HK1116850A - Storing device for liquefied gas fuel - Google Patents

Description

Storage device for liquefied gas fuel

Technical Field

The present invention relates to a liquefied gas fuel storage device that stores liquefied gas fuel used as vehicle fuel and pressure feeds the liquefied gas fuel to an engine.

Background

In recent years, with the enhancement of exhaust gas regulations, vehicles using LPG (liquefied petroleum gas), DME (dimethyl ether), or the like as fuel for the purpose of reducing pollution tend to increase. In particular, DME is regarded as having a high cetane number and emitting extremely small amounts of PM and NOx.

As a device using DME as fuel, for example, as disclosed in patent document 1, a device has been proposed in which DME fuel pressure-fed from a fuel tank to an engine is returned to a purge tank and depressurized, and then fed to the fuel tank. This is because DME fuel is pumped from the fuel tank to the engine at a high pressure, and therefore, is depressurized in the purge tank and returned to the fuel tank. That is, in such a configuration, the purge tank is merely a device for depressurizing the DME fuel remaining when the engine is stopped.

In addition, since liquefied gas fuels such as LPG and DME have a low energy density per unit volume, when used as vehicle fuels, it is required to store a large amount of liquefied gas fuels in order to extend the cruising range of the vehicle. In order to store a large amount of liquefied gaseous fuel, a large-capacity storage tank or a plurality of small-and medium-capacity storage tanks are mounted. Here, in the latter structure in which a plurality of storage tanks are mounted, the total storage amount can be appropriately designed by changing the number of the mounted storage tanks according to the size, weight, required cruising distance, and the like of the vehicle, and the convenience of replacement, maintenance, and the like is also excellent. Therefore, a configuration in which a plurality of storage tanks are mounted on a vehicle will be the mainstream in the future.

Patent document 1: japanese patent laid-open publication No. 2003-56409

Problems to be solved by the invention

In the above-described structure in which a plurality of storage tanks are mounted, a feed pump for feeding liquefied gas fuel under pressure to the engine is generally provided for each storage tank. In the case where the liquefied gas fuel is pressure-fed to the engine from the plurality of storage tanks sequentially by sequentially and alternately operating the feed pumps, control for smoothly feeding the liquefied gas fuel to the engine at the time of the switching is necessary.

In a configuration in which a plurality of storage tanks are loaded in the same manner, the storage tanks are connected such that the gas phase regions in the storage tanks communicate with each other and the liquid phase regions in the storage tanks communicate with each other. This is a device for making the storage amount of liquefied gas fuel in each storage tank uniform by communicating the gas phase and the liquid phase of each storage tank, respectively. In this configuration, the storage amounts of the storage tanks can be equalized, so that the feed pumps disposed in the respective storage tanks are simultaneously operated to pump substantially equal amounts of the liquefied gas fuel from the storage tanks. However, since the surroundings of a plurality of storage tanks mounted on a vehicle are different depending on the mounting positions, the temperatures and the tank internal pressures of the respective storage tanks are different. Therefore, it is practically impossible to equalize the storage amounts of the liquefied gas fuel in the storage tanks and consume the liquefied gas fuel unevenly, and there is a problem that the liquefied gas fuel fed under pressure to the engine is liable to become unstable.

In addition, in a feed pump for pressure-feeding a liquefied gas fuel to an engine, a pump and a motor for pressure-feeding the liquefied gas fuel at a relatively high pressure are required, and an inverter or the like for controlling a discharge amount is required. Therefore, in the structure in which a plurality of storage tanks are mounted and a feed pump is disposed in each storage tank as described above, the weight of the vehicle as a whole increases, and therefore the fuel consumption thereof deteriorates. In addition, since the feed pump is a component having the above-described function, the purchase cost or the manufacturing cost thereof is high, and the cost is increased. Therefore, as a structure for storing the liquefied gas fuel and pressure-feeding the liquefied gas fuel to the engine, weight reduction and cost reduction are required.

Disclosure of Invention

The present invention provides a liquefied gas fuel storage device which solves the above problems, and which can store a liquefied gas fuel capable of obtaining a sufficient cruising distance and pressure-feed the liquefied gas fuel to an engine.

Means for solving the problems

The present invention is a storage device for liquefied gas fuel, including: a first storage tank storing liquefied gaseous fuel; a feed pump for pumping the liquefied gas fuel in the first storage tank to the engine; a second storage tank connected to the first storage tank by a supply line for supplying liquefied gas fuel, the second storage tank storing liquefied gas fuel; a fuel supply mechanism for supplying the liquefied gas fuel in the second storage tank to the first storage tank through a supply line; and a supply control means for controlling the fuel supply means in accordance with the consumption of the liquefied gas fuel in the first storage tank, and supplying the liquefied gas fuel from the second storage tank to the first storage tank.

In the structure, a first storage tank and a second storage tank for storing liquefied gas fuel are provided, and the first storage tank is used as a component for feeding the liquefied gas fuel to the engine under pressure; the second storage tank is used as a means for supplying liquefied gas fuel to the first storage tank. That is, the first storage tank and the second storage tank are respectively configured as components having different functions. And a feed pump for feeding the liquefied gas fuel under pressure to the engine at a relatively high pressure is disposed in the first storage tank.

In this way, since the liquefied gas fuel pressure-fed to the engine is integrally stored and pressure-fed in the first storage tank, the liquefied gas fuel can be stably fed to the engine by simply operating and controlling the feed pump disposed in the first storage tank. In addition, in this configuration, compared to the above-described conventional configuration in which a plurality of storage tanks are mounted and feed pumps are disposed in the respective storage tanks, the number of feed pumps is reduced, and weight and cost reduction can be achieved. Further, since this structure does not require the communicating structure portion as in the conventional structure in which the gas phase regions and the liquid phase regions of the plurality of storage tanks communicate with each other, it is possible to achieve weight reduction and reduction in manufacturing cost.

In addition, since the structure is provided with the first storage tank and the second storage tank that store the liquefied gas fuel, the total storage amount of the liquefied gas fuel increases. Thus, the cruising distance of a vehicle equipped with the storage device for liquefied gas fuel of this structure can be sufficiently extended.

Here, the supply line may be constituted by a line through which the liquefied gas fuel is sent, and may be constituted by a line for supplying the liquefied gas fuel only from the second storage tank to the first storage tank, or may be constituted by a line for connecting the supply line and another line (for example, a line for filling the liquefied gas fuel) and partially piping the lines. In the configuration using other piping, a shut-off valve or the like that opens and closes at the connection portion is provided, and the flow direction of the liquefied gas fuel is determined by controlling the opening and closing operation of the shut-off valve, and it is most preferable to form the shut-off valve as a supply line.

Further, the supply control means may be controlled to supply the liquefied gas fuel from the second storage tank immediately after the liquefied gas fuel in the first storage tank is pressure-fed to the engine, or may be controlled to supply the liquefied gas fuel if the storage amount in the first storage tank is smaller than a predetermined amount.

