Fuel cell denitrification control method and device and denitrification time length correction method

Abstract

The invention discloses a fuel cell denitrogenation control method and device and a denitrogenation duration correction method. The method comprises the following steps: calculating the mass of mixed gas at the anode side of a fuel cell at the current moment; according to the mass of the mixed gas at the anode side of the fuel cell at the current moment, calculating the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset duration at the current moment; according to the mass of the mixed gas on the anode side of the fuel cell at the current moment and the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset duration at the current moment, the nitrogen concentration of the anode side of the fuel cell after the first preset duration at the current moment is calculated; and when the nitrogen concentration of the anode side of the fuel cell is lower than a preset value, after the first preset duration, stopping executing the nitrogen removal operation, and recording the total nitrogen removal duration. Therefore, the hydrogen consumption is reduced, and the working efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and further relates to a fuel cell nitrogen exhaust control method, device and nitrogen exhaust duration correction method. Background Art

[0002] Proton exchange membrane fuel cell (PEMFC) generates electricity for vehicles through electrochemical reaction of hydrogen on the anode side and oxygen in the air on the cathode side. It is a pollution-free clean energy.

[0003] The fuel cell hydrogen supply system usually includes components such as a hydrogen injection valve, a hydrogen circulation pump, and an ejector, through which a certain pressure of hydrogen can be supplied to the anode side of the fuel cell.

[0004] When the fuel cell is working, hydrogen will circulate continuously in the hydrogen path. In order to deal with the nitrogen and water vapor in the cathode air slowly diffusing to the anode through the proton exchange membrane, the hydrogen concentration on the anode side will decrease after long-term operation (the amount of nitrogen contained in it will increase). It is necessary to open the hydrogen discharge valve from time to time to discharge the mixed gas with a low hydrogen concentration from the anode. At the same time, the hydrogen injection valve will continuously inject pure hydrogen into the anode side pipeline of the fuel cell stack, thereby increasing the hydrogen concentration on the anode side of the fuel cell and restoring the hydrogen concentration to normal levels. This process is the anode purge.

[0005] There are many difficulties in the anode purge process mentioned above, such as how to evaluate the extent to which the hydrogen concentration has dropped and how long the hydrogen discharge valve should be opened. The fundamental reason is that the nitrogen content in hydrogen cannot be detected in real time in the delivered product. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a fuel cell nitrogen exhaust control method, device and nitrogen exhaust time correction method, so that the fuel cell system can detect the nitrogen content in hydrogen in real time, and also provide a basis for controlling the opening time of the hydrogen exhaust valve, thereby reducing the waste of hydrogen.

[0007] Specifically, the technical solution of the present invention is as follows:

[0008] A method for controlling nitrogen exhaust of a fuel cell, comprising the steps of:

[0009] Calculating the mass of the mixed gas at the anode side of the fuel cell at the current moment;

[0010] Calculating the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset time has passed at the current moment according to the mass of the mixed gas at the anode side of the fuel cell at the current moment;

[0011] Calculate the nitrogen concentration on the anode side of the fuel cell after the first preset time period has passed at the current moment according to the mass of the mixed gas on the anode side of the fuel cell at the current moment and the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time period has passed at the current moment;

[0012] When it is determined that the nitrogen concentration on the anode side of the fuel cell is lower than a preset value, the nitrogen exhaust operation is stopped after the first preset time has passed, and the total nitrogen exhaust time is recorded.

[0013] By calculating the mass of the mixed gas on the anode side of the fuel cell at the current moment, the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time period at the current moment, and the mass of the added pure hydrogen, and according to the mass of the mixed gas on the anode side of the fuel cell at the current moment and the mass of the mixed gas discharged from the anode side of the fuel cell, the nitrogen concentration on the anode side of the fuel cell after the first preset time period at the current moment is obtained. This method enables the fuel cell system to detect the nitrogen content in hydrogen in real time, and can also control the opening time of the hydrogen exhaust valve according to the detected nitrogen content, thereby improving the working efficiency of the equipment and reducing hydrogen waste.

[0014] Furthermore, when the nitrogen concentration on the anode side of the fuel cell reaches a preset value, the nitrogen exhaust operation is stopped. When the nitrogen concentration on the anode side of the fuel cell reaches a preset value, the nitrogen exhaust operation is stopped, further reducing the waste of hydrogen and the loss of equipment.

[0015] In some embodiments, the calculation of the mass of the mixed gas on the anode side of the fuel cell at the current moment specifically includes the steps of:

[0016] Obtaining the volume of the anode side pipeline of the fuel cell at the current moment, the pressure value of the anode side of the fuel cell at the current moment, the temperature of the mixed gas on the anode side of the fuel cell at the current moment, and the molar ratio of hydrogen and nitrogen in the mixed gas on the anode side of the fuel cell at the current moment;

[0017] Calculate the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell at the current moment and the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment according to the volume of the pipeline on the anode side of the fuel cell, the pressure value on the anode side of the fuel cell, the temperature of the mixed gas on the anode side of the fuel cell, and the molar ratio of hydrogen to nitrogen in the mixed gas on the anode side of the fuel cell at the current moment;

[0018] The mass of the mixed gas on the anode side of the fuel cell at the current moment is calculated according to the molar number of hydrogen on the anode side of the mixed gas of the fuel cell at the current moment and the molar number of nitrogen on the anode side of the mixed gas of the fuel cell at the current moment.

[0019] In some embodiments, after calculating the mass of the mixed gas on the anode side of the fuel cell at the current moment, the method further comprises the following steps:

[0020] Obtaining the cross-sectional area of ​​the internal flow channel of the anode-side hydrogen exhaust valve of the fuel cell and the upstream and downstream pressure difference of the anode-side hydrogen exhaust valve of the fuel cell;

[0021] Calculate the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset time period at the current moment according to the mass of the mixed gas at the anode side of the fuel cell, the volume of the pipeline at the anode side of the fuel cell, the cross-sectional area of ​​the internal flow channel of the hydrogen exhaust valve at the anode side of the fuel cell, and the upstream and downstream pressure difference of the hydrogen exhaust valve at the anode side of the fuel cell, and calculate the number of moles of hydrogen discharged from the anode side of the fuel cell and the number of moles of nitrogen discharged from the anode side of the fuel cell after the first preset time period at the current moment according to the mass of the mixed gas discharged from the anode side of the fuel cell;

[0022] Calculate the number of moles of hydrogen introduced into the anode side of the fuel cell after the first preset time has passed at the current moment according to the mass of the mixed gas discharged from the anode side of the fuel cell and the volume of the pipeline on the anode side of the fuel cell;

[0023] Calculate the nitrogen concentration on the anode side of the fuel cell according to the mole number of hydrogen in the mixed gas on the anode side of the fuel cell, the mole number of nitrogen in the mixed gas on the anode side of the fuel cell, the mole number of hydrogen discharged from the anode side of the fuel cell, the mole number of nitrogen discharged from the anode side of the fuel cell, and the mole number of hydrogen introduced into the anode side of the fuel cell;

[0024] When it is determined that the nitrogen concentration on the anode side of the fuel cell is lower than a preset value, the nitrogen exhaust operation is stopped after the first preset time has passed, and the total nitrogen exhaust time is recorded.

[0025] The nitrogen concentration on the anode side of the fuel cell is calculated by the molar number of hydrogen in the mixed gas on the anode side of the fuel cell, the molar number of nitrogen in the mixed gas on the anode side of the fuel cell, the molar number of hydrogen discharged from the anode side of the fuel cell, the molar number of nitrogen discharged from the anode side of the fuel cell, and the molar number of new hydrogen on the anode side of the fuel cell. This simplifies the calculation process, improves the accuracy and work efficiency of monitoring the nitrogen concentration on the anode side of the fuel cell, and further reduces resource waste.

[0026] In some embodiments, when the nitrogen concentration on the anode side of the fuel cell is less than a preset value, before stopping the nitrogen exhaust operation, after calculating the nitrogen concentration on the anode side of the fuel cell at the current moment after the first preset time has passed, the step further includes:

[0027] Determining whether the nitrogen concentration is lower than the preset value;

[0028] If the nitrogen concentration is not lower than the preset value, after the first preset time period, the nitrogen exhaust operation is continued, and the nitrogen concentration on the anode side of the fuel cell at the current moment after the first preset time period is repeatedly calculated.

