Compressed air energy storage device system and method using supercritical pressure water as heat medium

Abstract

The present invention provides a compressed air energy storage device system and method using supercritical pressure water as a heat medium. The compressed air heat storage and heat release processes both use a secondary circuit, using supercritical pressure water as an intermediate heat medium, and using thermal oil as a heat storage medium. The good safety of supercritical pressure water and the low heat storage pressure and large temperature range of thermal oil are utilized to avoid the problem of high-temperature and high-pressure storage of water and solve the problem of leakage of high-temperature air to thermal oil. The pressure of the supercritical pressure water of the heat medium is always controlled above the critical pressure to prevent the supercritical pressure water from turning into steam, reduce the volume of pipelines and equipment, and also make the system simpler. As an intermediate heat medium, supercritical pressure water only flows in a closed cycle, does not store heat, and does not significantly increase investment. Compared with the traditional thermal storage type compressed air energy storage system using thermal oil, the present invention has greatly improved safety and is suitable for large-scale industrial promotion and application.

Description

Technical Field

[0001] The present invention relates to the technical field of electric energy storage, and in particular to a compressed air energy storage device system and method using supercritical pressure water as a heat medium. Background Art

[0002] Compressed air energy storage refers to a storage method that uses electrical energy to compress air during the low load period of the power grid, seals the air at high pressure in the energy storage device, and releases the compressed air to drive the turbine to generate electricity during the peak load period of the power grid. Compressed air energy storage can usually be divided into supplementary combustion compressed air energy storage system and thermal storage compressed air energy storage system.

[0003] The compressed air energy storage system will generate a large amount of heat during the energy storage process. If it is not stored, it will lead to a waste of heat energy. The thermal storage compressed air energy storage system uses a heat storage medium to store this heat during energy storage and utilize it during energy release. Therefore, the thermal storage compressed air energy storage system is more efficient than the supplementary combustion compressed air energy storage system, does not consume external energy, and has become the main direction of development.

[0004] CN113982708A discloses a compressed air energy storage system coupled with a Kalina cycle, wherein the system includes a double-layer storage tank and a Kalina cycle unit, wherein the double-layer storage tank, a multi-stage cooler, a heat storage tank, a multi-stage regenerator, a C1 port, and a D1 port are connected in sequence to form a circulation loop, and the internal flow medium is heat transfer oil, which is heated by compressed air and stored in the heat storage tank, and the heat transfer oil heats the compressed air flowing through the multi-stage regenerator, and the heat transfer oil uses the residual temperature to heat the ammonia solution flowing through the evaporator, and flows back to the double-layer storage tank; the B1 port, the separator, the ammonia expander, the absorber, the condenser, the working fluid pump, the C2 port, the D2 port, and the A1 port are connected in sequence to form a circulation loop, and the internal flow medium is ammonia solution, and the ammonia expander is used to expand the ammonia-rich vapor from the separator to do work and drive the second generator to output electricity. In this way, the energy storage capacity of the system can be effectively increased, the heat loss during the energy storage process can be reduced, and the energy storage efficiency can be improved.

[0005] CN106438297A discloses a temperature-adaptive heat storage type compressed air energy storage system, including a multi-stage air compression system, an air storage system, a multi-stage air expansion work system, a cascade heat storage system and a thermal energy cascade utilization system. By adding a multi-channel heat regenerator and a medium-temperature heat storage tank, adaptive adjustment of the air outlet temperature and the heat storage medium outlet temperature and cascade utilization of energy of different qualities can be achieved, thereby improving system efficiency and control flexibility, effectively solving the problems of wet air condensation and large temperature fluctuations during non-steady-state operation in traditional compressed air energy storage systems, and promoting the development of compressed air energy storage technology and large-scale commercial applications.

[0006] CN211598766U discloses a distributed combined heat and power compressed air energy storage system, including a compressor, a cooler, a high-pressure air storage tank, a pressure reducing valve, a reheater, an expander, a normal temperature heat storage tank, a high temperature heat storage tank, a medium temperature heat storage tank, a heat exchanger and a heat pump; the energy storage system has a simple structure, and by setting a heat exchanger and an air source heat pump, the low-grade heat in the system is recovered, waste heat utilization and combined heat and power are realized, and the overall efficiency of energy utilization of the compressed air energy storage system is improved. In the non-energy release stage, the heat storage medium stored in the medium temperature heat storage tank exchanges heat with the atmosphere in the heat exchanger, and then the heated atmosphere is used as the heat source of the air source heat pump, which effectively avoids energy waste, greatly improves the overall efficiency of the system, and realizes uninterrupted heating throughout the day.

[0007] The above-mentioned thermal storage compressed air energy storage systems all use thermal oil to store heat, but there is a problem of high-pressure air leaking into the thermal oil, which will cause serious safety hazards.

