CN115188990A - Air subsystem, hydrogen fuel cell and frame purging method in hydrogen fuel cell - Google Patents

Abstract

The invention discloses an air subsystem, a hydrogen fuel cell and a frame purging method of the hydrogen fuel cell, wherein the hydrogen fuel cell comprises a frame and an electric pile, the electric pile is arranged in the frame, the frame is provided with a first air inlet and a first exhaust port, the cathode of the electric pile corresponds to a second exhaust port, the air subsystem comprises a frame gas taking loop and a frame exhaust loop, one end of the frame gas taking loop is communicated with the second exhaust port, the other end of the frame gas taking loop is communicated with the first air inlet, and the frame gas taking loop is used for introducing purging gas into the frame; the frame body exhaust loop is communicated with the first exhaust port and used for exhausting gas in the frame body. The gas source of the purging frame body is set as the tail gas of the cathode of the electric pile, so that the power consumption of the air compressor can be reduced, the utilization rate of the power consumption of the air compressor is improved, and the economy of the whole air subsystem is improved; the inert gas content of the gas blown into the frame body is high, the possibility of the risk of explosion of the frame body is reduced, and the safety performance of blowing the frame body is improved.

Description

Air subsystem, hydrogen fuel cell and frame purging method in hydrogen fuel cell

Technical Field

The invention relates to the technical field of hydrogen fuel cells, in particular to an air subsystem, a hydrogen fuel cell and a frame purging method in the hydrogen fuel cell.

Background

A hydrogen fuel cell is a power generation device that directly converts chemical energy of hydrogen and oxygen into electrical energy. The basic principle is as follows: hydrogen is sent to an anode plate (cathode) of the fuel cell, one electron in hydrogen atoms is separated out under the action of a catalyst (platinum), hydrogen ions (protons) losing electrons pass through a proton exchange membrane and reach a cathode plate (anode) of the fuel cell, the electrons cannot pass through the proton exchange membrane, and the electrons can only pass through an external circuit and reach the cathode plate of the fuel cell, so that current is generated in the external circuit. After reaching the cathode plate, the protons recombine with oxygen atoms and hydrogen ions to form water. Since oxygen supplied to the cathode plate can be obtained from the air, electric power can be continuously supplied as long as hydrogen is continuously supplied to the anode plate, air is supplied to the cathode plate, and water (steam) is timely taken away. The electricity generated by the fuel cell is used for supplying power to the motor through the devices such as an inverter, a controller and the like, and then the wheels are driven to rotate through a transmission system, a drive axle and the like, so that the vehicle can run on the road. Compared with the traditional automobile, the energy conversion efficiency of the fuel cell vehicle is as high as 60 to 80 percent, which is 2 to 3 times of that of the internal combustion engine. The fuel cell fuel is hydrogen and oxygen and the product is clean water, which works as such without producing carbon monoxide and carbon dioxide, and without sulfur and particulate emissions. Therefore, the hydrogen fuel cell automobile is a zero-emission and zero-pollution automobile in the true sense, and the hydrogen fuel is a perfect automobile energy source.

An on-board fuel cell system generally consists of an air subsystem, a hydrogen subsystem, a thermal management system, and a control system. The air inlet and outlet system provides clean air with proper flow, temperature, pressure and humidity for the electric pile. The principle of a conventional air intake and exhaust system is shown in the figure I, and mainly comprises an air filter, an air compressor, an intercooler, a humidifier, a throttle valve and other core components. The air filter not only filters physical particles, but also has a certain filtering function on toxic gases such as nitric oxide, sulfide and the like; the air compressor is used for pressurizing air and working in coordination with the throttle valve according to the requirements of the galvanic pile to ensure that the air flow and the pressure entering and exiting the galvanic pile are in a proper range; after passing through the air compressor, the air temperature can be increased to more than 100 ℃, the air temperature exceeds the applicable temperature of the electric pile, and compressed air needs to be cooled by an intercooler; and the humidifier performs damp-heat exchange between the high-temperature and high-humidity tail gas at the cathode outlet of the galvanic pile and the air at the outlet of the air compressor, so that the humidity requirement of the galvanic pile on the air is met.