[0029] The present invention also provides a fuel cell nitrogen exhaust control device, comprising:

[0030] A first calculation unit, used to calculate the mass of the mixed gas at the anode side of the fuel cell at the current moment;

[0031] A second calculation unit, configured to calculate the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset time has passed at the current moment according to the mass of the mixed gas at the anode side of the fuel cell at the current moment;

[0032] a third calculation unit, configured to calculate the nitrogen concentration at the anode side of the fuel cell after the first preset time period has passed at the current moment according to the mass of the mixed gas at the anode side of the fuel cell at the current moment and the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time period has passed at the current moment;

[0033] The first execution unit is used to determine that when the nitrogen concentration on the anode side of the fuel cell is lower than a preset value, stop executing the nitrogen exhaust operation after the first preset time period has passed, and record the total nitrogen exhaust time.

[0034] In some implementations, the first computing unit specifically includes:

[0035] An acquisition module, used to acquire the volume of the anode side pipeline of the fuel cell at the current moment, the pressure value of the anode side of the fuel cell at the current moment, the temperature of the mixed gas on the anode side of the fuel cell at the current moment, and the molar ratio of hydrogen and nitrogen in the mixed gas on the anode side of the fuel cell at the current moment;

[0036] A first calculation module, for calculating the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell at the current moment and the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment according to the volume of the pipeline on the anode side of the fuel cell, the pressure value on the anode side of the fuel cell, the temperature of the mixed gas on the anode side of the fuel cell, and the molar ratio of hydrogen to nitrogen in the mixed gas on the anode side of the fuel cell at the current moment;

[0037] The second calculation module is used to calculate the mass of the mixed gas on the anode side of the fuel cell at the current moment according to the molar number of hydrogen and the molar number of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment.

[0038] In some embodiments, the acquisition module is also used to acquire the cross-sectional area of ​​the internal flow channel of the anode-side hydrogen exhaust valve of the fuel cell and the upstream and downstream pressure difference of the anode-side hydrogen exhaust valve of the fuel cell.

[0039] The second computing unit specifically includes:

[0040] a third calculation module, for calculating the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset time period has passed at the current moment according to the mass of the mixed gas on the anode side of the fuel cell, the volume of the pipeline on the anode side of the fuel cell, the cross-sectional area of ​​the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell, and the upstream and downstream pressure difference on the anode side of the fuel cell, and calculating the number of moles of hydrogen discharged from the anode side of the fuel cell and the number of moles of nitrogen discharged from the anode side of the fuel cell after the first preset time period has passed at the current moment according to the mass of the mixed gas discharged from the anode side of the fuel cell;

[0041] a fourth calculation module, for calculating the number of moles of hydrogen introduced into the anode side of the fuel cell after the first preset time has passed at the current moment according to the mass of the mixed gas discharged from the anode side of the fuel cell, the mass of the mixed gas on the anode side of the fuel cell, and the volume of the pipeline on the anode side of the fuel cell;

[0042] The third computing unit specifically includes:

[0043] The fifth calculation module is used to calculate the nitrogen concentration on the anode side of the fuel cell based on the molar number of hydrogen in the mixed gas on the anode side of the fuel cell, the molar number of nitrogen in the mixed gas on the anode side of the fuel cell, the molar number of hydrogen discharged from the anode side of the fuel cell, the molar number of nitrogen discharged from the anode side of the fuel cell, and the molar number of hydrogen introduced into the anode side of the fuel cell.

[0044] In some embodiments, it further comprises:

[0045] A judging unit, used to judge whether the nitrogen concentration is lower than the preset value;

[0046] The second execution unit is used to continue to perform the nitrogen exhaust operation after the first preset time if the nitrogen concentration is not lower than the preset value, and repeatedly calculate the nitrogen concentration on the anode side of the fuel cell after the first preset time at the current moment.

[0047] The present invention also provides a method for correcting nitrogen removal time, comprising the steps of:

[0048] Obtaining a first pressure on the anode side of the fuel cell at the current moment and a first temperature of the mixed gas on the anode side of the fuel cell at the current moment, and calculating the total nitrogen discharge time when the nitrogen concentration on the anode side of the fuel cell is lower than the preset value through the fuel cell nitrogen discharge control method described in the above embodiment according to the first pressure on the anode side of the fuel cell and the first temperature of the mixed gas on the anode side of the fuel cell;

[0049] According to the first pressure and the first temperature, a correction coefficient is obtained by looking up a table, wherein the correction coefficient is obtained by experimentally collecting the nitrogen concentration at the outlet end of the hydrogen exhaust valve on the anode side of the fuel cell under the first pressure and the first temperature conditions, recording the actual working time of the corresponding nitrogen exhaust operation according to the nitrogen concentration variation range on the anode side of the fuel cell, and calculating the theoretical working time corresponding to the nitrogen concentration variation range on the anode side of the fuel cell according to the fuel cell nitrogen exhaust control method described in the aforementioned embodiment, and calculating the correction coefficient according to the theoretical working time and the actual working time;

[0050] The total nitrogen exhaust time is corrected according to the correction coefficient.

[0051] The present invention also provides a fuel cell system, which includes a processor, a memory connected to the processor, and program instructions stored in the memory. When the processor executes the program instructions, the fuel cell nitrogen exhaust control method as described above is implemented.

[0052] The present invention also provides a computer medium having a computer program stored thereon, wherein the program, when executed, implements the above-mentioned fuel cell nitrogen exhaust control method.

[0053] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0054] 1. By calculating the mass of the mixed gas on the anode side of the fuel cell at the current moment, the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time, and the mass of the added pure hydrogen, and according to the mass of the mixed gas on the anode side of the fuel cell at the current moment, the mass of the mixed gas discharged from the anode side of the fuel cell, and the mass of the added pure hydrogen on the anode side of the fuel cell, the nitrogen concentration on the anode side of the fuel cell after the first preset time is obtained. This method enables the fuel cell system to detect the nitrogen content in hydrogen in real time, and can also control the opening time of the hydrogen exhaust valve according to the detected nitrogen content, thereby improving the working efficiency of the equipment and reducing hydrogen waste.

[0055] Furthermore, when the nitrogen concentration on the anode side of the fuel cell reaches a preset value, the nitrogen exhaust operation is stopped. When the nitrogen concentration on the anode side of the fuel cell reaches a preset value, the nitrogen exhaust operation is stopped, further reducing the waste of hydrogen and the loss of equipment.

[0056] 2. The nitrogen concentration on the anode side of the fuel cell is calculated by the molar number of hydrogen in the mixed gas on the anode side of the fuel cell, the molar number of nitrogen in the mixed gas on the anode side of the fuel cell, the molar number of hydrogen discharged from the anode side of the fuel cell, the molar number of nitrogen discharged from the anode side of the fuel cell, and the molar number of new hydrogen on the anode side of the fuel cell. This simplifies the calculation process, improves the accuracy and work efficiency of monitoring the nitrogen concentration on the anode side of the fuel cell, and further reduces resource waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The preferred implementation modes will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0058] Figure 1 is a flow chart of an embodiment of a fuel cell nitrogen exhaust control method of the present invention;

[0059] Figure 2 is a flow chart of an embodiment of a fuel cell nitrogen exhaust control method of the present invention;

[0060] Figure 3 is a flow chart of another embodiment of a fuel cell nitrogen exhaust control method of the present invention;

[0061] Figure 4 is a structural diagram of an embodiment of a fuel cell nitrogen exhaust control device of the present invention;

[0062] Figure 5 is a structural diagram of an embodiment of a fuel cell nitrogen exhaust control device of the present invention;

[0063] Figure 6 is a structural diagram of another embodiment of a fuel cell nitrogen exhaust control device of the present invention;

[0064] Figure 7 It is a simplified structural diagram of a fuel cell system of the present invention.

