Middle-and-large-sized solid oxide battery system

Abstract

A medium-and-large-sized solid oxide battery system is suitable for medium-and-large-sized distributed power stations above an MW level, and is characterized in that a plurality of electric pile modules are connected in parallel and are jointly connected with a BOP system, and a first switch valve is arranged between each electric pile module and the BOP system to realize physical separation between the electric pile module and the BOP system; tail gas generated by the galvanic pile module is conveyed to the collecting and purifying system, then is connected to the tail gas heat energy recycling device and is coupled to the BOP system, so that a complete heat energy utilization system is formed; or, an energy conversion device outside the fuel cell system is connected, an external independent combustor is additionally arranged to be connected with a natural gas feeding pipeline, an air feeding pipeline and respective control valves of the natural gas feeding pipeline and the air feeding pipeline, and high-temperature gas of the external independent combustor is conveyed and connected to a device needing to be preheated in the BOP system and then is emptied through an exhaust pipeline. Through the innovative configuration of the BOP system and the electric pile hot area, the efficient tail gas utilization strategy and the flexible application of the independent combustor, the equipment cost and the maintenance difficulty are remarkably reduced, and the overall efficiency, the flexibility and the environmental protection performance of the system are improved.

Description

Technical Field

[0001] This utility model belongs to the field of solid fuel cell technology, and relates to a medium-to-large solid oxide battery system for medium-to-large distributed power stations of MW level and above. Background Technology

[0002] With the increasing global demand for clean energy, medium and large-scale distributed power plants, as an important component of power supply, are receiving increasing attention for their efficiency, economy, and environmental performance. As a clean energy technology, solid oxide fuel cell systems (SOCF) have shown great potential in the distributed power plant field due to their high energy efficiency, low emissions, and fuel flexibility. In existing SOCF systems applied to medium and large-scale distributed power plants, one stack module corresponds to one BOP (Balance of Plant) module; the material flow and energy coupling design between the stack module and the BOP module can maximize power generation efficiency. However, existing technologies often face challenges in practical applications, such as high system complexity, high equipment cost, and difficult maintenance. Their shortcomings are as follows:

[0003] 1. Difficulty in maintaining high-power equipment: The 1-to-1 design of fuel cell stack modules and BOP modules means that high-power equipment requires high-power fuel cell stack modules; once a fuel cell stack in the fuel cell stack module needs to be replaced, the entire equipment needs to be shut down, and the operation is complicated and time-consuming, which affects the operating efficiency of the power plant.

[0004] II. Difficulty in thermal balance adjustment: The high coupling between the fuel cell stack and the BOP system results in slow thermal balance adjustment speed and many influencing factors; when it is necessary to adjust the power generation capacity frequently over a wide range, it is difficult to accurately adjust the parameters, which affects the optimal operating conditions of the fuel cell stack.

[0005] Third, the utilization of low-grade exhaust gas is limited: the high coupling between the fuel cell stack and the BOP system also leads to limited adjustment of the thermoelectric ratio of the equipment and low exhaust gas temperature, which limits the application scope of combined heat and power or combined cooling, heating and power.

[0006] Therefore, it is necessary to optimize the existing solid oxide fuel cell systems of medium and large-scale distributed power plants to improve the overall efficiency of the system, reduce equipment costs, enhance the maintainability and replaceability of the system, and at the same time realize the recovery and utilization of exhaust gas. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a medium-to-large solid oxide battery system suitable for medium-to-large distributed power stations of MW level and above. It has the characteristics of scientific and reasonable system design, high efficiency and low maintenance difficulty, while reducing equipment costs and improving system reliability, flexibility and overall energy efficiency.

[0008] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a medium-to-large solid oxide battery system, suitable for medium-to-large distributed power stations of MW level and above, comprising multiple stack modules, a BOP system, and a tail gas collection and purification system, characterized in that:

[0009] Multiple fuel cell stack modules are connected in parallel to a single BOP system, and a first switching valve is installed between each fuel cell stack module and the BOP system to achieve physical separation between the two.

