A compressed air energy storage and power generation system with low-temperature purification

Abstract

This invention discloses a compressed air energy storage and power generation system with cryogenic purification, relating to the field of compressed air energy storage and power generation technology. The compressed air energy storage and power generation system with cryogenic purification includes an energy release branch and a cooling circuit. The energy release branch includes a purification device and an expander generator set. A spray liquid cooler is installed on the connecting pipe between the first outlet of the spray tank and the inlet of the sprayer, and an absorbent liquid cooler is installed on the connecting pipe between the outlet of the absorption tank and the inlet of the swirl-jet absorber. The cooling circuit includes a cold storage tank and refrigeration equipment; the cold storage tank is used to store the cryogenic circulating medium. This invention solves the technical problem of impurities in the compressed air extracted by existing compressed air energy storage systems, which affects the efficiency of expansion power generation. It has the advantage of reducing the saturated water content and impurity content in the compressed air, ensuring that the compressed air flowing into the expander generator set is clean and dry with low saturated water content, thereby improving the system's efficiency, service life, safety, and stability.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage and power generation technology, and in particular to a compressed air energy storage and power generation system with low-temperature purification. Background Technology

[0002] Compressed air power generation technology uses compressed air energy storage (CAES) technology to store electrical energy during off-peak hours and release it when needed to generate electricity and connect it to the grid. It is a new energy power generation technology. When storing energy, a compressor is used to compress the air in nature into compressed air with high density and high pressure, and the compressed air is stored through an air storage system. When releasing energy, the stored compressed air is taken out through an expansion power generation system to generate electricity.

[0003] In the process of developing this invention, the inventors discovered at least the following problems in the prior art: The compressed air used in current compressed air energy storage systems for energy release contains various impurities. For example, compressor units contain oil, resulting in compressed air containing oily substances. Acid ions, acidic or alkaline gases may be introduced into the compressed air storage device, a phenomenon particularly pronounced in underground storage. Furthermore, the water carried by cryogenic compressed air energy storage systems exists in liquid form, while the aforementioned acidic or alkaline gases are highly soluble in liquid water and exist in ionic form. The compressed air storage device may also contain solid particulate impurities such as dust, silt, rust, and rock salt particles. Compressed air containing these impurities poses serious safety hazards and corrodes downstream equipment during subsequent use.

[0004] Therefore, how to provide a compressed air energy storage and power generation system with low-temperature purification that can simultaneously remove various types of impurities carried by compressed air, such as oil, solid dust, free water, and dissolved chemical impurities, and produce clean, dry compressed gas after purification, thereby improving the operating efficiency of the power generation system, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a compressed air energy storage and power generation system with low-temperature purification, which can remove oil, solid dust, free water and dissolved chemical impurities carried in compressed air, and reduce the saturated water content in compressed air, thereby improving the service life, safety and stability of the compressed air energy storage and power generation system.

[0006] To achieve this objective, on the one hand, a compressed air energy storage and power generation system with low-temperature purification is provided, comprising an energy release branch and a cooling circuit; the energy release branch includes a purification device and an expander generator set, the purification device including a sprayer, a spray tank, a swirl-jet absorber, and an absorption tank; the impurity-laden compressed air enters from the sprayer, flows out from the sprayer and then into the swirl-jet absorber, and flows out from the swirl-jet absorber and then into the expander generator set; the spray tank is used to store the spraying medium for use by the sprayer, and the absorption tank is used to store the absorbent for use by the swirl-jet absorber; the first outlet of the spray tank and the inlet of the sprayer... A spray liquid cooler is installed on the connecting pipeline to cool the spraying medium entering the sprayer; an absorbent liquid cooler is installed on the connecting pipeline between the outlet of the absorber tank and the inlet of the swirl spray absorber to cool the absorbent entering the swirl spray absorber; the cooling circuit includes a cold storage tank and a refrigeration device, the cold storage tank being used to store the low-temperature circulating medium; the outlet of the cold storage tank is connected to the cold path inlet of the spray liquid cooler, the cold path outlet of the spray liquid cooler is connected to the inlet of the refrigeration device, the outlet of the refrigeration device is connected to the cold path inlet of the absorbent liquid cooler, and the cold path outlet of the absorbent liquid cooler is connected to the inlet of the cold storage tank.

