Dual-fuel combustor system and its control method and fuel cell system

Abstract

This invention belongs to the field of fuel cell technology and discloses a dual-fuel burner system, its control method, and a fuel cell system. In this dual-fuel burner system, a natural gas storage tank and a hydrogen-containing fuel storage tank are respectively connected to the two air inlets of a first mixer. The input end of a first control valve is connected to the air outlet of the first mixer, and the output end of the first control valve is connected to the diffusion zone of the burner. A first igniter is used to ignite the diffusion zone of the burner. The input end of a second control valve is connected to the air outlet of the first mixer, and the output end of the second control valve and an air input pipe are respectively connected to the two air inlets of a second mixer. The air outlet of the second mixer is connected to the premixing zone of the burner, and a second igniter is used to ignite the premixing zone of the burner. One end of a cooling pipe is connected to the air input pipe, and the other end is connected to the inlet of the burner. The system employs control logic of low-temperature premixed combustion and high-temperature diffusion combustion to achieve stable combustion with low pollutants.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular to a dual-fuel burner system, a control method thereof and a fuel cell system. BACKGROUND

[0002] A large amount of hot air is needed to heat components in the starting process of a fuel cell, and hot air as an oxidant of the fuel cell also exists for a long time in the stable operation process. In a fuel cell system, an air preheater is used to heat air, and a burner is used to produce high-temperature flue gas to heat the air preheater and other components of the fuel cell system that need to be heated. The burner generally uses natural gas and / or hydrogen-containing fuel as fuel, and the natural gas and / or hydrogen-containing fuel and the preheated air enter the natural gas for combustion. The temperature of the preheated air gradually increases with the operation of the fuel cell system, and the preheated air with a too high temperature can cause the hydrogen-containing fuel with a high hydrogen content to self-ignite when premixed with the preheated air. In the prior art, in order to avoid the hydrogen-containing fuel from self-igniting in the high-temperature air, diffusion combustion or premixed combustion with an extremely short residence time is generally used. However, diffusion combustion can cause long flame and high pollutant emission, which is not conducive to the intensive development of equipment. In addition, when the temperature of the premixed structure is too high, the premixed combustion with an extremely short residence time can cause backfiring and other adverse conditions, and long-time operation can cause damage to the equipment. SUMMARY

[0003] The present application aims to provide a dual-fuel burner system, a control method thereof and a fuel cell system, so as to solve the problems in the prior art that, in order to avoid the hydrogen-containing fuel from self-igniting in the high-temperature air, diffusion combustion or premixed combustion with an extremely short residence time is generally used. Diffusion combustion can cause long flame and high pollutant emission, which is not conducive to the intensive development of equipment. In addition, when the temperature of the premixed structure is too high, the premixed combustion with an extremely short residence time can cause backfiring and other adverse conditions, and long-time operation can cause damage to the equipment.

[0004] To achieve the above purpose, the present application adopts the following technical scheme:

[0005] The dual-fuel burner system comprises:

[0006] a natural gas storage tank, a hydrogen-containing fuel storage tank and a first mixer, the natural gas storage tank and the hydrogen-containing fuel storage tank are respectively communicated with two gas inlets of the first mixer, and natural gas and hydrogen-containing fuel are mixed in the first mixer to form a mixed fuel;

[0007] a first control valve and a burner, an input end of the first control valve is communicated with a gas outlet of the first mixer, and an output end of the first control valve is communicated with a diffusion zone of the burner;

[0008] a first igniter for igniting the diffusion zone of the burner;

[0009] a second control valve, a second mixer and an air input pipe, the input end of the second control valve being in communication with the gas outlet of the first mixer, the output end of the second control valve and the air input pipe being in communication with the two gas inlets of the second mixer respectively, the gas outlet of the second mixer being in communication with the premixing zone of the burner;

[0010] a second igniter for igniting the premixing zone of the burner;

[0011] a cooling pipe, one end of the cooling pipe being in communication with the air input pipe and the other end being in communication with the inlet of the burner.

