Software-based control system and control method for carrier gas intelligent electromagnetic valve of gas chromatograph

Abstract

The application discloses a software control gas chromatograph carrier gas intelligent electromagnetic valve system and a control method, relates to the technical field of gas chromatograph carrier gas source safety control and automation, and comprises a normally closed electromagnetic valve assembly installed between a gas cylinder gas outlet and a gas chromatograph, a control unit, a digital display module, an audible and visual alarm module, a sensor module and control software running on an intelligent terminal or a server. The control software has the function of automatically scanning, verifying and non-inductive connection of an authorized control unit after starting, can remotely send encrypted switch valve instructions, the control unit is provided with double-state leakage judgment logic, can adopt different pressure drop threshold values to judge leakage according to the opening and closing states of the electromagnetic valve, automatically executes the valve closing action and synchronously triggers the on-site audible and visual alarm and terminal alarm, and the digital display module can display the valve state and pressure data in real time on the gas cylinder site.

Description

Technical Field

[0001] This invention relates to the field of safety control and automation technology for carrier gas sources in gas chromatographs, and particularly to a software-controlled intelligent solenoid valve system and control method for carrier gas sources in gas chromatographs, used for intelligent management and control of carrier gas sources in laboratory gas chromatographs. Background Technology

[0002] Gas chromatographs are widely used separation and analysis instruments in laboratories. The carrier gas, as the mobile phase in gas chromatography, requires a stable and safe supply to ensure normal instrument operation and experimental safety. Currently, laboratory gas chromatographs primarily rely on manual mechanical valves for opening and closing the carrier gas supply. This traditional approach has the following drawbacks:

[0003] Inconvenient to operate and poor emergency response capability: Operators need to approach the high-pressure gas cylinder and manually rotate the valve to complete the opening and closing operation. In case of gas leaks, fires or other emergencies, the gas source cannot be quickly cut off, which may lead to further expansion of the disaster and threaten the safety of personnel and equipment.

[0004] Lack of intuitive on-site perception and effective alarm: Existing carrier gas sources generally use mechanical pressure gauges, which are limited by their detection accuracy and cannot accurately read pressure values, nor can they accurately display valve status and gas flow at the gas cylinder end; at the same time, commonly used carrier gases such as nitrogen and helium are colorless and odorless gases, and traditional solutions are not equipped with gas leak detection sensors and on-site audible and visual alarm devices, so test personnel cannot detect the danger of leakage in the first place.

[0005] Status monitoring is lagging and software interaction is cumbersome: it is impossible to know the actual opening and closing status of the valve in real time, and most of the existing monitoring software requires manual input of IP address, scanning code or input of pairing code to connect to the device, which seriously affects the response speed in emergency situations and is prone to gas leakage or waste of resources due to human negligence.

[0006] Safety management is difficult and there are systemic risks: In scenarios where multiple instruments are used in a distributed manner, it is impossible to achieve centralized authorization management, traceability of usage records, or automatic shutdown at set times; manual valves are prone to jamming and sealing failure after prolonged use, and cannot be linked with the laboratory's existing safety system for control.

[0007] In recent years, although some Chinese patents have disclosed technologies related to intelligent valves for gas cylinders and safety control in gas chromatography, such as patent application number 202511091493.X which discloses a civilian gas intelligent solenoid valve control system, and patent application number 202221175937.X which discloses a leak detection and shut-off device at the hydrogen inlet of a gas chromatograph, these disclosed technologies still have significant limitations: the former is designed for civilian low-pressure gas scenarios, and its pressure resistance and sealing performance cannot meet the requirements for high-pressure carrier gas (10-15MPa) in gas chromatography, and it does not have a dedicated leak detection algorithm designed for the low-flow characteristics of gas chromatography carrier gas; the latter can only achieve partial shut-off at the instrument inlet or inside, and cannot completely shut off the carrier gas supply from the gas cylinder source, and it lacks remote control, centralized management of multiple gas cylinders, and operation log traceability functions. Currently, there is no integrated intelligent solenoid valve control solution for the carrier gas source outlet of a gas chromatograph that can simultaneously achieve remote switching, dual-state leak detection, on-site intuitive display, and digital safety management. Summary of the Invention

