Isothermal compressed air energy storage device

Abstract

The invention discloses an isothermal compressed air energy storage device, and belongs to the technical field of compressed air energy storage. The isothermal compressed air energy storage device comprises an air storage chamber, and the air storage chamber is provided with a rapid temperature change area and a slow temperature change area; one end of the gas transmission channel is communicated with the gas storage chamber; the gas-liquid heat exchange assembly is mounted in the slow temperature change area; the phase change heat storage and exchange assembly is mounted in the rapid temperature change area; the circulating pipeline is connected between the gas-liquid heat exchange assembly and the phase change heat storage and exchange assembly; and the circulating pump is mounted on the circulating pipeline. The mode that phase change heat storage and heat exchange are matched is adopted, uniform temperature distribution in the gas storage chamber can be promoted, the temperature in the gas storage chamber is maintained to be close to the freezing point of the phase change heat storage material, thermal fatigue damage caused by periodic alternating temperature and local temperature gradient of a wall face material is reduced, the service life of equipment is prolonged, and the service life of the equipment is prolonged. And the equipment safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressed air energy storage, and in particular to an isothermal compressed air energy storage device. Background Art

[0002] Compressed air energy storage (CAES) is considered one of the most promising large-scale, long-duration energy storage technologies. It can effectively address the intermittent and unstable nature of renewable energy generation and facilitate the large-scale integration of renewable energy into the power grid. Large-scale CAES systems typically utilize large-capacity gas storage devices. Currently, the most widely used gas storage devices fall into two categories: natural and artificial. The former are primarily represented by natural salt caverns, abandoned mines, and rock caverns, while the latter primarily include high-pressure gas tanks, pipeline steel, and man-made underground chambers.

[0003] The construction of natural gas storage devices is subject to significant geographical constraints, which is one of the main factors limiting the promotion and application of compressed air energy storage technology. Artificially excavated underground chambers offer flexible site selection and fewer restrictions. In recent years, many domestic compressed air energy storage power station projects have adopted artificial chamber gas storage solutions. However, during the periodic energy storage and release processes of the gas storage devices in large-scale compressed air energy storage power stations, on the one hand, the temperature inside the energy storage devices fluctuates significantly due to the effects of heating during inflation and cooling during exhaust. On the other hand, the uneven temperature field inside the gas storage devices can cause extremely high or low temperatures in local areas of the gas storage wall. This not only increases power consumption during compression and significantly decreases power during exhaust, resulting in reduced system efficiency, but also the alternating temperatures and local high temperature gradients can cause thermal fatigue and crack damage to the wall materials of the gas storage chamber (such as lining and surrounding rock), affecting system safety and lifespan.

[0004] Patent publication CN112283079A discloses a compressed air energy storage system with an air tank reheat system and its control method. This compressed air energy storage system incorporates a heat exchanger within the air storage chamber. During energy storage and release, an external circulating pump controls the flow rate and temperature of the fluid entering the heat exchanger, thereby maintaining the compressed air temperature within the air storage chamber within a set temperature range. However, in actual engineering applications, this compressed air energy storage system has the following shortcomings:

[0005] 1. The internal heat exchange fluid and the cooling and heating medium between the compressor and the expander share the cold storage tank and the heat storage tank, which may cause the heat exchange temperature range to not match and cause the system to Losses increased.

[0006] 2. There is still an uneven temperature field inside the gas storage chamber, which will result in poor actual temperature control effect.

[0007] 3. Additional electricity is required to maintain the stable temperature inside the gas storage chamber. Summary of the Invention

[0008] In view of this, an object of the present invention is to provide an isothermal compressed air energy storage device to solve the technical problem of the uneven temperature field inside the existing air storage chamber.

[0009] The technical solution adopted by the present invention is: an isothermal compressed air energy storage device, comprising:

[0010] An air storage chamber, wherein the air storage chamber has a rapid temperature change zone and a slow temperature change zone;

[0011] a gas transmission channel, one end of which is in communication with the gas storage chamber;

[0012] A gas-liquid heat exchange component installed in a slow temperature change zone;

[0013] Phase-change heat storage and exchange components, wherein the phase-change heat storage and exchange components are installed in a rapid temperature change zone;

[0014] A circulation pipeline connected between the gas-liquid heat exchange component and the phase change heat storage and exchange component;

[0015] A circulation pump is installed on the circulation pipeline and is used to drive the circulating working medium to circulate between the gas-liquid heat exchange component and the phase change heat storage and exchange component.

