Dynamic Airflow Control in a Fuel Cell System

Abstract

Disclosed herein are aspects of a method for controlling airflow to a fuel cell stack and a cooling fan within a housing, which fluidly connects a predetermined minimum amount of airflow through the housing to the fan, and a series of louvers, adjustable openings, and bypass valves dynamically adjust the airflow to at least one of the fuel cell stack and the fan to provide the above-mentioned required minimum amount of fluid to the fan during various controller-based operations.

Description

Technical Field

[0001] The present disclosure generally relates to an apparatus and method for controlling and uniformly distributing the amount of air passing through an air-cooled fuel cell stack.

Background Art

[0002] Conventional electrochemical fuel cells convert fuel and an oxidant into electrical energy and reaction products. A common type of electrochemical fuel cell has a membrane electrode assembly (MEA), which includes a polymer ion (proton) exchange membrane between the flow channels or gas diffusion structures of the anode and cathode. A fuel such as hydrogen and an oxidant such as oxygen in air pass through respective sides of the MEA, and electrical energy and water are generated as reaction products. A stack can be formed having a number of such fuel cells arranged with separate anode and cathode fluid flow channels. Such a stack is typically in the form of a block having a number of individual fuel cell plates held together by end plates at both ends of the stack. Such fuel cells can be used to power various technologies such as material handling equipment (MHE), stationary power applications, and unmanned aerial vehicles (UAVs).

[0003] For efficient operation, it is important for the polymer ion exchange membrane to maintain a hydrated state. It is also important to control the temperature of the stack. Thus, a coolant may be supplied to the stack for cooling and / or hydration. It may be necessary to use a purge gas to purge the coolant, contaminants, or reaction by-products from the flow channels or gas diffusion structures of the fuel cell at a particular time or periodically. The purge gas may have fuel (e.g., hydrogen), and this purge gas may be flowed through the anode flow channel to purge the fuel cell.

[0004] In an air-cooled fuel cell system, one technique for adjusting a fuel cell stack has "stack pulsing" or "fan pulsing", and in this method, the flow of air to the cathode of the fuel cell stack is periodically blocked or greatly restricted to deplete the oxygen at the cathode, and since the stack is discharged with a large current through a load resistor, energy dissipation occurs during this air flow restriction period.

[0005] Air-cooled fuel cell stacks can be very sensitive to the flow of air at the cathode. Even a small amount of air movement through the cathode air flow path is sufficient for the stack to generate a large amount of power. The more unnecessary air there is, the more difficult it is to generate fan pulses. Therefore, it may be desirable to achieve a highly restricted air flow during fan pulses. For example, if blocking the air flow is inefficient, the fan pulse may fail.

[0006] Air-cooled fuel cell systems have traditionally restricted the flow of air at the cathode to operate under cooler conditions by reducing the speed of the fan or partially closing the flow path. These solutions have an adverse effect on the distribution of the cathode flow through the stack, resulting in temperature fluctuations and, as a result, a decrease in stack performance. When partially closed, turbulence occurs and the path changes at the partially open position. This makes it impossible to finely adjust a small amount of cathode flow rate. With the minimum required air flow rate by the fan, the cooling efficiency decreases and the performance of the stack may decrease. SUMMARY OF THE INVENTION

[0007] This disclosure in terms of air flow control is directed to systems, structures, and methods for directing the flow in a desired pattern to control the path and supply of air flow in a fuel cell system.

[0008] The above needs are met by various aspects of the coolant distribution system, fuel cell power system, and method of use disclosed through this application. According to a given aspect of the present disclosure, a method of providing an air flow to a fuel cell stack and a cooling fan within a housing is taught, the method having the steps of arranging the fuel cell stack and the fan, both within the housing, to be in fluid communication, and fluidly connecting a pre-determined minimum amount of air flow through the housing to the fan by one or more of the following modes, these modes being A. A mode of restricting the air flow to the air intake surface of the fuel cell stack by diverting a portion of the air flow from the fuel cell stack through a bypass assembly downstream of the fuel cell stack; B. A mode of reducing the air flow from the cathode exhaust of the fuel cell stack by diverting a portion of the air flow from the intake surface through the bypass assembly and closing one or more louvers disposed between the cathode exhaust and the fan; C. A mode of regulating the air flow from the cathode exhaust surface of the fuel cell stack to the fan by closing the louvers and closing at least a portion of the opening through the louvers; D. A mode of opening the bypass valve and the louvers to provide an air flow to both the intake surface and the fan; E. A mode of opening the bypass valve and closing the louvers, and at least one of the openings, and at least a portion of the opening through the louvers; and F. A mode of the bypass valve and closing the louvers, either open or closed.

[0009] In some cases, each louver is configured to close via a magnetic catch within the housing. In some cases, each louver consists of two plates, each plate includes an opening, the plates are configured to be nested together, and when the louver is closed, the opening is adjusted from a closed state to a fully open state via the controller by sliding one plate relative to the other plate through the action of a cam. In some cases, at least one of the two plates is provided with a surface coating and faces the other plate, and is configured to have higher lubricity than the uncoated plate. In some cases, the opening is an elongated horizontal gap. In some cases, at least a part of the opening is an isosceles trapezoid. In some cases, this method further includes the step of forming a convex portion that adds turbulence to the air flow to the intake surface on the inner side of the housing closest to the intake surface. In some cases, this method further includes the step of forming an air flow disturbing fin that makes the linear flow of the intake air to the fuel cell stack more turbulent adjacent to the air intake surface of the fuel cell stack.

