A hydrogen fuel cell exhaust hydrogen concentration detection device

Abstract

The utility model relates to hydrogen energy technology field discloses a kind of hydrogen fuel cell tail exhaust hydrogen concentration detection devices, including the exhaust pipe for receiving hydrogen fuel cell system's tail gas and being vertically arranged, vertically arranged sampling pipe is connected in parallel on exhaust pipe, power source for extracting tail gas in exhaust pipe to sampling pipe is arranged on sampling pipe, hydrogen concentration sensor and temperature sensor one are arranged on sampling pipe, the hydrogen concentration detection device of the utility model, when the tail gas discharged by hydrogen fuel cell system is passed into exhaust pipe, sampling pipe can synchronously collect tail gas received by exhaust pipe, and the temperature value measured by temperature sensor one is used as the starting condition of hydrogen concentration sensor using the physical relationship of gas humidity and temperature.When the temperature value measured by temperature sensor one is close to ambient temperature, it indicates that gas in sampling pipe will not continue to precipitate liquid water, hydrogen concentration sensor is started at this time, and the hydrogen concentration of gas in sampling pipe can be accurately detected.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen energy technology, and in particular to a hydrogen concentration detection device for hydrogen fuel cell exhaust. Background Technology

[0002] Currently, an increasing number of companies are involved in the research and development of hydrogen fuel cell systems and vehicles, and more and more hydrogen fuel cell vehicles are being registered. Fuel cells and vehicles use hydrogen as fuel, and hydrogen is flammable and explosive, with an explosive range of 4%-75.6%. Therefore, hydrogen concentration sensors are used in fuel cell system off-line testing and in vehicles to monitor the hydrogen concentration in the exhaust, thereby determining whether there are risks such as hydrogen leakage or accumulation.

[0003] However, the internal operating temperature of hydrogen fuel cells is high, and the temperature of the exhaust gas gradually decreases during discharge, causing moisture in the gas to gradually precipitate out, resulting in a high-temperature and high-humidity state at the outlet gas path. This high-temperature and high-humidity gas forms a water film on the surface of the hydrogen concentration sensor, leading to reduced sensor accuracy or even failure, posing a significant safety hazard. Under these conditions, a special hydrogen concentration sensor is required, typically a heated hydrogen concentration sensor. These sensors are very expensive to use and have unstable performance, easily leading to high maintenance costs for the fuel cell system and even affecting the safety and performance of the fuel cell system.

[0004] In the utility model patent with announcement number CN 208076472U, a venturi tube and a waterproof and breathable membrane are used to avoid the use of hydrogen concentration sensors in high temperature and high humidity environments. However, this device increases the flow resistance of the tailpipe and poses a risk of clogging of the waterproof and breathable membrane, which can easily lead to inaccurate detection. Therefore, it still needs to be improved. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a hydrogen concentration detection device for hydrogen fuel cell exhaust. This device can accurately detect the hydrogen concentration in the exhaust gas while ensuring unobstructed flow in the exhaust of the hydrogen fuel cell system, thereby improving the safety and performance of the fuel cell system.

[0006] To solve the above-mentioned technical problems, the present invention provides a solution through the following technical method:

[0007] A hydrogen concentration detection device for hydrogen fuel cell exhaust includes an exhaust pipe for receiving exhaust gas from a hydrogen fuel cell system and arranged vertically, a sampling pipe arranged vertically in parallel on the exhaust pipe, a power source for drawing exhaust gas from the exhaust pipe to the sampling pipe on the sampling pipe, a water collection pipe connected to the lower end of the sampling pipe, a switch for switching the sampling pipe on and off at the air inlet end of the sampling pipe, and a hydrogen concentration sensor and a temperature sensor on the sampling pipe.

[0008] When the power source draws exhaust gas from the exhaust pipe to the sampling pipe, the switch cuts off the sampling pipe to lower the temperature of the exhaust gas collected in the sampling pipe, thereby precipitating liquid water and collecting it in the water collection pipe; when the temperature sensor detects that the difference between the measured temperature in the sampling pipe and the ambient temperature is less than or equal to the set difference, the hydrogen concentration sensor operates to detect the hydrogen concentration in the sampling pipe; otherwise, the hydrogen concentration sensor does not operate.

