CN110715168A

CN110715168A - Controller for CNG (compressed natural gas) dispenser, LNG (liquefied natural gas) dispenser, gas filling column and gas discharging column

Info

Publication number: CN110715168A
Application number: CN201911013345.XA
Authority: CN
Inventors: 何平
Original assignee: Chongqing Yuandun Technology Co Ltd
Current assignee: Chongqing Yuandun Technology Co Ltd
Priority date: 2019-10-23
Filing date: 2019-10-23
Publication date: 2020-01-21
Anticipated expiration: 2039-10-23
Also published as: CN110715168B

Abstract

A controller for a CNG gas dispenser, an LNG liquid dispenser, a gas filling column and a gas discharging column realizes that the CNG gas dispenser, the LNG liquid dispenser, the gas filling column and the gas discharging column can be controlled by the same controller through the improvement of a power panel and a power panel control electromagnetic valve; the circuit structure realizes the control output of the intrinsic safety power supply under the action of taking the control function into consideration, and ensures that the surrounding flammable and explosive gas cannot be ignited even if the circuit is short-circuited or electric sparks occur; the multi-level storage mode of the ferroelectric memory and the EEPROM memory is adopted, so that the storage efficiency is improved; by adopting the MAC module, the gas filling record and other important parameter verification can be failed once a user tampers with data and replaces the storage module, the single chip microcomputer or any other important device, so that the safety of the data and the integrity of the system are ensured, and the anti-theft function is realized.

Description

Controller for CNG (compressed natural gas) dispenser, LNG (liquefied natural gas) dispenser, gas filling column and gas discharging column

Technical Field

The invention relates to the technical field of gas filling control, in particular to a controller compatible with control of a CNG (compressed natural gas) gas filling machine, an LNG (liquefied natural gas) liquid filling machine, a gas filling column and a gas discharging column.

Background

The conventional centralized design mode is generally adopted for the current gas dispenser controller, and the problems of unstable work, inaccurate metering, record loss, card reading and writing errors and the like easily occur. And because there is not standardized design, lead to equipment hardware such as CNG gas filling machine, LNG liquid filling machine, LNG gas column of unloading all to have different, increased production debugging cost and degree of difficulty.

The invention patent of 'a measurement and control method and system of an intrinsic safety type LNG dispenser' is disclosed in CN105114808A, and the invention patent discloses technical characteristics of an intrinsic safety type power supply, a main board, a keyboard board, a gas station PLC control system, an electromagnetic valve, a mass flowmeter and the like, and discloses corresponding gas dispensing steps. However, the problems that the comparison document cannot solve include: 1. the control compatibility of a CNG gas dispenser, an LNG liquid dispenser, a gas filling column and a gas discharging column; 2. the specific circuits of the main board, the power supply, the keyboard board and the printer power supply board are not disclosed; 3. a general storage mode is adopted for data storage, and the storage efficiency is low; 4. the problem of data encryption is not solved, and the condition of gas filling by stealing cannot be prevented.

Disclosure of Invention

The invention aims to provide a controller for a CNG (compressed natural gas) dispenser, an LNG (liquefied natural gas) liquid adding machine, a gas filling column and a gas discharging column, which is compatible with the CNG dispenser, the LNG liquid adding machine, the gas filling column and the gas discharging column.

The invention is realized by the technical scheme, which comprises a transformer, a power supply board, a main board, a keyboard board, a printer power supply board and a display board; the main board receives temperature, pressure and flow rate information, compares the temperature, pressure and flow rate information with preset parameters, judges whether gas and liquid are added or not, opens a valve through a power panel, collects flowmeter data and displays the flowmeter data on a keyboard board, and the power panel comprises a relay control signal output module;

the relay control signal output module controls the electromagnetic valve to work by outputting the intrinsic safety power supply to control the switches of the three relays according to the control signal sent by the mainboard; the three relays are used for controlling three low-pressure, medium-pressure and high-pressure electromagnetic valves of the CNG filling machine, or two of the relays are used for controlling a liquid-phase electromagnetic valve and a gas-phase electromagnetic valve of the LNG filling machine, or one of the relays is used for controlling a working electromagnetic valve of a filling column or a discharging column.

