Carbon dioxide energy storage method, carbon dioxide energy storage device and control method thereof

Abstract

The present application belongs to the field of energy storage technology, and provides a carbon dioxide energy storage method, a carbon dioxide energy storage device and a control method thereof, including a gas storage reservoir, an energy storage component, a purification component, a liquid storage tank and an energy release component connected in sequence, wherein the energy storage component is used to compress a first mixed fluid including gaseous carbon dioxide and gaseous water flowing out of the gas storage reservoir and then cool it to obtain a second mixed fluid. The purification component is used to separate liquid water from the second mixed fluid, and cool the gaseous carbon dioxide in the second mixed fluid to liquefy it into liquid carbon dioxide and then store it in the liquid storage tank. The energy release component is used to make the liquid carbon dioxide flowing out of the liquid storage tank absorb heat and heat up to gaseous carbon dioxide and expand and do work before storing it in the gas storage reservoir. The carbon dioxide energy storage device provided in the present application can dehydrate online with low energy consumption during the energy storage process, thereby avoiding corrosion of the pipelines, liquid storage tanks and other devices of the energy storage device, and improving the safety of the operation of the carbon dioxide energy storage device.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a carbon dioxide energy storage method, a carbon dioxide energy storage device and a control method thereof. Background Art

[0002] Carbon dioxide energy storage technology uses carbon dioxide as a circulating working fluid and utilizes the gas-liquid conversion and two-state coordination of carbon dioxide to store and release energy. It can be used to reduce peak loads, adjust grid energy load, and stabilize grid frequency.

[0003] The operating principle of the carbon dioxide energy storage device is as follows: when there is a need to store excess electricity, the device will use the excess electricity to compress the gaseous carbon dioxide in the gas storage reservoir into high-temperature and high-pressure gas. After the high-temperature and high-pressure carbon dioxide gas stores heat energy through the thermal storage medium, it is condensed and liquefied into liquid and stored in the storage tank, realizing the conversion of excess electrical energy into pressure energy and internal energy. When energy release is required, the device will use the stored heat energy to heat the liquid carbon dioxide to gaseous state. The gaseous carbon dioxide drives the turbine to drive the generator to generate electricity, realizing the conversion of compression energy and internal energy into electrical energy, and the gaseous carbon dioxide after work can be returned to the gas storage reservoir for recycling.

[0004] The carbon dioxide energy storage device has many advantages such as simple structure, safety, reliability and high efficiency. However, during the operation of the carbon dioxide energy storage device, it was found that the pipes, liquid storage tanks and other devices of the carbon dioxide energy storage device are easily corroded by the working fluid, which will pose a serious threat to the operation of the device. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a carbon dioxide energy storage method, a carbon dioxide energy storage device and a control method thereof, so as to solve the technical problem that the pipelines, liquid storage tanks and other devices of the carbon dioxide energy storage device in the prior art are prone to corrosion.

[0006] To achieve the above purpose, the technical solution adopted in this application is:

[0007] In a first aspect, a carbon dioxide energy storage device is provided, comprising a gas storage reservoir, an energy storage component, a purification component, a liquid storage tank and an energy release component connected in sequence, wherein the energy storage component is used to compress a first mixed fluid including gaseous carbon dioxide and gaseous water flowing out of the gas storage reservoir and then cool it to obtain a second mixed fluid, wherein the second mixed fluid includes gaseous carbon dioxide; the purification component is used to separate liquid water from the second mixed fluid, and cool the gaseous carbon dioxide in the second mixed fluid to liquefy it into liquid carbon dioxide and then store it in the liquid storage tank; the energy release component is used to make the liquid carbon dioxide flowing out of the liquid storage tank absorb heat and heat up to become gaseous carbon dioxide, expand and do work, and then store it in the gas storage reservoir.

[0008] In some embodiments, the purification component includes a shell and a cooling pipe, the shell having a accommodating chamber and a mixed fluid inlet, a first outlet, and a second outlet respectively connected to the accommodating chamber, the cooling pipe is arranged in the accommodating chamber and is used for allowing the first cold fluid to circulate to cool and liquefy the second mixed fluid; the setting height of the mixed fluid inlet is higher than the setting heights of the first outlet and the second outlet; the first outlet is used to supply liquid water to flow out of the accommodating chamber, and the second outlet is used to supply liquid carbon dioxide to flow out of the accommodating chamber.

[0009] In some embodiments, the first outlet is disposed at a height lower than that of the second outlet.

[0010] In some embodiments, the purification component also includes a partition, which is arranged at the bottom of the accommodating chamber and divides the bottom of the accommodating chamber into a first groove and a second groove arranged in sequence along the horizontal direction, the first groove is connected to the first outlet, the second groove is connected to the second outlet, and the cooling pipe is located above the first groove.

[0011] In some embodiments, the purification component also includes a controller and a first pressure sensor, a second pressure sensor, a temperature sensor and a liquid level sensor which are electrically connected to the controller respectively, the first pressure sensor being used to measure the gas phase pressure in the accommodating chamber, the temperature sensor being used to measure the temperature in the accommodating chamber, the liquid level sensor being used to measure the liquid level in the accommodating chamber, the second pressure sensor being used to measure the pressure on the bottom wall of the accommodating chamber when the setting height of the first outlet is lower than the setting height of the second outlet, and the second pressure sensor being used to measure the pressure on the bottom wall of the first tank when the purification component also includes a partition.

[0012] In some embodiments, the shell is further provided with a cold fluid outlet and a cold fluid inlet which are arranged up and down, and the two ends of the cooling pipe are respectively connected to the cold fluid outlet and the cold fluid inlet; the purification component also includes a guide plate, which is arranged on the cavity wall of the accommodating cavity, and the setting height of the guide plate on the cavity wall of the accommodating cavity is higher than the setting height of the cold fluid inlet, and lower than the setting height of the mixed fluid inlet, and in the direction from the outside to the inside of the accommodating cavity, at least a partial area of ​​the guide plate gradually tilts upward.

[0013] In some embodiments, a first gas impurity outlet is further provided on the top of the shell, and the first gas impurity outlet is communicated with the accommodating cavity.

[0014] In some embodiments, the purification component further includes a separation element, which is disposed in the accommodating chamber and located between the mixed fluid inlet and the first gas impurity outlet for capturing liquid droplets.

[0015] In some embodiments, the purification component includes a first separator and a cooler, the energy storage component, the first separator, the cooler and the liquid storage tank are connected in sequence, the first separator is used to separate liquid water from the second mixed fluid to obtain a third mixed fluid, and the cooler is used to liquefy the third mixed fluid to obtain a fourth mixed fluid.

[0016] In some embodiments, the first mixed fluid also includes gas impurities; the cooler has a shell side and a tube side, the shell side and the tube side are respectively used for the circulation of the third mixed fluid and the second cold fluid, and a second gas impurity outlet is provided on the top of the cooler, and the second gas impurity outlet is interconnected with the shell side, for allowing the gas impurities in the third mixed fluid to flow out of the shell side.

[0017] In some embodiments, the purification component further includes a second separator, which is disposed between the cooler and the liquid storage tank and is used to separate liquid water from the fourth mixed fluid.

[0018] In some embodiments, the carbon dioxide energy storage device further includes a third separator, which is disposed at the inlet side of the liquid storage tank and is used to separate liquid water from the fluid flowing into the liquid storage tank.

