Fuel cell system of single-ended supply combustor

Abstract

The invention discloses a fuel cell system of a single-end supply combustor. The fuel cell system comprises a control module, a fuel cell, a first fuel supply device, an air preheater, a flame combustor and a catalytic combustor, the output end of the first fuel supplier is connected with the first input end of the flame burner, the output end of the fuel cell is connected with the second input end of the flame burner, the output end of the flame burner is connected with the input end of the catalytic burner, and the output end of the catalytic burner is connected with the first input end of the air preheater. The second input end of the air preheater is used for inputting air at the room temperature, and the control module is used for controlling the first fuel supplier to provide fuel for the flame burner when the temperature in the flame burner is larger than or equal to the tolerable temperature of the catalytic carrier and smaller than the spontaneous combustion temperature of the fuel, so that the fuel is conveyed to the catalytic burner through the flame burner, and the catalytic burner is used for supplying the fuel to the catalytic carrier. Therefore, the catalytic burner is started successfully, the system is quickly started again, and the downtime is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and particularly to a fuel cell system with a single-end supply burner. Background Art

[0002] A fuel cell system is a device for generating electricity from gas under high-temperature conditions. The fuel cell system includes a burner and a fuel cell. The burner is used for burning and recycling the exhaust gas discharged from the fuel cell.

[0003] When the existing fuel cell system restarts within a short time after the burner is extinguished, it is necessary to reheat the burner, wasting the heat required for the original heating and prolonging the downtime. Summary of the Invention

[0004] The present invention provides a fuel cell system with a single-end supply burner to achieve a quick start when the fuel cell restarts after entering the shutdown state from the self-stable operation state, and shorten the downtime.

[0005] According to one aspect of the present invention, there is provided a fuel cell system with a single-end supply burner, including a control module, a fuel cell, a first fuel supply device, an air preheater, and a burner. The burner includes a flame burner and a catalytic burner;

[0006] The output end of the first fuel supply device is connected to the first input end of the flame burner. The output end of the fuel cell is connected to the second input end of the flame burner. The output end of the flame burner is connected to the input end of the catalytic burner. The output end of the catalytic burner is connected to the first input end of the air preheater. The second input end of the air preheater is used for inputting air at room temperature. The first output end of the air preheater is connected to the input end of the fuel cell. The air preheater is used to provide heat to the fuel cell. A catalytic carrier is provided in the catalytic burner, and the catalytic carrier is arranged between the input end and the output end of the catalytic burner;

[0007] The control module is connected to the first fuel supply device. When the fuel cell system with a single-end supply burner needs to restart after entering the shutdown state from the self-stable operation state, and when the temperature in the flame burner is greater than or equal to the tolerance temperature of the catalytic carrier and less than the spontaneous combustion temperature of the fuel, the control module controls the first fuel supply device to supply fuel to the flame burner, so that the fuel is transmitted to the catalytic burner through the flame burner. After the catalytic burner is successfully started, combustion occurs in the catalytic burner.

[0008] Optionally, the fuel cell system with a single-ended supply burner further includes a first valve. The input end of the first valve is connected to the output end of the first fuel supply device, the output end of the first valve is connected to the first input end of the flame burner, and the control end of the first valve is connected to the control module.

[0009] Optionally, the fuel cell system with a single-ended supply burner further includes a first temperature acquisition module. The first temperature acquisition module is arranged inside the flame burner and is used to acquire the temperature inside the flame burner.

[0010] The control module is connected to the first temperature acquisition module.

[0011] Optionally, the fuel cell system with a single-ended supply burner further includes a sixth temperature acquisition module. The sixth temperature acquisition module is arranged at the second input end of the conveying flame burner and is used to acquire the temperature at the second input end of the flame burner.

[0012] The control module is connected to the sixth temperature acquisition module. The control module is used to determine the heat required by the burner according to the temperature at the second input end of the flame burner and the set catalytic combustion temperature, and control the flow rate of the fuel output from the first fuel supply device to the flame burner according to the heat required by the burner.

[0013] Optionally, for the first fuel cell stack and the second fuel cell stack, the fuel cell system with a single-ended supply burner includes a first-stage reformer and a first-stage mixer. Both the first fuel cell stack and the second fuel cell stack include an anode, an electrolyte, and a cathode.

[0014] The first output end of the first-stage reformer is connected to the anode of the first fuel cell stack, the second output end of the first-stage reformer is connected to the cathode of the first-stage fuel cell stack. The anode of the first fuel cell stack is also connected to the anode of the second fuel cell stack. The cathode of the first fuel cell stack is connected to the first input end of the first-stage mixer. The output end of the first-stage mixer is connected to the cathode of the second fuel cell stack. Both the anode and the cathode of the second fuel cell stack are connected to the second input end of the flame burner. The second input end of the first-stage mixer is used to input air at room temperature.

