Adaptive purging for fuel cell systems

Abstract

Aspects of adaptive purging technology for purging a fuel cell are disclosed, which adjust the time delay between subsequent purges based in part on one or more parameters of the fuel cell. The difference between two similar parameters is measured before and after the activation of a valve used to allow the inflow of purge gas. The degree of the difference between the two parameters is used to determine the time delay, i.e., the time when the valve should be activated again to allow the next purge of the fuel cell. In addition to the time delay, the parameters may be used to determine the time interval or period during which the valve should be activated so that it remains open during a purge event.

Description

Technical Field

[0001] This application is a PCT application claiming priority to UK Patent Application No. 2213374.8 filed on September 13, 2022, the disclosure of which is hereby incorporated by reference in its entirety as if fully set forth herein.

[0002] This application relates to a fuel cell system, and more particularly to adaptively managing a control valve for purging one or more fuel cells of a fuel cell system.

Background Art

[0003] Conventional electrochemical fuel cells convert fuel and an oxidant into electrical energy and reaction products. A common type of electrochemical fuel cell includes a membrane electrode assembly (MEA), which includes a polymeric ion (proton) conducting 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 to produce electrical energy and water as reaction products. A stack may be formed that includes a number of fuel cells with separate anode and cathode fluid flow paths. Such a stack typically takes the form of a block that includes a number of individual fuel cell plates held together by end plates at both ends of the stack.

[0004] For efficient operation, it is important for the polymeric ion conducting 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. At certain times or periodically, it may be necessary to use a purge gas to remove coolant, contaminants, or reaction by-products from the flow channels or gas diffusion structures of the fuel cell.

[0005] Periodically, water and other gases need to be purged (removed) from fuel cells. The purged gas may contain fuel (e.g., hydrogen), and this purged gas flows through the anode channel to remove water and gases from the fuel cell. Conventional fuel cells are configured to perform this purging process at specified times, regardless of whether purging is actually needed at a particular time. This can lead to inefficient use of the gas used to remove water, especially if the gas is also used to generate electrical energy. Disclosure

[0006] According to one aspect of this disclosure, a fuel cell system is provided, comprising: a fuel cell assembly having an anode exhaust port and a fuel cell; a valve configured to discharge a purge gas from the anode exhaust port; and a valve controller configured to acquire a first parameter of the fuel cell before a first purge of the fuel cell with the purge gas; acquire a second parameter of the fuel cell after the first purge, acquire the difference between the first parameter and the second parameter, and determine a time delay for a second purge after the first purge based on the difference.

[0007] According to other aspects of this disclosure, a fuel cell system is provided, comprising: a fuel cell assembly having an anode exhaust port and a fuel cell; a valve configured to discharge a purge gas from the anode exhaust port; and a valve controller configured to obtain a first parameter of the fuel cell before a first purge of the fuel cell with the purge gas, obtain a second parameter of the fuel cell after the first purge, obtain the difference between the first parameter and the second parameter, and determine, based on the difference, a purge period during which the valve remains open for a second purge after the first purge.

[0008] In other aspects of this disclosure, a fuel cell system is provided, comprising: a fuel cell assembly having an anode exhaust port and a fuel cell; a valve configured to discharge a purge gas from the anode exhaust port; and a valve controller configured to take a first parameter of the fuel cell before a first purge of the fuel cell with the purge gas, take a second parameter of the fuel cell after the first purge, take the difference between the first parameter and the second parameter, and based on that difference, perform a purge cluster which includes a series of operations of opening and then closing the valve over a predetermined number of times.

[0009] In any of the above aspects of this disclosure, the first parameter may be a first output voltage, a first temperature, a first humidity, or a first current of the fuel cell, and the second parameter may be a corresponding second output voltage, a second temperature, a second humidity, or a second current of the fuel cell. In some aspects, the above first parameter may be a first altitude or a first humidity of the fuel cell, and the second parameter may be a second altitude or a second humidity of the fuel cell.