[0019] In some embodiments, the carbon dioxide energy storage device also includes a delivery pump and a fourth separator. The delivery pump, the fourth separator and the liquid storage tank are connected in a closed loop in sequence. The delivery pump is used to pump the liquid fluid in the liquid storage tank to the fourth separator to remove liquid water and then pump it back to the liquid storage tank.

[0020] In a second aspect, a carbon dioxide energy storage method is provided. The carbon dioxide energy storage method is implemented by the carbon dioxide energy storage device provided by the first aspect, and the carbon dioxide energy storage method comprises:

[0021] Pressurizing and cooling a first mixed fluid including gaseous carbon dioxide and gaseous water to obtain a second mixed fluid;

[0022] Cooling and liquefying the gaseous water in the second mixed fluid into liquid water, and cooling and liquefying the gaseous carbon dioxide in the second mixed fluid into liquid carbon dioxide;

[0023] Liquid carbon dioxide and liquid water are separated by liquid-liquid separation.

[0024] In a third aspect, a carbon dioxide energy storage method is provided, the carbon dioxide energy storage method is implemented by the carbon dioxide energy storage device provided by the first aspect, and the carbon dioxide energy storage method comprises:

[0025] First pressurizing and then cooling a first mixed fluid including gaseous carbon dioxide and gaseous water, so that the gaseous water in the first mixed fluid is at least partially condensed into liquid water, and the gaseous carbon dioxide in the first mixed fluid is kept in a gaseous state, so as to obtain a second mixed fluid;

[0026] Separating liquid water from the second mixed fluid by gas-liquid separation to obtain a third mixed fluid;

[0027] The third mixed fluid is cooled and liquefied to obtain a fourth mixed fluid.

[0028] In a fourth aspect, a control method of a carbon dioxide energy storage device is provided. The control method of the carbon dioxide energy storage device is implemented by the above-mentioned carbon dioxide energy storage device, and the control method of the carbon dioxide energy storage device includes:

[0029] Obtaining the gas phase temperature in the accommodating chamber , gas phase pressure , Liquid level and the liquid phase pressure at the bottom of the liquid water below the liquid carbon dioxide in the containing chamber ;

[0030] Adjust at least one of the temperature, flow rate, and composition of the first cold fluid so that the gas phase temperature With preset gas phase temperature The deviation is less than the preset temperature difference , and the gas phase pressure With preset gas phase pressure The deviation is less than the first preset pressure difference ;

[0031] When the liquid pressure and The difference is greater than the second preset pressure difference When the first outlet is controlled to open and discharge liquid water until the liquid phase pressure value and The difference is less than or equal to the second preset pressure difference ,in, is the preset liquid water level value, is the gas phase pressure and gas phase temperature The density of liquid carbon dioxide at is the gas phase pressure and gas phase temperature The density of liquid water at room temperature and pressure.

[0032] The carbon dioxide energy storage method, carbon dioxide energy storage device and control method thereof provided by the present application have the following beneficial effects: compared with the prior art, the carbon dioxide energy storage device provided by the present application has a purification component set between the energy storage component and the liquid storage tank. Since the carbon dioxide energy storage device needs to use the energy storage component to compress the first mixed fluid in the gas storage reservoir to high temperature and high pressure during the energy storage process, the high temperature and high pressure mixed gas is stored in the heat exchange device, and then cooled and liquefied to liquid for storage, thereby realizing the conversion of excess electrical energy into pressure energy and internal energy. Therefore, the carbon dioxide energy storage device provided by the present application has a purification component between the energy storage component and the storage tank. After the purification components are set between the liquid tanks, the purification components can directly use the compression energy and cold energy consumed in the energy storage process to separate liquid water, which can improve the purity of carbon dioxide in the carbon dioxide energy storage device, thereby avoiding corrosion of the pipelines, liquid storage tanks and other devices of the energy storage device as much as possible, and improving the safety of the operation of the carbon dioxide energy storage device; and, the purification components directly use the compression energy and cold energy consumed in the energy storage process to separate liquid water. On the one hand, it can reduce the additional energy required for the dehydration operation, and on the other hand, it can also avoid the shutdown of the energy storage device due to dehydration needs, thereby achieving the effect of online dehydration. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0034] Figure 1 This is a schematic diagram of the structure of a carbon dioxide energy storage device in some embodiments of the present application;

[0035] Figure 2 This is a schematic diagram of the structure of a carbon dioxide energy storage device in some embodiments of the present application;

[0036] Figure 3 This is a schematic diagram of the main structure of a purification component of a carbon dioxide energy storage device according to some embodiments of the present application, wherein the internal components of the purification component are in a perspective state;

[0037] Figure 4 A schematic diagram of a top view of a purification component of a carbon dioxide energy storage device according to some embodiments of the present application;

[0038] Figure 5 This is a schematic diagram of the main structure of a purification component of a carbon dioxide energy storage device according to some embodiments of the present application;

[0039] Figure 6 This is a schematic diagram of the structure of a carbon dioxide energy storage device in some embodiments of the present application;

[0040] Figure 7 This is a schematic diagram of the structure of a carbon dioxide energy storage device in some embodiments of the present application;

[0041] Figure 8 This is a schematic diagram of the structure of a carbon dioxide energy storage device in some embodiments of the present application;

[0042] Fig. 9 A partial structural schematic diagram of a carbon dioxide energy storage device according to some embodiments of the present application;

[0043] Fig.10 A flow chart of a carbon dioxide energy storage method according to some embodiments of the present application;

[0044] Fig.11 A flow chart of a carbon dioxide energy storage method according to some embodiments of the present application;

[0045] Fig.12 This is a module diagram of a controller, a temperature sensor, a liquid level sensor, a first pressure sensor, and a second pressure sensor of a carbon dioxide energy storage device in some embodiments of the present application.

[0046] Among them, the reference numerals in the figure are:

[0047] 100. Gas storage;

[0048] 200, energy storage component; 210, compressor; 220, energy storage heat exchanger;

[0049] 300, purification component; 310, shell; 311, accommodating chamber; 3111, first slot; 3112, second slot; 312, mixed fluid inlet; 313, first outlet; 314, second outlet; 315, first gas impurity outlet; 316, cold fluid outlet; 317, cold fluid inlet; 320, partition; 330, cooling pipe; 340, guide plate; 341, first guide section; 342, second guide section; 350, separation element; 360, first separator; 361, dehydration tower; 362, gas impurity separator; 370, cooler; 371, shell side; 372, tube side; 373, second gas impurity outlet; 380, second separator; 391, controller; 392, first pressure sensor; 393, second pressure sensor; 394, temperature sensor; 395, liquid level sensor;

[0050] 400, liquid storage tank;

[0051] 500, energy release component; 510, energy release heat exchanger; 520, expander;

[0052] 600, third separator;

[0053] 700, delivery pump;

[0054] 800. The fourth separator. DETAILED DESCRIPTION

[0055] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0056] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0057] In addition, the terms "first" and "second" 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" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0058] Carbon dioxide energy storage technology uses carbon dioxide as a circulating working fluid and utilizes the gas-liquid conversion and two-state coordination of carbon dioxide to store and release energy. It can be used to reduce peak loads, adjust grid energy load, and stabilize grid frequency.

