JP2002364396A - Fuel mixing and filling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mix a liquid fuel of high inflammability with a gaseous fuel through safe pressurization. SOLUTION: In this fuel mixing and filling system 10, a gaseous fuel past a first fuel supply path 12 and a liquid fuel past a second fuel supply path 14 converge in a manifold 56 and then pass through a third fuel supply path 16 to fill a fuel tank 15 of a vehicle. The liquid fuel is supplied under pressurization by an air-driven booster pump 34. A drive part of the air-driven booster pump 34 is fed with compressed air generated by an air compressor 48. The air-driven booster pump 34 used to pressurize an inflammable liquid fuel can eliminate a risk of firing by an electric spark and pressurize the liquid fuel safely because of no electric system, and can be structurally compact because of no need for an explosion-proof structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel mixing and filling system, and more particularly to a CNG (compressed natural gas) in a filling tank.
Gas fuel consisting of LPG (Liquefied Petroleum)
The present invention relates to a fuel mixing and filling system configured to be charged with a liquid fuel composed of gases.

[0002]

2. Description of the Related Art In recent years, studies have been made on fuels that can replace petroleum (gasoline and light oil) from the viewpoint of cleaning exhaust gas emitted from automobile engines and effectively utilizing resources. A method of using gaseous fuel as a fuel for vehicles as one of alternative fuels whose exhaust gas is cleaner than burning light oil is being studied.

[0003] Compressed natural gas as a gaseous fuel is mainly composed of methane (CH ₄ ), emits 20 to 30% less carbon dioxide (CO ₂ ) than gasoline and the like, and has a low sulfur content.
PM (Suspended Particle Matter)
There is an advantage that the generation amount of SOx (sulfur oxide) and SOx (sulfur oxide) is small, and since it is supplied to each household as city gas, a sufficient supply amount is secured.

[0004] However, compressed natural gas has a low energy density, which is about 1/4 that of gasoline. That is, in a natural gas vehicle using compressed natural gas as a fuel, the running distance is shorter than that of a gasoline-powered vehicle, and it is necessary to increase the capacity of a fuel tank in order to extend the running distance by one gas filling. was there.

[0005] Therefore, it has been considered to increase the mileage of an automobile by filling a fuel tank of the automobile with a fuel obtained by dissolving and mixing compressed natural gas and a liquid fuel having a high energy density.

[0006]

As described above, in a fuel mixing and filling system for filling a fuel tank of an automobile with compressed natural gas and liquid fuel, compressed natural gas as a gaseous fuel is charged at a high pressure of, for example, 200 kg / cm ^2. Therefore, it is necessary to pressurize and fill liquefied petroleum gas as a liquid fuel.

As described above, as means for pressurizing liquefied petroleum gas, for example, it is considered that a pump driven by an electric motor is disposed in a liquefied petroleum gas supply line to increase the pressure to a level higher than the pressure of compressed natural gas. I have.

However, in the fuel mixing and filling system, a means for pressurizing the flammable liquefied petroleum gas is required to have high explosion-proof performance. Therefore, the pump itself must have an explosion-proof structure. As the number of pumps increases, the size of the pump may increase, and there is a problem that practical use is difficult.

In view of the above problems, an object of the present invention is to provide a fuel mixing and filling system capable of improving safety, reducing the number of parts, and increasing control efficiency.

[0010]

In order to solve the above problems, the present invention has the following features.

According to a first aspect of the present invention, there is provided a fuel mixing and filling system for filling a liquid fuel and the gaseous fuel into a container at a predetermined ratio, wherein the liquid fuel is pressurized to a pressure higher than a supply pressure of the gaseous fuel. Since the air-driven boost pump is provided and it is not necessary to cover with an explosion-proof case unlike the method driven by an electric motor, the number of parts of the pump can be reduced, the structure can be simplified, and the pump can be downsized.

According to a second aspect of the present invention, the ratio of the liquid fuel supplied from the second fuel supply path is adjusted by adjusting the supply pressure of the gaseous fuel by a control valve disposed in the first fuel supply path. The liquid fuel is adjusted to an arbitrary value, and the liquid fuel can be filled into the container to be filled with a pressure corresponding to the supply pressure of the gaseous fuel. For example, the liquid fuel is supplied to an air-driven pressurizing pump that pressurizes the liquid fuel. If the air pressure is constant, by controlling the supply pressure of the gaseous fuel, the gaseous fuel and the liquid fuel can be mixed at a ratio corresponding to the pressure difference.

According to a third aspect of the present invention, a stroke of a drive-side piston or a pump-side piston is detected, and an operation state of an air-driven pressure-boosting pump is determined based on the detected piston stroke. Or leakage of liquid fuel from the stroke of the pump side piston,
Air mixing and volume flow rate can be determined.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of a fuel mixing and filling system according to the present invention. As shown in FIG. 1, the fuel mixing and filling system 10 includes a first fuel supply path 12 for supplying compressed natural gas (hereinafter, referred to as “gas fuel”) and a liquefied petroleum gas (hereinafter, “liquid fuel”). Second fuel supply path 1 for supplying
4, a third fuel supply path 12 and a second fuel supply path 14 merge at an upstream end and a third fuel whose downstream end is connected to a fuel tank (filled container) 15 of the vehicle. And a supply path 16.

