Rapid and accurate filling device and method for liquid carbon dioxide

Abstract

The invention discloses a device and a method for quickly and accurately filling liquid carbon dioxide, an absolute pressure storage tank leads to a filling container through a pneumatic pressurizing module, and an initial parameter sensor unit for collecting initial pressure and temperature is arranged on an initial pipeline between the absolute pressure storage tank and the pneumatic pressurizing module; an output parameter sensor unit is arranged on an output pipeline between the pneumatic pressurizing module and the filling container, and the output pipeline is arranged in an air conditioning unit and connected with a pneumatic control stop valve; the initial parameter sensor unit, the first electromagnetic valve controlling the working state of the pneumatic pressurization module, the air conditioner unit, the output parameter sensor unit, the second electromagnetic valve controlling the pneumatic control stop valve and the precision electronic scale used for weighing the filling container are connected with the same control unit to form a closed loop feedback system. Real-time monitoring and dynamic regulation and control of parameters such as pressure, temperature, flow and quality in the filling process are achieved, the filling safety and stability are both considered, and the filling precision is high.

Description

Technical Field

[0001] This invention belongs to the field of liquid carbon dioxide filling technology, specifically relating to a rapid and accurate liquid carbon dioxide filling device and method. Background Technology

[0002] Liquid carbon dioxide, with its unique properties such as phase change heat absorption and expansion work that can drive rapid load movement, occupies an indispensable position in modern industry and people's lives, especially in food refrigeration, welding protection, chemical synthesis, fire fighting, and mining blasting. In these applications, liquid carbon dioxide is usually the core working medium, and its filling quality and efficiency directly determine the stability, safety, and economy of subsequent processes. Therefore, precise filling preparation of liquid carbon dioxide using specialized filling equipment is necessary before operation, which is a key prerequisite for ensuring the smooth progress of the entire production and operation process.

[0003] However, liquid carbon dioxide exhibits extremely poor phase stability, with its phase transitions being highly sensitive to temperature and pressure conditions. Under different temperature and pressure combinations, it dynamically switches between solid, gaseous, and liquid phases. This characteristic presents a severe technical challenge to the liquid carbon dioxide filling process—temperature and pressure must be strictly controlled within specific ranges to ensure that it is filled in a stable liquid form. If the temperature and pressure control is unbalanced, when the system is in a low-temperature, high-pressure environment, liquid carbon dioxide easily condenses into solid dry ice, directly causing blockage in the filling pipeline; conversely, when the temperature rises or the pressure drops sharply, liquid carbon dioxide will rapidly vaporize, leading to a sharp increase in system pressure. Both situations will cause the filling operation to be interrupted, severely impacting production efficiency.

[0004] Current mainstream liquid carbon dioxide filling technologies generally suffer from insufficient temperature and pressure control precision, a core deficiency that triggers a series of chain reactions. In actual filling operations, traditional devices cannot adapt to the dynamic changes in temperature and pressure during the filling process in real time, often resulting in freezing and blockage of the filling pipeline, forcing frequent interruptions in filling operations. This not only reduces work efficiency but also increases the cost of equipment cleaning and maintenance. More critically, when using traditional devices to fill containers at room temperature, the temperature difference between the container and the liquid carbon dioxide causes a large amount of liquid carbon dioxide to rapidly vaporize in a short period of time. This causes the internal pressure of the container to rise rapidly and exceed the output pressure of the filling system, ultimately forcing the filling operation to stop, further exacerbating the problem of low filling efficiency.

[0005] Besides issues with filling stability and efficiency, traditional filling technology suffers from a fatal flaw: low precision in filling quality control. Because it cannot accurately measure the mass and control the phase of liquid carbon dioxide during the filling process, there is a significant deviation between the actual filling volume and the preset value. This deviation is particularly problematic in scenarios with stringent energy control requirements—for example, in mining blasting and high-pressure catapults, the amount of liquid carbon dioxide filled directly determines the energy required for its expansion; inaccurate filling can lead to insufficient or excessive blasting or catapult power, causing safety hazards. In chemical synthesis, deviations in raw material dosage can affect product purity and yield, resulting in economic losses.

