A solid oxide fuel cell stack module testing system and operation method thereof

Abstract

The present invention relates to a solid oxide fuel cell (SOFC) stack module testing system and an operating method thereof, comprising an SOFC stack module, an air preheater, a fuel preheater, a main fan, an anode side fan, a main burner, a tail gas burner, a hybrid steam generator, a deionized water pump, an anode tail gas back pressure valve, a mass flow controller, a temperature sensor, a pressure sensor, a heating tape, a control system, a shut-off valve, a pipeline, etc.; the system is provided with a main burner and an anode tail gas burner, which cooperate with the air preheater and the fuel preheater to recover the high-temperature cathode tail gas and anode tail gas at the outlet of the SOFC stack, thereby reducing system power consumption and reducing the cold shock on the high-temperature SOFC stack module caused by restarting the system after emergency shutdown; the use of the anode tail gas back pressure valve and the hybrid steam generator improves the safety of the system and reduces the complexity of the system; the system has low power consumption, is stable and reliable, and has strong operability.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell systems, and in particular to a solid oxide fuel cell stack module testing system and an operating method thereof. Background Art

[0002] Solid oxide fuel cells (SOFCs) are highly efficient energy conversion devices with theoretical power generation efficiencies exceeding 50% on their own, and over 75% when used in conjunction with steam turbines. SOFCs are the most efficient of all power generation technologies, with low pollutant emissions, making them a clean, low-carbon, safe, and efficient method of generating electricity. Therefore, they are considered one of the new energy generation technologies with the broadest development and application prospects in the future, attracting numerous researchers.

[0003] Solid oxide fuel cells have a variety of different structures, and their power generation scale ranges from tens of watts to hundreds of megawatts, with a wide range of application scenarios. For a single SOFC cell, a cell can usually generate a voltage of 0.5-1V. In order to generate higher voltage and higher power generation, several single cells need to be stacked to form a SOFC stack, and then multiple SOFC stacks need to be integrated and packaged to form a SOFC stack module. After the stack module is designed and installed in the SOFC system, it is necessary to pass fuel with appropriate composition, flow rate, and temperature to carry out temperature and power generation tests, etc., to verify the uniformity of fuel distribution within the stack module, the consistency of the temperature field, the airtightness of the pipeline connection during multiple temperature increases and decreases, the conductivity and insulation under high temperature conditions, the thermal standby performance, and the discharge conditions under different power requirements.

[0004] The SOFC stack module test system is a dedicated device for fully understanding the operating characteristics of the SOFC stack module. It mainly includes a fuel supply unit, an air supply unit, an exhaust gas treatment unit, and an electronic control unit. The SOFC stack module has specific heating and cooling rates, and also requires air and fuel of a certain temperature and flow rate during power generation and hot standby. This places high demands on the power consumption of the SOFC stack module test system and the performance of the electric heater. Secondly, the sufficient mixing of water vapor and fuel is also an important factor in ensuring the normal power generation and long life of the SOFC stack module. In particular, when the SOFC stack module is under high temperature conditions and the system experiences an emergency shutdown due to a fault or power outage, the temperature of the air and fuel will drop slowly after the system is restarted. When the temperature of the air and fuel entering the SOFC stack module is significantly lower than that of the SOFC stack module, it will cause a cold shock to the SOFC stack module, seriously affecting its operating performance. Therefore, designing a SOFC module test system with complete functions, low power consumption, high safety and strong operability plays an important role in conducting research on the characteristics of SOFC stack modules. Summary of the Invention

[0005] In response to the high power consumption and inadequate protection of conventional SOFC stack module test systems, the present invention proposes a novel solid oxide fuel cell stack module test system. The system is equipped with a main burner and an anode tail gas burner, which cooperate with an air preheater and a fuel preheater to recover the high-temperature cathode tail gas and anode tail gas at the outlet of the SOFC stack, effectively reducing system power consumption and the cold shock caused to the high-temperature SOFC stack module by restarting the system after an emergency shutdown. The use of an anode tail gas back pressure valve and a hybrid steam generator improves the safety of the SOFC stack module and reduces the complexity of the system. The system has low power consumption, is stable and reliable, and has strong operability. The present invention provides the following technical solutions:

[0006] The first purpose of the present invention is to provide a solid oxide fuel cell stack module testing system, including a control system for controlling the entire system and an air preheater, a main fan for providing air, and a fuel preheater, a hybrid steam generator for providing mixed fuel, and a deionized water pump for providing deionized water, which are respectively connected to the SOFC stack module in sequence; the air preheater is also connected to the main burner, which is respectively connected to natural gas, the anode side fan for providing air, and the SOFC stack module for providing cathode tail gas; the fuel preheater is also connected to the anode tail gas burner, which is respectively connected to the anode side fan and the SOFC stack module for providing cathode tail gas; the air preheater and the fuel preheater are respectively connected to exhaust ducts.

