JP2014058997A - Filling system and filling method for liquefied fuel gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filling system for liquefied fuel gas, which enables an operator to check whether or not an excess flow valve for preventing the liquefied fuel gas from flowing out at a specified flow rate or above is operated, during an operation, and a filling method for the liquefied fuel gas.SOLUTION: A filling system for liquefied fuel gas includes a CU (control unit) 41 (56) that determines that an excess flow valve 17 blocks a circulation passage 12, makes an excess flow valve 17 block the circulation passage 12, and turns on an alarm lamp 42 (57), when differential pressure ΔP between filling destination pressure Pa of a gaseous phase Ga of DME (dimethyl ether) in a main tank 4 and filling source pressure Pb (Ps) of a gaseous phase Gb (Gs) of DME in a sub-tank 5 (reservoir 31) is equal to or higher than a predetermined differential pressure determination value Pn.

Description

  The present invention relates to a liquefied gas fuel filling system including an overflow prevention valve that prevents leakage of liquefied gas fuel such as dimethyl ether (hereinafter referred to as DME), and a filling method of the filling system.

  At present, the use of a liquefied gas fuel such as dimethyl ether (DME) is attracting attention as an alternative fuel for light oil used in diesel engines. When filling DME into a vehicle from a filling stand, the DME fuel is similar to LP gas and liquefies at about 5 atmospheres at room temperature. Therefore, the DME is pressurized on the filling stand side. Was adopted.

  During filling by the indentation filling method, there was a case where the differential pressure between the pressure in the fuel tank and the filling pressure of the filling equipment was small. In this case, the filling speed was slow and the filling time was long. In particular, under high temperature conditions such as in summer, the pressure in the fuel tank increases, and the filling speed may become slower. This is particularly a problem in vehicles that require a large amount of fuel, such as trucks.

  Therefore, a filling method called a pressure equalization method has been proposed in which the gas phase of the fuel tank of the vehicle and the gas phase of the storage tank of the filling stand are connected by piping to equalize the internal pressure of the fuel tank and the internal pressure of the storage tank. (For example, refer to Patent Document 1).

  Here, the filling method of the pressure equalization method will be described with reference to FIG. A filling system 3X for supplying DME to the engine 2 of the vehicle 1X includes a main tank 4, a sub tank 5, and a coupling 6. The coupling 6 is provided with a liquid phase filling port 6a and a gas phase filling port 6b.

  The liquid phase line 7 branches off from the liquid phase filling port 6a, and is connected to the first liquid phase valve 20a of the main tank 4 and the second liquid phase valve 20b of the sub tank 5; Supply pipe 23 connected from the first pump 22 to the engine 2, return pipe 24 for returning surplus fuel from the engine 2 to the main tank 4, and replenishment connected from the second pump 25 of the sub tank 5 to the main tank 4 A pipe 26 is provided, and check valves (check valves) 27a and 27b are provided in the filling pipe 21 and the supplementary pipe 26, respectively.

  The gas phase line 8 branches off from the gas phase filling port 6 b and is connected to the first gas phase valve 10 a of the main tank 4 and the second gas phase valve 10 b of the sub tank 5.

  At the time of filling, a nozzle 33 having a liquid-phase filling port 33a and a gas-phase filling port 33b connected to a measuring device 32 connected to a storage tank 31 of the filling stand 30 is connected to the coupling 6, and the first gas The phase valve 10a, the second gas phase valve 10b, the first liquid phase valve 20a, and the second liquid phase valve 20b are filled in an opened state.

  Since the coupling 6 at this time is integrated with gas and liquid, the vapor phase Ga and Gb of the main tank 4 and the sub tank 5 and the vapor phase Gs of the storage tank 31 communicate with each other simultaneously with filling DME. The pressures of the respective gas phases Ga, Gb, and Gs become uniform, and the filling rate of DME can be increased.

At the time of supply to the engine 2, the first pump 22 supplies the engine 2 via the supply pipe 23, and the excess fuel is returned from the engine 2 via the return pipe 24. At this time, the third liquid phase valve 20c and the fourth liquid phase valve 20d provided in the supply pipe 23 and the return pipe 24 are opened.

