A heat recovery device for a hydrogen fuel cell system

Abstract

The application relates to the technical field of hydrogen fuel cells, and discloses a heat recovery device for a hydrogen fuel cell system, which comprises a hydrogen fuel cell and a heat recovery box, the left side of the hydrogen fuel cell is fixedly connected with a hydrogen inlet pipe, the right side of the hydrogen fuel cell is fixedly connected with an oxygen inlet pipe and a tail gas outlet pipe, one end of the tail gas outlet pipe is connected with the inside of the heat recovery box, and the heat recovery device further comprises a tail gas waste heat recovery assembly, a hot water conveying assembly, two heat insulation cylinders and two water outlet pipes; the tail gas waste heat recovery assembly is arranged on the heat recovery box. The application has the following advantages and effects: the heat in the tail gas generated in the operation process of the hydrogen fuel cell can be fully recovered, low-temperature clean water can be converted into hot water, the hot water can be simultaneously used for preheating of hydrogen and oxygen and for domestic water use, the effect of waste heat resource utilization is achieved, the heat utilization rate of the hydrogen fuel cell system is significantly improved, and the energy-saving effect is achieved.

Description

Technical Field

[0001] This application relates to the field of hydrogen fuel cell technology, and in particular to a heat recovery device for a hydrogen fuel cell system. Background Technology

[0002] A hydrogen fuel cell is a power generation device that directly converts the chemical energy of hydrogen and oxygen into electrical energy. Its basic principle is the reverse reaction of water electrolysis. Hydrogen and oxygen are supplied to the anode and cathode, respectively. Hydrogen diffuses outward through the anode and reacts with the electrolyte, releasing electrons that travel through an external load to the cathode. In this process, hydrogen and oxygen react to produce water and generate electricity. Its characteristics include no pollution, no noise, and high efficiency.

[0003] During operation, hydrogen fuel cell systems generate high-temperature exhaust gas in addition to outputting electrical energy. This exhaust gas contains a significant amount of recoverable heat energy. Current technologies for exhaust gas heat recovery in hydrogen fuel cell systems mostly utilize the heat in the exhaust gas to convert low-temperature clean water into hot water for domestic use. However, they lack the function of preheating the intake air. Since the hydrogen and oxygen intake air of hydrogen fuel cells typically requires preheating to improve the stack's reaction activity and energy conversion efficiency, existing hydrogen and oxygen intake preheating methods rely on external energy sources, often employing additional electric heating, which increases the energy consumption of the hydrogen fuel cell system and fails to maximize the value of heat recovery. Therefore, we propose a heat recovery device for hydrogen fuel cell systems to address the aforementioned problems.

[0004] Based on existing technology searches, the following known technical solutions exist:

[0005] Authorization announcement number CN220138354U discloses a heat recovery device and system for a hydrogen fuel cell system. The heat recovery device includes a housing connected to an air compressor and a fuel cell stack in the hydrogen fuel cell system, and a heat exchange core installed inside the housing. The housing is provided with a compressed gas inlet connected to the air compressor, an exhaust gas inlet and a compressed gas outlet connected to the fuel cell stack, an exhaust gas outlet, a water inlet, and a water outlet. A heat recovery system based on this device is also disclosed. However, this prior art utilizes the heat from the exhaust gas to convert low-temperature clean water into hot water for domestic use, lacking the function of preheating the intake air, making it inconvenient to use the heat from the exhaust gas to preheat the hydrogen and oxygen intake air. Utility Model Content

[0006] The purpose of this application is to provide a heat recovery device for a hydrogen fuel cell system, which can fully recover the heat in the exhaust gas generated during the operation of the hydrogen fuel cell, convert low-temperature clean water into hot water, and the hot water can be used simultaneously for preheating the intake gas of hydrogen and oxygen and for domestic water use, thereby realizing the resource utilization of waste heat, significantly improving the heat utilization rate of the hydrogen fuel cell system, and also achieving energy-saving effects.