[0007] The main burner uses pipeline natural gas or bottled compressed natural gas as fuel and the high-temperature cathode exhaust gas at the outlet of the SOFC stack module as a combustion aid. The high-temperature flue gas generated by the main burner enters the air preheater to heat the room temperature air on the cold side of the air preheater to the target temperature. The heated air enters the cathode inlet of the SOFC stack module for heating, cooling the SOFC stack module or providing the SOFC stack module with an oxidant for power generation.

[0008] The cold-side air outlet pipe of the air preheater is provided with a temperature sensor for monitoring the temperature of the heated air; the fuel inlet pipe of the main burner is provided with a mass flow controller for adjusting the natural gas flow at the inlet of the main burner, thereby adjusting the air temperature at the air preheater outlet.

[0009] A first stop valve is provided on the air duct between the anode side fan and the main burner, and the first stop valve is usually in a closed state. A second stop valve is provided on the air duct between the anode side fan and the anode tail gas burner, and the second stop valve is usually in an open state. Restarting the SOFC stack module after an emergency stop of the system under high temperature conditions requires opening the first stop valve on the air duct between the anode side fan and the main burner, closing the second stop valve on the air duct between the anode side fan and the anode tail gas burner, and then opening the anode side fan and introducing natural gas into the main burner. When the main burner reaches the target temperature, the main fan is opened again, and high-temperature air of a suitable temperature is supplied to the SOFC stack module through heat exchange in the air preheater.

[0010] The hybrid steam generator comprises a carrier gas inlet, a deionized water inlet, a mixed gas outlet, and a foam metal electric heating unit. The mixed fuel dried at room temperature enters the hybrid steam generator through the carrier gas inlet. When a certain amount of water vapor needs to be added to the dry mixed fuel, the deionized water enters the hybrid steam generator and is rapidly vaporized in the foam metal heating unit to generate steam. The steam is fully mixed with the mixed fuel in the foam metal and further heated to a target temperature, thereby avoiding uneven mixing of the room temperature mixed fuel and water vapor and partial condensation. The mixed fuel is finally discharged from the mixed gas outlet. A heating tape is arranged on the mixed gas outlet pipe to prevent condensation of water vapor. When the dry mixed fuel does not need to be added with water vapor and only needs to be heated, the deionized water pump is turned off, the mixed fuel directly enters the foam metal heating unit, is heated to the target temperature, and is then discharged from the mixed gas outlet.

[0011] The anode tail gas burner uses the high-temperature anode tail gas at the outlet of the SOFC stack module as fuel and the air provided by the anode side fan as a combustion aid. The high-temperature flue gas generated by the anode tail gas burner enters the fuel preheater to heat the mixed fuel at the outlet of the hybrid steam generator to the target temperature. The heated mixed fuel enters the anode inlet of the SOFC stack module for power generation of the SOFC stack module. The flue gas at the outlet of the fuel preheater and the flue gas at the outlet of the air preheater are mixed and discharged from the system together.

[0012] The fuel preheater fuel side outlet pipe is provided with a temperature sensor for monitoring the temperature of the mixed fuel after being heated; the control system adjusts the air flow entering the anode tail gas burner and the temperature of the flue gas after combustion by adjusting the speed of the anode side fan, thereby adjusting the temperature of the mixed fuel at the fuel preheater outlet.

[0013] Pressure sensors are provided on the cathode tail gas outlet pipe and the anode tail gas outlet pipe of the SOFC stack module near the outlet of the SOFC stack module. In addition, an anode tail gas back pressure valve is provided downstream of the pressure sensor on the anode tail gas outlet pipe. The control system automatically adjusts the opening of the anode tail gas back pressure valve according to the pressures of the cathode tail gas and the anode tail gas so that the anode tail gas pressure is always appropriately higher than the cathode tail gas pressure, thereby effectively reducing the safety risk caused by internal leakage of the SOFC stack module.

