An exhaust gas treatment system for a fuel cell

Abstract

This utility model relates to the field of fuel cell exhaust gas treatment technology, and discloses a fuel cell exhaust gas treatment system, including an ejector, a fuel cell, an open environment treatment loop, a closed environment treatment loop, and a switching valve assembly. The inlet end of the fuel cell is connected to the outlet end of the ejector. The open treatment loop includes a first hydrogen separator, a first hydrogen return branch, and a first emission branch, which are connected to each other. The closed environment treatment loop includes a second hydrogen separator, a hydrogen treatment module, and a second emission branch, which are connected to each other. The switching valve assembly is located at the exhaust end of the fuel cell and is used to control the exhaust end of the fuel cell to be connected to the first hydrogen separator or the second hydrogen separator, so that the exhaust gas treatment system can collect and reuse hydrogen in the exhaust gas when operating in an open environment, thereby solving the problem that the exhaust gas treatment system of the prior art cannot improve the working efficiency of the fuel cell system when operating in an open environment.

Description

Technical Field

[0001] This utility model relates to the field of fuel cell exhaust gas treatment technology, and in particular to a fuel cell exhaust gas treatment system. Background Technology

[0002] Fuel cell systems generate electricity through the electrochemical reaction of hydrogen and oxygen, producing liquid water and water vapor mixed with hydrogen in the process. If a hydrogen fuel cell vehicle is in a closed environment, hydrogen in the exhaust gas can easily accumulate, posing a significant safety hazard. Existing zero-hydrogen emission technologies for closed environments utilize exhaust gas treatment systems that employ physical hydrogen storage methods, using hydrogen adsorption materials to adsorb hydrogen from the exhaust gas, achieving zero hydrogen emissions.

[0003] The existing document CN112403194A discloses a "Hydrogen Storage Exhaust Gas Treatment System for Fuel Cell Hydrogen Energy Vehicles," which specifically discloses a fuel cell exhaust gas treatment system. This system uses a drain tank to treat water vapor in the exhaust gas, and then further filters the dried exhaust gas using the same exhaust gas treatment system. However, this system does not differentiate between open and closed environments for exhaust gas treatment; regardless of whether it is in a closed or open environment, all hydrogen emitted by the fuel cell is adsorbed and recovered through the same exhaust gas treatment system. Therefore, when the exhaust gas treatment device operates in an open environment, the consumption of adsorption material used to treat the exhaust gas remains enormous. Furthermore, due to the lack of a return loop, the system efficiency is low, and the driving range of the fuel cell system is reduced. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the present invention provides a fuel cell exhaust gas treatment system, which solves the problem that the exhaust gas treatment system of the prior art cannot improve the working efficiency of the fuel cell system when operating in an open environment.

[0005] To avoid electromagnetic interference from metal products on the workpiece under test, the angle of the test antenna cannot be precisely adjusted.

[0006] To address the aforementioned technical problems, this utility model provides a fuel cell exhaust gas treatment system, the treatment system comprising:

[0007] ejector;

[0008] A fuel cell, wherein the inlet end of the fuel cell is connected to the outlet end of the ejector;

[0009] An open environment processing loop is provided, the open processing loop including a first hydrogen separator, a first hydrogen reflux branch and a first discharge branch. The first hydrogen separator is provided with a first hydrogen exhaust end, a first air inlet end and a first drain end. The first hydrogen reflux branch is connected to the first hydrogen exhaust end and the air inlet end of the ejector. The first air inlet end is connected to the exhaust end of the fuel cell. The first drain end is connected to the first discharge branch.

[0010] A closed-loop environment treatment circuit includes a second hydrogen separator, a hydrogen treatment module, and a second discharge branch. The second hydrogen separator is provided with a second inlet end, a second hydrogen exhaust end, and a second drain end. The second inlet end is connected to the exhaust end of the fuel cell, the second hydrogen exhaust end is connected to the inlet end of the hydrogen treatment module, and the second drain end is connected to the second discharge branch.

[0011] A switching valve assembly is located at the exhaust end of the fuel cell and is used to control the exhaust end of the fuel cell to be connected to the first hydrogen separator or the second hydrogen separator.