[0059] The operating principle of the carbon dioxide energy storage device is as follows: when there is a need to store excess electricity, the device will use the excess electricity to compress the gaseous carbon dioxide in the gas storage reservoir into high-temperature and high-pressure gas. After the high-temperature and high-pressure carbon dioxide gas stores heat energy through the thermal storage medium, it is condensed and liquefied into liquid and stored in the storage tank, realizing the conversion of excess electrical energy into pressure energy and internal energy. When energy release is required, the device will use the stored heat energy to heat the liquid carbon dioxide to gaseous state. The gaseous carbon dioxide drives the turbine to drive the generator to generate electricity, realizing the conversion of compression energy and internal energy into electrical energy, and the gaseous carbon dioxide after work can be returned to the gas storage reservoir for recycling.

[0060] Carbon dioxide energy storage devices have many advantages such as simple structure, safety, reliability, and high efficiency. However, during the operation of carbon dioxide energy storage devices, it was found that the pipes, liquid storage tanks and other devices of the carbon dioxide energy storage devices are easily corroded by the working fluid, which will pose a serious threat to the operation of the device.

[0061] In order to solve the above problems, this application provides a carbon dioxide energy storage device, please refer to Figure 1 and Figure 2 , the carbon dioxide energy storage device provided by the embodiment of the present application is now described. The carbon dioxide energy storage device includes a gas storage reservoir 100, an energy storage component 200, a purification component 300, a liquid storage tank 400 and an energy release component 500 connected in sequence, the energy storage component 200 is used to compress and then cool the first mixed fluid including gaseous carbon dioxide and gaseous water flowing out of the gas storage reservoir 100 to obtain a second mixed fluid, the second mixed fluid including gaseous carbon dioxide; the purification component 300 is used to separate liquid water from the second mixed fluid, and cool the gaseous carbon dioxide in the second mixed fluid to liquefy it into liquid carbon dioxide and then store it in the liquid storage tank 400, and the energy release component 500 is used to make the liquid carbon dioxide flowing out of the liquid storage tank 400 absorb heat and heat up to gaseous carbon dioxide and expand and do work before storing it in the gas storage reservoir 100.

[0062] It should be noted that under normal operating conditions, the gas storage reservoir 100 is used to store gaseous carbon dioxide. However, during the installation, testing, and operation of the energy storage device, insufficient gas replacement and local leakage may occur inside the energy storage device, causing impurities such as moisture and air to be mixed into the circulating working fluid of the energy storage device. Therefore, the first mixed fluid flowing out of the gas storage reservoir 100 may include impurities such as water and air in addition to carbon dioxide as the circulating medium.

[0063] Specifically, the energy storage component 200 may include a compressor 210 and an energy storage heat exchanger 220. The compressor 210 may be driven by a motor to compress the first mixed fluid so that the pressure and temperature of the first mixed fluid are increased. The energy storage heat exchanger 220 is used to cool the first mixed fluid after the pressure and temperature are increased, so that the consumed electrical energy can be partially converted into compression energy and internal energy. It should be noted that the second mixed fluid obtained after compression and cooling by the energy storage component 200 includes gaseous carbon dioxide. Depending on the amount of cold provided by the energy storage heat exchanger 220, the second mixed fluid can be close to a pure gas phase, that is, most of the water and most of the carbon dioxide in the second mixed fluid are gaseous. The second mixed fluid can also be a gas-liquid two-phase, for example, most of the carbon dioxide in the second mixed fluid remains in the gas phase, while part of the water in the second mixed fluid is gaseous and the other part of the water is liquid.

[0064] Specifically, according to the different states of the water in the second mixed fluid, the purification component 300 can separate liquid water from the second mixed fluid in a variety of different ways. For example, when at least part of the liquid water is included in the second mixed fluid, the purification component 300 can separate most of the liquid water and gaseous carbon dioxide from each other by gas-liquid separation to obtain dehydrated gaseous carbon dioxide, and then cool the gaseous carbon dioxide to liquefy it into liquid carbon dioxide and store it in the liquid storage tank 400. No matter what state the water in the second mixed fluid is, the purification component 300 can separate liquid water from the second mixed fluid by liquid-liquid separation. The purification component 300 can cool the second mixed fluid so that most of the carbon dioxide and most of the water in the second mixed fluid are all liquefied, and then separate the liquid carbon dioxide and liquid water by a liquid-liquid separation device to obtain dehydrated liquid carbon dioxide. The present embodiment does not make a unique limitation on the specific structure of the purification component 300.

[0065] Specifically, see Figure 7 The energy release component 500 may include an energy release heat exchanger 510 and an expander 520. The energy release heat exchanger 510 can convert the liquid carbon dioxide in the liquid storage tank 400 into gaseous carbon dioxide and input it into the expander 520. The gaseous carbon dioxide can drive the expander 520 to do work, drive the generator to generate electricity, and realize the conversion of compression energy into electrical energy. The gaseous carbon dioxide after doing work can be returned to the gas storage reservoir 100 for recycling.

[0066] In the technical solution of the embodiment of the present application, a purification component 300 is arranged between the energy storage component 200 and the liquid storage tank 400. Since the carbon dioxide energy storage device, during the energy storage process, needs to use the energy storage component 200 to compress the first mixed fluid in the gas storage reservoir 100 and cool it into a liquid fluid and then store it in the liquid storage tank 400, so as to achieve the effect of converting electrical energy into internal energy and compression energy for storage. Therefore, after the carbon dioxide energy storage device provided in the present application is provided with the purification component 300 between the energy storage component 200 and the liquid storage tank 400, the purification component 300 can directly use the compression energy and cold energy consumed in the energy storage process to separate liquid water, so as to achieve the effect of improving the purity of carbon dioxide in the carbon dioxide energy storage device, thereby minimizing corrosion of the pipelines of the energy storage device, the liquid storage tank 400 and other devices, and improving the safety of the operation of the carbon dioxide energy storage device.

[0067] Furthermore, in the technical solution of the embodiment of the present application, the purification component 300 directly uses the compression energy and cooling energy consumed in the energy storage process to separate the liquid water, which can reduce the additional energy consumed in the dehydration operation.

[0068] In addition, compared with the method of multiple purging of the interior of the energy storage device or multiple replacement of the gas in the energy storage device before the operation of the carbon dioxide energy storage device, the carbon dioxide energy storage device provided in the embodiment of the present application directly sets the purification component 300 between the energy storage component 200 and the liquid storage tank 400, which can achieve online dehydration during the operation of the device, avoid shutdown of the energy storage device, and help shorten the construction period of the device and improve operation efficiency and economic benefits.

[0069] See also Figure 3 In some embodiments, the purification component 300 includes a shell 310 and a cooling pipe 330. The shell 310 has a accommodating chamber 311 and a mixed fluid inlet 312, a first outlet 313, and a second outlet 314 respectively connected to the accommodating chamber 311. The cooling pipe 330 is used for allowing the first cold fluid to flow to cool the gaseous carbon dioxide and gaseous water in the liquefied second mixed fluid. The setting height of the mixed fluid inlet 312 is higher than the setting heights of the first outlet 313 and the second outlet 314. The first outlet 313 is used to supply liquid water to flow out of the accommodating chamber 311, and the second outlet 314 is used to supply liquid carbon dioxide to flow out of the accommodating chamber 311.