  When DME in the main tank 4 is consumed and DME is replenished from the sub tank 5 to the main tank 4, the fifth liquid phase valve 20e of the sub tank 5 and the first liquid phase valve 20a of the main tank 4 are opened, The main tank 4 is replenished from the pump 25 through the refilling pipe 26.

  At this time, the first gas phase valve 10a and the second gas phase valve 10b are opened to replenish DME, and at the same time, the gas phase Ga of the main tank 4 and the gas phase Gb of the sub tank 5 are communicated. Thus, the respective pressures are equalized, and the DME replenishment speed can be increased.

  On the other hand, a pipe for liquefied gas fuel such as LP gas or DME needs to be provided with a device that prevents a large amount of fuel from leaking due to damage to the fuel pipe due to an accident or the like. Therefore, in the filling system 3X, as shown in FIG. 8, the DME gas phase flows to the first gas phase valve 10a of the main tank 4 and the second gas phase valve 10b of the sub tank 5 to a flow rate higher than the specified flow rate. In such a case, an overflow prevention valve 17 is provided for blocking the flow path.

  The first gas phase valve 10a includes a flow passage 12 in a housing 11, the first opening 13 of the flow passage 12 serves as a communication port of the main tank 4, and the second opening 14 serves as a gas phase line. 8 communication port. In addition, a main valve 15 for opening or blocking the flow passage 12 and an overflow prevention valve 17 for blocking the first opening 13 are provided. The space between the main valve 15 and the housing 11 is sealed with an O-ring Or. In addition, the overflow prevention valve 17 and the fixed shaft 19 are joined.

  As shown in FIG. 9, the overflow prevention valve 17 is configured so that the DME gas phase flows above a specified flow rate due to the relationship between the spring 18 disposed in the flow passage 12 and the passage resistance of the DME gas phase flowing through the flow passage 12. The pressure is higher than the set pressure of the spring 18 and the flow passage 12 is closed. When the overflow prevention valve 17 closes upward in the figure and closes the first opening 13, the fixed shaft 19 also moves upward.

  As described above, the conventional filling system 3X includes the DME gas-phase line 8, so that the pressure between the tanks 4, 5, and 31 can be equalized and smoothly filled. By providing the overflow prevention valve 17 in the first gas phase valve 10a and the second gas phase valve 10b, the DME is prevented from leaking from the pipe.

  However, in the case of the above equal pressure type filling system 3X, when the nozzle 33 is connected to the vehicle-side coupling 6 and filling is started, the internal pressure of the main tank 4 and the sub tank 5 may be higher than the internal pressure of the storage tank 31. Yes, the gas phase of DME in the gas phase line 8 instantaneously flows from the main tank 4 and the sub tank 5 to the storage tank 31, and the overflow prevention valve 17 operates.

  Even in this case, the filling flow rate is reduced, but the filling is possible. Therefore, the driver may not notice that the overflow prevention valve 17 is activated and the flow passage 12 through which the gas phase of DME flows is closed. . When the vehicle starts to travel with the overflow prevention valve 17 closed as described above, when the DME filling operation from the sub tank 5 to the main tank 4 is started, the overflow prevention valve 17 is activated and the flow path is started. Since the gas phase line 8 is closed because 12 is shut off, the pressure between the main tank 4 and the sub tank 5 is not equalized, and only the pressure of the main tank 4 rises and fills. There is a possibility that the working time becomes long and the worst filling cannot be performed.

JP 2007-262903 A

  The present invention has been made in view of the above-mentioned problems, and the purpose of the present invention is to confirm whether or not the overflow prevention valve that prevents the liquefied gas fuel from flowing out beyond the specified flow rate is operating. It is an object of the present invention to provide a liquefied gas fuel filling system and a filling method thereof.

  In order to solve the above-described object, a liquefied gas fuel filling system according to the present invention includes a fuel tank for storing liquefied gas fuel, and a gas phase of the liquefied gas fuel between the fuel tank and a filling source via a valve device. A gas phase line that circulates and a liquid phase line that transfers the liquid phase of the liquefied gas fuel from the filling source to the fuel tank, and the valve device distributes the gas phase of the liquefied gas fuel. A liquefied gas comprising a passage and an overflow prevention valve that shuts off the flow passage when a gas phase of liquefied gas fuel flows from the fuel tank to the filling source at a flow rate equal to or higher than a predetermined flow rate. In the fuel filling system, the differential pressure between the gas-phase filling destination pressure of the liquefied gas fuel in the fuel tank and the gas-phase filling source pressure of the liquefied gas fuel in the filling source is a predetermined differential pressure determination. If the value exceeds the value, the overflow prevention valve Determines that blocked the flow passage, and provided with a warning device, wherein the excess flow valve for generating a warning that blocked the flow passage.

