A solid oxide fuel cell system and control method

Abstract

This application relates to the field of solid oxide fuel cell technology, specifically to a solid oxide fuel cell system and control method. The system includes a battery assembly, a first supply assembly, a second supply assembly, and a first recovery assembly. The battery assembly includes battery cells; the first recovery assembly includes a first heat exchanger and a second heat exchanger; the cathode outlet is connected to the hot-side inlet of the first heat exchanger; the hot-side outlet of the first heat exchanger is connected to the hot-side inlet of the second heat exchanger; the hot-side outlet of the second heat exchanger is connected to the external atmosphere; the first supply assembly is connected to the cold-side inlet of the first heat exchanger; the cold-side outlet of the first heat exchanger is connected to the cathode inlet; the second supply assembly is connected to the cold-side inlet of the second heat exchanger; the cold-side outlet of the second heat exchanger is connected to the anode inlet; thereby solving the problem of low energy utilization in solid oxide fuel cell systems.

Description

Technical Field

[0001] This application relates to the field of solid oxide fuel cell technology, and more specifically, to a solid oxide fuel cell system and control method. Background Technology

[0002] Solid oxide fuel cell systems mainly consist of a stack module, a fuel supply unit, an air supply unit, and supporting piping components. During operation, the air supply unit delivers external air to the cathode side of the stack module, where it acts as an oxidant in the electrochemical reaction, reacting with the fuel introduced from the anode side in a redox reaction to achieve a stable output of electrical energy.

[0003] However, in the solid oxide fuel cell system architecture, the exhaust gas after participating in the cathode reaction is directly discharged into the atmosphere through the exhaust channel after completing the oxygen supply function, resulting in low energy utilization and prominent energy loss problems in the solid oxide fuel cell system. Summary of the Invention

[0004] To address the issue of low energy utilization in solid oxide fuel cell systems, this application provides a solid oxide fuel cell system and its control method.

[0005] In a first aspect, this application provides a solid oxide fuel cell system, the solid oxide fuel cell system comprising:

[0006] A battery assembly includes battery cells; each battery cell is provided with a cathode inlet, an anode inlet, a cathode outlet, and an anode outlet.

[0007] A first supply component is used to supply air to the battery assembly;

[0008] A second supply component is used to supply hydrogen to the battery assembly;

[0009] The first recovery assembly includes a first heat exchanger and a second heat exchanger; the cathode outlet is connected to the hot-side inlet of the first heat exchanger; the hot-side outlet of the first heat exchanger is connected to the hot-side inlet of the second heat exchanger; the hot-side outlet of the second heat exchanger is connected to the outside atmosphere; the first supply assembly is connected to the cold-side inlet of the first heat exchanger; the cold-side outlet of the first heat exchanger is connected to the cathode inlet; the second supply assembly is connected to the cold-side inlet of the second heat exchanger; and the cold-side outlet of the second heat exchanger is connected to the anode inlet.

[0010] Optionally, the solid oxide fuel cell system further includes a second recovery component; the second recovery component includes a first separator and a mixer; the first separator is connected to the anode outlet; the first gas outlet of the first separator is connected to the mixer; and the second heat exchanger is connected to the anode inlet through the mixer.

[0011] Optionally, the second recovery assembly further includes a condenser and a second separator; the inlet of the condenser is connected to the second gas outlet of the first separator; the outlet of the condenser is connected to the second separator; and the outlet of the second separator is connected to the second supply assembly.

[0012] Optionally, the second supply assembly includes a water tank, a water pump, a reaction chamber, and a gas cylinder; the water tank is connected to the water pump; the water pump is connected to the reaction chamber; the liquid outlet of the second separator is connected to the water tank; the gas cylinder is connected to the reaction chamber; the gas outlet of the second separator is connected to the gas cylinder; and the gas cylinder is connected to the cold-side inlet of the second heat exchanger.

[0013] Optionally, the battery assembly further includes a preheating unit; the preheating unit is connected to the battery cell; the preheating unit is located at the cathode of the battery cell.

[0014] Secondly, this application provides a control method for a solid oxide fuel cell system, applied to the solid oxide fuel cell system described in any one of the first aspects, wherein the control method for the solid oxide fuel cell system includes:

[0015] The first supply component is controlled to supply air at a first flow rate to the cathode inlet of the battery cell through the cold side channel of the first heat exchanger;

[0016] The second supply component is controlled to supply hydrogen at a second flow rate to the anode inlet of the battery cell through the cold side channel of the second heat exchanger;

[0017] The cathode outlet of the battery cell is connected in sequence to the hot side channel of the first heat exchanger and the hot side channel of the second heat exchanger.

