CNG gas dispenser metering out-of-tolerance control method based on intelligent detection and control

Abstract

The invention discloses a method for controlling over-tolerance metering of a CNG filling machine based on intelligent detection and control, which comprises: firstly detecting the working state of a system working parameter, secondly detecting the working state of a mass flow meter zero drift, detecting the working state of a solenoid valve with or without leakage, detecting the working state of a safety unit pressure transmitter in response to a pressure change outputting an analog quantity specification, and detecting the working state of a fluid pressure change increment; if the working states are all normal, outputting the logical characteristic output state value of 1 respectively, otherwise 0; the system automatically performs a logical AND operation on the logical characteristic output values ​​of all the working state states mentioned above, if the logical AND output result is 1, instructing to start the solenoid valve to control the gas filling process; if the logical AND output result is 0, initiating fault management, navigating to the location of the fault target, requesting maintenance troubleshooting authentication, and if the authentication is passed, releasing the fault code state prohibiting the use of the gas filling function, allowing the enabling instruction to start the solenoid valve gas filling process control, and achieving the purpose of controlling over-tolerance metering.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluid metering and control, and specifically relates to a CNG filling machine metering over-tolerance control method based on intelligent detection and control. Background Art

[0002] Compressed natural gas filling machine, also known as CNG filling machine, is a measuring instrument used for accurate pressure-limited filling and trade settlement of natural gas vehicles (abbreviated as "NGV"). The accuracy, repeatability and safety of trade settlement must comply with the national standards for the equipment and the requirements of the measurement and safety technical performance indicators of the periodic mandatory inspection of the quality supervision department before it can be used legally, otherwise it is prohibited to use in violation of regulations. The core measuring instruments of CNG filling machine include mass flow meters based on the principle of Coriolis mechanics. The remarkable advantages of this flowmeter are: based on the principle of Coriolis fluid mechanics, with its precision design structure, the components include flow tube, electromagnetic drive unit and intelligent transmitter unit, no moving parts, no interference with fluid, small pressure loss, large range ratio, and a flowmeter that directly measures mass in the true sense, rather than the mass measurement of gas equation conversion and correction effect in the traditional sense. Therefore, its measurement accuracy and repeatability are not related to the temperature, pressure, viscosity and conductivity of the fluid under standard use conditions, but only to the geometric process characteristics of its flow tube and its material properties, the process fluid velocity and the composite velocity of the electromagnetic drive. At the same time, it can realize the measurement of multiphase turbulent parameters. It is a high-cost, accurate and reliable flowmeter that leads the technology in the field of modern high-pressure fluid measurement and is an indispensable alternative. It is widely used in the field of high-pressure fluid measurement and trade settlement. Therefore, it must be the first choice of flowmeter in the high-pressure fluid CNG filling machine metering instrument industry, and it is also a high-cost flowmeter that is currently irreplaceable in this field. As the domestic and foreign countries began to adjust the energy structure, comprehensively utilize oil and gas resources, replace oil with gas, and promote the popularization of energy-saving and environmentally friendly NGV vehicles with significant social and economic benefits since the late 1970s, this flow meter has been widely used in traditional domestic and foreign petroleum, chemical, pharmaceutical and other industries. It has been used in the measurement and trade settlement of CNG gas dispensers, the terminal sales equipment of the CNG industry that has been promoted and popularized and continues to flourish to this day.

[0003] Although the mass flow meter in the CNG dispenser metering instrument integrates technical performance, high cost performance and leading technology, it still reflects and shows four problems in actual use:

[0004] First, the flow meter zero drift is out of tolerance;

[0005] Second, the reliability of the flow meter electrical unit is weakened, resulting in metering failure and out-of-tolerance;

[0006] The performance of the electrical appliances in the third and secondary measurement and control system units is weakened or fails, which directly leads to measurement failure;

[0007] Fourth, the meson purification degree during the measurement process, the external installation working condition dynamic noise interference, and the leakage of automatic valves are out of tolerance.

