Dual-preheating SOFC / SOEC hybrid test system and method

Abstract

The invention belongs to the technical field of cell testing, and particularly discloses a dual-preheating SOFC / SOEC hybrid testing system and method, the system comprises an air heating pipeline and a fuel gas heating pipeline, the air heating pipeline is connected with the cathode side of an SOFC / SOEC electric pile, and the fuel gas heating pipeline is connected with the anode side of the SOFC / SOEC electric pile; the cathode side of the SOFC / SOEC electric pile is also connected with the inlet of the combustor; an outlet of the combustor is connected to the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline, so that tail gas of the combustor can preheat air and fuel gas participating in the reaction next time and then is discharged from the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline. The SOFC testing system and the SOEC testing system are integrated, meanwhile, tail gas waste heat can be efficiently recycled, air and fuel gas are preheated through the tail gas waste heat, and the energy consumption of the testing system is further reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of energy storage device testing, and more specifically, to a double preheating SOFC / SOEC hybrid testing system and method. Background Art

[0002] Solid oxide fuel cells (SOFC) and solid oxide electrolyzers (SOEC) are two important energy conversion and storage technologies that have great potential in achieving efficient energy utilization and promoting green and low-carbon development. SOFC is a power generation device that directly converts the chemical energy of fuel into electrical energy in an efficient, low-carbon and environmentally friendly manner at medium and high temperatures. It is currently one of the most efficient new energy technology routes for power generation in the world. SOEC is a relatively advanced and forward-looking hydrogen production technology that can effectively utilize waste heat and stably provide low-carbon electricity. It has the advantages of high flexibility, long life, low cost, and the use of industrial waste heat.

[0003] There is only a SOFC test system in the prior art, and there is no more mature SOFC / SOEC hybrid integrated test system. For example, Chinese patent document CN117571352A discloses a performance test system and test analysis method for a SOFC air preheater. The performance test system includes a burner, an air preheater, an air heater, an air supply pipeline, a methane supply pipeline and a water vapor supply pipeline for supplying methane and water vapor to the burner respectively. The normal temperature air provided by the air supply pipeline flows through the cold side of the air preheater and the air heater in turn, and enters the burner for combustion after being heated to a certain temperature. The combustion product gas generated by the combustion enters the hot side of the air heat exchanger as a hot side fluid, and exchanges heat with the normal temperature air on the cold side. It is used to evaluate the heat exchange performance of the SOFC air preheater, and at the same time provides a correction method for the measured temperature to improve the accuracy of the test results. However, the system cannot realize the SOEC mode test, and there are problems such as high system heat loss, low overall energy efficiency, and poor total energy utilization efficiency. Therefore, it is urgent to design a high-efficiency SOFC / SOEC integrated test system. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of the present application is to provide a double preheating SOFC / SOEC hybrid testing system and method, aiming to solve the problem of high energy consumption of the testing system.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present application, a double-preheating SOFC / SOEC hybrid test system is provided, characterized in that it includes: an air heating pipeline and a fuel gas heating pipeline, the air heating pipeline is connected to the cathode side of the SOFC / SOEC stack, and the fuel gas heating pipeline is connected to the anode side of the SOFC / SOEC stack; the cathode side of the SOFC / SOEC stack is also connected to the inlet of the burner; the outlet of the burner is connected to the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline, so that the exhaust gas of the burner can preheat the air and fuel gas participating in the next reaction and then be discharged from the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline.

[0006] The present application reasonably arranges the connection relationship between the air heating pipeline, the fuel gas heating pipeline and the SOFC / SOEC stack, and passes the exhaust gas of the burner into the air heating pipeline and / or the fuel gas heating pipeline, so that the remaining heat is used to preheat the air and the fuel gas, thereby reducing the electric energy required for any mode test, thereby achieving the purpose of reducing the energy consumption of the test system.

[0007] The outlet of the first heater is connected to the cathode side of the SOFC / SOEC stack, and air enters from the inlet of the first heat exchanger and passes into the SOFC / SOEC stack through the first heater.