[0018] Optionally, the first flow rate is greater than the second flow rate.

[0019] Optionally, the control method further includes:

[0020] Based on the first supply component being in an air supply state; the preheating unit preheats the cathode-side air of the battery cell until the cathode-side air of the battery cell reaches a preset temperature, and then stops the preheating;

[0021] The control of the second supply component to supply hydrogen at a second flow rate to the anode inlet of the battery cell through the cold side channel of the second heat exchanger includes:

[0022] When the air on the cathode side of the battery cell reaches the preset temperature, the second supply component is controlled to supply hydrogen at a second flow rate to the anode inlet of the battery cell through the cold side channel of the second heat exchanger.

[0023] Optionally, the step of preheating the cathode-side air of the battery cell by means of a preheating unit, based on the first supply component being in an air supply state, until the cathode-side air of the battery cell reaches a preset temperature and then stopping the preheating, includes:

[0024] The first supply component is in an air supply state, and the air on the cathode side of the battery cell is preheated by the preheating unit until the air on the cathode side of the battery cell reaches a reference temperature, and the power of the preheating unit is reduced; wherein, the reference temperature is lower than the preset temperature;

[0025] Preheating stops when the air on the cathode side of the battery cell reaches a preset temperature.

[0026] Optionally, the control method further includes:

[0027] Obtain the gas flow rate requirement of the battery cell;

[0028] When the gas flow rate requirement of the battery cell increases, the separation rate of the first separator is increased;

[0029] When the gas flow rate requirement of the battery cell decreases by a first magnitude, the separation rate of the first separator is increased, and the supply flow rates of the second supply component and the first supply component are reduced.

[0030] When the gas flow demand of the battery cell decreases by a second magnitude, the supply flow of the second supply component and the first supply component is reduced; wherein the first magnitude is greater than the second magnitude.

[0031] To address the issue of low energy efficiency in solid oxide fuel cell systems, this application offers the following advantages:

[0032] By sequentially connecting the cathode outlet of the battery unit to the hot-side inlet of the first heat exchanger and the hot-side inlet of the second heat exchanger, the high-temperature air discharged from the cathode outlet can flow through the hot-side channels of the first and second heat exchangers in sequence. This allows the air supplied by the first supply component and the hydrogen supplied by the second supply component to exchange heat with the hot-side channels of the first and second heat exchangers respectively before entering the cathode inlet, thereby gaining a higher temperature. This fully recovers the energy carried by the exhaust gas from the cathode outlet, reduces the direct emission loss of system energy, and ultimately effectively improves the energy utilization rate of the solid oxide fuel cell system. Attached Figure Description

[0033] Figure 1 A schematic diagram of the solid oxide fuel cell system of Embodiment 1 is shown;

[0034] Figure 2 A flowchart of the control method for the solid oxide fuel cell system of Example 2 is shown.

[0035] Reference numerals: Battery assembly 10; Battery cell 11; First supply assembly 20; Second supply assembly 30; Water tank 31; Water pump 32; Reaction chamber 33; Gas cylinder 34; First recovery assembly 40; First heat exchanger 41; Second heat exchanger 42; Second recovery assembly 50; First separator 51; Mixer 52; Condenser 53; Second separator 54. Detailed Implementation

[0036] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.

[0037] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0038] In a solid oxide fuel cell system, the battery assembly 10 includes battery cells 11, each with a cathode inlet, an anode inlet, a cathode outlet, and an anode outlet. During system operation, air is supplied to the battery assembly 10 by a first supply component 20, and hydrogen is supplied by a second supply component 30. The air and hydrogen enter the battery cells 11 through the cathode inlet and anode inlet, respectively, and participate in the electrochemical reaction. The reacted gases are then discharged through the cathode outlet and anode outlet. Because the high-temperature reaction exhaust gas discharged from the cathode outlet carries a large amount of energy, this heat energy is directly dissipated into the external atmosphere, resulting in ineffective energy loss and ultimately leading to a low energy utilization rate for the solid oxide fuel cell system.

