Carbon dioxide energy storage system

Abstract

The utility model relates to the technical field of energy storage, and provides a carbon dioxide energy storage system which comprises an energy storage unit, an energy release unit and a heat storage unit, the energy storage unit comprises a gas storage device, a compressor, a cooler, a liquefier and a liquid storage device, and the energy release unit comprises a vaporizer, a heater and an expansion machine. The energy storage unit and the energy release unit are connected to form a carbon dioxide circulation loop; the heat storage unit comprises a cold storage device and a heat storage device, the cooler is connected between an outlet of the cold storage device and an inlet of the heat storage device, and the vaporizer and the heater are connected between an outlet of the heat storage device and an inlet of the cold storage device. Through the arrangement, the heat storage device can store compression heat of the compressor and provide heat for the vaporizer and the heater when the energy release unit operates, the cold storage device can store cold energy generated during vaporization of carbon dioxide and provide cold energy for the cooler when the energy storage unit operates, and the compression heat and the cold energy generated during vaporization are fully utilized; and the energy utilization rate is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to a carbon dioxide energy storage system. Background Art

[0002] Carbon dioxide energy storage technology is mainly used to store and release electrical energy. It is an innovative energy storage technology. During the off-peak period of electricity consumption, the surplus electrical energy is converted into the pressure energy of carbon dioxide (or other forms of energy) and stored. When the demand for electricity increases or the power supply is insufficient, the stored energy is converted back into electrical energy and released into the power grid to meet the electricity demand. Carbon dioxide energy storage technology can provide peak load regulation, frequency regulation and black start services for power grid operation, significantly improving the flexibility and safety of the power system.

[0003] Carbon dioxide energy storage systems generally include compression units, expansion units and heat exchange units. However, in the current energy conversion process, the compression heat generated by the compression unit and the cold released during vaporization are not fully utilized, and these two parts of energy are independent of each other, resulting in low energy utilization.

[0004] Therefore, how to solve the problem of low energy utilization of the carbon dioxide energy storage system in the prior art due to insufficient utilization of the compression heat and the cold energy generated by the evaporation of carbon dioxide has become an important technical problem to be solved by those skilled in the art. Utility Model Content

[0005] The utility model provides a carbon dioxide energy storage system, which is used to solve the defect of low energy utilization rate caused by insufficient utilization of compression heat and cold energy generated when carbon dioxide vaporizes in the carbon dioxide energy storage system in the prior art.

[0006] The utility model provides a carbon dioxide energy storage system, comprising:

[0007] An energy storage unit, comprising a gas storage device, a compressor, a cooler, a liquefier and a liquid storage device, wherein the cooler has a first channel and a second channel, the liquefier has a third channel and a fourth channel, the gas storage device, the compressor, the first channel, the third channel and the liquid storage device are connected in sequence, and the fourth channel is suitable for connecting to an external cooling device;

[0008] An energy release unit, comprising a vaporizer, a heater and an expander, wherein the vaporizer has a fifth channel and a sixth channel, the heater has a seventh channel and an eighth channel, the fifth channel, the seventh channel, the expander and the gas storage device are connected in sequence, the fifth channel is connected to the liquid storage device, the energy storage unit and the energy release unit are connected to form a carbon dioxide circulation loop, and the expander is suitable for connecting to a generator to generate electricity;

[0009] The heat storage unit comprises a cold storage device and a heat storage device, wherein two ends of the second channel are respectively connected to the outlet of the cold storage device and the inlet of the heat storage device, two ends of the sixth channel are respectively connected to the outlet of the heat storage device and the inlet of the cold storage device, and two ends of the eighth channel are respectively connected to the outlet of the heat storage device and the inlet of the cold storage device.

[0010] According to a carbon dioxide energy storage system provided by the utility model, the cold storage device includes a cold storage tank and a first power pump, the inlet of the cold storage tank is suitable for connecting the sixth channel and the eighth channel, the outlet of the cold storage tank is connected to the inlet of the first power pump, and the outlet of the first power pump is connected to the second channel.