[0008] Furthermore, the fuel gas heating pipeline includes a third heat exchanger and a second heater connected in sequence, the outlet end of the second heater is connected to the anode side of the SOFC / SOEC stack, and the fuel gas enters the third heat exchanger and passes through the second heater into the anode side of the SOFC / SOEC stack.

[0009] Furthermore, the fuel gas heating pipeline also includes a second heat exchanger, a first three-way valve and a second three-way valve connected in sequence, and the second three-way valve is connected to the third heat exchanger; in the SOEC test mode, the fuel gas also enters the third heat exchanger via the second heat exchanger, the first three-way valve and the second three-way valve.

[0010] Furthermore, the first three-way valve is also connected to a water vapor supply device, and the water vapor supply device is used to provide water vapor for the fuel gas heating pipeline in the SOEC test mode.

[0011] Furthermore, a third three-way valve is provided on the pipeline between the SOFC / SOEC stack and the burner, and the third three-way valve is connected to the second heat exchanger, and the second heat exchanger is also connected to the gas storage tank; in the SOEC test mode, the third three-way valve is used to pass a part of the fuel gas generated by the SOFC / SOEC stack into the second heat exchanger and then into the gas storage tank for storage, and pass the remaining fuel gas into the burner for continued combustion.

[0012] Furthermore, the water vapor supply device includes a water storage tank and an evaporator connected in sequence, and the evaporator is connected to the second heat exchanger.

[0013] Furthermore, the anode end of the SOFC / SOEC stack is also connected to a power supply, and the power supply is used to supply power to the SOFC / SOEC stack.

[0014] According to another aspect of the present application, a SOFC / SOEC hybrid testing method for double preheating using a hybrid testing system as described in any of the above items is also disclosed, characterized in that the method includes the following steps: allowing air to enter the cathode side of the SOFC / SOEC stack via an air heating pipeline, and allowing fuel gas to enter the anode side of the SOFC / SOEC stack via a fuel gas heating pipeline; passing the remaining air after the reaction of the fuel gas and air in the SOFC / SOEC stack into the burner for reaction; and then allowing the exhaust gas after the burner reaction to enter the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline, so that the exhaust gas of the burner can preheat the air and fuel gas participating in the next reaction and then be discharged from the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline.

[0015] Furthermore, in the SOEC test mode, the following steps are also included:

[0016] The fuel gas is also allowed to enter the third heat exchanger through the second heat exchanger, the first three-way valve and the second three-way valve; the water vapor supply device is allowed to pass water vapor into the first three-way valve for mixing with the fuel gas; the third three-way valve is opened, a portion of the fuel gas generated by the SOFC / SOEC stack is passed into the second heat exchanger and then input into the gas storage tank for storage, and the remaining fuel gas is passed into the burner for continued combustion.

[0017] In general, the above technical solutions conceived by this application have the following technical advantages compared with the prior art:

[0018] 1. In the SOFC / SOEC hybrid test system provided in the present application, the exhaust gas in the burner is introduced into the air heating pipeline and / or the fuel gas heating pipeline, so that the waste heat of the exhaust gas is used to preheat the air and the fuel gas. At the same time, the air heating pipeline and the fuel gas heating pipeline themselves have a heating function, thereby realizing double heating, satisfying the preheating requirements of the air and the fuel gas with very little electric energy, which can reduce the electric energy required during the test, thereby achieving the purpose of reducing the energy consumption of the test system.

[0019] 2. The SOFC / SOEC hybrid test system provided in the present application includes two test systems, which can realize flexible switching of different test modes to adapt to different test requirements and working conditions; in the SOEC test mode, there is also a fuel gas that enters the third heat exchanger through the second heat exchanger, the first three-way valve and the second three-way valve, and at the same time, water vapor is mixed into the fuel gas through the water vapor supply device. A part of the fuel gas generated by the SOFC / SOEC stack can enter the gas storage tank for storage after passing through the second heat exchanger, and the remaining fuel gas is passed into the burner to continue burning to generate exhaust gas to participate in the next fuel gas preheating, thereby optimizing thermal management and helping to improve the overall thermal efficiency and stability of the system; the above-mentioned fuel gas is turned off when conducting SOFC testing.