[0012] As a preferred solution of the above-mentioned dual-fuel burner system, the dual-fuel burner system further comprises a first MFC, the first MFC being arranged between the natural gas storage tank and the gas inlet of the first mixer, the first MFC being used for adjusting the gas flow into the first mixer.

[0013] As a preferred solution of the above-mentioned dual-fuel burner system, the dual-fuel burner system further comprises a fan and a second MFC, the second MFC being arranged between the fan and the air input pipe, the second MFC being used for adjusting the gas flow into the air input pipe.

[0014] As a preferred solution of the above-mentioned dual-fuel burner system, the dual-fuel burner system further comprises a first flow sensor or a first pressure sensor, the first flow sensor or the first pressure sensor being used for detecting whether gas flows into the diffusion zone of the burner.

[0015] As a preferred solution of the above-mentioned dual-fuel burner system, the dual-fuel burner system further comprises a second flow sensor or a second pressure sensor, the second flow sensor or the second pressure sensor being used for detecting whether gas flows into the premixing zone of the burner.

[0016] As a preferred solution of the above-mentioned dual-fuel burner system, the dual-fuel burner system further comprises a first temperature sensor, the first temperature sensor being used for detecting the air temperature at the inlet of the burner.

[0017] As a preferred solution of the above-mentioned dual-fuel burner system, the dual-fuel burner system further comprises a second temperature sensor, the second temperature sensor being used for detecting the air temperature at the outlet of the burner.

[0018] The application further provides a control method of the dual-fuel combustor system, which adopts the dual-fuel combustor system.

[0019] S1: air is introduced into the combustor, and the temperature of the air at the inlet of the combustor is detected;

[0020] S2: it is judged whether the temperature of the air at the inlet of the combustor is greater than or equal to the minimum ignition temperature of the mixed fuel;

[0021] If not, S3 is performed;

[0022] If yes, S6 is performed;

[0023] S3: the first control valve is closed, and the second control valve is opened;

[0024] S4: the second igniter performs an ignition operation;

[0025] S5: it is judged whether the ignition of the premixing area of the combustor is successful;

[0026] If yes, S2 is returned to;

[0027] S6: the first control valve is opened, and the second control valve is closed;

[0028] S7: it is judged whether the mixed fuel is self-ignited in the diffusion area of the combustor;

[0029] If not, S8 is performed;

[0030] S8: the first igniter performs an ignition operation.

[0031] As a preferred solution of the control method of the dual-fuel combustor system, in S5, if the ignition of the premixing area of the combustor is not successful, S51 is performed;

[0032] S51: it is judged whether the number of ignition times of the second igniter is less than or equal to a set number;

[0033] If yes, S4 is returned to;

[0034] If not, an alarm is performed.

[0035] The application further provides a fuel cell system, which comprises the dual-fuel combustor system, further comprises an air preheater and a component to be heated, the gas flowing out of the outlet of the combustor can heat the component to be heated and the air preheater, the air preheater and the component to be heated are both heat exchangers, and the air preheater is used for heating air.

[0036] The application has the following beneficial effects:

[0037] The present application provides a dual fuel burner system and its control method and a fuel cell system. Natural gas from a natural gas tank enters a first mixer, hydrogen-containing fuel from a hydrogen-containing fuel tank enters the first mixer, and the natural gas and the hydrogen-containing fuel are mixed in the first mixer to form a mixed fuel. When the air temperature T1 at the inlet of the burner is less than the minimum ignition temperature t1 of the mixed fuel, the second control valve is opened and the first control valve is closed, the mixed fuel formed by mixing the natural gas and the hydrogen-containing fuel in the first mixer enters the second mixer through the second control valve, a part of the air output from the air input pipe enters the second mixer, and the other part enters the inlet of the burner through the cooling pipeline. The air and the mixed fuel are mixed in the second mixer and then enter the premixing zone of the burner, and the second igniter ignites. When the air temperature T1 at the inlet of the burner is greater than or equal to the minimum ignition temperature t1 of the mixed fuel, the first control valve is opened and the second control valve is closed, the mixed fuel enters the diffusion zone of the burner through the first control valve, a part of the air output from the air input pipe enters the second mixer, and the other part enters the inlet of the burner through the cooling pipeline. The air enters the premixing zone of the burner from the second mixer. Since the air temperature at the inlet of the burner is too high, the mixed fuel is likely to self-ignite in the diffusion zone of the burner. If the mixed fuel does not self-ignite, the first igniter ignites. The dual fuel burner system adopts the control logic of low-temperature premixing combustion and high-temperature diffusion combustion. When the air temperature T1 at the inlet of the burner is less than the minimum ignition temperature t1 of the mixed fuel, the premixing combustion technology is adopted to reduce the flame core zone temperature, hinder the generation of nitrogen oxides, and realize low-pollutant emission combustion. When the air temperature T1 at the inlet of the burner is greater than or equal to the minimum ignition temperature t1 of the mixed fuel, the diffusion combustion technology is adopted, the mixed fuel is directly thermally decomposed after contacting with high-temperature air, the high-temperature air enhances the combustibility of the fuel, reduces the generation of pollutants, and realizes low-pollutant stable combustion. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 Figure is a structural schematic diagram of the dual fuel burner system provided by the embodiment of the present application.

[0039] In the figure:

[0040] 1, natural gas tank; 2, hydrogen-containing fuel tank; 3, first mixer; 4, first control valve; 5, second control valve; 6, second mixer; 7, burner; 8, first igniter; 9, second igniter; 10, cooling pipeline; 11, fan; 12, first MFC; 13, second MFC; 14, first pressure sensor; 15, second pressure sensor; 16, first temperature sensor; 17, second temperature sensor; 18, air preheater; 19, component to be heated; 20, third pressure sensor; 21, air input pipe. DETAILED DESCRIPTION

[0041] The application will be further described below in conjunction with the drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the application and are not to be used to limit the application. In addition, it is to be understood that the drawings are only schematic and that they do not necessarily correspond to the precise implementation of the application.

[0042] In the description of the application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrated; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0043] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "under" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0044] In the description of the present embodiment, the terms "upper", "lower", "right", and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0045] The present application provides a dual-fuel burner system, such as Figure 1As shown, the dual-fuel burner system comprises a natural gas tank 1, a hydrogen-containing fuel tank 2, a first mixer 3, a first control valve 4, a burner 7, a first igniter 8, a second control valve 5, an air input pipe 21, a second mixer 6, a second igniter 9 and a cooling pipe 10. The natural gas tank 1 and the hydrogen-containing fuel tank 2 are respectively communicated with two gas inlets of the first mixer 3, and the natural gas and the hydrogen-containing fuel are mixed in the first mixer 3 to form a mixed fuel. An input end of the first control valve 4 is communicated with a gas outlet of the first mixer 3, and an output end of the first control valve 4 is communicated with a diffusion zone of the burner 7. The first igniter 8 is used for igniting the diffusion zone of the burner 7. An input end of the second control valve 5 is communicated with the gas outlet of the first mixer 3, and output ends of the second control valve 5 and the air input pipe 21 are respectively communicated with two gas inlets of the second mixer 6. A gas outlet of the second mixer 6 is communicated with a premixing zone of the burner 7. The second igniter 9 is used for igniting the premixing zone of the burner 7. One end of the cooling pipe 10 is communicated with an outlet of the air input pipe 21, and the other end of the cooling pipe 10 is communicated with an inlet of the burner 7.

[0046] The fuel of the burner 7 is natural gas or hydrogen-containing fuel, and air is used as a combustion-supporting agent. With the operation of the fuel cell stack, the air temperature gradually increases from room temperature to high temperature, so as to realize the smooth operation of the stack. The minimum ignition temperature of the mixed fuel formed by mixing the natural gas and the hydrogen-containing fuel is t1. The hydrogen-containing fuel tank 2 contains hydrogen-containing fuel which generates gas when the temperature exceeds t2, wherein 300℃ < t2 < t1.