[0065] Description of the drawings: first computing unit 100; second computing unit 200; third computing unit 300; first execution unit 400; acquisition module 110; first computing module 120; second computing module 130; third computing module 210; fourth computing module 220; fifth computing module 310. DETAILED DESCRIPTION

[0066] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0067] In order to simplify the drawings, only the parts related to the invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0068] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0069] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0071] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

[0072] In one embodiment, Figure 1 , 7 As shown, the present invention provides a fuel cell control method, comprising:

[0073] S100, calculating the mass of the mixed gas on the anode side of the fuel cell at the current moment.

[0074] Specifically, according to the formula PV = (m / M)RT, the mass of the mixed gas of hydrogen and nitrogen on the anode side of the fuel cell at the current moment is calculated. Where P is the pressure of the gas, obtained by taking the average value of the inlet and outlet pressure sensors corresponding to the anode side of the fuel cell; V is the volume of the gas, replaced by the volume of the pipeline on the anode side of the fuel cell; m is the mass of the gas; M is the molar mass of the gas; (m / M) is the number of moles of the gas; R is the universal constant of the gas, R = 8.31 J / mol; T is the temperature of the gas, obtained by the temperature sensor corresponding to the anode side of the fuel cell.

[0075] S110, calculating the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset time has passed from the current moment according to the mass of the mixed gas at the anode side of the fuel cell at the current moment.

[0076] Specifically, the mass of the mixed gas on the anode side of the fuel cell refers to the mass of the gas in the hydrogen circulation loop formed by the emitter, the fuel cell stack, the hydrogen circulation pump, and the hydrogen exhaust valve; the mass of the mixed gas discharged from the anode side of the fuel cell refers to the mass of the gas discharged from the hydrogen exhaust valve.

[0077] Furthermore, the density of the mixed gas at the current moment is calculated based on the mass of the mixed gas at the anode side of the fuel cell and the volume of the mixed gas at the anode side of the fuel cell. Since the density of the discharged mixed gas is the density of the mixed gas at the current moment, the density of the mixed gas at the current moment and the cross-sectional radius of the internal flow channel of the hydrogen exhaust valve at the anode side of the fuel cell are substituted into the formula: The mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time is calculated. Where r is the cross-sectional radius of the hydrogen exhaust valve, Q 排 is the mass of the mixed gas discharged within the first preset time, ρ is the density of the mixed gas, △P is the upstream and downstream pressure difference of the hydrogen exhaust valve, t is one cycle, that is, the first preset time is one cycle t.

[0078] Furthermore, the fuel cell system is based on the mass Q of the mixed gas on the anode side of the fuel cell at the current moment. 混 And the volume V of the mixed gas on the anode side of the fuel cell at the current moment, substitute it into the formula Calculate the density ρ of the mixed gas at the current moment; since the density of the discharged mixed gas is the density ρ of the mixed gas at the current moment, the cross-sectional radius r of the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell is calculated, and the cross-sectional area is πr 2 , and the upstream and downstream pressure difference △P of the hydrogen exhaust valve, substitute into the formula Calculate the mass Q of the mixed gas discharged from the anode side of the fuel cell within the first preset time period 排 .

[0079] S120, calculating the nitrogen concentration on the anode side of the fuel cell after the first preset time period has passed at the current moment based on the mass of the mixed gas on the anode side of the fuel cell at the current moment and the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time period has passed at the current moment.

[0080] Specifically, assuming that the current molar ratio of hydrogen to nitrogen is a / b (this ratio needs to be adjusted according to the specific minimum requirement of the fuel cell stack for hydrogen concentration), the current molar number of nitrogen in the mixed gas on the anode side of the fuel cell can be obtained. 氮初始 = (PV / RT)*(b / a+b), the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell at the current moment Mol 氢初始 is (PV / RT)*(a / a+b).

[0081] Furthermore, it is known that the molar masses of nitrogen and hydrogen are 28 g / mol and 2 g / mol respectively. Based on the molar numbers of nitrogen and hydrogen and the molar masses of nitrogen and hydrogen respectively, the mass of the mixed gas on the anode side of the fuel cell at the current moment is calculated as Q 混 =(PV / RT)*(b / a+b)*28+(PV / RT)*(a / a+b)*2.

[0082] Furthermore, through Q 混 The density ρ of the mixed gas on the anode side of the fuel cell is calculated by the volume of the mixed gas on the anode side of the fuel cell at the current moment. The cross-sectional radius r of the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell is used to calculate the cross-sectional area πr 2 , and the upstream and downstream pressure difference △P of the hydrogen exhaust valve, substitute into the formula Calculate the mass Q of the mixed gas discharged from the anode side of the fuel cell within the first preset time period 排 .

[0083] Furthermore, the corresponding moles of hydrogen and nitrogen discharged are set as Mol 氢排 and

[0084] Mol 氮排 , according to the following equation:

[0085] Mol 氢排 =(a / b)*Mol 氮排

[0086] 28*Mol 氮排 +2*Mol 氢排 =Q 排

[0087] Then we can find Mol 氢排 With Mol 氮排 .

[0088] Further, the number of moles of pure hydrogen gas introduced into the anode side of the fuel cell during the first preset time is calculated, and its volume is Q 排 / ρ. Combined with the formula PV = (m / M)RT, the number of moles of added hydrogen can be obtained: Mol 氢增 for (PQ 排 / ρ) / RT, where P is obtained by the stack pressure sensor.

[0089] The fuel cell system calculates the initial molar number of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment Mol 氮初始 and the initial moles of hydrogen, Mol 氢初始 , the number of moles of nitrogen discharged from the anode side of the fuel cell after the first preset time from the current moment Mol 氮排 and hydrogen moles Mol 氢排 , and the number of moles of hydrogen introduced into the anode side of the fuel cell during the first preset time period Mol 氢增 Substituting into the formula (Mol 氮初始 -Mol 氮排 ) / [(Mol 氮初始 -Mol 氮排 )+(Mol 氢初始 -Mol 氢排 +Mol 氢增 )], and calculate the nitrogen concentration on the anode side of the fuel cell after the first preset time period.

[0090] S130, when it is determined that the nitrogen concentration on the anode side of the fuel cell is lower than a preset value, the nitrogen exhaust operation is stopped after a first preset time, and the total nitrogen exhaust time is recorded.

[0091] Specifically, after determining that the nitrogen concentration on the anode side of the fuel cell is less than a preset value after the first preset time, the fuel cell system stops performing the nitrogen exhaust operation, and the total nitrogen exhaust time at this time is the first preset time.

[0092] Furthermore, when the nitrogen concentration on the anode side of the fuel cell is higher than the preset value, the nitrogen discharge operation continues, and the calculation is repeated to determine whether the nitrogen concentration on the anode side of the fuel cell is less than the preset value after the first preset time. If the nitrogen concentration is less than the preset value, the nitrogen discharge operation is stopped after the first preset time, and the actual total nitrogen discharge time is 2 times the first preset time; if the nitrogen concentration is higher than the preset value, the nitrogen discharge operation is repeated. Thus, multiple calculations and judgments are performed until the nitrogen discharge operation is terminated when the nitrogen concentration on the anode side of the fuel cell is lower than the preset value, that is, the total nitrogen discharge time is n times the first preset time (n is an integer greater than or equal to 1).

[0093] Furthermore, the nitrogen exhaust operation actually opens the hydrogen exhaust valve, which exhausts the mixed gas (a mixed gas of hydrogen and nitrogen) on the anode side of the fuel cell. Stopping the nitrogen exhaust operation means closing the hydrogen exhaust valve, which stops exhausting the mixed gas on the anode side of the fuel cell.

[0094] In this embodiment, the fuel cell system calculates the mass of the mixed gas of hydrogen and nitrogen on the anode side of the fuel cell at the current moment according to the formula PV = (m / M)RT. Where P is the pressure of the gas; V is the volume of the gas; m is the mass of the gas; M is the molar mass of the gas; (m / M) is the number of moles of the gas; R is the universal constant of the gas, R = 8.31 J / mol; and T is the temperature of the gas.

