Control system for replacement of pooled hydrogen molecules in fuel cell vehicle

Abstract

A control system for a vehicle including a fuel cell system includes at least one of a cooling fan and an aerodynamic device configured to selectively increase airflow below a hood of the vehicle. The thermal management controller is configured to control the at least one of the cooling fan and the aerodynamic device in response to a sensed temperature of a coolant of a coolant system of the vehicle. A sensor is configured to sense a concentration of hydrogen molecules below a hood of the vehicle. The hydrogen molecule airflow controller is configured to, using the at least one of the cooling fan and the aerodynamic device, selectively request additional airflow from the thermal management controller in response to a sensed concentration of hydrogen molecules below a hood of the vehicle being greater than a predetermined concentration.

Description

Background Technology

[0001] The information provided in this section is for the purpose of presenting the general context of this disclosure. The work described herein by the currently named inventors, and aspects that might not have otherwise qualified as prior art at the time of filing, are neither explicitly nor implicitly acknowledged as prior art to this disclosure.

[0002] This disclosure relates to fuel cell control systems, and more particularly to control systems for displacing pooled hydrogen molecules in fuel cell vehicles.

[0003] Fuel cell systems include: an electrochemical cell that converts the chemical energy of hydrogen molecules (H2) and oxygen molecules (O2) into electricity through a pair of redox reactions. Some fuel cell systems include: a proton exchange membrane (PEM) arranged between the cathode and anode electrodes. Fuel cell systems also include a gas storage system for hydrogen molecules. Summary of the Invention

[0004] A control system for a vehicle including a fuel cell system includes at least one of a cooling fan and an aerodynamic device configured to selectively increase airflow under the hood of the vehicle. A thermal management controller is configured to control at least one of the cooling fan and the aerodynamic device in response to a sensed temperature of the coolant in the vehicle's coolant system. A sensor is configured to sense the concentration of hydrogen molecules under the hood of the vehicle. A hydrogen molecule airflow controller is configured to selectively request additional airflow from the thermal management controller using at least one of the cooling fan and the aerodynamic device in response to a sensed concentration of hydrogen molecules under the hood of the vehicle exceeding a predetermined concentration.

[0005] Among other features, the predetermined concentration is in the range of 1% to 4%. The hydrogen molecule flow controller forms part of at least one of the fuel cell controller and the thermal management controller. The sensor is disposed in a downward-facing concave pocket formed under the hood of the vehicle. The hydrogen molecule flow controller is configured to: wake up after a predetermined period of time after the vehicle is turned off; and receive from the sensor the sensed concentration of hydrogen molecules under the hood of the vehicle. The predetermined period of time is in the range of 6 hours to 18 hours.

[0006] Among other features, the hydrogen molecule flow controller is configured to receive a sensed concentration of hydrogen molecules under the hood of the vehicle when the vehicle is powered on and the fuel cell system is active. The hydrogen molecule flow controller is also configured to cause the thermal management controller to perform at least one of the following operations when the sensed concentration of hydrogen molecules under the hood of the vehicle is greater than a predetermined concentration: activating the aerodynamic equipment and adjusting the operation of the cooling fan.

[0007] Among other features, the hydrogen molecule airflow controller is configured to stop requesting additional airflow from the thermal management controller when the sensed concentration of hydrogen molecules under the hood of the vehicle is less than the predetermined concentration.

[0008] Among other features, when the vehicle is off, the hydrogen molecule flow controller is configured to wake up periodically after a predetermined period of time to receive the sensed concentration of hydrogen molecules under the hood of the vehicle.

[0009] Among other features, the hydrogen molecule airflow controller is configured to activate the aerodynamic equipment and adjust the operation of the cooling fan when the sensed concentration of hydrogen molecules under the hood of the vehicle exceeds a predetermined concentration. The predetermined period is in the range of 6 to 18 hours.

[0010] A method for sensing hydrogen molecules under the hood of a vehicle including a fuel cell system includes: controlling at least one of a cooling fan and an aerodynamic device in response to a sensed temperature of a coolant system of the vehicle; sensing the concentration of hydrogen molecules under the hood of the vehicle; and selectively requesting additional airflow under the hood of the vehicle using at least one of the cooling fan and the aerodynamic device in response to a sensed concentration of hydrogen molecules under the hood of the vehicle being greater than a predetermined concentration.