[0010] In some cases, the fan is arranged upstream of the fuel cell stack. In some cases, the fan is arranged downstream of the fuel cell stack. In some cases, the bypass valve is arranged downstream of the fuel cell stack. In some cases, the bypass valve is arranged upstream of the fuel cell stack. In some cases, the fan is arranged upstream of the fuel cell stack and the fluid control assembly is arranged downstream of the fuel cell stack.

[0011] According to some aspects of the present disclosure, a system and method for regulating an airflow to a fuel cell stack within a housing includes at least one fluid channel, a fuel cell stack, a fan, and a fluid control assembly, and a partially open housing configured to provide an airflow, wherein the fluid control assembly includes at least one bypass valve and at least one louver having an adjustable opening, the housing, and a controller, the fluid channel is in fluid communication with the fluid control assembly, the controller controls at least one of opening and closing of the bypass valve, the louver, and the opening, and control of the amount of air flowing through the fan and the fuel cell stack is adjusted based on an operating mode.

[0012] In some cases, the controller controls opening and closing of the bypass exhaust port by a bypass motor. In some cases, a louver control assembly controls movement of the louver and opening and closing of the opening. In some cases, a louver control assembly controls movement of the louver and opening and closing of the opening, and a bypass motor controls opening and closing of the bypass exhaust port. In some cases, the louver control assembly further includes a drive shaft that passes through each louver and is connected to a cam attached to the louver. In some cases, a lower drive section is fixed to the drive shaft, an upper drive section is movably attached to the drive shaft between the lower drive section and a drive shaft guide, and a movable spring is movably attached to the drive shaft between the upper drive section and the drive shaft guide, whereby the nested plate moves upward or downward relative to a second nested plate by the cam and the spring.

[0013] In some cases, the first surface of at least one nested plate is polished to reduce roughness. In some cases, the first surface of at least one nested plate is coated to reduce roughness or enhance lubricity. In some cases, the louver control assembly is further configured to adjust at least one of the oxygen flow rate to the fuel cell stack and the dilution purge flow rate from the fuel cell stack.

[0014] According to some aspects of the present disclosure, a method and system for a fluid control assembly includes a fluid control housing, the flow control housing further including a fan duct, a magnetic catch, a louver control assembly, a louver having a variable opening therein, at least one bypass duct, at least one bypass valve, and a bypass motor, the bypass duct being in fluid connection with the flow control housing.

[0015] In some cases, a plurality of louvers are formed from two slidable nested plates, each of the slidable nested plates having an opening that aligns in a first position, the opening being variable in opening during displacement and closing the opening when fully displaced. The louver control assembly controls the movement of the louvers and the opening and closing of the openings. In some cases, the louver control assembly controls the movement of the louvers and the opening and closing of the openings, and the bypass motor controls the opening and closing of a bypass vent configured to open and close the flow of fluid through at least one bypass duct. In some cases, the louver control assembly further includes a drive shaft that passes through each louver and is connected to a cam attached to the louver.

[0016] In some aspects, the system may include one or more sensors therein. One or more sensors may be configured to detect parameters of the system. In some aspects, the sensors may be configured to detect the temperature of the fuel cell and / or fuel cell stack, the temperature of the coolant entering the system, the temperature of the coolant after the coolant fluid has flowed out of the system, the pressure of the coolant, the flow rate of the coolant, the composition of the coolant, the velocity of the coolant discharged from the exhaust port, or another parameter of the coolant or fuel cell stack.

[0017] In some aspects, the means for directing the flow of the coolant may operate according to various parameters including, but not limited to, (to the extent present in the specific embodiments) the size or shape of the fuel cell stack, the size or shape of the fuel cell stack, the distance between the fuel cell stack and the means for directing the flow of the coolant, the number of fuel cells within the fuel cell stack, the number of fuel cell stacks within the system, the relative arrangement of each fuel cell stack, the material of the means for directing the flow of the coolant, the structure of the means for directing the flow of the coolant, the velocity of the flow of the coolant through the system, the composition of the coolant, the temperature of the fuel cell stack, the desired temperature of the fuel cell stack, the desired use of the system, any combination of the above parameters, and / or any other suitable parameters that may affect the need for coolant distribution.

[0018] According to another aspect of the present disclosure, a fuel cell system includes a fuel cell stack having one or more fuel cells therein and a system for distributing coolant.

[0019] The system for distributing coolant may be any one or more of the systems described above, or a combination of the embodiments described herein. This system may or may not include the optional aspects described herein, and may include one or more optional aspects.

[0020] In some aspects, the fuel cell system may be configured to supply power to machine handling equipment (MHE) components. Optionally, the MHE component may be a forklift.

[0021] In some aspects, the fuel cell system may be configured to supply power to an unmanned aerial vehicle (UAV). Optionally, the UAV may be a drone. The drone may be a fixed-wing drone. The drone may be a multi-rotor drone.

