Waste heat recycling system and method of fuel cell

Abstract

The invention discloses a waste heat recycling system and method for a fuel cell, and the system comprises a first loop which comprises an electric pile and a radiator; the cooling liquid outlet is connected with the input end of the radiator; the second loop comprises a heat exchanger, a heater, a first monitoring module and a second monitoring module; the first monitoring module is used for monitoring air volume information of air input into the heat exchanger. The second monitoring module is used for monitoring temperature information of air output by the heat exchanger; the cooling liquid absorbs heat generated by the galvanic pile and flows to the heat exchanger, and the heat exchanger performs primary heating on air flowing through the heat exchanger through the heat of the cooling liquid; the air subjected to primary heating is converted into warm air, and the warm air is transmitted to the operation room after passing through the heater. According to the waste heat recycling system, the heat exchanger is arranged in the second loop, the heat exchanger heats the air through the heat generated by the electric pile, the heat exchange efficiency can be improved, the parasitic power consumption of the radiator can be reduced, and the output power of the engine is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell waste heat utilization, and in particular to a fuel cell waste heat recovery and utilization system and method. Background Art

[0002] During fuel cell engine operation, coolant flows through the stack flow path, removing heat generated by the internal reactions. After cooling in the radiator, it recirculates back into the stack to meet the stack's temperature control requirements. Recycling the coolant's waste heat can reduce parasitic power consumption in the radiator.

[0003] In the existing technology, a coolant branch is branched off from the main radiator inlet line. A heat exchanger is installed on this branch line to exchange heat with the coolant in the air conditioning and heating circuit. Because this heat exchanger is located in the coolant branch line, only a portion of the coolant diverted from the main line is heat-exchanged with the air conditioning circuit, resulting in limited waste heat recovery. This branch line is connected in parallel with the main radiator line, requiring design considerations for the pressure drop and flow diversion between the two lines, increasing the system design workload. The coolant in this branch line does not flow through the radiator, but instead flows directly into the fuel cell stack after heat exchange with the air conditioning circuit. The coolant temperature in this branch line cannot be actively adjusted, making stack temperature control more difficult. Summary of the Invention

[0004] The present invention provides a system and method for recovering and utilizing waste heat of a fuel cell. By adding a heat exchanger in the loop and connecting the heat exchanger to the coolant outlet of the fuel cell stack, the heat exchanger uses the waste heat generated by the fuel cell stack to perform primary heating of the air to increase the rate of air heating. This not only improves the heat exchange efficiency without considering the distribution relationship between the pressure drop and flow rate between the first loop and the second loop, but also uses the waste heat generated by the fuel cell stack to perform primary heating of the air to reduce the parasitic power consumption of the radiator, and reduce the power consumption of the vehicle-end heater, thereby improving the output power and engine efficiency of the fuel cell engine.

[0005] According to a first aspect of the present invention, there is provided a waste heat recovery system for a fuel cell, comprising:

[0006] The first circuit includes the battery stack and radiator;

[0007] The stack includes a coolant inlet and a coolant outlet, wherein the coolant inlet is connected to the output end of the radiator; and the coolant outlet is connected to the input end of the radiator;

[0008] The second circuit includes a heat exchanger, a heater, a first monitoring module and a second monitoring module;

[0009] The first input end of the heat exchanger is connected to the coolant outlet of the fuel cell stack, and the second input end of the heat exchanger is in communication with the air; the first output end of the heat exchanger is connected to the input end of the radiator; the second output end of the heat exchanger is connected to the operating room through the heater; the first monitoring module is used to monitor the air volume information of the air input to the heat exchanger; the input end of the second monitoring module is connected to the second output end of the heat exchanger, and the second monitoring module is used to monitor the temperature information of the air output from the heat exchanger;

[0010] The coolant absorbs the heat generated by the fuel cell stack and flows to the heat exchanger, which uses the heat from the coolant to perform primary heating on the air flowing through the heat exchanger. The air heated in the primary stage is converted into warm air and transmitted to the operating room after passing through the heater.

[0011] Optionally, the second loop further includes:

[0012] a first valve, wherein the output end of the first valve is connected to the second input end of the heat exchanger, the first input end of the first valve receives air from the external environment, and the second input end of the first valve receives air from the operating chamber; when the circulation mode set in the operating chamber is internal circulation, the opening degree of the first valve is 0%, and the heat exchanger only receives air from the operating chamber; when the circulation mode set in the operating chamber is external circulation, the opening degree of the first valve is 100%, and the heat exchanger only receives air from the external environment;

[0013] A second valve, wherein the input end of the second valve is connected to the first monitoring module, the first output end of the second valve is connected to the second input end of the heat exchanger, and the second output end of the second valve is connected to the heater.

[0014] Optionally, the heater is used to:

[0015] When the second monitoring module monitors that the temperature of the warm air is lower than a preset temperature, the operating power of the heater is increased to perform secondary heating on the warm air, and the opening of the second valve is increased;

[0016] When the second monitoring module monitors that the temperature of the warm air is greater than or equal to a preset temperature, the operating power of the heater is reduced and the opening of the second valve is reduced.

