JPH06331098A - Gas supply device - Google Patents

Abstract

PURPOSE:To provide a gas supply device which can accurately measure a supply amount of compressed gas. CONSTITUTION:A gas supply device has a pressure generation unit 4 which compresses gas to obtain the specified pressure and a dispenser unit 5. A variable pressure accumulator 18 and a high-pressure accumulator 19 are parallelly arranged on the pressure generation unit 4, while multistage compressor 15 supplies compressed gas alternately thereto for accumulation. The dispenser unit 5 is provided with a pressure governing valve 24, an interrupting valve 25, and a volume type flowmeter 26. A feedback pipe passage 28 has one end connected to the pipe on an upstream side of the volume type flowmeter 26, and the other end connected to a snapper tank 14 provided on the upstream side of the multistage compressor 15. After completion of gas supply, the interruption valve 25 is closed and an interruption valve 30 of the feedback pipe passage 28 is opened for feeding the residual gas in the supply hose 29 back to the snapper tank 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas supply device, and more particularly to a gas supply device configured to accurately measure the amount of supplied gas.

[0002]

2. Description of the Related Art For example, as a gas supply device for supplying compressed natural gas (CNG) obtained by compressing natural gas to another tank, there is a device as disclosed in Japanese Utility Model Laid-Open No. 4-64699. The device of the said gazette adopts a method of rapidly filling compressed gas, temporarily stores the gas whose pressure has been boosted to a predetermined pressure or higher by a compressor, and then stores the gas stored in the animal storage device. It is designed to be injected into a fuel tank of an automobile and filled until the inside of the fuel tank reaches a predetermined pressure.

The amount of gas supplied to the fuel tank of an automobile is measured by a flow meter, and the total flow rate filled in the fuel tank can be known. Also, the hose pulled out from the device body is connected to the fuel tank of the car before the gas supply,
It is removed from the fuel tank after the gas supply is completed. If pressurized gas remains in the hose, there is a risk of accidentally causing the gas to flow out of the hose.Therefore, after the gas supply is completed, the residual gas in the hose is stored in the upstream tank. It was refluxed.

[0004]

However, in the conventional gas supply device, the inside of the hose pulled out from the main body of the apparatus so that the flow meter is provided in the main body of the apparatus but extends downstream from the flow meter. Since this is also filled with gas, the flow rate display shows the flow rate including the gas in this hose. Therefore, conventionally, the flow rate measurement value displayed on the flow rate display also includes gas remaining on the downstream side of the flow meter that was not supplied to the fuel tank. Since it is displayed on the flow rate display as being supplied to, there is a problem that the flow rate measurement value is not accurate. Then, this invention aims at providing the gas supply apparatus which solved the said subject.

[0005]

According to the present invention, there is provided a pipe for feeding gas and a downstream end of the pipe, which is opened when the gas is supplied and closed after the gas is supplied. A supply nozzle, a gas pressure increasing means for increasing the pressure of the gas supplied to the downstream side through the pipeline to a predetermined pressure, and a flow meter for outputting a flow rate pulse according to the flow rate of the gas flowing through the pipeline, Provided in the pipe line so as to be located on the upstream side of the flow meter,
A first solenoid valve that opens and closes the conduit, one end connected to the conduit between the flow meter and the on-off valve, and the other end connected to an upstream conduit located upstream of the gas pressurizing means. And a second electromagnetic valve provided in the reflux conduit and opening and closing the reflux conduit, and a gas remaining in the conduit downstream of the flow meter after the gas supply is completed. After integrating the valve control means for closing the first solenoid valve and opening the second solenoid valve so as to return to the upstream of the gas pressure increasing means, and integrating the flow rate pulse output from the flow meter, Supply amount calculating means for calculating the gas supply amount by subtracting the flow rate pulse output from the flow meter when returning the gas remaining in the pipeline downstream of the flow meter to the upstream of the gas pressure increasing means, and It is characterized by

[0006]

After the gas supply is completed, the first electromagnetic valve for gas supply is closed and the second electromagnetic valve for gas recirculation is opened, so that the gas remaining on the downstream side of the flow meter is removed by the gas pressure increasing means. After returning to the upstream and integrating the flow rate pulse when supplying gas, the flow rate pulse when returning the gas remaining on the downstream side of the flow meter to the upstream of the gas booster is subtracted from this integrated value. It is possible to more accurately measure the flow rate measurement value of the gas supplied to the.

