Fuel cell injection ratio test system and method

Abstract

The invention provides a fuel cell injection ratio test system and method. The fuel cell injection ratio test system and method are used for accurately calculating the injection ratio under the condition that the flow resistance of a fuel cell system is not increased. According to the fuel cell injection ratio test system, the flow relationship in a fuel cell hydrogen system is deduced by utilizing the flow characteristic of hydrogen in the ejector and combining measurable parameters in the fuel cell system, and a calculation model of the injection ratio is deduced, so that the situation that the in-pile hydrogen flow of a fuel pile is directly measured through a flow sensor is avoided, and the measurement accuracy is improved. And the flow resistance in a fuel cell hydrogen system is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cell hydrogen simplification systems and fuel cell vehicles, and in particular relates to a fuel cell ejection ratio testing system and method. Background Art

[0002] Against the backdrop of the global push for a green energy transition, new energy vehicles have become a core focus of the automotive industry. Fuel cell vehicles, with their significant advantages such as zero emissions, high efficiency, short refueling times, and long driving range, stand out among other new energy vehicle types. They are considered a key solution for achieving sustainable development in the future transportation sector and a key development direction for new energy vehicles.

[0003] In fuel cell hydrogen simplification systems, ejectors are widely used to adjust the hydrogen stoichiometry, or the ejection ratio. This ratio is the ratio of hydrogen entering the fuel cell stack (inlet hydrogen flow) to the primary hydrogen flow at the ejector inlet. A higher ejection ratio results in a greater proportion of reflux hydrogen and a higher humidity in the incoming hydrogen. Self-humidifying fuel cell stacks, in particular, often require a higher inlet hydrogen humidity at low charge density points, thus placing a higher ejection ratio on the ejector.

[0004] In existing technologies, calculating the ejector ratio typically requires using a flow sensor to measure the hydrogen flow rate entering the fuel cell stack. However, the introduction of a flow sensor increases the system's flow resistance (resistance), thereby changing the actual hydrogen flow rate and reducing the ejector's stoichiometric ratio, making the measurement results inaccurately reflect the system's actual operating status.

[0005] Therefore, how to accurately calculate the injection ratio without increasing the system flow resistance is a technical challenge in the design and operation of simplified fuel cell hydrogen systems. Summary of the Invention

[0006] The present application provides a fuel cell ejection ratio test system and method for accurately calculating the ejection ratio without increasing the flow resistance of the fuel cell system.

[0007] The technical solution of this application is:

[0008] The present application provides a fuel cell ejection ratio test system, a test bench, and a fuel cell hydrogen simplification system, wherein the fuel cell hydrogen simplification system comprises: a fuel cell stack, a hydrogen inlet circuit, a stack inlet circuit, an ejection circuit, and an ejector, wherein the hydrogen inlet circuit enters the hydrogen outlet of the test bench, the ejector is connected between the hydrogen inlet circuit and the stack inlet circuit, the stack inlet circuit is connected to the hydrogen inlet of the fuel cell stack, and the ejection circuit is connected between the hydrogen outlet of the fuel cell stack and the ejector;

[0009] A flow meter is arranged on the hydrogen inlet circuit;

[0010] Controlling the startup of the fuel cell hydrogen simplification system, supplying hydrogen to the fuel cell hydrogen simplification system through the test bench, causing the stack power of the fuel cell hydrogen simplification system to change from zero loading to a target power that enables the fuel cell hydrogen simplification system to maintain stable operation; and measuring, through the flow meter, the total hydrogen intake volume provided to the fuel cell hydrogen simplification system by the test bench and the primary flow hydrogen flow rate at the primary flow inlet of the ejector during this process;

[0011] determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power;

[0012] The ejection ratio of the fuel cell hydrogen simplified system is determined according to the cumulative hydrogen consumption, the total hydrogen intake amount measured by the flow meter and the primary flow hydrogen flow at the primary flow inlet of the ejector.

[0013] Preferably, the step of determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power includes:

[0014] determining a ratio of an integral of the target power over the operating time to an integral of the efficiency of the fuel cell hydrogen simplified system over the operating time;

[0015] The cumulative hydrogen consumption of the fuel cell hydrogen simplified system is determined according to the product of the ratio and the lower calorific value of hydrogen.

