Energy storage system

Abstract

The utility model discloses an energy storage system, and an energy storage power generation device comprises a CO2 energy storage system which is provided with a CO2 medium; a fused salt medium is arranged in the fused salt energy storage system, and the fused salt medium is used for storing energy; the cement kiln waste gas system is provided with waste gas, and the waste gas has heat; the first heat exchanger is connected between the fused salt energy storage system and the cement kiln waste gas system and used for storing waste gas heat in the cement kiln waste gas system in the fused salt energy storage system; and the second heat exchanger is connected between the CO2 energy storage system and the fused salt energy storage system and is used for exchanging heat so as to heat the CO2 medium. Therefore, the energy storage system can store waste gas heat in the cement kiln waste gas system through the fused salt energy storage system, the energy release effect of a CO2 medium is further improved when the CO2 energy storage system is in an energy release state, and the energy utilization efficiency of the energy storage system is improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an energy storage system. Background Art

[0002] At present, low partial pressure flue gas is one of the main sources of CO2 emissions, especially in the cement industry. In the cement industry, coal-fired boilers, gas boilers, lime production, cement kilns and other devices will produce a large amount of low partial pressure flue gas, which in turn emits a large amount of CO2. For the high carbon emission cement industry, the existing carbon capture technology can effectively capture and store carbon emissions in the cement production process for production and scientific research.

[0003] Among the related technologies, CO2 utilization technologies are mostly in the experimental stage, and there is little consideration for the integrated utilization of CO2 with thermal energy, solar energy, and electric energy. In addition, the existing energy storage and surplus electricity and waste heat utilization systems such as CO2 energy storage systems and molten salt systems are inefficient, and there is no coordination between multiple systems. Moreover, the above systems are unstable and intermittent. Utility Model Content

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to propose an energy storage system, which can store heat in the cement kiln exhaust gas system through a molten salt energy storage system, and further enhance the energy release effect of the CO2 medium when the CO2 energy storage system is in an energy release state, thereby improving the energy utilization efficiency of the energy storage system.

[0005] The energy storage system according to the embodiment of the present application includes: a CO2 energy storage system, wherein the CO2 energy storage system is provided with a CO2 medium, and the CO2 medium can be used for energy storage or energy release; a molten salt energy storage system, wherein a molten salt medium is provided in the molten salt energy storage system, and the molten salt medium is used for energy storage; a cement kiln exhaust gas system, wherein the cement kiln exhaust gas system is provided with exhaust gas, and the exhaust gas has heat; a first heat exchanger, wherein the first heat exchanger is connected between the molten salt energy storage system and the cement kiln exhaust gas system, and is used to store the exhaust gas heat in the cement kiln exhaust gas system in the molten salt energy storage system; and a second heat exchanger, wherein the second heat exchanger is connected between the CO2 energy storage system and the molten salt energy storage system and is used for heat exchange to heat the CO2 medium.

[0006] In the present application, the waste gas heat in the cement kiln exhaust gas system can be transferred to the molten salt medium through the first heat exchanger and stored in the molten salt energy storage system. The heat in the molten salt energy storage system can be transferred to the CO2 energy storage system through the second heat exchanger to heat the CO2 medium through the molten salt energy storage system. Thus, the energy storage system can store the waste gas heat in the cement kiln exhaust gas system through the molten salt energy storage system, and further enhance the energy release effect of the CO2 medium when the CO2 energy storage system is in the energy release state, thereby improving the energy utilization efficiency of the energy storage system.

[0007] In some embodiments of the present application, the CO2 energy storage system includes: a compressor, which is used to compress the CO2 medium; a first storage tank, which is used to store the CO2 medium compressed by the compressor; a second storage tank, which is connected to the first storage tank, and the energy-consuming equipment is provided between the second storage tank and the first storage tank, and the second storage tank is used to store the CO2 medium flowing out of the energy-consuming equipment, and can transport the CO2 medium to the intake side of the compressor.

[0008] In some embodiments of the present application, the connection between the second heat exchanger and the CO2 energy storage system is provided between the first storage tank and the energy consuming device.

[0009] In some embodiments of the present application, the molten salt energy storage system includes: a third storage tank and a fourth storage tank, both of which are used to store the molten salt medium, the connection between the second heat exchanger and the molten salt energy storage system is arranged between the first end of the third storage tank and the first end of the fourth storage tank, and the connection between the first heat exchanger and the molten salt energy storage system is arranged between the second end of the third storage tank and the second end of the fourth storage tank.

[0010] In some embodiments of the present application, the energy storage system further includes a third heat exchanger, which is connected between the CO2 energy storage system and the cement kiln exhaust gas system, and the exhaust gas heat in the cement kiln exhaust gas system can heat the CO2 medium through the third heat exchanger.

[0011] In some embodiments of the present application, the connection between the third heat exchanger and the CO2 energy storage system is arranged between the first storage tank and the energy-consuming equipment, and on the path of transporting the CO2 from the first storage tank to the energy-consuming equipment, the third heat exchanger is located on the upstream side of the second heat exchanger.

[0012] In some embodiments of the present application, the cement kiln exhaust system also includes an exhaust gas discharge end, which is used to discharge exhaust gas, and the connection between the third heat exchanger and the cement kiln exhaust system is arranged between the first heat exchanger and the exhaust gas discharge end.