[0007] The above-mentioned technical objective of this application is achieved through the following technical solution: a heat recovery device for a hydrogen fuel cell system, comprising a hydrogen fuel cell and a heat recovery box, wherein a hydrogen inlet pipe is fixedly connected to the left side of the hydrogen fuel cell, and an oxygen inlet pipe and a tail gas outlet pipe are fixedly connected to the right side of the hydrogen fuel cell, one end of the tail gas outlet pipe is connected to the interior of the heat recovery box, and further comprising a tail gas waste heat recovery component, a hot water delivery component, two heat insulation cylinders, and two water outlet pipes; the tail gas waste heat recovery component is disposed on the heat recovery box and is used to heat clean water with the heat in the tail gas generated during the operation of the hydrogen fuel cell; the hot water delivery component is disposed on the heat recovery box and is used to deliver hot water; the two heat insulation cylinders are respectively fixedly sleeved on the hydrogen inlet pipe and the oxygen inlet pipe, and the ends of the two heat insulation cylinders that are close to each other are respectively fixedly connected to the left and right outer walls of the hydrogen fuel cell; the two water outlet pipes are respectively fixedly installed at the bottom of the corresponding heat insulation cylinders and are respectively connected to the corresponding heat insulation cylinders.

[0008] Optionally, the exhaust gas waste heat recovery assembly includes a thermally conductive hollow water distribution plate, a thermally conductive hollow water collection plate, multiple thermally conductive branch water pipes, an inlet pipe, an electromagnetic shut-off valve, and a hot water outlet pipe; the thermally conductive hollow water distribution plate is disposed inside the heat recovery box; the thermally conductive hollow water collection plate is disposed inside the heat recovery box and located to the left of the thermally conductive hollow water distribution plate; the right ends of the multiple thermally conductive branch water pipes are fixedly connected to the thermally conductive hollow water distribution plate, and the left ends of the multiple thermally conductive branch water pipes are fixedly connected to the thermally conductive hollow water collection plate; the inlet pipe is fixedly installed on the right side of the heat recovery box, and the left end of the inlet pipe extends into the heat recovery box and connects with the thermally conductive hollow water distribution plate; the electromagnetic shut-off valve is fixedly installed on the inlet pipe; the hot water outlet pipe is fixedly installed on the top of the heat recovery box, and one end of the hot water outlet pipe extends into the heat recovery box and connects with the thermally conductive hollow water collection plate.

[0009] Optionally, a plurality of heat-conducting fins are fixedly sleeved on the heat-conducting branch pipe, and the plurality of heat-conducting fins are evenly distributed.

[0010] Optionally, a tail gas conveying pipe is fixedly connected to the right side of the heat recovery box, and the tail gas conveying pipe is connected to the heat recovery box. A reinforcing block 1 is fixedly installed on the top of both the heat-conducting hollow water distribution plate and the heat-conducting hollow water collection plate. The top of both reinforcing blocks 1 is fixedly connected to the top inner wall of the heat recovery box. A reinforcing block 2 is fixedly installed on the bottom of both the heat-conducting hollow water distribution plate and the heat-conducting hollow water collection plate. The bottom of both reinforcing blocks 2 is fixedly connected to the bottom inner wall of the heat recovery box.

[0011] Optionally, inclined exhaust gas guide plates are fixedly installed on the top and bottom inner walls of the heat recovery box.

[0012] Optionally, the hot water delivery assembly includes a hot water pump, a hot water delivery main pipe, and two hot water delivery branch pipes; the hot water pump is fixedly installed on the top of the heat recovery tank, and one end of the hot water discharge pipe located inside the heat recovery tank is fixedly connected to the suction end of the hot water pump; one end of the hot water delivery main pipe is fixedly connected to the discharge end of the hot water pump; both hot water delivery branch pipes are fixedly connected to the hot water delivery main pipe, and the bottom ends of the two hot water delivery branch pipes are respectively fixedly connected to the corresponding heat insulation cylinder.

[0013] Optionally, an electromagnetic flow regulating valve 1 is fixedly installed on each of the two hot water delivery branch pipes, and an electromagnetic flow regulating valve 2 is fixedly installed on each of the two outlet pipes.

[0014] Optionally, temperature sensor 1 and temperature sensor 2 are fixedly installed on the top of each of the two heat insulation cylinders 1. The detection ends of the two temperature sensors 1 extend into the corresponding heat insulation cylinder 1, and the detection ends of the two temperature sensors 2 extend into the hydrogen inlet pipe and the oxygen inlet pipe, respectively.

