process of the working medium in the heat pump unit 10 is as follows:

[0066] After absorbing heat on the heat-absorbing side of the first evaporator 1 and the heat-absorbing side of the heat pump regenerator 2, the working fluid enters the heat pump compressor 3 (at this time, the working fluid's state is: 156°C, 1.5 MPa), where it is compressed. The compressed working fluid (at this time, the working fluid's state is: 176.5°C, 2.52 MPa) enters the heat-releasing side of the first condenser 4, where it transfers heat to the heat storage working fluid flowing in the heat-absorbing side of the first condenser 4. The heat storage working fluid flowing in the heat-absorbing side of the first condenser 4 is heated and then enters the second heat storage tank 22. The working fluid exiting the heat-releasing side of the first condenser 4 enters the heat-releasing side of the heat pump regenerator 2 (at this time, the working fluid's state is: 161°C, 2.52 MPa), heating the working fluid that has flowed out of the first evaporator 1 and entered the heat-absorbing side of the heat pump regenerator 2. The working fluid coming out of the heat release side of the heat pump regenerator 2 enters the pressure reducing device 5, that is, the turbine (the state of the working fluid at this time is: 159.4℃, 2.52MPa). The working fluid after turbine expansion and temperature reduction returns to the heat absorption side of the first evaporator 1.

[0067] In the heat storage unit 20, during the charging process, the heat storage medium in the first heat storage tank 21 is heated by the first condenser 4 and then sent to the second heat storage tank 22. During the discharge process, the heat storage medium in the second heat storage tank 22 absorbs heat through the organic Rankine cycle evaporator 31 and then flows into the first heat storage tank 21.

[0068] The working process of the heat storage medium in the heat storage unit 20 is as follows:

[0069] The heat storage medium flows from the outlet of the first heat storage tank 21 into the heat absorption side of the first condenser 4, is heated by the heat release side of the first condenser 4, and then flows into the inlet of the second heat storage tank 22. The heat storage medium flowing out of the outlet of the second heat storage tank 22 flows into the heat release side of the organic Rankine cycle evaporator 31, heating the working medium flowing in the heat absorption side of the organic Rankine cycle evaporator 31. The heat storage working medium flowing out of the heat release side of the organic Rankine cycle evaporator 31 enters the first heat storage tank through the inlet of the first heat storage tank 21.

[0070] In the organic Rankine cycle unit 30 , heat is recovered by relying on the exhaust air flow in the middle section of the organic Rankine cycle turbine 32 , thereby reducing the amount of heat absorbed by the organic Rankine cycle evaporator 31 and improving power generation efficiency.

[0071] After absorbing heat on the heat-absorbing side of the organic Rankine cycle evaporator 31, the working fluid performs work in the organic Rankine cycle turbine 32. A stream of working fluid that has completed work in the organic Rankine cycle turbine 32 is cooled in the organic Rankine cycle regenerator 34 and then in the organic Rankine cycle condenser 35 before entering the pump 36. The exhaust air from the middle section of the organic Rankine cycle turbine 32 enters the second regenerator 372, heating the combined working fluid. The exhaust air then enters the first regenerator 371, heating the working fluid exiting the pump 36. The exhaust air is then pressurized by the first compressor 39 and merges with the working fluid exiting the heat-absorbing side of the first regenerator 371, forming the combined working fluid. The combined working fluid passes through the heat-absorbing side of the second regenerator 372, where it is heated, before entering the organic Rankine cycle evaporator 31, where it is heated, and then entering the organic Rankine cycle turbine 32 to perform work.

