Graded discharge and recovery method for liquid carbon dioxide energy storage system

Abstract

The invention relates to a graded release and recovery method for a liquid carbon dioxide energy storage system, which comprises the following steps of: acquiring online data such as pressure, temperature, flow, liquid level and purification pressure difference after release is triggered, judging a phase state dominant type and a pollution risk grade of a release medium, and generating a release grade and a routing instruction; gas-liquid separation-condensation recovery of a low-pollution medium, injection pressurization secondary condensation recovery of uncondensed tail gas, recovery after isolation and purification of a high-pollution medium and safe tank combination under the condition of meeting the tank combination pressure difference are realized, so that the recovery rate and the quality of the recovered medium are remarkably improved while the discharge safety is ensured; and the risks of frosting blockage, liquid impact and instability in the recovery process caused by two-phase flash evaporation are reduced, and the operation reliability and economical efficiency of the liquid carbon dioxide energy storage system are improved.

Description

Technical Field

[0001] This application relates to the field of venting and recovery technology, and in particular to a staged venting and recovery method for liquid carbon dioxide energy storage systems. Background Technology

[0002] Liquid carbon dioxide energy storage systems utilize the phase changes of carbon dioxide under different pressure and temperature conditions to store and release energy. The system typically includes a pressurized storage tank, heat exchange and condensation units, pump and valve assemblies, and multi-stage piping. Due to operational conditions such as energy charging / discharging switching, valve group switching, shutdown pressure holding, heat exchange fluctuations, and abnormal temperature and pressure increases, pressurized equipment may face overpressure risks. Therefore, pressure needs to be released through venting mechanisms to ensure the safety of the equipment and the system.

[0003] In existing technologies, the released medium is often directly discharged into the venting pipeline or recovered via a single path. Because carbon dioxide easily flashes and forms a gas-liquid two-phase system during release, the phase composition of the released medium changes rapidly with operating conditions. Furthermore, the release process involves strong throttling and cooling, which can easily lead to frosting, blockage, and liquid hammer risks, resulting in blockage of the release channel or instability in the recovery process. Simultaneously, the cleanliness of the medium varies significantly between different release events, and the released medium may contain particulate impurities, lubricating oil mist, or moisture. If these contaminants are directly incorporated into the recovery tank without identification and isolation, the recovered medium is easily contaminated, affecting subsequent heat exchange efficiency, pump and valve reliability, and the quality of the medium in the tank, potentially even causing long-term operational risks to the system. Summary of the Invention

[0004] To at least partially overcome the lack of an online identification and graded disposal mechanism for the rapid phase changes and pollution risks of the released medium during the release process of liquid carbon dioxide energy storage systems, which leads to frosting blockage, liquid hammer, and unstable recovery caused by two-phase flash evaporation, this application provides a graded release and recovery method for liquid carbon dioxide energy storage systems.

[0005] The proposed solution is as follows:

[0006] A staged release and recovery method for a liquid carbon dioxide energy storage system includes: After receiving the discharge trigger signal, the discharge medium is introduced into the buffer flash container through the discharge access manifold, and the upstream pressure of the discharge access manifold, the temperature of the discharge medium, the discharge flow rate, the liquid level and its change in the buffer flash container, and the pressure difference of the purification unit are obtained within the preset sampling period after the trigger. The phase state of the discharged medium is determined based on the upstream pressure and the temperature of the discharged medium, and the dominant phase type is determined by combining the liquid level change in the buffer flash evaporation container and the discharged flow rate; the pollution risk level is determined based on the pressure difference of the purification unit. Based on the dominant phase type and the pollution risk level, a release level and routing instructions are generated, wherein the release level includes at least a low pollution recovery level and an isolation and purification level; When the venting level is a low-pollution recovery level, the liquid phase in the buffer flash container is subjected to particle filtration and coalescence demisting treatment according to the routing instructions, and then recovered to the recovery storage tank via the liquid phase recovery component; the gas phase in the buffer flash container is subjected to cyclone separation and condensation recovery treatment in sequence, and the obtained condensate is incorporated into the liquid phase recovery component; the uncondensed tail gas remaining after condensation recovery is sucked up and pressurized by the injection booster component, and then subjected to condensation recovery treatment again, and the obtained condensate is incorporated into the liquid phase recovery component; When the venting level is the isolation and purification level, the venting medium in the buffer flash container is introduced into the isolation and recovery tank according to the routing instructions. After purification by the purification unit, it is subjected to jet pressurization and condensation recovery treatment. When the pressure difference of the purification unit is within the preset tank-to-tank pressure difference range, the isolation and recovery tank and the recovery storage tank are connected and connected.

[0007] Preferably, determining the phase state of the venting medium based on the upstream pressure and the temperature of the venting medium includes: The pre-stored relationship between carbon dioxide pressure and saturation temperature is invoked to determine the corresponding saturation temperature value for the upstream pressure. Compare the temperature of the venting medium with the corresponding value of the saturation temperature; When the temperature of the discharge medium is higher than the corresponding value of the saturation temperature and exceeds the preset temperature tolerance range, the phase state is determined to be a gas phase state. When the temperature of the discharge medium is lower than the corresponding value of the saturation temperature and exceeds the preset temperature tolerance range, the phase state is determined to be a liquid phase state. When the temperature of the venting medium falls within the preset temperature tolerance range, the phase state is determined to be a two-phase state.

[0008] Preferably, the method further includes: The state of the two phases is verified based on the liquid level and its changes in the buffer flash container. When the liquid level in the buffer flash container continues to rise and the rise exceeds the preset liquid level change threshold, the two-phase state is maintained or corrected to a liquid phase state. When the liquid level in the buffer flash container remains stable or continues to decrease, the two-phase state is maintained or corrected to a gas phase state.

[0009] Preferably, determining the dominant phase type by combining the liquid level and its change in the buffer flash container with the discharge flow rate includes: The liquid level data of the buffer flash evaporation container at multiple moments is acquired within the preset sampling period, and the direction of liquid level change and cumulative change amplitude are determined based on the liquid level difference between adjacent moments. At the same time, the discharge flow rate and its change within the preset sampling period are also acquired. When the liquid level rises continuously within a preset duration and the cumulative rise exceeds the first liquid level change threshold, and the discharge flow rate is not lower than the first flow rate threshold, the phase dominance type is determined to be the liquid phase dominance type. When the liquid level remains stable or continuously decreases within a preset duration, and the discharge flow rate is not lower than the second flow rate threshold, the phase dominance type is determined to be the gas phase dominance type. When the liquid level fluctuates alternately between rising and falling during the preset sampling period and the fluctuation amplitude exceeds the second liquid level change threshold, and the fluctuation amplitude of the discharge flow exceeds the preset flow fluctuation threshold, the phase dominance type is determined to be a two-phase dominance type.