[0014] The second object of the present invention is to provide an operating method for the above-mentioned solid oxide fuel cell stack module test system, comprising the following steps: ① Before the SOFC stack module is heated up, the main fan is turned on, and the room temperature air enters the air heat exchanger, the SOFC stack module, and the main burner in sequence; the anode side fan is turned on, and the room temperature air enters the anode tail gas burner, the fuel preheater, and the exhaust pipe in sequence; ② In the first stage of SOFC stack module heating, a certain amount of natural gas is introduced into the main burner through the mass flow controller and ignited, and the high-temperature flue gas generated by the combustion enters the air preheater to heat the air, and the control system adjusts the flow of natural gas according to the temperature sensor arranged on the outlet pipe of the air preheater, thereby controlling The temperature rise rate of the SOFC stack module; after the main burner is ignited successfully, the dry mixed fuel is introduced into the carrier gas inlet of the hybrid steam generator, and the dry mixed fuel passes through the hybrid steam generator, the fuel preheater, the SOFC stack module, and the anode tail gas burner in sequence. The mixed fuel is mixed with air in the anode tail gas burner and ignited and burned. The flue gas generated by the combustion enters the fuel preheater to heat the mixed fuel. The control system adjusts the speed of the anode side fan according to the temperature sensor arranged on the outlet pipe of the fuel preheater, adjusts the air volume and flue gas temperature in the anode tail gas burner, so that the temperature of the mixed fuel and air entering the SOFC stack module are consistent; in addition, the control system adjusts The opening of the anode tail gas back pressure valve ensures that the anode tail gas pressure of the SOFC stack module is always appropriately higher than the cathode tail gas pressure; ③ In the second stage of SOFC stack module heating, when the temperature of the SOFC stack module and the temperature of the pipeline through which the mixed fuel passes reach above 120°C and the SOFC stack module needs to be fed with water vapor, turn on the deionized water pump, turn on the hybrid steam generator foam metal electric heating unit, turn on the heating tape on the hybrid evaporator outlet pipeline, and add appropriate water vapor to the mixed fuel. The control system adjusts the natural gas flow, the anode side fan speed, the electric heating of the hybrid evaporator foam metal electric heating unit, and the heating of the hybrid evaporator foam metal electric heating unit according to the air temperature at the air preheater outlet and the temperature of the mixed fuel at the fuel preheater outlet. Thermal power, thereby ensuring that the SOFC stack module is heated steadily at the set temperature rise rate; ④ During the power generation phase of the SOFC stack module, the control system adjusts the natural gas flow, mixed fuel flow, deionized water flow, anode side fan speed, and electric heating power of the hybrid evaporator foam metal electric heating unit according to the parameters of the SOFC stack module inlet and outlet temperature, power generation power, and power change rate, so as to achieve the target power generation state; ⑤ During the SOFC stack module cooling phase, the system control strategy is similar to that of the heating phase. When the temperature of the SOFC stack module and the temperature of the pipeline through which the mixed fuel passes drop to 120°C, or when the SOFC stack module no longer needs water vapor, the deionized water pump is turned off;⑥ When the SOFC stack module is in a high-temperature state and the system is suddenly stopped, restart it. First, open the first stop valve on the air duct between the anode side fan and the main burner, close the second stop valve on the air duct between the anode side fan and the anode tail gas burner, open the anode circulation fan, and introduce natural gas to the main burner. When the main burner reaches the target temperature, restart the main fan to provide a small flow of air. The small flow of air is heated by the air preheater and quickly reaches the appropriate temperature and enters the SOFC stack module. Then gradually increase the air flow of the main fan, increase the natural gas flow, and gradually reduce the air flow of the anode side fan. In this process, always keep the high-temperature air temperature of the air preheater outlet at the SOFC stack module. The temperature of the group; when the air flow of the main fan reaches the target value and the air flow of the anode side fan gradually decreases to 0, close the first stop valve on the air duct between the anode side fan and the main burner, open the second stop valve on the air duct between the anode side fan and the anode tail gas burner, then reopen the anode side fan, turn on the hybrid steam generator foam metal electric heating unit and heating tape, introduce mixed fuel into the hybrid steam generator, ignite the anode tail gas burner, adjust the air flow and mixed fuel flow of the anode side fan, and introduce deionized water after the fuel temperature at the outlet of the anode tail gas burner and fuel preheater reaches the target temperature; complete the restart of the SOFC stack module after the system is suddenly stopped in a high-temperature state.