In the above-described liquefied gas fuel storage device, a plurality of second storage tanks are arranged in parallel, and the supply control means controls the liquefied gas fuel in each of the second storage tanks to be sequentially supplied to the first storage tank.

In this case, a plurality of second storage tanks arranged in parallel are each connected to the first storage tank by a supply line, and the fuel supply means is designed to supply the liquefied gas fuel stored in each of the second storage tanks to the first storage tank. And the supply control means causes the plurality of second storage tanks to supply the liquefied gas fuel in the second storage tanks to the first storage tank in a predetermined order. That is, when the liquefied gas fuel in the first second storage tank is supplied and there is no available liquefied gas fuel in the tank, the liquefied gas fuel is supplied from the next second storage tank. Thus, the liquefied gas fuel supplied to the first storage tank is often transported by a second storage tank. Thus, even in a configuration in which a plurality of second storage tanks are arranged in parallel, the fuel supply mechanism for supplying liquefied gas fuel to the first storage tank can be stably and easily controlled. In addition, in this configuration, as the number of the second storage tanks increases, the total storage amount of the liquefied gas fuel can be increased to extend the cruising distance.

There has been proposed a configuration in which the liquefied gas fuel storage device is provided with a return line for returning the remaining liquefied gas fuel that is not used in the engine to the second storage tank.

In this configuration, the remaining part of the liquefied gas fuel that is not used for driving the engine is returned to the second storage tank through the return line. Thereby, the liquefied gas fuel is circulated such that it is pressure-fed from the first storage tank to the engine, and the remaining part thereof is returned to the second storage tank, from which it is sent to the first storage tank.

The liquefied gas fuel returned from the engine may be in a state of a mixture of a liquid phase and a gas phase, and may be supplied to the first storage tank after being stabilized by flowing the liquefied gas fuel into the second storage tank. Therefore, the liquefied gas fuel in the first storage tank can be kept in a relatively quiet stable state because the second storage tank is collected for the bubbling or the like caused by the liquefied gas fuel returned from the engine flowing into the tank. And the liquefied gas fuel can be more stably pressure-fed from the first storage tank to the engine by the feed pump.

As described above, this configuration allows the liquefied gas fuel to circulate in the order of the first storage tank, the engine, and the second storage tank, and allows the liquefied gas fuel to be supplied efficiently and stably.

Further, the return line may be configured to return the remaining liquefied gas fuel from the engine to the second storage tank, and may be configured to return the liquefied gas fuel to the first storage tank, instead of returning the liquefied gas fuel to the second storage tank alone. In the latter configuration, the return of the liquefied gas fuel to the first storage tank is normally impossible, and a configuration may be used in which the liquefied gas fuel is returned to the first storage tank when the second storage tank reaches an upper limit at which the liquefied gas fuel can be stored, or when the liquefied gas fuel that can be supplied is not stored in the second storage tank.

In the above-described liquefied gas fuel storage device, the fuel supply means is constituted by a supply pump disposed in the second storage tank and configured to pressure-feed the liquefied gas fuel in the second storage tank to the first storage tank through a supply line.

In such a configuration, as the liquefied gas fuel in the first storage tank is consumed, the supply control means controls the operation of the supply pump, and the liquefied gas fuel in the second storage tank is pressure-fed to the first storage tank. Here, since the supply amount of the liquefied gas fuel can be controlled relatively accurately and stably by controlling the operation of the supply pump, an appropriate amount of the liquefied gas fuel can be supplied in accordance with the liquefied gas fuel pressure-fed from the first storage tank to the engine.

Further, since the supply pump is used for supplying the liquefied gas fuel in the second storage tank to the first storage tank, the liquefied gas fuel can be stably and quietly supplied to the first storage tank. That is, the feed pump may have a capacity capable of pumping the liquefied gas fuel at a lower pressure (discharge pressure) than the feed pump, and therefore, a lightweight and low-cost product can be used. Therefore, even if the supply pump is disposed in the second storage tank, the overall weight of the entire apparatus can be suppressed, and the cost can be reduced.

In this case, it is proposed that an overfill prevention valve is arranged in the first storage tank, which prevents the liquefied gas fuel from flowing in beyond the maximum storage volume in the first storage tank; the supply line is communicated with the inside of the first reservoir tank through the overfill prevention valve, and the supply pump disposed in the second reservoir tank has a larger flow rate (hereinafter referred to as a discharge flow rate) for discharging the liquefied gas fuel than the feed pump.

In such a configuration, the flow rate of the liquefied gas fuel supplied from the second storage tank to the first storage tank is larger than the flow rate of the liquefied gas fuel pressure-fed from the first storage tank to the engine. Thereby, in a state where the liquefied gas fuel is supplied from the second storage tank, the liquefied gas fuel in the first storage tank is increased. Therefore, as long as liquefied gas fuel is stored in the second storage tank, sufficient liquefied gas fuel can be always stored in the first storage tank, and the liquefied gas fuel can be stably sent to the engine by the feed pump.

In addition, in this configuration, since the liquefied gas fuel supplied from the second storage tank is caused to flow into the first storage tank via the overfill prevention valve, even if a relatively large amount of liquefied gas fuel is pumped by the supply pump, the liquefied gas fuel is supplied to the first storage tank without exceeding the maximum storage amount (upper limit).

In addition, in the structure in which the return line is installed as described above, it is not necessary to connect the return line to the first storage tank. This is because the flow rate of the liquefied gas fed back from the return line to the first storage tank by the feed pump is large compared to the flow rate of the liquefied gas fed back from the return line. For example, in a state where the storage amount of the liquefied gas fuel in the second storage tank is the lower limit amount and the liquefied gas fuel in the first storage tank is lowered, almost all of the remaining liquefied gas fuel returned to the second storage tank is sequentially supplied to the first storage tank. Therefore, even if the return line is not connected to the first storage tank, the remaining liquefied gas fuel can be sent to the first storage tank. Therefore, there is also an advantage that the return line is less connected to the first storage tank, and the piping structure can be simplified.

In the above-described liquefied gas fuel storage device, it is proposed that the fuel supply means is constituted by a heater for heating the liquefied gas fuel in the second storage tank, and the liquefied gas fuel in the second storage tank is adjusted to be higher than the liquefied gas fuel in the first storage tank by the supply control means by a predetermined temperature.

In such a configuration, the liquefied gas fuel in the second storage tank is higher than the liquefied gas fuel in the first storage tank by a predetermined temperature, so that the internal pressure of the second storage tank is increased, and the liquefied gas fuel in the second storage tank is moved to the first storage tank by a pressure difference with the first storage tank. That is, the supply control means controls the operation of the heater in accordance with the consumption of the liquefied gas fuel in the first storage tank, so that the liquefied gas fuel can be supplied from the second storage tank to the first storage tank. The effects of the present invention can be suitably exhibited also in this configuration.