[0011] According to a carbon dioxide energy storage system provided by the utility model, the heat storage device includes a heat storage tank and a second power pump, the inlet of the heat storage tank is connected to the second channel, the outlet of the heat storage tank is connected to the inlet of the second power pump, and the outlet of the second power pump is connected to the sixth channel and the eighth channel.

[0012] According to a carbon dioxide energy storage system provided by the utility model, the system also includes:

[0013] The venting unit includes a first venting pipeline and a first control valve, wherein the first end of the first venting pipeline is connected to the exhaust port of the compressor, the second end of the first venting pipeline is suitable for connecting to the inlet of the gas storage device, the first control valve is arranged on the first venting pipeline, and a third control valve is arranged between the exhaust port of the compressor and the first channel.

[0014] According to a carbon dioxide energy storage system provided by the utility model, the energy storage unit further includes a first safety valve and a second safety valve, the first safety valve is arranged in the first channel, and the second safety valve is arranged in the third channel;

[0015] The energy release unit further includes a third safety valve and a fourth safety valve, wherein the third safety valve is arranged in the fifth channel, and the fourth safety valve is arranged in the seventh channel;

[0016] The venting unit also includes a second venting pipeline, and the first safety valve, the second safety valve, the third safety valve and the fourth safety valve are respectively connected to a second venting pipeline, and each second venting pipeline is suitable for supplying overpressure released carbon dioxide to the gas storage device.

[0017] According to a carbon dioxide energy storage system provided by the utility model, the venting unit also includes a main venting pipeline and a second control valve, the second end of the first venting pipeline and the second end of each of the second venting pipelines are connected to the inlet of the gas storage device through the main venting pipeline, and the second control valve is arranged on the main venting pipeline.

[0018] According to a carbon dioxide energy storage system provided by the utility model, the venting unit further includes a first pressure detection element and a second pressure detection element, and the first pressure detection element and the second pressure detection element are both electrically connected to the control system;

[0019] The first pressure detection element is disposed in the first venting pipeline, and the first pressure detection element is suitable for detecting the pressure at the exhaust port of the compressor;

[0020] The second pressure detection element is disposed in the main venting pipeline, and the second pressure detection element is suitable for detecting the pressure of the main venting pipeline.

[0021] According to a carbon dioxide energy storage system provided by the utility model, the venting unit further includes a first silencer and a second silencer, the first silencer is arranged on the first venting pipeline, and the second silencer is arranged on the main venting pipeline.

[0022] According to a carbon dioxide energy storage system provided by the utility model, the energy storage unit further includes a preheater, which is arranged between the gas storage device and the compressor, and is suitable for preheating the carbon dioxide at the outlet of the gas storage device.

[0023] According to a carbon dioxide energy storage system provided by the utility model, the energy release unit further includes a third power pump, the inlet of the third power pump is connected to the inlet of the liquid storage device, and the outlet of the third power pump is connected to the fifth channel.

[0024] The carbon dioxide energy storage system provided by the utility model comprises an energy storage unit, an energy release unit and a heat storage unit. The energy storage unit comprises a gas storage device, a compressor, a cooler, a liquefier and a liquid storage device. The cooler has a first channel and a second channel, the liquefier has a third channel and a fourth channel, the gas storage device, the compressor, the first channel, the third channel and the liquid storage device are connected in sequence, and the fourth channel is suitable for connecting an external cooling device. When the energy storage unit is in operation, it can convert the carbon dioxide gas in a low-pressure state into a carbon dioxide liquid in a high-pressure state to achieve energy storage. The energy release unit comprises a vaporizer, a heater and an expander. The vaporizer has a fifth channel and a sixth channel, the heater has a seventh channel and an eighth channel, the fifth channel, the seventh channel, the expander and the gas storage device are connected in sequence, the fifth channel is connected to the liquid storage device, and the expander is suitable for connecting a generator to generate electricity. The energy storage unit and the energy release unit are connected to form a carbon dioxide circulation loop. When the energy release unit is in operation, it can convert the carbon dioxide liquid in a high-pressure state into carbon dioxide gas in a low-pressure state, and output electrical energy through the generator to achieve energy release. The heat storage unit includes a cold storage device and a heat storage device, the two ends of the second channel are respectively connected to the outlet of the cold storage device and the inlet of the heat storage device, the two ends of the sixth channel are respectively connected to the outlet of the heat storage device and the inlet of the cold storage device, and the two ends of the eighth channel are respectively connected to the outlet of the heat storage device and the inlet of the cold storage device. In this way, when the energy storage unit is in operation, energy storage is realized, and the compression heat of the compressor is stored by the heat storage device. When the energy release unit is in operation, energy release is realized, and the cold generated when carbon dioxide is vaporized is stored by the cold storage device. The heat stored in the heat storage device can provide heat for carbon dioxide in the vaporizer and the heater when the energy release unit is in operation, thereby increasing the temperature of carbon dioxide. The cold stored in the cold storage device can provide cold for carbon dioxide in the cooler when the energy storage unit is in operation, thereby reducing the temperature of carbon dioxide. When the carbon dioxide energy storage system is in operation, the compression heat generated by compressing carbon dioxide and the cold generated when carbon dioxide is vaporized are fully utilized, thereby effectively improving the energy utilization rate, and solving the problem of low energy utilization rate caused by insufficient utilization of compression heat and cold generated when carbon dioxide is vaporized in the carbon dioxide energy storage system in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a structural principle diagram of the carbon dioxide energy storage system provided by the utility model (the first power pump, the second power pump and the third power pump are not shown).

