Station and method for filling one or more tanks

Abstract

The invention relates to a station for filling one or more tanks with pressurized gas, in particular pressurized hydrogen, the station comprising at least two source reservoirs of pressurized gas and a transfer pipe having an upstream end connected in parallel to the source reservoirs and a downstream end intended to be connected to a tank to be filled, the station comprising: a valve assembly for controlling the transfer of gas between the source reservoirs and the tank to be filled; and an electronic controller connected to the valve assembly and configured to control the valve assembly, the electronic controller being configured to implement a continuous transfer of gas between the source reservoirs and the tank to be filled by successive pressure equalization procedures, the electronic controller being configured to determine the temperature reached by the gas in the source reservoirs or by the source reservoirs during the transfer of gas, and to prevent or interrupt the transfer of gas or to reduce the flow rate of gas transferred during the transfer when the temperature reached is below a determined threshold. The invention also relates to a method for filling one or more tanks with pressurized gas by means of the station.

Description

TECHNICAL FIELD

[0001] The present invention relates to a station and a method for filling one or more tanks.

[0002] More particularly, the present invention relates to a station for filling one or more tanks with pressurized gas, in particular pressurized hydrogen, the station comprising at least two source reservoirs of pressurized gas, a transfer pipe having an upstream end connected in parallel to these source reservoirs and a downstream end intended to be connected to a tank to be filled, the station comprising: a valve assembly for controlling the transfer of gas between the sources and the tank to be filled; and an electronic controller connected to the valve assembly and configured to control the valve assembly, the electronic controller being configured to implement a successive pressure equalization procedure between the source reservoirs and the tank to be filled. BACKGROUND

[0003] The rapid filling (typically less than 15 minutes) of high-pressure gas tanks on board fuel cell powered vehicles is essentially performed by a successive pressure equalization procedure between high-pressure source volumes or reservoirs (for example 200 bar, 300 bar, 450 bar, 700 bar, 850 bar or 1000 bar) and on-board tanks. These methods, called "cascade" filling methods, have been extensively described in the literature.

[0004] When source reservoirs depressurize, they undergo a temperature drop (due to the isentropic expansion of the gas contained therein). In the case of successive filling of tanks, the successive depressurization of these gas tanks leads to a temperature drop below the minimum safe temperature of the tanks. This weakens the gas tanks and can lead to hydrogen leaks.

[0005] This phenomenon is particularly sensitive in composite source reservoirs. Said sources are in particular used in compressorless stations, in which these tanks are integrated in a frame on a mobile chassis of semi-trailer or MEGC (Multi-Element Gas Container) type. In addition, in the case of too rapid and too slow pressure decrease, the plastic internal sealing liner of these composite reservoirs can deform under the effect of the pressure drop ("liner collapse"). Excessive deformation can lead to leaks. SUMMARY

[0006] The object of the present invention is to overcome all or some of the above-mentioned drawbacks of the prior art.

[0007] To this end, the station according to the invention, which also provides the general definition according to the preamble described above, is essentially characterized in that the electronic controller is configured to determine the temperature reached by the gas in the source reservoirs or by the source reservoirs during the transfer of gas and to stop or interrupt this transfer of gas or to reduce the flow rate of gas transferred during said transfer when said reached temperature is below a determined threshold.

[0008] Furthermore, embodiments of the application can include one or more of the following features:

[0009] - the station comprises a set of sensors for measuring the temperature of the gas in the source reservoir, the electronic controller being configured to determine the temperature reached by the gas in the source reservoir or by the source reservoir during the transfer based on the values measured by the temperature measurement sensors;

[0010] - the station comprises a set of sensors for measuring the pressure of the gas in the source reservoir, the electronic controller being configured to determine the temperature reached by the gas in the source reservoir or by the source reservoir during the transfer based on the values measured by the pressure measurement sensors;

[0011] - the station comprises a sensor for measuring the ambient temperature, the electronic controller being configured to determine the temperature reached by the gas in the source reservoir or by the source reservoir during the transfer based on the values measured by the ambient temperature measurement sensor;

[0012] - the electronic controller is configured to determine the flow rate of the gas transferred during the transfer, and to determine the temperature reached by the gas in the source reservoir or by the source reservoir during the transfer based on the flow rate value;

[0013] - the electronic controller comprises a memory storing a reference table or graph of a set of gas transfer conditions, the electronic controller being configured to determine the temperature reached by the gas in the source reservoir or by the source reservoir during the transfer based on the reference table and the current gas transfer conditions;

[0014] - the electronic controller is configured to estimate the temperature reached by the gas in the source reservoir or by the source reservoir during the transfer based on a calculation module that, before and / or during the transfer, calculates the energy exchange balance in the walls of the source reservoir and the mass and enthalpy balance applied to the gas in the source reservoir using a gas state equation, ideal or real, and calculates the heat exchange balance between the walls of the source reservoir and the outside of the source reservoir.

