Handling machine with a gas storage tank positioned under the cab

Abstract

The invention relates to a handling machine (1) comprising: - a chassis (2) having a median longitudinal axis (X); - a lifting arm (3) pivotably mounted on the chassis (2); - a driver's cab (11) attached to the chassis (2) and positioned on a first side of the chassis (2) with respect to the median longitudinal axis (X) of the chassis (2); - a compartment (15) positioned under the driver's cab (11); and - at least one hydrogen storage tank (16) accommodated in the compartment (15).

Description

Handling machine with a gas storage tank positioned under the cabin

[0001] The invention relates to the field of handling machines comprising a load handling device and a tank intended to store a gas, such as hydrogen. Technological background

[0002] Document US6688481 discloses a crane that comprises a chassis, a telescopic arm that is articulated on the chassis and an electric motor that is configured to provide propulsion for the crane. In one embodiment, the crane comprises a fuel cell system that is connected to the electric motor in order to supply it with electrical energy. The fuel cell system is disposed on a rear portion of the vehicle chassis in order to form a counterweight.

[0003] Such a handling machine is not fully satisfactory, in particular in that the aforementioned arrangement of the fuel cell system does not allow the hydrogen tank to be effectively protected against impacts, even though these, along with fires, constitute the main causes of tank explosions. Summary

[0004] One idea behind the invention is to propose a handling machine comprising a tank intended to contain hydrogen and which offers increased safety.

[0005] According to a first subject, the invention relates to a handling machine comprising:- a chassis having a median longitudinal axis;- a lifting arm pivotally mounted on the chassis;- a driver's cab which is fixed to the chassis and is positioned on a first side of the chassis relative to the median longitudinal axis of the chassis;- a compartment which is positioned under the driver's cab; and- at least one hydrogen storage tank which is housed in the compartment.

[0006] Thus, the arrangement of the tank in the compartment positioned under the driver's cab offers excellent protection against falling objects.

[0007] According to embodiments, such a handling machine may have one or more of the following characteristics.

[0008] According to one embodiment, the handling machine further comprises an air intake circuit which comprises an inlet which is arranged to take air from outside the driver's cab, an outlet opening into an internal space of the driver's cab and a fan arranged to circulate air from the inlet to the outlet of the air intake circuit.

[0009] According to one embodiment, the handling machine comprises a pressurization device which comprises:- a pressure sensor configured to deliver a pressure signal representative of the pressure in the internal space of the driver's cab; and- a control unit which is configured to control the fan as a function of the pressure signal delivered by the pressure sensor and a pressure setpoint Cp greater than atmospheric pressure. Thus, the driver's cab is pressurized, which limits the risks of hydrogen leaking from the tank positioned in the compartment entering the driver's cab until explosive conditions are reached.

[0010] According to one embodiment, the pressure setpoint Cp is between 10 and 100 Pa relative.

[0011] According to one embodiment, the inlet of the air intake circuit is positioned at a height greater than 1.50 m. This limits the risks of hydrogen having leaked from the tank entering the internal space of the driver's cab via the air intake circuit and, at the very least, allows it to be diluted as it rises from the tank to the inlet of the intake circuit.

[0012] According to one embodiment, the inlet of the air intake circuit is positioned near or above a top of the driver's cab.

[0013] According to one embodiment, the compartment comprises an air inlet and an air outlet. This allows the compartment to be swept with an air flow.

[0014] According to one embodiment, the air inlet mouth is positioned at the front of the compartment.

[0015] According to one embodiment, the air exhaust outlet is formed in a side wall of the compartment.

[0016] According to one embodiment, the air exhaust outlet is positioned relative to the driver's cab, on the other side of the chassis. This allows any hydrogen leaks to be directed away from the handling machine.

[0017] According to an advantageous embodiment, the air exhaust outlet is positioned relative to the driver's cab transversely opposite the inlet of the air intake circuit.

[0018] According to one embodiment, the compartment comprises a fan configured to provide a forced airflow into the compartment, from the air inlet to the air exhaust outlet. This allows the compartment to be swept with a forced airflow, which further reduces the risks of the atmosphere inside the compartment reaching explosive conditions.

[0019] According to one embodiment, the compartment comprises an upper wall which comprises a portion which is inclined with a constant or strictly increasing slope so as to rise towards the air discharge outlet. This makes it possible to avoid the creation of gas pockets inside the compartment.

[0020] According to one embodiment, the portion which is inclined is an external lateral portion of the upper wall.

[0021] According to one embodiment, the upper wall of the compartment is divided by a diagonal line into an external lateral rear portion and an internal lateral front portion, the external lateral rear portion being inclined with a constant or strictly increasing slope so as to rise longitudinally from front to rear and transversely from inside to outside and the internal lateral front portion being arranged horizontally.

