# US 2026/0063377 A1 · Carbon dioxide phase change energy storage and release method and system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0063377 A1 - Document ID: US20260063377A1 - Status: Published application - Kind: A1 - Application number: 19/310,946 - Filed: 2025-08-27 - Published: 2026-03-05 - Earliest claimed: 2024-08-29 - Assignees: Exax Energy Technology (Shenzhen) Co., Ltd - Applicants: Exax Energy Technology (Shenzhen) Co., Ltd - Inventors: Hongtao Zheng; Wenping Zhang; Guolei Wang - Web page: https://patentgrep.com/patent/US20260063377A1 ## CPC - B01D 53/002: {by condensation} - F28D 20/028: {Control arrangements therefor} - F01K 25/00: Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for - F25J 3/0266: {separation of carbon dioxide (production of carbon dioxide in general C01B32/00)} - F25J 2220/80: Separating impurities from carbon dioxide, e.g. H2O or water-soluble contaminants - F28D 20/02: using latent heat - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) - F01K: STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES (gas-turbine or jet-propulsion plants F02; nuclear power plants, engine arrangements therein G21D) - F25J: LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS {OR LIQUEFIED GASEOUS} MIXTURES BY PRESSURE AND COLD TREATMENT {OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE (cryogenic pumps F04B37/08; gas storage vessels, gas holders F17; filing vessels with, or discharging from vessels, compressed, liquefied or solidified gases F17C; refrigeration machines, plants, or systems F25B)} ## Abstract A carbon dioxide phase change energy storage and release method and system are provided. The method includes an energy storage step, and the energy storage step includes a condensation stage. The condensation stage includes a liquid-phase carbon dioxide purification process. In the condensation stage, gas-phase carbon dioxide is converted into liquid-phase carbon dioxide by a first phase change converter, when a stored liquid level of the liquid-phase carbon dioxide reaches a set liquid level, the liquid-phase carbon dioxide purification process is performed to remove impurity liquid from the liquid-phase carbon dioxide. Therefore, the impurity liquid in the liquid carbon dioxide can be purified in a targeted manner through the liquid-phase carbon dioxide purification process, thereby achieving precise impurity removal of precise objects, eliminating adverse effects of the impurity liquid on liquefaction temperature change of the system and corrosion of various equipment pipelines, and making the system more perfect and optimized. ## Claims ### Claim 1 A carbon dioxide phase change energy storage and release method, comprising an energy storage step, wherein the energy storage step comprises a condensation stage; and the condensation stage comprises a liquid-phase carbon dioxide purification process; wherein the condensation stage comprises: converting, by a first phase change converter, gas-phase carbon dioxide into liquid-phase carbon dioxide; in response to a stored liquid level of the liquid-phase carbon dioxide reaching a set liquid level, performing the liquid-phase carbon dioxide purification process to remove impurity liquid from the liquid-phase carbon dioxide; and wherein the liquid-phase carbon dioxide purification process comprises: determining that the stored liquid level of the liquid-phase carbon dioxide is consistent with the set liquid level; wherein, when the stored liquid level of the liquid-phase carbon dioxide is consistent with the set liquid level, the impurity liquid is concentrated at a bottom of the liquid-phase carbon dioxide; opening an impurity liquid discharge pipeline to discharge the impurity liquid, obtaining a temperature of the impurity liquid discharge pipeline in real-time, and determining whether the temperature is within a preset threshold range; and in response to the temperature being within the preset threshold range, keeping the impurity liquid discharge pipeline open; otherwise, closing the impurity liquid discharge pipeline. ### Claim 2 (depends on 1) The carbon dioxide phase change energy storage and release method as claimed in claim 1, wherein the determining that the stored liquid level of the liquid-phase carbon dioxide is consistent with the set liquid level comprises: in response to a liquid level sensor being triggered by the liquid-phase carbon dioxide, determining that the stored liquid level of the liquid-phase carbon dioxide is consistent with the set liquid level, to thereby generate liquid level determination information; and wherein the opening an impurity liquid discharge pipeline to discharge the impurity liquid comprises: obtaining, by a controller, the liquid level determination information, and controlling, by the controller and according to the liquid level determination information, a valve on the impurity liquid discharge pipeline to open, to thereby open the impurity liquid discharge pipeline. ### Claim 3 (depends on 2) The carbon dioxide phase change energy storage and release method as claimed in claim 2, wherein the obtaining a temperature of the impurity liquid discharge pipeline in real-time, and determining whether the temperature is within a preset threshold range comprises: collecting, by a temperature sensor, the temperature in real-time; obtaining, by the controller, the temperature