Automatic filling system and method for compressed gas and cryogenic liquid cylinders

Abstract

The application provides a compressed gas and low-temperature liquefied gas cylinder automatic filling system and method, which comprises a storage tank and a main pipe unit, the storage tank is provided with a first sensor group for monitoring the state of gas in the storage tank, the main pipe is provided with a second sensor group for monitoring the state of gas in the main pipe, a low-pressure relief valve and a high-pressure relief valve; at least one filling station is connected with the main pipe, each filling station comprises a valve group panel and a weighing device, an electric control system comprises a PLC control unit; a man-machine interface unit is connected with the PLC control unit; the PLC control unit receives control formula parameters and sensor and weighing signals from the man-machine interface unit, automatically controls the opening and closing of each valve in the valve group panel and the relief valve on the main pipe, so as to execute the automatic filling process of the cylinder. The automatic control of the whole process of the cylinder is realized, and the safety, accuracy and traceability of the filling process are realized through parameterized formula management, multi-stage interlocking protection and data archiving.

Description

Technical Field

[0001] This invention belongs to the field of automatic gas filling technology, specifically relating to an automatic filling system and method for compressed gas and cryogenic liquefied gas cylinders. Background Technology

[0002] Currently, most companies still rely on manual or semi-automatic methods for filling gas cylinders containing high-pressure or low-temperature liquefied gases such as nitrous oxide. Existing technologies generally have the following characteristics and problems: 1. The filling process is highly dependent on manual operation. In traditional solutions, operators need to manually complete the following tasks: connecting and disconnecting the cylinder from the filling pipeline; opening and closing each valve (filling valve, vacuum valve, venting valve, etc.); and switching between different stages such as pipeline vacuuming, replacement, pressure holding, and filling.

[0003] The sequence of valve opening and closing, the degree of opening, and the duration of operation mainly depend on the operator's experience. There are significant differences between different operators, which can easily lead to omissions, incorrect sequences, or non-standard operations, thereby affecting the filling quality and safety.

[0004] 2. Filling parameters are difficult to control precisely. Many existing devices rely solely on pressure or time for control: weighing devices are often standalone units and cannot form a closed loop with the filling control logic; when the cylinder is nearing the target weight, the flow rate and impulse cannot be automatically reduced, forcing operators to rely on experience to determine when to slow down and stop. This often results in overfilling or underfilling: overfilling poses safety hazards and may keep the cylinder under high stress for extended periods; underfilling affects product yield and economic efficiency.

[0005] 3. Insufficient safety protection and interlocking. Many existing filling systems only employ the following safety measures: simple overpressure alarms; and a single safety valve for pressure relief.

[0006] There is a lack of systematic interlocking control for multiple parameters such as tank pressure, main pipe pressure, cylinder pressure, and pump operating conditions. If local instruments fail or operators fail to handle the situation in a timely manner, serious consequences such as excessive main pipe pressure, leakage, or even equipment damage can easily occur.

[0007] 4. Weak data recording and traceability capabilities In the traditional way, process data such as pressure, temperature, and weight during the filling process are either not recorded or exist only in the form of paper records or partial instrument memory.

[0008] This approach makes it difficult to trace the quality of product batches, and it is also not conducive to analyzing process fluctuations and optimizing filling parameters. Furthermore, it is difficult to integrate with the company's existing information system (MES).

[0009] 5. Low level of informatization, making centralized monitoring and management difficult. Many existing devices operate in isolation and have little connection with the MES / SCADA system: centralized storage and statistics of filling data cannot be achieved; there is no unified filling status screen on site, so managers cannot intuitively see the operation status of each workstation; and remote monitoring and remote diagnostic capabilities are insufficient.

[0010] Therefore, there is a need for an automatic cylinder filling system and its control method that is structurally sound, precisely controlled, has multi-level safety protection, and features comprehensive data management and remote monitoring functions, in order to solve the problems in the existing technologies mentioned above and improve the automation level, safety, and traceability of the cylinder filling process. Summary of the Invention

[0011] This invention provides an automatic filling system and method for compressed gas and cryogenic liquefied gas cylinders. With a PLC control unit as the core, it combines storage tank and main pipe unit, filling panel and filling station unit, electrical control system and PLC control cabinet, human-machine interface and remote monitoring unit, etc., to realize automatic control of the entire process of cylinder vacuuming, pipeline replacement, analysis, filling and pressure holding. Through parameterized formula management, multi-level interlock protection and data archiving, the filling process is made safe, accurate and traceable.