Here, the predetermined temperature in the second storage tank obtained by controlling the operation of the heater as the supply control means is set so that the liquefied gas fuel in the second storage tank flows relatively smoothly to the first storage tank by a pressure difference between the internal pressure of the second storage tank and the internal pressure of the first storage tank, which is increased by the temperature.

The heater may be disposed in the second storage tank to directly heat the liquefied gas fuel in the tank, or disposed on the outer periphery of the second storage tank to indirectly heat the tank. Here, the former configuration in which the heater is disposed in the tank can effectively heat the liquefied gas fuel, and therefore can be suitably used.

In the above-described liquefied gas fuel storage device, the fuel supply means is constituted by a fuel cooler provided in the return line and cooling the remaining liquefied gas fuel, and the supply control means adjusts the temperature of the remaining liquefied gas fuel returned to the second storage tank so that the liquefied gas fuel in the second storage tank becomes higher than the liquefied gas fuel in the first storage tank by a predetermined temperature.

In such a configuration, a fuel cooler is provided for cooling the liquefied gas fuel heated by the engine, and the temperature of the liquefied gas fuel flowing into the second storage tank is adjusted by the fuel cooler. The liquefied gas fuel returned to the second storage tank has a temperature higher than the temperature of the first storage tank by a predetermined temperature, and a pressure difference is generated between the two tanks, whereby the liquefied gas fuel in the second storage tank moves to the first storage tank.

The fuel supply means cools the liquefied gas fuel returned from the engine to a temperature higher by a predetermined temperature than that in the first storage tank by controlling the operation of the fuel cooler. The predetermined temperature is set such that the internal pressure of the second storage tank rises due to the temperature in the second storage tank which rises as a result of the inflow into the second storage tank, and the liquefied gas fuel in the second storage tank flows relatively smoothly into the first storage tank due to the pressure difference between the internal pressure and the internal pressure of the first storage tank. If the temperature of the liquefied gas fuel returned to the second storage tank is too high, the liquefied gas fuel mixes with the liquefied gas fuel before the flow into the second storage tank, and foaming or the like occurs. Therefore, the fuel cooler needs to control to cool the liquefied gas fuel to a temperature that can generate an internal pressure difference to the extent that the liquefied gas fuel in the second storage tank moves toward the first storage tank.

In the storage apparatus for liquefied gas fuel described above, a feed pump for feeding the liquefied gas fuel in the first storage tank to the engine under pressure is disposed in the first storage tank.

In such a configuration, the feed pump can directly take in the liquefied gas fuel stored in the first storage tank and pressure-feed the liquefied gas fuel. Therefore, even when the first storage tank is tilted due to a swing or the like while the vehicle is traveling, the liquefied gas fuel can be stably taken into the feed pump and can be stably and appropriately compressed and delivered to the engine.

Further, the feed pump is preferably configured to be able to reliably take in the liquefied gas fuel even when the liquefied gas fuel in the feed pump swings as the first storage tank tilts. For example, a configuration in which the suction port for the liquefied gas fuel is disposed in the first storage tank so as to be at the lowest position in a state in which the first storage tank is mounted on the vehicle, a configuration in which a region capable of storing the liquefied gas fuel around the feed pump is provided, or the like can be suitably used.

The present invention is a device for supplying liquefied gas fuel in a second storage tank to a first storage tank through a supply line by a fuel supply mechanism in accordance with consumption of liquefied gas fuel in the first storage tank while feeding liquefied gas fuel in the first storage tank to an engine by a feed pump, and therefore, it is possible to store liquefied gas fuel in the first storage tank and the second storage tank, increase the storage amount of liquefied gas fuel as a whole, and extend the cruising distance of a vehicle. Further, since the liquefied gas fuel pressure-fed to the engine is only the fuel stored in the first storage tank, the liquefied gas fuel can be stably fed to the engine by controlling the operation of the feed pump disposed in the first storage tank. The control process for operating the feed pump is relatively simple, so that the stability and accuracy of the operation control are good. In addition, since the number of feed pumps which can output a high pressure is limited, the weight and cost can be reduced as a whole.

In addition, in the configuration in which a plurality of second storage tanks are arranged in parallel and the supply control means controls the liquefied gas fuel in each second storage tank to be sequentially supplied to the first storage tank, the storage amount of the liquefied gas fuel can be increased according to the number of the second storage tanks, and the cruising distance can be further extended. Since the liquefied gas fuel to be supplied to the first storage tank is delivered from the second storage tank, the fuel supply mechanism can be controlled relatively easily and accurately, and the liquefied gas fuel can be stably supplied to the first storage tank.

In the configuration in which the return line for returning the remaining liquefied gas fuel that is not used in the engine to the second storage tank is provided, the liquefied gas fuel returned from the engine can be supplied to the first storage tank once a relatively quiet stable state is established in the second storage tank, and therefore the liquefied gas fuel can be more stably and efficiently pressure-fed from the first storage tank to the engine.

Further, when the fuel supply mechanism is constituted by a supply pump disposed in the second storage tank and configured to pressure-feed the liquefied gas fuel in the second storage tank to the first storage tank through the supply line, the supply amount of the liquefied gas fuel to be pressure-fed to the first storage tank can be relatively easily and accurately adjusted by controlling the operation of the supply pump, and it is easy to stably feed an appropriate liquefied gas fuel in accordance with the consumption of the liquefied gas fuel in the first storage tank.

Here, in the configuration in which the discharge amount of the liquefied gas fuel from the supply pump disposed in the second storage tank is larger than that from the feed pump, the liquefied gas fuel can be stably stored in the first storage tank because the liquefied gas fuel is supplied from the second storage tank to the engine more than the liquefied gas fuel pressure-fed to the engine.

In the above configuration, the fuel supply means is constituted by a heater for heating the liquefied gas fuel in the second storage tank, and the supply control means adjusts the liquefied gas fuel in the second storage tank to be higher than the liquefied gas fuel in the first storage tank by a predetermined temperature.

In the above configuration, the fuel supply means is constituted by a fuel cooler provided in the return line and cooling the remaining liquefied gas fuel, and the supply control means adjusts the temperature of the remaining liquefied gas fuel returned to the second storage tank so that the liquefied gas fuel in the second storage tank becomes higher than the liquefied gas fuel in the first storage tank by a predetermined temperature.

In the configuration in which the feed pump that pressure-feeds the liquefied gas fuel in the first storage tank to the engine is disposed in the first storage tank, the feed pump can stably take in the liquefied gas fuel and stably pressure-feed the liquefied gas fuel to the engine even when the first storage tank is inclined while the vehicle is traveling.

Drawings

Fig. 1 is a system configuration diagram of a liquefied gas fuel storage device 1A according to embodiment 1.

Fig. 2 is a schematic view showing a filling line I when the first storage tank 2A and the second storage tanks 3A, 4A are filled with liquefied gas fuel.

Fig. 3 is a schematic diagram showing a state in which (a) the supply line K1 and the return line R1 communicate with the second storage tank 3A, and (B) the supply line K2 and the return line R2 communicate with the second storage tank 4A, in driving of the engine 50.