[0010] This disclosure also describes adaptive purging techniques for purging a fuel cell, which in several respects adjust the time delay between subsequent purges based in part on one or more parameters of the fuel cell. The difference between two similar parameters is measured before and after the activation of a valve used to allow the passage of purge gas. The degree of the difference between the two parameters is used to determine the time delay, i.e., the time at which the valve should be activated again to allow the next purge of the fuel cell. In addition to the time delay, the parameters may be used to determine the time interval or duration at which the valve is activated to remain open during a purge event. Alternatively, or in combination, a purge cluster may be implemented by opening and closing the valve a predetermined number of times. [Brief explanation of the drawing]

[0011] The specific features of this invention are described in the appended claims. However, for the sake of illustrative purposes, some examples of the invention are shown in the following figures. [Figure 1] Figure 1 shows a schematic diagram of a fuel cell system including a fuel cell assembly, an exhaust assembly, and a control valve, according to several aspects of this invention. [Figure 2] Figures 2A and 2B show exemplary valves that can be operated in two operating positions, in accordance with aspects of this disclosure. [Figure 3] Figure 3 shows an exemplary valve that can be operated in two operating positions, in accordance with aspects of this disclosure. [Figure 4] Figure 4 shows a schematic diagram of an alternative fuel cell system in accordance with the aspects of this disclosure. [Figure 5] Figure 5 shows a schematic diagram of an alternative fuel cell system with multiple valves, in accordance with the aspects of this disclosure. [Figure 6] Figure 6 illustrates a method for adaptively purging a fuel cell in accordance with aspects of this disclosure. [Figure 7] Figure 7 illustrates an alternative method for adaptively purging a fuel cell in accordance with aspects of this disclosure. Detailed explanation

[0012] The disclosures described below are intended to illustrate various configurations of the subject technology and not to show only one configuration in which the subject technology can be implemented. The accompanying drawings are incorporated into this specification and constitute part of the detailed description. This disclosure includes specific details to provide a complete understanding of the subject technology. However, it will be apparent to those skilled in the art that the technology is not limited to the specific details described in this specification and can be implemented without these specific details. In some cases, well-known structures and components are shown in block diagram form so as not to obscure the concepts of the technology.

[0013] The present technology relates to adaptively purging a fuel cell based on various selected parameters of the fuel cell. For example, the time delay between valve operation (e.g., opening) or the purge time delay may vary in part based on the difference between two measured parameters. Specifically, the degree of the difference between the two measured parameters (e.g., whether the difference is large or small) is used by the valve controller to determine when to operate the valve for a subsequent purge event. The “difference” described herein may include the absolute value of the difference. Advantageously, valve operation occurs when the fuel cell needs to be purged, rather than at predetermined time intervals where purging may not be necessary.

[0014] Several parameters can be selected to determine adaptive purging. In non-limiting examples, parameters may include voltage, temperature, current, altitude, humidity (inflow air), gas quality, and moisture replenishment. In one example implementation, the fuel cell voltage output is measured before opening the valve to purge the fuel cell. The fuel cell voltage output is measured again after opening the valve. The delta, or difference, between the two measured voltages can be used to determine the time delay used for subsequent valve openings (including the next valve opening) to purge the fuel cell. In this regard, if the measured voltage output difference is relatively high (e.g., 20 millivolts (mV)), the time delay can be relatively short (e.g., 30 seconds (s)). Conversely, if the measured voltage output difference is relatively low (e.g., 5 mV), the time delay can be relatively short (e.g., 120 seconds). Thus, the time delay may be inversely proportional to the difference between the measured parameters.

[0015] In addition to the adaptive purge time delay between valve operation events for purging, additional time parameters may be integrated. For example, the time the valve is open (e.g., the time between opening and closing) representing the purge period may be partially varied based on the parameters described above. As a result, the fuel cell system may adaptively operate the valve so that it can adjust not only the time between subsequent valve openings but also the time the valve remains open.

[0016] The fuel cell systems described herein, equipped with adaptive purging capabilities, offer several advantages. For example, if the gas used for purging the fuel cell is also used to generate electrical energy, adaptive purging is a predictive technique, as opposed to conventional techniques which rely on predetermined time intervals between purge events, thus saving gas.