[0039] Example 1:

[0040] In this embodiment, a solid oxide fuel cell system is provided, such as Figure 1 As shown, the solid oxide fuel cell system includes a battery assembly 10, a first supply assembly 20, a second supply assembly 30, and a first recovery assembly 40.

[0041] The battery assembly 10 includes a battery cell 11. The battery cell 11 is provided with a cathode inlet, an anode inlet, a cathode outlet, and an anode outlet.

[0042] The first supply component 20 is used to supply air to the battery assembly 10. The second supply component 30 is used to supply hydrogen to the battery assembly 10. The first supply component 20 supplies air to the cathode inlet of the battery cell 11, and the second supply component 30 supplies hydrogen to the anode inlet of the battery cell 11. The air and hydrogen undergo an electrochemical reaction inside the battery cell 11. The first supply component 20 can be a blower.

[0043] The first recovery assembly 40 includes a first heat exchanger 41 and a second heat exchanger 42. The cathode outlet is connected to the hot-side inlet of the first heat exchanger 41. The hot-side outlet of the first heat exchanger 41 is connected to the hot-side inlet of the second heat exchanger 42. The hot-side outlet of the second heat exchanger 42 is connected to the outside atmosphere. The first supply assembly 20 is connected to the cold-side inlet of the first heat exchanger 41. The cold-side outlet of the first heat exchanger 41 is connected to the cathode inlet. The second supply assembly 30 is connected to the cold-side inlet of the second heat exchanger 42. The cold-side outlet of the second heat exchanger 42 is connected to the anode inlet.

[0044] In this embodiment, the cathode outlet of the battery unit 11 is sequentially connected to the hot-side inlet of the first heat exchanger 41 and the hot-side inlet of the second heat exchanger 42. This allows the high-temperature air discharged from the cathode outlet to flow sequentially through the hot-side channels of the first heat exchanger 41 and the second heat exchanger 42. Before entering the cathode inlet, the air supplied by the first supply component 20 and the hydrogen supplied by the second supply component 30 exchange heat with the hot-side channels of the first heat exchanger 41 and the second heat exchanger 42, respectively, and are heated. This fully recovers the energy carried by the exhaust gas from the cathode outlet, reduces the direct energy emission loss of the system, and ultimately effectively improves the energy utilization rate of the solid oxide fuel cell system.

[0045] Furthermore, the solid oxide fuel cell system also includes a second recovery assembly 50. The second recovery assembly 50 includes a first separator 51 and a mixer 52. The first separator 51 is connected to the anode outlet, and its first gas outlet is connected to the mixer 52. The second heat exchanger 42 is connected to the anode inlet via the mixer 52. Through the structure where the first separator 51 is connected to the anode outlet, the high-temperature hydrogen-containing exhaust gas discharged from the anode outlet can be separated into hydrogen and water vapor. The separated high-temperature hydrogen is then introduced into the mixer 52 via the first gas outlet. By connecting the mixer 52 to the outlet of the second heat exchanger 42 and the first gas outlet of the first separator 51 through pipelines, the hydrogen preheated by the second heat exchanger 42 and the high-temperature circulating hydrogen returning from the first separator 51 can be mixed in the mixer 52. The two streams of hydrogen are fully mixed by means of the swirling structure or static mixing unit inside the mixer 52. The waste heat of the high-temperature circulating hydrogen is used to reheat the preheated hydrogen, which makes up for the insufficient heat exchange of the second heat exchanger 42. This ensures that the temperature of the mixed hydrogen reaches the temperature condition for entering the battery cell 11, thus ensuring the stability of the anode inlet temperature.

[0046] When the hydrogen flow demand of battery cell 11 increases, the separation rate of the first separator 51 is increased, and the high-temperature circulating hydrogen obtained by the first separator 51 is used to supplement the hydrogen supply at the anode inlet to match the operating requirements of battery cell 11.

