A "gas-gas-liquid" three-phase heat exchange system for fuel cell thermal balance

Abstract

The present invention relates to a fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, belonging to the technical field of fuel cells, and solves the problems of energy waste of fuel cells and cold start affecting battery life. It includes a fuel cell stack, an air pipeline, a hydrogen pipeline, a deionized water pipeline, and heat exchange devices are provided on the hydrogen pipeline, the air pipeline, and the deionized water pipeline. In order to adapt to the operating environment of the fuel cell, air needs to be compressed before entering the fuel cell stack. The temperature after compression is higher than the operating temperature of the fuel cell stack, and it needs to be cooled before entering the battery stack; high-pressure liquid hydrogen needs to be decompressed in multiple stages before entering the fuel cell stack, and the temperature of the decompressed hydrogen is lower than the operating temperature of the fuel cell stack, and it needs to be heated before entering the fuel cell stack; heating deionized water enables the cold start of the fuel cell not to be damaged. Heat exchange devices are set up to drive low-temperature hydrogen with the heat of water and high-temperature air, adjust the overall temperature, and reduce the waste of thermal energy.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and particularly to a fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system. Background Art

[0002] The principle of a fuel cell is an electrochemical device with the same composition as a general battery, which converts chemical energy into electrical energy. When the battery operates, fuel and an oxidant are supplied externally, and the main raw materials are hydrogen and air. The oxygen required by the battery is sourced from the air, and the air needs to be filtered and compressed before entering the fuel cell stack. Currently, the temperature of the compressed air at the outlet of the air compressor is higher than the operating temperature range of the fuel cell stack, and it is necessary to solve the inlet temperature of the compressed air into the fuel cell stack. In the prior art, high-pressure gaseous hydrogen storage is the most widely used hydrogen storage method at present. To avoid the impact loss of hydrogen on the membrane electrode under high-pressure conditions, hydrogen can only enter the fuel cell stack after being depressurized in multiple stages. At this time, the temperature of the hydrogen entering the fuel cell stack is lower than the temperature of the air entering the fuel cell stack, resulting in a gradient temperature difference in the fuel cell stack and a gradient temperature difference on both sides of the membrane electrode. The membrane electrode is prone to accelerated aging and damage when working under the gradient temperature difference for a long time.

[0003] In the case of a fuel cell without special treatment or auxiliary tools, in a working environment below 0°C, the water generated by the reaction on the cathode side is prone to freezing, resulting in blockage of the catalytic layer and diffusion layer, hindering the progress of the reaction. Moreover, the volume change caused by the freezing of water will also damage the structure of the membrane electrode assembly, reducing the performance of the fuel cell.

[0004] Currently, the output power of fuel cell systems is getting higher and higher, and the raw materials consumed by the fuel cell stack are also increasing. Under the condition that the pipeline system and the fluid channel diameter of the stack remain unchanged, the air needs to be compressed. After the air is compressed, since its temperature is higher than the optimal working temperature environment of the fuel cell, it is necessary to cool the compressed air. To avoid the above defects, it is necessary to balance the temperatures of the hydrogen and compressed air entering the fuel cell stack. It is also necessary to process the fluid entering the fuel cell stack to enable the fuel cell stack to reach a suitable and stable working temperature environment. Summary of the Invention

[0005] The object of the present invention is to address the above problems existing in the prior art and propose a fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system.

[0006] To achieve the object of the present invention, the following technical solutions can be adopted: A fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system includes a fuel cell stack, an air pipeline, a hydrogen pipeline, and a deionized water pipeline, characterized in that: heat exchange devices are provided on the hydrogen pipeline, the air pipeline, and the deionized water pipeline.