Fig. 4 is a system configuration diagram of a liquefied gas fuel storage device 1B according to embodiment 2.

Fig. 5 is a system configuration diagram of a liquefied gas fuel storage device 1C according to embodiment 3.

Fig. 6 is a system configuration diagram of a liquefied gas fuel storage device 1D according to embodiment 4.

Fig. 7 is a system configuration diagram of a liquefied gas fuel storage apparatus 1E having another configuration.

Fig. 8 is a system configuration diagram of a liquefied gas fuel storage apparatus 1F having another configuration.

Fig. 9 is a system configuration diagram of a liquefied gas fuel storage apparatus 1G having another configuration.

Fig. 10 is a system configuration diagram of another liquefied gas fuel storage apparatus 1H.

Fig. 11 is a system configuration diagram of a liquefied gas fuel storage apparatus 1I having another configuration.

Fig. 12 is a system configuration diagram of a liquefied gas fuel storage apparatus 1J of another configuration.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[ example 1]

The liquefied gas fuel storage device 1A of the present embodiment is mounted on an automobile and stores liquefied gas fuel as fuel for the engine 50. Fig. 1 is a conceptual diagram of a liquefied gas fuel storage apparatus 1A equipped with a first storage tank 2A and two second storage tanks 3A, 4A for a total of three storage tanks.

The liquefied gas fuel storage apparatus 1A is equipped with a quick coupling 11 to which a filling gun (not shown) for filling liquefied gas fuel from the outside can be attached and detached, and a filling pipe 6 for connecting the first storage tank 2A and the second storage tanks 3A and 4A in parallel from the quick coupling 11. The filling pipe 6 branches and is connected to a filling valve 22 disposed in the first storage tank 2A, a filling valve 32 disposed in the second storage tank 3A, and a filling valve 42 disposed in the second storage tank 4A. Further, the filling shutoff valves 33 and 43 are disposed at positions immediately upstream of the filling valves 32 and 42 of the second reservoir tanks 3A and 4A of the filling pipe 6, respectively.

Overfill prevention valves 12, and 12 communicated with the respective filling valves 22, 32, and 42 are disposed in the respective first storage tank 2A and second storage tanks 3A and 4A. Thereby, the liquefied gas fuel flowing from the filling pipe 6 through the filling valves 22, 32, and 42 can flow into the storage tanks 2A, 3A, and 4A through the overfill prevention valves 12, and 12. Here, each overfill prevention valve 12 is provided with a float 12A that floats in accordance with the liquid level of the liquefied gas fuel stored in each storage tank 2A, 3A, 4A, and when the float 12A reaches a predetermined height position, the overfill prevention valve 12 automatically closes to prevent the liquefied gas fuel from flowing in. The overfill prevention valve 12 is used to fill the liquefied gaseous fuel without exceeding a predetermined maximum filling amount. The overfill prevention valve 12 can be made of a product used in the prior art, and a detailed description thereof is omitted.

Further, the first reserve tank 2A is provided with a take-out valve 24, and a pressure-feed pipe 9 is provided from the take-out valve 24 toward the engine 50. A feed pump 25 connected to the take-out valve 24 and taking in and pressure-feeding the liquefied gas fuel is disposed inside the first storage tank 2A. By opening the take-out valve 24 and operating the feed pump 25, the liquefied gas fuel in the first storage tank 2A is pumped to the engine 50. Here, the feed pump 25 has a function of discharging the liquefied gas fuel at a relatively high pressure, and is configured to form a region for storing the liquefied gas fuel in a region around a suction port for sucking the liquefied gas fuel, so that the liquefied gas fuel can be stably sucked even when the first storage tank 2A is tilted while the vehicle is traveling.

Further, in the pressure-feed pipe 9, a high-pressure pump 53 for further increasing the pressure of the liquefied gas fuel fed from the pressure-feed pipe 9 and feeding the liquefied gas fuel to the engine 50 is disposed at an upstream side of the engine 50. The liquefied gas fuel sent from the high-pressure pump 53 to the engine 50 is accumulated in the common rail 52 and is discharged from each injector 51 (the injector 51 and the common rail 52 are omitted in fig. 2 and the following).

On the other hand, the supply pipe 7 is connected to the filling pipe 6 at a position upstream of the filling shutoff valves 33 and 43 via the supply shutoff valve 14, and the supply pipe 7 is branched and connected to the second reservoir tanks 3A and 4A via the supply extraction valves 34 and 44. In the supply pipe 7, check valves 36 and 46 are disposed at respective portions on the side of the second reservoir tanks 3A and 4A with respect to the branch portions. In the second storage tanks 3A and 4A, supply pumps 35 and 45 for taking in and pumping the liquefied gas fuel are disposed inside and connected to the supply take-out valves 34 and 44, respectively.

The above-described supply pumps 35 and 45 are pumps that pump the liquefied gas fuel at a lower pressure than the feed pump 25. This is to stably feed the liquefied gas fuel to the first storage tank 2A in which the feed pump 25 is operating, as quietly as possible, and to suppress turbulence generated by the inflow of the liquefied gas fuel into the first storage tank 2A, so that the feed pump 25 can stably press the liquefied gas fuel. The supply pumps 35 and 45 are disposed so that suction ports (not shown) for sucking the liquefied gas fuel are close to the bottom surfaces of the second storage tanks 3A and 4A. The suction ports of the supply pumps 35 and 45 are positioned at a lower limit at which liquefied gas fuel can be supplied from the second storage tanks 3A and 4A. That is, if the liquefied gas fuel in the second storage tanks 3A and 4A reaches the lower limit (lower limit amount), the liquefied gas fuel cannot be sucked by the supply pumps 35 and 45 and cannot be supplied to the first storage tank 2A.

A return pipe 8 is connected to the high-pressure pump 53. The return pipe 8 branches and is connected to the connection portion of the filling pipe 6 with the supply pipe 7, the portion between the filling stop valve 33 and the filling valve 32, and the portion between the filling stop valve 43 and the filling valve 42 via return stop valves 15, 16, and 17, respectively.

The return pipe 8 is used to return the remaining liquefied gas fuel that is not used in the high-pressure pump 53 and the engine 50, and the remaining liquefied gas fuel is returned to any one of the first storage tank 2A and the second storage tanks 3A and 4A by opening and closing the return shutoff valves 15, 16, and 17. Further, a fuel cooler 19 for cooling the liquefied gas fuel flowing through the return pipe 8 is disposed on the engine 50 side of the return pipe 8 with respect to the return shutoff valves 15, 16, and 17. Thereby, the liquefied gas fuel that has become a high temperature in the engine 50 can be cooled and returned.

In addition, liquid level gauges 13 each equipped with a float 13A floating in accordance with the liquid level of the liquefied gas fuel are disposed in the first storage tank 2A and the second storage tanks 3A and 4A, respectively. The level gauge 13 is used to measure the storage amount of the liquefied gas fuel according to the float of its float 13 a. In the present embodiment, the total amount of liquefied gas fuel measured by each of the liquid level gauges 13, and 13 is indicated by an informing device (not shown) disposed in the driver's seat of the vehicle, and is informed to the driver.