[0015] Optionally, the heat recovery device for the hydrogen fuel cell system further includes two heat-insulating cylinders II and two annular electric heating plates; the two heat-insulating cylinders II are respectively fixedly sleeved on the hydrogen inlet pipe and the oxygen inlet pipe, and the ends of the two heat-insulating cylinders II that are close to each other are respectively fixedly connected to the ends of the two heat-insulating cylinders I that are far from each other; the two annular electric heating plates are respectively fixedly sleeved on the hydrogen inlet pipe and the oxygen inlet pipe, and the two annular electric heating plates are respectively located inside the corresponding heat-insulating cylinders II.

[0016] Optionally, both the hydrogen inlet pipe and the oxygen inlet pipe are fixedly fitted with a plurality of uniformly arranged heat-conducting fins.

[0017] This application includes at least one of the following beneficial technical effects:

[0018] 1. This application utilizes the synergistic effect of a thermally conductive hollow water distribution plate, a thermally conductive hollow water collection plate, multiple thermally conductive branch water pipes, and multiple thermally conductive fins to significantly increase the heat exchange area with the exhaust gas. Combined with the use of two exhaust gas guide plates to guide the exhaust gas, the heat in the exhaust gas generated during the operation of the hydrogen fuel cell can be fully recovered, and the low-temperature clean water can be converted into hot water. The hot water can be used simultaneously for the preheating of hydrogen and oxygen intake and for domestic water use, realizing the effect of waste heat resource utilization and significantly improving the heat utilization rate of the hydrogen fuel cell system.

[0019] 2. This application utilizes the hot water generated by the recovery of exhaust heat to send it into two heat-insulating cylinders 1 through a hot water delivery component. With the coordinated action of multiple heat-conducting fins 2, it can preheat hydrogen and oxygen, improve the reaction activity and power conversion efficiency of the hydrogen fuel cell stack, reduce the impact of the inlet temperature difference on the stack, improve the operational stability of the hydrogen fuel cell, and achieve energy-saving effect.

[0020] 3. This application designs two temperature sensors (I), two temperature sensors (II), two electromagnetic flow regulating valves (I), and two electromagnetic flow regulating valves (II) to work together, which can accurately control the preheating temperature of hydrogen and oxygen, stably maintain the optimal inlet temperature range of hydrogen and oxygen, and avoid overheating or insufficient preheating.

[0021] 4. This application designs two annular electric heating plates and two heat insulation cylinders. When the hydrogen fuel cell is cold-started at low temperature and there is insufficient residual heat, it can provide electric auxiliary preheating of hydrogen and oxygen. Combined with hot water preheating of hydrogen and oxygen, it forms a dual-mode preheating, which ensures that the hydrogen fuel cell starts quickly and stably in low-temperature environment, prevents freezing, flooding and membrane damage, and extends the life of the stack. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a front-view stereoscopic structural diagram of this embodiment.

[0024] Figure 2 This is a top-view three-dimensional structural diagram of this embodiment.

[0025] Figure 3 This is a schematic diagram of the three-dimensional structure in a partial cross-section of the main view in this embodiment.

[0026] Figure 4 This is a front view sectional three-dimensional structural diagram of the heat recovery box.

[0027] Figure 5 yes Figure 3 A magnified structural diagram of part A in the middle.

[0028] In the diagram, 1. Hydrogen fuel cell; 101. Hydrogen inlet pipe; 102. Oxygen inlet pipe; 103. Exhaust gas outlet pipe; 2. Heat recovery box; 3. Thermally conductive hollow water distribution plate; 4. Thermally conductive hollow water collection plate; 5. Thermally conductive branch water pipe; 501. Thermally conductive fin one; 6. Water inlet pipe; 7. Electromagnetic shut-off valve; 8. Hot water outlet pipe; 9. Hot water pump; 10. Hot water delivery main pipe; 11. Hot water delivery branch pipe; 12. Electromagnetic flow regulating valve one; 13. Heat insulation cylinder one; 14. Water outlet pipe; 15. Electromagnetic flow regulating valve two; 16. Temperature sensor one; 17. Temperature sensor two; 18. Exhaust gas delivery pipe; 19. Reinforcing block one; 20. Reinforcing block two; 21. Exhaust gas guide plate; 22. Heat insulation cylinder two; 23. Annular electric heating plate; 24. Thermally conductive fin two. Detailed Implementation

