Hydrogen fuel cell system tail gas recovery device and method of draining

Abstract

The application provides a hydrogen fuel cell system tail gas recovery device and a drainage method thereof, and the method comprises the following steps: step one, obtaining the air compressor speed and the air compressor current in the current period; step two, obtaining the vortex end through flow in the current period and the drainage rate in the current period according to the air compressor speed and the air compressor current, and calculating the accumulated water amount when the valve is closed in the last period; step three, calculating the drainage valve opening time in the current period according to the vortex end through flow in the current period, the drainage rate in the current period and the accumulated water amount when the valve is closed in the last period; step four, judging whether the drainage valve opening time in the current period meets the constraint condition; step five, if the drainage valve opening time in the current period meets the constraint condition, controlling the drainage valve according to the calculated drainage valve opening time in the current period; and step six, if the drainage valve opening time in the current period does not meet the constraint condition, continuously opening the drainage valve in the current period.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell technology, and in particular to a hydrogen fuel cell system exhaust gas recovery device and its drainage method. Background Technology

[0002] Hydrogen fuel cell electric vehicles are pollution-free, highly energy-efficient, have a long driving range, and require short refueling times, making them one of the important directions for the development of new energy vehicles. The hydrogen fuel cell system is its core component.

[0003] The exhaust gas released during the operation of a hydrogen fuel cell system is a mixture of air, water vapor, and condensate, possessing a certain amount of heat, kinetic energy, and pressure. By recovering this exhaust gas through a turbine generator to generate electricity, which is then fed back to the battery or grid, the system's output power can be increased, improving its energy utilization efficiency.

[0004] Because the exhaust gas contains a significant amount of water vapor and liquid water, directly introducing it into the turbine generator during exhaust gas recovery would damage the generator. Therefore, a water separator is necessary to separate the water from the exhaust gas. However, the operation of the exhaust gas recovery device in a hydrogen fuel cell system is affected by the pressure, velocity, and water content of the exhaust gas. The separated water also affects the flow of gas within the recovery device, and its accumulation can negatively impact the water separator structure, reducing its water separation efficiency. Therefore, designing a control method to ensure efficient and automatic drainage of the water separator becomes a crucial issue. Summary of the Invention

[0005] The purpose of this invention is to provide a drainage method and apparatus for a hydrogen fuel cell system exhaust gas recovery device, so as to improve the water separation efficiency of the hydrogen fuel cell system exhaust gas recovery device.

[0006] To solve the above-mentioned technical problems, the present invention provides a drainage method for a hydrogen fuel cell system exhaust gas recovery device, comprising:

[0007] Step 1: Obtain the air compressor speed and air compressor current for the current cycle;

[0008] Step 2: Based on the air compressor speed and air compressor current, look up the table to obtain the flow rate through the vortex end and the drainage rate in the current cycle, and calculate the water accumulation when the valve was closed in the previous cycle.

[0009] Step 3: Calculate the opening time of the drain valve in the current cycle based on the flow rate through the vortex end in the current cycle, the drainage rate in the current cycle, and the water accumulation when the valve was closed in the previous cycle.

[0010] Step 4: Determine whether the opening time of the drain valve in the current cycle meets the constraints.

[0011] Step 5: If the opening time of the drain valve in the current cycle meets the constraint conditions, then control the drain valve according to the calculated opening time of the drain valve in the current cycle.

[0012] Step 6: If the opening time of the drain valve in the current cycle does not meet the constraint conditions, then the drain valve will continue to be opened in the current cycle.

[0013] Optionally, the drainage method for the exhaust gas recovery device of the hydrogen fuel cell system further includes calibrating the flow rate and drainage rate of the turbine generator's vortex end, which includes the following steps:

[0014] Based on different operating conditions of the fuel cell system, the peak speed and peak current of the air compressor are obtained;

[0015] The air compressor speed is divided into N velocity vectors X: 0, S1, ..., S, which increase by a unit speed from 0 to the peak speed. Max ;

[0016] The air compressor current is divided into M current vectors Y: 0, Iq1, ..., Iq, which increase in unit current increments. Max ;

[0017] With vectors X and Y as the horizontal and vertical coordinates respectively, establish the first test condition matrix regarding the flow rate through the vortex end;

[0018] A second test condition matrix for drainage rate is established with vectors X and Y as the horizontal and vertical coordinates, respectively.