[0016] Preferably, the phase-change heat storage and exchange assembly includes a phase-change heat storage unit, an inner heat exchange tube and an outer heat exchange plate. The phase-change heat storage unit includes a heat-conducting shell and a phase-change heat storage material. The phase-change heat storage material is filled in the heat-conducting shell. The inner heat exchange tube is immersed in the phase-change heat storage material, and both ends of the inner heat exchange tube extend to the outside of the phase-change heat storage unit and are connected to the circulation pipeline; the outer heat exchange plate is installed on the outside of the phase-change heat storage unit.

[0017] Preferably, a plurality of axial fins are distributed on the circumference of the inner heat exchange tube, and the axial fins are arranged along the axial direction of the inner heat exchange tube.

[0018] Preferably, the outer sides of the inner heat exchange tubes and the axial fins are coated with a graphite coating, and the inner side of the heat-conducting shell is coated with a graphite coating.

[0019] Preferably, the phase change thermal storage material is sodium sulfate decahydrate.

[0020] Preferably, the calculation formula for the amount of the phase change thermal storage material is:

[0021]

[0022] Among them, m PCMis the amount of phase change thermal storage material, ρ and c are the density and phase change latent heat of the phase change thermal storage material, T s is the ambient temperature of the gas storage device, R is the total thermal resistance from the high-pressure air in the gas storage device to the environment, q m is the flow rate of high-pressure air during the energy storage / release process, t is the duration of the energy storage / release process, Z 0,g and T0 are the compressibility factor and temperature of the air inside the gas storage device, respectively. g is the gas constant of air, V is the volume of the gas storage device, v1 and m1 are the specific volume and mass of the high-pressure air in the gas storage device at the initial moment, and A is the internal surface area of the gas storage device.

[0023] Preferably, an impeller is installed in the gas transmission channel, the circulation pump is installed in the gas storage chamber, and the impeller is transmission-connected to the circulation pump.

[0024] Preferably, the gas storage chamber is a cylindrical gas storage chamber, one end of the cylindrical gas storage chamber is connected to the gas transmission channel, and the rapid temperature change zone is located at the end of the cylindrical gas storage chamber away from the gas transmission channel, and the slow temperature change zone is located at the end of the cylindrical gas storage chamber close to the gas transmission channel.

[0025] Preferably, the impeller is coaxially arranged in the gas transmission channel, and the radial dimension of the impeller is 50% to 80% of the radial dimension of the gas transmission channel; the impeller includes 3 to 5 groups of axial flow impellers distributed axially at intervals, and each group of axial flow impellers includes 4, 6 or 8 blades.

[0026] Preferably, the circulating working fluid is an ethylene glycol aqueous solution, and the volume concentration of the ethylene glycol aqueous solution is 50% to 60%.

[0027] Beneficial effects of the present invention:

[0028] The present invention adopts a method of combining phase change heat storage and heat exchange. A phase change heat storage and exchange component is installed in the rapid temperature change zone of the air storage chamber, and a gas-liquid heat exchange component is installed in the slow temperature change zone of the air storage chamber, and the phase change heat storage and exchange component and the gas-liquid heat exchange component are connected by a circulation pipeline and a circulation pump. The phase change of the phase change heat storage material inside the phase change heat storage and exchange component can absorb the thermal energy of the compressed air during the energy storage process, and release the thermal energy to the compressed air during the energy release process, thereby maintaining the stability of the compressed air temperature in the rapid temperature change zone. At the same time, the circulating working medium is driven by the circulation pump to circulate between the gas-liquid heat exchange component and the phase change heat storage and exchange component, thereby improving the heat exchange efficiency of the rapid temperature change zone and the slow temperature change zone, promoting a more uniform temperature distribution in the air storage chamber, and maintaining the internal temperature of the air storage chamber near the solidification point of the phase change heat storage material, reducing the thermal fatigue damage of the wall material caused by periodic alternating temperature and local temperature gradient, extending the service life of the equipment, and improving the safety of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of the isothermal compressed air energy storage device of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the phase change heat storage and exchange component;

[0031] Figure 3 It is a three-dimensional schematic diagram of a phase change heat storage and exchange component;

[0032] Figure 4 Schematic diagram of the structure of the internal heat exchange tube.