[0022] According to other aspects of the present disclosure, a control system for guiding coolant through a system that distributes the coolant is disclosed. The control system includes a processor, a power source, and a sensor. The control system is configured to send an operating signal to the coolant distribution system to operate the coolant distribution system. The system for distributing the flow of the coolant may be any one or more of the systems described above, or a combination of the embodiments described herein. This system may not include any of the aspects described herein at all, or may include one or more arbitrary aspects.

[0023] The control system may include a processor, a power source, and a sensor. The control system is configured to send an operating signal to the refrigerant distribution system to operate the refrigerant distribution system.

[0024] In some aspects, the control system may be configured to communicate with a plurality of sensors. The sensors may be disposed within or on the system that distributes the coolant.

[0025] Optionally, the control system may be configured to operate based on a program. The program may provide operating instructions to the control system, and the control system may use those instructions to operate a system for distributing coolant and / or a fuel cell system. Optionally, the control system may be operated by a user. The user may send one or more signals to the control system and / or the system for distributing coolant to operate the system. Optionally, the control system may be configured to operate autonomously in response to parameters sensed by one or more sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] This application will be better understood when read in conjunction with the accompanying drawings. For the purpose of explaining the subject matter, the drawings show exemplary aspects of the subject matter. However, the subject matter disclosed herein is not limited to the specific methods, apparatuses, and systems disclosed. The drawings are as follows.

Figure 1

Figure 2A

Figure 2B

Figure 2C

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Figure 4A

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Figure 4C

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 7A

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Figure 8A

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Figure 9A

Figure 9B

Figure 9C

Figure 10

Figure 11

[0027] Next, aspects of the present disclosure will be described in detail with reference to the drawings. Here, unless otherwise specified, like reference numerals refer to like elements throughout. Detailed description

[0028] Precisely controlling the flow of a small amount of coolant through a fuel cell stack with a small installation area in an air-cooled fuel cell system has not heretofore achieved a practical solution. Disclosed herein are aspects of methods, apparatuses, and systems that utilize air routing, and coarse and fine control of air flow to provide consistent fuel cell stack operation under various conditions including, but not limited to, startup, high temperature operation, and low or sub-zero temperature operation.

[0029] In its most basic configuration, the systems and methods disclosed herein control the flow of fluid through a fuel cell stack via a series of louvers, apertures, and bypass valves. The innovative system enables coarse and fine adjustment of the fluid flow.

[0030] A fan that draws air through the fuel cell stack cools the stack, dilutes the released hydrogen, enables efficient operation of the stack through a number of power requirements, and supports the periodic purge of the system to maintain membrane efficiency and the integrity of the fuel cell stack.

[0031] One or more louver doors are each configured to rotate from a fully closed position through a range of positions to a fully open position, and each louver door comprises a plurality of parts having at least two nested slide plates. Each door in the closed position is configured for one plate to slide vertically up or down relative to the others and perpendicular to the cathode exhaust flow, thereby opening, partially closing, or fully closing a series of aligned apertures in the plate and effectively restricting the flow of air through the closed plate. The aperture is shown as horizontally elongated, but this figure is not limiting and other aperture shapes are within the scope of the present disclosure. The elongated shape is sometimes preferred as it supports a large flow rate with less movement of the sliding aperture plate, supporting at least smaller systems and / or higher flow rates.