The upstream end of the first fuel supply path 12 is
Gas storage device 1 in which gaseous fuel is compressed to a predetermined pressure and stored.
8 is connected. The gas storage 18 is supplied with gaseous fuel from a city gas pipe (not shown) and is compressed to a high pressure of, for example, about 200 kg / cm ² by a compressor (not shown).

In the first fuel supply path 12, a pressure gauge 20 for measuring the supply pressure of the gaseous fuel, a mass flowmeter 22 for measuring the flow rate of the gaseous fuel, and a shut-off valve which is opened at the time of filling to start supply of the gaseous fuel A valve 24, a control valve (control valve) 26 for controlling the flow rate and pressure of the gaseous fuel, and a check valve 28 for preventing the gaseous fuel from flowing back are provided.

The upstream end of the second fuel supply path 14 is
It is connected to an LPG tank 30 in which liquid fuel is stored. Further, the first fuel supply path 14 is
Primary pressure gauge 32 for measuring the secondary pressure, air-driven pressure pump 34, secondary pressure gauge 36 for measuring the secondary pressure of the liquid fuel pressurized by air-driven pressure pump 34, pressurized liquid fuel A mass flow meter 38 for measuring the flow rate of liquid fuel, a shut-off valve 40 that is opened at the time of filling to start supply of liquid fuel, a control valve (control valve) 42 for controlling the flow rate and pressure of pressurized liquid fuel, Check valve 4 to prevent backflow
4 are provided.

The air-driven boost pump 34 is configured to be driven by the pressure of compressed air, as described later, and is connected to an air supply pipe 46 for supplying compressed air. An air compressor 48 that generates compressed air, a shut-off valve 50 that opens to supply compressed air at the time of charging, a regulator 52 that adjusts the supply pressure of compressed air to a predetermined pressure, a compressed air A pressure gauge 54 for measuring the supply pressure of is provided.

Therefore, the compressed air generated by the air compressor 48 is adjusted to a predetermined driving pressure by the regulator 52 and is supplied to the driving section of the air-driven pressure boost pump 34. Although the air-driven pressure pump 34 pressurizes flammable liquid fuel, it does not require an electrical system, so there is no risk of ignition due to electric sparks (sparks) and there is no need to use an explosion-proof structure. . Therefore, the air-driven boost pump 34 does not need to be covered with an explosion-proof case or the like as in the system driven by an electric motor, so that the number of parts can be reduced accordingly, and the configuration is compact.

The gaseous fuel and the liquid fuel that have passed through the first fuel supply path 12 and the second fuel supply path 14 join at the manifold 56, pass through the third fuel supply path 16, and pass through the fuel tank 15 of the vehicle. Is filled. Further, the third fuel supply path 16 includes the first fuel supply path 12 and the second fuel supply path 12.
A pressure gauge 58 for measuring the pressure of the fuel supplied from the fuel supply path 14 is provided, and a filling nozzle 60 is provided at a downstream end of the third fuel supply path 16.

The fuel tank 15 is provided with a filling port 62 having a quick coupler with a check valve to which a filling nozzle 60 is connected. Then, the filling nozzle 60 is
, Fuel filling is started.

The first to third fuel supply paths 1
Each device arranged in 2, 14, and 16 is connected to the control circuit 63, and operates according to a control signal from the control circuit 63 as described later.

Here, the configuration of the air-driven boost pump 34 will be described. FIG. 2 is a longitudinal sectional view showing the internal configuration of the air-driven boost pump 34. In FIG. 2, a check valve 7 for sucking and discharging a liquid fuel described later is used.
8, 82 are omitted. As shown in FIG. 2, the air-driven pressurizing pump 34 includes an air compressor 4
8 to which the compressed air generated by the drive unit 8 is supplied.
And a pump unit 66 driven by the drive unit 64.

The driving section 64 includes a driving cylinder 68 and a driving piston 70 that moves in the driving cylinder 68 when driving air is supplied to the driving cylinder 68.
And a piston rod 72 having one end coupled to the drive-side piston 70. The drive side cylinder 68 is defined by a drive side piston 70 into an upper chamber 68a and a lower chamber 68b.

The four-way solenoid valve 71 has a port communicating with the air supply line 46, a port b communicating with the atmosphere, a port c communicating with the lower chamber 68b in the driving cylinder 68, and a d port.
The port communicates with the upper chamber 68 a in the driving cylinder 68. The four-way solenoid valve 71 is switched by a control signal from the control circuit 63 to supply the driving air generated by the air compressor 48 to one of the upper chamber 68a or the lower chamber 68b, and to control the upper chamber 68a or the lower chamber 68b. The other is exhausted as air communication. Thus, the driving-side piston 70 reciprocates in the driving-side cylinder 68 to transmit the driving force to the pump section 66.