[0047] As shown in FIG. 2, the dual-fuel burner system comprises a natural gas tank 1, a hydrogen-containing fuel tank 2, a first mixer 3, a first control valve 4, a burner 7, a first igniter 8, a second control valve 5, an air input pipe 21, a second mixer 6, a second igniter 9 and a cooling pipe 10. The natural gas tank 1 and the hydrogen-containing fuel tank 2 are respectively communicated with two gas inlets of the first mixer 3, and the natural gas and the hydrogen-containing fuel are mixed in the first mixer 3 to form a mixed fuel. An input end of the first control valve 4 is communicated with a gas outlet of the first mixer 3, and an output end of the first control valve 4 is communicated with a diffusion zone of the burner 7. The first igniter 8 is used for igniting the diffusion zone of the burner 7. An input end of the second control valve 5 is communicated with the gas outlet of the first mixer 3, and output ends of the second control valve 5 and the air input pipe 21 are respectively communicated with two gas inlets of the second mixer 6. A gas outlet of the second mixer 6 is communicated with a premixing zone of the burner 7. The second igniter 9 is used for igniting the premixing zone of the burner 7. One end of the cooling pipe 10 is communicated with an outlet of the air input pipe 21, and the other end of the cooling pipe 10 is communicated with an inlet of the burner 7. Figure 1As shown, in the dual-fuel burner system, natural gas from the natural gas tank 1 enters the first mixer 3, hydrogen-containing fuel from the hydrogen-containing fuel tank 2 enters the first mixer 3, and the natural gas and the hydrogen-containing fuel are mixed in the first mixer 3 to form a mixed fuel. When the air temperature T1 at the inlet of the burner 7 is less than the minimum ignition temperature t1 of the mixed fuel, the second control valve 5 is opened, the first control valve 4 is closed, the mixed fuel formed by mixing the natural gas and the hydrogen-containing fuel in the first mixer 3 enters the second mixer 6 through the second control valve 5, and a part of the air output from the air input pipe 21 enters the second mixer 6, and the other part enters the inlet of the burner 7 through the cooling pipeline 10. After the air and the mixed fuel are mixed in the second mixer 6, the air enters the premixing area of the burner 7, and the second igniter 9 ignites. When the air temperature T1 at the inlet of the burner 7 is greater than or equal to the minimum ignition temperature t1 of the mixed fuel, the first control valve 4 is opened, the second control valve 5 is closed, and the mixed fuel enters the diffusion area of the burner 7 through the first control valve 4. A part of the air flowing out from the air input pipe 21 enters the second mixer 6, and the other part enters the inlet of the burner 7 through the cooling pipeline 10. The air enters the premixing area of the burner 7 from the second mixer 6. Since the temperature of the air entering the inlet of the burner 7 is too high, the mixed fuel is likely to self-ignite in the diffusion area of the burner 7. If the mixed fuel does not self-ignite, the first igniter 8 ignites. The dual-fuel burner system adopts the control logic of low-temperature premixing combustion and high-temperature diffusion combustion. When the air temperature T1 at the inlet of the burner 7 is less than the minimum ignition temperature t1 of the mixed fuel, the premixing combustion technology is adopted to reduce the temperature of the flame core area, hinder the generation of nitrogen oxides, and realize low-pollutant emission combustion. When the air temperature T1 at the inlet of the burner 7 is greater than or equal to the minimum ignition temperature t1 of the mixed fuel, the diffusion combustion technology is adopted. After the mixed fuel contacts with the high-temperature air, the mixed fuel is directly thermally decomposed. The high-temperature air enhances the combustibility of the fuel and reduces the generation of pollutants, thereby realizing low-pollutant stable combustion.

[0048] It can be understood that the air entering the burner 7 from the cooling pipeline 10 will flow out of the burner 7 together with the flue gas after combustion, so as to cool the flue gas generated after the combustion of the burner 7 and maintain the temperature of the gas flowing out of the burner 7 constant.

[0049] It can be understood that the first control valve 4 and the second control valve 5 are both solenoid valves. The first igniter 8 and the second igniter 9 can be electric spark igniters.

