Partitioned hierarchical proton exchange membrane fuel cell bus temperature control system

Abstract

The application discloses a kind of partition grading proton exchange membrane fuel cell passenger car temperature control system, comprising: fuel cell stack, including proton exchange membrane;Compressed air heat exchange structure, including air compressor, compressed air heat exchanger, gas tank, humidifier, exhaust valve, first radiator and first circulating pump, wherein, compressed air heat exchanger and gas tank are sequentially connected between air compressor and humidifier, exhaust valve is connected with humidifier, one end of first circulating pump is connected with fuel cell stack;Hydrogen heat exchange structure, including high-pressure hydrogen tank, first solenoid valve, second solenoid valve, medium-pressure hydrogen tank, second circulating pump, third circulating pump, second radiator and hydrogen exhaust valve, medium-pressure hydrogen tank is equipped with internal heat exchanger, first solenoid valve is connected between high-pressure hydrogen tank and medium-pressure hydrogen tank;And refrigerant heat exchange structure, including fourth circulating pump, fifth circulating pump, heat exchange water tank, third solenoid valve, heat exchanger and third radiator.

Description

Technical Field

[0001] This invention relates to a temperature control system for fuel cell buses, and more specifically, to a zoned and graded proton exchange membrane fuel cell bus temperature control system. Background Technology

[0002] Thermal power generation and nuclear power have an efficiency of approximately 30% to 40%, while proton exchange membrane fuel cells can directly convert the chemical energy of fuel into electrical energy. They have advantages such as high power generation efficiency (electrochemical efficiency of 40-60%), less environmental pollution, and an operating temperature below 100°C, thus attracting widespread attention in the field of fuel cell buses.

[0003] However, the operating temperature of a fuel cell has a significant impact on its performance. At low temperatures, various polarizations within the cell intensify, and the ohmic impedance is also higher, thus deteriorating the cell's performance. Higher temperatures reduce ohmic impedance and polarization, and are beneficial for increasing the electrochemical reaction rate and proton transport within the membrane, improving cell performance. However, because the water content of the membrane strongly affects its conductivity, high temperatures can lead to membrane dehydration, decreased conductivity, and worsened cell performance. Simultaneously, the temperature distribution within the cell also significantly impacts performance, determining water evaporation and condensation, influencing water distribution, and affecting the diffusion and transport of multi-component gases through thermal surface tension and thermal buoyancy. Insufficient or ineffective cell cooling can lead to excessively high temperatures in the entire or localized areas of the cell, causing membrane dehydration, shrinkage, wrinkling, or even rupture. Furthermore, the typical catalyst for current automotive fuel cells is Pt / C, and changes in the operating conditions of the fuel cell under automotive conditions can cause variations in temperature and humidity, accelerating catalyst aging.

[0004] Typically, fuel cells with a power output below 200W utilize air supplied to the cathode for cooling, while those above 250W incorporate dedicated cooling channels on the bipolar plates. Existing Chinese patents (CN203800126U, CN106229530A, CN101447580A, CN102386430A, etc.) and US patents (US 6777115, WO 04025752, etc.) focus on the fuel cell system itself, addressing key issues such as liquid and gaseous water flow during low-temperature startup. They employ insulation and heating measures to prevent pipe blockage and valve freezing caused by the condensation of gaseous and liquid water at low temperatures, thus shortening the low-temperature startup time. Liquid injection is used to suppress icing, eliminating energy losses from heating the solenoid valve during subsequent cold starts and improving the efficiency of the fuel cell system. Current research on electrocatalyst degradation primarily focuses on the degradation resistance of catalyst supports.

[0005] None of the above studies are based on the entire proton exchange membrane fuel cell bus, nor are there any related patents, documents, or practical products for fuel cell bus temperature control systems that employ zoned or graded temperature control technology to meet the temperature requirements of different areas of the bus. Summary of the Invention

[0006] This invention provides a zoned and graded proton exchange membrane fuel cell bus temperature control system for zoned and graded temperature control in a proton exchange membrane fuel cell bus.