[0027] Reference numerals:

[0028] 1. Gas storage device; 2. Compressor; 3. Cooler; 4. Liquefier; 5. Liquid storage device; 6. Vaporizer; 7. Heater; 8. Expander; 9. Cold storage tank; 10. Heat storage tank; 11. First control valve; 12. Third control valve; 13. First safety valve; 14. Second safety valve; 15. Third safety valve; 16. Fourth safety valve; 17. Second control valve; 18. First pressure detection element; 19. Second pressure detection element; 20. First silencer; 21. Second silencer; 22. Preheater; 23. Fourth control valve; 24. Control system. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] Combine the following Figure 1 The carbon dioxide energy storage system of the utility model is described.

[0031] like Figure 1 As shown, the carbon dioxide energy storage system provided by the embodiment of the utility model includes an energy storage unit, an energy release unit and a heat storage unit.

[0032] Specifically, the energy storage unit includes a gas storage device 1 , a compressor 2 , a cooler 3 , a liquefier 4 and a liquid storage device 5 .

[0033] The gas storage device 1 is used to store carbon dioxide gas in a low-pressure state. The gas storage device 1 can be, but is not limited to, an airbag, and the airbag adopts a double-layer air film structure.

[0034] The compressor 2 is used to compress the carbon dioxide gas in a low-pressure state to form the carbon dioxide gas in a high-pressure state. When the compressor 2 compresses the carbon dioxide gas, compression heat is generated. The carbon dioxide gas in a high-pressure state absorbs the compression heat and has a higher temperature. In other words, the carbon dioxide entering the cooler 3 is a high-temperature and high-pressure carbon dioxide gas.

[0035] A fourth control valve 23 is provided between the air inlet of the compressor 2 and the air storage device 1 .

[0036] The cooler 3 is used to cool the carbon dioxide gas in a high-temperature and high-pressure state, which is beneficial to improving the compression efficiency of the compressor 2 .

[0037] The liquefier 4 is used to liquefy carbon dioxide, and the liquid storage device 5 is used to store high-pressure carbon dioxide liquid. The liquid storage device 5 can be, but is not limited to, a liquid storage tank that can withstand high pressure.

[0038] The cooler 3 and the liquefier 4 are similar to heat exchangers and each has two channels.

[0039] Specifically, the cooler 3 has a first channel and a second channel, the liquefier 4 has a third channel and a fourth channel, and the gas storage device 1, the compressor 2, the first channel, the third channel and the liquid storage device 5 are connected in sequence for the circulation of carbon dioxide.

[0040] The fourth channel is used to connect an external cooling device, and use an external cold source to provide cold energy to carbon dioxide to achieve liquefaction of carbon dioxide. The external cooling device here can be a ground source heat pump unit evaporator, and the ground source heat pump unit evaporator absorbs the heat of the medium in the fourth channel to provide cold energy to carbon dioxide, making full use of the energy of the ground source heat pump unit.

