METHOD AND DEVICE FOR FILLING A TANK WITH PRESSURIZED GAS

Abstract

Method for filling a tank with pressurized gas to a target pressure from at least one pressurized gas source via a transfer pipe provided with at least one valve, the tank having a predetermined inner length and predetermined inner diameter, the end of the transfer pipe forming an injector with a predetermined injection diameter; said method comprises a step for transferring pressurized gas from the source to the tank at a predetermined flow rate, the method comprising a step of controlling the transfer of gas from the source to the tank to reduce the heat produced in the tank, the step of controlling the transfer of gas comprising at least one of: sizing of the injection diameter, and sizing of the flow rate of the transferred gas; the control step being carried out according to the ratio L/D between the length and the diameter of the tank.

Claims

1-14. (canceled)

15. A method for filling a tank with pressurized gas to a target pressure from at least one pressurized gas source connected to the tank via a transfer pipe provided with at least one valve, the tank having a cylindrical shape of predetermined inner length L and of predetermined inner diameter D, the end of the transfer pipe connected to the tank forming an injector opening into the tank with a predetermined injection diameter D1, wherein the method comprises a step of transferring the pressurized gas from the source to the tank at a predetermined flow rate Q, the method comprising a step of regulating or of sizing the transfer of gas from the source to the tank to reduce the heating produced in the tank, characterized in that the step of regulating or sizing the gas transfer comprises at least one among: a sizing of the injection diameter D1 and a sizing of the flow rate Q of transferred gas; the step of regulating or sizing the gas transfer being carried out as a function of a ratio L/D.

16. The method of claim 15, further comprising a step of determining or calculating the L/D and a step of comparing the determined or calculated L/D with a first predetermined threshold S1.

17. The method of claim 16, further comprising a step of regulating a ratio, Q/D1.sup.2, that is achieved by controlling Q and/or sizing D1 as a function of said step of comparing.

18. The method of claim 17, wherein Q/D1.sup.2 is maintained above a second predetermined threshold S2 when L/D is less than S1.

19. The method of claim 18, wherein S1 is between two and four.

20. The method of claim 19, wherein S1 is three.

21. The method of claim 17, wherein Q/D1.sup.2 is maintained above S2 by increasing Q and/or decreasing D1.

22. The method of claim 21, wherein the second predetermined threshold S2 is a function of a filling target pressure of the tank.

23. The method of claim 22, wherein S2 increases when the filling target pressure of the tank increases.

24. The method of claim 22, wherein the gas is hydrogen and, when the filling target pressure of the tank is between 700 and 900 bar, S2 is between 175 and 225 kg.Math.m.sup.2.Math.s.sup.1.

25. The method of claim 24, wherein S2 is equal to 200 kg.Math.m.sup.2.Math.s.sup.1.

26. The method of claim 16, wherein Q/D1.sup.2 is maintained above a second predetermined threshold S2 and below a third predetermined threshold S3 when L/D is greater than S1.

27. The method of claim 26, Q/D1.sup.2 is maintained above S2 and below S3 by at least one of: increasing or decreasing Q, and increasing or decrease D1.

28. The method of claim 27, wherein, when the filling target pressure of the tank is between 700 and 900 bar, S3 is between 1200 and 1600 kg.Math.m.sup.2.Math.s.sup.1.

29. The method of claim 28, wherein S3 is equal to 1400 kg.Math.m.sup.2.Math.s.sup.1.

30. The method of claim 15, wherein said step of regulating or sizing is also carried out as a function of a filling target pressure of the tank.

31. A device for filling tanks with pressurized gas to a target pressure, comprising a pressurized gas source, a transfer pipe, and a computer, wherein: the transfer pipe has an end that is adapted and configured to be connected to a tank to be filled, thereby forming an injector having a predetermined injection diameter D1; the transfer pipe is adapted and configured to transfer the gas from the source to the tank; the transfer pipe is provided with at least one valve; the computer is adapted and configured to receive, store and process data; the computer is adapted and configured to control a filling of the tank with the gas of the source by controlling the at least one valve; the computer is adapted and configured to receive or calculate a ratio of a length L of the tank to be filled to a diameter D of the tank to be filled; the computer is adapted and configured to compare L/D with a first threshold S1, and as a function of said comparison, modify or signal a need to modify at least one parameter associated with filling the tank to be filled, said at least one parameter being D1, a flow rate Q of gas to be transferred from the source to the tank to be filled, of both D1 and Q.