In the actual power generation process of the hydrogen fuel cell, hydrogen can escape because the density of the hydrogen is low and the galvanic pile is in a sealed state. Especially, the frame body for sealing the electric pile often has escaped hydrogen, and if the hydrogen content is too high, the potential safety hazard exists. To reduce the hydrogen content in the enclosure, air is typically supplied to purge the enclosure. As shown in fig. 1, the air used to purge the frame in the prior art comes from the exhaust end of the intercooler. Therefore, the air compressor needs to supply air to the electric pile and the frame body, power consumption of the air compressor is increased, and economy is low.

Disclosure of Invention

The invention provides an air subsystem, a hydrogen fuel cell and a frame purging method in the hydrogen fuel cell, aiming at overcoming the defect of poor economy caused by the fact that a frame purging unit in the fuel cell increases the power consumption of an air compressor in the prior art.

The utility model provides an air subsystem for hydrogen fuel cell, hydrogen fuel cell includes frame and galvanic pile, the galvanic pile is located in the frame, first air inlet and first gas vent have on the frame, the negative pole of galvanic pile corresponds there is the second gas vent, air subsystem includes:

one end of the frame body gas taking loop is communicated with the second exhaust port, the other end of the frame body gas taking loop is communicated with the first gas inlet, and the frame body gas taking loop is used for introducing purge gas into the frame body;

and the frame body exhaust loop is communicated with the first exhaust port and is used for exhausting the gas in the frame body.

In some embodiments, the frame gas-taking loop includes a first inlet, a first pipeline and a first outlet, which are sequentially connected, the first inlet is connected to the second gas outlet, and the first outlet is connected to the first gas inlet, so that gas exhausted from a cathode of the stack enters the frame.

In some embodiments, the frame gas circuit further comprises a pressure regulating valve disposed on the first pipeline between the first inlet and the first outlet.

In some embodiments, the frame exhaust circuit includes a second inlet, a second pipeline and a second outlet which are sequentially communicated, the second inlet is communicated with the first exhaust port, and the second outlet is communicated with the atmosphere.

In some embodiments, the second conduit employs a negative pressure vent.

In some embodiments, the air subsystem further comprises a stack air circuit, the stack air circuit comprising:

the air filter is communicated with the atmosphere end and is used for filtering air;

the inlet end of the air compressor is communicated with the outlet end of the air filter and is used for pressurizing the air;

the inlet end of the intercooler is communicated with the outlet end of the air compressor and is used for cooling the air discharged from the air compressor;

the inlet end of the humidifying module is communicated with the outlet end of the intercooler and used for increasing the humidity of the air, and the outlet end of the humidifying module is communicated with the air inlet of the cathode side of the electric pile.

In some embodiments, the frame exhaust circuit includes a second inlet, a second pipeline and a second outlet, which are sequentially communicated, and the second inlet is communicated with the first exhaust port and is communicated with the inlet end of the air compressor.

In some embodiments, the air circuit further comprises an expander, an inlet end of the expander is in communication with the air compressor, an outlet end of the expander is in communication with an inlet end of the humidification module, and another outlet end of the expander is in communication with the atmosphere.

In some embodiments, the stack air circuit further comprises a bypass valve disposed in the conduit between the expander and the humidification module.

A hydrogen fuel cell comprising an air subsystem as described above.

A hydrogen fuel cell chassis purge method of purging the chassis with an air subsystem as described above, the hydrogen fuel cell chassis purge method comprising the steps of:

introducing gas exhausted from the cathode side of the electric pile into the frame gas taking loop from the second exhaust port;

introducing the gas into the frame body from the first gas inlet, and purging the frame body;

the hydrogen gas escaping into the frame body is driven out of the frame body from the first exhaust port by the gas.

In some embodiments, before the gas exhausted from the cathode side of the stack is introduced into the frame gas extraction circuit from the second exhaust port, the method further includes the following steps:

communicating two ends of the frame gas taking loop with the second gas outlet and the first gas inlet respectively;

communicating the frame exhaust circuit with the first exhaust port.