[0041] When the energy storage unit is in operation, it provides electrical energy to the compressor 2. The operation of the compressor 2 can convert the carbon dioxide gas in a low-pressure state into the carbon dioxide liquid in a high-pressure state, thereby realizing energy storage.

[0042] The energy release unit includes a vaporizer 6 , a heater 7 and an expander 8 .

[0043] The vaporizer 6 is used to vaporize the carbon dioxide, and the heater 7 is used to heat the carbon dioxide, which is beneficial to improving the power generation capacity.

[0044] The expander 8 is used to connect to an external generator, and uses the high-pressure carbon dioxide gas to expand and generate electricity. At the same time, the high-pressure carbon dioxide gas is converted into low-pressure carbon dioxide gas and stored in the gas storage device 1.

[0045] The vaporizer 6 and the heater 7 are similar to heat exchangers and each have two channels.

[0046] Specifically, the vaporizer 6 has a fifth channel and a sixth channel, the heater 7 has a seventh channel and an eighth channel, the fifth channel is connected to the liquid storage device 5, and the fifth channel, the seventh channel, the expander 8 and the gas storage device 1 are connected in sequence for the circulation of carbon dioxide.

[0047] When the energy release unit is in operation, it can convert high-pressure carbon dioxide liquid into low-pressure carbon dioxide gas, and output electrical energy through a generator to achieve energy release.

[0048] The energy storage unit and the energy release unit are connected to form a carbon dioxide circulation loop. The energy storage unit can use the low-pressure carbon dioxide gas generated by the energy release unit to generate high-pressure carbon dioxide liquid; the energy release unit can use the high-pressure carbon dioxide liquid generated by the energy storage unit to generate low-pressure carbon dioxide gas.

[0049] The heat storage unit includes a cold storage device and a heat storage device.

[0050] The two ends of the second channel of the cooler 3 are respectively connected to the outlet of the cold storage device and the inlet of the heat storage device, the two ends of the sixth channel of the vaporizer 6 are respectively connected to the outlet of the heat storage device and the inlet of the cold storage device, and the two ends of the eighth channel of the heater 7 are respectively connected to the outlet of the heat storage device and the inlet of the cold storage device.

[0051] A heat storage medium flows in the heat storage unit. The heat storage medium enters the heat storage device after absorbing compression heat in the second channel of the cooler 3. When the vaporizer 6 and the heater 7 are required to provide heat to the carbon dioxide, the heat storage medium enters the vaporizer 6 and the heater 7. The heat storage medium enters the cold storage device after releasing heat in the sixth channel of the vaporizer 6 and the eighth channel of the heater 7. When the cooler 3 is required to provide cold to the carbon dioxide, the heat storage medium enters the cooler 3.

[0052] With such an arrangement, energy can be stored when the energy storage unit is in operation, and the heat of compression of the compressor 2 can be stored by the heat storage device. Energy can be released when the energy release unit is in operation, and the cold energy generated when the carbon dioxide is vaporized can be stored by the cold storage device. The heat stored in the heat storage device can provide heat to the liquid carbon dioxide in the vaporizer 6 and the heater 7 when the energy release unit is in operation, thereby increasing the temperature of the carbon dioxide. The cold energy stored in the cold storage device can provide cold energy to the gaseous carbon dioxide in the cooler 3 when the energy storage unit is in operation, thereby reducing the temperature of the carbon dioxide. When the carbon dioxide energy storage system is in operation, the heat of compression generated by compressing the carbon dioxide and the cold energy generated when the carbon dioxide is vaporized are fully utilized, thereby effectively improving the energy utilization rate, and solving the problem of low energy utilization rate in the carbon dioxide energy storage system in the prior art due to the fact that the heat of compression and the cold energy generated when the carbon dioxide is vaporized are not fully utilized.

[0053] The compressor 2 may be, but is not limited to, a piston compressor, a screw compressor or a centrifugal compressor.

[0054] The compressor 2 may be configured as a single-stage compressor or a multi-stage compressor.

[0055] The expander 8 may be configured as a single-stage expander or a multi-stage expander.

