FLUID STORAGE AND SUPPLY DEVICE AND VEHICLE AND METHOD COMPRISING SUCH A DEVICE

Description

[0001] The invention relates to a fluid storage and supply device, a vehicle and a method comprising such a device.

[0002] The invention relates more particularly to a device for storing and supplying fluid, in particular an on-board device for storing and supplying hydrogen to a user member, comprising a cryogenic tank for storing liquefied fluid, a withdrawal circuit comprising a first withdrawal pipe having a first upstream end connected to the upper part of the tank and a second downstream end intended to be connected to a user member, the first withdrawal pipe comprising a first reheating heat exchanger located outside the tank and a second reheating heat exchanger located inside the tank,the withdrawal circuit comprising a set of valve(s) configured to ensure the passage of a flow of fluid circulating from the first end to the second end by passing through the first heat exchanger then through the second heat exchanger or by passing only through the first heat exchanger without passing through the second heat exchanger.,

[0003] Such a device is for example described in document DE4329566A, but also in FR2706822A1.

[0004] On-board hydrogen storage in hydrogen-powered vehicles uses compressed gaseous or liquid hydrogen.

[0005] If the required stored capacity exceeds 50 kg, on-board storage in liquid form is preferred. Liquid hydrogen is generally stored in a low-pressure tank (less than 13 bar abs). At equilibrium, the hydrogen temperature is determined by the tank pressure via the saturation curve between the liquid and gas phases. This is valid up to the critical point of hydrogen, at a pressure slightly below 13 bar abs.

[0006] Liquid hydrogen is generally produced at a pressure close to atmospheric pressure, generally between 1.15 and 1.3 bar abs, corresponding to a temperature between 20.8K and 21.2K. It is transported and transferred into the on-board tank using cryogenic trucks and filling stations. Since transport and transfer are a source of thermal inputs, the temperature of the hydrogen in the tank corresponds to a saturation pressure of around 2 bar abs, or 22.9K.

[0007] Fuel cells (or possibly hydrogen-powered internal combustion engines "ICE") generally operate at a pressure of less than 2 bar abs at the cell core. However, for various operational reasons, most manufacturers require an interface pressure with the tank that is between 3 and 7 bar abs.

[0008] Since the full tank is initially at a lower pressure, it is then necessary to increase its pressure to a pressure higher than that of the fuel cell (ICE) and to control this pressure as gas is consumed. It is therefore necessary to include in the tank a means of controlling its pressure.

[0009] The aforementioned document provides for the supply of pressurized gas to the tank. This complicates the installation. This control method is not used in industry either due to the large quantities of gas required.

[0010] Another solution is to use an electric heating pin, preferably located in the liquid phase of the tank and configured to evaporate liquid to increase the tank pressure. This option has the advantage of being simple to implement but the major disadvantages of being very difficult to repair in the event of a breakdown (access to the tank) and of consuming part of the battery's electrical power.

[0011] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0012] To this end, the device according to the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that the device further comprises a system for pressurizing the tank comprising a pressurization pipe separate from the withdrawal circuit and comprising two ends connected respectively to the upper and lower parts of the tank, a vaporization heat exchanger and a set of valve(s) configured to allow the withdrawal of liquid from the tank, its reheating in the vaporization heat exchanger and its reintroduction into the tank.

[0013] Furthermore, embodiments of the invention may include one or more of the following features: the valve assembly(s) comprises a three-way valve connected respectively to an outlet of the first heat exchanger, to an inlet of the second heat exchanger and to the second end via a portion of the bypass draw-off circuit of the second heat exchanger the draw-off circuit comprises a third heat exchanger arranged in series downstream of the second heat exchanger so that the third heat exchanger receives the flow having passed through the second heat exchanger the first heat exchanger and the third heat exchanger are housed in the same exchanger housing in heat exchange with at least one flow of heat transfer fluid, the first heat exchanger and the vaporization heat exchanger are housed in the same exchanger housing in heat exchange with at least one flow of heat transfer fluid, the first heat exchanger,the third heat exchanger and the vaporization heat exchanger are housed in the same exchanger housing in heat exchange with at least one flow of heat transfer fluid, the device comprises an electronic controller configured to control all or part of the set of valve(s) of the device, the device comprises a fuel cell connected at the second downstream end, the device comprises a flow limiting and / or regulating member between the set of valve(s) and the second downstream end.