[0017] Optionally, the second circuit further includes a blower;

[0018] The input end of the blower is connected to the output end of the first valve, and the output end of the blower is connected to the input end of the second valve. The blower is used to control the air volume input to the heat exchanger.

[0019] Optionally, the second circuit further includes a filtering module;

[0020] The input end of the filter module is connected to the output end of the first valve, and the output end of the filter module is connected to the second input end of the heat exchanger. The filter module is used to filter particulate matter in the air transmitted from the first valve to the heat exchanger.

[0021] Optionally, the first circuit further includes a thermostat;

[0022] The input end of the thermostat is connected to the output end of the fuel cell stack, the first output end of the thermostat is connected to the first input end of the heat exchanger, and the second output end of the thermostat is connected to the output end of the radiator.

[0023] According to a second aspect of the present invention, a method for recovering waste heat from a fuel cell is provided, which is applicable to any of the waste heat recovery systems for the fuel cell described in the first aspect of the present invention. The waste heat recovery method comprises:

[0024] When a warm air on command is recognized, the preset air volume and temperature of the required warm air are obtained;

[0025] Adjusting the air volume of the air input to the heat exchanger according to the preset air volume so that the air heated by the first stage of the heat exchanger is transmitted to the second monitoring module;

[0026] Obtaining the real-time temperature of the warm air after passing through the heat exchanger;

[0027] Dynamically adjust the operating power of the heater according to the real-time temperature;

[0028] The warm air is transmitted to the operating room after passing through the heater.

[0029] Optionally, the second circuit of the waste heat recovery system further includes a second valve for obtaining the real-time temperature of the warm air after passing through the heat exchanger; and dynamically adjusting the operating power of the heater according to the real-time temperature, including:

[0030] When the real-time temperature is lower than the preset temperature, the operating power of the heater is increased to perform secondary heating on the warm air, and the opening of the second valve is increased;

[0031] When the real-time temperature is greater than or equal to the preset temperature, the operating power of the heater is reduced, and the opening of the second valve is reduced.

[0032] Optionally, the second circuit of the waste heat recovery system further includes a blower, which adjusts the air volume of the air input to the heat exchanger according to the preset air volume so that the air heated by the first stage of the heat exchanger is transmitted to the second monitoring module, including:

[0033] Obtaining the real-time air volume of the air transmitted to the heat exchanger;

[0034] When the real-time air volume is greater than or equal to the preset air volume, reducing the fan speed of the blower;

[0035] When the real-time air volume is less than the preset air volume, the fan speed of the blower is increased.

[0036] Optionally, the second circuit of the waste heat recovery system further includes a first valve; when a warm air on instruction is recognized, before obtaining the required preset warm air volume and preset temperature, the system further includes:

[0037] Obtain cycle mode instructions from the operating room;

[0038] When the circulation mode instruction is internal circulation, the heat exchanger only receives the air in the operating room; the opening of the first valve is adjusted to 0%, and the opening of the second valve is adjusted to 100%;

[0039] When the circulation mode instruction is external circulation, the heat exchanger only receives air from the external environment; the opening degree of the first valve is adjusted to 100%, and the opening degree of the second valve is adjusted to 100%.

[0040] The present invention discloses a waste heat recovery and utilization system for a fuel cell, comprising: a first circuit, comprising a fuel cell stack and a radiator; the fuel cell stack comprises a coolant inlet and a coolant outlet, the coolant inlet is connected to the output end of the radiator; the coolant outlet is connected to the input end of the radiator; a second circuit, comprising a heat exchanger, a heater, a first monitoring module and a second monitoring module; the first input end of the heat exchanger is connected to the coolant outlet of the fuel cell stack, and the second input end of the heat exchanger is connected to the air; the first output end of the heat exchanger is connected to the input end of the radiator; the second output end of the heat exchanger is connected to an operating room through the heater; the first monitoring module is used to monitor the air volume information of the air input to the heat exchanger; the input end of the second monitoring module is connected to the second output end of the heat exchanger, and the second monitoring module is used to monitor the temperature information of the air output from the heat exchanger; the coolant absorbs the heat generated by the fuel cell stack and flows to the heat exchanger, and the heat exchanger performs primary heating on the air flowing through the heat exchanger through the heat of the coolant; the air heated by the primary heating is converted into warm air and transmitted to the operating room after passing through the heater. The waste heat recovery and utilization system of the fuel cell provided by the present invention adds a heat exchanger in the loop, and the heat exchanger is connected to the coolant outlet of the fuel cell stack. The heat exchanger uses the waste heat generated by the fuel cell stack to perform primary heating of the air to increase the air heating rate. This not only improves the heat exchange efficiency without considering the distribution relationship between the pressure drop and flow rate between the first loop and the second loop, but also uses the waste heat generated by the fuel cell stack to perform primary heating of the air to reduce the parasitic power consumption of the radiator, and reduce the power consumption of the vehicle-end heater, thereby improving the output power and engine efficiency of the fuel cell engine.