[0007] In the prior art, air needs to be compressed before entering the fuel cell stack. The temperature of the compressed air is higher than the operating temperature range of the fuel cell stack, and it needs to be cooled down before entering the fuel cell stack. High-pressure liquid hydrogen needs to be depressurized in multiple stages before entering the fuel cell stack. The temperature of the depressurized hydrogen is lower than the operating temperature range of the fuel cell stack, and it needs to be heated up before entering the fuel cell stack. Compressing, decompressing, and adjusting the temperature of the gas all require the device to do work and generate heat energy. Deionized water is used to adjust the temperature of the fuel cell stack. This fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system is provided with heat exchange devices on the air pipeline, hydrogen pipeline, and deionized water pipeline, using the heat of water and high-temperature air to drive low-temperature hydrogen, reducing waste of heat energy and the overall heat cycle of the system.

[0008] In the above fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, a temperature compensation heater is provided in the heat exchange device. In the case of a fuel cell without special treatment or auxiliary tools, in an operating environment below 0°C, the water generated by the reaction on the cathode side is likely to freeze, resulting in blockage of the catalyst layer and diffusion layer, hindering the progress of the reaction. Moreover, the volume change caused by the freezing of water will also damage the structure of the membrane electrode assembly, reducing the performance of the fuel cell. To solve this problem, when the fuel cell is cold-started, the gas entering the fuel cell stack needs to be processed to make the fuel cell stack reach a stable operating temperature environment. The heat energy of the high-temperature compressed air is transferred to hydrogen and water through the heat exchange device. When the heat is insufficient, the temperature compensation heater in the heat exchange device can be started during the cold start of the fuel cell device.

[0009] In the above fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, fins in close contact with the hydrogen pipeline, air pipeline, and deionized water are provided in the heat exchange device. The fins play an important role in balancing the temperatures of high-temperature compressed air, low-temperature hydrogen, and deionized water. The hydrogen pipeline and air pipeline pass through the fins and are in close contact with the deionized water. The three gas pipelines are installed horizontally.

[0010] In the above fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, a hydrogen pipe temperature sensor is provided on the rear section pipeline of the heat exchange device of the hydrogen pipeline, and a solenoid valve for controlling the on-off of the fluid is provided on the front section. The heat exchange effect in the heat exchange device is adjusted according to the temperature feedback by the hydrogen pipe temperature sensor to adjust the temperature of the hydrogen after heat exchange.

[0011] In the above fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, an air pipe temperature sensor is provided on the rear section pipeline of the heat exchange device of the air pipeline, and a solenoid valve for controlling the on-off of the fluid is provided on the front section. The heat exchange effect in the heat exchange device is adjusted according to the temperature feedback by the air pipe temperature sensor to adjust the temperature of the air after heat exchange.

[0012] In the above fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, the deionized water pipeline is equipped with a temperature sensor of the heat exchange device in the heat exchange device. At the front section, there is a solenoid valve for controlling the on-off of the fluid. At the front end of the solenoid valve, there is a fuel cell stack heat dissipation system, and a temperature sensor of the fuel cell stack heat dissipation system is provided on the fuel cell stack heat dissipation system. After passing through the heat exchange, the deionized water flows through the fuel cell stack and then into the heat dissipation system of the fuel cell stack. After dissipating the excess heat, it then flows into the heat exchange device under the control of the solenoid valve. The heat dissipation effect of the overall system is adjusted by the water flow temperature feedback from the temperature sensor of the heat exchange device and the temperature sensor of the fuel cell stack heat dissipation system.

[0013] In the above fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, the heat exchange device includes a sealed container tank body, a sealed end cover, and a sealing gasket for cooperating with the end cover for sealing. The sealing gasket, the sealed end cover, and the sealed container tank body form a sealed whole to reduce the internal heat energy loss. Openings for installing and fixing the hydrogen pipeline and the air pipeline are provided on the sealed container tank body. A water inlet and outlet for directly flowing in deionized water are provided on the tank body. A temperature compensator port for installing a temperature compensating heater is also provided on the tank body. The deionized water directly flows into and fills the tank body, and can fully contact with the fins, the hydrogen pipeline, and the air pipeline. The temperature compensator port is provided below the openings of the air pipeline and the hydrogen pipeline because when heating is required, the heat dissipates upward, reducing waste.

