CONTROL SYSTEM FOR TRANSFERRING POOLED MOLECULAR HYDROGEN IN A FUEL CELL VEHICLE

Abstract

A control system for a vehicle incorporating a fuel cell system includes at least one cooling fan and one aerodynamic device configured to selectively increase airflow under the vehicle's hood. A thermal management controller is configured to control the at least one cooling fan and / or aerodynamic device in response to a detected temperature of a coolant in the vehicle's cooling system. A sensor is configured to detect the concentration of molecular hydrogen under the vehicle's hood.An airflow control for molecular hydrogen is configured to selectively request an additional airflow from the thermal management control using the cooling fan and / or aerodynamic device in response to the detected concentration of molecular hydrogen under the hood of the vehicle being greater than a predetermined concentration.

Description

INTRODUCTION

[0001] The information provided in this section serves the purpose of presenting the context of the disclosure in general. Works of the inventors currently named, insofar as they are described in this section, as well as aspects of the description that may not have been prior art at the time of filing, are neither expressly nor implicitly recognized as prior art with respect to the present disclosure.

[0002] The present disclosure relates to fuel cell control systems and in particular a control system for transferring pooled molecular hydrogen in a fuel cell vehicle.

[0003] A fuel cell system comprises an electrochemical cell that converts the chemical energy of molecular hydrogen (H₂) and molecular oxygen (O₂) into electricity through a pair of redox reactions. Some fuel cell systems include a proton exchange membrane (PEM) positioned between a cathode electrode and an anode electrode. The fuel cell system also includes a gas storage system for the molecular hydrogen.

[0004] German patent application DE 10 2014 215 340 B4 describes a vehicle equipped with a fuel cell system. The vehicle further comprises a cooling fan and an aerodynamic device configured to selectively increase airflow under the vehicle's hood. The cooling fan and / or the aerodynamic device are controlled in response to a detected temperature of a coolant in the vehicle's cooling system.

[0005] US patent 2016 / 0171797 A1 also describes a vehicle with a fuel cell system in which a sensor monitors the hydrogen concentration at various points in the vehicle. If the hydrogen concentration exceeds a certain threshold before or during vehicle start-up, a warning is issued to the driver to take safety precautions. SUMMARY

[0006] A control system for a vehicle incorporating a fuel cell system includes at least one cooling fan and one aerodynamic device configured to selectively increase airflow under the vehicle's hood. A thermal management controller is configured to control the at least one cooling fan and / or aerodynamic device in response to a detected temperature of a coolant in the vehicle's cooling system. A sensor is configured to detect the concentration of molecular hydrogen under the vehicle's hood.An airflow control for molecular hydrogen is configured to selectively request an additional airflow from the thermal management control using the cooling fan and / or aerodynamic device in response to the detected concentration of molecular hydrogen under the hood of the vehicle being greater than a predetermined concentration.

[0007] The airflow control system for molecular hydrogen is configured to wake up periodically, after a predetermined interval, when the vehicle is switched off, to receive the detected concentration of molecular hydrogen under the vehicle's hood. This predetermined interval is, for example, in the range of 6 to 18 hours.

[0008] In other characteristics, the predetermined concentration lies in a range of 1% to 4%. The molecular hydrogen airflow control forms part of at least one fuel cell control system and / or the thermal management control system. The sensor is located in a downward-facing concave pocket under the vehicle's hood.

[0009] In other features, the molecular hydrogen airflow control is configured to receive the detected concentration of molecular hydrogen under the vehicle's hood while the vehicle is powered on and the fuel cell system is active. The molecular hydrogen airflow control is configured to cause the thermal management control to open the aerodynamic device and stop the cooling fan if the detected concentration of molecular hydrogen under the vehicle's hood exceeds the predetermined concentration.

[0010] In other features, the molecular hydrogen airflow control is configured to stop requesting additional airflow from the thermal management control when the detected concentration of molecular hydrogen under the vehicle's hood is less than the predetermined concentration.

[0011] In other features, the molecular hydrogen airflow control is configured to cause the thermal management control to open the aerodynamic device and stop the cooling fan when the detected concentration of molecular hydrogen under the vehicle's hood exceeds the predetermined concentration. The predetermined period ranges from 6 to 18 hours.

[0012] A method for detecting molecular hydrogen under the hood of a vehicle comprising a fuel cell system comprises controlling at least one cooling fan and an aerodynamic device in response to a detected temperature of a coolant system of the vehicle; detecting a concentration of molecular hydrogen under the hood of the vehicle; and selectively requesting an additional airflow under the hood of the vehicle using the at least one cooling fan and aerodynamic device in response to the detected concentration of molecular hydrogen under the hood of the vehicle being greater than a predetermined concentration.

