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EP-4735295-A2 - ENERGY RECOVERY SYSTEM FOR A FUEL CELL VEHICLE AND RELATED CONTROL METHOD

EP4735295A2EP 4735295 A2EP4735295 A2EP 4735295A2EP-4735295-A2

Abstract

Vehicle comprising a propulsion system (1) provided with at least one electric machine (2), energy accumulator means (3) and a fuel cell module (4), the at least one electric machine (2), the energy accumulator means (3) and the fuel cell module (4) being electrically connected together, the vehicle further comprising a main tank (6) for storing hydrogen at a first pressure value, the main tank (6) being fluidly connected to the fuel cell module (4) via a first conduit (A), the vehicle further comprising an energy recover system (8) configured to be electrically connected to the electric machine (2) and produce hydrogen for the fuel cell module (4) when the electric machine (2) acts as generator.

Inventors

  • GELLY, Romain

Assignees

  • IVECO FRANCE S.A.S.

Dates

Publication Date
20260506
Application Date
20240628

Claims (13)

  1. 1.- Vehicle comprising a propulsion system (1) provided with at least one electric machine (2) , energy accumulator means (3) and a fuel cell module (4) , the at least one electric machine (2) , the energy accumulator means (3) and the fuel cell module (4) being electrically connected together, said vehicle further comprising a main tank (6) for storing hydrogen at a first pressure value, said main tank (6) being fluidly connected to said fuel cell module (4) via a first conduit (A) , the vehicle further comprising an energy recover system (8) configured to be electrically connected to said electric machine (2) and produce hydrogen for said fuel cell module (4) when the electric machine (2) acts as generator, wherein said energy recovery system (8) comprises an electrolyzer (9) , a water tank (11) and an auxiliary tank (12) , said electrolyzer (9) being electrically connected to said at least one electric machine (2) and fluidly connected via a second conduit (B) to said water tank (11) and a third conduit (C) to said auxiliary tank (12) , said auxiliary tank (12) being fluidly connected via a fourth conduit (D) to said first conduit (A) , said electrolyzer (9) being configured to receive electrical energy and generate hydrogen to be stored in said auxiliary tank (12) at a second pressure value via the water contained in said water tank
  2. 2.- Vehicle according to claim 1, wherein said fourth conduit (D) is fluidly connected to said first conduit (A) via fluid junction means (14) .
  3. 3.- Vehicle according to claim 2, wherein said fluid junction means (14) are integrated or realized separately with respect to said first and fourth conduits (A, D) .
  4. 4.- Vehicle according to claim 2 or 3, wherein said first pressure value is greater than said second pressure value, said fluid junction means (14) allowing the passage of hydrogen from said auxiliary tank (12) towards said first conduit (A) .
  5. 5.- Vehicle according to any of claims 2 to 4, wherein said fluid junction means (14) defines a venturi portion within said first conduit (A) , said fourth conduit (D) being fluidly connected in said venturi portion thereby providing a sucking effect towards said first conduit (A) .
  6. 6.- Vehicle according to any of the preceding claims, further comprising filtering means (13) fluidly interposed on said fourth conduit (D) upstream to the junction to said first conduit (A) .
  7. 7 Vehicle according to any of the preceding claims, further comprising valve means (7) fluidly interposed on said first conduit (A) upstream to said fuel cell module (4) and configured to regulate the pressure of hydrogen
  8. 8.- Vehicle according to claim any of the preceding claims, further comprising electric energy management means (5) electrically connecting said electric machine (2) to said fuel cell module (4) , to said energy accumulator means (3) and to said energy recovery system (8) .
  9. 9.- Vehicle according to claim 8, wherein said electric energy management means (5) comprises inverter means (5' ) and a high voltage distributor box (5 , f ) in series one with respect to the other between the electric machine (2) and fuel cell module (4) , energy accumulator means (3) and energy recovery system (8) .
  10. 10.- Vehicle according to any of the preceding claims, further comprising an electronic control unit electrically connected to said electric machine (2) , to said fuel cell module and/or to said energy accumulator means (3) and configured to control their operation, said electronic control unit comprise elaboration means configured to acquire data related to the state of charge of said accumulator means (3) and to receive a braking request and control consequently the operation of said electric machine (2) and of said energy recovery system (8) .
  11. 11.- Method for controlling a propulsion system of a vehicle according to any of the preceding claims and comprising the following steps: i) receiving a request of braking the vehicle; ii) detecting the state of charge of the energy accumulator means (3) ; ill) if the state of charge detected at step ii) is below a preset threshold, then control the electric machine (2) to act as generator and brake the vehicle generating electrical energy to be stored into the accumulator means (3) ; iv) if the state of charge detected at step ii) is above a preset threshold, then control the electric machine (2) to act as generator and brake the vehicle generating electrical energy to be used by the energy recovery system (8) to produce hydrogen.
  12. 12.- Method according to claim 11, wherein said state of charge threshold value is 80%
  13. 13.- Method according to claim 11 or 12, wherein said steps are memorized in the elaboration means of said electronic control unit and executed continuously or at a preset time interval till the braking request is required. ABSTRACT Vehicle comprising a propulsion system (1) provided with at least one electric machine (2) , energy accumulator means (3) and a fuel cell module (4) , the at least one electric machine (2) , the energy accumulator means (3) and the fuel cell module (4) being electrically connected together, the vehicle further comprising a main tank (6) for storing hydrogen at a first pressure value, the main tank (6) being fluidly connected to the fuel cell module (4) via a first conduit (A) , the vehicle further comprising an energy recover system (8) configured to be electrically connected to the electric machine (2) and produce hydrogen for the fuel cell module (4) when the electric machine (2) acts as generator . Fig. 1