[0014] In the above fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, the temperature compensating heater is a U-shaped electric heating rod uniformly and densely distributed under the fins. When the heat energy of the overall system is insufficient, external heating is adopted to reduce the damage to the device and the system caused by low temperature.

[0015] In the above fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, the exchange system includes a central processor that receives and processes the signals of each temperature sensor and adjusts the temperatures of the hydrogen pipeline, the air pipeline, the deionized pipeline, and the fuel cell stack with the temperature compensating heater. The central processor centrally processes and coordinates the global temperature. The temperature sensor transmits the temperature signal to the central processor, and after the central processor processes the signal, it controls the temperature heating compensator and the fuel cell heat dissipation system to coordinate the temperature.

[0016] Compared with the prior art, the fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system of the present invention thermally circulates most of the heat in the overall structure, reduces the unnecessary heat energy supply, and can ensure the operation in a low-temperature environment, saving energy and being environmentally friendly. Brief Description of the Drawings

[0017] Figure 1 It is a flow schematic diagram of the present invention;

[0018] Figure 2 This is a schematic structural diagram of the heat exchange device of the present invention.

[0019] In the figure, 1 is the air pipeline; 2 is the hydrogen pipeline; 3 is the deionized water pipeline; 4 is the heat exchange device; 41 is the sealed container tank body; 411 is the opening; 412 is the water inlet; 413 is the water outlet; 414 is the temperature compensation heater port; 42 is the sealed end cover; 43 is the gasket; 5 is the temperature compensation heater; 6 is the fin; 7 is the hydrogen pipe temperature sensor; 8 is the solenoid valve; 9 is the air pipe temperature sensor; 10 is the heat exchange device temperature sensor; 11 is the fuel cell stack heat dissipation system; 12 is the fuel cell stack heat dissipation system temperature sensor; 13 is the central processing unit. Specific embodiments

[0020] The following are specific embodiments of the present invention in combination with the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0021] As Figure 1 shown, the "gas-gas-liquid" three-phase heat exchange system for the thermal balance of the present fuel cell includes a fuel cell stack, an air pipeline 1, a hydrogen pipeline 2, a deionized water pipeline 3, and a heat exchange device 4 is provided on the hydrogen pipeline 2, the air pipeline 1, and the deionized water pipeline 3.

[0022] The air needs to be compressed before entering the fuel cell stack. The temperature of the compressed air is higher than the operating temperature range of the fuel cell stack and needs to be cooled before entering the fuel cell stack; the high-pressure liquid hydrogen needs to be decompressed in multiple stages before entering the fuel cell stack. The temperature of the decompressed hydrogen is lower than the operating temperature range of the fuel cell stack and needs to be heated before entering the fuel cell stack; Compressing, decompressing, and adjusting the temperature of the gas all require the device to do work and generate heat energy; deionized water is used to adjust the temperature of the fuel cell stack. The "gas-gas-liquid" three-phase heat exchange system for the thermal balance of the present fuel cell is provided with a heat exchange device 4 on the air pipeline 1, the hydrogen pipeline 2, and the deionized water pipeline 3, using the heat of water and high-temperature air to drive low-temperature hydrogen, reducing waste of heat energy and the overall heat cycle of the system.

[0023] A temperature compensation heater 5 is provided in the above-mentioned heat exchange device 4. In the case of a fuel cell without special treatment or auxiliary tools, in a working environment below 0 °C, the water generated by the reaction on the cathode side is likely to freeze, resulting in blockage of the catalytic layer and diffusion layer, hindering the progress of the reaction, and the volume change caused by the freezing of water will also damage the structure of the membrane electrode assembly, reducing the performance of the fuel cell. To solve this problem, when the fuel cell is cold-started, the gas entering the fuel cell stack needs to be processed to make the fuel cell stack reach a stable working temperature environment. The heat energy of the high-temperature compressed air is transferred to hydrogen and water through the heat exchange device 4. When the heat is insufficient, the temperature compensation heater 5 in the heat exchange device 4 can be started during the cold start of the fuel cell system.