[0070] It should be noted that, when the carbon dioxide energy storage device is in normal operation, the second mixed fluid is close to a pure gas phase, or a gas-liquid mixed phase. When the second mixed fluid enters the accommodating chamber 311 from the mixed fluid inlet 312, the second mixed fluid will contact the outer wall of the cooling tube 330, and condense on the outer wall of the cooling tube 330 to form droplets. The droplets formed on the outer wall of the cooling tube 330 will flow to the bottom of the accommodating chamber 311 under the action of gravity. Since the density of the liquid carbon dioxide in the shell 310 is usually less than the density of liquid water under normal operating conditions of the carbon dioxide energy storage device, when the droplets formed on the outer wall of the cooling tube 330 gather at the bottom of the accommodating chamber 311, the liquid water will settle to the bottom of the shell 310, and the liquid carbon dioxide will be above the liquid water. Furthermore, in the above process, one of the flow rate, temperature and composition of the first cold fluid can be adjusted, or the flow rate of the second mixed fluid can be adjusted, so that the first outlet 313 and the second outlet 314 are always closed by liquid water or liquid carbon dioxide, thereby preventing the gaseous substances in the second mixed fluid from overflowing from the first outlet 313 and the second outlet 314 to the outside of the accommodating chamber 311.

[0071] After the liquid droplets formed on the outer wall of the cooling tube 330 are collected at the bottom of the accommodating chamber 311 , the liquid carbon dioxide and the liquid water can be separated in different ways.

[0072] In one implementation, the height of the first outlet 313 can be set lower than the height of the second outlet 314. In this way, when most of the supersaturated water vapor and supersaturated carbon dioxide in the second mixed fluid will condense into mist droplets or larger droplets on the outer wall of the cooling tube 330 and settle in the accommodating chamber 311, the liquid water and liquid carbon dioxide will be stratified under the action of gravity. As mentioned above, since the density of liquid carbon dioxide is less than the density of water under the pressure and temperature of normal operation of the carbon dioxide energy storage device, after the liquid water and liquid carbon dioxide settle in the accommodating chamber 311, the liquid water will settle at the bottom of the accommodating chamber 311, and the liquid carbon dioxide will be dispersed on the top of the liquid water. In this way, the liquid water can flow out from the first outlet 313 with a lower setting height to the outside of the accommodating chamber 311, and the liquid carbon dioxide can be discharged from the accommodating chamber 311 from the second outlet 314 with a higher height.

[0073] In another implementation, the purification component 300 also includes a partition 320, which is disposed at the bottom of the accommodating chamber 311 and divides the bottom of the accommodating chamber 311 into a first groove 3111 and a second groove 3112. The first groove 3111 and the second groove 3112 are arranged in sequence along the horizontal direction, the first groove 3111 is connected to the second outlet 314, the second groove 3112 is connected to the first outlet 313, and the cooling pipe 330 is disposed above the first groove 3111.

[0074] Specifically, the partition 320 is used to separate the bottom of the accommodating cavity 311 into a first groove 3111 and a second groove 3112. The tops of the first groove 3111 and the second groove 3112 are both open to form an opening. The first groove 3111 and the second groove 3112 are arranged in sequence along the horizontal direction. It can be understood that the opening of the first groove 3111 and the opening of the second groove 3112 are arranged in sequence in the horizontal direction.

[0075] In addition, the partition 320 can be set to be fixed, that is, the partition 320 is fixed on the cavity wall of the accommodating chamber 311; the partition 320 can also be set to be adjustable, that is, the setting height of the partition 320 in the accommodating chamber 311 is adjustable. The adjustable height setting of the partition 320 can facilitate the control of the liquid-liquid interface of carbon dioxide-water under different processing volumes, different residence times, and different physical parameters, so that liquid carbon dioxide and water can be effectively separated.

[0076] When the above embodiment is adopted, during the operation of the carbon dioxide energy storage device, most of the supersaturated water vapor and supersaturated carbon dioxide in the second mixed fluid will condense into mist droplets or larger droplets on the outer wall of the cooling tube 330, and settle in the second tank 3112. Since the density of liquid carbon dioxide is less than the density of water under the pressure and temperature of normal operation of the carbon dioxide energy storage device, after the liquid water and liquid carbon dioxide settle in the second tank 3112, the liquid water will settle at the bottom of the second tank 3112, and the liquid carbon dioxide will be dispersed on the top of the liquid water. By setting the height of the partition 320, the liquid carbon dioxide can flow over the partition 320 into the first tank 3111, thereby realizing the separation of carbon dioxide and water.

[0077] In the technical solution of the embodiment of the present application, the purification component 300 directly uses the compression energy and cold energy consumed in the energy storage process to liquefy the gaseous carbon dioxide and gaseous water in the first mixed fluid, and allows the liquefied liquid carbon dioxide and liquid water to separate naturally under the action of gravity. The entire dehydration operation does not require additional condensing devices or mechanical energy-consuming devices. The dehydration operation consumes low additional energy, and can achieve the technical effect of removing most of the water in the device with lower energy consumption, which is beneficial to saving energy.

[0078] See also Figure 5 In some embodiments, the purification component 300 also includes a controller 391 and a first pressure sensor 392, a second pressure sensor 393, a temperature sensor 394 and a liquid level sensor 395 which are respectively electrically connected to the controller 391, the first pressure sensor 392 is used to measure the gas phase pressure in the accommodating chamber 311, the temperature sensor 394 is used to measure the temperature in the accommodating chamber 311, the liquid level sensor 395 is used to measure the liquid level in the accommodating chamber 311, the second pressure sensor 393 is used to measure the pressure on the bottom wall of the accommodating chamber 311 when the setting height of the first outlet 313 is lower than the setting height of the second outlet 314, and the second pressure sensor 393 is used to measure the pressure on the bottom wall of the first groove 3111 when the purification component 300 also includes a partition 320.

[0079] See also Fig.12 The embodiment of the present application also provides a control method of a carbon dioxide energy storage device, the control method of the carbon dioxide energy storage device is used to control the above-mentioned carbon dioxide energy storage device, and the control method of the carbon dioxide energy storage device includes:

[0080] S1: Obtaining the gas phase temperature in the accommodating chamber 311 , gas phase pressure , Liquid level and the liquid phase pressure at the bottom of the liquid water below the liquid carbon dioxide in the accommodating chamber 311 .

[0081] Specifically, the gas phase temperature measured by the temperature sensor 394 , the gas phase pressure is obtained through the first pressure sensor 392 , obtain the liquid phase pressure through the second pressure sensor 393 , the liquid level measured by the liquid level sensor 395 .

[0082] S2: Adjust at least one of the temperature, flow rate, and composition of the first cold fluid so that the gas phase temperature With preset gas phase temperature The deviation is less than the preset temperature difference , and the gas phase pressure With preset gas phase pressure The deviation is less than the first preset pressure difference .

[0083] S3: When the liquid phase pressure and The difference is greater than the second preset pressure difference When the first outlet 313 is opened, the liquid water is discharged until the liquid phase pressure value is and The difference is less than or equal to the second preset pressure difference ,in, (greater than 0) is the preset liquid water level value, is the gas phase pressure and gas phase temperature The density of liquid carbon dioxide at is the gas phase pressure and gas phase temperature The density of liquid water at room temperature and pressure.