[0012] According to a first aspect of the present invention, one or more embodiments of this application provide an automatic cylinder filling system for compressed gas and cryogenic liquefied gas, comprising: The storage tank and main pipeline unit includes a storage tank for storing gas to be filled and a main pipeline connected thereto. The storage tank is equipped with a first sensor group for monitoring the gas state inside the storage tank, and the main pipeline is equipped with a second sensor group for monitoring the gas state inside the main pipeline, a low-pressure relief valve, and a high-pressure relief valve. At least one filling station is connected to the main pipeline. Each filling station includes a valve assembly panel and a weighing device. The valve assembly panel is equipped with an automatic filling valve for connecting the main pipeline and the gas cylinder, a gas cylinder control valve for controlling the opening and closing state of the gas cylinder, a vacuum valve for connecting to the vacuum system, and a venting valve. The valve assembly panel of each filling station also includes an analysis valve and a pressure holding valve. The analysis valve is used to connect to a gas analysis device, and the pressure holding valve is used to maintain the pipeline pressure after filling. The weighing device is used to detect the weight of the gas cylinder in real time. Electrical control system, including PLC control unit; The human-machine interface unit is connected to the PLC control unit; The sensor signals of the storage tank and main pipe unit, the weighing signal of the weighing device, and the on / off status signals of each valve in the valve group panel are all transmitted to the PLC control unit. The PLC control unit is configured to automatically control the opening and closing of each valve in the valve group panel and the pressure relief valve on the main pipeline based on the control formula parameters received from the human-machine interface unit and the received sensor and weighing signals, so as to execute the automatic filling process of the gas cylinder.

[0013] According to the above-described technical solution of the present invention, the following improvements can also be made: Optionally, the automatic filling valve includes a motor, a reducer, a clamping frame, and a drive wheel. The motor is driven by the reducer, and the reducer is fixedly connected to the clamping frame. The clamping frame has a drive cavity and a clamping cavity that are interconnected. The output shaft of the reducer passes through one end of the clamping frame and extends into the drive cavity. The output shaft of the reducer is fixedly connected to the drive wheel. The drive wheel has a groove on the side facing the clamping cavity. The clamping cavity has a clamping part. After the end of the cylinder is fixed by the clamping part, it extends into the drive cavity and engages with the groove of the drive wheel. The handwheel at the end of the cylinder is then driven by the motor to rotate.

[0014] Optionally, the electrical control system also includes a cryogenic pump, and the PLC control unit is configured to control the operating status of the cryogenic pump according to the pump body temperature and outlet pressure during the filling process.

[0015] Optionally, the electronic control system further includes a frequency converter for controlling the cryogenic pump. The PLC control unit is configured to: during the filling process, adjust the operating frequency of the cryogenic pump through the frequency converter based on the difference between the real-time weight fed back by the weighing device and the target weight, so as to reduce the filling flow rate when approaching the target weight.

[0016] Optionally, the PLC control unit is configured to perform multi-level safety interlock control, the safety interlock including: controlling the opening and closing of the low-pressure relief valve and the high-pressure relief valve based on the signals of the second sensor group in the main pipe; monitoring pressure changes during the pressure holding stage after the pipeline is evacuated, and determining leakage and alarming if the pressure rises abnormally; and prohibiting the start of the filling process when the gas composition analysis is unqualified.

[0017] Optionally, a data archiving unit is also included, which is configured to record the cylinder number, target weight, actual filling weight, timestamp, key process parameter curves and alarm events for each filling process, and supports data query and traceability.

[0018] Optionally, a remote monitoring unit is also included. The remote monitoring unit is connected to the PLC control unit via an industrial Ethernet or wireless network and is used to view the system operating status, filling data and alarm information in real time on a remote terminal.

[0019] According to a second aspect of the present invention, one or more embodiments of this application provide an automatic filling method for cylinders containing compressed gas and cryogenic liquefied gas, comprising the following steps: Filling preparation: Enter cylinder information, call or set the filling formula parameters corresponding to the cylinder, and the PLC control unit controls the cryogenic pump to complete pre-cooling; Pipeline handling: Control the valves in the valve group panel to sequentially perform vacuuming, pressure holding and leak detection, and gas replacement and analysis on the pipelines connected to the gas cylinders; Automatic filling: Open the automatic filling valve and the cylinder control valve at the same time, start the cryogenic pump, and use the cylinder weight signal as the core feedback quantity, combined with the pipeline pressure signal, adjust the operating frequency of the cryogenic pump to control the filling flow rate until the target weight is reached. Post-filling processing: Close the automatic filling valve, cylinder control valve and cryogenic pump, enter the pressure holding stage, monitor the cylinder pressure and weight stability, record filling data and output filling results.

[0020] According to the above-described technical solution of the present invention, the following improvements can also be made: Optionally, the pipeline processing steps specifically include: Vacuuming and pressure holding: Close the automatic filling valve, open the vacuum valve to evacuate the pipeline to the target pressure and continue for the set time, then close the vacuum valve to enter the pressure holding stage. If the pressure rise during the pressure holding period does not exceed the limit, the pipeline is deemed to be sealed. Replacement and analysis: The gas to be filled is introduced into the pipeline for replacement, and the gas composition is analyzed by taking a sample through the analysis valve. If the analysis results are qualified, the automatic filling step is allowed.