[0033] Description of reference numerals in the figures:

[0034] 10. Gas storage chamber;

[0035] 20. Gas transmission channel;

[0036] 30. Gas-liquid heat exchange components;

[0037] 40. Phase change heat storage and exchange component; 41. Phase change heat storage unit; 42. Internal heat exchange tube; 43. External heat exchange plate; 44. Axial fin;

[0038] 50. Circulation pipeline;

[0039] 60. Circulation pump;

[0040] 70. Impeller. DETAILED DESCRIPTION

[0041] The following is a further detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, and are not intended to limit the present invention.

[0042] In the description of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0044] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0045] Examples, such as Figure 1-Figure 4 As shown, an isothermal compressed air energy storage device includes an air storage chamber 10, an air transmission channel 20, an air-liquid heat exchange component 30, a phase change heat storage and exchange component 40, a circulation pipeline 50 and a circulation pump 60; wherein, the air storage chamber 10 has a rapid temperature change zone and a slow temperature change zone, one end of the air transmission channel 20 is connected to the air storage chamber 10, the air-liquid heat exchange component 30 is installed in the slow temperature change zone, the phase change heat storage and exchange component 40 is installed in the rapid temperature change zone, the circulation pipeline 50 is connected between the air-liquid heat exchange component 30 and the phase change heat storage and exchange component 40, and the circulation pump 60 is installed on the circulation pipeline 50 to drive the circulating working medium to circulate between the air-liquid heat exchange component 30 and the phase change heat storage and exchange component 40 through the circulation pump 60.

[0046] The present invention adopts a method of combining phase change heat storage and heat exchange. A phase change heat storage and exchange component 40 is installed in the rapid temperature change zone of the air storage chamber 10, and a gas-liquid heat exchange component 30 is installed in the slow temperature change zone of the air storage chamber 10. The phase change heat storage and exchange component 40 and the gas-liquid heat exchange component 30 are connected through a circulation pipeline 50 and a circulation pump 60. The phase change heat storage material inside the phase change heat storage and exchange component 40 can absorb the heat energy of the compressed air during the energy storage process and release the heat energy to the compressed air during the energy release process, thereby maintaining the compressed air in the rapid temperature change zone. The temperature is stabilized, and at the same time, the circulating working medium is driven by the circulating pump 60 to circulate between the gas-liquid heat exchange component 30 and the phase change heat storage and exchange component 40, thereby improving the heat exchange efficiency of the rapid temperature change zone and the slow temperature change zone, promoting a more uniform temperature distribution inside the gas storage chamber 10 during the energy storage process and the energy release process, and maintaining the internal temperature of the gas storage chamber 10 near the freezing point of the phase change heat storage material, reducing the thermal fatigue damage of the wall material caused by periodic alternating temperature and local temperature gradient, extending the service life of the equipment, and improving the safety of the equipment.

[0047] Specific embodiment 1, as Figure 1-Figure 4 As shown, an isothermal compressed air energy storage device includes an air storage chamber 10, an air transmission channel 20, a gas-liquid heat exchange component 30, a phase change heat storage and exchange component 40, a circulation pipeline 50 and a circulation pump 60.

[0048] The air storage chamber 10 is used to store high-pressure air, and the air storage chamber 10 has a rapid temperature change zone and a slow temperature change zone. During the energy storage process and the energy release process, the temperature change rate (temperature change amplitude) of the rapid temperature change zone is greater than the temperature change rate (temperature change amplitude) of the slow temperature change zone.

[0049] Preferably, the specific locations of the rapid temperature change zone and the slow temperature change zone can be determined by analyzing the temperature field characteristics inside the gas storage chamber 10 during the energy storage and release process using the finite element method. The finite element method includes the following steps:

[0050] Based on the three-dimensional shape of the air storage chamber 10 , a model mesh of the air storage chamber 10 is constructed.

[0051] The finite element method is used to analyze and solve the temperature field distribution characteristics inside the gas storage chamber 10 during the energy storage and release processes.

[0052] According to the temperature field distribution characteristics inside the gas storage chamber 10 , it is determined that the position with the largest temperature change amplitude is the rapid temperature change zone, and the position with the smallest temperature change amplitude is the slow temperature change zone.