Further, the relay control signal output module comprises a jumper pin J1, a terminal J4, a voltage input terminal J8 and solenoid valve terminals J5, J6 and J7; a jumper pin J1 for selecting the working mode of the controller; a terminal J4 for outputting a relay switch signal to the PLC; j5, J6 and J7 are solenoid valve wiring terminals for connecting the solenoid valves; the voltage input terminal J8 is a 220V alternating-current voltage input terminal; control signals sent by the mainboard are input into the relay control signal output module through HVALVE, MVALVE, LVALVE and CVALVE ends, the HVALVE, MVALVE, LVALVE and CVALVE ends are respectively connected to bases of four triodes V13, V14, V15 and V16, emitting ends of the four triodes are respectively VH, VM, VL/P1 and P2 and are used for controlling voltage signal output of the relays K1, K2, K3, K4 and K5.

Furthermore, the power panel also comprises a main board keyboard board power supply module, a flowmeter power supply module and an LED backlight power supply module;

the main board keyboard board power supply module is used for outputting an intrinsic safety power supply to supply power to the main board and the keyboard board;

the flowmeter power supply module is used for outputting an intrinsic safety power supply to supply power to a CNG (compressed natural gas) dispenser or a flowmeter of the LNG dispenser;

and the LED backlight power supply module is used for outputting the intrinsic safety power supply to supply power to the LED backlight arranged on the back of the display panel.

Further, the main board keyboard board power supply module comprises a bridge V1, 12V alternating current voltage is input into the bridge V1 through a connecting terminal 12VAC1 and 12VAC2 and converted into direct current DC1_1 output, the direct current DC1_1 output is connected to a voltage stabilization chip U2 through a diode V3 and is output as DC1_2 after passing through a fuse tube F2, and electrolytic capacitors C1 and C3 provide filtering for the voltage stabilization chip U2; the regulated power supply DC1_2 is divided by resistors R3 and R5 to generate a sampling voltage, the sampling voltage is compared with a reference voltage generated by a voltage regulator V4 through a comparator Q1, and if the sampling voltage is higher than the reference voltage, a triode Q3 is conducted to output CTRL1_ 1; the regulated power supply DC1_2 is divided by resistors R4 and R6 to generate a sampling voltage, the sampling voltage is compared with a reference voltage generated by a voltage regulator V5 through a comparator Q2, and if the sampling voltage is higher than the reference voltage, a triode Q4 is conducted to output CTRL1_ 2; the current of a power supply DC1_2 is sampled by a resistor R13 and then is output as DC1_3, a voltage difference is formed at two ends of the resistor R13 at the moment, after the voltage difference reaches a preset value, triodes Q5 and Q6 can be conducted, CTRL1_1 and CTRL1_2 are output, the generated CTRL1_1 controls the opening and closing of a field effect tube V6, and the generated CTRL1_2 controls the opening and closing of the field effect tube V7; when the fets V6 and V7 are both turned on, DC1_3 becomes the output voltage through V6 and V7, which powers the digital circuits of the motherboard and the keypad.

Further, the power supply module of the flowmeter comprises 13V alternating current voltage, the 13V alternating current voltage is connected to a bridge consisting of diodes CR1, CR2, CR3 and CR4 through terminals 13VAC1 and 13VAC2 and converted into direct current DC2_1, the direct current DC2_1 is output as DC2_2 through a voltage stabilizing chip U1 and a fuse F1, the current of the whole circuit is limited by the fuse F1, the voltage of the circuit is limited by voltage stabilizing diodes VR1, VR2, VR3 and VR4, the voltage is divided by resistors R21 and R20 to generate sampling voltage, the sampling voltage is compared with negative electrode reference voltage in a comparator U3, and if the voltage is over-voltage, a field effect tube Q7 is closed.

Further, the LED backlight power supply module comprises a bridge V2, 12V alternating current voltage is input into the bridge V2 through a connecting terminal 12VAC3 and 12VAC4 and converted into direct current, a protective tube F3 and a current-limiting resistor R25 play a role in limiting current, and a voltage stabilizing diode V8, a voltage stabilizing resistor V9, a voltage stabilizing diode V10 and a voltage stabilizing diode V11 stabilize the voltage to 12V.