[0016] Preferably, the step of determining the ejection ratio of the fuel cell hydrogen simplified system according to the cumulative hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector includes:

[0017] Determining the hydrogen flow rate entering the stack based on the accumulated hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector;

[0018] The injection ratio of the simplified fuel cell hydrogen system is determined based on the ratio of the inflow hydrogen flow rate to the primary flow hydrogen flow rate.

[0019] Preferably, the step of determining the hydrogen flow rate into the stack based on the cumulative hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector includes:

[0020] When the stack power of the fuel cell hydrogen simplified system is loaded to a target power that enables the fuel cell hydrogen simplified system to maintain stable operation, the permeated nitrogen amount is subtracted from the cumulative hydrogen consumption to obtain the true cumulative hydrogen consumption;

[0021] First determine the difference between the total hydrogen intake volume measured by the flow meter and the actual cumulative hydrogen consumption;

[0022] Then, the sum of the difference and the primary flow hydrogen flow at the primary flow inlet of the ejector is divided by two to determine the hydrogen flow entering the stack;

[0023] Wherein, at the target power, if the ratio of the pre-calibrated nitrogen permeation rate per second to the pre-calibrated hydrogen consumption per second is greater than or equal to the preset ratio, the permeated nitrogen amount is the product of the pre-calibrated nitrogen permeation rate per second and the operating time; if the ratio of the pre-calibrated nitrogen permeation rate per second to the pre-calibrated hydrogen consumption per second is less than the preset ratio, the permeated nitrogen amount is zero.

[0024] Preferably, the fuel cell hydrogen simplification system does not discharge hydrogen to the outside during testing.

[0025] Preferably, the ejector circuit is provided with a hydrogen-water separator and a shut-off valve connected in sequence, and the shut-off valve is connected to the secondary inlet of the ejector.

[0026] Preferably, a proportional valve is provided in the hydrogen inlet circuit, and the proportional valve is connected to the primary inlet of the ejector.

[0027] The present application also provides a fuel cell ejection ratio test method, using the above-mentioned fuel cell ejection ratio test system, the fuel cell ejection ratio test method includes:

[0028] Controlling the startup of the fuel cell hydrogen simplification system, supplying hydrogen to the fuel cell hydrogen simplification system through the test bench, causing the stack power of the fuel cell hydrogen simplification system to change from zero loading to a target power that enables the fuel cell hydrogen simplification system to maintain stable operation; and measuring, through the flow meter, the total hydrogen intake volume provided to the fuel cell hydrogen simplification system by the test bench and the primary flow hydrogen flow at the ejector inlet during this process;

[0029] determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power;

[0030] The ejection ratio of the simplified fuel cell hydrogen system is determined according to the cumulative hydrogen consumption, the total hydrogen intake amount measured by the flow meter and the primary flow hydrogen flow at the ejector inlet.

[0031] Preferably, the step of determining the ejection ratio of the fuel cell hydrogen simplified system according to the cumulative hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector includes:

[0032] Determining the hydrogen flow rate entering the stack based on the accumulated hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector;

[0033] The injection ratio of the simplified fuel cell hydrogen system is determined based on the ratio of the inflow hydrogen flow rate to the primary flow hydrogen flow rate.

[0034] Preferably, the step of determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power includes:

[0035] determining a ratio of an integral of the target power over the operating time to an integral of the efficiency of the fuel cell hydrogen simplified system over the operating time;

[0036] The cumulative hydrogen consumption of the fuel cell hydrogen simplified system is determined according to the product of the ratio and the lower calorific value of hydrogen.

[0037] The beneficial effects of this application are:

[0038] By utilizing the flow characteristics of hydrogen inside the ejector and combining it with the measurable parameters in the fuel cell system, the flow relationship in the fuel cell hydrogen system is derived, and a calculation model for the ejection ratio is derived, thereby avoiding directly measuring the hydrogen flow entering the fuel cell stack through a flow sensor and reducing the flow resistance in the fuel cell hydrogen system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural diagram of an existing fuel cell hydrogen system;

[0040] Figure 2 This is a schematic structural diagram of a simplified fuel cell hydrogen system in an embodiment of the present application;

[0041] Figure 3 Schematic diagram of the flow chart of the fuel cell ejection ratio testing method in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The present invention is further described below with reference to the following embodiments and accompanying drawings. This embodiment is based on the technical solution of the present invention and provides a detailed implementation method and specific operation process, but the scope of protection of the present invention is not limited to the following embodiments.