[0053] One end of the air delivery channel 20 is connected to the air storage chamber 10. The air delivery channel 20 is used to deliver compressed air into the air storage chamber 10 during the energy storage process and to output compressed air to the outside during the energy release process.

[0054] The gas-liquid heat exchange component 30 is installed in the slow temperature change zone. Through the heat exchange between the circulating working fluid inside the gas-liquid heat exchange component 30 and the compressed air, the gas-liquid heat exchange component 30 and the compressed air in the slow temperature change zone are exchanged, thereby maintaining the air temperature in the slow temperature change zone near the solidification temperature point of the phase change thermal storage material during the energy storage and release processes.

[0055] The phase change heat storage and exchange component 40 is installed in the rapid temperature change zone to realize heat exchange between the phase change heat storage and exchange component 40 and the compressed air in the rapid temperature change zone through the phase change of the phase change heat storage material inside the phase change heat storage and exchange component 40, thereby maintaining the air temperature in the rapid temperature change zone near the solidification temperature point of the phase change heat storage material during the energy storage and release processes.

[0056] The circulation pipeline 50 is connected between the gas-liquid heat exchange component 30 and the phase-change heat storage and exchange component 40 , and is used to allow the circulating working medium to flow between the gas-liquid heat exchange component 30 and the phase-change heat storage and exchange component 40 .

[0057] It should be noted that: during the energy storage process, the air temperature in the slow temperature change zone and the rapid temperature change zone is higher than the solidification temperature point of the phase change thermal storage material after rising. The temperature rise rate and amplitude of the slow temperature change zone are lower than those of the rapid temperature change zone. The slow temperature change zone exchanges heat with the circulating working fluid through the gas-liquid heat exchange component 30. The circulating working fluid after heating or cooling enters the phase change heat storage component 40 to exchange heat with the phase change thermal storage material. After the temperature of the circulating working fluid decreases or increases, it returns to the gas-liquid heat exchange component 30 to continue heat exchange to maintain the air temperature near the solidification temperature point of the phase change thermal storage material. The temperature rise amplitude of the rapid temperature change zone is more intense, and it directly exchanges heat with the internal phase change thermal storage material through the phase change heat storage component 40 to maintain the air temperature near the solidification temperature point of the phase change thermal storage material. near the solidification temperature point of the material; in the energy release process, the air temperature in the slow temperature change zone and the rapid temperature change zone is lower than the solidification temperature point of the phase change thermal storage material after it is reduced, and the temperature reduction rate and amplitude of the slow temperature change zone are lower than those of the rapid temperature change zone. The slow temperature change zone absorbs heat from the circulating working fluid through the gas-liquid heat exchange component 30, and the cooled circulating working fluid enters the phase change heat storage component 40 to absorb heat from the phase change thermal storage material. After the temperature of the circulating working fluid rises, it returns to the gas-liquid heat exchange component 30 to continue releasing heat, maintaining the air temperature near the solidification temperature point of the phase change thermal storage material, while the temperature drop amplitude of the rapid temperature change zone is more drastic, and it directly exchanges heat with the internal phase change thermal storage material through the phase change heat storage component 40 to maintain the air temperature near the solidification temperature point of the phase change thermal storage material.

[0058] The circulation pump 60 is installed on the circulation pipeline 50 to drive the circulating working medium to circulate between the gas-liquid heat exchange component 30 and the phase change heat storage and exchange component 40 through the circulation pump 60, thereby improving the heat exchange efficiency of the compressed air in the rapid temperature change zone and the slow temperature change zone, thereby ensuring a relatively uniform temperature distribution in the air storage chamber 10.

[0059] Preferably, Figure 1 、 Figure 2 and Figure 3 As shown, there are multiple phase-change heat storage and exchange components 40, and each phase-change heat storage and exchange component 40 includes a phase-change heat storage unit 41, an inner heat exchange tube 42 and an outer heat exchange plate 43, wherein the phase-change heat storage unit 41 includes a heat-conducting shell and a phase-change heat storage material, the heat-conducting shell is cylindrical or prismatic as a whole, and the material of the heat-conducting shell is stainless steel, and a graphite coating is applied on the inner surface of the heat-conducting shell to improve the thermal conductivity and corrosion resistance of the heat-conducting shell.