[0017] According to some aspects of examples, for example, as shown in Figure 1, the fuel cell system 100 has a fuel cell assembly 102 and a control valve (or simply a valve) 104 for controlling the exhaust flow of purge gas. Thus, the control valve 104 may be called a purge control valve, forming part of an exhaust assembly configured to receive fluids exiting from the anode passage and the cathode passage through the fuel cell assembly 102. During the purging operation, a gas such as fuel (e.g., hydrogen) flows through the anode passage, purging coolant, hydration fluid, contaminants, and / or reaction byproducts from the anode passage. The control valve 104 is configured to control the exhaust flow of purge gas discharged from the fuel cell assembly 102.

[0018] The fuel cell assembly 102 in this example includes a fuel cell stack comprising multiple proton exchange membrane fuel cells stacked on top of each other. The fuel cell assembly 102 is configured to receive a flow of fuel, such as hydrogen, from the anode inlet 106 and a flow of oxidizer, such as air, from the cathode inlet 108. An anode exhaust 110 is provided to allow unused fuel and purge gas to pass through. A cathode exhaust 112 is provided to allow the oxidizer to pass through. A control valve 104 is connected to the anode exhaust 110 and includes a two-port, two-position valve. A schematic diagram of the control valve 104 is shown in Figure 1, and examples of valve positions are shown in Figures 2A and 2B.

[0019] Referring to Figures 2A and 2B, the control valve 104 includes a valve body 116 that encloses a valve member 118. The valve member 118 is slidably mounted within the valve body 116 and is movable between a first position (Figure 2A) and a second position (Figure 2B). The valve body 116 includes an inlet port 120 that receives purge gas discharged from the fuel cell assembly 102 (shown in Figure 1) and an outlet port 122 that provides an outlet for the purge gas.

[0020] In the first position (Figure 2A), the valve member 118 acts to prevent the discharged purge gas (shown by the dotted line) from flowing between the inlet port 120 and the outlet port 122. In the second position (Figure 2B), the valve member 118 allows the purge gas to flow between the inlet port 120 and the outlet port 122. Thus, the valve member 118 is configured to close the inlet port 120 in the first position and to open the inlet port 120 in the second position. Specifically, the inlet port 120 includes a valve seat 124 which is sealed by the sealing surface 126 of the valve member 118 in the first position. When the sealing surface 126 of the valve member 118 is not engaged with the valve seat 124 (as shown in Figure 2B), the purge gas can flow through the control valve 104.

[0021] The valve member 118 is biased to a first position by a biasing means, which may include, in non-limiting examples, a spring. The control valve 104 may include a solenoid valve, and thus the valve member 118 is movable between the first and second positions by the actuation of a solenoid (not shown) configured to move the valve member 118 to a second position against the force of the biasing means.

[0022] Referring to Figure 1, during the purging operation, fuel may flow through the anode passage of the fuel cell assembly 102. The control valve 104 is actuated via a solenoid, moving the valve member 118 from a first position to a second position, thereby allowing the purge gas to flow through the fuel cell assembly 102.

[0023] Referring to FIG. 3, the fuel cell assembly 202 includes n fuel cells of fuel cell 230a, fuel cell 230b, fuel cell 230c, and fuel cell 230n. In this regard, the fuel cell assembly 202 may include a fuel cell stack composed of fuel cells 230a to 230n. Further, since fuel cells 230a and 230n represent the two outermost fuel cells, they may be referred to as end cells.

[0024] Furthermore, the fuel cell assembly 202 includes one or more sensors 232 designed to monitor at least one of fuel cells 230a to 230n. In some examples, the one or more sensors 232 include a voltmeter designed to determine the output voltage of at least one of fuel cells 230a to 230n. Further, in some examples, the one or more sensors 232 include a temperature sensor designed to measure the temperature of at least one of fuel cells 230a to 230n. Further, in some examples, the one or more sensors 232 include a barometric pressure sensor designed to measure the pressure (e.g., ambient pressure) of at least one of fuel cells 230a to 230n. In this regard, the one or more sensors 232 can determine the altitude (i.e., relative altitude with respect to sea level) of the fuel cell assembly 202 based on the measured pressure. Instead of the barometric pressure sensor, the one or more sensors 232 may include an altimeter used to determine altitude. Further, in some examples, the one or more sensors 232 include a humidity sensor designed to measure the relative humidity of the air entering at least one of fuel cells 230a to 230n. Also, in some examples, the one or more sensors 232 include a gas analyzer designed to measure the gas composition that can be used to determine the purity / quality of the gas in at least one of fuel cells 230a to 230n. Also, in some examples, the one or more sensors 232 include a moisture sensor designed to measure the amount of liquid in at least one of fuel cells 230a to 230n.

