Control method of fuel cell system and fuel cell system

Abstract

The invention relates to the technical field of fuel cells, particularly provides a control method of a fuel cell system and the fuel cell system, and aims to solve the problem that a cooling mode of an existing fuel cell system easily causes poor temperature stability of a fuel cell. Therefore, the fuel cell system comprises a fuel cell, a radiator, a heat exchanger, a heat storage water tank and a bypass cooling pipe, the bypass cooling pipe and the radiator are arranged in parallel, and the control method comprises the steps that in the process of cooling the fuel cell, the temperature of the fuel cell is obtained; and according to the temperature of the fuel cell, selectively enabling the cooling liquid discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe and return to the cooling liquid inlet of the fuel cell. The bypass cooling pipe connected in parallel with the radiator is arranged, and the backflow path of the cooling liquid is selected according to the temperature of the fuel cell, so that the stability of the temperature of the fuel cell stack is favorably maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and specifically provides a control method for a fuel cell system and a fuel cell system. Background Art

[0002] A fuel cell system is usually composed of a fuel cell, a fuel supply subsystem, an oxidant supply subsystem, a hydrothermal subsystem, a control subsystem, etc. At present, hydrogen is commonly used as a fuel, and air is used as an oxidant. The operating principle of a fuel cell is as follows: hydrogen and air are supplied to the anode and cathode of the fuel cell respectively. Hydrogen decomposes into hydrogen ions and electrons at the anode. The hydrogen ions reach the cathode through the electrolyte (such as a proton exchange membrane) between the cathode and the cathode, and the electrons are conducted to the cathode through an external circuit. Oxygen in the air combines with hydrogen ions and electrons at the cathode to generate water. Electrons generate current during the conduction process through the external circuit. At the same time, due to the electrochemical reaction itself and the internal resistance of the battery, the fuel cell will also generate a certain amount of heat. The generated current can be used for external power supply, and the generated heat is used for external heating.

[0003] In order to ensure the best performance of the fuel cell, the fuel cell needs to be cooled. In the prior art, a heat exchanger and a radiator are usually set on the cooling pipeline to absorb or dissipate the heat carried by the coolant. However, this cooling method easily causes large temperature fluctuations in the fuel cell and poor system operation stability.

[0004] Therefore, this field needs a new technical solution to solve the above problems. Summary of the invention

[0005] The present invention aims to solve the above technical problem, that is, to solve the problem that the cooling method of the existing fuel cell system easily leads to poor temperature stability of the fuel cell.

[0006] In a first aspect, the present invention provides a control method for a fuel cell system, the fuel cell system comprising a fuel cell, a radiator, a heat exchanger and a hot water storage tank, the coolant outlet of the fuel cell is communicated with the first inlet of the heat exchanger through a first cooling pipe, the first outlet of the heat exchanger is communicated with the first end of the radiator through a second cooling pipe, the second end of the radiator is communicated with the coolant inlet of the fuel cell through a third cooling pipe, the water outlet of the hot water storage tank is communicated with the second inlet of the heat exchanger through a first circulation pipe, the second outlet of the heat exchanger is communicated with the return water port of the hot water storage tank through a second circulation pipe, the fuel cell system further comprises a bypass cooling pipe, the two ends of the bypass cooling pipe are respectively communicated with the first outlet of the heat exchanger and the coolant inlet, the control method comprises:

[0007] In the process of cooling the fuel cell, obtaining the temperature of the fuel cell;

[0008] The coolant discharged from the first outlet of the heat exchanger is selectively made to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the temperature of the fuel cell.

[0009] In the preferred technical solution of the control method of the above fuel cell system, the step of "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the temperature of the fuel cell" specifically includes:

[0010] Comparing the temperature of the fuel cell with a first set temperature and a second set temperature respectively; wherein the first set temperature is lower than the second set temperature;

[0011] According to the comparison result, the coolant discharged from the first outlet of the heat exchanger is selectively made to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell.

[0012] In the preferred technical solution of the control method of the above fuel cell system, the step of "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the comparison result" specifically includes:

[0013] If the temperature of the fuel cell is lower than the first set temperature, the coolant discharged from the first outlet of the heat exchanger is made to flow through the bypass cooling pipe back to the coolant inlet of the fuel cell.