[0020] 3. The mixed test provided in the present application is easy to operate, and the two test methods can be switched at will. By reasonably distributing and processing the fuel gas, the safety risks caused by fuel accumulation can be reduced. Both test methods can achieve full combustion of the fuel gas and secondary utilization of the exhaust gas heat energy. Therefore, by passing the exhaust gas after combustion in the burner into the heat exchanger to preheat the air and hydrogen, the overall efficiency of the test bench can be further improved and the power consumption required for preheating the gas can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of a double preheated SOFC / SOEC hybrid test system provided in Example 1 of the present application;

[0022] Figure 2 This is a schematic diagram of the structure of a double preheated SOFC / SOEC hybrid test system provided in Example 2 of the present application;

[0023] Figure 3 This is a schematic diagram of the structure of the double preheating SOFC / SOEC hybrid test system provided in Example 31 of the present application.

[0024] In all the drawings, the same figure numbers are used to represent the same elements or structures, wherein: 1-first heat exchanger, 2-first heater, 3-SOFC / SOEC stack, 4-burner, 5-second heat exchanger, 6-third heat exchanger, 7-second heater, 8-first three-way valve, 9-second three-way valve, 10-third three-way valve, 11-gas storage tank, 12-water storage tank, 13-evaporator, 14-power supply, 15-load. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] Example 1

[0027] The present embodiment provides a double preheating SOFC / SOEC hybrid test system, including two working states of SOFC test mode and SOEC test mode. The integrated system includes an air heating pipeline and a fuel gas heating pipeline. The air heating pipeline includes a first heat exchanger 1 and a first heater 2 connected in sequence. The outlet of the first heater 2 is connected to the cathode side of the SOFC / SOEC stack 3. Air enters from the inlet of the first heat exchanger 1 and passes into the SOFC / SOEC stack 3 through the first heater 2. The fuel gas heating pipeline includes a third heat exchanger 6 and a second heater 7 connected in sequence. The outlet end of the second heater 7 is connected to the anode side of the SOFC / SOEC stack 3. After the fuel gas enters the third heat exchanger 6, it passes into the anode side of the SOFC / SOEC stack 3 through the second heater 7. In this embodiment, the anode end of the SOFC / SOEC stack 3 is also connected to a power supply 14, which is used to supply power to the SOFC / SOEC stack 3. The cathode end of the SOFC / SOEC stack 3 is also connected to an external load 15. By rationally designing each gas path, high integration of SOFC test mode and SOEC test mode and efficient utilization of tail gas can be achieved.

[0028] During the test, air is first allowed to enter the cathode side of the SOFC / SOEC stack 3 through the air heating pipeline, and the fuel gas is allowed to enter the anode side of the SOFC / SOEC stack 3 through the fuel gas heating pipeline; the remaining air after the reaction of the fuel gas and air in the SOFC / SOEC stack 3 is passed into the burner 4 for reaction; and the exhaust gas after the reaction of the burner 4 is allowed to enter the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline, so that the exhaust gas of the burner 4 can preheat the air and fuel gas participating in the next reaction and then be discharged from the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline.

[0029] The cathode side of the aforementioned SOFC / SOEC stack 3 is also connected to the inlet of the burner 4; the outlet of the burner 4 is respectively connected to the first heat exchanger 1 of the air heating pipeline and the third heat exchanger 6 of the fuel gas heating pipeline, so that the exhaust gas of the burner 4 can preheat the air and fuel gas participating in the next reaction and then be discharged from the air inlet end of the air heating pipeline and the air inlet end of the fuel gas heating pipeline.