[0015] Compared with the existing technology, the advantages of the present invention are: the system does not adopt a conventional air electric heating device, but is equipped with a main burner and an anode tail gas burner to recover the high-temperature cathode tail gas and anode tail gas at the outlet of the SOFC stack, and cooperates with the air preheater and fuel preheater to provide high-temperature air and fuel for the SOFC stack module, effectively reducing the power consumption of the SOFC stack module test system, and also effectively avoiding the cold shock to the SOFC stack module when the system is restarted after an emergency shutdown; the use of the anode tail gas back pressure valve reduces the safety risk caused by internal leakage of the SOFC stack module; the hybrid steam generator reduces the complexity of the system and improves the uniformity of fuel mixing; the system has low power consumption, is stable and reliable, and has strong operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic diagram of the overall structure of a solid oxide fuel cell stack module test system;

[0018] Among them: 1. SOFC stack module; 2. Air preheater; 3. Fuel preheater; 4. Main fan; 5. Anode side fan; 6. Main burner; 7. Tail gas burner; 8. Hybrid steam generator; 9. Deionized water pump; 10. Anode tail gas back pressure valve; 11. First stop valve; 12. Second stop valve. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0020] The specific embodiments of the present invention will be described below with reference to the accompanying drawings:

[0021] like Figure 1 As shown, the first purpose of the present invention is to provide a solid oxide fuel cell stack module testing system, including a SOFC stack module 1, an air preheater 2, a fuel preheater 3, a main fan 4, an anode side fan 5, a main burner 6, an exhaust gas burner 7, a hybrid steam generator 8, a deionized water pump 9, an anode exhaust gas back pressure valve 10, a first stop valve 11, and a second stop valve 12.

[0022] The main burner 6 uses pipeline natural gas or bottled compressed natural gas as fuel and the high-temperature cathode exhaust gas at the outlet of the SOFC stack module 1 as a combustion aid. The high-temperature flue gas generated by the main burner 6 enters the air preheater 2 to heat the room temperature air on the cold side of the air preheater 2 to the target temperature. The heated air enters the cathode inlet of the SOFC stack module 1 for heating, cooling the SOFC stack module 1 or providing the SOFC stack module 1 with an oxidant for power generation.

[0023] The cold side air outlet pipe of the air preheater 2 is provided with a temperature sensor for monitoring the temperature of the heated air; the fuel inlet pipe of the main burner 6 is provided with a mass flow controller for adjusting the natural gas flow at the inlet of the main burner 6, thereby adjusting the outlet air temperature of the air preheater 2.

[0024] A second stop valve 12 is provided on the air duct between the anode side fan 5 and the main burner 6, and the second stop valve 12 is usually in a closed state. A first stop valve 11 is provided on the air duct between the anode side fan 5 and the anode tail gas burner 7, and the first stop valve 11 is usually in an open state; restarting the SOFC stack module 1 after an emergency stop of the system under high temperature conditions requires opening the second stop valve 12 on the air duct between the anode side fan 5 and the main burner 6, closing the first stop valve 11 on the air duct between the anode side fan 5 and the anode tail gas burner 7, and then opening the anode circulation fan and introducing natural gas into the main burner 6. When the main burner 6 reaches the target temperature, the main fan 4 is opened again, and high-temperature air of suitable temperature is supplied to the SOFC stack module 1 through heat exchange in the air preheater 2.

[0025] The hybrid steam generator 8 has a carrier gas inlet, a deionized water inlet, a mixed gas outlet, a foam metal electric heating unit, etc. The mixed fuel dried at room temperature enters the hybrid steam generator through the carrier gas inlet. When a certain amount of water vapor needs to be added to the dry mixed fuel, the deionized water enters the hybrid steam generator and is rapidly vaporized in the foam metal heating unit to generate steam. The steam is fully mixed with the mixed fuel in the foam metal and further heated to the target temperature, thereby avoiding uneven mixing of the room temperature mixed fuel and water vapor and partial condensation. The mixed fuel is finally discharged from the mixed gas outlet. A heating tape is arranged on the mixed gas outlet pipe to prevent condensation of water vapor. When the dry mixed fuel does not need to be added with water vapor and only needs to be heated, the deionized water pump 9 is turned off, and the mixed fuel directly enters the foam metal heating unit to be heated to the target temperature and then discharged from the mixed gas outlet.

