Cryogenic fluid storage device

Abstract

The invention relates to a cryogenic fluid storage device comprising a reservoir (2) extending along a longitudinal direction (A) and intended to contain liquefied gas (3) in equilibrium with a gaseous phase, a liquid injection ramp (4) extending along the longitudinal direction (A) in the upper part of the reservoir (2), the injection ramp (4) comprising a plurality of outlet orifices (5) spaced along the longitudinal direction (A), the reservoir (2) comprising a guide element (6, 7, 8) extending vertically downwards in the reservoir from the orifices (5), the guide element being configured to guide the liquid downwards in the reservoir by increasing the surface area and duration of heat exchange of this liquid with the gaseous phase of the reservoir (2). Abstract figure: Fig. 1

Description

Title of the invention: Cryogenic fluid storage device

[0001] The invention relates to a cryogenic fluid storage device.

[0002] The invention applies in particular to the storage of liquid hydrogen.

[0003] The invention relates more particularly to a cryogenic fluid storage device comprising a tank extending in a longitudinal direction and intended to contain liquefied gas in equilibrium with a gaseous phase, a liquid injection ramp in the tank extending in the longitudinal direction in the upper part of the tank, the injection ramp comprising a plurality of outlet orifices spaced in the longitudinal direction.

[0004] To carry out fillings in trucks or more generally in cryogenic tanks, it is known to provide ramps or perforated bars in the tanks to ensure good uniformity of filling.

[0005] This is intended to ensure uniform filling of the liquid through the vapor headspace. This is intended to ensure heat exchange between the liquid phase, which is generally subcooled, and the vapor in the vapor headspace present in the tank. This is intended to partially condense the vapor headspace in the tank with the incoming liquid (or at least cool it or keep it as cold as possible).

[0006] Without any further action during filling, the liquid level rises and the vapor from the gaseous sky begins to compress, which leads both to its temperature rising and to the pressure rising throughout the entire tank by piston effect.

[0007] The temperature increase can lead to vaporization and therefore loss of cryogenic liquid. It also causes temperature stratification along the vertical height. The pressure increase can very quickly cause pressure equalization and thus reduce the injection bar's ability to deliver more liquid into the tank. This negatively impacts the mass efficiency of the filling process.

[0008] Known solutions involve using injection rods with perforations (holes drilled on the lateral surface). These perforations aim to better distribute and even out the liquid flow in the gaseous space in order to improve heat exchange and keep the liquid cold or even partially condense it to maintain a low pressure level. However, the impact of this solution remains very marginal compared to the ideal case.

[0009] One object of the present invention is to overcome all or part of the disadvantages of the prior art noted above.

[0010] To this end, the device according to the invention, which otherwise conforms to the generic definition given in the preamble above, is essentially characterized in that the reservoir comprises a guiding element extending vertically downwards in the tank from the orifices, the guiding element being configured to guide the liquid towards the bottom of the tank by increasing the surface area and duration of heat exchange of this liquid with the gaseous phase of the tank.

[0011] Furthermore, embodiments of the invention may include one or more of the following features: - the guiding element extends vertically at least to the midpoint of the tank's height, - the guiding element comprises a set of plate(s) forming linings, - The guiding element comprises a set of plate(s) forming waves; - the waves are arranged vertically and are associated with plates planes, approximately horizontal, diffusing the liquid longitudinally from the orifices towards the probes, - the guiding element comprises a set of inclined plates arranged consecutively with alternating directions of inclination, - the platforms are inclined at an angle of inclination of less than ten degrees and preferably less than five degrees, - the trays are perforated, - the plates are shaped to form channels.

[0012] The invention may also relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

[0013] Other features and advantages will become apparent from the following description, made with reference to the figures in which: Brief description of the figures

[0014] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0015] [Fig-1] is a schematic and partial vertical cross-sectional view of a device storage according to a first example of an embodiment of the invention,

[0016] [Fig.2] is a schematic and partial vertical cross-sectional view of a device storage according to a second embodiment of the invention,

[0017] [Fig.3] is a schematic and partial vertical cross-sectional view of a device storage according to a third embodiment of the invention. Detailed description

[0018] In all figures, the same references refer to the same elements.

[0019] In this detailed description, the following embodiments are examples. Although the description refers to one or more embodiments, this does not mean not that the characteristics apply only to a single embodiment. Simple characteristics from different embodiments can also be combined and / or interchanged to provide other embodiments.

[0020] The cryogenic fluid storage device 1 illustrated in [Fig.1] comprises a reservoir 2 extending along a longitudinal direction A and intended to contain liquefied gas 3 in equilibrium with a gaseous phase.

[0021] For the sake of simplicity, the reservoir is represented by a single wall 2. Of course, this wall 2, delimiting the storage volume, can be surrounded by a second wall to form a double-walled tank with thermal insulation between the two walls.

[0022] The tank 2 includes an upper liquid injection ramp 4 in the tank 2 which extends along the longitudinal direction A in the upper part of the tank 2.

[0023] The injection ramp 4 comprises a plurality of outlet orifices 5 spaced along the longitudinal direction A.