  According to this configuration, the overflow prevention valve determines that the flow passage has been blocked from the differential pressure between the fuel tank and the filling source, and warns the driver. You can know if you did. As a result, if liquefied gas fuel is leaking from the pipe, it can be dealt with promptly. On the other hand, if liquefied gas fuel is not leaking, the overflow prevention valve can be returned to its original state for smooth filling. Can do.

  The overflow prevention valve referred to here can prevent the gas phase of the liquefied gas fuel from flowing out from one of the flow passages to the other at a specified flow rate or more, and the gas phase of the liquefied gas fuel from the other to one side. It is a device that allows it to flow out. Thereby, it is possible to prevent a large amount of the liquid phase or gas phase of the liquefied gas fuel from leaking out due to piping breakage or the like in the system provided with the valve device.

  In the above liquefied gas fuel filling system, the valve device shuts off the flow passage separately from the overflow prevention valve, and opens the overflow prevention valve when the flow passage is shut off. When configured with a valve, a driver who has been warned that the overflow prevention valve has been actuated can close the main valve and cope with leakage of liquefied gas fuel from the piping. If there is no leakage of liquefied gas fuel from the piping, the closed main valve is opened and the overflow prevention valve is returned to its original state, so the liquefied gas fuel is filled while the overflow prevention valve is operating. It is possible to prevent the filling operation time from becoming longer or the filling operation from being disabled.

  In addition, in the above liquefied gas fuel filling system, when the fuel tank is a main tank and the filling source is constituted by at least one sub tank or a storage tank of a filling stand, the filling source is constituted by a sub tank. The driver can confirm whether or not the overflow prevention valve is activated during the driving of the vehicle. Further, when the filling source is constituted by the storage tank of the filling stand, the driver can confirm whether or not the overflow prevention valve is activated when the vehicle is filled with the liquefied gas fuel.

Furthermore, the filling method of the liquefied gas fuel filling system for solving the above-mentioned problem includes a fuel tank for storing the liquefied gas fuel, and a valve device for the gas phase of the liquefied gas fuel between the fuel tank and the filling source. And a liquid phase line for transferring the liquid phase of the liquefied gas fuel from the filling source to the fuel tank, and the valve device circulates the gas phase of the liquefied gas fuel. And an overflow prevention valve that shuts off the flow path when the gas phase of the liquefied gas fuel flows from the fuel tank to the filling source at a flow rate equal to or higher than a predetermined flow rate. In the filling method of the liquefied gas fuel filling system, a differential pressure between a gas phase filling destination pressure of the liquefied gas fuel in the fuel tank and a gas phase filling source pressure of the liquefied gas fuel in the filling source is previously set. When the differential pressure judgment value exceeds the set value Wherein determining that excess flow valve is cut off the flow passage, a method characterized in that the over-flow valve for generating a warning that blocked the flow passage.

  Moreover, in the filling method of the liquefied gas fuel filling system, after the warning, the main valve provided in the valve device is used to check the filling system by shutting off the flow path separately from the overflow prevention valve, When there is no liquid phase or gas phase leak of liquefied gas fuel in the filling system, it is preferable to open the overflow prevention valve when opening the flow passage blocked by the main valve.

  In the case of a conventional pressure equalization type filling system, when the filling hose is connected to the vehicle and the filling is started, the internal pressure of the fuel tank on the vehicle side may be higher than the pressure on the storage tank side. The overflow prevention valve may be activated due to the flow of the gas in the phase line. When driving is started in that state, when the filling operation from the main tank to the sub tank is started, the overflow prevention valve is activated and the flow passage is shut off, so the pressure between the tanks is not equalized, and the main tank Pressure increases, filling operation becomes longer, and filling may not be performed.