[0021] Optionally, the automatic filling step includes: controlling the pump to operate at a higher frequency when the real-time weight is far from the target weight; and automatically reducing the pump operating frequency to reduce the filling flow rate when the real-time weight is close to the target weight.

[0022] The beneficial effects of this invention are: This invention provides an automatic filling system and method for compressed gas and cryogenic liquefied gas cylinders, with a high degree of automation in the filling process: By controlling the operation of the cryogenic pump and valve group panel through PLC, the entire process of tank precooling, pipeline vacuuming, pipeline replacement, empty cylinder analysis, automatic filling, and pressure holding is programmed and controlled, which significantly reduces manual intervention and lowers the probability of human error.

[0023] High filling accuracy and good consistency: The system uses the weighing signal as the core control quantity and combines pressure, temperature and time conditions to achieve closed-loop control: it automatically reduces the flow rate when approaching the target weight to avoid overfilling or underfilling; it improves the filling consistency between different cylinders, which helps to ensure product quality and stability.

[0024] Safety and reliability are significantly improved: through multi-stage pressure relief (low-pressure relief, high-pressure relief), pressure / temperature / time integrated interlocking, abnormal exit and fault reset mechanisms, etc. It can automatically take shutdown and pressure relief measures in case of overpressure, overtemperature or abnormal filling; the valve adopts a structure that combines pneumatic and manual operation, so even if the air source or electrical control fails, the valve can still be quickly shut off or opened manually, improving the overall safety and reliability of the system.

[0025] Parametric formula control with strong adaptability: Parameters such as pump operating range, target pressure and duration at each stage, and target weight can be uniformly set through the human-machine interface to form a standard formula; the same set of hardware devices can be adapted to different media and cylinders of different specifications by calling different formulas, which facilitates process replication and optimization.

[0026] Comprehensive data management facilitates quality traceability and production management: The system automatically records key data for each bottle filling and can interface with a host computer or MES / SCADA to achieve: full lifecycle data recording of products from raw material storage tanks to finished steel cylinders; rapid traceability and cause analysis of abnormal batches; and data support for production statistics, equipment maintenance, and process optimization.

[0027] Supports remote monitoring and information integration: Enables remote monitoring of the filling process and equipment status via network: Managers can view the content of the large screen, the status of each workstation, and alarm information in real time from their office or other locations; This is conducive to building digital workshops and smart factories, reducing the intensity of on-site inspections, and improving management efficiency. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the cylinder control valve according to a preferred embodiment of the present invention; Figure 2 This is a structural schematic diagram of the cylinder control valve of a preferred embodiment of the present invention from the front end view. Figure 3 This is a system principle block diagram of a preferred embodiment of the present invention; Figure 4 This is a schematic diagram of the method flow of a preferred embodiment of the present invention.

[0029] Explanation of reference numerals in the attached drawings: 1. Motor; 2. Reducer; 3. Output shaft; 4. Drive wheel; 5. Clamping frame; 6. Groove; 7. Fine-tuning bolt; 8. Pad; 9. Manual adjustment wheel; 10. Clamping cavity; 11. Drive cavity; 12. Adjusting rod; 13. Slot. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0031] It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in one or more embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0032] like Figures 1-4 As shown, the present invention provides an automatic filling system and method for compressed gas and cryogenic liquefied gas cylinders. With a PLC control unit as the core, it combines storage tank and main pipe unit, filling panel and filling station unit, electrical control system and PLC control cabinet, human-machine interface and remote monitoring unit, etc., to realize automatic control of the entire process of cylinder vacuuming, pipeline replacement, analysis, filling and pressure holding. Through parameterized formula management, multi-level interlock protection and data archiving, the filling process is made safe, accurate and traceable.

[0033] The system includes: The storage tank and main pipeline unit includes a storage tank for storing gas to be filled and a main pipeline connected to it. The storage tank is equipped with a first sensor group for monitoring the gas state inside the tank, and the main pipeline is equipped with a second sensor group for monitoring the gas state inside the main pipeline, a low-pressure relief valve, and a high-pressure relief valve. The first sensor group includes a storage tank pressure transmitter for detecting the gas pressure inside the storage tank; a storage tank temperature sensor for detecting the gas temperature inside the storage tank; and automatic valves such as a feed valve and a return valve connected to the upstream process. The second sensor group includes a main pipeline pressure transmitter and a main pipeline temperature sensor for monitoring the pressure and temperature in the delivery pipeline; low-pressure relief valves and high-pressure relief valves are used for safety protection; the main pipeline may also be equipped with a shut-off valve and a reflux valve. The PLC control unit collects the pressure and temperature signals from the storage tank and main pipeline, and, in conjunction with process settings: during the pre-cooling stage, it controls the cryogenic pump and the reflux valve to adjust the main pipeline temperature and pressure to a suitable range; during operation, it automatically controls the opening and closing of the low-pressure relief valve and the high-pressure relief valve according to the main pipeline pressure, achieving multi-stage pressure relief and safety interlocking.

