A pressurized gas distribution station and a method for preventing or limiting icing of such a station

Abstract

Method (200) for preventing or limiting icing of a pressurized gas distribution station (100), the station (100) comprising a filling line having in series one end connected to a pressurized gas source (1), a first heat exchanger (2) for cooling a gas stream from the source (1), and a distribution terminal (3) for distributing the cooled stream to a tank (4) to be filled, the distribution station (100) also comprising a bypass line (L4) from the filling line at the first heat exchanger (2), the method (200) comprising a step (S1) for transferring a relatively hot gas stream to the distribution terminal (3) via the bypass line (L4), the relatively hot gas stream being at a temperature higher than a predefined temperature at the outlet of the first heat exchanger (2). Abstract figure: Fig. 1

Description

Title of the invention: Pressurized gas distribution station and method for preventing or limiting icing of such a station

[0001] The invention relates to a distribution station for a gas under pressure. The gas under pressure may be hydrogen.

[0002] The invention also relates to a method for preventing or limiting the icing of such a distribution station.

[0003] Hydrogen from a distribution station is generally pre-cooled to a temperature range of -33°C to -26°C before being transferred to a tank to be filled. This pre-cooling is carried out to prevent Joule-Thomson expansion effects at a terminal of the distribution station, and in particular on the pressure regulating valve located at that terminal. Furthermore, this pre-cooling is performed to limit the temperature increase of the hydrogen in the tank to be filled. The maximum temperature threshold not to be exceeded is generally set at 85°C.

[0004] When pre-cooled within the temperature range indicated above, the hydrogen cools the dispensing terminal, causing condensation followed by freezing of the moisture present in the ambient air. The presence of frost on the dispensing terminal can be a source of discomfort for the user, particularly when removing the dispensing terminal from a receptacle in the tank to be filled.

[0005] To limit the formation of ice on the dispensing terminal, a known method includes a step of diffusing a flow of air or nitrogen over the dispensing terminal. This solution therefore requires an air or nitrogen reservoir, which represents a certain cost and whose integration into the dispensing station poses a number of technical difficulties.

[0006] The objective of this invention is to overcome at least in part the disadvantages listed above.

[0007] To this end, according to a first aspect, the invention proposes a method to prevent the icing of a pressurized gas distribution station.

[0008] In particular, the distribution station includes a filling line which has in series one end connected to a pressurized gas source, a first heat exchanger for cooling the gas from the source, and a distribution terminal for supplying a flow of pre-cooled gas to a tank to be filled. The distribution station also includes a branch line from the filling line at the first heat exchanger.

[0009] According to this first aspect of the invention, the method comprises a step of transferring a relatively hot gas stream to the distribution terminal via the bypass line. The relatively hot gas stream is at a temperature higher than a predefined temperature at the outlet of the first heat exchanger.

[0010] The predefined temperature at the outlet of the first heat exchanger is that at which a pre-cooled gas flow is distributed to the tank to be filled at the outlet of the distribution terminal.

[0011] The relatively hot gas flow sent to the distribution terminal heats it by conduction and prevents freezing. When freezing is already present on the terminal, the relatively hot gas flow helps to thaw it.

[0012] Furthermore, embodiments of this first aspect of the invention may include one or more of the following features: - The relatively hot gas flow transferred to the distribution terminal during the transfer stage via the bypass line is injected into the tank to be filled, - The step of transferring the relatively hot gas flow to the distribution terminal via the bypass line occurs after a phase of distributing a pre-cooled gas flow into the tank to be filled, - the relatively hot gas flow transferred to the distribution terminal during the transfer stage via the bypass line is not introduced into the tank to be filled, - The step of transferring the relatively hot gas flow to the distribution terminal via the bypass line includes an operation to control the flow rate of the relatively hot gas towards the distribution terminal, - The flow control operation is carried out using a control device located on the bypass line, - The temperature of the relatively hot gas stream is obtained through the bypass line by Joule-Thomson expansion of the pressurized gas coming from the gas source, - the temperature of the relatively hot gas flow is obtained through the bypass line using an active heating means, for example a second heat exchanger, arranged on the bypass line, - The method includes a step of purging the relatively hot gas flow via a purge line located near the distribution terminal, - the method includes a step of controlling a rise in gas pressure at the distribution terminal.