[0006] In summary, existing liquid carbon dioxide filling technologies generally suffer from problems such as slow filling speed, low operating efficiency, poor filling accuracy, and susceptibility to pipeline blockage and pressure runaway. These problems severely restrict the promotion and in-depth application of liquid carbon dioxide in various fields and fail to meet the high-quality requirements of modern industry for filling operations in terms of safety, stability, and accuracy. Therefore, developing a filling device and method that can achieve rapid and accurate liquid carbon dioxide filling while effectively solving the phase runaway problem has become a pressing technological bottleneck in this field. Summary of the Invention

[0007] To address the shortcomings in the aforementioned background technology, this invention proposes a rapid and accurate liquid carbon dioxide filling device and method. The technical problem to be solved is: how to balance the high-quality requirements of safety, stability, and accuracy in liquid carbon dioxide filling operations.

[0008] The technical solution of this invention is as follows: A rapid and precise liquid carbon dioxide filling device comprises an absolute pressure storage tank connected to a filling container via a pneumatic booster module. An initial parameter sensor unit for collecting initial pressure and temperature is installed on the initial pipeline between the absolute pressure storage tank and the pneumatic booster module. An output parameter sensor unit for collecting output pressure, temperature, mass flow rate, and density is installed on the output pipeline between the pneumatic booster module and the filling container. The output pipeline is located within an air conditioning unit and is connected to a pneumatically controlled shut-off valve. The initial parameter sensor unit, a solenoid valve 1 controlling the operation of the pneumatic booster module, the air conditioning unit, the output parameter sensor unit, the solenoid valve 2 controlling the pneumatically controlled shut-off valve, and a precision electronic scale for weighing the filling container are all connected to the same control unit to form a closed-loop feedback system.

[0009] The beneficial effects of this technical solution are as follows: By installing multi-parameter sensors in the initial and output pipelines, and combining them with the air conditioning unit, pneumatic shut-off valve, and precision electronic scale and control unit to form a closed-loop feedback, real-time monitoring and dynamic control of parameters such as pressure, temperature, flow rate, and mass are achieved during the filling process. It can adapt to dynamic changes in the temperature and pressure of liquid carbon dioxide in real time, avoiding phase runaway leading to icing blockage or vaporization overpressure, thus ensuring both filling safety and stability; at the same time, dual measurement through mass flow rate and weighing improves filling accuracy.

[0010] Based on the above technical solutions, as a preferred technical solution for the liquid carbon dioxide rapid and accurate filling device, the initial parameter sensor unit includes a temperature sensor and a pressure sensor, and the output parameter sensor unit includes a mass flow meter, a temperature sensor, and a pressure sensor.

[0011] Based on the above technical solutions, as a preferred technical solution for the liquid carbon dioxide rapid and accurate filling device, the output end of the pneumatic control shut-off valve is connected to a pneumatic control pressure relief valve and a pressure sensor three. The solenoid valve three controlling the pneumatic control pressure relief valve and the pressure sensor three are both connected to the control unit.

[0012] Based on the above technical solutions, as a preferred technical solution for the liquid carbon dioxide rapid and accurate filling device, a filter is installed in front of the initial parameter sensor unit on the initial pipeline, and a safety valve is installed on the output pipeline.

[0013] Based on the above technical solutions, as a preferred technical solution for the liquid carbon dioxide rapid and accurate filling device, the pneumatic booster module, the pneumatic shut-off valve, and the pneumatic pressure relief valve are connected in parallel on the same driving air supply unit, and the pneumatic pressure pipeline of the driving air supply unit is equipped with a manual pressure regulating valve and a solenoid valve connected to the control unit.