The pump section 66 has a pump-side cylinder 74 formed smaller in diameter than the drive-side cylinder 68, and a pump-side piston 76 connected to the other end of the piston rod 72. The pump-side cylinder 74 includes the pump-side piston 7.
6, an upper chamber 74a and a lower chamber 74b are defined, and a suction port 74c is provided at the bottom of the lower chamber 74b.
A discharge port 74b is provided on a side surface of the upper chamber 74a.

Therefore, the pump-side piston 76 is formed integrally with the drive-side piston 70 via the piston rod 72. When the drive-side piston 70 is driven by the pressure of the compressed air, it reciprocates in the pump-side cylinder 74. To move the liquid fuel from the suction port 74c and pressurize the liquid fuel sucked into the pump side cylinder 74 to discharge the liquid fuel.
Discharge from 4d.

As described above, the air-driven boost pump 34
Is driven by the supply of compressed air, so there is no electric system that generates sparks, it can safely discharge fuel even when pressurizing highly flammable fuel, and it is driven by an electric motor Since it is not necessary to cover with an explosion-proof case, the number of parts of the pump can be reduced, the structure can be simplified, and the size of the pump can be reduced.

FIG. 3 is a longitudinal sectional view showing the inside of the pump section 66 in an enlarged manner. As shown in FIG.
Is provided with a check valve 78 for opening and closing the suction port 74c at the bottom of the pump-side cylinder 74. The check valve 78 opens when the pump-side piston 76 moves upward, and the pump-side piston 76 moves downward. This closes the valve. The check valve 78 is formed in a ball shape, and a lattice member 80 for preventing the check valve 78 from dropping is provided around the suction port 74c. The shape of the check valve 78 is not limited to a ball shape. For example, a plate-shaped valve body may be formed so that only one side is fixed and the other side can freely swing.

The pump-side piston 76 is provided with a center hole 76a through which liquid fuel passes at the center of a shaft 76d connected to the piston rod 72. A valve seat 76b is provided in the center hole 76a.
A check valve 82 formed in a ball shape is provided in contact with b. The check valve 82 closes when the pump-side piston 76 moves upward, and opens when the pump-side piston 76 moves downward. A communication hole 76c that connects the center hole 76a and the upper chamber 74a is provided above the valve seat 76b.

Therefore, when the pump-side piston 76 moves downward, the check valve 82 separates from the valve seat 76b to open the valve, so that the liquid fuel sucked into the lower chamber 74b moves downward from the pump-side piston 76. With pump side piston 7
6 through the center hole 76a and the communication hole 76c.
a, and is discharged from the discharge port 74d.

At this time, the discharge pressure is
The value Sa obtained by multiplying the pressure receiving area Sa of 0 by the pressure Pa of the compressed air.
The value Sa · Pa / Sb obtained by dividing Pa by the pressure receiving area Sb of the pump-side piston 76. Therefore, the air-driven boost pump 34 is configured such that the larger the ratio of the pressure-receiving area Sa of the drive-side piston 70 to the pressure-receiving area Sb of the pump-side piston 76,
The liquid fuel can be discharged under pressure.

Here, the performance of the air-driven boost pump 34 configured as described above will be described with reference to FIGS.

FIG. 4 is a graph showing the relationship between the air supply pressure of the air-driven boost pump 34 and the discharge pressure of the liquid fuel. FIG. 5 is a graph showing the relationship between the air supply amount of the air-driven boost pump 34 and the discharge flow rate of the liquid fuel.

The discharge pressure P of the liquid fuel is proportional to the pressure Pa of the compressed air supplied to the pump-side cylinder 74 as shown in the following equation (1).
a to the pressure receiving area Sb of the pump-side piston 76:
Determined by Sb.

Discharge pressure P = Sa · Pa / Sb (1) The discharge flow rate Q of the liquid fuel discharged from the air-driven boost pump 34 is expressed by the volume Va of the drive-side cylinder 68 as expressed by the following equation (2). , The volume Vb of the pump side cylinder 74 and the supply air flow rate Qa supplied to the drive side cylinder 68.

Discharge flow rate Q = Qa / (Va · Vb) (2) That is, in the air-driven type booster pump 34, FIGS.
As can be seen from the graphs I and II shown in FIG. 1, the discharge pressure P and the discharge flow rate Q of the liquid fuel are controlled by adjusting the pressure Pa and the supply air flow rate Qa of the compressed air supplied to the drive side cylinder 68. Can be.

Accordingly, if the air pressure supplied to the air-driven boost pump 34 for pressurizing the liquid fuel is constant, the supply pressure of the gaseous fuel is controlled so as to correspond to the pressure difference between the gaseous fuel and the liquid fuel. They can be mixed in proportions.
Therefore, in the fuel mixing and filling system 10, by controlling the pressure of the gaseous fuel, the pressure and the flow rate of the liquid fuel are necessarily adjusted by the pressure balance, so that it is not necessary to control the pressure and the flow rate of the liquid fuel. In addition, the system control can be simplified and the load on the control system can be reduced.

Here, control processing of the in-line blending by the fuel mixing and filling system 10 will be described with reference to FIG.