[0022] According to one embodiment, the handling machine comprises an opening hingedly mounted at the rear of the driver's cab, said opening being hingedly mounted on the driver's cab along a lower edge of said opening or along an external lateral edge which is positioned on the same side as the air exhaust outlet of the compartment.

[0023] According to one embodiment, the handling machine comprises a fire detection and management device which comprises a control unit and at least one sensor chosen from:- a temperature sensor configured to deliver a signal representative of the temperature of the tank;- a pressure sensor configured to deliver a signal representative of the pressure prevailing inside the tank;- a temperature sensor configured to deliver a signal representative of the temperature prevailing in the compartment; and- an opacity sensor configured to deliver a signal representative of the opacity of the gaseous medium inside the compartment;the control unit being configured to:- compare a value delivered by the at least one sensor with a threshold value;- detect a risk of fire when the value delivered by the at least one sensor is greater than or equal to said threshold value;and- order the closing of a shut-off valve associated with the tank in response to the detection of a fire risk.;

[0024] Such a fire detection and management device thus makes it possible to limit the risks of explosion and / or of a fire continuing to be fueled with hydrogen from the tank even though a risk of fire has been detected.

[0025] According to one embodiment, the handling machine comprises a leak detection and management device comprising:- a pressure sensor configured to deliver a signal representative of the pressure prevailing inside the tank;- a hydrogen sensor configured to deliver a signal representative of a hydrogen concentration inside the compartment; and- a control unit which is configured to:- process the signal delivered by the pressure sensor and determine a value ∆P representative of a pressure gradient per unit of time in the tank;- compare each of the values ​​among the value ∆P and a value delivered by the pressure sensor with at least one respective threshold value;- detect a leak according to said comparisons; and- control a fan which is configured to ensure a forced air flow in the compartment in response to the detection of a leak.

[0026] Such a leak detection and management device is particularly advantageous in that it can detect many leak cases and minimize the risks of these leaks generating a fire or explosion.

[0027] According to one embodiment, the handling machine comprises a box in which are housed a fuel cell connected to the tank, an air-liquid heat exchanger configured to cool the fuel cell and a fan associated with said heat exchanger.

[0028] According to one embodiment, the handling machine comprises a ventilation management device in said box comprising:- a temperature sensor configured to deliver a signal representative of the temperature of a heat transfer fluid circulating in the heat exchanger;- a hydrogen sensor which is configured to deliver a signal representative of a hydrogen concentration inside the box; and- a control unit which is configured to:- control the fan associated with the heat exchanger as a function of the signal delivered by the temperature sensor and / or as a function of the signal delivered by the hydrogen sensor.

[0029] According to one embodiment, the tank is a pressurized hydrogen tank suitable for storing hydrogen at a maximum pressure of between 300 and 700 bars, for example of the order of 350 bars. According to another embodiment, the tank is a tank for storing hydrogen in the form of metal hydrides.

[0030] According to one embodiment, the handling machine further comprises hydrogen-consuming equipment which is connected to the tank and which is chosen from a fuel cell and a hydrogen internal combustion engine.

[0031] According to one embodiment, the handling machine comprises a box which is fixed to the chassis and is arranged on a second side of the chassis, opposite the first side, relative to the median longitudinal axis and the hydrogen consuming equipment is housed in the box. Such an arrangement is advantageous in that, on the one hand, it allows the energy consuming equipment to be positioned at a distance from the driver, which increases his safety, and, on the other hand, allows the hydrogen consuming equipment to be separated from the tank, which limits the risk of fire in said tank.

[0032] According to one embodiment, the handling machine comprises at least one electric motor which is configured to move the handling machine or operate the load handling device and the hydrogen consuming equipment is a fuel cell which is configured to generate electrical energy intended to power the electric motor.

[0033] According to one embodiment, the handling machine comprises a cooling device for cooling the fuel cell, said cooling device comprising a cooling circuit equipped with a heat exchanger, and being housed in the box.

[0034] According to one embodiment, the load handling device comprises a lifting arm which extends in a longitudinal plane between the box and the driver's cab and which is mounted articulated on the chassis along a transverse pivot axis P.

[0035] According to one embodiment, the lifting arm is a telescopic arm.

[0036] According to one embodiment, the handling machine is a telescopic forklift. Brief description of the figures

[0037] The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the accompanying drawings.

[0038] This is a schematic side view of a handling machine equipped with a compartment positioned under the driver's cab and in which hydrogen storage tanks are housed.

[0039] This is a schematic top view of the handling machine.

[0040] This is a schematic view similar to illustrating a handling machine, according to a second embodiment.

[0041] The figure represents views in orthogonal projection, rear, left, front, bottom and top of the driver's cab of the handling machine according to the first and second embodiments.

[0042] This is a detailed view of an inlet of the air intake circuit according to one embodiment.

