Method for filling a tank with liquefied gas

Abstract

Method for filling a liquefied gas tank with pressurized liquefied gas from a source of liquefied gas using a filling apparatus comprising a transfer circuit that is provided with first and second pipes, each connecting between the source via respective first ends and the tank via respective second ends, third and fourth pipes each connecting between the first and second pipes, and a set of valves controlling flows of fluid in the pipes. The tank is depressurized and at least part of the circuit is cooled by transferring pressurized vaporization gas from the tank to the first end of the second pipes via the second end of the second pipe, the third pipe, the first pipe, and the fourth pipe.

Claims

1. A method for filling a liquefied gas tank with pressurized liquefied gas from a source of liquefied gas, comprising: transferring liquefied gas from the source of liquefied gas to the liquefied gas tank using a filling apparatus comprising a transfer circuit that is provided with a first pipe for liquid transfer, a second pipe for gas transfer, a third pipe, a fourth pipe, and a set of valves for controlling flows of fluid in said pipes, the first pipe comprising a first end connected to the source of liquefied gas and a second end connected to the liquefied gas tank, the second pipe comprising a first end connected to a gas recovery member and a second end connected to said liquefied gas tank, each of the third and fourth pipes connecting the first and second pipes; and prior to the transfer of liquefied gas from the source of liquefied gas to the liquefied gas tank, depressurizing the liquefied gas tank and cooling at least part of the transfer circuit, wherein said step of depressurizing and cooling comprises transferring pressurized vaporization gas contained in the liquefied gas tank via the second end of the second pipe, the third pipe, the first pipe, the fourth pipe, and the first end of the second pipe.

2. The method of claim 1, wherein the third pipe is situated at the second ends of the first and second pipes and the fourth pipe is situated at the first ends of the first and second pipes.

3. The method of claim 1, wherein the liquefied gas tank, before said step of depressurizing and cooling, is at a pressure of between 1.2 and 10 bar and, after said step of depressurizing and cooling, is at a pressure of between 1.1 and 1.4 bar.

4. The method of claim 3, wherein the liquefied gas tank, before said step of depressurizing and cooling, is at a pressure of between 1.4 and 7 bar.

5. The method of claim 1, further comprising, after said step of depressurizing and cooling, a step of transferring liquefied gas from the source to the liquefied gas tank via the first transfer pipe.

6. The method of claim 1, wherein the liquefied gas is hydrogen or helium.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Further distinctive features and advantages will become apparent on reading the description below, made with reference to the figures, in which:

(2) FIG. 1 shows a schematic and partial view illustrating an example of the configuration and operation of the filling apparatus and method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(3) The apparatus 1 comprises a fluid circuit provided with a first pipe 3 for liquid transfer comprising a first end, for example to the left of a valve 13 in the schematic view, intended to be connected to a source 4 of liquefied gas, in particular to the liquid phase of a supply tank, and a second end, for example to the right or left of a valve 23 in the schematic illustration, intended to be connected to a tank 2 to be filled, in particular to its liquid phase.

(4) The source 4 typically comprises a store of liquefied gas surmounted by a gaseous phase. The source is or can be pressurized, it being possible for this pressure to be the force that drives the fluid to be transferred. A transfer pump may also be envisaged.

(5) The circuit comprises a second pipe 6 for gas transfer, comprising a first end 16 intended to be connected to the source 4 of liquefied gas, for example to its gaseous phase, or to a gas recovery member 8, and a second end intended to be connected to said tank 2 to be filled, for example to its gaseous phase.

(6) The circuit comprises a third transfer pipe 5 connecting the first 3 and second 6 so transfer pipes and provided with a valve 15.

(7) The circuit comprises a fourth transfer pipe 7 connecting the first 3 and second 6 transfer pipes and provided with a valve 17.

(8) The third transfer pipe 5 and the fourth transfer pipe 7 are preferably situated at the two ends of the circuit, respectively, towards the tank 2 to be filled and towards the source 4.

(9) For example, and without limitation, the third pipe 5 can be part of a circuitry integral with the tank 2 and provided with fluidic connectors such as removable or quick connectors and configured to be connected to tubing forming the first 3 and second 6 pipes, for example, to the right of the flexible portions shown symbolically by wavy lines.

(10) The circuit comprises a set of valves for controlling the flows of fluid in the pipes of the circuit. For example, the first pipe 3 for liquid transfer comprises at least one insulation and/or flow control valve 33.

(11) Similarly, the second transfer pipe 6 comprises at least one insulation and/or flow control valve 36, 46.

(12) This architecture permits filling of tanks 2 in single flow, in first liquid pipe 3, or in double flow, in first pipe 3 transferring liquid and second pipe 6 evacuating gas in the opposite direction.

(13) The third transfer pipe 5 and the fourth transfer pipe 7 each preferably comprise at least one insulation and/or flow control valve 15, 17.

(14) Before the transfer of liquefied gas from the source 4 to the liquefied gas tank 2, a depressurization of the liquefied gas tank 2 and a cooling of at least part of the transfer circuit must be carried out.

(15) At least part of the depressurization of the liquefied gas tank 2 and the cooling of the transfer circuit are carried out by transfer of pressurized vaporization gas contained in the liquefied gas tank 2 via the second end 26 of the second pipe 6 for gas transfer, the third transfer pipe 5, the first transfer pipe 3, the fourth transfer pipe 7 and the first end 16 of the second transfer pipe 6.

(16) That is to say, the flow of cold depressurization gas is diverted on at least part of the first liquid pipe 3 via deviations that are formed by the third transfer pipe 5 and fourth transfer pipe 7. This can be achieved by control of the appropriate valves, for example, by valves 15, 33, 17, 56 being open during this depressurization and the others being closed.

(17) This cooling of the circuit is thus effected during the depressurization and the evaporation of the liquefied gas at the start of filling. For a hydrogen application, this process permits a reduction in evaporation of 0.02 kg to 0.08 kg of hydrogen (H2) depending on the installation.

(18) This makes it possible to utilize gaseous returns of the tank 2 to be filled by virtue of the cooling of the liquid line 3 during the depressurization step.

(19) This solution has numerous advantages.

(20) Thus, this method permits a saving in terms of the energy balance because no flashing of the liquid coming from the source 4 or a liquefier occcurs.

(21) This solution makes it possible to save 4 to 14 kg of liquid hydrogen by cooling, at each filling, depending to the installation.

(22) Moreover, this solution allows time to be saved in the sequence of filling tanks 2 with hydrogen, such as 5-10 minutes depending upon the installation, without loss of substance.

(23) As is illustrated, the circuit can have several transverse pipes connecting the first pipe 3 to the second pipe 6, particularly towards the tank 2 to be filled. For example, two transverse pipes are provided at the second end and can each be provided with a valve. These two transverse pipes can be rigidly connected to the tank 2. Moreover, two valves 33, 46 can be provided between these two transverse pipes, respectively on the first and second transfer pipes.

(24) The flow of vaporization gas coming from the tank 2 to be filled can be conveyed through one or more of these transverse pipes by the appropriate opening of the set of valves.

(25) 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.

(26) The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.

(27) “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”.

(28) “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.

(29) 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.

(30) 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.

(31) 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.