In the liquefied gas fuel storage device 1A, a control processing device 10 including a CPU, a memory device ROM, RAM, and the like, which are not shown, is disposed. The control processing device 10 controls the operations of the feed pump 25, the supply pumps 35, 45, and the fuel cooler 19, and controls the opening and closing operations of the filling valves 22, 32, and 42, the take-out valves 24, 34, and 44, the filling shutoff valves 33 and 43, the supply shutoff valve 14, and the return shutoff valves 15, 16, and 17, and is electrically connected to these valves. Further, the control processing device 10 is electrically connected to the liquid level meters 13, and a temperature sensor (not shown) and a pressure sensor (not shown) disposed in each storage tank, respectively, and thereby can obtain various information on the storage amount in each storage tank, the temperature of the liquefied gas fuel, and the tank internal pressure. In fig. 1, circuit lines for connecting the control processing device 10 to the valves, the shutoff valves, and the like are not shown as appropriate.

In this embodiment, the fuel supply mechanism of the present invention is constituted by the supply pumps 35 and 45, and the supply control device of the present invention is constituted by the control processing device 10.

Next, the operation of the liquefied gas fuel storage device 1A according to example 1 will be described.

When the liquefied gaseous fuel is filled in the first storage tank 2A and the second storage tanks 3A and 4A, the filling valves 22, 32 and 42 and the filling shutoff valves 33 and 43 are opened, and the supply shutoff valve 14 and the return shutoff valves 15, 16 and 17 are closed. Thereafter, a filling gun, not shown, is connected to the quick coupling 11, and the first storage tank 2A and the second storage tanks 3A and 4A are filled with liquefied gas fuel through the filling pipe 6. In this filling, as shown in fig. 2, liquefied gas fuel is injected into the first storage tank 2A and the second storage tanks 3A and 4A in parallel through the quick-coupling 11, and substantially the same filling is performed. In addition, a line through which the liquefied gas fuel flows at the time of this filling is a so-called filling line I.

When the first storage tank 2A and the second storage tanks 3A and 4A are filled with liquefied gas fuel to the maximum filling amount, the overfill prevention valves 12 are closed and are not filled to the maximum filling amount. At the end of filling, the filling gun is removed from the quick coupling 11. Then, the filling valves 22, 32, and 42 and the filling shut-off valves 33 and 43 are closed, respectively.

When the engine 50 is driven, the filling valve 32 and the return shutoff valve 16 are opened, and the supply extraction valve 34 and the supply shutoff valve 14 are opened. Further, the take-out valve 24 is opened. As a result, as shown in fig. 3(a), the return pipe 8 communicates only with the second storage tank 3A, and the supply pipe 7 communicates the second storage tank 3A with the first storage tank 2A via a part of the partial filling pipe 6. Here, the conduit of the return pipe 8 communicating with the second storage tank 3A is the return line R1 of the present invention, and the conduit communicating the second storage tank 3A and the first storage tank 2A via the supply pipe 7 and a part of the filling pipe 6 is the supply line K1 of the present invention.

The feed pump 25 of the first storage tank 2A and the supply pump 35 of the second storage tank 3A are operated. By the operation of the feed pump 25, the liquefied gas fuel in the first storage tank 2A is pumped to the engine 50, and the remaining liquefied gas fuel that is not used in the engine 50 is returned via the return pipe 8. At this time, the remaining liquefied gas fuel is cooled by the fuel cooler 19 to a temperature substantially equal to that of the liquefied gas fuel in the second storage tank 3A, and flows into the second storage tank 3A. On the other hand, the liquefied gas fuel in the second storage tank 3A is supplied to the first storage tank 2A through the supply pipe 7 by the operation of the supply pump 35.

In this way, the liquefied gas fuel is pumped from the first storage tank 2A to the engine 50, and the remaining part is returned to the second storage tank 3A, and is supplied from the second storage tank 3A to the first storage tank 2A.

Thereafter, the liquefied gas fuel in the second storage tank 3A becomes a lower limit amount that cannot be sucked by the supply pump 35, and the supply pump 35 stops operating, and closes the return shutoff valve 16, the filling valve 32, and the supply take-out valve 34. Thereafter, the return shutoff valve 17, the filling valve 42, and the supply extraction valve 44 are opened. Thus, as shown in fig. 3(B), the return pipe 8 is communicated only with the second storage tank 4A, and the pipe line through which the return pipe 8 is communicated only with the second storage tank 4A is the return line R2 of the present invention. In addition, the first storage tank 2A and the second storage tank 4A communicate with a partial filling pipe 6 through a supply pipe 7, and the communicating pipe forms a supply line K2 of the present invention.

The supply pump 45 of the second storage tank 4A is operated to supply the liquefied gas fuel in the second storage tank 4A to the first storage tank 2A through the supply pipe 7. At this time, the liquefied gas fuel is pumped from the first storage tank 2A to the engine 50, and the remaining part is returned to the second storage tank 4A, and is sent from the second storage tank 4A to the first storage tank 2A, and thus circulated.

Thereafter, when the liquefied gas fuel in the second storage tank 4A reaches the lower limit amount, the supply pump 45 is stopped, and the return shutoff valve 17, the filling valve 42, the supply extraction valve 44, and the supply shutoff valve 14 are closed. Thereafter, the return shutoff valve 15 is opened to communicate the return pipe 8 with the first storage tank 2A. Thereby, since the liquefied gas fuel circulates in the first storage tank 2A and the engine 50, only the liquefied gas fuel in the first storage tank 2A is reduced. Here, the reduction in the remaining amount of the liquefied gas fuel in the first storage tank 2A means that the remaining amount of the liquefied gas fuel storage apparatus 1A as a whole is reduced. If the remaining amount of the liquefied gas fuel is small, the liquefied gas fuel can be filled as described above.

As described above, in the liquefied gas fuel storage device 1A of example 1, three storage tanks are arranged in total in the first storage tank 2A and the second storage tanks 3A and 4A, and a large amount of liquefied gas fuel can be stored, and the liquefied gas fuel pumped to the engine 50 is integrally stored in the first storage tank 2A, and the liquefied gas fuel is supplied from the second storage tanks 3A and 4A to the first storage tank 2A. For this reason, in the storage apparatus 1A for liquefied gas fuel, the liquefied gas fuel in the second storage tanks 3A and 4A is consumed first, and the liquefied gas fuel in the first storage tank 2A is consumed last.

By unifying the pressure feeding of such liquefied gas fuel to the engine 50 in the first storage tank 2A, the operation control of the feed pump 25 can be stably and easily performed, and the liquefied gas fuel can be stably and accurately fed to the engine 50. Further, the excess liquefied gas fuel returned from the engine 50 is returned to the second storage tanks 3A, 4A at a time, and after the excess liquefied gas fuel is stabilized in substantially the same state as the state in the first storage tank 2A, the excess liquefied gas fuel is supplied to the first storage tank 2A, so that the state in the first storage tank 2A can be stably maintained.