[0043] Reference Figure 1For a conventional fuel cell hydrogen system, hydrogen enters the fuel cell hydrogen system from the hydrogen supply circuit 1, enters the first mapper 30 through the first proportional valve 40, and enters the second ejector 50 through the second proportional valve 60. Hydrogen enters the first ejector 30 or the second ejector 50 according to the flow rate, and enters the fuel cell 10 through the stack feed circuit 3, the pressure sensor 20, and the feed circuit 3. The water and remaining hydrogen produced after the reaction in the fuel cell 10 enter the hydrogen-water separator 80 through the ejector circuit 4. The first ejector 30 or the second mapper 50 injects part of the hydrogen back into the stack circuit through the shut-off valve 70. After accumulating in the hydrogen-water separator 80 for a period of time, the water passes through the drain valve 100 and the drain circuit 6, and the remaining hydrogen passes through the hydrogen discharge valve 90 and the hydrogen discharge circuit 5 and enters the air exhaust circuit 2 to be discharged from the fuel cell hydrogen system.

[0044] Due to the characteristics of the ejector, fuel cell hydrogen systems cannot accurately control the inflow hydrogen flow rate Q2. Therefore, they typically lack an inflow flow sensor, relying solely on the inflow pressure sensor 20 to maintain the fuel cell stack's air-hydrogen differential pressure within a normal range. Therefore, the ejection ratio R of a simplified fuel cell hydrogen system cannot be calculated using the ratio of the inflow hydrogen flow rate Q2 to the primary hydrogen flow rate Q1.

[0045] Reference Figure 2 , the embodiment of the present application provides a fuel cell ejection ratio test system, a test bench and a fuel cell hydrogen simplification system, the fuel cell hydrogen simplification system comprising: a fuel cell stack 30, a hydrogen inlet circuit 1, an ejector 20, a stack inlet circuit 2 and an ejection circuit 3, the hydrogen inlet circuit 1 enters the hydrogen outlet of the test bench, the ejector 20 is connected between the hydrogen inlet circuit 1 and the stack inlet circuit 2, the stack inlet circuit 2 is connected to the hydrogen inlet of the fuel cell stack 30, and the ejection circuit 3 is connected between the hydrogen outlet of the fuel cell stack 30 and the ejector 20;

[0046] A flow meter 10 is arranged on the hydrogen inlet circuit 1 .

[0047] In order to facilitate the analysis of the fuel cell hydrogen simplified system in the embodiment of the present application Figure 1 The fuel cell hydrogen system in the embodiment omits components that have little impact on the flow characteristics, such as the shut-off valve 70, the hydrogen-water separator 80, the proportional valve 40, and the second proportional valve 60. This simplified processing helps to reduce the complexity of the calculation without affecting the accuracy of the calculation results. Of course, in order to simulate a more realistic situation, the simplified fuel cell hydrogen system can also be built according to the real fuel cell hydrogen system, that is, the ejection circuit is provided with a hydrogen-water separator and a shut-off valve connected in sequence, and the shut-off valve is connected to the secondary inlet of the ejector. The hydrogen inlet circuit is provided with a proportional valve, and the proportional valve is connected to the primary inlet of the ejector.

[0048] The flow meter 10 is a flow sensor of the test bench. The test bench can ensure that the flow rate and pressure of the hydrogen entering the fuel cell simplified system are the same as the actual ones. Therefore, the test bench flow meter 10 does not affect the system flow resistance.

[0049] Among them, the test bench serves as the hydrogen supply source and is responsible for providing stable and clean hydrogen to the entire system. The hydrogen outlet of the test bench is connected to the hydrogen inlet circuit through a pipeline to ensure that the hydrogen can smoothly enter the fuel cell hydrogen simplification system. The ejector is a key node for the flow of hydrogen in the fuel cell hydrogen simplification system. It is connected between the hydrogen inlet circuit and the stack inlet circuit, and uses the high-speed flow of the primary flow hydrogen to drive the secondary flow hydrogen. The hydrogen inlet of the fuel cell stack is the channel for hydrogen to enter the stack. The stack inlet circuit needs to ensure that hydrogen can enter the stack evenly and stably to maintain the efficient operation of the stack. The hydrogen discharged from the fuel cell stack is reintroduced into the ejector through the ejector circuit to achieve the recycling of hydrogen.