[0011] Among other characteristics, the predetermined concentration is greater than 1%. The method includes sensing the concentration of hydrogen molecules in a downward-facing concave pocket beneath the hood of the vehicle. The method also includes sensing the concentration of hydrogen molecules for a predetermined period of time after the vehicle is turned off. The predetermined period of time is in the range of 6 to 18 hours.

[0012] Among other features, the method includes: sensing the concentration of hydrogen molecules under the hood of the vehicle when the vehicle is powered on and the fuel cell system is active. The method includes: activating the aerodynamic equipment and operating the cooling fan when the sensed concentration of hydrogen molecules under the hood of the vehicle is greater than a predetermined concentration. The method includes: stopping the request for additional airflow under the hood of the vehicle in response to the sensed concentration of hydrogen molecules under the hood of the vehicle being less than the predetermined concentration.

[0013] Further applicability of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0014] This disclosure will be more fully understood from the detailed description and accompanying drawings, in which: Figure 1 This is a functional block diagram of an example vehicle according to the present disclosure, the vehicle including 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; Figure 2 The illustration shows the sensing of hydrogen molecule concentration at one or more locations beneath the hood of a vehicle according to this disclosure; and Figure 3 This is a flowchart illustrating an example of a method according to the present disclosure for sensing hydrogen molecule concentration and selectively requesting additional airflow by controlling one or more cooling fans and / or one or more aerodynamic louvers in response to the hydrogen molecule concentration.

[0015] In the accompanying drawings, reference numerals may be reused to identify similar and / or identical elements. Detailed Implementation

[0016] Although this disclosure describes an airflow control system for a vehicle comprising one or more fuel cell stacks, the airflow control system can be used in stationary applications and / or other applications.

[0017] Some fuel cells use hydrogen molecules (hydrogen molecule flow controllers) as their energy source. Hydrogen molecules are known for their ability to leak and / or permeate from gas storage systems, connecting pipes, and / or one or more fuel cell stacks. Hydrogen molecules are lighter than air and can rise and become trapped under the hood of a vehicle. For example, hydrogen molecules can become trapped in an upside-down concave pocket under the hood.

[0018] Hydrogen molecules are flammable when the concentration is greater than 4% and an ignition source is present. Some jurisdictions require that the concentration of hydrogen molecules (hydrogen molecule flow controller) be maintained below a first concentration (e.g., 4%). When the hydrogen concentration rises above the first concentration, these jurisdictions require remedial actions, such as a complete shutdown of the fuel cell system. A complete shutdown of the fuel cell system may leave the occupants of the vehicle stranded.

[0019] In some examples, when the vehicle is parked or being driven, the hydrogen molecule flow controller according to this disclosure monitors the concentration of hydrogen molecules sensed by one or more hydrogen sensors at one or more locations under the hood. The hydrogen molecule flow controller uses a cooling fan and / or aerodynamic devices to selectively request additional airflow from a thermal management controller. The hydrogen molecule flow controller increases the airflow under the hood in response to a second concentration that is less than a first concentration (requiring a complete shutdown).

[0020] The hydrogen molecule flow controller may be part of, or work in conjunction with, a fuel cell controller and / or a thermal controller. Typically, a thermal management controller operates fans and / or aerodynamic devices in response to thermal loads, such as sensed coolant temperatures in a coolant system cooling one or more fuel cell stacks. According to this disclosure, the hydrogen molecule flow controller requests additional airflow from beneath the hood of the thermal management controller to reduce the concentration of hydrogen molecules before it reaches a first concentration requiring a complete shutdown. The additional airflow expels trapped hydrogen molecules from one or more locations into the atmosphere.

[0021] When the concentration of hydrogen molecules is above a second concentration (but below a first concentration requiring complete shutdown), the hydrogen molecule flow controller causes the thermal management controller to activate one or more aerodynamic devices and / or one or more cooling fans to increase airflow under the vehicle's hood, thereby diluting the concentration of hydrogen molecules in those locations. In effect, the hydrogen molecule flow controller selectively causes the thermal management controller to adjust or override thermal management-based controls in response to additional airflow requests.