[0008] Therefore, it is of great significance to develop a thermal storage type compressed air energy storage system that can effectively prevent high-pressure air from leaking into the thermal oil and improve the safety of thermal oil heat storage. Summary of the invention

[0009] In view of the problems existing in the prior art, the present invention provides a compressed air energy storage device system and method using supercritical pressure water as a heat medium. The device system utilizes the good safety of supercritical pressure water and the low heat storage pressure and large temperature range of thermal oil, which not only avoids the problem of difficulty in storing ordinary water under high temperature and high pressure, but also solves the problem of leakage of high temperature and high pressure gas to thermal oil, thereby improving the safety of the entire device system.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a compressed air energy storage device system using supercritical pressure water as a heat medium, wherein the compressed air energy storage device system comprises a first air compression device, a first heat medium heat absorption device, a second heat medium heat absorption device, a second air compression device, a third heat medium heat absorption device, a fourth heat medium heat absorption device, a compressed air storage device, a first heat medium heat release device, a first expander, a second heat medium heat release device, and a second expander connected in sequence;

[0012] The first heat medium heat absorbing device is provided with a first gas channel and a first liquid channel which are independent of each other; the second heat medium heat absorbing device is provided with a second gas channel and a second liquid channel which are independent of each other; the third heat medium heat absorbing device is provided with a third gas channel and a third liquid channel which are independent of each other; the fourth heat medium heat absorbing device is provided with a fourth gas channel and a fourth liquid channel which are independent of each other;

[0013] The device system also includes a first heat transfer oil heat exchange device and a second heat transfer oil heat exchange device;

[0014] The first heat-conducting oil heat exchange device is provided with a fifth liquid channel and a first heat-conducting oil channel which are independent of each other; the second heat-conducting oil heat exchange device is provided with a sixth liquid channel and a second heat-conducting oil channel which are independent of each other;

[0015] The first heat transfer oil heat exchange device is cyclically connected with the second heat medium heat absorption device and the first heat medium heat absorption device in sequence;

[0016] The first heat transfer oil heat exchange device is also cyclically connected to the fourth heat medium heat absorption device and the third heat medium heat absorption device in sequence;

[0017] The second heat transfer oil heat exchange device is cyclically connected to the first heat medium heat release device;

[0018] The second heat transfer oil heat exchange device is also cyclically connected to the second heat medium heat release device.

[0019] The heat storage and heat release processes of the compressed air energy storage device system using supercritical pressure water as a heat medium described in the present invention both adopt a secondary circuit, using supercritical pressure water as an intermediate heat medium, and using thermal oil as a heat storage medium. The primary circuit is air-supercritical pressure water heat exchange, and the secondary circuit is supercritical pressure water-thermal oil heat exchange. Taking advantage of the good safety of supercritical pressure water and the low heat storage pressure and large temperature range of thermal oil, the problem of difficulty in storing ordinary water under high temperature and high pressure is avoided, and the problem of leakage of high temperature and high pressure gas to thermal oil is solved, and the safety of the system is greatly improved. Moreover, in the device system described in the present invention, supercritical pressure water is only used as an intermediate heat medium and only flows in a closed cycle of supercritical pressure water. It does not store heat, and will not significantly increase investment.

[0020] Preferably, a first water delivery device is provided on the outlet pipeline of the first thermal oil heat exchange device.

[0021] Preferably, a second water delivery device is provided on the outlet pipeline of the second thermal oil heat exchange device.

[0022] In the present invention, both the first heat transfer oil heat exchange device and the second heat transfer oil heat exchange device are sparsely arranged, and the spacing between the tube rows meets the requirements of radiographic detection. Pipe joints are milled on the heat exchanger tube sheet, and the heat exchange tubes and the pipe joints on the tube sheet are connected by butt welds. All welds are 100% radiographically inspected, which can effectively avoid leakage. Compared with the prior art, the heat storage type compressed air energy storage system uses a large-scale tube-in-tube high-pressure air heat exchanger with a large number of heat exchange tubes and a small tube spacing to absorb the heat of the compressed air, which greatly improves the safety of compressed air energy storage. Moreover, in the prior art, there is a fillet weld between the heat exchange tube and the tube sheet, which cannot be inspected by radiography and has a great risk of leakage.

[0023] Preferably, the compressed air energy storage device system further includes a first deoxygenation device and a second deoxygenation device.

[0024] The compressed air energy storage device system of the present invention preferably also includes a first deoxygenation device and a second deoxygenation device because during long-term operation, oxygen in the air will enter the supercritical pressure water of the heat medium, causing corrosion of the heat medium transportation pipeline, so a deoxygenation device is required to remove the oxygen in the heat medium.

[0025] Preferably, the first deoxygenation device is connected to the first heat medium absorption device via a third water delivery device.

[0026] Preferably, the first heat medium absorption device is connected to the first deoxygenation device via a first regulating valve.

[0027] Preferably, the second deoxygenation device is connected to the third heat medium absorption device via a fourth water delivery device.

[0028] Preferably, the third heat medium absorption device is connected to the second deoxygenation device via a second regulating valve.

[0029] The present invention adopts a split flow recirculation bypass deoxygenation method and utilizes the heat of compressed air to remove dissolved oxygen in supercritical pressure water.

