A megawatt fuel cell power plant thermal management system and method of controlling the same

Abstract

The application discloses a megawatt fuel cell power station thermal management system and a control method thereof. The system comprises an air compressor system, a fuel cell power station power generation system, a fuel cell power station internal cooling system and a fuel cell power station external cooling system. The fuel cell power station internal cooling system comprises a first internal cooling branch pipeline, a second internal cooling branch pipeline and a third internal cooling branch pipeline. The fuel cell power station external cooling system comprises a first external cooling branch pipeline and a second external cooling branch pipeline. According to the fuel cell power station power generation state and demand, the application can adjust the switch state of each stop valve and the opening degree of the cooling water flow regulating valve, so that the fuel cell power station can be rapidly heated during startup, and waste heat can be provided to the user end for recycling during normal operation of the fuel cell power station.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more specifically, to a thermal management system and control method for a megawatt-level fuel cell power plant. Background Technology

[0002] With increasingly prominent environmental issues and growing environmental awareness worldwide, hydrogen energy, as a clean, pollution-free, renewable green energy source, has garnered widespread attention globally. A hydrogen fuel cell is a chemical device that directly converts the chemical energy of fuel into electrical energy. Globally, major developed countries, considering resource and environmental perspectives, highly value the development of hydrogen energy technology and industry. Hydrogen energy is one of the most promising new energy sources, and major countries and energy companies worldwide are accelerating their hydrogen energy industry development. In the context of dual carbon emissions, fuel cell power plants are a crucial application area for fuel cells. These power plants require increased capacity to meet high-power output, leading to low heat dissipation efficiency in fuel cell systems, a critical technical problem that urgently needs to be addressed. Summary of the Invention

[0003] To address the aforementioned technical problem of low heat dissipation efficiency in existing fuel cell systems, this invention provides a megawatt-level fuel cell power plant thermal management system and its control method. Applying this invention, the on / off states of various shut-off valves and the opening degree of the cooling water flow regulating valve can be adjusted according to the power generation status and demand of the fuel cell power plant. This enables rapid heating during startup, and during normal operation, waste heat is provided to the user for recovery and reuse. Alternatively, if the user has no heat demand, the waste heat is directly dissipated by the cooling tower, or a combination of both methods can be employed: some waste heat is utilized while the rest is dissipated.

[0004] The technical means employed in this invention are as follows:

[0005] A megawatt-level fuel cell power plant thermal management system includes: an air compressor system, a fuel cell power plant power generation system, an internal cooling system for the fuel cell power plant, and an external cooling system for the fuel cell power plant;

[0006] The air compressor system includes an air compressor and a first heat exchanger;

[0007] The internal cooling system of the fuel cell power station includes a first internal cooling branch pipe, a second internal cooling branch pipe, and a third internal cooling branch pipe, wherein:

[0008] The first internal cooling branch pipe is used to guide the cooling water flowing out of the fuel cell power station power generation system to the first heat exchanger for heat exchange treatment before sending it back to the fuel cell power station power generation system.

[0009] The second internal cooling branch pipe is used to guide the cooling water flowing out of the fuel cell power plant power generation system to the second heat exchanger for heat exchange treatment before sending it back to the fuel cell power plant power generation system.

[0010] The third internal cooling branch pipeline is used to guide the cooling water flowing out of the fuel cell power station power generation system to the third heat exchanger for heat exchange treatment and then send it back to the fuel cell power station power generation system.

[0011] The external cooling system of the fuel cell power station includes a first external cooling branch pipe and a second external cooling branch pipe, wherein:

[0012] The first external cooling branch pipeline is used to guide the cooling water flowing out of the user end to the second heat exchanger for heat exchange treatment and then send it back to the user end.

[0013] The second external cooling branch pipeline includes two parallel loops: parallel loop one guides the cooling water flowing out of the cooling tower to the first heat exchanger for heat exchange treatment and then sends it back to the cooling tower; parallel loop two guides the cooling water flowing out of the cooling tower to the third heat exchanger for heat exchange treatment and then sends it back to the cooling tower.

[0014] Furthermore, the system also includes a cooling system controller, which is used to control the on / off operation of the first internal cooling branch pipe, the second internal cooling branch pipe, the third internal cooling branch pipe, the first external cooling branch pipe, and the second external cooling branch pipe according to usage requirements.

[0015] Furthermore, the first internal cooling branch pipe, the second internal cooling branch pipe, and the third internal cooling branch pipe are respectively equipped with a shut-off valve and a flow control valve.

[0016] Furthermore, the first external cooling branch pipe and the second external cooling branch pipe are respectively equipped with a shut-off valve and a flow control valve.

[0017] This invention also discloses a control method for the thermal management system of a megawatt-level fuel cell power plant as described above, comprising the following steps:

[0018] When the fuel cell power generation system starts up, the first internal cooling branch pipe is opened, while the second and third internal cooling branch pipes are blocked, so that the fuel cell cooling water exchanges heat with the first heat exchanger, thereby rapidly heating the fuel cell cooling water to the operating temperature.