[0022] Some of the leakage or seepage of hydrogen molecules can be transient in nature. In other words, the leakage or seepage exists for a period of time and then resolves itself. Instead of requiring a complete shutdown of the fuel cell, the hydrogen molecule flow controller according to this disclosure periodically monitors the concentration of hydrogen molecules and selectively requests additional airflow under the hood to attempt to reduce the concentration before a complete shutdown of the fuel cell system is required.

[0023] In some cases, the airflow control system can transform an unrecoverable fault or remedial action into a recoverable one. The airflow control system can also improve the efficiency of a fuel cell system by reducing the need for continuous operation of high-power cooling fans for non-thermal reasons.

[0024] Now for reference Figure 1 The vehicle 100 includes 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 sense 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 adjust the operation of the one or more fuel cell stacks 120. A hydrogen source 140 supplies hydrogen molecules to the one or more fuel cell stacks 120. In some examples, a fuel supply controller 144 controls / meters the supply of hydrogen molecules to the one or more fuel cell stacks 120.

[0025] Fuel cell controller 150 controls the one or more fuel cell stacks 120 and communicates with fuel supply controller 144, actuator 124, and thermal management controller 160. Thermal management controller 160 controls airflow based on heat load (coolant temperature) and / or additional airflow requests. In some examples, fuel cell controller 150 (or optionally, thermal management controller 160) also includes a hydrogen molecule flow controller 161, which selectively requests additional airflow under the hood based on sensed hydrogen molecule concentration (and independent of heat load). As will be appreciated, fuel cell controller 150, thermal management controller 160, and / or hydrogen molecule flow controller 161 may be implemented by the same controller, or two or more separate controllers may be used.

[0026] In some examples, the fuel cell controller 150 monitors sensor 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.

[0027] 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 (such as under the hood of the vehicle) in response to sensed temperature, vehicle load, and / or additional airflow requests. For example, during normal operation, thermal management controller 160 uses the one or more aerodynamic devices 182 to selectively allow or restrict airflow into the volume under the hood in response to one or more coolant or other temperatures sensed by sensor 128 and / or sensor 163. One or more cooling fans 180 may be used to increase the airflow into the volume under the hood, independent of the one or more aerodynamic devices 182 (which may be turned off, partially turned on, or fully turned on).

[0028] The one or more fuel cell stacks 120 output power to one or more loads 174, such as one or more electric motors, battery modules, and / or vehicle accessory loads. The vehicle controller 190 receives user input, such as vehicle "on" and vehicle "off" signals, torque requests, braking requests, etc. For example, the fuel cell controller 150 adjusts the output of the one or more fuel cell stacks 120 based on torque requests.

[0029] One or more hydrogen sensors 194 are disposed in one or more locations. For example, the one or more hydrogen sensors 194 may be disposed in a pocket under the hood of a vehicle in which hydrogen molecules are likely to rise and pool. The one or more hydrogen sensors 194 sense the concentration of hydrogen molecules in the one or more locations. In some examples, each of the sensed locations includes one hydrogen sensor or a pair of hydrogen sensors that can be used to provide sensing redundancy.

[0030] Now for reference Figure 2 A hydrogen sensor 194 is positioned beneath the hood 198 of the vehicle 199. Hydrogen molecules may leak or permeate from the one or more fuel cell stacks 120 and flow upwards into pocket 196 or other locations beneath the hood. The hydrogen sensor 194 senses the concentration of hydrogen molecules in pocket 196. A hydrogen molecule flow controller 161 requests additional airflow from a thermal management controller. In response to the request for additional airflow, the thermal management controller selectively adjusts aerodynamic devices 182 (e.g., aerodynamic louvers) and / or cooling fans 180 to dilute the concentration of hydrogen molecules.

[0031] Now for reference Figure 3 This illustrates a method for controlling airflow at one or more vehicle locations (e.g., under the hood) in a fuel cell vehicle. At 210, a timer is reset. At 214, the method determines whether the timer has exceeded a predetermined time period (t).TH In some examples, the scheduled time period ranges from 6 to 18 hours, although shorter or longer periods may be used. In some examples, the scheduled time period ranges from 10 to 14 hours (e.g., 12 hours), although shorter or longer periods may be used. If 214 is false, the method determines whether the vehicle is "on" and whether the fuel cell system is active.