[0030] Preferably, the compressed air energy storage device system further includes a first thermal oil storage device and a second thermal oil storage device.

[0031] Preferably, the first thermal oil storage device is connected to the second thermal oil storage device via the first thermal oil delivery device and the second thermal oil heat exchange device in sequence.

[0032] Preferably, the second thermal oil storage device is connected to the first thermal oil storage device via the second thermal oil delivery device and the first thermal oil heat exchange device in sequence.

[0033] Preferably, the compressed air energy storage device system also includes a heat medium pressure stabilizing device.

[0034] Preferably, the heat medium pressure stabilizing device is connected to the first heat transfer oil heat exchange device via a first two-way valve.

[0035] Preferably, the heat medium pressure stabilizing device is connected to the second heat transfer oil heat exchange device via a second two-way valve.

[0036] The function of the heat medium pressure stabilizing device of the present invention is to adjust the pressure of supercritical pressure water in the air-supercritical pressure water heat exchange circuit and the supercritical pressure water-heat transfer oil heat exchange circuit, so that it is always maintained above 22.115MPa to prevent the supercritical pressure water from turning into steam.

[0037] Preferably, the first air compression device and the second air compression device are coaxially connected to the electric motor.

[0038] Preferably, the first expander and the second expander are coaxially connected to a generator.

[0039] In a second aspect, the present invention also provides a compressed air energy storage method using supercritical pressure water as a heat medium, wherein the method is carried out using the compressed air energy storage device system using supercritical pressure water as a heat medium as described in the first aspect; the method includes an energy storage process and an energy release process.

[0040] Preferably, the energy storage process includes: air enters the first air compression device to become the first compressed air, the first compressed air passes through the first heat medium heat absorption device and the second heat medium heat absorption device in turn to enter the second air compression device to become the second compressed air; the second compressed air passes through the third heat medium heat absorption device and the fourth heat medium heat absorption device in turn to enter the compressed air storage device for storage;

[0041] The supercritical pressure water is divided into two paths through the first water delivery device. One path enters the second heat medium heat absorption device in sequence. The first heat medium heat absorption device absorbs the heat of the first compressed air and then returns to the first heat transfer oil heat exchange device. The other path enters the fourth heat medium heat absorption device in sequence. The third heat medium heat absorption device absorbs the heat of the second compressed air and then returns to the first heat transfer oil heat exchange device, forming a first supercritical pressure water closed cycle.

[0042] The heat transfer oil in the second heat transfer oil storage device is transported to the first heat transfer oil heat exchange device through the second heat transfer oil transport device to absorb the heat of the supercritical pressure water, and then enters the first heat transfer oil storage device for storage.

[0043] Preferably, during the energy storage process, the electric motor drives the first air compression device and the second air compression device to compress air.

[0044] Preferably, during the energy storage process, the supercritical pressure water is deoxygenated by means of a split flow recirculation bypass deoxygenation method.

[0045] Preferably, the diversion recirculation bypass deoxygenation includes: part of the supercritical pressure water at the outlet of the first heat medium heat absorption device enters the first deoxygenation device for deoxygenation, part of the heat and pressure are lost in the deoxygenation process, the supercritical pressure water after deoxygenation returns to the first heat medium heat absorption device through a third water delivery device, and the amount of supercritical pressure water entering the first deoxygenation device is controlled by a first regulating valve; part of the supercritical pressure water at the outlet of the third heat medium heat absorption device is deoxygenated in the second deoxygenation device, the supercritical pressure water after deoxygenation returns to the third heat medium heat absorption device through a fourth water delivery device, and the amount of supercritical pressure water entering the second deoxygenation device is controlled by a second regulating valve.

[0046] Preferably, during the energy storage process, the heat medium pressure stabilizing device controls the heat medium water pressure in the first supercritical pressure water closed cycle to be above 22.115 MPa through the first two-way valve. For example, it can be 22.115 MPa, 22.2 MPa, 22.3 MPa, 22.5 MPa, 23 MPa or 23.5 MPa, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] Preferably, the energy release process includes: the second compressed air stored in the compressed air storage device first enters the first heat medium heat release device, absorbs the heat of the heat medium discharged from the second heat transfer oil heat exchange device, and then enters the first expander to perform work; the air after doing work enters the second heat medium heat release device to absorb the heat of the heat medium discharged from the second heat transfer oil heat exchange device, and then enters the second expander to perform work, and the air after doing work is discharged into the atmosphere;

[0048] After the supercritical pressure water absorbs the heat of the heat transfer oil in the second heat transfer oil heat exchange device, it is divided into two paths through the second water delivery device. One path enters the first heat medium heat release device to transfer the heat to the compressed air from the outlet of the compressed air storage device, and the other path enters the second heat medium heat release device to transfer the heat to the air after the first expander does work. The heat medium after heat release returns to the second heat transfer oil heat exchange device, forming a second supercritical pressure water closed cycle;

[0049] The heat transfer oil in the first heat transfer oil storage device enters the second heat transfer oil heat exchange device through the first heat transfer oil delivery device to transfer heat to the heat medium water, and then enters the second heat transfer oil storage device for storage.