[0015] The application also relates to a method for filling one or more tanks with pressurized gas, in particular pressurized hydrogen, by means of a station comprising at least two source reservoirs of pressurized gas, a transfer pipe having upstream ends connected in parallel to these source reservoirs and downstream ends intended to be connected to the tanks to be filled, the method comprising successive steps of transferring gas between the source reservoirs and the tanks by means of a pressure equalization program, the method comprising a step of determining the temperature reached by the gas in the source reservoir or by the source reservoir during the transfer of gas, a step of comparing the reached temperature with a determined threshold, and a step of preventing or interrupting the transfer or a step of reducing the flow rate of the gas transferred when the reached temperature is lower than the threshold.

[0016] According to other possible functions:

[0017] - the method comprises the steps of measuring the temperature and / or the pressure of the gas in the source reservoir before and / or during the gas transfer; and calculating the temperature reached during the transfer on the basis of the respective temperature and / or pressure measurements;

[0018] - the method comprises the step of measuring the ambient temperature before the gas transfer; and the step of calculating the temperature reached during the transfer on the basis of the measurement of the ambient temperature;

[0019] - the step of determining the temperature is performed before or at the beginning of the gas transfer, the determining step predictively determining the time of gas transfer for which the temperature reaches the threshold value, if there is a threshold value to be reached;

[0020] - during the gas transfer, the temperature is reduced by the gas in the source reservoir or by the temperature reached by the source reservoir during the transfer, the method comprising the steps of interrupting the gas transfer from the relevant source reservoir before the temperature reaches the threshold value; and transferring the gas from another source reservoir;

[0021] - the step of determining the temperature is performed before the gas transfer from the first source reservoir, and wherein the method comprises, after the completion of the step of determining the temperature, the step of determining the first amount of gas to be transferred by the first source reservoir to the tank to be filled before the moment at which the determined temperature reaches the threshold value, the method comprising the step of replacing the source reservoir to transfer the gas via a second source reservoir, i.e. without using the first source reservoir to transfer the gas, when the first amount of gas is lower than the determined amount. The present invention can also relate to any alternative device or method comprising any combination of the above or below mentioned features within the scope of the claims. BRIEF DESCRIPTION OF DRAWINGS

[0022] Other features and advantages will become apparent by reading the following description, made with reference to the attached drawings, of which:

[0023] Figure 1 is a partial and schematic view showing an example of the structure and operation of a filling station according to the present invention;

[0024] Figure 2 is a partial and schematic view showing an example of the operation of a filling station according to the present invention. DETAILED DESCRIPTION

[0025] The station 1 illustrated comprises a transfer pipe 7, the upstream end of which is connected in parallel to four pressurized gas source reservoirs 3, 4, 5, 6. The transfer pipe 7 comprises a downstream end intended to be connected to a reservoir 2 to be filled. Of course, a plurality of parallel / collocated downstream ends for filling a plurality of reservoirs 2 simultaneously can be envisaged. Similarly, the number of source reservoirs can be less or more and, if applicable, supplemented by other pressurized gas sources.

[0026] The station 1 comprises a valve assembly for controlling the gas transfer between the sources and the reservoir 2 to be filled. For example, at least one valve 12, preferably controlled, can be provided at the output of each source reservoir. In the case where the source reservoirs consist of a plurality of individual containers installed in parallel, each container can be equipped with a specific isolation valve, for example controlled. Similarly, upstream of the downstream end, the transfer pipe 7 can comprise at least one valve 13, in particular a pressure and / or flow regulation valve.

[0027] The station also comprises an electronic controller 8 connected to and configured to control the valve assembly. The electronic controller 8 can comprise a computer and / or a microprocessor. The electronic controller 8 is configured, i.e. programmed and / or controlled, to enable the continuous / sequential gas transfer between the gas sources 3, 4, 5, 6 and the reservoir 2 to be filled by successive / sequential pressure equalization programs. In other words, the electronic controller 8 is able and designed to enable the filling operation by cascading equalization programs. Of course, the station can comprise other additional sources (e.g. liquefied gas sources connected to evaporators and / or compressors).