[0050] During testing, the test bench supplied hydrogen to the fuel cell's simplified hydrogen system. The hydrogen first entered the hydrogen inlet circuit, was monitored by a flow meter, and then flowed into the ejector. The ejector, utilizing the high-speed flow of the primary hydrogen, drove the secondary hydrogen into the stack inlet circuit and ultimately into the fuel cell. Hydrogen exhausted from the fuel cell returned to the ejector through the ejector circuit, achieving hydrogen recycling.

[0051] In an embodiment of the present application, in order to determine the ejection ratio, the primary flow hydrogen flow at the inlet of the ejector 20 in the fuel cell hydrogen simplification system is set to Q1. This flow is the hydrogen flow entering the fuel cell hydrogen simplification system and can be measured using a flow meter 10.

[0052] The flow rate of hydrogen entering the stack is set to Q2, which is unmeasurable. Therefore, the ejection ratio R=Q2 / Q1 in the embodiment of the present application cannot be directly obtained.

[0053] The transient hydrogen consumption Q3 and the return hydrogen flow Q4 of the fuel cell are set. These two parameters cannot be directly measured.

[0054] In addition, relevant parameters are set, including the fuel cell hydrogen simplified system power P, the total hydrogen intake volume M and the cumulative hydrogen consumption ΔQ; the fuel cell hydrogen simplified system power P can be obtained by the fuel cell controller, the total hydrogen intake volume M can be obtained by the flow meter 10, and the cumulative hydrogen consumption ΔQ cannot be directly measured.

[0055] When the fuel cell hydrogen simplified system is in the process of starting up and reaching a stable state, since the fuel cell hydrogen simplified system does not exhaust, the total hydrogen intake volume M is equal to the sum of the cumulative hydrogen consumption ΔQ and the amount of hydrogen still in circulation (i.e., the current hydrogen flow rate Q2 entering the stack and the hydrogen return flow rate Q4), that is:

[0056] Total hydrogen intake volume M = cumulative hydrogen consumption ΔQ + hydrogen flow rate into the reactor Q2 + hydrogen flow rate back to the reactor Q4 (1)

[0057] The total hydrogen intake volume M can be obtained from the flow meter 10, and the cumulative hydrogen consumption ΔQ can be calculated based on the stack power P and efficiency η of the simplified fuel cell hydrogen system:

[0058] η=1000*P / (ΔQ*LHV)*100%(2)

[0059] In formula (2), LHV is the lower heating value of hydrogen, 1.2*10 5 kJ / kg; P is the fuel cell stack power, unit is kW.

[0060] The efficiency η of the simplified fuel cell hydrogen system can be fitted based on the steady-state efficiency curves of the fuel cell at various operating points obtained in the previous calibration, and the efficiency η of the simplified fuel cell hydrogen system and the multi-factor formula under the stack power P can be obtained:

[0061] η=x1P n +x2P n-1 +x3P n-2 ...x n P+C(3)

[0062] Wherein, x1, x2, x3, .....xn are pre-calibrated polynomial coefficients, and C represents a constant.

[0063] Since the description is about the process from startup to stabilization of the fuel cell hydrogen simplified system rather than the stable state, the cumulative hydrogen consumption meets the following requirements:

[0064]

[0065] Where t is the time from startup to stabilization of the fuel cell hydrogen simplified system, LHV represents the lower heating value of hydrogen, from which the cumulative hydrogen consumption of the fuel cell ΔQ can be obtained.

[0066] Among them, for the fuel cell stack, nitrogen will permeate from the cathode side to the anode side, and the reaction will produce water vapor, which will increase the cumulative hydrogen consumption after passing through the stack, but according to the calculated ratio, it is less than 1% and can be ignored. If the nitrogen permeability of the fuel cell stack of the simplified hydrogen system is too large during the test, it is necessary to increase the correction factor and deduct this part of the permeated nitrogen from the cumulative hydrogen consumption ΔQ. In other words, when the stack power of the simplified hydrogen system of the fuel cell is stable at the target power, if the ratio of the pre-calibrated nitrogen permeation per second to the pre-calibrated hydrogen consumption per second is greater than or equal to the preset ratio (such as 1%), it is necessary to subtract the permeated nitrogen from the cumulative hydrogen consumption ΔQ. The permeated nitrogen amount is the product of the pre-calibrated nitrogen permeation per second and the operating time; if the ratio of the pre-calibrated nitrogen permeation per second to the pre-calibrated hydrogen consumption per second is less than the preset ratio (1%), the permeated nitrogen amount is zero.