Furthermore, the power panel, the mainboard, the relay and the keyboard panel are connected through the flat cable, the power supply is connected to the power panel and the printer power panel after being reduced by the transformer, and the power panel and the printer power panel are used for reducing voltage and outputting voltage-limiting current-limiting intrinsic safety power to control the mainboard and the keyboard panel.

Furthermore, the mainboard comprises a singlechip module, a watchdog and voltage detection module, a storage module, a manual operator interface module, a flowmeter communication module, a PLC communication module and a pressure sensor sampling module;

the singlechip module is used for receiving, processing and outputting control signals;

the watchdog is used for detecting whether the single chip microcomputer is dead, and if the single chip microcomputer is dead, a low-level reset signal is sent out to reset the single chip microcomputer; the voltage detection module is used for detecting whether external power supply is interrupted or not, if the external power supply is interrupted, a low level signal is sent to inform the single chip microcomputer, and the single chip microcomputer executes a power failure processing program;

the storage module is used for storing setting parameters, gas filling process data and gas filling record data;

the manual operator interface module is used for being connected with a manual operator;

the flowmeter communication module is used for receiving data information acquired by the flowmeter;

the PLC communication module is used for data interaction with the PLC;

and the pressure sensor sampling module is used for receiving the pressure information acquired by the pressure sensor.

Furthermore, the keyboard board is provided with a multi-level storage module which comprises a ferroelectric memory and an EEPROM memory, and parameters such as starting time, card number, balance, quantitative value, cumulative amount and air entrainment real-time data are cached in the ferroelectric memory, such as transaction time and amount, and are stored in the EEPROM memory.

Further, the keyboard board comprises an MAC module, the MAC module comprises a chip, and a globally unique 48-bit code is arranged in the chip; after the codes of the MAC module are encrypted, the codes are stored in the singlechip, the ferroelectric memory, the EEPROM memory, the word bank chip and the real-time clock module.

Due to the adoption of the technical scheme, the invention has the following advantages:

1. according to the invention, through the improvement of the power panel and the control electromagnetic valve of the power panel, the compatible control of the CNG filling machine, the LNG filling machine, the filling column and the gas discharging column by the same controller is realized; 2. the circuit structure of the power panel, the mainboard, the keyboard panel and the printer power panel which are specially designed realizes the control output of the intrinsic safety power supply under the action of taking the control function into consideration, and ensures that the surrounding flammable and explosive gas cannot be ignited even if the circuit is short-circuited or the electric spark occurs; 3. the invention adopts the multi-level storage mode of the ferroelectric memory and the EEPROM memory, thereby improving the storage efficiency; 4. the invention adopts the MAC module, and once a user tampers with data and replaces a storage module, a singlechip or any other important device, the verification of gas filling records and other important parameters can fail, so that the safety of the data and the integrity of the system are ensured, and the anti-theft function is realized.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof.

Drawings

The drawings of the present invention are described below.

FIG. 1 is a schematic diagram of the circuit structure of the present invention;

FIG. 2 is a schematic block circuit diagram of a power strip;

FIG. 3 is a schematic block circuit diagram of a motherboard;

FIG. 4 is a schematic block circuit diagram of a keypad board;

FIG. 5 is a circuit diagram of a motherboard power supply module;

FIG. 6 is a circuit diagram of a power module of the flow meter;

FIG. 7 is a circuit diagram of an LED backlight power supply module;

fig. 8 is a circuit diagram of the relay control signal output module.

Detailed Description

The invention is further illustrated by the following figures and examples.