[0007] Furthermore, the second outlet of the spray tank and the inlet of the absorption tank are connected by a liquid distribution pipeline, which is equipped with a low-pressure pump and a liquid distribution valve; the outlet of the absorption tank is equipped with an absorption tank switch valve.

[0008] Furthermore, the purification device also includes a liquid distribution bypass pipe, one end of which is connected to the second outlet of the spray tank, and the other end of which is connected to the outlet pipe of the absorption tank switch valve; a liquid distribution bypass valve is provided on the liquid distribution bypass pipe; and a first high-pressure pump is provided on the outlet pipe of the absorption tank switch valve.

[0009] Furthermore, a pH detection device is installed on the drain pipe of the rotary jet absorber; the pH detection device controls the opening degree of the liquid dispensing valve, the outlet pressure of the low-pressure pump, the opening degree of the absorption tank switch valve, and the outlet pressure of the first high-pressure pump.

[0010] Furthermore, a second high-pressure pump is provided on the pipeline connecting the hot inlet of the spray liquid cooler and the first outlet of the spray tank.

[0011] Furthermore, a separator is provided between the sprayer and the swirl jet absorber; compressed air flows out from the outlet of the sprayer and into the inlet of the separator, and then flows out from the outlet of the separator and into the inlet of the swirl jet absorber; the separator is used to dry the compressed air.

[0012] Furthermore, a slug trap is provided before the inlet of the sprayer; the compressed air to be purified enters the inlet of the slug trap, flows out from the outlet of the slug trap, and then enters the inlet of the sprayer.

[0013] Furthermore, it also includes a first heating branch and a heat storage tank, the heat storage tank being used to store high-temperature circulating media. One end of the first heating branch is connected to the outlet of the heat storage tank, and the other end is connected to the inlet of the cold storage tank. The energy release branch also includes a first heat exchanger, the hot path of which is located on the first heating branch. The cold path inlet of the first heat exchanger is connected to the outlet of the swirl jet absorber, and the cold path outlet of the first heat exchanger is connected to the inlet of the expansion generator set.

[0014] Furthermore, it also includes a second heating branch and a heat storage tank, the heat storage tank being used to store high-temperature circulating media, one end of the second heating branch being connected to the outlet of the heat storage tank, and the other end being connected to the inlet of the cold storage tank; the energy release branch also includes a second heat exchanger and at least one stage of expander unit, the hot path of the second heat exchanger being located on the second heating branch, and the cold path inlet of the second heat exchanger being connected to the outlet of the expander unit.

[0015] Furthermore, it also includes a gas storage branch, which includes a gas storage tank, a third heat exchanger, and at least one stage compressor unit. The hot inlet of the third heat exchanger is connected to the outlet of the last stage compressor unit, and the hot outlet of the third heat exchanger is connected to the inlet of the gas storage tank. The cold inlet of the third heat exchanger is connected to the outlet of the cold storage tank through a cooling branch, and the cold outlet of the third heat exchanger is connected to the inlet of the heat storage tank.

[0016] Furthermore, the refrigeration equipment uses a cooling tower.

[0017] Furthermore, the spray tank contains water, and the absorption tank contains alkali or acid.

[0018] Furthermore, the separator is a cyclone separator or a blade separator.

[0019] One of the above technical solutions has the following beneficial effects:

[0020] The compressed air energy storage and power generation system with low-temperature purification includes an energy release branch, which uses compressed air extracted from the gas storage tank to expand and generate electricity. The energy release branch has a purification device, which is used to purify the compressed air extracted from the gas storage tank. The expansion generator set is used for expansion and power generation.

[0021] The purification device includes a sprayer, a spray tank, a swirl jet absorber, and an absorption tank. Impurity-laden compressed air enters from the sprayer, flows out of the sprayer, enters the swirl jet absorber, and then flows out of the swirl jet absorber before entering the expansion generator set. The spray tank stores the spraying medium for the sprayer, and the absorption tank stores the absorbent for the swirl jet absorber. Impurity-laden compressed air enters from the sprayer's inlet and exits from the sprayer's outlet. The compressed air passing through the sprayer removes oil droplets and dust from the impurities and reduces the concentration of dissolved substances in the free water carried in the compressed air. A spray liquid cooler is installed on the connecting pipe between the first outlet of the spray tank and the inlet of the sprayer to cool the spraying medium entering the sprayer. The cooled spraying medium, upon entering the sprayer, lowers the temperature of the impurity-laden compressed air being sprayed, thereby reducing the saturated water content in the compressed air and reducing the solubility of chemical impurities.