[0032] Figures 1 - 2C show the main aspects of the fuel cell air distribution device and system 10. The main housing 12 is configured to include an inlet 14 for air flow into the housing and an outlet 16 for fluid outflow from the housing. Inside the housing is a sub - assembly shown here as having two side faces 20A 、20B and a positioning insert 22. 20 (shown in Figure 4C) is shown. The sub - assembly 20It can be formed from fewer or more parts, and those skilled in the art will recognize that such design choices remain within the scope of the disclosure. The sub-assembly surrounds the fuel cell stack 100 at one end and the fan 200 at the opposite end. The fluid control assembly 300 is downstream of the fuel cell stack but upstream of the fan. This fluid control assembly 300 connects the air path at the inlet 14 through the fluid channel 24 to the intake surface 25 for the stack, thereby enabling the air flow to move from the inlet to the fuel cell stack. The sub-assembly includes the fuel cell stack 100 at one end and the fan 200. The fluid flow assembly 300 is downstream of the fuel cell stack but upstream of the fan. The fluid control assembly is a basic part that fluidly connects the cathode exhaust to the fan and controls the air flow to and the exhaust from the fuel cell stack. The flow control housing 302 provides a fan duct 304 that supports a magnetic catch 305 for holding the louver door in the closed position and at least one bypass duct 306. Each bypass duct houses a valve 308, which is attached to a bypass motor 312 and can be opened and closed via a control arm 310 controlled by a controller. The opening louver door 320 is movably attached to the flow control housing. Each door is composed of two plates. The first door consists of nested plates 321A and 321B. Each plate has a first surface 401A and a second surface 401B. Elongated openings 400A and 400B that can align winches are formed in each plate. The second door consists of nested plates 323A and 323B, and elongated openings 402A and 402B that can be aligned are formed in each plate. The nested plates need to fit tightly to minimize fluid leakage, and at least one of the nested doors must have sufficient lubricity to slide vertically up and down perpendicular to the other door. The louver control assembly 330 is attached to each set of nested doors via a drive shaft 333 that fits into a guide formed through a pair of nested doors.The drive motor 334 is part of the louver control assembly. The drive shaft 333 is driven by the gear connection shown in the louver control assembly. The through guide 336 is not part of the rotation or movement of the door, and the drive shaft is connected to the louver door via a cam that acts to rotate the door to open and close it. The magnet 305 stops the door in the fully closed position (Figure 6B). The magnet is a means of stopping the movement of the louver, and other means such as ball plungers, and other latches and catches are also within the scope of the present disclosure. It is preferred that upon rotation of the drive shaft after closure, the opening is adjusted from the open state to a partially open state and then to the closed state. Figures 2C, 7A, and 7B show the nested plates (321A / 321B and 323A / 323B) that form the louver doors 321 and 323. Each door is movably connected to the drive shaft 333 via a cam 500. The cam has a lower drive section 502A, 502B is fixed to the drive shaft, the upper drive section 502B is fixed to the nested plate, and is driven up and down relative to the flow control housing 302. Spring means 325 through which the drive shaft passes is disposed between the cam 500 and the louver guide 327. When the slide plate moves upward by the cam action, the spring is compressed, and when the slide plate moves downward by the cam action, the spring is released from compression and moves the slide plate downward to align the openings. Figure 7A shows that the elongated opening 400A through the first nested plate of the louver door 321 is misaligned with the elongated opening 400B of the second nested plate of the louver door 321, and in this configuration, the elongated opening blocks the flow of fluid through the louver door. When the drive shaft 333 rotates, the lower drive section 502A of the cam moves downward, and as shown in Figure 7B, the gap 504 between the upper drive section and the lower drive section is closed, and the elongated openings 400A and 400B are aligned to allow the flow of fluid, and the spring means biases the slide plate downward during rotation of the cam. Further, the louver door is controlled by a moving means (here shown as a stepping motor 334), and the moving means cooperates with a gear 335 to rotate the shaft.In some cases, the motor controller communicates with the moving means via signal. In other examples, motor control is incorporated within the system controller. When a motor control device exists, it communicates with the system controller via signal, thereby adjusting the positions of the louver door and the elongated opening. The system controller is configured to adjust the bypass valve, the louver door, and the opening in response to measured values within the system or the state of the system. Measurements by the sensor 425 include, but are not limited to, one or more of power requirements, temperature, pressure, humidity, hydrogen concentration in the exhaust, stop, fan pulsation, and purge. The sensor communicates with the system controller via signal and can be placed anywhere within the system. The display of the sensor 425 near the intake surface 101 of the fuel cell stack, near the fluid control assembly, and near the fan is not limited.

[0033] Figures 3 to 4B show cutaway top views taken from below approximately along the line A - A of Figure 1. Only the block structures showing the main components are provided, and these figures show the air flow in various states of the system. However, not all states are shown. Some states range from a completely closed state with an opening ratio of 0% across the spectrum to an open state of 100% including all partial openings within that spectrum. For the sake of brevity, only the fully open louver, the fully closed louver with a fully closed opening, and the fully closed louver with a fully open opening are shown, and the existence of states intermediate between a partially open and a closed opening should not be construed as a mere intermediate or non - disclosed invention. Figure 4C shows the exterior of the assembled sub - assembly 20 and the air - disturbing fins formed thereon.

[0034] Disclosed herein is a method of operating a fuel cell power system in which a minimum air flow rate for the operation of the fan 200 is maintained by controlling the air flow through the louvers, bypass valve, and openings. During operation, the fan, when the air flow requirement through the fuel cell stack is less than the minimum air flow requirement of the fan involving the system controller, moves a minimal amount of air within the system even at a low RPM through the air flow dynamic control disclosed herein. At least one of the bypass valve and the louvers directs the air flow while maintaining the necessary minimum air flow. When the air flow rate available to the fan is less than the minimum value, the load on the fan increases, the efficiency of the system decreases, and the parasitic losses increase. The steering of the air flow by the fluid flow assembly 300 is controlled by the controller.

[0035] The flow of fluid, including air, enters the system through the inlet 14 and enters the fluid channel 24 that is also fluidly connected to the fuel cell stack. The fluid flow assembly 300 also enables the louver to transition from a fully open position to a fully closed position in a short time. The speed of opening and closing of the door in conjunction with the bypass valve and duct cooperate to provide at least the necessary minimum amount of air to the fan and provide the required amount of air flow to the first face 101 of the fuel cell stack under various situations, which is dynamic and responsive to the system sensor 425. Induce the air flow from the fluid channel 24 while bypassing the fuel cell stack and the door. FIG. 5 is a table showing the adjustment of the operating state, operating mode, opening and closing of the louver door accompanying the opening and closing of the opening of the louver door, and the opening and closing of the bypass valve configured to operate by at least one controller.

[0036] During high-temperature operation (see the tables in FIGS. 4A and 5), the bypass valve 308 is closed, and the air flow through the fluid channel is not obstructed. Rather, the air flow flows through the fluid channel to the intake surface, and the louver doors 321 and 323 open to distribute the air flow from the fluid channel to one of the first surface 101 and the fan 200. The open louver doors have moving means (321A / 321B and 323A / 323B) for sliding the doors, and the stationary state is open.