[0019] Once the fuel cell cooling water reaches its operating temperature, the second external cooling branch pipe and parallel loop two are opened, and the flow rate of parallel loop two is controlled according to heat exchange requirements. The first internal cooling branch pipe is blocked, and the second and third internal cooling branch pipes are opened or closed as needed. Specifically:

[0020] When the demand is for complete waste heat utilization, the first and third internal cooling branch pipes are blocked, and the second internal cooling branch pipe is opened to exchange heat with the user end, thus achieving complete waste heat utilization.

[0021] When there is no need to utilize waste heat, the first and second internal cooling branch pipes are blocked, and the third internal cooling branch pipe is opened to exchange heat with the third heat exchanger, thus achieving heat dissipation of the internal cooling system.

[0022] When there is a demand for partial waste heat utilization but some waste heat is lost, the first internal cooling branch pipe is blocked, and the second and third internal cooling branch pipes are opened to achieve partial waste heat utilization.

[0023] Furthermore, it also includes the following steps:

[0024] After the fuel cell power generation system is started, when the temperature of the air compressor aftercooler exceeds the set value, the second external cooling branch pipe is opened and connected to the first circuit to dissipate heat to the air compressor aftercooler through the first heat exchanger, thereby maintaining the working temperature of the air compressor aftercooler.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] Based on the system of this invention, when the fuel cell power station starts up, the waste heat of the air compressor is used to exchange heat with the power station's cooling water to quickly heat the fuel cell cooling water to the fuel cell operating temperature, thereby enabling the fuel cell power station to generate electricity quickly. At the same time, the waste heat generated during the stable operation of the fuel cell power station can be fully utilized, partially utilized, or not utilized as needed, thereby realizing thermal management of the fuel cell power station and improving the efficiency of the fuel cell power station. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a block diagram of a thermal management system for a megawatt-level fuel cell power plant according to the present invention.

[0029] In the diagram: 1. Air compressor aftercooler; 2. First heat exchanger; 3. First shut-off valve; 4. First flow control valve; 5. Second heat exchanger; 6. Second shut-off valve; 7. Second flow control valve; 8. Third heat exchanger; 9. Third shut-off valve; 10. Third flow control valve; 11. First flow meter; 12. Water tank; 13. First water pump; 14. User end; 15. Fourth shut-off valve; 16. Fourth flow control valve; 17. Cooling tower; 18. Main pipeline flow meter; 19. Second water pump; 20. Fifth shut-off valve; 21. Fifth flow control valve; 22. Sixth shut-off valve; 23. Sixth flow control valve. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] like Figure 1 As shown, the present invention provides a megawatt-level fuel cell power plant thermal management system, including: an air compressor system, a fuel cell power plant power generation system, an internal cooling system for the fuel cell power plant, and an external cooling system for the fuel cell power plant.

[0033] The air compressor system consists of an air compressor aftercooler 1 and a first heat exchanger 2. In this embodiment, the fuel cell power station power generation system consists of five fuel cell power generation modules.

[0034] The internal cooling system of the fuel cell power station consists of a first water pump 13, a water tank 12, a first flow meter 11, and various internal cooling branch pipes.

[0035] The first internal cooling branch pipe consists of the first shut-off valve 3, the first flow control valve 4, and the first heat exchanger 2.

[0036] The second internal cooling branch pipe consists of the second shut-off valve 6, the second flow control valve 7, and the second heat exchanger 5.

[0037] The third internal cooling branch pipe consists of the third shut-off valve 9, the third flow control valve 10, and the third heat exchanger 8.

[0038] The external cooling system of the fuel cell power station consists of a user terminal 14 and an external cooling tower 17 connected in parallel. The user terminal 14, together with the second heat exchanger 5, the fourth shut-off valve 15, and the fourth flow control valve 16, forms a branch. The external cooling tower 17, together with the main pipeline flow meter 18, the second water pump 19, the fifth shut-off valve 20, the fifth flow control valve 21, and the first heat exchanger 2, forms the first external cooling branch pipeline. The external cooling tower 17, together with the main pipeline flow meter 18, the second water pump 19, the sixth shut-off valve 22, the sixth flow control valve 23, and the third heat exchanger 8, forms the second external cooling branch pipeline.

[0039] Another aspect of this invention discloses a control method for the aforementioned system. Specifically, it includes:

[0040] The power station controller issues a power generation command to the fuel cell system, the air compressor starts, the internal cooling water system of the power station starts, the second shut-off valve 6 and the third shut-off valve 9 are closed, the first shut-off valve 3 is opened, and the flow rate of the first flow regulating valve 4 is controlled so that the internal cooling water system is heated by the first heat exchanger and quickly rises to the working temperature of the fuel cell power station.