[0019] Through testing, the vortex end was calibrated by flow rate and drainage rate under different speeds and currents, and the first test condition matrix and the second test condition matrix were obtained. These were then converted into data tables that the control program could directly query and use.

[0020] Optionally, the drainage method for the exhaust gas recovery device of the hydrogen fuel cell system further includes:

[0021] The allowable water accumulation height h of the water distributor is calibrated, and the maximum allowable water accumulation Q is calculated.

[0022] Determine the appropriate cycle time T based on the operating conditions of the fuel cell system and the actual measurement of exhaust gas.

[0023] During each cycle, steps one through six are repeated.

[0024] The cycle time is the sum of the opening time of the drain valve in the current cycle and the closing time of the drain valve in the current cycle.

[0025] Optionally, in the drainage method of the exhaust gas recovery device of the hydrogen fuel cell system, the drainage valve is a bypass valve.

[0026] Actual measurements of fuel cell system operating conditions and exhaust gases include: determining and maintaining the opening of the drain valve based on position sensors during the turbine generator test;

[0027] The moisture content A of the exhaust gas was measured using a humidity sensor; and

[0028] The amount of water separated by the water separator is measured by a flow sensor, and the water separation efficiency Eff is calculated. The water separation efficiency is the ratio of the amount of water separated to the water content in the exhaust gas.

[0029] Optionally, the drainage method for the exhaust gas recovery device of the hydrogen fuel cell system further includes:

[0030] Set the initial water volume Q 2,0 =0, initial vortex end flow rate q 1,0 =0;

[0031] In the nth period, the vortex end obtained from the initial query passes through a flow rate q. 1,n and drainage rate f 2,n Calculate the opening and closing times of the bypass valve; calculate the actual water distribution rate f. 1,n The calculation formula is f 1,n =q 1,n *A*Eff;

[0032] The actual water distribution Q was calculated. 1,n The calculation formula is Q 1,n =f 1,n *T;

[0033] The water accumulation Q when the bypass valve is closed in the (n-1)th cycle is calculated. 2,n-1 The water accumulation is the bypass valve closing time t in the (n-1)th cycle. 2,n-1 The water volume inside, the flow rate through the vortex end in the (n-1)th cycle is q 1,n-1 The calculation formula is Q 2,n-1 =f 1,n-1 *t 2,n-1 =q 1,n-1 *A*Eff*t 2,n-1 ;

[0034] The bypass valve opening time t was calculated. 1,n and bypass valve closing time t 2,n The calculation formula is t 1,n =(Q 1,n +Q 2,n-t ) / f 2,n ;t2,n =Tt 1,n ;

[0035] During the calculation process, it is determined whether the following constraints are met:

[0036]

[0037] Optionally, in the drainage method of the exhaust gas recovery device of the hydrogen fuel cell system,

[0038] A drainage control unit is installed in the exhaust gas recovery device of the hydrogen fuel cell system to control the bypass valve according to the drainage method described above.

[0039] Position sensors, humidity sensors, and flow sensors are installed in the exhaust gas recovery device of the hydrogen fuel cell system.

[0040] The present invention also provides a hydrogen fuel cell system exhaust gas recovery device, comprising:

[0041] The air path of the hydrogen fuel cell system is configured to compress the exhaust gas through an air compressor and then deliver it to the water distributor.

[0042] The water separator is configured to separate the exhaust gas into gas and liquid, then deliver the gas to the turbine generator and the liquid to the drain valve.

[0043] The drainage control unit is configured to perform the drainage method of the hydrogen fuel cell system exhaust gas recovery device as described in claim 1, in order to control the opening and closing of the drainage valve.

[0044] Optionally, the hydrogen fuel cell system exhaust gas recovery device further includes:

[0045] The turbine generator controller is configured to control the turbine engine;

[0046] A pressure sensor is positioned between the turbine engine and the water distributor;

[0047] A silencer is installed on the outside of the drain valve.