[0022] Compressed air flowing from the sprayer's outlet enters the swirl jet absorber, where the absorbent is stored in the absorption tank. The swirl jet absorber creates a swirling flow field inside. The compressed air to be purified enters through the inlet and is subjected to centrifugal force. Simultaneously, the absorbent is sprayed radially from the side, impacted, cut, and atomized by the compressed air, forming numerous absorbent droplets. These droplets react with free water containing chemical impurities in the compressed air. Due to the swirling flow field inside the swirl jet absorber, the purified compressed air is dry and exits from the central exhaust pipe. The reacted absorbent droplets are discharged from the drain port. Therefore, the swirl jet absorber can remove free water and acid / alkali ions from compressed air. The purified compressed air flowing out of the swirl jet absorber's outlet is used to power an expander generator. An absorbent cooler is installed on the connecting pipe between the absorber tank's outlet and the swirl jet absorber's inlet to cool the absorbent entering the swirl jet absorber. After cooling, the absorbent medium enters the absorber and can further reduce the temperature of the absorbed compressed air containing impurities, thereby reducing the saturated water content in the compressed air and reducing the solubility of chemical impurities.

[0023] The compressed air energy storage and power generation system with low-temperature purification also includes a cooling circuit, which includes a cold storage tank and refrigeration equipment. The cold storage tank is used to store the low-temperature circulating medium. The outlet of the cold storage tank is connected to the cold circuit inlet of the spray liquid cooler, the cold circuit outlet of the spray liquid cooler is connected to the inlet of the refrigeration equipment, the outlet of the refrigeration equipment is connected to the cold circuit inlet of the absorbent liquid cooler, and the cold circuit outlet of the absorbent liquid cooler is connected to the inlet of the cold storage tank.

[0024] The cooling circuit provides cooling capacity to the spray liquid cooler and the absorbent liquid cooler, which is provided by refrigeration equipment and cryogenic circulating medium. A cold storage tank in the cooling circuit stores the cryogenic circulating medium. The outlet of the cold storage tank is connected to the cold path inlet of the spray liquid cooler. The cryogenic circulating medium from the cold storage tank first provides a cold source to the spray liquid cooler. After passing through the spray liquid cooler, the cryogenic circulating medium enters the refrigeration equipment for cooling. The cryogenic circulating medium, now back to a low temperature, then enters the cold path of the absorbent liquid cooler, providing cooling energy to the absorbent liquid cooler. The refrigeration equipment is used to keep the temperature of the absorbent liquid lower than that of the spray liquid, and also provides additional cooling capacity when the cryogenic circulating medium's cooling energy is insufficient. This solution, due to the inclusion of a cooling circuit, improves the cold energy utilization rate of the compressed air power generation system during the energy release process compared to existing technologies. Furthermore, the inclusion of refrigeration equipment in the cooling circuit reduces the saturated water content carried by the product gas, thereby improving the system's purification effect. Based on this, the compressed air energy storage and power generation system with low-temperature purification provided in this solution first removes oil, dust, free water and chemical impurities from the compressed air before it enters the expander generator set. Furthermore, the purification device operates under low-temperature conditions, which reduces the saturated water content in the compressed air. This results in the compressed air flowing into the expander generator set being clean and dry with low saturated water content, thereby improving the system's efficiency, service life, safety and stability. Attached Figure Description

[0025] Figure 1 This is a flowchart of Example 1.

[0026] In the diagram: 110-Sprayer; 120-Spray tank; 130-Swirl spray absorber; 140-Absorption tank; 150-Spray liquid cooler; 160-Absorption liquid cooler; 170-Separator; 180-Slug flow trap; 111-Low-pressure pump; 112-Dispensing valve; 113-Absorption tank on / off valve; 114-Dispensing bypass valve; 115-First high-pressure pump; 116-Second high-pressure pump; 131-pH detection device; 210-Cold storage tank; 220-Refrigeration equipment; 211-First cold water pump; 221-Second cold water pump; 212 213-First cold circuit switch valve; 214-Second cold circuit switch valve; 222-Third cold water pump; 222-Third cold water valve; 300-Heat storage tank; 310-First hot water pump; 311-First hot water valve; 312-First cold water valve; 320-Second hot water pump; 321-Second hot water valve; 322-Second cold water valve; 400-First heat exchanger; 500-Second heat exchanger; 600-Third heat exchanger; 700-Expander unit; 710-Gas storage tank; 720-Compressor unit; 711-Gas storage tank inlet valve; 712-Gas storage tank outlet valve. Detailed Implementation

[0027] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] Example 1:

[0031] like Figure 1 As shown, the compressed air energy storage and power generation system with low-temperature purification includes an energy release branch, which uses compressed air extracted from the gas storage tank to expand and generate electricity. The energy release branch has a purification device, which is used to purify the compressed air extracted from the gas storage tank. The expansion generator set is used for expansion and power generation.

