ELECTRIC VEHICLE POWERED BY A HYDROGEN FUEL CELL WITH A HYDROGEN TANK LOCATED IN THE FRONT COMPARTMENT

Abstract

This hydrogen fuel cell electric vehicle comprises an electric drive unit (11) for driving at least one drive wheel of the vehicle, at least one battery (13) for electrical energy storage, at least one fuel cell module (14), and a hydrogen tank (15) for the fuel cell. The hydrogen tank (15) is located in a front compartment of the vehicle, at the front of the vehicle passenger compartment. (See Figure 2 for abbreviations.)

Description

Title of the invention: HYDROGEN FUEL CELL ELECTRIC VEHICLE HAVING A TANK HYDROGEN PLACED IN THE FRONT COMPARTMENT technical field

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

[0002] It relates more particularly to the installation of a hydrogen tank intended to supply a hydrogen fuel cell. 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 thermal 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 comprises a high-pressure hydrogen tank 2 (e.g., 700 bar) supplied from a filling pipe 3 (Arrow F1) which opens onto the vehicle body, a fuel cell 4 supplied with hydrogen from the tank 2 (arrow F2), and a battery 5 supplied with electrical energy from the fuel cell. fuel 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] In the event of a leak, the mass flow rate of hydrogen released into the atmosphere is directly proportional to the gas pressure in the pipes. Consequently, the high-pressure section of the circuit is by far the most dangerous in the event of a leak.

[0018] Motor vehicle manufacturers seek to implement the various components of the hydrogen circuit, and in particular the tank, in such a way as to obtain a good autonomy while avoiding confinement of the high-pressure part of the hydrogen circuit.

[0019] US7303211B2 describes a vehicle architecture in which high-pressure hydrogen tanks are positioned longitudinally in a frame located in the car chassis.

[0020] US patent 7703564B2 describes a vehicle architecture in which the high-pressure hydrogen tanks are positioned at the rear of the vehicle.

[0021] In order to reduce the energy consumption of vehicles, we seek to lower the floor of vehicles in order to improve the aerodynamics of the car by reducing the drag coefficient known as SCx.

[0022] These designs are not compatible with a low floor, unless the size of the onboard tank is considerably reduced. Furthermore, the ventilation of the tank and the components (pipes, fittings, etc.) of the high-pressure section of the circuit is poor. Description of the invention

[0023] The aim of the invention is to overcome these disadvantages and to propose a vehicle architecture compatible with low floors, and which allows for good vehicle autonomy while avoiding confinement of the high-pressure part of the hydrogen circuit.

[0024] The invention therefore relates to a hydrogen fuel cell 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 and a hydrogen tank for the fuel cell.

[0025] The hydrogen tank is placed in a front compartment of the vehicle, at the front of the vehicle's passenger compartment.

[0026] Preferably, the hydrogen tank is placed in a rearward position relative to the front face of the vehicle exposed to frontal impacts.

[0027] According to another feature of the vehicle, the hydrogen tank is arranged transversely in the front compartment.

[0028] According to yet another feature, the fuel cell module is placed under the rear seats of the vehicle.

[0029] Furthermore, in one embodiment, the powertrain comprises an electric machine and an inverter located at the rear axle of the vehicle.

[0030] The battery can be placed under the floor of the vehicle. Brief description of the drawings

[0031] 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:

[0032] - Fig. 1 is a perspective view of the chassis of a vehicle according to the state of the technique;

[0033] - Fig. 2 is a perspective view of the chassis of a conforming vehicle to the invention, showing the placement of the hydrogen tank, fuel cell, traction battery, and powertrain; and

[0034] - Figure [Fig. 3] is a top view of the chassis of a vehicle according to the invention, showing the placement of the hydrogen tank, fuel cell, traction battery and powertrain. Detailed description

[0035] Figures 2 and 3 show an electric motor vehicle with a hydrogen fuel cell according to the invention and in particular the chassis 10 of the vehicle on which is fixed a powertrain 11 of the vehicle intended to drive at least one drive wheel of the vehicle, here the two rear wheels of the vehicle.

[0036] The powertrain includes in particular an electric machine and an inverter positioned at the rear axle 12 of the vehicle.

[0037] The vehicle is a "hydrogen fuel cell electric vehicle", or FCEV. The powertrain thus comprises two energy sources, namely at least one high-voltage battery 13 and at least one fuel cell module (FC) 14, the battery being able to be recharged either from the fuel cell, while driving the vehicle, or from an electrical power supply network, while parked.

[0038] The high-voltage battery 13 is advantageously located under the floor of the vehicle.

[0039] The fuel cell module is located under the rear seats, i.e. under the second row seats. It is supplied with hydrogen from a high-pressure hydrogen tank 15 integrated transversely in the front compartment of the vehicle and in a position set back from the front face which is more exposed to crash stresses.

[0040] The tank is thus 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 of the vehicle exposed to frontal impacts.

[0041] This architecture has several advantages:

[0042] It allows a large quantity of hydrogen to be carried while preserving passenger space and ergonomics in the passenger compartment and controlling the height of the car and consequently the vehicle's drag coefficient SCx to the benefit of its range.

[0043] Positioning the tank in a forward location allows the powerful fans already present in the front of all cars to be used to ventilate the entire high-pressure hydrogen storage area and the hydrogen supply circuit, which is the area most at risk from potential hydrogen leaks. This forced ventilation plays a crucial safety role because it dilutes the hydrogen and keeps the density below the risk threshold in the event of a leak.

[0044] The front-end fans are components already present in electric or internal combustion engine vehicles without hydrogen. They are typically used to cool components. The ability to also use them to ensure safety related to the storage and distribution of high-pressure hydrogen does not increase the manufacturing cost or the vehicle's weight. This results in significant cost savings, as well as considerable weight and volume reductions compared to a different design that would require adding new fans dedicated to safety.

Claims

Demands

1. Hydrogen fuel cell electric vehicle, comprising an electric powertrain (11) for driving at least one drive wheel of the vehicle, at least one electrical energy storage battery (13), at least one fuel cell module (14) and a hydrogen tank (15) for the fuel cell, characterized in that the hydrogen tank is placed in a front compartment of the vehicle, at the front of the vehicle passenger compartment.

2. Electric vehicle according to claim 1, in which the hydrogen tank (15) is placed in a position set back from the front face of the vehicle exposed to frontal impacts.

3. Vehicle according to any one of claims 1 and 2, wherein the hydrogen tank (15) is arranged transversely in the front compartment.

4. Vehicle according to any one of claims 1 to 3, wherein the fuel cell module (14) is placed under the rear seats of the vehicle.

5. Vehicle according to any one of claims 1 to 4, wherein the powertrain (11) comprises an electric machine and an inverter located at the rear axle (2) of the vehicle.

6. Vehicle according to any one of claims 1 to 5, wherein the battery (13) is placed under the floor of the vehicle.

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