[0025] Referring to FIG. 4, the fuel cell system 300 includes a fuel cell assembly 302 and a control valve 304 operated by a controller 334. The fuel cell assembly 302 includes a fuel cell 330 and one or more sensors 332 that monitor the fuel cell 330. The one or more sensors 332 may include any of the sensors described above. Also, as shown in the figure, the one or more sensors 332 are integrated with the fuel cell assembly 302. However, it should be noted that the one or more sensors 332 can be separated from the fuel cell assembly 302 and still monitor the fuel cell 330 and communicate with the controller 334.

[0026] The controller 334 includes a memory 336 representing one or more memory circuits that store executable code or executable instructions. The controller 334 further includes a processor 338 representing a processing circuit in the form of a central processing unit, a programmable logic circuit, and / or an application-specific integrated circuit. The processor 338 is designed to execute the instructions / codes stored in the memory 336. For example, the processor 338 can use the instructions stored in the memory 336 to operate (i.e., open and close) the control valve 304. When the controller 334 opens the control valve 304, gas 340 passes through the fuel cell assembly 302 to purge the fuel cell 330. The gas 340 may include hydrogen, for example, as a non-limiting example.

[0027] Furthermore, the processor 338 can be used to obtain data (e.g., numerical values) from one or more sensors 332 by sending instructions stored in memory 336. In this regard, the controller 334 can receive data from one or more sensors 332 by requesting the data periodically (e.g., on the order of milliseconds or seconds), or can continuously receive updated data from one or more sensors 332. In some examples, the controller 334 obtains data from one or more sensors 332 before and after the operation of the control valve 304. For example, the controller 334 can obtain data from one or more sensors 332 before the controller 334 opens the control valve 304. Furthermore, after the controller 334 closes the control valve 304, the controller 334 can obtain data (i.e., updated data) from one or more sensors 332.

[0028] As an example, one or more sensors 332 include at least one voltmeter designed to monitor and determine the output voltage of the fuel cell 330. Before the controller 334 opens the control valve 304, the controller 334 can obtain the output voltage from one or more sensors 332. Furthermore, after the controller 334 closes the control valve 304, the controller 334 can obtain the output voltage from one or more sensors 332. Opening and closing the control valve 304 represents a purge event.

[0029] Using memory 336 and processor 338, controller 334 can determine the difference between two output voltages and determine a time delay to instruct control valve 304 for the next purge event. In other words, controller 334 uses the difference in output voltages to determine when to start the next purge event. The time delay between consecutive purge events may be inversely proportional. For example, if the difference in output voltages is relatively small, the time delay may be relatively long, and conversely, if the difference in output voltages is relatively large, the time delay may be relatively short. This process may include an iterative process of comparing the difference in output voltages at consecutive purge events and adjusting the time delay for the next purge event. Beneficially, fuel cell system 300 may include adaptive purging techniques that predict subsequent purges, thereby reducing the number of purge events to conserve gas 340, or alternatively, increasing the number of purge events to operate fuel cell assembly 302 (particularly fuel cell 330) more efficiently to promote increased energy output, or limiting or preventing damage to fuel cell assembly 302.

[0030] Furthermore, in some cases, if the difference between two parameters (e.g., the difference between two measured output voltages) falls below a threshold difference, the controller 334 does not adaptively adjust the time delay. In other words, the change in time delay is 0 seconds in the subsequent purge, and the previous time delay is used.

[0031] Generally, the above example may be implemented in a similar manner using different sensors. For example, if one or more sensors 332 include at least one temperature sensor that monitors and determines the temperature of the fuel cell 330, the controller 334 may obtain voltages from the one or more sensors 332 both before the control valve 304 is opened and after the control valve 304 is closed, determine the temperature difference between the two obtained temperatures, and determine a time delay based on the temperature difference. Alternatively, the measured temperatures may be compared to an ideal set of temperatures on a curve (such as a bell curve), and the time delay may be calculated based on the deviation from the curve.