[0034] At least one filling station is connected to the main pipeline. Each filling station includes a valve assembly panel and a weighing device. The valve assembly panel is equipped with an automatic filling valve for connecting the main pipeline to the gas cylinder, a gas cylinder control valve for controlling the opening and closing state of the gas cylinder, a vacuum valve for connecting to a vacuum system, and a venting valve. The valve assembly panel of each filling station also includes an analysis valve and a pressure holding valve. The analysis valve is used to connect to a gas analysis device, and the pressure holding valve is used to maintain pipeline pressure after filling. The weighing device is used to detect the weight of the gas cylinder in real time. The automatic filling valve controls the gas to be filled to enter the main pipeline connected to the gas cylinder. The gas cylinder control valve controls the opening and closing of the gas cylinder, and its connection state with the main pipeline is automatically controlled. The vacuum valve is used to connect to the vacuum system to evacuate the filling pipeline. The venting valve is used to vent or release gas from the filling pipeline. The analysis valve sends the gas in the pipeline to the analysis device for component detection. The pressure holding valve maintains a certain pressure condition after filling.

[0035] The valves mentioned above are preferably pneumatic valves, and each pneumatic valve is equipped with a manual operating mechanism: during normal operation, the pneumatic valve is automatically opened and closed by the PLC control unit through the solenoid valve; when the air source or electrical control fails, the operator can manually operate the valve to close it in an emergency, thereby improving the controllability and safety of the system under abnormal conditions.

[0036] Each filling station also includes a weighing device, such as a platform scale or load cell, for real-time detection of the cylinder weight. The weighing device connects to the PLC control unit via communication methods such as MODBUS, uploading the cylinder weight in real time as the core feedback for automatic filling control. The cylinder clamping and valve opening / closing mechanism, i.e., the cylinder control valve described in the embodiment, can use a gripper structure of "clamp + servo motor" to achieve automatic opening and closing of the cylinder valve. Please refer to the detailed description of the cylinder control valve structure in the subsequent paragraphs of the embodiment for this structure.

[0037] The electrical control system includes a PLC control unit; the electrical control system includes the PLC control unit and supporting electrical components installed in the main control cabinet: PLC master station and I / O modules, used to acquire various analog and digital signals and output control signals; frequency converter, used to control the operating frequency of the cryogenic pump to achieve flow and pressure regulation; low-voltage electrical appliances, relays and power modules, providing stable power supply and signal isolation for the system; terminal blocks and wiring terminals, used to connect signals from the storage tank area, pump area, filling pan, weighing device and other field areas to the control cabinet.

[0038] The main control cabinet is equipped with: a general industrial control panel, which displays the overall process flow, tank area and pump area operating status, etc.; an emergency stop button, which is used to quickly cut off the control signals of key equipment in an emergency to achieve emergency shutdown of the entire system; and a signal light tower, which is used to visually display the system's operation, alarm and fault status from a distance.

[0039] PLC substations or field control boxes are set up near the pump area and filling pan, and communicate with the PLC master station through industrial Ethernet or fieldbus to achieve centralized control, distributed data acquisition and execution.

[0040] A human-machine interface (HMI) unit is connected to the PLC control unit. In this embodiment, an HMI is set on each filling panel. The HMI displays and operates the following content: equipment general diagram and process flow diagram; schematic diagram of single-station pipeline and valve status, which intuitively displays the opening / closing status of automatic filling valve, cylinder control valve, vacuum valve, venting valve, analysis valve, pressure holding valve, etc., as well as pipeline pressure; real-time process parameters, including tank pressure, tank temperature, main pipe pressure, main pipe temperature, filling pressure, ambient temperature, pump body temperature, driving gas pressure, target filling weight, current weight, cylinder number, etc.; current step status information, such as "pump precooling not completed", "pipeline vacuuming in progress", "empty cylinder analysis qualified", "filling in progress", etc.

[0041] The HMI is also used for: recipe calling and parameter setting, such as target filling weight, analysis weight increase, precooling temperature, target pressure and duration for each stage, pump operating pressure range and frequency range, overpressure shutdown value, etc.; mode switching, including manual mode, automatic mode, empty bottle analysis mode, etc.; start and stop operations, such as "start filling", "abnormal exit", "fault reset", etc.; historical data query, alarm record viewing, user login and permission management.

[0042] In addition, the system is equipped with a large on-site dashboard to centrally display the filling progress, current weight, filling time, pressure and temperature information of each workstation, facilitating remote monitoring by on-site personnel.