[0047] Furthermore, the second recovery assembly 50 also includes a condenser 53 and a second separator 54. The inlet of the condenser 53 is connected to the second gas outlet of the first separator 51. The outlet of the condenser 53 is connected to the second separator 54. The outlet of the second separator 54 is connected to the second supply assembly 30. It should be understood that because the first separator 51 uses a high-cost palladium-silver alloy metal membrane, its operating degree is small when the hydrogen flow demand of the battery unit 11 is low. A small amount of hydrogen and a large amount of water vapor remain in the gas discharged from the second gas outlet after separation by the first separator 51. Through the structure connecting the condenser 53 to the second gas outlet of the first separator 51, this portion of the discharged gas can be condensed, causing the gaseous water to condense into liquid. By connecting the outlet of the condenser 53 to the second separator 54, the liquid water and residual hydrogen can be further separated within the second separator 54. The recovered hydrogen is returned to the second supply assembly 30 through the outlet of the second separator 54, thereby ensuring system heat recovery while achieving further hydrogen recovery and utilization, reducing fuel consumption.

[0048] Furthermore, the second supply assembly 30 includes a water tank 31, a water pump 32, a reaction chamber 33, and a gas cylinder 34. The water tank 31 is connected to the water pump 32, and the water pump 32 is connected to the reaction chamber 33. This allows the water pump 32 to transport water from the water tank 31 to the reaction chamber 33, whereby the materials in the reaction chamber 33 undergo a hydrolysis reaction with the supplied water under the action of a catalyst, providing a stable supply of hydrogen gas required for the reaction to the battery assembly 10. Simultaneously, a drying device must be installed at the hydrogen outlet of the reaction chamber 33 to ensure that the gas entering the gas cylinder 34 is dry hydrogen gas.

[0049] The liquid outlet of the second separator 54 is connected to the water tank 31, which can return the liquid water separated by the second separator 54 to the water tank 31 for recycling, realizing the reuse of water resources. At the same time, it can improve the material circulation system of the system by cooperating with the hydrogen recovery process of the anode tail gas.

[0050] Gas cylinder 34 is connected to reaction chamber 33, the gas outlet of second separator 54 is connected to gas cylinder 34, and gas cylinder 34 is connected to the cold side inlet of second heat exchanger 42. By connecting gas cylinder 34 to reaction chamber 33, the gas outlet of second separator 54, and the cold side inlet of second heat exchanger 42, the hydrogen generated in reaction chamber 33 and the hydrogen recovered by second separator 54 can be stored and buffered. When the hydrogen production rate in reaction chamber 33 fluctuates or the hydrogen supply is untimely, the pre-stored hydrogen in gas cylinder 34 can be continuously supplied to the second heat exchanger 42, maintaining the continuity and stability of the hydrogen supply to the anode side. This reduces the impact of hydrogen supply fluctuations on battery unit 11, avoids fluctuations in the operating status of battery unit 11, and ensures stable overall system operation.

[0051] Gas cylinder 34 is a buffer gas cylinder 34 with a working pressure lower than that of the high-pressure gas storage cylinder 34 of the transmission. It is used to suppress hydrogen fluctuations in the reaction chamber 33. Gas cylinder 34 is equipped with a valve at its gas outlet, which is used to provide a stable flow of hydrogen to the battery unit 11 by controlling the valve.

[0052] Furthermore, the battery assembly 10 also includes a preheating unit. The preheating unit is connected to the battery cell 11 and is located at the cathode of the battery cell 11. During the startup phase of the solid oxide fuel cell system, it provides preheating to the battery cell 11, enabling it to quickly reach its operating temperature. Simultaneously, it heats the air entering the cathode side, allowing the heated air to participate in subsequent heat exchange processes, providing a temperature basis for these processes. Integrating the preheating unit into the cathode side of the battery cell 11 reduces the independent layout space required for the solid oxide fuel cell system, thereby reducing the overall system volume and improving the structural integration of the battery assembly 10.

[0053] The battery assembly 10 also includes a heat insulation device connected to both the battery cell 11 and the preheating unit. The heat insulation device reduces heat loss, thereby ensuring that the preheating unit can quickly preheat the battery cell 11 and the cathode air.

[0054] Example 2:

[0055] In this embodiment, a control method for a solid oxide fuel cell system is provided, such as... Figure 2 As shown, the control method for a solid oxide fuel cell system includes steps S10 to S30. Steps S10, S20, and S30 can be executed simultaneously without a specific order.

[0056] Step S10: Control the first supply component 20 to supply air of a first flow rate to the cathode inlet of the battery cell 11 through the cold side channel of the first heat exchanger 41.

[0057] In step S20, the second supply component 30 is controlled to supply hydrogen at a second flow rate to the anode inlet of the battery cell 11 through the cold side channel of the second heat exchanger 42.