[0032] In other examples, if one or more sensors 332 include an ammeter, the measured current is compared to a predetermined range (e.g., an optimal range), and the time delay is determined based on the deviation from this range.

[0033] Other examples of the one or more sensors 332 include a barometric pressure sensor, an altimeter, a humidity sensor, a gas analyzer, and / or a moisture replenishment sensor. In a similar manner, the controller 334 may acquire data from the alternative examples of the one or more sensors 332 before opening the control valve 304 and after closing the control valve 304, determine the difference between the two acquired data sets, and determine a time delay based on the determined difference. The time delay may be inversely proportional to the determined difference. For example, if the altitude difference (determined by the barometric pressure sensor or altimeter) is relatively large, the time delay between consecutive purge events may decrease. Similarly, if the humidity difference (determined by the humidity sensor) is relatively large, the time delay between consecutive purge events may decrease.

[0034] Instead of, or in combination with, a time delay between consecutive purge events, the duration of a purge event may be adaptively adjusted. The duration of a purge event may refer to the time (and the time between opening and closing) of the control valve 304. For example, the controller 334 may use the output voltage difference to determine the duration of a subsequent purge event (or a series of purge events) including the next purge event. Gas 340 may be saved by further adaptively controlling the control valve 304 to shorten the purge period. Alternatively, by further adaptively controlling the control valve 304 to extend the purge period, the fuel cell assembly 302 (particularly the fuel cell 330) can operate more efficiently to promote increased energy output and / or prevent damage. It should be noted that, in addition to the voltmeter, the purge period may be associated with any implementation of the one or more examples of sensors 332.

[0035] Referring to Figure 5, the fuel cell system 400 includes a plurality of fuel cell assemblies. As shown in the figure, the fuel cell system 400 includes n fuel cell assemblies and n control valves. Fuel cell assemblies 402a, 402b, and 402n are shown. Fuel cell assembly 402a includes a fuel cell 430a and one or more sensors 432a. Fuel cell assembly 402b includes a fuel cell 430b and one or more sensors 432b. Fuel cell assembly 402n includes a fuel cell 430n and one or more sensors 432n. One or more sensors 432a, 432b, and 432n may include any of the sensors described herein.

[0036] Furthermore, control valves 404a, 404b, and 404n are used to allow gas 440 to purge fuel cells 430a, 430b, and 430n, respectively. The fuel cell system 400 further includes a controller 434 used to activate each of the control valves 404a, 404b, and 404n in order to purge fuel cells 430a, 430b, and 430n, respectively. Also, as shown in the figure, one or more sensors 432a, 432b, and 432n are integrated with fuel cell assemblies 402a, 402b, and 402n, respectively. However, it should be noted that even if one or more sensors 432a, 432b, and 432n are separated from fuel cell assemblies 402a, 402b, and 402n, they can still monitor fuel cells 430a, 430b, and 430n and continue to communicate with the controller 434, respectively.

[0037] The controller 434 includes memory 436 representing one or more memory circuits for storing executable code or executable instructions. The controller 434 further includes a processor 438 representing a processing circuit in the form of a central processing unit, a programmable logic control circuit, and / or an application-specific integrated circuit. The processor 438 is designed to execute instructions / code stored in memory 436. For example, the processor 438 can use instructions stored in memory 436 to actuate (i.e., open and close) the control valves 404a, 404b, and 404n. When the controller 434 opens the control valves 404a, 404b, and 404n, gas 440 passes through the fuel cell assemblies 402a, 402b, and 402n, respectively, purging the fuel cells 430a, 430b, and 430n. Gas 440 may include hydrogen as an example, but is not limited. Furthermore, the controller 434 is designed to actuate the control valves 404a, 404b, and 404n independently. In this way, fuel cells 430a, 430b, and 430n can be purged independently.