In FIG. 6, the fuel mixing and filling system 10
The control circuit 63 of step S11 (hereinafter referred to as “step”)
), The customer's vehicle arrives at the filling area,
Proceeding to S12, when the customer or the worker connects the filling nozzle 60 to the filling port 62 of the fuel tank 15 and inputs the filling ratio (the ratio between the liquid fuel and the gaseous fuel) and the filling amount, the customer or the worker enters the fuel tank 15 of the arriving vehicle. The filling data such as the gas fuel to be filled and the filling amount is set.

In the next step S13, it is confirmed that the start switch button has been turned on, and the customer or the worker confirms the filling data set by the customer or the worker and turns on the start switch button. Then, the process proceeds to S14, where a signal from a limit switch (not shown) provided in the shutoff valves 24, 40, 50 is detected, and the shutoff valves 24, 40, 50 are detected.
Check that 50 is closed. In S14,
If the shut-off valves 24, 40, 50 are not closed, S1
Proceed to 5 to close the shutoff valves 24, 40, 50.

Then, in S14, the shutoff valves 24, 4
When 0 and 50 are closed, the process proceeds to S16, and it is confirmed that the control valves 26 and 42 and the regulator 52 are closed. If the control valves 26 and 42 and the regulator 52 are not closed in S16, the process proceeds to S17, and the control valves 26 and 42 and the regulator 52 are closed.

Then, in S16, the control valves 26, 4
2. If the regulator 52 is closed, the process proceeds to S18, where the shut-off valve 50 of the air supply pipe 46 is opened. In the next S19, the pressure reduction value by the regulator 52 is adjusted. As a result, the compressed air generated by the air compressor 48 is adjusted to a predetermined pressure by the regulator 52 and supplied to the drive unit 64 of the air-driven boost pump 34.

In the next step S20, it is confirmed that the air supply pressure detected by the pressure gauge 54 has been adjusted to a preset pressure. In S19 and S20, the regulator 52 is adjusted until the air supply pressure detected by the pressure gauge 54 becomes equal to the pressure set in advance in S12.

In the next step S21, the air-driven boost pump 3
4 is started. The air-driven boost pump 34 is
When the drive-side piston 70 is driven by the pressure of the compressed air from the air compressor 48 as described above, the pump-side piston 76 reciprocates in the pump-side cylinder 74 and sucks the liquid fuel from the suction port 74c. The liquid fuel sucked into the pump side cylinder 74 is pressurized and discharged from the discharge port 74d. Thereby, the LPG tank 30
The liquid fuel stored in the pump is pressurized and discharged by the air-driven pressurizing pump 34 and sent to the manifold 56 via the second fuel supply path 14.

Then, the program proceeds to S22, where the shut-off valve 24 is opened. As a result, the gaseous fuel stored in the gas storage 18 is supplied to the manifold 56 via the first fuel supply path 12.
Liquid. Therefore, in the manifold 56, the gaseous fuel and the liquid fuel are mixed and charged into the fuel tank 15 via the third fuel supply path 16.

In S23, the control valve 26 is adjusted to control the pressure and flow rate of the gaseous fuel supplied from the gas storage unit 18. In the next S24, the filling pressure of the fuel tank 15 detected by the pressure gauge 58 is read, and it is checked whether or not the filling pressure has reached the preset pressure set in S12.

Then, in S24, the fuel tank 15
By repeating the processes of S23 and S24 until the filling pressure of the fuel tank reaches the set pressure, the fuel tank 15 is filled with the mixed fuel of the gaseous fuel and the liquid fuel.
As described above, the pressurized liquid fuel and the gas fuel compressed to a high pressure are stored in the sealed fuel tank 15 as a critical fluid in which the gas fuel and the liquid fuel are mixed.

In S24, when the filling pressure of the fuel tank 15 reaches the set pressure, the routine proceeds to S25, where the shut-off valve 24,
40 and 50 are closed. This completes the current filling processing by the inline blending.

FIG. 7 is a block diagram showing a modification of the fuel mixing and filling system. It should be noted that in FIG.
The same parts as those described above are denoted by the same reference numerals and description thereof will be omitted. As shown in FIG. 7, in the fuel mixture filling system 90 of the modified example, a three-way solenoid valve 92 is provided instead of the above-described manifold 56, and the third fuel supply path 16
Is provided with a shut-off valve 94. In the fuel mixing and filling system 90, gas fuel and liquid fuel are charged alternately by the switching operation of the three-way solenoid valve 92.
The cutoff valve 24 and the check valve 28 of the first fuel supply path 12 and the cutoff valve 40 and the check valve 44 of the second fuel supply path 14 shown in FIG. 1 are removed.

The fuel mixing and filling system 90 is a serial batch blending system in which gas fuel and liquid fuel are alternately charged into the fuel tank 15 by switching operation of the three-way solenoid valve 92. The three-way solenoid valve 92 includes an a port to which the first fuel supply path 12 is connected, and a second fuel supply path 1
4 has a b port connected thereto and a c port connected to the third fuel supply path 16. And the three-way solenoid valve 9
2 is switched to a gas fuel filling mode in which the a port and the c port communicate with each other or a liquid fuel filling mode in which the b port and the c port communicate with each other according to a control signal from the control circuit 63.