[0010] The exhaust gas generated by the fuel cell stack module is transported to the collection and purification system, then connected to the exhaust gas heat recovery device, and coupled to the BOP system to form a complete heat energy utilization system; or, it is connected to an energy conversion device outside the fuel cell system, and an external independent burner is added to connect the natural gas feed line and the air feed line and their respective control valves. The high-temperature gas from the external independent burner is transported to the device in the BOP system that needs to be preheated, and then discharged through the exhaust pipe.

[0011] Furthermore, the devices requiring preheating in the BOP system include a fuel preheater, an evaporator, an air preheater, and a reformer.

[0012] Furthermore, the collection and purification system includes a high-temperature anode tail gas collection device and a high-temperature cathode tail gas collection device. The anode tail gas of each fuel cell module is collected and sent to the high-temperature anode tail gas collection device, and the cathode tail gas of each fuel cell module is collected and sent to the high-temperature cathode tail gas collection device.

[0013] Preferably, the high-temperature anode tail gas collection device and the high-temperature cathode tail gas collection device are arranged in parallel.

[0014] Furthermore, the high-temperature anode exhaust gas collection device is connected to the internal exhaust gas burner via a second switch valve and pipeline. At the same time, the high-temperature cathode exhaust gas collection device is also connected to the internal exhaust gas burner via a second switch valve and pipeline. In conjunction with combustion and heating, the high-temperature gas is transported through the second switch valve and pipeline to the reformer, fuel preheater, air preheater and evaporator for auxiliary preheating, and finally discharged through the exhaust pipe.

[0015] Furthermore, the MW level refers to the range from 1MW to 100MW.

[0016] Furthermore, the BOP system is an auxiliary system for the fuel cell, comprising a hydrogen circulation system, an air circulation system, a water circulation system, and a hydrothermal management system.

[0017] Furthermore, the BOP system is divided into a cold zone BOP and a hot zone BOP. The cold zone BOP includes feed pipelines for natural gas, water, and air, as well as metering modules on their respective pipelines. The hot zone BOP includes a reformer, a fuel preheater, an evaporator, an air preheater, an internal exhaust gas burner, and connecting pipelines and valves.

[0018] Finally, the energy conversion device is a heating engine, a refrigeration engine, or a gas turbine.

[0019] Compared with the prior art, the advantages of this utility model are:

[0020] 1. Design a modular architecture that allows multiple fuel cell stack modules to share a BOP system, reducing the number of BOP systems, thereby reducing equipment costs and maintenance difficulty. Each fuel cell stack module has the ability to operate independently. The intelligent control system realizes the coordination and balance between modules, improving the reliability and flexibility of the system.

[0021] 2. A first switching valve V1 is installed between the fuel cell stack and the BOP system to achieve physical separation between the two, which simplifies the system control process, reduces system complexity, and improves system maintainability.

[0022] 3) Design an exhaust gas heat recovery device to recover and utilize the heat energy of the exhaust gas;

[0023] This invention features a scientifically sound design, high system efficiency, and stable operation. Through innovative BOP system and fuel cell stack hot zone configuration, efficient exhaust gas utilization strategy, and flexible application of independent burners, it not only significantly reduces the equipment cost and maintenance difficulty of medium and large-scale distributed power plants, but also improves the overall system efficiency, flexibility, and environmental performance. Simultaneously, it reduces equipment costs, enhances system reliability, flexibility, and comprehensive energy efficiency, and strengthens system maintainability and replaceability. It has broad application prospects and significant promotional value in the field of large-scale distributed power plants. Attached Figure Description

[0024] Figure 1 This is a structural block diagram of the solid oxide fuel cell system provided by this utility model. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1 As shown, an optimization method for medium-to-large solid oxide battery systems suitable for medium-to-large distributed power stations with capacities of MW or higher is presented, where MW ranges from 1MW to 100MW; specifically:

[0027] 1) Multiple fuel cell stack modules are connected in parallel and share a single BOP (Balance of Plant) system. The BOP system is an auxiliary system for fuel cells, including a hydrogen circulation system, an air circulation system, a water circulation system, and a hydrothermal management system. The BOP system is divided into a cold zone BOP and a hot zone BOP. The cold zone BOP includes the feed lines for natural gas, water, and air, as well as the metering modules on their respective lines. The hot zone BOP includes a reformer, a fuel preheater, an evaporator, an air preheater, and its internal exhaust gas burner, connecting lines, and valves.