[0043] This is a side view, from the left, of a driver's cab equipped with an opening according to a first variant of the embodiment.

[0044] This is a top view of a driver's cab equipped with an opening according to a second embodiment.

[0045] This is a schematic illustration of a fire detection and management device capable of equipping a handling machine according to the first or second embodiment.

[0046] This is a schematic illustration of a leak detection and management device capable of equipping a handling machine according to the second embodiment.

[0047] This is a schematic illustration of a ventilation management device in a box housing a fuel cell and its cooling circuit.

[0048] This is a schematic view of a hydrogen circuit according to one embodiment.

[0049] By convention, the "longitudinal" direction of the handling machine corresponds to its front-rear orientation. Furthermore, the terms "rear" and "front", respectively designated AV and AR in the figures, are used to define the relative position of one element with respect to another in the longitudinal direction. The median longitudinal axis, designated X in the figures, is an axis oriented in the longitudinal direction and passing through the middle of the front and rear axles of the handling machine. The "transverse" direction is oriented perpendicular to the longitudinal direction.

[0050] With reference to Figures 1 and 2, a handling machine 1 is described. The handling machine 1 comprises a chassis 2 and a load handling device, here a lifting arm 3, which is movably mounted on the chassis 2.

[0051] The chassis 2 is mobile. To achieve this, the handling machine 1 has two axles, a front axle 4 and a rear axle 5, which are each mounted on the chassis 2 along a transverse axis and are each equipped with two wheels, one on the left and the other on the right.

[0052] In the embodiment shown, the chassis 2 comprises a pair of two side members 6, 7, visible in the figure. The side members 6, 7 are metal parts, generally flat, parallel to each other, which extend parallel to the median longitudinal axis X, respectively on either side of said median longitudinal axis X.

[0053] The lifting arm 3 extends in a longitudinal plane which is preferably median, that is to say that the median longitudinal axis X is included in this plane. The lifting arm 3 is articulated to the two longitudinal members 6, 7, between them, so as to be pivotally movable relative to the two longitudinal members 6, 7 about a transverse pivot axis P. The lifting arm 3 can be produced in different ways, in particular in the form of several telescopic sections. In this case, the handling machine 1 can in particular be a telescopic forklift. Alternatively, the lifting arm 3 is in the form of an arm of fixed length. One end of the lifting arm 3, opposite the pivot axis P, can carry a work tool 8 or a modular tool holder capable of receiving work tools 8 of several types. By work tool 8, we mean for example a pair of forks, a bucket, a winch, a clamp, etc.

[0054] The handling machine 1 comprises one or more linear actuators, not shown, such as hydraulic cylinders, which are each mounted articulated, on the one hand, on the lifting arm 3 and, on the other hand, on the chassis 2 of the handling machine 1, which makes it possible to pivot the lifting arm 3 relative to the chassis 2. The hydraulic cylinders are connected to a hydraulic circuit equipped with a hydraulic pump 9, visible on the. In the embodiment shown, the hydraulic pump 9 is driven by a motor, such as an electric motor 10. The hydraulic pump 9 as well as the electric motor 10 are here housed in the chassis 2, between the two side members 6, 7 but can be positioned at other locations.

[0055] Furthermore, the handling machine 1 comprises a driver's cab 11 defining an internal space in which a driver can take place and which is in particular equipped with a seat, not shown, and equipment for controlling the handling machine 1. The driver's cab 11 is positioned, on a first side of the median longitudinal axis X, on the left side in the embodiment shown, and between the front axle 4 and the rear axle 5. The driver's cab 11 is fixed to the chassis 2 and more particularly to one of the side members 7 thereof.

[0056] The handling machine 1 further comprises a box 12, visible in the, which is positioned relative to the driver's cab 11, on the other side of the median longitudinal axis X of the handling machine 1. The box 12 is fixed to the other of the side members 6. The box 12 and the driver's cab 11 are therefore positioned on either side of the pair of side members 6, 7.

[0057] The handling machine 1 also comprises a compartment 15 in which one or more tanks 16 are housed for storing hydrogen. The compartment 15 is positioned under the driver's cab 11, between the front axle 4 and the rear axle 5.

[0058] The tank 16 is, for example, suitable for storing hydrogen in the gaseous state at a maximum pressure of between 300 and 700 bars, for example of the order of 350 bars. According to another embodiment, the tank 16 is suitable for storing hydrogen in the solid state in the form of metal hydrides. The tank 16 is associated with a shut-off valve 18, visible in the, which makes it possible to prevent hydrogen from escaping from the tank 16.

[0059] The tanks 16 are connected to a fuel cell 17, also visible in the, by a hydrogen circuit. In the, the fuel cell 17 is housed in the box 12.

