CN112072147A

CN112072147A - Dehydrogenation device for fuel cell tail gas, fuel cell stack and dehydrogenation method

Info

Publication number: CN112072147A
Application number: CN202010978028.8A
Authority: CN
Inventors: 高勇
Original assignee: SHANGHAI EVERPOWER TECHNOLOGIES Ltd
Current assignee: Hydrogen Xinward (Shanghai) New Energy Development Co.,Ltd.
Priority date: 2020-09-16
Filing date: 2020-09-16
Publication date: 2020-12-11
Anticipated expiration: 2040-09-16
Also published as: CN112072147B

Abstract

The invention relates to a hydrogen removal device and method for fuel cell tail gas, the device comprises a catalytic cell assembly and a control device, air and hydrogen in the fuel cell tail gas are input into the catalytic cell assembly in a mixed or unmixed mode, the catalytic cell assembly comprises at least two gas channels formed by a membrane electrode in a mode of staggered sequencing of an anode and a cathode, a load device is arranged between the anode of one gas channel and the cathode of the other gas channel, and through the structural arrangement of a plurality of layers of gas channels, the hydrogen can be rapidly consumed, and tail gas emission of the hydrogen approaching zero is realized.

Description

Dehydrogenation device for fuel cell tail gas, fuel cell stack and dehydrogenation method

Technical Field

The invention relates to the technical field of fuel cells, in particular to a fuel cell stack of a dehydrogenation device for fuel cell tail gas and a dehydrogenation method.

Background

The fuel cell is widely applied to various vehicles such as a carrying device for space flight and aviation, a vehicle, a ship, an entertainment vehicle and the like. The hydrogen-oxygen fuel cell uses hydrogen as a reducing agent and oxygen as an oxidizing agent, and chemical energy is converted into electric energy through the combustion reaction of the fuel. The hydrogen proportion in the fuel cell tail gas is below 3%. The tail gas valve of the fuel cell is intermittently opened and closed, so that the removal of the tail gas is not continuous but intermittent, and the hydrogen concentration in the tail gas is not necessarily the same every time. Therefore, how to monitor and judge the hydrogen concentration in the tail gas of the fuel cell in the hydrogen removal process and determine that the hydrogen concentration in the tail gas of the fuel cell is reduced to a specified concentration is a technical problem to be solved. Generally use gas concentration sensor to monitor the hydrogen concentration in the gas among the prior art, but gas concentration sensor can't set up the in-process of eliminating at tail gas, need carry out the accurate monitoring of hydrogen concentration with tail gas storage simultaneously, and this must increase the volume and the monitoring link of dehydrogenation device, is unfavorable for the simplification of dehydrogenation device. In the prior art, the hydrogen concentration in the tail gas of the fuel cell is low or even no hydrogen is ensured by multi-stage dehydrogenation.

For example, chinese patent document CN107813691A discloses an energy-saving and environment-friendly hydrogen hybrid electric vehicle, which includes a vehicle body, wheels, an engine, a turbocharger, a kohlepu unit, a three-stage deep purification system for exhaust gas, and an auxiliary power system. The coanda unit includes a secondary combustor, a hydrogen heat compression unit, an expander, and an intermediate reheater. The tail gas three-stage deep purification system comprises a high-temperature catalytic coil, a medium-temperature three-way catalyst or a medium-temperature NOx purifier and a low-temperature tail gas purifier. The expander outlet is connected to the expander inlet by a hydrogen thermal compression unit. The exhaust port of the engine is connected to the inlet of the secondary combustor through a high-temperature catalytic coil, a turbocharger, a medium-temperature three-way catalyst or a medium-temperature NOx purifier. The outlet of the secondary combustor is connected to the exhaust pipe through a hydrogen thermal compression unit, an intermediate reheater, a low-temperature tail gas purifier and a tail gas real-time monitor. The expander is connected with a generator shaft, and the generator is connected with an auxiliary power system circuit. The tail gas of the automobile comes from a combustor and a fuel cell, the component content of the tail gas is complex, and a multi-stage deep purification system is required to carry out catalysis at different temperatures respectively to purify various substances. The three-stage deep purification system for tail gas is not suitable for tail gas treatment of fuel cells only needing dehydrogenation, cannot monitor the hydrogen content in the tail gas and determine whether to carry out circulating dehydrogenation, and only can monitor the purified tail gas.