[0030] The aforementioned first heat exchanger 1 is composed of a series of compactly arranged pipes or plates to maximize heat exchange efficiency. It is used to preheat the air entering the system and improve energy utilization efficiency by recovering the exhaust heat in the system burner.

[0031] The aforementioned first heater 2 adopts electric heating or thermal fluid heating to ensure that the air reaches a suitable temperature before entering the stack, and is used to further heat the air preheated by the first heat exchanger to ensure that the air has a sufficient temperature when entering the cathode side of the SOFC / SOEC stack, so as to optimize the operating efficiency of the stack.

[0032] The aforementioned third heat exchanger 6 is responsible for preheating the fuel gas and at the same time improving the energy utilization efficiency by recovering the exhaust gas heat in the system burner.

[0033] The aforementioned second heater 7 is used to heat the fuel gas specifically, and the heating method is the same as or different from that of the first heater 2.

[0034] In the SOEC mode, the fuel gas heating pipeline also includes a second heat exchanger 5, a first three-way valve 8 and a second three-way valve 9 connected in sequence, and the second three-way valve 9 is connected to the third heat exchanger 6; in the SOEC test mode, the fuel gas also enters the third heat exchanger 6 via the second heat exchanger 5, the first three-way valve 8 and the second three-way valve 9. Specifically, in the SOEC test mode, the optimized design of the fuel gas heating pipeline significantly improves the efficiency and flexibility of the system. The second heat exchanger 5, as the starting point of the pipeline, has the main function of preheating the fuel gas and recovering the heat energy of the burner exhaust gas to lay the foundation for the subsequent heating process. By connecting the first three-way valve 8 and the second three-way valve 9 between the second heat exchanger 5 and the third heat exchanger 6, more control possibilities are provided for the fuel gas heating pipeline. Each three-way valve can adjust the flow direction and flow rate of the fuel gas to adapt to different working conditions and requirements.

[0035] The aforementioned second three-way valve 9 is connected to the third heat exchanger 6, so that the fuel gas can be introduced into the SOFC / SOEC stack 3 in both test modes, and in the SOEC test mode, this design allows the fuel gas to enter the third heat exchanger 6 for further heating using the waste heat of the burner exhaust gas after being pre-treated by the second heat exchanger 5 and the first three-way valve 8, thereby ensuring that the fuel gas can fully utilize the waste heat of the exhaust gas to achieve the ideal temperature condition before entering the anode side of the SOFC / SOEC stack 3. This fine temperature and gas flow control not only improves the thermal efficiency of the entire test system, but also enhances the adaptability and reliability of the test system. Through this design, the performance of the SOFC / SOEC stack 3 can be accurately evaluated and optimized under different test and operating conditions.

[0036] In this embodiment, the first three-way valve 8 is also connected to a water vapor supply device, which is used to provide water vapor for the fuel gas heating pipeline in the SOEC test mode. Specifically, the water vapor supply device includes a water storage tank 12 and an evaporator 13 connected in sequence, and the evaporator 13 is connected to the second heat exchanger 5. The evaporator 13 evaporates the water provided by the water storage tank 12 into water vapor and then inputs it into the second heat exchanger 5.

[0037] A third three-way valve 10 is also provided on the pipeline between the SOFC / SOEC stack 3 and the burner 4. The three-way valve is used to adjust the flow direction of the fuel gas. The third three-way valve 10 is connected to the second heat exchanger 5, and the second heat exchanger 5 is also connected to the gas storage tank 11. In the SOEC test mode, when the third three-way valve 10 is opened, a part of the fuel gas generated by the SOFC / SOEC stack 3 is passed into the second heat exchanger 5 for preheating, and then the preheated fuel gas is input into the gas storage tank 11 for storage, and the remaining fuel gas is passed into the burner 4 for continued combustion.