[0050] Preferably, during the energy release process, the first expander and the second expander drive the generator to generate electricity.

[0051] Preferably, during the energy release process, the heat medium pressure stabilizing device controls the heat medium water pressure in the second supercritical pressure water closed cycle to be above 22.115 MPa through the second two-way valve. For example, it can be 22.115 MPa, 22.2 MPa, 22.3 MPa, 22.5 MPa, 23 MPa or 23.5 MPa, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] The pressure of the supercritical pressure water during the energy storage and release process of the present invention is always controlled above the critical pressure of 22.115 MPa, which prevents the supercritical pressure water from turning into steam, reduces the volume of pipelines and equipment, and simplifies the entire device system.

[0053] Preferably, the pressure of the air entering the compressed air storage device is 15-18 MPa, for example, it can be 15 MPa, 16 MPa, 17 MPa, 17.5 MPa or 18 MPa, etc., but it is not limited to the listed values, and other unlisted values ​​within the numerical range are equally applicable; the temperature is 50-80°C, for example, it can be 50°C, 60°C, 65°C, 70°C, 75°C or 80°C, etc., but it is not limited to the listed values, and other unlisted values ​​within the numerical range are equally applicable.

[0054] As a preferred technical solution of the present invention, the method includes an energy storage process and an energy release process;

[0055] The energy storage process includes: air enters the first air compression device to become the first compressed air, the first compressed air passes through the first heat medium heat absorption device and the second heat medium heat absorption device in turn to enter the second air compression device to become the second compressed air; the second compressed air passes through the third heat medium heat absorption device and the fourth heat medium heat absorption device in turn to become the compressed air with a pressure of 15-18MPa and a temperature of 50-80°C, and enters the compressed air storage device for storage;

[0056] The supercritical pressure water is divided into two paths through the first water delivery device. One path enters the second heat medium heat absorption device in sequence. The first heat medium heat absorption device absorbs the heat of the first compressed air and then returns to the first heat transfer oil heat exchange device. The other path enters the fourth heat medium heat absorption device in sequence. The third heat medium heat absorption device absorbs the heat of the second compressed air and then returns to the first heat transfer oil heat exchange device, forming a first supercritical pressure water closed cycle.

[0057] The heat transfer oil in the second heat transfer oil storage device is transported to the first heat transfer oil heat exchange device through the second heat transfer oil transport device to absorb the heat of the supercritical pressure water, and then enters the first heat transfer oil storage device for storage;

[0058] During the energy storage process, the motor drives the first air compression device and the second air compression device to compress the air; the supercritical pressure water is deoxygenated by a split recirculation bypass deoxygenation method; the split recirculation bypass deoxygenation includes: part of the supercritical pressure water at the outlet of the first heat medium heat absorption device enters the first deoxygenation device for deoxygenation, and part of the heat and pressure are lost during the deoxygenation process. The deoxygenated supercritical pressure water returns to the first heat medium heat absorption device through the third water delivery device, and the amount of supercritical pressure water entering the first deoxygenation device is controlled by the first regulating valve; part of the supercritical pressure water at the outlet of the third heat medium heat absorption device is deoxygenated in the second deoxygenation device, and the deoxygenated supercritical pressure water returns to the third heat medium heat absorption device through the fourth water delivery device, and the amount of supercritical pressure water entering the second deoxygenation device is controlled by the second regulating valve; the heat medium pressure stabilizing device controls the heat medium water pressure in the first supercritical pressure water closed cycle to be above 22.115MPa through the first two-way valve;

[0059] The energy release process includes: the second compressed air stored in the compressed air storage device first enters the first heat medium heat release device, absorbs the heat of the heat medium discharged from the second heat transfer oil heat exchange device, and then enters the first expander to perform work; the air after doing work enters the second heat medium heat release device to absorb the heat of the heat medium discharged from the second heat transfer oil heat exchange device, and then enters the second expander to perform work, and the air after doing work is discharged into the atmosphere;

[0060] After the supercritical pressure water absorbs the heat of the heat transfer oil in the second heat transfer oil heat exchange device, it is divided into two paths through the second water delivery device. One path enters the first heat medium heat release device to transfer the heat to the compressed air from the outlet of the compressed air storage device, and the other path enters the second heat medium heat release device to transfer the heat to the air after the first expander does work. The heat medium after heat release returns to the second heat transfer oil heat exchange device, forming a second supercritical pressure water closed cycle;

[0061] The heat transfer oil in the first heat transfer oil storage device enters the second heat transfer oil heat exchange device through the first heat transfer oil delivery device to transfer heat to the heat medium water, and then enters the second heat transfer oil storage device for storage;

[0062] During the energy release process, the first expander and the second expander drive the generator to generate electricity; the heat medium pressure stabilizing device controls the heat medium water pressure in the second supercritical pressure water closed cycle to be above 22.115MPa through the second two-way valve.