[0015] The first output end of the air preheater is connected to the first input end of the first-stage reformer.

[0016] The control module is further configured to, when the temperature in the flame burner is greater than or equal to the auto-ignition temperature of the fuel, control the second input end of the first-stage mixer to input air at room temperature to cool down the flame burner, so that the temperature in the flame burner is greater than or equal to the tolerance temperature of the catalytic carrier and less than the auto-ignition temperature of the fuel.

[0017] Optionally, when the control module is configured to control the second input end of the first-stage mixer to input air at room temperature, it controls the flow rate of the input air so that the temperature change rate of the air entering the catalytic burner is greater than or equal to a set temperature drop rate, where the temperature drop rate is less than zero.

[0018] Optionally, the control module is further configured to, when the temperature in the flame burner is greater than or equal to the ignition temperature of the catalytic carrier and less than the tolerance temperature of the catalytic carrier, control the second input end of the first-stage mixer to input air at room temperature to cool down the flame burner, so that the temperature in the flame burner is less than the ignition temperature of the catalytic carrier;

[0019] The control module is further configured to, when the temperature in the flame burner is less than the ignition temperature of the catalytic carrier, control the first fuel supplier to supply fuel to the flame burner so that the flame burner is successfully started, and the fuel burns in the flame burner.

[0020] Optionally, the fuel cell system with a single-end supply burner further includes a second fuel supplier, a liquid water supplier, and an evaporator;

[0021] The output end of the second fuel supplier is connected to the first input end of the evaporator, the output end of the liquid water supplier is connected to the second input end of the evaporator, the output end of the evaporator is connected to the second input end of the first-stage reformer, and the second output end of the air preheater is connected to the third input end of the evaporator;

[0022] The control module is connected to the second fuel supplier, and the control module is configured to control the second fuel supplier to output fuel and control the liquid water supplier to output water so that the fuel cell generates electricity;

[0023] The control module is further configured to, when the fuel cell generates electricity, control the flow rate of the fuel output by the first fuel supplier to gradually decrease, and after determining that the flame burner is extinguished, control the catalytic burner to start.

[0024] Optionally, the fuel cell system with a single-end supply burner further includes a third fuel supplier, a second-stage mixer, and a second-stage reformer;

[0025] The output end of the third fuel supplier is connected to the first input end of the second-stage mixer, and the second input end of the second-stage mixer is used for inputting gaseous water;

[0026] The output end of the second-stage mixer is connected to the first input end of the second-stage reformer, the second input end of the second-stage reformer is connected to the anode of the first fuel cell stack, and the first output end of the second-stage mixer is connected to the anode of the second fuel cell stack.

[0027] Optionally, the fuel cell system with a single-end supply burner further includes a cooler and a gas-water separator;

[0028] The input end of the cooler is connected to the second output end of the second-stage reformer, the output end of the cooler is connected to the input end of the gas-water separator, the first output end of the gas-water separator is connected to the second input end of the second-stage mixer, and the second output end of the gas-water separator is connected to the second input end of the evaporator;

[0029] The control module is further configured to control the third fuel supplier to output fuel so that the fuel cell generates electricity;

[0030] The control module is further configured to control the power of the cooler to decrease after a set power generation time of the fuel cell.

[0031] In the technical solution of the embodiment of the present invention, when the fuel cell system with a single-end supply burner needs to be restarted after entering the shutdown state from the self-stable operation state, the fuel cell system is controlled to enter the hot start preheating process. When entering the hot start preheating process, when the temperature in the flame burner is greater than or equal to the tolerance temperature of the catalytic carrier and less than or equal to the spontaneous combustion temperature of the fuel, the first fuel supplier is controlled to supply fuel to the flame burner so that the fuel is transmitted to the catalytic burner through the flame burner. After the catalytic burner is successfully started, combustion is carried out. Since the temperature of the flame burner is still relatively high in a short time after the fuel cell system enters the shutdown state from the self-stable operation state, and when the temperature in the flame burner is greater than or equal to the tolerance temperature of the catalytic carrier, relying on the high-temperature gas output by the flame burner, the catalytic burner can be started at high temperature to burn the anode tail gas for system preheating. There is no need to restart the flame burner to burn the tail gas, and the rapid start of the fuel cell system can be realized. The catalytic burner is triggered to start by the heat retained during the last start of the flame burner, saving energy.