[0095] Furthermore, the pressure of the mixed gas at the current moment is essentially the pressure value on the anode side of the fuel cell, which can be obtained through a pressure sensor; the volume of the mixed gas at the current moment is essentially the volume of the pipeline on the anode side of the fuel cell, which can be obtained through measurement; thus, the pressure value on the anode side of the fuel cell, the volume of the pipeline on the anode side of the fuel cell and the temperature of the mixed gas on the anode side of the fuel cell are substituted into the formula PV = (m / M)RT, and the mass of the mixed gas of hydrogen and nitrogen on the anode side of the fuel cell at the current moment can be obtained.

[0096] Furthermore, according to the mass of the mixed gas on the anode side of the fuel cell at the current moment and the volume of the mixed gas on the anode side of the fuel cell at the current moment, substitute into the formula Calculate the density ρ of the mixed gas at the current moment; since the density of the discharged mixed gas is the density ρ of the mixed gas at the current moment, substitute the density ρ of the mixed gas at the current moment, the cross-sectional radius r of the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell, and the upstream and downstream pressure difference △P of the hydrogen exhaust valve into the formula Calculate the mass of the mixed gas discharged from the anode side of the fuel cell within one cycle t. Then, the mass of the mixed gas discharged within one cycle Q 排 Substitute the density ρ of the mixed gas into the formula Calculate the volume v of the mixed gas discharged in one cycle. The newly added volume of pure hydrogen is the same as the volume v of the mixed gas discharged, that is, the newly added volume of hydrogen multiplied by the density of hydrogen can give the mass of the newly added pure hydrogen.

[0097] Furthermore, the mass of the mixed gas at the anode side of the fuel cell at the current moment, the mass of the mixed gas discharged from the anode side of the fuel cell, and the mass of the pure hydrogen added to the anode side of the fuel cell are substituted into the formula (Mol 氮初始 -Mol 氮排 ) / [(Mol 氮初始 -Mol 氮排 )+(Mol 氢初始 -Mol 氢排+Mol 氢增 )], calculate the nitrogen concentration on the anode side of the fuel cell after one cycle t.

[0098] When it is determined that the nitrogen concentration at the anode side of the fuel cell is less than a preset value after one cycle t, the fuel cell system stops performing the nitrogen exhaust operation.

[0099] In one embodiment, the present invention provides a fuel cell nitrogen exhaust control method. Based on the above embodiment, the calculation of the mass of the mixed gas on the anode side of the fuel cell at the current moment specifically includes:

[0100] S101, obtaining the volume of the anode side pipeline of the fuel cell at the current moment, the pressure value of the anode side of the fuel cell at the current moment, the temperature of the mixed gas on the anode side of the fuel cell at the current moment, and the molar ratio of hydrogen and nitrogen in the mixed gas on the anode side of the fuel cell at the current moment.

[0101] Specifically, the fuel cell system obtains the volume of the pipeline on the anode side of the fuel cell at the current moment, which can be obtained by measurement; obtains the cross-sectional area of ​​the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell at the current moment, which can also be obtained by measuring the cross-sectional radius r of the valve; obtains the pressure value on the anode side of the fuel cell at the current moment, which can be obtained by a pressure sensor, etc.; obtains the temperature of the mixed gas on the anode side of the fuel cell at the current moment, which can also be obtained by a temperature sensor, etc.

[0102] S102, calculates the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell at the current moment and the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment based on the volume of the pipeline on the anode side of the fuel cell, the pressure value on the anode side of the fuel cell, the temperature of the mixed gas on the anode side of the fuel cell, and the molar ratio of hydrogen and nitrogen in the mixed gas on the anode side of the fuel cell at the current moment.

[0103] Specifically, the fuel cell system substitutes the volume v of the fuel cell anode side pipeline, the pressure value p of the fuel cell anode side, and the temperature t0 of the mixed gas on the fuel cell anode side into the formula PV = (m / M)RT to calculate the total mass Q of the fuel cell mixed gas at the current moment. 混 Assuming that the current ratio of the number of moles of hydrogen and nitrogen is a / b (this ratio needs to be adjusted according to the specific minimum requirement of the fuel cell stack for hydrogen concentration), it can be known that the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment is Mol 氮初始 = (PV / RT)*(b / a+b), the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell at the current moment Mol 氢初始 is (PV / RT)*(a / a+b).

[0104] S103, calculating the mass of the mixed gas on the anode side of the fuel cell at the current moment according to the molar number of hydrogen and the molar number of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment.

[0105] Specifically, since the molar masses of hydrogen and nitrogen are 2 g / mol and 28 g / mol respectively, according to the molar masses of hydrogen and nitrogen, the molar number of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment Mol 氮初始 (PV / RT)*(a / a+b) and the number of moles of hydrogen Mol 氢初始 (PV / RT)*(b / a+b), calculate the total mass Q of the mixed gas on the anode side of the fuel cell at the current moment 混 =28*(PV / RT)*(a / a+b)+2*(PV / RT)*(b / a+b).

[0106] In one embodiment, Figure 2 , 7 As shown, the present invention provides a fuel cell nitrogen exhaust control method. Based on the above embodiment, after calculating the mass of the mixed gas on the anode side of the fuel cell at the current moment, the method specifically includes:

[0107] The cross-sectional area of ​​the internal flow channel of the anode-side hydrogen exhaust valve of the fuel cell and the upstream and downstream pressure difference of the anode-side hydrogen exhaust valve of the fuel cell are obtained.

[0108] S200, based on the mass of the mixed gas on the anode side of the fuel cell at the current moment, the volume of the pipeline on the anode side of the fuel cell, the cross-sectional area of ​​the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell, and the upstream and downstream pressure difference of the hydrogen exhaust valve on the anode side of the fuel cell, calculate the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time has passed at the current moment; and based on the mass of the mixed gas discharged from the anode side of the fuel cell, calculate the number of moles of hydrogen discharged from the anode side of the fuel cell and the number of moles of nitrogen discharged from the anode side of the fuel cell after the first preset time has passed at the current moment.

[0109] Specifically, the fuel cell system is based on the mass Q of the mixed gas on the anode side of the fuel cell at the current moment. 混 And the volume V of the mixed gas on the anode side of the fuel cell at the current moment, substitute it into the formula Calculate the density ρ of the mixed gas at the current moment; since the density of the discharged mixed gas is the density ρ of the mixed gas at the current moment, the cross-sectional radius r of the hydrogen exhaust valve on the anode side of the fuel cell is used to calculate the cross-sectional area πr 2 , and the upstream and downstream pressure difference △P of the hydrogen exhaust valve, substitute into the formula Calculate the mass Q of the mixed gas discharged from the anode side of the fuel cell within a cycle t排 .

[0110] Furthermore, the molar numbers of hydrogen and nitrogen discharged from the anode side of the fuel cell within a corresponding period t are respectively set as Mol 氢排 With Mol 氮排 , assuming the ratio of the two is c / d. According to Mol 氢排 =(c / d)*Mol 氮排 , 28*Mol 氮排 +2*Mol 氢排 =Q 排 , solve Mol 氢排 With Mol 氮排 The specific value of .

[0111] S210, calculating the number of moles of hydrogen introduced into the anode side of the fuel cell after a first preset time has passed at the current moment based on the mass of the mixed gas discharged from the anode side of the fuel cell, the mass of the mixed gas on the anode side of the fuel cell, and the volume of the pipeline on the anode side of the fuel cell.

[0112] Specifically, the fuel cell system is based on the density ρ of the mixed gas discharged in a cycle t and the mass Q of the mixed gas discharged from the anode side of the fuel cell 排 , through the formula Calculate the volume of the mixed gas discharged in one cycle v = Q 排 / ρ. The newly added pure hydrogen volume is the same as the volume v of the discharged mixed gas, that is, the newly added hydrogen volume is Q 排 / ρ, and combined with the formula PV=(m / M)RT, the number of moles of hydrogen introduced into the anode side of the fuel cell can be obtained as Mol 氢增 for (PQ 排 / ρ) / RT.

[0113] S220, calculate the nitrogen concentration on the anode side of the fuel cell based on the molar number of hydrogen in the mixed gas on the anode side of the fuel cell, the molar number of nitrogen in the mixed gas on the anode side of the fuel cell, the molar number of hydrogen discharged from the anode side of the fuel cell, the molar number of nitrogen discharged from the anode side of the fuel cell, and the molar number of hydrogen introduced into the anode side of the fuel cell.