[0084] It can be understood that in the gas phase space, the gas phase pressure The temperature changes with the operation of the compression and condensation conditions of the carbon dioxide energy storage device. According to the physical properties of carbon dioxide, the density of liquid carbon dioxide formed by the condensation of gaseous carbon dioxide under different pressures is different, and the gas phase pressure will be obtained. The first pressure sensor 392 is connected to the controller 391, and the controller 391 can query the liquid carbon dioxide expansion line table to obtain the pressure of different gas phases under the compression and condensation conditions of the carbon dioxide energy storage device. The density of the liquid carbon dioxide at the bottom of the lower housing 310 is .

[0085] It can also be understood that when the height of the liquid column of liquid water in the housing 310 is , the height of the liquid column of liquid carbon dioxide is The theoretical pressure at the bottom of the liquid water below the liquid carbon dioxide should be equal to , the theoretical pressure value is compared with the measured liquid phase pressure For comparison, if the measured liquid pressure is greater than the theoretical pressure, it means that the height of the liquid water in the housing 310 is greater than , it is necessary to discharge part of the liquid water so that the height of the liquid column of the liquid water in the housing 310 is less than or equal to , so that a very small amount of liquid water is maintained in the shell 310, thereby improving the purity of the circulating working fluid.

[0086] In the technical solution of the embodiment of the present application, the start and closing of the first outlet 313 is controlled, and the automatic discharge and isolation of the liquid water at the bottom of the shell 310 is controlled, which can effectively improve the carbon dioxide concentration quality of the carbon dioxide energy storage device, improve the regulation quality of the energy storage device control, and also ensure the safe operation of the energy storage device.

[0087] See also Figure 3 and Figure 4 In some embodiments, the shell 310 is provided with a cold fluid outlet 316 and a cold fluid inlet 317 which are arranged up and down, and the two ends of the cooling pipe 330 are respectively connected with the cold fluid outlet 316 and the cold fluid inlet 317; the purification component 300 also includes a guide plate 340, which is arranged on the cavity wall of the accommodating cavity 311, and the setting height of the guide plate 340 on the cavity wall of the accommodating cavity 311 is higher than the setting height of the cold fluid inlet 317 and lower than the setting height of the mixed fluid inlet 312, and in the direction from the outside to the inside of the accommodating cavity 311, at least a part of the area of ​​the guide plate 340 gradually tilts upward.

[0088] It can be understood that when the cooling tube 330 is not installed, the cold fluid outlet 316 and the cold fluid inlet 317 are both connected to the accommodating cavity 311, and after one end of the cooling tube 330 is connected to the cold fluid inlet 317 and the other end of the cooling tube 330 is connected to the cold fluid outlet 316, the first cold fluid will flow from bottom to top in the cooling tube 330.

[0089] In the technical solution of the embodiment of the present application, the guide plate 340 can guide the second mixed fluid upward so that the second mixed fluid flows from top to bottom in the accommodating chamber 311, which can improve the uniformity of distribution of the second mixed fluid in the accommodating chamber 311, and can also make the flow direction of the second mixed fluid opposite to the flow direction of the first cold fluid in the cooling tube 330, thereby improving the heat exchange efficiency of the first cold fluid and the second mixed fluid.

[0090] For example, see Figure 3 and Figure 4The guide plate 340 includes a first guide section 341 and a second guide section 342. One end of the first guide section 341 is fixed on the cavity wall of the accommodating cavity 311. The first guide section 341 is arranged parallel to the penetration direction of the mixed fluid inlet 312. The second guide plate 340 is connected to the other end of the first guide section 341. In the direction from the inside of the accommodating cavity 311 to the outside of the accommodating cavity 311, the second guide section 342 is gradually inclined upward. In this way, the first guide section 341 helps to smoothly guide the second mixed fluid into the accommodating cavity 311, reduce the eddy current and turbulence of the fluid, and improve the flow efficiency of the fluid. The second guide section 342 can guide the second mixed fluid upward so that the second mixed fluid flows from top to bottom in the accommodating chamber 311, thereby improving the distribution uniformity of the second mixed fluid in the accommodating chamber 311 and making the flow direction of the second mixed fluid opposite to the flow direction of the first cold fluid in the cooling tube 330, thereby improving the heat exchange efficiency between the first cold fluid and the second mixed fluid.

[0091] See also Figure 3 and Figure 4 In some embodiments, the first mixed fluid further includes gas impurities; a first gas impurity outlet 315 is further provided at the top of the shell 310 , and the first gas impurity outlet 315 is communicated with the accommodating chamber 311 .

[0092] It should be noted that gas impurities refer to gases that are not easily liquefied into liquid form under various operating conditions of the carbon dioxide energy storage device, which can be N 2 , O 2 、SO x wait.

[0093] Specifically, a gas storage container may be connected to the first gas impurity outlet 315, and the gas impurities may be collected in the gas storage container and then discharged periodically.

[0094] When gas impurities exist in the carbon dioxide energy storage device, the volume that can be used to store carbon dioxide in the device will be reduced, the energy storage efficiency will be reduced, and the gas impurities may have a negative impact on the heat exchange efficiency, working pressure and other aspects of the device. Therefore, in the technical solution of the embodiment of the present application, a first gas impurity outlet 315 is set at the top of the shell 310. After the gas impurities accumulate at the top of the shell 310, the gas impurities in the shell 310 can be discharged by regular discharge, or the gas impurities in the shell 310 can be discharged after the pressure at the top of the shell 310 reaches a certain value, so as to improve the purity of the carbon dioxide in the device, thereby improving the energy storage efficiency and the safety of the operation of the device.

[0095] See also Figure 3 and Figure 4In some embodiments, the purification component 300 further includes a separation element 350, which is disposed in the accommodating chamber 311 and between the mixed fluid inlet 312 and the first gas impurity outlet 315, and is used to capture water droplets or carbon dioxide droplets.

[0096] Specifically, the separation element 350 can have a variety of forms. The separation element 350 can be set as a metal wire mesh separation element, such as a wire mesh demister. The wire mesh demister mainly uses collision separation to remove droplets from the gas. The separation element 350 can also be set as a grille baffle type mist collector. The grille baffle type mist collector uses expansion and centrifugal force to capture droplets. The gas carrying the droplets passes through the mist collector. The gas is forced to flow along the flow channel in the mist collector. Due to the high density and inertia of the droplets, they cannot completely change direction with the airflow, so some droplets will collide and adhere to the baffle. The droplets attached to the baffle will flow down from the baffle under the action of gravity, thereby achieving gas-liquid two-phase separation. Of course, the separation element 350 can also be set in the form of an inclined plate or a diffuser assembly. This embodiment does not limit the specific structure of the separation element 350.

[0097] In the technical solution of the embodiment of the present application, by setting a separation element 350 between the mixed fluid inlet 312 and the first gas impurity outlet 315, the probability of carbon dioxide droplets escaping from the gas impurity outlet to the outside of the accommodating chamber 311 can be reduced, thereby minimizing the loss of circulating working fluid.

[0098] See also Figures 6 to 8 In some embodiments, the purification component 300 includes a first separator 360 and a cooler 370, the energy storage component 200, the first separator 360, the cooler 370 and the liquid storage tank 400 are connected in sequence, the first separator 360 is used to separate liquid water from the second mixed fluid to obtain a third mixed fluid, and the cooler 370 is used to liquefy the third mixed fluid to obtain a fourth mixed fluid.