Therefore, the first fuel supply path 12 and the second fuel supply path 12
The gaseous fuel and the liquid fuel that have passed through the fuel supply path 14 of the first embodiment alternately pass through the third fuel supply path 16 by the switching operation of the three-way solenoid valve 92 and are charged into the fuel tank 15 of the vehicle.

When the shut-off valve 24 provided in the first fuel supply path 12 is opened, the gaseous fuel stored in the gas storage 18 is supplied to the first fuel supply at a flow rate adjusted by the control valve 26. The liquid is sent to the port a of the three-way solenoid valve 92 via the path 12. The three-way solenoid valve 92 switches between the port a and the port c in accordance with the control signal output from the control circuit 63, so that the first fuel supply path 12
Is supplied to the fuel tank 15 via the third fuel supply path 16.

As will be described later, the air-driven pressurizing pump 34 is provided with a piston position detecting sensor 80 for detecting the position of the driving-side piston 70 at the bottom of the driving-side cylinder 68 of the driving section 64. The position detection sensor 80 outputs a piston position detection signal to the control circuit 63. Further, in the air-driven boost pump 34, as described above, the discharge pressure P and the discharge flow rate Q of the liquid fuel are adjusted by adjusting the pressure Pa and the supply air flow rate Qa of the compressed air supplied to the drive side cylinder 68. Control (see FIGS. 4 and 5).

Accordingly, as described above, the air-driven boost pump 34 has the drive-side piston 70 having the air compressor 4
When driven by the pressure of the compressed air from the pump 8, the pump-side piston 76 reciprocates in the pump-side cylinder 74 to suck the liquid fuel from the suction port 74 c and the liquid fuel sucked into the pump-side cylinder 74. Pressurized to discharge port 7
Discharge from 4d. As a result, the liquid fuel stored in the LPG tank 30 is pressurized and discharged by the air-driven pressurizing pump 34 and sent to the port b of the three-way solenoid valve 92 via the second fuel supply path 14.

The three-way solenoid valve 92 is connected to the control circuit 63
The liquid fuel supplied from the second fuel supply path 14 is switched to the third fuel supply path 16 because the b port and the c port are switched so as to communicate with each other in accordance with the control signal output from the second fuel supply path 16.
Is filled into the fuel tank 15.

Therefore, in the fuel tank 15, the gaseous fuel and the liquid fuel filled through the three-way solenoid valve 92 and the third fuel supply path 16 are mixed, and the ratio of the gaseous fuel to the liquid fuel becomes three-way. It is determined by the switching operation time of the solenoid valve 92. As described above, the pressurized liquid fuel and the gas fuel compressed to a high pressure are stored in the sealed fuel tank 15 as a critical fluid in which the gas fuel and the liquid fuel are mixed.

FIG. 8 is a longitudinal sectional view showing a modified example of the air-driven pressure boosting pump 34. In FIG. 8, the check valves 78 and 82 for sucking and discharging the liquid fuel are omitted. As shown in FIG. 8, the air-driven pressure-boosting pump 34 detects a position of a driving-side piston 70 at the bottom of a driving-side cylinder 68 of a driving unit 64 and a piston-position detecting sensor 80. And an amplifier 82 as a signal transmission means for outputting the converted signal.

The piston position detecting sensor 80 comprises, for example, an ultrasonic sensor, an encoder, or the like.
0 movement position or stroke amount is detected without contact,
It is a piston position detecting means for outputting the detection signal.

The operation status of the air-driven boost pump 34 can be determined by monitoring the detection signal from the piston position detection sensor 80. For example, if the amount of movement of the drive-side piston 70 is small even though the pressure of the compressed air from the air compressor 48 is sufficient, leakage of the compressed air, increase in the load on the drive-side piston 70, or increase in the resistance of the pump-side piston 76 Can be determined.

Accordingly, in order to detect the stroke of the drive-side piston or the pump-side piston, and to determine the operating state of the air-driven pressure-boosting pump based on the detected piston stroke, the stroke of the drive-side piston or the pump-side piston is determined based on the stroke. It is possible to detect the leakage of fuel or the entrainment of air and the volumetric flow due to the vaporization of liquid fuel. Further, when a line is stopped during operation as in a motor-driven pump, a mechanical load is less likely to be applied, and pump failure and heat generation are reduced. In addition, if gas is mixed into the liquid fuel, the stroke cycle will be significantly shortened. For example, it is detected that liquid fuel, which is easily vaporized due to pressure drop or temperature rise, such as liquefied petroleum gas (LPG), has vaporized in the pump. can do.

In FIG. 8, the driving cylinder 68
Although the example in which the piston position detection sensor 80 is provided at the bottom of the piston is shown, the invention is not limited to this, and a configuration in which the piston position detection sensor 80 is provided in the pump side cylinder 74 to detect the moving position or the stroke amount of the pump side piston 76 is also possible. good.

Here, the control processing of the serial batch blend executed by the control circuit 63 of the modified example will be described with reference to FIGS. 9 and 10.