[0024] In the above-mentioned heat exchange device 4, there are fins 6 in close contact with the hydrogen pipeline 2, the air pipeline 1, and deionized water. The fins 6 play an important role in balancing the temperatures of the high-temperature compressed air, low-temperature hydrogen, and deionized water. The hydrogen pipeline 2 and the air pipeline 1 penetrate through the fins 6, and the pipelines are installed horizontally.

[0025] In the above-mentioned hydrogen pipeline 2, a hydrogen pipe temperature sensor 7 is provided on the rear-section pipeline of the heat exchange device 4, and a solenoid valve 8 for controlling the on-off of the fluid is provided on the front section. The heat exchange effect in the heat exchange device 4 is adjusted through the temperature fed back by the hydrogen pipe temperature sensor 7 to adjust the temperature of the hydrogen after heat exchange. On the rear-section pipeline of the heat exchange device 4 of the air pipeline 1, an air pipe temperature sensor 9 is provided, and a solenoid valve 8 for controlling the on-off of the fluid is provided on the front section. The heat exchange effect in the heat exchange device 4 is adjusted through the temperature fed back by the air pipe temperature sensor 9 to adjust the temperature of the air after heat exchange. The ratio of hydrogen to air is controlled and adjusted to achieve the best effect of heating low-temperature hydrogen with high-temperature compressed air.

[0026] In the above-mentioned deionized water pipeline 3, a heat exchange device temperature sensor 10 is provided in the heat exchange device 4, and a solenoid valve 8 for controlling the on-off of the fluid is provided on the front section. A fuel cell stack heat dissipation system 11 is provided at the front end of the solenoid valve 8, and a fuel cell stack heat dissipation system temperature sensor 12 is provided on the fuel cell stack heat dissipation system 11. After passing through the heat exchange, the deionized water flows through the fuel cell stack and then into the fuel cell stack heat dissipation system 11, dissipates the excess heat, and then flows through the solenoid valve 8 into the heat exchange device 4. The heat dissipation effect of the overall system is adjusted through the water flow temperatures fed back by the heat exchange device temperature sensor 10 and the fuel cell stack heat dissipation system temperature sensor 12.

[0027] As Figure 2 shown: The above-mentioned heat exchange device 4 includes a sealed container tank body 41, a sealed end cover 42, and a gasket 43 for sealing in cooperation with the end cover. Openings 411 for installing and fixing the hydrogen pipeline 2 and the air pipeline 1 are provided on the sealed container tank body 41. An inlet 412 and an outlet 413 for directly flowing in deionized water are provided on the tank body. A temperature compensation heater port 414 for installing the temperature compensation heater 5 is also provided on the tank body. The gasket 43, the sealed end cover 42, and the sealed container tank body 41 form a sealed whole to reduce the loss of internal heat energy. The deionized water directly flows into and fills the tank body, and can be in full contact with the fins 6, the hydrogen pipeline 2, and the air pipeline 1. The temperature compensation heater port 414 is provided below the openings 411 of the air pipeline 1 and the hydrogen pipeline 2. The temperature compensation heater 5 is a U-shaped electric heating rod uniformly and densely distributed under the fins. When the heat energy of the overall system is insufficient, external heating is used to reduce the damage to the device and the system caused by low temperature.

[0028] The described switching system includes a central processor 13 that receives and processes the signals of each temperature sensor to regulate the temperature of the hydrogen pipeline 2, air pipeline 1, deionized water pipeline 3, and fuel cell stack through a temperature compensation heater. The central processor centrally processes and coordinates the global temperature. Each temperature sensor transmits the temperature signal to the central processor, and after processing the signal, the central processor controls the temperature heating compensator and the fuel cell heat dissipation system to coordinate the temperature.