  According to the above filling method, the driver can be warned that the overflow prevention valve has been activated and the flow passage has been blocked. Thereby, when there is a leak or the like in the pipe, the driver can take measures to block the flow passage with the main valve. Moreover, when there is no leakage in the piping, the driver can open the main valve so that the overflow prevention valve can be opened, so that the above problem can be solved.

  According to the present invention, the driver can check whether or not the overflow prevention valve that prevents the liquefied gas fuel from flowing out beyond the specified flow rate is operating. Thereafter, the driver can check the leakage from the piping by closing the main valve of the valve device. If there is no leakage from the piping, the overflow prevention valve can be returned to the original state.

It is the schematic which shows the filling system of the liquefied gas fuel of 1st Embodiment which concerns on this invention. It is a flowchart which shows operation | movement of the filling system of the liquefied gas fuel of 1st Embodiment which concerns on this invention. It is an expanded sectional view which shows the valve apparatus of FIG. 1, and shows the state which closed the main valve. It is the schematic which shows the filling system of FIG. 1, and shows the state which fills each fuel tank from a filling stand. It is the schematic which shows the filling system of FIG. 1, and shows the state which fills a main tank from a sub tank. It is the schematic which shows the filling system of the liquefied gas fuel of 2nd Embodiment which concerns on this invention. It is the schematic which shows the filling system of the conventional liquefied gas fuel. It is an expanded sectional view which shows the valve apparatus of FIG. 7, and shows the state which the overflow prevention valve opened. It is an expanded sectional view which shows the valve apparatus of FIG. 7, and shows the state which the overflow prevention valve closed.

Hereinafter, a liquefied gas fuel filling system and a filling method of the filling system according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a vehicle using dimethyl ether (hereinafter referred to as DME) as liquefied gas fuel will be described. For example, liquefied petroleum gas (LPG), liquefied natural gas (LNG), liquefied butane gas (LBG) ), And liquefied hydrogen fuel. Further, although a vehicle equipped with two tanks for storing DME will be described, the present invention can also be applied to a vehicle equipped with two or more tanks.

  First, a vehicle equipped with a liquefied gas fuel filling system according to a first embodiment of the present invention will be described with reference to FIG. In addition to the configuration of the conventional filling system 3X shown in FIG. 7, the filling system 3 fills a main tank (fuel tank) 4 with a filling destination pressure sensor 40a and a sub tank (filling source) 5 as shown in FIG. Each of the pressure sensors 40b includes a CU (control unit; control device) 41 connected to each of the pressure sensors 40a and 40b, and a warning lamp 42 controlled by the CU 41.

  Each of the pressure sensors 40a and 40b is composed of a sensor of a well-known technology, and detects the pressure of the gas phase Ga of DME in the main tank 4 and the pressure of the gas phase Gb of DME in the sub tank 5 serving as a filling source. Yes. The filling pressure sensor 40a and the filling pressure sensor 40b are connected to the CU 41 by signal lines.

  Therefore, in this filling system 3, the main tank 4 is used as a filling destination fuel tank, the filling destination pressure sensor 40 a detects the filling destination pressure Pa, the sub tank 5 is used as the filling source, and the filling source pressure sensor 40 b is used as the gas in the sub tank 5. The filling source pressure Pb of the phase Gb is detected.

  In this embodiment, the pressure sensors 40a and 40b and the CU 41 are connected by signal lines. For example, the information detected by the pressure sensors 40a and 40b is input to the CU 41 by radio signals. Also good.

  The CU 41 is a microcontroller that controls turning on and off of the warning lamp 42 by an electric circuit, and compares the differential pressure value detected by each pressure sensor 40a and 40b with a predetermined differential pressure determination value. It is determined whether or not the overflow prevention valve 17 is closed. In this embodiment, although provided separately from the ECU (engine control unit) that controls the engine 2 and the like, an ECU having the control function may be used instead.

  The warning lamp 42 is a device that can be lit to notify the driver that the overflow prevention valve 17 is closed and the flow passage 12 is blocked. In this embodiment, a device that notifies the driver of the state by lighting is used, but the present invention is not limited to this. For example, a device that emits a warning sound when the overflow prevention valve 17 is closed and the flow passage 12 is blocked may be used.

  Next, operation | movement of this filling system 3 is demonstrated, referring the flowchart of FIG. Here, the operation when filling the DME from the sub tank 5 as the filling source to the main tank 4 while the vehicle 1 is traveling will be described. In addition, the filling pressure of the gas phase Ga in the main tank 4 is Pa, and the filling pressure of the gas phase Gb in the sub tank 5 is Pb.