[0029] The technical solution of this application will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0030] See Figures 1-5 This application provides a heat recovery device for a hydrogen fuel cell system, including a hydrogen fuel cell 1 and a heat recovery box 2. A hydrogen inlet pipe 101 is fixedly connected to the left side of the hydrogen fuel cell 1, and an oxygen inlet pipe 102 and a tail gas outlet pipe 103 are fixedly connected to the right side of the hydrogen fuel cell 1. One end of the hydrogen inlet pipe 101 is fixedly connected to an external hydrogen supply pipe for supplying hydrogen to the hydrogen fuel cell 1. One end of the oxygen inlet pipe 102 is fixedly connected to an external oxygen supply pipe for supplying oxygen to the hydrogen fuel cell 1. This allows the chemical energy of hydrogen and oxygen in the hydrogen fuel cell 1 to be directly converted into electrical energy. It should be noted that the method of directly converting the chemical energy of hydrogen and oxygen in the hydrogen fuel cell 1 into electrical energy is a mature technology in the field, and those skilled in the art can understand it by referring to the specification, technical manual, and other relevant materials without any creative effort. Therefore, it will not be described in detail here. One end of the tail gas outlet pipe 103 is connected to the inside of the heat recovery box 2. The tail gas outlet pipe 103 is designed to discharge hydrogen fuel into electricity. The high-temperature exhaust gas generated during the operation of the fuel cell 1 is transported to the heat recovery box 2. The heat recovery box 2 also includes an exhaust gas waste heat recovery component, a hot water delivery component, two heat insulation cylinders 13, and two water outlet pipes 14. The exhaust gas waste heat recovery component is installed on the heat recovery box 2 and is used to heat clean water with the heat from the exhaust gas generated during the operation of the hydrogen fuel cell 1, thus achieving heat recovery. The hot water delivery component is installed on the heat recovery box 2 and is used to deliver hot water. Part of the delivered hot water can be used as domestic water, and the other part is used to preheat the hydrogen inlet pipe 101 and the oxygen inlet pipe 102, in order to improve the stack reaction activity and power conversion efficiency within the hydrogen fuel cell 1, thereby achieving energy saving. The two heat insulation cylinders 13 are respectively fixedly sleeved on the hydrogen inlet pipe 101 and the oxygen inlet pipe 102, with the ends of the two heat insulation cylinders 13 close to each other and fixedly connected to the left and right outer walls of the hydrogen fuel cell 1. The two water outlet pipes 14 are respectively fixedly installed at the bottom of the corresponding heat insulation cylinders 13 and are connected to the corresponding heat insulation cylinders 13.

[0031] In this embodiment, the exhaust gas waste heat recovery assembly includes a heat-conducting hollow water distribution plate 3, a heat-conducting hollow water collection plate 4, multiple heat-conducting branch water pipes 5, an inlet pipe 6, an electromagnetic shut-off valve 7, and a hot water discharge pipe 8. The heat-conducting hollow water distribution plate 3 is installed inside the heat recovery tank 2. The heat-conducting hollow water collection plate 4 is installed inside the heat recovery tank 2 and located to the left of the heat-conducting hollow water distribution plate 3. The right ends of the multiple heat-conducting branch water pipes 5 are fixedly connected to the heat-conducting hollow water distribution plate 3, and the left ends of the multiple heat-conducting branch water pipes 5 are fixedly connected to the heat-conducting hollow water collection plate 4. The inlet pipe 6 is fixedly installed on the right side of the heat recovery tank 2, and the left end of the inlet pipe 6 extends into the heat recovery tank 2 and connects with the heat-conducting hollow water collection plate 4. The heat-conducting hollow water distribution plate 3 is connected, and the right end of the water inlet pipe 6 is fixedly connected to the external clean water pipe so that clean water can be transported to the heat-conducting hollow water distribution plate 3 through the water inlet pipe 6; the electromagnetic shut-off valve 7 is fixedly installed on the water inlet pipe 6; the hot water discharge pipe 8 is fixedly installed on the top of the heat recovery box 2, and one end of the hot water discharge pipe 8 extends into the heat recovery box 2 and is connected to the heat-conducting hollow water collection plate 4. By utilizing the flow process of clean water passing through the heat-conducting hollow water distribution plate 3, multiple heat-conducting branch water pipes 5 and heat-conducting hollow water collection plate 4 in sequence, the heat in the exhaust gas can be transferred to the clean water to heat the clean water. The heated clean water can be discharged through the hot water discharge pipe 8.

