An anhydrous fuel cell system with a post-reformer and a control method thereof
By adopting a post-reformer design in the SOFC system, combined with anode tail gas recirculation and filters, the problems of catalyst shedding from the reformer and pressure drop from the filter were solved, thus improving the reliability of the system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WEICHAI POWER CO LTD
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-29
AI Technical Summary
In existing SOFC systems, the reformer is located at the stack inlet, which leads to catalyst shedding and excessively high gas temperature, making it difficult to control filter pressure drop and affecting system reliability.
The design employs a post-reformer, which is installed in the anode tail gas path of the fuel cell stack and connected to the filter via an anode tail gas circulation pump. Combined with an adiabatic or heat-exchange reformer and a mass flow controller, this ensures that the reformer catalyst does not fall off, reduces the filter temperature, and maintains the filter pressure drop.
This effectively prevents catalyst shedding from the reformer, reduces filter temperature, and improves the reliability of the anhydrous fuel cell system.
Smart Images
Figure CN122117964A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of fuel cell design technology, and particularly relates to an anhydrous fuel cell system with a post-reformer and its control method. Background Technology
[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.
[0003] Solid-state fuel cells (SOFCs) are clean and efficient power generation devices that convert the chemical energy in fuel into electrical energy through electrochemical reactions. Their applications are very broad, covering power levels from hundreds of watts to megawatts. SOFCs can use gaseous hydrocarbon fuels (natural gas, propane, etc.) as their power generation fuel. Power is generated by reforming water vapor and gaseous hydrocarbon fuels into syngas, which is then fed into the SOFC stack.
[0004] In existing technologies, SOFC systems generally employ two configurations: external reforming and internal reforming. By configuring a reformer and a reforming water system, the fuel gas is partially reformed outside the stack to increase the hydrogen concentration at the stack inlet. However, in this design, the reformer is located at the stack inlet, resulting in limited space. This not only makes the stack prone to failure due to catalyst shedding from the reformer but also easily leads to problems such as excessively high fuel gas temperatures and difficulty in controlling filter pressure drop, thus limiting the reliability of the fuel cell system. Summary of the Invention
[0005] To overcome the shortcomings of the prior art, the present invention provides an anhydrous fuel cell system with a post-reformer and its control method. The post-reformer can maintain the filter pressure drop while avoiding catalyst shedding, thus enabling the anhydrous fuel cell system to have better reliability.
[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions: The first aspect of the present invention provides an anhydrous fuel cell system with a post-reformer.
[0007] A post-reformer anhydrous fuel cell system, comprising: Blower, fuel cell stack, burner and reformer; The blower is connected to the cathode inlet of the fuel cell stack via the first heat exchanger and the second heat exchanger in sequence, and the cathode outlet of the fuel cell stack is connected to the first inlet of the burner to form an air passage. The outlet of the burner is connected to the first heat exchanger to form an exhaust gas passage; The anode outlet of the fuel cell stack is connected to the reformer via a pipeline. The reformer passes through a filter and an anode exhaust gas circulation pump in sequence, and is connected to the second heat exchanger before returning to the anode inlet of the fuel cell stack, forming a gas flow path.
[0008] Furthermore, the anhydrous fuel cell system includes two adjustment methods: adiabatic adjustment and heat exchange adjustment. In the adiabatic adjustment method, the reformer is an adiabatic reformer; in the heat exchange adjustment method, the reformer is a heat exchange reformer.
[0009] Furthermore, the waterless fuel cell system also includes a first mass flow controller and a second mass flow controller.
[0010] Furthermore, in the adiabatic adjustment mode, the first mass flow controller is connected to the second inlet of the burner; the second mass flow controller is connected to the inlet of the adiabatic reformer, and the outlet of the adiabatic reformer is connected to a filter.
[0011] Furthermore, in the heat exchange adjustment mode, the first mass flow controller is connected to the second inlet of the burner; the anode outlet of the fuel cell stack and the second mass flow controller are respectively connected to the first inlet and the second inlet of the adiabatic reformer, and the first outlet and the second outlet of the second mass flow controller are respectively connected to the filter and the burner.
[0012] Furthermore, the anhydrous fuel cell system also includes a control module configured to perform the following operations: control the MFC fuel flow rate of the first mass flow controller and the second mass flow controller; and determine the exhaust gas composition and flow rate at the anode outlet of the fuel cell stack based on the output current of the fuel cell stack, the MFC fuel flow rate, and the fuel utilization rate.