[0014] In the preferred technical solution of the control method of the above fuel cell system, the step of "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the comparison result" specifically includes:

[0015] If the temperature of the fuel cell is greater than the second set temperature, the coolant discharged from the first outlet of the heat exchanger is made to flow through the radiator back to the coolant inlet of the fuel cell.

[0016] In the preferred technical solution of the control method of the above fuel cell system, the step of "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the comparison result" specifically includes:

[0017] If the temperature of the fuel cell is greater than or equal to the first set temperature and less than or equal to the second set temperature, the coolant discharged from the first outlet of the heat exchanger flows through the radiator and the bypass cooling pipe back to the coolant inlet of the fuel cell.

[0018] In the preferred technical solution of the control method of the above fuel cell system, the control method further includes:

[0019] Obtaining the temperature of the coolant in the first cooling pipe, recorded as a first temperature;

[0020] The flow rate of the coolant flowing through the radiator is determined according to the first temperature and the target return water temperature of the coolant.

[0021] In the preferred technical solution of the control method of the above fuel cell system, the control method further includes:

[0022] Obtaining the temperature of the coolant at the coolant inlet of the fuel cell, recorded as a second temperature;

[0023] The flow rate of the coolant flowing through the radiator is selectively adjusted according to the second temperature and the target return water temperature.

[0024] In the preferred technical solution of the control method of the above fuel cell system, the control method further includes:

[0025] A preset flow rate corresponding to the temperature of the fuel cell is obtained, so that the water in the first circulation pipe and the second circulation pipe flows according to the preset flow rate.

[0026] In the preferred technical solution of the control method of the above fuel cell system, the control method further includes:

[0027] Comparing the temperature of the fuel cell with a third set temperature; wherein the third set temperature is lower than the first set temperature;

[0028] If the temperature of the fuel cell is lower than the third set temperature, cooling the fuel cell is stopped.

[0029] In a second aspect, the present invention further provides a fuel cell system, comprising a controller, wherein the controller is configured to execute the above control method.

[0030] When adopting the above technical solution, the present invention is beneficial to maintaining the stability of the temperature of the fuel cell stack by setting a bypass cooling pipe in parallel with the radiator and selecting the coolant reflux path according to the temperature of the fuel cell. Specifically, when the temperature of the fuel cell is lower than the first set temperature, the coolant discharged from the first outlet of the heat exchanger directly flows through the bypass cooling pipe and returns to the coolant inlet of the fuel cell; when the temperature of the fuel cell is higher than the second set temperature, the coolant discharged from the first outlet of the heat exchanger flows through the radiator to dissipate heat and then returns to the coolant inlet of the fuel cell; when the temperature of the fuel cell is between the first set temperature and the second set temperature, a part of the coolant discharged from the first outlet of the heat exchanger flows through the radiator to dissipate heat and then returns to the coolant inlet of the fuel cell, and the other part of the coolant flows directly through the bypass cooling pipe and returns to the coolant inlet of the fuel cell.

[0031] Furthermore, the present invention determines the flow rate of the coolant flowing through the radiator according to the temperature of the coolant in the first cooling pipe and the target return water temperature of the coolant, which is more conducive to maintaining the temperature of the fuel cell stable.

[0032] Furthermore, the present invention can further improve the temperature stability of the fuel cell by determining whether the flow rate of the coolant flowing through the radiator needs to be adjusted based on the temperature of the coolant at the coolant inlet of the fuel cell and the target return water temperature.

[0033] Furthermore, the present invention is more conducive to maintaining a stable temperature of the fuel cell by matching the flow rate of water in the first circulation pipe and the second circulation pipe with the temperature of the fuel cell.

[0034] In addition, the fuel cell system further provided by the present invention on the basis of the above technical solution adopts the above control method, thereby having the technical effects of the above control method. Compared with the fuel cell system before the improvement, the fuel cell system of the present invention has better stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0036] Figure 1 is a system schematic diagram of a first embodiment of a fuel cell system of the present invention;

[0037] Figure 2 is a system schematic diagram of a second embodiment of a fuel cell system of the present invention;

[0038] Figure 3 is a flow chart of a control method of a fuel cell system of the present invention;

[0039] Figure 4It is a flowchart of an embodiment of a control method of a fuel cell system of the present invention.