  This operation is an operation that is started when the engine key is turned on and the engine 2 is started, or an operation that is performed at certain intervals during the operation of the engine 2. First, step S10 is performed in which the filling destination pressure sensor 40a detects the filling destination pressure Pa of the gas phase Ga in the main tank 4, and the filling source pressure sensor 40b detects the filling source pressure Pb of the gas phase Gb in the sub tank 5.

Next, the CU 41 performs step S20 in which it is determined whether or not the differential pressure ΔP between the filling destination pressure Pa and the filling source pressure Pb is larger than a predetermined differential pressure determination value Pn. If the differential pressure ΔP is larger than the differential pressure determination value Pn in step S20, pressure equalization cannot be achieved between the main tank 4 and the sub tank 5 that is the filling source, that is, the first gas-phase valve 10a and the second gas It is determined that at least one of the overflow prevention valves 17 of the phase valve 10b is closed.

  When the differential pressure ΔP exceeds the capacity of the second pump 25 that transfers DME from the sub tank 5 to the main tank 4, filling is impossible. Therefore, the differential pressure determination value Pn is based on the pump differential pressure (also referred to as pump capacity) of the second pump 25. For example, if the pump differential pressure (usually 0.3 MPa to 0.5 MPa) of the second pump 25 is 0.5 MPa, the differential pressure determination value Pn is set to 0.5 MPa, or 0.5 MPa to 0.7 MPa. The

  If it is determined in step S20 that the differential pressure ΔP is greater than the differential pressure determination value Pn, the CU 41 then performs step S30 in which the warning lamp 42 is lit, and returns to step S10 again. On the other hand, if it is determined in step S20 that the differential pressure ΔP is equal to or less than the differential pressure determination value Pn, then step S40 for turning off the warning lamp 42 is performed, and the process returns to the start.

  According to this operation, when the differential pressure ΔP is larger than the differential pressure determination value Pn, it is determined that the overflow prevention valve 17 is operated and the flow passage 12 through which the DME gas phase flows is blocked, and the warning light 42 Is lit, so that the driver knows that the overflow prevention valve 17 has been activated while the vehicle 1 is traveling, or that the overflow prevention valve 17 has been activated when filling from the filling stand 30. it can.

  Next, a countermeasure after the warning lamp 42 is turned on will be described with reference to FIGS. 3, 8, and 9. First, as shown in FIG. 9, when the warning lamp 42 is turned on, the driver who knows that the overflow prevention valve 17 is closed and the flow passage 12 is blocked is shown in FIG. The respective handles 16 of the first gas phase valve 10a and the second gas phase valve 10b are operated, the main valve 15 is closed, and the flow passage 12 is shut off.

  At this time, the main valve 15 blocks the flow passage 12 and simultaneously pushes the fixed shaft 19 downward in the drawing to open the overflow prevention valve 17 joined to the fixed shaft 19. Even when the overflow prevention valve 17 is in the open state, the main valve 15 itself blocks the flow passage 12, so that the gas phase of DME does not flow.

  Next, the liquid phase line 7, the gas phase line 8, the filling pipe 21, and the supplementary pipe 26 (hereinafter, unified with pipes) in the vehicle 1 are inspected to determine whether there is a leak of DME. to decide. If there is a leak from the piping, repair it promptly. On the other hand, if there is no leakage from the piping as a result of the inspection, the handle 16 is operated to open the main valve 15 and open the flow passage 12 as shown in FIG.

  By this operation, the overflow prevention valve 17 can be returned to the normal position. As a result, the problem that occurred in the case of the conventional pressure equalization type filling system 3X, that is, when there was no leakage from the pipe during filling, the overflow prevention valve 17 was activated and the flow passage 12 was blocked. In this state, the filling operation from the sub tank 5 to the main tank 4 is started, the pressure in the main tank 4 and the sub tank 5 cannot be equalized, the pressure in the main tank 4 rises, the filling operation becomes long, and the filling cannot be performed. Can be solved.