[0014] Based on the above technical solutions, as a preferred technical solution for the liquid carbon dioxide rapid and accurate filling device, the control unit includes a central processing unit and an analog input module connected to each sensor. The central processing unit is connected to solenoid valve one, air conditioning unit, solenoid valve two, solenoid valve three, precision electronic scale, and mass flow meter.

[0015] Based on the above technical solutions, as a preferred technical solution for the liquid carbon dioxide rapid and accurate filling device, the central processing unit is connected to the human-machine interface, the host computer, and the reserved network interface through a switch.

[0016] Based on the above technical solutions, as a preferred technical solution for the liquid carbon dioxide rapid and accurate filling device, the absolute pressure storage tank is a Dewar flask, which is equipped with a pressure reducing valve and a liquid level sensor connected to the control unit.

[0017] Based on the above technical solutions, as a preferred technical solution for the liquid carbon dioxide rapid and accurate filling device, all carbon dioxide pipelines are equipped with insulation layers, the absolute pressure storage tank is connected to a quick connector one for connecting the initial pipeline, and the output pipeline is connected to a quick connector two for connecting the filling container.

[0018] A rapid and precise liquid carbon dioxide filling method employs the aforementioned rapid and precise liquid carbon dioxide filling device. Before filling each filling container, air is vented through a pneumatically controlled pressure relief valve to remove the original air and some of the carbon dioxide that has undergone flash evaporation phase change. After connecting the pipeline, the equipment begins operation, first cooling the entire system by opening the pneumatically controlled pressure relief valve at the end of the system to release air. The vaporization process of the liquid carbon dioxide removes a large amount of heat, allowing the system temperature to be controlled to approximately -20°C. Pressure, temperature, mass flow rate, and density parameters are monitored in real time and transmitted to the control unit. The control unit dynamically corrects the operating parameters of the pneumatic booster module and the air conditioning unit based on the deviation between the set parameters and the measured parameters using an algorithm.

[0019] The beneficial effects of this technical solution are as follows: before filling, the air is vented through the pneumatic pressure relief valve, which can remove air and flash carbon dioxide from the container and reduce vaporization interference caused by the initial temperature difference; the system is cooled to about -20℃, close to the stable temperature of liquid carbon dioxide, creating a stable temperature environment for filling; combined with real-time parameter dynamic correction of the parameters of the pressurization module and the air conditioning unit, it can adapt to the nonlinear changes in temperature and pressure during the filling process, achieving rapid filling (more than 30% faster than traditional devices) while ensuring accuracy (error ≤ ±0.5%).

[0020] The liquid carbon dioxide rapid and accurate filling device and method of the present invention, through the collaborative design of "real-time monitoring of multiple parameters - closed-loop dynamic control - multiple safety protections", solves the problems of phase loss (icing blockage, vaporization overpressure), slow filling speed, low accuracy and poor safety in traditional filling technology. The overall beneficial effects are as follows: Significantly enhanced safety: Multiple protections, including pneumatic pressure relief valves, safety valves, and pressure sensors, combined with closed-loop control for real-time pressure regulation, effectively prevent overpressure risks; filters prevent pipeline blockage, and Dewar flasks and insulation layers reduce phase transitions, lowering the probability of equipment damage and safety accidents.

[0021] Significantly enhanced stability: The air conditioning unit provides precise temperature control, and the pneumatic booster module provides stable pressure regulation. Combined with real-time monitoring by the initial / output temperature and pressure sensors, the liquid carbon dioxide phase can be stabilized within a preset range (temperature -20℃±5℃, pressure 2.0-6.0MPa), avoiding filling interruptions caused by phase transitions.

[0022] Balancing accuracy and efficiency: Dual metering with mass flow meter and precision electronic scale, combined with dynamic parameter correction algorithm, allows filling error to be controlled within ±0.5%; quick connectors shorten auxiliary time, system pre-cooling reduces vaporization interference, and filling speed is increased by more than 30% compared with traditional devices, meeting the needs of mass production.