[0032] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. Description of the Drawings

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 It is a schematic structural diagram of a fuel cell system with a single - end supply burner provided by an embodiment of the present invention;

[0035] Figure 2 It is a schematic diagram of a temperature acquisition module arranged at different positions of a burner in a fuel cell system provided by an embodiment of the present invention;

[0036] Figure 3 It is a schematic structural diagram of another fuel cell system with a single - end supply burner provided by an embodiment of the present invention. Detailed implementation manners

[0037] In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above - mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non - exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0039] Figure 1 It is a schematic structural diagram of a fuel cell system with a single - end supply burner provided by an embodiment of the present invention. The fuel cell system with a single - end supply burner includes a fuel cell 26, a first fuel supply device 10, an air pre - heater 11 and a burner. The burner includes a flame burner 13 and a catalytic burner 14;

[0040] The output end of the first fuel supplier 10 is connected to the first input end of the flame burner 13, the output end of the fuel cell is connected to the second input end of the flame burner 13, the output end of the flame burner 13 is connected to the input end of the catalytic burner 14, the output end of the catalytic burner 14 is connected to the first input end of the air preheater 11, the second input end of the air preheater 11 is used for inputting air at room temperature, the first output end of the air preheater 11 is connected to the input end of the fuel cell 26, the air preheater 11 is used for providing heat required for heating reaction raw materials to the fuel cell, a catalytic carrier is arranged in the catalytic burner 14, and the catalytic carrier is arranged between the input end and the output end of the catalytic burner 14;

[0041] The control module is connected to the first fuel supplier 10. When the fuel cell system with a single-end supply burner restarts after entering the shutdown state from the self-stable operation state, when the temperature in the flame burner is greater than or equal to the tolerance temperature of the catalytic carrier and less than the spontaneous combustion temperature of the fuel, the control module controls the first fuel supplier 10 to supply fuel to the flame burner 13, so that the fuel is transmitted to the catalytic burner through the flame burner 13. After the catalytic burner 14 is successfully started, combustion occurs in the catalytic burner.

[0042] After the fuel cell system enters the shutdown state from the self-stable operation state, the fuel cell system is controlled to enter the hot start preheating process. Among them, in the self-stable operation state, the fuel cell 26 operates at full load. In the shutdown state, the flame burner 13 goes out and the catalytic burner 14 goes out.

[0043] After the fuel cell system with a single-end supply burner operates at full load and stably for a period of time, the burner goes out due to a fuel cell failure, and the fuel cell system is controlled to enter the shutdown state. When it is necessary to restart the fuel cell system with a single-end supply burner to generate electricity within a short time after the fuel cell enters the shutdown state, the fuel cell system with a single-end supply burner is controlled to start the burner in the hot start preheating mode to provide heat required for power generation for the fuel cell system.

[0044] The tolerance temperature of the catalytic carrier is greater than the ignition temperature of the catalytic carrier. Therefore, when the temperature in the flame burner 13 is greater than or equal to the tolerance temperature of the catalytic carrier, after the fuel is output from the flame burner 13 and enters the catalytic burner 14, the catalytic burner 14 can be triggered to achieve high-temperature ignition for combustion. The spontaneous combustion temperature of the fuel is the temperature at which the fuel can spontaneously combust at the current temperature. High-temperature ignition in the flame burner 13 will cause a series of problems. The temperature in the flame burner 13 should be less than the spontaneous combustion temperature of the fuel to avoid spontaneous combustion of the fuel entering the flame burner 13 due to the too high temperature in the flame burner 13 and avoid restarting of the flame burner 13, thereby improving the reliability and stability of the system. Figure 2Schematic diagram of a temperature acquisition module provided in an embodiment of the present invention and arranged at different positions of a burner in a fuel cell system. Refer to Figure 1 and Figure 2 Optionally, the fuel cell system with a single-end supply burner further includes a first temperature acquisition module 1. The first temperature acquisition module 1 is arranged inside the flame burner 13 and is used to acquire the temperature inside the flame burner 13. The control module is connected to the first temperature acquisition module 1. The first temperature acquisition module 1 can be a temperature sensor, a thermometer, etc., for acquiring the temperature inside the flame burner 13.

[0045] Optionally, the fuel cell system with a single-end supply burner further includes a first valve F1. The input end of the first valve F1 is connected to the output end of the first fuel supplier 10, the output end of the first valve F1 is connected to the first input end of the flame burner 13, and the control end of the first valve F1 is connected to the control module. The control module controls whether the first fuel supplier 10 supplies fuel to the flame burner 13 by controlling the on or off state of the first valve F1. The control module is used to control the first valve F1 to conduct when it is determined that the temperature inside the flame burner 13 is greater than or equal to the tolerance temperature of the catalytic carrier and less than the spontaneous combustion temperature of the fuel, so as to control the first fuel supplier 10 to supply fuel to the flame burner 13. The fuel enters the catalytic combustor 14 through the flame burner 13. Since the temperature inside the flame burner 13 is relatively high, the temperature of the fuel entering the catalytic combustor 14 is relatively high. The fuel is mixed with air inside the flame burner 13 and then ignites at the catalytic combustor 14 to trigger the start of the catalytic combustor 13.