[0041] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 Schematic diagram of the structure of a waste heat recovery system for a fuel cell provided by an embodiment of the present invention;

[0044] Figure 2 1 is a schematic structural diagram of another fuel cell waste heat recovery system provided by an embodiment of the present invention;

[0045] Figure 3 1 is a schematic structural diagram of another fuel cell waste heat recovery system provided by an embodiment of the present invention;

[0046] Figure 4 1 is a schematic structural diagram of another fuel cell waste heat recovery system provided by an embodiment of the present invention;

[0047] Figure 5 1 is a schematic structural diagram of another fuel cell waste heat recovery system provided by an embodiment of the present invention;

[0048] Figure 6 1 is a schematic structural diagram of another fuel cell waste heat recovery system provided by an embodiment of the present invention;

[0049] Figure 7 This is a flow chart of a method for recovering waste heat from a fuel cell provided by an embodiment of the present invention;

[0050] Figure 8 This is a flow chart of another method for recovering waste heat from a fuel cell provided by an embodiment of the present invention;

[0051] Figure 9 This is a flow chart of another method for recovering waste heat from a fuel cell provided by an embodiment of the present invention;

[0052] Figure 10 This is a flow chart of another method for recovering waste heat from a fuel cell provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0054] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0055] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0056] Figure 1 This is a schematic diagram of the structure of the waste heat recovery system of the fuel cell provided by the embodiment of the present invention, with reference to Figure 1The waste heat recovery and utilization system of the fuel cell provided by the embodiment of the present invention includes a first loop 1 and a second loop 2. The first loop 1 includes a fuel cell stack 11 and a radiator 12; the fuel cell stack 11 includes a coolant inlet 1101 and a coolant outlet 1102, the coolant inlet 1101 is connected to the output end 1201 of the radiator 12; the coolant outlet 1102 is connected to the input end 1202 of the radiator 12; the second loop 2 includes a heat exchanger 21, a heater 22, a first monitoring module 23 and a second monitoring module 24; the first input end of the heat exchanger 21 is connected to the coolant outlet 1102 of the fuel cell stack 11, and the second input end of the heat exchanger 21 is connected to the air; the heat exchanger The first output end of the heat exchanger 21 is connected to the input end 1202 of the radiator 12; the second output end of the heat exchanger 21 is connected to the operating room 3 through the heater 22; the first monitoring module 23 is used to monitor the air volume information of the air input to the heat exchanger 21; the input end of the second monitoring module 24 is connected to the second output end of the heat exchanger 21, and the second monitoring module 24 is used to monitor the temperature information of the air output from the heat exchanger 21; the coolant absorbs the heat generated by the fuel cell stack 11 and flows to the heat exchanger 21, and the heat exchanger 21 uses the heat in the coolant to perform primary heating on the air flowing through the heat exchanger 21; the air that has been heated at the first stage is converted into warm air and transmitted to the operating room 3 after passing through the heater 22.

[0057] Among them, the waste heat recovery and utilization system of the fuel cell provided in the embodiment of the present invention is used in a fuel cell engine and is applicable to any area where warm air needs to be provided (such as the cab in a vehicle, the operating room where the staff of a power station are located, etc.). The embodiment of the present invention takes the cab in a vehicle as an example for explanation. The cold air in the cab or the cold air in the external environment enters the heat exchanger, and the coolant absorbs the waste heat generated by the fuel cell stack and is also transmitted to the heat exchanger. Therefore, the heat exchanger can use the heat in the coolant to perform a first-stage heating of the cold air. After at least one stage of heating, the cold air is converted into warm air and transmitted to the cab to provide warm air for the user. A fuel cell engine is an engine system that converts chemical energy of hydrogen and oxygen into electrical energy through an electrochemical reaction. The fuel cell stack generally includes an air supply system, a hydrogen supply system, a thermal management system, an electrical system, and a control system. The fuel cell stack 11 is composed of multiple single cells stacked in series, with bipolar plates and membrane electrode layers alternately stacked. Seals are embedded between the cells, and the cells are compressed by front and rear end plates and secured with screws or steel straps to form a fuel cell stack. The thermal management system dissipates heat generated by the stack to prevent damage to the bipolar plates and membrane electrode layers due to excessive temperatures. It typically includes components such as a water pump, radiator, and thermostat, and circulates coolant to meet the stack's temperature control requirements.

[0058] Specifically, the waste heat recovery and utilization system of the fuel cell provided in an embodiment of the present invention includes a first circuit 1, the first circuit 1 includes a fuel cell stack 11 and a radiator 12, the fuel cell stack 11 has a coolant inlet 1101 and a coolant outlet 1102. For example, the coolant inlet 1101 and the coolant outlet 1102 here refer to the coolant. Since the fuel cell generates a large amount of waste heat during operation, the so-called coolant is used to efficiently take away this waste heat, maintain the stability of the fuel cell stack temperature, and avoid local overheating leading to performance degradation or material damage.

[0059] The radiator 12 is a core component of the fuel cell thermal management system, responsible for dissipating waste heat generated by the fuel cell stack 11 and auxiliary components (such as the air compressor) to the environment, maintaining a stable system temperature. The coolant inlet 1101 is connected to the output end 1201 of the radiator 12, and the coolant outlet 1102 is connected to the input end 1202 of the radiator 12.