[0043] The sensor signals of the storage tank and main pipe unit, the weighing signal of the weighing device, and the on / off status signals of each valve in the valve group panel are all transmitted to the PLC control unit. The PLC control unit is configured to automatically control the opening and closing of each valve in the valve group panel and the pressure relief valve on the main pipeline based on the control formula parameters received from the human-machine interface unit and the received sensor and weighing signals, in order to execute the automatic filling process of the gas cylinder. Through the human-machine interface, the operator can set or call the following parameters: lower and upper pressure limits of the pump operating range, overpressure shutdown value; low frequency, target frequency, and high frequency of the pump, as well as the automatic adjustment frequency range and adjustment cycle; target vacuum pressure and vacuum duration; target pressure and replacement duration of pipeline replacement; target pressure and holding time; upper and lower limits of analysis pressure and analysis venting time; target filling weight and analysis increase weight; pre-cooling temperature and pre-cooling time; filling weighing judgment time, pressure or temperature overdue judgment time, valve action delay time, etc.

[0044] The PLC control unit generates the corresponding control formula based on the above parameters to automatically control the operation of the cryogenic pump and various valves. For different specifications of cylinders and different media, only the formula needs to be selected or adjusted, without changing the hardware structure.

[0045] In addition, it also includes a data archiving unit. The system in this embodiment records data on the filling process of each cylinder, including at least: cylinder number; target filling weight and actual filling weight; filling start time, end time and duration; key process parameter curves (such as changes in pressure, temperature and weight over time); alarm and interlock event records; operator information.

[0046] It also includes a remote monitoring unit that connects to remote terminals via industrial Ethernet and wireless networks: managers can view the equipment operating status and filling data in real time on tablets, office computers, and large-screen displays; the MES system can send process parameters (such as target weight, filling speed limits, etc.) to the PLC control unit; the PLC then transmits the status of field equipment, faults, and line stop information back to the upper system, realizing digital and information-based management of workshop production.

[0047] For detailed explanation, the cylinder control valve in this embodiment includes a motor 1, a reducer 2, a clamping frame 5, and a drive wheel 4. The motor 1 is connected to the reducer 2 in a transmission manner, and the reducer 2 is fixedly connected to the clamping frame 5. The clamping frame 5 has a drive cavity 11 and a clamping cavity 10 that are interconnected. The output shaft 3 of the reducer 2 passes through the clamping frame 5 and extends into the drive cavity 11. The output shaft 3 of the reducer 2 is fixedly connected to the drive wheel 4. The drive wheel 4 has a groove on the side facing the clamping cavity 10. In this embodiment, the groove 6 is a petal groove. The groove can be designed with teeth to facilitate engagement, or it can be designed with other shapes that match the cylinder handwheel. The clamping cavity 10 has a clamping part. After the end of the cylinder is fixed by the clamping part, it extends into the drive cavity 11 and engages with the drive wheel 4. Then, the motor 1 drives the handwheel at the end of the cylinder to rotate.

[0048] It is understandable that the motor 1 is a servo motor 1, and the reducer 2 is a reducer 2 with an encoder. The output shaft 3 of the reducer 2 is driven to rotate by the motor 1, thereby driving the drive wheel 4 to rotate. The cylinder has a handwheel for adjusting the opening and closing state of the gas valve. During filling, the handwheel of the cylinder is inserted into the petal groove of the drive wheel 4 in the clamping cavity 10. The function of the clamping part is to limit the upper end of the cylinder to prevent it from jumping out, and at the same time, it has an adjustment function so that the handwheel of the cylinder can be aligned with the petal groove.

[0049] In this embodiment, the clamping part includes a manual adjustment mechanism, which is disposed on the clamping frame 5 where the clamping cavity 10 is located. The manual adjustment mechanism includes a manual adjustment wheel 9 and an adjustment rod 12. The clamping frame 5 has a threaded hole that passes through the clamping cavity 10. The adjustment rod 12 is threadedly connected to the threaded hole. The outer end of the adjustment rod 12 is fixedly connected to the manual adjustment wheel 9. The other end of the adjustment rod 12 rotates within the clamping cavity 10 based on the threaded hole and performs telescopic movement.

[0050] It is understandable that the clamping part is adjusted by a manual adjustment mechanism. Specifically, after the manual adjustment wheel 9 is rotated, the adjustment rod 12 will rotate in or out of the clamping cavity 10 to adjust the structural position of the cylinder at this position. During filling, the cylinder's air inlet valve faces downwards because in this embodiment, the bottom is set as an open end to connect the gas source with the air inlet valve to achieve filling.

[0051] In this embodiment, the clamping part further includes a pad 8, which is located opposite to the manual adjustment mechanism and fixed to the inner wall of the clamping cavity 10.