[0012] As an optional solution, electromagnetic drain valves are installed on both the first and second discharge branches.

[0013] As an optional feature, the electromagnetic drain valve is equipped with a heating function.

[0014] As an optional feature, a liquid level sensor is also installed in the second hydrogen separator;

[0015] The liquid level sensor is used to detect the liquid level height inside the second hydrogen separator.

[0016] As an optional solution, the switching valve assembly is a solenoid three-way valve;

[0017] The first outlet of the electromagnetic three-way valve is connected to the exhaust end of the fuel cell, the second outlet of the electromagnetic three-way valve is connected to the inlet end of the first hydrogen separation module, and the third outlet of the electromagnetic three-way valve is connected to the inlet end of the second hydrogen separation module.

[0018] As an optional solution, a one-way valve is provided between the air inlet end of the ejector and the first exhaust end, and the one-way valve only allows hydrogen to flow from the first hydrogen exhaust end to the air inlet end of the ejector.

[0019] As an optional solution, the closed environment processing loop also includes a pre-drying device and / or a post-drying device;

[0020] The air inlet of the pre-drying device is connected to the second hydrogen exhaust end, and the exhaust end of the pre-drying device is connected to the air inlet of the hydrogen absorption module.

[0021] The air inlet of the post-drying device is connected to the exhaust outlet of the hydrogen absorption module, and the exhaust outlet of the post-drying device is connected to the outside.

[0022] The pre-drying device dries the fuel cell exhaust gas passing through it, and the post-drying device dries the moisture in the air entering the post-drying device.

[0023] As an optional solution, the closed environment processing circuit also includes a second hydrogen reflux branch, which connects the second hydrogen exhaust end and the ejector inlet end.

[0024] Compared with the prior art, the exhaust gas treatment system of this utility model has the following advantages: the exhaust gas treatment system is equipped with both an open environment treatment circuit and a closed environment treatment circuit. When the exhaust gas treatment system operates in an open environment, it can use the first hydrogen separator in the open unit to separate hydrogen from the exhaust gas. This hydrogen is then gathered by the ejector to the inlet end of the fuel cell for use by the fuel cell. This allows the exhaust gas treatment system to collect and reuse hydrogen from the exhaust gas when operating in an open environment, thereby solving the problem that the exhaust gas treatment system of the prior art cannot improve the working efficiency of the fuel cell system when operating in an open environment. Attached Figure Description

[0025] Figure 1 This is an overall schematic diagram of the exhaust gas treatment system for the fuel cell of this utility model;

[0026] In the diagram, 1 is the ejector; 2 is the fuel cell; 3 is the switching valve assembly; 4 is the first hydrogen separator; 5 is the second hydrogen separator; 501 is the liquid level sensor; 6 is the hydrogen treatment module; 7 is the electromagnetic drain valve; 8 is the pre-drying device; and 9 is the post-drying device. Detailed Implementation

[0027] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0028] like Figure 1 As shown, this utility model provides an exhaust gas treatment system for a fuel cell 2, including: an ejector 1, a fuel cell 2, an open environment treatment reflux, a closed environment treatment loop, and a switching valve assembly 3.

[0029] The inlet of the fuel cell 2 is connected to the outlet of the ejector 1. The ejector 1 uses the Venturi effect to accelerate the collection of hydrogen gas introduced from the outside, so that the hydrogen gas entry rate can meet the working requirements of the fuel cell 2.

[0030] The open processing loop includes a first hydrogen separator 4, a first hydrogen reflux branch, and a first discharge branch. The first hydrogen separator 4 is provided with a first hydrogen exhaust end, a first inlet end, and a first drain end. The first hydrogen reflux branch connects the first hydrogen exhaust end and the inlet end of the ejector 1. At this time, the inlet end of the ejector 1 draws two parts of hydrogen: one part is the original hydrogen inlet, and the other part is the hydrogen recovered and reused in the first hydrogen separator 4. The first inlet end is connected to the exhaust end of the fuel cell 2, and the first drain end is connected to the first discharge branch. The first discharge branch is connected to the outside. The fluid flowing out of the first drain end enters the outside through the first discharge branch. The composition of this part of the fluid is liquid water, a small amount of residual hydrogen, and oxygen.

