LIQUIFIED NATURAL GAS SUPPLY SYSTEM AND ASSOCIATED METHOD

Abstract

 The liquified gas supply system (1) comprises a dispensing unit (5) for transferring liquified natural gas from a gas storage (2) to the gas tank (4) of a vehicle (3) and remote servers (8) located outside the dispensing unit.

Description

[0001] The present invention concerns liquified natural gas supply systems.

[0002] More particularly, the present invention concerns a liquified natural gas supply system for transferring liquified natural gas from a gas storage to the gas tank of a vehicle comprising a dispensing unit and remote servers.

[0003] The invention also concerns a method for controlling the liquified gas supply system.

[0004] Generally, a liquified natural gas supply system comprises a gas storage supplying a dispensing unit connected to the gas tank of a vehicle for refuelling the gas tank.

[0005] Documents JP 2009115195 and JP 2015021572 each disclose a liquified gas filling system for refuelling a vehicle tank comprising a dispenser unit including a control unit and a supply line provided with a flowmeter to measure the gas flow rate supplied to the vehicle tank and with a solenoid valve comprising an adjusting valve to adjust the flow rate of the liquified gas supplied.

[0006] To refuel the vehicle tank, a supply nozzle of the supply line is connected to the tank of the vehicle and the flow rate adjusting valve of the solenoid valve is controlled by the control unit of the dispenser unit.

[0007] When the tank of the vehicle is nearly empty, gas is vaporized inside the tank causing the pressure inside the tank to rise above its threshold during refuelling making refuelling impossible.

[0008] Otherwise, in case of a failure of the dispenser unit, the system is out of duty until the intervention of an operator. Moreover, an operator must intervene on site to adjust settings of the system.

[0009] One aim of the present invention is to overcome these drawbacks.

[0010] According to an aspect, a liquified gas supply system is proposed.

[0011] The liquified gas supply system comprises a dispensing unit for transferring liquified natural gas from a gas storage to the gas tank of a vehicle and remote servers located outside the dispensing unit, wherein:

• the dispensing unit comprises:
  a return line comprising a first input intended to be connected to the gas tank of the vehicle, a gas return valve fluidly connected to the first input, a by-pass valve connected to the gas return valve and a return pressure sensor measuring the pressure of gas flowing into the return line,
• a supply line comprising:
  • a first output intended to be connected to the gas tank of the vehicle,
  • a filling valve for transferring liquified natural gas from the gas storage to the gas tank of the vehicle and fluidly connected to the first output,
  • a flowmeter fluidly connected to a first input of the supply line intended to be connected to the gas storage,
  • a proportional filling valve disposed between the flowmeter and the filling valve and fluidly connected to the return line between the by-pass valve and the gas return valve, and
  • pressure and temperature sensors measuring the pressure and the temperature of gas flowing into the supply line, and
• a controller to control the by-pass valve, the gas return valve, the filling valve and the proportional filling valve to perform the degassing of the vehicle tank, the cooling of the flowmeter and the filling of the gas tank according to setpoints, the pressure measured in the return line, the temperature and the pressure measured in the supply line, the controller comprising means for communicating with the remote servers,
• the remote servers comprise means for configuring the setpoints of the by-pass valve, the filling valve, the gas return valve and the proportional filling valve, and means for communicating with the controller to transfer these setpoints to the controller.

[0012] The dispensing unit is controlled by the controller communicating with the remote servers to reduce the intervention of an operator on site.

[0013] The optimization in real time of the setpoints of the dispensing unit permits to optimize the performance of the dispenser remotely without operator intervention needed on location.

[0014] Preferably, the liquified gas supply system further comprises a supply device connected to the first input of the supply line to supply gas to the supply line the controller of the dispensing unit controlling the supply device.

[0015] Advantageously, the return line further comprises a check valve disposed between the first input and the gas return valve,

[0016] Preferably, the supply line further comprises a check valve disposed between the flowmeter and the proportional filling valve.

[0017] Preferably, the dispensing unit further comprises a connecting line connected to the return line between the gas return valve and the by-pass valve, and fluidly connected to the proportional filling valve.