[0060] A hydrogen circuit is illustrated, by way of example, in the. The hydrogen circuit comprises a filling line 54 which is equipped with a chute 55 intended to receive a filling nozzle of a hydrogen refueling station. The filling line 54 connects the chute 55 to a hydrogen flow regulating device 56 associated with each of the tanks 16 through a non-return valve 57. Each hydrogen flow regulating device 56 comprises in particular a shut-off valve 18.

[0061] The hydrogen circuit also comprises a supply line 58 intended to conduct the hydrogen from the tanks 16 to the fuel cell 17. The supply line 58 comprises a filter 59 as well as a pressure regulator 60 which makes it possible to reduce the pressure in order to supply the fuel cell 17 with hydrogen having a pressure compatible with its operation, that is to say lower than that at which it is stored in the tanks 16. By convention, the portion of the supply line 58 which is arranged upstream of the pressure regulator 60 is designated the high-pressure portion while the portion arranged downstream of the latter is designated the low-pressure portion. Furthermore, the hydrogen circuit comprises a drain circuit 61 which makes it possible to empty the contents of the tanks 16, in particular in the event of an emergency. To do this, the drain circuit 61 is connected to a degassing valve 62 associated with each of the tanks 16.

[0062] The hydrogen circuit also comprises a pressure limiter circuit 63 which is connected to the low pressure portion and which is equipped with a pressure limiter device 64 which is configured to evacuate the hydrogen circulating in the low pressure portion when its pressure is higher than a set pressure, which makes it possible to protect the fuel cell 17.

[0063] Furthermore, the low pressure portion is also equipped with a manually controlled valve 65 and a connection device 66 for connecting the fuel cell 17 to the low pressure portion of the supply line 58.

[0064] In a manner known per se, the fuel cell 17 is the seat of an oxidation-reduction reaction which transforms the hydrogen coming from the tank and the oxygen in the air supplied by a compressor into electricity, water and heat. Also, the handling machine 1 comprises a cooling device 20, visible in the, intended to cool the fuel cell 17. The cooling device 20 is also housed inside the box 12. The cooling device 20 comprises a cooling circuit equipped with an air-liquid heat exchanger 21. It further comprises a fan 22 which is associated with the heat exchanger 21 and which thus makes it possible to further improve the performance of the cooling device 20.The box 12 also comprises an air inlet, not shown, which is advantageously arranged at the front of said box 12 as well as an air outlet, also not shown, which is advantageously arranged at the rear of the box 12, which allows air to circulate through the box 12.

[0065] Furthermore, the handling machine 1 comprises at least one motor, such as an electric motor 13, 14, for example, which is configured to ensure the movement of the handling machine 1. In the embodiment shown in the, the handling machine 1 comprises two electric motors 13, 14 ensuring its movement. Each electric motor 13, 14 is coupled to one of the front 4 or rear 5 axles via a transmission device.

[0066] The handling machine 1 comprises an electrical energy storage device comprising one or more batteries 19 and / or one or more supercapacitors. The terminals of the batteries 19 and / or the supercapacitors are connected to the electric motor(s) 10, 13, 14 in parallel with the fuel cell 17.

[0067] The handling machine 1 further comprises power electronic equipment, not illustrated, which comprises in particular a DC / DC voltage converter which is connected, on one side, to the fuel cell 17 and on the other side to the electric motors 10, 13, 14 and to the electrical energy storage device, here the batteries 19. The DC / DC voltage converter makes it possible to convert the voltage level delivered by the fuel cell 17 to the voltage level required by the electric motors 10, 13, 14 and the batteries 19. Control means, also not illustrated, are configured to control the fuel cell 17, the electric motors 10, 13, 14 as well as the DC / DC voltage converter as a function of the control signals delivered by control equipment of the handling machine 1, such as an accelerator pedal and / or a control joystick, in particular.

[0068] In another embodiment, not shown, the motor that is configured to ensure the movement of the handling machine 1 is not an electric motor but a hydrogen internal combustion engine. Such engines are generally designated by the acronym HICE for “Hydrogen Internal Combustion Engine” in English. In this case, the hydrogen internal combustion engine can in particular be arranged, in place of the fuel cell 17 of the embodiment of FIGS. 1 and 2, that is to say in the box 12.

[0069] The handling machine 1 is advantageously equipped with means for protecting the driver who is installed in the driver's cab 11 in the event of a hydrogen leak. It includes in particular means having the function of preventing, or at least limiting the risks, of hydrogen being present in the internal space of the driver's cab 11 under explosive conditions.

[0070] To do this, the handling machine 1 is equipped with an air intake circuit which comprises an inlet 23, visible schematically in the, which is arranged to take air from outside the driver's cab 11, an outlet 24 opening into the internal space of the driver's cab 11 as well as a fan 25, visible in the, making it possible to circulate air from the inlet 23 to the outlet 24 of the air intake circuit. As described in detail below, the inlet 23 of the air intake circuit is positioned at a distance from equipment, such as the tanks 16, which may be the source of hydrogen leaks.