[0013] According to a second aspect, the invention relates to a distribution station for a gas under pressure, such as hydrogen.

[0014] The station comprises a filling line having in series one end connected to a pressurized gas source, a first heat exchanger for cooling a gas stream from the source, and a distribution terminal for distributing the cooled stream to a tank to be filled. Furthermore, the distribution station includes a branch line from the filling line at the first heat exchanger.

[0015] According to this second aspect of the invention, the station comprises an electronic component configured to control the transfer of a relatively hot gas stream to the distribution terminal via the bypass line. The relatively hot gas stream is at a temperature higher than a predefined temperature at the outlet of the first heat exchanger.

[0016] Other features and advantages will become apparent upon reading the following description, made with reference to the following figures in which:

[0017] [Fig.1] is a schematic view illustrating a pressurized gas distribution station.

[0018] [Fig.2] illustrates steps of a method to prevent freezing on the distribution station illustrated in [Fig.1].

[0019] Fig. 1 illustrates a pressurized gas distribution station 100.

[0020] Station 100 comprises a filling line and the following connected elements in series by the filling line: a pressurized gas source 1, a first heat exchanger 2 configured to cool a gas stream from the gas source 1, and a distribution terminal 3 intended to supply the cooled gas stream to a tank 4 to be filled.

[0021] In particular, the filling line includes a first circuitry L1 connecting the gas source 1 to an inlet of the first heat exchanger 2, and a second circuitry L2 connecting an outlet of the first heat exchanger 2 to the distribution terminal 3.

[0022] The first circuit L1 is provided with a first valve XVI, a flow meter FE1, a first pressure controller PCV1, and a second valve XV2.

[0023] The second circuit L2 is provided with a third valve XV3, a pressure sensor PT2 and a temperature sensor TT2.

[0024] The distribution station 100 may also include a storage tank 5 connected to the filling line via a third circuit L3. In particular, the third circuit L3 is connected to the first circuit L1 at a junction point located upstream of the first valve XVI, the flow meter FE1, the first pressure controller PCV1 and the second valve XV2.

[0025] The distribution station 100 also includes a branch line L4 from the filling line at the first heat exchanger 2.

[0026] In particular, the branch line L4 has a first end connected to the first circuit L1 at a first junction point JP1 located upstream of the first heat exchanger 2. Furthermore, the branch line L4 has a second end connected to the second circuit L2 at a second junction point JP2 located downstream of the first heat exchanger 2.

[0027] It should be noted that the first valve XVI, the flow meter FE1, and the first pressure controller PCV1 of the first circuit L1 are located upstream of the first junction point JP1. The second valve XV2 of the first circuit L1 is located downstream of the first junction point JP1.

[0028] It should also be noted that the third valve XV3 of the second circuit L2 is located upstream of the second junction point JP2. The pressure sensor PT2 and the temperature sensor TT2 of the second circuit L2 are located downstream of the second junction point JP2.

[0029] Furthermore, the L4 bypass line includes a heating system for the flow from the gas source 1 and / or the storage tank 5.

[0030] This heating system may include a calibrated orifice (not shown) or a second PCV2 pressure controller, each configured to expand a gas stream from the gas source 1 and / or the storage tank 5, and thus allow heating of this gas stream by Joule-Thomson expansion.

[0031] Alternatively, or in addition, the heating system may include a second heat exchanger 10 configured to actively heat the gas flow as opposed to the passive heating induced by Joule-Thomson expansion.

[0032] Finally, the distribution station 100 may include a first purge line L5 connected to the filling line at the level of the second circuit L2. The first purge line L5 is provided with a fourth valve XV4. In the illustrated example, the first purge line L5 carries the pressure sensor PT2.

[0033] To prevent or eliminate freezing on the distribution terminal 3 of station 100 described above, the invention introduces a method 200 described below.

[0034] Method 200 includes a step SI of transferring a hot gas stream from the gas source 1 and / or from the storage tank 5 to the distribution terminal 3 via the bypass line L4. The hot gas stream is at a temperature above a predefined temperature at which a cooled gas stream is distributed to the tank 4 to be filled at the outlet of the distribution terminal 3.

[0035] Step SI of transferring the hot gas flow to the distribution terminal 3 can result in the introduction of the hot gas flow into the tank 4 to be filled. This step SI then occurs after a phase of distributing a pre-cooled gas flow to the tank 4. Such a transfer of hot gas flow into the tank 4 is permitted. provided that the mixture with the pre-cooled gas already present in tank 4 does not exceed the maximum permitted temperature.