[0099] It should be noted that when all the water in the second mixed fluid is liquid water, the first separator 360 can remove almost all the water in the liquid carbon dioxide. In this case, the third mixed fluid obtained by the first separator 360 only includes gaseous carbon dioxide. When part of the water in the second mixed fluid is liquid water and part of the water is gaseous water, the gaseous carbon dioxide removed by the first separator 360 also contains part of the gaseous water. That is to say, in this case, the third mixed fluid obtained by the first separator 360 includes gaseous carbon dioxide and part of the gaseous water, and the third mixed fluid can be further dehydrated.

[0100] Specifically, in some implementations, the first separator 360 can be configured as a gravity separator that does not consume additional energy. For example, the first separator 360 can be configured as a liquid collection bag integrated on a pipe section between the energy storage assembly 200 and the cooler 370 .

[0101] In some other implementations, the first separator 360 may be configured as a centrifugal separator that consumes energy; of course, the first separator 360 may also be a gas-liquid separator in other forms, and this embodiment does not make the sole limitation thereto.

[0102] In some other implementations, see Fig. 9 The first separator 360 includes a dehydration tower 361 and a gas impurity separator 362. The energy storage component 200, the dehydration tower 361, the gas impurity separator 362 and the cooler 370 are connected in sequence. The dehydration tower 361 is used to separate water from the second mixed fluid, and the gas impurity separator 362 is used to separate gas impurities from the fluid flowing out of the dehydration tower 361. The number of dehydration towers 361 can be two, and the two dehydration towers 361 are connected in parallel between the energy storage component 200 and the gas impurity separator 362. The two dehydration towers 361 can be used alternately. After the water in one of the dehydration towers 361 is saturated, the dehydration tower 361 can be regenerated, cold purged and pressurized so that the dehydration tower 361 can absorb water again.

[0103] The regeneration process includes the following steps: first, the pressure of the dehydration tower 361 is reduced in the opposite direction of adsorption, and then the dry regeneration gas is heated by the heater and enters the dehydration tower 361 to fully heat the solid adsorbent in the dehydration tower 361. In the process of increasing the adsorbent temperature and reducing the pressure, the adsorption amount of the adsorbent decreases, and the originally adsorbed water and other impurities are separated from the adsorbent to achieve regeneration. The regeneration gas is discharged from the dehydration tower 361 with the desorbed water, and can enter the cooling device for cooling. The cooled wet regeneration gas can separate the liquid water from the gaseous regeneration gas through the separator, and the regeneration gas is discharged through the separator.

[0104] The cold purge and pressurization process includes the following steps: the dry regenerated gas is not heated, and the dehydration tower 361 is cold purged until its temperature reaches the adsorption temperature. The purge gas at the outlet of the dehydration tower 361 is cooled by a cooling device, separated by a separator, and then discharged. The dehydrated regenerated gas is pressurized in the dehydration tower 361 until it reaches the adsorption pressure.

[0105] In the technical solution of the embodiment of the present application, since the compression work and cooling energy consumed when liquefying the gaseous water in the first mixed fluid belong to the compression energy and cooling energy originally required to be consumed in the energy storage process, in the technical solution of the embodiment of the present application, no additional compression work and cooling energy are required to liquefy the gaseous water; in this way, when the first separator 360 does not consume additional energy, the entire dehydration process does not require additional energy consumption, and when the first separator 360 needs to consume energy, the energy consumed in the dehydration process is only the energy consumed by the first separator 360, and the energy consumption is relatively low.

[0106] See also Figure 6 In some embodiments, the first mixed fluid also includes gas impurities; the cooler 370 has a shell side 371 and a tube side 372, the shell side 371 and the tube side 372 are respectively used for the circulation of the third mixed fluid and the second cold fluid, and a second gas impurity outlet 373 is provided at the top of the cooler 370, and the second gas impurity outlet 373 is interconnected with the shell side 371, so as to allow the gas impurities in the third mixed fluid to flow out of the shell side 371.

[0107] It should be noted that, in the technical solution of this embodiment, the gas impurity refers to the gas that is not easily liquefied into liquid under various working conditions of the carbon dioxide energy storage device, which can be N 2 , O 2 、SO x wait.

[0108] Specifically, a gas storage container may be connected to the second gas impurity outlet 373, and the gas impurities may be collected in the gas storage container and then discharged periodically.

[0109] In the technical solution of the embodiment of the present application, a second gas impurity outlet 373 interconnected with the shell side 371 is provided. After the gas impurities accumulate at the top of the shell side 371, the gas impurities in the shell side 371 can be discharged by regular discharge to improve the purity of carbon dioxide in the device, thereby improving the energy storage efficiency and operation safety.

[0110] See also Figure 7 In some embodiments, the purification component 300 further includes a second separator 380 , which is disposed at the inlet side of the liquid storage tank 400 and is used to separate liquid water from the fluid flowing into the liquid storage tank 400 .

[0111] In some implementations, see Figure 7 , the second separator 380 is disposed between the cooler 370 and the liquid storage tank 400; in some other implementations, please refer to Figure 1 and Figure 2 The second separator 380 can be disposed between the purification component 300 and the liquid storage tank 400. Figure 1 and Figure 2The second separator 380 is not shown.

[0112] Specifically, in some implementations, the second separator 380 can be configured as a centrifugal separator that requires energy consumption; for example, the second separator 380 can be configured as a butterfly centrifuge, and a fluid inlet is provided on the disc of the butterfly centrifuge. The fourth mixed fluid flows to the disc gap through the fluid inlet. Under the action of centrifugal force, the liquid water in the fourth mixed fluid flows along the inclined surface of the disc and moves toward the inner wall of the drum. It is continuously discharged from the heavy liquid outlet, and the liquid carbon dioxide moves upward along the inclined surface of the disc and is discharged through the light liquid outlet after merging.

[0113] In some other implementations, the second separator 380 can be configured as a gravity separator that does not consume additional energy. For example, the second separator 380 can also be configured as a liquid collecting container located between the cooler 370 and the liquid storage tank 400 and integrated with a liquid collecting bag. The second separator 380 can be configured as a liquid collecting bag integrated on the pipe section between the cooler 370 and the liquid storage tank 400. Of course, the second separator 380 can also adopt other forms of liquid-liquid separators, and this embodiment does not make a sole limitation on this.

[0114] In the technical solution of the embodiment of the present application, by setting a second separator 380 between the cooler 370 and the liquid storage tank 400, liquid water can be separated from the fourth mixed fluid, further reducing the water content in the energy storage device, and improving energy storage efficiency and operation safety.

[0115] See also Figure 7 In some embodiments, the carbon dioxide energy storage device further includes a third separator 600 , which is disposed between the liquid storage tank 400 and the energy release assembly 500 , and is used to separate liquid water from the liquid fluid flowing from the liquid storage tank 400 to the energy release assembly 500 .

[0116] Specifically, in some implementations, the third separator 600 can be configured as a gravity separator that does not consume additional energy. For example, the third separator 600 can be configured as a liquid collecting container integrated with a liquid collecting bag, and the liquid collecting container is respectively connected to the liquid storage tank 400 and the energy release component 500, and the liquid collecting bag can collect and discharge liquid water; for another example, the third separator 600 can also be configured as a liquid collecting bag integrated on the pipe section between the liquid storage tank 400 and the energy release component 500.