[0008] The existence of these four problems will directly or indirectly lead to the measurement deviation of CNG filling machine or commercial disputes in trade settlement, etc. Although the source factors are different, the result is unique: measurement deviation. The main reasons are: the multiple limitations of the flow meter based on the design structure of the realization principle, the process manufacturing and the use of the quality and performance of the flow tube material; and the electrical detection and transformation processing unit and the configuration installation processing implementation engineering method of the CNG filling machine, the abnormality or durability of the automatic control valve parts, etc., which weaken the long-term effective reliability guarantee of the system. Therefore, there is no CNG filling machine that is absolutely reliable and does not exceed the deviation in one fell swoop. Therefore, the CNG filling machine using mass flowmeter will inevitably produce measurement deviation problems when used in all-weather and all-time working conditions. The first three problems can be attributed to the internal uncertainties such as the improvement of design process, material fatigue, and aging of electrical components; the fourth problem is caused by the external deterministic fluid medium pollution, installation noise and mechanical wear of automatic control valve parts or electrical abnormalities leading to leakage interference. However, after comprehensive analysis and classification, it was confirmed that the zero drift characteristics and metering failure characteristics are the root causes of the CNG filling machine metering problems. Summary of the invention

[0009] The purpose of the present invention is to provide a CNG filling machine metering out-of-tolerance control method based on intelligent detection and control in view of the above-mentioned deficiencies in the prior art, so as to solve or improve the above-mentioned problems.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is:

[0011] A CNG filling machine metering out-of-tolerance control method based on intelligent detection and control, comprising:

[0012] S1, detect the working state of the system working parameters. If the working state is normal, the output value of the working state logic characteristic is 1, otherwise it is 0;

[0013] S2, detect the zero drift working state of the mass flow meter. If the working state is normal, the output value of the working state logic characteristic is 1, otherwise it is 0;

[0014] S3, detect whether the solenoid valve has a leakage working state. If there is no leakage, the output value of the working state logic characteristic is 1, otherwise it is 0;

[0015] S4, detect the safety unit pressure transmitter responding to the pressure change output analog quantity standard working state, if the working state is normal, then the working state logic characteristic output value is 1, otherwise it is 0;

[0016] S5, detecting the working state of the fluid pressure change increment, if the working state is normal, the output value of the working state logic characteristic is 1, otherwise it is 0;

[0017] S6, perform a logical AND operation on all the operating state logic characteristic output values ​​in step S1 to step S5. If the logical AND output result is 1, the command starts the solenoid valve to control the gas filling process. If the logical AND output result is 0, the fault management is started;

[0018] S7. Navigate to the fault target and request maintenance troubleshooting management authentication. If authentication is passed, the warning status and the fault code status that prohibits the use of the refueling function are released, and the enable command is allowed to start the solenoid valve refueling process control.

[0019] Preferably, if the logic and output results in steps S1 to S5 are 1, the instruction starts the solenoid valve to control the gas filling process: metering and pricing, display storage and enabling I / O port output.

[0020] Preferably, if the logical AND output result in steps S1 to S5 is 0, the fault management is started: including triggering the buzzer and LED to warn of the fault, displaying the fault code, and prohibiting the enabling of the gas filling instruction and interrupting the gas filling process of the solenoid valve that has been instructed to start.

[0021] Preferably, in step S7, the accurate metering function of the gas dispenser can be enabled again only when the fault indicated by the requested warning code is eliminated and logical judgment is performed, and the online detection and certification of steps S1 to S6 are passed normally.

[0022] A CNG gas dispenser metering out-of-tolerance control system based on intelligent detection and control, comprising:

[0023] The main control board of the measurement and control system is used to perform intelligent detection and control of the system's working parameters, working conditions, power-on and processes;

[0024] The mass flow meter is connected to the forward channel of the main control board of the measurement and control system to enable the metering and transmission functions. It is the basic shared data information source to ensure accurate metering and achieve the control requirements of various working conditions.

[0025] IC card LCD keyboard display assembly is connected to the forward channel of the main control board of the measurement and control system, and is responsible for human-computer interaction management: used for preset and correction parameters and special function options and process response command control and its management needs of warning code display, text operation, fault navigation and multi-mode query printing function management;

[0026] The safety unit pressure transmitter is connected to the forward channel of the main control board of the measurement and control system, and is used to sense and transmit pressure changes during the filling process;

[0027] LCD UV-resistant wide-temperature display, connected to the display driver I / O port of the measurement and control system main control board, is used to display current transaction data and special information in real time;

[0028] The explosion-proof power supply relay controller is connected to the command output I / O port of the main control board of the measurement and control system to realize the safe drive of the intrinsic safety command;

[0029] The explosion-proof solenoid valve is connected to the output I / O port of the explosion-proof power supply relay controller to realize the command control of the solenoid valve filling process.