[0026] The anode tail gas burner 7 uses the high-temperature anode tail gas at the outlet of the SOFC stack module 1 as fuel and the air provided by the anode side fan 5 as a combustion aid. The high-temperature flue gas generated by the anode tail gas burner 7 enters the fuel preheater 3 to heat the mixed fuel at the outlet of the hybrid steam generator 8 to the target temperature. The heated mixed fuel enters the anode inlet of the SOFC stack module 1 for power generation of the SOFC stack module 1. The flue gas at the outlet of the fuel preheater 3 and the flue gas at the outlet of the air preheater 2 are mixed and discharged from the system together.

[0027] The fuel side outlet pipe of the fuel preheater 3 is provided with a temperature sensor for monitoring the temperature of the mixed fuel after being heated; the control system adjusts the air flow entering the anode tail gas burner 7 and the temperature of the flue gas after combustion by adjusting the speed of the anode side fan 5, thereby adjusting the temperature of the mixed fuel at the outlet of the fuel preheater 3.

[0028] Pressure sensors are provided on the cathode tail gas outlet pipe and the anode tail gas outlet pipe of the SOFC stack module 1 near the outlet of the SOFC stack module 1. In addition, an anode tail gas back pressure valve 10 is provided downstream of the pressure sensor on the anode tail gas outlet pipe. The control system automatically adjusts the opening of the anode tail gas back pressure valve 10 according to the pressures of the cathode tail gas and the anode tail gas so that the anode tail gas pressure is always appropriately higher than the cathode tail gas pressure, thereby effectively reducing the safety risk caused by internal leakage of the SOFC stack module 1.