[0008] In view of the problems mentioned above or existing manual valves, such as inconvenience in operation, lack of remote control capability, low accuracy of leak detection, lack of on-site alarms, and lack of digital traceability for equipment and personnel management, this invention proposes a software-controlled intelligent solenoid valve system and control method for carrier gas of a gas chromatograph.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a software-controlled intelligent solenoid valve system and control method for a gas chromatograph carrier gas, comprising:

[0010] A software-controlled intelligent solenoid valve system for a gas chromatograph carrier gas source includes:

[0011] The gas cylinder itself;

[0012] An electromagnetic valve assembly installed between the gas cylinder body outlet and the gas chromatograph inlet;

[0013] The control unit is electrically connected to the solenoid valve assembly;

[0014] The digital display module and the audible and visual alarm module are electrically connected to the control unit.

[0015] The sensor module electrically connected to the control unit; and

[0016] Control software that runs on smart terminals or servers;

[0017] The control software has the function of automatically scanning, verifying and seamlessly connecting to authorized control units in the background after startup, and can send encrypted valve opening / closing commands and receive status feedback.

[0018] The control unit has built-in leakage detection logic, which can distinguish between the open and closed states of the solenoid valve assembly based on the pressure data collected by the sensor module to determine whether a leak has occurred.

[0019] Furthermore;

[0020] The solenoid valve assembly is a normally closed solenoid valve with an automatic reset function when power is off. It adopts a G5 / 8 or W21.8 standard threaded interface and can be directly connected in series after the original manual valve or replace the original manual valve.

[0021] Furthermore;

[0022] The leakage detection logic of the control unit is as follows:

[0023] If the carrier gas pressure drops by ≥0.3MPa within 1 hour when the solenoid valve assembly is in the open state, it is considered a leak.

[0024] If the carrier gas pressure drops by ≥0.2MPa within 1 hour when the solenoid valve assembly is in the closed state, it is considered a leak.

[0025] Once a leak is detected, the control unit automatically closes the valve and simultaneously triggers the on-site audible and visual alarm module and sends a leak alarm signal to the control software.

[0026] Furthermore;

[0027] The digital display module is installed on the outer housing of the solenoid valve assembly or control unit and is used to display the valve opening and closing status, the current gas cylinder pressure value, and the communication connection status in real time at the gas cylinder site.

[0028] Furthermore;

[0029] The audible and visual alarm module includes a high-decibel buzzer and a high-brightness LED indicator. When it receives an abnormal signal from the control unit, it will simultaneously issue a continuous audible alarm and a flashing light alarm.

[0030] Furthermore;

[0031] The sensor module includes a pressure sensor, a gas flow sensor, and a gas leak sensor, which are used to monitor the internal pressure of the gas cylinder, the instantaneous gas flow rate, and the concentration of carrier gas in the environment, respectively.

[0032] Furthermore;

[0033] The control software also has the following functions:

[0034] It displays real-time information such as the on / off status of the solenoid valve assembly, gas cylinder pressure, and cumulative flow.

[0035] Set a timed valve on / off schedule;

[0036] Configure automatic valve shut-off logic that is linked to the gas leak sensor;

[0037] Record and export all valve operation logs and alarm events;

[0038] Multi-user hierarchical access control;

[0039] Batch valve shut-off operations in emergency situations.

[0040] Furthermore;

[0041] The control unit includes a microcontroller, a wireless communication module, and a power management module;

[0042] The wireless communication module supports Bluetooth, Wi-Fi, 4G or LoRa communication methods;

[0043] The power management module supports both battery power and external power supply modes.