[0040] List of reference numerals:

[0041] 1. Fuel cell; 11. Coolant inlet; 12. Coolant outlet;

[0042] 2. Radiator;

[0043] 3. Heat exchanger; 31. First inlet; 32. First outlet; 33. Second inlet; 34. Second outlet;

[0044] 4. Hot water storage tank; 41. Water outlet; 42. Water return outlet;

[0045] 51, first cooling pipe; 52, second cooling pipe; 53, third cooling pipe;

[0046] 61. first circulation pipe; 62. second circulation pipe;

[0047] 71. first water pump; 72. second water pump;

[0048] 8. Bypass cooling pipe;

[0049] 91. First solenoid valve; 92. Second solenoid valve; 93. Three-way valve; 94. Three-way solenoid valve. DETAILED DESCRIPTION

[0050] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0051] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that, in the description of the present invention, although the various steps of the control method of the present invention are described in this application in a specific order, these orders are not restrictive, and those skilled in the art may perform the steps in different orders without departing from the basic principles of the present invention.

[0052] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0053] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "setting", "connection" and "installation" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] Specifically, the present invention provides a fuel cell system, such as Figure 1 and Figure 2 As shown, the fuel cell system of the present invention includes a fuel cell 1, a radiator 2, a heat exchanger 3 and a hot water storage tank 4.

[0055] Among them, the coolant outlet 12 of the fuel cell 1 is connected to the first inlet 31 of the heat exchanger 3 through the first cooling pipe 51, the first outlet 32 ​​of the heat exchanger 3 is connected to the first end of the radiator 2 (the right end of the radiator 2 as seen in the figure) through the second cooling pipe 52, the second end of the radiator 2 (the left end of the radiator 2 as seen in the figure) is connected to the coolant inlet 11 of the fuel cell 1 through the third cooling pipe 53, the water outlet 41 of the hot water storage tank 4 is connected to the second inlet 33 of the heat exchanger 3 through the first circulation pipe 61, and the second outlet 34 of the heat exchanger 3 is connected to the return water port 42 of the hot water storage tank 4 through the second circulation pipe 62.

[0056] Exemplarily, a first water pump 71 is installed on the first cooling pipe 51, and a second water pump 72 is installed on the first circulation pipe 61. When the fuel cell 1 needs to be cooled, the first water pump 71 and the second water pump 72 are started, and the coolant enters from the coolant inlet 11 of the fuel cell 1 to cool the fuel cell 1, and then is discharged from the coolant outlet 12 of the fuel cell 1 and enters the first cooling pipe 51. The coolant flows into the heat exchanger 3 from the first inlet 31 of the heat exchanger 3 along the first cooling pipe 51, and the water in the hot water tank 4 is discharged from the water outlet 41 of the hot water tank 4 and enters the first circulation pipe 61. The water flows from the second inlet 31 of the heat exchanger 3 along the first circulation pipe 61. The water flows into the heat exchanger 3 from the second outlet 33, exchanges heat with the coolant in the heat exchanger 3, absorbs the heat carried by the coolant, and then is discharged from the second outlet 34 of the heat exchanger 3 and enters the second circulation pipe 62, and finally flows back to the hot water storage tank 4 from the return water outlet 42 of the hot water storage tank 4 along the second circulation pipe 62. The temperature of the coolant after the heat exchange is reduced, and then it is discharged from the first outlet 32 ​​of the heat exchanger 3 and enters the second cooling pipe 52. The coolant enters the radiator 2 along the second cooling pipe 52 to dissipate heat, and the temperature of the coolant is further reduced. The coolant discharged from the radiator 2 flows back to the fuel cell 1 along the third cooling pipe 53 to continue cooling the fuel cell 1.

[0057] Furthermore, if Figure 1 and Figure 2As shown, the fuel cell system of the present invention further includes a bypass cooling pipe 8, both ends of which are respectively connected to the first outlet 32 ​​of the heat exchanger 3 and the coolant inlet 11, that is, the bypass cooling pipe 8 is arranged in parallel with the radiator 2.

[0058] In the first preferred case, if Figure 1 As shown, the fuel cell system of the present invention bypasses the first end of the cooling pipe 8 (from Figure 1 The right end of the bypass pipe (as viewed from above) is connected to the first outlet 32 ​​of the heat exchanger 3 and the second cooling pipe 52, and the second end of the bypass cooling pipe 8 (from the right end) is connected to the second outlet 32 ​​of the heat exchanger 3 through another three-way valve 93. Figure 1 The left end of the bypass line as seen from above) is connected to the coolant inlet 11 of the fuel cell 1 and the third cooling pipe 53. In addition, a first solenoid valve 91 is installed on the bypass cooling pipe 8, and a second solenoid valve 92 is installed on the second cooling pipe 52. Of course, the second solenoid valve 92 can also be installed on the third cooling pipe 53.