In FIG. 9, the fuel mixing and filling system 90
When the customer's vehicle arrives at the filling area in S31, the process proceeds to S32, in which the customer or the worker connects the filling nozzle 60 to the filling port 62 of the fuel tank 15, and the filling ratio (liquid fuel and gaseous fuel) When the fuel tank 15 of the arriving vehicle is filled with the gaseous fuel, the filling data such as the filling amount are set. At this time, the filling ratio between the gaseous fuel and the liquid fuel may be set in advance. Further, the calculation may be performed in such a manner that the residual gas amount in the fuel tank 15 is corrected.

In the next step S33, it is confirmed that the start switch button has been turned on, and the customer or the worker confirms the filling data set by the customer or the worker and turns on the start switch button. Then, the process proceeds to S34, where a signal from a limit switch (not shown) provided in the shutoff valves 50, 94 is detected, and it is confirmed that the shutoff valves 50, 94 are closed. In S34, the shutoff valve 5
When 0 and 94 are not closed, the process proceeds to S35, and the shutoff valves 50 and 94 are closed.

Then, in S34, the shutoff valves 50, 9
If the valve 4 is closed, the process proceeds to S36, where the control valves 26,
42, confirm that the regulator 52 is closed. If the control valves 26 and 42 and the regulator 52 are not closed in S36, the process proceeds to S37 and the control valve 2
6, 42, the regulator 52 is closed.

Then, in S36, the control valves 26, 4
2. If the regulator 52 is closed, the process proceeds to S38, where the shutoff valve 50 of the air supply pipe 46 is opened. In the next S39, the pressure reduction value by the regulator 52 is adjusted. As a result, the compressed air generated by the air compressor 48 is adjusted to a predetermined pressure by the regulator 52 and supplied to the drive unit 64 of the air-driven boost pump 34.

In the next S40, it is confirmed that the air supply pressure detected by the pressure gauge 54 has been adjusted to a preset set pressure. In steps S39 and S40, the regulator 52 is adjusted until the air supply pressure detected by the pressure gauge 54 becomes equal to a preset pressure.

In the next step S41, the air-driven boost pump 3
4 is started. The air-driven boost pump 34 is
When the drive-side piston 70 is driven by the pressure of the compressed air from the air compressor 48 as described above, the pump-side piston 76 reciprocates in the pump-side cylinder 74 and sucks the liquid fuel from the suction port 74c. The liquid fuel sucked into the pump side cylinder 74 is pressurized and discharged from the discharge port 74d. Thereby, the LPG tank 30
Is pressurized and discharged by the air-driven pressurizing pump 34 and sent to the three-way solenoid valve 92 via the second fuel supply path 14.

Then, the program proceeds to S42, in which the detection signal from the piston position detection sensor 80 (see FIG. 7) provided in the drive section 64 of the air-driven pressure-up pump 34 is read, and the stroke (reciprocating distance) of the drive-side piston 70 is read. )
It is checked whether the detected stroke of the drive-side piston 70 is an abnormal value. In S42, when the stroke of the drive-side piston 70 is larger than a predetermined value,
It is determined that a leak has occurred in the middle of the path from the air-driven boost pump 34 to the shut-off valve 94, and the supply of compressed air to the air-driven boost pump 34 is stopped in S43.
Then, when the above-described abnormality occurs, an alarm (alarm) is output to notify the customer or the operator, and the shutoff valve 50 is closed to finish the current filling process.

In S42, the driving piston 7
If the stroke of 0 is normal (below a predetermined value), S
Proceeding to 44, the shut-off valve 94 is opened. As a result, the liquid fuel pressurized by the air-driven boost pump 34 is supplied to the three-way solenoid valve 92 via the second fuel supply path 14.

At this time, the three-way solenoid valve 92 has been switched to the liquid fuel charging mode in which the b port and the c port are communicated, and the liquid fuel pressurized by the air-driven boost pump 34 is supplied to the third fuel supply mode. The fuel tank 15 is filled through the passage 16.

In step S45, the control valve 42 provided in the second fuel supply path 14 is adjusted to control the supply pressure of the liquid fuel to a preset pressure and flow rate. Next S46
Now, the pressure gauge 58 provided in the third fuel supply path 16 will be described.
Is read, and it is checked whether the pressure of the liquid fuel filled in the fuel tank 15 has reached the set pressure set in S12.

In S46, if the pressure value (the filling pressure of the fuel tank 15) detected by the pressure gauge 58 has not reached the set pressure, the flow proceeds to S47. In step S47, a stroke (reciprocating distance) of the drive-side piston 70 is detected by reading a detection signal from a piston position detection sensor 80 (see FIG. 8) provided in the drive unit 64 of the air-driven boost pump 34, and the drive is performed. It is checked whether the stroke of the side piston 70 is abnormal.

In step S47, if the value detected by the piston position detection sensor 80 exceeds the number of strokes calculated from the flow rate, the pump operation is stopped due to the vaporization of the liquid fuel inside the air-driven boost pump 34. It is determined that there is a possibility that cavitation may occur due to idling or mixing of the air with the liquid fuel, and the supply of the compressed air to the air-driven boost pump 34 is stopped in S48. Then, an alarm (alarm) is output to notify the customer or the worker, and the shutoff valve 50 is closed to finish the current filling process.