32. The device of claim 31, the computer is adapted and configured to establish or modify Q and/or D1 in order to maintain a ratio Q/D1.sup.2 above a second predetermined threshold S2 and/or maintain Q/D1.sup.2 in a range of from S2 to a third predetermined threshold S3.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0034] Further particular features and advantages will become apparent from reading the following description, given with reference to the figures, in which:

[0035] FIG. 1 represents a schematic and partial side view illustrating an example of the structure and operation of a filling device according to the invention,

[0036] FIG. 2 schematically and partially represents an example of the operation of such a filling method.

DETAILED DESCRIPTION OF THE INVENTION

[0037] As illustrated in FIG. 1, the filling of tanks 1 with pressurized gas can be implemented by a filling device (or station) comprising a pressurized gas source 2, a gas transfer pipe 3 connected to the source 2 and provided with at least one valve 4 for controlling the flow rate. The transfer pipe 3 comprises at least one end intended to be connected to a tank 1 to be filled.

[0038] Conventionally, the pressurized gas source 2 can comprise at least one among: one or more pressurized gas tanks, at least one compressor, a source of liquefied gas and a vaporizer, etc.

[0039] The end of the transfer pipe 3 intended to be connected to the tank 1 forms or comprises an injector 5 having a predetermined injection diameter D1. The device preferably additionally comprises an electronic member 6 for controlling the filling that serves to control the at least one valve 4 and/or other members of the filling device.

[0040] The device is configured or used to fill a tank 1 with pressurized gas to a target pressure, for example 250 bar or 350 bar or 500 bar or 700 bar or more, in particular 800 or 900 bar.

[0041] The device is in particular intended for preferably filling cylindrical tanks 1 in the horizontal position (that is to say lying down along their longitudinal direction).

[0042] The tanks 1 have a cylindrical shape of predetermined inner length L and of predetermined inner diameter D.

[0043] The end of the transfer pipe 3 is connected at an orifice situated at a longitudinal end of the tank 1.

[0044] According to the invention, the transfer of pressurized gas from the source 2 and the interior of the tank 1 is carried out at a predetermined flow rate Q (in particular a mass flow rate).

[0045] According to the invention, the transfer of gas from the source 2 to the tank 1 is adapted to reduce the heating produced in the tank 1. This adaptation of the gas transfer comprises at least one among a sizing of the injection diameter D1, a sizing of the flow rate Q of transferred gas, and this modification is carried out as a function of the ratio L/D between the length L and the diameter D of the tank 1.

[0046] Thus, this ratio L/D can delimit two types of tank 1, for example so-called short tanks (L/D below a first threshold S1) and so-called long tanks (L/D above the first threshold S1).

[0047] Specifically, the inventors have identified that, as a function of this geometric criterion, it is possible to adapt the injection diameter D1 or the flow rate Q of transferred gas in order to successfully reduce the temperature heterogeneities of the gas in the tank 1, that is to say to reduce the excessively hot points during the filling.

[0048] Thus, when the ratio L/D between the length L and the diameter D of the tank 1 is less than a first predetermined threshold S1, which is between two and four and preferably equal to three (cf. ref. 11, FIG. 2), the regulating step preferably consists in maintaining the ratio Q/D1.sup.2 between the mass flow rate Q of the transferred gas and the square of the injection diameter D1 above a second predetermined threshold S2 (cf. ref. 11, FIG. 2). If this ratio Q/D1.sup.2 is greater than the second threshold S2, the filling F can be carried out without risk of excessive heating (cf. ref. 12, FIG. 2).

[0049] Specifically, the ratio Q/D1.sup.2=rho.Math..Math.V/4, where rho is the density of the gas and V is the average velocity of the gas at the injector, being the constant pi equal to 3.14159.

[0050] Rho is tabulated for each gas as a function of its temperature and of its pressure. In other words, fora given temperature and pressure, the density of the gas depends on its nature. Therefore, the ratio Q/D1.sup.2 also depends on the nature of the gas.

[0051] The limit S2 is calculated with the velocity value V equal to 5 m/s under the end-of-filling conditions, and the limit S3 is calculated with the velocity value of 100 m/s for the start-of-filling conditions.

[0052] The thresholds S2 and S3 are preferably dependent on (or a function of) the filling target pressure of the tank 1 and preferably also on the nature of the gas.