[0032] If not, the method returns to 214. If 214 or 218 is true, the method continues at 220 and monitors one or more hydrogen sensors sensing the hydrogen molecule concentration at one or more vehicle locations. At 224, the method determines whether the hydrogen molecule concentration is greater than a predetermined threshold C corresponding to a second concentration. TH In some examples, the predetermined threshold is in the range of 1% to 4%. In other examples, the predetermined threshold is in the range of 1% to 2%.

[0033] If 224 is true, the method continues at 228 and determines whether the fan activation condition is met. In some examples, the fan activation condition includes: the ambient temperature being higher than a predetermined temperature. For example, operating the cooling fan might lower the temperature under the hood, which could lead to malfunctions in the cooling system due to excessive airflow. In some examples, the fan activation condition might require the hood to be closed.

[0034] If 228 is true, the method continues at 232 and adjusts or activates (one or more) aerodynamic devices. At 236, the method operates the cooling fans. The method continues at 220. If 224 or 228 is false, the method stops overriding the thermal drive control of the one or more cooling fans at 240 and stops overriding the thermal drive control of the one or more aerodynamic devices. At 248, the method determines whether the vehicle is "on" and active. If true, the method returns to 220. If false, the method continues at 210. Increased airflow to the location of the one or more vehicles dilutes the hydrogen molecule concentration at those locations.

[0035] In some examples, when the sensed concentration is greater than a second concentration (e.g., 1%) but less than a first concentration (e.g., 4%), the hydrogen molecule flow controller sets a first type of fault. In some examples, when the sensed concentration is greater than the first concentration (e.g., 4%), the hydrogen molecule flow controller sets a second type of fault, and the hydrogen molecule flow controller performs other remedial actions, such as shutting down the fuel cell stack or preventative operations.

[0036] The above description is illustrative in nature and is in no way intended to limit this disclosure, its application, or use. The broad teachings of this disclosure can be implemented in many forms. Therefore, although this disclosure includes specific examples, its true scope should not be so limited, as other modifications will become apparent upon study of the drawings, specification, and appended claims. It should be understood that one or more steps within the method can be performed in a different order (or simultaneously) without altering the principles of this disclosure. Furthermore, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of this disclosure may be implemented in any other embodiment and / or combined with features of any other embodiment, even if such combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the arrangement of one or more embodiments with respect to each other remains within the scope of this disclosure.

[0037] Various terms are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including “connection,” “joint,” “coupled,” “adjacent,” “immediately next to,” “on top of,” “above,” “below,” and “set.” Unless explicitly described as “direct,” when describing a relationship between first and second elements in the above disclosure, the relationship can be a direct relationship in which no other intermediary element exists between the first and second elements, or an indirect relationship in which one or more intermediary elements exist (spatially or functionally) between the first and second elements. As used herein, the phrase “at least one of A, B, and C” should be understood to mean logically (A or B or C) using the non-exclusive logic “OR,” and should not be understood to mean “at least one of A, at least one of B, and at least one of C.”

[0038] In the accompanying drawings, as indicated by the arrows, the direction of the arrows generally illustrates the flow of information of interest to the illustration (such as data or instructions). For example, when components A and B exchange various types of information, but the information transmitted from component A to component B is relevant to the illustration, the arrow may point from component A to component B. This unidirectional arrow does not imply that no other information is transmitted from component B to component A. Furthermore, for information sent from component A to component B, component B may send a request for that information or a positive response to receive that information to component A.

[0039] In this application, which includes the definitions below, the term "circuit" may be used instead of the terms "module" or "controller". The term "module" may refer to, be part of, or include the following: application-specific integrated circuit (ASIC); digital, analog, or mixed-signal analog / digital discrete circuit; digital, analog, or mixed-signal analog / digital integrated circuit; combinational logic circuit; field-programmable gate array (FPGA); processor circuitry (shared, dedicated, or group) that executes code; memory circuitry (shared, dedicated, or group) that stores code executed by the processor circuitry; other suitable hardware components that provide the described functionality; or combinations of some or all of the above, such as in a system-on-a-chip.