[0117] In some other implementations, the third separator 600 may be configured as a centrifugal separator that consumes energy, such as a butterfly centrifuge; of course, the third separator 600 may also be other forms of liquid-liquid separators, and this embodiment does not make the sole limitation to this.

[0118] In the technical solution of the embodiment of the present application, by setting a third separator 600 between the energy release component 500 and the liquid storage tank 400, liquid water in the liquid fluid flowing from the liquid storage tank 400 to the energy release component 500 can be removed, further reducing the water content in the energy storage device, thereby improving energy storage efficiency and operational safety.

[0119] See also Figure 2 and Figure 8 In some embodiments, the carbon dioxide energy storage device further includes a delivery pump 700 and a fourth separator 800. The delivery pump 700, the fourth separator 800 and the liquid storage tank 400 are connected in a closed loop in sequence. The delivery pump 700 is used to pump the liquid fluid in the liquid storage tank 400 to the fourth separator 800 to remove the liquid water and then pump it back to the liquid storage tank 400.

[0120] Specifically, in some implementations, the fourth separator 800 can be configured as a gravity separator that does not consume additional energy. For example, the fourth separator 800 can be configured as a liquid collecting container integrated with a liquid collecting bag, and the liquid collecting container is connected to the liquid storage tank 400 and the delivery pump 700 respectively, and the liquid collecting bag can collect and discharge liquid water; for another example, the fourth separator 800 can be configured as a liquid collecting bag integrated on the pipe section between the liquid storage tank 400 and the delivery pump 700.

[0121] In some other implementations, the fourth separator 800 may also be configured as a centrifugal separator that consumes energy, such as a butterfly centrifuge; of course, the fourth separator 800 may also adopt other forms of liquid-liquid separators, and this embodiment does not make the sole limitation to this.

[0122] Since the liquid fluid stored in the liquid storage tank 400 may contain liquid water, in the technical solution of the embodiment of the present application, the liquid fluid in the liquid storage tank 400 is dehydrated using a delivery pump 700 and a fourth separator 800. The structure is simple and will not affect the operation of the device. Together with the purification component 300, secondary dehydration can be achieved, which is beneficial to further reduce the water content of carbon dioxide and improve the energy storage efficiency of the device and the safety of the device operation.

[0123] See also Fig.10 The embodiment of the present application provides a carbon dioxide energy storage method, which is implemented by the above-mentioned carbon dioxide energy storage device, and the carbon dioxide energy storage method includes:

[0124] S10a: pressurizing and cooling a first mixed fluid including gaseous carbon dioxide and gaseous water to obtain a second mixed fluid.

[0125] S20a: Cooling and liquefying the gaseous water in the second mixed fluid into liquid water, and cooling and liquefying the gaseous carbon dioxide in the second mixed fluid into liquid carbon dioxide.

[0126] S30a: Separating the liquid carbon dioxide and liquid water obtained in the above step S20a by liquid-liquid separation.

[0127] It should be noted that the second mixed fluid obtained by step S10a can be in gas phase, that is, the second mixed fluid only includes gaseous carbon dioxide and gaseous water, and the second mixed fluid obtained by step S10a can also be in gas-liquid two-phase, that is, the second mixed fluid includes gaseous carbon dioxide, gaseous water and liquid water at the same time.

[0128] Specifically, in step S30a, a centrifugal separator that requires mechanical energy can be used to separate liquid carbon dioxide and liquid water, or a gravity separator that does not require additional energy can be used to separate liquid carbon dioxide and liquid water. Of course, liquid carbon dioxide and liquid water can also be separated by other methods, and this embodiment does not make the sole limitation to this.

[0129] In the technical solution of the embodiment of the present application, liquid water is separated from liquid carbon dioxide by liquid-liquid separation directly during the energy storage process of the energy storage device to improve the purity of carbon dioxide in the carbon dioxide energy storage device. There is no need to purge the inside of the device multiple times or replace the gas in the device multiple times before the device is operated. Dehydration can be achieved during the operation of the device, which is beneficial to shorten the construction period of the device and improve the operating efficiency and economic benefits.

[0130] Moreover, in the technical solution of the embodiment of the present application, step S10a and step S20a can directly utilize the compression energy and cold energy consumed in the energy storage process to liquefy gaseous water and gaseous carbon dioxide without consuming additional energy. When no energy is consumed in the liquid-liquid separation process of step S30a, the technical effect of removing moisture from the device can be achieved without consuming additional energy. When energy is consumed in the liquid-liquid separation process of step S30a, the energy consumed in the entire dehydration process is only the energy consumed in step S30a, and the energy consumption is relatively low.

[0131] See also Fig.11 The embodiment of the present application provides a carbon dioxide energy storage method, which is implemented by the above-mentioned carbon dioxide energy storage device, and the carbon dioxide energy storage method includes:

[0132] S10b: pressurizing and then cooling the first mixed fluid including gaseous carbon dioxide and gaseous water, so that the gaseous water in the first mixed fluid is at least partially condensed into liquid water, and the gaseous carbon dioxide in the first mixed fluid is kept in a gaseous state, so as to obtain a second mixed fluid;

[0133] S20b: Separating liquid water from the second mixed fluid by gas-liquid separation to obtain a third mixed fluid.

[0134] S30b: Cooling and liquefying the gaseous carbon dioxide in the third mixed fluid into liquid carbon dioxide to obtain a fourth mixed fluid.

[0135] Specifically, in step S20b, a centrifugal separator that requires mechanical energy can be used to separate liquid water from the second mixed fluid, or a gravity separator that does not require additional energy can be used to separate liquid water from the second mixed fluid. Of course, liquid water can also be separated from the second mixed fluid by other methods, and this embodiment does not make a sole limitation to this.

[0136] In the technical solution of the embodiment of the present application, liquid water is separated from liquid carbon dioxide by gas-liquid separation directly during the energy storage process of the energy storage device to improve the purity of carbon dioxide in the carbon dioxide energy storage device. There is no need to purge the inside of the device multiple times or replace the gas in the device multiple times before the device is operated. Dehydration can be achieved during the operation of the device, which is beneficial to shorten the construction period of the device and improve the operating efficiency and economic benefits.

[0137] Furthermore, since the compression work and cooling capacity consumed in liquefying the gaseous water in the first mixed fluid in step S10b belong to the compression energy and cooling capacity originally required to be consumed in the energy storage process, step S10b does not require additional compression work and cooling capacity consumption; in this way, when the gas-liquid separation process in step S20b does not consume additional energy, the entire dehydration process does not require additional energy consumption. When the gas-liquid separation process in step S20b needs to consume energy, the energy consumed by the dehydration process is only the energy consumed by the gas-liquid separation process in step S20b, and the energy consumption is relatively low.

[0138] See also Fig.11 In some embodiments, the carbon dioxide energy storage method further comprises after step S30b:

[0139] Step S40b: separating liquid water from the fourth mixed fluid by liquid-liquid separation.

[0140] Specifically, in step S40b, a centrifugal separator that consumes mechanical energy may be used to separate liquid water from the fourth mixed fluid, or a gravity separator that does not consume additional energy may be used to separate liquid water from the fourth mixed fluid, and this embodiment is not intended to be the only limitation.

[0141] In the technical solution of the embodiment of the present application, liquid water is separated from the fourth mixed fluid by liquid-liquid separation, which is beneficial to further reduce the water content in the energy storage device and to improve the energy storage efficiency and operation safety.