[0018] Advantageously, the connecting line is connected to the supply line between the proportional filling valve and the filling valve.

[0019] Advantageously, the controller comprises phase detector means to determine if single phase fluid is flowing through the flowmeter.

[0020] Preferably, the dispensing unit comprises a counter connected to the controller of the dispensing unit to determine the total amount of gas filled in the gas tank of the vehicle and to communicate the total amount of gas.

[0021] Advantageously, the remote servers comprise a human machine interface to control manually and remotely the dispensing unit and to monitor the dispensing unit.

[0022] Further, the setpoints may be configured through the human machine interface of the remote servers.

[0023] Preferably, the setpoints configured by the remote servers comprise a pressure opening gas return value and a gas return valve opening duration and a pre-set duration to stop the degassing, and an opening degree of the proportional filling valve during the cooling of the flowmeter, an opening degree of the proportional filling valve during the refuelling of the tank, and a maximum cooling duration of the flowmeter, and a maximal duration to close the by-pass valve, and a minimum flow rate during a pre-set duration to stop the filling of the tank, and a target hose pressure to stop filling of the tank, and a maximum filling duration, and a maximal degassing duration.

[0024] Advantageously, the liquified gas supply system further comprises a liquid gas nozzle holder configured to store a liquid gas nozzle connected to the supply line and comprising heating means to heat the liquid gas nozzle, the setpoints configured by the remote servers comprising a pre-set temperature to start the heating means, and a pre-set temperature to stop the heating means.

[0025] Preferably, the liquified gas supply system further comprises refuelling control means configured to start the refuelling of the tank, the setpoints configured by the remote servers comprising a minimal duration to push the refuelling control means to start the refuelling of the tank.

[0026] Advantageously, the first communicating means transfer the measured pressures, temperature and flow rate and valve status to remote servers.

[0027] According to another aspect, a method for configuring a liquified gas supply system during refuelling of a gas tank of a vehicle from a gas storage, the system comprising a dispensing unit provided with

• a return line comprising a first input, a gas return valve fluidly connected to the first input, a by-pass valve the gas return valve being disposed between the by-pass valve and the first input and a return pressure sensor measuring the pressure of gas flowing into the return line,
• a supply line including

  a first output connected to the gas tank of a vehicle,

  a filling valve for transferring liquified natural gas from the gas storage to the gas tank of a vehicle and fluidly connected to the first output,

  a flowmeter fluidly connected to a first input of the supply line intended to be connected to the gas storage,

  a proportional filling valve disposed between the flowmeter and the filling valve and fluidly connected to the return line between the by-pass valve and the gas return valve, and

  pressure and temperature sensors measuring the pressure and the temperature of gas flowing into the supply line, is proposed.

[0028] The method comprises:

• configuring setpoints of the by-pass valve, the gas return valve, the filling valve and the proportional filling valve,
• transferring to a controller the setpoints determined by remote servers located outside the dispensing unit, and
• controlling the by-pass valve, the gas return valve, the filling valve and the proportional filling valve according to the transferred setpoints to perform degassing of the gas tank, cooling of the flowmeter and filling of the tank.

[0029] Advantageously, the method comprises monitoring the dispensing unit with the remote servers and controlling the dispensing unit with the remote servers.

[0030] The present invention and its advantages will be better understood by studying the detailed description of specific embodiments given by way of non-limiting examples and illustrated by the appended drawings on which:

• Figure 1 illustrates an example of a liquified gas supply system, and
• Figure 2 and Figure 3 illustrate an example of a method for controlling the liquified gas supply system.

[0031] Figure 1 illustrates an example of a liquified gas supply system 1 connected to a gas storage 2 filled with liquified natural gas and a vehicle 3 comprising a gas tank 4 to be refuelled.

[0032] It is assumed that the gas tank 4 comprises a degassing connection DEG and a refuelling connection REF.

[0033] The liquified gas supply system 1 comprises a dispensing unit 5 for transferring liquified natural gas from the gas storage 2 to the gas tank 4 of the vehicle, a supply device 6 for supplying the dispensing unit 5 with liquified natural gas from the gas storage 2and remote servers 8.

[0034] The supply device 6 is controlled by the dispensing unit 5.