[0114] Specifically, the number of hydrogen moles Mol of the mixed gas on the anode side of the fuel cell 氢初始 , the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell Mol 氮初始 、The number of moles of hydrogen discharged from the anode side of the fuel cell Mol 氢排 、The number of moles of nitrogen discharged from the anode side of the fuel cell Mol 氮排 And the number of moles of hydrogen added to the anode side of the fuel cell Mol 氢增 , substitute into the formula (Mol 氮初始 -Mol 氮排) / [(Mol 氮初始 -Mol 氮排 )+(Mol 氢初始 -Mol 氢排 +Mol 氢增 )], the nitrogen concentration on the anode side of the fuel cell after a cycle t can be obtained.

[0115] S230, when it is determined that the nitrogen concentration on the anode side of the fuel cell is lower than a preset value, the nitrogen exhaust operation is stopped after a first preset time, and the total nitrogen exhaust time is recorded.

[0116] Specifically, when it is determined that the nitrogen concentration on the anode side of the fuel cell reaches a preset value, the fuel cell system stops performing the nitrogen exhaust operation.

[0117] In this embodiment, the fuel cell system obtains the volume v of the anode side pipeline of the fuel cell at the current moment, which can be obtained by measurement; obtains the cross-sectional radius πr of the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell at the current moment 2 , the cross-sectional area can also be obtained by measuring the cross-sectional radius r of the valve; the pressure value p on the anode side of the fuel cell at the current moment is obtained, and the pressure value can be obtained by a pressure sensor, etc.; the temperature t0 of the mixed gas on the anode side of the fuel cell at the current moment is obtained, and the temperature can also be obtained by a temperature sensor, etc.

[0118] Further, the volume v of the anode side pipeline of the fuel cell, the pressure value p of the anode side of the fuel cell, and the temperature t0 of the mixed gas on the anode side of the fuel cell are substituted into the formula PV = (m / M)RT to calculate the total mass Q of the mixed gas in the fuel cell at the current moment. 混 Assuming that the current ratio of the number of moles of hydrogen to nitrogen is a / b, we can know the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment, Mol 氮初始 = (PV / RT)*(a / a+b), the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell at the current moment Mol 氢初始 = (PV / RT)*(b / a+b). Since the molar masses of hydrogen and nitrogen are 2 and 28 respectively, according to the molar masses of hydrogen and nitrogen and the molar number of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment, Mol 氮初始 (PV / RT)*(a / a+b) and the number of moles of hydrogen Mol 氢初始 (PV / RT)*(b / a+b), calculate the total mass Q of the mixed gas on the anode side of the fuel cell at the current moment 混 =28*(PV / RT)*(a / a+b)+2*(PV / RT)*(b / a+b).

[0119] Furthermore, the fuel cell system is based on the mass Q of the mixed gas on the anode side of the fuel cell at the current moment.混 And the volume v of the mixed gas on the anode side of the fuel cell at the current moment, substitute it into the formula Calculate the density ρ of the mixed gas at the current moment; since the density of the discharged mixed gas is the density ρ of the mixed gas at the current moment, substitute the density ρ of the mixed gas at the current moment, the cross-sectional radius r of the hydrogen exhaust valve on the anode side of the fuel cell, and the upstream and downstream pressure difference △P of the hydrogen exhaust valve into the formula Calculate the mass Q of the mixed gas discharged from the anode side of the fuel cell within a cycle t 排 .

[0120] Furthermore, the molar numbers of hydrogen and nitrogen discharged from the anode side of the fuel cell within a corresponding period t are respectively set as Mol 氢排 With Mol 氮排 According to Mol 氢排 =(a / b)*Mol 氮排 , 28*Mol 氮排 +2*Mol 氢排 =Q 排 , solve Mol 氢排 With Mol 氮排 The specific value of .

[0121] Furthermore, the fuel cell system is based on the density ρ of the mixed gas discharged in a cycle t and the mass Q of the mixed gas discharged from the anode side of the fuel cell 排 , through the formula Calculate the volume of the mixed gas discharged in one cycle V1 = Q 排 / ρ. The newly added pure hydrogen volume is the same as the volume V1 of the discharged mixed gas, that is, the newly added hydrogen volume is Q 排 / ρ, and combined with the formula PV=(m / M)RT, the number of moles of hydrogen added to the anode side of the fuel cell can be obtained: Mol 氢增 =(pQ 排 / ρ) / Rt0.

[0122] Furthermore, the number of hydrogen moles Mol of the mixed gas on the anode side of the fuel cell 氢初始 , the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell Mol 氮初始 、The number of moles of hydrogen discharged from the anode side of the fuel cell Mol 氢排 、The number of moles of nitrogen discharged from the anode side of the fuel cell Mol 氮排 And the number of moles of hydrogen added to the anode side of the fuel cell Mol 氢增 , substitute into the formula (Mol 氮初始 -Mol 氮排 ) / [(Mol 氮初始 -Mol 氮排 )+(Mol 氢初始-Mol 氢排 +Mol 氢增 )], the nitrogen concentration on the anode side of the fuel cell after a period t can be obtained. Then, when it is determined that the nitrogen concentration on the anode side of the fuel cell reaches a preset value, the fuel cell system stops performing the nitrogen exhaust operation. In this embodiment, all parameters are cited for ease of understanding and do not necessarily mean that they will be used in actual applications.

[0123] In one embodiment, Figure 3 As shown, the present invention provides a fuel cell nitrogen exhaust control method. Based on the above embodiment, when the nitrogen concentration on the anode side of the fuel cell is less than a preset value, before stopping the nitrogen exhaust operation, after calculating the nitrogen concentration on the anode side of the fuel cell after the first preset time at the current moment, the method further includes:

[0124] S300, determining whether the nitrogen concentration is lower than a preset value.

[0125] S310, if the nitrogen concentration is not lower than the preset value, after the first preset time period, the nitrogen exhaust operation is continued, and the nitrogen concentration on the anode side of the fuel cell after the first preset time period at the current moment is repeatedly calculated.

[0126] Specifically, after the calculation of the nitrogen concentration after the first preset time t on the anode side of the fuel cell is completed, it is determined whether the nitrogen concentration reaches the preset value. If the nitrogen concentration does not reach the preset value, the nitrogen discharge operation is continued, and the nitrogen concentration after the first preset time t at the current moment is repeatedly calculated to determine whether the nitrogen concentration is lower than the preset value, and the corresponding operation is performed according to the judgment result. Thus, this embodiment obtains a relatively accurate nitrogen discharge time of the fuel cell, reduces the waste of hydrogen and improves the working efficiency.

[0127] In one embodiment, the present invention provides a method for correcting nitrogen removal time, comprising the steps of:

[0128] Obtaining a first pressure on the anode side of the fuel cell at the current moment and a first temperature of the mixed gas on the anode side of the fuel cell at the current moment, and calculating the total nitrogen discharge time when the nitrogen concentration on the anode side of the fuel cell is lower than the preset value through the fuel cell nitrogen discharge control method described in the above embodiment according to the first pressure on the anode side of the fuel cell and the first temperature of the mixed gas on the anode side of the fuel cell;

[0129] According to the first pressure and the first temperature, a correction coefficient is obtained by looking up a table, wherein the correction coefficient is obtained by experimentally collecting the nitrogen concentration at the outlet end of the hydrogen exhaust valve on the anode side of the fuel cell under the first pressure and the first temperature conditions, recording the actual working time of the corresponding nitrogen exhaust operation according to the nitrogen concentration variation range on the anode side of the fuel cell, and calculating the theoretical working time corresponding to the nitrogen concentration variation range on the anode side of the fuel cell according to the fuel cell nitrogen exhaust control method described in the above embodiment, and calculating the correction coefficient according to the theoretical working time and the actual working time;

[0130] The total nitrogen exhaust time is corrected according to the correction coefficient.