collected by the temperature sensor in real-time, and comparing the temperature to the preset threshold range; and in response to the temperature being within the preset threshold range, obtaining a first comparison result, and controlling, by the controller and according to the first comparison result, the valve to keep open; otherwise, obtaining a second comparison result, and controlling, by the controller and according to the second comparison result, the valve to close. ### Claim 4 (depends on 1) The carbon dioxide phase change energy storage and release method as claimed in claim 1, wherein the impurity liquid at least comprises water liquid, and the water liquid comprises at least one of free water and dissolved water. ### Claim 5 (depends on 1) The carbon dioxide phase change energy storage and release method as claimed in claim 1, further comprising an energy release step, wherein the energy release step comprises a vaporization stage; and the carbon dioxide phase change energy storage and release method further comprises a gas-phase carbon dioxide purification process; wherein the carbon dioxide phase change energy storage and release method comprises: in the vaporization stage, converting, by a second phase change converter, the liquid-phase carbon dioxide obtained through the liquid-phase carbon dioxide purification process into gas-phase carbon dioxide; and after the vaporization stage and before the condensation stage, performing the gas-phase carbon dioxide purification process, to remove impurities from the gas-phase carbon dioxide; wherein types of the impurities are one or more. ### Claim 6 (depends on 5) The carbon dioxide phase change energy storage and release method as claimed in claim 5, wherein the types of the impurities are more; wherein the after the vaporization stage and before the condensation stage, performing the gas-phase carbon dioxide purification process, to remove impurities from the gas-phase carbon dioxide comprises: performing, by using a plurality of different purification components in a same purification device, the gas-phase carbon dioxide purification process to remove a plurality of types of the impurities; wherein the plurality of different purification components are configured to purify different types of the impurities; or performing, by using a plurality of different purification devices arranged along a flow pipeline of the gas-phase carbon dioxide, the gas-phase carbon dioxide purification process to remove a plurality of types of the impurities; wherein the plurality of different purification devices are configured to purify different types of the impurities; or performing, by using a plurality of same purification devices arranged along the flow pipeline of the gas-phase carbon dioxide, the gas-phase carbon dioxide purification process to remove a plurality of types of the impurities; wherein the plurality of same purification devices are configured to purify same types of the impurities. ### Claim 7 (depends on 6) The carbon dioxide phase change energy storage and release method as claimed in claim 6, wherein the impurities comprise at least liquid impurities and solid impurities; wherein the gas-phase carbon dioxide purification process comprises at least a solid purification process and a liquid purification process; wherein the performing, by using a plurality of different purification components in a same purification device, the gas-phase carbon dioxide purification process to remove a plurality of types of the impurities comprises: performing, by using a first purification component in the purification device, the solid purification process to remove the solid impurities; and performing, by using a second purification component in the purification device, the liquid purification process to remove the liquid impurities; or wherein the performing, by using a plurality of different purification devices arranged along a flow pipeline of the gas-phase carbon dioxide, the gas-phase carbon dioxide purification process to remove a plurality of types of the impurities comprises: performing, by using one of the plurality of different purification devices, the solid purification process to remove the solid impurities; and performing, by using another one of the plurality of different purification devices, the liquid purification process to remove the liquid impurities. ### Claim 8 (depends on 7) The carbon dioxide phase change energy storage and release method as claimed in claim 7, wherein the liquid impurities comprise at least one of moisture and grease; and wherein the solid impurifies comprise at least one selected from the group consisting of metal rust powder, abrasive powder, environmental dust, inorganic powder, and metal powder. ### Claim 9 (depends on 5) The carbon dioxide phase change energy storage and release method as claimed in claim 5, further comprising a pre-purification process; wherein the carbon dioxide phase change energy storage and release method comprises: after the vaporization stage and before the gas-phase carbon dioxide purification process, performing the pre-purification process to remove particulate matters from the gas-phase carbon dioxide; wherein a particle size of each of the particulate matters is greater than that of each of the solid impurifies. ### Claim 10 (depends on 9) The carbon dioxide phase change energy storage and