  In this embodiment, the first gas phase valve 10a configured to manually rotate the handle 16 and close the main valve 15 has been described as an example. However, the present invention is not limited to this, for example, An electromagnetic valve may be provided instead of the handle 16, and the main valve 15 may be opened and closed with the electromagnetic valve. If the main valve 15 is configured to be opened and closed with a solenoid valve, the driver can operate the main valve 15 to be opened and closed from the driver's seat, and convenience is improved.

Next, a filling method of the filling system 3 will be described with reference to FIGS. 4 and 5. Here, in FIGS. 4 and 5, the white arrow indicates the DME vapor phase flow, and the solid arrow indicates the DME liquid phase flow.

  When filling the main tank 4 and the sub tank 5 from the storage tank 31 with DME, the nozzle 33 is first connected to the coupling 6 as shown in FIG. The coupling 6 is configured to open the flow path when connected to the nozzle 33 and to be blocked when not connected. Further, the coupling 6 is configured such that when the nozzle 33 is connected, the liquid phase line 7 and the gas phase line 8 are simultaneously connected to the filling stand 30 side.

  Each valve 10a, 10b, 20a-20e is normally open except when the overflow prevention valve 17 is closed and the filling system 3 needs to be repaired or when the vehicle is serviced. 33, the gas phases Ga, Gb, and Gs communicate with each other via the first gas phase valve 10a of the main tank 4 and the second gas phase valve 10b of the sub tank 5, and the main tank The liquid phase portions Fa, Fb, and Fs communicate with each other through the first liquid phase valve 20a and the second liquid phase valve 20b of the sub tank 5.

  The liquid phase of DME is pressurized by a pump (not shown), and filling of the main tank 4 and the sub tank 5 from the filling stand 30 is started. Then, the main tank 4 and the sub tank 5 are filled with the DME liquid phase via the liquid phase line 7. At this time, the gas phases Ga, Gb, and Gs are equalized by the gas phase line 8.

  At this time, each pressure Pa or Pb of the main tank 4 or the sub tank 5 may be higher than the pressure Ps on the storage tank 31 side, and the gas phase of DME instantaneously flows from the vehicle 1 to the storage tank 31 to prevent overflow. The valve 17 may be activated. However, as described above, according to the present invention, after the engine 2 is started, the operating state of the overflow prevention valve 17 can be known by the lighting of the warning light 42, and each pipe is inspected. The overflow prevention valve 17 can be returned to the original state. Thereby, it can suppress that the filling operation | work during driving | running | working of the vehicle 1 becomes long, or it becomes impossible to perform filling.

  Next, a case where DME is filled from the sub tank 5 to the main tank 4 will be described. During traveling, DME is supplied from the main tank 4 to the engine 2 by the first pump 22. At this time, surplus fuel is returned from the engine 2 to the main tank 4.

  When the DME in the main tank 4 is consumed, the DME is replenished from the sub tank 5 to the main tank 4 by the second pump 25. At this time, since the first gas phase valve 10a and the second gas phase valve 10b are open, the internal pressures of the main tank 4 and the sub tank 5 are equalized, that is, the pressures of the respective gas phase Ga and Gb are equalized. To do.

  At this time, there is a case where the overflow prevention valve 17 of at least one of the first gas phase valve 10a and the second gas phase valve 10b is activated and pressure equalization between the main tank 4 and the sub tank 5 cannot be performed. However, as described above, according to the present invention, the driver can know the operating state of the overflow prevention valve 17 by turning on the warning light 42, and if there is no problem after checking each pipe, 17 can be restored to its original state. Thereby, even when DME is filled from the sub tank 5 to the main tank 4, the DME can be filled from the sub tank 5 to the main tank 4 without decreasing the filling speed.

  The above-described filling system 3 can obtain the above-described effects only by adding the pressure sensors 40a and 40b, the CU 41, and the warning lamp 42 to the configuration of the conventional filling system 3X. Since there are no significant changes or changes in the configuration of the gas-phase valves 10a and 10b, the problem can be solved at low cost.

  Next, a liquefied gas fuel filling system 50 according to a second embodiment of the present invention will be described with reference to FIG. The filling system 50 includes a liquid phase line 51, a gas phase line 52, and a check valve 53 between the coupling tank 6 and the subtank 5 removed from the configuration of the filling system 3 of the first embodiment. The storage tank 31 of the filling stand 54 includes a filling source pressure sensor 55 that detects the filling source pressure Ps of the DME gas phase Gs in the storage tank 31. Further, a CU 56 connected to the filling destination pressure sensor 40 a and the filling source pressure sensor 55, and a warning lamp 57 controlled by the CU 56 are provided.

