Fuel cell water balance regulation system and method

Abstract

The present invention relates to the field of fuel cell water balance regulation, and discloses a fuel cell water balance regulation system and method, comprising: an electronic control unit, a first electronically controlled three-way valve, an air outlet throttle, a humidifier, a second electronically controlled three-way valve, and a fuel cell stack, wherein the electronic control unit is connected to the first electronically controlled three-way valve, the air outlet throttle, the second electronically controlled three-way valve, and the fuel cell stack respectively, the first electronically controlled three-way valve, the humidifier, and the access end of the fuel cell stack are connected in sequence, the outlet end of the fuel cell stack, the second electronically controlled three-way valve, the humidifier, and the air outlet throttle are connected in sequence, and a voltage inspection module is provided on the fuel cell stack, which is connected to the electronic control unit. The present invention analyzes the impedance value detected in real time by the voltage inspection module through the electronic control unit, then determines whether it is necessary to change the fuel cell stack intake humidity based on the analysis result, and then completes the internal water balance regulation of the fuel cell stack by regulating the fuel cell stack water temperature, the air outlet throttle, and the second electronically controlled three-way valve.

Description

Technical Field

[0001] The present invention relates to the field of fuel cell water balance regulation, and in particular to a fuel cell water balance regulation system and method. Background Art

[0002] Hydrogen is non-toxic, harmless, and renewable, replacing traditional petrochemical resources like oil and coal. It's been called the ultimate energy source of the 21st century. A hydrogen-oxygen fuel cell is a power generation device that directly converts the chemical energy of hydrogen and oxygen into electricity. Its basic principle is the reverse reaction of water electrolysis. Its advantages are zero emissions and pollution, and the air filter element can also act as an air purifier. However, the internal structure of the hydrogen-oxygen fuel cell stack is invisible, making it difficult to regulate the stack water balance. Existing technologies also suffer from complex structures, a single control method, and incomplete functionality, failing to provide timely feedback on the true status of the stack water balance. Summary of the Invention

[0003] In order to solve the problem in the prior art that the interior of a fuel cell stack is invisible and thus difficult to adjust the water balance of the stack, the present invention provides a fuel cell water balance adjustment system and method.

[0004] The technical contents of the present invention are as follows:

[0005] A fuel cell water balance regulation system, comprising:

[0006] An electronic control unit, a first electronically controlled three-way valve, an air outlet throttle, a humidifier, a second electronically controlled three-way valve and a fuel cell stack, the electronic control unit is respectively connected to the first electronically controlled three-way valve, the air outlet throttle, the second electronically controlled three-way valve and the fuel cell stack, the first electronically controlled three-way valve, the humidifier and the access end of the fuel cell stack are connected in sequence, the outlet end of the fuel cell stack, the second electronically controlled three-way valve, the humidifier and the air outlet throttle are connected in sequence, a voltage patrol module is provided on the fuel cell stack, the voltage patrol module is connected to the electronic control unit, the voltage patrol module applies a disturbance current to the fuel cell stack and calculates the impedance value and feeds it back to the electronic control unit.

[0007] Furthermore, the second electronically controlled three-way valve is regulated by the electronic control unit to achieve sequential connection between the outlet end of the fuel cell stack, the second electronically controlled three-way valve and the outlet throttle.

[0008] Furthermore, the battery stack is connected to a DCDC converter, and the DCDC converter applies a disturbance current to the battery stack.

[0009] Furthermore, the fuel cell water balance regulation system also includes a tail exhaust muffler, which is connected to the first electronically controlled three-way valve and the tail exhaust muffler is connected to the outlet throttle.

[0010] Furthermore, the fuel cell water balance regulation system further includes an intercooler connected to the first electronically controlled three-way valve. The intercooler is used to reduce the temperature of the gas, and the cooled gas enters the humidifier through the first electronically controlled three-way valve.

[0011] Furthermore, the fuel cell water balance regulation system further includes an air compressor connected to the intercooler and the air inlet to increase the temperature and pressure of the incoming gas.

