Patent Application
20230012928
The invention relates to a device and a method for filling tanks.
The invention relates more particularly to a device for filling pressurized gas tanks, in particular pressurized hydrogen tanks, comprising a source of pressurized gas, a transfer pipe having an upstream end connected to the source and a downstream end intended to be connected to a tank that is to be filled, the transfer pipe comprising a set of valve(s) for controlling the flow of gas from the source towards the downstream end, the transfer pipe comprising a compressor, the device comprising a sensor for detecting the presence of oil in the gas flowing in the transfer pipe downstream of the compressor, the device comprising a bypass pipe connected to the transfer pipe downstream of the compressor.
It may be necessary to detect the presence of oil at the compressor outlet to check whether an oil leak is contaminating the compressed gas. This may be of particular relevance to hydrogen filling stations.
A known technology consists in using a coalescing filter and an optoelectronic oil level sensor. Most sensors, and in particular this type of sensor, cannot withstand pressures above 500 bar. This is incompatible with the very high pressures reached in certain filling devices, in particular for pressurized hydrogen.
One aim of the present invention is to overcome all or some of the drawbacks of the prior art set out above.
To that end, the device according to the invention, which is moreover in accordance with the generic definition thereof given in the preamble above, is essentially characterized in that the bypass pipe comprises a set of at least two valve(s) in series configured to allow, in a first configuration, the drawing-off of gas flowing in the transfer pipe into the bypass pipe and, in a second configuration, fluidic isolation between the bypass pipe and the transfer pipe, in which the set of valve(s) of the transfer pipe defines in the second configuration a closed storage volume for the drawn-off gas trapped in the bypass pipe, the closed storage volume comprising a system for reducing the pressure of the drawn-off gas trapped in the bypass pipe to lower the pressure of the trapped gas to a pressure lower than the pressure of the gas flowing in the transfer pipe, the sensor for detecting the presence of oil providing detection of oil in said closed storage volume.
Furthermore, embodiments of the invention can comprise one or more of the following features:
The invention also relates a method for filling pressurized gas tank(s), in particular pressurized hydrogen tanks, in which pressurized gas is transferred from a pressurized gas source into a tank via a transfer pipe comprising a compressor, the method comprising detecting the presence of oil in the gas flowing in the transfer pipe downstream of the compressor, the method comprising a step of drawing-off a volume of gas flowing in the transfer pipe downstream of the compressor towards a bypass pipe, said volume of drawn-off gas being trapped and expanded in a closed storage volume, the detection of the presence of oil being carried out in said trapped and expanded drawn-off gas volume.
According to other possible distinctive features:
The invention may also relate to any alternative device or method comprising any combination of the features above or below within the scope of the claims.
Other features and advantages will appear from reading the following description, which is given with reference to the figures, in which:
The pressurized-gas tank filling device 1 illustrated in [
The filling device 1 comprises a transfer pipe 3 having an upstream end connected to the at least one source 2 and at least one downstream end intended to be connected to a tank 4 that is to be filled. Of course, multiple downstream ends can be provided to fill several separate tanks 4, either simultaneously or non-simultaneously.
The transfer pipe 3 can conventionally comprise a set of valve(s) 5 to control the flow of gas from the source 2 towards the downstream end, for example a controlled valve 5 for controlling the flow rate and/or the pressure. Other members can conventionally be provided on this transfer pipe 3, in particular at least one among: a gas cooling member, an isolation valve, pressure and/or temperature sensor(s).
The transfer pipe 3 comprises at least one compressor 6 and the device 1 comprises a sensor 11 for detecting the presence of oil in the gas flowing in the transfer pipe 3 downstream of the compressor 6. To avoid exposing the sensor 11 to too high a pressure, the device 1 comprises a bypass pipe 7 connected to the transfer pipe 3 downstream of the compressor 6. The bypass pipe 7 preferably comprises a set of at least two valve(s) 8, 9, 10 in series configured such that, in a first configuration, they allow gas flowing in the transfer pipe 3 to be drawn off into the bypass pipe 7 and, in a second configuration, they fluidically isolate the bypass pipe 7 from the transfer pipe 3. In the second configuration, the set of valve(s) 8, 9, 10 of the transfer pipe 3 defines a closed storage volume for the drawn-off gas trapped in the bypass pipe 7. The closed storage volume includes a system for reducing the pressure of the gas drawn-off at very high pressure and trapped in the bypass pipe 7 to lower the pressure of the trapped gas to a pressure lower than the pressure of the gas flowing in the transfer pipe 3. The sensor 11 for detecting the presence of oil measures the presence of oil in said closed storage volume, that is to say that it is exposed to a pressure below that of the gas flowing in the transfer pipe 3.