[0035] The supply device 6 and the remote servers 8 are located outside the dispensing unit 5.

[0036] The dispensing unit 5 refuels the gas tank 4 of the vehicle with liquified natural gas supplied by the supply device 6.

[0037] The liquified natural gas is stored in the gas storage 2 preferably up to a maximum pressure of 10 bar at a temperature of -160°C.

[0038] The liquified gas is stored in the tank 4 of the vehicle 3 preferably up to a maximum pressure of 15.2 bar.

[0039] The supply device 6 comprises an input 7 connected to the gas storage 2 and an output 9 connected to the dispensing unit 5.

[0040] The supply device 6 delivers a variable flow rate according to instructions from a controller 38 of the dispensing unit 5.

[0041] The instructions comprise for example the flow rate of liquified natural gas supplied by supply device 6.

[0042] The dispensing unit 5 comprises a return line 17 and a supply line 18.

[0043] The return line 17 comprises a first input 19 intended to be connected to the gas tank 4 of the vehicle during the degassing of this gas tank, a gas return valve 20 fluidly connected to the first input 19, a by-pass valve 21 fluidly connected to the gas return valve 20 and a return pressure sensor 22 measuring the pressure of gas flowing into the return line 17.

[0044] The return line 17 further comprises a first output 23 intended to be connected to the gas storage 2. The by-pass valve 21 is disposed on the return line 17 between the first output 23 and the gas return valve 20.

[0045] The return line 17 further comprises a check valve 24 disposed between the first input 19 and the gas return valve 20 to prevent gas to flow into the gas tank 4 during degassing.

[0046] In the illustrated example, the return pressure sensor 22 is located between the check valve 24 and the first input 19.

[0047] This permits to measure the pressure at the first input 19 regardless the opening position of the by-pass valve 21 and the gas return valve 20.

[0048] The first input 19 of the return line 17 is intended to be connected to the tank 4 with a first hose 25 comprising a gas return nozzle 26. The gas return nozzle 26 is intended to be inserted in the degassing connection DEG of the tank 4.

[0049] The pressure measured by the return pressure sensor at the first input 19 is similar to the pressure in the tank 4 and the first hose 25 when the gas return nozzle 26 is inserted in the degassing connection DEG of the tank 4.

[0050] The dispensing unit 5 also comprises an intermediate line 27 connecting the return line 17 and the supply line 18.

[0051] The intermediate connecting line 27 is connected to the return line 17 between the gas return valve 20 and the by-pass valve 21.

[0052] The supply line 18 comprises:

• a first output 28 intended to be connected to the gas tank 4 of the vehicle during refuelling of this gas tank,
• a filling valve 29 fluidly connected to the first output 28,
  • a proportional filling valve 30 for controlling the flow of liquified natural gas from the gas storage 2 to the gas tank 4, and fluidly connected to the filling valve 29, and
• a flowmeter 31 fluidly connected to the proportional filling valve 30 and to a first input 32 of the supply line connected to the first output 9 of the supply device 6.

[0053] The proportional filling valve 30 is disposed on the supply line 18 between the filling valve 29 and the flowmeter 31. The flowmeter 31 is disposed on the supply line 18 between the proportional filling valve 30 and the first input 31. The intermediate connecting line 27 of the dispensing unit is connected to the supply line 18 between the proportional filling valve 30 and the filling valve 29.

[0054] In another embodiment, the intermediate connecting line 27 of the dispensing unit may be connected directly to the proportional filling valve 30.

[0055] The supply line 18 also comprises pressure and temperature sensors 33, 34 measuring the pressure and the temperature of gas flowing into the supply line.

[0056] In the illustrated example, the pressure sensor 33 is located between the filling valve 29 and the first output 28 of the supply line 8. This minimizes pressure drops between the pressure sensor 33 and the gas tank 4 to determine accurately the pressure in the gas tank 4.

[0057] In the illustrated example, the temperature sensor 34 is located between the filling valve 29 and the proportional filling valve 30 so that the temperature sensor 34 measures the temperature of the gas flowing in the supply line 18 and flowing in the intermediate connecting line 27 if the filling valve 29 is closed and the by-pass valve 21 is open.