[0071] According to an advantageous embodiment, the air intake circuit is associated with a device for overpressurizing the internal space of the driver's cab 11. The overpressurizing device comprises a pressure sensor 26 which is placed in the internal space of the driver's cab 11 and which is configured to deliver a pressure signal representative of the pressure prevailing inside the driver's cab 11 as well as a control unit 27 which is connected to said pressure sensor 26. The control unit 27 is configured to control the fan 25 as a function of the pressure signal delivered by the pressure sensor 26 and a pressure setpoint C pwhich is higher than atmospheric pressure. Such overpressure of the driver's cab 11 thus limits the risk of possible hydrogen leaks from the tanks 16 positioned in the compartment 15 entering the driver's cab 11. The value of the pressure setpoint C p is preferably between 10 and 100 Pa relative and, for example, of the order of 20 Pa relative.

[0072] The driver's cab 11 is advantageously equipped with sealing gaskets, in particular between the openings and their respective frames, so as to facilitate its pressurization.

[0073] Furthermore, the compartment 15 is equipped with means for ensuring that said compartment 15 is swept by an air flow in order to evacuate the hydrogen therefrom in the event of a leak. To do this, the compartment 15 has an air inlet 28 which is preferably arranged at the front of the compartment 15 and which makes it possible to supply air to the compartment 15.

[0074] In the embodiment of the, the sweeping of said compartment 15 is ensured by a natural air flow while in that of the, it is ensured by a forced air flow. In other words, in the embodiment of the, the compartment 15 also comprises a fan 29 making it possible to ensure the circulation of air.

[0075] As shown in the, the compartment 15 comprises an air exhaust outlet 30 which is formed in one of the side walls of the compartment 15, here the external side wall 31, that is to say the one which defines the left side of the compartment 15 when the driver's cab 11 is positioned to the left of the chassis 2. The air exhaust outlet 30 is positioned in a rear portion of said external side wall 31 and close to the upper wall 32 of the compartment 15.

[0076] Advantageously, the upper wall 32 of the compartment 15 has a geometry which makes it possible to avoid the creation of gas pockets in the compartment 15 and to direct the air flow towards the air discharge outlet 30. To do this, the upper wall 32 comprises an external lateral rear portion 33 which is inclined with a constant or strictly increasing slope so as to rise longitudinally from the front to the rear and transversely from the inside to the outside. In the embodiment shown, the upper wall 32 is, in projection in a horizontal plane, of rectangular shape and is divided into two portions, namely the aforementioned external lateral rear portion 33 and an internal lateral front portion 34, by a diagonal line which extends between the external front apex and the internal rear apex of said upper wall 32.In the embodiment shown, the internal lateral front portion 34 is arranged horizontally, which makes it easier to construct the upper wall 32 and more generally the compartment 15.

[0077] As also illustrated in the, the inlet 23 of the air intake circuit is positioned, relative to the driver's cab 11, transversely opposite the air exhaust outlet 30 of the compartment 15. Therefore, when the air exhaust outlet 30 of the compartment 15 is formed on the external side wall 31 of the compartment 15, as in the embodiment shown, the inlet 23 of the air intake circuit is positioned above the chassis 2. Preferably, the inlet 23 of the air intake circuit is positioned at a height greater than 1.50 m, for example near the top of the driver's cab 11. Such an arrangement limits the risks of hydrogen having leaked from the tanks 16 entering the internal space of the driver's cab 11 via the air intake circuit or at least diluting it.

[0078] According to an advantageous embodiment, in order to further limit the risks of hydrogen having leaked from the tanks 16 entering the internal space of the driver's cab 11, a deflector 35, illustrated in the, is arranged under the inlet 23 of the air intake circuit. The deflector 35 has an annular shape which extends radially all around a duct 36 of the air intake circuit which is connected to the inlet 23. The deflector 35 is, preferably, domed and arranged so that its convex face is directed towards the ground. Thus, the deflector 35 makes it possible to direct a flow of gas rising along the duct 36 (and consequently likely to contain hydrogen which is lighter than air) radially outwards relative to the axis of said duct 36, which moves it away from the inlet 23.

[0079] According to embodiments, illustrated in Figures 6 and 7, the driver's cab 11 comprises, at the rear, an opening 37. Advantageously, the opening 37 has an opening direction making it possible to limit the risks of hydrogen having leaked from the tanks 16 and escaping from the compartment 15 through the air evacuation outlet 30 entering the internal space of the driver's cab 11.

[0080] To do this, in the embodiment of the, the opening 37 is mounted articulated on the driver's cab 11 by means of a hinge pin 38 which is positioned along the lower edge of said opening 37. Furthermore, in its open position shown in the, the opening 37 has an inclination such that the upper edge of the opening 37 is positioned rearward relative to its lower edge. Therefore, the flow of gas rising along the opening 37 moves away from the driver's cab 11.