[0028] 2) A first switching valve is installed between each fuel cell stack module and the BOP system to achieve physical separation between the two;

[0029] 3) After collection and purification, the exhaust gas generated by the fuel cell stack module can be treated according to one of the following modes: collection and purification include parallel high-temperature anode exhaust gas treatment and high-temperature cathode exhaust gas treatment. The anode exhaust gas from each fuel cell stack module is collected and sent to the high-temperature anode exhaust gas treatment, and the cathode exhaust gas from each fuel cell stack module is collected and sent to the high-temperature cathode exhaust gas treatment.

[0030] 3.1) The exhaust gas heat energy is recovered and coupled to the BOP system to form a complete heat energy utilization system;

[0031] 3.2) The BOP system is equipped with multiple external independent burners to provide heat energy to the BOP system. The exhaust gas is used for energy conversion processes outside the system, such as heating engines, refrigeration engines, or gas turbines.

[0032] Optimized solid oxide fuel cell systems for medium to large-scale distributed power plants of MW level and above, such as Figure 1As shown, it includes multiple fuel cell stack modules, a Balance of Production (BOP) system, and an exhaust gas collection and purification system. The multiple fuel cell stack modules are connected in parallel to a single BOP system. A first switching valve V1 is installed between each fuel cell stack module and the BOP system to achieve physical separation between them. Typically, a first switching valve V1 can be installed on the pipelines before and after each fuel cell stack module. The BOP system is divided into a cold zone BOP and a hot zone BOP. The cold zone BOP includes the feed pipelines for natural gas, water, and air, and their respective metering modules. The hot zone BOP includes a reformer, fuel preheater, evaporator, air preheater, and its internal exhaust gas burner. Connecting pipelines and valves; the exhaust gas generated by the fuel cell stack module is transported to the collection and purification system, then connected to the exhaust gas heat recovery device, and coupled to the BOP system to form a complete heat energy utilization system; alternatively, it is connected to an energy conversion device outside the fuel cell system via pipelines and the third switching valve V3. The energy conversion device can be a heating engine, a cooling engine, or a gas turbine, etc., and an external independent burner is added, connecting to the natural gas feed pipeline and the air feed pipeline and their respective control valves. The high-temperature gas from the external independent burner is transported to the devices requiring preheating in the BOP system via pipelines and the third switching valve V3, and then vented through the exhaust pipe. Devices requiring preheating in the BOP system include the fuel preheater, evaporator, air preheater, and reformer, etc. In this embodiment, high-temperature gas from one external independent burner is supplied via pipeline and third switch valve V3 to the internal exhaust gas burner, reformer, and fuel preheater for sequential auxiliary preheating, and finally the low-temperature exhaust gas is discharged. Similarly, high-temperature gas from another external independent burner is supplied via pipeline and third switch valve V3 to the air preheater and evaporator for sequential auxiliary preheating, and finally the low-temperature exhaust gas is discharged. The collection and purification system includes a high-temperature anode exhaust gas collection device and a high-temperature cathode exhaust gas collection device, which can be arranged in parallel. The anode exhaust gas from each fuel cell module is collected and sent to the high-temperature anode exhaust gas collection device, and the cathode exhaust gas from each fuel cell module is collected and sent to the high-temperature cathode exhaust gas collection device. The high-temperature anode exhaust gas collection device is connected to the internal exhaust gas burner via the second switch valve V2 and pipeline. At the same time, the high-temperature cathode exhaust gas collection device is also connected to the internal exhaust gas burner via the second switch valve V2 and pipeline. In conjunction with combustion heating, the high-temperature gas is transported through the second switch valve V2 and pipeline to the reformer, fuel preheater, air preheater and evaporator for auxiliary preheating. The second switch valve V2 is connected between the fuel preheater and the air preheater. In this embodiment, sequential preheating is adopted, and finally the gas is discharged through the exhaust pipe.