[0013] In some embodiments of the present application, the CO2 energy storage system further includes a first cooling device, which is connected between the energy consuming equipment and the second storage tank and is used to cool the CO2 medium.

[0014] In some embodiments of the present application, the energy storage system also includes: a water energy storage system, which is provided with a water medium; a fourth heat exchanger, which is connected between the CO2 energy storage system and the water energy storage system, and the fourth heat exchanger is arranged on the exhaust side of the compressor, and the CO2 medium is suitable for heating the water medium at the fourth heat exchanger; a fifth heat exchanger, which is connected between the CO2 energy storage system and the water energy storage system, and the fifth heat exchanger is arranged between the first storage tank and the energy consuming equipment, and the water medium is suitable for heating the CO2 medium at the fifth heat exchanger.

[0015] In some embodiments of the present application, on the path of transporting the CO 2 from the first storage tank to the energy-consuming equipment, the fifth heat exchanger is located on the upstream side of the second heat exchanger.

[0016] In some embodiments of the present application, the water energy storage system includes: a fifth storage tank and a sixth storage tank, both of which are used to store the water medium, the connection between the fourth heat exchanger and the water energy storage system is arranged between the first end of the fifth storage tank and the first end of the sixth storage tank, and the connection between the fifth heat exchanger and the water energy storage system is arranged between the second end of the fifth storage tank and the second end of the sixth storage tank.

[0017] In some embodiments of the present application, the water energy storage system further includes a second cooling device, which is disposed between the fifth heat exchanger and the second end of the sixth storage tank and is used to cool the water medium.

[0018] In some embodiments of the present application, the energy consuming device is configured as a generator.

[0019] In some embodiments of the present application, the energy storage system further includes a power generation module, wherein the power generation module is used to be connected to a compressor in the CO2 energy storage system and to drive the compressor to operate.

[0020] In some embodiments of the present application, the power generation module includes: a photovoltaic power generation device and an AC-DC converter, the photovoltaic power generation device is used to generate electricity, and the AC-DC converter is connected between the photovoltaic power generation device and the compressor; and / or, the power generation module includes: a cement kiln waste heat power generation device, and the cement kiln waste heat power generation device is connected to the compressor.

[0021] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 is a schematic diagram of an energy storage system according to an embodiment of the present application;

[0024] Figure 2 It is a control flow chart of the energy storage system according to an embodiment of the present application.

[0025] Reference numerals:

[0026] Energy storage power generation system 100;

[0027] CO2 energy storage system 1; generator 11; compressor 12; first storage tank 13; second storage tank 14; first cooling device 15; first valve 16; second valve 17;

[0028] Molten salt energy storage system 2; third storage tank 21; fourth storage tank 22; first drive unit 23; second drive unit 24;

[0029] Cement kiln exhaust system 3; exhaust gas discharge end 31; fan 32;

[0030] Water energy storage system 4; fifth storage tank 41; sixth storage tank 42; third driving unit 43; fourth driving unit 44; second cooling device 45;

[0031] A first heat exchanger 51; a second heat exchanger 52; a third heat exchanger 53; a fourth heat exchanger 54; a fifth heat exchanger 55;

[0032] Photovoltaic power generation device 61; AC / DC converter 62; cement kiln preheating power generation device 63. DETAILED DESCRIPTION

[0033] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0034] Reference below Figure 1 An energy storage system 100 according to an embodiment of the present application is described.

[0035] The energy storage system 100 according to the embodiment of the present application includes: a CO2 energy storage system 1, a molten salt energy storage system 2 and a cement kiln exhaust gas system 3.

[0036] Among them, the CO2 energy storage system 1 is provided with a CO2 medium, and an energy-consuming device or system is connected to the CO2 energy storage system 1, and the CO2 medium can apply the stored energy to the energy-consuming device. Among them, "energy-consuming device or system" refers to a device or system that can utilize the energy of the CO2 medium, such as: a generator, a heat pump system, a refrigeration system, etc. Taking the generator 11 as an example, the generator 11 can be specifically constructed as a steam turbine, and the CO2 medium can be used to drive the generator 11 to operate during the energy release process to realize the power generation function of the generator 11. It should be noted that in this application, the energy-consuming device is described as a generator 11.

[0037] The molten salt energy storage system 2 is provided with a molten salt medium, and the molten salt medium can be used for energy storage, so that heat can be stored in the molten salt energy storage system 2 through the molten salt medium. The cement kiln exhaust gas system 3 has exhaust gas, and the exhaust gas has high heat. The cement kiln exhaust gas system 3 can perform dust removal on the exhaust gas to discharge the exhaust gas after the exhaust gas is treated in compliance with regulations.

[0038] Furthermore, the energy storage system 100 also includes a first heat exchanger 51 and a second heat exchanger 52, the first heat exchanger 51 is connected between the molten salt energy storage system 2 and the cement kiln exhaust gas system 3, and the first heat exchanger 51 is used to store the exhaust gas heat in the cement kiln exhaust gas system 3 in the molten salt energy storage system 2, and the second heat exchanger 52 is connected between the CO2 energy storage system 1 and the molten salt energy storage system 2 and is used for heat exchange to heat the CO2 medium.