[0038] Furthermore, the processor 438 may be used to transmit instructions stored in memory 436 to acquire data from one or more sensors 432a, 432b, and 432n in the manner described above. Thus, the controller 434 can independently and adaptively purge each of the fuel cells 430a, 430b, and 430n. For example, the time delays between consecutive purge events for each of the fuel cells 430a, 430b, and 430n may differ from one another, or two or more fuel cells 430a, 430b, and 430n may have the same time delays between consecutive purge events based on data from one or more sensors 432a, 432b, and 432n. Advantageously, the fuel cell assemblies 402a, 402b, and 402n can be managed independently, which may improve the hardware efficiency of the controller 434 (i.e., the processor 438) and conserve gas 440.

[0039] Instead of, or in combination with, a time delay between consecutive purge events, the duration of purge events can be adaptively adjusted. For example, the controller 434 uses data from one or more sensors 432a, 432b, and 432n to determine the duration of subsequent purge events for fuel cells 430a, 430b, and 430n, respectively. By further adaptively controlling the control valves 404a, 404b, and 404n to shorten the purge duration, gas 440 can be saved. Alternatively, by further adaptively controlling the control valves 404a, 404b, and 404n to extend the purge duration, the fuel cell assemblies 402a, 402b, and 402n can operate more efficiently to promote increased energy output or prevent damage.

[0040] Referring to Figure 6, a method 500 for adaptively purging a fuel cell is shown. The various steps of method 500 may be performed by a fuel system controller as shown and described herein.

[0041] In step 502, before performing the first purge, the first parameter of the fuel cell is obtained. "Purge" refers to an event in which a gas (e.g., purge gas) is introduced to remove unwanted liquids (e.g., water) and gases (e.g., nitrogen). The first parameter of the fuel cell may be measured / monitored by a sensor. In non-limiting examples, the sensor may include a voltmeter, temperature sensor, barometer, altimeter, humidity sensor, gas analyzer, or moisture sensor. The controller can obtain data related to the first parameter from the sensor.

[0042] In step 504, following the execution of the first purge, the second parameter of the fuel cell is acquired. Similar to the first parameter, the controller can acquire data related to the second parameter from sensors. The second parameter can also be measured / monitored using the same sensors that were used to measure / monitor the first parameter.

[0043] In step 506, the difference between the first and second parameters is obtained. The difference may include subtracting the first parameter value of the first parameter from the second parameter value of the second parameter. Alternatively, the difference may include deviations from the ideal parameter (or ideal range of parameters) determined from the curve / plot.

[0044] In step 508, the time delay for the second purge following the first purge is determined based on the difference. The time delay can represent the time it takes for the controller to initiate the second, i.e., the next purge, after the first purge.

[0045] Referring to Figure 7, a method 600 for adaptively purging a fuel cell is shown. The various steps of method 600 may be performed by a fuel system controller as shown and described herein.

[0046] In step 602, prior to the first purge, the initial parameters of one or more fuel cells are obtained. "Purge" refers to the event in which a gas (e.g., purge gas) enters and unwanted liquids (e.g., water) and gases (e.g., nitrogen) are removed. If at least two fuel cells are present, a fuel cell represents a fuel stack. In this regard, one or more sensors can be used to monitor selected fuel cells or all fuel cells. In some examples, the last cell of the fuel stack is monitored by one or more sensors.

[0047] In step 604, after the first purge, the second parameters of one or more fuel cells are acquired. Similar to the first parameters, the controller can acquire data related to the second parameters from sensors. Alternatively, the second parameters can be measured / monitored using the same sensors that were used to measure / monitor the first parameters.

[0048] In step 606, the difference between the first parameter and the second parameter is obtained. If there are at least two fuel cells, the difference between the first parameter and the second parameter is obtained for each fuel cell.

[0049] In step 608, it is determined whether the one or more differences are greater than a threshold difference (or set of threshold differences). If there are at least two fuel cells, it is determined whether each difference is above or below a predetermined threshold difference. If the difference is below the predetermined threshold difference, method 600 returns to step 602 to determine a new first parameter before purging. Furthermore, if the difference is not above the predetermined threshold difference, the controller does not need to implement a new time delay in the subsequent purging of the fuel cells. If the difference is above the predetermined threshold difference, method 600 proceeds to step 610. If there are at least two fuel cells, the controller can manage each fuel cell independently and evaluate each fuel cell to proceed independently in method 600.