[0058] In step S30, the cathode outlet of the control battery unit 11 is connected in sequence to the hot side channel of the first heat exchanger 41 and the hot side channel of the second heat exchanger 42.

[0059] By controlling the gas supply flow and heat exchange path in steps S10 to S30, the high-temperature air discharged from the cathode outlet can flow sequentially through the hot-side channels of the first heat exchanger 41 and the second heat exchanger 42, respectively, and complete heat transfer with the air and hydrogen in the cold-side channels. This warms up the hydrogen and air before they enter the battery unit 11, thereby fully recovering the energy carried by the cathode exhaust, reducing the direct heat loss of the solid oxide fuel cell system, and ultimately improving the energy utilization rate of the solid oxide fuel cell system.

[0060] Furthermore, since the first flow rate is greater than the second flow rate and the air cost is lower, the high-temperature air discharged from the cathode outlet can still retain sufficient heat exchange energy after being preheated by the first heat exchanger 41. This allows the air to continuously provide heat to the hydrogen in the second heat exchanger 42, ensuring the stable operation of the two-stage heat exchange process, ensuring that the hydrogen is sufficiently heated, and fully recovering the waste heat from the cathode exhaust.

[0061] Furthermore, the control method also includes step S40. Step S40 is executed before step S10. In this case, step S10 needs to be executed before step S20 is executed.

[0062] In step S40, based on the first supply component 20 being in an air supply state, the air on the cathode side of the battery unit 11 is preheated by the preheating unit, so that the air on the cathode side of the battery unit 11 is rapidly heated to the preset reaction temperature, providing a suitable temperature basis for the electrochemical reaction to proceed, until the air on the cathode side of the battery unit 11 reaches the preset temperature, and the preheating stops.

[0063] Step S20 includes step S21, which is a further optimization of step S20. Step S21 is executed after step S40 is executed.

[0064] In step S21, when the air on the cathode side of battery cell 11 reaches a preset temperature, the second supply component 30 is controlled to supply hydrogen at a second flow rate to the anode inlet of battery cell 11 through the cold side channel of the second heat exchanger 42. By controlling the timing of hydrogen supply after the preheating unit stops preheating and the air on the cathode side reaches the preset temperature, the situation where hydrogen cannot fully participate in the reaction under low-temperature conditions can be avoided, ensuring the reaction effectiveness of battery cell 11 during the start-up phase and improving the stability and reliability of the solid oxide fuel cell system during the start-up process.

[0065] Furthermore, step S40 includes steps S41 and S42, which are further optimizations of step S40.

[0066] Step S41: Based on the first supply component 20 being in an air supply state, the air on the cathode side of the battery cell 11 is preheated by the preheating unit until the air on the cathode side of the battery cell 11 reaches the reference temperature, and the power of the preheating unit is reduced. The reference temperature is lower than a preset temperature.

[0067] Step S42: When the air on the cathode side of battery cell 11 reaches the preset temperature, preheating is stopped.

[0068] It should be understood that when the air temperature on the cathode side rises to a reference temperature lower than the preset temperature, the operating power of the preheating unit is reduced first, and the air temperature continues to rise by relying on residual heat. Once the preset temperature is reached, the preheating is stopped. This avoids the preheating unit operating at high power throughout the process to reach the target temperature, thereby effectively reducing the energy consumption of the preheating unit. At the same time, it can smooth the air heating rate, avoid temperature overshoot, and ensure that the preheating process is stable and controllable.

[0069] Furthermore, the control method also includes step S50, which includes steps S51, S52, S53, and S54. Step S50 must be executed after the preheating is completed, that is, step S50 is executed after step S40.

[0070] Step S51: Obtain the gas flow requirement of battery cell 11.

[0071] Step S52: When the gas flow rate requirement of battery unit 11 increases, the separation rate of the first separator 51 is increased to quickly match the operating requirements of battery unit 11.

[0072] In step S53, when the gas flow demand of battery cell 11 decreases by a first magnitude, air reheat occurs in the solid oxide fuel cell system, increasing the separation rate of the first separator 51 to compensate for the heat exchange in the system and reducing the supply flow of the second supply component 30 and the first supply component 20. Increasing the separation rate of the first separator 51 results in more hydrogen flowing to the mixer 52.

[0073] Step S54: When the gas flow demand of battery cell 11 decreases by a second magnitude, the supply flow of the second supply component 30 and the first supply component 20 is reduced. The first magnitude is greater than the second magnitude.