[0048] Optionally, in the hydrogen fuel cell system exhaust gas recovery device, the structure of the air path of the hydrogen fuel cell system includes an intake air filter, an intake flow meter, an air compressor, an intercooler, a humidifier, a fuel cell stack, and a back pressure valve connected in sequence.

[0049] The present invention also provides an electric vehicle having the aforementioned hydrogen fuel cell system exhaust gas recovery device.

[0050] The inventors of this invention discovered through research that in traditional drainage processes, the drain valve is often kept open for continuous drainage. However, applying this method to hydrogen fuel cell exhaust gas recovery and power generation would cause high-temperature, high-pressure exhaust gas to flow out, resulting in energy loss. Furthermore, the valve opening directly affects the intake of the turbine generator, and an inappropriate valve opening could even have negative effects, damaging the turbine generator. Alternatively, a water level sensor could be used to monitor the water level and drain the water periodically, but this method would increase system costs and would not allow for the development of corresponding drainage strategies in advance under varying operating conditions, increasing the risk of malfunctions.

[0051] In addition, during the exhaust gas recovery process, the flow rate and pressure of the exhaust gas discharged by the air compressor change with the operating conditions, which directly affects the flow rate through the turbine generator vortex and the water accumulation rate in the distributor. Therefore, under varying operating conditions, determining the flow rate through the vortex and the drainage speed, and finding the optimal drainage method, has become an urgent problem to be solved.

[0052] In summary, traditional drainage control methods mostly have certain problems and shortcomings, making them unsuitable for turbine generator systems. Therefore, new control methods are needed for adaptation.

[0053] Based on the above insights, this invention provides a hydrogen fuel cell system exhaust gas recovery device and its drainage method. By looking up tables based on the air compressor speed and current, the flow rate through the vortex end and the drainage rate in the current cycle can be obtained in a timely manner. Based on the flow rate through the vortex end, the drainage rate, and the amount of water accumulated when the valve was closed in the previous cycle, the opening time of the drainage valve in the current cycle is calculated. The opening and closing of the drainage valve is controlled in real time in each cycle, which is more flexible and adaptable to drainage strategies under various operating conditions. In addition, by judging whether the opening time of the drainage valve in the current cycle meets the constraints, normal drainage is carried out when the conditions are met to reduce the energy loss of the exhaust gas. If the conditions are not met, the drainage valve is kept open in the current cycle, which improves the reliability and safety of the system and achieves the best dynamic balance between improving efficiency and safety. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of a drainage method for a hydrogen fuel cell system exhaust gas recovery device according to an embodiment of the present invention;

[0055] Figure 2 This is a schematic diagram of a hydrogen fuel cell system exhaust gas recovery device according to an embodiment of the present invention. Detailed Implementation

[0056] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0057] It should be noted that the components in the various figures may be shown exaggeratedly for illustrative purposes and are not necessarily to scale. In each figure, the same reference numerals are used for components that are identical or have the same function.

[0058] In this invention, unless otherwise specified, "arranged on," "arranged above," and "arranged on" do not exclude the possibility of an intermediate element between them. Furthermore, "arranged on or above" merely indicates the relative positional relationship between two components, and in certain cases, such as when the product orientation is reversed, it can also be converted to "arranged below or under," and vice versa.

[0059] In this invention, the various embodiments are merely intended to illustrate the solutions of the invention and should not be construed as limiting.

[0060] In this invention, unless otherwise specified, the quantifiers “a” and “one” do not exclude scenarios involving multiple elements.

[0061] It should also be noted that, in the embodiments of the present invention, only a portion of the components or parts may be shown for clarity and simplicity. However, those skilled in the art will understand that, under the teachings of the present invention, necessary components or parts can be added as needed for specific scenarios. Furthermore, unless otherwise stated, features in different embodiments of the present invention can be combined with each other. For example, a feature in the second embodiment can replace a corresponding or functionally identical or similar feature in the first embodiment, and the resulting embodiment will also fall within the scope of disclosure or description of this application.

[0062] It should also be noted that, within the scope of this invention, the terms "same," "equal," and "equal to" do not imply that the two values ​​are absolutely equal, but rather allow for a certain reasonable margin of error. In other words, the terms also encompass "substantially the same," "substantially equal," and "substantially equal to." Similarly, in this invention, the directional terms "perpendicular to," "parallel to," etc., also encompass the meanings of "substantially perpendicular to" and "substantially parallel to."