[0058] The supply line 18 further comprises a check valve 35 disposed between the flowmeter 31 and the proportional filling valve 30 to prevent gas from flowing into the flowmeter 31.

[0059] The first output 28 of the supply line 18 may be connected to the tank 4 with a second hose 36 comprising a liquid gas nozzle 37 intended to be connected with the refuelling connection REF of the gas tank 4.

[0060] The controller 38 further controls the by-pass valve 21, the gas return valve 20, the filling valve 29 and the proportional filling valve 30 to perform the degassing of the vehicle tank 4, the cooling of the flowmeter 31 and the filling of the gas tank 4 according to setpoints SET and the pressure measured by the return pressure sensor 22 of the return line 17 and the pressure and the temperature measured by the pressure sensor 33 and the temperature sensor 34 of the supply line 18.

[0061] The by-pass valve 21, the gas return valve 20 and the filling valve 29 may comprise ON/OFF valves, for example ON/OFF solenoid valves or ON/OFF pneumatically actuated ball valves.

[0062] The dispensing unit 5 further comprises refuelling control means 39, for example a dead man button, connected to the controller 38 to start refuelling of the tank 4.

[0063] The refuelling control means 39 are activated for example by the driver of the vehicle 2 who refuels the tank 4.

[0064] The pressure measured by the return pressure sensor 22 and the pressure sensor 33, the temperature measured by the temperature sensor 34 and the flow measured by the flowmeter 31 are transmitted to the controller 38.

[0065] As soon as the controller 38 received the setpoints SET from the remote servers 8 of the liquified gas supply system, the controller 38 may control the dispensing unit 5 independently from the remote servers 8. The setpoints SET may be stored in a memory 40 of the controller 38.

[0066] The controller 38 comprises for example a processing unit.

[0067] The controller 38 further comprises means 41 for communicating with the remote servers 8.

[0068] The communicating means 41 transfer to the remote servers 8 the pressure measured by the return pressure sensor 22 and the pressure sensor 33, the temperature measured by the temperature sensor 34 and the flow rate measured by the flowmeter 31.

[0069] The communicating means 41 also transfer to the remote servers 8 the status of the by-pass valve 21, the gas return valve 20, the filling valve 29 and the proportional filling valve 30.

[0070] The status of the by-pass valve 21, the gas return valve 20, the filling valve 29 comprises if the said valve is open or closed. The status of the proportional filling valve 30 comprises the degree of openness of the valve for example in a range of 0 to 100%, 0% meaning that the said valve is closed and 100% meaning that the said valve is fully open.

[0071] From the data transferred by the communicating means 41, the remote servers 8 monitor the dispensing unit 5.

[0072] The controller 23 comprises phase detector means 42 to determine if single phase fluid is flowing through the flowmeter 31.

[0073] The phase detector means 42 determine the density of the gas flowing in the supply line 18 according to the flow rate measured by the flowmeter 31 and compare the density of the gas and the temperature measured by the temperature sensor 34 to reference values.

[0074] According to the result of the comparison, the phase detector means 42 conclude if single phase fluid is flowing through the flowmeter 31.

[0075] The controller 38 also comprises a counter 43. A human machine interface 44 of the dispensing unit 5 is connected to the counter 43. The counter 43 determines the amount of gas filled in the gas tank 4 of the vehicle. The human machine interface 44 comprises for example a screen displaying the amount of filled gas and the price of the refuelling of the tank 4.

[0076] The dispensing unit 4 may also comprise means of payment (not illus trated).

[0077] The dispensing unit 5 further comprises a liquid gas nozzle holder 45 comprising heating means HEAT controlled by the controller 38 to heat the liquid gas nozzle 37 according to the temperature measured by a temperature sensor in the holder 45 when the liquid nozzle is inserted in the holder 45 after the use of the liquid gas nozzle.

[0078] During refuelling of the gas tank 4, the liquid gas nozzle 37 freezes and is not available for a next refuelling. The heating means HEAT heat the liquid gas nozzle 37 so that the nozzle 37 is unfrozen to allow for the next refuelling.