[0013] In other characteristics, the predetermined concentration is greater than 1%. The method involves measuring the concentration of molecular hydrogen in a downward-facing concave pocket under the vehicle's hood. The method also involves measuring the molecular hydrogen concentration for a specific period after the vehicle is switched off. This predetermined period is in the range of 6 to 18 hours.

[0014] In other features, the method includes sensing the concentration of molecular hydrogen under the vehicle's hood while the vehicle is powered on and the fuel cell system is active. In other features, the method includes opening the aerodynamic device and / or operating the cooling fan when the detected concentration of molecular hydrogen under the vehicle's hood is greater than the predetermined concentration. The method includes stopping the request for additional airflow under the vehicle's hood in response to the detected concentration of molecular hydrogen under the vehicle's hood being less than the predetermined concentration.

[0015] Further applications of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and the specific examples serve only for illustration and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present revelation will be better understood with the help of the detailed description and the accompanying drawings, whereby: Fig. 1 is a functional block diagram of a vehicle comprising one or more fuel cell stacks, a fuel cell controller, a thermal management controller, one or more cooling fans, one or more aerodynamic devices and one or more hydrogen sensors according to the present disclosure; Fig. Figure 2 illustrates the measurement of the concentration of molecular hydrogen at one or more locations under the hood of the vehicle according to the present disclosure; and Fig. Figure 3 is a flowchart illustrating an example of a method for detecting the molecular hydrogen concentration and selectively requesting an additional airflow by controlling the cooling fan(s) and / or the aerodynamic flap(s) in response to the molecular hydrogen concentration according to the present disclosure.

[0017] Reference symbols can be reused in the drawings to identify similar and / or identical elements. DETAILED DESCRIPTION

[0018] Although the present disclosure describes an airflow control system for a vehicle comprising one or more fuel cell stacks, the airflow control system can also be used in stationary applications and / or other applications.

[0019] Some fuel cells use molecular hydrogen (airflow control for molecular hydrogen) as an energy source. Molecular hydrogen is known to leak from and / or permeate gas storage systems, connecting lines, and / or fuel cell stack(s). Molecular hydrogen is lighter than air and can rise and become trapped under the vehicle's hood. For example, the molecular hydrogen can be trapped in downward-facing pockets under the hood.

[0020] Molecular hydrogen is flammable if the concentration exceeds 4% and an ignition source is present. In some countries, the molecular hydrogen concentration (molecular hydrogen airflow control) must be kept below an initial concentration (such as 4%). If the hydrogen concentration rises above this initial concentration, these regulations require remedial action, such as completely shutting down the fuel cell system. Completely shutting down the fuel cell system can leave the vehicle's occupants trapped.

[0021] In some examples, an airflow control for molecular hydrogen according to the present disclosure monitors the concentration of molecular hydrogen measured by one or more hydrogen sensors at one or more locations under the hood while the vehicle is parked or in motion. The molecular hydrogen airflow control selectively requests additional airflow from a thermal management control using a cooling fan and / or an aerodynamic device. The molecular hydrogen airflow control increases the airflow under the hood in response to a measured concentration of molecular hydrogen that is greater than a second concentration that is less than the first (which necessitates a complete shutdown).

[0022] The airflow control for molecular hydrogen can be part of, or work in conjunction with, the fuel cell control and / or the thermal control. Normally, the thermal management control regulates the fan and / or aerodynamic devices in response to thermal load (e.g., a measured coolant temperature of a cooling system that cools one or more fuel cell stacks). According to the present disclosure, the airflow control for molecular hydrogen requests an additional airflow from the thermal management control under the hood to reduce the concentration of molecular hydrogen before it reaches the first concentration that necessitates a complete shutdown. The additional airflow forces the trapped molecular hydrogen out of one or more locations into the atmosphere.

[0023] When the molecular hydrogen concentration is above the second concentration threshold (and below the first concentration threshold, which requires complete shutdown), the molecular hydrogen airflow control causes the thermal management control to open one or more aerodynamic devices and / or activate one or more cooling fans to increase the airflow under the vehicle's hood, thereby diluting the molecular hydrogen concentration at one or more locations. The molecular hydrogen airflow control selectively causes the thermal management control to adjust or override the thermal management-based control in response to the request for additional airflow.