[0046] Refer to Figure 1 and Figure 2 Optionally, in this embodiment, a second temperature acquisition module 2 is further arranged at the front end of the catalytic carrier, and a third temperature acquisition module 3 is arranged at the rear end of the catalytic carrier. The second temperature acquisition module 2 is used to acquire the temperature at the front end of the catalytic carrier, and the third temperature acquisition module 3 is used to acquire the temperature at the rear end of the catalytic carrier. The control module is respectively connected to the second temperature acquisition module 2 and the third temperature acquisition module 3. The control module is used to determine that the catalytic combustor 14 starts successfully when the difference between the temperature at the rear end of the catalytic carrier and the temperature at the front end of the catalytic carrier is greater than or equal to the catalytic success temperature threshold within a set time. Among them, the catalytic success temperature threshold depends on the experimentally measured value.

[0047] In this embodiment, a fifth temperature acquisition module 5 is further provided at the output end of the catalytic combustor 14. The fifth temperature acquisition module 5 is used to acquire the temperature at the output end of the catalytic combustor 14. The control module is connected to the fifth temperature acquisition module 5. The control module is used to determine, within a set time, based on the temperature at the output end of the catalytic combustor 14 at different moments, that the rate of change of the temperature at the output end of the catalytic combustor 14 is less than the set catalytic decay rate, determine that the startup of the catalytic combustor 14 fails, and control the fuel cell system with a single-end supply combustor to shut down, where the catalytic decay rate is less than zero.

[0048] Optionally, the fuel cell system with a single-end supply combustor further includes a sixth temperature acquisition module 6. The sixth temperature acquisition module 6 is disposed at the second input end of the flame combustor 14. The sixth temperature acquisition module 6 is used to acquire the temperature at the second input end of the flame combustor 13. The control module is connected to the sixth temperature acquisition module 6. The control module is used to determine the heat required by the combustor based on the temperature at the second input end of the flame combustor 13 and the set catalytic combustion temperature, and control the flow rate of the fuel output from the first fuel supply 10 to the flame combustor 13 according to the heat required by the combustor.

[0049] The catalytic combustion temperature is a fixed value, set in advance. After the control module controls the fuel flow output from the first fuel supply 10 so that the fuel burns in the combustor, it controls the temperature at the output end of the catalytic combustor 14 to always maintain at the catalytic combustion temperature. The control module is used to determine the heat required by the combustor based on the difference between the temperature at the input end of the flame combustor 13 and the set catalytic combustion temperature, and control the first fuel supply 10 to output an appropriate amount of fuel into the flame combustor 13 according to the heat required by the combustor, so as to ensure that the temperature at the output end of the catalytic combustor 14 is maintained at the catalytic combustion temperature. Since the temperature at the second input end of the flame combustor 13 is the same as the temperature at the first input end, in other embodiments, the sixth temperature acquisition module 6 can also be disposed at the first input end of the flame combustor 13 to acquire the temperature at the first input end of the flame combustor 13, and determine the heat required by the combustor based on the temperature at the first input end of the flame combustor 13 and the set catalytic combustion temperature.

[0050] After the fuel cell system with a single-ended supply burner enters the shutdown state from the self-stabilized operation state, the temperature of the flame burner remains relatively high in a short period of time. If cold air is introduced to cool the flame burner and then ignition is carried out within a short time, not only will the heat required for the original temperature rise be wasted and the shutdown time be extended, but also the catalytic carrier will rupture due to excessive temperature drop. In this embodiment, when the temperature in the flame burner is greater than or equal to the tolerance temperature of the catalytic carrier, relying on the high-temperature gas output by the flame burner, the catalytic burner can achieve high-temperature startup to burn the anode tail gas and provide the heat required for the system power generation, without restarting the flame burner for tail gas combustion, and the fuel cell system can be quickly started. The startup of the catalytic burner is triggered by the heat remaining when the flame burner goes out, saving energy and improving the system stability. At the same time, only fuel is supplied to the flame burner, the system is simpler, and the control process is easier to implement.

[0051] Figure 3 FIG. is a schematic structural diagram of another fuel cell system with a single-ended supply burner provided by an embodiment of the present invention. Refer to Figure 3 Optionally, on the basis of the above embodiment, the fuel cell includes a first fuel cell stack 15 and a second fuel cell stack 16. Both the first fuel cell stack 15 and the second fuel cell stack 16 include an anode, an electrolyte, and a cathode. The fuel cell system with a single-ended supply burner further includes a first-stage reformer 12 and a first-stage mixer 17;

[0052] The first output end of the first-stage reformer 12 is connected to the anode of the first fuel cell stack 15, the second output end of the first-stage reformer 12 is connected to the cathode of the first fuel cell stack 15. The anode of the first fuel cell stack 15 is also connected to the anode of the second fuel cell stack 16. The cathode of the first fuel cell stack 15 is connected to the first input end of the first-stage mixer 17. The output end of the first-stage mixer 17 is connected to the cathode of the second fuel cell stack 16. Both the anode and the cathode of the second fuel cell stack 16 are connected to the second input end of the flame burner 13. The second input end of the first-stage mixer 17 is used to input air at room temperature;

[0053] The first output end of the air preheater 11 is connected to the first input end of the first-stage reformer 12, and the second input end of the first-stage reformer 121 is used to input reaction raw materials.