In the configuration of embodiment 1, since the feed pump 25 for pressure-feeding the liquefied gas fuel to the engine 50 at a relatively high pressure is disposed in the first reservoir tank 2A, the operation control can be simplified as compared with the conventional configuration in which a feed pump is disposed in each reservoir tank. In addition, since the supply pumps 35 and 45 arranged in the second storage tanks 3A and 4A of the present configuration have a smaller output for pumping the liquefied gas fuel than the feed pump 25, the pumps themselves are lightweight, and the manufacturing cost and the purchase cost can be reduced. Therefore, the liquefied gas fuel storage device 1A can be reduced in weight as a whole and can be reduced in cost as compared with the conventional configuration.

Further, in embodiment 1, since the liquefied gas fuel in the second storage tanks 3A and 4A is supplied to the first storage tank 2A by the supply pumps 35 and 45, there is an advantage that the liquefied gas fuel can be stably and accurately supplied by controlling the supply pumps 35 and 45.

[ example 2]

As shown in fig. 4, the liquefied gas fuel storage apparatus 1B according to embodiment 2 has two second storage tanks 3B and 4B, and heaters 61 and 62 are provided at respective lower positions inside the two second storage tanks. Then, suction pipes 63 and 64 communicating with the supply pipe 7 via the supply extraction valves 34 and 44 are disposed in the second storage tanks 3B and 4B, respectively. Here, the lower ends of the suction tubes 63 and 64 are provided at positions close to the bottom of the tank. That is, the lower end positions of the suction pipes 63 and 64 are lower limits of the second storage tanks 3B and 4B to which liquefied gas fuel can be supplied.

In example 2, similarly to example 1, a control processing device 10 for controlling the operation of each pump, each valve, and the like is provided, and the operation of the heaters 61 and 62 is controlled by the control processing device 10. The control processing device 10 controls the operation of the heaters 61 and 62 based on temperature data of the respective liquefied gas fuels obtained by respective temperature sensors (not shown) disposed in the respective storage tanks 2A, 3B, and 4B and pressure data in the respective tanks obtained by respective pressure sensors (not shown).

The operation of the heaters 61 and 62 is controlled so that the liquefied gas fuel in the second storage tanks 3B and 4B is higher than the liquefied gas fuel in the first storage tank 2A by a predetermined temperature. Since the second storage tanks 3B, 4B have a higher internal pressure than the first storage tank 2A with the temperature difference between the second storage tanks 3B, 4B and the first storage tank 2A, liquefied gas fuel flows from the second storage tanks 3B, 4B to the first storage tank 2A. Here, the control processing device 10 controls the operation of the heaters 61 and 62 based on data obtained by the temperature sensors (not shown) and the pressure sensors (not shown) to heat and maintain the liquefied gas fuel in the second storage tanks 3B and 4B within a predetermined temperature range, and controls the difference in tank internal pressures between the second storage tanks 3B and 4B and the first storage tank 2A to be a range in which the liquefied gas fuel smoothly flows from the second storage tanks 3B and 4B to the first storage tank 2A.

That is, when the liquefied gas fuel in the second storage tank 3B is supplied to the first storage tank 2A, the temperature data and the pressure data of the second storage tank 3B and the first storage tank 2A are checked. Based on these data, the heater 61 is operated and controlled so that the liquefied gas fuel in the second storage tank 3B is higher than the first storage tank 2A by a predetermined temperature. As a result, the tank internal pressure of the second storage tank 3B becomes higher than the first storage tank 2A by a predetermined pressure, and the liquefied gas fuel in the second storage tank 3B flows to the first storage tank 2A through the supply pipe 7. Thus, the liquefied gas fuel in the second storage tank 3B is supplied to the first storage tank 2A. The same applies to the case where liquefied gas fuel is supplied from the second storage tank 4B to the first storage tank 2A.

In the present embodiment 2, the supply pumps 35 and 45 of the above-described embodiment 1 are not disposed, and the heaters 61 and 62 and the suction pipes 63 and 64 are disposed in the second storage tanks 3B and 4B, respectively, and the heaters 61 and 62 are operated and controlled by the control processing device 10. Further, since the configuration is the same as that of embodiment 1 described above except for these configurations, by controlling the operations of the feed pump 25, the valves, the shutoff valves, and the like as in embodiment 1, it is possible to perform the operations of filling the liquefied gas fuel, pressure-feeding the liquefied gas fuel to the engine 50, returning the remaining liquefied gas fuel, and supplying the liquefied gas fuel from the second storage tanks 3B and 4B to the first storage tank 2A in the same manner. In embodiment 2, the same components as those in embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted.

As described above, in example 2, as in example 1, as the liquefied gas fuel in the first storage tank 2A is pressure-fed to the engine 50, the liquefied gas fuel is supplied from the second storage tanks 3B and 4B to the first storage tank 2A by sequentially operating the heaters 61 and 62. Therefore, the same operational effects as in example 1 can be exhibited also in example 2.

[ example 3]

In the storage apparatus 1C for liquefied gas fuel according to embodiment 3, the second storage tanks 3C and 4C are installed, in which the heaters 61 and 62 are removed from the configuration of embodiment 2 described above, and the operation of the fuel cooler 19 is controlled by the control processing device 10, so that the liquefied gas fuel of high temperature returned from the engine 50 is cooled to a predetermined temperature range. As shown in fig. 5, the supply pumps 35 and 45 of example 1 and the heaters 61 and 62 of example 2 are not provided.

Here, as the operation control of the fuel cooler 19 by the control processing device 10, the remaining liquefied gas fuel is made to flow into the second storage tanks 3C, 4C within a predetermined temperature range, so that the temperature of the liquefied gas fuel in the second storage tanks 3C, 4C is made higher than that in the first storage tank 2A. That is, as in example 2, the temperature of the liquefied gas fuel in the second storage tanks 3C and 4C is increased to increase the internal pressure of the second storage tanks 3C and 4C, and the liquefied gas fuel flows from the second storage tanks 3C and 4C to the first storage tank 2A by the internal pressure difference between the second storage tanks 3C and 4C and the first storage tank 2A. The predetermined temperature range in which the remaining liquefied gas fuel is cooled by the fuel cooler 19 is set to a temperature at which the liquefied gas fuel in the second storage tanks 3C and 4C can smoothly flow to the first storage tank 2A.

Thereafter, the control processing device 10, in response to the pressure-feeding of the liquefied gas fuel from the first storage tank 2A to the engine 50, cools the remaining part of the liquefied gas fuel, which is not used in the engine 50, to a predetermined temperature by the fuel cooler 19, and returns the cooled liquefied gas fuel to the second storage tanks 3C and 4C. Thereby, the temperature of the liquefied gas fuel in the second storage tanks 3C, 4C rises, and the liquefied gas fuel is sent to the first storage tank 2A through the supply pipe 7.