[0023] Excellent intelligence and scalability: The human-machine interface and host computer enable visual operation and data traceability, and reserved interfaces support intelligent upgrades; the modular design (such as the drive air unit and sensor unit) facilitates maintenance and functional expansion, and adapts to the needs of multiple scenarios such as food refrigeration and mining blasting. Attached Figure Description

[0024] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a control principle diagram of the present invention.

[0026] Explanation of reference numerals in the attached figures: Absolute pressure storage tank 1, initial pipeline 1-2, pneumatic booster module 2, solenoid valve 1 2-0, air filter 2-1, output pipeline 2-3, filling container 3, air conditioning unit 4, pneumatic shut-off valve 5, solenoid valve 2 5-0, precision electronic scale 6, pneumatic pipeline 7, manual pressure regulating valve 701; Filter 100, Temperature sensor 101, Pressure sensor 102, Quick connector 103, Quick connector 2 301; Mass flow meter 200, temperature sensor 201, pressure sensor 202, pneumatic pressure relief valve 203, solenoid valve 3 203-0, pressure sensor 3 204, safety valve 205. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the core concept of the present invention and the following embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] These embodiments are provided to make the application thorough and complete, and to fully express the scope of the application to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions and values ​​illustrated in these embodiments should be interpreted as merely exemplary and not as limiting.

[0029] It should be noted that, in the description of this application, unless otherwise stated, "several" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "axial," "radial," etc., indicating orientation or positional relationships are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0030] Furthermore, the terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well.

[0031] It should also be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0032] All terms used in this application have the same meaning as understood by one of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0033] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0034] A rapid and precise liquid carbon dioxide filling device, such as Figure 1 and Figure 2 As shown, the absolute pressure storage tank 1 is connected to the filling container 3 through the pneumatic booster module 2. The initial parameter sensor unit for collecting initial pressure and temperature is installed on the initial pipeline 1-2 between the absolute pressure storage tank 1 and the pneumatic booster module 2. The output parameter sensor unit for collecting output pressure, temperature, mass flow rate and density is installed on the output pipeline 2-3 between the pneumatic booster module 2 and the filling container 3. The output pipeline 2-3 is located in the air conditioning unit 4 and is connected to the pneumatic control shut-off valve 5. The initial parameter sensor unit, the solenoid valve 2-0 that controls the working state of the pneumatic booster module 2, the air conditioning unit 4, the output parameter sensor unit, the solenoid valve 5-0 that controls the pneumatic control shut-off valve 5, and the precision electronic scale 6 for weighing the filling container 3 are all connected to the same control unit to form a closed-loop feedback system.

[0035] The beneficial effects of this implementation are as follows: By installing multi-parameter sensors in the initial and output pipelines, and combining them with the air conditioning unit, pneumatic shut-off valve, and precision electronic scale and control unit to form a closed-loop feedback, real-time monitoring and dynamic control of parameters such as pressure, temperature, flow rate, and mass are achieved during the filling process. It can adapt to dynamic changes in the temperature and pressure of liquid carbon dioxide in real time, avoiding phase runaway leading to icing blockage or vaporization overpressure, thus ensuring both filling safety and stability; at the same time, dual measurement of mass flow rate and weighing improves filling accuracy.

[0036] Based on the above embodiments, as a preferred embodiment of the liquid carbon dioxide rapid and accurate filling device, the initial parameter sensor unit includes a temperature sensor 101 and a pressure sensor 102, and the output parameter sensor unit includes a mass flow meter 200, a second temperature sensor 201, and a second pressure sensor 202.

[0037] Further beneficial effects of this implementation: Temperature sensor 1 and pressure sensor 1 in the initial pipeline can capture the initial temperature and pressure status output from the absolute pressure storage tank in real time, providing a benchmark for subsequent pressurization control; the mass flow meter in the output pipeline directly measures the instantaneous and cumulative mass of liquid carbon dioxide, and combined with temperature sensor 2 and pressure sensor 2 to monitor the temperature and pressure at the output end in real time, realizes "temperature, pressure and flow" linkage analysis, provides multi-dimensional data support for phase judgment and accurate measurement, and solves the problems of single measurement and insufficient accuracy of traditional devices.