[0007] To achieve the above objectives, the present invention provides a zoned and graded proton exchange membrane fuel cell bus temperature control system, comprising:

[0008] Fuel cell stack, including proton exchange membrane;

[0009] The compressed air heat exchange structure includes an air compressor, a compressed air heat exchanger, an air tank, a humidifier, an exhaust valve, a first radiator, and a first circulating pump. The compressed air heat exchanger and the air tank are sequentially connected between the air compressor and the humidifier. The exhaust valve is connected to the humidifier. One end of the first circulating pump is connected to the fuel cell stack, and the other end is connected to the first radiator. The other end of the first radiator is connected to the fuel cell stack. The compressed air heat exchanger and the first radiator are connected in parallel.

[0010] A hydrogen heat exchange structure includes a high-pressure hydrogen tank, a first solenoid valve, a second solenoid valve, a medium-pressure hydrogen tank, a second circulation pump, a third circulation pump, a second radiator, and a hydrogen discharge valve. The medium-pressure hydrogen tank has an internal heat exchanger. The first solenoid valve is connected between the high-pressure and medium-pressure hydrogen tanks. The second circulation pump is connected in series with the second radiator and then in parallel with the medium-pressure hydrogen tank. One end of the second solenoid valve is connected to the fuel cell stack, and the other end is connected to the medium-pressure hydrogen tank and the third circulation pump. The hydrogen discharge valve is connected to the fuel cell stack and the third circulation pump.

[0011] The refrigerant heat exchange structure includes a fourth circulation pump, a fifth circulation pump, a hot water tank, a third solenoid valve, a heat exchanger, and a third radiator. One end of the fourth circulation pump is connected to the fuel cell stack, and the other end is sequentially connected to the hot water tank, the third solenoid valve, and the heat exchanger before being connected to the fuel cell stack. The fifth circulation pump is connected to the third radiator and then in parallel with the heat exchanger.

[0012] The first, second, and third radiators are located inside the vehicle body.

[0013] In one embodiment of the present invention, a thermometer and a pressure gauge are provided at the input and output ends of the air compressor, the output end of the air storage tank, and each port of the fuel cell stack.

[0014] The zoned and graded proton exchange membrane fuel cell bus temperature control system provided by this invention adopts zoned and graded temperature control technology, which can ensure that the temperature in each area of ​​the fuel cell bus is within a suitable range. It can not only meet the temperature control requirements of fuel cells for temperature range, uniform temperature distribution and temperature limit, but also delay the accelerated aging of catalysts caused by changes in temperature and humidity due to changes in vehicle operating conditions. Moreover, it can effectively utilize the heat emitted into the environment during the process of converting chemical energy into electrical energy by fuel cells, further improving the energy utilization rate of fuel cell buses. Attached Figure Description

[0015] 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the partitioned and graded proton exchange membrane fuel cell bus temperature control system provided by the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0018] Figure 1 This is a schematic diagram of the partitioned and graded proton exchange membrane fuel cell bus temperature control system provided by the present invention, as shown below. Figure 1 As shown, the partitioned and graded proton exchange membrane fuel cell bus temperature control system provided by the present invention includes:

[0019] The fuel cell stack R1 includes a proton exchange membrane (not shown in the figure);

[0020] The compressed air heat exchange structure includes an air compressor Y1, a compressed air heat exchanger H1, an air tank U1, a humidifier D1, an exhaust valve E1, a first radiator H5, and a first circulation pump B4. The compressed air heat exchanger H1 and the air tank U1 are sequentially connected between the air compressor Y1 and the humidifier D1. The exhaust valve E1 is connected to the humidifier D1. One end of the first circulation pump B4 is connected to the fuel cell stack R1, and the other end is connected to the first radiator H5. The other end of the first radiator H5 is connected to the fuel cell stack R1. The compressed air heat exchanger H1 and the first radiator H5 are connected in parallel.