[0012] The present invention also provides a fuel cell water balance adjustment method, comprising any of the above fuel cell water balance adjustment systems, the specific steps of which include:

[0013] S1: Under the premise of starting the fuel cell water balance adjustment system, the impedance value and current are detected in real time through the set electronic control unit, and the impedance value is analyzed;

[0014] S2: The electronic control unit analyzes the corresponding operating status of the fuel cell stack and the impedance value under the current detected in real time to determine whether the water balance inside the fuel cell stack is normal. If the judgment result is yes, the process proceeds to step S3; if the judgment result is no, the process proceeds to step S4;

[0015] S3: The electronic control unit receives a signal indicating a normal water balance within the stack, stops adjusting the opening of the second electronically controlled three-way valve, and returns to step S1;

[0016] S4: The electronic control unit receives a signal indicating an abnormal water balance state in the stack, and determines whether the MEA is flooded or dry based on the high and low frequencies of the impedance values. If the determination result is that the MEA is dry, the process proceeds to step S5; if the determination result is that the MEA is flooded, the process proceeds to step S6;

[0017] S5: The electronic control unit increases the proportion of gas at the outlet of the fuel cell stack passing through the humidifier by adjusting the opening of the second electronically controlled three-way valve, controls the outlet throttle to increase the air side pressure and reduce the water temperature of the fuel cell stack until the water balance inside the fuel cell stack returns to normal, and returns to step S1;

[0018] S6: The electronic control unit reduces the proportion of gas at the outlet of the fuel cell stack passing through the humidifier by adjusting the opening of the second electronically controlled three-way valve, regulates the outlet throttle to reduce the air side pressure and increase the water temperature of the fuel cell stack until the water balance inside the fuel cell stack returns to normal, and returns to step S1.

[0019] Furthermore, the electronic control unit applies a disturbance current to the fuel cell stack by controlling the voltage inspection module, and then analyzes the current collected by the voltage inspection module and the impedance value detected in real time.

[0020] Furthermore, the electronic control unit applies a disturbance current to the battery stack by controlling the DCDC converter, and then analyzes the current collected by the voltage inspection module and the impedance value detected in real time.

[0021] The beneficial effects of the present invention include at least:

[0022] (1) Analyze the impedance value detected in real time by the voltage inspection module through the electronic control unit, and then judge whether it is necessary to change the humidity of the fuel cell stack intake air based on the analysis results, and then complete the internal water balance adjustment of the fuel cell stack by regulating the fuel cell stack water temperature, the outlet throttle valve, and the second electronically controlled three-way valve;

[0023] (2) The structure of the present invention realizes automatic adjustment of the water balance inside the fuel cell stack, effectively shortening the system shutdown purge time. The purge time can be automatically adjusted according to the surrounding environment to ensure that the water content inside the fuel cell stack is in the optimal state when the system is shut down, avoiding the membrane electrode being too dry or the membrane electrode containing too much water affecting the secondary startup, thereby extending the service life of the fuel cell stack;

[0024] (3) The second electronically controlled three-way valve can be adjusted to allow the air at the outlet of the stack to bypass the humidifier, reducing the water content inside the humidifier and avoiding damage caused by low-temperature freezing;

[0025] (4) The first electronically controlled three-way valve, the second electronically controlled three-way valve and the air outlet throttle valve cooperate with each other to complete the function of turning on / off the machine or diluting the tail exhaust hydrogen concentration during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the fuel cell water balance regulation system of the present invention.

[0027] Figure 2 This is a flow chart of the fuel cell water balance adjustment method of the present invention.

[0028] in:

[0029] 1-Electronic control unit;

[0030] 2- battery stack;

[0031] 21- voltage inspection module;

[0032] 3-DCDC converter;

[0033] 4- Second electronically controlled three-way valve;

[0034] 5-Humidifier;

[0035] 6-Exhaust throttle;

[0036] 7-Tail exhaust muffler;

[0037] 8-first electronically controlled three-way valve;

[0038] 9-Intercooler;

[0039] 10-Air compressor. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0041] Combine Figure 1-2 As shown, the present invention discloses a fuel cell water balance regulation system, comprising:

[0042] The electronic control unit 1, the first electronically controlled three-way valve, the air outlet throttle 6, the humidifier 5, the second electronically controlled three-way valve 4 and the fuel cell stack 2, the electronic control unit 1 is respectively connected to the first electronically controlled three-way valve, the air outlet throttle 6, the second electronically controlled three-way valve 4 and the fuel cell stack 2, the first electronically controlled three-way valve, the humidifier 5 and the access end of the fuel cell stack 2 are connected in sequence, the outlet end of the fuel cell stack 2, the second electronically controlled three-way valve 4, the humidifier 5 and the air outlet throttle 6 are connected in sequence, and a voltage patrol module 21 is provided on the fuel cell stack 2, and the voltage patrol module 21 is connected to the electronic control unit 1, and the voltage patrol module 21 applies a disturbance current to the fuel cell stack 2 and calculates the impedance value and feeds it back to the electronic control unit 1.