[0037] During high-temperature mode operation (FIG. 4A), by closing the bypass valve 308, the maximum amount of fluid is sent through the fluid channel to the first surface 101, and at least 90% of the intake air is forcibly drawn through the stack via the intake surface. In this mode, it is preferred that 95% of the fluid is drawn through the stack, and most preferably, more than 99% of the air is drawn through the stack in this mode. In this first mode, the louvers are fully open, and the obstruction to the cathode exhaust fluid discharged from the system via the axial flow of the fan 200 is minimized. Ideally, the same amount of air flowing into the inlet 14 passes through the fuel cell stack. An additional advantage of this operation is that there is surely very low concentration of hydrogen in the cathode stream.

[0038] During operation of the system, it may also be beneficial to introduce turbulence into the fluid flow entering the fuel cell stack. The fuel cell stack 100 includes a first face 101 and a second face 102. The first face 101 is fluidly connected to the fluid channel 24 and configured to receive air through the intake face 25. To enhance the dispersion of the fluid flowing within the housing 12, a convex bump 400 (FIG. 3) may optionally be formed at one end of the housing opposite the first face 101 to provide the Coanda effect, which is a phenomenon where a jet flow adheres. It adheres to a nearby surface and remains attached even when the surface bends away from the initial jet direction, guiding the air towards the center of the first face. Optionally, air turbulence fingers 405 may be disposed around the intake face to disrupt the fluid flow and create a more uniform distribution across the first face 101. When these flow disruption features are disposed on the intake face, they convert the linear flow of the intake fluid into a turbulent flow immediately prior to being drawn in by the fuel cell stack. This helps to evenly distribute the fluid rather than having it drawn in only around the perimeter of the stack. The turbulence fingers and the Coanda effect may be used either in combination or individually.

[0039] During the low-temperature mode configuration (see Figure 4B), the louver doors 321 / 323 are closed and the bypass valve 308 is opened, allowing a greater amount of air to flow through the bypass valve to the fan and then to the fuel cell stack. With this configuration and method of operation, most of the fluid in the fluid channels is quickly discharged from the system without interacting with the fuel cell stack. In this second mode, the elongated openings 400A and 400B in the closed louvers are used to throttle the fluid exiting the stack as cathode exhaust, allowing only the necessary amount of intake fluid (such as air) to flow through the fuel cell stack. A controller that is in signal communication with means for moving the louver doors, which may be the louver control assembly 330, and the bypass motor 312 and bypass vent 308 are configured to adjust their respective openings and closings to support the operation of the fuel cell stack and the fan. The controller is further configured to vary the upward or downward movement of the sliding nested doors forming the louvers to vary the volume of fluid passing through the openings.

[0040] During the first medium-temperature mode configuration (see Figure 5), the louver doors 321 / 323 are closed and the bypass valve 308 is also closed, causing the same amount of air to flow to the fan and be directed to flow through the fuel cell stack. In this third mode of operation, the elongated openings 400A and 400B in the closed louvers are used to throttle the fluid exiting the stack as cathode exhaust, allowing only the necessary amount of intake fluid (such as air) to flow through the fuel cell stack. The controller is in signal communication with means for moving the louver doors and is configured to vary the upward or downward movement of the sliding nested doors forming the louvers to vary the volume of fluid passing through the openings.

[0041] During the second medium-temperature mode configuration (see Figure 5), the louver doors 321 / 323 are open and the bypass valve 308 is open, thus providing a greater airflow to the fan than to the fuel cell stack.

[0042] Figures 6A - 6C show the basic operation of the louver door. In the high - temperature mode where maximum air flow through the fuel cell stack is required, the louver doors 321 / 323 open (Figure 6A) and the bypass valve is closed. In the restricted fluid flow configuration which is either low - temperature or medium - temperature, the louver doors 321 / 323 are closed (Figure 6B), the magnet 305 holds the doors 321 / 323 in the closed position, the cam 500 is in the lowered position, whereby the elongated openings 402A / 402B are aligned in the open position and are configured such that the amount of fluid flowing through the aligned openings is maximized. Figure 6C shows a top view of the flow control housing 302 and the cooperating gears which form means for opening and closing the louvers and sliding one of the nested plates 321A / 321B and 323A and 323B upward and downward. Figures 7A and 7B show partial views of the closed openings and the openings opened by cam movement in alignment. Figures 8A - 8C show the operation of the throttle and the configuration of the nested doors. The louver door is shown in the open state and section "B" is an enlarged view of the louver door and the elongated opening. Figure 8B shows an end view of the nested door of section "B" along the line of arrow "B - B" with a coating 510 formed on the first surface 401A of the nested plate 321A. The coating is configured with high lubricity (such as PTFE, ceramic, or other materials more lubricious than the material from which the plate is formed) to facilitate the movement of the nested door relative to the nested plate 321B. The elongated opening has a height "h" and when the nested plates are aligned, the openings cooperate to form a fluid passage of height "h". Figure 8C shows an end view of an alternative set of nested plates of section "B" along the line of arrow "B - B" with a coating 510 formed on the first surface of the first nested plate 321A and a coating 520 formed on the first surface of the second nested plate 321B. The coatings are configured to have high lubricity to facilitate the movement of the nested door relative to the second nested door 321B. Figures 9A - 9C show the operation of the openings and the configuration of the nested doors. The louver door is shown in a partially closed state and section "B" is an enlarged view of the louver door and the elongated opening.Figure 9B shows a partial closure. Figure 9C shows an end view of the nested door of section "B" along the line of arrow "C - C". Although the elongated opening has a height "h", when the nested door is wrung or partially closed, the openings cooperate to form a fluid passage of height "h2", and the fluid flow decreases. In this embodiment, it is not described that the nested plates are coated. However, the first surface 410A of each nested plate may be coated, and polishing or other surface finishing may be applied to reduce roughness to support smooth sliding. Further, at least one plate may be formed of a single material having sufficient lubricity to promote smooth sliding. Figure 10 shows various additional opening shapes, all of which are within the scope of the present disclosure. The displacement of one slide plate to completely close the opening is defined by a height "h3" equal to the height of one of the two openings. The vertical opening 602 requires more displacement to close than the square opening 604 or the circular opening 604. The elongated openings 606 and 608 require less displacement. In our tests, the elongated oval openings 400A / 400B were found to provide a controllable air flow with minimal displacement.