As described above, the conventional small-sized catalytic cell module can consume hydrogen in the cell exhaust gas, but requires a small-sized stack for generating electricity by hydrogen and air along respective channels, and has a complicated channel structure, low hydrogen consumption efficiency, and no exhaust gas treatment device having a simple structure and high hydrogen consumption efficiency. Moreover, even if the content of the fuel cell off-gas is low, it cannot be currently applied to equipment or devices in an enclosed space, and the fundamental reason is that even the low content of hydrogen is concentrated on the top layer of the enclosed space with time, thereby forming a certain amount of hydrogen gas. Once exposed to fire, the enclosed space is susceptible to explosion. Therefore, how to reduce the content of the tail gas to approach zero is a crucial technical problem even realizing zero emission of hydrogen in the tail gas, and is also a key technical problem for popularizing the application range of the fuel cell.

Furthermore, on the one hand, due to the differences in understanding to the person skilled in the art; on the other hand, since the inventor has studied a lot of documents and patents when making the present invention, but the space is not limited to the details and contents listed in the above, however, the present invention is by no means free of the features of the prior art, but the present invention has been provided with all the features of the prior art, and the applicant reserves the right to increase the related prior art in the background.

Disclosure of Invention

In view of the deficiencies of the prior art, the present invention provides a hydrogen removal device for fuel cell exhaust, the device comprising at least one catalytic cell assembly connected to a fuel cell, the catalytic cell assembly being connected to a control device, wherein air and hydrogen in the exhaust intermittently discharged from the fuel cell are introduced into the catalytic cell assembly in a mixed or non-mixed manner, wherein the catalytic cell assembly comprises at least two gas channels formed by at least one membrane electrode in an anode and cathode staggered arrangement manner, at least one load device is disposed between at least one anode of one gas channel and a cathode of at least one other gas channel, and the hydrogen and the oxygen chemically react and/or electrochemically react under the catalytic action of the cathode and the anode in the at least two gas channels to generate a potential difference between the anode and the cathode of the two gas channels, the load device consumes the current generated on the basis of the potential difference between the anode and the cathode of the two gas channels in an energy-converting manner, so that the energy consumption state of the load device is correlated with the hydrogen content.

Preferably, the load device is an adjustable resistor, an adjusting end of the adjustable resistor is connected with the control device, and the control device adjusts a current value of the adjustable resistor to a limited range based on temperature change of the adjustable resistor.

Preferably, in the case where the off-gas and air are introduced into different gas passages without mixing,

a potential difference is formed between the cathode and the anode of the first gas channel into which hydrogen is fed and the second gas channel into which air is fed, so that the hydrogen and the air electrochemically react with each other in the case where the load device communicates the cathode with the anode.

Preferably, the device comprises at least one catalytic device connected with the catalytic cell assembly through a pipeline, the catalytic device is connected with the control device,

the catalytic device carries out catalytic oxidation on hydrogen in the mixture discharged by the catalytic battery assembly so as to discharge the catalyzed gas in a state that the hydrogen content approaches zero hydrogen.

Preferably, at least two catalytic cell assemblies are connected in series and/or in parallel to form a catalytic cell assembly, the load device of the catalytic cell assembly is connected with the control device, and hydrogen and air are subjected to at least two chemical reactions and/or electrochemical reactions in the at least two catalytic cell assemblies to reduce the hydrogen content to a specified range.

Preferably, the catalytic cell assembly is connected with at least one catalytic device through a pipeline, the mixed gas of hydrogen and air is subjected to catalytic treatment through at least two stages of catalytic cell assemblies, and when the hydrogen content in the mixture discharged from the catalytic cell assembly is reduced to a specified range, the mixture is discharged into the catalytic device through the pipeline to catalyze the mixture to a state that the hydrogen content approaches zero.

Preferably, the catalytic device comprises at least a catalytic layer and a catalytic outer layer,

the catalytic outer layer is arranged on the surface of the catalytic layer in a wrapping mode so as to reduce the temperature of the catalytic layer.

The invention provides a dehydrogenation method of fuel cell tail gas, which is characterized by comprising the following steps:

at least two membrane electrodes are arranged according to an anode and a cathode in a relative staggered mode and form at least one gas channel of the catalytic cell assembly, at least one load device is arranged between the at least one anode and the at least one cathode of the catalytic cell assembly, air and tail gas discharged by a fuel cell in an intermittent mode are fed into the catalytic cell assembly in a mixed mode or an unmixed mode, chemical reaction and/or electrochemical reaction of hydrogen and oxygen are carried out in the at least two gas channels under the catalytic action of the cathode and the anode so as to reduce the content of the hydrogen, and the load device consumes current generated based on the potential difference between the anode and the cathode of the two gas channels in an energy conversion mode, so that the energy consumption state of the load device is related to the content of the hydrogen.