A controller for CNG dispenser, LNG dispenser, gas column and gas column comprises a transformer, a power board, a printer power board, a main board, a keyboard board, a display board, etc., as shown in FIG. 1. The 220V alternating current is reduced in voltage by the transformer and then is connected to the power panel and the printer power panel, the intrinsic safety power supply for limiting voltage and current is output after the voltage is reduced by the two board subcircuits, and the power panel and the mainboard are connected through the flat cable. The valve control signal is also transmitted to the power panel from the main board through the flat cable to control each relay. The main board is provided with a display panel output interface for connecting the display panel. The main board also has a keyboard board connecting cable for connecting to the keyboard board for supplying power to the keyboard board and for communication between the two boards. The power panel is provided with three 220V relay output contacts which are respectively interfaces of a low pressure valve, a medium pressure valve and a high pressure valve when used as a CNG (compressed natural gas) dispenser controller; when the controller is used as an LNG gas dispenser controller, the interfaces of the liquid phase valve and the gas phase valve are respectively provided, and meanwhile, a control signal is output to the PLC through a direct current relay; when the gas filling column or the gas discharging column is used, only one valve interface is needed to be connected.

When the keyboard works, the keyboard board utilizes the keys and the liquid crystal display screen to carry out man-machine interaction with an operator. The circuit schematic block diagram of the keyboard board is shown in fig. 4, when an operator sends a gas filling and liquid adding instruction, the keyboard board is communicated with the main board through a flat cable, the main board is communicated with the flowmeter through a 485 interface, the flowmeter is informed of emptying accumulated number, and gas filling and liquid adding metering is prepared. The main board circuit schematic diagram is shown in fig. 3, and the main board judges whether gas and liquid can be added or not according to the current parameters of temperature, pressure, flow rate and the like. Once the conditions are met, the main board informs the power panel to open the corresponding valve to fill gas or add liquid, collects the data of the flowmeter and displays the data on the display panel and the keyboard panel in real time. And when gas and liquid are added, the mainboard collects parameters such as temperature, pressure, flow velocity and the like continuously, compares the parameters with preset parameters, and judges whether the valve needs to be changed or the gas and liquid adding needs to be stopped. Once the valve needs to be changed, the main board informs the power panel to close the current valve, switches to the next valve, and sends the state of changing the valve to the keyboard panel for display. Once gas and liquid filling are required to be stopped, the main board informs the power panel to close all the valves, and after metering is stopped, the main board reads final data of the flow meter and sends the data to the keyboard board. And the keyboard board carries out operations such as deduction, record storage, statistics accumulation and the like according to the final metering data, and then sends the record to the background of the upper computer through a 485 interface.

The invention adopts a multi-level storage system to ensure the safety and the integrity of data, as shown in figure 4, the keyboard board is provided with a multi-level storage module which is composed of a ferroelectric memory with higher reading and writing speed and smaller capacity and an EEPROM memory with lower reading and writing speed and larger capacity. Before gas filling is started, the keyboard board caches sensitive data of the transaction, such as parameters of starting time, card number, balance, quantitative value, accumulated amount and the like, in the ferroelectric memory, and then sends a gas filling instruction to the main board. In the process, if the keyboard single chip microcomputer is reset, the keyboard single chip microcomputer can be quickly restored to the state which the keyboard single chip microcomputer is supposed to be in according to the data cached in the ferroelectric memory. After the main board enters the air-entrapping state, the keyboard board caches air-entrapping real-time data into the ferroelectric memory at regular time, and meanwhile, the main board also stores the air-entrapping data into a storage module of the main board in real time. When gas is added, the keyboard board or the main board can be quickly restored to a normal state no matter faults such as resetting occur; if power is cut off at this time, the mainboard can supply power by depending on the battery on the mainboard, and the transaction record is finished. Even if the battery of the main board fails, the system is immediately and comprehensively powered off after power failure, and after the system is powered on again, the main board and the keyboard board can be immediately restored to a normal state according to the cached data, and unfinished transaction of the time is recorded. When the record is stored, the keyboard board firstly searches whether the current transaction is recorded in the EEPROM according to the parameters of the current transaction, such as time, amount and the like, and if the record exists, the cache in the ferroelectric is emptied; if the record does not exist, the transaction record is stored, and then the cache is emptied. At this point, the complete transaction flow is complete.