[0059] In this embodiment, the first solenoid valve 91 can be opened and the second solenoid valve 92 can be closed, so that the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 flows through the bypass cooling pipe 8 and returns to the coolant inlet 11 of the fuel cell 1, and no longer flows through the radiator 2 for heat dissipation; alternatively, the first solenoid valve 91 can be closed and the second solenoid valve 92 can be opened, so that the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 flows through the radiator 2 and returns to the coolant inlet 11 of the fuel cell 1; alternatively, the first solenoid valve 91 and the second solenoid valve 92 can be opened at the same time, so that part of the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 flows through the bypass cooling pipe 8 and returns to the coolant inlet 11 of the fuel cell 1, and the other part of the coolant flows through the radiator 2 and returns to the coolant inlet 11 of the fuel cell 1.

[0060] In a second preferred embodiment, Figure 2 As shown, the fuel cell system of the present invention bypasses the first end of the cooling pipe 8 (from Figure 2 The right end of the bypass pipe as viewed from above) is connected to the first outlet 32 ​​of the heat exchanger 3 and the second cooling pipe 52. Specifically, the inlet of the three-way solenoid valve 94 is connected to the first outlet 32 ​​of the heat exchanger 3, and the two outlets of the three-way solenoid valve 94 are connected to the bypass cooling pipe 8 and the second cooling pipe 52 respectively. The fuel cell system of the present invention also connects the second end of the bypass cooling pipe 8 (from the right end of the bypass pipe 8) to the third cooling pipe 52 through a three-way valve 93. Figure 2 The left end of the bypass line (as seen from above) is connected to the coolant inlet 11 of the fuel cell 1 and the third cooling pipe 53.

[0061] In this embodiment, the three-way solenoid valve 94 can be used to control the first outlet 32 ​​of the heat exchanger 3 to be connected only to the bypass cooling pipe 8, and the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 flows through the bypass cooling pipe 8 to return to the coolant inlet 11 of the fuel cell 1, and no longer flows through the radiator 2 for heat dissipation; or, the three-way solenoid valve 94 can be used to control the first outlet 32 ​​of the heat exchanger 3 to be connected only to the second cooling pipe 52, and the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 flows through the radiator 2 to return to the coolant inlet 11 of the fuel cell 1; or, the three-way solenoid valve 94 can be used to control the first outlet 32 ​​of the heat exchanger 3 to be connected to the bypass cooling pipe 8 and the second cooling pipe 52 at the same time, and a part of the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 flows through the bypass cooling pipe 8 to return to the coolant inlet 11 of the fuel cell 1, and the other part of the coolant flows through the radiator 2 to return to the coolant inlet 11 of the fuel cell 1.

[0062] Based on the above-described fuel cell system, the present invention also provides a control method for the fuel cell system, such as Figure 3 As shown, the control method of the present invention comprises the following steps:

[0063] During the cooling of the fuel cell 1,

[0064] S100: Acquire the temperature of the fuel cell;

[0065] S200: According to the temperature of the fuel cell, selectively allow the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell.

[0066] Selecting the coolant return path according to the temperature of the fuel cell 1 is helpful to maintain the stability of the temperature of the fuel cell 1 stack.

[0067] It should be noted that the above “selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe to return to the coolant inlet of the fuel cell” includes the following three situations: situation 1, only the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 is allowed to flow through the radiator 2 and return to the coolant inlet 11 of the fuel cell 1; situation 2, only the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 is allowed to flow through the bypass cooling pipe 8 and return to the coolant inlet 11 of the fuel cell 1; situation 3, the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 is allowed to flow through the radiator 2 and the bypass cooling pipe 8 at the same time and return to the coolant inlet 11 of the fuel cell 1.

[0068] Preferably, if Figure 4As shown, step S200, "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the temperature of the fuel cell" specifically includes:

[0069] S210: Compare the temperature of the fuel cell with a first set temperature and a second set temperature respectively; wherein the first set temperature is lower than the second set temperature;

[0070] S220 : Based on the comparison result, selectively allow the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell 1 .

[0071] It should be noted that the present invention does not limit the specific values ​​of the first set temperature and the second set temperature. Those skilled in the art can flexibly set the specific values ​​of the first set temperature and the second set temperature based on experiments or experience in practical applications.