[0024] According to an advantageous feature, the reservoir 2 includes a guide element 6 extending vertically downwards in the reservoir from the orifices 5. This guide element 6 is configured to guide the liquid downwards in the reservoir by increasing the surface area and the duration of heat exchange of this liquid with the gaseous phase of the reservoir 2. In this example of an embodiment, the guide element includes a set of plate(s) forming packings 6, for example made of aluminum.

[0025] By packing, we mean corrugated or shaped plates designed to ensure a large exchange surface area per unit volume. This type of packing is known in the field of cryogenic distillation.

[0026] This increases the exchange surface area within the volume of the gaseous space. This guide element can therefore be placed in the tank 2 up to the midpoint of the tank 2 (the inner wall of the tank in contact with the fluid).

[0027] In the embodiment of [Fig.2], the guiding member comprises a set of plate(s) forming waves 7. For example, a metallic exchange surface is arranged between the liquid and the gas so as to increase heat exchange.

[0028] The liquid can be spread on metal sheets, for example aluminium, in order to disperse the liquid as much as possible and increase its contact surface before falling into the liquid located at the bottom of the reservoir 2.

[0029] The subcooled liquid will be able to exchange its cooling capacity with the metal sheets, and the surrounding gas will be able to recover this cooling capacity. The superheated gas will initially cool down to the dew point temperature and then condense.

[0030] In this embodiment one or more distributors and exchange waves can be placed in the gaseous space of the reservoir 2.

[0031] The waves 7 can be corrugated plates used, for example, in brazed plate and fin heat exchangers. A flat plate 17 can be brazed to the upper part of the wave 6 to ensure the distribution of liquid to the probes 7. The upper flat plate(s) 17 can receive the liquid jets from the orifices 5 to spread them out. The waves 7 can be placed below to collect the liquid on one of their faces. The heat exchange wave 7 is preferably not perforated, unlike those conventionally used in brazed plate and fin heat exchangers. The heat exchange waves 7 increase the surface area for exchange with the liquid.

[0032] Condensation of the gaseous layer can occur on the face opposite the face receiving the liquid. The heat transfer wave 7 can be more or less inclined relative to the vertical in order to increase the exchange. The heat transfer waves 7 can also be partially or totally immersed in the liquid bath. The advantage of the heat transfer waves 7 in contact with the liquid bath is to reduce the thermal gradient of the gaseous layer. Indeed, the waves 7 allow heat exchange between the liquid bath 3 and the gaseous layer before, during, and after the filling phase of the tank 2. It should be noted that condensation increases the heat transfer coefficient on the vapor side since this generates a relatively large local pressure difference which advantageously pumps the remaining vapor from the gaseous layer.

[0033] In the embodiment of [Fig.3], the guiding member comprises a set of inclined plates 8 arranged consecutively with alternating directions of inclination.

[0034] These inclined plates 8 (perforated or not) constitute, for example, a channel for the incoming liquid in cryogenic tanks containing cryogenic liquid. This improves filling at the top, at the level of the gaseous headspace. These plates 8 preferably have a shallow inclination, for example, between a few degrees and 5 degrees.

[0035] As illustrated, several consecutive plates 8 can have alternating directions of inclination (forming, for example, back and forth movements in the reservoir 2)

[0036] The invention makes it possible to increase the surface area and the exchange time in the volume of the gaseous space between the liquid and the gas.

[0037] The invention can be applied to the filling of any type of cryogenic liquid tank.

Claims

Demands

1. Cryogenic fluid storage device comprising a tank (2) extending along a longitudinal direction (A) and intended to contain liquefied gas (3) in equilibrium with a gaseous phase, a liquid injection ramp (4) in the tank (2) extending along the longitudinal direction (A) in the upper part of the tank (2), the injection ramp (4) comprising a plurality of outlet orifices (5) spaced along the longitudinal direction (A), characterized in that the tank (2) comprises a guide member (6, 7, 8) extending vertically downwards in the tank from the orifices (5), the guide member being configured to guide the liquid downwards in the tank by increasing the surface area and duration of heat exchange of this liquid with the gaseous phase of the tank (2).

2. Device according to the preceding claim, characterized in that the guiding member extends vertically at least to the mid-height of the tank (2).

3. Device according to any one of the preceding claims, characterized in that the guiding member comprises a set of plate(s) forming waves (7).

4. Device according to the preceding claim, characterized in that the waves (7) are arranged vertically and are associated with substantially horizontal flat plates and diffusing the liquid longitudinally from the orifices (5) to the waves (7).

5. Device according to any one of the preceding claims, characterized in that the guiding member comprises a set of inclined plates (8) arranged consecutively with alternating directions of inclination.

6. Device according to the preceding claim, characterized in that the plates (8) are inclined with an angle of inclination of less than ten degrees and preferably less than five degrees.

7. Device according to any one of claims 5 or 6, characterized in that the trays (8) are perforated.

8. A device according to any one of claims 5 to 7, characterized in that the plates (8) are shaped to form canals.

Images