[0050] In step 610, the time delay for the second purge is determined based on the difference. The time delay can represent the time after the first purge when the controller initiates the second purge, i.e., the next purge. If there are at least two fuel cells, the time delay for each fuel cell can be determined independently based on the respective evaluations of the first and second parameters.

[0051] For convenience, various examples of aspects of this disclosure are set forth below as clauses. These are provided as examples and do not limit the subject art, nor do they limit the scope of this disclosure and claims as understood by those skilled in the art.

[0052] Clause A: The fuel cell system comprises: a fuel cell assembly having an anode exhaust and a fuel cell; a valve configured to discharge purge gas from the anode exhaust port; and a valve controller configured to obtain a first parameter of the fuel cell before a first purge of the fuel cell by purging; obtain a second parameter of the fuel cell after the first purge; obtain the difference between the first parameter and the second parameter; and determine a time delay for a second purge after the first purge based on that difference.

[0053] Clause B: A method for adaptively purging a fuel cell includes: the steps of: obtaining a first parameter of the fuel cell before performing a first purge; obtaining a second parameter of the fuel cell after performing a first purge; obtaining the difference between the first parameter and the second parameter; and determining a time delay for a second purge following the first purge based on the difference.

[0054] One or more of the preceding clauses may include one or more of the features described below. Note that the following clauses can be combined in any combination and may be placed in separate clauses, for example, clause A or clause B.

[0055] Clause 1: The first parameter has a first output voltage of the fuel cell, and the second parameter has a second output voltage of the fuel cell.

[0056] Clause 2: The first parameter has a first temperature of the fuel cell, and the second parameter has a second temperature of the fuel cell.

[0057] Clause 3: The first parameter has the first current of the fuel cell, and the second parameter has the second current of the fuel cell.

[0058] Clause 4: The first parameter has the first current of the fuel cell, and the second parameter has the second current of the fuel cell.

[0059] Clause 5: The first parameter has a first altitude or first humidity of the fuel cell, and the second parameter has a second altitude or second humidity of the fuel cell.

[0060] Clause 6: The valve controller shall be configured to perform a second purge at a time equal to the time delay.

[0061] Article 7: The difference is inversely proportional to the time delay.

[0062] Clause 8: The valve controller shall be configured to set the time delay to zero if the difference falls below a threshold difference.

[0063] Clause 9: The step of obtaining the first parameter includes the step of measuring the first output voltage of the fuel cell, and the step of obtaining the second parameter includes the step of measuring the second output voltage of the fuel cell.

[0064] Clause 10: The step of obtaining the first parameter includes the step of measuring the first temperature of the fuel cell, and the step of obtaining the second parameter includes the step of measuring the second temperature of the fuel cell.

[0065] Clause 11: The step of obtaining the first parameter includes the step of measuring the first temperature of the fuel cell, and the step of obtaining the second parameter includes the step of measuring the second temperature of the fuel cell.

[0066] Clause 12: The step of obtaining the first parameter includes the step of measuring the first current of the fuel cell, and the step of obtaining the second parameter includes the step of measuring the second current of the fuel cell.

[0067] Clause 13: Further includes a step of performing a second purge in case of a purge time delay.

[0068] As used here, the phrase "at least one" preceding a list of items is preceded by the terms "and" or "or" to separate any of the items and modifies the entire list, rather than each member of the list (i.e., each item). The phrase "at least one" does not require you to select at least one of each item listed; rather, it allows for the meaning of including at least one of any one of the items, and / or at least one of any combination of the items, and / or at least one of each item. For example, the phrase "at least one of A, B, and C" or "at least one of A, B, or C" refers to A only, B only, or C only, any combination of A, B, and C, and / or at least one of each of A, B, and C, respectively.

[0069] The predicates “configured,” “operable,” and “programmed” are not intended to imply any specific tangible or intangible change of subject, but are intended to be used interchangeably. In one or more implementations, a processor configured to monitor and control an operation or component may mean a processor programmed to monitor and control an operation, or a processor operable to monitor and control an operation. Similarly, a processor configured to execute code may be interpreted as a processor programmed to execute code, or a processor operable to execute code.