[0052] The pad 8 is fixed inside the clamping frame 5 and is mainly used to limit and buffer the corresponding position of the gas cylinder, which can prevent the gas cylinder from leaving the position during the adjustment process of the manual adjustment wheel 9.

[0053] In this embodiment, the pad 8 has a slot 13.

[0054] The cylinder is further engaged at the corresponding position via the slot 13. Specifically, the slot 13 matches the side profile of the cylinder end. This engagement is possible based on the structure of a standard cylinder. If the structure is not standard, the pad 8 can be replaced, and a corresponding slot 13 shape can be designed to engage the cylinder at that position. In this embodiment, at least this unit, and most units within this region, use cylinders with the structure provided in this embodiment.

[0055] Furthermore, the pad 8 is made of a wear-resistant material. Since the pad 8 needs to have a certain strength and wear resistance, a pad 8 made of POM / PA / PEEK / polyurethane is preferred.

[0056] In this embodiment, the clamping part further includes a fine-tuning mechanism, which includes a fine-tuning bolt 7. One end of the fine-tuning bolt 7 is located on the upper end of the clamping frame 5 corresponding to the clamping cavity 10, and the other end is located inside the clamping cavity 10.

[0057] The fine-tuning mechanism uses a fine-tuning bolt 7 or a fine-tuning wheel and lead screw combination structure. It is mainly used to stabilize the cylinder's state during filling, from the angle shown in the attached diagram of this embodiment, i.e., from top to bottom. That is, the fine-tuning mechanism described in this embodiment is not on the same side as the manual adjustment mechanism and the pad block 8. It can be seen from... Figure 1 and Figure 2 As determined in the embodiment, the fine-tuning mechanism is located at the top, while the manual adjustment mechanism and pad 8 are located on both sides, and the bottom is an open end design.

[0058] A bushing or bearing is provided at the connection between the output shaft 3 of the reducer 2 and the clamping frame 5. The bushing or bearing is fixed inside the clamping frame 5, and the output shaft 3 of the reducer 2 passes through the bushing or bearing. This design is used to reduce friction between the output shaft 3 and the clamping frame 5 and reduce interference.

[0059] In this embodiment, the reducer 2 is equipped with an encoder, the encoder is connected to a controller, the motor 1 and the reducer 2 are respectively connected to the controller, and the controller is also connected to an air source control valve.

[0060] It is understandable that the encoder is used to collect data on the rotational state of the output shaft 3. It can also work with angle sensors, current sensors, torque sensors, etc., and interact with the controller, specifically through I / O or bus communication. The controller can be a PLC / GUI controller. Based on the operating state of motor 1 or the gearbox, corresponding parameters can be obtained, thereby adjusting the output of motor 1 and issuing control commands to the entire valve.

[0061] In another embodiment, an automatic filling method for compressed gas and cryogenic liquefied gas cylinders is provided, comprising the following steps: 1. Filling preparation steps The operator logs into their account on the HMI and selects the target filling station. They then enter the cylinder number manually or by scanning a code. The system reads the cylinder weight information from the database, and manual input or correction is also supported. The operator sets or calls the filling formula corresponding to the cylinder, including parameters such as target filling weight, analysis of added weight, and pre-cooling temperature / time. The operator checks whether the cylinder and filling interface are properly connected and confirms that the relevant manual valves are in the predetermined positions. If any items are not in place or not confirmed, the system will prompt on the interface and prevent the filling process from starting.

[0062] 2. Pump precooling and main pipe preparation steps The PLC controls the cryogenic pump to enter the precooling process, and controls the operation of the pump based on signals such as pump body temperature and outlet pressure. When the pump body temperature drops to the set precooling temperature and is maintained for a set time, the system determines that precooling is complete. If precooling is not complete, the system displays "Pump precooling not complete" on the operation interface and prohibits the subsequent filling steps.

[0063] 3. Pipeline vacuuming and pressure holding steps Close the automatic filling valve, open the vacuum valve, and evacuate the filling pipeline. When the pipeline pressure is lower than the target vacuum pressure and the duration reaches the set value, the vacuuming is considered complete. Then close the vacuum valve and enter the pipeline pressure holding stage. Monitor the pipeline pressure change within the set pressure holding time: if the pressure rise does not exceed the allowable range, the pipeline is considered to be well sealed; if the pressure rises abnormally, it is considered that there is a leak, the system issues an alarm and prohibits entering the next step.

[0064] 4. Pipeline replacement and analysis steps Open the corresponding valves (automatic filling valve and cylinder control valve) to inject a small amount of gas to be filled into the pipeline to replace the medium in the pipeline; send a gas sample to the analysis device through the analysis valve to test whether the gas composition is qualified; if the analysis result is within the set range, the system displays "Empty cylinder analysis qualified" on the HMI, allowing the filling step to proceed; if the analysis result is unqualified, the system alarms and prohibits filling. During the analysis, the cylinder control valve is in the open state. Because the gas pressure inside the cylinder is greater than the gas pressure inside the pipeline, the replacement gas introduced during the analysis and the remaining gas in the pipeline will not enter the cylinder.