[0054] The gas with a certain temperature output by the catalytic burner 14 enters the air preheater 11 to heat the air in the air preheater 11, so that the hot air output by the air preheater 11 exchanges heat with the first-stage reformer 12, and the air after the heat exchange enters the cathode of the first fuel cell stack 15 through the second output end in the first-stage reformer 12.

[0055] The control module is also used to control the air at room temperature to be input into the second input end of the first-stage mixer 17 when the temperature in the flame burner 13 is greater than or equal to the spontaneous combustion temperature of the fuel, so as to cool down the flame burner 13, so that the temperature in the flame burner 13 is greater than or equal to the tolerance temperature of the catalytic carrier and less than the spontaneous combustion temperature of the fuel.

[0056] When the temperature in the flame burner 13 is greater than or equal to the spontaneous combustion temperature of the fuel, it will cause the fuel to spontaneously ignite and start after being introduced into the flame burner 13. There is a possibility of ignition failure and delay in the spontaneous ignition start of the flame burner 13. To improve the reliability of system ignition, it is not recommended to start the flame burner 13 again when the temperature in the flame burner 13 is relatively high. Therefore, when the temperature in the flame burner 13 is greater than or equal to the spontaneous combustion temperature of the fuel, it is necessary to introduce the air at room temperature into the flame burner 13 through the first-stage mixer 17 to cool down the flame burner 13 until the temperature in the flame burner 13 is greater than or equal to the tolerance temperature of the catalytic carrier and less than the spontaneous combustion temperature of the fuel, and the control system enters the hot start preheating process. That is, the control module controls the first fuel supply device 10 to supply fuel to the flame burner 13, so that the fuel is transmitted to the catalytic burner through the flame burner 13. After the catalytic burner 14 is successfully started, combustion occurs in the catalytic burner. Optionally, when the control module controls the air at room temperature to be input into the second input end of the first-stage mixer 17, it controls the flow rate of the input air so that the temperature change rate of the air entering the catalytic burner 14 is greater than or equal to the set temperature drop rate, where the temperature drop rate is less than zero. The set temperature drop rate is related to the structural strength characteristics of the catalytic carrier. Since the catalytic burner 14 includes a catalytic carrier, if the temperature change rate of the air in the catalytic burner 14 is too large, it will cause the catalytic carrier to crack. Therefore, when the air is input into the second input end of the first-stage mixer 17, the flow rate of the air should not be too large to avoid damaging the catalytic carrier.

[0057] During the hot start preheating process of the fuel cell system with a single-end supply burner, by precisely setting the temperature range, the service life of the catalytic carrier is extended and the reliability of the system is improved.

[0058] Continue to refer to Figure 3 Optionally, the control module is also used to control the air at room temperature to be input into the second input end of the first-stage mixer 17 when the temperature in the flame burner is greater than or equal to the ignition temperature of the catalytic carrier and less than the tolerance temperature of the catalytic carrier, so as to cool down the flame burner 13 and make the temperature in the flame burner 13 less than the ignition temperature of the catalytic carrier.

[0059] The setting of the ignition temperature of the catalytic carrier is to avoid the situation that during hot start, the initial flame burns the inlet air at too high a temperature, resulting in too high a temperature of the flue gas reaching the catalytic carrier during the hot start process, which may damage the catalytic carrier. The maximum operating temperature of the catalytic carrier is an important reference for setting the ignition temperature of the catalytic carrier. If the temperature in the flame burner 13 is between the ignition temperature and the tolerance temperature of the catalytic carrier, the fuel cell system with a single-end supply burner remains in a shutdown state to cool the flame burner 13. The control module controls the air at room temperature to enter the flame burner 13 through the first-stage mixer 17 and the second fuel cell stack 16 to cool the flame burner 13 until the temperature in the flame burner 13 is less than the ignition temperature of the catalytic carrier, and then enters the cold start preheating process. Since the difference between the ignition temperature and the tolerance temperature of the catalytic carrier is between 100°C and 200°C, the shutdown cooling time is short and will not have too much impact on the startup duration of the system. When the fuel cell is generating electricity, in addition to supplying reaction raw materials such as fuel and water to the fuel cell, it is also necessary to make the reaction raw materials input to the fuel cell have a certain temperature. The cold start preheating process is a process of heating the reaction raw materials, namely fuel and water, and the cold start preheating process is a startup process carried out at room temperature. Specifically, the control module is also used to control the first fuel supply device 10 to supply fuel to the flame burner 13 when the temperature in the flame burner is less than the ignition temperature of the catalytic carrier, so that the flame burner 13 can be successfully started, the fuel burns in the flame burner 13, and the gas output after the combustion of the flame burner 13 is input into the air preheater 11 through the catalytic burner 14.