[0030] The CNG filling machine metering out-of-tolerance control method based on intelligent detection and control provided by the present invention has the following beneficial effects:

[0031] The present invention solves the problem of over-tolerance in the existing CNG filling machine, and achieves the effect of ensuring that the CNG filling machine always has no over-tolerance in the process of metering, and realizing the stable, reliable and accurate operation of the CNG filling machine. It also ensures that the metering trade settlement of the CNG filling machine in commercial operation is accurate, long-term and reliable, and avoids commercial disputes, and has great practicality and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the main program flow chart of the CNG filling machine metering out-of-tolerance control method based on intelligent detection and control.

[0033] Figure 2 This is the electrical principle block diagram of the CNG filling machine metering out-of-tolerance control system based on intelligent detection and control.

[0034] Figure 3 This is the configuration structure diagram of the CNG filling machine metering out-of-tolerance control system based on intelligent detection and control.

[0035] Among them, 1. Gas pipe interface; 2. Shock-resistant pressure gauge; 3. LCD anti-ultraviolet wide temperature display; 4. Upstream stop ball valve; 5. Explosion-proof power supply relay controller; 6. Explosion-proof solenoid valve; 7. Branch ball valve; 8. Safety unit pressure transmitter; 9. Safety valve; 10. IC card LCD keyboard display assembly; 11. Mass flow meter; 12. Check valve; 13. Filter; 14. Downstream stop ball valve; 15. CNG manifold. DETAILED DESCRIPTION

[0036] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0037] According to one embodiment of the present application, referring to Figure 1 The CNG gas dispenser metering out-of-tolerance control method based on intelligent detection and control in this solution includes:

[0038] S1. Detect the working state of the system working parameters. If the working state is normal, the output value of the logical characteristic of the working state of the system working parameters is 1, otherwise it is 0;

[0039] S2, detect the zero drift working state of the mass flow meter 11. If the working state is normal, the output value of the flow meter zero drift working state logic characteristic is 1, otherwise it is 0;

[0040] S3, detecting whether the electromagnetic valve 6 has a leakage condition. If there is no leakage, the output value of the logic characteristic of the electromagnetic valve 6 having a leakage condition is 1, otherwise it is 0;

[0041] S4, detecting the safety unit pressure transmitter 8 responding to the pressure change to output the analog quantity of the standard working condition state. If the working condition state is normal, the safety unit pressure transmitter 8 responding to the pressure change to output the analog quantity of the standard working condition state logic characteristic output value is 1, otherwise it is 0;

[0042] S5, detecting the working state of the fluid pressure change increment. If the working state is normal, the output value of the logic characteristic of the fluid pressure change increment working state is 1, otherwise it is 0;

[0043] S6, perform a logical AND operation on all the logical characteristic output values ​​of the working conditions in step S1 to step S5. If the logical AND output result is 1, directly instruct to start the solenoid valve to control the gas filling process, metering and pricing, display storage and enable I / O port output; if the logical AND output result is 0, start the fault management: trigger the buzzer and LED to warn of the fault, display the fault code, and prohibit enabling the gas filling instruction and interrupting the gas filling process of the solenoid valve that has been instructed to start;

[0044] S7, navigate to the fault target location, request maintenance troubleshooting management authentication, and if the authentication is passed, the fault code status prohibiting the use of the gas filling function is released, and the enable instruction is allowed to start the solenoid valve gas filling process control. The specific steps include:

[0045] Navigation troubleshooting certification management: operate the navigation text menu, identify the fault target, conveniently and efficiently perform maintenance and troubleshooting management, request maintenance and troubleshooting certification, and if the certification is passed, the fault code status that prohibits the use of the gas filling function will be lifted, and the enable command will be allowed to start the solenoid valve gas filling process control.

[0046] Otherwise, if the fault warning code is not removed, the gas dispenser will continue to prohibit the use of the gas filling function. The purpose is to prohibit the output of zero drift and metering failure caused by the structure and electrical properties of the measuring instrument indicated by the warning fault code, and to troubleshoot and enable it in time. Only when the fault indicated by the requested warning code is eliminated and logical judgment is applied, and it is normal after online detection, can the accurate metering function of the gas dispenser be enabled again.