[0043] Furthermore, the second electronically controlled three-way valve 4 is regulated by the electronic control unit 1 to achieve sequential connection between the outlet end of the fuel cell stack 2 , the second electronically controlled three-way valve 4 and the outlet throttle valve 6 .

[0044] Furthermore, the fuel cell stack 2 is connected to a DCDC converter 3 , and the DCDC converter 3 applies a disturbance current to the fuel cell stack 2 .

[0045] Furthermore, the fuel cell water balance regulation system further includes a tail exhaust muffler 7 , which is connected to the first electronically controlled three-way valve 8 , and is also connected to the outlet throttle valve 6 .

[0046] Furthermore, the fuel cell water balance adjustment system further includes an intercooler 9, which is connected to the first electronically controlled three-way valve 8. The intercooler 9 is used to reduce the gas temperature, and the cooled gas enters the humidifier 5 through the first electronically controlled three-way valve 8.

[0047] Furthermore, the fuel cell water balance regulation system further includes an air compressor 10, which is connected to the intercooler 9. The air compressor 10 is connected to the air inlet to increase the temperature and pressure of the incoming gas.

[0048] The present invention also provides a fuel cell water balance adjustment method, comprising any of the above fuel cell water balance adjustment systems, the specific steps of which include:

[0049] S1: Under the premise of starting the fuel cell water balance adjustment system, the impedance value and current are detected in real time through the set electronic control unit, and the impedance value is analyzed;

[0050] S2: The electronic control unit analyzes the corresponding operating status of the fuel cell stack and the impedance value under the current detected in real time to determine whether the water balance inside the fuel cell stack is normal. If the judgment result is yes, the process proceeds to step S3; if the judgment result is no, the process proceeds to step S4;

[0051] S3: The electronic control unit receives a signal indicating a normal water balance within the stack, stops adjusting the opening of the second electronically controlled three-way valve, and returns to step S1;

[0052] S4: The electronic control unit receives a signal indicating an abnormal water balance state in the stack, and determines whether the MEA is flooded or dry based on the high and low frequencies of the impedance values. If the determination result is that the MEA is dry, the process proceeds to step S5; if the determination result is that the MEA is flooded, the process proceeds to step S6;

[0053] S5: The electronic control unit increases the proportion of gas at the outlet of the fuel cell stack passing through the humidifier by adjusting the opening of the second electronically controlled three-way valve, controls the outlet throttle to increase the air side pressure and reduce the water temperature of the fuel cell stack until the water balance inside the fuel cell stack returns to normal, and returns to step S1;

[0054] S6: The electronic control unit reduces the proportion of gas at the outlet of the fuel cell stack passing through the humidifier by adjusting the opening of the second electronically controlled three-way valve, regulates the outlet throttle to reduce the air side pressure and increase the water temperature of the fuel cell stack until the water balance inside the fuel cell stack returns to normal, and returns to step S1.

[0055] Furthermore, the electronic control unit applies a disturbance current to the fuel cell stack by controlling the voltage inspection module, and then analyzes the current collected by the voltage inspection module and the impedance value detected in real time.

[0056] Furthermore, the electronic control unit applies a disturbance current to the battery stack by controlling the DCDC converter, and then analyzes the current collected by the voltage inspection module and the impedance value detected in real time.

[0057] The electronically controlled three-way valve used in the present invention is controlled by CAN communication. It can cooperate with impedance measurement and can also pre-calibrate the opening according to needs to regulate the direction of air with high humidity, so as to achieve the purpose of reducing the water content of the battery stack and the humidifier.

[0058] Compared with the prior art, the structure of the water balance system adopted in the present invention is more streamlined and more convenient to control. When the system is shut down and purged, the direction of the air with high humidity is controlled, which helps to reduce the water content inside the fuel cell stack and the humidifier.

[0059] The present invention achieves the functions of powering on / off or diluting the tail exhaust hydrogen concentration during operation through the interaction of the first and second electronically controlled three-way valves and the outlet throttle. During startup, to protect the fuel cell stack and meet the startup strategy requirements, the first electronically controlled three-way valve can be adjusted to allow all air to bypass the tail exhaust and prevent it from entering the fuel cell stack, thereby diluting the tail exhaust hydrogen concentration. During operation, the total air flow rate can be increased, and the opening of the first electronically controlled three-way valve can be adjusted to allow excess air to bypass the tail exhaust and dilute the tail exhaust hydrogen concentration.