[0060] The fuel cell system further includes a pulse igniter, which is connected to the flame burner 13 and is used to release a pulse voltage to complete ignition at the flame burner 13 to start the flame burner 13, so that the fuel output by the first fuel supply device 10 burns in the flame burner 13. After the hot gas output after combustion in the flame burner 13 is input into the air preheater 11 through the catalytic burner 14, it heats the air at room temperature input in the air preheater 11, so that the hot air enters the first-stage reformer 12 to increase the temperature in the first-stage reformer 12 until the temperature in the first-stage reformer 15 reaches the first set temperature. After the temperature in the first-stage reformer 15 reaches the first set temperature, the control system inputs fuel and water into the first-stage reformer 12 for the fuel cell to carry out an electrochemical reaction to generate electricity.

[0061] Continue to refer to Figure 3 , optionally, the fuel cell system with a single-end supply burner further includes a second fuel supply device 18, a liquid water supply device 19 and an evaporator 20;

[0062] The output end of the second fuel supplier 18 is connected to the first input end of the evaporator 20, the output end of the liquid water supplier 19 is connected to the second input end of the evaporator 20, the output end of the evaporator 20 is connected to the second input end of the first-stage reformer 12, and the second output end of the air preheater 11 is connected to the third input end of the evaporator 20;

[0063] The control module is further configured to control the second fuel supplier 18 to output fuel and control the liquid water supplier to output water so that the fuel cell generates electricity;

[0064] The control module is further configured to, when the fuel cell generates electricity, control the flow rate of the fuel output by the first fuel supplier 10 to gradually decrease, and after determining that the flame burner 13 is extinguished, control the catalytic burner 14 to start.

[0065] A second valve F2 is connected between the output end of the second fuel supplier 18 and the first input end of the evaporator 20. The second valve F2 is connected to the control module, and the control module controls the second fuel supplier 18 to output fuel by controlling the second valve F2 to conduct. A third valve F3 is connected between the output end of the liquid water supplier 19 and the second input end of the evaporator 20. The third valve F3 is connected to the control module, and the control module controls the liquid water supplier 19 to output liquid water by controlling the third valve F3 to conduct. The evaporator 20 is configured to convert the liquid water into gas and then transport it to the first-stage reformer 12 together with the fuel. The water and the fuel exchange heat with the air output by the air preheater 11 in the first-stage reformer 12 and then are input into the first-stage fuel cell stack 15 for electrochemical reaction power generation.

[0066] After the system completes the cold start preheating process, the control module controls the second fuel supplier 18 to output fuel and controls the liquid water supplier to output water so that the fuel cell generates electricity. Among them, when the temperature in the first-stage reformer 12 reaches the first set temperature, it indicates that the cold start preheating process is completed.

[0067] The flow rate of the fuel input into the flame burner 13 gradually decreases due to the combustion of the anode exhaust gas of the fuel cell to generate supplementary heat after the fuel cell generates electricity, until the flame burner 13 can no longer maintain the combustion of the fuel and the anode exhaust gas, and the flame burner 13 goes out. Refer to Figure 2 and Figure 3, optionally, a fourth temperature acquisition module 4 is provided at the output end of the flame burner 13. The fourth temperature acquisition module 4 is used to acquire the temperature at the output end of the flame burner 13. The control module is further configured to determine that the absolute value of the temperature change rate at the output end of the flame burner 13 is greater than the absolute value of the flame attenuation rate based on the temperatures at different moments within a set time at the output end of the flame burner 13, determine that the flame burner 13 is extinguished, and the flame attenuation rate is less than zero. When the absolute value of the temperature change rate at the output end of the flame burner 13 is greater than the absolute value of the flame attenuation rate, it indicates that the temperature at the output end of the flame burner 13 drops sharply, and the flame burner 13 is extinguished and cannot continue to generate heat. The control module is configured to control the catalytic burner 14 to start after determining that the flame burner 13 is extinguished.

[0068] Within a short time after the system shuts down, after the temperature in the flame burner 13 is lower than the ignition temperature of the catalytic carrier, it is no longer possible to achieve high-temperature ignition of the catalytic burner 14. Therefore, the control system starts with cold start preheating to restart the heat required for the fuel supply system of the flame burner 13.

[0069] Continue to refer to Figure 3 , optionally, the fuel cell system with a single-end supply burner further includes a third fuel supplier 21, a second-stage mixer 22, and a second-stage reformer 23;

[0070] The output end of the third fuel supplier 21 is connected to the first input end of the second-stage mixer 22, and the second input end of the second-stage mixer 22 is used to input gaseous water;

[0071] The output end of the second-stage mixer 22 is connected to the first input end of the second-stage reformer 23. The second input end of the second-stage reformer 23 is connected to the anode of the first fuel cell stack 15, and the first output end of the second-stage mixer 22 is connected to the anode of the second fuel cell stack 16.