[0047] As for the tolerance caused by deterministic external dynamic noise and fluid medium purification interference, the present invention will still display it in the LCD with different warning codes and navigate to the location of the fault. It can suppress and eliminate the tolerance of interference measurement by applying standardized installation structure process adjustment, process inspection, and precise filtration and purification of fluid medium. Ultimately, it ensures real-time monitoring of the S1-S5 status of the CNG filling machine process, efficiently navigates to clarify the system maintenance and obstacle removal goals, improves the reliability of the system online application, ensures the active anticipation of process measurement to prevent the superposition of measurement tolerance, so as to achieve the purpose of accurate measurement and stable and reliable operation.

[0048] According to one embodiment of the present application, referring to Figure 2 The CNG gas dispenser metering out-of-tolerance control system based on intelligent detection and control in this solution includes:

[0049] The embedded architecture measurement and control system motherboard 3.0 is the control core, and its built-in I / O interface enables the expansion of digital-to-analog / analog-to-digital conversion and multi-mode functions for detection and acquisition functions.

[0050] The forward input channel of the measurement and control system main board 3.0 is connected to the mass flow meter 11, the safety unit pressure transmitter 8, and the IC card LCD keyboard display assembly 10; the backward output channel of the measurement and control system main board is cascaded to the LCD anti-ultraviolet wide temperature display 3.1, the explosion-proof power supply relay controller 5, the explosion-proof solenoid valve 6 and the remote communication terminal interfaces 3.2 and 3.3 for visualization and interactive data.

[0051] The system structure of the present invention is standardized, reasonable, coordinated and compact. The units are modularized and highly integrated, which is conducive to navigation partition operation and ensures convenient, efficient, economical and reliable operation and maintenance. The following describes each of the above systems in detail.

[0052] The measurement and control system mainboard is mainly used to enable the intelligent detection of the system working parameters and conditions at power-on and during the process. Ensuring the normal operation of the core main control board of the measurement and control system is a necessary and sufficient condition for ensuring the normal enabling and metering tolerance control of the entire CNG filling machine. Under this condition, the detection and enabling of the flow meter working condition, solenoid valve working condition, safety unit and fluid pressure change increment working condition are realized.

[0053] The mass flow meter 11 enables the metering and transmission functions and is the basic shared data information source to ensure accurate metering and achieve the control requirements of various working conditions.

[0054] IC card LCD keyboard display assembly, mainly used for human-machine interaction management: used for preset, correction parameters and special function options and process response command control and its management needs of warning code display, text operation, fault navigation and multi-mode query printing function management.

[0055] The safety unit pressure transmitter 8 is mainly responsible for sensing the pressure change response and transmission during the filling process. Combined with the structured redundant safety valve 9, it ensures the static safety of the CNG gas filling machine system and the dynamic filling pressure limit safety standards and the special control requirements of the fluid pressure change increment, and can be used to detect the fluid pressure change increment working condition.

[0056] The LCD UV-resistant wide temperature display 3.1 is connected to the display driver I / O port of the measurement and control system mainboard to display the current transaction data information and special information in real time.

[0057] The explosion-proof power supply relay controller 5 is connected to the command output I / O port of the measurement and control system mainboard to realize safe and effective command driving.

[0058] The explosion-proof solenoid valve 6 is connected to the output I / O port of the explosion-proof power supply relay controller 5 through isolation safety protection, and is used to implement the command control of the solenoid valve gas filling process.

[0059] The remaining visualization and data interaction terminal interfaces of the backward channel provide backup and scalable background client or server management requirements.

[0060] According to one embodiment of the present application, referring to Figure 3 , including a CNG filling machine body, at the CNG gas inlet at the bottom of the CNG filling machine body, a downstream cut-off ball valve 14 is installed to realize functions such as natural gas transmission, cut-off, and special adjustment.

[0061] A filter 13 is provided on the upper end pipeline of the downstream stop ball valve 14 to realize the input filtering control of the fluid medium; a shunt ball valve 7 is symmetrically provided on the pipelines on both sides of the filter 13, and the shunt ball valve 7 is connected between the filter and the explosion-proof solenoid valve to meet the requirements of troubleshooting and maintenance isolation of the fluid medium; a safety valve 9 and a one-way valve 12 are provided on the CNG manifold 15 to realize the controllability of the medium flow channel; the safety valve 9 is used to control the system pressure in the gas filling pipeline to not exceed the specified value; the explosion-proof solenoid valve 6 is connected to the output I / O port of the explosion-proof power supply relay controller 5 through isolation safety protection, and is used to safely realize the command control solenoid valve gas filling process. The explosion-proof power supply relay controller 5 is connected to the command output I / O port of the measurement and control system mainboard, and is used to realize the safety and effectiveness of command drive.