[0044] A method for controlling an intelligent solenoid valve for a carrier gas source in a gas chromatograph includes the following steps:

[0045] S1: After the system is powered on, the solenoid valve assembly is in the closed state by default, the control unit enters the standby mode, and the digital display module lights up and displays the initial state;

[0046] S2: After the control software starts, it automatically executes the background scanning logic. Once an authorized control unit is found, it automatically establishes an encrypted connection and synchronizes the current device status data.

[0047] S3: Users can view the status of all authorized gas cylinders through the control software. After clicking the valve open button, the control software will send an encrypted valve open command to the corresponding control unit.

[0048] S4: The control unit receives the command and verifies its validity. If the command is valid, it drives the solenoid valve assembly to open, updates the digital display module to show the status as open, and sends a success message to the control software. If the command is invalid, it refuses to execute and sends an error message to the control software.

[0049] Furthermore;

[0050] When any of the following conditions are met, the control unit will automatically close the valve, trigger the audible and visual alarm module to issue a field alarm, and send an alarm message to the control software:

[0051] The control software issues a valve-closing command;

[0052] The set timeout period has elapsed;

[0053] When the pressure sensor detects that the solenoid valve assembly is in the open state, the carrier gas pressure drops by ≥0.3MPa within 1 hour, or when the solenoid valve assembly is in the closed state, the carrier gas pressure drops by ≥0.2MPa within 1 hour.

[0054] The gas leak sensor detected that the carrier gas concentration exceeded a set threshold.

[0055] The user does not have operating privileges or the command signature verification failed.

[0056] The physical emergency stop button or the software virtual emergency stop button is triggered;

[0057] The communication connection between the control software and the control unit was lost for more than 30 seconds.

[0058] The beneficial effects of this invention are as follows:

[0059] Significantly enhances the safety of gas source use, achieving multi-layered safety protection. By employing a normally closed solenoid valve assembly and directly installing it at the gas cylinder outlet, safe shut-off is achieved at the gas source, avoiding the shortcomings of traditional valves that can only partially shut off at the instrument end. Built-in dual-state pressure drop leakage judgment logic sets precise leakage judgment thresholds for both open and closed operating states of the gas chromatograph carrier gas, greatly improving leakage detection accuracy. It is also equipped with an on-site audible and visual alarm module and remote terminal alarm function. Combined with an automatic power-off reset design and an emergency batch valve shut-off function, it can shut off all authorized valves within 1.5 seconds in emergencies such as leaks and fires, effectively reducing the risk of explosions, poisoning, and experimental failures caused by gas leaks.

[0060] Significantly improves operational convenience and reduces personnel workload. The control software features automatic scanning, verification, and seamless connection to authorized control units upon startup, eliminating the need for manual input of IP addresses, scanning codes, or pairing codes. Operations can be executed immediately in emergencies. Operators can control valve opening and closing without close contact with the high-pressure gas cylinder, making it particularly suitable for hazardous environments or operations involving cylinders at heights. The digital display module integrated into the equipment housing directly displays valve opening / closing status, real-time pressure, and communication connection status at the gas cylinder site, enabling rapid acquisition of core data without the need for terminal equipment, significantly improving on-site operational efficiency.

[0061] This system enables digital management of gas sources, meeting laboratory compliance requirements. It supports multi-user hierarchical access control, allowing different operators to be assigned different cylinder operation permissions. It comprehensively records all valve operation logs and alarm events, supporting querying by time range and exporting to CSV / Excel files, ensuring traceability and accountability. It also provides a timed valve opening / closing plan setting function, automatically opening or closing valves at specified times, effectively preventing gas waste caused by human error in forgetting to close valves. Implementation results show that this system can reduce gas waste caused by manually left valves slightly ajar by more than 90%.

[0062] The retrofit is low-cost and easy to promote and apply. The solenoid valve assembly adopts laboratory standard thread interfaces such as G5 / 8 and W21.8, which can be directly connected in series after the existing manual valve or replace the existing manual valve without replacing the gas cylinder or modifying the existing gas circuit system. The retrofit cost is low and the installation is convenient. The control unit supports multiple wireless communication methods such as Bluetooth, Wi-Fi, 4G, and LoRa, which can be flexibly selected according to the network environment of different laboratories. The power management module supports both battery power and external power supply modes, which are suitable for various installation scenarios.