[0072] Preferably, if Figure 4 As shown, step S220, "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the comparison result" specifically includes:

[0073] S221: If the temperature of the fuel cell is lower than the first set temperature, the coolant discharged from the first outlet of the heat exchanger is allowed to flow through the bypass cooling pipe and return to the coolant inlet of the fuel cell.

[0074] When the temperature of the fuel cell 1 is lower than the first set temperature, it indicates that the temperature of the fuel cell 1 is not too high. In this case, the heat carried by the coolant can be absorbed only by the hot water storage tank 4. The coolant discharged from the first outlet 32 ​​of the heat exchanger 3 can directly flow through the bypass cooling pipe 8 back to the coolant inlet 11 of the fuel cell 1 without having to flow through the radiator 2 for heat dissipation.

[0075] Preferably, if Figure 4 As shown, step S220, "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the comparison result" specifically includes:

[0076] S222: If the temperature of the fuel cell is greater than the second set temperature, the coolant discharged from the first outlet of the heat exchanger is allowed to flow through the radiator and return to the coolant inlet of the fuel cell.

[0077] When the temperature of the fuel cell 1 is greater than the second set temperature, it means that the temperature of the fuel cell 1 is very high. In this case, not only does the heat carried by the coolant need to be absorbed by the hot water tank 4, but the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 also needs to flow through the radiator 2 for heat dissipation, and then return to the coolant inlet 11 of the fuel cell 1.

[0078] Preferably, if Figure 4 As shown, step S220, "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the comparison result" specifically includes:

[0079] S223: If the temperature of the fuel cell is greater than or equal to the first set temperature and less than or equal to the second set temperature, the coolant discharged from the first outlet of the heat exchanger flows through the radiator and the bypass cooling pipe and returns to the coolant inlet of the fuel cell.

[0080] When the temperature of the fuel cell 1 is between the first set temperature and the second set temperature, it means that the temperature of the fuel cell 1 is too high. In this case, the heat carried by the coolant is first absorbed by the hot water storage tank 4. A part of the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 needs to flow through the radiator 2 for heat dissipation, and then return to the coolant inlet 11 of the fuel cell 1. The other part of the coolant does not need to flow through the radiator 2 for heat dissipation, and can directly flow through the bypass cooling pipe 8 and return to the coolant inlet 11 of the fuel cell 1.

[0081] Preferably, the control method of the present invention further comprises the following steps:

[0082] S300: comparing the temperature of the fuel cell with a third set temperature; wherein the third set temperature is lower than the first set temperature;

[0083] S400: If the temperature of the fuel cell is lower than the third set temperature, stop cooling the fuel cell.

[0084] When the temperature of the fuel cell 1 is lower than the third set temperature, the fuel cell 1 does not need to be cooled, and the stack of the fuel cell 1 can dissipate heat by itself.

[0085] It should be noted that the present invention does not limit the specific value of the third set temperature, and those skilled in the art can flexibly set the specific value of the third set temperature based on experiments or experience in practical applications.

[0086] The control method of the present invention is described below by taking the third set temperature = 75° C., the first set temperature = 85° C., and the second set temperature = 90° C. as an example.

[0087] When the temperature of the fuel cell 1 is below 75°C, there is no need to cool the fuel cell 1, and the fuel cell stack 1 can dissipate heat by itself; when the temperature of the fuel cell 1 reaches or exceeds 75°C, the first water pump 71 and the second water pump 72 are started to start cooling the fuel cell 1, and at the same time, the heat generated by the fuel cell 1 is recovered.

[0088] Among them, if the temperature of the fuel cell 1 does not reach 85°C, in this case, the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 directly flows through the bypass cooling pipe 8 and returns to the coolant inlet 11 of the fuel cell 1; if the temperature of the fuel cell 1 reaches or exceeds 85°C, but does not exceed 90°C, in this case, a part of the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 needs to flow through the radiator 2 for heat dissipation, and then return to the coolant inlet 11 of the fuel cell 1, and the other part of the coolant does not need to flow through the radiator 2 for heat dissipation, and can directly flow through the bypass cooling pipe 8 and return to the coolant inlet 11 of the fuel cell 1; if the temperature of the fuel cell 1 exceeds 90°C, in this case, all the coolant discharged from the first outlet 32 ​​of the heat exchanger 3 needs to flow through the radiator 2 for heat dissipation, and then return to the coolant inlet 11 of the fuel cell 1.