[0074] By precisely controlling the separation rate of the first separator 51 in relation to the gas flow demand of the battery unit 11 and the heat exchange temperature of the solid oxide fuel cell system, the operating losses of the first separator 51 are reduced, and the service life of the equipment is extended. This control method provides differentiated regulation for different operating conditions of the solid oxide fuel cell system. Under both conditions of increased flow demand and significantly decreased flow demand, the separation rate is increased to match the gas supply demand and supplement the heat exchange heat, respectively. When the flow demand decreases slightly, the separation rate is appropriately reduced, and the hydrogen supply regulation capability of the reaction chamber 33 is used to quickly adapt to the operating conditions and store hydrogen for later use. This precise matching and control method can avoid long-term high-load and ineffective operation of the first separator 51, significantly reduce the loss of the palladium-silver alloy membrane, and effectively extend the overall service life of the first separator 51 while ensuring the stable operation of the battery unit 11 throughout the process and solving the problem of insufficient air reheating.

[0075] The solid oxide fuel cell system also includes a load assembly and a control assembly. The load assembly is connected to the power output terminal of the battery cell 11.

[0076] The power output terminal of battery unit 11 is connected to an AC / DC converter. One end of the AC / DC converter is connected to the load component, and the other end is connected to the battery. The control component is electrically connected to the first recovery component 40, the second recovery component 50, the first supply component 20, and the second supply component 30, respectively, and is used to regulate the normal operation of the solid oxide fuel cell system.

[0077] This application removes the combustion chamber used in conventional systems to process the exhaust gases from the anode and cathode. Instead, the hydrogen and water vapor mixture emitted from the anode of battery cell 11 is introduced into condenser 53 for cooling. The condensed liquid water then flows into water tank 31 as a reactant for hydrogen production via hydrolysis. This closed-loop design not only solves the problem of water supply required for the continuous hydrolysis reaction, significantly reducing reliance on additional water replenishment devices, but also allows for a substantial reduction in the volume of water tank 31 due to water recycling, further enhancing the energy density of the entire system.

[0078] Since the air flow rate on the cathode side of the battery unit 11 is much higher than the hydrogen flow rate on the anode side during operation, most of the waste heat is stored in the exhaust high-temperature air. Therefore, after the combustion chamber is removed, the high-temperature exhaust gas from the cathode outlet of the battery unit 11 is introduced into the first heat exchanger 41 and the second heat exchanger 42 to preheat the hydrogen and air entering the battery unit 11. This efficiently meets the gas preheating requirements of the cathode inlet and anode inlet, ensuring the thermal efficiency of the system.

[0079] Gas cylinder 34 effectively alleviates the energy supply-demand mismatch problem on a time scale, while the gas-liquid separation and reflux mechanism solves the problem of insufficient material utilization. System performance is improved through three mechanisms: First, it provides stable flow and pressure anode gas to battery unit 11, ensuring the stability of battery unit 11's output voltage and power. Second, it enhances the system's adaptability to fluctuations in hydrogen production parameters, improving operational reliability. Third, by recycling unreacted hydrogen at the anode, it significantly improves the system's overall fuel utilization rate, enhancing system economy. This dual mechanism, combining flow regulation and material recycling, maintains stable stack inlet conditions while achieving efficient utilization of unreacted fuel.

[0080] The solid oxide fuel cell system actively regulates the gas flow entering the anode reaction gas of the battery cell 11 through a first recovery component 40 and a second recovery component 50. Changing the cycle ratio can affect several aspects of the system: firstly, it can alter the total gas flow rate and velocity entering the battery cell 11, which helps enhance mass transfer in practical systems; secondly, it can adjust the hydrogen concentration at the anode inlet, thereby affecting the electrochemical reaction rate; and thirdly, it can utilize the high-temperature circulating gas to preheat hydrogen and air, improving heat exchange efficiency.

[0081] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the scope of this disclosure.