[0007]

1 and 2 show an embodiment of the gas supply device according to the present invention.

In both figures, the gas supply device 1 is installed, for example, in a gas supply station for supplying compressed natural gas (CNG) obtained by compressing city gas to a predetermined pressure to a fuel tank 3 of an automobile 2. Note that the compressed natural gas is an example, and the gas handled by the gas supply device 1 is not limited to this, and includes gas used by being compressed in a high pressure range from atmospheric pressure to about 200 atm.

The gas supply device 1 generally includes a pressure generation unit 4 for increasing the city gas to a predetermined pressure, a dispenser unit 5 for supplying the gas compressed by the pressure generation unit 4 to the fuel tank 3, and a customer card. A card reader 6 for reading, a pressure generation unit 4, a dispenser unit 5, a POS terminal 7 connected to the card reader 6, and a controller 8 for controlling the pressure generation unit 4 and the dispenser unit 5.

The pressure generating unit 4, the dispenser unit 5, and the card reader 6 are installed in a gas supply area for performing gas supply work, and the POS terminal 7 and the control unit 8 are provided.
Is installed in the building 9.

The pressure generating unit 4 includes a branch line 1 connected to an intermediate pressure line 10 before city gas is branched to a home.
1, a strainer 12 from the upstream side, a shutoff valve 13 composed of a solenoid valve, a snapper tank 14, a multistage compressor as a gas booster (a cylinder for medium pressure and a cylinder for high pressure are provided, and gas compressed by the cylinder for medium pressure is further increased in pressure). (Compressed to a high pressure by a cylinder for use) 15. In addition, the pressure generating unit 4 is provided in parallel with the gas supply pipelines 16 and 17
A variable storage device 18 and a high-pressure storage device 19 are provided in the.
The upstream ends of the gas supply pipe lines 16 and 17 are connected to the first switching valve 20 which is a three-way solenoid valve, and the downstream ends are connected to the second switching valve 21 which is a three-way solenoid valve. There is.

The first switching valve 20 connects the branch pipes 11 and 16 when the gas compressed by the compressor 15 is stored in the variable pressure storage device 18, and is stored in the high pressure storage device 19 when stored in the high pressure storage device 19. The branch lines 11 and 17 are switched so as to communicate with each other.

Further, the second switching valve 21 supplies a gas compressed to a predetermined pressure to the dispenser unit 5 as described later, and connects the pressure generating unit 4 and the dispenser unit 5 with a gas feed conduit 22. Then, switching is performed so that the gas stored in the variable pressure storage device 18 or the gas stored in the high pressure storage device 19 is fed. The pressure of the gas discharged from the variable accumulator 18 and the high-pressure accumulator 19 is determined by the line 22.
The pressure is detected by the pressure detector 38 disposed at.

[0014] In the present embodiment, if the maximum pressure of the fuel tank 3 has a 200 kgf / cm ^2, the maximum pressure of the variable accumulator 18 is set to 100 kgf / cm ^2, the maximum pressure of the high-pressure accumulator 19 Is set to 250 kgf / cm ² . Therefore, the compressor 15 compresses the city gas (about 5 to 8 kgf / cm ² ) supplied from the medium pressure pipe 10 to the branch pipe 11 to bring the pressures of the variable pressure storage device 18 and the high pressure storage device 19 to the above set pressure. To do.

Further, the dispenser unit 5 has a pipe line 23 connected to the gas feed pipe line 22, and a regulating valve 24 for adjusting the pressure and flow rate of the gas fed to the pipe line 23,
A shutoff valve (first electromagnetic valve) 25, which is an electromagnetic valve that is closed when gas supply is completed or when an emergency stop is performed, and a positive displacement flowmeter 26 that measures the flow rate of gas flowing through the conduit 23 are provided. .

The positive displacement type flow meter 26 is disposed downstream of the shutoff valve 25, and the pipe 23 between the positive displacement type flow meter 26 and the shutoff valve 25, that is, the inlet of the positive displacement type flow meter 26. One end of a return line 28 is connected to the near line 23. The other end of the return conduit 28 is connected to the snapper tank 14 of the pressure generating unit 4. The snapper tank 14 of this embodiment forms a part of the upstream pipe line located upstream of the compressor 15, and the reflux pipe line 28 is connected to the upstream pipe line of the snapper tank 14 and is connected to the compressor 15 by the compressor 15. Similar effects can be obtained even if the structure is connected to an upstream pipe located upstream.