[0081] In the embodiment of the, the opening 37 is mounted hinged on the driver's cab 11 by means of a hinge pin 39 which is positioned along an external lateral edge of said opening 37, which is positioned on the same side as the air exhaust outlet 30, i.e. the left in the embodiment shown. This also makes it possible, in the event of a hydrogen leak, to limit the quantity of hydrogen likely to penetrate into the internal space of the driver's cab 11, when the opening 37 is open.

[0082] According to an advantageous embodiment, the handling machine 1 is also equipped with a fire detection and management device 40, illustrated schematically in the. The fire detection and management device 40 comprises a plurality of sensors described below and each making it possible to deliver a parameter capable of being modified when a fire breaks out.

[0083] In the embodiment shown, the fire detection and management device 40 comprises: - a temperature sensor 41, associated with each of the tanks 16, configured to deliver a signal representative of the temperature of said tank 16; - a pressure sensor 42, associated with each of the tanks 16, configured to deliver a signal representative of the pressure prevailing inside said tank 16; - a temperature sensor 43, arranged in one or more of the closed spaces of the handling machine 1, namely the compartment 15, the box 12, the driver's cab 11, and configured to deliver a signal representative of the temperature prevailing in said closed space; and - an opacity sensor 44 or opacimeter, arranged in one or more of the aforementioned closed spaces, and configured to deliver a signal representative of the opacity of the gaseous medium inside said closed space.

[0084] In other embodiments, the fire detection and management device 40 may comprise only some of the aforementioned sensors or, on the contrary, additional sensors.

[0085] The aforementioned sensors 41, 42, 43, 44 are connected to a control unit 45 which compares each of the measurements delivered by these sensors 41, 42, 43, 44 with a respective threshold value.

[0086] As soon as at least one of the measurements reaches or exceeds the corresponding threshold value, the control unit 45 detects a risk of fire.

[0087] Thus, the control unit 45 compares each temperature measurement delivered by the temperature sensors 41, 43 to a temperature threshold value and detects a risk of fire when the temperature measurement is greater than or equal to said temperature threshold value. The control unit 45 also compares the pressure measurement delivered by each pressure sensor 42 to a pressure threshold value. Alternatively or additionally, the control unit 45 is configured to process the signals delivered by the pressure sensor 42 and deduce therefrom a value ∆P representative of a pressure gradient per unit of time in each tank 16 and then compare it to a pressure gradient threshold value.The control unit 45 detects a risk of fire, that is to say an anomaly symptomatic of a fire, when the pressure measurement is greater than or equal to said pressure threshold value and / or the ∆P value is greater than the pressure gradient threshold value. Note, however, that other phenomena may also lead to a rise in pressure, such as mechanical deformation of the tank 16. Similarly, the control unit 45 compares each opacity value of the gaseous medium delivered by the opacity sensor 44 to an opacity threshold value and detects a risk of fire when the opacity measurement is greater than said opacity threshold value.

[0088] In response to the detection of a risk of fire, the control unit 45 controls the closing of the shut-off valve 18 associated with each tank 16. This makes it possible to isolate the hydrogen circuit and thus limit the risks of explosion and / or that the fire continues to be supplied with hydrogen from the tanks 16 while a risk of fire has been detected.

[0089] Furthermore, according to one embodiment, the tanks 16 are associated with thermal fuse safety systems (designated by the acronym TPRD for “Thermal Pressure Relief Device” in English) allowing the tanks 16 to be quickly discharged to the outside of the handling machine 1, when the thermal fuse has melted.

[0090] The control unit 45 may also be configured to transmit a visual or audible alert signal to the driver informing him that a fire risk has been detected and / or that the handling machine 1 has been secured by a closing action of the shut-off valve 18. The alert signal is, for example, a message which is displayed on a dashboard 46 of the handling machine 1.

[0091] Alternatively or additionally, the handling machine 1 further comprises a leak detection and management device 47 which is shown schematically in the.

[0092] The leak detection and management device 47 also comprises a pressure sensor 42, associated with each of the tanks 16, configured to deliver a signal representative of the pressure prevailing inside said tank 16. The leak detection and management device 47 also comprises at least one hydrogen sensor which is positioned in the compartment 15 and which is configured to deliver a signal representative of a hydrogen concentration inside the compartment 15.

[0093] The leak detection and management device 47 also comprises a control unit 49 which may be different or identical to the control unit 45 of the fire detection and management device 40. The control unit 49 is connected to the pressure sensors 42 and to the hydrogen sensor 48. The control unit 49 is configured to process the signals delivered by the pressure sensors 42 and to deduce therefrom a value ∆P representative of a pressure gradient per unit of time in each tank 16. The value ∆P may be calculated indifferently in pressure unit per unit of time or in quantity of molar or mass material per unit of time.