[0056] The above-mentioned cooler 3 can be provided with only one, or at least two coolers connected in series can be provided to achieve multi-stage cooling.

[0057] The above-mentioned heater 7 can be provided with only one, or at least two heaters connected in series can be provided to achieve multi-stage heating.

[0058] In this embodiment, the energy storage unit further includes a preheater 22, which is disposed between the gas storage device 1 and the compressor 2, and is used to preheat the carbon dioxide at the outlet of the gas storage device 1. In this configuration, the preheater 22 can heat the carbon dioxide at the outlet of the gas storage device 1, ensure that the working conditions of the air inlet of the compressor 2 meet the design requirements, and ensure that there is no liquid at the air inlet of the compressor 2. The preheater 22 can use an external heat source to heat the carbon dioxide.

[0059] Specifically, the preheater 22 can be controlled to operate under the working condition of low external ambient temperature such as winter; and the preheater 22 can be controlled to stop operating under the working condition of high external ambient temperature such as summer.

[0060] The energy release unit further includes a third power pump, the inlet of the third power pump is connected to the inlet of the liquid storage device 5, and the outlet of the third power pump is connected to the fifth channel. The third power pump can provide power for the circulation of carbon dioxide in the energy release unit. When the third power pump is running, carbon dioxide can enter the fifth channel of the vaporizer 6, the seventh channel of the heater 7, the expander 8 and the gas storage device 1 in sequence.

[0061] In an embodiment of the utility model, the cold storage device includes a cold storage tank 9 and a first power pump, the sixth channel and the eighth channel are simultaneously connected to the inlet of the cold storage tank 9, the outlet of the cold storage tank 9 is connected to the inlet of the first power pump, and the outlet of the first power pump is connected to the second channel of the cooler 3.

[0062] The heat storage device includes a heat storage tank 10 and a second power pump, the inlet of the heat storage tank 10 is connected to the second channel, the outlet of the heat storage tank 10 is connected to the inlet of the second power pump, and the sixth channel and the eighth channel are simultaneously connected to the outlet of the second power pump.

[0063] With such arrangement, the first power pump can provide power for the circulation of the heat storage medium between the cold storage tank 9, the second channel of the cooler 3 and the heat storage tank 10. When the first power pump is in operation, the heat storage medium in the cold storage tank 9 can enter the second channel of the cooler 3 and the heat storage tank 10 in sequence. The second power pump can not only provide power for the circulation of the heat storage medium between the heat storage tank 10, the sixth channel of the vaporizer 6 and the cold storage tank 9, but also provide power for the circulation of the heat storage medium between the heat storage tank 10, the eighth channel of the heater 7 and the cold storage tank 9. When the second power pump is in operation, the heat storage medium in the heat storage tank 10 can enter the sixth channel of the vaporizer 6 and the cold storage tank 9 in sequence, and can also enter the eighth channel of the heater 7 and the cold storage tank 9 in sequence.

[0064] The exterior of the heat storage tank 10 and the cold storage tank 9 are coated with heat-insulating materials to reduce heat loss.

[0065] In the embodiment of the utility model, the carbon dioxide energy storage system also includes a venting unit.

[0066] The venting unit includes a first venting pipeline and a first control valve 11 . The first end of the first venting pipeline is connected to the exhaust port of the compressor 2 , and the second end of the first venting pipeline is used to connect to the inlet of the gas storage device 1 .

[0067] The first control valve 11 is disposed on the first venting pipeline, and the first control valve 11 can control the on-off of the first venting pipeline.

[0068] A third control valve 12 is provided between the exhaust port of the compressor 2 and the first channel of the cooler 3, and the on-off state of the exhaust port of the compressor 2 and the first channel of the cooler 3 can be controlled by the third control valve 12. A check valve should also be provided at the exhaust port of the compressor 2 to prevent the working medium carbon dioxide from flowing back to the compressor 2 when the energy storage unit is shut down.