In S47, the driving piston 7
If the stroke of 0 is normal, the process returns to S45, and the control valve 42 provided in the second fuel supply path 14 is adjusted again to control the supply pressure of the liquid fuel to the preset set pressure and flow rate. I do.

In S46, when the pressure value (the filling pressure of the fuel tank 15) detected by the pressure gauge 58 has reached the set pressure, the filling of the liquid fuel has been completed, so the flow proceeds to S49 and the shut-off valve The control valve 42 is closed while the valve 94 is closed.

In the next step S50, the three-way solenoid valve 92 is switched to the gaseous fuel filling mode in which the ports a and c communicate with each other, and the first fuel supply path 1 for supplying gaseous fuel is set.
The second and third fuel supply paths 16 are communicated with each other.

Subsequently, in S51 shown in FIG. 10, a detection signal from the piston position detection sensor 80 (see FIG. 7) provided in the drive section 64 of the air-driven pressure boosting pump 34 is read, and the driving piston 70 is read. The stroke (reciprocating distance) is detected, and it is checked whether the detected stroke of the driving piston 70 is an abnormal value. If a stroke signal is output in S51, it is determined that there is a possibility of leakage of liquid fuel between the air-driven boost pump 34 and the control valve 42, and compression in the air-driven boost pump 34 is performed in S52. Turn off the air supply. Then, an alarm (alarm) is output to notify the customer or the worker, and the shutoff valve 50 is closed to finish the current filling process.

In S51, the driving piston 7
If the zero stroke is normal, the process proceeds to S53, where the shut-off valve 94 is opened. As a result, in S54, the high-pressure gas fuel stored in the gas storage 18 is supplied to the three-way solenoid valve 92.
The fuel is supplied from the first fuel supply path 12 to the third fuel supply path 16 via the first fuel supply path 12, and is filled in the fuel tank 15. At this time, the inside of the fuel tank 15 is filled with the liquid fuel. However, since the gaseous fuel has a higher pressure, the gaseous fuel can be filled in a short time.

In the next step S55, the control valve 26 is adjusted to control the pressure and the flow rate of the gaseous fuel supplied from the gas storage unit 18. In the next step S56, the filling pressure of the fuel tank 15 detected by the pressure gauge 58 provided in the third fuel supply path 16 is read, and it is checked whether the filling pressure has reached a preset set pressure.

Then, in S56, the fuel tank 15
The fuel tank 15 is filled with the gaseous fuel by repeating the processing of S55 and S56 until the filling pressure of the above becomes the set pressure set in S32. Therefore, in the fuel tank 15, the gaseous fuel and the liquid fuel are mixed. As described above, the pressurized liquid fuel and the gas fuel compressed to a high pressure are mixed in the sealed fuel tank 15.
It is stored as a critical fluid in which gaseous fuel and liquid fuel are mixed.

In S56, when the filling pressure of the fuel tank 15 reaches the set pressure, the process proceeds to S57, where the shut-off valve 94 and the control valves 26, 40 are closed. This completes the filling process by the current serial batch blending.

Further, in the above embodiment, the case where compressed natural gas (CNG) as a gaseous fuel and liquefied petroleum gas (LPG) as a liquid fuel are mixed is described as an example. However, the present invention is not limited to this. It goes without saying that the present invention can also be applied to a fuel mixing and filling system for mixing a gaseous fuel and a liquid fuel composed of the above components.

In the above-described embodiment, the configuration in which the compressed natural gas (CNG) and the liquefied petroleum gas (LPG) are filled into the fuel tank 15 mounted on a vehicle such as an automobile has been described as an example. However, the compressed natural gas (C
Of course, the present invention can also be applied to a filling system for filling NG) and liquefied petroleum gas (LPG).

Further, in the above-described embodiment, the mass flow meter 38 is used for measuring the filling amount of the liquid fuel. However, the present invention is not limited to this, and the stroke amount of the driving-side piston 70 detected by the piston position detection sensor 80 and The volume flow rate may be calculated based on the stroke cycle, and the mass flow rate of the liquid fuel to be charged may be obtained by performing temperature and pressure correction.

[0087]

As described above, according to the first aspect of the present invention, there is provided a fuel mixing and filling system for filling a liquid fuel and the gaseous fuel into a container at a predetermined ratio, wherein the liquid fuel is a gaseous fuel. Equipped with an air-driven pressurizing pump that pressurizes to a pressure higher than the supply pressure, so that even when pressurizing highly flammable fuel, fuel can be safely discharged, and explosion-proof like a system driven by an electric motor Since it is not necessary to cover the case, the number of parts of the pump is reduced, the structure can be simplified, and the size of the pump can be reduced.

According to the second aspect of the present invention, the control valve provided in the first fuel supply path adjusts the supply pressure of the gaseous fuel to thereby control the liquid fuel supplied from the second fuel supply path. In order to adjust the ratio to an arbitrary value, it becomes possible to fill the container with the liquid fuel at a pressure corresponding to the supply pressure of the gaseous fuel, and for example, the liquid fuel is supplied to an air-driven pressurizing pump that pressurizes the liquid fuel If the air pressure is constant, by controlling the supply pressure of the gaseous fuel, the gaseous fuel and the liquid fuel can be mixed at a ratio corresponding to the pressure difference.