[0039] It can be understood that the first heat exchanger 51 is respectively connected to the molten salt energy storage system 2 and the cement kiln exhaust gas system 3, and the exhaust gas heat in the cement kiln exhaust gas system 3 can be transferred to the molten salt medium in the molten salt energy storage system 2 through the first heat exchanger 51, so as to store the heat in the molten salt energy storage system 2 through the molten salt medium; the second heat exchanger 52 is respectively connected to the molten salt energy storage system 2 and the CO2 energy storage system 1, and the heat of the molten salt medium in the molten salt energy storage system 2 can be transferred to the CO2 medium on one side of the CO2 energy storage system 1 through the second heat exchanger 52, so as to heat the CO2 medium and increase the temperature of the CO2 medium, thereby improving the energy release effect of the CO2 medium.

[0040] It should be noted that when the energy-consuming device is configured as a steam turbine, the steam turbine can convert steam thermal energy into mechanical work, such as converting the thermal energy of the CO2 medium in a high temperature state into mechanical energy for the rotation of the turbine rotor, etc. Therefore, the power generation effect of the CO2 energy storage system 1 can be further improved by increasing the temperature of the CO2 medium.

[0041] It should be noted that, at present, in the cement industry, coal-fired boilers, gas boilers, lime production, cement kilns and other devices will produce a large amount of low-pressure flue gas and emit a large amount of CO2. In the related technology, the waste heat utilization system of cement kilns is unstable and intermittent, which leads to many adverse effects on the utilization of waste heat of cement kilns. Among them, CO2 utilization technology is mostly in the experimental stage, and there is little consideration for the scenario of integrated utilization of CO2 with thermal energy, solar energy, and electric energy. In addition, the existing energy storage and waste electricity and waste heat utilization systems such as CO2 energy storage systems and molten salt systems are inefficient, and there is no connection between multiple systems. Moreover, the waste heat utilization system of cement kilns and photovoltaic power generation systems are unstable and intermittent. Generally, the above energy is converted into electrical energy and stored through batteries, but the cost of battery energy storage is high, which leads to low heat utilization of cement kiln preheating and photovoltaic power generation systems.

[0042] In the present application, the exhaust gas heat in the cement kiln exhaust gas system 3 can be transferred to the molten salt medium through the first heat exchanger 51 and stored in the molten salt energy storage system 2. The heat in the molten salt energy storage system 2 can be transferred to the CO2 energy storage system 1 through the second heat exchanger 52, so as to heat the CO2 medium through the molten salt energy storage system 2, thereby improving the energy release effect of the CO2 medium in the CO2 energy storage system 1, thereby improving the energy utilization efficiency of the energy storage system 100 in the cement kiln exhaust gas system 3.

[0043] Reference Figure 1 It can be understood that when the cement kiln exhaust gas system 3 discharges exhaust gas, the heat of the exhaust gas can be first stored in the molten salt energy storage system 2, and when the CO2 energy storage system 1 is releasing energy, the stored heat is transferred to the CO2 energy storage system 1 through the molten salt energy storage system 2 to prevent the energy release efficiency of the CO2 energy storage system 1 from being reduced due to insufficient CO2 medium temperature, thereby improving the energy storage system 100's utilization effect of the exhaust gas heat in the cement kiln exhaust gas system 3, and solving the problem of low utilization rate of cement kiln waste heat due to the instability and intermittent nature of cement kiln waste heat.

[0044] like Figure 1 As shown, in some embodiments of the present application, the CO2 energy storage system 1 includes: a compressor 12 , a first storage tank 13 and a second storage tank 14 .

[0045] Among them, the compressor 12 is used to compress the CO2 medium, the first storage tank 13 is used to store the CO2 medium compressed by the compressor 12, the second storage tank 14 is connected to the first storage tank 13, and the above-mentioned generator 11 is provided between the second storage tank 14 and the first storage tank 13, the second storage tank 14 is used to store the CO2 medium flowing out of the generator 11, and the second storage tank 14 can transport the CO2 medium to the intake side of the compressor 12.

[0046] Reference Figure 1It can be understood that the compressor 12 is used to compress the CO2 medium to convert the CO2 medium into a high-temperature and high-pressure state, and the CO2 medium compressed by the compressor 12 can be stored in the first storage tank 13, that is, the first storage tank 13 is used to store the CO2 medium in a high-pressure state. When the CO2 energy storage system 1 needs to generate electricity, the CO2 medium in a high-pressure state in the first storage tank 13 is transported to the second storage tank 14, and the generator 11 can be driven to generate electricity during the transportation of the CO2 medium.

[0047] Furthermore, after the CO2 medium flows through the generator 11, it can further flow to the second storage tank 14 and be stored in the second storage tank 14. The CO2 medium consumes energy in the process of flowing through the generator 11 and is converted into a low-pressure CO2 medium and stored in the second storage tank 14. That is, the CO2 medium in the second storage tank 14 is in a low-pressure state.

[0048] When the content of high-pressure CO2 medium in the CO2 energy storage system 1 decreases, the second storage tank 14 delivers CO2 medium to the compressor 12 to generate high-pressure CO2 medium through compression by the compressor 12 to meet the power generation demand of the CO2 energy storage system 1.