[0024] Some molecular hydrogen leaks or permeations may be temporary. In other words, the leak or permeation is present for a time and then disappears on its own. Instead of requiring a complete shutdown of the fuel cell, the molecular hydrogen airflow control system, as disclosed herein, periodically monitors the molecular hydrogen concentration and selectively requests additional under-hood airflow to attempt to lower the concentration before a complete shutdown of the fuel cell system becomes necessary.

[0025] In some situations, the airflow control system transforms an unfixable fault or remedy into a fixable one. The airflow control system can also improve the efficiency of the fuel cell system by reducing the need to run a high-powered fan continuously for non-thermal reasons.

[0026] With reference to the following Fig. 1. A vehicle 100 comprises one or more fuel cell stacks 120. In some examples, the one or more fuel cell stacks 120 include one or more sensors 128 configured to detect the operating parameters of the one or more fuel cell stacks 120. In some examples, the one or more fuel cell stacks 120 include one or more actuators 124 to control the operation of the one or more fuel cell stacks 120. A hydrogen source 140 supplies molecular hydrogen to the one or more fuel cell stacks 120. In some examples, a fuel supply controller 144 controls / meters the supply of molecular hydrogen to the one or more fuel cell stacks 120.

[0027] A fuel cell controller 150 controls one or more fuel cell stacks 120 and communicates with the fuel supply controller 144, the actuators 124, and a thermal management controller 160. The thermal management controller 160 controls the airflow based on the heat load, the coolant temperature, and / or a request for additional airflow. In some examples, the fuel cell controller 150 (or optionally the thermal management controller 160) also includes a molecular hydrogen airflow controller 161, which selectively requests the additional airflow under the hood based on the measured concentration of molecular hydrogen (and independently of the heat load).The fuel cell control 150, the thermal management control 160 and / or the airflow control 161 for molecular hydrogen can be implemented by the same control unit, or two or more separate control units can be used.

[0028] In some examples, the fuel cell controller 150 monitors the sensors 128 and / or other sensors 163 (e.g. temperature, pressure, flow rate, load and / or other parameters) to control the one or more fuel cell stacks 120.

[0029] The thermal management controller 160 controls the operation of one or more cooling fans 180 and / or one or more aerodynamic devices 182 to adjust the airflow supplied to one or more vehicle locations (e.g., under the vehicle's hood) depending on the measured temperatures, the vehicle load, and / or the requirement for additional airflow. For example, during normal operation, the thermal management controller 160 uses one or more aerodynamic devices 182 to selectively allow or restrict airflow into a volume under the hood in response to one or more coolant or other temperatures detected by sensors 128 and / or sensors 163.One or more cooling fans 180 can be used to increase the airflow into the engine compartment, independently of one or more aerodynamic devices 182 (which may be closed, partially open or fully open).

[0030] The one or more fuel cell stacks 120 supply power to one or more consumers 174, such as one or more electric motors, a battery module, and / or vehicle accessory consumers. A vehicle controller 190 receives user inputs such as "vehicle ON" and "vehicle OFF" signals, torque requests, braking requests, etc. The fuel cell controller 150, for example, adjusts the power output of the one or more fuel cell stacks 120 based on the torque request.

[0031] One or more hydrogen sensors 194 are arranged at one or more locations. For example, the one or more hydrogen sensors 194 may be arranged in pockets under the hood of the vehicle, where molecular hydrogen can rise and accumulate. The one or more hydrogen sensors 194 measure the concentration of molecular hydrogen at the one or more locations. In some examples, each of the detected locations includes one hydrogen sensor or a pair of hydrogen sensors, which can be used to provide detection redundancy.

[0032] With reference to the following Fig. 2 The hydrogen sensor 194 is located under the hood 198 of a vehicle 199. Molecular hydrogen can escape from or pass through one or more fuel cell stacks 120 and flow upward into a pocket 196 or another location under the hood. The hydrogen sensor 194 detects the concentration of molecular hydrogen in the pocket 196. The molecular hydrogen airflow control 161 requests additional airflow from the thermal management control. In response to the request for additional airflow, the thermal management control selectively adjusts the aerodynamic devices 182 (e.g., an aerodynamic flap) and / or the cooling fan 180 to dilute the concentration of molecular hydrogen.

[0033] With reference to the following Fig.Figure 3 describes a method for controlling the airflow at one or more locations on the vehicle (e.g., under the hood) of a fuel cell vehicle. Figure 210 resets a timer. Figure 214 determines whether the timer is longer than a predetermined period (t). TH ). In some examples, the predetermined period is in the range of 6 to 18 hours, although shorter or longer periods are also possible. In some examples, the predetermined period is in the range of 10 to 14 hours (e.g., 12 hours), although shorter or longer periods are also possible. If 214 is false, the procedure determines whether the vehicle is "ON" and the fuel cell system is active.