[0060] The second loop 2 includes a heat exchanger 21, a heater 22, a first monitoring module 23 and a second monitoring module 24; the first input end of the heat exchanger 21 is connected to the coolant outlet 1102 of the fuel cell stack 11, and the first output end of the heat exchanger 21 is connected to the input end 1202 of the radiator 12. This arrangement allows the waste heat of the fuel cell stack 11 to be absorbed by the coolant and then transferred to the heat exchanger 21. The remaining heat after heat exchange in the heat exchanger 21 is transferred to the heat exchanger 21 and finally discharged to the outside by the heat exchanger 21. The second input end of the heat exchanger 21 is connected to the air, wherein the air can be the air in the operating room 3 or the air in the atmospheric environment. Figure 1 Only the air transmitted to the heat exchanger 21 is shown to be provided by the operating room 3; the second output end of the heat exchanger 21 is connected to the operating room 3 through the heater 22; the input end of the first monitoring module 23 is connected to the second input end of the heat exchanger 21, and the first monitoring module 23 is used to monitor the air volume information of the air input to the heat exchanger 21, where the air volume information includes but is not limited to the air flow rate; the input end of the second monitoring module 24 is connected to the second output end of the heat exchanger 21, and the second monitoring module 24 is used to monitor the temperature information of the air output from the heat exchanger 21, that is, to monitor the temperature of the air transmitted by the heat exchanger 21 in real time;

[0061] The specific workflow is as follows:

[0062] The fuel cell stack 11 generates a large amount of waste heat during operation. The coolant absorbs a large amount of waste heat and then transmits it to the heat exchanger 21. At the same time, the heat exchanger 21 also receives a large amount of cold air. When the large amount of waste heat absorbed by the coolant and a large amount of cold air are transmitted to the heat exchanger 21, the heat exchanger 21 can use the waste heat absorbed by the coolant to perform a first-level heating on the cold air; after the first-level heating, the cold air is heated and converted into warm air, which is then transmitted to the operating room 3 through the heater 22 from the second output end of the heat exchanger 21. At the same time, the first monitoring module 23 monitors the air volume information in real time, and the second monitoring module 24 monitors the air temperature information in real time. After providing warm air to the operating room 3, the waste heat that has not been used up in the heat exchanger 21 is transmitted to the radiator 12 through the first output end of the heat exchanger 21, and is finally discharged to the outside of the fuel cell engine by the radiator 12.

[0063] The fuel cell waste heat recovery and utilization system provided by the embodiment of the present invention is provided with a heat exchanger on the main line of the radiator. The coolant can directly heat the air for primary heating to improve the heat exchange efficiency. After the air is heated for the first time, the remaining coolant is all returned to the radiator. The radiator outlet coolant temperature is monitored and controllable, which is beneficial to the temperature control of the fuel cell stack. Using the coolant for the first-level heating of the air can reduce the parasitic power consumption of the radiator and reduce the power consumption of the warm air heater on the whole vehicle end, thereby improving the output power and engine efficiency of the fuel cell engine.

[0064] Figure 2 This is a schematic diagram of the structure of another fuel cell waste heat recovery system provided by an embodiment of the present invention, with reference to Figure 2 Optionally, the second loop 2 further includes:

[0065] A first valve 25, wherein the output end of the first valve 25 is connected to the second input end of the heat exchanger 21. The first input end of the first valve 25 receives air from the external environment, and the second input end of the first valve 25 receives air from the operating room 3. When the circulation mode set for the operating room 3 is internal circulation, the opening degree of the first valve 25 is 0%, and the heat exchanger 21 only receives air from the operating room 3. When the circulation mode set for the operating room 3 is external circulation, the opening degree of the first valve 25 is 100%, and the heat exchanger 21 only receives air from the external environment.

[0066] The second valve 26 has an input end connected to the first monitoring module 23 , a first output end connected to the second input end of the heat exchanger 21 , and a second output end connected to the heater 22 .

[0067] Anode recirculation closes the vehicle's external air intake, allowing air inside the vehicle to circulate through the system without exchanging air with the outside world. Anode recirculation draws fresh air from outside, which is filtered through the air filter before entering the vehicle. This contrasts sharply with anode recirculation: the internal recirculation draws air from the operating room 3, while the external recirculation draws air from the outside environment.

[0068] Specifically, the second loop 2 further includes:

[0069] The first valve 25, the first input end of the first valve 25 receives the air in the operating room 3. When the circulation mode set by the user in the operating room 3 is internal circulation, the opening degree of the first valve 25 is 0%. At this time, the air is drawn from the operating room 3, so that the heat exchanger 21 only receives the air in the operating room 3. When the circulation mode set by the user in the operating room 3 is external circulation, the opening degree of the first valve 25 is 100%. At this time, the air is drawn from the external environment, so that the heat exchanger 21 only receives the air from the external environment.

[0070] The second valve 26, the input end of the second valve 26 is connected to the first monitoring module 23, the first output end of the second valve 26 is connected to the second input end of the heat exchanger 21, and the second output end of the second valve 26 is connected to the heater 22. Preferably, the default initial mode of the warm air in the embodiment of the present invention is the internal circulation mode. Compared with the external circulation mode, the internal circulation mode can increase the air temperature in the vehicle faster.