[0040] A 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 a combination thereof. The functionality of any given module of this disclosure may be distributed among multiple modules connected via the interface circuits. For example, multiple modules may allow for load balancing. In a further example, a server (also referred to as a remote or cloud) module may perform a function on behalf of a client module.

[0041] As used above, the term "code" can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuitry" covers a single processor circuitry that executes some or all of the code from multiple modules. The term "group processor circuitry" covers a processor circuitry that, in conjunction with additional processor circuitry, executes some or all of the code from one or more modules. References to multiple processor circuitry cover multiple processor circuitry on discrete dies, multiple processor circuitry on a single die, multiple cores of a single processor circuitry, multiple threads of a single processor circuitry, or a combination of the above. The term "shared memory circuitry" covers a single memory circuitry that stores some or all of the code from multiple modules. The term "group memory circuitry" covers a memory circuitry that, in conjunction with additional memory, stores some or all of the code from one or more modules.

[0042] The term "memory circuit" is a subset of the term "computer-readable medium." As used herein, the term "computer-readable medium" does not cover transient electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term "computer-readable medium" can therefore be considered tangible and non-transient. Non-limiting examples of non-transient tangible computer-readable media are non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only memory circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0043] The apparatus and methods described in this application can be implemented, in part or in whole, by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. The function blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs by the routine work of a skilled technician or programmer.

[0044] A computer program includes processor-executable instructions stored on at least one non-transient tangible computer-readable medium. A computer program may also include or depend on the stored data. A computer program may encompass a basic input / output system (BIOS) for interacting with the hardware of a special-purpose computer, device drivers for interacting with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0045] Computer programs may 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 (JIT) compiler; and so on. As an example only, source code can be written using syntax from languages ​​including: C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Fortran, Perl, Pascal, Curl, OCaml, HTML5 (Hypertext Markup Language, 5th Revision), Ada, ASP (Dynamic Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Visual Lua, MATLAB, SIMULINK and

Claims

1. A control system for a vehicle including a fuel cell system, comprising: At least one of a cooling fan and an aerodynamic device configured to selectively increase airflow under the hood of the vehicle; A thermal management controller is configured to control at least one of the cooling fan and the aerodynamic device in response to a sensed temperature of the coolant in the vehicle's coolant system; The sensor is configured to: sense the concentration of hydrogen molecules beneath the hood of the vehicle; and A hydrogen molecule airflow controller is configured to selectively request additional airflow from the thermal management controller in response to a sensed concentration of hydrogen molecules under the hood of the vehicle being greater than a predetermined concentration, using at least one of the cooling fan and the aerodynamic device.

2. The control system of claim 1, wherein the predetermined concentration is in the range of 1% to 4%.

3. The control system of claim 1, wherein the hydrogen molecule flow controller forms part of at least one of the fuel cell controller and the thermal management controller.

4. The control system of claim 1, wherein the sensor is disposed in a downward-facing concave pocket formed under the hood of the vehicle.

5. The control system of claim 1, wherein the hydrogen molecule flow controller is configured to: wake up after a predetermined period of time following the shutdown of the vehicle; and receive from the sensor the sensed concentration of hydrogen molecules under the hood of the vehicle.

6. The control system of claim 5, wherein the predetermined time period is in the range of 6 hours to 18 hours.

7. The control system of claim 1, wherein the hydrogen molecule flow controller is configured to receive a sensed concentration of hydrogen molecules under the hood of the vehicle when the vehicle is started and the fuel cell system is active.

8. The control system of claim 1, wherein the hydrogen molecule airflow controller is configured to: when the sensed concentration of hydrogen molecules under the hood of the vehicle is greater than the predetermined concentration, cause the thermal management controller to perform at least one of the following: turn on the aerodynamic equipment and adjust the operation of the cooling fan.

9. The control system of claim 1, wherein the hydrogen molecule airflow controller is configured to: stop requesting additional airflow from the thermal management controller when the sensed concentration of hydrogen molecules under the hood of the vehicle is less than the predetermined concentration.

10. The control system of claim 1, wherein when the vehicle is turned off, the hydrogen molecule flow controller is configured to wake up periodically after a predetermined period of time to receive the sensed concentration of hydrogen molecules under the hood of the vehicle.

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