The bionic foot type robot based on the concentrated driving four-degree-of-freedom leg structure has the following advantages:

the air subsystem provided by the invention supplies air to the frame through the frame air-taking loop so as to purge the interior of the frame and further discharge hydrogen escaping in the frame. And the frame gas taking circuit is communicated with a second exhaust port corresponding to the cathode side of the electric pile, so that the gas for purging the frame comes from the air after reaction from the cathode side of the electric pile. Because the gas discharged from the second exhaust port on the cathode side of the galvanic pile is the air after reaction, the oxygen content in the gas is relatively low, and the nitrogen content in the gas is relatively high. The gas source of the blowing frame body is set as the tail gas of the cathode of the electric pile, on one hand, the gas does not need to be compressed by an air compressor, and the air compressed by the air compressor only supplies air to the electric pile, so that the gas blown into the frame body is not compressed by the air compressor any more, and compared with the scheme in the prior art, the technical scheme can reduce the power consumption of the air compressor, thereby improving the utilization rate of the power consumption of the air compressor and further improving the economy of the whole air subsystem; on the other hand, the discharge gas on the cathode side of the electric pile is adopted for gas supply, and the nitrogen content in the discharge gas on the cathode side is higher, which is equivalent to the content of inert gas, so that the inert gas content of the gas blown into the frame body is higher, the probability of explosion danger of the frame body is reduced, and the safety performance of blowing of the frame body is further improved.

Drawings

FIG. 1 is a schematic diagram of the piping connections of an air subsystem in accordance with the related art of the present invention;

FIG. 2 is a schematic diagram of the plumbing connections for the air subsystem provided by one embodiment of the present invention;

FIG. 3 is a schematic diagram of the plumbing connections for an air subsystem provided by another embodiment of the present invention;

FIG. 4 is a schematic diagram of the plumbing connections for an air subsystem provided by yet another embodiment of the present invention;

fig. 5 is a schematic flow chart of a hydrogen fuel cell frame purging method according to an embodiment of the present invention.

The reference numbers are as follows:

S1-S3; a frame body 10; a stack 20; a frame gas-taking circuit 30; a frame exhaust circuit 40; a pressure regulating valve 50; an air filter 60; an air compressor 70; an intercooler 80; a humidification module 90; an expander 100; a bypass valve 110.

Detailed Description

In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention.

Referring to fig. 1, which is a schematic view showing the pipeline communication of the air subsystem in the related art, it can be seen that the beginning of the frame air intake circuit 30 for purging the frame 10 in the related art is connected to the end of the intercooler, and the end of the frame exhaust circuit 40 is connected to the exhaust of the expander. Set up like this, the gas that blows to the framework derives from the air after compressing through the air compressor machine and through the intercooler cooling, just so makes the air after the air compressor machine compression both to carry out the air feed to the cathode side of galvanic pile 20, will supply air to the framework again to make the framework sweep the consumption that has increased the air compressor machine, lead to whole air subsystem's economic nature relatively poor.

Therefore, as shown in fig. 2, the present embodiment provides an air subsystem for a hydrogen fuel cell, the hydrogen fuel cell includes a frame 10 and an electric pile 20, the electric pile 20 is disposed in the frame 10, the frame 10 has a first air inlet and a first air outlet, a cathode of the electric pile 20 corresponds to a second air outlet, the air subsystem includes a frame air-taking circuit 30 and a frame air-discharging circuit 40, wherein one end of the frame air-taking circuit 30 is communicated with the second air outlet, the other end is communicated with the first air inlet, and the frame air-taking circuit 30 is used for introducing purge gas into the frame 10; and a housing exhaust circuit 40 communicating with the first exhaust port and exhausting the gas in the housing 10.