[0028] For example, the gas can be compressed from a low pressure source (rack / frame, 200 bar semi-trailer, electrolysis device, etc.) to a high pressure source reservoir (typically between 450 and 1000 bars). The gas transfer is performed between the source reservoir and the reservoir 2 to be filled by passive equalization.

[0029] The reservoir 2 can be directly filled by a container installed on a semi-trailer. The cascading filling involves performing successive / sequential equalization programs, first using the source reservoir with the lowest pressure, then using the source reservoirs with increasingly higher pressures. When the pressure between the current source reservoir and the reservoir is equal or substantially equal (and / or when the flow of gas transferred falls below a threshold value), the transfer is interrupted and another source reservoir with a higher pressure is used.

[0030] According to an advantageous feature, the electronic controller 8 is configured to determine the temperature reached by the gas during the gas transfer from the source reservoirs 3, 4, 5, 6 or the temperature reached by the source reservoirs 3, 4, 5, 6 and to prevent or interrupt the transfer or to reduce the flow of gas transferred during said transfer when said reached temperature is below a determined threshold.

[0031] For example, the electronic controller 8 uses a prediction module to calculate the pressure and temperature at the end of the balancing procedure, thus allowing a predictive calculation of whether the temperature in the source reservoir will be lower than the minimum safety temperature allowed for the source reservoir.

[0032] If this is the case, it is possible to stop the balancing procedure before it is completed and / or to cancel it in favour of another balancing procedure (the next scheduled procedure). Alternatively or additionally, it is possible to modify, i.e. reduce, the flow rate of gas transfer between the source reservoir and the reservoir 2, in order to reduce the cooling within the source reservoir. This reduced flow rate can be, for example, the maximum flow rate determined by previous tests, thus allowing the risk of damaging the reservoir to be reduced or eliminated.

[0033] For example, this predictive estimate can be based on tests of extraction of gas from the supply device at different flow rates and on measurements of the temperature, so that a reference graph or table can be constructed. These tests can be associated with visual inspection (in particular, internal inspection) of the source reservoir, tomography or any other method for checking the damage to the liner (polymer, liner), so that the conditions in which the damage occurs (cracking, deformation of the liner, etc.) can be identified and the graph established.

[0034] Alternatively and / or cumulatively, the prediction can be based on artificial intelligence routines (for example, machine learning based on tests).

[0035] Therefore, by knowing the current conditions (temperature, and / or pressure and / or flow rate) and the type of source reservoir, the electronic controller 8 is able to determine in advance the temperature that will be reached during the gas transfer (for example, the temperature curve as a function of time).

[0036] Alternatively, this temperature during the gas transfer can be determined by a documented calculation module. For example, the temperature of the gas in the source reservoir and / or the temperature in the walls of the source reservoir can be based on the methods described in one of the following publications:

[0037] “The temperature evolution in compressed gas filling processes: A review”, International Journal of Hydrogen Energy, pages 1-25, 2017 (T. Bourgeois, F. Ammouri, D. Baraldi, P. Moretto);

[0038] - "Optimization of hydrogen vehicle refuelling requirements", International Journal of Hydrogen Energy, pages 1-21, 2017 (T. Bourgeois, T. Brachmann, F. Barth, F. Ammouri, D. Zaepffel, D. Baraldi, D. Melideo);

[0039] - "Evaluating the temperature inside a tank during a filling with highly-pressurized gas", International Journal of Hydrogen Energy, pages 1-8, 2015 (T. Bourgeois, F. Ammouri, M. Weber, C. Knapik).

[0040] In particular, the modelling of the estimation of the temperature of the gas in the source reservoir and / or of the temperature of the walls of the source reservoir can be based on a simplified zero-dimensional (0D) model of the gas and a one-dimensional (1D) model for the reservoir walls, which takes into account the conservation of mass and energy and the heat exchange at the source reservoir walls, to estimate the evolution of the temperature in the reservoir as a function of the pressure.

[0041] This estimation can be corrected and / or verified (redundancy) by measuring the temperature of the gas leaving the source reservoir considered.

[0042] It is noted that this value of the temperature of the gas leaving the source reservoir (or the temperature measurement at a local position of the source reservoir walls) does not always represent the lowest temperature reached inside the source reservoir. Indeed, since the temperature distribution can not be uniform, the use of a model provides more precise results.