[0063] Compared with the prior art, the present invention has at least the following beneficial effects:

[0064] (1) The compressed air energy storage device system using supercritical pressure water as a heat medium provided by the present invention uses supercritical pressure water as a heat medium, which can effectively prevent high-temperature and high-pressure compressed air from leaking into the heat transfer oil, thereby greatly improving safety; and supercritical pressure water, as an intermediate heat medium, only flows in a closed cycle without storing heat, which will not significantly increase investment;

[0065] (2) The heat exchange tubes of the heat transfer oil heat exchange device in the compressed air energy storage device system using supercritical pressure water as the heat medium provided by the present invention are connected to the pipe joints on the tube plate by butt welding, which effectively avoids leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a structural schematic diagram of a compressed air energy storage device system using supercritical pressure water as a heat medium provided by the present invention.

[0067] Figure 2 It is a schematic diagram of the connection method between the heat exchange tube and the tube sheet in the heat transfer oil heat exchange device.

[0068] In the figure: 1-first air compression device; 2-second air compression device; 3-motor; 4-second heat medium heat absorption device; 5-first heat medium heat absorption device; 6-first deoxidation device; 7-fourth heat medium heat absorption device; 8-third heat medium heat absorption device; 9-second deoxidation device; 10-first heat transfer oil heat exchange device; 11-first heat transfer oil storage device; 12-second heat transfer oil storage device; 13-heat transfer oil pressure stabilizing device; 14-compressed air storage device; 15-first expander; 16 -second expansion machine; 17-generator; 18-second heat transfer oil heat exchange device; 19-first heat medium heat release device; 20-second heat medium heat release device; 21-first regulating valve; 22-second regulating valve; 23-first two-way valve; 24-second two-way valve; 25-first water delivery device; 26-third water delivery device; 27-fourth water delivery device; 28-second heat transfer oil delivery device; 29-first heat transfer oil delivery device; 30-second water delivery device; 31-heat exchange tube; 32-tube sheet. DETAILED DESCRIPTION

[0069] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0070] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0071] It should be understood that, in the description of the present invention, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0072] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0073] Those skilled in the art should understand that the present invention necessarily includes necessary pipelines, conventional valves and general pump equipment for realizing a complete process, but the above content does not belong to the main inventive point of the present invention. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection, and the present invention does not make special requirements and specific limitations on this.

[0074] As a specific embodiment of the present invention, a compressed air energy storage device system using supercritical pressure water as a heat medium is provided, and its structural schematic diagram is shown as follows: Figure 1 shown.

[0075] The compressed air energy storage device system comprises a first air compression device 1, a first heat medium heat absorption device 5, a second heat medium heat absorption device 4, a second air compression device 2, a third heat medium heat absorption device 8, a fourth heat medium heat absorption device 7, a compressed air storage device 14, a first heat medium heat release device 19, a first expander 15, a second heat medium heat release device 20 and a second expander 16 connected in sequence;

[0076] The first heat medium heat absorbing device 5 is provided with a first gas channel and a first liquid channel which are independent of each other; the second heat medium heat absorbing device 4 is provided with a second gas channel and a second liquid channel which are independent of each other; the third heat medium heat absorbing device 8 is provided with a third gas channel and a third liquid channel which are independent of each other; the fourth heat medium heat absorbing device 7 is provided with a fourth gas channel and a fourth liquid channel which are independent of each other;

[0077] The device system further includes a first thermal oil heat exchange device 10 and a second thermal oil heat exchange device 18;

[0078] The first heat transfer oil heat exchange device 10 is provided with a fifth liquid channel and a first heat transfer oil channel which are independent of each other; the second heat transfer oil heat exchange device 18 is provided with a sixth liquid channel and a second heat transfer oil channel which are independent of each other;

[0079] The first heat-conducting oil heat exchange device 10 is circularly connected with the second heat medium heat absorption device 4 and the first heat medium heat absorption device 5 in sequence; the first heat-conducting oil heat exchange device 10 is also circularly connected with the fourth heat medium heat absorption device 7 and the third heat medium heat absorption device 8 in sequence; the second heat-conducting oil heat exchange device 18 is circularly connected with the first heat medium heat release device 19; the second heat-conducting oil heat exchange device 18 is also circularly connected with the second heat medium heat release device 20.

[0080] A first water delivery device 25 is provided on the outlet pipeline of the first thermal oil heat exchange device 10;

[0081] A second water delivery device 30 is provided on the outlet pipeline of the second thermal oil heat exchange device 18 .

[0082] The first heat transfer oil heat exchange device 10 and the second heat transfer oil heat exchange device 18 are both sparsely arranged, and the spacing between the tube rows meets the requirements of radiographic detection. The heat exchange tubes in the first heat transfer oil heat exchange device 10 and the second heat transfer oil heat exchange device 18 are connected to the tube sheet in the following manner: Figure 2 As shown, a pipe joint is milled out on the tube sheet 32, and the heat exchange tube 31 is connected to the pipe joint on the tube sheet 32 ​​by butt welding.