[0060] The present invention solves the problem of regulating the water balance inside the fuel cell stack, avoids shutdown and frequent switching of the fuel cell stack due to water flooding, and avoids permanent damage to the fuel cell stack due to water flooding of the reverse electrode, thereby affecting the service life of the fuel cell stack. At the same time, it avoids the phenomenon that the fuel cell stack increases power generation and reduces efficiency due to ohmic loss caused by membrane drying, and avoids the phenomenon that the shutdown purge time is too long and the shutdown purge time does not match the external environment, resulting in the freezing of the fuel cell stack and the puncture of the membrane electrode, thereby affecting the safety and life of the fuel cell stack.

[0061] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fuel cell water balance regulation system, characterized by: include: An electronic control unit, a first electronically controlled three-way valve, an air outlet throttle, a humidifier, a second electronically controlled three-way valve and a fuel cell stack. The electronic control unit is respectively connected to the first electronically controlled three-way valve, the air outlet throttle, the second electronically controlled three-way valve and the fuel cell stack. The first electronically controlled three-way valve, the humidifier and the access end of the fuel cell stack are connected in sequence. The outlet end of the fuel cell stack, the second electronically controlled three-way valve, the humidifier and the air outlet throttle are connected in sequence. A voltage inspection module is provided on the fuel cell stack. The voltage inspection module is connected to the electronic control unit. The fuel cell stack is connected to a DCDC converter. The DCDC converter applies a disturbance current to the fuel cell stack. The voltage inspection module calculates an impedance value for the fuel cell stack and feeds it back to the electronic control unit. The second electronically controlled three-way valve is regulated by the electronic control unit to realize the sequential connection between the outlet end of the fuel cell stack, the second electronically controlled three-way valve and the outlet throttle valve; Wherein, the fuel cell water balance regulation system further includes a tail exhaust muffler, the tail exhaust muffler is connected to the first electronically controlled three-way valve, and the tail exhaust muffler is connected to the outlet throttle valve; Wherein, the fuel cell water balance regulation system further includes an intercooler, and the intercooler is connected to the first electronically controlled three-way valve; Wherein, the fuel cell water balance adjustment system further includes an air compressor, and the air compressor is connected to the intercooler.

2. A fuel cell water balance adjustment method, comprising the fuel cell water balance adjustment system according to claim 1, characterized in that: The specific steps include: S1: Under the premise of starting the fuel cell water balance adjustment system, the impedance value and current are detected in real time through the set electronic control unit, and the impedance value is analyzed; S2: The electronic control unit analyzes the corresponding operating status of the fuel cell stack and the impedance value under the current detected in real time to determine whether the water balance inside the fuel cell stack is normal. If the judgment result is yes, the process proceeds to step S3; if the judgment result is no, the process proceeds to step S4; S3: The electronic control unit receives a signal indicating a normal water balance within the stack, stops adjusting the opening of the second electronically controlled three-way valve, and returns to step S1; S4: The electronic control unit receives a signal indicating an abnormal water balance state in the stack, and determines whether the MEA is flooded or dry based on the high and low frequencies of the impedance values. If the determination result is that the MEA is dry, the process proceeds to step S5; if the determination result is that the MEA is flooded, the process proceeds to step S6; S5: The electronic control unit increases the proportion of gas at the outlet of the fuel cell stack passing through the humidifier by adjusting the opening of the second electronically controlled three-way valve, controls the outlet throttle to increase the air side pressure and reduce the water temperature of the fuel cell stack until the water balance inside the fuel cell stack returns to normal, and returns to step S1; S6: The electronic control unit reduces the proportion of gas at the outlet of the fuel cell stack passing through the humidifier by adjusting the opening of the second electronically controlled three-way valve, regulates the outlet throttle to reduce the air side pressure and increase the water temperature of the fuel cell stack until the water balance inside the fuel cell stack returns to normal, and returns to step S1.

3. A fuel cell water balance adjustment method according to claim 2, characterized in that: The electronic control unit applies a disturbance current to the battery stack by controlling the DCDC converter, and then analyzes the current collected by the voltage inspection module and the impedance value detected in real time.

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