The recirculation pipe 28 is a pipe for recirculating the residual gas downstream of the positive displacement flow meter 26 to the snapper tank 14 after the gas supply is completed. Further, the recirculation pipe 28 is normally closed to prevent the gas flowing through the pipe 23 from being supplied to the recirculation pipe 28, and is opened after completion of the gas supply to open the residual gas in the supply hose 29. A shut-off valve (first electromagnetic valve) 30 including an electromagnetic valve for returning to the snapper tank 14 is provided.

That is, after the gas supply is completed, the supply nozzle 31
When is closed, the high-pressure gas supplied from the high-pressure pressure vessel 19 remains in the supply hose 29. Therefore, when the shutoff valve 30 provided in the return conduit 28 is opened as described later, the residual gas in the supply hose 29 is removed from the snapper tank 1.
Since it is higher than the pressure of 4, it is returned to the snapper tank 14 through the return line 28. Therefore, the pressure in the supply hose 29 is reduced to the same pressure as before the gas supply.

The pipe line 23 is connected to the base end of the supply hose 29, and the supply nozzle 3 connected to the supply port (not shown) of the fuel tank 3 is connected to the tip of the supply hose 29.
1 is provided.

The positive displacement type flow meter 26 is provided with, for example, a pair of elliptical gears (not shown) that mesh with each other so as to be rotatable, and when the gas flowing through the conduit 23 flows to the supply hose 29 on the downstream side, When the pair of elliptical gears positively rotates at a rotational speed proportional to the flow rate, and after the gas supply is completed, the residual gas in the supply hose 29 is flown to the reflux pipe 28 and returned to the snapper tank 14 as described later. Reversely rotates at the number of rotations proportional to the flow rate of the refluxed. Then, the positive displacement flow meter 26 outputs a flow rate pulse according to the rotation speed and the rotation direction of the pair of elliptical gears. A Roots-type positive displacement flow meter having a cocoon-shaped rotor may be used as the positive displacement flow meter 26.

As shown in FIG. 3, a coupler half 39 is provided at the tip of the discharge pipe 31a of the supply nozzle 31, and a coupler half 40 is provided at the gas supply port 3a of the fuel tank 3. The coupler halves 39 and 40 are connected to each other and hold the discharge pipe 31a of the supply nozzle 31 and the gas supply port 3a of the fuel tank 3 in a communicating state. The coupler 41 including the coupler halves 39 and 40 is constructed so as not to come off when the internal pressure is high.

That is, the coupler 41 cannot be separated when the high-pressure gas remains in the supply hose 29, and the worker forgets to accidentally depressurize the supply hose 29 and removes it to eject the high-pressure gas. To prevent it. In addition, the supply nozzle 31 has a valve (not shown) for opening and closing the flow passage therein. When the operator operates the nozzle lever 31b, the valve is opened, and the nozzle lever 31b is returned. The valve closes.

Returning to FIG. 2, description will be made again.

Reference numeral 32 denotes a safety coupling, which is provided in the middle of the supply hose 29 and should be connected in the event that the automobile 2 starts with the supply nozzle 31 connected to the supply port (not shown) of the fuel tank 3. At the same time as releasing, the shutoff valve 25 is closed to prevent gas leakage.

A positioner 33 outputs a detection signal to close the shutoff valve 25 when an earthquake or an automobile collides with the dispenser unit 5. Reference numeral 34 denotes a supply switch, which is operated at the start of supply, the end of supply, or an emergency stop.

Reference numeral 35 denotes a display storage case, which has a pressure and explosion-proof structure in which a display 36 for displaying the flow rate and the supply pressure and a control circuit 37 are stored. As will be described later, the control circuit 37 includes an integrating counter (supply amount calculating means) for integrating flow rate pulses when the rotor of the positive displacement flow meter 26 is rotating forward and a reverse rotation of the rotor of the positive displacement flow meter 26. It has a subtraction counter (supply amount calculation means) for subtracting the flow rate pulse during operation, and valve control means for switching and controlling each valve of the pressure generation unit 4 and the dispenser unit 5.

Next, the operation of the gas supply device 1 having the above-mentioned configuration and the processing executed by the control circuit 37 will be described.