[0049] like Figure 1 As shown, in some embodiments of the present application, the connection between the second heat exchanger 52 and the CO2 energy storage system 1 is arranged between the first storage tank 13 and the generator 11, so that the heat stored in the molten salt energy storage system 2 can be used to heat the CO2 medium transported from the first storage tank 13 to the generator 11 side, so as to increase the temperature of the CO2 medium transported to the generator 11 and ensure the power generation effect of the generator 11.

[0050] like Figure 1 As shown, in some embodiments of the present application, the molten salt energy storage system 2 includes a third storage tank 21 and a fourth storage tank 22 .

[0051] Among them, the third storage tank 21 and the fourth storage tank 22 are both used to store molten salt medium, the connection between the second heat exchanger 52 and the molten salt energy storage system 2 is arranged between the first end of the third storage tank 21 and the first end of the fourth storage tank 22, and the connection between the first heat exchanger 51 and the molten salt energy storage system 2 is arranged between the second end of the third storage tank 21 and the second end of the fourth storage tank 22. Thus, molten salt medium of different temperatures can be stored in the third storage tank 21 and the fourth storage tank 22 respectively, and when the molten salt medium flows through the first heat exchanger 51, it exchanges heat with the exhaust gas in the cement kiln exhaust system 3.

[0052] In a further embodiment of the present application, the molten salt energy storage system 2 further includes a first driving unit 23 and a second driving unit 24, wherein the first driving unit 23 is used to drive the molten salt medium in the third storage tank 21 to be transported to the side of the fourth storage tank 22, and the second driving unit 24 is used to drive the molten salt medium in the fourth storage tank 22 to be transported to the side of the third storage tank 21. Thus, the circulation of the molten salt medium in the third storage tank 21 and the fourth storage tank 22 can be achieved.

[0053] Reference Figure 1 The first driving unit 23 is disposed between the second end of the third storage tank 21 and the first heat exchanger 51 , and the second driving unit 24 is disposed between the first end of the fourth storage tank 22 and the second heat exchanger 52 .

[0054] In the process of the first driving unit 23 driving the molten salt medium to be transported from the third storage tank 21 to the fourth storage tank 22, the molten salt medium flows through the first heat exchanger 51, and the exhaust gas in the cement kiln exhaust system 3 can be heat exchanged with the molten salt medium through the first heat exchanger 51 to increase the temperature of the molten salt medium, and the molten salt medium with increased temperature can be stored in the fourth storage tank 22; in the process of the second driving unit 24 driving the molten salt medium to be transported from the fourth storage tank 22 to the third storage tank 21, the molten salt medium flows through the second heat exchanger 52, and the high-temperature molten salt medium exchanges heat with the CO2 medium through the second heat exchanger 52 to increase the temperature of the CO2 medium, and the CO2 medium with increased temperature is transported to the generator 11 to ensure the power generation efficiency of the generator 11, and the molten salt medium is stored in the third storage tank 21 after the temperature drops.

[0055] It is understandable that the temperature of the molten salt medium stored in the third storage tank 21 is lower than the temperature of the molten salt medium stored in the fourth storage tank 22. When the molten salt medium is in a low temperature state, the molten salt medium is in a solid state; when the molten salt medium is in a high temperature state, the molten salt medium is in a liquid state.

[0056] In some embodiments of the present application, the first driving unit 23 and the second driving unit 24 can be configured as a molten salt pump, which has the advantages of high efficiency, stable operation, low vibration, low noise, and long service life, and can ensure the transportation effect of the molten salt medium. The molten salt medium can be nitrate, etc., and the type of the molten salt medium is not specifically limited here.

[0057] like Figure 1 As shown, in some embodiments of the present application, the energy storage system 100 also includes a third heat exchanger 53, which is connected between the CO2 energy storage system 1 and the cement kiln exhaust gas system 3, and the exhaust gas heat in the cement kiln exhaust gas system 3 can heat the CO2 medium through the third heat exchanger 53.

[0058] Among them, the exhaust gas in the cement kiln exhaust gas system 3 has the characteristic of high temperature. When the exhaust gas flows through the third heat exchanger 53, the exhaust gas in a high temperature state can exchange heat with the CO2 medium to increase the temperature of the CO2 medium, thereby heating the CO2 medium through the waste heat in the cement kiln exhaust gas system 3, and improving the power generation effect of the generator 11 by increasing the temperature of the CO2 medium.

[0059] like Figure 1 As shown, in a further embodiment of the present application, the connection between the third heat exchanger 53 and the CO2 energy storage system 1 is arranged between the first storage tank 13 and the generator 11, and the third heat exchanger 53 is located on the upstream side of the second heat exchanger 52 on the path of transporting CO2 from the first storage tank 13 to the generator 11.

[0060] Among them, when the first storage tank 13 transports the CO2 medium to the side of the generator 11, the exhaust gas can exchange heat with the CO2 medium at the third heat exchanger 53 to increase the temperature of the CO2 medium, and the molten salt medium can exchange heat with the CO2 medium at the second heat exchanger 52 to further increase the temperature of the CO2 medium. In this way, the CO2 medium is heated multiple times on the path of transporting the CO2 medium from the first storage tank 13 to the side of the generator 11 to gradually increase the temperature of the CO2 medium, so that the CO2 medium in a high temperature state is input into the generator 11 to generate electricity for load use.