[0010] Preferably, determining the pollution risk level based on the pressure difference of the purification unit includes: The pressure difference of the purification unit at multiple moments is acquired within the preset sampling period, and the current value of the pressure difference of the purification unit and the rate of change of the pressure difference of the purification unit determined based on the pressure difference value between adjacent moments are determined. The flow range to which the discharge flow belongs is determined based on the discharge flow, and a pressure difference judgment threshold group corresponding to the flow range is selected. The pressure difference judgment threshold group includes at least a first pressure difference threshold, a second pressure difference threshold, a first rate threshold and a second rate threshold, wherein the first pressure difference threshold is less than the second pressure difference threshold and the first rate threshold is lower than the second rate threshold. When the current value of the differential pressure of the purification unit is lower than the first differential pressure threshold and the rate of change of the differential pressure of the purification unit is lower than the first rate threshold, the pollution risk level is determined to be a low pollution level. When the current value of the differential pressure of the purification unit is higher than the second differential pressure threshold or the rate of change of the differential pressure of the purification unit is higher than the second rate threshold, the pollution risk level is determined to be a high pollution level. When the current value of the pressure difference of the purification unit is between the first pressure difference threshold and the second pressure difference threshold, the pressure difference change rate of the purification unit is compared with the first rate threshold. If the pressure difference change rate of the purification unit is lower than the first rate threshold, the pollution risk level is determined to be a low pollution level; otherwise, the pollution risk level is determined to be a high pollution level.

[0011] Preferably, generating a release level and routing instructions based on the dominant phase type and the pollution risk level includes: Obtain the dominant phase type and the pollution risk level, and input the dominant phase type and the pollution risk level into a pre-configured hierarchical routing rule set; When the pollution risk level is high pollution level, the release level is determined to be isolation and purification level, and a routing instruction is generated for introducing the release medium in the buffer flash container into the isolation recovery tank, and for the recovery medium output from the isolation recovery tank to be purified by the purification unit and then subjected to jet pressurization and condensation recovery treatment. When the pollution risk level is low pollution level, the release level is determined to be low pollution recovery level, and routing instructions are generated for performing particle filtration and coalescence demisting treatment on the liquid phase in the buffer flash container and then recovering it to the recovery storage tank through the liquid phase recovery component; performing cyclone separation and condensation recovery treatment on the gas phase in the buffer flash container; and using the injection pressurization component to draw in the uncondensed tail gas remaining after condensation recovery and then performing condensation recovery treatment again.

[0012] Preferably, after introducing the venting medium into the buffer flash evaporation vessel, the method further includes: The back pressure regulating component is controlled to maintain the inlet pressure of the buffer flash container within the target back pressure range.

[0013] Preferably, the method further includes: The back pressure target range is determined based on the dominant phase type, and the back pressure target range is corrected based on the liquid level and its change in the buffer flash container during the preset sampling period. When the dominant phase type is two-phase and the fluctuation range of the liquid level in the buffer flash container exceeds the preset liquid level fluctuation threshold, the back pressure target range is increased or the discharge flow is limited so that the flash generation position is maintained in the buffer flash container and the risk of two-phase formation in the pipeline is reduced.

[0014] Preferably, the driving flow of the injection pressurization assembly is provided by the high-pressure branch medium of the buffer flash container, and the driving flow intensity is adjusted by the driving flow adjustment assembly; The driving flow intensity is determined based on the phase dominance type and the discharge flow rate. When the phase dominance type is a gas phase dominance type or a two-phase dominance type, the driving flow intensity is increased or the working time of the injection booster component is extended to improve the suction capacity of the uncondensed exhaust gas.

[0015] Preferably, before connecting the isolation recovery tank and the recovery storage tank, the method further includes: Continuously monitor the pressure difference and its changes in the purification unit; When the pressure difference of the purification unit is continuously within the preset range of the combined tank pressure difference and the rate of change of the pressure difference of the purification unit is lower than the preset rate of change of the pressure difference threshold, a combined tank allow command is output. Under the command to allow tank merging, the pressure equalization connection channel is first opened to gradually equalize the pressure of the isolation recovery tank and the pressure of the recovery storage tank until the pressure difference between the two is lower than the preset pressure difference threshold. Then, the tank merging connection channel is opened to complete the tank merging.

[0016] The technical solution provided in this application may include the following beneficial effects: This technical solution, upon triggering the release, acquires data such as upstream pressure, release medium temperature, release flow rate, buffer flash container liquid level and its changes, and purification unit pressure difference to determine the phase state, dominant phase type, and pollution risk level of the release medium. Based on this, it generates release level and routing instructions for either low-pollution recovery level or isolation purification level. Under the low-pollution recovery level, flash buffering and gas-liquid separation are first completed in the buffer flash container. The liquid phase is then filtered for particles and coalesced for demisting before being recovered to the recovery storage tank. The gas phase undergoes cyclone separation and condensation recovery. Uncondensed exhaust gas is then drawn and pressurized using a jet booster assembly before being condensed and recovered again, thereby improving the exhaust gas recovery rate and reducing emission losses. Under the isolation purification level, the release medium is introduced into the isolation recovery tank and purified by the purification unit before being recovered. Simultaneously, connection and paralleling with the recovery storage tank are only permitted when the pressure difference of the purification unit is within the preset paralleling pressure difference range, thereby effectively preventing the polluting medium from being directly integrated into the recovery storage tank. This can improve recovery efficiency and recovery medium quality while ensuring safe venting, reduce the risks of frosting blockage, liquid hammer and instability in the recovery process caused by two-phase venting, and improve the long-term operational reliability and economy of liquid carbon dioxide energy storage systems.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] Figure 1 This is a schematic flowchart of a staged release and recovery method for a liquid carbon dioxide energy storage system provided in one embodiment of this application. Detailed Implementation

[0020] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0021] Example 1 In traditional liquid carbon dioxide energy storage systems, the phase composition of the released medium changes rapidly with operating conditions during overpressure release, accompanied by strong throttling and cooling. This can easily lead to frosting, blockage, and liquid hammer risks, causing blockage of the release channel or instability in the recovery process. Furthermore, the released medium may contain particulate impurities, lubricating oil mist, or moisture, which, if not identified and isolated before being directly incorporated into the recovery tank, can easily contaminate the recovered medium. This can affect subsequent heat exchange efficiency, pump and valve reliability, and the quality of the medium within the tank, potentially even causing long-term operational risks to the system.