[0071] Optional, continue to refer to Figure 2 , the heater 22 is used to:

[0072] When the second monitoring module 24 monitors that the temperature of the warm air is lower than the preset temperature, the operating power of the heater 22 is increased to perform secondary heating on the warm air, and the opening of the second valve 26 is increased;

[0073] When the second monitoring module 24 monitors that the temperature of the warm air is greater than or equal to the preset temperature, the operating power of the heater 22 is reduced and the opening of the second valve 26 is decreased.

[0074] Specifically, when the temperature of the warm air monitored by the second monitoring module 24 is lower than the preset temperature (i.e., when the reading of the second monitoring module 24 is lower than the preset temperature), the heater 22 is turned on, and the operating power of the heater 22 is increased to PkW (the operating power P of the heater 22 is strongly correlated with the reading t of the second monitoring module 24, and there is a corresponding relationship between the two. The smaller the reading of the second monitoring module 24, the greater the operating power P of the heater 22, and the greater the heating amount of the air. The specific implementation can be calibrated according to actual conditions), and the opening of the second valve 26 is increased to ensure that more air flows into the heat exchanger 21, and reduce the air flowing directly from the second output end of the second valve 26 to the heater 22, so as to reach the preset temperature value set by the user in the operating room 3;

[0075] When the temperature of the warm air monitored by the second monitoring module 24 is greater than or equal to the preset temperature (that is, when the reading of the second monitoring module 24 is less than the preset temperature), the working power P of the heater 22 is reduced, or even the heater 22 is turned off, and the opening of the second valve 26 is reduced. The opening of the second valve 26 is set to X%. The opening X% of the second valve 26 is strongly correlated with the reading of the second monitoring module 24, and there is a corresponding relationship between the two. The higher the reading of the second monitoring module 24, the smaller the opening X% of the second valve 26, and the greater the flow rate of the air in the bypass passage without the heater, thereby reducing the amount of air flowing through the heat exchanger 21 in the main passage, so that a part of the air that has not been heated in the first stage flows directly to the front end of the heater 22 and mixes with the air that has been heated in the first stage, thereby reducing the temperature to reach the preset temperature set by the user in the operating room 3. Exemplarily, the second monitoring module 24 can be a temperature sensor.

[0076] Optional, Figure 3 This is a schematic diagram of the structure of another fuel cell waste heat recovery system provided by an embodiment of the present invention, with reference to Figure 3 , the second circuit 2 also includes a blower 27;

[0077] An input end of the blower 27 is connected to an output end of the first valve 25 , and an output end of the blower 27 is connected to an input end of the second valve 26 . The blower 27 is used to control the air volume input to the heat exchanger 21 .

[0078] Specifically, the input end of the blower 27 is connected to the output end of the first valve 25, and the output end of the blower 27 is connected to the input end of the second valve 26. The blower 27 is used to control the air volume input to the heat exchanger 21. The blower 27 is turned on to provide power for the air transmitted by the first valve 25. The initial speed of the blower is set to R rpm. The blower speed R rpm is strongly correlated with the air volume level M, and there is a corresponding relationship between the two. The blower speed R rpm is preset according to the air volume level M. After the blower 27 reaches the preset speed and stabilizes, the reading of the first monitoring module 23 is used to determine whether the air flow rate has reached the threshold. The reading of the first monitoring module 23 has a one-to-one correspondence with the air volume level. The reading of the first monitoring module 23 is used to determine whether the initial speed R rpm of the blower 27 meets the air volume level requirement. If the flow rate does not meet the requirement, the blower 27 speed needs to be adjusted again until the air flow rate meets the requirement.

[0079] Figure 4 This is a schematic diagram of the structure of another fuel cell waste heat recovery system provided by an embodiment of the present invention, with reference to Figure 4 , Optionally, the second circuit 2 further includes a filtering module 28;

[0080] The input end of the filter module 28 is connected to the output end of the first valve 25 , and the output end of the filter module 28 is connected to the second input end of the heat exchanger 21 . The filter module 28 is used to filter particulate matter in the air transmitted from the first valve 25 to the heat exchanger 21 .

[0081] Specifically, the filter module 28 can filter the air output by the first valve 25, filter out impurities and particulate matter in the air, and then transmit the air to the heat exchanger 21. By adding the filter module 28, the air transmitted to the heat exchanger 21 can be purer and the heat exchange efficiency can be improved. Exemplarily, the filter module 28 can be an air filter element.

[0082] Figure 5 This is a schematic diagram of the structure of another fuel cell waste heat recovery system provided by an embodiment of the present invention, with reference to Figure 5 , optionally, the first circuit 1 further includes a thermostat 13;

[0083] An input end of the thermostat 13 is connected to an output end of the fuel cell stack 11 , a first output end of the thermostat 13 is connected to a first input end of the heat exchanger 21 , and a second output end of the thermostat 13 is connected to an output end 1201 of the radiator 12 .

[0084] Specifically, the first circuit 1 also includes a thermostat 13, which can intelligently adjust the coolant circulation path to ensure that the fuel cell stack 11 quickly heats up and stabilizes at the optimal operating temperature (usually 60°C-80°C). By setting up the thermostat 13, the fuel cell system can better operate in an optimal temperature environment.