Preferably, the method further comprises: the control device adjusts the current value of the adjustable resistor to a limited range based on the temperature change of the adjustable resistor.

The invention also provides a fuel cell stack, which at least comprises a fuel cell main body consisting of membrane electrodes, cathode gas channels and anode gas channels, wherein at least one catalytic cell assembly is arranged at the downstream of a gas discharge channel of the fuel cell main body, the catalytic cell assembly comprises at least one gas channel formed by at least one membrane electrode in a mode that an anode and an anode are arranged in parallel, and at least one load device is arranged between at least one anode of one gas channel and a cathode of at least one other gas channel.

Preferably, at least one catalytic device is arranged in the flow channel downstream of the mixture discharged from at least one catalytic battery assembly, and the catalytic device is connected with the control device, and the catalytic device performs catalytic oxidation on hydrogen in the mixture discharged from the catalytic battery assembly so as to discharge the catalyzed gas in a state that the hydrogen content approaches zero hydrogen.

The invention also provides a hydrogen removal device for fuel cell tail gas, which comprises at least one catalytic cell assembly, wherein the catalytic cell assembly comprises at least one membrane electrode, at least one gas channel is formed by at least one membrane electrode at intervals in a mode that an anode and an anode are arranged in parallel, at least one load device is arranged between at least one anode of one gas channel and a cathode of at least one other gas channel, and the load device circulates current generated by the potential difference between the anode and the cathode.

Preferably, the catalytic battery assembly is connected to the control device, the load device is connected to the control device, and the control device adjusts a load current based on an operating state of the load device and/or the catalytic battery assembly.

Preferably, the fuel cell tail gas hydrogen removal device comprises at least one catalytic device connected with the catalytic cell assembly, and the catalytic device carries out catalytic oxidation on hydrogen in a mixture discharged from the catalytic cell assembly until the hydrogen content approaches zero.

Preferably, at least two catalytic battery assemblies are connected in series and/or in parallel to form a catalytic battery combination, the load device of at least one catalytic battery assembly is connected with the control device,

the hydrogen and the air are chemically and/or electrochemically reacted in the at least two-stage catalytic cell assembly to be discharged in a state that the hydrogen content tends to zero.

Preferably, the load device is an adjustable resistor, and an adjusting end of the adjustable resistor is connected with the control device.

Preferably, at least one catalytic device is arranged downstream of the flow channel of the discharged mixture of the catalytic cell assembly, and the catalytic device at least comprises a catalytic layer and a catalytic outer layer, and the catalytic outer layer is arranged on the surface of the catalytic layer in a coating manner so as to reduce the temperature of the catalytic layer.

The invention also relates to a dehydrogenation method of the dehydrogenation device for the fuel cell tail gas, which is characterized by comprising the following steps: at least one membrane electrode is disposed in such a manner that an anode and a cathode are arranged in parallel to constitute at least one gas channel of the catalytic cell assembly, at least one load device is disposed between at least one anode and at least one cathode of the catalytic cell assembly, and an electric current generated by a potential difference between the anode and the cathode flows through the load device.

The invention also relates to a preparation method of the fuel cell stack, which comprises the following steps: the fuel cell main body is constituted by a membrane electrode, a cathode gas passage and an anode gas passage, characterized in that the method further comprises: at least one catalytic cell assembly is arranged at the downstream of the flow channel of the fuel cell main body for discharging gas, at least one membrane electrode is arranged in a mode that an anode and an anode are arranged in parallel to form the catalytic cell assembly comprising a plurality of gas channels, and at least one load device is arranged between at least one anode of one gas channel and a cathode of at least one other gas channel.

The invention also relates to a carrier provided with the catalytic cell assembly of the invention.

The invention also relates to a carrier provided with a fuel cell stack according to the invention.

The invention has the beneficial technical effects that:

(1) the load is arranged on the catalytic cell assembly to consume a trace amount of electric energy generated by hydrogen oxidation, and a redundant cell device is not required. And whether the hydrogen content of the tail gas in the catalytic battery assembly is reduced to a specified range or not is judged by monitoring the energy consumption state of the load, so that the removal effect of the hydrogen can be intuitively judged without concentrating the tail gas.

(2) According to the catalytic cell assembly, the electrochemical reaction of hydrogen oxidation can be carried out on the mixed gas of hydrogen and air through the structure of the multilayer gas channel, and the electrochemical reaction of hydrogen oxidation can also be carried out on the condition that hydrogen and air are independently input, so that the gas input structure and the gas input requirement are simplified, the assembly of the catalytic cell assembly and the combination thereof is simple, and the safety is higher.