[0089] Preferably, the control method of the present invention further comprises: obtaining a preset flow rate corresponding to the temperature of the fuel cell 1 , so that the water in the first circulation pipe 61 and the second circulation pipe 62 flows at the preset flow rate.

[0090] Among them, the preset flow rate is positively correlated with the temperature of the fuel cell 1, that is, the higher the temperature of the fuel cell 1, the larger the value of the preset flow rate. By matching the flow rate of water in the first circulation pipe 61 and the second circulation pipe 62 with the temperature of the fuel cell 1, it is more conducive to keeping the temperature of the fuel cell 1 stable.

[0091] It should be noted that the flow rate of water in the first circulation pipe 61 and the second circulation pipe 62 is controlled by the second water pump 72. Therefore, a "temperature and speed comparison table" can be compiled through test data and pre-stored in the controller of the fuel cell 1 system. After obtaining the temperature of the fuel cell 1, the corresponding speed is searched through the "temperature and speed comparison table" to make the second water pump 72 run at the speed. Alternatively, an empirical formula can be compiled through test data and pre-stored in the controller of the fuel cell 1 system. After obtaining the temperature of the fuel cell 1, the corresponding speed is calculated through the empirical formula to make the second water pump 72 run at the speed.

[0092] Preferably, in the above situation 3, the control method of the present invention further includes:

[0093] Obtaining the temperature of the coolant in the first cooling pipe, recorded as the first temperature T1;

[0094] The flow rate of the coolant flowing through the radiator is determined according to the first temperature T1 and the target return water temperature T0 of the coolant.

[0095] Among them, the target return water temperature of the coolant refers to the target temperature of the coolant entering from the coolant inlet 11 of the fuel cell 1. The target return water temperature is generally set in advance by the staff and pre-stored in the controller of the fuel cell 1. By determining the flow rate of the coolant flowing through the radiator 2 according to the temperature of the coolant in the first cooling pipe 51 and the target return water temperature of the coolant, it is more conducive to keeping the temperature of the fuel cell stable.

[0096] Specifically, based on the difference between the temperature of the coolant in the first cooling pipe 51 and the target return water temperature of the coolant, as well as the flow rate of the coolant, the total heat that needs to be released when the coolant drops from the first temperature T1 to the target return water temperature T0 can be calculated using thermodynamic formulas. The total heat minus the heat that can be absorbed by the hot water storage tank 4 is the heat that needs to be dissipated by the radiator 2, thereby determining the flow rate of the coolant flowing through the radiator 2. The remaining coolant returns to the coolant inlet 11 of the fuel cell 1 through the bypass cooling pipe 8.

[0097] It should be noted that, in actual applications, the art can compile a temperature difference (temperature difference = temperature of the coolant in the first cooling pipe - target return water temperature) flow comparison table based on test data and pre-store it in the controller of the fuel cell 1 system. After obtaining the temperature T1 of the coolant in the first cooling pipe 51, calculate the temperature difference (T1-T0) with the target return water temperature T0, and then look up the corresponding flow through the "Temperature Difference Flow Comparison Table". In a first preferred embodiment of the fuel cell system, the flow of the coolant flowing through the radiator 2 can be controlled by controlling the opening of the first solenoid valve 91 and the second solenoid valve 92. In a second preferred embodiment of the fuel cell system, the flow of the coolant flowing through the radiator 2 can be controlled by controlling the opening ratio of the two outlets of the three-way solenoid valve 94.

[0098] Furthermore, the control method of the present invention further includes:

[0099] Obtaining the temperature of the coolant at the coolant inlet of the fuel cell, recorded as the second temperature T2;

[0100] The flow rate of the coolant flowing through the radiator is selectively adjusted according to the second temperature T2 and the target return water temperature T0.

[0101] By determining whether the flow rate of the coolant flowing through the radiator 2 needs to be adjusted based on the coolant temperature at the coolant inlet 11 of the fuel cell 1 and the target return water temperature, the temperature stability of the fuel cell can be further improved.

[0102] Exemplarily, the difference △T between the second temperature T2 and the target return water temperature T0 is calculated, △T = |T2-T0|, and the difference △T is compared with a preset value A (for example, A = 1.0). If △T≤A, there is no need to adjust the flow rate of the coolant flowing through the radiator 2; conversely, if △T>A, there is no need to adjust the flow rate of the coolant flowing through the radiator 2. Specifically, if T2>T0, it is necessary to increase the flow rate of the coolant flowing through the radiator 2. Conversely, if T2<T0, it is necessary to reduce the flow rate of the coolant flowing through the radiator 2.