[0067] When the fuel cell hydrogen simplified system enters a stable state, that is, when the fuel cell stack power decreases from 0 to the target power of the stable working state, the inflow hydrogen flow Q2 minus the fuel cell transient hydrogen consumption Q3 equals the return hydrogen flow Q4; at the same time, the ejection flow Q4 plus the primary flow hydrogen flow Q1 equals the inflow hydrogen flow Q2. Therefore, the flow of the fuel cell hydrogen simplified system satisfies:

[0068] Into-stack hydrogen flow rate Q2 - return hydrogen flow rate Q4 = fuel cell transient hydrogen consumption Q3 (5);

[0069] Return hydrogen flow Q4 + primary flow hydrogen flow Q1 = inlet hydrogen flow Q2 (6).

[0070] According to formula (5) and formula (6), we can get:

[0071] The primary hydrogen flow rate Q1 = the fuel cell transient hydrogen consumption Q3 (7).

[0072] According to formula (1), formula (5) and formula (7), we can get:

[0073] Hydrogen flow rate into the stack Q2 = (total hydrogen intake M - cumulative hydrogen consumption ΔQ + primary flow hydrogen flow rate Q1) / 2 (8);

[0074] According to formula (8) and the injection ratio expression, we can get:

[0075] Injection ratio R = hydrogen flow rate into the stack Q2 / primary flow hydrogen flow rate Q1 = (total hydrogen intake M - cumulative hydrogen consumption ΔQ + primary flow hydrogen flow rate Q1) / primary flow hydrogen flow rate Q1 / 2 (9).

[0076] Furthermore, the fuel cell hydrogen simplification system is installed on a test bench for data testing, and a flow meter is used to record the primary hydrogen flow rate Q1 and the total hydrogen intake volume M. The stack power is loaded from zero to the specified target power. During this period, the fuel cell hydrogen simplification system is not subjected to hydrogen discharge treatment, and the change of the stack power over time is recorded until the stack power stabilizes. During the operation of the actual fuel cell hydrogen system, hydrogen is not often discharged for economic reasons, and generally exhausts for a few tenths of a second every 10-20 seconds. Therefore, simplifying the hydrogen discharge process during the test in the embodiment of the present application will not affect the accuracy of the calculation results.

[0077] Summarized by the above principles, Figure 3 The fuel cell injection ratio test system in the embodiment of the present application performs the following steps when performing the injection ratio test:

[0078] S101, controlling the start-up of the fuel cell hydrogen simplification system, supplying hydrogen to the fuel cell hydrogen simplification system through the test bench, causing the stack power of the fuel cell hydrogen simplification system to change from zero loading to a target power that enables the fuel cell hydrogen simplification system to maintain stable operation; and measuring, through the flow meter, the total hydrogen intake amount provided to the fuel cell hydrogen simplification system by the test bench and the primary flow hydrogen flow rate at the primary flow inlet of the ejector during this process;

[0079] S102, determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power;

[0080] S103, determining the ejection ratio of the simplified hydrogen system of the fuel cell according to the accumulated hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow at the primary flow inlet of the ejector.

[0081] The step S102 of determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power includes:

[0082] determining a ratio of an integral of the target power over the operating time to an integral of the efficiency of the fuel cell hydrogen simplified system over the operating time;

[0083] The cumulative hydrogen consumption of the fuel cell hydrogen simplified system is determined according to the product of the ratio and the lower calorific value of hydrogen.

[0084] The step S103 of determining the injection ratio of the fuel cell hydrogen simplified system according to the accumulated hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow at the primary flow inlet of the ejector comprises:

[0085] S1031, determining the hydrogen flow rate entering the stack based on the accumulated hydrogen consumption, the total hydrogen intake volume measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector;

[0086] S1032: Determine the injection ratio of the simplified hydrogen system of the fuel cell according to the ratio of the hydrogen flow rate entering the stack to the hydrogen flow rate of the primary flow.