[0063] It possesses excellent scalability and linkage capabilities. The system can interface with existing laboratory fire alarm systems, emergency power-off systems, and video surveillance systems via a standard Modbus protocol interface to achieve multi-system collaborative safety protection; it can also be linked with the gas chromatograph host to automatically control valve opening and closing based on the instrument's operating status, further reducing human error. Attached Figure Description

[0064] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the 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.

[0065] Figure 1 This is a block diagram of the overall structure of the system described in this invention;

[0066] Figure 2 This is a block diagram of the internal modules of the control unit described in this invention;

[0067] Figure 3 This is a schematic diagram of the core interface of the control software described in this invention;

[0068] Figure 4 This is a flowchart of the control method described in this invention;

[0069] Figure 5 This is a schematic diagram showing the installation position of the solenoid valve assembly described in this invention.

[0070] Figure label:

[0071] 1-Gas cylinder body; 2-Solenoid valve assembly;

[0072] 3-Control unit, 31-Microcontroller, 32-Wireless communication module, 33-Power management module, 34-Solenoid valve drive circuit, 35-Sensor interface circuit, 36-Local memory;

[0073] 4-Sensor module, 41-Pressure sensor, 42-Gas flow sensor, 43-Gas leak sensor;

[0074] 5-Digital display module; 6-Audible and visual alarm module;

[0075] 7-Control software, 71-PC host computer interface, 72-Mobile APP interface;

[0076] 8 - Gas chromatograph; 9 - Standard threaded interface; 11 - Spring seat; 12 - Spring; 13 - Stop; 14 - Nameplate; 15 - Cross-head pan head screw. Detailed Implementation

[0077] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0078] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0079] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0080] Example 1

[0081] This embodiment provides a single gas cylinder mobile APP control system based on Bluetooth communication for intelligent management and control of the carrier gas cylinders of a single gas chromatograph.

[0082] Combination Figure 1 , Figure 5A normally closed solenoid valve assembly 2 with a nominal pressure of 16MPa is installed in series between the outlet of the nitrogen cylinder body 1 and the inlet of the gas chromatograph 8 via a G5 / 8 standard threaded interface 9. The rear end of the solenoid valve assembly 2 is connected to the gas flow sensor 42 and the gas chromatograph 8 in sequence.

[0083] Combination Figure 2 The control unit 3 uses an ESP32 microcontroller 31 as its core, integrating a Bluetooth 5.0 wireless communication module 32, a 4.2V lithium battery power management module 33, a solenoid valve drive circuit 34, and a sensor interface circuit 35. A 1.3-inch OLED digital display module 5 and a high-decibel sound and light alarm module 6 are installed on the outer casing. The pressure sensor 41 is installed at the air inlet of the solenoid valve assembly 2 and is directly connected to the gas cylinder body 1.

[0084] Develop corresponding Android / iOS mobile app control software 7. The software interface can be found in [link / reference]. Figure 3 The complete system operation logic is referenced. Figure 4 When a user completes the device authorization and binding process for the first time, the APP will automatically execute the background scanning logic upon subsequent openings. It can establish an encrypted connection with the authorized control unit 3 without manually entering a pairing code. At this time, the OLED digital display module 5 displays the valve opening and closing status, the current gas cylinder pressure, and the Bluetooth connection status in real time.