[0032] The purification device includes a sprayer 110, a spray tank 120, a swirl jet absorber 130, and an absorption tank 140. Impurity-laden compressed air enters through the sprayer 110, passes through the swirl jet absorber 130, and then enters the expansion generator set for power generation. The spray tank 120 stores the spraying medium used by the sprayer 110, and the absorption tank 140 stores the absorbent used by the swirl jet absorber 130. Impurity-laden compressed air enters through the inlet of the sprayer 110 and exits through the outlet. The compressed air passing through the sprayer 110 removes oil droplets and dust from the impurities and reduces the concentration of dissolved substances in the free water carried in the compressed air. A spray liquid cooler 150 is provided on the connecting pipe between the first outlet of the spray tank 120 and the inlet of the sprayer 110. It is used to cool the spray working medium entering the sprayer 110. After the spray working medium is cooled, it can reduce the temperature of the sprayed compressed air containing impurities, thereby reducing the saturated water content in the compressed air and reducing the solubility of chemical impurities.

[0033] Compressed air flowing from the outlet of sprayer 110 enters the swirl jet absorber 130, where the absorbent is stored in the absorption tank 140. A swirling flow field is formed inside the swirl jet absorber 130. The compressed air to be purified enters tangentially from the inlet and is subjected to centrifugal force. Simultaneously, the absorbent is sprayed radially from the side and atomized by the compressed air, forming numerous absorbent droplets. These droplets react with free water containing chemical impurities in the compressed air. Due to the swirling flow field inside the swirl jet absorber 130, the purified compressed air is dry and exits from the central exhaust pipe of the swirl jet absorber 130. The reacted absorbent droplets are discharged from the drain port of the swirl jet absorber 130. Therefore, the swirl jet absorber 130 can remove free water and acid / alkali ions from the compressed air. The purified compressed air flowing out from the outlet of the swirl jet absorber 130 is used to generate electricity in the expander generator set. An absorbent cooler 160 is installed on the connecting pipe between the first outlet of the absorber tank 140 and the inlet of the swirl-jet absorber 130 to cool the absorbent entering the swirl-jet absorber 130. After cooling, the absorbent enters the absorber and can reduce the temperature of the compressed air containing impurities, thereby reducing the saturated water content in the compressed air and reducing the solubility of chemical impurities.

[0034] The compressed air energy storage and power generation system with cryogenic purification also includes a cooling circuit, which comprises a cold storage tank 210 and a refrigeration unit 220. The cold storage tank 210 is used to store the cryogenic circulating medium. The cryogenic circulating medium refers to a circulating medium with a low temperature. The outlet of the cold storage tank 210 is connected to the cold path inlet of the spray liquid cooler 150, the cold path outlet of the spray liquid cooler 150 is connected to the inlet of the refrigeration unit 220, the outlet of the refrigeration unit 220 is connected to the cold path inlet of the absorbent liquid cooler 160, and the cold path outlet of the absorbent liquid cooler 160 is connected to the inlet of the cold storage tank 210. The cooling circuit provides cooling capacity to the spray liquid cooler 150 and the absorbent liquid cooler 160, which is provided by the refrigeration unit 220 and the cryogenic circulating medium. The cold storage tank 210 in the cooling circuit is used to store the low-temperature circulating medium. The outlet of the cold storage tank 210 is connected to the cold circuit inlet of the spray liquid cooler 150. The low-temperature circulating medium from the cold storage tank 210 first provides a cold source for the spray liquid cooler 150. After passing through the spray liquid cooler 150, the low-temperature circulating medium enters the refrigeration equipment for cooling. The low-temperature circulating medium, now back to a low-temperature state, then enters the cold circuit of the absorbent cooler 160, providing cooling energy to the absorbent cooler 160. The refrigeration equipment 220 is used to keep the temperature of the absorbent liquid lower than that of the spray liquid, and also provides additional cooling when the low-temperature circulating medium's cooling energy is insufficient. This solution, due to the inclusion of a cooling circuit, improves the cold energy utilization rate of the compressed air power generation system during the energy release process compared to existing technologies. Furthermore, the inclusion of refrigeration equipment in the cooling circuit reduces the saturated water content carried by the product gas, thereby improving the system's purification effect.