[0013] Furthermore, the control module is also configured to determine the gas molar flow rate entering the reformer inlet based on the flow rate of the tail gas mixed with the MFC fuel at the anode outlet of the reformer stack; wherein the gas molar flow rate at the reformer inlet is determined by the reformer equilibrium temperature.
[0014] Furthermore, the control module is also configured to obtain the actual flow rate of the anode circulation pump based on the reformed fuel entering the anode circulation pump, according to the anode circulation pump speed, pressure difference before and after, and fuel composition, and combine it with the MFC fuel flow rate to obtain the AOG circulation flow rate and circulation rate.
[0015] A second aspect of the present invention provides a control method for an anhydrous fuel cell system with a post-reformer as described in the first aspect.
[0016] A control method, comprising: Obtain the output current of the fuel cell stack; Control the first and second mass flow controllers to set the MFC fuel flow rate; The composition and flow rate of the exhaust gas at the anode outlet of the fuel cell stack are determined based on the output current of the fuel cell stack, the MFC fuel flow rate, and the fuel utilization rate. The gas molar flow rate entering the reformer inlet is determined based on the flow rate of the tail gas mixed with the MFC fuel at the anode outlet of the reformer stack; wherein the gas molar flow rate at the reformer inlet is determined by the reformer equilibrium temperature. Based on the reformed fuel entering the anode circulation pump, the actual flow rate of the anode circulation pump is obtained according to the pump speed, pressure difference before and after, and fuel composition. Combined with the MFC fuel flow rate, the AOG circulation flow rate and circulation rate are obtained.
[0017] Furthermore, one control method also includes a filter status monitoring step, namely: real-time monitoring of the inlet and outlet pressure difference of the filter, and issuing a maintenance prompt signal when the inlet and outlet pressure difference exceeds a set threshold, so as to ensure the filtration effect and smooth flow of the waterless fuel cell system.
[0018] The above one or more technical solutions have the following beneficial effects: This invention connects the anode outlet of the fuel cell stack to a reformer via a pipeline. The reformer sequentially passes through a filter, an anode exhaust gas recirculation pump, and a second heat exchanger before returning to the anode inlet of the fuel cell stack. By employing this anode recirculation combined with external reforming, and by installing the reformer at the anode exhaust gas path of the fuel cell stack outlet, while simultaneously adding a filter, the risk of the reformer coating detaching and entering the fuel cell stack can be avoided. Furthermore, the filter operating temperature can be reduced, and the filter pressure drop can be maintained, resulting in better reliability for the anhydrous fuel cell system.
[0019] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0021] Figure 1 This is a structural diagram of the anhydrous fuel cell system with a post-adiabatic reformer in Embodiment 1 of the present invention.
[0022] Figure 2 This is a structural diagram of the anhydrous fuel cell system with a post-displacement heat reformer in Embodiment 1 of the present invention.
[0023] Figure 3 This is a flowchart for calculating the anode tail gas circulation flow rate in Embodiment 1 of the present invention.
[0024] In the diagram: 1. Blower; 2. Fuel cell stack; 3. Burner; 4. Reformer; 5. First heat exchanger; 6. Second heat exchanger; 7. Filter; 8. Anode exhaust gas recirculation pump; 9. Mass flow controller. Detailed Implementation
[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0026] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.
[0027] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.
[0028] Example 1 This embodiment discloses a waterless fuel cell system with a post-reformer.
[0029] like Figure 1 As shown, a post-reformer waterless fuel cell system includes: Blower 1, fuel cell stack 2, burner 3, and reformer 4; The blower 1 is connected to the cathode inlet of the fuel cell stack via the first heat exchanger 5 and the second heat exchanger 6 in sequence, and the cathode outlet of the fuel cell stack is connected to the first inlet of the burner 3 to form an air passage. The outlet of the burner 3 is connected to the first heat exchanger 5 to form an exhaust gas passage; The anode outlet of the fuel cell stack 2 is connected to the reformer 4 via a pipeline. The reformer 4 passes through the filter 7 and the anode tail gas circulation pump 8 in sequence, and is connected to the second heat exchanger 6 and returns to the anode inlet of the fuel cell stack 2, forming a gas passage.
[0030] Based on the above systematic design, this invention, through a post-reformer, can maintain the filter pressure drop while avoiding catalyst shedding from the reformer, thus enabling the anhydrous fuel cell system to have better reliability. To facilitate understanding of the technical solution of this invention, the specific implementation methods of this invention will be further explained and described below.