[0085] When the user clicks the "Open Valve" button in the app, the software sends an AES-encrypted valve opening command. After the control unit 3 verifies the command signature, it activates the relay to power up the solenoid valve assembly 2, opening the gas supply and sending a success message back to the app. Clicking the "Close Valve" button or if communication between the app and control unit 3 is interrupted for more than 30 seconds will cause control unit 3 to automatically close the solenoid valve assembly 2. Control unit 3 has a built-in dual-state leakage detection logic. When the pressure drops by ≥0.3MPa within one hour while solenoid valve assembly 2 is open, or by ≥0.2MPa within one hour while it is closed, it immediately executes a valve closing action, simultaneously triggering the audible and visual alarm module 6 to emit a continuous buzzer and flash a red light, and pushing a leakage alarm message to the app. All valve operation records and alarm events are stored in the control unit 3's local Flash memory 36 and can be exported as a CSV file via the app for traceability.

[0086] Example 2

[0087] This embodiment provides a single-cylinder PC-based timed control system based on Wi-Fi communication, suitable for carrier gas management in a gas chromatograph used for fixed time periods. The overall assembly structure of this system is as follows: Figure 1 , Figure 5As shown, the hardware configuration of the solenoid valve assembly 2, control unit 3, sensor module 4, digital display module 5, and audible and visual alarm module 6 is the same as that in Embodiment 1;

[0088] Combination Figure 2 The wireless communication module 32 in control unit 3 is replaced with a Wi-Fi module, which connects to the local PC host computer control software 7 via the laboratory LAN. The host computer operation interface is as follows: Figure 3 As shown,

[0089] The overall operation process of the equipment is as follows Figure 4 As shown.

[0090] The PC-based host computer software, developed in C#, features real-time monitoring, valve control, scheduled task setting, historical data query, and report export functions. Administrators can set scheduled valve opening and closing plans through the software, such as automatically opening the valve at 8:00 AM and automatically closing it at 5:30 PM, Monday through Friday. The system will automatically execute the corresponding actions at the set times without manual intervention. The software displays cylinder pressure, instantaneous flow rate, cumulative flow rate, and valve status in real time, updating the data every second and automatically generating historical data curves. In the event of abnormal pressure, gas leakage, or command verification failure, the host computer software displays a red alarm window and plays an audible alert, while control unit 3 triggers the on-site audible and visual alarm module 6.

[0091] All operation logs and alarm records are automatically saved to a local database, supporting querying by time range and exporting to Excel reports, meeting the laboratory's ISO / IEC 17025 compliance management requirements. Furthermore, the host computer software supports multi-user hierarchical access control; the administrator account has full operational permissions, while ordinary operator accounts can only view status and perform valve on / off operations, and cannot modify system parameters or delete logs.

[0092] Example 3

[0093] This embodiment provides a cloud-based centralized management and control system for multiple gas cylinders based on 4G communication, which is suitable for laboratory gas cylinder warehouses or centralized gas supply scenarios for multiple gas chromatographs.

[0094] For details on the overall system composition and connections, please refer to Figure 1 For details on the installation method of the solenoid valve assembly 2, the gas cylinder body 1, and the gas chromatograph 8, please refer to [link / reference]. Figure 5 The internal module structure of control unit 3 is referenced. Figure 2 Refer to the cloud management platform interface Figure 3 The logic for equipment operation and handling of malfunctions is as follows: Figure 4 .

[0095] Intelligent solenoid valve systems were installed on each of the 20 different-sized carrier gas cylinders 1 in the warehouse. Each control unit 3 has a built-in 4G full-network wireless communication module 32, which uploads data to the Alibaba Cloud server in real time via the mobile internet. Administrators manage the system centrally through a web-based cloud management platform 7. The platform supports adding multiple operator accounts and assigning different cylinder operation permissions, and allows setting the permitted usage time and cumulative gas consumption limit for each cylinder. For example, the system can be configured for the analysis lab operator to operate only five designated nitrogen cylinders from 8:00 AM to 6:00 PM on weekdays. When the cumulative gas consumption reaches the set 5000 standard liters, the system automatically shuts off the solenoid valve assembly 2 of the corresponding cylinder and sends an SMS notification to the administrator.