[0022] In response, this application proposes a staged release and recovery method for liquid carbon dioxide energy storage systems. (Refer to...) Figure 1 ,include: S1. After receiving the discharge trigger signal, the discharge medium is introduced into the buffer flash container through the discharge access manifold, and the upstream pressure of the discharge access manifold, the temperature of the discharge medium, the discharge flow rate, the liquid level and its change in the buffer flash container, and the pressure difference of the purification unit are obtained within the preset sampling period after the trigger. S2. Determine the phase state of the discharged medium based on the upstream pressure and the temperature of the discharged medium, and determine the dominant phase type by combining the liquid level change in the buffer flash evaporation container and the discharged flow rate; determine the pollution risk level based on the pressure difference of the purification unit. S3. Generate release level and routing instructions based on the dominant phase type and pollution risk level, wherein the release level includes at least a low pollution recovery level and an isolation and purification level; S4. When the venting level is low pollution recovery level, the liquid phase in the buffer flash container is subjected to particle filtration and coalescence demisting treatment according to the routing instructions, and then recovered to the recovery storage tank through the liquid phase recovery component; the gas phase in the buffer flash container is subjected to cyclone separation and condensation recovery treatment in sequence, and the obtained condensate is incorporated into the liquid phase recovery component; the uncondensed tail gas remaining after condensation recovery is sucked up by the injection pressurization component and then injected pressurized, and then subjected to condensation recovery treatment again, and the obtained condensate is incorporated into the liquid phase recovery component; S5. When the venting level is the isolation and purification level, the venting medium in the buffer flash container is introduced into the isolation and recovery tank according to the routing instructions. After purification by the purification unit, the jet pressurization and condensation recovery treatment is performed. When the pressure difference of the purification unit is within the preset tank-to-tank pressure difference range, the isolation and recovery tank and the recovery storage tank are connected and connected.

[0023] It should be noted that the discharge trigger signal refers to the signal issued by the system to start the discharge process when it detects overpressure, overtemperature or abnormal liquid level, etc., or it can be generated by operation commands.

[0024] The venting medium refers to the carbon dioxide fluid that needs to be discharged from the liquid carbon dioxide energy storage system due to overpressure or other abnormal operating conditions. It may be in the liquid phase, gas phase, or gas-liquid two-phase state and may contain impurities.

[0025] A buffer flash vessel is a pressure vessel used to receive vented media. It is designed to provide a buffer space for the vented media and promote flash evaporation of the media when the pressure drops sharply, thereby achieving gas-liquid separation.

[0026] The preset sampling period refers to the time window during which the system continuously monitors and records relevant process parameters (such as pressure, temperature, flow rate, liquid level, differential pressure, etc.) after the venting is triggered.

[0027] The pressure difference of the purification unit refers to the pressure difference generated before and after the discharged medium passes through the purification unit. The change of this pressure difference can reflect the operating status of the purification unit and the degree of contamination of the medium.

[0028] Phase state describes the physical state of the venting medium under specific temperature and pressure conditions, including liquid phase, gas phase, or two phases.

[0029] Phase dominance type refers to the main phase characteristics determined by a comprehensive analysis of parameters such as the phase state of the discharged medium, liquid level changes, and discharge flow rate during the discharge process, such as liquid phase dominance, gas phase dominance, or two-phase dominance.

[0030] Pollution risk level is the level of pollutant content in the released medium or the potential risk of pollution to the recovery system, assessed based on parameters such as the pressure difference of the purification unit.

[0031] The release level is the treatment level of the released medium determined comprehensively based on the dominant phase type and pollution risk level, guiding the subsequent recovery or purification path.

[0032] Routing instructions are specific operational instructions generated based on the discharge level. They are used to control equipment such as valves and pumps, and guide the discharged medium to different treatment paths.

[0033] A jet booster assembly is a device that uses the kinetic energy of a high-pressure fluid (driving flow) to draw in a low-pressure fluid and pressurize it. It is often used in recovery systems to increase the pressure of low-pressure exhaust gases for subsequent treatment.