[0033] The improvements of this utility model are described in detail below:

[0034] (1) Mode 1: High-efficiency utilization mode of exhaust gas heat energy, close all second switch valves (normal process opening valve V2), open all third switch valves (high exhaust gas process opening valve V3).

[0035] Design of an exhaust gas heat recovery device: Integrate a highly efficient exhaust gas heat recovery device into the BOP system. This device can capture and convert the heat energy in the exhaust gas generated by the SOFC stack. This heat energy is then used to preheat the reactant gases entering the stack, heat water, or generate steam, thereby significantly improving the overall energy efficiency of the system. Advantages: This mode is particularly suitable for situations where the system operates stably and the output power demand is relatively stable. By maximizing the recovery and utilization of exhaust gas heat energy, energy waste is reduced and the system's economics are improved.

[0036] (2) Mode 2: Exhaust gas non-recovery and independent burner mode, close all third switch valves (high exhaust gas process opening valve V3), open all second switch valves (normal process opening valve V2) and use the exhaust gas for other purposes: When the system faces frequent and large-scale changes in output power or large-scale heating demand, it can switch to this mode. At this time, the exhaust gas is no longer recovered into the system, but is collected centrally and used for other energy conversion processes.

[0037] Independent burner introduction: The system is equipped with an independent burner that uses the collected exhaust gas as fuel or combustion-supporting gas for combustion. The resulting high-temperature, high-pressure gas or steam can be used for heating, power generation, or other industrial processes. This design allows for flexible adjustment of operating parameters, such as adjusting the heat-to-power ratio according to actual needs, ensuring that the type and amount of energy output by the system can meet varying demands.

[0038] Advantages: This mode enhances the system's flexibility and responsiveness, enabling it to quickly adapt to fluctuations in external loads and diverse energy demands. Simultaneously, by flexibly adjusting the thermoelectric ratio, it maintains a consistent thermal environment for the fuel cell stack, contributing to improved stack stability and extended service life.

[0039] Switching between the two modes mentioned above:

[0040] Intelligent Control System: An advanced intelligent control system is introduced to monitor the system's operating status and changes in external demands in real time. Based on preset strategies or real-time data analysis results, it can automatically or semi-automatically achieve smooth switching between two modes.

[0041] Optimized operating efficiency: Through precise control of the intelligent system, the system maintains optimal operating conditions and energy utilization efficiency in different operating modes. Mode 1 is used when high power output is required to maximize the utilization of exhaust gas heat energy; when flexible adjustment of output power or large-scale heating is required, it switches to Mode 2 to meet diverse energy demands.

[0042] Specific embodiments of this utility model

[0043] I. Modular Fuel Cell Stack and BOP System Design: Based on the power plant scale and requirements, multiple SOFC fuel cell stack modules are designed, each module containing a certain number of fuel cell units. All fuel cell stack modules share a single BOP system, which uses pipes and valves to transfer and distribute heat and gas.

[0044] II. High-Temperature Valves and Localized Maintenance: High-temperature valves are installed between the fuel cell stack modules and the BOP system to ensure that the connection between the two can be quickly disconnected or restored when needed. When a fuel cell stack module requires maintenance, the corresponding high-temperature valve is closed and the module is isolated for localized maintenance operations.

[0045] III. Design of Exhaust Gas Heat Recovery Device:

[0046] Equipment selection: Based on the characteristics of the exhaust gas generated by the SOFC stack (such as temperature, flow rate, composition, etc.), select a suitable exhaust gas heat recovery device. This device should have high thermal efficiency and durability, and be able to withstand corrosive components in the exhaust gas.

[0047] System Integration: The exhaust gas heat recovery device is integrated into the BOP system to ensure that the exhaust gas flows smoothly into the recovery device and effectively releases heat energy. At the same time, a reasonable heat transfer path is designed so that the recovered heat energy can be used to preheat reaction gases, heat water, or generate steam, etc.

[0048] Thermal energy utilization optimization: Rationally allocate recovered thermal energy according to system requirements. For example, when preheating the reaction gas, ensure that the preheating temperature is moderate and uniform to avoid overheating or undercooling from adversely affecting the performance of the fuel cell stack.