[0043] Figure 11 shows a broken top view showing the main components of the system and method disclosed herein for controlling the air flow to the fuel cell stack and the fan through the air intake upstream of the fuel cell stack. The operating modes are the same as those described with reference to Figures 3 - 4B and 6A - 10.

[0044] The intake surface 25 passing through the housing provides a fluid path for the air 1000 entering the system. The air enters the fan 200 and is blown towards the first surface 101 of the fuel cell stack 100 to cool the inside of the fuel cell stack 100. The fluid control assembly 300 is preferably provided upstream of the fuel cell stack. However, in some cases, the fluid control assembly 300' may be disposed downstream of the fuel cell stack together with a bypass valve 308 disposed in a bypass duct 308 upstream of the fuel cell stack.

[0045] When the fuel cell stack is upstream of the fan, the fan operates to draw in the air flow through the stack, resulting in a more uniform air distribution across the entire air inlet surface 101 of the stack and pushing the air into the stack as shown in FIG. 11. Uniform cooling is achieved by drawing in the air, improving the performance of the fuel cell stack. Further, in an air intake configuration with a fan downstream of the fuel cell stack, the fan can be mounted in close proximity to the fuel cell stack outlet surface 102, resulting in a higher volumetric power density of the system as compared to the air extrusion embodiment. The fuel cell stack is disposed downstream of the fan such that the air flow from the fan is pushed into the first surface 101 (inlet surface) of the fuel cell stack.

[0046] In FIG. 11, a configuration for pushing out air is shown, and this embodiment has the advantage of maximizing the efficiency of the fan, as opposed to drawing (or sucking) air through the system. The air-pushing fan configuration moves cold ambient air rather than heated air as it passes through the fuel cell stack. Since cold air has a higher density, when a certain amount of air moves, the mass of the air supplied to the fuel cell stack increases, and as a result, a greater cooling capacity can be obtained. However, when air 1000 is pressed against the first surface 101, the air distribution becomes non-uniform unless a complex structure is added to smooth the air flow or a large distance is formed between the fuel cell stack and the fan. When the distance between the stack and the fan is relatively long, the minimum volume of the entire system increases, meaning that the volumetric power density is inferior compared to the system.

[0047] The systems described through this disclosure can be utilized for various applications to supply power generated by fuel cells. In some aspects, the systems disclosed through this application can be used in material handling equipment (MHE) such as forklifts. In some aspects, the systems can be used in unmanned aerial vehicles (UAVs) such as fixed or multi-rotor drones. In some aspects, the systems disclosed herein can be used in automotive applications such as automobiles. It will be understood that the systems can be used in various other applications, and specific functional and physical parameters such as the size and quantity of components can be changed according to specific applications and determined by the requirements of specific applications. In addition to the advantages described above, it can be cited as advantages that the systems and related components (such as fuel canister cylinders) can be housed in a smaller space and that the systems and related components can be arranged.

[0048] The components disclosed herein can utilize known materials used in the industry.

[0049] Throughout this specification, words shall be given their ordinary meaning as understood by those skilled in the relevant art, unless the meaning of specific terms is specifically defined or clarified to avoid misunderstanding.

[0050] Although the present disclosure has been described in connection with various embodiments in various drawings, it will be understood by those skilled in the art that modifications can be made to the above-described embodiments without departing from the broad inventive concept. Accordingly, it is understood that the present disclosure is not limited to the specific embodiments disclosed, but encompasses modifications within the spirit and scope of the present disclosure as defined by the claims.

[0051] The features of the present disclosure described above in connection with individual embodiments may be provided in combination in a single embodiment. Conversely, the various features of the present disclosure described in connection with a single embodiment may be provided individually or in any sub-combination. Finally, although embodiments may be described as part of a series of steps or part of a more general structure, each of those steps is considered to be an independent embodiment in itself and can also be combined with others.