[0065] 5. Automatic filling process The automatic filling valve and cylinder control valve are opened simultaneously. The PLC controls the cryogenic pump to start, and the pump frequency is adjusted by the frequency converter to start at a higher frequency, improving filling efficiency while ensuring safety. During the filling process, the PLC uses the weighing signal as the core control variable, while also referring to signals such as filling pressure and ambient temperature. When the weighing value is far from the target weight, the pump is kept running near the target frequency. When the weighing value gradually approaches the target weight, the pump frequency and flow rate are automatically reduced to reduce inertia and prevent overfilling. During the filling process, the PLC uses a multi-condition comprehensive judgment of "weight + time + pressure". If the target weight is not reached within the specified time, or if the pressure or temperature is abnormal, the system issues an alarm and executes corresponding shutdown or load reduction actions.

[0066] 6. End and Pressure Holding Steps Once the weighing value reaches the target filling weight and meets the preset time and pressure conditions, the PLC closes the automatic filling valve and related upstream valves, stops the cryogenic pump, and enters the pressure holding stage. During the pressure holding time, the bottle side pressure and weighing changes are monitored: if the pressure and weight are basically stable, the filling is considered successful; if there is a significant drop, it indicates that there may be leakage or other abnormalities, and manual re-inspection is required.

[0067] 7. Data archiving steps The database stores information such as the cylinder number, target weight, actual filling weight, start / end time, key process parameter curves, alarm information, and operator information for each filling operation. It also supports queries by date, batch, cylinder number, and other criteria, enabling data traceability throughout the product's entire lifecycle.

[0068] It should be noted that, in this embodiment, the following alternative solutions can be adopted: Variations in applicable media: In addition to nitrous oxide, this system can also be used for filling cylinders of other compressed gases or cryogenic liquefied gases such as carbon dioxide, ammonia, hydrogen, and mixed gases. Simply adjust the tank temperature, filling pressure, pipeline materials, and related process formula parameters according to different media.

[0069] Variations in valve assembly structure and quantity: The number and type of valves on the valve assembly panel can be increased or decreased according to actual process needs. For example, reflux valves, pre-cooling valves, purge valves, etc., can be added; some valves can be proportional valves or other types of control valves. As long as the PLC control unit still performs programmed control, the same or similar technical effects as this invention can be achieved.

[0070] Variations of the weighing device: The weighing device can be a platform scale, a suspended load cell, or other form of weight detection equipment. As long as it can communicate with the PLC in real time and meet the required accuracy requirements, it can be used as an alternative to the present invention.

[0071] Variations in cylinder valve actuators: The opening and closing of cylinder valves can be achieved manually, with pneumatic actuators, electric actuators, or a motor-driven gripper structure. Other publicly available or undisclosed structural forms can also be used, as long as they can reliably and automatically open and close the cylinder valve based on PLC control signals.

[0072] Variations in control system and communication methods: The PLC control unit can be replaced with other types of industrial controllers (such as DCS, industrial PC control systems, etc.); the communication method can adopt various methods such as fieldbus, industrial Ethernet, and wireless industrial communication, as long as it can realize the sending of process parameters and the collection and transmission of field data, it is within the protection scope of this invention.

[0073] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0074] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An automatic cylinder filling system for compressed gas and cryogenic liquefied gas, characterized in that, include: The storage tank and main pipeline unit includes a storage tank for storing gas to be filled and a main pipeline connected to it. The storage tank is equipped with a first sensor group for monitoring the gas state inside the storage tank, and the main pipeline is equipped with a second sensor group for monitoring the gas state inside the main pipeline, a low-pressure relief valve and a high-pressure relief valve. At least one filling station is connected to the main pipeline. Each filling station includes a valve assembly panel and a weighing device. The valve assembly panel is equipped with an automatic filling valve for connecting the main pipeline and the gas cylinder, a gas cylinder control valve for controlling the opening and closing state of the gas cylinder, a vacuum valve for connecting to the vacuum system, and a venting valve. The valve assembly panel of each filling station also includes an analysis valve and a pressure holding valve. The analysis valve is used to connect to a gas analysis device, and the pressure holding valve is used to maintain the pipeline pressure after filling. The weighing device is used to detect the weight of the gas cylinder in real time. Electrical control system, including PLC control unit; The human-machine interface unit is connected to the PLC control unit; The sensor signals of the storage tank and main pipe unit, the weighing signal of the weighing device, and the on / off status signals of each valve in the valve group panel are all transmitted to the PLC control unit. The PLC control unit is configured to automatically control the opening and closing of each valve in the valve group panel and the pressure relief valve on the main pipeline based on the control formula parameters received from the human-machine interface unit and the received sensor and weighing signals, so as to execute the automatic filling process of the gas cylinder.