[0049] Energy efficiency monitoring: Install energy efficiency monitoring equipment to monitor the exhaust gas heat recovery efficiency and the overall system energy efficiency in real time. Adjust the operating parameters of the heat recovery device promptly based on the monitoring results to ensure the system always operates at its optimal state.

[0050] Efficient utilization of exhaust gas in BOP and flexible switching modes of independent burners

[0051] Implementation of Mode 1

[0052] I. Exhaust Gas Collection and Purification:

[0053] First, the exhaust gas produced by the SOFC stack is collected through pipelines. The exhaust gas may contain unreacted fuel, water vapor, and small amounts of pollutants.

[0054] The exhaust gas is purified to remove pollutants, ensuring that the exhaust gas entering the BOP system is clean and pollution-free. Purification methods may include dust removal, desulfurization, and denitrification.

[0055] II. Exhaust gas heat recovery:

[0056] A heat recovery device, such as a heat exchanger, is installed in the BOP system. When the exhaust gas passes through the heat exchanger, its heat energy is transferred to the medium that needs to be preheated (such as air, water, or heat transfer oil).

[0057] Based on system requirements, the structure and process of the heat exchanger should be designed rationally to ensure that the thermal energy of the exhaust gas is maximized.

[0058] Coupled heat transfer and system integration:

[0059] Connect the exhaust gas heat recovery device with other parts of the BOP system (such as the preheater, steam generator, etc.) to form a complete heat energy utilization system.

[0060] The intelligent control system precisely controls the coupled heat exchange process, ensuring that the system maintains high energy efficiency under different operating conditions.

[0061] Implementation of Mode 2

[0062] Independent burner configuration

[0063] Equipment selection: Choose a suitable independent burner based on system requirements. The burner should feature high-efficiency combustion, stable and reliable operation, and flexible adjustment.

[0064] Thermoelectric ratio adjustment: The thermoelectric ratio is adjusted according to the actual needs of the system. Precise control of thermoelectric output is achieved through the flow rate and combustion efficiency of independent burners.

[0065] Thermal environment maintenance: While adjusting the thermoelectric ratio, it is important to monitor and maintain the consistency of the thermal environment of the fuel cell stack. By adjusting parameters such as preheating temperature and reactant gas flow rate, ensure that the fuel cell stack always operates in the optimal thermal environment to improve its stability and lifespan.

[0066] Two-mode switching and intelligent control

[0067] Mode switching logic:

[0068] The system features a clear logic and conditions for mode switching. It automatically or semi-automatically switches between the two modes based on system operating status and changes in external demand (such as output power requirements, heating requirements, etc.).

[0069] Set reasonable switching thresholds and delay mechanisms to avoid frequent switching from adversely affecting system stability and energy efficiency.

[0070] Intelligent control system:

[0071] An advanced intelligent control system is introduced to monitor and analyze system operation status and changes in external demand in real time. Through algorithm optimization and data processing technologies, the system's response speed and decision-making accuracy are improved.

[0072] It integrates a human-machine interface and remote monitoring functions, facilitating real-time monitoring and remote operation by personnel. It also provides fault diagnosis and early warning functions to ensure the safe and stable operation of the system.

[0073] The technical effects achieved by this utility model are:

[0074] I. Significantly Reduced Equipment Costs and Investment Risks: By adopting a modular design where one auxiliary system corresponds to multiple small reactor areas, the large-scale reactor area construction required for a single high-power device is effectively reduced, thereby lowering the overall equipment cost. At the same time, the modular design makes system construction more flexible, allowing for gradual expansion according to actual needs, thus reducing the risk of initial investment.

[0075] II. Enhanced System Maintainability and Replaceability: When a small reactor section fails, this invention allows for rapid replacement of the entire reactor section without shutting down the entire system, significantly reducing maintenance time and impacting power plant operations. This design not only improves system maintainability but also enhances system reliability and stability.

[0076] III. Enhanced System Flexibility and Adaptability: By adding a high-temperature shut-off valve and an independent burner to the BOP system, this invention achieves flexible switching of the gas path and workflow. This flexibility allows the system to better adapt to changes in external load and diverse heating demands. Whether it's frequent and large-scale changes in output power or large-scale heating, the requirements can be met by switching the workflow.