[0050] It can be understood that if the diffusion area and the premixing area of the burner 7 are relatively close, the first igniter 8 and the second igniter 9 can be the same igniter. If the diffusion area and the premixing area of the burner 7 are relatively far away, the first igniter 8 and the second igniter 9 are two different igniters respectively arranged in the diffusion area and the premixing area. The distance between the diffusion area and the premixing area of the burner 7 is determined by the structure of the burner 7.

[0051] In this embodiment, the high-temperature flue gas flowing out of the outlet of the burner 7 can provide heat for the fuel cell's components 19 that need to be heated and the air preheater 18, both of which are heat exchangers. The air preheater 18 can preheat the air, and the preheated air can enter the air input pipe 21, and the air passing through the air preheater 18 can enter the second mixer 6 and the cooling pipeline 10.

[0052] The diffusion zone of the burner 7 is a zone in which the fuel that has not been mixed with air flows out of the burner 7 and is mixed with air while being burned; and the premixing zone of the burner 7 is a zone in which the fuel that has been mixed with air flows out of the burner 7 and is completely mixed with air while being burned. The diffusion zone is characterized in that the fuel is not premixed with air, the combustion process is a process of mixing and burning, the air in the diffusion zone can be used as an oxidizer and can be used to cool the flame. The premixing zone is characterized in that the fuel is completely premixed with air in advance, and then the combustion process is completed in the premixing zone, and the air in the premixing zone is mainly used to cool the flame.

[0053] Optionally, the dual-fuel burner system further comprises a first MFC 12, which is arranged between the natural gas storage tank 1 and the air inlet of the first mixer 3, and is used to adjust the flow of gas entering the first mixer 3. The MFC is a mass flow controller (MFC), which is used to precisely measure and control the mass flow of gas or liquid, i.e., has the functions of measuring the mass flow and adjusting the mass flow. The mass flow can be set as needed, and the mass flow of gas or liquid is automatically controlled to be constant at the set value. Therefore, the first MFC 12 can control the flow of gas entering the first mixer 3 from the natural gas storage tank 1.

[0054] Optionally, the dual-fuel burner system further comprises a fan 11 and a second MFC 13, which is arranged between the fan 11 and the air input pipe 21, and is used to adjust the flow of gas entering the air input pipe 21. The second MFC 13 can control the flow of air entering the second mixer 6 and the cooling pipeline 10 from the fan 11.

[0055] Optionally, the dual-fuel burner system further comprises a first temperature sensor 16, which is used to detect the temperature of the air at the inlet of the burner 7. In this embodiment, the first temperature sensor 16 is arranged in the air input pipe 21.

[0056] Optionally, the dual-fuel burner system further comprises a second temperature sensor 17 for detecting the air temperature at the outlet of the burner 7. In the present embodiment, the second temperature sensor 17 is arranged at the outlet of the burner 7.

[0057] Optionally, the dual-fuel burner system further comprises a first flow sensor or a first pressure sensor 14 for detecting whether gas is flowing into the diffusion zone of the burner 7. In the present embodiment, the first flow sensor or the first pressure sensor 14 is arranged on the pipeline between the first control valve 4 and the burner 7.

[0058] Optionally, the dual-fuel burner system further comprises a second flow sensor or a second pressure sensor 15 for detecting whether gas is flowing into the premixing zone of the burner 7. In the present embodiment, the second flow sensor or the second pressure sensor 15 is arranged on the pipeline between the second control valve 5 and the second mixer 6.

[0059] Optionally, the dual-fuel burner system further comprises a third flow sensor or a third pressure sensor 20 arranged on the pipeline between the hydrogen-containing fuel tank 2 and the first mixer 3, which is capable of detecting whether hydrogen-containing fuel is flowing into the first mixer 3.

[0060] The present application also provides a control method for the dual-fuel burner system, which employs the dual-fuel burner system as described above, and the control method for the dual-fuel burner system comprises:

[0061] S1: air is introduced into the burner 7, and the air temperature at the inlet of the burner 7 is detected. The air fan 11 is started to introduce air into the burner 7. The air temperature T1 at the inlet of the burner 7 is detected by the first temperature sensor 16.