Claims

1. A solid oxide fuel cell system, characterized in that, The solid oxide fuel cell system includes: A battery assembly includes battery cells; each battery cell is provided with a cathode inlet, an anode inlet, a cathode outlet, and an anode outlet. A first supply component is used to supply air to the battery assembly; A second supply component is used to supply hydrogen to the battery assembly; The first recovery assembly includes a first heat exchanger and a second heat exchanger; the cathode outlet is connected to the hot-side inlet of the first heat exchanger; the hot-side outlet of the first heat exchanger is connected to the hot-side inlet of the second heat exchanger; the hot-side outlet of the second heat exchanger is connected to the outside atmosphere; the first supply assembly is connected to the cold-side inlet of the first heat exchanger; the cold-side outlet of the first heat exchanger is connected to the cathode inlet; the second supply assembly is connected to the cold-side inlet of the second heat exchanger; and the cold-side outlet of the second heat exchanger is connected to the anode inlet.

2. The solid oxide fuel cell system according to claim 1, characterized in that, The solid oxide fuel cell system further includes a second recovery component; the second recovery component includes a first separator and a mixer; the first separator is connected to the anode outlet; the first gas outlet of the first separator is connected to the mixer; and the second heat exchanger is connected to the anode inlet through the mixer.

3. A solid oxide fuel cell system according to claim 2, characterized in that, The second recovery assembly further includes a condenser and a second separator; the inlet of the condenser is connected to the second gas outlet of the first separator; the outlet of the condenser is connected to the second separator; and the outlet of the second separator is connected to the second supply assembly.

4. A solid oxide fuel cell system according to claim 3, characterized in that, The second supply assembly includes a water tank, a water pump, a reaction chamber, and a gas cylinder; the water tank is connected to the water pump; the water pump is connected to the reaction chamber; the liquid outlet of the second separator is connected to the water tank; the gas cylinder is connected to the reaction chamber; the gas outlet of the second separator is connected to the gas cylinder; and the gas cylinder is connected to the cold side inlet of the second heat exchanger.

5. A solid oxide fuel cell system according to claim 1, characterized in that, The battery assembly further includes a preheating unit; the preheating unit is connected to the battery cell; the preheating unit is located at the cathode of the battery cell.

6. A control method for a solid oxide fuel cell system, applied to the solid oxide fuel cell system according to any one of claims 1-5, characterized in that, The control method for the solid oxide fuel cell system includes: The first supply component is controlled to supply air at a first flow rate to the cathode inlet of the battery cell through the cold side channel of the first heat exchanger; The second supply component is controlled to supply hydrogen at a second flow rate to the anode inlet of the battery cell through the cold side channel of the second heat exchanger; The cathode outlet of the battery cell is connected in sequence to the hot side channel of the first heat exchanger and the hot side channel of the second heat exchanger.

7. The control method for a solid oxide fuel cell system according to claim 6, characterized in that, The first flow rate is greater than the second flow rate.

8. The control method for a solid oxide fuel cell system according to claim 6, characterized in that, The control method further includes: Based on the first supply component being in an air supply state; the preheating unit preheats the cathode-side air of the battery cell until the cathode-side air of the battery cell reaches a preset temperature, and then stops the preheating; The control of the second supply component to supply hydrogen at a second flow rate to the anode inlet of the battery cell through the cold-side channel of the second heat exchanger includes: When the air on the cathode side of the battery cell reaches the preset temperature, the second supply component is controlled to supply hydrogen at a second flow rate to the anode inlet of the battery cell through the cold side channel of the second heat exchanger.

9. The control method for a solid oxide fuel cell system according to claim 8, characterized in that, The step of preheating the cathode-side air of the battery cell by means of a preheating unit, based on the first supply component being in an air supply state, until the cathode-side air of the battery cell reaches a preset temperature and then stopping the preheating, includes: The first supply component is in an air supply state, and the air on the cathode side of the battery cell is preheated by the preheating unit until the air on the cathode side of the battery cell reaches a reference temperature, and the power of the preheating unit is reduced; wherein, the reference temperature is lower than the preset temperature; Preheating stops when the air on the cathode side of the battery cell reaches a preset temperature.

10. The control method for a solid oxide fuel cell system according to claim 6, characterized in that, The control method further includes: Obtain the gas flow rate requirement of the battery cell; When the gas flow rate requirement of the battery cell increases, the separation rate of the first separator is increased; When the gas flow rate requirement of the battery cell decreases by a first magnitude, the separation rate of the first separator is increased, and the supply flow rates of the second supply component and the first supply component are reduced. When the gas flow demand of the battery cell decreases by a second magnitude, the supply flow of the second supply component and the first supply component is reduced; wherein the first magnitude is greater than the second magnitude.

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