[0035] Furthermore, a first cold water pump 211 and a first cold circuit switch valve 212 are provided between the outlet of the cold storage tank 210 and the cold circuit inlet of the spray liquid cooler 150; the cooling capacity entering the cooling circuit from the cold storage tank 210 can be adjusted by adjusting the opening degree of the first cold circuit switch valve 212 and the outlet pressure of the first cold water pump 211. A second cold water pump 221 is provided between the outlet of the refrigeration equipment 220 and the cold circuit inlet of the absorbent liquid cooler 160 to control the cooling capacity entering the cold circuit of the absorbent liquid cooler 160. A third cold water valve 222 is provided between the cold circuit outlet of the absorbent liquid cooler 160 and the cold storage tank 210 to adjust the opening and closing of the cooling circuit and the flow rate.

[0036] Furthermore, the refrigeration equipment 220 uses a cooling tower. The refrigeration equipment can also use a refrigeration unit or utilize the cold energy of LNG.

[0037] Furthermore, the most commonly used spraying medium in the sprayer is water, i.e., water stored in the spray tank. Preferably, one of desalinated water, purified water, or distilled water is used. The absorption tank 214 contains either alkali or acid. If the compressed air to be purified is alkaline, water is added to the spray tank and acid is added to the absorption tank. If the compressed air to be purified is acidic, water is added to the spray tank and alkali is added to the absorption tank.

[0038] Furthermore, the second outlet of the spray tank 120 and the inlet of the absorption tank 140 of the purification device are connected by a liquid distribution pipeline, which includes a low-pressure pump 111 and a liquid distribution valve 112. The outlet of the absorption tank 140 is equipped with an absorption tank switch valve 113. The spraying medium in the spray tank 120 can enter the absorption tank 140 through the liquid distribution pipeline and mix with the absorbent medium in the absorption tank. This allows adjustment of the component concentration of the working medium in the absorption tank, thereby adjusting the component concentration of the absorbent entering the rotary jet absorber. Adjusting the opening of the liquid distribution valve 112 and regulating the outlet pressure of the low-pressure pump 111 can adjust the amount of spraying medium entering the absorption tank, thereby adjusting the component concentration of the absorbent.

[0039] Furthermore, the purification device also includes a liquid distribution bypass pipe, one end of which is connected to the second outlet of the spray tank 120, and the other end of which is connected to the outlet pipe of the absorption tank switch valve 113; a liquid distribution bypass valve 114 is provided on the liquid distribution bypass pipe; a first high-pressure pump 115 is provided on the outlet pipe of the absorption tank switch valve 113. Since the compressed air to be absorbed entering the cyclone absorber is of medium to high pressure, a high-pressure pump is used when introducing the absorbent into the cyclone absorber. The purification device also includes a liquid distribution bypass pipe, which is used to introduce the spraying medium into the cyclone absorber for cyclone absorption.

[0040] The purification device in this embodiment can select the working fluid based on the composition of the compressed air to be purified. That is, the compressed air to be purified may contain both acid radicals and / or bases, both readily soluble in free water. The solution after dissolving in free water is either entirely acidic or entirely alkaline, and in rare cases, neutral. The chemical properties of the compressed air to be purified can be determined before it enters the purification device. This solution can select whether to use the working fluid from the spray tank or a mixture of the spray tank and absorption tank in the swirl jet absorber based on the impurity composition of the unpurified compressed air flowing out of the air storage system.

[0041] Furthermore, a pH detection device 131 is installed on the drain pipe of the rotary jet absorber 130 to detect the pH value of the wastewater discharged from the rotary jet absorber. The pH detection device 131 controls the opening degree of the liquid mixing valve 112, the outlet pressure of the low-pressure pump 111, the opening degree of the absorption tank switch valve 113, and the outlet pressure of the first high-pressure pump 115.