[0032] In this embodiment, multiple heat-conducting fins 501 are fixedly sleeved on the heat-conducting diversion pipe 5. The multiple heat-conducting fins 501 are evenly distributed. The design of the heat-conducting fins 501 can increase the contact area with the exhaust gas, improve the heat transfer area, and thus improve the uniformity and effect of heating the clean water, and make the heat recovery more complete.

[0033] In this embodiment, a tail gas conveying pipe 18 is fixedly connected to the right side of the heat recovery box 2. The tail gas conveying pipe 18 is connected to the heat recovery box 2 and is used to convey the tail gas after heat release in the heat recovery box 2. The end of the tail gas conveying pipe 18 away from the heat recovery box 2 is fixedly connected to the inlet end of an external tail gas separation device to separate hydrogen, water, and oxygen in the tail gas for reuse. Reinforcing blocks 19 are fixedly installed on the top of both the thermally conductive hollow water distribution plate 3 and the thermally conductive hollow water collection plate 4. The tops of both reinforcing blocks 19 are fixedly connected to the inner top wall of the heat recovery box 2. Reinforcing blocks 20 are fixedly installed at the bottom of each plate 4. The bottom of both reinforcing blocks 20 is fixedly connected to the bottom inner wall of the heat recovery box 2. The design of reinforcing blocks 19 and 20 can enhance the stability of the heat-conducting hollow water distribution plate 3 and the heat-conducting hollow water collection plate 4 installed and fixed in the heat recovery box 2. It can also leave a gap between the top of the heat-conducting hollow water distribution plate 3 and the heat-conducting hollow water collection plate 4 and the top inner wall of the heat recovery box 2, and leave a gap between the bottom of the heat-conducting hollow water distribution plate 3 and the heat-conducting hollow water collection plate 4 and the bottom inner wall of the heat recovery box 2. The gap is used for the flow of exhaust gas in the heat recovery box 2.

[0034] In this embodiment, inclined exhaust gas guide plates 21 are fixedly installed on the top inner wall and bottom inner wall of the heat recovery box 2. The design of the exhaust gas guide plates 21 can guide the exhaust gas flow direction into the heat recovery box 2, which helps to guide the exhaust gas to flow between multiple heat-conducting diversion water pipes 5, ensuring that the residual heat in the exhaust gas is efficiently transferred to the clean water.

[0035] In this embodiment, the hot water delivery assembly includes a hot water pump 9, a hot water delivery main pipe 10, and two hot water delivery branch pipes 11. The hot water pump 9 is fixedly installed on the top of the heat recovery tank 2, and the end of the hot water discharge pipe 8 located inside the heat recovery tank 2 is fixedly connected to the suction end of the hot water pump 9. One end of the hot water delivery main pipe 10 is fixedly connected to the discharge end of the hot water pump 9. The two hot water delivery branch pipes 11 are both fixedly connected to the hot water delivery main pipe 10, and the bottom ends of the two hot water delivery branch pipes 11 are respectively fixedly connected to the corresponding heat insulation cylinder 13. By operating the hot water pump 9, the heated hot water in the heat-conducting hollow water collecting plate 4 can be extracted through the hot water discharge pipe 8 and then transported away through the hot water delivery main pipe 10. The hot water transported in the hot water delivery main pipe 10 can flow in three directions. One direction is discharged from the end of the hot water delivery main pipe 10 away from the hot water pump 9 and can be used for domestic water use. The other two directions can be transported to the corresponding heat insulation cylinder 13 through the two hot water delivery branch pipes 11, and the heat in the hot water can be used to preheat hydrogen and oxygen respectively.

[0036] In this embodiment, electromagnetic flow regulating valve 12 is fixedly installed on each of the two hot water delivery branch pipes 11, and electromagnetic flow regulating valve 25 is fixedly installed on each of the two water outlet pipes 14. By using electromagnetic flow regulating valve 12 and electromagnetic flow regulating valve 25 together, the flow rate of hot water entering and exiting the heat insulation cylinder 13 can be controlled, thereby adjusting the preheating temperature of hydrogen and oxygen to a suitable temperature value according to the requirements.