[0038] Based on the above embodiments, as a preferred embodiment of the liquid carbon dioxide rapid and accurate filling device, the output end of the pneumatic shut-off valve 5 is connected to a pneumatic pressure relief valve 203 and a pressure sensor 204. The solenoid valve 203-0 controlling the pneumatic pressure relief valve 203 and the pressure sensor 204 are both connected to the control unit.

[0039] Further beneficial effects of this implementation: The addition of a pneumatic pressure relief valve and pressure sensor three at the output end of the pneumatic shut-off valve can quickly discharge air and flash carbon dioxide from the filling container before filling, reducing vaporization interference caused by initial temperature difference; if the pressure inside the container exceeds the preset value during filling, pressure sensor three triggers the control unit to open the pneumatic pressure relief valve to release pressure, avoiding filling interruption or safety risks caused by pressure runaway, and further improving system safety.

[0040] Based on the above embodiments, as a preferred embodiment of the liquid carbon dioxide rapid and accurate filling device, a filter 100 is provided on the initial pipeline 1-2 in front of the initial parameter sensor unit, a safety valve 205 is provided on the output pipeline 2-3, and an air filter 2-1 is provided at the front end of the air supply pipeline of the pneumatic booster module 2.

[0041] Further beneficial effects of this implementation: The filter on the initial pipeline can intercept impurities in the output medium of the absolute pressure storage tank, such as dry ice particles and solid contaminants, to prevent blockage of subsequent pipelines or sensors and ensure smooth system operation; the safety valve on the output pipeline acts as a passive safety barrier, automatically releasing pressure when the system pressure exceeds the limit value, forming a double safety protection with the actively controlled pneumatic pressure relief valve, reducing the risk of equipment damage and safety accidents.

[0042] Based on the above embodiments, as a preferred embodiment of the liquid carbon dioxide rapid and accurate filling device, the pneumatic booster module 2, the pneumatic shut-off valve 5, and the pneumatic pressure relief valve 203 are connected in parallel on the same driving air supply unit, and the pneumatic pipeline 7 of the driving air supply unit is equipped with a manual pressure regulating valve 701 and a solenoid valve connected to the control unit.

[0043] Further beneficial effects of this implementation: the pneumatic booster module, pneumatic shut-off valve, and pneumatic pressure relief valve share the same drive air supply unit, simplifying the pipeline structure and reducing energy consumption; the manual pressure regulating valve can preset the drive air pressure reference, and the solenoid valve realizes automatic on / off and pressure regulation through the control unit, taking into account both manual emergency operation and automatic precise control, ensuring that pneumatic components, such as booster pumps and valves, respond quickly and operate reliably.

[0044] Based on the above embodiments, as a preferred embodiment of the liquid carbon dioxide rapid and accurate filling device, the control unit includes a central processing unit and an analog input module connected to each sensor. The analog input module is connected to each sensor, and the central processing unit is connected to solenoid valve 2-0, air conditioning unit 4, solenoid valve 5-0, solenoid valve 203-0, precision electronic scale 6, and mass flow meter 200.

[0045] Further beneficial effects of this implementation: The analog input module can efficiently acquire continuous signals from various sensors, such as temperature, pressure, and flow rate. The central processing unit analyzes the data in real time through algorithms, quickly generates control commands, and adjusts the output of the booster module, air conditioning temperature, and valve opening and closing, realizing a closed-loop response of "acquisition-analysis-control". The response speed is fast, solving the phase state loss of control problem caused by the lag in the control of traditional devices.

[0046] Based on the above embodiments, as a preferred embodiment of the liquid carbon dioxide rapid and accurate filling device, the central processing unit is connected to a human-machine interface, a host computer, and a reserved network interface via a switch.