[0072] The working process of the working medium in the organic Rankine cycle unit 30 is as follows:

[0073] The working fluid enters the heat absorption side of the organic Rankine cycle evaporator 31 (at this time, the working fluid is at 82.95°C, 4.3 MPa), where it exchanges heat with the heat storage working fluid flowing out of the second heat storage tank 22 and entering the heat release side of the organic Rankine cycle evaporator 31. The working fluid flowing out of the heat absorption side of the organic Rankine cycle evaporator 31 enters the organic Rankine cycle turbine 32 (at this time, the working fluid is at 166.55°C, 4.3 MPa), where it performs work. A stream of working fluid that has completed work in the organic Rankine cycle turbine 32 (at this time, the working fluid is at 121.98°C, 1.253 MPa) is cooled on the heat release side of the organic Rankine cycle regenerator 34, further cooled by the organic Rankine cycle condenser 35, and then enters the pump 36 (at this time, the working fluid is at 25°C, 1.253 MPa). The working fluid flowing out of the pump 36 passes through the heat absorption side of the organic Rankine cycle regenerator 34 and then flows into the heat absorption side of the first regenerator 371 .

[0074] like Figure 1 As shown by the dotted line in the figure, the exhaust air flow extracted from the middle section of the organic Rankine cycle turbine 32 (the working medium state at this time is: 161.16°C, 3.77 MPa) enters the heat release side of the second regenerator 372, heats the working medium flowing on the heat absorption side of the second regenerator 372 (i.e., the working medium after converging), and then enters the heat release side of the first regenerator 371 to heat the working medium passing through the pump 36 and the heat absorption side of the organic Rankine cycle regenerator 34. The exhaust air flowing out of the heat release side of the first regenerator 371 is finally pressurized by the first compressor 39 (the working medium is now in a state of 106.45°C, 3.77 MPa) and merges with the working medium flowing from the first regenerator 371 to the second regenerator 372 (the working medium flowing from the heat absorption side of the organic Rankine cycle regenerator 34 to the heat absorption side of the first regenerator 371), forming a merged working medium. The merged working medium first enters the heat absorption side of the second regenerator 372 and then flows back to the heat absorption side of the organic Rankine cycle evaporator 31, completing the cycle.

[0075] The Carnot battery energy storage system 100 of the embodiment of the present application includes a heat pump unit 10, a heat storage unit 20, and an organic Rankine cycle unit 30. The three units work together to use electrical energy to efficiently convert waste heat into high-temperature thermal energy for storage, and convert the thermal energy into electrical energy when needed. The heat pump unit 10 uses the thermal energy of the low-grade waste heat source to increase the temperature of the second heat storage tank 22. The supercritical compression and heat recovery organic Rankine cycle unit 30 converts the thermal energy of the second heat storage tank 22 into electrical energy and releases it. The Carnot battery energy storage system 100 solves the heat exchange problems faced by Carnot batteries in the field of energy storage between the waste heat source and the heat pump unit 10, and the heat pump unit 10 and the organic Rankine cycle unit 30. While improving the heat exchange effect of the heat exchanger, it also takes advantage of the high efficiency of the supercritical compression and heat recovery organic Rankine cycle.

[0076] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A Carnot battery energy storage system, characterized in that: It comprises a heat pump unit (10), a heat storage unit (20), and an organic Rankine cycle unit (30); the heat pump unit (10) is used to absorb heat energy from a waste heat source, transfer it to the heat storage unit (20), and store it; The organic Rankine cycle unit (30) includes: an organic Rankine cycle evaporator (31), an organic Rankine cycle turbine (32), an organic Rankine cycle regenerator (34), an organic Rankine cycle condenser (35), a pump (36), and a regenerator assembly (37); The heat storage working medium side of the organic Rankine cycle evaporator (31) is connected in series to the heat storage unit (20), the outlet of the organic Rankine cycle side of the organic Rankine cycle evaporator (31) is connected to the inlet of the heat release side of the organic Rankine cycle regenerator (34) through the organic Rankine cycle turbine (32), the outlet of the heat release side of the organic Rankine cycle regenerator (34) is connected to the inlet of the heat absorption side of the organic Rankine cycle regenerator (34) through the organic Rankine cycle condenser (35) and the pump (36); the outlet of the heat absorption side of the organic Rankine cycle regenerator (34) is connected to the inlet of the organic Rankine cycle side of the organic Rankine cycle evaporator (31) through the heat absorption side of the regenerator assembly (37); The middle section of the organic Rankine cycle turbine (32) is connected to the heat release side of the regenerator assembly (37).