[0036] The SI step of transferring the hot gas flow to the distribution terminal 3 can also take place without resulting in the introduction of this hot gas flow into the tank 4 to be filled.

[0037] In this case, method 200 may include a step S2a for purging the hot gas flow via a second purge line L6 located at the distribution terminal 3. Advantageously, the second purge line L6 may be connected to the first purge line L5.

[0038] In the absence of a second L6 purge line at the distribution terminal 3, the hot gas accumulated at the distribution terminal 3 can rise in pressure and present a risk to the integrity of this terminal 3. Therefore, advantageously, method 200 can include a step 2b of controlling a rise in gas pressure at the distribution terminal 3.

[0039] In all cases, the SI step of transferring the hot gas flow to the distribution terminal 3 may include an operation to control the flow rate and / or temperature of the hot gas flow. This control may be performed using a control device (not shown) configured to communicate with the second PCV2 pressure controller located on the L4 bypass line and / or with the TT2 temperature sensor located on the second L2 circuit.

[0040] When the SI step of transferring the hot gas flow to the distribution terminal 3 results in the introduction of the hot gas flow into the tank 4 to be filled, the control device monitors in particular that the temperature of the gas in the tank 4 to be filled does not exceed the maximum threshold set.

Claims

Demands

1. Method (200) for preventing or limiting the icing of a pressurized gas distribution station (100), the station (100) comprising a filling line having in series one end connected to a pressurized gas source (1), a first heat exchanger (2) for cooling a gas stream from the source (1), and a distribution terminal (3) for distributing the cooled stream to a tank (4) to be filled, the distribution station (100) also comprising a bypass line (L4) from the filling line at the first heat exchanger (2), the method (200) comprising a step (SI) of transferring a relatively hot gas stream to the distribution terminal (3) via the bypass line (L4), the relatively hot gas stream being at a temperature higher than a predefined temperature at the outlet of the first heat exchanger (2).

2. Method (200) according to the preceding claim, wherein the relatively hot gas stream transferred to the distribution terminal (3) during step (SI) is injected into the tank (4) to be filled.

3. Method (200) according to the preceding claim, wherein the step (SI) of transferring the relatively hot gas flow occurs after a phase of distributing a pre-cooled gas flow into the tank (4) to be filled.

4. Method (200) according to claim 1, wherein the relatively hot gas flow transferred to the distribution terminal (3) during step (SI) is not introduced into the tank (4) to be filled.

5. Method (200) according to any one of the preceding claims, wherein the step (SI) of transferring the relatively hot gas flow includes an operation of controlling a flow rate of the relatively hot gas flow to the distribution terminal (3).

6. Method (200) according to the preceding claim, wherein the flow control operation is performed using a control device (PCV2) disposed on the bypass line (L4).

7. A method (200) according to any one of the preceding claims, wherein the temperature of the relatively hot gas stream is obtained through the bypass line (L4) by expansion Joule-Thomson of pressurized gas from the source (1) of gas.

8. Method (200) according to any one of claims 1 to 6, wherein the temperature of the relatively hot gas stream is obtained through the bypass line (L4) by means of an active heating means, for example a second heat exchanger (10), disposed on the bypass line (L4).

9. Method (200) according to any one of claims 4 to 8, comprising a step (S2a) of purging the relatively hot gas stream via a purge line (L6) disposed near the distribution terminal (3).

10. Method (200) according to any one of claims 4 to 9, comprising a step (2b) of controlling a rise in gas pressure at the distribution terminal (3).

11. A pressurized gas distribution station (100), such as hydrogen, comprising a filling line having in series one end connected to a pressurized gas source (1), a first heat exchanger (2) for cooling a gas stream from the source (1), and a distribution terminal (3) for distributing the cooled stream to a tank (4) to be filled, the distribution station (100) also comprising a bypass line (L4) from the filling line at the first heat exchanger (2), characterized in that it comprises an electronic device configured to control a transfer of a relatively hot gas stream to the distribution terminal (3) via the bypass line (L4), the relatively hot gas stream being at a temperature higher than a predefined temperature at the outlet of the first heat exchanger (2).

Images