According to the air subsystem provided by the technical scheme, the frame body 10 is supplied with air through the frame body air taking loop 30 so as to purge the interior of the frame body 10, and then hydrogen escaping in the frame body 10 is discharged. The frame gas intake circuit 30 is connected to a second exhaust port corresponding to the cathode side of the cell stack 20, so that the gas for purging the frame 10 is derived from the air reacted on the cathode side of the cell stack 20. Since the gas discharged from the second exhaust port of the cathode side of the stack 20 is the air after the reaction, the oxygen content in the gas is relatively low and the nitrogen content in the gas is relatively high. The source of the gas for purging the frame body 10 is set as the tail gas of the cathode of the electric pile 20, on one hand, the gas does not need to be compressed by the air compressor 70, and the air compressed by the air compressor 70 only supplies air to the electric pile 20, so that the gas for blowing the frame body 10 is not compressed by the air compressor 70 any more, and compared with the scheme in the prior art, the technical scheme can reduce the power consumption of the air compressor 70, thereby improving the utilization rate of the power consumption of the air compressor 70 and further improving the economy of the whole air subsystem; on the other hand, when the discharge gas at the cathode side of the stack 20 is used for supplying gas, the nitrogen content in the discharge gas at the cathode side is higher, which is equivalent to the content of the inert gas, so that the inert gas content of the gas purged into the frame 10 is higher, the probability of the risk of explosion of the frame 10 is reduced, and the purging safety performance of the frame 10 is further improved.

In some embodiments, the frame gas-taking circuit 30 includes a first inlet, a first pipeline and a first outlet, which are sequentially connected, the first inlet is used for air intake, the first inlet is connected to the second exhaust port, the first outlet is used for air exhaust, and the first outlet is connected to the first gas inlet, so that the gas exhausted from the cathode side of the cell stack 20 flows into the first pipeline from the first inlet, then flows into the first gas inlet in the frame from the first outlet, and then flows into the frame 10, so as to purge the frame 10. The frame gas taking loop 30 provided by the technical scheme has a simple structure, does not pass through the air compressor 70, effectively utilizes the exhaust gas on the cathode side of the electric pile 20, reduces the power consumption of the air compressor 70, improves the economy of the whole air subsystem and also improves the purging safety of the frame 10 compared with the prior art.

Further, as shown in fig. 3, the frame gas-taking circuit 30 further includes a pressure regulating valve 50, and the pressure regulating valve 50 is disposed on the first pipeline and located between the first inlet and the first outlet. The proton membrane in the hydrogen fuel cell has a certain mechanical strength, and if the pressure difference between the two sides of the membrane electrode is too large, the membrane electrode can be damaged, so that the dynamic pressure difference control of the air side pressure and the hydrogen side pressure is particularly important for the reliability of the whole fuel cell system. It is generally required that the hydrogen side pressure is equal to or slightly higher than the air side pressure and that the same rise and fall, i.e., the pressure difference is kept constant, is ensured when the pressures on both sides are adjusted to reduce damage to the proton membrane. Therefore, a pressure regulating valve 50 is provided on the frame gas intake circuit 30, that is, at the cathode-side first exhaust port, to regulate the pressure at the cathode-side exhaust port of the stack 20. The pressure regulating valve in this embodiment employs a back pressure valve for measuring and tracking pressure change of hydrogen gas on the anode side and regulating and controlling pressure on the exhaust side on the cathode side.

In some embodiments, the frame exhaust circuit 40 includes a second inlet, a second pipeline and a second outlet, which are connected in sequence, the second inlet is used for gas to enter, the second inlet is connected to the first exhaust port, and the second outlet is connected to the atmosphere. So that the gas discharged from the inside of the frame 10 enters the second pipe from the second inlet and is discharged to the atmosphere through the second outlet. Of course, the gas exhausted from the frame 10 can be recycled, for example, the gas can also enter the cathode side of the electric pile 20 to participate in the reaction. It should be noted that, in this embodiment, the second pipeline is a negative pressure vent pipe, and the use of the negative pressure vent pipe is beneficial to improving the efficiency of discharging the gas in the frame 10.

In some embodiments, as shown in fig. 3 and 4, the air subsystem further comprises a stack 20 air circuit, the stack 20 air circuit comprising an air filter 60, an air compressor 70, an intercooler 80, and a humidification module 90, the air filter 60 being in communication with the atmosphere for filtering air; the inlet end of the air compressor 70 is communicated with the outlet end of the air filter 60 for pressurizing air; the inlet end of the intercooler 80 is communicated with the outlet end of the air compressor 70 and is used for cooling the air discharged from the air compressor 70; the inlet end of the humidification module 90 is in communication with the outlet end of the intercooler 80 for increasing the humidity of the air, and the outlet end of the humidification module 90 is in communication with the air inlet of the cathode side of the cell stack 20. The air is filtered by the air filter 60 to remove impurities in the air, is pressurized by the air compressor 70, is cooled by the intercooler 80, is humidified by the humidification module 90 to reach the states of temperature, pressure, humidity and the like required by the operation of the fuel cell stack, and finally enters the fuel cell stack for electrochemical reaction.