[0042] If the pH detection device detects that the pH at the drain outlet of the rotary jet absorber is acidic or alkaline, it controls the opening of the liquid mixing valve 112 and the absorption tank switch valve 113, and closes the liquid mixing bypass valve 114, thereby adjusting the component concentration of the working fluid in the absorption tank 140. The pH detection device can also control the outlet pressure of the low-pressure pump 111 and the first high-pressure pump 115. By adjusting the outlet pressure of the low-pressure pump 111 and the first high-pressure pump 115 based on the acidity or alkalinity detected by the pH detection device, the acid / alkalinity concentration of the working fluid in the absorption tank is adjusted.

[0043] Furthermore, a second high-pressure pump 116 is provided on the pipeline connecting the hot inlet of the spray liquid cooler 150 and the first outlet of the spray tank 120. Since the compressed air to be sprayed entering the sprayer is of medium to high pressure, a high-pressure pump is used when the spraying working fluid is introduced into the sprayer.

[0044] Furthermore, a separator 170 is provided between the sprayer 110 and the swirl-jet absorber 130; compressed air flows out from the outlet of the sprayer 110 and enters the inlet of the separator 170, and flows out from the outlet of the separator 170 and enters the inlet of the swirl-jet absorber 130; the separator 170 is used to dry the compressed air.

[0045] The compressed air after spraying will introduce excess spray liquid. This excess spray liquid will then be further separated by separator 170, further reducing the absolute amount of total dissolved substances in the liquid carried by the compressed air. If the working fluid in the spray tank is water, then water will be introduced into the compressed air after spraying. This water will then be further separated by separator, further reducing the absolute amount of total dissolved substances in the liquid carried by the compressed air.

[0046] Furthermore, separator 170 may be a cyclone separator or a vane separator; and / or, separator 170 may be a cyclone separator or a vane separator, selected according to the operating conditions. If the operating conditions of the compressed air are stable, such as stable flow rate and pressure, a cyclone separator may be used; if the operating conditions of the compressed air have a large range of flexibility, a vane separator may be used.

[0047] Furthermore, a slug trap 180 is installed before the inlet of the sprayer 110; the compressed air to be purified enters the inlet of the slug trap 180, flows out from the outlet of the slug trap 180, and then enters the inlet of the sprayer 110. A slug trap is also installed before the inlet of the sprayer; the compressed air to be purified from the gas storage tank enters the inlet of the slug trap, flows out from the outlet of the slug trap, and then enters the inlet of the sprayer. When the raw material gas passes through the undulating pipeline, free water carried by it will accumulate at the bottom of the pipeline. After reaching a certain volume, slug flow will occur inside the pipe. Therefore, the raw material gas is first passed through the slug trap to receive any slug flow that may occur before the compressed air to be purified enters the purification process, separating the slug flow carried by the raw material gas. The function of the slug trap is to eliminate slug flow, provide stable downstream transport, and also to initially separate some large oil particles from the raw material gas. Furthermore, the slug catcher can be either container-type or pipeline-type, depending on the site conditions.

[0048] Furthermore, it also includes a first heating branch and a heat storage tank 300, the heat storage tank 300 being used to store a high-temperature circulating medium, which refers to a circulating medium with a high temperature. One end of the first heating branch is connected to the outlet of the heat storage tank 300, and the other end is connected to the inlet of the cold storage tank 210; the energy release branch also includes a first heat exchanger 400, the hot path of the first heat exchanger 400 being located on the first heating branch, the cold path inlet of the first heat exchanger 400 being connected to the air outlet of the rotary jet absorber 130, and the cold path outlet of the first heat exchanger 400 being connected to the inlet of the expansion generator set. Since the purification device in this embodiment has a spray liquid cooler and an absorbent liquid cooler, the purified compressed air is low-temperature compressed air. The expansion power generation device includes an expander unit and a generator. If the inlet temperature of the expander is too low, it will affect the expansion ratio. Therefore, the compressed air power generation system in this embodiment is also equipped with a first heat exchanger 400 for heating the purified compressed air. The heat source for the first heat exchanger 400 is provided by the high-temperature circulating medium in the heat storage tank. After heat exchange, the high-temperature circulating medium, whose temperature has decreased, becomes a low-temperature circulating medium and flows back to the cold storage tank. The circulating medium in this embodiment can be a commonly used circulating medium for heat exchangers, such as water or antifreeze.