The invention adopts the MAC authentication method to ensure the safety of data and the integrity of the system. As shown in fig. four, the keypad board has a MAC module, which is a 6-pin chip with a globally unique 48-bit code built in. When the gas dispenser controller leaves a factory, the codes of the MAC module are encrypted and then stored in modules with storage functions, such as a single chip microcomputer, a clock module, a ferroelectric memory, an EEPROM memory, a word bank chip and the like. This operation binds the important components of the device to this uniquely numbered MAC module. All data, gas filling records and the like of the gas filling machine are encrypted by using the unique code. Once a user tampers with data, replaces a storage module, a single chip microcomputer or any other important device, the gas filling records and other important parameter verification can fail. Thereby ensuring the security of data and the integrity of the system.

The power panel has a circuit schematic block diagram as shown in fig. 2, and includes a relay control signal output module, a main board keyboard board power supply module, a flowmeter power supply module, and an LED backlight power supply module.

As shown in fig. 5, the main board keyboard board power supply module inputs 12V ac voltage to the bridge V1 through the terminals 12VAC1 and 12VAC2, and converts the voltage into DC1_ 1. Diode V3 protects against voltage reversal. The electrolytic capacitors C1 and C3 provide filtering for the voltage stabilizing chip U2. The direct current DC1_1 passes through a voltage stabilizing chip U2 and a fuse F2 and then is output as DC1_ 2. The fuse tube F2 performs current limiting protection on the current of the whole circuit. The regulated power DC1_2 is divided by resistors R3 and R5 to generate a sampling voltage, the sampling voltage is compared with a reference voltage generated by a voltage regulator V4 through a comparator Q1, if the sampling voltage is higher than the reference voltage, a triode Q1 is conducted, and a field effect tube V6 is further closed, so that the purpose of overvoltage protection is achieved. The same overvoltage protection circuit has two paths in total to ensure the function. After the current is sampled by the resistor R13, a voltage difference is formed at two ends of the resistor R13, the triodes Q5 and Q6 can be switched on after the voltage difference reaches a certain value, and the field effect transistor V6/V7 can be switched off in the same way, so that the purpose of overcurrent protection is achieved. The same super current protection circuit has two paths in total to ensure the function. The intrinsically safe output is used as a digital circuit power supply for the main control board and the keyboard board.

As shown in FIG. 6, in the power supply module of the flowmeter, a 13V alternating current voltage is connected to a bridge consisting of diodes CR1, CR2, CR3 and CR4 through terminals 13VAC1 and 13VAC2, converted into a direct current DC2_1, and output as DC2_2 through a voltage stabilizing chip U1 and a fuse F1. The fuse tube F1 performs current limiting protection on the current of the whole circuit. The voltage limiting diodes VR1, VR2, VR3 and VR4 limit the voltage of the circuit. The sampling voltage is generated after voltage division by resistors R21 and R20, the sampling voltage is compared with the negative electrode reference voltage in a comparator U3, and if the voltage is excessive, a field effect transistor Q7 is closed, so that the purpose of overvoltage protection is achieved. The road intrinsically safe output is used as a flow meter power supply.

As shown in fig. 7, the LED backlight power supply module has 12V ac voltage input to a bridge V2 through terminals 12VAC3 and 12VAC4 to be converted into dc voltage. The fuse tube F3 and the current limiting resistor R25 play a role in limiting current. The zener diodes V8, V9, V10, V11 regulate the voltage to 12V. The intrinsically safe output is used as LED backlight power.