In one embodiment, the frame exhaust circuit 40 includes a second inlet, a second pipeline and a second outlet, which are connected in sequence, wherein the second inlet is connected to the first exhaust port and is connected to the inlet end of the air compressor 70. So that the gas exhausted from the frame 10 enters the second pipeline from the second inlet and enters the air compressor 70 again through the second outlet for recycling.

Further, as shown in fig. 4, the air circuit of the stack 20 further includes an expander 100, an inlet end of the expander 100 is communicated with the air compressor 70, one outlet end of the expander 100 is communicated with an inlet end of the humidification module 90, and the other outlet end of the expander 100 is communicated with the atmosphere. The system of the stack 20 is most sensitive to pressure variations, and although increasing the oxygen supply pressure can improve the efficiency of the fuel cell, the air compressor 70 also consumes power as a source for supplying high-pressure oxygen, and the energy of the air compressor 70 is derived from the output of the cell. Therefore, in order to obtain overall performance, the most efficient compression must be sought. Since the exhaust gas discharged from the stack 20 has a certain pressure and temperature, and the exhaust gas discharged from the stack 20 also has a high recoverable energy, it is necessary to absorb the exhaust gas with the expander 100 to reduce the energy consumption of the air compressor 70 in order to improve the fuel cell efficiency. The expander 100 recovers energy to provide driving energy for the circulation of the air compressor 70.

In some embodiments, as shown in fig. 4, the air circuit of the stack 20 further includes a bypass valve 110, the bypass valve 110 being disposed in the line between the expander 100 and the humidification module 90. The bypass valve 110 is provided as a backup conduit, and by isolating the air compressor 70 when the air compressor 70 is damaged, or by closing the main conduit, opening the bypass valve 110 also allows the apparatus to continue to operate, thereby improving the reliability of the operation of the entire air subsystem.

A hydrogen fuel cell comprising an air subsystem as above. The air subsystem is used in the hydrogen fuel cell, and the gas source of the blowing frame body 10 is set as the tail gas of the cathode of the electric pile 20, so that the power consumption of the air compressor 70 can be reduced, the utilization rate of the power consumption of the air compressor 70 is improved, and the economy of the whole air subsystem is improved; the inert gas content of the gas purged into the frame body 10 is also made higher, so that the probability of the risk of explosion of the frame body 10 is reduced, and the purging safety performance of the frame body 10 is further improved.

As shown in fig. 5, an embodiment of the present invention further provides a hydrogen fuel cell frame purging method, which purges the frame through the above air subsystem, and the hydrogen fuel cell frame purging method includes the following steps: step S10, introducing gas exhausted from the cathode side of the galvanic pile 10 into the frame gas taking loop 30 from a second exhaust port; step S20, introducing gas into the frame body 10 from the first gas inlet, and purging the frame body 10; in step S30, the hydrogen gas escaping into the housing 10 is expelled from the housing 10 through the first exhaust port by the gas.

In this embodiment, the gas discharged from the cathode side of the cell stack 20 enters the frame gas taking circuit 30, and then enters the frame 10 through the first gas inlet of the frame 10 to purge the frame 10, so that the gas for purging the frame 10 comes from the gas after the cathode side of the cell stack 20 has reacted, the oxygen content in the gas is relatively low, the nitrogen content in the gas is relatively high, and further the possibility of the risk of explosion of the frame 10 is reduced, thereby improving the safety performance of purging the frame 10; and sweep the framework through the cathode side exhaust gas of pile, this gas need not be compressed through air compressor machine 70, and the air after the air compressor machine 70 compression only supplies air to pile 20, makes the gas of blowing no longer through air compressor machine 70 compression to framework 10 like this, and relative prior art's scheme like this, this technical scheme can reduce air compressor machine 70's consumption to improve the utilization ratio of air compressor machine 70's consumption, and then improve the economic nature of whole air subsystem.