[0049] The first heating branch has a first hot water pump 310 and a first hot water valve 311. By adjusting the outlet pressure of the first hot water pump 310 and the opening degree of the first hot water valve 311, the heat entering the first heat exchanger 400 from the heat storage tank 300 is controlled. There is a first cold water valve 312 between the hot outlet of the first heat exchanger 400 and the cold storage tank 210, which is used to control the opening and closing of the first heating branch and the flow rate.

[0050] Furthermore, it also includes a second heating branch and a heat storage tank 300. The heat storage tank 300 is used to store the high-temperature circulating medium. One end of the second heating branch is connected to the outlet of the heat storage tank 300, and the other end is connected to the inlet of the cold storage tank 210. The energy release branch also includes a second heat exchanger 500 and at least one stage expander unit. The hot path of the second heat exchanger 500 is located on the second heating branch, and the cold path inlet of the second heat exchanger 500 is connected to the outlet of the expander unit. Since the expander unit 700 may have multiple stages, and the interstage of each expander unit 700 also needs to be heated, this embodiment uses the second heat exchanger 500 to heat the expanded low-temperature compressed air before it enters the next stage expander unit. Of course, the low-temperature compressed air that has been heated and expanded by the second heat exchanger 500 meets the discharge temperature standard and can be directly discharged.

[0051] The second heating branch has a second hot water pump 320 and a second hot water valve 321. By adjusting the opening of the second hot water valve 321 and the outlet pressure of the second hot water pump 320, the amount of heat entering the second heat exchanger 500 from the heat storage tank 300 can be adjusted. A second cold water valve 322 is located between the hot outlet of the second heat exchanger 500 and the cold storage tank 210, used to control the opening and closing of the second heating branch and its flow rate.

[0052] Furthermore, it also includes a gas storage branch, which comprises a gas storage tank, a third heat exchanger 600, and at least one stage compressor unit 720. The hot inlet of the third heat exchanger 600 is connected to the outlet of the last stage compressor unit, and the hot outlet of the third heat exchanger 600 is connected to the inlet of the gas storage tank. The cold inlet of the third heat exchanger 600 is connected to the outlet of the cold storage tank 210 via a cooling branch, and the cold outlet of the third heat exchanger 600 is connected to the inlet of the cold storage tank 300. Air from nature is compressed into compressed air by the compressor unit and stored in the gas storage tank 710. The temperature of the compressed air increases, and in this embodiment, the heat of compression is recovered through the third heat exchanger 600. The cooling capacity of the third heat exchanger 600 is also provided through the cold storage tank 210. The cooling branch of the cold storage tank 210 and the third heat exchanger 600 has a second cold circuit switch valve 213 and a third cold water pump 214. By controlling the opening degree of the second cold circuit switch valve 213 and the outlet pressure of the third cold water pump 214, the amount of cold entering the cold circuit of the third heat exchanger 600 is controlled.

[0053] Furthermore, there is a gas storage inlet valve 711 on the pipeline from the compressor unit to the gas storage tank, and a gas storage outlet valve 712 on the pipeline from the gas storage tank to the gas storage tank.

[0054] Based on this, the compressed air energy storage and power generation system with low-temperature purification provided in this solution first removes oil, dust, free water and chemical impurities from the compressed air before it enters the expander generator set. Furthermore, the purification device operates under low-temperature conditions, which reduces the saturated water content in the compressed air. This results in the compressed air flowing into the expander generator set being clean and dry with low saturated water content, thereby improving the system's efficiency, service life, safety and stability.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A compressed air energy storage and power generation system with low-temperature purification, characterized in that, Including energy release branches and cooling circuits; The energy release branch includes a purification device and an expansion generator set. The purification device includes a sprayer, a spray tank, a swirl jet absorber, and an absorption tank. Impurity-laden compressed air enters from the sprayer, flows out of the sprayer, enters the swirl jet absorber, and then flows out of the swirl jet absorber and enters the expansion generator set. The spray tank stores the spraying medium for use by the sprayer, and the absorption tank stores the absorbent for use by the swirl jet absorber. A spray liquid cooler is installed on the connecting pipe between the first outlet of the spray tank and the inlet of the sprayer to cool the spraying medium entering the sprayer. An absorbent liquid cooler is installed on the connecting pipe between the outlet of the absorption tank and the inlet of the swirl jet absorber to cool the absorbent entering the swirl jet absorber. The cooling circuit includes a cold storage tank and a refrigeration device. The cold storage tank is used to store a low-temperature circulating medium. The outlet of the cold storage tank is connected to the cold path inlet of the spray liquid cooler. The cold path outlet of the spray liquid cooler is connected to the inlet of the refrigeration device. The outlet of the refrigeration device is connected to the cold path inlet of the absorbent liquid cooler. The cold path outlet of the absorbent liquid cooler is connected to the inlet of the cold storage tank. The drain outlet of the rotary jet absorber is equipped with a pH detection device to detect the pH value of the wastewater discharged from the rotary jet absorber. A separator is also provided between the sprayer and the swirl jet absorber; compressed air flows out from the outlet of the sprayer and into the inlet of the separator, and then flows out from the outlet of the separator and into the inlet of the swirl jet absorber; the separator is used to dry the compressed air.