In embodiment 3, since the configuration other than the above-described configuration is the same as that of embodiment 2, the control processing device 10 can perform the operations of filling the liquefied gas fuel, pressure-feeding the engine 50, returning the remaining liquefied gas fuel, and supplying the second storage tanks 3C and 4C to the first storage tank 2A in the same manner by controlling the feed pump 25, the valves, the shutoff valves, and the like in the same manner as in embodiment 1. Note that the same components as those in embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

As described above, in embodiment 3, the fuel cooler 19 for cooling the remaining liquefied gas fuel returned from the engine 50 is controlled so that a pressure difference is generated between the second reserve tanks 3C, 4C and the first reserve tank 2A, and the liquefied gas fuel in the second reserve tanks 3C, 4C is supplied to the first reserve tank 2A. Thus, the supply pumps 35 and 45 are not required as in example 1 described above, and the heaters 61 and 62 are not required as in example 2 described above, so that there is an advantage that the entire apparatus can be further reduced in weight, and the manufacturing cost can be further reduced.

In addition, in embodiment 3, as in embodiment 1, the liquefied gas fuel in the first storage tank 2A is fed under pressure to the engine 50, and the liquefied gas fuel is sequentially supplied from the second storage tanks 3C and 4C to the first storage tank 2A by controlling the operation of the fuel cooler 19, so that the same operational effects as in embodiment 1 can be exhibited.

[ example 4]

As shown in fig. 6, a liquefied gas fuel storage device 1D according to embodiment 4 is configured such that a return pipe 73 for returning excess liquefied gas fuel from the engine 50 is connected only to a position between the filling valve 32 and the filling stop valve 33 and a position between the filling valve 42 and the filling stop valve 43. This configuration is different from embodiment 1 described above in that the excess liquefied gas fuel returned from the return pipe 73 is not returned to the first storage tank 2A. That is, the return line constituted by the return pipe 73 is either communicated with the second storage tank 3D (see fig. 3 a) or communicated with the second storage tank 4D (see fig. 3B).

Further, in example 4, the supply pumps 71 and 72 disposed in the second storage tanks 3D and 4D have a function of increasing the flow rate (discharge flow rate) of the liquefied gas fuel to be pressure-fed, as compared with the feed pump 25 disposed in the first storage tank 2A. Accordingly, the liquefied gas fuel flows into first storage tank 2A more than the liquefied gas fuel flows out of first storage tank 2A. For this reason, the liquefied gas fuel in the first storage tank 2A is kept near the maximum filling amount until the liquefied gas fuel in the second storage tanks 3D, 4D becomes the lower limit amount. When the second storage tank 3D is set to the lower limit amount and the second storage tank 4D is set to the lower limit amount, the liquefied gas fuel supplied from the second storage tank 4D to the first storage tank 2A is almost the same as the amount returned by the return pipe 73, and therefore the liquefied gas fuel in the first storage tank 2A decreases. Here, even when the liquefied gas fuel supplied from the second storage tank 4D becomes an excess amount returned by the return pipe 73, the flow rate of the supply pump 72 is larger than the excess amount, and therefore the excess amount becomes the supply amount to the first storage tank 2A. For this reason, the present embodiment 4 does not require the return line to communicate with the first storage tank 2A as in the above-described embodiment 1.

Here, the above-described case where the liquefied gas fuel is held in the vicinity of the maximum filling amount in the first storage tank 2A will be described in detail. Since the inflow amount of the first reserve tank 2A is larger than the liquefied gas fuel flowing out to the engine 50, the overfill prevention valve is actuated to stop the supply from the second reserve tanks 3D and 4D when the maximum filling amount is reached. Then, when the liquefied gas fuel is pressure-fed by the feed pump 25 and the filling amount is decreased, the liquefied gas fuel is immediately supplied. This decrease and increase from the maximum filling amount is repeated until the liquefied gas fuel in the second storage tank 3D, 4D reaches the lower limit amount. For this reason, the liquefied gas fuel is kept near its maximum filling amount in the first storage tank 2A.

In embodiment 4, as in embodiment 1 described above, the control processing device 10 controls the valves and the shut-off valve to operate so that the liquefied gas fuel is supplied from the second storage tank 3D as the liquefied gas fuel is pressure-fed from the first storage tank 2A. At this time, the return pipe 73 communicates with the second storage tank 3D. Thereafter, when the liquefied gas fuel in the second storage tank 3D reaches the lower limit amount, the liquefied gas fuel is supplied from the second storage tank 4D, and the operations of the valves and the shut-off valve are controlled so that the return pipe 73 communicates with the second storage tank 4D. Then, the operation control is performed so that the liquefied gas fuel in the first storage tank 2A is set to the lower limit amount, or the supply line and the return line are communicated with the second storage tank 4D until the liquefied gas fuel is filled (see fig. 3B).

As described above, the liquefied gas fuel storage device 1D according to embodiment 4 is the same as that according to embodiment 1 except that the return pipe 73 is disposed and the supply pumps 71 and 72 having a discharge flow rate larger than that of the feed pump 25 are disposed in the second storage tanks 3D and 4D as described above. For this reason, the operations other than the control of connecting the return line to the second storage tank 4D are performed in the same manner as in embodiment 1. The same components as those in embodiment 1 are denoted by the same reference numerals, and descriptions thereof are omitted.

In embodiment 4, since all the remaining liquefied gas fuel returned from the engine 50 is returned to the second storage tanks 3D and 4D, the piping structure of the return pipe 73 can be simplified as compared with embodiment 1 described above, and the valve operation control and the shutoff valve operation control for returning the remaining liquefied gas fuel to the first storage tank 2A are not necessary, and the operation control process can be simplified.

Further, in example 4, as in example 1, the liquefied gas fuel in the first storage tank 2A is pressure-fed to the engine 50, and the liquefied gas fuel is sequentially supplied from the second storage tanks 3D and 4D to the first storage tank 2A by controlling the operations of the supply pumps 71 and 72, so that the same operational effects as in example 1 can be exhibited.

In embodiment 4, since the liquefied gas fuel is first supplied from the second storage tank 3D to the first storage tank 2A and then supplied from the second storage tank 4D, substantially the same operational effect can be achieved even if the supply pump 72 having a function larger than the discharge flow rate of the feed pump 25 is disposed only in the second storage tank 4D that is supplied last.

As described above, in embodiments 1 to 4, the supply pipe 7 is connected to the filling pipe 6 via the supply shutoff valve 14, but as another piping configuration, for example, as shown in fig. 7, a configuration may be adopted in which the supply pipe 76 is connected via the supply filling valve 77 disposed in the first storage tank 2B. In the liquefied gas fuel storage apparatus 1E having such a configuration, the supply pipe 76 is connected to the first storage tank 2B and the second storage tanks 3A and 4A independently, and forms a supply line of the present invention. Further, inside the first storage tank 2B, an overfill prevention valve 78 connected to the supply filling valve 77 is disposed, separately from the overfill prevention valve 12 connected to the filling valve 22. For this purpose, the liquefied gas fuel in the second storage tanks 3A, 4A is supplied from the supply pipe 76 to the first storage tank 2B via the overfill prevention valve 78. Fig. 7 illustrates a configuration using the supply pumps 35 and 45 as in example 1, and the same components as in example 1 are denoted by the same reference numerals and their description is omitted.