Description

"ENERGY RECOVERY SYSTEM FOR A FUEL CELL VEHICLE AND RELATED CONTROL METHOD" Cross-Reference to Related Applications This Patent Application claims priority from Italian Patent Application No . 102023000013386 filed on June 28 , 2023 , the entire disclosure of which is incorporated herein by reference . Technical Field The present invention concerns an energy recovery system for a fuel cell vehicle . The present invention finds its preferred, although not exclusive , application in public transport vehicles such as buses . Reference will be made to this application by way of example below . Background of the Invention Vehicles tends more and more to avoid the use of internal combustion engines in order to reduce emissions of pollutive elements . In particular, an alternative to the internal combustion engine is a fuel cell propulsion system . As known, fuel cell vehicles comprise a fuel cell configured to use hydrogen gas and provide , via chemical reactions , electrical energy that can feed an electric traction system such as an electric machine for the transmission of the vehicle or a plurality of electric machines , one or more for each wheel of the vehicle . Therefore , in synthesis , fuel cell vehicles are electric vehicles wherein the electric energy is generated by the fuel cell and can be stored in energy accumulator means such as batteries . In order to brake fuel cell vehicles , so-called regenerative brake is performed . Such operative mode foresees the operation of the electric machine in generator mode , thereby applying a braking torque to the transmission of the vehicle or directly to the wheels . The electric machine therefore generates electrical energy from mechanical power derived from the transmission/wheels thereby braking the vehicle and charging the energy accumulator means . However, energy accumulator means cannot absorb a continuous amount of energy and therefore , one a speci fic state of charge is reached, then the surplus of electrical energy should be dispersed via energy dispersion means such as retarders or resistors . Moreover, when the energy accumulator means are almost filled up, i . e . when state of charge is comprised between 80% and 100% the braking capacity is drastically reduced till zero . Therefore , the only way of safely braking is the use of mechanical brakes that however suf fers of wear and need to be periodically checked . It is clear from the above that the regenerative braking suf fers of drawbacks that may lead the safety of the drive of the vehicle and furthermore is a waste of energy that cannot be tolerated . Therefore , the need is felt to improve the braking performance of a fuel cell vehicle while at the same time avoiding waste of energy during braking . An aim of the present invention is to satis fy the above mentioned needs in a cost-ef fective and optimi zed manner . Summary of the Invention The aforementioned aim is reached by a fuel cell vehicle comprising an energy recovery system and a related control method as claimed in the appended set of claims . Brief Description of Drawings For a better understanding of the present invention, a preferred embodiment is described in the following, by way of a non-limiting example , with reference to the attached drawings wherein : • Figure 1 is a schematic representation of a fuel cell vehicle propulsion system according to the invention; and • Figure 2 is a schematic representation of a portion of the fuel cell vehicle of figure 1 . Detailed Description of the Invention In figure 1 it is schematically disclosed a propulsion system 1 of a fuel cell vehicle (not shown in its entirety) comprising at least one electric machine 2 and energy accumulator means 3 such as battery means electrically connected to the at least one electric machine 2 . The propulsion system 2 further comprises a fuel cell module 4 that is electrically connected to both the electric machine 2 and accumulator means 3 . In detail , the electric machine 2 , accumulator means 3 and fuel cell module 4 are electrically connected via electric energy management means 5 . Preferably, such electric energy management means 5 comprises an inverter 5 ' and a high voltage distribution box 5 ' ’ ; in detail , the inverter 5 ' is electrically interposed between the high voltage distribution box 5 ' ' and the electric machine 2 while the high voltage distribution box 5 ' ' is voted to electrically connect together the accumulator means 3 and the fuel cell module 4 . The electric machine 2 can operate as electric motor when supplied of electric energy from the accumulator means 3 and/or the fuel cell module 4 in order to provide a mechanical torque to a transmission/wheels of the vehicle or as generator when absorbing a mechanical torque from the transmission/wheels of the vehicle and produce electrical energy to be stored in accumulator means 3 or used by other devices of the vehicle . The propulsion system 1 further comprises a main tank 6 c