That is to say that gas at very high pressure is drawn-off from the outlet of the compressor 6 and is expanded before any presence of oil therein is detected.
In the illustrated examples, the bypass pipe 7 comprises an upstream end connected to the transfer pipe 3 downstream of the compressor 6 and a downstream end. The bypass pipe 7 comprises, arranged in series between its upstream and downstream ends: a first isolation valve 8, a second isolation valve 9 and a third isolation valve 10.
In normal operation (when filling a tank 4 for example), the first isolation valve 8 is open and the second isolation valve 9 is closed. If oil is contained in the very high pressure gas supplied by the compressor, this oil will penetrate with the gas which contains it into the volume of the bypass pipe 7 located between the first 8 and second 9 isolation valves.
A filter 18 can be arranged at the intersection between the transfer pipe 3 and the bypass pipe 7 and/or in the bypass pipe 7 to collect this possible oil.
When the oil level is to be checked, the first isolation valve 8 can be closed and then the second isolation valve 9 can be opened. When the second isolation valve 9 opens, the small volume of hydrogen and oil that is trapped will expand into a larger closed storage volume. This volume can be obtained by providing, downstream of the second isolation valve 9, pipes of larger diameter and/or a length of pipes that is sufficient to increase the volume for the trapped gas.
For example, the bypass pipe 7 may comprise an increase in section 13 of its piping downstream of the second isolation valve 9.
For example, before opening the second isolation valve 9, the pressure downstream of this second isolation valve 9 may be relatively lower than in the transfer pipe 3, for example less than 200 bar.
The volume between the first two isolation valves 8, 9, and the closed storage volume when the second isolation valve 9 is open, can be dimensioned relatively to reduce the pressure in the closed storage volume to below the value of maximum pressure that the sensor 11 can withstand.
Thus, the sensor can detect the possible presence of oil without being exposed to excessive pressure.
When the detection has been carried out, the trapped gas must be evacuated to carry out another measurement.
As illustrated in [
As shown schematically in dotted lines, the downstream end can be connected to an evacuation zone (vent to the atmosphere for example) and/or to the inlet of the compressor 6 in order to recycle the gas therein. This gas could also be returned to the pressurized gas source 2.
This evacuation of the closed storage volume can for example lower the pressure to a determined value, for example 15 bar.
All or some of the valves can be controlled valves which can be controlled automatically by an electronic controller 17 comprising a data storage and processing device such as a microprocessor or a computer.
This means that the process can be automated. The test (measurement to detect the presence of any oil) can be done at any time before filling or during filling, periodically at each filling, several times per filling or according to any other frequency.
In the event that the sensor 11 detects the presence of oil, the device can be configured to generate a corresponding signal to indicate that the gas leaving the compressor 6 is contaminated. In this case, it may be pointless to repeat the test. The signal generated can interrupt the operation of the compressor and/or warn operators so that they can intervene.
It should be noted that in the case, for example, where all or part of the valves are of the manually actuated type, the optoelectronic level sensor can be replaced or supplemented by piping having a transparent portion. This allows operators to monitor whether or not oil is present (and save the cost of the sensor if applicable).
The downstream end of the bypass pipe 7 can be connected to an oil recovery member 14. Thus, when the pressure in the bypass pipe 7 has been lowered, the third isolation valve 10 can be opened to evacuate the collected oil.
As illustrated, a calibrated orifice 12 can be placed in the bypass pipe 7 downstream of the second isolation valve 9. This allows a progressive increase in pressure downstream to spare the material.
As also illustrated, a pressure sensor 15 can be provided to measure the pressure in the closed storage volume of the bypass pipe 7 (in particular between the second 9 and third 10 isolation valves).
Of course, the invention is not limited to the examples described above. For example, it can be envisaged to remove the second isolation valve 9 from the bypass pipe 7 in certain configurations.
Thus, for example, if the pressure downstream of the compressor is not too high for the oil presence detection sensor 11 (for example less than or equal to 500 bar), the second valve 9 can be omitted. In this case, the first isolation valve 8 is open when the compressor 6 is running. The high-pressure gas is admitted into the bypass pipe 7 through a calibrated orifice and can undergo oil detection in the volume located between the first valve 8 and the end valve 10.
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.
The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.
“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”.
“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.
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.
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.
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| FR 1914629 | Dec 2019 | FR | national |
This application is a § 371 of International PCT Application PCT/EP2020/081904, filed Nov. 12, 2020, which claims § 119(a) foreign priority to French patent application FR 1914629, filed Dec. 17, 2019.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/081904 | 11/12/2020 | WO |