Further, in the above-described embodiments 1 to 3, the return pipe 8 is connected to the filling pipe 6 via the return shutoff valve 15, but as another piping configuration, for example, as shown in fig. 8, the return pipe 81 may be connected via a return valve 82 disposed in the first storage tank 2C and also connected via return valves 83 and 84 disposed in the second storage tanks 3E and 4E, respectively. In the liquefied gas fuel storage system 1F configured as described above, the return pipe 81 independently connects the first storage tank 2C and the second storage tanks 3E and 4E, and therefore the piping of the return pipe 81 alone constitutes the return line of the present invention. Fig. 8 also shows an example of a configuration using the supply pumps 35 and 45 as in example 1, and the same components as in example 1 are given the same reference numerals and their description is omitted.

Further, as shown in fig. 9, the supply pipe 76 may be connected to the supply filling valve 77 of the first storage tank 2D, and the return pipe 81 may be connected to the return valve 82 of the first storage tank 2D and the return valves 83 and 84 of the second storage tanks 3E and 4E, respectively. The liquefied gas fuel storage apparatus 1G having this configuration is constituted by combining the supply line (see fig. 7) of the liquefied gas fuel storage apparatus 1E and the return line (see fig. 8) of the liquefied gas fuel storage apparatus 1F, and the filling line, the supply line, and the return line are independent of each other. Therefore, the number of the respective shut valves can be reduced as in the above embodiments 1 to 3, and the operation and control can be simplified.

In example 4, as in the liquefied gas fuel storage apparatus 1F described above, the return pipes may be connected to return valves disposed in the second storage tanks.

In addition, in the configurations of embodiments 1 to 4, the feed pump 25 is disposed inside the first storage tank 2A, but as another configuration, as shown in fig. 10, a configuration may be adopted in which the feed pump 91 is externally attached to the first storage tank 2E. In the liquefied gas fuel storage apparatus 1H having this configuration, the feed pump 91 is connected to the first storage tank 2E through the take-out valve 24. Further, in order to take in the liquefied gas fuel in the first storage tank 2E and pressure-feed the liquefied gas fuel to the engine 50 even when the first storage tank 2E is tilted in accordance with the swing of the vehicle during traveling, a piping structure (not shown) is required which is disposed below the first storage tank 2E and which can take in the liquefied gas fuel to the feed pump 91 when tilted. In fig. 10, the configuration using the supply pumps 35 and 45 is illustrated as in embodiment 1, and the same reference numerals are used for the same components as in embodiment 1, and the description thereof is omitted.

In addition, in embodiments 1 to 4, the shutoff valves are disposed for each pipe at the connection points of the filling pipes, the supply pipe, and the return pipe, and as another configuration, a configuration using a three-way valve or a four-way valve is possible. For example, as shown in fig. 11, as the piping structure similar to that of embodiment 1, a four-way valve 95 may be disposed at a connection portion where the filling pipe 6, the supply pipe 7, and the return pipe 8 are gathered, a three-way valve 96 may be disposed at a portion where the filling pipe 6 and the return pipe 8 are gathered and connected to the second storage tank 3A, and a three-way valve 97 may be disposed at a portion where the filling pipe 6 and the return pipe 8 are gathered and connected to the second storage tank 4A. In the storage apparatus 1I for liquefied gas fuel having such a configuration, the filling, supply, and return of liquefied gas fuel can be performed by controlling the opening and closing operations of the four-way valve 95 and the three-way valves 96 and 97 at the time of filling, supply, and return as in the above-described embodiment 1.

The present invention is not limited to the above-described embodiments, and can be suitably used within the scope of the gist of the present invention. For example, as shown in fig. 12, the return pipe 99 may not be connected to the portions immediately upstream of the filling valves 32 and 42 of the second storage tanks 3A and 4A. In the liquefied gas fuel storage device 1J having this configuration, the liquefied gas fuel returned from the engine 50 directly flows into the first storage tank 2A. In addition, although the above embodiments 1 to 4 are configured to dispose two second storage tanks, a configuration in which one second storage tank is disposed or a configuration in which a plurality of second storage tanks such as three, four, etc. are disposed may be employed.

Claims (8)

1. A storage device for liquefied gas fuel, comprising:

a first storage tank storing liquefied gaseous fuel;

a feed pump for pumping the liquefied gas fuel in the first storage tank to the engine;

a second storage tank connected to the first storage tank via a supply line for supplying liquefied gas fuel, the second storage tank storing liquefied gas fuel;

a fuel supply mechanism for supplying the liquefied gas fuel in the second storage tank to the first storage tank via a supply line;

and a supply control means for controlling the fuel supply means to supply the liquefied gas fuel from the second storage tank to the first storage tank in accordance with the consumption of the liquefied gas fuel in the first storage tank.

2. A liquefied gas fuel storage apparatus as claimed in claim 1, wherein a plurality of second storage tanks are arranged in parallel, and the supply control means controls the supply of the liquefied gas fuel in each of the second storage tanks to the first storage tank in sequence.

3. A storage device for liquefied gas fuel as claimed in claim 1 or 2, wherein a return line for returning the remaining liquefied gas fuel not used in the engine to the second storage tank is provided.

4. A liquefied gas fuel storage device as claimed in any one of claims 1 to 3, wherein the fuel supply means is constituted by a supply pump disposed in the second storage tank and pressure-feeding the liquefied gas fuel in the second storage tank to the first storage tank via a supply line.

5. A storage apparatus for liquefied gas fuel as claimed in claim 4, wherein a flow rate of the liquefied gas fuel discharged from the feed pump disposed in the second storage tank is larger than that of the feed pump.

6. A storage apparatus for liquefied gas fuel as claimed in any one of claims 1 to 3, wherein the fuel supply means is constituted by a heater for heating the liquefied gas fuel in the second storage tank, and the supply control means performs adjustment so that the liquefied gas fuel in the second storage tank becomes higher than the liquefied gas fuel in the first storage tank by a predetermined temperature.

7. A liquefied gas fuel storage apparatus as claimed in claim 3, wherein the fuel supply means is constituted by a fuel cooler disposed in the return line for cooling the remaining liquefied gas fuel, and the supply control means adjusts the temperature of the remaining liquefied gas fuel returned to the second storage tank so that the liquefied gas fuel in the second storage tank becomes higher than the liquefied gas fuel in the first storage tank by a predetermined temperature.

8. A storage device for liquefied gas fuel as claimed in any one of claims 1 to 7, wherein a feed pump for pressure-feeding the liquefied gas fuel of the first storage tank to the engine is disposed in the first storage tank.