release method as claimed in claim 9, wherein the energy storage step comprises a pressurization stage and the condensation stage sequentially set in that order; and the carbon dioxide phase change energy storage and release method comprises: in the pressurization stage, performing the pre-purification process on low-pressure gas-phase carbon dioxide to obtain pre-purified low-pressure gas-phase carbon dioxide, at least compressing the pre-purified low-pressure gas-phase carbon dioxide to obtain high-pressure gas-phase carbon dioxide, performing the gas-phase carbon dioxide purification process on the high-pressure gas-phase carbon dioxide to obtain purified high-pressure gas-phase carbon dioxide, wherein the purified high-pressure gas-phase carbon dioxide enters the condensation stage. ### Claim 11 A carbon dioxide phase change energy storage and release system, comprising an energy storage sub-system, wherein the energy storage sub-system comprises a condensation assembly; wherein the condensation assembly comprises a first phase change converter, a liquid storage member and a liquid-phase carbon dioxide purification assembly, and the first phase change converter and the liquid-phase carbon dioxide purification assembly are connected to the liquid storage member individually; wherein the first phase change converter is configured to convert gas-phase carbon dioxide into liquid-phase carbon dioxide, the liquid storage member is configured to store the liquid-phase carbon dioxide, and the liquid-phase carbon dioxide purification assembly is configured to: in response to a stored liquid level of the liquid-phase carbon dioxide reaching a set liquid level, perform a liquid-phase carbon dioxide purification process to remove impurity liquid from the liquid-phase carbon dioxide; wherein the liquid-phase carbon dioxide purification assembly comprises an impurity liquid discharge pipeline, a liquid level sensor, a temperature sensor, a valve and a controller; and the temperature sensor and the valve are disposed on the impurity liquid discharge pipeline, and the liquid level sensor and the temperature sensor are signally connected to the controller; and wherein the liquid level sensor is configured to determine the stored liquid level of the liquid-phase carbon dioxide and generate liquid level determination information, the temperature sensor is configured to collect a temperature of the impurity liquid discharge pipeline in real-time, and the controller is configured to control the valve to open according to the liquid level determination information, and control the valve to keep open or control the valve to close according to the temperature. ### Claim 12 (depends on 11) The carbon dioxide phase change energy storage and release system as claimed in claim 11, further comprising an energy release sub-system, wherein the energy release sub-system comprises a vaporization assembly; wherein the vaporization assembly comprises a liquid-phase pipeline and a second phase change converter, the liquid storage member is connected to the second phase change converter through the liquid-phase pipeline, and the second phase change converter is configured to convert the liquid-phase carbon dioxide into gas-phase carbon dioxide; and wherein the energy storage and release system further comprises a gas-phase carbon dioxide purifier, the gas-phase carbon dioxide purifier is disposed between the first phase change converter and the second phase change converter, and the gas-phase carbon dioxide purifier is configured to perform a gas-phase carbon dioxide purification process to remove impurifies from the gas-phase carbon dioxide. ### Claim 13 (depends on 12) The carbon dioxide phase change energy storage and release system as claimed in claim 12, further comprising a pre-purification assembly, wherein the pre-purification assembly is disposed between a gas storage member and the gas-phase carbon dioxide purifier, the gas storage member is connected to the vaporization assembly, and the pre-purification assembly is configured to perform a pre-purification process to remove particulate matters from the gas-phase carbon dioxide; and a particle size of each of the particulate matters is greater than that of each of solid impurifies. ### Claim 14 (depends on 13) The carbon dioxide phase change energy storage and release system as claimed in claim 13, wherein the energy storage sub-system comprises a pressurization assembly and the condensation assembly sequentially disposed in that order; and wherein the pressurization assembly comprises the gas storage member, a compressor, and a first heat exchanger sequentially connected in that order, the pre-purification assembly is connected between the gas storage member and the compressor, and the gas-phase carbon dioxide purifier is connected between the first heat exchanger and the first phase change converter. ### Claim 15 (depends on 14) The carbon dioxide phase change energy storage and release system as claimed in claim 14, wherein the pre-purification assembly comprises a pre-purifier and a metal cotton board disposed in the pre-purifier; and wherein the pre-purifier defines a first gas inlet and a second gas outlet on opposite sides of the metal cotton board respectively, and the first gas inlet and the second gas outlet are connected to the gas storage member and the compressor respectively.