HYDROGEN ELECTRIC VEHICLE INCLUDING GUIDE DUCTS FOR THE INSERTION OF SENSORS, IN PARTICULAR HYDROGEN.

Abstract

This hydrogen-powered electric vehicle comprises an electric drive unit for driving at least one drive wheel of the vehicle, at least one electrical energy storage battery, at least one fuel cell module, a hydrogen tank for the fuel cell, and a hydrogen circuit connected to the tank, including components through which hydrogen circulates. It includes a set of hollow guide conduits (12, 13), each having a first end (14) opening at a component of the hydrogen circuit and a second accessible end. Figure for the abbreviation: Fig 2

Description

Title of the invention: HYDROGEN-POWERED ELECTRIC VEHICLE COMPRISING CONDUITS GUIDING GUIDE FOR THE INSERTION OF SENSORS, PARTICULARLY HYDROGEN SENSORS. technical field

[0001] The present invention relates to an electric motor vehicle with a hydrogen fuel cell.

[0002] It relates more particularly to hydrogen supply circuits and the detection of hydrogen leaks. Previous techniques

[0003] Electric vehicles currently in circulation are mainly vehicles whose powertrain energy source is a battery. They are commonly called BEVs (English acronym for "Battery Electric Vehicles").

[0004] In parallel with BEVs, some motor vehicle manufacturers are beginning to develop electric vehicles with two energy sources: a battery and a fuel cell (FC) powered by hydrogen from a hydrogen tank. These vehicles are commonly called "hydrogen fuel cell electric vehicles," or FCEVs (for "Fuel Cell Electric Vehicle").

[0005] By incorporating hydrogen in addition to a battery, FCEVs offer a long range while optimizing the capacity of the onboard traction battery, thereby controlling its size and associated weight. Furthermore, refueling with hydrogen is as quick as refueling with conventional carbon-based fuels, taking only a few minutes.

[0006] Whatever the operating temperatures of these vehicles, the thermal management between the traction battery and the heat produced by the operation of the fuel cell makes it possible to guarantee stable and repeatable range and motor power despite a very variable temperature range which is penalizing for simple electric vehicles, i.e. not equipped with a fuel cell.

[0007] An example of FCEV vehicle architecture can be seen in [Fig.1].

[0008] In the example shown in [Fig. 1], which depicts a chassis 1, the vehicle includes a high-pressure hydrogen tank 2 (e.g., 700 bar) supplied from a filling pipe 3 (Arrow Fl) which opens onto the vehicle body, and a fuel cell 4 supplied with hydrogen from the tank 2 (arrow F2), a battery 5 supplied with electrical energy from the fuel cell 4 and which powers an electric motor 6 which drives at least one wheel of the vehicle, for example the two rear wheels (arrow F3).

[0009] In order to increase the vehicle's range, it is desirable to be able to house a large hydrogen tank inside the vehicle.

[0010] One of the main problems associated with introducing hydrogen into a vehicle is related to safety management. Indeed, the hydrogen molecule (H2, dihydrogen) is the smallest existing molecule. The risk of leakage is therefore higher than for other gases.

[0011] Hydrogen is a highly flammable and reactive gas. It forms explosive mixtures with air above a low volume concentration, on the order of 4% (Lower Explosive Limit - LEL; Lower Flammable Limit - LFL).

[0012] The amount of energy required to cause the ignition of hydrogen (minimum ignition energy - MIE) is low, on the order of 0.01 mJ. For comparison, the energy of an electrostatic discharge is on the order of 10 mJ.

[0013] It is therefore necessary to avoid the risks of leakage and to avoid the lack of ventilation, in particular around the so-called "high pressure" part of the hydrogen circuit, which is the most critical.

[0014] Indeed, the hydrogen circuit includes a first portion 7 extending from the filling pipe to the tank (the so-called filling or "refuelling" part) and a second portion 8 extending from the tank to the fuel cell (the so-called distribution or "defuelling" part).

[0015] The distribution portion itself comprises three parts, each characterized by a different pressure level between the reservoir and the fuel cell.

[0016] It comprises a high-pressure section in which, during operation, the hydrogen stored in the tank is distributed at a high nominal pressure, for example 700 bar, and reaches a main pressure regulator (not shown); a medium-pressure section between the main pressure regulator and an internal expansion valve in the fuel cell module, in which the hydrogen is then distributed between 12 and 20 bar, depending on the characteristics of the fuel cell; and a low-pressure section between the expansion valve of the fuel cell module and the stack of electrochemical cells of the fuel cell, in which the hydrogen is finally distributed at a pressure below 3 bar.

[0017] The various parts of the hydrogen circuit generally consist of a set of pipes and fittings that may present risks of leakage. In this respect, the high-pressure part is likely to present increased risks of leakage.

[0018] It is therefore necessary to implement hydrogen leakage controls at the fittings, and to ensure ventilation or dilution of any hydrogen leaks, both when the vehicle is running and when stopped.