[0079] The remote servers 8 of the liquified gas supply system comprise means 46 for configuring the setpoints SET of the by-pass valve 21, the filling valve 29, the gas return valve 20 and the proportional filling valve 30.

[0080] The remote servers 8 also comprise means 47 for communicating with the controller 38 to transfer the configured setpoints SET to the controller 38. The communication means 47 also receive, from the communications means 41 of the controller, the pressures measured by the return pressure sensor 22 of the return line and the pressure sensor 33 of the supply line 18, the temperature measured by the temperature sensor 34 of the supply line 18, the flow rate measured by the flow meter 31, the status of the by-pass valve 21, the gas return valve 20, the filling valve 29 and the proportional filling valve 30.

[0081] The remote servers 8 comprise a human machine interface 48 to control manually and remotely the dispensing unit 5, and to monitor the dispensing unit 5.

[0082] The remote servers 8 monitor the dispensing unit 5 and may control the dispensing unit 5 remotely for example if the dispensing unit is failing or if a user of the dispensing system 1 needs some help.

[0083] If the dispensing unit 5 is failing, the remote servers 8 may trigger an alarm to warn an operator which can physically intervene on the dispensing unit 5.

[0084] Preventive maintenance is reinforced due to the monitoring of the dispensing unit 5.

[0085] The setpoints SET configured by the remote servers 8 comprise a pressure opening gas return value and a gas return valve 20 opening duration and a pre-set duration to stop the return, and an opening degree of the proportional filling valve 30 during the cooling of the flowmeter 31, an opening degree of the proportional filling valve 30 during the refuelling of the tank 4, and a maximum cooling duration of the flowmeter, and a maximal duration to close the by-pass valve 21, and a minimal duration to push the means 39 to start the refuelling of the tank 4, a minimum flow rate during a pre-set duration to stop the filling of the tank 4, and a target hose pressure to stop filling of the tank, and a maximum filling duration, and a pre-set temperature to start the heating means HEAT, and a pre-set temperature to stop the heating means HEAT, and a maximal return duration.

[0086] The setpoints SET are configured for example empirically or by numerical simulations simulating the dispensing unit refuelling a gas tank.

[0087] The setpoints SET stored in the controller 38 may be changed remotely to adjust in real time the said setpoints to the operations of the dispensing unit 5 according for example to the pressures and temperature measured by the sensors 22, 33 and 34.

[0088] The optimization in real time of the setpoints of the dispensing unit 5 permits for example to reduce the duration of the refuelling of the gas tank 4.

[0089] Otherwise, less interventions on the dispensing system 1 on site are needed.

[0090] An example of a method for controlling the liquified gas supply system 1 to refuel the gas tank 4 will be now described.

[0091] Firstly, the controller 38 is configured by the remote servers 8. After the configuration of the controller 38, the dispensing unit 5 is ready to refuel the gas tank 4 of the vehicle 3.

[0092] In the following, an example of a method for configuring the controller 38 is described and then an example of a method for controlling the liquified gas supply system 1 during refuelling of the gas tank 4 of the vehicle 3 is described.

[0093] Figure 2 illustrates an example of the method for configuring the controller 38.

[0094] In a first step 50, the setpoints configuring means 46 of the remote servers configure the setpoints SET.

[0095] In a second step 51, the communicating means 30 of the remote servers 8 transfer the setpoints SET to the communicating means 47 of the controller 38. The setpoints SET are stored in the memory 40 of the controller 38.

[0096] Figure 3 illustrates an example of the method for refuelling the gas tank 4 of the vehicle 3.

[0097] It is assumed that the setpoints SET are already stored in the memory 40.

[0098] The gas return valve 20, the by-pass valve 21, the filling valve 29 and the proportional filling valve 30 are closed. The pump 11 does not deliver liquified natural gas.

[0099] As the tank 4 comprises the return connection DEG, the gas return nozzle 26 is connected to the return connection DEG for example by the driver of the vehicle 3 (step 60).

[0100] The return pressure sensor 22 measures the pressure in the first hose 25 which is similar to the pressure in the tank 4.

[0101] If the measured pressure by the return pressure sensor 22 is above the pressure opening gas return value of the setpoints SET (step 61), degassing of the tank 4 is needed.