[0043] Figure 2 Possible embodiments are depicted.

[0044] When considering the transfer of gas from a first source reservoir S i When transferring gas from a first source reservoir Si (step 14), the station can start by determining the pressure of the gas in the source reservoir PSi(t=t0) and the initial temperature TSi(t=0), and the initial pressure in the reservoir 2 to be filled P2(t=0) (step 15), and preferably also the ambient temperature Tamb.

[0045] In a next step (step 16), the temperature at the end of the transfer (equilibrium procedure) in the source reservoir Si (Tsi(t=tf)) can be calculated, as previously described. At this time, the pressure in the source reservoir Si at the end of the equilibrium procedure PSi(t=tf) can also be calculated, and optionally the pressure in the reservoir 2 at the end of the equilibrium procedure can be calculated.

[0046] Subsequently (step 17), the temperature Tsi at the end of the transfer of the source reservoir (t = tf) is compared with a determined threshold Tm (for example, the lowest temperature allowed to be stored).

[0047] If the temperature Tsi at the end of the transfer of the source reservoir (t = tf) is lower than this determined threshold Tm (Y), the pressure of the source reservoir or the time elapsed for the temperature of the source reservoir to reach this determined threshold Tm can be determined in a subsequent step (step 18). This time can be defined as the end of the update of the balancing program (i.e. the end of the balancing program can be advanced in time to avoid an excessive drop in temperature).

[0048] The balancing program can thus be activated until such an expected end (step 19). As an alternative (see alternative 20), step 20 can comprise switching to the next source reservoir with the pressure order i = i + 1. In other words, the transfer of gas from the source reservoir in question is cancelled to take the next source reservoir. In particular in the case where the transfer time with the current reservoir is extremely short and would lead to too rapid an approach to the threshold, the following choice (step 21) is made: switching to the next reservoir i = i + 1 by "jumping out" of the current reservoir (incomplete transfer of gas). Thus, according to the estimated temperature of the source reservoir, the system can decide not to use a source reservoir whose temperature is too low and which would only be able to transfer a very small quantity before reaching the lower limit allowed.

[0049] The extraction flow (flow of transferred gas) can be calculated each time and compared with a threshold flow.

[0050] Alternatively, the prediction model can be run in real time on the basis of the metering data, in particular the ambient temperature. Similarly, on delivery of a new semitrailer with source reservoirs, the pressure of the buffer reservoirs can be started in the model on the basis of the ambient temperature. In this way, the control system continuously takes into account the history of these source reservoirs to determine an estimate of the temperature in these source reservoirs.

[0051] Thus, if at any time, in particular during the transfer of gas, the estimated temperature approaches the determined threshold (preferably with a safety margin), the system can automatically switch to another source reservoir.

[0052] Thus, the station 1 can use pressurized source reservoirs with high pressure to cascade fill the tanks of vehicles using a prediction system calculating the temperature in the source reservoirs, while avoiding weakening these reservoirs.

[0053] Thus, the continuous temperature is controlled during extraction to prevent the source reservoirs from reaching a temperature lower than their minimum operating temperature.

Claims

1. A station for injecting pressurized gas into one or more storage tanks (2), the station comprising at least two source reservoirs (3, 4, 5, 6) for pressurized gas and a transfer pipe (7) having an upstream end connected in parallel to the source reservoirs (3, 4, 5, 6) and a downstream end intended to be connected to the storage tank (2) to be injected, the station (1) comprising: A valve assembly for controlling the gas transfer between the source reservoir and the tank (2) to be filled; and an electronic controller (8), which is connected to and configured to control the valve assembly, the electronic controller (8) being configured to achieve continuous gas transfer between the source reservoirs (3, 4, 5, 6) and the tank (2) to be filled via a continuous pressure balancing procedure, characterized in that the electronic controller (8) is configured to: The prediction module is used to calculate the predicted temperature that the gas in the source reservoirs (3, 4, 5, 6) or the gas expected to reach during the gas transfer, and When the predicted temperature is lower than a determined threshold corresponding to the minimum safe temperature allowed by the source reservoir, the gas transfer is prevented or interrupted, or the flow rate of the gas transferred during the transfer is reduced.

2. The station according to claim 1, characterized in that, The station includes a set of temperature measuring sensors (9) for measuring the temperature of the gas in the source reservoirs (3, 4, 5, 6), wherein the electronic controller (8) is configured to determine the predicted temperature of the gas in the source reservoir or the source reservoir during transfer based on the values ​​measured by the temperature measuring sensors (9).