[0062] An upstream stop ball valve 4 is installed on the upper pipeline of the mass flowmeter 11, and cooperates with the downstream stop ball valve 14 to realize the functions of CNG transportation, cutoff and special adjustment of the manifold medium; a seismic-resistant pressure gauge 2 and a safety unit pressure transmitter 8 are set on the pipeline of the upstream stop ball valve 4 to realize real-time online pressure display and transmission.

[0063] Among them, the safety unit pressure transmitter 8 is mainly responsible for sensing the pressure change response and transmission during the filling process, and combined with the safety valve 9, it ensures the realization of the static safety of the CNG gas filling machine system and the dynamic filling pressure limit safety standard and the special control requirements of the fluid pressure change increment.

[0064] Symmetrically arranged IC card LCD keyboard display assemblies 10 are installed on both sides of the CNG filling machine body to realize the operation of human-computer interaction management efficiently and conveniently.

[0065] The LCD UV-resistant wide temperature display 3 integrates a measurement and control system mainboard 3.0, which has built-in enabling expansion of real analog I / O interface and remote communication interface 3.1 and 3.2. It is the core guarantee for achieving system measurement out-of-tolerance detection and control.

[0066] The forward input channel of the measurement and control system mainboard is connected to the mass flowmeter 11, the safety unit pressure transmitter 8, and the IC card LCD keyboard display assembly 10; the backward output channel of the measurement and control system mainboard is cascaded with the LCD anti-ultraviolet wide temperature display 3, the explosion-proof power supply relay controller 5, the explosion-proof solenoid valve 6 and the visualization, interactive data remote communication terminal interface 3.3 and the built-in extended digital and analog I / O interface 3.2. The structural hardware cascade structure fully realizes the global functional guarantee.

[0067] Although the specific implementation of the invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A CNG filling machine metering out-of-tolerance control method based on intelligent detection and control, characterized in that: include: S1, detect the working state of the system working parameters. If the working state is normal, the output value of the working state logic characteristic is 1, otherwise it is 0; S2, detect the zero drift working state of the mass flow meter. If the working state is normal, the output value of the working state logic characteristic is 1, otherwise it is 0; S3, detect whether the solenoid valve has a leakage working state. If there is no leakage, the output value of the working state logic characteristic is 1, otherwise it is 0; S4, detect the safety unit pressure transmitter responding to the pressure change output analog quantity standard working condition state, if the working condition state is normal, then the working condition state logic characteristic output value is 1, otherwise it is 0; S5, detecting the working state of the fluid pressure change increment, if the working state is normal, the output value of the working state logic characteristic is 1, otherwise it is 0; S6, perform a logical AND operation on all the operating state logic characteristic output values ​​in step S1 to step S5. If the logical AND output result is 1, the command starts the solenoid valve to control the gas filling process. If the logical AND output result is 0, the fault management is started; S7, navigate to the fault target, request maintenance troubleshooting management authentication, pass the authentication, remove the warning state and the fault code state that prohibits the use of the gas filling function, and allow the enable command to start the solenoid valve gas filling process control; Navigation troubleshooting certification management: operate the navigation text menu, identify the fault target, conveniently and efficiently perform maintenance and troubleshooting management, request maintenance and troubleshooting certification, and if the certification is passed, the fault code status that prohibits the use of the gas filling function will be lifted, and the enable command will be allowed to start the solenoid valve gas filling process control; Otherwise, if the fault warning code is not cleared, the gas dispenser will continue to prohibit the use of the gas filling function; Its purpose is to prohibit the output of zero drift and metering failure caused by structural and electrical factors of the metering instrument indicated by the warning fault code, and to troubleshoot in time to enable normal operation. Only when the fault indicated by the warning code requested is eliminated and logical judgment is applied, and the online detection is normal, can the accurate metering function of the gas dispenser be enabled again; As for the tolerance caused by deterministic external dynamic noise and fluid medium purification interference, different warning codes are displayed on the LCD, and the fault location is navigated. Through the corresponding methods of standardized installation structure process adjustment, process inspection, and precise filtration and purification of fluid medium, the tolerance caused by interference measurement can be suppressed and eliminated; CNG gas dispenser metering out-of-tolerance control system includes: CNG dispenser body: A downstream cut-off ball valve is installed at the CNG air inlet at the bottom of the CNG dispenser body to realize the natural gas transmission, cut-off and special adjustment functions; A filter is set on the upper end pipeline of the downstream stop ball valve to realize the input filtration control of the fluid medium; shunt ball valves are symmetrically set on the pipelines on both sides of the filter, and the shunt ball valves are connected between the filter and the explosion-proof solenoid valve to meet the needs of troubleshooting and maintenance isolation of fluid medium; a safety valve and a one-way valve are set on the CNG manifold to realize the controllability of the medium flow channel; the safety valve is used to control the system pressure in the gas pipeline to not exceed the specified value; the explosion-proof solenoid valve is connected to the output I / O port of the explosion-proof power supply relay controller through isolation safety protection, which is used to safely realize the command control of the solenoid valve gas filling process; the explosion-proof power supply relay controller is connected to the command output I / O port of the measurement and control system mainboard, which is used to realize the safety and effectiveness of command drive; An upstream stop ball valve is installed on the upper pipeline of the mass flow meter, and cooperates with the downstream stop ball valve to realize the CNG transportation, stop and special adjustment functions of the manifold medium; a seismic-resistant pressure gauge and a safety unit pressure transmitter are installed on the pipeline of the upstream stop ball valve to realize real-time online pressure display and transmission; Among them, the safety unit pressure transmitter is responsible for sensing the pressure change response and transmission during the filling process. Combined with the safety valve, it ensures the realization of the static safety of the CNG filling machine system and the dynamic filling pressure limit safety standard and the special control requirements of the fluid pressure change increment; Symmetrically arranged IC card LCD keyboard display assemblies are installed on both sides of the CNG dispenser body, which can realize the operation of human-machine interactive management efficiently and conveniently. The LCD UV-resistant wide-temperature display integrates the measurement and control system mainboard 3.