[0102] In a degassing step 62, the gas return valve 20 and the by-pass valve 21 are opened by the controller 38 at the end of the gas return valve opening duration of the setpoints SET starting from the connection of the degassing connection DEG. The gas flows from the tank 4 to the gas storage 2 through the gas return valve 20 and the by-pass valve 21 of the return line.

[0103] If the pressure measured by the return pressure sensor 22 is still above the pressure opening gas return value of the setpoints SET, the degassing of the tank 4 continues (step 62).

[0104] If the measured pressure by the return pressure sensor 22 is below the pressure opening gas return value for a duration equal to the pre-set duration to stop the return of the setpoints SET or the return step reaches a duration equal to the maximal return duration of the setpoints SET (step 63), the gas return valve 20 and the by-pass valve 21 are closed by the controller 38. The degassing step is finished and the controller 38 controls the human machine interface 44 to indicate to the driver that the degassing step is finished so that the driver can disconnect the gas return nozzle 26 from the degassing connection DEG and the driver can store the gas return nozzle 26 in a nozzle holder of the dispensing unit 5.

[0105] In step 64, the driver connects the liquid gas nozzle 37 stored in the liquid gas nozzle holder 45 to the refuelling connection REF.

[0106] In step 65, a cooling down of the flowmeter 31 is performed before refuelling the tank 4 of the vehicle.

[0107] The intermediate cooling line 27 is used for the cooling down of the flowmeter 31.

[0108] The flowmeter 31 is cooled down to give accurate measurements of the flow rate of liquified gas flowing through the flowmeter 31.

[0109] The pump 11 is started by the system controller 7 receiving the instructions from the controller 38, the by-pass valve 21 and the proportional filling valve 30 are opened by the controller 38 so that liquified natural gas flows through the flowmeter 31 and flows back in the storage 2.

[0110] The gas supplied by the pump 11 flows through the proportional filling valve 30, the intermediate connecting line 27 and flows back in the storage 2 through the by-pass valve 21.

[0111] The instructions emitted by the controlled 38 comprise a value of flow rate supplied by the pump 11.

[0112] The opening degree of the proportional filling valve 30 is equal to the opening degree of the proportional filling valve 30 during the cooling of the flowmeter 31 of the setpoints SET.

[0113] Cooling of the flowmeter 31 is performed until the phase detector means 42 detect a single gas phase flowing through the flowmeter 31 or until the maximum cooling duration of the flowmeter of the setpoints SET is reached. Then, the by-pass valve 21 is closed by the controller 38 and the counter 27 is reset by the controller 38. The proportional filling valve 30 remains open.

[0114] If the by-pass valve 21 is not closed in the maximal duration to close the by-pass valve 21 of the setpoints SET after reception of the controlled signal emits by the controller 38 or the phase detector means 42 detect more than a single gas phase flowing through the flowmeter 31 (step 66), refuelling of the tank 4 is aborted and an alarm is triggered by the controller 38 (step 67).

[0115] If the measured pressure by the return pressure sensor 22 is below the pressure opening gas return value of the setpoints SET (step 61), it continues to step 64.

[0116] If the tank 4 does not comprise the degassing connection DEG, the method for refuelling the gas tank 4 of the vehicle 3 starts at step 64.

[0117] In step 68, if the driver activates the refuelling control means 39 during at least the minimal duration of the setpoints SET to push the means 39 to start the refuelling of the tank 4, and before the pre-set duration to stop the filling of the tank 4 of the setpoint SET starting from the confirmation of the refuelling transaction by the driver on the human machine interface 44, the controller 38 opens the filling valve 29 so that the gas in the storage 2 refuels the tank 4, the proportional filling valve 30 being open, the degree of opening of the proportional filling valve 30 being equal to the opening degree of the proportional filling valve 30 during the refuelling of the setpoints SET.

[0118] A counter is started.

[0119] The flowmeter 31 measures the amount of gas flowing in the tank 4 and delivers the amount to the counter 43 and the pressure sensor 33 measures the pressure in the second hose 36.