[0019] The architecture of electric vehicles is, however, highly constrained, as the hydrogen circuit is generally intertwined with the various vehicle components according to crash test requirements, the assembly order of the various components at the factory, and the optimization of the hydrogen circuit to reduce the volume of hydrogen to be dispersed in the event of a frontal collision. The space available for integrating hydrogen sensors is therefore generally insufficient. Description of the invention

[0020] The aim of the invention is to overcome these various drawbacks and to propose an architecture which allows for the implementation of hydrogen leakage controls at the level of the fittings, and to ensure ventilation or dilution of any hydrogen leaks at the level in inaccessible locations.

[0021] The invention therefore relates to a hydrogen electric vehicle, comprising an electric powertrain intended to drive at least one drive wheel of the vehicle, at least one electrical energy storage battery, at least one fuel cell module, a hydrogen tank for the fuel cell and a hydrogen circuit connected to the tank comprising components in which the hydrogen circulates.

[0022] It comprises a set of hollow guide or suction conduits, each comprising a first end opening at the location of a component of the hydrogen circuit and a second accessible end.

[0023] The second end is thus accessible for the insertion of a measuring sensor or a suction device into the conduit up to the first end of the guide conduit.

[0024] For example, the second end of the guide conduit is accessible from underneath the vehicle body.

[0025] In one embodiment, the second ends of the conduits are grouped together in a common pipe.

[0026] In different embodiments, the guide conduits are flexible or rigid. Brief description of the drawings

[0027] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0028] - [Fig. 1] is a perspective view of the chassis of a vehicle according to the state of the technical; and

[0029] - [Fig.2] and [Fig.3] are respectively a view of the hydrogen tank and a Detailed view of part of a hydrogen circuit, showing the hollow suction or guidance ducts. Detailed description

[0030] Reference will first be made to [Fig.2] which illustrates a hydrogen tank for a hydrogen fuel cell motor vehicle.

[0031] The tank, designated by the general numerical reference 10, is illustrated mounted on a cradle 11 to which it is fixed, for example by means of straps.

[0032] It is advantageously located in an advanced position relative to the vehicle's passenger compartment, at the level of the front axle, while being positioned further back relative to the front face of the vehicle exposed to frontal impacts.

[0033] The tank is equipped with a control valve for opening and closing the tank, called the "OTV" valve (for "On Tank Valve"), which provides the interface between the tank and a hydrogen circuit (not shown in the figures).

[0034] Conventionally, the hydrogen circuit is formed of conduits and fittings in which hydrogen circulates at high pressure, for example on the order of 700 bars, at medium pressure, for example on the order of 12 and 20 bars, and at low pressure, for example on the order of 3 bars.

[0035] Referring also to [Fig.3], in order to be able to detect hydrogen leaks at the fittings, in inaccessible areas, blindly, the circuit is equipped with guides, such as 12 and 13, which allow a measuring means to be brought as close as possible to the fittings.

[0036] These are flexible or rigid guides which are in the form of hollow conduits, one end of which, such as 14, opens into view of a fitting.

[0037] The other end of the guide is accessible from the underside of the vehicle and allows the insertion of a measuring tool of the hydrogen sensor type, mounted at the end of a flexible rod.

[0038] The tool can thus be inserted and guided through the hollow conduits to the fittings.

[0039] The second end of the guides is accessible in dedicated areas on housings with interfaces to connect to the continuous measurement cannulas of gas detection beacons, for example.

[0040] Alternatively, the different ends of said pipes which are not opposite the fittings can be grouped together on a plurality of pipes bundled together ([Fig.2]) in a single pipe (not shown on [Fig.2]) which allows the aspiration of hydrogen as well as the detection of hydrogen, for example before an intervention on the vehicle.

[0041] It is thus possible to position the fittings without taking into account the problem of accessibility for the control of the hydrogen tightness, and without taking into account the multiple design constraints such as the environment available in the architecture of the vehicle, by integrating either guides or pipes to connect a point and manual or continuous measurement tool with measurements via a gas detection beacon.

[0042] This allows mechanics or professionals working on the vehicle to check all interfaces or connections that may leak, by accessing the housing without worrying about the number and position of the connections to be checked.

Claims

Demands

1. . Hydrogen electric vehicle, comprising an electric powertrain for driving at least one drive wheel of the vehicle, at least one electrical energy storage battery, at least one fuel cell module, a hydrogen tank (10) for the fuel cell and a hydrogen circuit connected to the tank comprising components through which hydrogen flows, characterized in that it comprises a set of hollow guide conduits (12, 13) each comprising a first end (14) opening at the location of a component of the hydrogen circuit and a second accessible end.

2. Hydrogen electric vehicle according to claim 1, wherein the second end of the guide duct is accessible from the underside of the vehicle body.

3. Vehicle according to any one of claims 1 and 2, wherein the second ends of the conduits are grouped together in a common pipe.

4. Vehicle according to any one of claims 1 to 3, wherein the guide ducts (12, 13) are flexible.

5. Vehicle according to any one of claims 1 to 3, wherein the guide ducts (12, 13) are rigid.

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