[0069] When it is necessary to stop the energy storage unit, the first control valve 11 can be opened, and the third control valve 12 and the fourth control valve 23 can be closed, so that the gas at the exhaust port of the compressor 2 can flow to the gas storage device 1 through the first venting pipeline, and the compressor 2 gradually changes to an idling state. When the exhaust pressure of the compressor 2 drops to the intake design pressure state, the power supply to the motor of the compressor 2 is stopped, so that the compressor 2 stops running. With such a configuration, when the compressor 2 starts running again, the compressor 2 can start without back pressure, which is beneficial to reduce the starting current of the motor driving the compressor 2. By controlling the first control valve 11, the compressor 2 can be started without back pressure, which is easy to operate and has minimal no-load load.

[0070] In the embodiment of the utility model, the energy storage unit further includes a first safety valve 13 and a second safety valve 14. The first safety valve 13 is arranged in the first channel, and is used to discharge the working medium carbon dioxide to the design pressure when the operating pressure at the first channel of the cooler 3 exceeds the design pressure. The second safety valve 14 is arranged in the third channel, and is used to discharge the working medium carbon dioxide to the design pressure when the operating pressure at the third channel of the liquefier 4 exceeds the design pressure, so as to ensure the safety and reliability of the energy storage unit.

[0071] The energy release unit further includes a third safety valve 15 and a fourth safety valve 16. The third safety valve 15 is arranged in the fifth channel, and is used to release the working medium carbon dioxide to the design pressure when the operating pressure at the fifth channel of the vaporizer 6 exceeds the design pressure. The fourth safety valve 16 is arranged in the seventh channel, and is used to release the working medium carbon dioxide to the design pressure when the operating pressure at the seventh channel of the heater 7 exceeds the design pressure, so as to ensure the safety and reliability of the energy release unit.

[0072] In this embodiment, the venting unit also includes a second venting pipeline, and the first safety valve 13, the second safety valve 14, the third safety valve 15 and the fourth safety valve 16 are respectively connected to a second venting pipeline, and each second venting pipeline is used to supply the overpressure released carbon dioxide to flow to the gas storage device 1, so as to realize the recovery of the released carbon dioxide and avoid waste, thereby reducing the amount of carbon dioxide supplemented to the carbon dioxide energy storage system.

[0073] In this embodiment, the venting unit also includes a main venting pipeline and a second control valve 17. The second end of the first venting pipeline and the second end of each second venting pipeline are connected to the inlet of the gas storage device 1 through the main venting pipeline. The carbon dioxide at the exhaust port of the compressor 2 and the carbon dioxide released by the first safety valve 13, the second safety valve 14, the third safety valve 15 and the fourth safety valve 16 can all flow to the gas storage device 1 through the main venting pipeline.

[0074] The second control valve 17 is arranged on the main venting pipeline, and the opening and closing of the main venting pipeline can be controlled by the second control valve 17 .

[0075] When the carbon dioxide at the exhaust port of the compressor 2 needs to flow to the gas storage device 1, the first control valve 11 and the second control valve 17 need to be opened, and the third control valve 12 and the fourth control valve 23 need to be closed. When at least one of the first safety valve 13, the second safety valve 14, the third safety valve 15 and the fourth safety valve 16 needs to be released, the second control valve 17 is opened, and the state of the first control valve 11 is controlled according to the needs of the compressor 2.

[0076] It should be noted that corresponding control valves may also be provided on each second venting pipeline to control the on-off of each second venting pipeline individually.

[0077] In the embodiment of the utility model, the venting unit further includes a first pressure detection element 18 and a second pressure detection element 19 .

[0078] The first pressure detection element 18 is provided in the first venting pipeline, and is used to detect the pressure at the exhaust port of the compressor 2. The second pressure detection element 19 is provided in the main venting pipeline, and is used to detect the pressure of the main venting pipeline.

[0079] The motor of compressor 2, the first pressure detection element 18 and the second pressure detection element 19 are all electrically connected to the control system 24. When the energy storage unit needs to stop running, the pressure in the first vent pipeline and the pressure in the main vent pipeline can be detected in real time. When the pressure in the first vent pipeline and the pressure in the main vent pipeline are reduced to the system intake design pressure, the control system 24 controls the power off of the motor of compressor 2, which is conducive to realizing automatic control.