[0037] In this embodiment, temperature sensor 16 and temperature sensor 27 are fixedly installed on the top of each of the two heat insulation cylinders 13. The detection ends of the two temperature sensors 16 extend into the corresponding heat insulation cylinder 13, and the detection ends of the two temperature sensors 27 extend into the hydrogen inlet pipe 101 and the oxygen inlet pipe 102, respectively. The two temperature sensors 16 are used to detect the water temperature in the corresponding heat insulation cylinder 13, and the two temperature sensors 27 are used to detect the temperature of hydrogen and oxygen, respectively, so as to accurately control the opening of the electromagnetic flow regulating valve 12 and the electromagnetic flow regulating valve 25, and to more accurately preheat hydrogen and oxygen.

[0038] In this embodiment, the heat recovery device for the hydrogen fuel cell system may further include two heat-insulating cylinders 22 and two annular electric heating plates 23. The two heat-insulating cylinders 22 are respectively fixedly sleeved on the hydrogen inlet pipe 101 and the oxygen inlet pipe 102, with the ends of the two heat-insulating cylinders 22 close to each other and respectively fixedly connected to the ends of the two heat-insulating cylinders 13 far from each other. The two annular electric heating plates 23 are respectively fixedly sleeved on the hydrogen inlet pipe 101 and the oxygen inlet pipe 102, and are respectively located inside the corresponding heat-insulating cylinders 22. Using the two annular electric heating plates 23, hydrogen and oxygen can be preheated electrically, respectively, for use during cold start-up of the hydrogen fuel cell 1 in a low-temperature environment or for exhaust gas. When residual heat is insufficient, preheating is used to ensure the stable operation of the hydrogen fuel cell 1 in the early stage under low temperature environment. The design of the heat insulation cylinder 22 can effectively reduce the heat transfer from the annular electric heating plate 23 to the external environment. It should be noted that both annular electric heating plates 23 are temperature-adjustable electric heating plates. The temperature value of the two annular electric heating plates 23 when energized is set according to the actual preheating temperature of hydrogen and oxygen. The temperature value of the two annular electric heating plates 23 is obtained through a limited number of experiments. Those skilled in the art can set the heating temperature value according to the experiment. The specific heating temperature value of the two annular electric heating plates 23 is not within the scope of protection of this solution, so it will not be described in detail in this article.

[0039] In this embodiment, both the hydrogen inlet pipe 101 and the oxygen inlet pipe 102 are fixedly fitted with a plurality of uniformly arranged heat-conducting fins 24. The arrangement of the heat-conducting fins 24 can enhance the heating area with the hot water, and can more efficiently transfer the heat in the hot water to the hydrogen and oxygen, thereby improving the efficiency of hydrogen and oxygen preheating.

[0040] In this embodiment, it should be noted that the electromagnetic shut-off valve 7, hot water pump 9, electromagnetic flow regulating valve 12, electromagnetic flow regulating valve 25, temperature sensor 16, temperature sensor 27, and annular electric heating plate 23 can all be purchased on the market or customized in the factory. Their wiring connection method and control method are conventional technical means that can be reasonably selected and implemented by those skilled in the art based on their ordinary technical knowledge without creative labor, and therefore do not need to be described in detail in the specification.

[0041] With the above structure, the working principle of the heat recovery device for a hydrogen fuel cell system provided in this application is as follows:

[0042] During the operation of the hydrogen fuel cell 1, the high-temperature exhaust gas (65℃-85℃) generated enters the heat recovery box 2 through the exhaust gas discharge pipe 103. Under the guidance of two exhaust gas guide plates 21, the exhaust gas in the heat recovery box 2 flows evenly through the space of multiple heat-conducting branch water pipes 5 and multiple heat-conducting fins 501. By opening the electromagnetic shut-off valve 7, low-temperature clean water enters the heat-conducting hollow water distribution plate 3 through the water inlet pipe 6, and is then evenly distributed to multiple heat-conducting branch water pipes 5. The clean water entering the multiple heat-conducting branch water pipes 5 then flows into the heat-conducting hollow water collection plate 4. During the flow of clean water, the heat in the exhaust gas can be efficiently and evenly transferred to the clean water, so that the clean water entering the heat-conducting hollow water collection plate is hot water that absorbs heat, realizing the recovery and utilization of exhaust gas heat.