[0085] Figure 6 This is a schematic diagram of the structure of another fuel cell waste heat recovery system provided by an embodiment of the present invention, with reference to Figure 6 Optionally, the fuel cell waste heat recovery system provided in the embodiment of the present invention further includes:

[0086] Water pump 4, the input end of the water pump 4 is connected to the output end 1201 of the radiator 12, and the output end of the water pump 4 is connected to the input end 1101 of the fuel cell stack 11. The water pump 4 is mainly used to drive the coolant circulation and accurately control the temperature of the fuel cell stack 11;

[0087] Intercooler 5, the input end of intercooler 5 receives high-temperature air from the air compressor, the first output end of intercooler 5 is connected to the external environment, the second output end of intercooler 5 is connected to the input end 1101 of the fuel cell stack 11, and the third output end of intercooler 5 is connected to the output end 1102 of the fuel cell stack 11. Intercooler 5 is the core heat exchange component of the fuel cell, and is mainly responsible for cooling the high-temperature compressed air to improve the working efficiency of the fuel cell stack 11 and the quality of oxygen supply. The embodiment of the present invention does not adopt a branch diversion solution, and can fully utilize the heat generated by the fuel cell stack of the coolant in the main line and the heat dissipation of the intercooler, without considering the pressure drop and flow distribution relationship between the main line and the branch line, as well as the problem of insufficient heat exchange caused by diversion.

[0088] According to the same inventive concept, Figure 7 This is a flow chart of a method for recovering waste heat from a fuel cell according to an embodiment of the present invention. Figure 7 An embodiment of the present invention provides a method for recovering waste heat from a fuel cell, which is applicable to the waste heat recovery system for a fuel cell in any of the above-mentioned embodiments of the invention. The waste heat recovery method includes:

[0089] S100: When a warm air on instruction is recognized, a preset air volume and a preset temperature of the required warm air are obtained.

[0090] Specifically, after the controller recognizes the warm air on command initiated by the user in the operating room, it simultaneously obtains the preset air volume and preset temperature of the warm air required by the user (for example, the preset air volume is level 3 and the preset temperature is 24°C).

[0091] S101. Adjust the air volume of the air input to the heat exchanger according to a preset air volume so that the air heated by the first stage of the heat exchanger is transmitted to the second monitoring module.

[0092] Specifically, the air volume of the input heat exchanger is adjusted according to the preset air volume to reach the preset air volume of warm air required by the user (for example, level three), and the air is accelerated to pass through the heat exchanger for primary heating, and the air after primary heating is transmitted to the second monitoring module.

[0093] S102: Acquire the real-time temperature of the warm air after passing through the heat exchanger.

[0094] Specifically, after the warm air passes through the heat exchanger for primary heating, the second monitoring module connected to the heat exchanger monitors and obtains the real-time temperature of the warm air in real time.

[0095] S103 , dynamically adjusting the operating power of the heater according to the real-time temperature.

[0096] Specifically, according to the real-time temperature information of the warm air monitored in the previous step S102 , the operating power of the heater is dynamically adjusted according to the real-time temperature information to achieve secondary heating of the warm air.

[0097] S104: The warm air passes through the heater and is transmitted to the operating room.

[0098] Specifically, the warm air after the first-stage heating is transmitted to the operating room to meet the needs of users in the operating room.

[0099] Based on the above-mentioned embodiment of the invention, the embodiment of the present invention further refines the dynamic adjustment of the working power of the heater according to the real-time temperature. Figure 8 This is a flow chart of another method for recovering waste heat from a fuel cell provided by an embodiment of the present invention. Figure 8 , methods include:

[0100] S200: When a warm air on instruction is recognized, a preset air volume and a preset temperature of the required warm air are obtained.

[0101] S201. Adjust the air volume of the air input to the heat exchanger according to the preset air volume so that the air heated by the first stage of the heat exchanger is transmitted to the second monitoring module.

[0102] S202: Acquire the real-time temperature of the warm air passing through the heat exchanger.

[0103] S203: Dynamically adjust the operating power of the heater according to the real-time temperature.

[0104] The obtained real-time temperature is compared with the preset temperature. When the real-time temperature is lower than the preset temperature, step S2031 is executed; when the real-time temperature is higher than or equal to the preset temperature, step S2032 is executed.

[0105] S2031. When the real-time temperature is lower than the preset temperature, the operating power of the heater is increased to perform secondary heating on the warm air, and the opening of the second valve is increased.

[0106] Specifically, when the real-time temperature of the warm air monitored by the second monitoring module is lower than the preset temperature (that is, when the reading of the second monitoring module is lower than the preset temperature), the heater is turned on and the working power of the heater is increased to PkW (the working power P of the heater is strongly correlated with the reading t of the second monitoring module, and there is a corresponding relationship between the two. The smaller the reading of the second monitoring module, the greater the working power P of the heater, and the greater the heating amount of the air) to perform secondary heating of the warm air, and increase the opening of the second valve to ensure that the air flows completely into the heat exchanger, and prevent the air from flowing directly from the second output end of the second valve to the heater, thereby reaching the preset temperature value set by the user in the operating room.