[0060] The phase-change heat storage material is sodium sulfate decahydrate, and the sodium sulfate decahydrate is filled in the heat-conducting shell.

[0061] The inner heat exchange tube 42 is installed in the heat-conducting shell and immersed in the phase-change heat storage material. Both ends of the inner heat exchange tube 42 extend to the outside of the phase-change heat storage unit 41 and are connected to the circulation pipeline 50; the outer heat exchange plate 43 is installed on the outside of the phase-change heat storage unit 41, and the number of the outer heat exchange plates 43 is multiple. The multiple outer heat exchange plates 43 are installed on the heat-conducting shell at equal intervals in the vertical direction to improve the heat exchange efficiency between the phase-change heat storage unit 41 and the compressed air.

[0062] More preferably, the inner heat exchange tube 42 is a U-shaped tube, and a plurality of axial fins 44 are circumferentially distributed on the two straight sections of the inner heat exchange tube 42. The axial fins 44 are arranged along the axial direction of the inner heat exchange tube 42 to improve the heat exchange efficiency between the circulating working medium and the phase change heat storage material, and prevent the phase change heat storage material from crystallizing on the inner heat exchange tube 42 and hindering the occurrence of heat exchange. At the same time, a graphite coating is coated on the outer wall surface of the inner heat exchange tube 42 and the surface of the axial fins 44 to improve thermal conductivity and corrosion resistance.

[0063] The phase-change heat storage and exchange component is located at the position where the temperature inside the air storage chamber 10 changes most dramatically. The phase-change heat storage unit 41 fully exchanges heat with the compressed air through multiple metal external heat exchange plates 43. At the same time, the phase-change heat storage material in the phase-change heat storage unit 41 can fully exchange heat with the circulating working medium through the internal heat exchange tube 42 and the axial fin 44.

[0064] In order to achieve a relatively uniform temperature distribution inside the gas storage chamber 10, the calculation formula for the amount of phase change thermal storage material is:

[0065] Among them, m PCM is the amount of phase change thermal storage material, ρ and c are the density and phase change latent heat of the phase change thermal storage material, T s is the ambient temperature of the gas storage device, R is the total thermal resistance from the high-pressure air in the gas storage device to the environment, q m is the flow rate of high-pressure air during the energy storage / release process, t is the duration of the energy storage / release process, Z 0,g and T0 are the compressibility factor and temperature of the air inside the gas storage device, respectively. g is the gas constant of air, V is the volume of the gas storage device, v1 and m1 are the specific volume and mass of the high-pressure air in the gas storage device at the initial moment, and A is the internal surface area of the gas storage device.

[0066] Specific embodiment 2, as Figure 1-Figure 4 As shown, an isothermal compressed air energy storage device includes an air storage chamber 10, an air transmission channel 20, a gas-liquid heat exchange component 30, a phase change heat storage and exchange component 40, a circulation pipeline 50, a circulation pump 60 and an impeller 70.

[0067] The air storage chamber 10 is used to store high-pressure air, and the air storage chamber 10 has a rapid temperature change zone and a slow temperature change zone. In the prior art, during the energy storage process and the energy release process, the temperature change rate of the rapid temperature change zone is greater than the temperature change rate of the slow temperature change zone.

[0068] Preferably, the gas storage chamber 10 is a cylindrical gas storage chamber, and the cylindrical gas storage chamber has a high aspect ratio, for example Figure 1 In the figure, the arrow indicates the axis of the gas storage chamber 10. One end of the cylindrical gas storage chamber is connected to the gas transmission channel 20, which is coaxially arranged with the cylindrical gas storage chamber. The rapid temperature change zone is located at the end of the cylindrical gas storage chamber away from the gas transmission channel 20, and the slow temperature change zone is located at the end of the cylindrical gas storage chamber close to the gas transmission channel 20. The distance between the gas-liquid heat exchange assembly 30 and the gas transmission channel is 5m to 10m.

[0069] One end of the air delivery channel 20 is connected to one end of the air storage chamber 10. The air delivery channel 20 is used to deliver compressed air into the air storage chamber 10 during the energy storage process and to output compressed air to the outside during the energy release process.