[0094] According to an embodiment not shown, the leak detection and management device 47 may also comprise one or more pressure sensors configured to deliver a signal representative of the pressure prevailing in the low pressure or high pressure part of the supply line 58. To detect a leak in the supply line, the control unit 49 is configured to close the shut-off valve 18 of each of the tanks and process the signals delivered by said pressure sensors and deduce therefrom a value ∆P representative of a pressure gradient per unit of time in the supply line 58 when the shut-off valve 18 is closed.

[0095] The control unit 49 is also configured to deliver a control signal to the fan 29 positioned in the compartment 15, in the embodiment of the, as well as to deliver a control signal to the shut-off valve 18 associated with each tank 16. The fan 29 as well as the shut-off valve(s) 18 are controlled as a function, on the one hand, of the measurement of the hydrogen concentration C(H2) delivered by the hydrogen sensor 48 and, on the other hand, of the value ∆P representative of a pressure gradient per unit of time in each tank 16 and / or in the supply line 58.

[0096] According to a particular embodiment, the control unit 49 compares the hydrogen concentration measurement C(H2) to two concentration threshold values ​​C1, C2 with C1 < C2 < LEL and LEL: the lower flammability limit of hydrogen, namely 4.1% by volume. For example, C1 = 0.5% by volume and C2 = 2% by volume.

[0097] Similarly, the control unit 49 compares the value ∆P representative of a pressure gradient per unit of time in each tank to two pressure gradient thresholds ∆P1 and ∆P2 with ∆P1<∆P2.

[0098] As soon as at least one of the following two inequalities is respected: C2 ≥ C(H2) ≥ C1 and P2 ≥ ∆P ≥ ∆P1, the control unit 49 controls the fan 29 with a first set speed V1 as long as C(H2) < C2 and ∆P < ∆P2. Furthermore, as soon as at least one of the following two inequalities is respected C(H2) > C2 and ∆P > ∆P2, the control unit controls the fan 29 with a second set speed V2 which is greater than V1 and controls the closing of each stop valve 18. Furthermore, the control unit 49 keeps the fan 29 in operation as long as the following two inequalities are not simultaneously respected C(H2) < C1 and ∆P < ∆P1.

[0099] The control unit 49 may also be configured to transmit a visual or audible alert signal to the driver informing him that a leak has been detected when C(H2) ≥ C1 and / or ∆P ≥ P1. The alert signal is, for example, a message that is displayed on a dashboard of the handling machine 1.

[0100] Diagrammatically illustrates a device 50 for managing the ventilation of the space in which the fuel cell 17 is housed, here the box 12. This management device 50 controls the fan 22 which is associated with the heat exchanger 21 of the cooling circuit of the fuel cell 17. The management device 50 comprises a control unit 51, a temperature sensor 52 delivering a signal representative of the temperature of the heat transfer fluid circulating in the heat exchanger 21 as well as at least one hydrogen sensor 53 which is configured to deliver a signal representative of a hydrogen concentration inside the box 12.

[0101] The control unit 51 compares the hydrogen concentration measurement C(H2) with two concentration threshold values ​​C'1, C'2 with C'1 < C'2 < LEL and LEL: the lower flammability limit of hydrogen, namely 4.1% by volume. For example, C'1 = 0.5% by volume and C'2 = 2% by volume.

[0102] As long as C(H2) < C'1, the control unit 51 controls the fan 22 according to the temperature measurement of the heat transfer fluid delivered by the temperature sensor 52. In other words, in such circumstances, the role of the fan 22 is to ensure the temperature regulation of the heat exchanger 21 and the control unit 51 controls the fan 22 so as to regulate the temperature of the heat transfer fluid to a set temperature. Advantageously, the regulation is implemented with a hysteresis.

[0103] When C'2 ≥ C(H2) ≥ C'1, the priority of the fan 22 consists of ensuring the ventilation of the box 12. From then on, the control unit 51 controls the fan 22 at a first set speed V'1 which is higher than the speed of fan 22 when it ensures the temperature regulation of the heat exchanger 21.

[0104] When C(H2) > C'2, the control unit 51 controls the fan 22 at a second set speed V'2 greater than V'1. The control unit 51 further controls the stopping of the fuel cell 17.

[0105] Some elements shown, in particular the control unit 27 as well as the control units 45, 49, 51 can be implemented in different forms, in a unitary or distributed manner, by means of hardware and / or software components. Usable hardware components are specific integrated circuits ASIC, programmable logic networks FPGA or microprocessors. Software components can be written in different programming languages, for example C, C++, Java or VHDL. This list is not exhaustive.