[0014] The invention also relates to a vehicle, in particular a boat, comprising a device according to any one of the characteristics above or below.

[0015] The invention also relates to a method for supplying fluid to a user member, by means of a device according to any one of the characteristics above or below or of a vehicle mentioned above, in which the user member is connected to the second end of the withdrawal circuit, the method comprising a step of supplying fluid from the reservoir to the user member by withdrawing liquefied fluid from the reservoir via the first withdrawal line, the method being characterized in that, prior to the step of supplying fluid, if the pressure within the reservoir is below a determined threshold, the method comprises a step of pressurizing the reservoir via the reservoir pressurization system to a determined pressure level.

[0016] 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.

[0017] Other features and advantages will appear on reading the description below, made with reference to the figures in which: [ Fig.1 ] represents a schematic and partial view illustrating the structure and operation of a first exemplary embodiment of the invention, [ Fig.2 ] represents a schematic and partial view illustrating the structure and operation of a second exemplary embodiment of the invention.

[0018] The illustrated fluid storage and supply device 1 may be a device on board a vehicle (boat or other) for storing and supplying hydrogen to a user unit such as a fuel cell or an engine for example.

[0019] The device 1 comprises a cryogenic tank 2 for storing liquefied fluid, for example a tank with two spaced walls with vacuum insulation between the two walls.

[0020] The device has a withdrawal circuit comprising a first withdrawal pipe 3 comprising a first upstream end 13 connected to the upper part of the reservoir 2 and a second downstream end 23 intended to be connected to a user member.

[0021] The first withdrawal pipe 3 comprises a first reheating heat exchanger 4 located outside the tank 2 and a second reheating heat exchanger 5 located inside the tank 2, preferably in the liquid part, i.e. in the lower part.

[0022] The withdrawal circuit comprises a set of valve(s) 6 configured to ensure the passage of a flow of fluid circulating from the first 13 end to the second 23 end by passing through the first heat exchanger 4 then through the second heat exchanger 5 or by passing only through the first heat exchanger 4.

[0023] That is to say that the withdrawal circuit comprises a pipe in which the first heat exchanger 4 and the second heat exchanger 5 are arranged in series between the first 13 and second end 23 and a bypass portion connecting the outlet of the first heat exchanger 4 to the second end 23 without passing through the second heat exchanger 5.

[0024] The set of valve(s) 6 comprises for example a three-way valve connected respectively to an outlet of the first heat exchanger 4, to an inlet of the second heat exchanger 5 and to the second 23 end via a bypass portion 7 ensuring a bypass of the second heat exchanger 5. The three-way valve 6 may be of the proportional type (with, for example, a portion of the fluid being directed towards the second heat exchanger 5). Of course, any other type of valve(s) may be envisaged to ensure the routing or distribution of the fluid flows. For example, the three-way valve may be replaced by two two-way valves arranged respectively in the pipe supplying the second exchanger 5 and the bypass pipe 7.

[0025] As illustrated, the withdrawal circuit may comprise a third heat exchanger 12 arranged in series downstream of the second heat exchanger 5 so that the third heat exchanger 12 receives the flow having passed through the first heat exchanger 4 and then through the second heat exchanger 5. A control and / or safety valve 17 is preferably provided downstream of the third heat exchanger 12 at the second end 23 (upstream of the user member 123). A temperature and / or pressure sensor may also be provided at the outlet of this heat exchanger 12 (similarly, a pressure sensor may be provided at the first end 13 of the withdrawal circuit).

[0026] Thus, the set of valve(s) 6 makes it possible to draw gas from the tank 2 which is circulated in the first 4 heat exchanger then in the second 5 heat exchanger and then in the third heat exchanger 12 before the second end 23. Alternatively, the set 6 of valve(s) makes it possible to draw gas from the tank 2 which is circulated only in the first 4 heat exchanger before arriving at the second end 23. Note that a flow rate limiting and / or regulating member 21 is preferably provided in the downstream circuit of the set of valve(s) (6) and the second downstream end (23), in the bypass portion 7 of the third heat exchanger 12.