[0087] The step S1031 of determining the hydrogen flow rate entering the stack according to the accumulated hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector comprises:

[0088] S10311, when the stack power of the fuel cell hydrogen simplified system is loaded to a target power that enables the fuel cell hydrogen simplified system to maintain stable operation, subtract the permeated nitrogen amount from the cumulative hydrogen consumption to obtain a true cumulative hydrogen consumption;

[0089] S10312, first determine the difference between the total hydrogen intake volume measured by the flow meter and the actual cumulative hydrogen consumption;

[0090] S10313, dividing the sum of the difference and the primary flow hydrogen flow at the primary flow inlet of the ejector by two to determine the hydrogen flow entering the stack;

[0091] Wherein, at the target power, if the ratio of the pre-calibrated nitrogen permeation rate per second to the pre-calibrated hydrogen consumption per second is greater than or equal to the preset ratio, the permeated nitrogen amount is the product of the pre-calibrated nitrogen permeation rate per second and the operating time; if the ratio of the pre-calibrated nitrogen permeation rate per second to the pre-calibrated hydrogen consumption per second is less than the preset ratio, the permeated nitrogen amount is zero.

[0092] In fuel cell stacks, nitrogen permeates from the cathode to the anode, and the reaction produces water vapor, which increases the cumulative hydrogen consumption after passing through the stack. However, this percentage is calculated to be less than 1% and can be ignored. If the nitrogen permeability of the fuel cell stack is too high during testing, a correction factor will be added to offset this amount of permeated nitrogen in the cumulative hydrogen consumption ΔQ.

[0093] The above-mentioned fuel cell ejection ratio test system in the embodiment of the present application does not set a flow sensor in the stack feed circuit for calculating the ejection ratio, thereby avoiding the flow sensor increasing the flow resistance; and utilizes the flow characteristics of hydrogen inside the ejector, combined with the measurable parameters in the fuel cell system, to deduce the flow relationship in the fuel cell hydrogen system, derive the calculation model of the ejection ratio, and improve the accuracy of the ejection ratio calculation results.

[0094] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0095] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0096] It should also be noted that, in this document, the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are for the purpose of facilitating the description of the present invention and simplifying the description, rather than indicating or implying that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, relational terms such as "first" and "second" are used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any actual relationship or order between these entities or operations, nor should they be understood as indicating or implying relative importance. Moreover, the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements does not include those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or terminal device comprising the element.

[0097] The technical solutions provided by the present invention have been described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is intended only to facilitate understanding of the present invention, and the contents of this specification should not be construed as limiting the present invention. Furthermore, those skilled in the art will appreciate that various modifications may be made to the specific implementation methods and scope of application according to the present invention. It is not necessary and impossible to exhaustively enumerate all implementation methods herein, and any obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A fuel cell ejection ratio test system, characterized in that: A test bench and a simplified fuel cell hydrogen system, the simplified fuel cell hydrogen system comprising: a fuel cell stack, a hydrogen inlet circuit, a stack inlet circuit, an ejector circuit, and an ejector, the hydrogen inlet circuit entering the hydrogen outlet of the test bench, the ejector connected between the hydrogen inlet circuit and the stack inlet circuit, the stack inlet circuit connected to the hydrogen inlet of the fuel cell stack, and the ejector circuit connected between the hydrogen outlet of the fuel cell stack and the ejector; A flow meter is arranged on the hydrogen inlet circuit; Controlling the startup of the fuel cell hydrogen simplification system, supplying hydrogen to the fuel cell hydrogen simplification system through the test bench, causing the stack power of the fuel cell hydrogen simplification system to change from zero loading to a target power that enables the fuel cell hydrogen simplification system to maintain stable operation; and measuring, through the flow meter, the total hydrogen intake volume provided to the fuel cell hydrogen simplification system by the test bench and the primary flow hydrogen flow rate at the primary flow inlet of the ejector during this process; determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power; The ejection ratio of the fuel cell hydrogen simplified system is determined according to the cumulative hydrogen consumption, the total hydrogen intake amount measured by the flow meter and the primary flow hydrogen flow at the primary flow inlet of the ejector.