[0070] The terms such as aspects, the above aspects, other aspects, some aspects, one or more aspects, implementation, the above implementation, other implementations, some implementations, one or more implementations, examples, the above examples, other examples, some examples, one or more examples, configurations, the above configurations, other configurations, some configurations, one or more configurations, the subject technology, disclosures, this disclosure, and other variations thereof are for convenience only and do not imply that disclosures related to such terms are essential to the subject technology or that such disclosures apply to all configurations of the subject technology. Disclosures related to such terms may apply to all configurations or one or more configurations. Disclosures related to such terms may implement one or more examples. Terms such as aspects or some aspects may refer to one or more aspects, and vice versa, and this is also true for the other terms mentioned above.

[0071] Herein, the term “exemplary” is used in the sense of “serving as an example, case, or illustration.” An example described herein as “exemplary” or “example” is not necessarily construed as being preferable or more favorable than other examples. Furthermore, to the extent that terms such as “includes” or “complements” are used in the disclosure or claims, such terms are intended to be inclusive, as the term “has” is construed when used as a transitional term in a claim.

Claims

1. A fuel cell assembly having anode exhaust and a fuel cell, A valve configured to discharge purge gas from the anode exhaust, Before the first purging of the fuel cell with the above-mentioned purge gas, the first parameter of the fuel cell is obtained. After the first purge described above, the second parameter of the fuel cell is obtained. Obtain the difference between the first parameter and the second parameter described above. A fuel cell system characterized by having a valve controller configured to determine the time delay of a second purge after a first purge based on the above difference.

2. The first parameter described above has a first altitude or a first humidity of the fuel cell. The fuel cell system according to claim 1, wherein the second parameter is the second altitude or second humidity of the fuel cell.

3. The first parameter described above has the first temperature of the fuel cell. The second parameter described above has the second temperature of the fuel cell. The fuel cell system according to claim 1, wherein the valve controller is configured to perform the second purge at a time equal to the time delay.

4. The fuel cell system according to claim 1, wherein the above difference is inversely proportional to the above time delay.

5. The first parameter described above has the first current of the fuel cell. The fuel cell system according to claim 4, wherein the above second parameter is the second current of the fuel cell.

6. The first parameter described above has the first output voltage of the fuel cell. The fuel cell system according to claim 1, wherein the second parameter is the second output voltage of the fuel cell.

7. The first parameter described above has the first temperature of the fuel cell. The fuel cell system according to claim 1, wherein the second parameter is the second temperature of the fuel cell.

8. The above valve controller is The first parameter described above has the first temperature of the fuel cell. The fuel cell system according to claim 1, wherein the second parameter is configured to have the second temperature of the fuel cell.

9. The fuel cell system according to claim 1, wherein the valve controller is configured to set the time delay to zero when the difference falls below a threshold difference.

10. In a method for adaptively purging fuel cells, Before performing the first purge, the steps include obtaining the first parameter of the fuel cell, After performing the first purge described above, the step is to obtain the second parameter of the fuel cell, The steps include determining the purge delay time based on the difference between the first parameter and the second parameter, The method is characterized by having the step of performing a second purge following the first purge with a purge time delay.

11. The step of obtaining the first parameter includes the step of measuring the first output voltage of the fuel cell. The method according to claim 10, wherein the step of obtaining the second parameter comprises the step of measuring the second output voltage of the fuel cell.

12. The step of obtaining the above first parameter includes the step of measuring the first temperature of the fuel cell. The method according to claim 10, wherein the step of obtaining the second parameter is further comprising the step of measuring the second temperature of the fuel cell.

13. The step of obtaining the above first parameter includes measuring the first temperature of the fuel cell. The method according to claim 10, wherein the step of obtaining the second parameter is further comprising the step of measuring the second temperature of the fuel cell.

14. The step of obtaining the above first parameter includes the step of measuring the first current of the fuel cell. The method according to claim 10, wherein the step of obtaining the above-mentioned second parameter is further comprising the step of measuring the second current of the fuel cell.

15. The step of obtaining the above first parameter includes the step of measuring the first humidity of the fuel cell. The method according to claim 10, wherein the step of obtaining the second parameter is further comprising the step of measuring the second humidity of the fuel cell.

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