[0029] The second object of the present invention is to provide an operating method for the above-mentioned solid oxide fuel cell stack module test system, comprising the following steps: ① Before the SOFC stack module 1 is heated up, the main fan 4 is turned on, and the room temperature air enters the air preheater 2, the SOFC stack module 1, and the main burner 6 in sequence; the anode side fan 5 is turned on, and the room temperature air enters the tail gas burner 7, the fuel preheater 3, and the exhaust pipe in sequence; ② In the first heating stage of the SOFC stack module 1, a certain amount of natural gas is introduced into the main burner 6 through the mass flow controller and ignited, and the high-temperature flue gas generated by the combustion enters the air preheater 2 to heat the air, and the control system adjusts the flow rate of the natural gas according to the temperature sensor arranged on the outlet pipe of the air preheater 2. amount, thereby controlling the temperature rise rate of the SOFC stack module 1; after the main burner 6 is ignited successfully, the dry mixed fuel is introduced into the carrier gas inlet of the hybrid steam generator 8, and the dry mixed fuel passes through the hybrid steam generator 8, the fuel preheater 3, the SOFC stack module 1, and the tail gas burner 7 in sequence. The mixed fuel is mixed with air in the tail gas burner 7 and ignited and burned. The flue gas generated by the combustion enters the fuel preheater 3 to heat the mixed fuel. The control system adjusts the speed of the anode side fan 5 according to the temperature sensor arranged on the outlet pipe of the fuel preheater 3, adjusts the air volume and the flue gas temperature in the tail gas burner 7, so that the temperature of the mixed fuel and air entering the SOFC stack module 1 are consistent. ; In addition, the control system adjusts the opening of the anode tail gas back pressure valve 10 to ensure that the anode tail gas pressure of the SOFC stack module 1 is always appropriately higher than the cathode tail gas pressure; ③ In the second heating stage of the SOFC stack module 1, when the temperature of the SOFC stack module 1 and the temperature of the pipeline through which the mixed fuel passes reach above 120°C and the SOFC stack module 1 needs to be fed with water vapor, turn on the deionized water pump 9, turn on the electric heating module of the hybrid steam generator 8, turn on the heating tape on the outlet pipeline of the hybrid evaporator, and add appropriate water vapor to the mixed fuel. The control system adjusts the natural gas flow, the speed of the anode side fan 5, the speed of the mixed steam generator 8 and the speed of the mixed steam generator 8 according to the outlet air temperature of the air preheater 2 and the temperature of the mixed fuel at the outlet of the fuel preheater 3. The electric heating power of the generator is controlled to ensure that the SOFC stack module 1 is heated steadily at the set temperature rise rate; ④ During the power generation phase of the SOFC stack module 1, the control system adjusts the natural gas flow rate, the mixed fuel flow rate, the deionized water flow rate, the speed of the anode side fan 5, the electric heating power of the hybrid evaporator, etc. according to parameters such as the temperature of the inlet and outlet of the SOFC stack module 1, the power generation power, and the power change rate, so as to achieve the target power generation state; ⑤ During the cooling phase of the SOFC stack module 1, the control strategy of the system is similar to that of the heating phase. When the temperature of the SOFC stack module 1 and the temperature of the pipeline through which the mixed fuel passes drop to 120°C, or when the SOFC stack module 1 no longer needs water vapor, the deionized water pump 9 is turned off;⑥ When the SOFC stack module 1 is in a high-temperature state and the system is suddenly stopped, first open the second stop valve 12 on the air pipe between the anode side fan 5 and the main burner 6, close the first stop valve 11 on the air pipe between the anode side fan 5 and the anode tail gas burner 7, open the anode circulation fan, and pass natural gas to the main burner 6. When the main burner 6 reaches the target temperature, restart the main fan 4 to provide a small flow of air. The small flow of air quickly reaches the appropriate temperature after being heated by the air preheater 2 and enters the SOFC stack module 1. Then gradually increase the air flow of the main fan 4, increase the natural gas flow, and gradually reduce the air flow of the anode side fan 5. In this process, the high-temperature air temperature at the outlet of the air preheater 2 is always kept at SOFC. C. The temperature of the stack module 1. When the air flow of the main fan 4 reaches the target value and the air flow of the anode-side fan 5 gradually decreases to 0, close the second stop valve 12 on the air duct between the anode-side fan 5 and the main burner 6, open the first stop valve 11 on the air duct between the anode-side fan 5 and the anode tail gas burner 7, then reopen the anode-side fan 5, turn on the electric heating module and heating tape of the hybrid steam generator 8, introduce the mixed fuel into the hybrid steam generator 8, ignite the anode tail gas burner 7, adjust the air flow and mixed fuel flow of the anode-side fan 5, and introduce deionized water after the fuel temperature at the outlet of the burner and fuel preheater 3 reaches the target temperature. This completes the restart of the SOFC stack module 1 after the system is shut down in a high-temperature state.

[0030] Compared with the prior art, the advantages of the present invention are: the system does not adopt a conventional air electric heating device, but is equipped with a main burner 6 and an anode tail gas burner 7, which recovers the high-temperature cathode tail gas and anode tail gas at the outlet of the SOFC stack, and cooperates with the air preheater 2 and the fuel preheater 3 to provide high-temperature air and fuel for the SOFC stack module 1, effectively reducing the power consumption of the SOFC stack module 1 test system, and also effectively avoiding the cold shock to the SOFC stack module 1 when the system is restarted after an emergency shutdown; the use of the anode tail gas back pressure valve 10 reduces the safety risk caused by internal leakage of the SOFC stack module 1; the hybrid steam generator 8 reduces the complexity of the system and improves the uniformity of fuel mixing; the system has low power consumption, is stable and reliable, and has strong operability.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solid oxide fuel cell stack module test system, comprising a control system for controlling the entire system and an air preheater, a main air blower for supplying air, a fuel preheater, a hybrid steam generator for supplying mixed fuel, and a deionized water pump for supplying deionized water, which are sequentially connected to the SOFC stack module; the air preheater is also connected to a main burner, which is respectively connected to natural gas, an anode side blower for supplying air, and a SOFC stack module for supplying cathode tail gas; the fuel preheater is also connected to an anode tail gas burner, which is respectively connected to the anode side blower and the SOFC stack module for supplying cathode tail gas; the air preheater and the fuel preheater are respectively connected to a smoke exhaust duct; the main burner uses pipeline natural gas or bottled compressed natural gas as fuel, and the high-temperature cathode at the outlet of the SOFC stack module is connected to the fuel preheater. The tail gas is a combustion aid, and the high-temperature flue gas generated by the main burner enters the air preheater to heat the room temperature air on the cold side of the air preheater to the target temperature. The heated air enters the cathode inlet of the SOFC stack module to heat and cool the SOFC stack module or provide the SOFC stack module with an oxidant for power generation; the anode tail gas burner uses the high-temperature anode tail gas at the outlet of the SOFC stack module as fuel and the air provided by the anode side fan as a combustion aid. The high-temperature flue gas generated by the anode tail gas burner enters the fuel preheater to heat the mixed fuel at the outlet of the mixed steam generator to the target temperature, and the heated mixed fuel enters the anode inlet of the SOFC stack module for power generation of the SOFC stack module. The flue gas at the outlet of the fuel preheater and the flue gas at the outlet of the air preheater are mixed and discharged from the system together.