[0077] IV. Improving Overall System Efficiency and Energy Utilization: By optimizing the configuration of the Base-of-Plant (BOP) and the fuel cell stack's hot zones, and employing efficient exhaust gas utilization strategies within the BOP, the system's internal thermal equilibrium is accelerated, allowing the fuel cell stack to maintain optimal operating conditions more precisely, thereby improving overall system efficiency. Simultaneously, the efficient exhaust gas utilization strategy not only reduces energy waste but also broadens the application scope of combined heat and power (CHP) and combined cooling, heating, and power (CCHP), further enhancing the system's energy utilization rate.

[0078] V. Facilitating Flexible Adjustment of Heat-to-Power Ratio: The introduction of independent burners allows the system to adjust the heat-to-power ratio as needed to meet energy demands in different application scenarios. This flexibility not only improves the system's operating efficiency but also enhances its adaptability to varying energy requirements.

[0079] VI. Enhanced environmental performance:

[0080] This further improves the system's energy efficiency, reduces energy waste and pollutant emissions, and helps achieve a green and low-carbon power supply.

[0081] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A medium-to-large-scale solid oxide battery system, suitable for medium-to-large-scale distributed power stations of MW level and above, comprising multiple stack modules, a BOP system, and a tail gas collection and purification system, characterized in that: Multiple fuel cell stack modules are connected in parallel to a single BOP system, and a first switching valve is installed between each fuel cell stack module and the BOP system to achieve physical separation between the two. The exhaust gas generated by the fuel cell stack module is transported to the collection and purification system, then connected to the exhaust gas heat recovery device, and coupled to the BOP system to form a complete heat energy utilization system; or, it is connected to an energy conversion device outside the fuel cell system, and an external independent burner is added to connect the natural gas feed line and the air feed line and their respective control valves. The high-temperature gas from the external independent burner is transported to the device in the BOP system that needs to be preheated, and then discharged through the exhaust pipe.

2. The medium-to-large solid oxide battery system according to claim 1, characterized in that: The devices requiring preheating in the BOP system include fuel preheaters, evaporators, air preheaters, and reformers.

3. The medium-to-large solid oxide battery system according to claim 2, characterized in that: The collection and purification system includes a high-temperature anode tail gas collection device and a high-temperature cathode tail gas collection device. The anode tail gas of each fuel cell module is collected and sent to the high-temperature anode tail gas collection device, and the cathode tail gas of each fuel cell module is collected and sent to the high-temperature cathode tail gas collection device.

4. The medium-to-large solid oxide battery system according to claim 3, characterized in that: The high-temperature anode tail gas collection device and the high-temperature cathode tail gas collection device are arranged in parallel.

5. The medium-to-large solid oxide battery system according to claim 3, characterized in that: The high-temperature anode exhaust gas collection device is connected to the internal exhaust gas burner via a second switch valve and pipeline. At the same time, the high-temperature cathode exhaust gas collection device is also connected to the internal exhaust gas burner via a second switch valve and pipeline. In conjunction with combustion and heating, the high-temperature gas is transported through the second switch valve and pipeline to the reformer, fuel preheater, air preheater and evaporator for auxiliary preheating, and finally discharged through the exhaust pipe.

6. The medium-to-large solid oxide battery system according to claim 1, characterized in that: The MW level refers to the range from 1MW to 100MW.

7. The medium-to-large solid oxide battery system according to claim 1, characterized in that: The BOP system is an auxiliary system for fuel cells, which includes a hydrogen circulation system, an air circulation system, a water circulation system, and a hydrothermal management system.

8. The medium-to-large solid oxide battery system according to claim 1, characterized in that: The BOP system is divided into a cold zone BOP and a hot zone BOP. The cold zone BOP includes the feed pipelines for natural gas, water, and air, as well as the metering modules on their respective pipelines. The hot zone BOP includes a reformer, a fuel preheater, an evaporator, an air preheater, and its internal exhaust gas burner, connecting pipelines, and valves.

9. The medium-to-large solid oxide battery system according to claim 1, characterized in that: The energy conversion device is a heating engine, a refrigeration engine, or a gas turbine.

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