[0131] Specifically, the first pressure on the anode side of the fuel cell at the current moment and the first temperature of the mixed gas on the anode side of the fuel cell at the current moment are obtained, and based on the first pressure and the first temperature, the total nitrogen exhaust time when the nitrogen concentration on the anode side of the fuel cell is lower than the preset value is calculated using the fuel cell nitrogen exhaust control method described in the aforementioned embodiment.

[0132] Furthermore, a correction coefficient under the first pressure and first temperature conditions is obtained by looking up a table, and the total nitrogen exhaust time is corrected by the correction coefficient.

[0133] Furthermore, the correction coefficient is obtained by the following method:

[0134] In the existing experiments, according to the gas circulation route and the location of nitrogen penetration, it can be basically determined that the nitrogen concentration at the outlet of the hydrogen exhaust valve is relatively the highest. By collecting the nitrogen concentration data at the outlet of the hydrogen exhaust valve, when the nitrogen concentration data is lower than the preset value, the working time of this nitrogen exhaust operation is recorded, that is, the opening time of the hydrogen exhaust valve.

[0135] As described in the above embodiment, the duration of the hydrogen discharge valve opening is calculated based on the pressure and temperature data on the anode side of the fuel cell. Therefore, in the experimental calibration, the stack needs to be operated to a certain pressure and temperature value first; then the hydrogen discharge valve is opened and closed, and the change of nitrogen concentration at the outlet of the hydrogen discharge valve is collected at the same time; and then several sets of data (data on the duration of the hydrogen discharge valve opening) of the nitrogen concentration changing from high to low are obtained; based on these data on the nitrogen concentration changing from high to low, the duration of the hydrogen discharge valve opening can also be obtained through the logical calculation described in the above embodiment; there is a deviation in the data on both sides, so the logical calculation results of the above embodiment are corrected.

[0136] Further, assuming that the initial value of the nitrogen concentration on the anode side of the fuel cell is d, and there are three preset values ​​of the nitrogen concentration a, b, and c, the hydrogen exhaust valve is opened, and the time required for the nitrogen concentration at the exhaust valve outlet to reach the preset values ​​a, b, and c from the initial value d is measured as rt1, rt2, and rt3, respectively. Through the nitrogen exhaust operation control method proposed in the aforementioned embodiment, under the same temperature and pressure conditions as the experiment, the calculated time required for the nitrogen concentration on the anode side of the fuel cell to reach the preset values ​​a, b, and c from the initial value d is ct1, ct2, and ct3, and the correction coefficient k can be obtained by minimizing the value of (rt1-kct1)^2+(rt2-kct2)^2+(rt3-kct3)^2.

[0137] Furthermore, by multiplying the correction coefficient k by the nitrogen exhaust time reference value (the total nitrogen exhaust time described in the aforementioned embodiment), the fuel cell system can automatically control the working time of the nitrogen exhaust operation on the anode side of the fuel cell according to the multiplication result.

[0138] In one embodiment, Figure 4 As shown, the present invention provides a fuel cell nitrogen exhaust control device, including: a first calculation unit 100, a second calculation unit 200, a third calculation unit 300, and a first execution unit 400.

[0139] The first calculation unit 100 is used to calculate the mass of the mixed gas at the anode side of the fuel cell at the current moment.

[0140] Specifically, the first calculation unit 100 calculates the mass of the mixed gas of hydrogen and nitrogen on the anode side of the fuel cell at the current moment according to the formula PV=(m / M)RT, where P is the pressure of the gas; V is the volume of the gas; m is the mass of the gas; M is the molar mass of the gas; (m / M) is the number of moles of the gas; R is the universal constant of the gas, R=8.31 ​​J / mol; and T is the temperature of the gas.

[0141] The second calculation unit 200 is used to calculate the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time period at the current moment, and the mass of pure hydrogen added to the anode side of the fuel cell after the first preset time period, based on the mass of the mixed gas on the anode side of the fuel cell.

[0142] Specifically, the second calculation unit 200 calculates the density of the mixed gas at the current moment according to the mass of the mixed gas at the anode side of the fuel cell at the current moment and the volume of the mixed gas at the anode side of the fuel cell at the current moment; since the density of the discharged mixed gas is the density of the mixed gas at the current moment, the density of the mixed gas at the current moment and the cross-sectional radius of the hydrogen exhaust valve at the anode side of the fuel cell are substituted into the formula The second calculation unit 200 calculates the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time. Where r is the cross-sectional radius of the hydrogen exhaust valve, Q 排 is the mass of the mixed gas discharged in one cycle, ρ is the density of the mixed gas, △P is the upstream and downstream pressure difference of the hydrogen exhaust valve (the upstream pressure of the hydrogen exhaust valve can be approximated by the data of the stack pressure sensor on the anode side of the fuel cell. The downstream pressure of the hydrogen exhaust valve is not directly detected by a sensor for the time being, but the downstream pipeline is directly connected to the external environment, that is, the final pressure is the ambient pressure), t is one cycle, that is, the first preset time length is one cycle t.

[0143] Furthermore, the second calculation unit 200 calculates the mixed gas mass Q discharged in one cycle. 排 The volume of the mixed gas discharged in one cycle is calculated by multiplying the density of the mixed gas by the volume of the newly added pure hydrogen and the volume of the mixed gas discharged. That is, the mass of the newly added pure hydrogen can be obtained by multiplying the volume of the newly added hydrogen by the density of the hydrogen.

[0144] The third calculation unit 300 is used to calculate the nitrogen concentration on the anode side of the fuel cell at the current moment after the first preset time has passed, based on the mass of the mixed gas on the anode side of the fuel cell at the current moment, the mass of the mixed gas discharged from the anode side of the fuel cell at the current moment, and the mass of pure hydrogen added to the anode side of the fuel cell after the first preset time has passed.

[0145] Specifically, the third calculation unit 300 substitutes the mass of the mixed gas at the anode side of the fuel cell at the current moment, the mass of the mixed gas discharged from the anode side of the fuel cell, and the mass of the pure hydrogen added to the anode side of the fuel cell into the formula (Mol 氮初始 -Mol 氮排 ) / [(Mol 氮初始 -Mol 氮排 )+(Mol 氢初始 -Mol 氢排 +Mol 氢增 )], calculate the nitrogen concentration on the anode side of the fuel cell after one cycle t.

[0146] The first execution unit 400 is used to stop the nitrogen exhaust operation after a first preset time period when it is determined that the nitrogen concentration on the anode side of the fuel cell is less than a preset value, and to record the total nitrogen exhaust time period.

[0147] Specifically, after determining that the nitrogen concentration on the anode side of the fuel cell is less than a preset value after one cycle t, the first execution unit 400 stops executing the nitrogen exhaust operation.

[0148] Furthermore, when the nitrogen concentration on the anode side of the fuel cell is higher than the preset value, the nitrogen discharge operation continues, and the calculation is repeated to determine whether the nitrogen concentration on the anode side of the fuel cell is less than the preset value after the first preset time. If the nitrogen concentration is less than the preset value, the nitrogen discharge operation is stopped after the first preset time, and the actual total nitrogen discharge time is 2 times the first preset time; if the nitrogen concentration is higher than the preset value, the nitrogen discharge operation is repeated. Thus, multiple calculations and judgments are performed until the nitrogen discharge operation is terminated when the nitrogen concentration on the anode side of the fuel cell is lower than the preset value, that is, the total nitrogen discharge time is n times the first preset time (n is an integer greater than or equal to 1).

[0149] In this embodiment, the first calculation unit 100 calculates the mass of the mixed gas of hydrogen and nitrogen on the anode side of the fuel cell at the current moment according to the formula PV=(m / M)RT. Where P is the pressure of the gas; V is the volume of the gas; m is the mass of the gas; M is the molar mass of the gas; (m / M) is the number of moles of the gas; R is the universal constant of the gas, R=8.31 ​​J / mol; and T is the temperature of the gas.

[0150] Furthermore, the pressure of the mixed gas at the current moment is essentially the pressure value on the anode side of the fuel cell, which can be obtained through a pressure sensor; the volume of the mixed gas at the current moment is essentially the volume of the pipeline on the anode side of the fuel cell, which can be obtained through measurement; thus, the pressure value on the anode side of the fuel cell, the volume of the pipeline on the anode side of the fuel cell and the temperature of the mixed gas on the anode side of the fuel cell are substituted into the formula PV = (m / M)RT, and the mass of the mixed gas of hydrogen and nitrogen on the anode side of the fuel cell at the current moment can be obtained.