[0047] Further benefits of this implementation include: the human-machine interface facilitates operators in setting parameters, monitoring real-time data, and receiving fault alarms, improving operational convenience; the host computer enables historical data storage, filling process traceability, and batch task management, meeting the information needs of industrial production; and the reserved network interface supports integration with MES systems and IoT platforms, providing expansion space for intelligent upgrades, such as remote monitoring and adaptive filling.

[0048] Based on the above embodiments, as a preferred embodiment of the liquid carbon dioxide rapid and accurate filling device, the absolute pressure storage tank 1 is a Dewar flask, which is equipped with a pressure reducing valve and a liquid level sensor connected to the control unit.

[0049] Further beneficial effects of this implementation: The Dewar flask has excellent thermal insulation properties, which can maintain the low temperature and high pressure state of liquid carbon dioxide in the tank for a long time, reducing the loss of natural vaporization; the pressure reducing valve can stably output the initial pressure, avoiding the impact of pressure fluctuations in the tank on filling stability; the liquid level sensor monitors the remaining amount in the tank in real time, promptly reminds you to replenish the material, prevents filling interruptions due to material shortage, and ensures continuous operation.

[0050] Based on the above embodiments, as a preferred embodiment of the liquid carbon dioxide rapid and accurate filling device, all carbon dioxide pipelines are provided with a heat insulation layer, the absolute pressure storage tank 1 is connected to a quick connector 103 for connecting the initial pipeline 1-2, and the output pipeline 2-3 is connected to a quick connector 301 for connecting the filling container 3.

[0051] Further beneficial effects of this implementation: The insulation layer covering the carbon dioxide pipeline can reduce heat exchange with the environment, reduce the probability of liquid carbon dioxide vaporization due to heat absorption, and maintain phase stability; the quick connector 1 between the absolute pressure storage tank and the initial pipeline, and the quick connector 2 between the output pipeline and the filling container enable quick connection / disconnection of the pipeline, shorten auxiliary operation time, and improve filling efficiency, which is especially suitable for continuous filling scenarios of batch containers.

[0052] A rapid and precise liquid carbon dioxide filling method is provided, employing the aforementioned rapid and precise liquid carbon dioxide filling device. Before filling each filling container 3, air is vented through the pneumatic pressure relief valve 203 to remove the original air and some of the carbon dioxide that has undergone flash evaporation phase change from the filling container 3. After connecting the pipeline, the equipment starts working, first cooling the entire system by opening the pneumatic pressure relief valve 203 at the end of the system to vent. The vaporization process of the liquid carbon dioxide removes a large amount of heat, allowing the system temperature to be controlled to around -20℃. Pressure, temperature, mass flow rate, and density parameters are monitored in real time and transmitted to the control unit. The control unit dynamically corrects the operating parameters of the pneumatic booster module 2 and the air conditioning unit 4 based on the deviation between the set parameters and the measured parameters using an algorithm.

[0053] Further beneficial effects of this implementation: Before filling, the air is vented through the pneumatic pressure relief valve, which can remove air and flash carbon dioxide from the container and reduce vaporization interference caused by the initial temperature difference; the system is cooled to about -20℃, close to the stable temperature of liquid carbon dioxide, creating a stable temperature environment for filling; combined with real-time parameter dynamic correction of the parameters of the pressurization module and the air conditioning unit, it can adapt to the nonlinear changes in temperature and pressure during the filling process, achieving rapid filling (more than 30% faster than traditional devices) while ensuring accuracy (error ≤ ±0.5%).

[0054] As a preferred embodiment of the liquid carbon dioxide rapid and accurate filling device, it mainly consists of a PLC controller, a touch screen, a pneumatic booster pump, various valves, filters, pressure sensors, temperature sensors, mass flow meters, a refrigeration box, as well as piping systems, connectors, and a housing.