[0083] The compressed air energy storage device system further includes a first deoxygenation device 6 and a second deoxygenation device 9;

[0084] The first deoxygenation device 6 is connected to the first heat medium heat absorption device 5 via the third water delivery device 26; the first heat medium heat absorption device 5 is connected to the first deoxygenation device 6 via the first regulating valve 21;

[0085] The second deoxygenating device 9 is connected to the third heat medium absorbing device 8 via the fourth water conveying device 27 ; the third heat medium absorbing device 8 is connected to the second deoxygenating device 9 via the second regulating valve 22 .

[0086] The compressed air energy storage device system further includes a first thermal oil storage device 11 and a second thermal oil storage device 12;

[0087] The first thermal oil storage device 11 is connected to the second thermal oil storage device 12 via the first thermal oil delivery device 29 and the second thermal oil heat exchange device in sequence;

[0088] The second thermal oil storage device 12 is connected to the first thermal oil storage device 11 via the second thermal oil delivery device 28 and the first thermal oil heat exchange device 10 in sequence.

[0089] The compressed air energy storage device system also includes a heat medium pressure stabilizing device 13;

[0090] The heat medium pressure stabilizing device 13 is connected to the first heat transfer oil heat exchange device 10 via a first two-way valve 23 ; the heat medium pressure stabilizing device 13 is connected to the second heat transfer oil heat exchange device 18 via a second two-way valve 24 .

[0091] The first air compressing device 1 and the second air compressing device 2 are coaxially connected with the motor 3;

[0092] The first expander 15 and the second expander 16 are coaxially connected to a generator 17 .

[0093] As a specific embodiment of the present invention, a compressed air energy storage method using supercritical pressure water as a heat medium is also provided. The method is carried out using the above-mentioned compressed air energy storage device system using supercritical pressure water as a heat medium; the method includes an energy storage process and an energy release process.

[0094] The energy storage process includes: air with a temperature of 20°C and a pressure of 0.1MPa enters the first air compression device 1 and becomes the first compressed air with a temperature of 400°C and a pressure of 1.4MPa. The first compressed air enters the first heat medium heat absorption device 5 to transfer heat to supercritical pressure water, and the temperature is reduced to 240°C; then enters the second heat medium heat absorption device 4 to transfer heat to supercritical pressure water again, and the temperature is reduced to 80°C. Air with a temperature of 80°C and a pressure of 1.4MPa enters the second air compression device 2 and becomes the second compressed air with a temperature of 400°C and a pressure of 15.5MPa; the second compressed air enters the third heat medium heat absorption device 8 to transfer heat to supercritical pressure water, and the temperature is reduced to 240°C; then enters the fourth heat medium heat absorption device 7 to transfer heat to supercritical pressure water again, becoming compressed air with a pressure of 15.5MPa and a temperature of 80°C, and enters the compressed air storage device 14 for storage;

[0095] The supercritical pressure water at 73°C is divided into two paths through the first water delivery device 25. One path enters the second heat medium heat absorption device 4 and the first heat medium heat absorption device 5 in sequence to absorb the heat of the first compressed air and raise the temperature to 380°C, and then returns to the first heat transfer oil heat exchange device 10. The other path enters the fourth heat medium heat absorption device 7 and the third heat medium heat absorption device 8 in sequence to absorb the heat of the second compressed air and raise the temperature to 380°C, and then returns to the first heat transfer oil heat exchange device 10 to transfer the heat to the heat transfer oil and reduce the temperature to 73°C, thereby forming a first supercritical pressure water closed cycle.

[0096] The heat transfer oil in the second heat transfer oil storage device 12 with a temperature of 68°C is transported to the first heat transfer oil heat exchange device 10 through the second heat transfer oil transport device 28 to absorb the heat of the supercritical pressure water and increase the temperature to 370°C, and then enters the first heat transfer oil storage device 11 for storage;

[0097] During the energy storage process, the motor 3 drives the first air compression device 1 and the second air compression device 2 to compress air;

[0098] During the energy storage process, the supercritical pressure water is deoxygenated by means of a shunt recirculation bypass deoxygenation method; the shunt recirculation bypass deoxygenation includes: part of the supercritical pressure water at the outlet of the first heat medium heat absorption device 5 enters the first deoxygenation device 6 for deoxygenation, and part of the heat and pressure are lost in the deoxygenation process. The deoxygenated supercritical pressure water returns to the first heat medium heat absorption device 5 through the third water delivery device 26, and the amount of supercritical pressure water entering the first deoxygenation device 6 is controlled by the first regulating valve 21; part of the supercritical pressure water at the outlet of the third heat medium heat absorption device 8 is deoxygenated in the second deoxygenation device 9, and the deoxygenated supercritical pressure water returns to the third heat medium heat absorption device through the fourth water delivery device 27, and the amount of supercritical pressure water entering the second deoxygenation device 9 is controlled by the second regulating valve 22; the heat medium pressure stabilizing device 13 controls the heat medium water pressure in the first supercritical pressure water closed cycle at 23MPa through the first two-way valve 23.