[0009] Using the above scheme, when the exhaust gas from the hydrogen fuel cell system is introduced into the exhaust pipe, the sampling tube can simultaneously collect the exhaust gas received by the exhaust pipe. Utilizing the physical relationship between gas humidity and temperature (i.e., when the gas temperature is close to ambient temperature, it will not continue to precipitate liquid water), the temperature value measured by temperature sensor one is used as the activation condition for the hydrogen concentration sensor. When the temperature value measured by temperature sensor one is close to ambient temperature, it indicates that the gas in the sampling tube will not continue to precipitate liquid water (or the precipitated liquid water is negligible). At this time, activating the hydrogen concentration sensor allows for accurate detection of the hydrogen concentration in the gas within the sampling tube, thereby effectively determining whether there are risks such as hydrogen leakage or accumulation in the hydrogen fuel cell system.

[0010] Preferably, the upper and lower ends of the sampling tube are respectively provided with an outlet pipe and an inlet pipe, both of which are connected to the exhaust pipe. A switch is provided on the inlet pipe to realize the opening and closing of the inlet pipe.

[0011] By adopting the above scheme, the on / off switch can quickly switch the gas inlet of the sampling tube on and off, and the on / off point will not interfere with the water collection pipe below the sampling tube. At the same time, it can ensure that there is a sufficient gas sample in the sampling tube, thereby effectively improving the detection accuracy and efficiency of hydrogen concentration.

[0012] Preferably, the exhaust pipe is equipped with a connecting pipe that connects to the tailpipe of the hydrogen fuel cell system.

[0013] The above solution enables the exhaust pipe to be precisely connected to the tailpipe of the hydrogen fuel cell system and efficiently collect the exhaust gas emitted by the battery system.

[0014] As a preferred option, the water collection pipe is equipped with a switch for switching the water collection pipe on and off.

[0015] Using the above scheme, the switching on and off of the second switch can respectively realize the drainage of liquid water in the water collection pipe and the sealing of the sampling pipe, thereby completing the accurate detection of hydrogen concentration detection device and system cleaning.

[0016] Preferably, the lower end of the water collection pipe is connected to a water collection cavity.

[0017] By adopting the above scheme, the water collection chamber can increase the water storage capacity of the hydrogen concentration detection device and avoid ground pollution caused by frequent drainage.

[0018] Preferably, a liquid level sensor is installed on the water collection cavity to detect the water level value inside the water collection cavity.

[0019] By adopting the above scheme, the hydrogen concentration detection device can accurately determine the water level changes in the water collection chamber, thereby enabling timely drainage operations.

[0020] Preferably, a controller is coupled to the level sensor, and a switch three is coupled to the controller. A drain pipe is provided on the water collection chamber, and the switch three is provided on the drain pipe to realize the opening and closing of the drain pipe.

[0021] When the level sensor detects that the water level in the water collection chamber is higher than the preset water level, the controller controls the switch three to open the drain pipe to complete the drainage; otherwise, the controller controls the switch three to cut off the drain pipe to stop the drainage.

[0022] By adopting the above scheme, the hydrogen concentration detection device can automatically complete the drainage operation according to the water level change in the water collection chamber, thereby improving the operating efficiency and convenience of the device.

[0023] Preferably, the upper end of the water collection chamber is connected to the lower end of the exhaust pipe to collect the liquid water that precipitates out of the exhaust pipe.

[0024] Using the above scheme, due to the long stroke of the exhaust pipe, the temperature of the exhaust gas drops rapidly as it runs inside, causing liquid water to continuously precipitate. At this time, the water collection chamber can efficiently collect the liquid water generated during the exhaust process, reducing the humidity inside the exhaust pipe and improving the dehumidification efficiency in the sampling tube. This, in turn, makes the detection of hydrogen concentration more accurate and efficient.

[0025] Preferably, a baffle plate is provided at the connection between the exhaust pipe and the water collection chamber. There are two baffle plates, which are respectively located on two opposite side walls inside the drain pipe. A water outlet interval is maintained between the two baffle plates to allow liquid water to pass through.