[0063] Furthermore, the numbering of the steps in the methods of the present invention does not limit the execution order of the method steps. Unless otherwise specified, the method steps may be executed in different orders.

[0064] The exhaust gas recovery device and drainage method for a hydrogen fuel cell system proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this invention.

[0065] The purpose of this invention is to provide a hydrogen fuel cell system exhaust gas recovery device and its drainage method, so as to improve the water separation efficiency of the hydrogen fuel cell system exhaust gas recovery device.

[0066] To achieve the above objectives, the present invention provides a hydrogen fuel cell system exhaust gas recovery device and its drainage method, comprising: Step 1, obtaining the air compressor speed and air compressor current in the current cycle; Step 2, obtaining the vortex end flow rate and drainage rate in the current cycle by looking up a table based on the air compressor speed and air compressor current, and calculating the water accumulation when the valve was closed in the previous cycle; Step 3, calculating the drainage valve opening time in the current cycle based on the vortex end flow rate, drainage rate, and water accumulation when the valve was closed in the previous cycle; Step 4, determining whether the drainage valve opening time in the current cycle meets the constraint conditions; Step 5, if the drainage valve opening time in the current cycle meets the constraint conditions, controlling the drainage valve according to the calculated drainage valve opening time in the current cycle; Step 6, if the drainage valve opening time in the current cycle does not meet the constraint conditions, continuously opening the drainage valve in the current cycle.

[0067] This invention relates to the field of hydrogen fuel cell system products, and more specifically, to a method for controlling the automatic discharge of water separated from the exhaust gas using a water separator during the exhaust gas recovery process in a fuel cell system, through a calibration method of the flow rate and drainage rate of the turbine generator's vortex end.

[0068] Figure 1 and Figure 2 The drainage method for the exhaust gas recovery device of the hydrogen fuel cell system and the exhaust gas recovery device of the hydrogen fuel cell system are shown respectively. In combination Figure 1 Before explaining the drainage methods, we must first combine Figure 2 Describe the exhaust gas recovery device for hydrogen fuel cell systems.

[0069] Figure 2 A schematic diagram of a hydrogen fuel cell system exhaust gas recovery device according to an embodiment of the present invention is shown. Figure 2 As shown, the exhaust gas emitted by each hydrogen fuel cell system first passes through the air path section of the fuel cell system. The exhaust gas of one or more fuel cell systems can be integrated into the same exhaust gas recovery device for processing. That is, a single turbine generator system assembly can centrally recover the exhaust gas energy of one or more fuel cell systems. Among them, 200, 300, ..., N00 are the air path sections of one or more fuel cell systems. This is the conventional structure.

[0070] Each air path section includes the following connected sequentially:

[0071] The intake air filter 201 is a device for filtering air to remove harmful substances, foreign objects, dust, etc., and to prevent them from entering the turbine generator and causing malfunctions.

[0072] Air intake flow meter 202 measures the real-time air flow rate;

[0073] Air compressor 204 compresses air and lowers its boiling point, allowing water vapor in the exhaust gas of the subsequent cooling stage to exist in liquid form, making it easier to separate from the hot gas when it enters the water separator. Air compressor controller 203 controls the operation of the air compressor.

[0074] Intercooler 205 cools the air;

[0075] Humidifier 206 regulates the humidity of the air;

[0076] The fuel cell stack 207 drives the exhaust gas into the subsequent exhaust gas recovery device (water separator);

[0077] Back pressure valve 208 controls the flow rate of exhaust gas entering the distributor;

[0078] The exhaust gas recovery device of the hydrogen fuel cell system also includes a battery 000 that supplies power to the turbine generator controller 102 and the air compressor controller 203 (this invention patent only references this structure and does not protect this structure).