[0061] like Figure 1 As shown, in some embodiments of the present application, the cement kiln exhaust system 3 also includes an exhaust gas discharge port 31, which is used for exhausting exhaust gas, and the connection between the third heat exchanger 53 and the cement kiln exhaust system 3 is arranged between the first heat exchanger 51 and the exhaust gas discharge port 31.

[0062] On the exhaust gas discharge path in the cement kiln exhaust gas system 3, the first heat exchanger 51 is arranged upstream of the third heat exchanger 53, that is, in the exhaust gas discharge process, the exhaust gas first exchanges heat with the molten salt medium at the first heat exchanger 51, and then exchanges heat with the CO2 medium at the third heat exchanger 53.

[0063] It can be understood that, in the exhaust path of the exhaust gas, since the first heat exchanger 51 is arranged upstream of the third heat exchanger 53, the temperature of the exhaust gas that exchanges heat with the molten salt medium at the upstream is higher than the temperature of the exhaust gas that exchanges heat with the CO2 medium at the downstream, that is, more heat in the exhaust gas is stored in the molten salt energy storage system 2. Therefore, the heating effect of the molten salt energy storage system 2 on the CO2 medium at the second heat exchanger 52 is better than the heating effect of the exhaust gas on the CO2 medium at the third heat exchanger 53, so that the temperature of the CO2 medium can be gradually increased through the third heat exchanger 53 and the second heat exchanger 52 respectively.

[0064] like Figure 1As shown, in some embodiments of the present application, the CO2 energy storage system 1 further includes a first cooling device 15, which is connected between the generator 11 and the second storage tank 14, and is used to cool the CO2 medium.

[0065] It is understandable that the CO2 medium discharged from the generator 11 needs to flow through the first cooling device 15 when flowing to the second storage tank 14. The first cooling device 15 is used to cool the CO2 medium to prevent the temperature of the CO2 medium from being too high, thereby ensuring the storage effect of the second storage tank 14 on the CO2 medium in a low-pressure state.

[0066] Among them, the first cooling device 15 can be constructed as a cooler, which can exchange heat with the outside to reduce the temperature of the CO2 medium, and after the temperature of the CO2 medium approaches the ambient temperature, it can be stored in the second storage tank 14 for the next round of energy storage process.

[0067] In some embodiments of the present application, the energy storage system 100 further includes a water energy storage system 4, and the water energy storage system 4 is provided with a water medium, where the "water medium" refers to a liquid medium such as pure water or an aqueous solution.

[0068] Reference Figure 1 The energy storage system 100 further includes a fourth heat exchanger 54 and a fifth heat exchanger 55. The fourth heat exchanger 54 is connected between the CO2 energy storage system 1 and the water energy storage system 4, and the fourth heat exchanger 54 is arranged on the exhaust side of the compressor 12, and the CO2 medium can heat the water medium at the fourth heat exchanger 54; the fifth heat exchanger 55 is connected between the CO2 energy storage system 1 and the water energy storage system 4, and the fifth heat exchanger 55 is arranged between the first storage tank 13 and the generator 11, and the water medium can heat the CO2 medium at the fifth heat exchanger 55.

[0069] Among them, the fourth heat exchanger 54 is arranged on the exhaust side of the compressor 12, and the water medium can exchange heat with the CO2 medium at the fourth heat exchanger 54 to store the heat in the CO2 energy storage system 1 in the water energy storage system 4. At the same time, the compressed CO2 medium in a high temperature and high pressure state can be cooled by the water energy storage system 4, so as to facilitate the storage of the high-pressure CO2 medium through the first storage tank 13.

[0070] Furthermore, the water medium in the water energy storage system 4 can exchange heat with the CO2 medium at the fifth heat exchanger 55 to increase the temperature of the CO2 medium to ensure the driving effect of the CO2 medium on the generator 11. In other words, the water energy storage system 4 can cool the compressed CO2 medium so as to store the high-pressure CO2 medium through the first storage tank 13, and the heat stored in the water energy storage system 4 can be fed back to the CO2 medium transported from the first storage tank 13 to the generator 11 through the fifth heat exchanger 55, so as to store thermal energy through the water energy storage system 4, and increase the temperature of the CO2 medium when power generation is required to ensure the power generation efficiency of the generator 11.

[0071] like Figure 1 As shown, in some embodiments of the present application, on the path of transporting CO 2 from the first storage tank 13 to the generator 11 , the fifth heat exchanger 55 is located on the upstream side of the second heat exchanger 52 .

[0072] It is understandable that, based on the specific heat capacity characteristics of the water medium and the molten salt medium, the ability of the water medium to store heat is weaker than that of the molten salt medium, so that the heating effect of the molten salt medium on the CO2 medium at the second heat exchanger 52 is better than the heating effect of the water medium on the CO2 medium at the fifth heat exchanger 55. Therefore, on the path of transporting CO2 from the first storage tank 13 to the generator 11, the second heat exchanger 52 is arranged downstream of the fifth heat exchanger 55. After the temperature of CO2 is increased at the fifth heat exchanger 55 by the water medium, the temperature of the CO2 medium can be further increased at the second heat exchanger 52 by the molten salt medium, thereby increasing the temperature of the CO2 medium entering the generator 11, improving the power generation efficiency of the generator 11, and ensuring the power generation effect of the generator 11.