[0151] Further, the second calculation unit 200 substitutes the mass of the mixed gas on the anode side of the fuel cell at the current moment and the volume of the mixed gas on the anode side of the fuel cell at the current moment into the formula Calculate the density ρ of the mixed gas at the current moment; since the density of the discharged mixed gas is the density ρ of the mixed gas at the current moment, substitute the density ρ of the mixed gas at the current moment, the cross-sectional radius r of the hydrogen exhaust valve on the anode side of the fuel cell, and the upstream and downstream pressure difference △P of the hydrogen exhaust valve into the formula The mass of the mixed gas discharged from the anode side of the fuel cell within a cycle t is calculated. Then, the second calculation unit 200 calculates the mass Q of the mixed gas discharged within a cycle 排 Substitute the density ρ of the mixed gas into the formula Calculate the volume v of the mixed gas discharged in one cycle. The newly added volume of pure hydrogen is the same as the volume v of the mixed gas discharged, that is, the newly added volume of hydrogen multiplied by the density of hydrogen can give the mass of the newly added pure hydrogen.

[0152] Further, the third calculation unit 300 substitutes the mass of the mixed gas at the anode side of the fuel cell at the current moment, the mass of the mixed gas discharged from the anode side of the fuel cell, and the mass of the pure hydrogen added to the anode side of the fuel cell into the formula (Mol 氮初始 -Mol 氮排 ) / [(Mol 氮初始 -Mol 氮排 )+(Mol 氢初始 -Mol 氢排 +Mol 氢增 )], calculate the nitrogen concentration on the anode side of the fuel cell after one cycle t.

[0153] When it is determined that the nitrogen concentration at the anode side of the fuel cell is less than a preset value after one cycle t, the first execution unit 400 stops executing the nitrogen exhaust operation.

[0154] In one embodiment, Figure 5 As shown, the present invention provides a fuel cell nitrogen exhaust control device. Based on the above embodiment, the first calculation unit 100 specifically includes: an acquisition module 110, a first calculation module 120, and a second calculation module 130.

[0155] The acquisition module 110 is used to obtain the volume of the pipeline on the anode side of the fuel cell at the current moment, the cross-sectional radius of the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell at the current moment, the pressure value on the anode side of the fuel cell at the current moment, and the temperature of the mixed gas on the anode side of the fuel cell at the current moment.

[0156] Specifically, the acquisition module 110 obtains the volume of the pipeline on the anode side of the fuel cell at the current moment, and the volume can be obtained through measurement; obtains the cross-sectional radius of the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell at the current moment, and the cross-sectional area can also be obtained by measuring the cross-sectional radius r of the valve; obtains the pressure value on the anode side of the fuel cell at the current moment, and the pressure value can be obtained through a pressure sensor, etc.; obtains the temperature of the mixed gas on the anode side of the fuel cell at the current moment, and the temperature can also be obtained through a temperature sensor, etc.

[0157] The first calculation module 120 is used to calculate the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell and the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment based on the volume of the pipeline on the anode side of the fuel cell, the pressure value on the anode side of the fuel cell, and the temperature of the mixed gas on the anode side of the fuel cell.

[0158] Specifically, the first calculation module 120 substitutes the volume v of the anode side pipeline of the fuel cell, the pressure value p of the anode side of the fuel cell, and the temperature t0 of the mixed gas on the anode side of the fuel cell into the formula PV=(m / M)RT to calculate the total mass Q of the mixed gas in the fuel cell at the current moment. 混Assuming that the current molar ratio of hydrogen to nitrogen is a:b (this ratio needs to be adjusted according to the specific minimum requirement of the fuel cell stack for hydrogen concentration), we can know the current molar number of nitrogen in the mixed gas on the anode side of the fuel cell, Mol 氮初始 = (PV / RT)*(a / a+b), the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell at the current moment Mol 氢初始 It is (PV / RT)*(b / a+b).

[0159] The second calculation module 130 is used to calculate the mass of the mixed gas on the anode side of the fuel cell at the current moment according to the molar number of hydrogen in the mixed gas on the anode side of the fuel cell and the molar number of nitrogen in the mixed gas on the anode side of the fuel cell.

[0160] Specifically, since the molar masses of hydrogen and nitrogen are 2 and 28 respectively, according to the molar masses of hydrogen and nitrogen, the molar number of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment Mol 氮初始 (PV / RT)*(a / a+b) and the number of moles of hydrogen Mol 氢初始 (PV / RT)*(b / a+b), the second calculation module 130 calculates the total mass Q of the mixed gas on the anode side of the fuel cell at the current moment 混 =28*(PV / RT)*(a / a+b)+2*(PV / RT)*(b / a+b).

[0161] In one embodiment, Figure 6 As shown, the present invention provides a fuel cell nitrogen exhaust control device. Based on the above embodiment, the second calculation unit 200 specifically includes:

[0162] The third calculation module 210 is used to calculate the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time period has passed from the current moment based on the mass of the mixed gas on the anode side of the fuel cell, the volume of the pipeline on the anode side of the fuel cell, the cross-sectional radius of the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell, and the pressure value on the anode side of the fuel cell, and calculate the number of moles of hydrogen discharged from the anode side of the fuel cell and the number of moles of nitrogen discharged from the anode side of the fuel cell after the first preset time period has passed from the current moment based on the mass of the mixed gas discharged from the anode side of the fuel cell.

[0163] The fourth calculation module 220 is used to calculate the number of moles of hydrogen added to the anode side of the fuel cell after a first preset time has passed from the current moment based on the mass of the mixed gas discharged from the anode side of the fuel cell, the mass of the mixed gas on the anode side of the fuel cell, and the volume of the pipeline on the anode side of the fuel cell.

[0164] The third calculation unit 300 specifically includes:

[0165] The fifth calculation module 310 is used to calculate the nitrogen concentration on the anode side of the fuel cell based on the molar number of hydrogen in the mixed gas on the anode side of the fuel cell, the molar number of nitrogen in the mixed gas on the anode side of the fuel cell, the molar number of hydrogen discharged from the anode side of the fuel cell, the molar number of nitrogen discharged from the anode side of the fuel cell, and the molar number of newly added hydrogen on the anode side of the fuel cell.

[0166] The details of this embodiment have been described in detail in the above embodiments, and will not be repeated here.

[0167] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for controlling nitrogen exhaust of a fuel cell, characterized in that: Includes steps: Calculating the mass of the mixed gas at the anode side of the fuel cell at the current moment; Calculating the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset time has passed at the current moment according to the mass of the mixed gas at the anode side of the fuel cell at the current moment; Calculate the nitrogen concentration on the anode side of the fuel cell after the first preset time period has passed at the current moment according to the mass of the mixed gas on the anode side of the fuel cell at the current moment and the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time period has passed at the current moment; When it is determined that the nitrogen concentration on the anode side of the fuel cell is lower than a preset value, the nitrogen exhaust operation is stopped after the first preset time has passed, and the total nitrogen exhaust time is recorded.

2. The fuel cell nitrogen exhaust control method according to claim 1, characterized in that: The calculation of the mass of the mixed gas at the anode side of the fuel cell at the current moment specifically includes the steps of: Obtaining the volume of the anode side pipeline of the fuel cell at the current moment, the pressure value of the anode side of the fuel cell at the current moment, the temperature of the mixed gas on the anode side of the fuel cell at the current moment, and the molar ratio of hydrogen and nitrogen in the mixed gas on the anode side of the fuel cell at the current moment; Calculate the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell at the current moment and the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment according to the volume of the pipeline on the anode side of the fuel cell, the pressure value on the anode side of the fuel cell, the temperature of the mixed gas on the anode side of the fuel cell, and the molar ratio of hydrogen to nitrogen in the mixed gas on the anode side of the fuel cell at the current moment; The mass of the mixed gas on the anode side of the fuel cell at the current moment is calculated according to the molar number of hydrogen on the anode side of the mixed gas of the fuel cell at the current moment and the molar number of nitrogen on the anode side of the mixed gas of the fuel cell at the current moment.

