Patent Application
20250006957
The present disclosure relates to the technical field of fuel cells, and specifically relates to a system for waste heat recovery of fuel cell and a vehicle.
The operating temperature of low-temperature proton exchange membrane fuel cells is generally between 70-90° C., and a large amount of heat is generally generated during the operation, and heating power of the fuel cell can be roughly equal to its generation power. In larger power stacks, the heating power can be as high as 100 kW or even higher. At the same time, in order to expand the scope of applications, improve product competitiveness, and meet lower cold start temperature performance requirements, the existing stack system is equipped with electric heating equipment to ensure the low-temperature cold start performance of the stack. However, additional heating equipment will occupy the volume and mass of the system, resulting in a decrease in the volume power density and mass power density of the system. Therefore, on the one hand, from the perspective of heat dissipation, dissipating such a huge amount of heat brings out more stringent requirements for the vehicle cooling system; and from the perspective of vehicle energy utilization, dissipating the heat in vain is a huge waste of energy. On the other hand, solving the cold start problem of the stack without increasing the volume and quality of the system is the key to high-power fuel cell stack systems.
The technical problem to be solved by the present disclosure is to provide a device capable of recycling waste heat of a fuel cell and a vehicle.
In order to solve the above technical problems, the technical solution adopted by the present disclosure is:
A system for waste heat recovery of a fuel cell, comprising a cold source side, a heat source side, and a thermoelectric conversion module located between the cold source side and the heat source side;
Preferably, the thermoelectric conversion module outputs through a DCDC inverter.
Preferably, the thermoelectric conversion module includes multiple groups of thermoelectric materials connected in series, ends at one side of the thermoelectric materials are connected by conductor to form a PN junction and are in contact with the heat source side, and ends at the other side of the thermoelectric materials are in contact with the cold source side . . .
Preferably, insulators are respectively arranged between the thermoelectric conversion module and the heat source side, and between the thermoelectric conversion module and the cold source side.
In order to solve the above technical problems, another technical solution adopted by the present disclosure is:
Preferably, the cold source side comprises a cold source box and pipelines, the cold source box comprises a cold source fluid inlet and a cold source fluid outlet, and the cold source fluid inlet and the cold source fluid outlet are respectively communicated with the cooler through the pipelines; there is cold source fluid in the cold source box.
Preferably, the fuel cell comprises a cooling flow channel;
Preferably, the vehicle also comprises a controller, a temperature sensor, a first pump, and a second pump;
Preferably, the vehicle also comprises a storage battery, and the storage battery is electrically connected to the controller, the temperature sensor, the first pump, the second pump, and the thermoelectric conversion module;
The beneficial effect of the present disclosure is that by adopting a thermoelectric conversion module and utilizing the Seebeck effect of semiconductor thermoelectric power generation materials to directly convert low-grade thermal energy into electrical energy, it can not only reduce the heat dissipation burden of the heat dissipation system, but also convert low-grade thermal energy into electrical energy, which can be reused by other vehicle-mounted electrical appliances to improve system operating efficiency and achieve energy saving. At the same time, the stack can be heated in reverse under energized conditions to improve the cold start performance of the system. There is no need to heat the fuel cell through PTC, reducing the number of system components and the complexity of the system, effectively reducing the system cost.
In order to describe the technical content, achieved objectives and effects of the present disclosure in detail, the following description will be made in conjunction with the embodiments and the accompanying drawings.
Referring to
The thermoelectric conversion module 3 outputs through a DCDC inverter 4.
The thermoelectric conversion module 3 includes multiple groups of thermoelectric materials 31 connected in series, ends at one side of the thermoelectric materials 31 are connected by conductor to form a PN junction and are in contact with the heat source side, and ends at the other side of the thermoelectric materials are in contact with the cold source side . . .
Insulators 32 are respectively arranged between the thermoelectric conversion module 3 and the heat source side, and between the thermoelectric conversion module 3 and the cold source side.