[0070] The gas-liquid heat exchange component 30 is installed in the slow temperature change zone to achieve heat exchange between the gas-liquid heat exchange component 30 and the compressed air in the slow temperature change zone through heat exchange between the circulating working medium inside the gas-liquid heat exchange component 30 and the compressed air.

[0071] The phase change heat storage and exchange component 40 is installed in the rapid temperature change zone to achieve heat exchange between the phase change heat storage and exchange component 40 and the compressed air in the rapid temperature change zone through the phase change of the phase change heat storage material inside the phase change heat storage and exchange component 40.

[0072] The circulation pipeline 50 is installed inside the gas storage chamber 10 , and the circulation pipeline 50 is connected between the gas-liquid heat exchange component 30 and the phase change heat storage and exchange component 40 .

[0073] The circulation pump 60 is installed on the circulation pipeline 50 to drive the circulating working medium to circulate between the gas-liquid heat exchange component 30 and the phase change heat storage and exchange component 40 through the circulation pump 60, thereby improving the heat exchange efficiency of the compressed air in the rapid temperature change zone and the slow temperature change zone.

[0074] The impeller 70 is installed in the gas transmission channel 20, and the impeller 70 is connected to the circulation pump 60 in a transmission manner. During the energy storage process and the energy release process, the high-pressure gas flowing through the gas transmission channel 20 can drive the impeller 70 to rotate. The impeller 70 can drive the circulation pump 60 to drive the circulating working medium in the circulation pipeline 50 to flow, thereby realizing automatic adjustment and stabilization of the internal temperature of the gas storage chamber 10 during the energy storage process and the energy release process, and reducing the use of external equipment and the consumption of external electricity, which helps to reduce the failure rate and maintenance costs.

[0075] Specifically, the impeller 70 is connected to the circulation pump 60 through a coupling. The circulation pump 60 is provided with a gear reducer, which converts the high speed and low torque generated by the high-speed airflow driving the impeller 70 into a low speed and high torque output to overcome the flow loss of the circulating working fluid in the gas-liquid heat exchange component 30, the circulation pipeline 50 and the phase change heat storage and exchange component 40.

[0076] Preferably, the impeller 70 is coaxially arranged in the gas transmission channel 20, and the radial dimension of the impeller 70 is 50% to 80% of the radial dimension of the gas transmission channel 20; the impeller 20 is composed of 3 to 5 groups of axial flow impellers distributed axially at intervals, and each group of axial flow impellers includes 4, 6 or 8 blades.

[0077] More preferably, the circulating working fluid is an ethylene glycol aqueous solution, and the volume concentration of ethylene glycol in the ethylene glycol aqueous solution is 50% to 60%, so as to improve the heat exchange efficiency in the rapid temperature change zone and the slow temperature change zone and prevent condensation at low temperatures.

[0078] The working process of the isothermal compressed air energy storage device of the present invention is as follows:

[0079] The compressed air flowing in the air transmission channel 20 can drive the impeller 70 to rotate, and the impeller 70 drives the circulating pump 60 to operate. The circulating pump 60 transports the circulating working medium to the gas-liquid heat exchange component 30. The circulating working medium absorbs heat from the compressed air in the slow temperature change zone or releases heat to the compressed air. The circulating working medium circulates between the slow temperature change zone and the rapid temperature change zone through the circulation pipeline 50. The phase change heat storage and exchange component 40 can exchange heat with the compressed air in the rapid temperature change zone, and can also exchange heat with the circulating working medium, thereby realizing rapid heat exchange between the slow temperature change zone and the rapid temperature change zone.