Further, before the gas exhausted from the cathode side of the stack is introduced into the frame gas-taking circuit 30 from the second exhaust port, the method further includes the following steps: two ends of the frame gas taking loop 30 are respectively communicated with the second exhaust port and the first gas inlet; the frame exhaust circuit 30 is connected to the first exhaust port. Through these two steps, a necessary conduit connection system is provided for purging the frame on the cathode side of the stack, and a necessary physical condition is provided for smoothly purging the frame 10.

While the invention has been described with reference to several embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (12)

1. An air subsystem for a hydrogen fuel cell, the hydrogen fuel cell includes a frame and an electric pile, the electric pile is arranged in the frame, the frame is provided with a first air inlet and a first exhaust port, the cathode side of the electric pile corresponds to a second exhaust port, and the air subsystem includes:

one end of the frame body gas taking loop is communicated with the second exhaust port, the other end of the frame body gas taking loop is communicated with the first gas inlet, and the frame body gas taking loop is used for introducing purge gas into the frame body;

and the frame body exhaust loop is communicated with the first exhaust port and used for exhausting gas in the frame body.

2. The air subsystem as claimed in claim 1, wherein the frame air-extracting circuit includes a first inlet, a first pipeline and a first outlet, which are sequentially connected, the first inlet is connected to the second air outlet, and the first outlet is connected to the first air inlet, so that the air exhausted from the cathode of the stack enters the frame.

3. The air subsystem as recited in claim 2 wherein said frame air extraction circuit further comprises a pressure regulating valve disposed on said first conduit between said first inlet and said first outlet.

4. The air subsystem as claimed in claim 1, wherein the frame exhaust circuit comprises a second inlet, a second pipeline and a second outlet which are communicated in sequence, the second inlet is communicated with the first exhaust port, and the second outlet is communicated with the atmosphere.

5. The air subsystem of claim 4, wherein the second conduit employs a negative pressure vent.

6. The air subsystem of any of claims 1-5, further comprising a stack air circuit, the stack air circuit comprising:

the air filter is communicated with the atmosphere end and is used for filtering air;

the inlet end of the air compressor is communicated with the outlet end of the air filter and is used for pressurizing the air;

the inlet end of the intercooler is communicated with the outlet end of the air compressor and is used for cooling the air discharged from the air compressor;

the inlet end of the humidifying module is communicated with the outlet end of the intercooler and used for increasing the humidity of the air, and the outlet end of the humidifying module is communicated with the air inlet of the cathode side of the electric pile.

7. The air subsystem as claimed in claim 6, wherein the frame exhaust circuit comprises a second inlet, a second pipeline and a second outlet which are sequentially communicated, and the second inlet is communicated with the first exhaust port and communicated with the inlet end of the air compressor.

8. The air subsystem of claim 6 wherein the stack air circuit further comprises an expander, an inlet end of the expander being in communication with the air compressor, an outlet end of the expander being in communication with the inlet end of the humidification module, another outlet end of the expander being in communication with the atmosphere.

9. The air subsystem of claim 8, wherein the stack air circuit further comprises a bypass valve disposed on the line between the expander and the humidification module.

10. A hydrogen fuel cell, characterized in that it comprises an air subsystem according to any one of claims 1-9.

11. A hydrogen fuel cell frame purge method of purging the frame through the air subsystem of any of claims 1-9, the hydrogen fuel cell frame purge method comprising the steps of:

introducing gas exhausted from the cathode side of the electric pile into the frame gas taking loop from the second exhaust port;

introducing the gas into the frame body from the first gas inlet, and purging the frame body;

the hydrogen gas escaping into the frame body is driven out of the outside of the frame body from the first exhaust port by the gas.

12. The frame purge method for a hydrogen fuel cell according to claim 11, wherein the step of introducing the gas exhausted from the cathode side of the stack into the frame gas-taking circuit from the second exhaust port further comprises:

communicating two ends of the frame gas taking loop with the second gas outlet and the first gas inlet respectively;

and communicating the frame exhaust loop with the first exhaust port.

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