[0099] The energy release process includes:

[0100] The second compressed air stored in the compressed air storage device 14 with a pressure of 15.5 MPa and a temperature of 80°C first enters the first heat medium heat release device 19, absorbs the heat of the heat medium discharged from the second heat transfer oil heat exchange device 18, and after the temperature rises to 355°C, enters the first expander 15 to perform work, and becomes air with a pressure of 1.05 MPa and a temperature of 45°C; the air after performing work enters the second heat medium heat release device 20 to absorb the heat of the heat medium discharged from the second heat transfer oil heat exchange device 18, and after the temperature rises to 355°C, enters the second expander 16 to perform work, and the air with a pressure of 0.105 MPa and a temperature of 80°C after performing work is discharged into the atmosphere;

[0101] After the supercritical pressure water at 73°C absorbs the heat of the heat transfer oil in the second heat transfer oil heat exchange device 18 and the temperature rises to 365°C, it is divided into two paths through the second water delivery device 30. One path enters the first heat medium heat release device 19 to transfer the heat to the compressed air at the outlet of the compressed air storage device 14, and the temperature is reduced to 85°C. The other path enters the second heat medium heat release device 20 to transfer the heat to the air after work from the first expander 15, and the temperature is reduced to 55°C. The supercritical pressure water after heat release is mixed with the temperature of 63°C and returns to the second heat transfer oil heat exchange device 18, forming a second supercritical pressure water closed cycle;

[0102] The heat transfer oil with a temperature of 370°C in the first heat transfer oil storage device 11 enters the second heat transfer oil heat exchange device 18 through the first heat transfer oil delivery device 29 to transfer heat to the heat medium water. After the temperature drops to 68°C, it enters the second heat transfer oil storage device 12 for storage.

[0103] During the energy release process, the first expander 15 and the second expander 16 drive the generator 17 to generate electricity; the heat medium pressure stabilizing device 13 controls the heat medium water pressure in the second supercritical pressure water closed cycle to 23 MPa through the second two-way valve 24.

[0104] In summary, the compressed air energy storage device system provided by the present invention uses supercritical pressure water as the heat medium. Both the heat storage and heat release processes use a secondary circuit, supercritical pressure water is used as the intermediate heat medium, and heat transfer oil is used as the heat storage medium. The water heat medium has good safety and the heat transfer oil has low heat storage pressure and a large temperature range. It not only avoids the problem of high-temperature and high-pressure storage of water, but also solves the problem of leakage of high-temperature air to heat transfer oil. The present invention controls the pressure of the heat medium water above the critical pressure at all times to avoid the heat medium supercritical pressure water from turning into steam, reduces the volume of pipelines and equipment, and simplifies the device system. Compared with the traditional heat storage type compressed air energy storage system using heat transfer oil, the safety of the present invention is greatly improved, and it has a prospect for industrial promotion and application.

[0105] The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0106] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. A compressed air energy storage device system using supercritical pressure water as heat medium, characterized in that: The compressed air energy storage device system comprises a first air compression device, a first heat medium heat absorption device, a second heat medium heat absorption device, a second air compression device, a third heat medium heat absorption device, a fourth heat medium heat absorption device, a compressed air storage device, a first heat medium heat release device, a first expander, a second heat medium heat release device and a second expander connected in sequence; The first heat medium heat absorbing device is provided with a first gas channel and a first liquid channel which are independent of each other; the second heat medium heat absorbing device is provided with a second gas channel and a second liquid channel which are independent of each other; the third heat medium heat absorbing device is provided with a third gas channel and a third liquid channel which are independent of each other; the fourth heat medium heat absorbing device is provided with a fourth gas channel and a fourth liquid channel which are independent of each other; The device system also includes a first heat transfer oil heat exchange device and a second heat transfer oil heat exchange device; The first heat-conducting oil heat exchange device is provided with a fifth liquid channel and a first heat-conducting oil channel which are independent of each other; the second heat-conducting oil heat exchange device is provided with a sixth liquid channel and a second heat-conducting oil channel which are independent of each other; The first heat transfer oil heat exchange device is cyclically connected with the second heat medium heat absorption device and the first heat medium heat absorption device in sequence; The first heat transfer oil heat exchange device is also cyclically connected to the fourth heat medium heat absorption device and the third heat medium heat absorption device in sequence; The second heat transfer oil heat exchange device is cyclically connected to the first heat medium heat release device; The second heat transfer oil heat exchange device is also cyclically connected to the second heat medium heat release device.

2. The compressed air energy storage device system according to claim 1, characterized in that: A first water delivery device is provided on the outlet pipeline of the first heat transfer oil heat exchange device; A second water delivery device is provided on the outlet pipeline of the second heat transfer oil heat exchange device.

3. The compressed air energy storage device system according to claim 1, characterized in that: The compressed air energy storage device system also includes a first deoxygenation device and a second deoxygenation device; The first deoxygenation device is connected to the first heat medium absorption device via the third water delivery device; The first heat medium heat absorbing device is connected to the first deoxygenating device via a first regulating valve; The second deoxygenation device is connected to the third heat medium absorption device via the fourth water delivery device; The third heat medium heat absorbing device is connected to the second deoxygenating device via a second regulating valve.