[0080] During the energy storage process, low-temperature and high-pressure air enters the air storage chamber 10. Due to the inflation heating effect, the driving work for maintaining the flow of low-temperature and high-pressure air is converted into thermal energy of the compressed air in the air storage chamber 10, causing the temperature of the compressed gas inside the air storage chamber 10 to continue to rise during the energy storage process, especially the gas temperature in the rapid temperature change zone rises rapidly and forms a local high-temperature area; the phase change heat storage material in the phase change heat storage and exchange component 40 absorbs the heat of the compressed air through the external heat exchange plate 43, so that the gas temperature in the rapid temperature change zone drops (compared to the temperature change in the prior art) and is slightly higher than the freezing point of the phase change heat storage material (at the end of the energy storage process, the temperature of the rapid temperature change zone is slightly higher than the freezing point of the phase change heat storage material, and most or all of the phase change heat storage material is liquid). At the same time, during the energy storage process, the high-pressure air can drive the impeller 70 to rotate when passing through the air transmission channel 20. The impeller 70 drives the circulation pump 60 to drive the circulating working medium to flow in the circulation pipeline 50. The air temperature in the slow temperature change zone is directly affected by the inlet air temperature. When the air temperature in the slow temperature change zone is higher than the solidification temperature of the phase change heat storage material, the air in the slow temperature change zone releases heat to the circulating working medium in the gas-liquid heat exchange component 30. After absorbing heat, the circulating working medium enters the phase change heat storage component 40 to release heat. After the temperature drops, the circulating working medium flows back to the gas-liquid heat exchange component 30 through the circulation pipeline 50, and absorbs heat from the surrounding high-temperature gas through the gas-liquid heat exchange component 30, so that the air temperature in the slow temperature change zone is maintained near the solidification temperature point of the phase change heat storage material. When the air temperature in the slow temperature change zone is lower than the solidification temperature of the phase change heat storage material, the air in the slow temperature change zone exchanges heat with the circulating working fluid in the gas-liquid heat exchange component 30. After releasing heat, the circulating working fluid enters the phase change heat storage and exchange component 40 to absorb heat. After the temperature rises, the circulating working fluid flows back to the gas-liquid heat exchange component 30 through the circulation pipeline 50, and releases heat to the surrounding low-temperature gas through the gas-liquid heat exchange component 30, so that the air temperature in the slow temperature change zone is maintained near the solidification temperature point of the phase change heat storage material.

[0081] During the energy release process, the high-pressure air in the air storage chamber 10 flows out through the air transmission channel 20. The high-pressure air inside the air storage chamber 10 performs work externally, causing the temperature of the gas inside the air storage chamber 10 to drop, especially the temperature in the rapid temperature change zone. The phase-change thermal storage material in the phase-change heat storage and exchange assembly 40 releases heat to the compressed air through the external heat exchange plate, maintaining the gas temperature in the rapid temperature change zone slightly below the freezing point of the phase-change thermal storage material. Simultaneously, during the energy release process, the high-pressure air passing through the air transmission channel 20 drives the impeller 70 to rotate. The impeller 70 drives the circulating pump 60 to drive the circulating fluid in the circulation pipeline 50. The temperature of the circulating fluid flowing out of the phase-change heat storage and exchange assembly is the same as the freezing point of the phase-change thermal storage material. The circulating fluid enters the gas-liquid heat exchange assembly 30 and dissipates heat to the surrounding low-temperature gas, reducing the temperature drop in the slow temperature change zone. The low-temperature circulating fluid then returns to the phase-change heat storage and exchange assembly to absorb heat and increase its temperature.

[0082] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0083] The phase change heat storage and exchange component is arranged in the rapid temperature change zone inside the gas storage chamber where the temperature change amplitude is the largest. It can maintain the near-isothermal conditions inside the gas storage chamber during the energy storage and release processes, improve the unit energy storage density, reduce the power consumption of the compressor during the energy storage process, and improve the ability of the expander to smooth the power output during the energy release process.

[0084] By connecting the phase change heat storage and exchange components and the gas-liquid heat exchange components through a circulation pipeline, the heat exchange efficiency between the local high-temperature and low-temperature areas inside the gas storage chamber can be greatly improved, promoting a more uniform temperature distribution inside the gas storage chamber. At the same time, the temperature inside the gas storage chamber is maintained near the solidification point of the phase change heat storage material, reducing the thermal fatigue damage of the wall material caused by periodic alternating temperatures and local temperature gradients, extending the service life of the equipment and improving safety.

[0085] By driving the circulation pump through the impeller in the gas transmission channel, the kinetic energy of the high-pressure air in the gas transmission channel during the energy storage and release process of the air storage chamber can be utilized. No external energy is required to drive the flow of the circulating working fluid in the circulation pipeline, which reduces the complexity of the system and reduces maintenance costs.

[0086] It can effectively stabilize the temperature changes of the air inside the gas storage chamber during the energy storage and release process, realize a nearly isothermal energy storage and release process and a relatively uniform temperature distribution inside the gas storage chamber, improve system efficiency, and ensure the safe operation of the gas storage chamber.