[0106] Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0107] The use of the verb "comprise", "comprise" or "include" and its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0108] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

Handling machine (1) comprising:- a chassis (2) having a median longitudinal axis (X);- a lifting arm (3) pivotally mounted on the chassis (2);- a driver's cab (11) which is fixed to the chassis (2) and is positioned on a first side of the chassis (2) relative to the median longitudinal axis (X) of the chassis (2);- a compartment (15) which is positioned under the driver's cab (11); and- at least one hydrogen storage tank (16) which is housed in the compartment (15). Handling machine (1) according to claim 1, further comprising an air intake circuit which comprises an inlet (23) which is arranged to take air from outside the driver's cab (11), an outlet (24) opening into an internal space of the driver's cab (11) and a fan (25) arranged to circulate air from the inlet (23) to the outlet of the air intake circuit. Handling machine (1) according to claim 2, comprising a pressure relief device which comprises:- a pressure sensor (26) configured to deliver a pressure signal representative of the pressure in the internal space of the driver's cab (11); and- a control unit (27) which is configured to control the fan (25) as a function of the pressure signal delivered by the pressure sensor (26) and a pressure setpoint C p higher than atmospheric pressure. Handling machine (1) according to claim 2 or 3, in which the inlet (23) of the air intake circuit is positioned at a height greater than 1.50 m. Handling machine (1) according to any one of claims 2 to 4, in which the inlet (23) of the air intake circuit is positioned relative to the driver's cab (11), on the side of the chassis (2). Handling machine (1) according to any one of claims 2 to 5, further comprising a deflector (35) which is arranged under the inlet (23) of the air intake circuit and which is configured to direct an upward air flow away from the inlet (23) of the air intake circuit. Handling machine (1) according to any one of claims 1 to 6, in which the compartment (15) comprises an air inlet (28) and an air exhaust outlet (30). Handling machine (1) according to claim 7, wherein the air exhaust outlet (30) is formed in a side wall (31) of the compartment (15). Handling machine (1) according to claim 8, wherein the air exhaust outlet (30) is positioned relative to the driver's cab (11), on the other side of the chassis (2). Handling machine (1) according to any one of claims 7 to 9, wherein the compartment (15) comprises a fan (29) configured to provide a forced air flow in the compartment (15) from the air inlet mouth (29) to the air exhaust outlet (30). Handling machine (1) according to any one of claims 7 to 10, in which the compartment (15) comprises an upper wall (32) which comprises a portion (33) which is inclined with a constant or strictly increasing slope so as to rise towards the air discharge outlet (30). Handling machine (1) according to any one of claims 1 to 11, comprising a fire detection and management device (40) comprising a control unit (45) and at least one sensor chosen from:- a temperature sensor (41) configured to deliver a signal representative of the temperature of the tank (16);- a pressure sensor (42) configured to deliver a signal representative of the pressure prevailing inside the tank (16);- a temperature sensor (43) configured to deliver a signal representative of the temperature prevailing in the compartment (15); and- an opacity sensor (44) configured to deliver a signal representative of the opacity of the gaseous medium inside the compartment (15);the control unit (45) being configured to:- compare a value delivered by the at least one sensor with a threshold value;- detecting a risk of fire when the value delivered by the at least one sensor is greater than or equal to said threshold value; and - controlling the closing of a shut-off valve (18) associated with the tank (16) in response to the detection of a risk of fire.; Handling machine (1) according to any one of claims 1 to 12, comprising a leak detection and management device (47) comprising:- a pressure sensor (42) configured to deliver a signal representative of the pressure prevailing inside the tank (16);- a hydrogen sensor (48) configured to deliver a signal representative of a hydrogen concentration inside the compartment (15); and- a control unit (45) which is configured to:- process the signal delivered by the pressure sensor (42) and determine a value ∆P representative of a pressure gradient per unit of time in the tank (16);- compare each of the values among the value ∆P and a value delivered by the pressure sensor (42) with at least one respective threshold value;- detect a leak according to said comparisons;and- controlling a fan (29) which is configured to provide a forced airflow into the compartment (15) in response to the detection of a leak.; Handling machine (1) according to any one of claims 1 to 13, comprising a box (12) in which are housed a fuel cell (17) connected to the tank (16), a heat exchanger (21) configured to cool the fuel cell (17) and a fan (22) associated with said heat exchanger (21). Handling machine (1) according to claim 14, further comprising a device (50) for managing ventilation in said box (12) comprising:- a temperature sensor (52) configured to deliver a signal representative of the temperature of a heat transfer fluid circulating in the heat exchanger (21);- a hydrogen sensor (53) which is configured to deliver a signal representative of a hydrogen concentration inside the box (12); and- a control unit (51) which is configured to:- control the fan (22) associated with the heat exchanger (21) as a function of the signal delivered by the temperature sensor (52) and / or as a function of the signal delivered by the hydrogen sensor (53).

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