[0034] In this embodiment, the staged release and recovery method is first activated upon receiving a release trigger signal. This release trigger signal can be automatically generated by monitoring devices such as pressure sensors, temperature sensors, or level sensors within the system when abnormal operating conditions are detected, or it can be manually issued by the operator based on the site conditions. Once the signal is received, the released medium is guided to the buffer flash container through the release access manifold. The release access manifold can be a simple conduit used to collect media from different release points. The buffer flash container, as an intermediate buffer unit, is designed to stabilize the release process and promote phase change of the medium. During a preset sampling period after the release trigger, the system continuously acquires key process parameters, including the upstream pressure of the release access manifold, the temperature of the released medium, the release flow rate, the level and its changes in the buffer flash container, and the pressure difference of the purification unit. These parameters can be measured using independent sensors, such as mechanical pressure gauges, thermocouples, orifice flow meters, float level gauges, etc., and recorded through a data acquisition system. The preset sampling period can be a fixed time window, such as lasting several seconds or minutes, to ensure sufficient data is acquired for analysis. Furthermore, based on the acquired upstream pressure and the temperature of the discharged medium, the phase state of the discharged medium can be determined. For example, by consulting a pre-stored carbon dioxide phase diagram and based on the measured pressure and temperature values, it can be manually determined whether the medium is in the liquid phase, gas phase, or a two-phase system. Simultaneously, by combining the liquid level and its changes in the buffer flash container with the discharge flow rate, the dominant phase type can be determined. For example, if the liquid level in the buffer flash container is observed to rise rapidly and continuously with a large discharge flow rate, it is initially judged to be a liquid-dominated type; if the liquid level remains stable or continues to fall with a large discharge flow rate, it is initially judged to be a gas-dominated type. In addition, the pollution risk level can be determined based on the pressure difference of the purification unit. For example, if the absolute value of the pressure difference of the purification unit is higher than a certain empirical threshold, the discharged medium is considered to have a high pollution risk; conversely, the pollution risk is considered to be low. Based on the determined dominant phase type and pollution risk level, the system will generate corresponding discharge levels and routing instructions. Discharge levels include at least a low-pollution recovery level and an isolation purification level. Routing instructions are a series of operational commands used to control equipment such as valves and pumps to guide the released medium to different treatment paths. For example, a preset decision logic can generate an isolation and purification level and corresponding routing instructions when the pollution risk level is high, regardless of the dominant phase type; when the pollution risk level is low, a low-pollution recovery level and corresponding routing instructions are generated based on the dominant phase type. When the release level is determined to be low-pollution recovery level, the system will process the released medium in the buffer flash container according to the generated routing instructions. Specifically, for liquid media, particle filtration can be performed first through a simple filter to remove larger solid impurities, followed by coalescence and demisting treatment through a packed tower or simple baffle to separate tiny droplets or oil mist entrained in the liquid phase.The treated liquid medium is then recovered to a recovery tank via a liquid phase recovery assembly, such as a pipeline and pump system. For the gaseous medium in the buffer flash container, cyclone separation and condensation recovery are performed sequentially. The cyclone separator removes any entrained droplets from the gas phase, which then enters a conventional coil condenser for condensation. The resulting condensate is incorporated into the piping of the liquid phase recovery assembly. Uncondensed exhaust gas remaining after condensation recovery is drawn in and pressurized using a jet pressurization assembly. This assembly can be a Venturi injector, utilizing the kinetic energy of a high-pressure drive flow (e.g., high-pressure carbon dioxide from within the system) to draw in low-pressure exhaust gas and increase its pressure. The pressurized exhaust gas undergoes condensation recovery again, with the resulting condensate also incorporated into the liquid phase recovery assembly. When the venting level is determined to be an isolation cleanup level, the system will guide the vented medium from the buffer flash container to an isolation recovery tank according to routing instructions. The isolation recovery tank is a separate container used to temporarily store high-risk vented media, preventing direct contamination of the recovery tank. The discharged medium, after being introduced into the isolation and recovery tank, is then purified by a purification unit, for example, by passing it through an adsorbent bed (such as activated carbon or molecular sieve) to remove particulate impurities, oil, or moisture. The purified medium then undergoes jet pressurization and condensation recovery to achieve medium recovery. Furthermore, when the pressure difference of the purification unit remains within the preset tank-to-tank pressure difference range, it indicates that the purification effect has met the requirements. At this point, the isolation and recovery tank can be connected and merged with the recovery storage tank, safely transferring the purified medium to the recovery storage tank. Connecting and merging the tanks can be achieved manually by operating valves, ensuring that merging only occurs when the medium cleanliness meets the requirements. The graded discharge and recovery method proposed in this application achieves intelligent graded treatment of the discharged medium by real-time assessment of the phase state, dominant phase type, and pollution risk level of the discharged medium from the liquid carbon dioxide energy storage system, and generating graded discharge levels and routing instructions accordingly. This method effectively avoids problems such as frosting, blockage, liquid hammer, and contamination of the recovered medium caused by the complex phase state and contaminant mixing of the medium in traditional venting and recovery processes. It ensures the stability of the venting process and the quality of the recovered medium, thereby guaranteeing the long-term reliability and efficiency of the system. It should be noted that the phase state of the venting medium is determined based on the upstream pressure and the temperature of the venting medium, including: Call the pre-stored relationship between carbon dioxide pressure and saturation temperature to determine the corresponding saturation temperature value for the upstream pressure; Compare the temperature of the discharged medium with the corresponding value of the saturation temperature; When the temperature of the discharged medium is higher than the corresponding value of the saturation temperature and exceeds the preset temperature tolerance range, the phase state is determined to be the gas phase state. When the temperature of the discharged medium is lower than the corresponding value of the saturation temperature and exceeds the preset temperature tolerance range, the phase state is determined to be the liquid phase state. When the temperature of the discharged medium falls within the preset temperature tolerance range, the phase state is determined to be a two-phase state.

[0035] This application utilizes a pre-stored relationship between carbon dioxide pressure and saturation temperature, combined with real-time measured temperature of the released medium, and introduces a temperature tolerance range to accurately and robustly determine the phase state of the released medium. This determination method effectively avoids phase misjudgment problems that may occur due to sensor measurement errors, system fluctuations, or when the medium is near the saturation line. Especially during the release process of liquid carbon dioxide energy storage systems, the medium phase is complex and variable, and accurate phase determination is the foundation for the effective implementation of subsequent staged release and recovery strategies. By clearly distinguishing between gaseous, liquid, and two-phase states, it provides a more reliable and accurate basis for subsequent determination of the dominant phase type, pollution risk level assessment, release level generation, and routing command execution, thereby significantly improving the intelligence, safety, and processing efficiency of the entire release and recovery method.

[0036] Furthermore, the method also includes: The two-phase state was verified based on the liquid level and its changes in the buffer flash container. When the liquid level in the buffer flash container continues to rise and the rise exceeds the preset liquid level change threshold, maintain the two-phase state or correct it to the liquid phase state. When the liquid level in the buffer flash container remains stable or continues to decrease, maintain the two-phase state or correct it to a gas phase state.