[0087] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. An isothermal compressed air energy storage device, characterized in that: include: An air storage chamber (10), wherein the air storage chamber (10) has a rapid temperature change zone and a slow temperature change zone; an air delivery channel (20), one end of the air delivery channel (20) being in communication with the air storage chamber (10); A gas-liquid heat exchange component (30), wherein the gas-liquid heat exchange component (30) is installed in a slow temperature change zone; A phase-change heat storage and exchange component (40), wherein the phase-change heat storage and exchange component (40) is installed in a rapid temperature change zone; A circulation pipeline (50), wherein the circulation pipeline (50) is connected between the gas-liquid heat exchange component (30) and the phase change heat storage and exchange component (40); A circulation pump (60) is installed on the circulation pipeline (50) and is used to drive the circulating working medium to circulate between the gas-liquid heat exchange component (30) and the phase change heat storage and exchange component (40).

2. The isothermal compressed air energy storage device according to claim 1, characterized in that: The phase-change heat storage and exchange assembly (40) comprises a phase-change heat storage unit (41), an inner heat exchange tube (42) and an outer heat exchange plate (43); the phase-change heat storage unit (41) comprises a heat-conducting shell and a phase-change heat storage material; the phase-change heat storage material is filled in the heat-conducting shell; the inner heat exchange tube (42) is immersed in the phase-change heat storage material; and both ends of the inner heat exchange tube (42) extend to the outside of the phase-change heat storage unit (41) and are connected to a circulation pipeline (50); the outer heat exchange plate (43) is installed outside the phase-change heat storage unit (41).

3. The isothermal compressed air energy storage device according to claim 2, characterized in that: A plurality of axial fins (44) are distributed on the circumference of the inner heat exchange tube (42), and the axial fins (44) are arranged along the axial direction of the inner heat exchange tube (42).

4. The isothermal compressed air energy storage device according to claim 3, characterized in that: The outer sides of the inner heat exchange tube (42) and the axial fins (44) are coated with a graphite coating, and the inner side of the heat-conducting shell is coated with a graphite coating.

5. The isothermal compressed air energy storage device according to claim 2, characterized in that: The phase change heat storage material is sodium sulfate decahydrate.

6. The isothermal compressed air energy storage device according to claim 2, characterized in that: The calculation formula for the amount of phase change thermal storage material is: Among them, m PCM is the amount of phase change thermal storage material, ρ and c are the density and phase change latent heat of the phase change thermal storage material, T s is the actual ambient temperature of the gas storage, R is the total thermal resistance from the high-pressure air in the gas storage chamber to the environment, q m is the flow rate of high-pressure air during the energy storage / release process, t is the duration of the energy storage / release process, Z 0,g and T0 are the compressibility factor and temperature of the air inside the air storage chamber, respectively. g is the gas constant of air, V is the volume of the air storage chamber, v1 and m1 are the specific volume and mass of the high-pressure air in the air storage chamber at the initial moment, and A is the internal surface area of the air storage chamber.

7. An isothermal compressed air energy storage device according to any one of claims 1 to 6, characterized in that: An impeller (70) is installed in the gas transmission channel (20), the circulation pump (60) is installed in the gas storage chamber (10), and the impeller (70) is transmission-connected to the circulation pump (60).

8. The isothermal compressed air energy storage device according to claim 7, characterized in that: The gas storage chamber (10) is a cylindrical gas storage chamber, one end of which is connected to the gas transmission channel (20), and the rapid temperature change zone is located at the end of the cylindrical gas storage chamber away from the gas transmission channel (20), and the slow temperature change zone is located at the end of the cylindrical gas storage chamber close to the gas transmission channel (20).

9. The isothermal compressed air energy storage device according to claim 7, characterized in that: The impeller (70) is coaxially arranged in the gas transmission channel (20), and the radial dimension of the impeller (70) is 50% to 80% of the radial dimension of the gas transmission channel (20); the impeller (70) includes 3 to 5 groups of axial flow impellers distributed at intervals in the axial direction, and each group of the axial flow impellers includes 4, 6 or 8 blades.

10. The isothermal compressed air energy storage device according to claim 1, characterized in that: The circulating working medium is an ethylene glycol aqueous solution, and the volume concentration of the ethylene glycol aqueous solution is 50% to 60%.

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