[0079] The hydrogen fuel cell system exhaust gas recovery device also includes a turbine generator system assembly 100, which is part of the hydrogen fuel cell system exhaust gas recovery device of the present invention, and includes:

[0080] The water separator 104 divides the exhaust gas, with a portion of the liquid entering the bypass valve (drain valve) 105 and the other portion of the gas entering the pressure sensor 103. The drainage method of the hydrogen fuel cell system exhaust gas recovery device provided by the present invention achieves timely drainage by measuring the amount of water accumulated in the water separator and controlling the opening time of the bypass valve (drain valve) 105.

[0081] Bypass valve (drain valve) 105 discharges liquid water, and silencer 106 silences the discharged liquid water.

[0082] Pressure sensor 103 detects the pressure of gaseous exhaust gas;

[0083] The turbine generator 101 generates electricity by being driven by gaseous exhaust gas; the turbine generator controller 102 controls the turbine generator.

[0084] Figure 1 A schematic diagram of a drainage method for a hydrogen fuel cell system exhaust gas recovery device according to an embodiment of the present invention is shown. Figure 1As shown, before the drainage process begins, initialization work needs to be performed, including: calibrating the allowable water accumulation height h of the water distributor and calculating the maximum allowable water accumulation Q; and determining the appropriate cycle time T based on the fuel cell system operating conditions and actual exhaust gas measurements.

[0085] The exhaust gas recovery process begins, and the automatic drainage process begins. Steps one through six are repeated within each cycle; the cycle time is the sum of the drain valve opening time and the drain valve closing time for the current cycle. This includes:

[0086] Step 1: Obtain the air compressor speed and air compressor current for the current cycle. This can be obtained from existing parameters in the air compressor controller. Generally, air compressors have built-in speed and current sensors, which provide the detected air compressor speed and current to the air compressor controller to accurately control the operation of the air compressor. Therefore, this parameter can be obtained using existing hardware and software without incurring additional costs.

[0087] Step two: Based on the air compressor speed and current, look up the table to obtain the flow rate through the vortex head and the drainage rate for the current cycle. Calculate the actual water distribution rate and volume based on the flow rate and drainage rate, and also calculate the accumulated water volume when the valve was closed in the previous cycle; for example:

[0088] Set the initial water volume Q 2,0 =0, initial vortex end flow rate q 1,0 =0;

[0089] In the nth period, the vortex end obtained from the initial query passes through a flow rate q. 1,n and drainage rate f 2,n Calculate the opening and closing times of the bypass valve; calculate the actual water distribution rate f. 1,n The calculation formula is f 1,n =q 1,n *A*Eff;

[0090] The actual water distribution Q was calculated. 1,n The calculation formula is Q 1,n =f 1,n *T;

[0091] The water accumulation Q when the bypass valve is closed in the (n-1)th cycle is calculated. 2,n-1 The water accumulation is the bypass valve closing time t in the (n-1)th cycle. 2,n-1 The water volume inside, the flow rate through the vortex end in the (n-1)th cycle is q 1,n-1 The calculation formula is Q 2,n-1 =f 1,n-1 *t 2,n-1 =q 1,n-1*A*Eff*t 2,n-1 ;

[0092] Step 3: Based on the vortex end flow rate, the drainage rate, and the water accumulation when the valve was closed in the previous cycle, calculate the opening time of the drainage valve for the current cycle; for example:

[0093] The bypass valve opening time t was calculated. 1,n and bypass valve closing time t 2,n The calculation formula is t 1,n =(Q 1,n +Q 2,n-t ) / f 2,n ;t 2,n =Tt 1,n ;

[0094] Step 4: Determine whether the opening time of the drain valve in the current cycle meets the constraints.

[0095] Step 5: If the opening time of the drain valve in the current cycle meets the constraint conditions, then control the drain valve according to the calculated opening time of the drain valve in the current cycle.