[0038] The SOFC / SOEC hybrid test method is performed using the double preheating SOFC / SOEC hybrid test system provided in this embodiment, which mainly includes two test modes, the SOFC test mode and the SOEC test mode. Figure 1 As shown, the solid line represents the flow path in SOFC mode, and the dotted line represents the flow path in SOEC mode:

[0039] The common points of the two modes are: air enters the cathode side of the SOFC / SOEC stack 3 through the first heat exchanger 1 and the first heater 2, and the fuel gas enters the anode side of the SOFC / SOEC stack 3 through the second three-way valve 9, the third heat exchanger 6, and the second heater 7; the fuel gas and air react in the SOFC / SOEC stack 3, and the remaining air after the reaction is passed into the burner 4 to continue the reaction; then the exhaust gas discharged from the burner 4 enters the first heat exchanger 1 of the air heating pipeline and the third heat exchanger 6 of the fuel gas heating pipeline, so that the exhaust gas of the burner 4 can preheat the air and fuel gas participating in the next reaction and then be discharged from the first heat exchanger 1 and the third heat exchanger 6.

[0040] The differences between the two modes are:

[0041] In the SOFC test mode, the outlet of the SOFC anode side contains residual fuel gas, and this part of the fuel gas enters the burner 4 through the third three-way valve 10 .

[0042] In the SOEC test mode, in addition to entering the third heat exchanger 6 from the second three-way valve 9, the fuel gas also enters the third heat exchanger 6 via the second heat exchanger 5, the first three-way valve 8 and the second three-way valve 9, that is, it includes two gas paths; at the same time, water vapor is introduced into the first three-way valve 8 through the water storage tank 12 and the evaporator 13 to mix with the fuel gas; the three ways of the third three-way valve 10 are fully opened, and a part of the fuel gas generated by the SOFC / SOEC stack 3 is introduced into the second heat exchanger 5 and then input into the gas storage tank 11 for storage, and the remaining fuel gas is introduced into the burner 4 for continued combustion.

[0043] Example 2

[0044] This embodiment provides a double preheating SOFC / SOEC hybrid test system, such as Figure 2 As shown, the difference from Example 1 is that the outlet of the burner 4 is connected to one of the inlets of the first heat exchanger 1, and one outlet of the first heat exchanger is connected to an inlet of the third heat exchanger 6, so that the exhaust gas can preheat the air in the first heat exchanger and exchange heat with the fuel gas in the third heat exchanger 6 in turn, and the exhaust gas after heat exchange is discharged from the third heat exchanger 6 to the external environment.

[0045] Example 3

[0046] This embodiment provides a double preheating SOFC / SOEC hybrid test system, such as Figure 3 As shown, the difference from Example 1 and Example 2 is that the outlet of the burner 4 is connected to one of the inlets of the third heat exchanger 6, and one outlet of the third heat exchanger 6 is connected to an inlet of the first heat exchanger 1, so that the exhaust gas can preheat the fuel gas in the third heat exchanger 6 and exchange heat with the air in the first heat exchanger 1 in turn, and the exhaust gas after heat exchange is discharged from the first heat exchanger 1 to the external environment where the material gas is preheated and then discharged from the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline.

[0047] In general, the dual preheating SOFC / SOEC hybrid test system provided in the present application can further reduce the test power consumption in the SOFC mode and the SOEC mode while ensuring the preheating temperature of air and fuel gas.

[0048] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations or constituent elements, and do not limit one or more additional functions, operations and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components or combinations thereof.

[0049] It should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0051] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0052] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A double preheating SOFC / SOEC hybrid test system, characterized in that: include: An air heating pipeline and a fuel gas heating pipeline, wherein the air heating pipeline is connected to the cathode side of the SOFC / SOEC stack (3), and the fuel gas heating pipeline is connected to the anode side of the SOFC / SOEC stack (3); the cathode side of the SOFC / SOEC stack (3) is also connected to the inlet of a burner (4); the outlet of the burner (4) is connected to the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline, so that the exhaust gas of the burner (4) can preheat the air and fuel gas participating in the next reaction and then be discharged from the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline.