[0096] Control unit 3 collects gas cylinder pressure data in real time and uploads it to the cloud platform. The platform has a built-in dual-state leakage detection logic consistent with the local control unit 3. When an abnormal pressure drop is detected in any gas cylinder, a forced valve closure command is immediately issued to the corresponding control unit 3. The average time from triggering the pressure sensor 41 to the complete closure of the solenoid valve assembly 2 is less than 1.5 seconds. At the same time, the platform pushes APP and SMS alarms to all online administrators and triggers the audible and visual alarm modules 6 of all gas cylinders on site to remind personnel to evacuate. The cloud platform automatically generates usage logs and alarm statistics reports for all gas cylinders, supporting one-click export and printing, realizing digital management of the entire life cycle of gas cylinders. The implementation results show that the system reduces gas waste caused by manual valves not being closed tightly by more than 90%, and all operations can be traced back to the specific responsible person and time point.

[0097] Example 4

[0098] This embodiment provides an intelligent solenoid valve control system that integrates with a laboratory safety system to achieve multi-system collaborative safety protection. The overall system hardware architecture is as follows: Figure 1 As shown, the mounting structure of the solenoid valve assembly 2 is as follows: Figure 5 As shown, the internal circuit modules of control unit 3 are as follows: Figure 2 As shown, the human-computer interaction software interface is as follows: Figure 3 As shown, the control flow of the entire equipment is as follows: Figure 4 As shown.

[0099] The system hardware configuration is the same as in Example 3. The cloud management platform control software 7 interfaces with the laboratory's existing fire alarm system, emergency power outage system, and video surveillance system through a standard Modbus protocol interface.

[0100] When the laboratory fire alarm system detects a fire or smoke, it immediately sends an emergency stop signal to the cloud platform. Upon receiving the signal, the platform automatically issues a batch valve-closing command to all online control units 3, closing the solenoid valve assemblies 2 of all carrier gas cylinders within 3 seconds to prevent gas leakage from escalating the fire risk. Simultaneously, the video monitoring system automatically switches to the cylinder area view, allowing administrators to remotely monitor the situation. When the laboratory emergency power-off button is pressed or a mains power outage occurs, the control unit 3 continues to operate powered by its built-in lithium battery. The solenoid valve assemblies 2 remain normally closed to ensure safety, and a power outage alarm is immediately reported to the cloud platform.

[0101] Furthermore, the system can also be linked with the gas chromatograph 8 main unit. When the gas chromatograph 8 analysis software is detected to be running, the solenoid valve assembly 2 of the corresponding gas cylinder is automatically opened; when the analysis software is shut down for more than 10 minutes, the solenoid valve assembly 2 is automatically closed, further reducing gas waste caused by human negligence. This integrated system realizes the upgrade from single device control to global safety linkage, and builds a multi-level, all-round laboratory gas source safety protection system.

[0102] In the description of this invention, it should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0103] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0104] In the several embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0105] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0106] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0107] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0108] Furthermore, although the operations of the method of the present invention are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

Claims

1. A software-controlled intelligent solenoid valve system for the carrier gas source of a gas chromatograph. Its features are, include: Gas cylinder body (1); Solenoid valve assembly (2) installed between the outlet of the gas cylinder body (1) and the inlet of the gas chromatograph (8); Control unit (3) electrically connected to the solenoid valve assembly (2); The digital display module (5) and the audible and visual alarm module (6) are electrically connected to the control unit (3); The sensor module (4) is electrically connected to the control unit (3); and Control software running on a smart terminal or server (7); The control software (7) has the function of automatically scanning, verifying and seamlessly connecting to the authorized control unit (3) in the background after startup, and can send encrypted valve opening / closing commands and receive status feedback; The control unit (3) has built-in leakage detection logic, which can distinguish between the open and closed states of the solenoid valve assembly (2) based on the pressure data collected by the sensor module (4) to determine whether leakage has occurred.

2. The system according to claim 1, Its features are, The solenoid valve assembly (2) is a normally closed solenoid valve with an automatic reset function when power is off. It adopts a G5 / 8 or W21.8 standard threaded interface (9) and can be directly connected in series after the original manual valve or replace the original manual valve.