[0027] This organ, which can be for example a calibrated orifice, makes it possible to compensate for the pressure losses in the heat exchanger(s) 5 and 12 in particular.

[0028] The first heat exchanger 4 and the third heat exchanger 12 can be housed in the same heat exchanger housing 15 with at least one flow 14 of heat transfer fluid (water or any other fluid).

[0029] As illustrated, preferably, a pressure relief valve safety device 18 is provided at the first end 13 to release any excess pressure from the tank 2.

[0030] The device 1 further comprises a system for pressurizing the tank 2 comprising a pressurization pipe 8 separate from the withdrawal circuit and comprising two ends connected respectively to the upper and lower parts of the tank 2, a vaporization heat exchanger 9 and a set of valve(s) 10, 11 configured to allow the withdrawal of liquid from the tank 2, its reheating in the vaporization heat exchanger 9 and its reintroduction into the tank 2. For example, two valves are arranged on either side of the vaporization heat exchanger 9.

[0031] Thus, this auxiliary pressurization system allows the initial pressurization of the tank and in particular the start-up of a fuel cell connected to the second end 23, without using the withdrawal circuit.

[0032] The method of realization of the [ Fig.2 ] is distinguished from that of the [ Fig.1] in that the vaporization heat exchanger 9 is housed in the same exchanger housing 15 as the first heat exchanger 4 (and where appropriate the third heat exchanger 12) and in heat exchange with at least one flow 14 of heat transfer fluid (via for example a circuit provided with valve(s) 140, 141).

[0033] In this case, to vaporize the liquid in the vaporization heat exchanger 9, the latter can be put into heat exchange with a hotter fluid, air, or by circulating hot water in at least one flow 14 of heat transfer fluid.

[0034] Note that, contrary to the schematic representation, preferably this same exchanger housing 15 is arranged below the tank 2.

[0035] A possible operation of the device for supplying fluid to a user organ 123 will now be described.

[0036] When the pressure in the tank 2 is below a determined threshold, the three-way valve 6 can be configured to pass the fluid drawn from the tank 2 (and heated in the first heat exchanger 4) into the second heat exchanger 5 (to provide calories in the tank 2 and therefore increase its pressure). This fluid is then heated again in the third heat exchanger 12 before being supplied to the user member 123.

[0037] When the pressure in the tank is higher than a determined level, the three-way valve 6 can be configured to pass the fluid drawn from the tank 2 (and heated in the first heat exchanger 4) without passing through the second heat exchanger located in the tank 2 to the user 123 (preferably via a flow limiting member 21). In this mode, the liquid and gas phases can be maintained in thermodynamic equilibrium, at the same temperature. Thus, in steady state, the gas drawn from the tank 2 comes from the evaporation of liquid generated by the second heat exchanger 5. This gas having bubbled through the liquid present in the tank, it is in thermodynamic equilibrium with the liquid. The pressure of the tank 2 is therefore fixed by the temperature of the liquid and the gas. This mode of operation therefore makes it possible to have a tank 2 in which the liquid is at the equilibrium temperature with the gas.In this case, if the tank is shaken, the mixture of the liquid and gas phase does not affect its pressure because they are at the same temperature.

[0038] As illustrated, an electronic controller 16 (including a microprocessor and / or a computer) may be provided and configured to control all or part of the valve assembly(s) of the device.

[0039] This withdrawal at the gaseous part is more advantageous than a liquid withdrawal because it allows a better renewal of the gaseous phase. In addition, it limits the thermal gradient of this phase, and consequently minimizes the gap in equilibrium between the liquid and the vapors of the phases.

[0040] The device therefore allows control of the pressure of the reservoir 2 with gas extraction and an internal recirculation loop in the liquid phase if necessary. The device can be mobile and in particular can undergo rotations relative to the three axes (Oxyz) greater than five degrees° and accelerations along these axes which are greater than 0.5 g (which can cause liquid / gas mixtures potentially leading to pressure instabilities in the devices of the prior art).