[0062] S2: it is determined whether the air temperature at the inlet of the burner 7 is greater than or equal to the minimum ignition temperature of the mixed fuel; if not, S3 is performed; if yes, S6 is performed.

[0063] S3: the first control valve 4 is closed, and the second control valve 5 is opened.

[0064] S4: the second igniter 9 performs an ignition operation. Between S3 and S4, it is further determined whether gas is flowing into the premixing zone of the burner 7; if yes, S4 is performed. Whether gas is flowing into the premixing zone of the burner 7 is detected by the second flow sensor or the second pressure sensor 15.

[0065] S5: it is determined whether the ignition of the premixing zone of the burner 7 is successful; if yes, S2 is returned; if not, S51 is performed.

[0066] S51: determine whether the number of ignitions of the second igniter 9 is less than or equal to a set number; if yes, return to S4; if no, perform an alarm. In this embodiment, the set number is three. If the second igniter 9 fails to ignite for three times, an alarm is performed to remind the staff that the second igniter 9 fails to ignite.

[0067] S6: open the first control valve 4 and close the second control valve 5.

[0068] Between S6 and S7, there is also a step of determining whether gas flows into the diffusion zone of the burner 7; if yes, perform S7. Whether gas flows into the diffusion zone of the burner 7 is detected by the first flow sensor or the first pressure sensor 14.

[0069] S7: determine whether the mixed fuel is self-ignited in the diffusion zone of the burner 7; if yes, return to S3; if no, perform S8.

[0070] S8: the first igniter 8 performs an ignition operation. When the air temperature at the inlet of the burner 7 is too high, the mixed fuel is likely to be self-ignited in the diffusion zone. If it fails to be self-ignited, the first igniter 8 is used to ignite. The first igniter 8 plays an auxiliary ignition role and should not be continuously ignited.

[0071] The control method of the dual-fuel burner system is suitable for the working conditions of cold start and high-temperature restart of a fuel cell.

[0072] The required heat provided by the burner 7 is obtained according to the difference between the air temperature at the inlet of the burner 7 and the gas temperature at the outlet of the burner 7; the required flow of natural gas is obtained according to the required heat provided by the burner 7; and the first MFC 12 is adjusted according to the required flow of natural gas. The temperature at the outlet of the burner 7 is generally set to a constant value, the air temperature at the inlet of the burner 7 is detected by the first temperature sensor 16, and the gas temperature at the outlet of the burner 7 is detected by the second temperature sensor 17. According to the difference between the air temperature at the inlet of the burner 7 and the gas temperature at the outlet of the burner 7, it is obtained how much heat the burner 7 needs to provide to make the temperature at the outlet of the burner 7 reach the constant value. The heat generated by the combustion of the burner 7 can be controlled by controlling the flow of natural gas, so that the required flow of natural gas can be obtained according to the required heat provided by the burner 7, and the first MFC 12 is adjusted according to the required flow of natural gas. The change of the flow of natural gas by the first MFC 12 realizes the change of the combustion power of the burner 7.

[0073] The present application further provides a fuel cell system, comprising the dual-fuel combustor system as described above, further comprising an air preheater 18 and a component 19 to be heated, the gas flowing out of the combustor 7 can heat the component 19 to be heated and the air preheater 18, the air preheater 18 and the component 19 to be heated are both heat exchangers, and the air preheater 18 is used to heat air. In this embodiment, the component 19 to be heated can be a water vapor generator, water is converted into water vapor by the water vapor generator, the water vapor and the fuel are subjected to a reforming reaction in the reformer, and then enter the anode of the fuel cell. The air heated by the air preheater 18 flows into the air input pipe 21 in part, and flows into the cathode of the fuel cell in the other part.