In FIG. 4, the control circuit 37 supplies the supply switch 3 in step S1 (hereinafter "step" is omitted).
Checking whether 4 has been operated on. As shown in FIG. 3, an operator connects the coupler half body 39 of the supply nozzle 31 to the coupler half body 40 of the gas supply port 3 a provided in the fuel tank 3 of the automobile 2 to move the nozzle lever 31 b of the supply nozzle 31. After pulling to open the valve, supply switch 3
When 4 is turned on, the process proceeds to S2. In S2, the shutoff valve 25 is opened to connect the conduit 23 and the supply hose 29. Then, the shutoff valve 30 is closed (S3).

When the supply switch 34 is not turned on in S1, the process proceeds to S4 and the process of maintaining the pressure of the high pressure accumulator 19 (high pressure tank supply subroutine) is executed. That is, the gas compressed by the compressor 15 is supplied to the high pressure accumulator 19 via the switching valve 20, and the pressure of the high pressure accumulator 19 is set to about 250 kgf / cm ² in this embodiment.

In S5, the switching valves 20 and 21 are switched to connect the pipe line 11 and the pipe line 16 with each other and the variable storage device 18 and the pipe line 22 to communicate with each other. Then, the valve opening of the adjusting valve 24 is set to a predetermined opening (S6).

In the next step S7, the multi-stage compressor 15 is started and the compressed gas is supplied to the variable pressure condenser 18. With this, the gas stored in the variable storage device 18 is adjusted by the adjusting valve 24,
It is supplied to the fuel tank 3 of the automobile 2 through the shutoff valve 25, the positive displacement meter 26, the supply hose 29, and the supply nozzle 31.

In this embodiment, the pressure of the variable pressure storage device 18 is maintained at about 100 kgf / cm ² , and the fuel tank 3 is supplied with gas of 100 kgf / cm ² or less. The positive displacement flow meter 26 detects the number of rotations of the internal rotor and outputs a flow rate pulse proportional to the flow rate Q of the gas supplied to the fuel tank 3, and the pressure detector 38 outputs the gas supplied to the fuel tank 3. The pressure P of is detected.

Accordingly, the control circuit 37 calculates the instantaneous flow rate Q by integrating the flow rate pulses output from the positive displacement flow meter 26 in S8, and reads the pressure P detected by the pressure detector 38. The integration counter of the control circuit 37 always integrates the flow rate pulses output by the rotor of the positive displacement flow meter 26 rotating normally.

In next step S9, it is checked whether or not the pressure P of the gas supplied to the fuel tank 3 has reached the judgment pressure P ₁ of the first stage. In this S9, until P ≧ P ₁ increases the valve opening degree of the adjustment valve 24 proceeds to S10, to check whether the flow rate Q in the next S11 is reached to a predetermined target flow rate Q _1.

In S11, when Q ≧ Q ₁ , the process returns to S9 and the processes of S9 to S11 are repeated. The flow rate of gas changes as shown in FIG. 5 by the gas supply process.

When P ≧ P ₁ in S9, the process proceeds to S12, in which the switching valves 20 and 21 are switched and the pipeline 1
1 and the pipe line 17 are communicated with each other, and the high-pressure accumulator 19 and the pipe line 22 are communicated with each other. Thus, the gas stored in the high-pressure storage device 19 is supplied to the fuel tank 3 of the automobile 2 through the regulating valve 24, the shutoff valve 25, the positive displacement flow meter 26, the supply hose 29, and the supply nozzle 31.

In next step S13, it is checked whether or not the pressure P of the gas supplied to the fuel tank 3 has reached the determination pressure P ₂ of the second stage. In this S13, P ≧ P
_When it becomes ₂ , the process proceeds to S14 and the shutoff valve 25 is closed. As a result, the gas supply to the fuel tank 3 of the automobile 2 is stopped.

In S15, it is checked whether the supply switch 34 is turned off. In S15, when the worker returns the nozzle lever 31b of the supply nozzle 31 to close the valve and operates the supply switch 34 to turn it off, the process proceeds to S16 to open the shutoff valve 30. That is, S1
In 6, the shut-off valve 30 provided in the reflux pipe 28 opens, so that the gas remaining downstream of the positive displacement flow meter 26 flows backward in the positive displacement flow meter 26 into the reflux conduit 28. The gas remaining in the supply hose 29 is returned to the snapper tank 14 via the reflux pipe 28.

Therefore, the pressure in the supply hose 29 is reduced to the same pressure as before the gas supply. Further, the flow rate of the gas flowing through the positive displacement flow meter 26 changes as shown in FIG. 5, and the flow rate of the gas passing through the reflux pipe 28 and flowing back becomes negative.