[0026] By adopting the above solution, the cooperation of the two baffles can not only allow the liquid water in the exhaust pipe to enter the water collection chamber smoothly, but also reduce the risk of liquid water in the water collection chamber flowing back into the exhaust pipe, thereby further improving the drying effect of the exhaust pipe.

[0027] Preferably, the two baffles are set at an angle and their edges are positioned downstream of each other.

[0028] Using the above solution, the inclined baffle can guide the liquid water produced by the exhaust pipe to flow into the water collection chamber more quickly, and the baffle effect is better, making it more difficult for the liquid water in the water collection chamber to flow back.

[0029] This invention, by employing the above technical solution, achieves significant technical advantages: When the exhaust gas from the hydrogen fuel cell system is introduced into the exhaust pipe, the sampling tube can simultaneously collect the exhaust gas received by the exhaust pipe. Utilizing the physical relationship between gas humidity and temperature (i.e., when the gas temperature is close to the ambient temperature, it will not continue to precipitate liquid water), the temperature value measured by the temperature sensor is used as the activation condition for the hydrogen concentration sensor. When the temperature value measured by the temperature sensor is close to the ambient temperature, it indicates that the gas in the sampling tube will not continue to precipitate liquid water (or the precipitated liquid water is negligible). At this point, activating the hydrogen concentration sensor allows for accurate detection of the hydrogen concentration in the gas within the sampling tube, thereby effectively determining whether there is a risk of hydrogen leakage or accumulation in the hydrogen fuel cell system. Attached Figure Description

[0030] Figure 1 This is a system structure diagram of this embodiment;

[0031] Figure 2 This is a system architecture diagram for this embodiment.

[0032] The parts referred to by the numbers in the above attached diagrams are as follows: 1. Hydrogen fuel cell system; 2. Exhaust pipe; 3. Sampling pipe; 4. Power source; 5. Water collection pipe; 6. Switch one; 7. Hydrogen concentration sensor; 8. Temperature sensor one; 9. Gas outlet pipe; 10. Gas inlet pipe; 11. Tail outlet; 12. Connecting pipe; 13. Switch two; 14. Water collection chamber; 15. Liquid level sensor; 16. Controller; 17. Switch three; 18. Drain pipe; 19. Water baffle; 20. Water outlet interval; 21. Temperature sensor two. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0034] like Figure 1 and Figure 2As shown in this embodiment, a hydrogen concentration detection device for hydrogen fuel cell exhaust includes an exhaust pipe 2 vertically arranged for receiving exhaust gas from a hydrogen fuel cell system 1. A connecting pipe 12, which is fixedly installed on the side wall of the exhaust pipe 2 and connected to the exhaust port 11 of the hydrogen fuel cell system 1, is connected to the inner cavity of the exhaust pipe 2. A sampling pipe 3 vertically arranged is connected in parallel to one side of the exhaust pipe 2. An outlet pipe 9 and an inlet pipe 10 extend from the upper and lower ends of the sampling pipe 3, respectively. Both the outlet pipe 9 and the inlet pipe 10 are fixedly connected to the exhaust pipe 2. A switch 6 is installed on the inlet pipe 10 to control its opening and closing. A power source 4 is installed on the sampling pipe 3 to draw exhaust gas from the exhaust pipe 2 to the sampling pipe 3. The power source 4 is preferably a peristaltic pump, which ensures the stability and reliability of the intake gas and simplifies the air path structure of the hydrogen fuel cell system 1. A water collection pipe 5 is fixedly connected to the lower end of the sampling tube 3. A hydrogen concentration sensor 7 and a temperature sensor 8 are installed on the sampling tube 3. Specifically, two detection holes (not shown) are opened on the side wall of the sampling tube 3, which are connected to the inner cavity of the sampling tube 3. The detection ends of the hydrogen concentration sensor 7 and the temperature sensor 8 are respectively threaded into the two detection holes, thereby enabling accurate detection of hydrogen concentration and temperature changes inside the sampling tube 3.