[0034] If not, the procedure returns to 214. If either 214 or 218 is true, the procedure continues at 220 and monitors one or more hydrogen sensors that measure the molecular hydrogen concentration at one or more vehicle locations. At 224, the procedure determines whether the molecular hydrogen concentration is greater than a predetermined threshold C. TH is the concentration that corresponds to the second concentration. In some examples, the predetermined threshold is in a range of 1% to 4%. In some examples, the predetermined threshold is in a range of 1% to 2%.

[0035] If 224 is true, the procedure proceeds to 228 and determines whether the conditions for blower activation are met. In some examples, the conditions for blower activation include an ambient temperature that is higher than a predetermined temperature. For example, operating the cooling fan might reduce the temperature under the hood, which could cause malfunctions in a cooling system due to excessive airflow. In some examples, the conditions for blower activation might require the hood to be closed.

[0036] If 228 is true, the procedure continues at 232 and the aerodynamic device(s) is set or opened. At 236, the procedure starts the cooling fan. The procedure continues at 220. If either 224 or 228 is false, the procedure stops overriding the heat-controlled regulation of the one or more cooling fans at 240 and stops overriding the heat-controlled regulation of the one or more aerodynamic devices. At 248, the procedure determines whether the vehicle is "ON" and active. If so, the procedure returns to 220. If false, the procedure continues at 210. The increased airflow to the one or more vehicle locations dilutes the molecular hydrogen concentration at those locations.

[0037] In some examples, the airflow control for molecular hydrogen sets a first error type when the detected concentration is greater than the second concentration (e.g., 1%) but less than the first concentration (e.g., 4%). In other examples, the airflow control for molecular hydrogen sets a second error type when the measured concentration is greater than the first concentration (e.g., 4%) and implements other corrective actions, such as shutting down or preventing the fuel cell stack from operating.

[0038] The foregoing description serves only for illustration and is in no way intended to limit the disclosure, its application, or use. The comprehensive teachings of the disclosure can be implemented in a whole range of forms. Although this disclosure includes certain examples, the true scope of the disclosure should therefore not be limited to them, since other modifications will become apparent upon study of the drawings, the patent specification, and the following claims. It is understood that one or more steps within a process may be carried out in a different order (or simultaneously) without altering the principles of the present disclosure.Even though the embodiments described above are each provided with certain features, each or more of these features described in relation to one embodiment of the disclosure can also be implemented with features of any of the other embodiments and / or combined with them, even if this combination is not expressly described. In other words, the described embodiments are not mutually exclusive, and the interchangeability of one or more embodiments remains within the scope of this disclosure.

[0039] Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "interlocking," "coupled," "adjacent," "next to," "on top of," "above," "below," and "arranged." Unless a relationship between first and second elements is expressly described as "direct" in the preceding disclosure, this relationship may be a direct relationship in which no other intervening elements exist between the first and second elements, or an indirect relationship in which one or more intervening elements (either spatial or functional) exist between the first and second elements.As used herein, the expression “A, B and / or C” should be interpreted using a non-exclusive logical OR operation as logical (A OR-connected with B OR-connected with C) and not as “at least one of A, at least one of B and at least one of C”.

[0040] In the diagrams, the direction of an arrow, as indicated by its tip, generally illustrates the flow of information (such as data or instructions) that is relevant to the illustration. For example, if Element A and Element B exchange a variety of information, but the information sent from Element A to Element B is relevant for the illustration, the arrow may point from Element A to Element B. This unidirectional arrow does not mean that no other information is sent from Element B to Element A. Furthermore, Element B may send requests or acknowledgments of information to Element A in response to the information sent from Element A to Element B.

[0041] In this application, which includes the following definitions, the term "module" or the term "controller" may be replaced by the term "circuit". The term "module" may refer to, be a section thereof, or include: an application-specific integrated circuit (ASIC), a digital, analog, or mixed analog / digital discrete circuit, a digital, analog, or mixed analog / digital integrated circuit, a combinational logic circuit, a field-programmable gate array (FPGA), a processor circuit (common, dedicated, or group) that executes code, a memory circuit (common, dedicated, or group) that stores code executed by the processor circuit, other suitable hardware components that provide the described functionality, or a combination of some or all of the above components, such as in a system-on-a-chip.