[0021] A hydrogen heat exchange structure includes a high-pressure hydrogen tank G3, a first solenoid valve F0, a second solenoid valve F1, a medium-pressure hydrogen tank G2, a second circulation pump B3, a third circulation pump B5, a second radiator H4, and a hydrogen discharge valve E2. The medium-pressure hydrogen tank G2 has an internal heat exchanger H6. The first solenoid valve F0 is connected between the high-pressure hydrogen tank G3 and the medium-pressure hydrogen tank G2. The second circulation pump B3 is connected in series with the second radiator H4 and then in parallel with the medium-pressure hydrogen tank G2. One end of the second solenoid valve F1 is connected to the fuel cell stack R1, and the other end is connected to the medium-pressure hydrogen tank G2 and the third circulation pump B5. The hydrogen discharge valve E2 is connected to the fuel cell stack R1 and the third circulation pump B5.

[0022] The refrigerant heat exchange structure includes a fourth circulation pump B2, a fifth circulation pump B1, a hot water tank G1, a third solenoid valve F2, a heat exchanger H3, and a third radiator H2. One end of the fourth circulation pump B2 is connected to the fuel cell stack R1, and the other end is sequentially connected to the hot water tank G1, the third solenoid valve F2, and the heat exchanger H3 before being connected to the fuel cell stack R1. The fifth circulation pump B1 is connected to the third radiator H2 and then connected in parallel with the heat exchanger H3.

[0023] The first radiator H5, the second radiator H4, and the third radiator H2 are located inside the vehicle body.

[0024] like Figure 1 As shown, in this invention, each port of the air compressor Y1 (input and output ends), the air storage tank U1 (output end), and the fuel cell stack R1 is equipped with a thermometer (T1-T11) and a pressure gauge (P1-P11). This invention can also include flow meters at some locations, such as... Figure 1 L1 to L3 in the diagram are flow meters.

[0025] In this invention, the fuel cell stack R1 is the core temperature control zone, which requires strict temperature control. The compressed air heat exchanger H1, internal heat exchanger H6, and heat exchanger H3 constitute the primary temperature control zone, with temperature control requirements second only to the core temperature control zone. The third radiator H2, second radiator H4, and first radiator H5 constitute the secondary temperature control zone, with the lowest temperature control requirements. This forms a three-tiered temperature control system: the core temperature control zone, the primary temperature control zone, and the secondary temperature control zone. Through temperature zoning, primary and secondary temperature control are achieved, effectively utilizing the heat released during the conversion of chemical energy into electrical energy in the fuel cell stack R1, realizing cascaded energy utilization, and improving energy efficiency.

[0026] Coolant in the hot water tank G1 is pumped to the fuel cell stack R1 via the fourth circulation pump B2 to absorb waste heat from the fuel cell stack R1. This heat is then transferred to the third radiator H2 via the heat exchanger H3, operated by the fifth circulation pump B1. The third radiator H2 releases the heat into the vehicle interior (when heating is needed in winter) or the atmosphere, ensuring the temperature of the fuel cell stack R1 remains within acceptable limits. Compressed air heat exchanger H1, operated by the first circulation pump B4, uses coolant to cool the high-temperature compressed air discharged from the air compressor Y1, reducing it to the operating temperature of the fuel cell stack R1. The heat absorbed by the compressed air heat exchanger H1 is released into the vehicle interior (when heating is needed in winter) or the atmosphere via the first radiator H5. Internal heat exchanger H6 inside the medium-pressure hydrogen tank G2 uses coolant, operated by the second circulation pump B3, to cool the hydrogen discharged from the high-pressure hydrogen tank G3 due to throttling and heating, reducing it to the operating temperature of the fuel cell stack R1. The heat absorbed by the internal heat exchanger H6 is released into the vehicle interior (when heating is needed in winter) or the atmosphere via the second radiator H4.

[0027] The zoned and graded proton exchange membrane fuel cell bus temperature control system provided by this invention adopts zoned and graded temperature control technology, which can ensure that the temperature in each area of ​​the fuel cell bus is within a suitable range. It can not only meet the temperature control requirements of fuel cells for temperature range, uniform temperature distribution and temperature limit, but also delay the accelerated aging of catalysts caused by changes in temperature and humidity due to changes in vehicle operating conditions. Moreover, it can effectively utilize the heat emitted into the environment during the process of converting chemical energy into electrical energy by fuel cells, further improving the energy utilization rate of fuel cell buses.