[0031] When fuel cell 2 is in an open environment, the residual hydrogen in the exhaust gas is not likely to cause safety risks. Therefore, maximizing the reuse of this hydrogen can effectively reduce the hydrogen consumption of fuel cell 2.

[0032] The closed-environment treatment circuit includes a second hydrogen separator 5, a hydrogen treatment module 6, and a second discharge branch. The second hydrogen separator 5 is provided with a second air inlet, a second hydrogen exhaust end, and a second drain end. The second air inlet is connected to the exhaust end of the fuel cell 2, and the second hydrogen exhaust end is connected to the air inlet of the hydrogen treatment module 6. The separated hydrogen enters the hydrogen treatment module 6 and is absorbed by it. The second drain end is connected to the second discharge branch, and the fluid flowing out of the second drain end enters the outside through the first discharge branch. The composition of this fluid is liquid water and a small amount of oxygen.

[0033] The hydrogen treatment module 6 includes an absorption container and a hydrogen adsorption material. The hydrogen adsorption material is disposed inside the absorption container, and the absorption container is divided into two regions by the hydrogen adsorption material. The inlet of the absorption container and the inlet of the absorption container are located in the two regions respectively. The hydrogen adsorption material achieves complete adsorption of hydrogen.

[0034] When fuel cell 2 is in a closed environment, if residual hydrogen in the exhaust gas is released into the external space, it is easy to accumulate and cause deflagration. Therefore, when working in a closed environment, it is necessary to deal with the residual hydrogen in the exhaust gas to the greatest extent possible.

[0035] The switching valve assembly 3 is located at the exhaust end of the fuel cell 2. The switching valve assembly 3 is used to control the exhaust end of the fuel cell 2 to connect to the first hydrogen separator 4 or the second hydrogen separator 5. The switching valve assembly 3 ensures the normal operation of the fuel cell 2 in both states. The switching timing of the switching valve assembly 3 can be switched manually or by a judgment device installed on the vehicle. The corresponding judgment device can be a control sensor for the vehicle's active grille shutter or an electric vehicle charging system used to compare the expected temperature and the actual temperature outside the parked vehicle.

[0036] Due to the limited space inside a car, the specific method of hydrogen purification must be selected based on the specific environment of the car's exhaust gas treatment system. When using technologies such as pressure swing adsorption and membrane separation, a certain temperature or pressure is required during the separation process, which in turn requires the engine to provide energy. In a car, a product that needs to maximize the use of battery power, adding an extra consumption step is not practical. When using technologies such as metal cyanide and catalytic deoxygenation, the cost of the catalyst is high and byproducts are generated during the separation process, which contradicts the original intention of using fuel cell 2 as a clean energy source. Therefore, both the first hydrogen separator 4 and the second hydrogen separator 5 process hydrogen through cooling separation.

[0037] Both the first hydrogen separator 4 and the second hydrogen separator 5 include a separation container and cooling pipes. Several cooling pipes are fixedly installed inside the separation container. The separation container is provided with an air inlet, an exhaust outlet and a water outlet. The water outlet is located at the bottom of the separation container and the exhaust outlet is located at the top of the separation container.

[0038] The cooling pipe is located between the water outlet and the exhaust port. The cooling pipe cools all the exhaust gas entering through the air inlet. The cooling temperature of the cooling pipe is within the liquefaction temperature range of water vapor. After cooling by the cooling pipe, the hydrogen and oxygen in the exhaust gas will separate due to their respective densities. The hydrogen accumulates at the top of the separation container and flows out through the exhaust port, while the oxygen and liquefied water accumulate at the bottom of the separation container and are discharged through the water outlet. Both ends of the cooling pipe are connected to a cooling container storing condensate to form a flow loop. The cooling pipe is filled with condensate to achieve cooling and temperature reduction of the exhaust gas.