[0042] The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the internet, a wide area network (WAN), or combinations thereof. The functionality of any given module of this disclosure may be distributed across multiple modules connected by interface circuits. For example, multiple modules may enable load balancing. In another example, a server module (also called a remote or cloud module) may perform some functions on behalf of a client module.

[0043] The term "code," as used above, may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term "common processor circuit" encompasses a single processor circuit that executes code from multiple modules section by section or as a whole. The term "group processor circuit" encompasses a processor circuit that, in combination with additional processor circuits, executes code from one or more modules section by section or as a whole. References to multiple processor circuits include multiple processor circuits on discrete chips, multiple processor circuits on a single chip, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination thereof.The term "shared memory circuit" refers to a single memory circuit that stores code from multiple modules, either sectionally or in its entirety. The term "group memory circuit" refers to a memory circuit that, in combination with additional memory, stores code from one or more modules, either sectionally or in its entirety.

[0044] The term "memory circuit" is a subset of the term "computer-readable medium". The term "computer-readable medium", as used herein, does not include transitory electrical or electromagnetic signals that propagate through a medium (such as on a carrier wave); the term "computer-readable medium" can therefore be considered tangible and non-transient.Non-restrictive examples of a non-transient, tangible, computer-readable medium include non-volatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

[0045] The devices and methods described in this application can be implemented in part or in whole by a specialized computer created by configuring a general-purpose computer to perform one or more specific functions contained in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through the routine work of an experienced technician or programmer.

[0046] Computer programs comprise processor-executable instructions stored on at least one non-transient, concrete, computer-readable medium. Computer programs may also include or rely on stored data. Computer programs may include a basic input / output system (BIOS) that interacts with the hardware of the specialized computer, device drivers that interact with specific devices of the specialized computer, one or more operating systems, user applications, background services, background applications, and so on.

[0047] Computer programs can include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation); (ii) assembly code; (iii) object code generated from source code by a compiler; (iv) source code for execution by an interpreter; (v) source code for compilation and execution by a just-in-time compiler; and so on. For example, source code can be written using the syntax of languages ​​such as C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th Revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, and Lua. MATLAB, SIMULINK and Python® are included. legend

[0048] In the drawing, Y stands for yes.

Claims

[1] Control system for a vehicle (100, 199) comprising a fuel cell system, comprising: at least one of a cooling fan (180) and an aerodynamic device (182) configured to selectively increase the airflow under a hood (198) of the vehicle (100, 199); a thermal management control (160) configured to control the cooling fan (180) and / or the aerodynamic device (182) in response to a detected temperature of a coolant of a cooling system of the vehicle (100, 199); a sensor (194) configured to detect a concentration of molecular hydrogen under the hood (198) of the vehicle (100, 199); and an airflow control (161) for molecular hydrogen configured to selectively request an additional airflow from the thermal management control (180) using the cooling fan (180) and / or the aerodynamic device (182) in response to the detected concentration of molecular hydrogen under the hood (198) of the vehicle (100, 199) being greater than a predetermined concentration, wherein the airflow control (161) for molecular hydrogen when the vehicle (100, 199) is switched off is configured to wake up on a periodic basis after a predetermined period to receive the detected concentration of molecular hydrogen under the hood (198) of the vehicle (100, 199). [2] Control system according to claim 1, wherein the predetermined concentration is in a range of 1% to 4%. [3] Control system according to claim 1, wherein the airflow control (161) for molecular hydrogen forms part of at least one of a fuel cell control (150) and / or the thermal management control (160). [4] Control system according to claim 1, wherein the sensor (194) is arranged in a downwardly pointing concave pocket (196) under the hood (198) of the vehicle (100, 199). [5] Control system according to claim 1, wherein the predetermined period is in a range of 6 hours to 18 hours. [6] Control system according to claim 1, wherein the airflow control (161) for molecular hydrogen is configured to receive the detected concentration of molecular hydrogen under the hood (198) of the vehicle (100, 199) while the vehicle (100, 199) is switched on and the fuel cell system is active. [7] Control system according to claim 1, wherein the airflow control (161) for molecular hydrogen is configured to cause the thermal management control (160) to open at least one of the aerodynamic device (182) and stop the operation of the cooling fan (180) when the detected concentration of molecular hydrogen under the hood (198) of the vehicle (100, 199) is greater than the predetermined concentration. [8] Control system according to claim 1, wherein the airflow control (161) for molecular hydrogen is configured to stop the request for an additional airflow from the thermal management control (160) when the detected concentration of molecular hydrogen under the hood (198) of the vehicle (100, 199) is less than the predetermined concentration.

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