(3) The catalytic battery assembly provided with the loading device is combined with the catalytic device for use, so that the hydrogen content in the tail gas before entering the catalytic device can be reduced to the safe gas in the specified range, the loss of the catalyst in the catalytic device is low, the service life of the catalytic device is prolonged, the catalytic device does not need to be frequently replaced, and the hydrogen content after being catalyzed by the catalytic device does not need to be further monitored.

(4) The hydrogen content in the tail gas is controlled to be reduced to be trace by utilizing the catalytic battery assembly provided with the load device, the dehydrogenation function of the catalytic device enables the hydrogen content in the tail gas to be reduced to approach zero, even the hydrogen content is reduced to zero, and the tail gas emission of zero hydrogen is realized.

Drawings

FIG. 1 is a schematic view of a first cross-section of a catalytic cell assembly of the present invention;

FIG. 2 is a first schematic cross-sectional view of a catalytic cell assembly of the present invention coupled to a catalytic device;

FIG. 3 is a schematic diagram of a second cross-section of a second end of a catalytic cell assembly of the present invention;

FIG. 4 is a schematic view of a first cross-sectional configuration of another unidirectional gas feed to the catalytic cell assembly;

FIG. 5 is a schematic diagram of a first cross-sectional configuration of a bi-directional gas input to the catalytic cell assembly;

FIG. 6 is a schematic diagram of a first cross-sectional structure of a catalytic cell assembly;

FIG. 7 is a schematic diagram of a first cross-sectional configuration of a catalytic cell assembly coupled to a catalytic device;

FIG. 8 is a schematic cross-sectional view of one of the catalytic devices of the present invention;

FIG. 9 is another schematic cross-sectional view of a catalytic device of the present invention.

List of reference numerals

1: mixing the gas; 2: mixing; 3: a catalytic battery assembly; a: an anode assembly; c: a cathode assembly; 4: a load device; 5: a catalytic device; 6: zero hydrogen tail gas; 7: a control device; 21: a first order mixture; 22: a secondary mixture; 2 n: a N-stage mixture; 31: a primary catalytic battery assembly; 32: a secondary catalytic battery component; 3 n: an N-level catalytic battery assembly; 51: a catalytic bed; 52: a catalytic outer layer; 53: a temperature control assembly; 8: a membrane electrode; 81: a proton exchange membrane; a: an anode; c: a cathode; 91: a first end; 92: a second end.

Detailed Description

The following detailed description is made with reference to the accompanying drawings.

The fuel cell intermittently discharges the hydrogen-containing off-gas during power generation. The hydrogen content of the tail gas is very low. The prior art methods for dehydrogenation of tail gas from fuel cells include both tail gas recycle and dehydrogenation processes. For the tail gas circulation mode, because the hydrogen content in the tail gas is lower, and the hydrogen content in the tail gas every time is different, the tail gas is concentrated and is collected and is introduced into the hydrogen inlet of the power generation system after being treated through modes such as water-gas separation, wherein the concentration of hydrogen inevitably can increase the potential safety hazard, and also can increase the device volume of tail gas treatment. The dehydrogenation treatment of the fuel cell tail gas comprises small-sized galvanic pile consumption, catalyst catalysis, combustion and the like to remove hydrogen. The hydrogen in the tail gas is consumed only by a small galvanic pile, so that the content of the hydrogen can be further reduced, and the near zero emission of the hydrogen in the tail gas cannot be realized. The dehydrogenation is carried out only by the catalysis of the catalyst, the catalytic life of the catalytic device is limited, and the catalytic part in the catalytic device needs to be replaced periodically. When the catalyst loss of the catalytic device completely leads the catalytic effect to lose the effect in advance, the tail gas can not realize the near zero emission of the hydrogen, and workers can not predict the failure of the catalyst in advance, so that the catalyst can not be replaced in time. Moreover, the catalytic device is costly, requiring significant replacement costs for periodic replacement.

Therefore, how to reduce the hydrogen content in the tail gas to the minimum or even realize zero emission of hydrogen with a simple catalytic structure is a technical problem which cannot be solved by the prior art and is also a technical problem to be solved by the invention.

The invention relates to a catalytic cell assembly and a catalytic method, also can be called a fuel cell tail gas catalytic device and a method, and also can be called a hydrogen zero-emission fuel cell tail gas treatment device and system. The catalytic cell assembly of the present invention can be installed in the gas downstream of the fuel cell, and can also be referred to as part of the fuel cell stack, and can also be installed in various vehicles for removing hydrogen from the exhaust.