[0142] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A carbon dioxide energy storage device, characterized in that: The carbon dioxide energy storage device comprises a gas storage reservoir, an energy storage component, a purification component, a liquid storage tank and an energy release component connected in sequence, wherein the energy storage component is used to compress a first mixed fluid including gaseous carbon dioxide and gaseous water flowing out of the gas storage reservoir and then cool it to obtain a second mixed fluid, wherein the second mixed fluid includes gaseous carbon dioxide; the purification component is used to separate liquid water from the second mixed fluid, and cool the gaseous carbon dioxide in the second mixed fluid to liquefy it into liquid carbon dioxide and then store it in the liquid storage tank; the energy release component is used to make the liquid carbon dioxide flowing out of the liquid storage tank absorb heat and heat up to gaseous carbon dioxide and expand to do work before storing it in the gas storage reservoir; The purification component comprises a shell and a cooling pipe, wherein the shell has a containing chamber and a mixed fluid inlet, a first outlet and a second outlet respectively connected to the containing chamber, the cooling pipe is arranged in the containing chamber and is used for allowing a first cold fluid to flow through to cool and liquefy the second mixed fluid; the setting height of the mixed fluid inlet is higher than the setting heights of the first outlet and the second outlet; the first outlet is used for allowing liquid water to flow out of the containing chamber, and the second outlet is used for allowing liquid carbon dioxide to flow out of the containing chamber; The control method of the carbon dioxide energy storage device implemented by the carbon dioxide energy storage device includes: Obtaining the gas phase temperature in the accommodating cavity , gas phase pressure , Liquid level and the liquid phase pressure at the bottom of the liquid water below the liquid carbon dioxide in the containing chamber ; Adjust at least one of the temperature, flow rate, and composition of the first cold fluid so that the gas phase temperature With preset gas phase temperature The deviation is less than the preset temperature difference , and the gas phase pressure With preset gas pressure The deviation is less than the first preset pressure difference ; When the and The difference is greater than the second preset pressure difference When the first outlet is controlled to open and discharge liquid water until the liquid phase pressure and The difference is less than or equal to the second preset pressure difference ,in, is the preset liquid water level value, is the gas phase pressure and gas phase temperature The density of liquid carbon dioxide at is the gas phase pressure and gas phase temperature The density of liquid water at room temperature and pressure.

2. The carbon dioxide energy storage device according to claim 1, characterized in that: The setting height of the first outlet is lower than the setting height of the second outlet; Alternatively, the purification component also includes a partition, which is arranged at the bottom of the accommodating chamber and divides the bottom of the accommodating chamber into a first groove and a second groove arranged in sequence along the horizontal direction, the first groove is connected to the first outlet, the second groove is connected to the second outlet, and the cooling pipe is located above the first groove.

3. The carbon dioxide energy storage device according to claim 2, characterized in that: The purification component also includes a controller and a first pressure sensor, a second pressure sensor, a temperature sensor and a liquid level sensor which are electrically connected to the controller respectively. The first pressure sensor is used to measure the gas phase pressure in the accommodating chamber, the temperature sensor is used to measure the temperature in the accommodating chamber, the liquid level sensor is used to measure the liquid level in the accommodating chamber, the second pressure sensor is used to measure the pressure on the bottom wall of the accommodating chamber when the setting height of the first outlet is lower than the setting height of the second outlet, and the second pressure sensor is used to measure the pressure on the bottom wall of the first tank when the purification component also includes a partition.

4. The carbon dioxide energy storage device according to claim 1, characterized in that: The shell is also provided with a cold fluid outlet and a cold fluid inlet which are arranged up and down, and the two ends of the cooling pipe are respectively connected with the cold fluid inlet and the cold fluid outlet; the purification component also includes a guide plate, which is arranged on the cavity wall of the accommodating cavity, and the setting height of the guide plate on the cavity wall of the accommodating cavity is higher than the setting height of the cold fluid inlet, and lower than the setting height of the mixed fluid inlet, and in the direction from the outside to the inside of the accommodating cavity, at least a part of the area of ​​the guide plate gradually tilts upward.

5. The carbon dioxide energy storage device according to claim 1, characterized in that: The top of the shell is also provided with a first gas impurity outlet, and the first gas impurity outlet is communicated with the accommodating cavity.

6. The carbon dioxide energy storage device according to claim 5, characterized in that: The purification component further comprises a separation element, which is arranged in the accommodating chamber and located between the mixed fluid inlet and the first gas impurity outlet for capturing liquid droplets.

7. The carbon dioxide energy storage device according to claim 1, characterized in that: The purification component includes a first separator and a cooler. The energy storage component, the first separator, the cooler and the liquid storage tank are connected in sequence. The first separator is used to separate liquid water from the second mixed fluid to obtain a third mixed fluid. The cooler is used to liquefy the third mixed fluid to obtain a fourth mixed fluid.

8. The carbon dioxide energy storage device according to claim 7, characterized in that: The cooler comprises a shell side and a tube side, wherein the shell side and the tube side are respectively used for the circulation of the third mixed fluid and the second cold fluid. A second gas impurity outlet is provided at the top of the cooler, and the second gas impurity outlet is interconnected with the shell side for allowing the gas impurities in the third mixed fluid to flow out of the shell side.

9. The carbon dioxide energy storage device according to any one of claims 1 to 8, characterized in that: The purification component further includes a second separator, which is disposed at the inlet side of the liquid storage tank and is used to separate liquid water from the fluid flowing into the liquid storage tank.

10. The carbon dioxide energy storage device according to any one of claims 1 to 8, characterized in that: The carbon dioxide energy storage device further comprises a third separator, which is disposed between the liquid storage tank and the energy release component, and is used to separate liquid water from the liquid fluid flowing from the liquid storage tank to the energy release component; And / or, the carbon dioxide energy storage device also includes a delivery pump and a fourth separator, the delivery pump, the fourth separator and the liquid storage tank are connected in a closed loop in sequence, and the delivery pump is used to pump the liquid fluid in the liquid storage tank to the fourth separator to remove liquid water and then pump it back to the liquid storage tank.

11. A carbon dioxide energy storage method, characterized in that: The carbon dioxide energy storage method is implemented by the carbon dioxide energy storage device according to claim 1, and the carbon dioxide energy storage method comprises: Pressurizing and cooling a first mixed fluid including gaseous carbon dioxide and gaseous water to obtain a second mixed fluid; Cooling and liquefying the gaseous water in the second mixed fluid into liquid water, and cooling and liquefying the gaseous carbon dioxide in the second mixed fluid into liquid carbon dioxide; Liquid carbon dioxide and liquid water are separated by liquid-liquid separation.

12. A carbon dioxide energy storage method, characterized in that: The carbon dioxide energy storage method is implemented by the carbon dioxide energy storage device according to claim 1, and the carbon dioxide energy storage method comprises: First pressurizing and then cooling a first mixed fluid including gaseous carbon dioxide and gaseous water, so that the gaseous water in the first mixed fluid is at least partially condensed into liquid water, and the gaseous carbon dioxide in the first mixed fluid is kept in a gaseous state, so as to obtain a second mixed fluid; Separating liquid water from the second mixed fluid by gas-liquid separation to obtain a third mixed fluid; The third mixed fluid is cooled and liquefied to obtain a fourth mixed fluid.

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