[0107] S2032: When the real-time temperature is greater than or equal to the preset temperature, reduce the operating power of the heater and decrease the opening of the second valve.

[0108] Specifically, when the second monitoring module monitors that the temperature of the warm air is greater than or equal to the preset temperature (that is, when the reading of the second monitoring module is less than the preset temperature), the operating power P of the heater is reduced, or even the heater is turned off, and the opening of the second valve is reduced. The opening of the second valve is set to X%. The opening X% of the second valve is strongly correlated with the reading of the second monitoring module, and there is a corresponding relationship between the two. The higher the reading of the second monitoring module, the smaller the opening X% of the second valve, and the greater the flow rate of air in the bypass passage without heater, thereby reducing the amount of air flowing through the heat exchanger in the main passage, so that a part of the air that has not undergone the first-stage heating flows directly to the front end of the heater and mixes with the air that has undergone the first-stage heating, thereby lowering the temperature to reach the preset temperature set by the user in the operating room. Exemplarily, the second monitoring module can be a temperature sensor.

[0109] S204: The warm air passes through the heater and is transmitted to the operating room.

[0110] Based on the above-mentioned embodiment of the invention, the embodiment of the present invention adjusts the air volume of the air input to the heat exchanger according to the preset air volume so that the air heated by the first stage of the heat exchanger is transmitted to the second monitoring module. Figure 9 This is a flow chart of another method for recovering waste heat from a fuel cell according to an embodiment of the present invention. Figure 9 , methods include:

[0111] S300: When a warm air on instruction is recognized, a preset air volume and a preset temperature of the required warm air are obtained.

[0112] S301. Adjust the air volume of the air input to the heat exchanger according to the preset air volume so that the air heated by the first stage of the heat exchanger is transmitted to the second monitoring module.

[0113] S302: Acquire the real-time air volume of the air transmitted to the heat exchanger.

[0114] The obtained real-time air volume is compared with the preset air volume. When the real-time air volume is greater than or equal to the preset air volume, step S3021 is executed; when the real-time air volume is less than the preset air volume, step S3022 is executed.

[0115] S3021. When the real-time air volume is greater than or equal to the preset air volume, reduce the fan speed of the blower.

[0116] Specifically, when the real-time air volume obtained in the above step S302 is greater than or equal to the preset air volume, the fan speed of the blower is reduced so that the air meets the required air volume of the user in the operating room.

[0117] S3022: When the real-time air volume is less than the preset air volume, increase the fan speed of the blower.

[0118] Specifically, when the real-time air volume obtained in the above step S302 is less than the preset air volume, the fan speed of the blower is increased to make the air meet the required air volume of the user in the operating room.

[0119] S303: Acquire the real-time temperature of the warm air passing through the heat exchanger.

[0120] S304: Dynamically adjust the operating power of the heater according to the real-time temperature.

[0121] S305: The warm air passes through the heater and is transmitted to the operating room.

[0122] Based on the above-mentioned embodiment of the invention, the embodiment of the present invention further refines the process of obtaining the preset air volume and temperature of the required warm air when a warm air on instruction is recognized. Figure 10 This is a flow chart of another method for recovering waste heat from a fuel cell provided by an embodiment of the present invention. Figure 10 , methods include:

[0123] S400: Obtain a circulation mode instruction issued by the operating room.

[0124] Specifically, a controller in the vehicle obtains a circulation mode instruction issued by a user in the operating room, wherein the circulation module includes an inner circulation and an outer circulation.

[0125] S4001: When the circulation mode instruction is internal circulation, the heat exchanger only receives air from the operating room; the opening of the first valve is adjusted to 0%, and the opening of the second valve is adjusted to 100%;

[0126] Specifically, when the circulation mode instruction recognized by the controller is internal circulation, the opening of the first valve is adjusted to 0%, and the opening of the second valve is adjusted to 100%, so that the heat exchanger only receives air in the operating room.

[0127] S4002. When the circulation mode instruction is external circulation, the heat exchanger only receives air from the external environment; the opening of the first valve is adjusted to 100%, and the opening of the second valve is adjusted to 100%.

[0128] Specifically, when the circulation mode instruction recognized by the controller is external circulation, the opening of the first valve is adjusted to 100%, and the opening of the second valve is adjusted to 100%, so that the heat exchanger only receives air from the external environment.

[0129] S401: When a warm air on instruction is recognized, a preset air volume and a preset temperature of the required warm air are obtained.

[0130] S402: Adjust the air volume of the air input to the heat exchanger according to the preset air volume so that the air heated by the first stage of the heat exchanger is transmitted to the second monitoring module.

[0131] S403: Acquire the real-time temperature of the warm air passing through the heat exchanger.

[0132] S404: Dynamically adjust the operating power of the heater according to the real-time temperature.

[0133] S405: The warm air passes through the heater and is transmitted to the operating room.