0. The measurement and control system mainboard has built-in enabling expansion of real analog I / O interface and remote communication interface 3.1 and 3.2; it is the core guarantee for realizing system measurement out-of-tolerance detection and control.

2. The CNG filling machine metering out-of-tolerance control method based on intelligent detection and control according to claim 1 is characterized in that: If the logic and output results in steps S1 to S5 are 1, the command starts the solenoid valve to control the gas filling process: metering and pricing, display storage and enable I / O port output.

3. The CNG gas dispenser metering out-of-tolerance control method based on intelligent detection and control according to claim 1 is characterized in that: If the logical output result in steps S1 to S5 is 0, the fault management is started: including triggering the buzzer and LED to warn of the fault, displaying the fault code, and prohibiting the enabling of the gas filling instruction and interrupting the gas filling process of the solenoid valve that has been instructed to start.

4. The CNG gas dispenser metering out-of-tolerance control method based on intelligent detection and control according to claim 1 is characterized in that: In step S7, the accurate metering function of the gas dispenser can be enabled again only when the fault indicated by the requested warning code is eliminated and logical judgment is performed and the online detection and certification from step S1 to step S6 are passed normally.

5. A CNG gas filling machine metering out-of-tolerance control system according to any one of claims 1-4, characterized in that: include: The main control board of the measurement and control system is used to perform intelligent detection and control of the system's working parameters, working conditions, power-on and processes; The mass flow meter is connected to the forward channel of the main control board of the measurement and control system to enable the metering and transmission functions. It is the basic shared data information source to ensure accurate metering and achieve the control requirements of various working conditions. IC card LCD keyboard display assembly is connected to the forward channel of the main control board of the measurement and control system, and is responsible for human-computer interaction management: used for preset and correction parameters and special function options and process response command control and its management needs of warning code display, text operation, fault navigation and multi-mode query printing function management; The safety unit pressure transmitter is connected to the forward channel of the main control board of the measurement and control system, and is used to sense and transmit pressure changes during the filling process; LCD UV-resistant wide-temperature display, connected to the display driver I / O port of the measurement and control system main control board, is used to display current transaction data and special information in real time; The explosion-proof power supply relay controller is connected to the command output I / O port of the main control board of the measurement and control system to realize the safe drive of the intrinsic safety command; The explosion-proof solenoid valve is connected to the output I / O port of the explosion-proof power supply relay controller to realize the command control of the solenoid valve filling process.

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