[0037] Specifically, the two-phase state is verified based on the liquid level and its changes in the buffer flash evaporation container. This technical feature aims to verify and correct the initially determined two-phase state by real-time monitoring of the liquid level and its dynamic changes within the buffer flash evaporation container. Its function is to introduce feedback from the actual physical state to improve the accuracy and robustness of phase state judgment, especially when the medium is in a critical or dynamically changing two-phase region. Specifically, liquid level data can be continuously acquired by installing a liquid level sensor (e.g., a differential pressure level gauge, radar level gauge, or ultrasonic level gauge) on the buffer flash evaporation container. This data is then transmitted to the control system for processing and analysis to identify the trend and magnitude of liquid level changes. When the liquid level in the buffer flash evaporation container continues to rise and the increase exceeds a preset liquid level change threshold, the two-phase state is maintained or corrected to a liquid phase state. This technical feature describes a mechanism for verification based on the rising trend of the liquid level. When the liquid level in the buffer flash evaporation container shows a continuous upward trend over a period of time, and its cumulative increase exceeds a preset liquid level change threshold, it indicates that a large amount of liquid phase medium is entering or condensing within the container. In this situation, even if initially judged to be a two-phase state, it should be maintained as a two-phase state (if the liquid phase accumulation rate is slow or fluctuates) or corrected to a liquid phase state (if the liquid phase accumulation rate is fast and continuous, indicating that the liquid phase is dominant) based on the actual liquid level change trend. The preset liquid level change threshold is a configurable parameter, and its setting should comprehensively consider the geometry of the buffer flash evaporation container, the discharge flow rate, and the system's sensitivity requirements to liquid phase accumulation. When the liquid level in the buffer flash evaporation container remains stable or continues to decrease, the two-phase state should be maintained or corrected to a gas phase state. This technical feature describes another mechanism for verification based on the stability or decreasing trend of the liquid level. When the liquid level in the buffer flash evaporation container remains relatively stable for a period of time, or shows a continuous decreasing trend, it indicates that there is no significant accumulation of the liquid phase medium in the container, and it may even be vaporizing or being discharged. In this situation, even if initially judged to be a two-phase state, it should be maintained as a two-phase state (if the liquid level is stable but there is still gas-liquid coexistence) or corrected to a gas phase state (if the liquid level continues to decrease, indicating that vaporization or gas phase discharge is dominant) based on the actual liquid level change trend. "Remaining stable" typically refers to liquid level fluctuations within a very small range, with no obvious upward or downward trend. "Continuously declining" refers to a clear downward trend in liquid level. It should be noted that determining the dominant phase type involves combining the liquid level and its changes in the buffer flash container with the discharge flow rate, including: The system acquires multi-moment liquid level data of the buffer flash container within a preset sampling period, and determines the direction and cumulative magnitude of liquid level change based on the liquid level difference between adjacent moments. At the same time, it acquires the discharge flow rate and its changes within the preset sampling period. When the liquid level continues to rise within a preset duration and the cumulative rise exceeds the first liquid level change threshold, and the discharge flow rate is not lower than the first flow rate threshold, the phase dominance type is determined to be the liquid phase dominance type. When the liquid level remains stable or continues to decrease within a continuously preset duration, and the discharge flow rate is not lower than the second flow rate threshold, the phase dominance type is determined to be the gas phase dominance type. When the liquid level fluctuates alternately between rising and falling within a preset sampling period, and the fluctuation amplitude exceeds the second liquid level change threshold, and the change amplitude of the discharge flow exceeds the preset flow fluctuation threshold, the phase dominance type is determined to be a two-phase dominance type. Specifically, the preset sampling period refers to the time window during which the system continuously monitors and collects data after receiving the discharge trigger signal. The length of this period can be configured according to the system response speed and the dynamic characteristics of the discharge process, for example, it can be set to several seconds to tens of seconds. The multi-moment liquid level data are liquid level readings in the buffer flash container collected by a liquid level sensor (e.g., a radar level gauge, differential pressure level gauge, or float level gauge, etc.) at a fixed frequency or dynamic frequency within the preset sampling period. By performing differential calculations on the continuously collected liquid level data, it can be determined whether the liquid level is rising, falling, or remaining stable, and its degree of change can be quantified. For example, the liquid level change rate per unit time or the total liquid level change can be calculated. The discharge flow rate and its changes are obtained by using a flow meter (e.g., a vortex flow meter, Coriolis mass flow meter, or orifice plate flow meter) within the same sampling period to collect instantaneous flow data of the discharged medium and analyze its trend over time. For example, the average, maximum, and minimum flow rates, as well as the flow fluctuation amplitude, can be calculated. The continuously preset duration refers to the minimum time required for the liquid level to continuously rise or fall, used to eliminate the interference of instantaneous fluctuations or measurement noise on the judgment and ensure that the trend of liquid level change is stable and meaningful. The first liquid level change threshold is used as a quantitative standard to determine whether the liquid level rise is significant. For example, it can be set as a certain percentage of the total height of the buffer flash container or a fixed value. The first flow rate threshold is used to determine whether the discharge flow rate reaches the minimum flow rate value of the liquid phase dominance characteristic. This threshold can be determined by experiments or simulations based on system design and medium characteristics. When the liquid level continuously rises within the continuously preset duration, and the cumulative rise exceeds the first liquid level change threshold, while the discharge flow rate is not lower than the first flow rate threshold, it indicates that a large amount of liquid phase medium has entered the buffer flash container, thus determining the phase dominance type as liquid phase dominance. The second flow threshold is used to determine whether the discharge flow rate reaches the minimum flow rate value for a gas-dominant characteristic. This threshold may be the same as or different from the first flow threshold, and can also be set according to actual operating conditions. When the liquid level remains stable or continuously decreases within a continuously preset duration, and the discharge flow rate is not lower than the second flow threshold, it indicates that the liquid phase accumulation in the buffer flash container is not significant or the liquid phase is decreasing, while the gas phase is continuously discharged. Therefore, the phase dominance type is determined to be gas-dominant. The second liquid level change threshold is used as a quantitative standard to determine whether the liquid level fluctuation is significant. For example, it can be set as a small percentage of the total height of the buffer flash container or a fixed value. The preset flow rate fluctuation threshold is used as a quantitative standard to determine whether the discharge flow rate fluctuation is significant. For example, it can be set as a certain percentage of the average flow rate.When the liquid level fluctuates alternately between rising and falling within the preset sampling period, and the fluctuation amplitude exceeds the second liquid level change threshold, and the fluctuation amplitude of the discharge flow exceeds the preset flow fluctuation threshold, it indicates that there may be severe flashing, boiling, or two-phase flow instability phenomena in the buffer flash evaporation container, with both liquid and gas phases accounting for a significant proportion. Therefore, the dominant phase type is determined to be two-phase dominant. It should be noted that the pollution risk level is determined based on the pressure difference of the purification unit, including: The pressure difference of the purification unit is acquired at multiple times within a preset sampling period, and the current value of the pressure difference of the purification unit and the rate of change of the pressure difference of the purification unit are determined based on the pressure difference value between adjacent times. The flow range to which the discharge flow belongs is determined based on the discharge flow, and a pressure difference judgment threshold group corresponding to the flow range is selected. The pressure difference judgment threshold group includes at least a first pressure difference threshold, a second pressure difference threshold, a first rate threshold, and a second rate threshold, wherein the first pressure difference threshold is less than the second pressure difference threshold, and the first rate threshold is lower than the second rate threshold. When the current value of the differential pressure of the purification unit is lower than the first differential pressure threshold and the rate of change of the differential pressure of the purification unit is lower than the first rate threshold, the pollution risk level is determined to be low pollution level. When the current value of the differential pressure of the purification unit is higher than the second differential pressure threshold or the rate of change of the differential pressure of the purification unit is higher than the second rate threshold, the pollution risk level is determined to be a high pollution level. When the current value of the differential pressure of the purification unit is between the first differential pressure threshold and the second differential pressure threshold, the rate of change of the differential pressure of the purification unit is compared with the first rate threshold. If the rate of change of the differential pressure of the purification unit is lower than the first rate threshold, the pollution risk level is determined to be low pollution level; otherwise, the pollution risk level is determined to be high pollution level.