[0052] The description of a range of values herein is merely intended to serve as a shorthand way of referring individually to each individual value within that range, unless otherwise stated herein, and each individual value is incorporated into the specification as if it were individually recited. All methods described herein can be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by the context. The following are the technical features described herein. [Technical Feature 1] A method for providing an air flow to a fuel cell stack and a cooling fan within a housing, comprising the steps of arranging a fuel cell stack, both within the housing, in fluid communication with a fan, and fluidly connecting a predetermined minimum amount of air flow through the housing to the fan by one or more of the following modes: wherein the modes are: A. A mode of restricting the air flow to the air intake surface of the fuel cell stack by diverting a portion of the air flow from the fuel cell stack through a bypass assembly downstream of the fuel cell stack; B. A mode of diverting a portion of the air flow from the air intake surface through a bypass assembly and reducing the air flow from the cathode exhaust of the fuel cell stack by closing one or more louvers disposed between the cathode exhaust and the fan; C. A mode of adjusting the air flow from the cathode exhaust surface of the fuel cell stack to the fan by closing the louvers and closing at least a portion of the openings through the louvers; D. A mode of opening a bypass valve and a louver to provide an air flow to both the air intake surface and the fan; E. A mode of opening a bypass valve and closing the louver, and at least one of the openings, and at least a portion of the openings through the louver; and F. A mode of closing a bypass valve and a louver, whether open or closed. A method characterized by the above. [Technical Feature 2] The method according to Technical Feature 1, wherein each louver is configured to close via a magnetic catch within the housing. [Technical Feature 3] The method according to Technical Feature 1, wherein each louver consists of two plates, each plate includes an opening, the plates are configured to be nested together, and when the louver is closed, the opening is adjusted from a closed state to a fully open state via a controller by sliding one plate relative to the other through the action of a cam (500). [Technical Feature 4] The method according to technical feature 3, wherein at least one of the two plates is provided with a surface coating and faces the other plate, and is configured to have higher lubricity than the uncoated plate. [Technical Feature 5] The method according to technical feature 3 or 4, wherein the opening is an elongated horizontal gap. [Technical Feature 6] The method according to technical feature 5, wherein at least a part of the opening is an isosceles trapezoid. [Technical Feature 7] The method according to technical feature 1, further comprising the step of forming a convex portion on the inner side of the housing closest to the air intake surface to add turbulence to the air flow to the intake surface. [Technical Feature 8] The method according to any one of the preceding technical features, further comprising the step of forming an air flow disturbance fin adjacent to the air intake surface of the fuel cell stack to make the straight flow of the intake air to the fuel cell stack more turbulent. [Technical Feature 9] The fan is disposed downstream of the exhaust port of the fuel cell stack, The method according to technical feature 1, wherein the fluid control assembly is configured to change the volume of the air flow drawn through the fuel cell stack by the fan. [Technical Feature 10] A system for adjusting the air flow to a fuel cell stack in a housing, Comprising at least one fluid channel (24), a fuel cell stack (100), a fan (200), and a fluid control assembly (300), and a partially open housing configured to provide an air flow, wherein the fluid control assembly has at least one bypass valve and at least one louver with an adjustable opening formed therein, the housing, And a controller, The fluid channel is fluidly connected to the fluid control assembly, and the controller controls at least one of the opening and closing of the bypass valve, the louver, and the opening, The system is characterized in that the control of the amount of air flowing through the fan and the fuel cell stack is adjusted based on the operating mode. [Technical Feature 11] The system according to technical feature 10, wherein the controller comprises a bypass motor (312) for controlling the opening and closing of the bypass exhaust port (308). [Technical Feature 12] The system according to technical feature 10, wherein the controller has a louver control assembly (330) for controlling the movement of the louver and the opening and closing of the opening. [Technical Feature 13] The system according to Technical Feature 10, wherein the controller includes a louver control assembly (330) that controls the movement of the louvers and the opening and closing of the opening, and a bypass motor (312) that controls the opening and closing of the bypass exhaust port (308). [Technical Feature 14] The system according to Technical Feature 12 or 13, wherein the louver control assembly (330) further includes a drive shaft (333) that penetrates each louver and is connected to a cam attached to the louver. [Technical Feature 15] The cam further includes a lower drive section (502A) fixed to the drive shaft (333), an upper drive section (502B) movably attached to the drive shaft between the lower drive section and the drive shaft guide (327), and a movable spring fixed to the drive shaft between the upper drive section and the drive shaft guide, whereby the nested plate (323B) moves upward or downward relative to the second nested plate (323A) by the cam and the spring. The system according to Technical Feature 14. [Technical Feature 16] The system according to Technical Feature 15, wherein the first surface of at least one nested plate is polished to reduce roughness. [Technical Feature 17] The system according to Technical Feature 15, wherein the first surface of at least one nested plate is coated to reduce roughness or enhance lubricity. [Technical Feature 18] The system according to Technical Feature 12, wherein the louver control assembly is further configured to adjust at least one of the oxygen flow rate to the fuel cell stack and the dilution purge flow rate from the fuel cell stack. [Technical Feature 19] In a fluid control assembly, having a fluid control housing (302), the fluid control housing (302) further includes a fan duct (304), a magnet catch (305), a louver control assembly (330), a louver having a variable opening inside, at least one bypass duct (306), at least one bypass valve (308), and a bypass motor, wherein the bypass duct is in fluid connection with the fluid control housing. A fluid control assembly. [Technical Feature 20] Further comprising a louver, said louver being formed from two sliding nested plates (321A / 321B), each of said sliding nested plates (321A / 321B) having an opening (402A and 402B) that aligns in a first position, said opening having the technical feature 19 of varying the opening upon displacement and closing the opening when fully displaced. The fluid control assembly described above. [Technical Feature 21] The louver control assembly (330) is the fluid control assembly described in Technical Feature 20 that controls the movement of the louver and the opening and closing of the opening. [Technical Feature 22] The louver control assembly (330) controls the movement of the louver and the opening and closing of the opening, and the bypass motor (312) controls the opening and closing of a bypass vent (308) configured to open and close the flow of fluid through at least one bypass duct. The fluid control assembly described in Technical Feature 20. [Technical Feature 23] The louver control assembly (330) further has a drive shaft (333) that passes through each louver and is connected to a cam attached to the louver. The fluid control assembly described in Technical Feature 21 or 22. [Explanation of Reference Signs] 10 Fuel Cell Air Distribution Device and System 12 Main Housing 14 Inlet 16 Outlet 20A Side 22 Insert 24 Fluid Channel 25 Intake Surface 100 Fuel Cell Stack 101 First Surface 102 Second Surface 200 Fan 300 Fluid Control Assembly 302 Flow Control Housing 304 Fan Duct 305 Magnetic Catch 306 Bypass Duct 308 Valve 310 Control Arm 312 Bypass Motor 320 Opening Louver Door 321 / 323 Louver Door 321A / 321B Sub - Plate 325 Spring Means 327 Louver Guide 330 Louver Control Assembly 333 Drive Shaft 334 Drive Motor 334 Stepping Motor 335 Gear 336 Pass - Through Guide 400 Convex Bump 401A First Surface 401B Second Surface 405 Air Turbulence Fingers 425 System Sensor 500 Cam 502A Lower Drive Section 502B Upper Drive Section