[0029] As shown in the embodiment, after being compressed, the air carries thermal energy and dissipates the thermal energy to the hydrogen heat exchange pipe and deionized water through the fins. After the high-pressure hydrogen is decompressed, its temperature decreases, and it absorbs the thermal energy in the air heat exchange pipe and deionized water through the fins to reach the conditions for fuel cell use respectively; the deionized water also passes through the fuel cell stack and the heat dissipation system of the battery stack, absorbs the thermal energy and then returns to the heat exchange device to recycle most of the thermal energy; when the overall battery is in a working environment below 0 °C, the thermal energy brought by the compressed air is not enough to support the temperature of the overall structure, and it is necessary to start the temperature compensation heater to enable the fuel cell to work normally. In addition, the central processor controls and coordinates the global temperature.

[0030] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar methods to substitute them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system, comprising a fuel cell stack, an air pipeline (1), a hydrogen pipeline (2), and a deionized water pipeline (3). Characterized in that: Heat exchange devices (4) are provided on the hydrogen pipeline, the air pipeline, and the deionized water pipeline, and fins (6) in close contact with the hydrogen pipeline (2), the air pipeline (1), and the deionized water are provided in the heat exchange devices (4); The heat exchange device comprises a sealed container tank body (41), a sealed end cover (42), and a sealing gasket (43) for sealing cooperation with the end cover. The sealing gasket (43), the sealed end cover (42), and the sealed container tank body (41) form a sealed whole. Openings (411) for installing and fixing the hydrogen pipeline and the air pipeline are provided on the sealed container tank body (41). An inlet (412) for directly flowing in deionized water and an outlet (413) for flowing out deionized water are provided on the tank body. The deionized water directly flows into and fills the sealed container tank body (41), and is in full contact with the fins (6), the hydrogen pipeline (2), and the air pipeline (1). A temperature compensation heater (5) is provided in the heat exchange device (4), and a temperature compensation heater port (414) for installing the temperature compensation heater (5) is further provided on the tank body; The three-phase heat exchange system comprises a central processor (13) that receives and processes the signals of each temperature sensor and adjusts the temperatures of the hydrogen pipeline (2), the air pipeline (1), the deionized water pipeline (3), and the fuel cell stack with the temperature compensation heater (5); The air enters the fuel cell stack after being compressed. The temperature of the compressed air is higher than the operating temperature range of the fuel cell stack and needs to be cooled before entering the fuel cell stack; The high-pressure liquid hydrogen enters the fuel cell stack after being depressurized in multiple stages. The temperature of the depressurized hydrogen is lower than the operating temperature range of the fuel cell stack and needs to be heated before entering the fuel cell stack; The deionized water is used to adjust the temperature of the fuel cell stack.

2. A fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system according to claim 1, Characterized in that: A hydrogen pipe temperature sensor (7) is provided on the rear section pipeline of the hydrogen pipeline (2) in the heat exchange device (4), and a solenoid valve (8) for controlling the on-off of the fluid is provided on the front section.

3. A fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system according to claim 2, Characterized in that: An air pipe temperature sensor (9) is provided on the rear section pipeline of the air pipeline (1) in the heat exchange device (4), and a solenoid valve (8) for controlling the on-off of the fluid is provided on the front section.

4. A fuel cell thermal balance "gas-gas-liquid" three-phase heat exchange system according to claim 3, Characterized in that: A heat exchange device temperature sensor (10) is provided in the heat exchange device on the deionized water pipeline (3), a solenoid valve (8) for controlling the on-off of the fluid is provided on the front section, a fuel cell stack heat dissipation system (11) is provided in front of the solenoid valve, and a fuel cell stack heat dissipation system temperature sensor (12) is provided on the fuel cell stack heat dissipation system.

5. A "gas-gas-liquid" three-phase heat exchange system for fuel cell thermal balance according to claim 1, characterized in that: the temperature compensation heater (5) is a uniformly distributed electric heating rod.

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