[0035] To control the collection of precipitated liquid water, a switch 13 is installed on the water collection pipe 5 to control its operation. The lower end of the water collection pipe 5 is connected to a water collection chamber 14. The upper end of the water collection chamber 14 is simultaneously fixedly connected to the lower end of the exhaust pipe 2 to collect the precipitated liquid water from the exhaust pipe 2. A baffle plate 19 is fixedly installed at the connection between the exhaust pipe 2 and the water collection chamber 14. The baffle plate 19 has two pieces and is located on two opposite side walls inside the drain pipe 18. A water outlet gap 20 is maintained between the two baffle plates 19 to allow liquid water to pass through. The two baffle plates 19 are inclined, and their edges that are close to each other are both in the downstream position.

[0036] To control the drainage of the water collection chamber 14, a level sensor 15 is installed on the water collection chamber 14 to detect the water level. A controller 16 is coupled to the level sensor 15, preferably a microcontroller. A switch 17 is coupled to the controller 16. A drain pipe 18 is fixedly installed on the water collection chamber 14, and the switch 17 is installed on the drain pipe 18 to control the opening and closing of the drain pipe 18. Temperature sensor 8 and hydrogen concentration sensor 7 are both coupled to the signal receiving end of the controller 16. Switch 6, power source 4, and switch 13 are all coupled to and controlled by the controller 16.

[0037] To add backflow prevention measures to the hydrogen concentration detection device, the connecting pipe 12, the outlet pipe 9 and the inlet pipe 10 are all set at an upward inclination, thereby effectively preventing the precipitated liquid water from flowing back in.

[0038] The specific usage process is as follows:

[0039] When the hydrogen fuel cell system 1 is running, the exhaust gas discharged from its tailpipe 11 enters the exhaust pipe 2 through the connecting pipe 12 and is discharged upward through the exhaust pipe 2. During this process, because the exhaust pipe 2 is relatively long, the exhaust gas entering the exhaust pipe 2 will gradually cool down, thereby precipitating liquid water. The liquid water can slide down the pipe wall of the exhaust pipe 2 to the inclined baffle plate 19, and then fall down along the baffle plate 19 into the water collection chamber 14.

[0040] When detecting the hydrogen concentration in the exhaust gas, controller 16 first controls switch 6 to open the intake pipe 10 and controls switch 13 to close the water collection pipe 5. Then, it controls power source 4 to operate, drawing the exhaust gas from exhaust pipe 2 into sampling pipe 3. After sampling, power source 4 is turned off, then switch 6 is controlled to cut off intake pipe 10, and switch 13 is controlled to open water collection pipe 5. At this time, the temperature of the exhaust gas sample in sampling pipe 3 drops, causing liquid water to precipitate. The liquid water can flow into water collection chamber 14 along water collection pipe 5. During this process, temperature sensor 8 can constantly detect the temperature in sampling pipe 3. When the difference between the measured temperature and the ambient temperature is less than or equal to the set difference built into controller 16 (i.e., the measured temperature is close to the ambient temperature), it indicates that the exhaust gas no longer precipitates liquid water. Then, controller 16 controls hydrogen concentration sensor 7 to operate, so as to accurately detect the hydrogen concentration in sampling pipe 3. Conversely, when temperature sensor 8 detects that the exhaust gas temperature in sampling tube 3 is significantly higher than the ambient temperature, hydrogen concentration sensor 7 will not operate to avoid deviations in hydrogen concentration detection. The ambient temperature can be obtained through an external temperature sensor 21 of the hydrogen concentration detection device, and the measured data will be transmitted to controller 16. By repeating the above steps, hydrogen concentration data in the exhaust gas can be acquired periodically, ensuring data accuracy.

[0041] During hydrogen concentration detection, the liquid level sensor 15 can monitor the water level change in the water collection chamber 14 in real time. When the liquid level sensor 15 detects that the water level in the water collection chamber 14 is higher than the preset water level, the controller 16 controls the switch 17 to open the drain pipe 18 to complete drainage. Conversely, the controller 16 controls the switch 17 to cut off the drain pipe 18 to stop drainage.

[0042] The above control process can be implemented by means of the built-in program of the controller 16 or an equivalent analog circuit, which is common knowledge in the field and will not be described in detail here.