[0096] Step six: If the opening time of the drain valve in the current cycle does not meet the constraint conditions, then the drain valve will remain open for the rest of the current cycle. For example:

[0097] During the calculation process, it is determined whether the following constraints are met:

[0098]

[0099] First, determine if the water volume when the valve was closed in the previous cycle is less than the maximum allowable water volume Q. If not, it indicates that the water volume in the previous cycle was already high, and the drain valve needs to remain open. If this constraint is not met, the valve can be directly controlled to continuously drain water without needing to check the latter two conditions. If this condition is met, then determine if the drain valve opening time in the current cycle is less than the appropriate cycle time T determined based on the fuel cell system operating conditions and actual exhaust gas measurements. If not, the drain valve needs to remain open. Finally, determine if the sum of the water volume in the current drainage cycle (based on the calculated valve opening time) and the water volume in the previous cycle is less than the maximum allowable water volume Q. If not, it indicates that the calculated valve opening time is too short to meet the drainage requirements, and the valve should remain open. When designing the software algorithm, determining if the water volume when the valve was closed in the previous cycle is less than the maximum allowable water volume Q can be completed before the end of the previous cycle, providing an early warning before the next cycle begins, thus improving reliability through advance prediction. After calculating the opening time of the drainage valve in the current cycle, it can be immediately determined whether it is less than the appropriate cycle time T. If the condition is not met, the full cycle drainage can be started as soon as possible. This not only provides early warning, but also eliminates the need to calculate and judge a complex third judgment condition, saving the computing power used by the computer.

[0100] The drainage method of the hydrogen fuel cell system exhaust gas recovery device of the present invention further includes calibrating the vortex-end flow rate and drainage rate of the turbine generator, which includes the following steps: obtaining the peak speed and peak current of the air compressor based on different operating conditions of the fuel cell system; dividing the air compressor speed from 0 to the peak speed into N velocity vectors X: 0, S1, ..., S... Max The air compressor current is divided into M current vectors Y: 0, Iq1, ..., Iq, which increase in unit current increments from 0 to the peak current. Max With vectors X and Y as the horizontal and vertical coordinates respectively, a first test condition matrix for the flow rate through the vortex end is established, as shown in Table 1.

[0101] Table 1

[0102]

[0103] A second test condition matrix for drainage rate is established with vectors X and Y as the horizontal and vertical coordinates, as shown in Table 2.

[0104] Table 2

[0105]

[0106] Through testing, the vortex end was calibrated by flow rate and drainage rate under different speeds and currents, and the first test condition matrix and the second test condition matrix were obtained. These were then converted into data tables that the control program could directly query and use.

[0107] like Figure 1 As shown, the drainage method of the hydrogen fuel cell system exhaust gas recovery device further includes: since the drainage valve in the hydrogen fuel cell system exhaust gas recovery device is a bypass valve, the actual operating conditions of the fuel cell system and the actual measurement of the exhaust gas include:

[0108] During the testing of the turbine generator, the opening of the drain valve is determined and maintained based on a position sensor. For example, an infrared sensor is installed on the valve to detect its position or height when it moves. The moisture content A of the exhaust gas is measured using a humidity sensor.

[0109] The amount of water B separated by the water separator is obtained by measuring the flow sensor, or by directly detecting the water level (accumulated water) in the water separator, and the water separation efficiency Eff is calculated. The water separation efficiency is the ratio of the amount of water B separated to the water content A in the exhaust gas.

[0110] During the testing of the turbine generator, based on existing test data, the system operated best when the valve opening was between 10% and 30%. Therefore, the valve opening was fixed at 10%, 20%, and 30%, etc. Similarly, based on existing test analysis, the moisture content in the exhaust gas is approximately 10% to 30%, i.e., the water content is 10% to 30%. Likewise, based on existing test analysis, the water separation efficiency (Eff) of the water distributor can be obtained.

[0111] Preferably, in the drainage method of the hydrogen fuel cell system exhaust gas recovery device, a drainage control unit is provided in the hydrogen fuel cell system exhaust gas recovery device to control the bypass valve according to the drainage method; a position sensor, a humidity sensor, and a flow sensor are provided in the hydrogen fuel cell system exhaust gas recovery device to implement the above method.

[0112] During the testing of the turbine generator, the opening of the drain valve is determined and maintained based on a position sensor. For example, an infrared sensor is installed on the valve to detect its position or height when it moves. The moisture content A of the exhaust gas is measured using a humidity sensor.

[0113] The amount of water B separated by the water separator is obtained by measuring the flow sensor, or by directly detecting the water level (accumulated water) in the water separator, and the water separation efficiency Eff is calculated. The water separation efficiency is the ratio of the amount of water B separated to the water content A in the exhaust gas.