A relay control signal output module, as shown in fig. 8, J1 is a jumper pin for selecting a controller operating mode; j4 is a binding post for outputting relay switch signal to PLC; j5, J6 and J7 are solenoid valve wiring terminals for connecting the solenoid valves; j8 is a 220V AC input terminal. The control signals transmitted from the main control board are HVALVE, MVALVE, LVALVE and CVALVE which are respectively connected to the bases of triodes V13, V14, V15 and V16, the emitters of the triodes are numbered as VH, VM, VL/P1 and P2 and are used as control voltage signal outputs of solid-state relays K1, K2, K3, K4 and K5. Wherein VL/P1 can select the controlled relay through jumper cap J1. When used as a CNG controller, the jumper cap shorts pins 2, 3 of J1, and the LVALVE signal controls relay K3 and not K1. The connection method of the electromagnetic valve is as follows: j5 is connected with a low pressure valve, J6 is connected with a medium pressure valve, J7 is connected with a high pressure valve, and J4 is not connected. When the levels of control signals LVALVE, MVAVLE and HVAVLE of the mainboard are changed, the conduction states of the triodes V15, V14 and V13 can be changed, and then the opening and closing states of the relays K3, K4 and K5 are changed, so that the purpose of controlling three low-voltage, medium-voltage and high-voltage electromagnetic valves is achieved; when used as an LNG controller, the jumper cap shorts pins 1, 2 of J1, at which time the LVALVE signal controls relay K1 and not K3. The connection method of the electromagnetic valve is as follows: j5 is not connected, J6 is connected with a liquid phase valve, J7 is connected with a gas phase valve, and J4 is connected with two groups of switching signals to a PLC control cabinet. When the level of the control signals MVAVLE and HVAVLE of the mainboard is changed, the conduction state of the triodes V14 and V13 can be changed, and then the opening and closing states of the relays K4 and K5 are changed, so that the purpose of controlling the liquid-phase electromagnetic valve and the gas-phase electromagnetic valve is achieved. Meanwhile, when the levels of control signals LVALVE and CVALVE of the main board are changed, the conducting states of the triodes V15 and V16 can be changed, the opening and closing states of the relays K1 and K2 are further changed, the relays can be opened and closed to form a combination of four states of 00, 01, 10 and 11, the standby, precooling, liquid adding and other operations of the LNG liquid adding machine are represented, the combination of the four states is transmitted to a PLC control cabinet through a wiring terminal J4, equipment under the control of the PLC can be linked, and the purpose of normal work of the liquid adding machine set is achieved; when used as a gas column or gas column controller, the jumper cap shorts pins 2 and 3 of J1, and the LVALVE signal controls relay K3 and not K1. The connection method of the electromagnetic valve is as follows: j5 is connected with the electromagnetic valve of gas filling column or gas discharging column, and J6, J7 and J4 are not connected. When the control signal LVALVE level of the mainboard changes, the conduction state of the triode V15 can be changed, and then the switching state of the relay K3 is changed, and the purpose of controlling the electromagnetic valve is achieved.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims

1. A controller for a CNG dispenser, an LNG dispenser, a gas column and a gas column comprises a transformer, a power panel, a main board, a keyboard board, a printer power panel and a display panel; the mainboard receives temperature, pressure, velocity of flow information, compares with preset parameter, judges whether to add the gas liquid feeding to open the valve through the power strip, gather flowmeter data and show on the keyboard board, its characterized in that: the power panel comprises a relay control signal output module;

2. The controller for a CNG dispenser, an LNG dispenser, a gas column, and a gas column as claimed in claim 1, wherein: the relay control signal output module comprises a jumper pin J1, a binding post J4, a voltage input binding post J8 and solenoid valve binding posts J5, J6 and J7; a jumper pin J1 for selecting the working mode of the controller; a terminal J4 for outputting a relay switch signal to the PLC; j5, J6 and J7 are solenoid valve wiring terminals for connecting the solenoid valves; the voltage input terminal J8 is a 220V alternating-current voltage input terminal; control signals sent by the mainboard are input into the relay control signal output module through HVALVE, MVALVE, LVALVE and CVALVE ends, the HVALVE, MVALVE, LVALVE and CVALVE ends are respectively connected to bases of four triodes V13, V14, V15 and V16, emitting ends of the four triodes are respectively VH, VM, VL/P1 and P2 and are used for controlling voltage signal output of the relays K1, K2, K3, K4 and K5.

3. The controller for a CNG dispenser, an LNG dispenser, a gas column, and a gas column as claimed in claim 1, wherein: the power panel also comprises a main board keyboard board power supply module, a flowmeter power supply module and an LED backlight power supply module;