[0043] By turning on the hot water pump 9, the hot water in the heat-conducting hollow water collection plate 4 can be extracted and distributed into three paths through the hot water delivery main pipe 10. One path can be externally output for domestic hot water use. By opening the two electromagnetic flow regulating valves 12 to the appropriate opening degree, the other two hot water paths are sent into the corresponding heat insulation cylinders 13 through the corresponding hot water delivery branch pipes 11. The hot water entering the two heat insulation cylinders 13 flows around the hydrogen inlet pipe 101 and the oxygen inlet pipe 102. With the help of the heat-conducting fins 24, the heat in the hot water can be efficiently transferred to the hydrogen and oxygen, achieving the effect of preheating the hydrogen and oxygen. The preheated hydrogen and oxygen then enter the hydrogen fuel cell 1 to directly convert chemical energy into electrical energy. The clean water after heat exchange and cooling in the two heat insulation cylinders 13 is discharged through the corresponding water outlet pipe 14. The end of the water outlet pipe 14 away from the heat insulation cylinder 13 is also externally output for domestic hot water use.

[0044] During the preheating process of hydrogen and oxygen, two temperature sensors 16 can be used to detect the hot water temperature in the corresponding heat insulation cylinder 13 in real time, and two temperature sensors 17 can be used to detect the inlet temperature of hydrogen and oxygen in real time. According to the set temperature, the opening of two electromagnetic flow regulating valves 12 and 15 can be adjusted respectively to control the flow rate of hot water entering the two heat insulation cylinders 13 and the flow rate of hot water discharged from the two outlet pipes 14. This allows for precise control of the preheating temperature of hydrogen (40℃-55℃) and oxygen (45℃-60℃), achieving a stable inlet preheating effect, thereby improving the stack reaction activity and power conversion efficiency of the hydrogen fuel cell 1 and achieving energy saving effect.

[0045] When the hydrogen fuel cell 1 is cold-started in a low-temperature environment or when the exhaust gas waste heat is insufficient, the two annular electric heating plates 23 are turned on and run at appropriate heating temperatures. The heat generated by the two annular electric heating plates 23 can preheat the hydrogen and oxygen respectively. After the stack in the hydrogen fuel cell 1 is running normally or the exhaust gas waste heat is sufficient, the two annular electric heating plates 23 are turned off, and the exhaust gas heat can be recovered to preheat the hydrogen and oxygen, thus achieving energy-saving operation.

Claims

1. A heat recovery device for a hydrogen fuel cell system, comprising a hydrogen fuel cell (1) and a heat recovery box (2), wherein a hydrogen inlet pipe (101) is fixedly connected to the left side of the hydrogen fuel cell (1), and an oxygen inlet pipe (102) and a tail gas outlet pipe (103) are fixedly connected to the right side of the hydrogen fuel cell (1), one end of the tail gas outlet pipe (103) being connected to the interior of the heat recovery box (2), characterized in that, Also includes: The exhaust gas waste heat recovery component is installed on the heat recovery box (2) and is used to heat the clean water with the heat generated in the exhaust gas generated during the operation of the hydrogen fuel cell (1). A hot water delivery assembly is installed on the heat recovery tank (2) for delivering hot water; Two heat insulation cylinders (13) are fixedly sleeved on the hydrogen inlet pipe (101) and the oxygen inlet pipe (102) respectively. The two heat insulation cylinders (13) are fixedly connected to the left and right outer walls of the hydrogen fuel cell (1) respectively. Two water outlet pipes (14) are fixedly installed at the bottom of the corresponding heat insulation cylinder (13), and the two water outlet pipes (14) are connected to the corresponding heat insulation cylinder (13).