[0073] like Figure 1 As shown, in some embodiments of the present application, the water energy storage system 4 includes: a fifth storage tank 41 and a sixth storage tank 42 .

[0074] The fifth storage tank 41 and the sixth storage tank 42 are both used to store water medium, the connection between the fourth heat exchanger 54 and the water energy storage system 4 is arranged between the first end of the fifth storage tank 41 and the first end of the sixth storage tank 42, and the connection between the fifth heat exchanger 55 and the water energy storage system 4 is arranged between the second end of the fifth storage tank 41 and the second end of the sixth storage tank 42. Thus, water medium of different temperatures can be stored through the fifth storage tank 41 and the sixth storage tank 42, respectively, and the high heat capacity characteristics of the water medium can be used to store heat energy in the water energy storage system 4. When the water medium flows through the fourth heat exchanger 54, the water medium can cool the CO2 medium and store energy; when the water medium flows through the fifth heat exchanger 55, the water medium can heat the CO2 medium and release energy.

[0075] In a further embodiment of the present application, the water energy storage system 4 further includes a third driving unit 43 and a fourth driving unit 44, wherein the third driving unit 43 is used to drive the water medium in the fifth storage tank 41 to be transported to the side of the sixth storage tank 42, and the fourth driving unit 44 is used to drive the water medium in the sixth storage tank 42 to be transported to the side of the fifth storage tank 41. Thus, the circulation of the water medium in the fifth storage tank 41 and the sixth storage tank 42 can be achieved.

[0076] Reference Figure 1 The third driving unit 43 is disposed between the first end of the sixth storage tank 42 and the fourth heat exchanger 54 , and the fourth driving unit 44 is disposed between the second end of the fifth storage tank 41 and the fifth heat exchanger 55 .

[0077] When the third driving unit 43 drives the water medium to be transported from the fifth storage tank 41 to the sixth storage tank 42, the water medium flows through the fifth heat exchanger 55, and the water medium in the water energy storage system 4 can exchange heat with the CO2 medium through the fifth heat exchanger 55 to increase the temperature of the CO2 medium, and the water medium is stored in the sixth storage tank 42 after the heat exchange between the water medium and the CO2 medium; when the fourth driving unit 44 drives the water medium to be transported from the sixth storage tank 42 to the fifth storage tank 41, the water medium flows through the fourth heat exchanger 54, and the water medium can exchange heat with the CO2 medium in a high temperature state after being compressed by the compressor 12 through the fourth heat exchanger 54 to reduce the temperature of the CO2 medium, and store the heat energy from the CO2 energy storage system 1 in the water energy storage system 4, and the heated water medium is stored in the fifth storage tank 41.

[0078] It can be understood that the temperature of the water medium in the fifth storage tank 41 is higher than the temperature of the water medium in the sixth storage tank 42 .

[0079] In a further embodiment of the present application, the water energy storage system 4 further includes a second cooling device 45, which is disposed between the fifth heat exchanger 55 and the second end of the sixth storage tank 42, and is used to cool the water medium.

[0080] Among them, the water medium after flowing through the fifth heat exchanger 55 is cooled at the second cooling device 45 and then flows into the sixth storage tank 42 for storage, so as to reduce the temperature of the water medium stored in the sixth storage tank 42, thereby improving the cooling effect of the water energy storage system 4 on the CO2 medium at the fourth heat exchanger 54.

[0081] It is understandable that the water energy storage system 4 cools the high-temperature CO2 medium compressed by the compressor 12 at the fourth heat exchanger 54 through the water medium. If the temperature of the water medium is high, the cooling effect of the water medium on the CO2 medium will be weakened. Therefore, by setting the second cooling device 45, the temperature of the water medium stored in the sixth storage tank 42 can be reduced, thereby ensuring the cooling effect of the water energy storage system 4 on the compressed CO2 medium.

[0082] like Figure 1 As shown, in some embodiments of the present application, the CO2 energy storage system 1 further includes a first valve 16 and a second valve 17. The first valve 16 is disposed between the second storage tank 14 and the compressor 12, and is used to control the on-off between the second storage tank 14 and the compressor 12, so as to selectively deliver the CO2 medium to the compressor 12 side; the second valve 17 is disposed between the first storage tank 13 and the generator 11, and is used to control the on-off between the first storage tank 13 and the generator 11, so as to selectively deliver the high-pressure CO2 medium to the generator 11 side.

[0083] Preferably, the second valve 17 is disposed between the third heat exchanger 53 and the first storage tank 13 .

[0084] In some embodiments of the present application, the cement kiln exhaust system 3 further includes a fifth driving unit, which is used to drive the exhaust gas to flow. The fifth driving unit is arranged upstream of the first heat exchanger 51 and is configured as a fan 32 .

[0085] like Figure 1 As shown, in some embodiments of the present application, the energy storage power generation system also includes a power generation module, which is used to be connected to the compressor 12 in the CO2 energy storage system 1, and the power generation module is used to drive the compressor 12 to operate, so that the CO2 medium can be compressed by the compressor 12.

[0086] Among them, the power generation module can directly output electric energy to the compressor 12 by means of power generation, and drive the compressor 12 to operate, so that the CO2 medium can be compressed by the compressor 12 to form a high-pressure CO2 medium, and further the generator 11 can be driven by the CO2 medium to generate electricity.