[0039] The operating timing of the first separator and the second separator is matched with the operating timing of the switching valve assembly 3; when the switching valve assembly 3 controls the exhaust gas to enter the open environment treatment circuit, the first hydrogen separator 4 operates and the second hydrogen separator 5 does not operate; when the switching valve assembly 3 controls the exhaust gas to enter the closed environment treatment circuit, the second hydrogen separator 5 operates and the first hydrogen separator 4 does not operate.

[0040] Based on this, the exhaust end of the fuel cell 2 is connected to both the open environment treatment unit and the closed environment treatment unit. When the exhaust gas of the fuel cell 2 flows to the open environment treatment unit, the hydrogen in the exhaust gas can be separated by the first hydrogen separation module and then re-collected into the fuel cell 2 by the diversion module. This allows the fuel cell 2 of this invention to recover and reuse a portion of the hydrogen when working in an open environment, thereby solving the problem that the exhaust gas treatment system of the prior art cannot improve the working efficiency of the fuel cell 2 system when working in an open environment.

[0041] Furthermore, such as Figure 1 As shown, both the first and second discharge branches are equipped with electromagnetic drain valves 7. The electromagnetic drain valves 7 control the timing of drainage in the first and second discharge branches. Since the exhaust gas enters the first hydrogen separator 4 or the second hydrogen separator 5 with a certain initial velocity, some gas may enter the first or second discharge branch before it has been completely cooled to the corresponding temperature, thus affecting the working effect of the first hydrogen separator 4 and the second hydrogen separator 5. Therefore, the electromagnetic drain valves 7 are used to limit the speed at which the fluid enters the first and second discharge branches, thereby ensuring that the exhaust gas is released at certain intervals while guaranteeing the working effect of the first hydrogen separator 4 and the second hydrogen separator 5.

[0042] Furthermore, this embodiment is not shown in the accompanying drawings. The electromagnetic drain valve 7 has a heating function, such as a "JORCM I CAH electrically heated electronic drain valve". The heating temperature of the electromagnetic drain valve 7 is less than 100°C. The electromagnetic drain valve 7 can prevent liquid water from condensing into a solid at the outlet and thus blocking the pipeline.

[0043] Furthermore, such as Figure 1 As shown, a liquid level sensor 501 is also installed inside the second hydrogen separator 5.

[0044] The liquid level sensor 501 is used to detect the liquid level height in the second hydrogen separator 5. The set height of the liquid level sensor 501 is between the outlet of the second hydrogen separator 5 and the cooling pipe. The electromagnetic drain valve 7 of the second hydrogen separator 5 opens and closes according to the liquid level height value detected by the liquid level sensor 501. The opening and closing interval of the electromagnetic drain valve 7 of the second hydrogen separator 5 caused by the set value of the liquid level sensor 501 matches the hydrogen separation rate of the second hydrogen separator 5. The liquid level sensor 501 is designed to prevent exhaust gas from being discharged to the outside before the hydrogen is separated, thereby ensuring the safe operation of the fuel cell 2 in a closed environment.

[0045] The matching method between the liquid level sensor 501 and the second hydrogen separator 5 is not further limited here. The liquid level sensor 501 is set with two liquid level height values, both of which can be higher than the outlet of the second separator. The height difference between the two values ​​is the amount of fluid discharged by the second separator each time. At this time, liquid water is always retained in the second hydrogen separator 5, which can effectively prevent hydrogen from flowing out. The liquid level sensor 501 can also be adjusted to the lower of the two liquid level height values ​​to the outlet position. At this time, the second hydrogen separator 5 will drain the liquid water remaining in the second separation container during a single drainage, avoiding the fact that part of the cooling effect of the cooling pipe is always applied to a part of the liquid water, thus reducing the energy consumption of the second separator.

[0046] Furthermore, such as Figure 1 As shown, the switching valve assembly 3 is an electromagnetic three-way valve.

[0047] The first outlet of the electromagnetic three-way valve is connected to the exhaust end of the fuel cell 2, the second outlet of the electromagnetic three-way valve is connected to the air inlet of the first hydrogen separation module, and the third outlet of the electromagnetic three-way valve is connected to the air inlet of the second hydrogen separation module. Each outlet of the electromagnetic three-way valve can be opened independently. The electromagnetic three-way valve simplifies the number of air passages in the equipment, thereby saving some space in the car.