[0055] This device allows users to set the filling quality via a human-machine interface, control the filling pressure of liquid carbon dioxide via a PLC controller and a gas-driven booster pump via a refrigeration chamber to maintain the ambient temperature of the liquid carbon dioxide, thus ensuring the liquid phase state of the carbon dioxide. At the same time, pressure and temperature sensors monitor the filling pressure and temperature data, and a mass flow meter and a precision electronic scale monitor the filling quality of liquid carbon dioxide in real time. A solenoid valve is used to release excess vaporized carbon dioxide, thereby ensuring rapid and accurate filling of liquid carbon dioxide.

[0056] Liquid carbon dioxide is typically stored in insulated tanks at low temperatures (-20°C to -30°C) and high pressures (approximately 2 MPa). The tanks are equipped with pressure-reducing valves and level sensors. The equipment is connected to the pressure-reducing tank (Dewar flask) via a hose. A filter is installed at the inlet to prevent impurities from entering. Temperature sensors, pressure sensors, and other components are installed on the pipeline to collect initial information from the storage flask and ensure a stable output of liquid carbon dioxide to the inlet of the gas-driven booster pump. The gas-driven booster pump uses compressed air (typically 0.4–0.8 MPa) as a power source to drive a piston or diaphragm within the pump, reciprocating to repressurize the liquid carbon dioxide. One-way valves are installed at the pump body's inlet and outlet. During the piston's return stroke, liquid carbon dioxide is drawn in; during the forward stroke, the inlet valve closes and the outlet valve opens, forcing the carbon dioxide into the output pipeline. The pressure can be increased to 5–20 MPa (adjustable as needed). Liquid carbon dioxide may absorb heat and vaporize during pressurization; therefore, the pipeline is equipped with a heat exchanger and insulation to maintain its low-temperature liquid state. Pressurized liquid carbon dioxide is injected into the target container (such as a gas cylinder or reaction vessel) through a high-pressure hose. The injection volume is monitored in real time by a flow meter, and the injection automatically stops when the set value is reached. To achieve precise filling and automation, components such as flow meters, pneumatic shut-off valves, temperature and pressure sensors are installed in the pipeline after the pump.

[0057] After the equipment starts operating and the pipelines are connected, the first step is to cool the entire system. This is done by opening the exhaust valve at the end of the system to release the vapors of the liquid carbon dioxide. The vaporization process removes a significant amount of heat, allowing the system temperature to be controlled to approximately -20°C. All pipelines should be designed for compact insulation to prevent flash evaporation of liquid carbon dioxide (a sudden pressure drop leading to vaporization). Additionally, venting is required before each new container is filled to remove existing air and some of the CO2 released during the flash phase change. The pressure control mechanism employs a closed-loop feedback system. Sensors are installed at the pump outlet or the target container to monitor the pressure signal in real time and transmit it to the PLC controller. The PLC controller dynamically adjusts the input of the driving air pressure based on the deviation between the set pressure and the measured pressure. Because the carbon dioxide phase change is pressure-sensitive (e.g., the saturation pressure at 20°C is approximately 5.7 MPa), the system requires an integrated temperature sensor and a cooling device. An algorithm is used to dynamically correct the pressure setpoint to prevent vaporization or overpressure.

[0058] During the process of adding liquid carbon dioxide using a pneumatic booster pump, the adding accuracy is controlled by a Coriolis mass flow meter. The core of this method is to achieve high-precision adding control by directly measuring the mass flow rate and density, combined with a closed-loop feedback system.

[0059] The device is equipped with safety protection measures. When the system pressure exceeds the safety threshold (such as 110% of the rated pressure), the pressure relief valve will automatically open to release excess carbon dioxide.

[0060] All aspects not detailed in this invention are conventional technical means known to those skilled in the art.