At the next step S17, the snapper tank 14 is fed from the integrated value of the integration counter, which is the integration of the flow rate pulses from the positive displacement flow meter 26 by the subtraction counter, via the return line 28.
The reflux flow rate returned to is subtracted. Then, the gas supply amount subtracted in S17, that is, the total supply amount supplied to the fuel tank 3 is displayed on the display 36.

Therefore, as described above, the gas supply amount is calculated and displayed on the display unit 36 in a state where the pressure in the supply hose 29 is reduced to the same pressure as before the gas supply, and therefore the actual gas supply amount is displayed. It is possible to measure and display a more accurate gas supply amount.

When the pressure in the supply hose 29 is reduced in this way, the worker can disconnect the coupler 41, separate the coupler halves 39 and 40, and connect the supply nozzle 31 to the nozzle. Put it back on the hook (not shown).

Subsequently, in S19, the fuel tank 3 of the automobile 2
The data such as the gas supply amount supplied to the card reader 6 and the POS terminal 7 are transferred.

In the above embodiment, the reflux pipe 28 is connected to the snapper tank 14, but the present invention is not limited to this. It may be configured to be connected.

In the above embodiment, the case where compressed natural gas (CNG) obtained by compressing city gas is supplied is given as an example, but the present invention is not limited to this, and gas such as butane and propane may be supplied. Of course, it can be applied.

In the above embodiment, the case where the fuel tank 3 of the automobile 2 is filled with the compressed gas has been described as an example, but the present invention is not limited to this, and a device for supplying the compressed gas to another container or the like. Needless to say, the present invention can also be applied to a device configured to be installed in the middle of a pipeline for simply feeding compressed gas to another place.

Further, in the above-mentioned embodiment, the city gas or the like is compressed from the medium pressure pipeline 10 before being branched to the home. However, the invention is not limited to this, and it is branched from the medium pressure pipeline 10, for example. The gas may be taken out from the household pipeline.

[0048]

As described above, in the gas supply device according to the present invention, after the gas supply is completed, the first solenoid valve for gas supply is closed and the second solenoid valve for gas recirculation is opened. ,
The gas remaining on the downstream side of the flow meter is returned to the upstream side of the gas pressurizing means, and the flow rate pulse when the gas is supplied is integrated. By subtracting the flow rate pulse when returning to the upstream, the flow rate measurement value of the actually supplied gas can be measured and displayed more accurately, improving the measurement accuracy of the gas supply amount and improving the reliability of the device itself. It has features such as improved productivity.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a gas supply device according to the present invention.

FIG. 2 is a configuration diagram of a pressure generating unit and a dispenser unit.

FIG. 3 is a diagram showing a connection between a supply nozzle and a gas supply port by a coupler.

FIG. 4 is a flowchart executed by a control circuit.

FIG. 5 is a diagram showing a change in mass flow rate measured when supplying compressed natural gas.

[Explanation of symbols]

 1 Gas Supply Device 3 Fuel Tank 4 Pressure Generation Unit 5 Dispenser Unit 14 Snapper Tank 15 Multi-Stage Compressor 18 Variable Pressure Accumulator 19 High Pressure Accumulator 24 Control Valve 25 Shutoff Valve 26 Positive Displacement Flow Meter 29 Supply Hose 31 Supply Nozzle 36 Indicator 37 Control Circuit 41 coupler

Claims (1)

[Claims] 1. A pipeline for feeding gas, a supply nozzle provided at a downstream end of the pipeline, opened at the time of gas supply, and closed after completion of gas supply, and the pipeline. A gas pressure increasing means for increasing the pressure of the gas supplied to the downstream side to a predetermined pressure through the flow path, a flow meter outputting a flow rate pulse according to the flow rate of the gas flowing through the pipe, A first solenoid valve provided in the pipeline so as to open and close the pipeline; one end is connected to the pipeline between the flow meter and the opening / closing valve, and the other end is the gas pressure increasing means. A reflux pipe connected to an upstream pipe located upstream of the second solenoid valve, a second solenoid valve provided in the reflux pipe for opening and closing the reflux pipe, and a downstream side of the flowmeter after completion of gas supply. The first solenoid valve is closed so that the gas remaining in the conduit of And valve control means for opening said second solenoid valve causes the, after integrating the outputted flow pulses from the flow meter,
A supply amount calculation means for calculating a gas supply amount by subtracting a flow rate pulse output from the flow meter when returning the gas remaining in the pipeline downstream of the flow meter to the upstream of the gas pressure increasing means, A gas supply device characterized in that