4. The compressed air energy storage device system according to claim 1, characterized in that: The compressed air energy storage device system also includes a first thermal oil storage device and a second thermal oil storage device; The first thermal oil storage device is connected to the second thermal oil storage device via the first thermal oil delivery device and the second thermal oil heat exchange device in sequence; The second heat transfer oil storage device is connected to the first heat transfer oil storage device via the second heat transfer oil delivery device and the first heat transfer oil heat exchange device in sequence.

5. The compressed air energy storage device system according to claim 1, characterized in that: The compressed air energy storage device system also includes a heat medium pressure stabilizing device; The heat medium pressure stabilizing device is connected to the first heat transfer oil heat exchange device via a first two-way valve; The heat medium pressure stabilizing device is connected to the second heat transfer oil heat exchange device via a second two-way valve.

6. The compressed air energy storage device system according to claim 1, characterized in that: The first air compression device and the second air compression device are coaxially connected to the electric motor; The first expander and the second expander are coaxially connected to a generator.

7. A compressed air energy storage method using supercritical pressure water as a heat medium, characterized in that: The method is carried out using a compressed air energy storage device system using supercritical pressure water as a heat medium as described in any one of claims 1 to 6; the method includes an energy storage process and an energy release process.

8. The method according to claim 7, characterized in that The energy storage process includes: air enters the first air compression device to become the first compressed air, the first compressed air passes through the first heat medium heat absorption device and the second heat medium heat absorption device in turn to enter the second air compression device to become the second compressed air; the second compressed air passes through the third heat medium heat absorption device and the fourth heat medium heat absorption device in turn to enter the compressed air storage device for storage; The supercritical pressure water is divided into two paths through the first water delivery device. One path enters the second heat medium heat absorption device in sequence. The first heat medium heat absorption device absorbs the heat of the first compressed air and then returns to the first heat transfer oil heat exchange device. The other path enters the fourth heat medium heat absorption device in sequence. The third heat medium heat absorption device absorbs the heat of the second compressed air and then returns to the first heat transfer oil heat exchange device, forming a first supercritical pressure water closed cycle. The heat transfer oil in the second heat transfer oil storage device is transported to the first heat transfer oil heat exchange device through the second heat transfer oil transport device to absorb the heat of the supercritical pressure water, and then enters the first heat transfer oil storage device for storage; During the energy storage process, the electric motor drives the first air compression device and the second air compression device to compress air; During the energy storage process, the supercritical pressure water is deoxygenated by using a split flow recirculation bypass deoxygenation method; The split recirculation bypass deoxidation includes: a portion of supercritical pressure water at the outlet of the first heat medium heat absorbing device enters the first deoxidation device for deoxidation, and a portion of heat and pressure are lost during the deoxidation process. The deoxidized supercritical pressure water returns to the first heat medium heat absorbing device through a third water delivery device, and the amount of supercritical pressure water entering the first deoxidation device is controlled by a first regulating valve; a portion of supercritical pressure water at the outlet of the third heat medium heat absorbing device is deoxidized in a second deoxidation device, and the deoxidized supercritical pressure water returns to the third heat medium heat absorbing device through a fourth water delivery device, and the amount of supercritical pressure water entering the second deoxidation device is controlled by a second regulating valve; During the energy storage process, the heat medium pressure stabilizing device controls the heat medium water pressure in the first supercritical pressure water closed cycle to be above 22.115 MPa through the first two-way valve.

9. The method according to claim 7, characterized in that: The energy release process includes: the second compressed air stored in the compressed air storage device first enters the first heat medium heat release device, absorbs the heat of the heat medium discharged from the second heat transfer oil heat exchange device, and then enters the first expander to perform work; the air after doing work enters the second heat medium heat release device to absorb the heat of the heat medium discharged from the second heat transfer oil heat exchange device, and then enters the second expander to perform work, and the air after doing work is discharged into the atmosphere; After the supercritical pressure water absorbs the heat of the heat transfer oil in the second heat transfer oil heat exchange device, it is divided into two paths through the second water delivery device. One path enters the first heat medium heat release device to transfer the heat to the compressed air from the outlet of the compressed air storage device, and the other path enters the second heat medium heat release device to transfer the heat to the air after the first expander does work. The heat medium after heat release returns to the second heat transfer oil heat exchange device, forming a second supercritical pressure water closed cycle; The heat transfer oil in the first heat transfer oil storage device enters the second heat transfer oil heat exchange device through the first heat transfer oil delivery device to transfer heat to the heat medium water, and then enters the second heat transfer oil storage device for storage; During the energy release process, the first expander and the second expander drive the generator to generate electricity; During the energy release process, the heat medium pressure stabilizing device controls the heat medium water pressure in the second supercritical pressure water closed cycle to be above 22.115 MPa through the second two-way valve.

10. The method according to claim 8, characterized in that The pressure of the air entering the compressed air storage device is 15-18 MPa, and the temperature is 50-80°C.

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