  Unlike the filling system 3 of the first embodiment, the filling system 50 uses the main tank 4 as a filling destination fuel tank, the filling destination pressure sensor 40a detects the filling destination pressure Pa, and fills the storage tank 31. The filling source pressure sensor 55 is configured to detect the filling source pressure Ps of the gas phase Gs in the storage tank 31.

  The signal line between the filling source pressure sensor 55 and the CU 56 is configured to be connected when the coupling 6 and the nozzle 33 are connected. In this embodiment, the pressure sensors 40a and 55 and the CU 56 are connected by signal lines. For example, the information detected by the pressure sensors 40a and 55 may be input to the CU 56 by radio signals. .

  Next, the operation of the filling system 50 can be described by assuming that the filling source pressure Pb in the flowchart shown in FIG. 2 is the filling source pressure Ps. The method for filling the main tank 4 with DME is substantially the same as the method described with reference to FIG.

  The operation of the filling system 50 is started when the nozzle 33 is connected to the coupling 6. When the operation is started, the filling pressure sensor 40 a detects the filling pressure Pa of the gas phase Ga in the main tank 4, and the filling pressure sensor 55 detects the filling pressure Ps of the gas phase Gs in the storage tank 31.

  Next, the CU 56 determines whether or not the differential pressure ΔP between the filling destination pressure Pa and the filling source pressure Ps is larger than a predetermined differential pressure determination value Pn. Here, when the differential pressure ΔP is larger than the differential pressure determination value Pn, the pressure is not equalized between the main tank 4 and the filling source storage tank 31, that is, the overflow prevention valve 17 of the first vapor phase valve 10a. Is determined to be closed. When it is determined that the differential pressure ΔP is greater than the differential pressure determination value Pn, the CU 56 next turns on the warning lamp 57. On the other hand, when it is determined that the differential pressure ΔP is equal to or less than the differential pressure determination value Pn, the warning lamp 57 is then turned off.

  According to this operation, when the differential pressure ΔP is larger than the differential pressure determination value Pn, it is determined that the overflow prevention valve 17 is activated and the flow passage 12 through which the DME gas phase flows is blocked, and the warning light 57 , The driver can know that the overflow prevention valve 17 has been activated when DME is filled into the main tank 4 of the filling system 50 from the filling stand 54.

  Thereby, during the filling of DME, the driver can know the operating state of the overflow prevention valve 17 by turning on the warning lamp 57, and each pipe is inspected. It can be returned to the state. Thereby, it can suppress that the filling operation | work becomes long during filling with DME, or it becomes impossible to perform filling.

In addition, it replaces with the filling stand 30 of 1st Embodiment, is equipped with the filling stand 54 of this 2nd Embodiment, and connects CU41 and the filling source pressure sensor 55, the main tank 4 and the filling stand 54 are connected. A warning may be issued both when the DME is filled in the sub tank 5 and when the DME is filled from the running sub tank 5 to the main tank 4. In this case, both the differential pressure determination with the filling destination fuel tank as the main tank 4 and the filling source as the storage tank 31 and the differential pressure determination with the filling destination fuel tank as the sub tank 5 and the filling source as the storage tank 31 are performed. I will do it.

  In the second embodiment, the CU 56 and the warning lamp 57 are installed in the vehicle, but may be installed in the filling stand 54. In this case, the filling operator can confirm the operation of the overflow prevention valve 17 and can respond quickly.

  The vehicle 1 equipped with the liquefied gas fuel charging system 3 or 50 according to the first or second embodiment of the present invention prevents a large amount of DME from leaking out due to the action of the overflow prevention valve 17, and also DME. When the overflow prevention valve 17 is activated and the flow passage 12 is interrupted during the filling operation, the operation state of the overflow prevention valve 17 is determined from the differential pressure between the tanks 4, 5, and 31. The operating state of the flow prevention valve 17 can be notified to the driver by turning on the warning lamp 42.