Claims

1. A method for providing an air flow to a fuel cell stack and a cooling fan within a housing, comprising: arranging a fuel cell stack, both within the housing, in fluid communication with the fan; and fluidly connecting a predetermined minimum amount of air flow through the housing to the fan by one or more of the following modes: wherein the modes are: A. a mode of adjusting the air flow from the cathode exhaust surface of the fuel cell stack to the fan by closing the louvers and at least partially closing an opening through the face of the louvers; and B. a mode of opening a bypass valve and closing the louvers, and at least one of the openings, and at least a portion of the opening through the face of the louvers characterized by the method.

2. The method according to claim 1, wherein each louver is configured to close via a magnetic catch within the housing.

3. The method according to claim 1, wherein each louver consists of two plates, each plate includes an opening, the plates are configured to be nested together, and when the louver is closed, the opening is adjusted from a closed state to a fully open state via a controller by sliding one plate relative to the other through the action of a cam (500).

4. The method according to claim 3, wherein at least one of the two plates has a surface coating and faces the other plate, and is configured to have higher lubricity than the uncoated plate.

5. The method according to claim 3, wherein the opening is an elongated horizontal gap.

6. The method according to claim 5, wherein at least a portion of the opening is in the shape of a trapezoid with equal legs.

7. The method according to claim 1, further comprising forming a convex portion on the inner side of the housing closest to the air intake surface to add turbulence to the air flow to the air intake surface.

8. The method according to claim 1, further comprising forming air flow disturbing fins adjacent to the air intake surface of the fuel cell stack to make the linear flow of the intake air to the fuel cell stack more turbulent.

9. The fan is disposed downstream of the exhaust port of the fuel cell stack, and the fluid control assembly is configured to change the volume of the air flow drawn through the fuel cell stack by the fan.

10. A system for regulating the airflow to a fuel cell stack within a housing, comprising at least one fluid channel (24), a fuel cell stack (100), a fan (200), and a fluid control assembly (300), the housing being a partially open housing configured to provide an airflow, the fluid control assembly having at least one bypass valve and at least one louver formed with an adjustable opening, the housing, and a controller, the fluid channel being in fluid connection with the fluid control assembly, the controller controlling at least one of opening and closing of the bypass valve, the louver, and the opening to adjust the amount of air flowing through at least one of the bypass valve, the louver, and the opening, and adjusting and controlling the amount of air flowing to the fan and the fuel cell stack based on an operating mode, a system characterized thereby.

11. The system according to claim 10, wherein the controller comprises a bypass motor (312) for controlling opening and closing of a bypass exhaust port (308).

12. The system according to claim 10, wherein the controller has a louver control assembly (330) for controlling the movement of the louver and the opening and closing of the opening.

13. The system according to claim 10, wherein the controller comprises a louver control assembly (330) for controlling the movement of the louver and the opening and closing of the opening, and a bypass motor (312) for controlling the opening and closing of a bypass exhaust port (308).

14. The system according to claim 12 or 13, wherein the louver control assembly (330) further has a drive shaft (333) passing through each louver and connected to a cam attached to the louver.

15. The cam further has, a lower drive section (502A) fixed to the drive shaft (333), an upper drive section (502B) movably attached to the drive shaft between the lower drive section and a drive shaft guide (327), and, a movable spring fixed to the drive shaft between the upper drive section and the drive shaft guide, whereby the nested plate (323B) moves upward or downward relative to the second nested plate (323A) by the cam and the spring, the system according to claim 14.

16. The system according to claim 15, wherein a first surface of at least one nested plate is polished to reduce roughness.

17. The system according to claim 15, wherein a first surface of at least one nested plate is coated to reduce roughness or enhance lubricity.

18. The system according to claim 12, wherein the louver control assembly is further configured to adjust at least one of an oxygen flow rate to the fuel cell stack and a dilution purge flow rate from the fuel cell stack.

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