Therefore, by controlling the pressure of the gaseous fuel, the pressure and flow rate of the liquid fuel are necessarily adjusted by the pressure balance, so that it is not necessary to control the pressure and flow rate of the liquid fuel, and the system control is simplified. And the load on the control system can be reduced.

According to the third aspect of the present invention, the stroke of the drive-side piston or the pump-side piston is detected, and the operating state of the air-driven pressure-boosting pump is determined based on the detected piston stroke. Or leakage of liquid fuel from the stroke of the pump side piston,
Alternatively, it is possible to detect the entrainment of air and the volume flow rate accompanying the vaporization of the liquid fuel. Further, a mechanical load is hardly applied to a line stop during operation as in a motor-driven pump, and the occurrence of pump failure and heat generation is small. In addition, if gas is mixed into the liquid fuel, the stroke cycle will be significantly shortened. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a fuel mixing and filling system according to the present invention.

FIG. 2 is a longitudinal sectional view showing the internal configuration of the air-driven pressure boost pump 34.

FIG. 3 is an enlarged longitudinal sectional view showing the inside of a pump section 66.

FIG. 4 is a graph showing a relationship between an air supply pressure of an air-driven boost pump 34 and a discharge pressure of a liquid fuel.

FIG. 5 is a graph showing a relationship between an air supply amount of an air-driven boost pump 34 and a discharge flow rate of liquid fuel.

FIG. 6 is a flowchart for explaining a filling process executed by a control circuit 63 of the fuel mixing and filling system 10.

FIG. 7 is a block diagram showing a modification of the fuel mixing and filling system.

FIG. 8 is a longitudinal sectional view showing a modified example of the air-driven boost pump 34.

FIG. 9 is a flowchart for explaining a filling process executed by a control circuit 63 of a fuel mixing and filling system 90 of a modified example.

FIG. 10 is a flowchart illustrating a control process performed after the process of FIG. 9;

[Explanation of symbols]

 10, 90 Fuel mixing and filling system 12 First fuel supply path 14 Second fuel supply path 15 Fuel tank 16 Third fuel supply path 18 Gas storage 20, 32, 36, 54, 58 Pressure gauge 22, 38 Mass Flow meter 24, 40, 50 Shut-off valve 26, 42 Control valve 30 LPG tank 34 Air-driven boost pump 46 Air supply line 48 Air compressor 52 Regulator 56 Manifold 60 Filling nozzle 63 Control circuit 64 Drive unit 66 Pump unit 68 Drive side Cylinder 70 Drive-side piston 71 Four-way solenoid valve 72 Piston rod 74 Pump-side cylinder 76 Pump-side piston 78, 82 Check valve 80 Piston position detection sensor 92 Three-way solenoid valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02M 21/02 F02M 21/02 301A 37/00 341D 301 F17C 5/00 37/00 341 C10L 3/00 A F17C 5/00 P (72) Inventor Toshitake Sasaki 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Yuji 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Yukio Terashima 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Takahisa Hirasawa 1-3-6 Fujimi, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Tokiko Corporation (72) Inventor Makoto Ohgiku Kanagawa 1-6-3 Fujimi, Kawasaki-ku, Kawasaki-shi, Tokiko F-term in Tokiko Corporation (reference) 3E072 AA03 DA10 3G092 AB07 AB08 AB11 BB20 DF03 DG06 EA28 FA06 FA50 HB01Z HB03Z

Claims (3)

[Claims] 1. A first fuel supply path to which gaseous fuel compressed to a predetermined pressure is supplied, a second fuel supply path to supply liquid fuel, and the first fuel supply at an upstream end. A downstream end of the path and a downstream end of the second fuel supply path merge, and a downstream end is connected to a container to be filled; a third fuel supply path; and a second fuel supply path. An air-driven pressure pump for pressurizing the liquid fuel to a pressure higher than the supply pressure of the gaseous fuel, and filling the container with the liquid fuel and the gaseous fuel at a predetermined ratio. Characterized fuel mixing and filling system. 2. A control valve disposed in the first fuel supply path adjusts a supply pressure of the gaseous fuel to set an arbitrary ratio of the liquid fuel supplied from the second fuel supply path. 2. The fuel mixing and filling system according to claim 1, further comprising control means for adjusting the value. 3. The air-driven pressure-boosting pump, wherein: a driving-side cylinder having an air supply port through which driving air is supplied and an exhaust port through which driving air is exhausted; A drive-side piston that moves in the drive-side cylinder by being supplied; a piston rod having one end connected to the drive-side piston; a suction formed to have a smaller diameter than the drive-side cylinder to suck the liquid fuel A pump-side cylinder having a port and a discharge port from which the liquid fuel is discharged; and a pump coupled to the other end of the piston rod. A pump-side piston for sucking fuel and discharging the liquid fuel sucked into the pump-side cylinder from the discharge port; Detecting means for detecting a stroke of the pump-side piston; and determining means for determining an operation state of the air-driven booster pump based on the piston stroke detected by the detecting means. The fuel mixing and filling system according to claim 1.