[0072] A fourth valve F4 is provided before the output end of the third fuel supplier 21 and the first input end of the second-stage mixer 22. The fourth valve F4 is connected to the control module, and the control module controls whether the fuel output by the third fuel supplier 21 is transmitted to the second-stage mixer 22 by controlling the conduction state of the fourth valve F4.

[0073] Continue to refer to Figure Figure 3, Optionally, the fuel cell system with a single - end supply burner further includes a cooler 24 and a gas - water separator 25. The input end of the cooler 24 is connected to the second output end of the secondary reformer 23, the output end of the cooler 24 is connected to the input end of the gas - water separator 25, the first output end of the gas - water separator 25 is connected to the second input end of the secondary mixer 22, and the second output end of the gas - water separator 25 is connected to the second input end of the evaporator 20. The control module is further configured to control the third fuel supplier to output fuel so that the fuel cell generates electricity.

[0074] The anode exhaust gas of the first fuel cell stack 15 is dehydrated through the secondary reformer 23, the cooler 24 and the gas - water separator 25, and the dehydrated water enters the secondary mixer 22. The fuel output by the third fuel supplier 21 and the water output by the gas - water separator 25 are mixed in the secondary mixer 22 and then enter the anode of the second fuel cell stack 16 through the secondary reformer 23 for electrochemical reaction to generate electricity. When controlling the second fuel supplier 18 to output fuel and the liquid water supplier 19 to output water so that the fuel cell generates electricity, the third fuel supplier 21 can also be controlled to output fuel so that the second fuel cell stack 16 undergoes an electrochemical reaction to generate electric energy.

[0075] After the fuel cell system completes the hot - start process, the flame burner 13 is in an extinguished state and can only rely on the catalytic burner 14 for transition, and the self - ignition property of the fuel in the flame burner 13 tends to zero under a high air - fuel ratio state.

[0076] The control module is further configured to control the power of the cooler 24 to decrease after a set time of fuel cell power generation, so as to weaken the cooling effect of the cooler 24, so that the water content input from the gas - water separator 25 to the flame burner 13 is greater than the water - content threshold.

[0077] When fuel undergoes self - ignition in the flame burner 13, it will cause fluctuations in the exhaust gas, which is not conducive to the stability of the system. Therefore, to avoid self - ignition of the fuel in the flame burner 13, the cooling effect of the cooler 24 should be weakened, so that the water content input from the gas - water separator 25 to the flame burner 13 through the second fuel cell stack 16 is greater than the water - content threshold, avoiding self - ignition of the fuel in the flame burner 13 and improving the stability of the system. When the flame burner and the catalytic burner burn to generate the heat required by the system, the hydrogen content in the anode exhaust gas is relatively high, making the fuel extremely prone to self - ignition in the flame burner at high temperatures. The present invention adjusts the cooler 24 and the gas - water separator 24 between stages to improve the fuel composition entering the burner and achieve safe switching of the system.

[0078] In this embodiment, the fuel cells are connected in series, and the burners adopt the scheme of a flame burner and a catalytic burner, and a control scheme that can meet cold - start and hot - start is provided. It can not only ensure the safe and rapid operation of the burner, but also achieve the rapid start of the system and the treatment of lean - burn anode exhaust gas.

[0079] It should be understood that the various forms of processes shown above can be used, with steps reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is imposed herein.

[0080] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A fuel cell system with a single-end supply burner, characterized in that: It includes a control module, a fuel cell, a first fuel supplier, an air preheater and a burner, wherein the burner includes a flame burner and a catalytic burner; The output end of the first fuel supplier is connected to the first input end of the flame burner, the output end of the fuel cell is connected to the second input end of the flame burner, the output end of the flame burner is connected to the input end of the catalytic burner, the output end of the catalytic burner is connected to the first input end of the air preheater, the second input end of the air preheater is used to input air at room temperature, the first output end of the air preheater is connected to the input end of the fuel cell, the air preheater is used to provide heat to the fuel cell, and a catalyst carrier is provided in the catalytic burner, and the catalyst carrier is provided between the input end and the output end of the catalytic burner; The control module is connected to the first fuel supplier, and is used to control the first fuel supplier to supply fuel to the flame burner when the fuel cell system with the single-end supply burner enters a shutdown state from a stable operation state and needs to be restarted, and when the temperature in the flame burner is greater than or equal to the tolerance temperature of the catalyst carrier and less than the auto-ignition temperature of the fuel, so that the fuel is transmitted to the catalytic burner through the flame burner, and the catalytic burner is burned in the catalytic burner after the catalytic burner is successfully started.

2. The fuel cell system with a single-end supply burner according to claim 1, characterized in that: It also includes a first valve, wherein the input end of the first valve is connected to the output end of the first fuel supplier, the output end of the first valve is connected to the first input end of the flame burner, and the control end of the first valve is connected to the control module.