[0028] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of one embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing the present invention.

[0029] Those skilled in the art will understand that the modules in the apparatus of the embodiments can be distributed in the apparatus of the embodiments as described in the embodiments, or they can be located in one or more devices different from this embodiment with corresponding changes. The modules of the above embodiments can be combined into one module, or they can be further divided into multiple sub-modules.

[0030] 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A zoned and graded proton exchange membrane fuel cell bus temperature control system, characterized in that, include: A fuel cell stack, including a proton exchange membrane, wherein each port of the fuel cell stack is equipped with a thermometer and a pressure gauge; The compressed air heat exchange structure includes an air compressor, a compressed air heat exchanger, an air tank, a humidifier, an exhaust valve, a first radiator, and a first circulating pump. The compressed air heat exchanger and the air tank are sequentially connected between the air compressor and the humidifier. The exhaust valve is connected to the humidifier. One end of the first circulating pump is connected to the fuel cell stack, and the other end is connected to the first radiator. The other end of the first radiator is connected to the fuel cell stack. The compressed air heat exchanger and the first radiator are connected in parallel. The input and output ends of the air compressor and the output end of the air tank are equipped with thermometers and pressure gauges. A hydrogen heat exchange structure includes a high-pressure hydrogen tank, a first solenoid valve, a second solenoid valve, a medium-pressure hydrogen tank, a second circulation pump, a third circulation pump, a second radiator, and a hydrogen discharge valve. The medium-pressure hydrogen tank has an internal heat exchanger. The first solenoid valve is connected between the high-pressure and medium-pressure hydrogen tanks. The second circulation pump is connected in series with the second radiator and then in parallel with the medium-pressure hydrogen tank. One end of the second solenoid valve is connected to the fuel cell stack, and the other end is connected to the medium-pressure hydrogen tank and the third circulation pump. The hydrogen discharge valve is connected to the fuel cell stack and the third circulation pump. The refrigerant heat exchange structure includes a fourth circulation pump, a fifth circulation pump, a hot water tank, a third solenoid valve, a heat exchanger, and a third radiator. One end of the fourth circulation pump is connected to the fuel cell stack, and the other end is sequentially connected to the hot water tank, the third solenoid valve, and the heat exchanger before being connected to the fuel cell stack. The fifth circulation pump is connected to the third radiator and then in parallel with the heat exchanger. The first radiator, the second radiator, and the third radiator are located inside the vehicle body; The fuel cell stack is the core temperature control zone. The compressed air heat exchanger, the internal heat exchanger, and the heat exchanger are the primary temperature control zones, whose temperature control requirements are second only to the core temperature control zone. The third radiator, the second radiator, and the first radiator are the secondary temperature control zones, whose temperature control requirements are the lowest. Thus, a three-level temperature control zone is formed, consisting of the core temperature control zone, the primary temperature control zone, and the secondary temperature control zone. Through temperature zoning, primary and secondary temperature control is achieved. The coolant in the heat exchange tank is pumped to the fuel cell stack via the fourth circulation pump to absorb waste heat from the fuel cell stack. The heat is then transferred to the third radiator via the heat exchanger under the action of the fifth circulation pump. The third radiator releases the heat into the vehicle interior or the atmosphere, ensuring the fuel cell stack temperature remains within acceptable limits. The compressed air heat exchanger, under the action of the first circulation pump, uses coolant to cool the high-temperature compressed air discharged from the air compressor, reducing it to the operating temperature of the fuel cell stack. The heat absorbed by the compressed air heat exchanger is released into the vehicle interior or the atmosphere via the first radiator. The internal heat exchanger inside the medium-pressure hydrogen tank uses coolant under the action of the second circulation pump to cool the hydrogen discharged from the high-pressure hydrogen tank due to throttling and temperature rise, reducing it to the operating temperature of the fuel cell stack. The heat absorbed by the internal heat exchanger is released into the vehicle interior or the atmosphere via the second radiator.

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