2. A double preheating SOFC / SOEC hybrid test system as claimed in claim 1, characterized in that: The air heating pipeline comprises a first heat exchanger (1) and a first heater (2) which are connected in sequence, wherein the outlet of the first heater (2) is connected to the cathode side of the SOFC / SOEC stack (3), and air enters from the inlet of the first heat exchanger (1) and passes into the SOFC / SOEC stack (3) via the first heater (2).

3. A double preheating SOFC / SOEC hybrid test system according to claim 1, characterized in that: The fuel gas heating pipeline comprises a third heat exchanger (6) and a second heater (7) which are connected in sequence, wherein the outlet end of the second heater (7) is connected to the anode side of the SOFC / SOEC stack (3), and after the fuel gas enters the third heat exchanger (6), it passes through the second heater (7) and enters the anode side of the SOFC / SOEC stack (3).

4. A double preheating SOFC / SOEC hybrid test system as claimed in claim 3, characterized in that: The fuel gas heating pipeline further comprises a second heat exchanger (5), a first three-way valve (8) and a second three-way valve (9) which are connected in sequence, and the second three-way valve (9) is connected to the third heat exchanger (6); in the SOEC test mode, the fuel gas also enters the third heat exchanger (6) via the second heat exchanger (5), the first three-way valve (8) and the second three-way valve (9).

5. A double preheating SOFC / SOEC hybrid test system as claimed in claim 4, characterized in that: The first three-way valve (8) is also connected to a water vapor supply device, and the water vapor supply device is used to provide water vapor for the fuel gas heating pipeline in the SOEC test mode.

6. A double preheating SOFC / SOEC hybrid test system as claimed in claim 4, characterized in that: A third three-way valve (10) is also provided on the pipeline between the SOFC / SOEC stack (3) and the burner (4), and the third three-way valve (10) is connected to the second heat exchanger (5), and the second heat exchanger (5) is also connected to the gas storage tank (11); in the SOEC test mode, the third three-way valve (10) is used to pass a part of the fuel gas generated by the SOFC / SOEC stack (3) into the second heat exchanger (5) and then into the gas storage tank (11) for storage, and pass the remaining fuel gas into the burner (4) for continued combustion.

7. A double preheating SOFC / SOEC hybrid test system as claimed in claim 5, characterized in that: The water vapor supply device comprises a water storage tank (12) and an evaporator (13) which are connected in sequence, and the evaporator (13) is connected to the second heat exchanger (5).

8. A double preheating SOFC / SOEC hybrid test system according to claim 1, characterized in that: The anode end of the SOFC / SOEC stack (3) is also connected to a power source (14).

9. A SOFC / SOEC hybrid testing method using a hybrid testing system according to any one of claims 1 to 8 for double preheating, characterized in that: The method comprises the following steps: allowing air to enter the cathode side of a SOFC / SOEC stack (3) through an air heating pipeline, and allowing fuel gas to enter the anode side of a SOFC / SOEC stack (3) through a fuel gas heating pipeline; passing the remaining air after the fuel gas and air in the SOFC / SOEC stack (3) into a burner (4) for reaction; and allowing the tail gas of the burner (4) after the reaction to enter the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline, so that the tail gas of the burner (4) can preheat the air and fuel gas participating in the next reaction and then be discharged from the air inlet end of the air heating pipeline and / or the air inlet end of the fuel gas heating pipeline.

10. A double preheated SSOFC / SOEC hybrid test method according to claim 9, characterized in that: In the SOEC test mode, the following steps are also included: The fuel gas is also passed through the second heat exchanger (5), the first three-way valve (8) and the second three-way valve (9) into the third heat exchanger (6); the water vapor supply device is used to pass water vapor into the first three-way valve (8) to mix with the fuel gas; the third three-way valve (10) is opened, a portion of the fuel gas generated by the SOFC / SOEC stack (3) is passed into the second heat exchanger (5) and then input into the gas storage tank (11) for storage, and the remaining fuel gas is passed into the burner (4) for continued combustion.

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