3. The station according to claim 1 or 2, characterized in that, The station includes a set of pressure measurement sensors (10) for measuring the pressure of the gas in the source reservoirs (3, 4, 5, 6), wherein the electronic controller (8) is configured to determine the predicted temperature of the gas in the source reservoirs or the source reservoirs during transfer based on the values ​​measured by the pressure measurement sensors (10).

4. The station according to claim 1 or 2, characterized in that, The station includes an ambient temperature measurement sensor (11) for measuring ambient temperature, wherein the electronic controller (8) is configured to determine the predicted temperature of the gas in the source reservoir or the source reservoir during transfer based on the value measured by the ambient temperature measurement sensor (11).

5. The station according to claim 1 or 2, characterized in that, The electronic controller (8) is configured to determine the flow rate of the gas transferred during the transfer and, based on the value of the flow rate, determine the predicted temperature reached by the gas in the source reservoir or by the source reservoir during the transfer.

6. The station according to claim 1 or 2, characterized in that, The electronic controller (8) includes a memory that stores a reference table of gas transfer conditions, wherein the electronic controller (8) is configured to determine, based on the reference table and the current gas transfer conditions, the predicted temperature reached by the gas in the source reservoir or by the source reservoir during transfer.

7. The station according to claim 1 or 2, characterized in that, The electronic controller (8) is configured to estimate the predicted temperature reached by the gas in the source reservoir or by the source reservoir during the transfer based on a calculation module. Before and / or during the transfer, the calculation module uses a gas equation of state to calculate the energy exchange balance in the wall of the source reservoir and the mass and enthalpy balance of the gas in the source reservoir, as well as the heat exchange balance between the wall of the source reservoir and the outside of the source reservoir, wherein the gas equation of state is an ideal gas or a real gas equation of state.

8. The station according to claim 1, characterized in that, The pressurized gas is pressurized hydrogen.

9. A method for injecting pressurized gas into one or more storage tanks (2) using a station (1), the station comprising a transfer pipe (7) and at least two source reservoirs (3, 4, 5, 6) for pressurized gas, the transfer pipe having an upstream end connected in parallel to the source reservoirs (3, 4, 5, 6) and a downstream end intended to be connected to the storage tank (2) to be injected, the method comprising a series of successive steps of transferring gas between the source reservoirs (3, 4, 5, 6) and the storage tank (2) through a pressure balancing procedure, the method comprising the following steps: The prediction module is used to calculate the predicted temperature that the gas in the source reservoir or the source reservoir is expected to reach during gas transfer. The predicted temperature is compared with a determined threshold corresponding to the minimum safe temperature allowed by the source storage device. and When the predicted temperature is below the determined threshold, the transfer is prevented or interrupted, or the flow rate of the transferred gas is reduced.

10. The method according to claim 9, characterized in that, The method includes the following steps: measuring the temperature and / or pressure of the gas in the source reservoirs (3, 4, 5, 6) before and / or during gas transfer; and calculating a predicted temperature to be reached during the transfer based on the corresponding temperature and / or pressure measurements.

11. The method according to claim 9 or 10, characterized in that, The method includes the following steps: measuring the ambient temperature before gas transfer; and calculating a predicted temperature to be reached during the transfer based on the measured ambient temperature.

12. The method according to claim 9 or 10, characterized in that, The predicted temperature determination step is performed before or at the start of gas transfer, wherein the predicted temperature determination step predictively determines the gas transfer time required for the predicted temperature to reach the threshold if it will reach the threshold.

13. The method according to claim 12, characterized in that, During gas transfer, the method includes the steps of: interrupting gas transfer from the relevant source reservoir; and transferring gas from another source reservoir before the predicted temperature reaches the threshold, either due to a decrease in the temperature of the gas in the source reservoir or a decrease in the predicted temperature of the source reservoir during the transfer.

14. The method according to claim 12, characterized in that, The predicted temperature determination step is performed before the gas is transferred from the first source reservoir, wherein the method after the predicted temperature determination step includes determining a first amount of gas transferred from the first source reservoir to the tank (2) to be filled until the determined predicted temperature reaches the threshold, wherein when the first amount of gas is lower than the determined amount, the method includes the following steps: replacing the first source reservoir to transfer the gas via a second source reservoir, i.e., not using the first source reservoir to transfer the gas.

15. The method according to claim 9, characterized in that, The pressurized gas is pressurized hydrogen.

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