[0114] During the testing of the turbine generator, based on existing test data, the system operated best when the valve opening was between 10% and 30%. Therefore, the valve opening was fixed at 10%, 20%, and 30%, etc. Similarly, based on existing test analysis, the moisture content in the exhaust gas is approximately 10% to 30%, i.e., the water content is 10% to 30%. Likewise, based on existing test analysis, the water separation efficiency (Eff) of the water distributor can be obtained.

[0115] A table of vortex flow rate and drainage rate at different compressor speeds and currents was obtained through bench testing. This table was then incorporated into the control program. By setting different valve opening and closing cycles, the automatic drainage effect was tested. Analysis revealed that this control method achieves a better drainage effect within a short cycle.

[0116] This invention has at least one or more of the following advantages:

[0117] The method described in this invention calibrates the vortex-end flow rate and drainage rate of a turbine generator. The system operating conditions are queried by looking up a table, which simplifies the calculation procedure and reduces the amount of calculation, saves time, and ensures the accuracy of the calculation structure based on actual system measurement data.

[0118] Automatic drainage is achieved through this control method, which operates in a closed loop, is simple and efficient, eliminates the need for sensor structures, and reduces system complexity and cost.

[0119] This control method identifies the appropriate opening and closing times of the bypass valve, minimizing exhaust gas leakage during drainage and improving the system's energy recovery efficiency.

[0120] First, this invention proposes a calibration method for the vortex end flow rate and drainage rate of a turbine generator during the exhaust gas recovery process of a hydrogen fuel cell system. This method solves the calibration problem of the vortex end flow rate of the turbine generator system under varying operating conditions and completes the calibration of the drainage rate of the bypass valve under different operating conditions.

[0121] Secondly, this invention proposes a control method for automatically draining water from a water distributor during the exhaust gas recovery process of a hydrogen fuel cell system. By controlling the bypass valve, an automatic, closed-loop drainage function can be achieved.

[0122] In summary, the above embodiments have provided detailed descriptions of different configurations of the exhaust gas recovery device and its drainage method for a hydrogen fuel cell system. Of course, this invention includes, but is not limited to, the configurations listed in the above embodiments. Any modifications made based on the configurations provided in the above embodiments are within the scope of protection of this invention. Those skilled in the art can apply the knowledge gained from the above embodiments to other situations.

[0123] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0124] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A method for draining wastewater from a hydrogen fuel cell system exhaust gas recovery device, characterized in that, include: Get the air compressor speed and air compressor current in the current cycle; The flow rate through the vortex end and the drainage rate in the current cycle are obtained by looking up the air compressor speed and air compressor current in the table, and the water accumulation when the valve was closed in the previous cycle is calculated. The opening time of the drain valve in the current cycle is determined based on the flow rate through the vortex in the current cycle, the drainage rate in the current cycle, and the amount of water accumulated when the valve was closed in the previous cycle. Determine whether the opening time of the drain valve in the current cycle meets the constraints. If the opening time of the drain valve in the current cycle meets the constraint conditions, then the drain valve will be controlled according to the opening time of the drain valve in the current cycle; and If the opening time of the drain valve in the current cycle does not meet the constraint conditions, the drain valve will continue to be opened in the current cycle. The constraints are as follows: t 1,n Q is the opening time of the bypass valve in the current nth cycle; T is the preset cycle time; Q 2,n-1 The water volume when the bypass valve is closed in the (n-1)th cycle; Q is the maximum allowable water volume of the distributor; f 1,n f is the actual water distribution rate in the current nth cycle; 2,n This represents the drainage rate in the current nth cycle. It also includes calibrating the turbine generator's vortex-end through-flow and drainage rates, which includes the following steps: Based on different operating conditions of the fuel cell system, the peak speed and peak current of the air compressor are obtained; The air compressor speed is divided into N velocity vectors X: 0, S1, ..., S, which increase by a unit speed from 0 to the peak speed. Max ; The air compressor current is divided into M current vectors Y: 0, Iq1, ..., Iq, which increase in unit current increments. Max ; With vectors X and Y as the horizontal and vertical coordinates respectively, establish the first test condition matrix regarding the flow rate through the vortex end; A second test condition matrix is ​​established with vectors X and Y as the horizontal and vertical coordinates, respectively, to determine the drainage rate; and Through testing, the vortex end was calibrated by flow rate and drainage rate under different speeds and currents, and the first test condition matrix and the second test condition matrix were obtained. These were then converted into data tables that the control program could directly query and use.