[0038] To improve the accuracy and adaptability of pollution risk assessment, this method determines the flow range to which the discharge flow belongs based on the current discharge flow rate. This is because the pressure difference change of the purification unit is closely related to the flow rate passing through it; the same degree of pollution may exhibit different pressure difference values ​​at different flow rates. The system presets multiple flow ranges, such as low flow, medium flow, and high flow ranges, each corresponding to a specific set of pressure difference judgment thresholds. This set of pressure difference judgment thresholds includes at least a first pressure difference threshold, a second pressure difference threshold, a first rate threshold, and a second rate threshold. The first pressure difference threshold is typically set as the upper limit of the pressure difference under normal operation or slight pollution conditions, while the second pressure difference threshold represents the critical pressure difference value for severe pollution or requiring immediate intervention, and the first pressure difference threshold is lower than the second pressure difference threshold. Similarly, the first rate threshold is used to define the normal fluctuation range of the pressure difference change rate, while the second rate threshold indicates the critical point where the pressure difference is rapidly increasing, and the first rate threshold is lower than the second rate threshold. These thresholds can be set through historical operating data analysis, experimental calibration, or expert experience, and can be optimized and adjusted according to actual operating conditions. After obtaining the current value and rate of change of the differential pressure of the purification unit, and selecting the corresponding threshold group, the system will determine the pollution risk level. When the current value of the differential pressure of the purification unit is lower than the first differential pressure threshold, and the rate of change of the differential pressure is lower than the first rate threshold, it indicates that the purification unit is operating well and the pollution level is slight; in this case, the pollution risk level is determined to be low pollution level. When the current value of the differential pressure of the purification unit is higher than the second differential pressure threshold, or the rate of change of the differential pressure is higher than the second rate threshold, it indicates that the purification unit is severely blocked or the pollution is rapidly worsening; in this case, the pollution risk level is determined to be high pollution level. For cases where the current value of the differential pressure of the purification unit is between the first and second differential pressure thresholds, the system will further compare the rate of change of the differential pressure with the first rate threshold. If the rate of change is lower than the first rate threshold, the pollution trend is considered controllable, and it is still determined to be low pollution level; conversely, if the rate of change is higher than or equal to the first rate threshold, it indicates that the pollution is worsening, and it is determined to be high pollution level. It should be noted that the discharge level and routing instructions are generated based on the dominant phase type and the pollution risk level, including: Obtain the dominant phase type and pollution risk level, and input the dominant phase type and pollution risk level into a pre-configured set of hierarchical routing rules; When the pollution risk level is high pollution level, the release level is determined to be isolation and purification level, and a routing instruction is generated to introduce the release medium in the buffer flash container into the isolation recovery tank, and to perform jet pressurization and condensation recovery treatment on the recovery medium output from the isolation recovery tank after purification by the purification unit. When the pollution risk level is low, the release level is determined to be low pollution recovery level, and routing instructions are generated for performing particle filtration and coalescence demisting treatment on the liquid phase in the buffer flash container and then recovering it to the recovery storage tank through the liquid phase recovery component; performing cyclone separation and condensation recovery treatment on the gas phase in the buffer flash container; and performing condensation recovery treatment on the uncondensed tail gas remaining after condensation recovery by using the injection pressurization component to draw it in and then perform injection pressurization treatment again.

[0039] Specifically, when the system determines the pollution risk level to be high, it will set the release level to an isolation and purification level. In this case, the system will generate corresponding routing instructions to guide the released medium from the buffer flash container into the isolation recovery tank. After receiving the medium, the recovered medium output from the isolation recovery tank will undergo deep purification treatment in a purification unit, such as removing contaminants through adsorption and distillation. Subsequently, it will undergo jet pressurization and condensation recovery treatment to ensure that the highly polluting medium is thoroughly treated and recovered. On the other hand, when the system determines the pollution risk level to be low, it will set the release level to a low-pollution recovery level. In this case, the system will generate a more refined set of routing instructions aimed at maximizing recovery efficiency. The instructions include: performing particle filtration and coalescence demisting treatment on the liquid phase medium in the buffer flash container to remove solid impurities and tiny droplets, and then recovering it to the recovery storage tank via the liquid phase recovery component; performing cyclone separation and condensation recovery treatment on the gas phase medium in the buffer flash container in sequence, and incorporating the obtained condensate into the liquid phase recovery component; for the uncondensed tail gas remaining after condensation recovery, in order to further improve the recovery rate, the jet pressurization component is used for suction and jet pressurization, and then condensation recovery treatment is performed again, and the obtained condensate is also incorporated into the liquid phase recovery component.

[0040] Example 2 It should be noted that after introducing the venting medium into the buffer flash container, the method also includes: The back pressure regulating component is controlled to maintain the inlet pressure of the buffer flash container within the target back pressure range.

[0041] Specifically, the back pressure regulating component is a device used to precisely control the pressure of a fluid system. Its implementation can take various forms. For example, it can be a self-operated back pressure valve that automatically adjusts its opening to maintain a set pressure by sensing upstream pressure; or it can be a closed-loop control system consisting of a pressure sensor, a controller, and an electric regulating valve. The pressure sensor monitors the inlet pressure of the buffer flash container in real time and feeds the signal back to the controller. The controller calculates the required valve opening based on a preset back pressure target range and drives the electric regulating valve for precise adjustment. In this way, the back pressure regulating component can dynamically respond to changes in the flow and pressure of the discharged medium, ensuring the stability of the inlet pressure of the buffer flash container. The buffer flash container is the first critical processing unit after the discharged medium enters the recovery system, and the stability of its inlet pressure is crucial for the subsequent flash separation efficiency. Maintaining the inlet pressure within the preset back pressure target range aims to provide an optimized flash environment for the discharged medium. The target back pressure range is typically determined based on the physical properties of carbon dioxide, system design parameters, and the desired flash evaporation effect. This ensures that the medium undergoes controllable and efficient flash evaporation within the container, promoting effective separation of the liquid and gas phases and preventing droplet entrainment or excessive flash evaporation due to pressure fluctuations. This provides stable operating conditions for subsequent processing steps such as liquid-phase particle filtration, coalescence demisting, gas-phase cyclone separation, and condensation recovery. Furthermore, the method also includes: The back pressure target range is determined based on the dominant phase type, and the back pressure target range is corrected based on the liquid level and its changes in the buffer flash container within the preset sampling period. When the dominant phase type is two-phase and the fluctuation range of the liquid level in the buffer flash container exceeds the preset liquid level fluctuation threshold, the back pressure target range is increased or the discharge flow is limited to keep the flash generation position within the buffer flash container and reduce the risk of two-phase formation in the pipeline.