2. The automatic cylinder filling system for compressed gas and cryogenic liquefied gas according to claim 1, characterized in that, The cylinder control valve includes a motor, a reducer, a clamping frame, and a drive wheel. The motor is driven by the reducer, and the reducer is fixedly connected to the clamping frame. The clamping frame has a drive cavity and a clamping cavity that are interconnected. The output shaft of the reducer passes through the clamping frame and extends into the drive cavity. The output shaft of the reducer is fixedly connected to the drive wheel. The drive wheel has a groove on the side facing the clamping cavity. The clamping cavity has a clamping part. After the end of the cylinder is fixed by the clamping part, it extends into the drive cavity and engages with the groove of the drive wheel. The handwheel at the end of the cylinder is then driven by the motor to rotate.

3. The automatic cylinder filling system for compressed gas and cryogenic liquefied gas according to claim 1, characterized in that, The electrical control system also includes a cryogenic pump, and the PLC control unit is configured to control the operating status of the cryogenic pump according to the pump body temperature and outlet pressure during the filling process.

4. The automatic cylinder filling system for compressed gas and cryogenic liquefied gas according to claim 3, characterized in that, The electrical control system also includes a frequency converter for controlling the cryogenic pump. The PLC control unit is configured to adjust the operating frequency of the cryogenic pump through the frequency converter during the filling process based on the difference between the real-time weight fed back by the weighing device and the target weight, so as to reduce the filling flow rate when approaching the target weight.

5. The automatic cylinder filling system for compressed gas and cryogenic liquefied gas according to claim 1, characterized in that, The PLC control unit is configured to perform multi-level safety interlock control, which includes: controlling the opening and closing of the low-pressure relief valve and the high-pressure relief valve based on the signals of the second sensor group in the main pipe; monitoring pressure changes during the pressure holding stage after the pipeline is evacuated, and determining a leak and alarming if the pressure rises abnormally; and prohibiting the start of the filling process when the gas composition analysis is unqualified.

6. The automatic cylinder filling system for compressed gas and cryogenic liquefied gas according to claim 1, characterized in that, It also includes a data archiving unit, which is configured to record the cylinder number, target weight, actual filling weight, timestamp, key process parameter curves and alarm events for each filling process, and supports data query and traceability.

7. The automatic cylinder filling system for compressed gas and cryogenic liquefied gas according to claim 1, characterized in that, It also includes a remote monitoring unit, which is connected to the PLC control unit via an industrial Ethernet or wireless network, and is used to view the system operating status, filling data and alarm information in real time on a remote terminal.

8. An automatic filling method for compressed gas and cryogenic liquefied gas cylinders, applied to an automatic filling system for compressed gas and cryogenic liquefied gas cylinders as described in any one of claims 1-7, characterized in that, Includes the following steps: Filling preparation: Enter cylinder information, call or set the filling formula parameters corresponding to the cylinder, and the PLC control unit controls the cryogenic pump to complete pre-cooling; Pipeline handling: Control the valves in the valve group panel to sequentially perform vacuuming, pressure holding and leak detection, and gas replacement and analysis on the pipelines connected to the gas cylinders; Automatic filling: Open the automatic filling valve and the cylinder control valve at the same time, start the cryogenic pump, and use the cylinder weight signal as the core feedback quantity, combined with the pipeline pressure signal, adjust the operating frequency of the cryogenic pump to control the filling flow rate until the target weight is reached. Post-filling processing: Close the automatic filling valve, cylinder control valve and cryogenic pump, enter the pressure holding stage, monitor the cylinder pressure and weight stability, record filling data and output filling results.

9. The automatic filling method for compressed gas and cryogenic liquefied gas cylinders according to claim 8, characterized in that, The pipeline processing steps specifically include: Vacuuming and pressure holding: Close the automatic filling valve, open the vacuum valve to evacuate the pipeline to the target pressure and continue for the set time, then close the vacuum valve to enter the pressure holding stage. If the pressure rise during the pressure holding period does not exceed the limit, the pipeline is deemed to be sealed. Replacement and analysis: The gas to be filled is introduced into the pipeline for replacement, and the gas composition is analyzed by taking a sample through the analysis valve. If the analysis results are qualified, the automatic filling step is allowed.

10. The automatic filling method for compressed gas and cryogenic liquefied gas cylinders according to claim 8, characterized in that, The automatic filling process includes: when the real-time weight is far from the target weight, controlling the pump to operate at a higher frequency; when the real-time weight is close to the target weight, automatically reducing the pump operating frequency to reduce the filling flow rate.

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