[0041] The device can be carried on a boat, plane, truck at a fixed position or in “full versus empty” mode of use.

[0042] The device 1 advantageously has an auxiliary pressurization heater 9 allowing the initial pressurization of the tank and the start-up of the cell without drawing off fluid (before the permanent drawing off operating mode described above).

[0043] Thus, preferably only to ensure a start-up, the pressurization of the tank 2 is carried out by the pressurization system separate from the draw-off circuit.

Claims

1. Fluid storage and supply device, in particular an on-board device for storing hydrogen and supplying it to a user member, comprising a cryogenic tank (2) for storing liquefied fluid, a withdrawal circuit comprising a first withdrawal line (3) having a first, upstream end (13) connected to the upper part of the tank (2) and a second, downstream end (23) intended to be connected to a user member, the first withdrawal line (3) comprising a first heating heat exchanger (4) located outside the tank (2) and a second heating heat exchanger (5) located inside the tank (2), the withdrawal circuit comprising an assembly of one or more valves (6) that is configured to ensure the passage of a flow of fluid circulating from the first end (13) to the second end (23), in the process entering the first heat exchanger (4) and then the second heat exchanger (5) or in the process entering solely the first heat exchanger (4) without entering the second heat exchanger (5), characterized in that the device (1) moreover comprises a system for pressurizing the tank (2), comprising a pressurization line (8) separate from the withdrawal circuit and comprising two ends connected respectively to the upper part and the lower part of the tank (2), a vaporization heat exchanger (9) and an assembly of one or more valves (10, 11) that is configured to allow liquid to be withdrawn from the tank (2), to be heated in the vaporization heat exchanger (9) and to be reintroduced into the tank (2), and in that the first heat exchanger (4) and the vaporization heat exchanger (9) are housed in one and the same exchanger housing (15) in a heat-exchange relationship with at least one flow (14) of heat-transfer fluid.

2. Device according to Claim 1, characterized in that the assembly (6) of one or more valves comprises a three-way valve, the ports of which are connected respectively to an outlet of the first heat exchanger (4), to an inlet of the second heat exchanger (5), and to the second end (23) via a portion (7) of the withdrawal circuit bypassing the second heat exchanger (5).

3. Device according to Claim 1 or 2, characterized in that the withdrawal circuit has a third heat exchanger (12) disposed in series downstream of the second heat exchanger (5) such that the third heat exchanger (12) receives the flow that has passed into the second heat exchanger (5).

4. Device according to Claim 3, characterized in that the first heat exchanger (4) and the third heat exchanger (12) are housed in one and the same exchanger housing (15) in a heat-exchange relationship with at least one flow (14) of heat-transfer fluid.

5. Device according to Claim 4, characterized in that the third heat exchanger (12) is also housed in the same heat exchanger housing (15) and in a heat-exchange relationship with the at least one flow (14) of heat-transfer fluid.

6. Device according to any one of Claims 1 to 5, characterized in that it has an electronic controller (16) configured to control all or some of the assembly of one or more valves of the device.

7. Device according to any one of Claims 1 to 6, comprising a fuel cell (123) connected at the second, downstream end (23).

8. Device according to any one of Claims 1 to 7, characterized in that it comprises a flow rate limiting and / or regulating member (21) between the assembly of one or more valves (6) and the second, downstream end (23).

9. Vehicle, in particular a boat, comprising a device according to any one of Claims 1 to 8.

10. Method for supplying fluid to a user member (123), by means of a device according to any one of Claims 1 to 9 or a vehicle according to Claim 10, wherein the user member (123) is connected to the second end (23) of the withdrawal circuit, the method comprising a step of supplying fluid from the tank (2) to the user member (123) by withdrawing liquefied fluid from the tank via the first withdrawal line (3), the method being characterized in that, prior to the fluid supplying step, if the pressure within the tank (2) is less than a determined threshold, the method comprises a step of pressurizing the tank (2) via the system for pressurizing the tank (2) up to a determined pressure level.