[0048] Furthermore, in this embodiment not shown in the accompanying drawings, the exhaust end of the fuel cell 2 can be configured with two different outlets, one of which is connected to the open environment treatment circuit and the other is connected to the closed environment treatment circuit. In this case, the switching valve assembly 3 consists of two independent on / off valves. When it is necessary to switch the treatment circuit, the corresponding on / off valve opens and the other on / off valve closes, so that the exhaust gas generated by the fuel cell 2 can enter the corresponding treatment circuit as soon as the switching valve assembly 3 is working, thereby ensuring the sensitivity of the exhaust gas treatment system.

[0049] Furthermore, such as Figure 1 As shown, a one-way valve is provided between the air inlet end of the ejector 1 and the first exhaust end. The one-way valve only allows hydrogen to flow from the first hydrogen exhaust end to the air inlet end of the ejector 1. The one-way valve prevents the hydrogen introduced into the air inlet end of the fuel cell 2 from flowing out through the first hydrogen separator 4, thereby improving the working efficiency of the fuel cell 2 when working in an open environment.

[0050] Furthermore, such as Figure 1 As shown, the closed environment processing circuit also includes a pre-drying device 8 and / or a post-drying device 9.

[0051] The inlet of the pre-drying device 8 is connected to the exhaust of the second hydrogen gas, and the exhaust of the pre-drying device 8 is connected to the inlet of the hydrogen absorption module; the inlet of the post-drying device 9 is connected to the exhaust of the hydrogen absorption module, and the exhaust of the post-drying device 9 is connected to the outside; the pre-drying device 8 dries the exhaust gas of the fuel cell 2 passing through it, and the post-drying device 9 dries the water vapor in the air entering the post-drying device 9; both the pre-drying device 8 and the post-drying device 9 are drying cylinders.

[0052] Due to the physical properties of most hydrogen adsorption materials, it is necessary to avoid water vapor contact with the hydrogen adsorption materials as much as possible when using these materials. The pre-drying device 8 dries the exhaust gas of the fuel cell 2 passing through it, and the post-drying device 9 dries the water vapor in the air so that the hydrogen treatment module 6 can work normally.

[0053] Furthermore, such as Figure 1 As shown, the closed-environment processing circuit also includes a second hydrogen reflux branch, which connects the second hydrogen exhaust end and the inlet end of the ejector 1. A solenoid three-way valve is installed at the confluence of the second hydrogen reflux branch, the inlet end of the ejector 1, and the first hydrogen reflux branch. An exhaust valve 10 is installed at the connection point between the second hydrogen reflux branch and the second hydrogen exhaust end. Both the solenoid three-way valve and the exhaust valve 10 work in conjunction with the second hydrogen separator 5. When the second hydrogen separator 5 is working, the exhaust valve 10 remains stationary. In the closed state, the gas in the second separator enters the second hydrogen return branch, where the hydrogen in this part of the gas is reused by the fuel cell 2. The remaining gas re-enters the second hydrogen separator 5. The exhaust valve 10 opens at a pre-designed opening frequency. Gas that cannot be consumed in the closed environment processing circuit is discharged to the environment through the gas flow branch where the exhaust valve 10 is located. At this time, port B of the electromagnetic three-way valve on the second hydrogen return branch is closed, thereby enabling the exhaust gas treatment device described in this utility model to maximize the secondary utilization of hydrogen and reduce hydrogen consumption.

[0054] The working process of this utility model is as follows: When the fuel cell 2 is in an open environment, the exhaust gas of the fuel cell 2 flows into the open environment treatment circuit, and the exhaust gas of the fuel cell 2 enters the first hydrogen separator 4. The first hydrogen separator 4 separates the water vapor, oxygen and hydrogen in the exhaust gas. The separated hydrogen is collected by the ejector 1 and flows back into the fuel cell 2, and the remaining fluid is discharged through the first drain port. When the fuel cell 2 is in a closed environment, the exhaust gas of the fuel cell 2 flows into the closed environment treatment circuit, and the exhaust gas of the fuel cell 2 flows through the second hydrogen separator 5. The second hydrogen separator 5 separates the water vapor, oxygen and hydrogen in the exhaust gas. The separated hydrogen enters the hydrogen treatment module 6 to prevent discharge, and the remaining fluid is discharged through the second drain port.