4. A controller for a CNG dispenser, an LNG dispenser, a gas column and a gas column as claimed in claim 3, wherein: the main board keyboard board power supply module comprises a bridge V1, 12V alternating current voltage is input into the bridge V1 through a wiring terminal 12VAC1 and 12VAC2 and converted into direct current DC1_1 output, the direct current DC1_1 output is connected into a voltage stabilization chip U2 through a diode V3 and is output as DC1_2 after passing through a fuse F2, and electrolytic capacitors C1 and C3 provide filtering for the voltage stabilization chip U2; the regulated power supply DC1_2 is divided by resistors R3 and R5 to generate a sampling voltage, the sampling voltage is compared with a reference voltage generated by a voltage regulator V4 through a comparator Q1, and if the sampling voltage is higher than the reference voltage, a triode Q3 is conducted to output CTRL1_ 1; the regulated power supply DC1_2 is divided by resistors R4 and R6 to generate a sampling voltage, the sampling voltage is compared with a reference voltage generated by a voltage regulator V5 through a comparator Q2, and if the sampling voltage is higher than the reference voltage, a triode Q4 is conducted to output CTRL1_ 2; the current of a power supply DC1_2 is sampled by a resistor R13 and then is output as DC1_3, a voltage difference is formed at two ends of the resistor R13 at the moment, after the voltage difference reaches a preset value, triodes Q5 and Q6 can be conducted, CTRL1_1 and CTRL1_2 are output, the generated CTRL1_1 controls the opening and closing of a field effect tube V6, and the generated CTRL1_2 controls the opening and closing of the field effect tube V7; when the fets V6 and V7 are both turned on, DC1_3 becomes the output voltage through V6 and V7, which powers the digital circuits of the motherboard and the keypad.

5. A controller for a CNG dispenser, an LNG dispenser, a gas column and a gas column as claimed in claim 3, wherein: the power supply module of the flowmeter comprises 13V alternating current voltage, the 13V alternating current voltage is connected into a bridge consisting of diodes CR1, CR2, CR3 and CR4 through terminals 13VAC1 and 13VAC2 to be converted into direct current DC2_1, the direct current DC2_1 is output as DC2_2 through a voltage stabilizing chip U1 and a protective tube F1, the protective tube F1 carries out current limiting protection on the current of the whole circuit, the voltage stabilizing diodes VR1, VR2, VR3 and VR4 carry out voltage limiting on the circuit, the voltage is divided through resistors R21 and R20 to generate sampling voltage, the sampling voltage is compared with negative reference voltage in a comparator U3, and if the voltage is excessive, a field effect tube Q7 is closed.

6. A controller for a CNG dispenser, an LNG dispenser, a gas column and a gas column as claimed in claim 3, wherein: the LED backlight power supply module comprises a bridge V2, 12V alternating current voltage is input into the bridge V2 through a connecting terminal 12VAC3 and a connecting terminal 12VAC4 and converted into direct current, a protective tube F3 and a current-limiting resistor R25 play a role in limiting current, and voltage is stabilized to 12V by voltage stabilizing diodes V8, V9, V10 and V11.

7. The controller for a CNG dispenser, an LNG dispenser, a gas column, and a gas column as claimed in claim 1, wherein: the power supply is connected with the power panel and the printer power panel after being stepped down by the transformer, and the power panel and the printer power panel are stepped down to output a voltage-limiting current-limiting intrinsic safety power supply to control the mainboard and the keyboard panel.

8. The controller for a CNG dispenser, an LNG dispenser, a gas column, and a gas column as claimed in claim 1, wherein: the main board comprises a single chip microcomputer module, a watchdog and voltage detection module, a storage module, a manual operator interface module, a flowmeter communication module, a PLC communication module and a pressure sensor sampling module;

the PLC communication module is used for data interaction with the PLC;

9. The controller for a CNG dispenser, an LNG dispenser, a gas column, and a gas column as claimed in claim 1, wherein: the keyboard board is provided with a multi-level storage module which comprises a ferroelectric memory and an EEPROM memory, and parameters such as starting time, card number, balance, quantitative value, cumulative amount and air entrainment real-time data are cached in the ferroelectric memory, such as transaction time and amount, and are stored in the EEPROM memory.

10. A controller for a CNG dispenser, an LNG dispenser, a gas column, and a gas column as claimed in claims 8 and 9, wherein: the keyboard board comprises an MAC module, the MAC module comprises a chip, and a globally unique 48-bit code is arranged in the chip; after the codes of the MAC module are encrypted, the codes are stored in a single chip microcomputer, a watchdog, a ferroelectric memory, an EEPROM memory, a word bank chip and a real-time clock module.