3. The fuel cell nitrogen exhaust control method according to claim 2, characterized in that: After the mass of the mixed gas on the anode side of the fuel cell at the current moment is calculated, the steps are specifically included: Obtaining the cross-sectional area of ​​the internal flow channel of the anode-side hydrogen exhaust valve of the fuel cell and the upstream and downstream pressure difference of the anode-side hydrogen exhaust valve of the fuel cell; Calculate the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset time period at the current moment according to the mass of the mixed gas at the anode side of the fuel cell, the volume of the pipeline at the anode side of the fuel cell, the cross-sectional area of ​​the internal flow channel of the hydrogen exhaust valve at the anode side of the fuel cell, and the upstream and downstream pressure difference of the hydrogen exhaust valve at the anode side of the fuel cell, and calculate the number of moles of hydrogen discharged from the anode side of the fuel cell and the number of moles of nitrogen discharged from the anode side of the fuel cell after the first preset time period at the current moment according to the mass of the mixed gas discharged from the anode side of the fuel cell; Calculate the number of moles of hydrogen introduced into the anode side of the fuel cell after the first preset time has passed at the current moment according to the mass of the mixed gas discharged from the anode side of the fuel cell and the volume of the pipeline on the anode side of the fuel cell; Calculate the nitrogen concentration on the anode side of the fuel cell according to the mole number of hydrogen in the mixed gas on the anode side of the fuel cell, the mole number of nitrogen in the mixed gas on the anode side of the fuel cell, the mole number of hydrogen discharged from the anode side of the fuel cell, the mole number of nitrogen discharged from the anode side of the fuel cell, and the mole number of hydrogen introduced into the anode side of the fuel cell; When it is determined that the nitrogen concentration on the anode side of the fuel cell is lower than the preset value, the nitrogen exhaust operation is stopped after the first preset time period, and the total nitrogen exhaust time period is recorded.

4. The fuel cell nitrogen exhaust control method according to claim 1, characterized in that: When the nitrogen concentration on the anode side of the fuel cell is lower than a preset value, before stopping the nitrogen exhaust operation, after calculating the nitrogen concentration on the anode side of the fuel cell at the current moment after the first preset time has passed, the method further includes the following steps: Determining whether the nitrogen concentration is lower than the preset value; If the nitrogen concentration is not lower than the preset value, after the first preset time period, the nitrogen exhaust operation is continued, and the nitrogen concentration on the anode side of the fuel cell at the current moment after the first preset time period is repeatedly calculated.

5. A fuel cell nitrogen exhaust control device, characterized in that: include: A first calculation unit, used to calculate the mass of the mixed gas at the anode side of the fuel cell at the current moment; A second calculation unit, configured to calculate the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset time has passed at the current moment according to the mass of the mixed gas at the anode side of the fuel cell at the current moment; a third calculation unit, configured to calculate the nitrogen concentration at the anode side of the fuel cell after the first preset time period has passed at the current moment according to the mass of the mixed gas at the anode side of the fuel cell at the current moment and the mass of the mixed gas discharged from the anode side of the fuel cell after the first preset time period has passed at the current moment; The first execution unit is used to determine that when the nitrogen concentration on the anode side of the fuel cell is lower than a preset value, stop executing the nitrogen exhaust operation after the first preset time period has passed, and record the total nitrogen exhaust time.

6. The fuel cell nitrogen exhaust control device according to claim 5, characterized in that: The first computing unit specifically includes: An acquisition module, used to acquire the volume of the anode side pipeline of the fuel cell at the current moment, the pressure value of the anode side of the fuel cell at the current moment, the temperature of the mixed gas on the anode side of the fuel cell at the current moment, and the molar ratio of hydrogen and nitrogen in the mixed gas on the anode side of the fuel cell at the current moment; A first calculation module, for calculating the number of moles of hydrogen in the mixed gas on the anode side of the fuel cell at the current moment and the number of moles of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment according to the volume of the pipeline on the anode side of the fuel cell, the pressure value on the anode side of the fuel cell, the temperature of the mixed gas on the anode side of the fuel cell, and the molar ratio of hydrogen to nitrogen in the mixed gas on the anode side of the fuel cell at the current moment; The second calculation module is used to calculate the mass of the mixed gas on the anode side of the fuel cell at the current moment according to the molar number of hydrogen and the molar number of nitrogen in the mixed gas on the anode side of the fuel cell at the current moment.

7. The fuel cell nitrogen exhaust control device according to claim 6, characterized in that: The acquisition module is also used to acquire the cross-sectional area of ​​the internal flow channel of the hydrogen exhaust valve on the anode side of the fuel cell and the upstream and downstream pressure difference of the hydrogen exhaust valve on the anode side of the fuel cell. The second computing unit specifically includes: a third calculation module, for calculating the mass of the mixed gas discharged from the anode side of the fuel cell after a first preset time period at the current moment according to the mass of the mixed gas at the anode side of the fuel cell, the volume of the pipeline at the anode side of the fuel cell, the cross-sectional area of ​​the internal flow channel of the hydrogen exhaust valve at the anode side of the fuel cell, and the upstream and downstream pressure difference of the hydrogen exhaust valve at the anode side of the fuel cell, and calculating the number of moles of hydrogen discharged from the anode side of the fuel cell and the number of moles of nitrogen discharged from the anode side of the fuel cell after the first preset time period at the current moment according to the mass of the mixed gas discharged from the anode side of the fuel cell; a fourth calculation module, for calculating the number of moles of hydrogen introduced into the anode side of the fuel cell after the first preset time has passed at the current moment according to the mass of the mixed gas discharged from the anode side of the fuel cell, the mass of the mixed gas on the anode side of the fuel cell, and the volume of the pipeline on the anode side of the fuel cell; The third computing unit specifically includes: The fifth calculation module is used to calculate the nitrogen concentration on the anode side of the fuel cell based on the molar number of hydrogen in the mixed gas on the anode side of the fuel cell, the molar number of nitrogen in the mixed gas on the anode side of the fuel cell, the molar number of hydrogen discharged from the anode side of the fuel cell, the molar number of nitrogen discharged from the anode side of the fuel cell, and the molar number of hydrogen introduced into the anode side of the fuel cell.

8. The fuel cell nitrogen exhaust control device according to claim 5, characterized in that: Also includes: A judging unit, used to judge whether the nitrogen concentration is lower than the preset value; The second execution unit is used to continue to perform the nitrogen exhaust operation after the first preset time if the nitrogen concentration is not lower than the preset value, and repeatedly calculate the nitrogen concentration on the anode side of the fuel cell after the first preset time at the current moment.

9. A method for correcting nitrogen removal time, characterized in that: Includes steps: Obtaining a first pressure on the anode side of the fuel cell at the current moment and a first temperature of the mixed gas on the anode side of the fuel cell at the current moment, and calculating the total nitrogen discharge time when the nitrogen concentration on the anode side of the fuel cell is lower than the preset value through the fuel cell nitrogen discharge control method according to any one of claims 1 to 4 according to the first pressure on the anode side of the fuel cell and the first temperature of the mixed gas on the anode side of the fuel cell; According to the first pressure and the first temperature, a correction coefficient is obtained by looking up a table, wherein the correction coefficient is obtained by experimentally collecting the nitrogen concentration at the outlet end of the hydrogen exhaust valve on the anode side of the fuel cell under the first pressure and the first temperature conditions, recording the actual working time of the corresponding nitrogen exhaust operation according to the nitrogen concentration variation range on the anode side of the fuel cell, and calculating the theoretical working time corresponding to the nitrogen concentration variation range on the anode side of the fuel cell according to the fuel cell nitrogen exhaust control method according to any one of claims 1 to 4 above, and calculating the correction coefficient according to the theoretical working time and the actual working time; The total nitrogen exhaust time is corrected according to the correction coefficient.

10. A fuel cell system, comprising a processor, a memory connected to the processor, and program instructions stored in the memory, wherein the processor implements the fuel cell nitrogen exhaust control method according to claims 1-4 when executing the program instructions.

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