[0031] The present invention provides a high-efficiency fuel cell system with a post-reformer, which eliminates the reforming water system in the prior art in its overall architecture. It utilizes water from the anode tail gas to achieve system O:C assessment, and places the reformer at the anode tail gas outlet of the fuel cell stack. Simultaneously, the gas inlet is adjusted to the front end of the reformer, and the high temperature of the anode tail gas provides the necessary heat for the reforming reaction. A filter is added after the reformer to prevent the reformer coating from peeling off and entering the anode circulation pump. Furthermore, the reformer can use both adiabatic reforming and heat exchange reforming schemes. In addition, the high-efficiency fuel cell system with a post-reformer also includes two mass flow controllers 9, namely a first mass flow controller and a second mass flow controller.
[0032] like Figure 1 As shown, in the adiabatic adjustment mode, the reformer is an adiabatic reformer, that is, the first mass flow controller is connected to the second inlet of the burner; the second mass flow controller is connected to the inlet of the adiabatic reformer, and the outlet of the adiabatic reformer is connected to a filter.
[0033] like Figure 2 As shown, in the heat exchange adjustment mode, the first mass flow controller is connected to the second inlet of the burner; the anode outlet of the fuel cell stack and the second mass flow controller are connected to the first inlet and the second inlet of the adiabatic reformer, respectively; and the first outlet and the second outlet of the second mass flow controller are connected to the filter and the burner, respectively.
[0034] based on Figure 1 and Figure 2 The architecture shown comprises the anode circulation pump flow rate, which consists of the fresh fuel gas flow rate and the anode tail gas circulation flow rate. The fresh fuel gas flow rate is precisely controlled by a mass flow controller. The anode tail gas circulation flow rate depends on the rotational speed of the anode circulation pump and the composition of the anode tail gas entering the pump. The composition of the tail gas entering the pump primarily depends on the system's fuel utilization rate and the reforming rate of the reformer (determined by the reformer's equilibrium temperature). Furthermore, the anhydrous fuel cell system also includes a control module for performing processes such as calculating the system's circulation flow rate and circulation rate.
[0035] like Figure 3 As shown, the calculation process for the circulation flow rate and circulation rate of the waterless fuel cell system is as follows: Based on the stack output current, MFC fuel flow rate, and system fuel system rate, the composition and flow rate of the stack outlet anode tail gas are calculated as follows: ; ; in, This indicates the molar flow rate of fuel at the fuel cell stack outlet. This represents the molar difference in fuel flow rate at the fuel stack outlet. This indicates the molar flow rate of fuel at the fuel stack inlet; This indicates the fuel flow rate controlled by MFC. This represents the H2 production ratio during in-heap reforming. This represents the H2O consumption coefficient during in-pile reforming.
[0036] The tail gas from the fuel cell stack outlet anode is mixed with fresh gas controlled by the MFC and enters the reformer. The gas molar flow rate at the reformer inlet is: ; in, This indicates the fuel flow rate entering the reformer. Indicates the reformed water flow rate. This indicates the anode exhaust gas recirculation rate.
[0037] The molar flow rate of the reformer outlet gas is determined by the reformer equilibrium temperature. ; in, This indicates the reformer outlet fuel flow rate. This represents the equilibrium temperature coefficient at the reformer outlet.
[0038] After being reformed, the fuel enters the AOGR pump. The actual flow rate of the AOGR pump is obtained based on the AOGR pump speed, the pressure difference before and after the pump, and the fuel composition. Combined with the MFC fuel flow rate, the AOG circulation flow rate and circulation rate can be obtained.
[0039] Example 2 This embodiment discloses a control method for an anhydrous fuel cell system with a post-reformer as described in Embodiment 1.
[0040] A control method, comprising: Obtain the output current of the fuel cell stack; Control the first and second mass flow controllers to set the MFC fuel flow rate; The composition and flow rate of the exhaust gas at the anode outlet of the fuel cell stack are determined based on the output current of the fuel cell stack, the MFC fuel flow rate, and the fuel utilization rate. The gas molar flow rate entering the reformer inlet is determined based on the flow rate of the tail gas mixed with the MFC fuel at the anode outlet of the reformer stack; wherein the gas molar flow rate at the reformer inlet is determined by the reformer equilibrium temperature. Based on the reformed fuel entering the anode circulation pump, the actual flow rate of the anode circulation pump is obtained according to the pump speed, pressure difference before and after, and fuel composition. Combined with the MFC fuel flow rate, the AOG circulation flow rate and circulation rate are obtained.