2. The fuel cell ejection ratio test system according to claim 1, characterized in that: The step of determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power includes: determining a ratio of an integral of the target power over the operating time to an integral of the efficiency of the fuel cell hydrogen simplified system over the operating time; The cumulative hydrogen consumption of the fuel cell hydrogen simplified system is determined according to the product of the ratio and the lower calorific value of hydrogen.

3. The fuel cell ejection ratio test system according to claim 1, characterized in that: The step of determining the injection ratio of the fuel cell hydrogen simplified system according to the cumulative hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector includes: Determining the hydrogen flow rate entering the stack based on the accumulated hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector; The injection ratio of the simplified fuel cell hydrogen system is determined based on the ratio of the inflow hydrogen flow rate to the primary flow hydrogen flow rate.

4. The fuel cell ejection ratio test system according to claim 3, characterized in that: The step of determining the hydrogen flow rate entering the stack according to the accumulated hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector comprises: When the stack power of the fuel cell hydrogen simplified system is loaded to a target power that enables the fuel cell hydrogen simplified system to maintain stable operation, the permeated nitrogen amount is subtracted from the cumulative hydrogen consumption to obtain the true cumulative hydrogen consumption; First determine the difference between the total hydrogen intake volume measured by the flow meter and the actual cumulative hydrogen consumption; Then, the sum of the difference and the primary flow hydrogen flow at the primary flow inlet of the ejector is divided by two to determine the hydrogen flow entering the stack; Wherein, at the target power, if the ratio of the pre-calibrated nitrogen permeation rate per second to the pre-calibrated hydrogen consumption per second is greater than or equal to the preset ratio, the permeated nitrogen amount is the product of the pre-calibrated nitrogen permeation rate per second and the operating time; if the ratio of the pre-calibrated nitrogen permeation rate per second to the pre-calibrated hydrogen consumption per second is less than the preset ratio, the permeated nitrogen amount is zero.

5. The fuel cell ejection ratio test system according to claim 1, characterized in that: The fuel cell hydrogen simplification system does not discharge hydrogen to the outside during testing.

6. The fuel cell ejection ratio test system according to claim 1, characterized in that: The ejector circuit is provided with a hydrogen-water separator and a shut-off valve connected in sequence, and the shut-off valve is connected to the secondary inlet of the ejector.

7. The fuel cell ejection ratio test system according to claim 1, characterized in that: A proportional valve is provided in the hydrogen inlet circuit, and the proportional valve is connected to the primary inlet of the ejector.

8. A fuel cell ejection ratio test method, using the fuel cell ejection ratio test system according to any one of claims 1 to 7, characterized in that: The fuel cell ejection ratio test method includes: Controlling the startup of the fuel cell hydrogen simplification system, supplying hydrogen to the fuel cell hydrogen simplification system through the test bench, causing the stack power of the fuel cell hydrogen simplification system to change from zero loading to a target power that enables the fuel cell hydrogen simplification system to maintain stable operation; and measuring, through the flow meter, the total hydrogen intake volume provided to the fuel cell hydrogen simplification system by the test bench and the primary flow hydrogen flow at the ejector inlet during this process; determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power; The ejection ratio of the simplified fuel cell hydrogen system is determined according to the cumulative hydrogen consumption, the total hydrogen intake amount measured by the flow meter and the primary flow hydrogen flow at the ejector inlet.

9. The fuel cell ejection ratio test method according to claim 8, characterized in that: The step of determining the injection ratio of the fuel cell hydrogen simplified system according to the cumulative hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector includes: Determining the hydrogen flow rate entering the stack based on the accumulated hydrogen consumption, the total hydrogen intake amount measured by the flow meter, and the primary flow hydrogen flow rate at the primary flow inlet of the ejector; The injection ratio of the simplified fuel cell hydrogen system is determined based on the ratio of the inflow hydrogen flow rate to the primary flow hydrogen flow rate.

10. The fuel cell ejection ratio testing method according to claim 8, characterized in that: The step of determining the cumulative hydrogen consumption of the fuel cell hydrogen simplification system according to the operating time consumed for the stack power to change to the target power and the target power includes: determining a ratio of an integral of the target power over the operating time to an integral of the efficiency of the fuel cell hydrogen simplified system over the operating time; The cumulative hydrogen consumption of the fuel cell hydrogen simplified system is determined according to the product of the ratio and the lower calorific value of hydrogen.

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