2. The compressed air energy storage and power generation system with low-temperature purification according to claim 1, characterized in that, The second outlet of the spray tank and the inlet of the absorption tank are connected by a liquid distribution pipeline, which is equipped with a low-pressure pump and a liquid distribution valve; the outlet of the absorption tank is equipped with an absorption tank switch valve.

3. The compressed air energy storage and power generation system with low-temperature purification according to claim 2, characterized in that, The purification device also includes a liquid distribution bypass pipe, one end of which is connected to the second outlet of the spray tank, and the other end of which is connected to the outlet pipe of the absorption tank switch valve. The liquid preparation bypass pipeline is equipped with a liquid preparation bypass valve; the outlet pipeline of the absorption tank switch valve is equipped with a first high-pressure pump.

4. The compressed air energy storage and power generation system with low-temperature purification according to claim 3, characterized in that, The pH detection device controls the opening degree of the liquid dispensing valve, the outlet pressure of the low-pressure pump, the opening degree of the absorption tank switch valve, and the outlet pressure of the first high-pressure pump.

5. The compressed air energy storage and power generation system with low-temperature purification according to claim 1, characterized in that, A second high-pressure pump is installed on the pipeline between the hot inlet of the spray liquid cooler and the first outlet of the spray tank.

6. The compressed air energy storage and power generation system with low-temperature purification according to claim 1, characterized in that, A slug trap is also installed before the inlet of the sprayer; the compressed air to be purified enters the inlet of the slug trap, flows out from the outlet of the slug trap, and then enters the inlet of the sprayer.

7. The compressed air energy storage and power generation system with low-temperature purification according to claim 1, characterized in that, It also includes a first heating branch and a heat storage tank, the heat storage tank being used to store high-temperature circulating medium, one end of the first heating branch being connected to the outlet of the heat storage tank, and the other end being connected to the inlet of the cold storage tank; The energy release branch also includes a first heat exchanger, the hot path of which is located on the first heating branch, the cold path inlet of which is connected to the outlet of the swirl jet absorber, and the cold path outlet of which is connected to the inlet of the expansion generator set.

8. The compressed air energy storage and power generation system with low-temperature purification according to claim 1, characterized in that, It also includes a second heating branch and a heat storage tank, the heat storage tank being used to store high-temperature circulating medium, one end of the second heating branch being connected to the outlet of the heat storage tank, and the other end being connected to the inlet of the cold storage tank; The energy release branch also includes a second heat exchanger and at least one expansion unit. The hot path of the second heat exchanger is located on the second heating branch, and the cold path inlet of the second heat exchanger is connected to the outlet of the expansion unit.

9. The compressed air energy storage and power generation system with low-temperature purification according to claim 1, characterized in that, It also includes a gas storage branch, which includes a gas storage tank, a third heat exchanger and at least one stage compressor unit. The hot inlet of the third heat exchanger is connected to the outlet of the last stage compressor unit, and the hot outlet of the third heat exchanger is connected to the inlet of the gas storage tank. The cold circuit inlet of the third heat exchanger is connected to the outlet of the cold storage tank via a cooling branch, and the cold circuit outlet of the third heat exchanger is connected to the inlet of the heat storage tank.

10. The compressed air energy storage and power generation system with low-temperature purification according to claim 1, characterized in that, The refrigeration equipment uses a cooling tower.

11. The compressed air energy storage and power generation system with low-temperature purification according to claim 1, characterized in that, The spray tank contains water, and the absorption tank contains alkali or acid.

12. The compressed air energy storage and power generation system with low-temperature purification according to claim 1, characterized in that, The separator is either a cyclone separator or a blade separator.

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