[0120] In step 69, when the pressure measured by the pressure sensor 33 is equal to the target hose pressure of the setpoints SET or if the counter has reached the maximum filling duration of the setpoints SET or the flow rate flowing through the flowmeter 31 is less than the minimum flow rate of the setpoints SET or the driver activates the refuelling control means 39 more than a pre-determined duration, for example 5 seconds, the refuelling of the tank is stopped.

[0121] The controller 38 closes the filling valve 29 and the proportional filling valve 30, and the system controller 7 disactivates the pump 11.

[0122] The screen of the human machine interface 44 displays a message to notify that the refuelling of the gas tank 4 is finished.

[0123] In the other cases, the screen of the human machine interface 44 displays a message to notify that the refuelling is aborted.

[0124] In step 70, after a message is displayed on the screen of the human machine interface 44, the driver puts the liquid gas nozzle 37 in the liquid gas nozzle holder 45.

[0125] If the temperature measured by the temperature sensor in the holder 45 is less than the pre-set temperature to start the heating means HEAT of the setpoints SET, the controller 38 starts the heating means HEAT to heat the liquid gas nozzle 37 until the temperature sensor in the holder 45 measures a temperature equal to the pre-set temperature to stop the heating means HEAT of the setpoints SET.

[0126] During steps 60 to 70, the remote servers 8 monitor the dispensing unit 5. If a failure of the dispensing unit 5 occurs, the dispensing unit 5 may be remotely controlled by the remote servers 8in particular by an operator through the human machine interface 48.

[0127] According to the measured values of the pressure sensors 22, 33 and the temperature sensor 34, the remote servers 8 may determine another setpoints and transfer them to the controller 38 to replace the previous setpoints, the dispensing unit 5 being controlled according to the another setpoints.

Claims

1. Liquified gas supply system (1) comprising a dispensing unit (5) for transferring liquified natural gas from a gas storage (2) to the gas tank (4) of a vehicle (3), and remote servers (8) located outside the dispensing unit, wherein:

- the dispensing unit comprises:

- a return line (17) comprising a first input (19) intended to be connected to the gas tank (4) of the vehicle, a gas return valve (20) fluidly connected to the first input (19), a by-pass valve (21), the gas return valve (20) being disposed between the by-pass valve (21) and the first input (19), and a return pressure sensor (22) measuring the pressure of gas flowing into the return line,

- a supply line (18) comprising:

- a first output (28) intended to be connected to the gas tank (4) of the vehicle,

- a filling valve (29) for transferring liquified natural gas from the gas storage (2) to the gas tank (4) of the vehicle and fluidly connected to the first output (28),

- a flowmeter (31) fluidly connected to a first input (32) of the supply line intended to be connected to the gas storage (2),

- a proportional filling valve (30) disposed between the flowmeter (31) and the filling valve (29) and fluidly connected to the return line (17) between the by-pass valve (21) and the gas return valve (20),
and

- pressure and temperature sensors (33, 34) measuring the pressure and the temperature of gas flowing into the supply line (18), and

- a controller (38) to control the by-pass valve (21), the gas return valve (20), the filling valve (29) and the proportional filling valve (30) to perform the return of the vehicle tank (4), the cooling of the flowmeter (31) and the filling of the gas tank according to setpoints (SET), the pressure measured in the return line, the temperature and the pressure measured in the supply line, the controller (38) comprising means (41) for communicating with the remote servers (8),

- the remote servers (8) comprise means (46) for configuring the setpoints (SET) of the by-pass valve, the filling valve, the gas return valve and the proportional filling valve, and means (47) for communicating with the controller (38) to transfer these setpoints to the controller.

2. Liquified gas supply system according to claim 1, further comprising a supply device (6) connected to the first input (32) of the supply line to supply gas to this supply line, the controller (38) of the dispensing unit controlling the supply device (6).

3. Liquified gas supply system according to claim 1 or 2, wherein the return line (17) further comprises a check valve (24) disposed between the first input (19) and the gas return valve (20).

4. Liquified gas supply system according to any of the preceding claims, wherein the supply line (18) further comprises a check valve (35) disposed between the flowmeter (31) and the proportional filling valve (30).