[0074] Obviously, the above embodiments of the present application are merely exemplary for the purpose of clarity and are not intended to limit the embodiments of the present application. For those skilled in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the scope of the present application. It is unnecessary and impossible to enumerate all the embodiments. Any modification, equivalent substitution and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A dual fuel burner system, characterized by The dual-fuel burner system comprises: a natural gas tank (1), a hydrogen-containing fuel tank (2), and a first mixer (3), the natural gas tank (1) and the hydrogen-containing fuel tank (2) being in communication with two gas inlets of the first mixer (3) respectively, and natural gas and hydrogen-containing fuel being mixed in the first mixer (3) to form a mixed fuel; a first control valve (4) and a burner (7), an input end of the first control valve (4) being in communication with a gas outlet of the first mixer (3), and an output end of the first control valve (4) being in communication with a diffusion zone of the burner (7); a first igniter (8) for igniting the diffusion zone of the burner (7); a second control valve (5), a second mixer (6), and an air input pipe (21), an input end of the second control valve (5) being in communication with the gas outlet of the first mixer (3), an output end of the second control valve (5) and the air input pipe (21) being in communication with two gas inlets of the second mixer (6) respectively, and a gas outlet of the second mixer (6) being in communication with a premixing zone of the burner (7); a second igniter (9) for igniting the premixing zone of the burner (7); a cooling pipeline (10), one end of the cooling pipeline (10) being in communication with the air input pipe (21), and the other end being in communication with an inlet of the burner (7).

2. The dual fuel burner system of claim 1, wherein, The dual-fuel burner system further comprises a first MFC (12) arranged between the natural gas tank (1) and the gas inlet of the first mixer (3), the first MFC (12) being used for adjusting the gas flow entering the first mixer (3).

3. The dual fuel burner system of claim 1, wherein, The dual-fuel burner system further comprises a fan (11) and a second MFC (13) arranged between the fan (11) and the air input pipe (21), the second MFC (13) being used for adjusting the gas flow entering the air input pipe (21).

4. The dual fuel burner system of claim 1, wherein, The dual-fuel burner system further comprises a first flow sensor or a first pressure sensor (14) for detecting whether gas flows into the diffusion zone of the burner (7).

5. The dual fuel burner system of claim 1, wherein, The dual-fuel burner system further comprises a second flow sensor or a second pressure sensor (15) for detecting whether gas flows into the premixing zone of the burner (7).

6. The dual fuel burner system of claim 1, wherein, The dual-fuel burner system further comprises a first temperature sensor (16) for detecting the temperature of air at the inlet of the burner (7).

7. The dual fuel burner system of claim 1, wherein, The dual-fuel burner system further comprises a second temperature sensor (17) for detecting the temperature of air at the outlet of the burner (7).

8. A method of controlling a dual fuel burner system, characterized by, The control method of the dual-fuel burner system according to any one of claims 1-7 comprises: S1: air is introduced into the burner (7), and the temperature of the air at the inlet of the burner (7) is detected; S2: it is determined whether the temperature of the air at the inlet of the burner (7) is greater than or equal to the minimum ignition temperature of the mixed fuel; if not, S3 is performed; if yes, S6 is performed; S3: the first control valve (4) is closed, and the second control valve (5) is opened; S4: the second igniter (9) performs an ignition operation; S5: it is determined whether the ignition of the premixing zone of the burner (7) is successful; if yes, S2 is returned to; S6: the first control valve (4) is opened, and the second control valve (5) is closed; S7: it is determined whether the mixed fuel is self-ignited in the diffusion zone of the burner (7); if not, S8 is performed; S8: the first igniter (8) performs an ignition operation.

9. The control method of the dual-fuel burner system according to claim 8, characterized in that, In S5, if the ignition of the premixing zone of the burner (7) is not successful, S51 is performed; S51: it is determined whether the number of ignitions of the second igniter (9) is less than or equal to a set number; if yes, S4 is returned to; if not, an alarm is performed.

10. A fuel cell system characterized by comprising: The dual-fuel burner system according to any one of claims 1-7, further comprising an air preheater (18) and a component (19) to be heated, the gas flowing out of the outlet of the burner (7) can heat the component (19) to be heated and the air preheater (18), the air preheater (18) and the component (19) to be heated are both heat exchangers, and the air preheater (18) is used for heating air.

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