3. The system according to claim 1, Its features are, The leakage determination logic of the control unit (3) is as follows: When the solenoid valve assembly (2) is in the open state, if the carrier gas pressure drops by ≥0.3MPa within 1 hour, it is determined to be a leak; When the solenoid valve assembly (2) is in the closed state, if the carrier gas pressure drops by ≥0.2MPa within 1 hour, it is determined to be a leak; Once a leak is detected, the control unit (3) automatically closes the valve and simultaneously triggers the on-site audible and visual alarm module (6) and sends a leak alarm signal to the control software (7).

4. The system according to claim 1, Its features are, The digital display module (5) is installed on the outer housing of the solenoid valve assembly (2) or the control unit (3) and is used to display the valve opening and closing status, the current gas cylinder pressure value and the communication connection status in real time at the gas cylinder site.

5. The system according to claim 1, Its features are, The sound and light alarm module (6) includes a high-decibel buzzer and a high-brightness LED indicator. When it receives an abnormal signal from the control unit (3), it simultaneously emits a continuous sound alarm and a flashing light alarm.

6. The system according to claim 1, Its features are, The sensor module (4) includes a pressure sensor (41), a gas flow sensor (42), and a gas leak sensor (43), which are used to monitor the internal pressure of the gas cylinder, the instantaneous flow rate of the gas, and the concentration of carrier gas in the environment, respectively.

7. The system according to claim 1, Its features are, The control software (7) also has the following functions: The on / off status of the solenoid valve assembly (2), gas cylinder pressure, cumulative flow and other information are displayed in real time. Set a timed valve on / off schedule; Set up automatic valve closing logic linked to the gas leak sensor (43); Record and export all valve operation logs and alarm events; Multi-user hierarchical access control; Batch valve shut-off operations in emergency situations.

8. The system according to claim 1, Its features are, The control unit (3) includes a microcontroller (31), a wireless communication module (32), and a power management module (33); The wireless communication module (32) supports Bluetooth, Wi-Fi, 4G or LoRa communication methods; The power management module (33) supports both battery power and external power supply modes.

9. A method for controlling an intelligent solenoid valve for a carrier gas source in a gas chromatograph. Using the system as described in any one of claims 1-8, Its features are, include The following steps: S1: After the system is powered on, the solenoid valve assembly (2) is in the closed state by default, the control unit (3) enters the standby mode, and the digital display module (5) lights up and displays the initial state; S2: After the control software (7) starts, it automatically executes the background scanning logic, and after discovering the authorized control unit (3), it automatically establishes an encrypted connection and synchronizes the current device status data; S3: The user can view the status of all authorized gas cylinders through the control software (7). After clicking the valve opening button, the control software (7) sends the encrypted valve opening command to the corresponding control unit (3). S4: The control unit (3) receives the instruction and verifies its legality. If the instruction is legal, it drives the solenoid valve assembly (2) to open, updates the display status of the digital display module (5) to "open", and sends a success message to the control software (7). If the instruction is invalid, it refuses to execute and sends an error message to the control software (7).

10. The control method according to claim 9, Its features are, When any of the following conditions are met, the control unit (3) automatically performs the valve closing action, triggers the audible and visual alarm module (6) to issue an on-site alarm, and sends alarm information to the control software (7): The control software (7) issues a valve closing command; The set timeout period has elapsed; The pressure sensor (41) detects that the carrier gas pressure drops by ≥0.3MPa within 1 hour when the solenoid valve assembly (2) is in the open state, or that the carrier gas pressure drops by ≥0.2MPa within 1 hour when the solenoid valve assembly (2) is in the closed state; The gas leak sensor (43) detected that the carrier gas concentration exceeded the set threshold; The user does not have operating privileges or the command signature verification failed. The physical emergency stop button or the software virtual emergency stop button is triggered; The communication connection between the control software (7) and the control unit (3) is lost for more than 30 seconds.

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