5. Liquified gas supply system according to any of the preceding claims, wherein the dispensing unit further comprises a connecting line (27) connected to the return line (17) between the gas return valve (20) and the by-pass valve (21), and fluidly connected to the proportional filling valve (30).

6. Liquified gas supply system according to claim 5, wherein the connecting line (27) is connected to the supply line (18) between the proportional filling valve (30) and the filling valve (29).

7. Liquified gas supply system according to any of the preceding claims, wherein the controller (38) comprises phase detector means (42) to determine if single phase fluid is flowing through the flowmeter (31).

8. Liquified gas supply system according to any of the preceding claims, wherein the dispensing unit comprises a counter (43) connected to the controller (38) of the dispensing unit to determine the total amount of gas filled in the gas tank (4) of the vehicle and to communicate the total amount of gas.

9. Liquified gas supply system according to any of the preceding claims, wherein the remote servers (8) comprise a human machine interface (48) to control manually and remotely the dispensing unit (5) and to monitor the dispensing unit (5).

10. Liquified gas supply system according to any of the preceding claims, wherein the setpoints configured by the remote servers (8) comprise a pressure opening gas return value (20) and a gas return valve opening duration and a pre-set duration to stop the degassing, and an opening degree of the proportional filling valve (30) during the cooling of the flowmeter (31), an opening degree of the proportional filling valve (30) during the refuelling of the tank (4), and a maximum cooling duration of the flowmeter (31), and a maximal duration to close the by-pass valve (21), and a minimum flow rate during a pre-set duration to stop the filling of the tank (4), and a target hose pressure to stop filling of the tank, and a maximum filling duration, and a maximal degassing duration.

11. Liquified gas supply system according to any of the preceding claims, further comprising a liquid gas nozzle holder (45) configured to store a liquid gas nozzle (37) connected to the supply line and comprising heating means (HEAT) to heat the liquid gas nozzle (37), the setpoints configured by the remote servers (8) comprising a pre-set temperature to start the heating means (HEAT), and a pre-set temperature to stop the heating means (HEAT).

12. Liquified gas supply system according to any of the preceding claims, further comprising refuelling control means (39) configured to start the refuelling of the tank, the setpoints configured by the remote servers (8) comprising a minimal duration to push the refuelling control means (39) to start the refuelling of the tank (4).

13. Liquified gas supply system according to any of the preceding claims, wherein the first communicating means (41) transfer the measured pressures, temperature and flow rate and valve status to remote servers (8).

14. Method for configuring a liquified gas supply system (1) during refuelling of a gas tank (4) of a vehicle (3) from a gas storage (2), the system comprising a dispensing unit (5) provided with:

- a return line (17) comprising a first input (19), a gas return valve (20) fluidly connected to the first input (19), a by-pass valve (21), the gas return valve (20) being disposed between the by-pass valve (21) and the first input (19)), and a return pressure sensor (22) measuring the pressure of gas flowing into the return line,

- a supply line (18) including:

a first output (28) connected to the gas tank (4) of the vehicle,

a filling valve (29) for transferring liquified natural gas from the gas storage (2) to the gas tank (4) of the vehicle and fluidly connected to the first output (28),

a flowmeter (31) fluidly connected to a first input (32) of the supply line intended to be connected to the gas storage (2),

a proportional filling valve (30) disposed between the flowmeter (31) and the filling valve (29) and fluidly connected to the return line (17) between the by-pass valve (21) and the gas return valve (20), and

pressure and temperature sensors (33, 34) measuring the pressure and the temperature of gas flowing into the supply line, the method comprising:

- configuring setpoints of the by-pass valve (21), the gas return valve (20), the filling valve (29) and the proportional filling valve (30),

- transferring to a controller (38) the setpoints determined by remote servers (8) located outside the dispensing unit, and

- controlling the by-pass valve (21), the gas return valve (20), the filling valve (29) and the proportional filling valve (30) according to the transferred setpoints to perform return of the gas tank (4), cooling of the flowmeter (31) and filling of the tank (4).

15. Method according to claim 14, comprising monitoring the dispensing unit with the remote servers (8) and controlling the dispensing unit with the remote servers (8).

Drawing