[0061] The above content shows and describes the basic principles, main features, and beneficial effects of the present invention. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rapid and precise liquid carbon dioxide filling device, characterized in that: The absolute pressure tank (1) is connected to the filling container (3) through the pneumatic booster module (2). The initial parameter sensor unit for collecting initial pressure and temperature is installed on the initial pipeline (1-2) between the absolute pressure tank (1) and the pneumatic booster module (2). The output parameter sensor unit for collecting output pressure, temperature, mass flow rate and density is installed on the output pipeline (2-3) between the pneumatic booster module (2) and the filling container (3). The output pipeline (2-3) is installed in the air conditioning unit (4). The output pipeline (2-3) is connected to the pneumatic shut-off valve (5). The initial parameter sensor unit, the solenoid valve one (2-0) that controls the working state of the pneumatic booster module (2), the air conditioning unit (4), the output parameter sensor unit, the solenoid valve two (5-0) that controls the pneumatic shut-off valve (5), and the precision electronic scale (6) used to weigh the filling container (3) are connected to the same control unit to form a closed-loop feedback system.

2. The liquid carbon dioxide rapid and precise filling device according to claim 1, characterized in that: The initial parameter sensor unit includes a temperature sensor (101) and a pressure sensor (102), and the output parameter sensor unit includes a mass flow meter (200), a temperature sensor (201), and a pressure sensor (202).

3. The rapid and precise liquid carbon dioxide filling device according to claim 2, characterized in that: The output end of the pneumatic shut-off valve (5) is connected to a pneumatic pressure relief valve (203) and a pressure sensor (204). The solenoid valve (203-0) and the pressure sensor (204) that control the pneumatic pressure relief valve (203) are both connected to the control unit.

4. The rapid and precise liquid carbon dioxide filling device according to claim 3, characterized in that: The initial pipeline (1-2) is equipped with a filter (100) located in front of the initial parameter sensor unit, and the output pipeline (2-3) is equipped with a safety valve (205).

5. The rapid and precise liquid carbon dioxide filling device according to claim 3 or 4, characterized in that: The pneumatic booster module (2), pneumatic shut-off valve (5), and pneumatic pressure relief valve (203) are connected in parallel to the same drive air supply unit. The pneumatic pipeline (7) of the drive air supply unit is equipped with a manual pressure regulating valve (701) and a solenoid valve connected to the control unit.

6. The rapid and precise liquid carbon dioxide filling device according to claim 5, characterized in that: The control unit includes a central processing unit and an analog input module connected to each sensor. The central processing unit is connected to solenoid valve 1 (2-0), air conditioning unit (4), solenoid valve 2 (5-0), solenoid valve 3 (203-0), precision electronic scale (6), and mass flow meter (200).

7. The rapid and precise liquid carbon dioxide filling device according to claim 6, characterized in that: The central processing unit is connected to the human-machine interface, the host computer, and the reserved network interface via a switch.

8. The rapid and precise liquid carbon dioxide filling device according to any one of claims 1-4 and 6-7, characterized in that: The absolute pressure storage tank (1) is a Dewar flask, which is equipped with a pressure reducing valve and a liquid level sensor connected to the control unit.

9. The rapid and precise liquid carbon dioxide filling device and method according to claim 8, characterized in that: All carbon dioxide pipelines are equipped with insulation layers. The pressure tank (1) is connected to a quick connector one (103) for connecting the initial pipeline (1-2), and the output pipeline (2-3) is connected to a quick connector two (301) for connecting the filling container (3).

10. A method for rapid and precise filling of liquid carbon dioxide, characterized in that: Using the liquid carbon dioxide rapid and precise filling device as described in claim 9, each filling container (3) is vented through the pneumatic pressure relief valve (203) before filling, so as to remove the original air and some carbon dioxide that has undergone flash evaporation phase change from the filling container (3); after connecting the pipeline, the equipment starts to work, first cooling the entire system, opening the pneumatic pressure relief valve (203) at the end of the system to vent, and the liquid carbon dioxide vaporization process takes away a large amount of temperature, so that the system temperature is controlled to about -20℃; real-time monitoring of pressure, temperature, mass flow rate, density parameters and transmission to the control unit, the control unit dynamically corrects the working parameters of the pneumatic booster module (2) and the air conditioning unit (4) through the algorithm according to the deviation between the set parameters and the measured parameters.

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