2. The solid oxide fuel cell stack module testing system according to claim 1, characterized in that: The cold-side air outlet pipe of the air preheater is provided with a temperature sensor for monitoring the temperature of the heated air; the fuel inlet pipe of the main burner is provided with a mass flow controller for adjusting the natural gas flow at the inlet of the main burner, thereby adjusting the air temperature at the air preheater outlet.

3. The solid oxide fuel cell stack module testing system according to claim 1, characterized in that: A first stop valve is provided on the air duct between the anode side blower and the main burner, and the first stop valve is usually in a closed state; a second stop valve is provided on the air duct between the anode side blower and the anode tail gas burner, and the second stop valve is usually in an open state; To restart the SOFC stack module after an emergency shutdown under high-temperature conditions, it is necessary to open the first stop valve on the air duct between the anode side fan and the main burner, close the second stop valve on the air duct between the anode side fan and the anode tail gas burner, then open the anode side fan and supply natural gas to the main burner. When the main burner reaches the target temperature, the main fan is opened again and high-temperature air of appropriate temperature is supplied to the SOFC stack module through heat exchange in the air preheater.

4. The solid oxide fuel cell stack module testing system according to claim 1, characterized in that: The hybrid steam generator comprises a carrier gas inlet, a deionized water inlet, a mixed gas outlet, and a foam metal electric heating unit. The mixed fuel dried at room temperature enters the hybrid steam generator through the carrier gas inlet. When a certain amount of water vapor needs to be added to the dry mixed fuel, the deionized water enters the hybrid steam generator and is rapidly vaporized in the foam metal heating unit to generate steam. The steam is fully mixed with the mixed fuel in the foam metal and further heated to a target temperature, thereby avoiding uneven mixing of the room temperature mixed fuel and water vapor and partial condensation. The mixed fuel is finally discharged from the mixed gas outlet. A heating tape is arranged on the mixed gas outlet pipe to prevent condensation of water vapor. When the dry mixed fuel does not need to be added with water vapor and only needs to be heated, the deionized water pump is turned off, the mixed fuel directly enters the foam metal heating unit, is heated to the target temperature, and is then discharged from the mixed gas outlet.

5. The solid oxide fuel cell stack module testing system according to claim 1, characterized in that: The fuel preheater fuel side outlet pipe is provided with a temperature sensor for monitoring the temperature of the mixed fuel after being heated; the control system adjusts the air flow entering the anode tail gas burner and the temperature of the flue gas after combustion by adjusting the speed of the anode side fan, thereby adjusting the temperature of the mixed fuel at the fuel preheater outlet.

6. The solid oxide fuel cell stack module testing system according to claim 1, characterized in that: Pressure sensors are provided on the cathode tail gas outlet pipe and the anode tail gas outlet pipe of the SOFC stack module near the outlet of the SOFC stack module. In addition, an anode tail gas back pressure valve is provided downstream of the pressure sensor on the anode tail gas outlet pipe. The control system automatically adjusts the opening of the anode tail gas back pressure valve according to the pressures of the cathode tail gas and the anode tail gas so that the anode tail gas pressure is always appropriately higher than the cathode tail gas pressure, thereby effectively reducing the safety risk caused by internal leakage of the SOFC stack module.