Claims

1. A hydrogen concentration detection device for hydrogen fuel cell exhaust, characterized in that: It includes an exhaust pipe (2) for receiving the exhaust gas of the hydrogen fuel cell system (1) and is arranged vertically. A sampling pipe (3) is arranged vertically in parallel on the exhaust pipe (2). A power source (4) for drawing the exhaust gas in the exhaust pipe (2) to the sampling pipe (3) is provided on the sampling pipe (3). A water collection pipe (5) is connected to the lower end of the sampling pipe (3). A switch (6) for switching the sampling pipe (3) on and off is provided at the air inlet end of the sampling pipe (3). A hydrogen concentration sensor (7) and a temperature sensor (8) are provided on the sampling pipe (3). When the power source (4) draws the exhaust gas from the exhaust pipe (2) to the sampling pipe (3), the switch (6) cuts off the sampling pipe (3) so that the temperature of the exhaust gas collected in the sampling pipe (3) drops, thereby precipitating liquid water and collecting it into the water collection pipe (5); when the temperature sensor (8) detects that the difference between the measured temperature in the sampling pipe (3) and the ambient temperature is less than or equal to the set difference, the hydrogen concentration sensor (7) operates to detect the hydrogen concentration in the sampling pipe (3); otherwise, the hydrogen concentration sensor (7) does not operate.

2. The hydrogen concentration detection device for hydrogen fuel cell exhaust gas according to claim 1, characterized in that: The upper and lower ends of the sampling tube (3) are respectively provided with an exhaust pipe (9) and an intake pipe (10). Both the exhaust pipe (9) and the intake pipe (10) are connected to the exhaust pipe (2). A switch (6) is provided on the intake pipe (10) to realize the opening and closing of the intake pipe (10).

3. The hydrogen concentration detection device for hydrogen fuel cell exhaust gas according to claim 1, characterized in that: The exhaust pipe (2) is provided with a connecting pipe (12) that connects to the tail outlet (11) of the hydrogen fuel cell system (1).

4. A hydrogen concentration detection device for hydrogen fuel cell exhaust gas according to claim 1, 2, or 3, characterized in that: A switch 2 (13) for switching the water collection pipe (5) on and off is provided on the water collection pipe (5).

5. The hydrogen concentration detection device for hydrogen fuel cell exhaust gas according to claim 4, characterized in that: The lower end of the water collection pipe (5) is connected to a water collection cavity (14).

6. The hydrogen concentration detection device for hydrogen fuel cell exhaust gas according to claim 5, characterized in that: A level sensor (15) is installed on the water collection chamber (14) to detect the water level in the water collection chamber (14).

7. The hydrogen concentration detection device for hydrogen fuel cell exhaust gas according to claim 6, characterized in that: A controller (16) is coupled to the level sensor (15), and a switch (17) is coupled to the controller (16). A drain pipe (18) is provided on the water collection chamber (14), and the switch (17) is provided on the drain pipe (18) to realize the opening and closing of the drain pipe (18). When the level sensor (15) detects that the water level in the water collection chamber (14) is higher than the preset water level, the controller (16) controls the switch three (17) to open the drain pipe (18) to complete the drainage; otherwise, the controller (16) controls the switch three (17) to cut off the drain pipe (18) to stop the drainage.

8. The hydrogen concentration detection device for hydrogen fuel cell exhaust gas according to claim 5, characterized in that: The upper end of the water collection chamber (14) is connected to the lower end of the exhaust pipe (2) to collect the liquid water that precipitates out of the exhaust pipe (2).

9. The hydrogen concentration detection device for hydrogen fuel cell exhaust gas according to claim 8, characterized in that: A baffle plate (19) is provided at the connection between the exhaust pipe (2) and the water collection chamber (14). There are two baffle plates (19) and they are respectively located on two opposite side walls inside the drain pipe (18). There is a water outlet gap (20) between the two baffle plates (19) for liquid water to pass through.

10. A hydrogen concentration detection device for hydrogen fuel cell exhaust gas according to claim 9, characterized in that: The two baffles (19) are set at an angle and their edges are located downstream of each other.

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