2. The heat recovery device for a hydrogen fuel cell system according to claim 1, characterized in that, The exhaust gas waste heat recovery component includes: A heat-conducting hollow water distribution plate (3) is installed inside the heat recovery box (2); A heat-conducting hollow water collection plate (4) is installed inside the heat recovery box (2) and located to the left of the heat-conducting hollow water distribution plate (3); Multiple thermally conductive branch water pipes (5) are fixedly connected at their right ends to the thermally conductive hollow water distribution plate (3), and the left ends of the multiple thermally conductive branch water pipes (5) are fixedly connected to the thermally conductive hollow water collection plate (4). The water inlet pipe (6) is fixedly installed on the right side of the heat recovery box (2), and the left end of the water inlet pipe (6) extends into the heat recovery box (2) and is connected to the heat-conducting hollow water distribution plate (3). An electromagnetic shut-off valve (7) is fixedly installed on the water inlet pipe (6); A hot water discharge pipe (8) is fixedly installed on the top of the heat recovery box (2). One end of the hot water discharge pipe (8) extends into the heat recovery box (2) and is connected to the heat-conducting hollow water collection plate (4).

3. The heat recovery device for a hydrogen fuel cell system according to claim 2, characterized in that, Multiple heat-conducting fins (501) are fixedly sleeved on the heat-conducting branch water pipe (5), and the multiple heat-conducting fins (501) are evenly distributed.

4. The heat recovery device for a hydrogen fuel cell system according to claim 2, characterized in that, The right side of the heat recovery box (2) is fixedly connected to the exhaust gas conveying pipe (18), which is connected to the heat recovery box (2). The top of the heat-conducting hollow water distribution plate (3) and the heat-conducting hollow water collection plate (4) are both fixedly installed with a first reinforcing block (19). The top of the two first reinforcing blocks (19) are both fixedly connected to the top inner wall of the heat recovery box (2). The bottom of the heat-conducting hollow water distribution plate (3) and the heat-conducting hollow water collection plate (4) are both fixedly installed with a second reinforcing block (20). The bottom of the two second reinforcing blocks (20) are both fixedly connected to the bottom inner wall of the heat recovery box (2).

5. The heat recovery device for a hydrogen fuel cell system according to claim 2, characterized in that, The heat recovery box (2) is fixedly installed with inclined exhaust gas guide plates (21) on the top inner wall and bottom inner wall.

6. The heat recovery device for a hydrogen fuel cell system according to claim 2, characterized in that, The hot water delivery assembly includes: A hot water pump (9) is fixedly installed on the top of the heat recovery box (2), and one end of the hot water discharge pipe (8) located inside the heat recovery box (2) is fixedly connected to the suction end of the hot water pump (9); One end of the hot water delivery main pipe (10) is fixedly connected to the discharge end of the hot water pump (9); Two hot water delivery branch pipes (11) are fixedly connected to the hot water delivery main pipe (10), and the bottom ends of the two hot water delivery branch pipes (11) are fixedly connected to the corresponding heat insulation cylinder (13).

7. The heat recovery device for a hydrogen fuel cell system according to claim 6, characterized in that, Electromagnetic flow regulating valve one (12) is fixedly installed on both of the hot water delivery branch pipes (11), and electromagnetic flow regulating valve two (15) is fixedly installed on both of the water outlet pipes (14).

8. The heat recovery device for a hydrogen fuel cell system according to claim 6, characterized in that, Temperature sensor 1 (16) and temperature sensor 2 (17) are fixedly installed on the top of each of the two heat insulation cylinders 1 (13). The detection ends of the two temperature sensors 1 (16) extend into the corresponding heat insulation cylinder 1 (13), and the detection ends of the two temperature sensors 2 (17) extend into the hydrogen inlet pipe (101) and the oxygen inlet pipe (102), respectively.

9. The heat recovery device for a hydrogen fuel cell system according to claim 1, characterized in that, Also includes: Two heat insulation cylinders (22) are fixedly sleeved on the hydrogen inlet pipe (101) and the oxygen inlet pipe (102), respectively. The ends of the two heat insulation cylinders (22) that are close to each other are fixedly connected to the ends of the two heat insulation cylinders (13) that are far apart from each other. Two annular electric heating plates (23) are fixedly sleeved on the hydrogen inlet pipe (101) and the oxygen inlet pipe (102), respectively, and the two annular electric heating plates (23) are respectively located in the corresponding heat insulation cylinder (22).

10. The heat recovery device for a hydrogen fuel cell system according to claim 1, characterized in that, Both the hydrogen inlet pipe (101) and the oxygen inlet pipe (102) are fixedly fitted with a plurality of uniformly arranged heat-conducting fins (24).

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