[0134] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A waste heat recovery system for a fuel cell, characterized in that: include: The first circuit includes the battery stack and radiator; The stack includes a coolant inlet and a coolant outlet, wherein the coolant inlet is connected to the output end of the radiator; and the coolant outlet is connected to the input end of the radiator; The second circuit includes a heat exchanger, a heater, a first monitoring module and a second monitoring module; The first input end of the heat exchanger is connected to the coolant outlet of the fuel cell stack, and the second input end of the heat exchanger is in communication with the air; the first output end of the heat exchanger is connected to the input end of the radiator; the second output end of the heat exchanger is connected to the operating room through the heater; the first monitoring module is used to monitor the air volume information of the air input to the heat exchanger; the input end of the second monitoring module is connected to the second output end of the heat exchanger, and the second monitoring module is used to monitor the temperature information of the air output from the heat exchanger; The coolant absorbs the heat generated by the fuel cell stack and flows to the heat exchanger, which uses the heat from the coolant to perform primary heating on the air flowing through the heat exchanger. The air heated in the primary stage is converted into warm air and transmitted to the operating room after passing through the heater.

2. The waste heat recovery system of a fuel cell according to claim 1, characterized in that: The second loop further includes: a first valve, wherein the output end of the first valve is connected to the second input end of the heat exchanger, the first input end of the first valve receives air from the external environment, and the second input end of the first valve receives air from the operating chamber; when the circulation mode set in the operating chamber is internal circulation, the opening degree of the first valve is 0%, and the heat exchanger only receives air from the operating chamber; when the circulation mode set in the operating chamber is external circulation, the opening degree of the first valve is 100%, and the heat exchanger only receives air from the external environment; A second valve, wherein the input end of the second valve is connected to the first monitoring module, the first output end of the second valve is connected to the second input end of the heat exchanger, and the second output end of the second valve is connected to the heater.

3. The waste heat recovery system of a fuel cell according to claim 2, characterized in that: The heater is used to: When the second monitoring module monitors that the temperature of the warm air is lower than a preset temperature, the operating power of the heater is increased to perform secondary heating on the warm air, and the opening of the second valve is increased; When the second monitoring module monitors that the temperature of the warm air is greater than or equal to a preset temperature, the operating power of the heater is reduced and the opening of the second valve is reduced.

4. The waste heat recovery system of a fuel cell according to claim 2, characterized in that: The second circuit also includes a blower; The input end of the blower is connected to the output end of the first valve, and the output end of the blower is connected to the input end of the second valve. The blower is used to control the air volume input to the heat exchanger.

5. The waste heat recovery system of a fuel cell according to claim 2, characterized in that: The second circuit also includes a filter module; The input end of the filter module is connected to the output end of the first valve, and the output end of the filter module is connected to the second input end of the heat exchanger. The filter module is used to filter particulate matter in the air transmitted from the first valve to the heat exchanger.

6. The waste heat recovery system of a fuel cell according to claim 1, characterized in that: The first circuit also includes a thermostat; The input end of the thermostat is connected to the output end of the fuel cell stack, the first output end of the thermostat is connected to the first input end of the heat exchanger, and the second output end of the thermostat is connected to the output end of the radiator.

7. A method for recovering waste heat from a fuel cell, characterized in that: A waste heat recovery system for a fuel cell according to any one of claims 1 to 6, wherein the waste heat recovery method comprises: When a warm air on command is recognized, the preset air volume and temperature of the required warm air are obtained; Adjusting the air volume of the air input to the heat exchanger according to the preset air volume so that the air heated by the first stage of the heat exchanger is transmitted to the second monitoring module; Obtaining the real-time temperature of the warm air after passing through the heat exchanger; Dynamically adjust the operating power of the heater according to the real-time temperature; The warm air is transmitted to the operating room after passing through the heater.

8. The method for recovering waste heat from a fuel cell according to claim 7, wherein: The second circuit of the waste heat recovery system further includes a second valve; dynamically adjusting the operating power of the heater according to the real-time temperature, including: When the real-time temperature is lower than the preset temperature, the operating power of the heater is increased to perform secondary heating on the warm air, and the opening of the second valve is increased; When the real-time temperature is greater than or equal to the preset temperature, the operating power of the heater is reduced, and the opening of the second valve is reduced.

9. The method for recovering waste heat from a fuel cell according to claim 7, wherein: The second circuit of the waste heat recovery system further includes a blower, which adjusts the air volume of the air input to the heat exchanger according to the preset air volume so that the air heated by the first stage of the heat exchanger is transmitted to the second monitoring module, including: Obtaining the real-time air volume of the air transmitted to the heat exchanger; When the real-time air volume is greater than or equal to the preset air volume, reducing the fan speed of the blower; When the real-time air volume is less than the preset air volume, the fan speed of the blower is increased.

10. The method for recovering waste heat of a fuel cell according to claim 8, characterized in that: The second circuit of the waste heat recovery system further includes a first valve; when a warm air start instruction is recognized, before obtaining the required warm air preset air volume and preset temperature, it also includes: Obtain cycle mode instructions from the operating room; When the circulation mode instruction is internal circulation, the heat exchanger only receives the air in the operating room; the opening of the first valve is adjusted to 0%, and the opening of the second valve is adjusted to 100%; When the circulation mode instruction is external circulation, the heat exchanger only receives air from the external environment; the opening degree of the first valve is adjusted to 100%, and the opening degree of the second valve is adjusted to 100%.

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