7. The operating method of the solid oxide fuel cell stack module test system according to any one of claims 1 to 6, comprising the following steps: ① Before the SOFC stack module is heated up, the main fan is turned on, and room temperature air enters the air heat exchanger, the SOFC stack module, and the main burner in sequence; the anode side fan is turned on, and room temperature air enters the anode tail gas burner, the fuel preheater, and the exhaust pipe in sequence; ② In the first heating stage of the SOFC stack module, a certain amount of natural gas is introduced into the main burner through the mass flow controller and ignited, and the high-temperature flue gas generated by the combustion enters the air preheater to heat the air, and the control system adjusts the flow rate of the natural gas according to the temperature sensor arranged on the outlet pipe of the air preheater. The amount of air is collected by the anode and the exhaust gas is then ignited, thereby controlling the temperature rise rate of the SOFC stack module; after the main burner is successfully ignited, a dry mixed fuel is introduced into the carrier gas inlet of the hybrid steam generator, and the dry mixed fuel passes through the hybrid steam generator, the fuel preheater, the SOFC stack module, and the anode tail gas burner in sequence. The mixed fuel is mixed with air in the anode tail gas burner and ignited and burned. The flue gas generated by the combustion enters the fuel preheater to heat the mixed fuel. The control system adjusts the speed of the anode side fan, the air amount in the anode tail gas burner, and the flue gas temperature according to the temperature sensor arranged on the outlet pipe of the fuel preheater, so as to keep the temperature of the mixed fuel and air entering the SOFC stack module consistent; In addition, the control system adjusts the opening of the anode tail gas back pressure valve to ensure that the anode tail gas pressure of the SOFC stack module is always appropriately higher than the cathode tail gas pressure; ③ In the second stage of SOFC stack module heating, when the temperature of the SOFC stack module and the temperature of the pipeline through which the mixed fuel passes reach above 120°C and the SOFC stack module needs to be fed with water vapor, turn on the deionized water pump, turn on the hybrid steam generator foam metal electric heating unit, turn on the heating tape on the hybrid evaporator outlet pipeline, and add appropriate water vapor to the mixed fuel. The control system adjusts the natural gas flow, the anode side fan speed, the hybrid evaporator according to the air temperature at the air preheater outlet and the temperature of the mixed fuel at the fuel preheater outlet. The electric heating power of the foam metal electric heating unit ensures that the SOFC stack module is heated steadily at the set temperature rise rate; ④ During the power generation phase of the SOFC stack module, the control system adjusts the natural gas flow rate, mixed fuel flow rate, deionized water flow rate, anode side fan speed, and the electric heating power of the hybrid evaporator foam metal electric heating unit according to the parameters of the SOFC stack module inlet and outlet temperature, power generation power, and power change rate, so as to achieve the target power generation state; ⑤ During the SOFC stack module cooling phase, when the temperature of the SOFC stack module and the temperature of the pipeline through which the mixed fuel passes drop to 120°C, or when the SOFC stack module no longer needs water vapor, the deionized water pump is turned off;⑥ When the SOFC stack module is in a high-temperature state and the system is suddenly stopped, restart it. First, open the first stop valve on the air duct between the anode side fan and the main burner, close the second stop valve on the air duct between the anode side fan and the anode tail gas burner, open the anode circulation fan, and introduce natural gas to the main burner. When the main burner reaches the target temperature, restart the main fan to provide a small flow of air. The small flow of air is heated by the air preheater and quickly reaches the appropriate temperature and enters the SOFC stack module. Then gradually increase the air flow of the main fan, increase the natural gas flow, and gradually reduce the air flow of the anode side fan. In this process, always keep the high-temperature air temperature of the air preheater outlet at the SOFC stack module. The temperature of the group; when the air flow of the main fan reaches the target value and the air flow of the anode side fan gradually decreases to 0, close the first stop valve on the air duct between the anode side fan and the main burner, open the second stop valve on the air duct between the anode side fan and the anode tail gas burner, then reopen the anode side fan, turn on the hybrid steam generator foam metal electric heating unit and heating tape, introduce mixed fuel into the hybrid steam generator, ignite the anode tail gas burner, adjust the air flow and mixed fuel flow of the anode side fan, and introduce deionized water after the fuel temperature at the outlet of the anode tail gas burner and fuel preheater reaches the target temperature; complete the restart of the SOFC stack module after the system is suddenly stopped in a high-temperature state.

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