  Thereby, when DME is leaking from piping, it can respond quickly. On the other hand, when there is no leakage from the piping, the overflow prevention valve 17 can be returned to the original state, and DME can be filled smoothly. In particular, the present invention is suitable for filling a large-capacity fuel tank provided in a large truck capable of traveling over a long distance.

  In the liquefied gas fuel filling system of the present invention, the driver can confirm during operation whether or not the overflow prevention valve that prevents the liquefied gas fuel from flowing out beyond the specified flow rate is operating. It can be used for a vehicle equipped with an engine using liquefied gas fuel such as DME.

1 Vehicle 2 Engine (Internal combustion engine)
3, 50 Filling system 4 Main tank (fuel tank)
5 Sub tank (fuel tank or filling source)
6 Coupling (filling port)
7, 51 Liquid phase line 8, 52 Gas phase line 10a First gas phase valve (valve device)
10b Second gas phase valve (valve device)
DESCRIPTION OF SYMBOLS 11 Housing 12 Flow path 13 1st opening part 14 2nd opening part 15 Main valve 16 Handle 17 Overflow prevention valve 18 Spring (biasing member)
19 Fixed shaft (separation member)
20a to 20e First liquid phase valve to fifth liquid phase valve 21 Filling pipe 22 First pump 23 Supply pipe 24 Return pipe 25 Second pump 26 Supplementary pipes 27a, 27b, 53 Check valve valve)
30, 54 Filling stand 31 Storage tank (filling source)
32 Meter 33 Nozzle 40a Filling destination pressure sensor 40b Filling source pressure sensor 41, 56 CU (control unit; control device)
42, 57 Warning light 55 Filling source pressure sensor

Claims (5)

A fuel tank for storing liquefied gas fuel; a gas phase line for passing a gas phase of liquefied gas fuel through a valve device between the fuel tank and a filling source; and a liquid phase of liquefied gas fuel for the fuel tank. And a liquid phase line to be transferred from the filling source,
When the valve device has a flow passage through which a gas phase of liquefied gas fuel flows and a gas flow of liquefied gas fuel flows from the fuel tank to the filling source at a flow rate higher than a predetermined flow rate, In a liquefied gas fuel filling system configured to include an overflow prevention valve that shuts off,
When the differential pressure between the gas-phase filling destination pressure of the liquefied gas fuel in the fuel tank and the gas-phase filling source pressure of the liquefied gas fuel in the filling source is equal to or higher than a predetermined differential pressure determination value, A liquefied gas fuel filling system comprising: a warning device that determines that the overflow prevention valve has blocked the flow passage and generates a warning that the overflow prevention valve has blocked the flow passage.   The valve device includes a main valve that shuts off the flow passage separately from the overflow prevention valve and opens the overflow prevention valve when the flow passage is shut off. The liquefied gas fuel filling system according to claim 1.   3. The liquefied gas fuel filling system according to claim 1, wherein the fuel tank is a main tank, and the filling source is at least one sub-tank or a storage tank of a filling stand. A fuel tank for storing liquefied gas fuel; a gas phase line for passing a gas phase of liquefied gas fuel through a valve device between the fuel tank and a filling source; and a liquid phase of liquefied gas fuel for the fuel tank. And a liquid phase line to be transferred from the filling source,
The valve device has a flow path through which a gas phase of liquefied gas fuel flows and a flow path when the gas phase of liquefied gas fuel flows from the fuel tank to the filling source at a flow rate equal to or higher than a predetermined flow rate. In a filling method of a liquefied gas fuel filling system comprising an overflow prevention valve for shutting off,
When the differential pressure between the gas-phase filling destination pressure of the liquefied gas fuel in the fuel tank and the gas-phase filling source pressure of the liquefied gas fuel in the filling source is equal to or higher than a predetermined differential pressure determination value, A filling method for a liquefied gas fuel filling system, wherein the overflow prevention valve determines that the flow passage has been blocked and generates a warning that the overflow prevention valve has blocked the flow passage.   After the warning, the main valve provided in the valve device shuts off the flow path separately from the overflow prevention valve to check the filling system, and there is a liquid phase or gas phase leak of liquefied gas fuel in the filling system. 5. The filling method of the liquefied gas fuel filling system according to claim 4, wherein when there is not, the overflow prevention valve is opened when the flow passage blocked by the main valve is opened.

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