The thermoelectric conversion module 3 realizes thermoelectric power generation. Thermoelectric power generation refers to the phenomenon that when there is a temperature difference between two ends of different thermoelectric materials 31, electromotance will be generated at both ends of the material to form a current, thereby achieving direct conversion of thermal energy into electrical energy. As shown in
A vehicle, comprising a cooler, a fuel cell and the system for waste heat recovery of a fuel cell according to any one of claims 1-4;
The cold source side comprises a cold source box 1 and pipelines, the cold source box 1 comprises a cold source fluid inlet 11 and a cold source fluid outlet 12, and the cold source fluid inlet 11 and the cold source fluid outlet 12 are respectively communicated with the cooler through the pipelines; there is cold source fluid in the cold source box.
The fuel cell comprises a cooling flow channel;
The vehicle also comprises a controller, a temperature sensor, a first pump, and a second pump;
The vehicle also comprises a storage battery, and the storage battery is electrically connected to the controller, the temperature sensor, the first pump, the second pump, and the thermoelectric conversion module 3;
When the fuel cell is in operation, the high-temperature hot fluid flowing out of the cooling flow channel of the fuel cell flows into the heat source box 2 through the heat source fluid inleent. The heat in the high-temperature fluid is transferred to the thermoelectric conversion module through the insulation sheet, causing the hot end temperature of thermoelectric conversion module 3 converge with the temperature of the high-temperature hot fluid. After the heat is transferred by the heat source box 2, the high-temperature fluid flows out of the heat source fluid outlet 22 and enters the cooling flow channel of the fuel cell of the original loop for heating; similarly, the cooler/heat dissipation module is installed at the front end of the vehicle where it hits the wind or other low-temperature places. The cold source fluid flows into the cold source box 1 through the cold source fluid inlet, and absorbs the heat from the cold end of the thermoelectric conversion module 3 in the cold source, so that its temperature converges with the temperature of the cold source. Accordingly, the temperature difference between the hot and cold ends of the thermoelectric conversion module 3 is realized, thereby achieving the thermoelectric conversion effect. The generated current is introduced into the DCDC inverter 4 through the wiring harness for rectification to meet the current and voltage requirements of the electrical appliances. The rectified current is output through the output port 5 to complete the operation process of the entire device.
In summary, the present disclosure utilizes the temperature difference between the internal heat source of the fuel cell and the cold source such as the environment. When using a low-temperature proton exchange membrane fuel cell, the temperature difference between the hot end and cold end can reach 40-100° C.; and when using high-temperature protons exchange membrane fuel cells or solid oxide fuel cells, the temperature difference can even reach hundreds of degrees. This temperature difference can be used to generate corresponding thermoelectric electromotance at two ends of the thermoelectric material, thereby generating current to supply the corresponding electrical appliances. On the one hand, a large amount of waste heat is recovered instead of dissipating directly into the atmosphere, which improves the operating efficiency of the fuel cell system; on the other hand, it provides an additional source of power for electrical appliances, reducing the consumption of fuel cell output power, achieving energy saving effect.
2. Directly use the high-temperature coolant flowing out of the fuel cell stack and the low-temperature coolant flowing out of the heat dissipation module as heat and cold sources. There is no need to make adaptive improvements to the existing system. This device can be directly connected to the cooling circuit of the existing fuel cell system for use, which is convenient, fast and low-cost.
3. The method and device can be applied to fuel cell vehicles and other fuel cell systems. It is not only suitable for low-temperature fuel cell systems (LT-PEMFC, HT-PEMFC, etc.), but also for high-temperature fuel cell systems (SOFC, etc.). The higher the operating temperature of the fuel cell, the higher the electrical energy converted by this method and device. Many; it can even be applied to the power battery cooling circuit of pure electric vehicles for heat recovery, which has strong universal applicability.
4. Integrating the stack heating function into the thermoelectric material reduces the need for PTC components. At the same time, direct heating of the stack can also make the stack temperature rise faster and improve the cold start performance of the system.
The above are only embodiments of the present disclosure, and do not limit the patent scope of the present disclosure. Any equivalent transformations made using the contents of the description and drawings of the present disclosure, or directly or indirectly applied in related technical fields, are equally included in within the scope of patent protection of this disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202111589714.7 | Dec 2021 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/111837 | 8/11/2022 | WO |