[0103] It should be noted that the fuel cell system of the present invention includes a controller, and the controller is configured to execute the above-mentioned control method.

[0104] In addition, it should be noted that the control method provided in this embodiment can be stored as a program in a computer-readable storage medium. The storage medium includes a number of instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to perform some steps of the methods of various embodiments of the present invention. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes.

[0105] Those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims of the present application, any one of the claimed embodiments may be used in any combination.

[0106] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A control method for a fuel cell system, characterized in that: The fuel cell system includes a fuel cell, a radiator, a heat exchanger and a hot water storage tank. The coolant outlet of the fuel cell is connected to the first inlet of the heat exchanger through a first cooling pipe, the first outlet of the heat exchanger is connected to the first end of the radiator through a second cooling pipe, the second end of the radiator is connected to the coolant inlet of the fuel cell through a third cooling pipe, the water outlet of the hot water storage tank is connected to the second inlet of the heat exchanger through a first circulation pipe, the second outlet of the heat exchanger is connected to the return water port of the hot water storage tank through a second circulation pipe, the fuel cell system also includes a bypass cooling pipe, the two ends of the bypass cooling pipe are respectively connected to the first outlet of the heat exchanger and the coolant inlet, and the control method includes: In the process of cooling the fuel cell, obtaining the temperature of the fuel cell; The coolant discharged from the first outlet of the heat exchanger is selectively made to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the temperature of the fuel cell.

2. The control method of the fuel cell system according to claim 1, characterized in that: The step of "selectively causing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the temperature of the fuel cell" specifically includes: Comparing the temperature of the fuel cell with a first set temperature and a second set temperature respectively; wherein the first set temperature is lower than the second set temperature; According to the comparison result, the coolant discharged from the first outlet of the heat exchanger is selectively made to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell.

3. The control method of the fuel cell system according to claim 2, characterized in that: The step of "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the comparison result" specifically includes: If the temperature of the fuel cell is lower than the first set temperature, the coolant discharged from the first outlet of the heat exchanger is made to flow through the bypass cooling pipe back to the coolant inlet of the fuel cell.

4. The control method of the fuel cell system according to claim 2, characterized in that: The step of "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the comparison result" specifically includes: If the temperature of the fuel cell is greater than the second set temperature, the coolant discharged from the first outlet of the heat exchanger is made to flow through the radiator back to the coolant inlet of the fuel cell.

5. The control method of the fuel cell system according to claim 2, characterized in that: The step of "selectively allowing the coolant discharged from the first outlet of the heat exchanger to flow through the radiator and / or the bypass cooling pipe back to the coolant inlet of the fuel cell according to the comparison result" specifically includes: If the temperature of the fuel cell is greater than or equal to the first set temperature and less than or equal to the second set temperature, the coolant discharged from the first outlet of the heat exchanger flows through the radiator and the bypass cooling pipe back to the coolant inlet of the fuel cell.

6. The control method of the fuel cell system according to claim 5, characterized in that: The control method further comprises: Obtaining the temperature of the coolant in the first cooling pipe, recorded as a first temperature; The flow rate of the coolant flowing through the radiator is determined according to the first temperature and the target return water temperature of the coolant.

7. The control method of the fuel cell system according to claim 6, characterized in that: The control method further comprises: Obtaining the temperature of the coolant at the coolant inlet of the fuel cell, recorded as a second temperature; The flow rate of the coolant flowing through the radiator is selectively adjusted according to the second temperature and the target return water temperature.

8. The control method of the fuel cell system according to claim 2, characterized in that: The control method further comprises: Comparing the temperature of the fuel cell with a third set temperature; wherein the third set temperature is lower than the first set temperature; If the temperature of the fuel cell is lower than the third set temperature, cooling the fuel cell is stopped.

9. The control method of the fuel cell system according to any one of claims 1 to 8, characterized in that: The control method further comprises: A preset flow rate corresponding to the temperature of the fuel cell is obtained, so that the water in the first circulation pipe and the second circulation pipe flows according to the preset flow rate.

10. A fuel cell system, comprising a controller, characterized in that: The controller is configured to be able to execute the control method according to any one of claims 1 to 9.

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