[0080] The first pressure detection element 18 and the second pressure detection element 19 may be, but are not limited to, pressure transmitters, which can convert the pressure of carbon dioxide into an electric signal. The pressure transmitter as the first pressure detection element 18 can be interlocked with the first control valve 11, and the pressure transmitter as the second pressure detection element 19 can be interlocked with the second control valve 17, so that the remote operation and automatic control of the venting unit can be realized through the control system 24.

[0081] The control system 24 may be a distributed control system, also known as a distributed control system, a decentralized control system or a distributed computer control system, referred to as a DCS control system.

[0082] It should be noted that pressure gauges are also provided on the first vent pipeline and the main vent pipeline, and the pressure gauge on the first vent pipeline can be provided on the side of the first control valve 11 close to the exhaust port of the compressor 2. The pressure gauge can intuitively display the pressure value, which is convenient for the staff to understand the operation of the carbon dioxide energy storage system.

[0083] In this embodiment, the venting unit further includes a first silencing device 20 and a second silencing device 21. The first silencing device 20 is arranged in the first venting pipeline, and the first silencing device 20 is used to eliminate the noise generated when carbon dioxide flows in the first venting pipeline. The second silencing device 21 is arranged in the main venting pipeline, and the second silencing device 21 is used to eliminate the noise generated when carbon dioxide flows in the main venting pipeline.

[0084] The first silencer 20 and the second silencer 21 may be silencers, or may be silencer cotton or sound-absorbing perforated plates. The silencer cotton may be wrapped on the outside of the venting pipeline, and the sound-absorbing perforated plates may be arranged on the inside of the venting pipeline.

[0085] The carbon dioxide energy storage system provided in the embodiment of the utility model enables the motor of the compressor 2, the first control valve 11, the second control valve 17, the third control valve 12, the fourth control valve 23, the first pressure detection element 18 and the second pressure detection element 19 to be electrically connected to the control system 24.

[0086] During the energy storage process, that is, when the energy storage unit is running, the discharge unit stops running.

[0087] When the energy storage unit runs for the preset energy storage time and needs to stop running, the control system 24 controls the first control valve 11 and the second control valve 17 to open, and closes the third control valve 12 and the fourth control valve 23, gradually reducing the pressure to make the compressor 2 idle, and the carbon dioxide in the compressor 2 and the venting pipeline flows into the gas storage device 1. When the exhaust pressure of the compressor 2 drops to the designed intake pressure, the control system 24 controls the motor of the compressor 2 to stop running; the first pressure detection element 18 is interlocked with the first control valve 11, and the second pressure detection element 19 is interlocked with the second control valve 17. The control system 24 controls the first control valve 11 and the second control valve 17 according to the pressure signals detected by the first pressure detection element 18 and the second pressure detection element 19.

[0088] If overpressure relief occurs during the operation of the energy storage unit, the first safety valve 13 and the second safety valve 14 are opened; at the same time, the second pressure detection element 19 is interlocked with the second control valve 17, and the control system 24 controls the second control valve 17 to open according to the pressure signal detected by the second pressure detection element 19, so that the released carbon dioxide flows into the gas storage device 1. When the pressure is released to the discharge pressure set by the first safety valve 13 and the second safety valve 14, the first safety valve 13 and the second safety valve 14 are closed; at the same time, the control system 24 controls the second control valve 17 to close according to the pressure signal detected by the second pressure detection element 19.