[0042] Through the above technical solution, this application can dynamically set the back pressure target range according to the dominant phase type of the released medium, and perform real-time correction in conjunction with the liquid level and its changes in the buffer flash container, thereby achieving precise control of the flash process. Especially when two phases dominate and the liquid level fluctuates violently, by increasing the back pressure target range or limiting the release flow rate, the intensity of flashing is effectively suppressed, ensuring that the flash process occurs stably inside the buffer flash container, preventing premature flashing in the pipeline, and significantly reducing the risk of two-phase formation in the pipeline. This not only improves the safety and operational stability of the release and recovery system, but also avoids problems such as equipment damage, measurement inaccuracies, and decreased system efficiency caused by pipeline flashing, thereby optimizing the release and recovery performance of the liquid carbon dioxide energy storage system.

[0043] Example 3 It should be noted that the driving flow of the injection booster assembly is provided by the high-pressure branch medium of the buffer flash container, and the driving flow intensity is adjusted by the driving flow adjustment assembly. The driving flow intensity is determined based on the phase dominance type and the discharge flow rate. When the phase dominance type is gas-phase or two-phase, the driving flow intensity is increased or the working time of the injection booster component is extended to improve the suction capacity of uncondensed exhaust gas.

[0044] Specifically, a jet booster assembly is a device that utilizes the momentum transfer of a high-speed fluid (driving flow) to draw in a low-pressure fluid (the drawn-in fluid, i.e., uncondensed exhaust gas) and pressurize it. In this embodiment, the driving flow does not originate from an external, independent high-pressure source, but is directly drawn from the system's internal buffer flash container. After receiving the venting medium, the buffer flash container maintains a certain pressure inside. This high-pressure medium (which can be gaseous or liquid carbon dioxide) is led out through a specially designed high-pressure branch as the driving flow for the jet booster assembly. This design fully utilizes the system's own energy, avoids the configuration of an additional high-pressure source, thereby simplifying the system structure and reducing operating costs. The driving flow regulating component is configured between the high-pressure branch of the buffer flash container and the driving flow inlet of the jet booster assembly. Its main function is to precisely control the flow rate or pressure of the driving flow entering the jet booster assembly. This component can be an electrically operated regulating valve, a pneumatic regulating valve, or a similar flow / pressure control device. By adjusting the opening or setpoint of this regulating component, the intensity of the driving flow can be steplessly or progressively adjusted, thereby changing the suction capacity and pressurization effect of the injection booster assembly to adapt to different operating conditions. The driving flow intensity is not fixed but dynamically adjusted based on the phase dominance type and discharge flow rate monitored in real time by the system. The system controller receives real-time data from the phase dominance type determination module and the discharge flow rate measurement module, and calculates the optimal driving flow intensity required for the current operating condition based on preset control logic, algorithms, or lookup tables. This intelligent adjustment mechanism ensures that the injection booster assembly always operates at optimal efficiency, avoiding insufficient suction or energy waste due to driving flow intensity mismatch. When the system determines that the phase dominance type of the discharge medium is gas-dominant or two-phase dominant, it usually means that the uncondensed exhaust gas may contain a large amount of gaseous components, or that stronger suction is needed for effective processing. In this case, the controller will instruct the driving flow regulating component to increase the flow rate or pressure of the driving flow, thereby improving the suction capacity of the injection booster assembly. Furthermore, if the injection booster unit supports intermittent operation, its operating duration can be extended to increase the total amount of uncondensed exhaust gas drawn in. By combining or applying these two methods individually, the efficiency of drawing in uncondensed exhaust gas remaining after condensation recovery can be significantly improved, ensuring that it is effectively pressurized and reintroduced into the condensation recovery process, thereby maximizing the carbon dioxide recovery rate.

[0045] Example 4 Before connecting the isolated recovery tank and the recovery storage tank, the method also includes: Continuously monitor the pressure difference and its changes in the purification unit; When the pressure difference of the purification unit is continuously within the preset range of the combined tank pressure difference and the rate of change of the pressure difference of the purification unit is lower than the preset rate of change of the pressure difference threshold, a combined tank allow command is output. Under the command to allow tank merging, the pressure equalization connection channel is first opened to gradually equalize the pressure of the isolation recovery tank and the recovery storage tank until the pressure difference between the two is lower than the preset pressure difference threshold. Then, the tank merging connection channel is opened to complete the tank merging.

[0046] This application introduces a more refined safety and quality control mechanism before connecting the isolation recovery tank and the recovery storage tank. By continuously monitoring the pressure difference and its rate of change in the purification unit, the stability and reliability of the purification effect can be dynamically assessed, effectively avoiding tank connection when purification is incomplete or when the purification unit has potential faults, thereby ensuring the purity of the recovered medium. Furthermore, the step-by-step operation of equalizing pressure before tank connection effectively avoids safety risks such as system shock, equipment damage, or medium splashing caused by excessive instantaneous pressure differences between the two tanks, ensuring the smoothness and safety of the tank connection process. This controlled tank connection strategy not only improves the quality of liquid carbon dioxide recovery but also significantly enhances the operational reliability and safety of the entire energy storage system.

[0047] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0048] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0049] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0050] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0051] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0052] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0053] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for staged release and recovery of liquid carbon dioxide energy storage systems, characterized in that, include: After receiving the discharge trigger signal, the discharge medium is introduced into the buffer flash container through the discharge access manifold, and the upstream pressure of the discharge access manifold, the temperature of the discharge medium, the discharge flow rate, the liquid level and its change in the buffer flash container, and the pressure difference of the purification unit are obtained within the preset sampling period after the trigger. The phase state of the venting medium is determined based on the upstream pressure and the temperature of the venting medium, and the dominant phase type is determined by combining the liquid level change in the buffer flash evaporation container with the venting flow rate. The pollution risk level is determined based on the pressure difference of the purification unit. Based on the dominant phase type and the pollution risk level, a release level and routing instructions are generated, wherein the release level includes at least a low pollution recovery level and an isolation and purification level; When the venting level is a low-pollution recovery level, the liquid phase in the buffer flash container is subjected to particle filtration and coalescence demisting treatment according to the routing instructions, and then recovered to the recovery storage tank via the liquid phase recovery component; the gas phase in the buffer flash container is subjected to cyclone separation and condensation recovery treatment in sequence, and the obtained condensate is incorporated into the liquid phase recovery component; the uncondensed tail gas remaining after condensation recovery is sucked up and pressurized by the injection booster component, and then subjected to condensation recovery treatment again, and the obtained condensate is incorporated into the liquid phase recovery component; When the venting level is the isolation and purification level, the venting medium in the buffer flash container is introduced into the isolation and recovery tank according to the routing instructions. After purification by the purification unit, it is subjected to jet pressurization and condensation recovery treatment. When the pressure difference of the purification unit is within the preset tank-to-tank pressure difference range, the isolation and recovery tank and the recovery storage tank are connected and connected.