[0055] In summary, this utility model provides an exhaust gas treatment system for a fuel cell 2. By adding an open environment treatment unit including a first hydrogen separator 4 to the exhaust gas treatment system, the system can separate the hydrogen component in the exhaust gas through the first hydrogen separator 4 when operating in an open environment. Then, the ejector 1 collects this hydrogen back to the inlet of the fuel cell 2, realizing the recovery and reuse of hydrogen in the exhaust gas in an open environment. This solves the problem that the existing exhaust gas treatment system cannot improve the working efficiency of the fuel cell 2 system when operating in an open environment.

[0056] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.

Claims

1. A fuel cell exhaust gas treatment system, characterized in that, The processing system includes: ejector; A fuel cell, wherein the inlet end of the fuel cell is connected to the outlet end of the ejector; An open environment processing loop includes a first hydrogen separator, a first hydrogen reflux branch, and a first discharge branch. The first hydrogen separator is provided with a first hydrogen exhaust end, a first air inlet end, and a first drain end. The first hydrogen reflux branch connects the first hydrogen exhaust end and the air inlet end of the ejector. The first air inlet end is connected to the exhaust end of the fuel cell, and the first drain end is connected to the first discharge branch. A closed-loop environment treatment circuit includes a second hydrogen separator, a hydrogen treatment module, and a second discharge branch. The second hydrogen separator is provided with a second inlet end, a second hydrogen exhaust end, and a second drain end. The second inlet end is connected to the exhaust end of the fuel cell, the second hydrogen exhaust end is connected to the inlet end of the hydrogen treatment module, and the second drain end is connected to the second discharge branch. A switching valve assembly is located at the exhaust end of the fuel cell and is used to control the exhaust end of the fuel cell to be connected to the first hydrogen separator or the second hydrogen separator.

2. The fuel cell exhaust gas treatment system according to claim 1, characterized in that, Both the first and second discharge branches are equipped with electromagnetic drain valves.

3. The fuel cell exhaust gas treatment system according to claim 2, characterized in that, The electromagnetic drain valve has a heating function.

4. The fuel cell exhaust gas treatment system according to claim 1, characterized in that, The second hydrogen separator is also equipped with a liquid level sensor; The liquid level sensor is used to detect the liquid level height inside the second hydrogen separator.

5. The fuel cell exhaust gas treatment system according to claim 1, characterized in that, The switching valve assembly is an electromagnetic three-way valve; The first outlet of the electromagnetic three-way valve is connected to the exhaust end of the fuel cell, the second outlet of the electromagnetic three-way valve is connected to the inlet end of the first hydrogen separation module, and the third outlet of the electromagnetic three-way valve is connected to the inlet end of the second hydrogen separation module.

6. The fuel cell exhaust gas treatment system according to claim 1, characterized in that, A one-way valve is provided between the air inlet of the ejector and the first hydrogen exhaust end. The one-way valve only allows hydrogen to flow from the first hydrogen exhaust end to the air inlet of the ejector.

7. The fuel cell exhaust gas treatment system according to claim 1, characterized in that, The closed environment processing circuit also includes a pre-drying device and / or a post-drying device. The air inlet of the pre-drying device is connected to the second hydrogen exhaust end, and the exhaust end of the pre-drying device is connected to the air inlet of the hydrogen absorption module. The air inlet of the post-drying device is connected to the exhaust outlet of the hydrogen absorption module, and the exhaust outlet of the post-drying device is connected to the outside. The pre-drying device dries the fuel cell exhaust gas passing through it, and the post-drying device dries the moisture in the air entering the post-drying device.

8. The fuel cell exhaust gas treatment system according to claim 7, characterized in that, The closed environment processing circuit also includes a second hydrogen reflux branch, which connects the second hydrogen exhaust end and the ejector inlet end.

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