[0089] If overpressure relief occurs when the energy release unit is in operation, the third safety valve 15 and the fourth safety valve 16 are opened, and at the same time, the second pressure detection element 19 is interlocked with the second control valve 17. The control system 24 controls the second control valve 17 to open according to the pressure signal detected by the second pressure detection element 19, so that the released carbon dioxide flows into the gas storage device 1. When the pressure is released to the discharge pressure set by the third safety valve 15 and the fourth safety valve 16, the third safety valve 15 and the fourth safety valve 16 are closed; at the same time, the control system 24 controls the second control valve 17 to close according to the pressure signal detected by the second pressure detection element 19.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A carbon dioxide energy storage system, characterized in that: include: An energy storage unit, comprising a gas storage device, a compressor, a cooler, a liquefier and a liquid storage device, wherein the cooler has a first channel and a second channel, the liquefier has a third channel and a fourth channel, the gas storage device, the compressor, the first channel, the third channel and the liquid storage device are connected in sequence, and the fourth channel is suitable for connecting to an external cooling device; An energy release unit, comprising a vaporizer, a heater and an expander, wherein the vaporizer has a fifth channel and a sixth channel, the heater has a seventh channel and an eighth channel, the fifth channel, the seventh channel, the expander and the gas storage device are connected in sequence, the fifth channel is connected to the liquid storage device, the energy storage unit and the energy release unit are connected to form a carbon dioxide circulation loop, and the expander is suitable for connecting to a generator to generate electricity; The heat storage unit comprises a cold storage device and a heat storage device, wherein two ends of the second channel are respectively connected to the outlet of the cold storage device and the inlet of the heat storage device, two ends of the sixth channel are respectively connected to the outlet of the heat storage device and the inlet of the cold storage device, and two ends of the eighth channel are respectively connected to the outlet of the heat storage device and the inlet of the cold storage device.

2. The carbon dioxide energy storage system according to claim 1, characterized in that: The cold storage device includes a cold storage tank and a first power pump, the inlet of the cold storage tank is suitable for connecting the sixth channel and the eighth channel, the outlet of the cold storage tank is connected to the inlet of the first power pump, and the outlet of the first power pump is connected to the second channel.

3. The carbon dioxide energy storage system according to claim 1, characterized in that: The heat storage device includes a heat storage tank and a second power pump, the inlet of the heat storage tank is connected to the second channel, the outlet of the heat storage tank is connected to the inlet of the second power pump, and the outlet of the second power pump is connected to the sixth channel and the eighth channel.

4. The carbon dioxide energy storage system according to claim 1, characterized in that: Also includes: The venting unit includes a first venting pipeline and a first control valve, wherein the first end of the first venting pipeline is connected to the exhaust port of the compressor, the second end of the first venting pipeline is suitable for connecting to the inlet of the gas storage device, the first control valve is arranged on the first venting pipeline, and a third control valve is arranged between the exhaust port of the compressor and the first channel.

5. The carbon dioxide energy storage system according to claim 4, characterized in that: The energy storage unit further includes a first safety valve and a second safety valve, wherein the first safety valve is arranged in the first channel, and the second safety valve is arranged in the third channel; The energy release unit further includes a third safety valve and a fourth safety valve, wherein the third safety valve is arranged in the fifth channel, and the fourth safety valve is arranged in the seventh channel; The venting unit also includes a second venting pipeline, and the first safety valve, the second safety valve, the third safety valve and the fourth safety valve are respectively connected to a second venting pipeline, and each second venting pipeline is suitable for supplying overpressure released carbon dioxide to the gas storage device.

6. The carbon dioxide energy storage system according to claim 5, characterized in that: The venting unit also includes a main venting pipeline and a second control valve, the second end of the first venting pipeline and the second ends of each of the second venting pipelines are connected to the inlet of the gas storage device through the main venting pipeline, and the second control valve is arranged on the main venting pipeline.

7. The carbon dioxide energy storage system according to claim 6, characterized in that: The venting unit further comprises a first pressure detection element and a second pressure detection element, wherein the first pressure detection element and the second pressure detection element are both electrically connected to the control system; The first pressure detection element is disposed in the first venting pipeline, and the first pressure detection element is suitable for detecting the pressure at the exhaust port of the compressor; The second pressure detection element is disposed in the main venting pipeline, and the second pressure detection element is suitable for detecting the pressure of the main venting pipeline.

8. The carbon dioxide energy storage system according to claim 6, characterized in that: The venting unit further includes a first silencer and a second silencer, wherein the first silencer is arranged on the first venting pipeline, and the second silencer is arranged on the main venting pipeline.

9. The carbon dioxide energy storage system according to claim 1, characterized in that: The energy storage unit further includes a preheater, which is disposed between the gas storage device and the compressor, and is suitable for preheating carbon dioxide at an outlet of the gas storage device.

10. The carbon dioxide energy storage system according to claim 1, characterized in that: The energy release unit further includes a third power pump, an inlet of the third power pump is connected to the inlet of the liquid storage device, and an outlet of the third power pump is connected to the fifth channel.

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