[0053] For example, for filling with hydrogen: [0054] when the filling target pressure of the tank 1 is between 200 and 300 bar, the second threshold S2 is between 75 and 100 kg.Math.m.sup.2.Math.s.sup.1 and preferably equal to 85 kg.Math.m.sup.2.Math.s.sup.1 [0055] when the filling target pressure of the tank 1 is between 300 and 400 bar, the second threshold S2 is between 100 and 140 kg.Math.m.sup.2.Math.s.sup.1 and preferably equal to 120 kg.Math.m.sup.2.Math.s.sup.1 [0056] when the filling target pressure of the tank 1 is between 450 and 600 bar, the second threshold S2 is between 140 and 175 kg.Math.m.sup.2.Math.s.sup.1 and preferably equal to 160 kg.Math.m.sup.2.Math.s.sup.1 [0057] when the filling target pressure of the tank 1 is between 700 and 900 bar, the second threshold (S2) is between 175 and 225 kg.Math.m.sup.2.Math.s.sup.1 and preferably equal to 200 kg.Math.m.sup.2.Math.s.sup.1.

[0058] Maintaining the ratio Q/D1.sup.2 above a second predetermined threshold S2 can be easily carried out by adapting the injection diameter D1 (decreasing for example) and/or by adapting the filling mass flow rate Q (increasing for example), cf. ref. 13, FIG. 2. These operating conditions can be in particular fixed before the filling or modified before or during the filling in view of the geometry of the tanks 1 which will have to be filled at a predetermined pressure.

[0059] That is to say that, as a function of the (known) geometry of the tanks 1 and possibly of the target pressure, the injection diameter D1 and/or the filling ramp (mass flow rate) is (are) adapted to satisfy the recommendation above (cf. ref. 13, FIG. 2).

[0060] It should be noted that, when the injector 5 penetrates in the interior of the tank 1 over a distance L1, the expression L/D<S1 is preferably modified as follows: (L-L1)/D<S1 in order to take into account the actual length of progression of the injected gas.

[0061] For a first threshold S1 equal to three, (L-L1)<3D is obtained for the short tanks and (L-L1)>3D is obtained for the long tanks (cf. FIG. 1).

[0062] For these short tanks, the inventors have demonstrated that there are no or few horizontal heterogeneities of temperatures owing, for example, to the fact that the injected gas jet does not laterally strike the walls of the tank (by virtue of the customary angle and shape of the gas jet of the injectors which are used).

[0063] The inventors have found that, in this geometric configuration, there is established, on the other hand, either a turbulent mixture regime or a vertically stratified regime in the tank 1. In a turbulent regime, the temperature is relatively very homogeneous (less than 3.5 C. between the average temperature and the maximum temperature of the inner wall for an injector of 6 mm in diameter or less than 5.5 C. for an injector diameter of 10 mm). On the other hand, in a vertically stratified regime there can be observed temperature gradients ranging up to 25 C., for example.

[0064] The inventors have demonstrated that the modification of the injection diameter and/or of the flow rate for maintaining the ratio Q/D1.sup.2 above the second threshold S2 makes it possible to minimize the risks of establishing a vertically stratified regime. That is to say that, according to this recommendation, a turbulent mixture regime which minimizes the temperature heterogeneities is established. This goes against the recommendations of the prior art, which, by contrast, encouraged reducing the filling flow rate in order to limit the heating.

[0065] When the ratio L/D is greater than the first threshold S1, the regulating step preferably consists in maintaining the ratio Q/D1.sup.2 above the second predetermined threshold S2 and below a third predetermined threshold S3 (cf. ref. 14, FIG. 2).

[0066] As above, the regulating step can comprise at least one among: an increase or a decrease of the flow rate Q of transferred gas, an increase or a decrease of the injection diameter D1, cf. ref. 15, FIG. 2. When this recommendation is satisfied, the filling F can be carried out without risk of excessive heating (cf. ref. 16, FIG. 2).

[0067] The inventors have demonstrated that the above regulations make it possible to control the gaseous regime in the long tank during filling. In particular, according to the invention the vertical and horizontal stratification regimes are reduced. That is to say that the temperature heterogeneities are also reduced for the long tanks via this regulation.

[0068] Thus, in the case of long tanks L/D>S1 or (L-L1)/D>S1, it is possible to define a ratio Q/D1.sup.2 range which makes it possible to reduce the temperature heterogeneities during filling.

[0069] As above, the third predetermined threshold S3 is preferably dependent on (or a function of) the filling target pressure of the tank 1 and preferably also on the nature of the gas.