[0087] In some embodiments of the present application, the power generation module includes: a photovoltaic power generation device 61 and an AC / DC converter 62, the photovoltaic power generation device 61 is used to generate electricity, and the AC / DC converter 62 is connected between the photovoltaic power generation device 61 and the compressor 12.

[0088] Therefore, the photovoltaic power generation device 61 can be used to convert light energy into electrical energy, and the compressor 12 can be driven by the electrical energy.

[0089] In some other embodiments of the present application, the power generation module includes: a cement kiln waste heat power generation device 63 , and the cement kiln waste heat power generation device 63 is connected to the compressor 12 .

[0090] Therefore, the cement kiln waste heat power generation device 63 can be used to convert thermal energy into electrical energy, and the compressor 12 can be driven by the electrical energy.

[0091] It can be understood that the power generation module can include both the photovoltaic power generation device 61 and the cement kiln waste heat power generation device 63, so as to generate electricity through the two power generation devices respectively to drive the compressor 12 to operate.

[0092] It should be noted that when the power generation power of the power generation module is greater than the load power, the power generation module can generate electricity to drive the compressor 12 to operate, so as to convert electrical energy into energy of CO2 medium and store it in the CO2 energy storage system 1, and release energy to generate electricity through the CO2 energy storage system 1 according to demand.

[0093] Reference Figure 1 , describing the energy storage and energy release process of each system in the energy storage system 100 according to an embodiment of the present application:

[0094] In the CO2 energy storage system 1, the electric energy generated by the power generation module drives the compressor 12 to operate, so as to compress the CO2 medium through the compressor 12, and cool the CO2 medium in a high-temperature and high-pressure state through the water medium at the fourth heat exchanger 54, and store the high-pressure CO2 in the first storage tank 13 to realize energy storage; when energy release is required, the CO2 is cut off and heated through the cement kiln exhaust gas system 3, the water energy storage system 4 and the molten salt energy storage system 2, and electricity is generated through the generator 11 (such as: steam turbine), and finally the cooled CO2 medium is stored in the second storage tank 14.

[0095] In the water energy storage system 4, through the high heat capacity characteristics of water, the water medium exchanges heat with the high-temperature CO2 at the fourth heat exchanger 54, so as to store the thermal energy in the fifth storage tank 41 through the water medium; when energy release is required, the CO2 medium is heated by the hot water stored in the fifth storage tank 41, and the water medium cooled by the second cooling device 45 can be stored in the sixth storage tank 42.

[0096] In the molten salt energy storage system 2, the molten salt medium has a high heat storage density and stability, and can be used for large-scale, long-term thermal energy storage. When the waste heat of the cement kiln is sufficient, the molten salt medium is melted by high-temperature exhaust gas and stored in the fourth storage tank 22 to achieve energy storage; when energy release is required, the high temperature of the molten salt medium is used to heat CO2, thereby assisting the CO2 energy storage system 1 in generating electricity.

[0097] It should be noted that the energy storage system 100 in the present application can realize power generation through the coordination of multiple systems. Among them, through the control system, the power generation output of the power generation module (photovoltaic power generation device 61 and cement kiln waste heat power generation device 63) and the energy storage and release status of the medium in each energy storage system (such as: water energy storage system 4, molten salt energy storage system 2) can be detected in real time, and the charging and discharging actions of the energy storage system 100 can be adjusted according to demand to achieve multi-energy coordination, thereby optimizing energy utilization efficiency.

[0098] Reference Figure 2When the power generation power of the power generation module is higher than the load power, the CO2 energy storage system 1 stores energy, and the first valve 16 is opened, the second valve 17 is closed, and the third drive unit 43 is opened. At this time, the CO2 medium in a high-pressure state can be stored in the first storage tank 13; when the power generation power of the power generation module is not higher than the load power, it is detected whether there is a high-pressure CO2 medium remaining in the first storage tank 13. If there is a high-pressure CO2 medium in the first storage tank 13, the CO2 energy storage system 1 is controlled to release energy, and the first storage tank 13 transports the CO2 medium to the generator 11 side. At this time, the first valve 16 is closed, the second valve 17 is opened, and the first drive unit 23, the second drive unit 24, the fourth drive unit 44 and the fifth drive unit are opened, and the third drive unit 43 is closed.

[0099] In the description of this application, "first feature" or "second feature" may include one or more of the features.

[0100] In the description of the present application, “plurality” means two or more.

[0101] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0102] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. An energy storage system, characterized in that: include: A CO2 energy storage system (1), wherein the CO2 energy storage system (1) is provided with a CO2 medium, and the CO2 medium can be used for energy storage or energy release; A molten salt energy storage system (2), wherein a molten salt medium is provided in the molten salt energy storage system (2), and the molten salt medium is used for energy storage; A cement kiln exhaust gas system (3), wherein the cement kiln exhaust gas system (3) contains exhaust gas, and the exhaust gas contains heat; a first heat exchanger (51), the first heat exchanger (51) being connected between the molten salt energy storage system (2) and the cement kiln exhaust gas system (3), and being used for storing exhaust gas heat in the cement kiln exhaust gas system (3) in the molten salt energy storage system (2); A second heat exchanger (52), the second heat exchanger (52) is connected between the CO2 energy storage system (1) and the molten salt energy storage system (2) and is used for heat exchange to heat the CO2 medium.