2. The Carnot battery energy storage system according to claim 1, characterized in that: The regenerator assembly (37) includes a first regenerator (371), a second regenerator (372), and a first compressor (39), wherein the heat absorption side of the first regenerator (371) and the heat absorption side of the second regenerator (372) are sequentially connected in series between the outlet of the heat absorption side of the organic Rankine cycle regenerator (34) and the inlet of the organic Rankine cycle side of the organic Rankine cycle evaporator (31); The heat release side of the first regenerator (371) and the heat release side of the second regenerator (38) are sequentially connected in series between the middle section of the organic Rankine cycle turbine (32) and the inlet of the first compressor (39), and the outlet of the first compressor (39) is connected to the inlet of the heat absorption side of the second regenerator (372).

3. The Carnot battery energy storage system according to claim 2, characterized in that: The outlet of the heat absorption side of the first regenerator (371) and the inlet of the heat absorption side of the second regenerator (372) are connected in series via a connecting pipe (373), and the outlet of the first compressor (39) is in communication with the connecting pipe (373).

4. The Carnot battery energy storage system according to claim 2, characterized in that: The middle section of the organic Rankine cycle turbine (32) is connected to the inlet of the heat release side of the second regenerator 372 through a pipeline, and a flow control valve is provided on the pipeline.

5. The Carnot battery energy storage system according to claim 1, characterized in that: The organic Rankine cycle turbine (32) is also connected to an organic Rankine cycle generator (33).

6. The Carnot battery energy storage system according to any one of claims 1 to 5, characterized in that: The heat pump unit (10) is configured as a Brayton heat pump unit, and the working fluid circulating in the heat pump unit is a gaseous working fluid.

7. The Carnot battery energy storage system according to claim 6, characterized in that: The heat pump unit (10) comprises: a first evaporator (1), a heat pump regenerator (2), a heat pump compressor (3), a first condenser (4), and a pressure reducing device (5); The heat release side of the first evaporator (1) is in communication with the waste heat source, and the outlet of the heat absorption side of the first evaporator (1) is in communication with the inlet of the heat absorption side of the heat pump regenerator (2); the outlet of the heat absorption side of the heat pump regenerator (2) is in communication with the inlet of the heat release side of the first condenser (4) through the heat pump compressor (3); the outlet of the heat release side of the first condenser (4) is in communication with the inlet of the heat release side of the heat pump regenerator (2); the outlet of the heat release side of the heat pump regenerator (2) is in communication with the inlet of the heat absorption side of the first evaporator (1) through the pressure reducing device (5).

8. The Carnot battery energy storage system according to claim 7, characterized in that: The pressure reducing device (5) is a turbine; The pressure reducing device (5) is also connected to a first generator, and the first generator is used to supply power to the heat pump compressor (3).

9. The Carnot battery energy storage system according to claim 7, characterized in that: The heat storage unit (20) comprises a first heat storage tank (21) and a second heat storage tank (22); The outlet of the first heat storage tank (21) is communicated with the inlet of the heat storage working medium side of the first condenser (4); the outlet of the heat storage working medium side of the first condenser (4) is communicated with the inlet of the second heat storage tank (22); the outlet of the second heat storage tank (22) is communicated with the inlet of the heat storage working medium side of the organic Rankine cycle evaporator (31); and the outlet of the heat storage working medium side of the organic Rankine cycle evaporator (31) is communicated with the inlet of the first heat storage tank (21).

10. The Carnot battery energy storage system according to claim 9, characterized in that: A switch valve is provided on the pipeline between the outlet of the first heat storage tank (21) and the inlet of the heat storage working medium side of the first condenser (4); and / or A switch valve is provided on the pipeline between the outlet of the heat storage medium side of the first condenser (4) and the inlet of the second heat storage tank (22); and / or A switch valve is provided on the pipeline between the outlet of the second heat storage tank (22) and the inlet of the heat storage working medium side of the organic Rankine cycle evaporator (31); and / or A switch valve is provided on the pipeline between the outlet of the heat storage medium side of the organic Rankine cycle evaporator (31) and the inlet of the first heat storage tank (21).

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