2. The method according to claim 1, characterized in that, Determining the phase state of the venting medium based on the upstream pressure and the temperature of the venting medium includes: The pre-stored relationship between carbon dioxide pressure and saturation temperature is invoked to determine the corresponding saturation temperature value for the upstream pressure. Compare the temperature of the venting medium with the corresponding value of the saturation temperature; When the temperature of the discharge medium is higher than the corresponding value of the saturation temperature and exceeds the preset temperature tolerance range, the phase state is determined to be a gas phase state. When the temperature of the discharge medium is lower than the corresponding value of the saturation temperature and exceeds the preset temperature tolerance range, the phase state is determined to be a liquid phase state. When the temperature of the venting medium falls within the preset temperature tolerance range, the phase state is determined to be a two-phase state.

3. The method according to claim 2, characterized in that, The method further includes: The state of the two phases is verified based on the liquid level and its changes in the buffer flash container. When the liquid level in the buffer flash container continues to rise and the rise exceeds the preset liquid level change threshold, the two-phase state is maintained or corrected to a liquid phase state. When the liquid level in the buffer flash container remains stable or continues to decrease, the two-phase state is maintained or corrected to a gas phase state.

4. The method according to claim 1, characterized in that, Determining the dominant phase type by combining the liquid level and its changes in the buffer flash container with the discharge flow rate includes: The liquid level data of the buffer flash evaporation container at multiple moments is acquired within the preset sampling period, and the direction of liquid level change and cumulative change amplitude are determined based on the liquid level difference between adjacent moments. At the same time, the discharge flow rate and its change within the preset sampling period are also acquired. When the liquid level rises continuously within a preset duration and the cumulative rise exceeds the first liquid level change threshold, and the discharge flow rate is not lower than the first flow rate threshold, the phase dominance type is determined to be the liquid phase dominance type. When the liquid level remains stable or continuously decreases within a preset duration, and the discharge flow rate is not lower than the second flow rate threshold, the phase dominance type is determined to be the gas phase dominance type. When the liquid level fluctuates alternately between rising and falling during the preset sampling period and the fluctuation amplitude exceeds the second liquid level change threshold, and the fluctuation amplitude of the discharge flow exceeds the preset flow fluctuation threshold, the phase dominance type is determined to be a two-phase dominance type.

5. The method according to claim 1, characterized in that, Determining the pollution risk level based on the pressure difference of the purification unit includes: The pressure difference of the purification unit at multiple moments is acquired within the preset sampling period, and the current value of the pressure difference of the purification unit and the rate of change of the pressure difference of the purification unit determined based on the pressure difference value between adjacent moments are determined. The flow range to which the discharge flow belongs is determined based on the discharge flow, and a pressure difference judgment threshold group corresponding to the flow range is selected. The pressure difference judgment threshold group includes at least a first pressure difference threshold, a second pressure difference threshold, a first rate threshold and a second rate threshold, wherein the first pressure difference threshold is less than the second pressure difference threshold and the first rate threshold is lower than the second rate threshold. When the current value of the differential pressure of the purification unit is lower than the first differential pressure threshold and the rate of change of the differential pressure of the purification unit is lower than the first rate threshold, the pollution risk level is determined to be a low pollution level. When the current value of the differential pressure of the purification unit is higher than the second differential pressure threshold or the rate of change of the differential pressure of the purification unit is higher than the second rate threshold, the pollution risk level is determined to be a high pollution level. When the current value of the pressure difference of the purification unit is between the first pressure difference threshold and the second pressure difference threshold, the pressure difference change rate of the purification unit is compared with the first rate threshold. If the pressure difference change rate of the purification unit is lower than the first rate threshold, the pollution risk level is determined to be a low pollution level; otherwise, the pollution risk level is determined to be a high pollution level.

6. The method according to claim 5, characterized in that, Based on the dominant phase type and the pollution risk level, a release level and routing instructions are generated, including: Obtain the dominant phase type and the pollution risk level, and input the dominant phase type and the pollution risk level into a pre-configured hierarchical routing rule set; When the pollution risk level is high pollution level, the release level is determined to be isolation and purification level, and a routing instruction is generated for introducing the release medium in the buffer flash container into the isolation recovery tank, and for the recovery medium output from the isolation recovery tank to be purified by the purification unit and then subjected to jet pressurization and condensation recovery treatment. When the pollution risk level is low pollution level, the release level is determined to be low pollution recovery level, and routing instructions are generated for performing particle filtration and coalescence demisting treatment on the liquid phase in the buffer flash container and then recovering it to the recovery storage tank through the liquid phase recovery component; performing cyclone separation and condensation recovery treatment on the gas phase in the buffer flash container; and using the injection pressurization component to draw in the uncondensed tail gas remaining after condensation recovery and then performing condensation recovery treatment again.

7. The method according to claim 1, characterized in that, After introducing the venting medium into the buffer flash evaporation vessel, the method further includes: The back pressure regulating component is controlled to maintain the inlet pressure of the buffer flash container within the target back pressure range.

8. The method according to claim 1, characterized in that, The method further includes: The back pressure target range is determined based on the dominant phase type, and the back pressure target range is corrected based on the liquid level and its change in the buffer flash container during the preset sampling period. When the dominant phase type is two-phase and the fluctuation range of the liquid level in the buffer flash container exceeds the preset liquid level fluctuation threshold, the back pressure target range is increased or the discharge flow is limited so that the flash generation position is maintained in the buffer flash container and the risk of two-phase formation in the pipeline is reduced.

9. The method according to claim 1, characterized in that, The driving flow of the injection pressurization component is provided by the high-pressure branch medium of the buffer flash container, and the driving flow intensity is adjusted by the driving flow adjustment component. The driving flow intensity is determined based on the phase dominance type and the discharge flow rate. When the phase dominance type is a gas phase dominance type or a two-phase dominance type, the driving flow intensity is increased or the working time of the injection booster component is extended to improve the suction capacity of the uncondensed exhaust gas.

10. The method according to claim 1, characterized in that, Before connecting the isolation recovery tank and the recovery storage tank, the method further includes: Continuously monitor the pressure difference and its changes in the purification unit; When the pressure difference of the purification unit is continuously within the preset range of the combined tank pressure difference and the rate of change of the pressure difference of the purification unit is lower than the preset rate of change of the pressure difference threshold, a combined tank allow command is output. Under the command to allow tank merging, the pressure equalization connection channel is first opened to gradually equalize the pressure of the isolation recovery tank and the pressure of the recovery storage tank until the pressure difference between the two is lower than the preset pressure difference threshold. Then, the tank merging connection channel is opened to complete the tank merging.

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