2. The energy storage system (100) according to claim 1, characterized in that: The CO2 energy storage system (1) comprises: A compressor (12), wherein the compressor (12) is used to compress the CO2 medium; A first storage tank (13), wherein the first storage tank (13) is used to store the CO2 medium compressed by the compressor (12); A second storage tank (14), wherein the second storage tank (14) is connected to the first storage tank (13), and an energy-consuming device is provided between the second storage tank (14) and the first storage tank (13), and the second storage tank (14) is used to store the CO2 medium flowing out of the energy-consuming device, and can transport the CO2 medium to the air intake side of the compressor (12).

3. The energy storage system (100) according to claim 2, characterized in that: The connection point between the second heat exchanger (52) and the CO2 energy storage system (1) is arranged between the first storage tank (13) and the energy consuming equipment.

4. The energy storage system (100) according to claim 3, characterized in that: The molten salt energy storage system (2) comprises: a third storage tank (21) and a fourth storage tank (22), wherein the third storage tank (21) and the fourth storage tank (22) are both used to store the molten salt medium, the connection between the second heat exchanger (52) and the molten salt energy storage system (2) is arranged between the first end of the third storage tank (21) and the first end of the fourth storage tank (22), and the connection between the first heat exchanger (51) and the molten salt energy storage system (2) is arranged between the second end of the third storage tank (21) and the second end of the fourth storage tank (22).

5. The energy storage system (100) according to claim 2, characterized in that: It also includes a third heat exchanger (53), which is connected between the CO2 energy storage system (1) and the cement kiln exhaust gas system (3), and the exhaust gas heat in the cement kiln exhaust gas system (3) can heat the CO2 medium through the third heat exchanger (53).

6. The energy storage system (100) according to claim 5, characterized in that: The connection point between the third heat exchanger (53) and the CO2 energy storage system (1) is arranged between the first storage tank (13) and the energy-consuming device, and on the path of transporting the CO2 from the first storage tank (13) to the energy-consuming device, the third heat exchanger (53) is located on the upstream side of the second heat exchanger (52).

7. The energy storage system (100) according to claim 5, characterized in that: The cement kiln exhaust gas system (3) further comprises an exhaust gas discharge end (31), wherein the exhaust gas discharge end (31) is used for exhausting the exhaust gas, and a connection point between the third heat exchanger (53) and the cement kiln exhaust gas system (3) is arranged between the first heat exchanger (51) and the exhaust gas discharge end (31).

8. The energy storage system (100) according to claim 2, characterized in that: The CO2 energy storage system (1) further comprises a first cooling device (15), wherein the first cooling device (15) is connected between the energy consuming device and the second storage tank (14) and is used to cool the CO2 medium.

9. The energy storage system (100) according to claim 2, characterized in that: Also includes: A water energy storage system (4), wherein the water energy storage system (4) is provided with a water medium; a fourth heat exchanger (54), the fourth heat exchanger (54) being connected between the CO2 energy storage system (1) and the water energy storage system (4), and the fourth heat exchanger (54) being arranged on the exhaust side of the compressor (12), the CO2 medium being suitable for heating the water medium at the fourth heat exchanger (54); A fifth heat exchanger (55), the fifth heat exchanger (55) is connected between the CO2 energy storage system (1) and the water energy storage system (4), and the fifth heat exchanger (55) is arranged between the first storage tank (13) and the energy consuming equipment, and the water medium is suitable for heating the CO2 medium at the fifth heat exchanger (55).

10. The energy storage system (100) according to claim 9, characterized in that: On the path for the first storage tank (13) to transport the CO2 to the energy-consuming equipment, the fifth heat exchanger (55) is located on the upstream side of the second heat exchanger (52).

11. The energy storage system (100) according to claim 9, characterized in that: The water energy storage system (4) comprises: a fifth storage tank (41) and a sixth storage tank (42), wherein the fifth storage tank (41) and the sixth storage tank (42) are both used to store the water medium, the connection point between the fourth heat exchanger (54) and the water energy storage system (4) is arranged between the first end of the fifth storage tank (41) and the first end of the sixth storage tank (42), and the connection point between the fifth heat exchanger (55) and the water energy storage system (4) is arranged between the second end of the fifth storage tank (41) and the second end of the sixth storage tank (42).

12. The energy storage system (100) according to claim 11, characterized in that: The water energy storage system (4) further comprises a second cooling device (45), which is arranged between the fifth heat exchanger (55) and the second end of the sixth storage tank (42) and is used to cool the water medium.

13. The energy storage system (100) according to claim 2, characterized in that: The energy consumer is designed as a generator (11).

14. The energy storage system (100) according to claim 1, characterized in that: It also includes a power generation module, which is used to be connected to the compressor (12) in the CO2 energy storage system (1) and to drive the compressor (12) to operate.

15. The energy storage system (100) according to claim 14, characterized in that: The power generation module comprises: a photovoltaic power generation device (61) and an AC / DC converter (62), wherein the photovoltaic power generation device (61) is used for generating electricity, and the AC / DC converter (62) is connected between the photovoltaic power generation device (61) and the compressor (12); And / or, the power generation module comprises: a cement kiln waste heat power generation device (63), and the cement kiln waste heat power generation device (63) is connected to the compressor (12).

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