3. The fuel cell system with a single-end supply burner according to claim 1, characterized in that: It also includes a first temperature acquisition module, which is disposed in the flame burner and is used to acquire the temperature in the flame burner; The control module is connected to the first temperature acquisition module.

4. The fuel cell system with a single-end supply burner according to claim 1, characterized in that: It also includes a sixth temperature acquisition module, which is arranged at the second input end of the flame burner and is used to acquire the temperature of the second input end of the flame burner; The control module is connected to the sixth temperature acquisition module, and the control module is used to determine the heat required by the burner based on the temperature of the second input end of the flame burner and the set catalytic combustion temperature, and control the flow rate of the fuel output from the first fuel supplier to the flame burner based on the heat required by the burner.

5. The fuel cell system with a single-end supply burner according to claim 1, characterized in that: The first fuel cell stack and the second fuel cell stack, the fuel cell system with a single-end supply burner comprises a first-stage reformer and a first-stage mixer, and the first fuel cell stack and the second fuel cell stack both comprise an anode, an electrolyte and a cathode; The first output end of the first-stage reformer is connected to the anode of the first fuel cell stack, the second output end of the first-stage reformer is connected to the cathode of the first-stage fuel cell stack, the anode of the first fuel cell stack is also connected to the anode of the second fuel cell stack, the cathode of the first fuel cell stack is connected to the first input end of the first-stage mixer, the output end of the first-stage mixer is connected to the cathode of the second fuel cell stack, the anode and cathode of the second fuel cell stack are both connected to the second input end of the flame burner, and the second input end of the first-stage mixer is used to input air at room temperature; The first output end of the air preheater is connected to the first input end of the first-stage reformer; The control module is also used to control the second input end of the first-stage mixer to input air at room temperature when the temperature inside the flame burner is greater than or equal to the auto-ignition temperature of the fuel, so as to cool the flame burner so that the temperature inside the flame burner is greater than or equal to the tolerance temperature of the catalytic carrier and less than the auto-ignition temperature of the fuel.

6. The fuel cell system with a single-end supply burner according to claim 5, characterized in that: The control module is used to control the flow rate of the input air when air at room temperature is input into the second input end of the first-stage mixer so that the temperature change rate of the air entering the catalytic burner is greater than or equal to a set temperature drop rate, wherein the temperature drop rate is less than zero.

7. The fuel cell system with a single-end supply burner according to claim 5, characterized in that: The control module is also used to control the second input end of the first-stage mixer to input air at room temperature to cool the flame burner when the temperature in the flame burner is greater than or equal to the ignition temperature of the catalyst carrier and less than the tolerance temperature of the catalyst carrier, so as to make the temperature in the flame burner less than the ignition temperature of the catalyst carrier; The control module is also used to control the first fuel supplier to provide fuel to the flame burner when the temperature in the flame burner is lower than the ignition temperature of the catalyst carrier, so that the flame burner can be successfully started and the fuel burns in the flame burner.

8. The fuel cell system with a single-end supply burner according to claim 5, characterized in that: Also included is a second fuel supplier, a liquid water supplier, and an evaporator; The output end of the second fuel supplier is connected to the first input end of the evaporator, the output end of the liquid water supplier is connected to the second input end of the evaporator, the output end of the evaporator is connected to the second input end of the first-stage reformer, and the second output end of the air preheater is connected to the third input end of the evaporator; The control module is connected to the second fuel supplier, and is used to control the second fuel supplier to output fuel and the liquid water supplier to output water, so that the fuel cell generates electricity; The control module is also used to control the flow rate of the fuel output by the first fuel supplier to gradually decrease when the fuel cell is generating electricity, and to control the catalytic burner to start after determining that the flame burner is extinguished.

9. The fuel cell system with a single-end supply burner according to claim 8, characterized in that: Also included is a third fuel supplier, a second stage mixer, and a second stage reformer; The output end of the third fuel supplier is connected to the first input end of the second stage mixer, and the second input end of the second stage mixer is used to input gaseous water; The output end of the second stage mixer is connected to the first input end of the second stage reformer, the second input end of the second stage reformer is connected to the anode of the first fuel cell stack, and the first output end of the second stage mixer is connected to the anode of the second fuel cell stack.

10. The fuel cell system with a single-end supply burner according to claim 9, characterized in that: It also includes a cooler and a gas-water separator; The input end of the cooler is connected to the second output end of the second-stage reformer, the output end of the cooler is connected to the input end of the gas-water separator, the first output end of the gas-water separator is connected to the second input end of the second-stage mixer, and the second output end of the gas-water separator is connected to the second input end of the evaporator; The control module is also used to control the third fuel supplier to output fuel so that the fuel cell generates electricity; The control module is also used to control the power of the cooler to decrease after the fuel cell generates electricity for a set time.

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