[0070] For example, for filling with hydrogen: [0071] when the filling target pressure of the tank 1 is between 200 and 300 bar, the third threshold S3 is between 600 and 800 kg.Math.m.sup.2.Math.s.sup.1 and preferably equal to approximately 715 kg.Math.m.sup.2.Math.s.sup.1 [0072] when the filling target pressure of the tank 1 is between 300 and 400 bar, the third threshold S3 is between 800 and 1000 kg.Math.m.sup.2.Math.s.sup.1 and preferably equal to 900 kg.Math.m.sup.2.Math.s.sup.1 [0073] when the filling target pressure of the tank 1 is between 450 and 600 bar, the third threshold S3 is between 1000 and 1300 kg.Math.m.sup.2.Math.s.sup.1 and preferably equal to 1150 kg.Math.m.sup.2.Math.s.sup.1 [0074] when the filling target pressure of the tank 1 is between 700 and 900 bar, the third threshold S3 is between 1300 and 1500 kg.Math.m.sup.2.Math.s.sup.1 and preferably equal to 1400 kg.Math.m.sup.2.Math.s.sup.1.

[0075] Thus, in a preferred embodiment, when the filling of tanks is intended, depending on the geometry of the tanks (short or long) and the filling target pressure, the ratio Q/D1.sup.2 is maintained above (and possibly below for S3) the above-defined thresholds. This is achieved by predefining the injection diameter and/or by adapting the filling mass flow rate. This reduces the heating problems by reducing the heterogeneity of the temperature of the gas and of the tank during the filling.

[0076] The calculations for complying with these operating conditions are relatively simple and can be readily performed by a calculator ora computer in order to predefine or adapt the operating conditions of a filling station.

[0077] In the case, for example, of filling with hydrogen at 700 bar of a short tank (L-Li)/D<3 having a volume of 30 liters that is initially provided with an injector diameter of 0.01 m and a mass flow rate of 0.004 kg/second, the calculation of the ratio Q/D1.sup.2 gives the result 40 kg.Math.m.sup.2.Math.s.sup.1.

[0078] This is below the recommendation of approximately 200 kg.Math.m.sup.2.Math.s.sup.1 at least (or even 197 kg.Math.m.sup.2.Math.s.sup.1). In order to avoid or limit the stratification phenomena (hot points), two strategies are possible. According to a first strategy, it is possible to decrease the injection diameter D1 to 0.003 m, thus making it possible to obtain a ratio Q/D1.sup.2 equal to 444 kg.Math.m.sup.2.Math.s.sup.1. A second strategy can consist in increasing the mass flow rate to 0.4 kg.Math.s.sup.1, for example. The ratio Q/D1.sup.2 then changes to 400 kg.Math.m.sup.2.Math.s.sup.1. This increase in the flow rate Q reduces the heterogeneities but can lead to an increase in the average temperature. In order to avoid this disadvantage, the two strategies above can be modulated and combined (smaller increase in the diameter and smaller increase in the flow rate), for example injection diameter D1=0.005 m and flow rate Q equal to 0.1 kg.Math.s.sup.1. This makes it possible to achieve a ratio of 400 kg.Math.m.sup.2.Math.s.sup.1.

[0079] The filling conditions associated with the examples above can be the following: a gas temperature of 0 C. for a filling at 350 bar, 20 C., 40 C. for a filling at 500 or 700 bar. The final filling velocity can be at least 5 m/s.

[0080] For example, an electronic storage member 6 for the acquisition and processing of data that forms part of the station or is remote from said station can be used. This electronic member 6 can, where appropriate, serve to control at least one element of the station, for example the at least one valve 4 of the transfer pipe (for example to regulate the transferred flow rate).

[0081] The invention is particularly adapted to the fillings of tanks 1 arranged horizontally during the filling (horizontal cylindrical generatrices of the portion). Moreover, the invention is particularly adapted to the fillings of tanks having ratios L/D of, for example, between 1.4 and 6.6. Moreover, these measures apply particularly well to injectors having a diameter of between 3 and 25 mm. Of course, other geometries or configurations of fillings are possible (vertical ones, different dimensions), where appropriate with lesser advantages or requiring small adaptations (thresholds, etc.).

[0082] By regulation of the gas transfer is meant in particular a (for example dynamic) control or a predetermined sizing of the filling conditions (D1 and/or Q in particular).

[0083] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

[0084] The singular forms a, an and the include plural referents, unless the context clearly dictates otherwise.

[0085] Comprising in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing i.e. anything else may be additionally included and remain within the scope of comprising. Comprising is defined herein as necessarily encompassing the more limited transitional terms consisting essentially of and consisting of; comprising may therefore be replaced by consisting essentially of or consisting of and remain within the expressly defined scope of comprising.

[0086] Providing in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.

[0087] Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

[0088] Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.

[0089] All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.