[0041] Once the cooling water temperature reaches the operating temperature of the fuel cell power station, the first shut-off valve 3 is closed and the second shut-off valve 6 is opened. The cooling water flows through the second internal cooling branch pipe, and the user end collects heat through the second heat exchanger 5 to achieve combined heat and power.

[0042] Once sufficient heat is collected at the user end, no more heat is needed. The second shut-off valve 6 and the first shut-off valve 3 are closed, the third shut-off valve 9 and the third flow control valve 10 are opened, the second water pump 19 is started, the sixth shut-off valve 22 is opened, and the sixth flow control valve 23 is adjusted. The heat generated by the power generation system of the power station is exchanged by the cooling tower 17, so that the fuel cell cooling water is kept within the operating temperature range of the fuel cell.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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 thermal management system for a megawatt-level fuel cell power plant, characterized in that, include: Air compressor system, fuel cell power station power generation system, fuel cell power station internal cooling system and fuel cell power station external cooling system; The air compressor system includes an air compressor and a first heat exchanger; The internal cooling system of the fuel cell power station includes a first internal cooling branch pipe, a second internal cooling branch pipe, and a third internal cooling branch pipe, wherein: The first internal cooling branch pipe is used to guide the cooling water flowing out of the fuel cell power station power generation system to the first heat exchanger for heat exchange treatment before sending it back to the fuel cell power station power generation system. The second internal cooling branch pipe is used to guide the cooling water flowing out of the fuel cell power plant power generation system to the second heat exchanger for heat exchange treatment before sending it back to the fuel cell power plant power generation system. The third internal cooling branch pipeline is used to guide the cooling water flowing out of the fuel cell power station power generation system to the third heat exchanger for heat exchange treatment and then send it back to the fuel cell power station power generation system. The external cooling system of the fuel cell power station includes a first external cooling branch pipe and a second external cooling branch pipe, wherein: The first external cooling branch pipeline is used to guide the cooling water flowing out of the user end to the second heat exchanger for heat exchange treatment and then send it back to the user end. The second external cooling branch pipeline includes two parallel loops: parallel loop one guides the cooling water flowing out of the cooling tower to the first heat exchanger for heat exchange treatment and then sends it back to the cooling tower; parallel loop two guides the cooling water flowing out of the cooling tower to the third heat exchanger for heat exchange treatment and then sends it back to the cooling tower.

2. The megawatt-level fuel cell power plant thermal management system according to claim 1, characterized in that, The system also includes a cooling system controller, which is used to control the on / off operation of the first internal cooling branch pipe, the second internal cooling branch pipe, the third internal cooling branch pipe, the first external cooling branch pipe, and the second external cooling branch pipe according to usage requirements.

3. The megawatt-level fuel cell power plant thermal management system according to claim 2, characterized in that, The first internal cooling branch pipe, the second internal cooling branch pipe, and the third internal cooling branch pipe are respectively equipped with a shut-off valve and a flow control valve.

4. The megawatt-level fuel cell power plant thermal management system according to claim 3, characterized in that, The first external cooling branch pipe and the second external cooling branch pipe are respectively equipped with a shut-off valve and a flow control valve.

5. A control method for a megawatt-level fuel cell power plant thermal management system as described in claim 1, characterized in that, Includes the following steps: When the fuel cell power generation system starts up, the first internal cooling branch pipe is opened, while the second and third internal cooling branch pipes are blocked, so that the fuel cell cooling water can exchange heat through the first heat exchanger to quickly heat the fuel cell cooling water to the working temperature. Once the fuel cell cooling water reaches its operating temperature, the second external cooling branch pipe and parallel loop two are opened, and the flow rate of parallel loop two is controlled according to heat exchange requirements. The first internal cooling branch pipe is blocked, and the second and third internal cooling branch pipes are opened or closed as needed. Specifically: When the demand is for complete waste heat utilization, the first and third internal cooling branch pipes are blocked, and the second internal cooling branch pipe is opened to exchange heat with the user end, thus achieving complete waste heat utilization. When there is no need to utilize waste heat, the first and second internal cooling branch pipes are blocked, and the third internal cooling branch pipe is opened to exchange heat with the third heat exchanger, thus achieving heat dissipation of the internal cooling system. When there is a demand for partial waste heat utilization and some waste heat is lost, the first internal cooling branch pipe is blocked, and the second and third internal cooling branch pipes are opened to achieve partial waste heat utilization.

6. The control method for the thermal management system of a megawatt-level fuel cell power plant according to claim 5, characterized in that, It also includes the following steps: After the fuel cell power generation system is started, when the temperature of the air compressor aftercooler exceeds the set value, the second external cooling branch pipe is opened and connected to the first circuit to dissipate heat to the air compressor aftercooler through the first heat exchanger, thereby maintaining the working temperature of the air compressor aftercooler.

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