[0041] Furthermore, one control method also includes a filter status monitoring step, namely: real-time monitoring of the inlet and outlet pressure difference of the filter, and issuing a maintenance prompt signal when the inlet and outlet pressure difference exceeds a set threshold, so as to ensure the filtration effect and smooth flow of the waterless fuel cell system.
[0042] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.
[0043] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.
Claims
1. A post-reformer anhydrous fuel cell system, characterized in that, include: Blower, fuel cell stack, burner and reformer; The blower is connected to the cathode inlet of the fuel cell stack via the first heat exchanger and the second heat exchanger in sequence, and the cathode outlet of the fuel cell stack is connected to the first inlet of the burner to form an air passage. The outlet of the burner is connected to the first heat exchanger to form an exhaust gas passage; The anode outlet of the fuel cell stack is connected to the reformer via a pipeline. The reformer passes through a filter and an anode exhaust gas circulation pump in sequence, and is connected to the second heat exchanger before returning to the anode inlet of the fuel cell stack, forming a gas flow path.
2. The anhydrous fuel cell system with a post-reformer as described in claim 1, characterized in that, The waterless fuel cell system includes two adjustment methods: adiabatic adjustment and heat exchange adjustment. In the adiabatic adjustment method, the reformer is an adiabatic reformer; in the heat exchange adjustment method, the reformer is a heat exchange reformer.
3. The anhydrous fuel cell system with a post-reformer as described in claim 2, characterized in that, The waterless fuel cell system also includes a first mass flow controller and a second mass flow controller.
4. The anhydrous fuel cell system with a post-reformer as described in claim 3, characterized in that, In the adiabatic adjustment mode, the first mass flow controller is connected to the second inlet of the burner; the second mass flow controller is connected to the inlet of the adiabatic reformer, and the outlet of the adiabatic reformer is connected to a filter.
5. The anhydrous fuel cell system with a post-reformer as described in claim 3, characterized in that, In the heat exchange adjustment mode, the first mass flow controller is connected to the second inlet of the burner; the anode outlet of the fuel cell stack and the second mass flow controller are respectively connected to the first inlet and the second inlet of the adiabatic reformer, and the first outlet and the second outlet of the second mass flow controller are respectively connected to the filter and the burner.
6. The anhydrous fuel cell system with a post-reformer as described in claim 1, characterized in that, The anhydrous fuel cell system further includes a control module configured to perform the following operations: control the MFC fuel flow rate of a first mass flow controller and a second mass flow controller; and determine the exhaust gas composition and flow rate at the anode outlet of the fuel cell stack based on the output current of the fuel cell stack, the MFC fuel flow rate, and the fuel utilization rate.
7. The anhydrous fuel cell system with a post-reformer as described in claim 6, characterized in that, The control module is also configured to determine the gas molar flow rate entering the reformer inlet based on the flow rates of the tail gas mixed with the MFC fuel at the anode outlet of the reformer stack; wherein the gas molar flow rate at the reformer inlet is determined by the reformer equilibrium temperature.
8. The anhydrous fuel cell system with a post-reformer as described in claim 6, characterized in that, The control module is also configured to obtain the actual flow rate of the anode circulation pump based on the reformed fuel entering the anode circulation pump, according to the anode circulation pump speed, pressure difference before and after, and fuel composition, and to obtain the AOG circulation flow rate and circulation rate by combining the MFC fuel flow rate.
9. A control method for an anhydrous fuel cell system as described in any one of claims 1-8, characterized in that, include: Obtain the output current of the fuel cell stack; Control the first and second mass flow controllers to set the MFC fuel flow rate; The composition and flow rate of the exhaust gas at the anode outlet of the fuel cell stack are determined based on the output current of the fuel cell stack, the MFC fuel flow rate, and the fuel utilization rate. The gas molar flow rate entering the reformer inlet is determined based on the flow rate of the tail gas mixed with the MFC fuel at the anode outlet of the reformer stack; wherein the gas molar flow rate at the reformer inlet is determined by the reformer equilibrium temperature. Based on the reformed fuel entering the anode circulation pump, the actual flow rate of the anode circulation pump is obtained according to the pump speed, pressure difference before and after, and fuel composition. Combined with the MFC fuel flow rate, the AOG circulation flow rate and circulation rate are obtained.
10. The control method as described in claim 9, characterized in that, It also includes a filter status monitoring step, namely: real-time monitoring of the pressure difference between the inlet and outlet of the filter, and issuing a maintenance prompt signal when the pressure difference exceeds a set threshold, so as to ensure the filtration effect and smooth flow of the waterless fuel cell system.