2. The drainage method of the hydrogen fuel cell system exhaust gas recovery device as described in claim 1, characterized in that, Also includes: The allowable water accumulation height h of the water distributor is calibrated, and the maximum allowable water accumulation Q is calculated. Determine the appropriate cycle time T based on the fuel cell system operating conditions and actual exhaust gas measurements; and The steps of claim 1 are repeated within each cycle time, wherein the cycle time is the sum of the drain valve opening time and the drain valve closing time of the current cycle.

3. The drainage method of the hydrogen fuel cell system exhaust gas recovery device as described in claim 2, characterized in that, The drain valve is a bypass valve; Actual measurements of fuel cell system operating conditions and exhaust gases include: determining and maintaining the opening of the drain valve based on position sensors during the turbine generator test; The moisture content A of the exhaust gas was measured using a humidity sensor; and The amount of water separated by the water separator is measured by a flow sensor, and the water separation efficiency Eff is calculated. The water separation efficiency is the ratio of the amount of water separated to the water content in the exhaust gas.

4. The drainage method of the hydrogen fuel cell system exhaust gas recovery device as described in claim 3, characterized in that, Also includes: Set the initial water volume Q 2,0 =0, initial vortex end flow rate q 1,0 =0; In the nth period, the vortex end obtained from the initial query passes through a flow rate q. 1,n and drainage rate f 2,n Calculate the opening and closing times of the bypass valve; calculate the actual water distribution rate f. 1,n The calculation formula is f 1,n =q 1,n A Eff; The actual water distribution Q was calculated. 1,n The calculation formula is Q 1,n =f 1,n T; The water accumulation Q when the bypass valve is closed in the (n-1)th cycle is calculated. 2,n-1 The water accumulation is the bypass valve closing time t in the (n-1)th cycle. 2,n-1 The water volume inside, the flow rate through the vortex end in the (n-1)th cycle is q 1,n-1 The calculation formula is Q 2,n-1 =f 1,n-1 t 2,n-1 =q 1,n-1 A Eff t 2,n-1 ; The bypass valve opening time t was calculated. 1,n and bypass valve closing time t 2,n The calculation formula is t 1,n =(Q 1,n +Q 2,n-t ) / f 2,n ;t 2,n =Tt 1,n .

5. The drainage method of the hydrogen fuel cell system exhaust gas recovery device as described in claim 4, characterized in that, A drainage control unit is installed in the exhaust gas recovery device of the hydrogen fuel cell system to control the bypass valve according to the drainage method described above; and Position sensors, humidity sensors, and flow sensors are installed in the exhaust gas recovery device of the hydrogen fuel cell system.

6. A hydrogen fuel cell system exhaust gas recovery device, characterized in that, include: The air path of the hydrogen fuel cell system is configured to compress the exhaust gas through an air compressor and then deliver it to the water distributor. The water separator is configured to separate the exhaust gas into gas and liquid, then deliver the gas to the turbine generator and the liquid to the drain valve. as well as The drainage control unit is configured to perform the drainage method of the hydrogen fuel cell system exhaust gas recovery device as described in any one of claims 1 to 5, in order to control the opening and closing of the drainage valve.

7. The hydrogen fuel cell system exhaust gas recovery device as described in claim 6, characterized in that, Also includes: The turbine generator controller is configured to control the turbine engine; A pressure sensor is positioned between the turbine engine and the water distributor; as well as The silencer is located on the outside of the drain valve.

8. The hydrogen fuel cell system exhaust gas recovery device as described in claim 6, characterized in that, The air path structure of a hydrogen fuel cell system includes an intake air filter, an intake flow meter, an air compressor, an intercooler, a humidifier, a fuel cell stack, and a back pressure valve, connected in sequence.

9. An electric vehicle having a hydrogen fuel cell system exhaust gas recovery device according to any one of claims 6 to 8.

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