In the invention, the load device is a general term and comprises a single resistor, a light-emitting device and an electric appliance, and can also be a general term of a plurality of resistors, a plurality of light-emitting devices and a plurality of electric appliances on the catalytic battery. The load device between the anode a and the cathode C may be a single device, or may be a load set formed in series and/or in parallel. As shown in fig. 1, a resistance with an adjustable resistance value is arranged between the anode a and the cathode C of each membrane electrode, the load device 4 of the catalytic cell assembly 3 includes several resistances.

In the invention, the control device can be a control system consisting of a plurality of chips or servers and controllers, and can also be one or more of a singlechip, a CPU, a special integrated chip, a server and a cloud server group with a control function.

The approach to zero emission in the present invention means that the proportion of hydrogen content is close to 0.5ppm (one part per million). The zero emission of the invention means that the hydrogen content is not higher than the hydrogen content proportion in the air, namely not higher than 0.5ppm, so as to realize the absolute safety of the tail gas emission.

Hydrogen in the present invention refers to hydrogen in the fuel cell tail gas. In the invention, tail gas in the fuel cell is directly discharged into the catalytic cell assembly. For clarity of discussion, the following description is made only with respect to hydrogen.

Example 1

As shown in fig. 1 to 5, the fuel cell exhaust gas catalytic system of the present invention includes at least one catalytic cell assembly 3 and a control device 7. The catalytic battery assembly 3 is connected with a control device 7, and the control device controls the catalytic battery assembly to be opened and closed. The catalytic cell assembly 3 comprises a housing and at least one membrane electrode with anodes and cathodes arranged alternately to form a multi-layer gas channel.

Preferably, at least one gas channel is formed in the housing of the catalytic cell assembly by at least one membrane electrode (8) in such a way that the anode (a) is arranged parallel to the anode (C). For example, a catalytic cell assembly having only one gas channel is formed by disposing the anode of one membrane electrode opposite the cathode of the other membrane electrode.

Under the condition that one surface of the membrane electrode is an anode and the other surface is a cathode, a plurality of membrane electrodes are arranged in parallel. Wherein the anode is opposite to the cathode and the interval between the anode and the cathode forms a gas channel. Alternatively, the anode and the cathode of two adjacent membrane electrodes are opposite to each other, so that different gas channels are formed between the adjacent electrodes.

For example, in the case where both surfaces of one part of the membrane electrodes are anodes and both surfaces of the other part of the membrane electrodes are cathodes, a plurality of membrane electrodes are disposed in such a manner that the anodes and the cathodes are adjacent to each other in parallel, so that gas channels are formed between the opposing anodes and cathodes.

For example, in a catalytic cell assembly having two or more gas channels, at least two membrane electrodes 8 arranged in such a manner that anodes and cathodes are staggered form the catalytic cell assembly in the case. Wherein, a space is arranged between the membrane electrodes to form a gas channel with the shell. Each layer of gas channels comprises at least one anode A and a cathode C which are oppositely arranged.

Preferably, the multilayer gas channel has at least one inlet duct in common. The multilayer gas channels can also be provided with independent gas inlet pipelines respectively. Preferably, the inlet duct is provided with at least one valve for controlling the actuation of the closure. Preferably, both ends of the gas channel of the catalytic cell assembly can be used for gas input and gas output. At least one pipeline is respectively arranged at two ends of the catalytic cell assembly and used for air intake or exhaust. For example, the duct communicates with all of the gas passages to simultaneously feed gas to all of the gas passages, or to simultaneously receive gas discharged from all of the gas passages. Alternatively, the plurality of pipes are connected to at least one gas passage, respectively.

For example, the anode a and the cathode C of the plurality of membrane electrodes 8 constitute a gas channel capable of promoting a chemical reaction or an electrochemical reaction of hydrogen and oxygen in one gas channel. Preferably, the anode a and the cathode C may be equal in length to the gas channel, or may be distributed in a part of the gas channel. For example, a plurality of anode assemblies and a plurality of cathode assemblies are dispersed in an opposing arrangement within the gas channel. The catalytic cell assembly 3 of the present invention has a plurality of gas channels, which is advantageous in that each gas channel is capable of chemically reacting hydrogen with oxygen in the air. Or the hydrogen and the oxygen generate electrochemical reaction when the hydrogen and the air are respectively input into the two gas channels to generate current and water.

Fig. 3 is a schematic cross-sectional view of another angle of the catalytic cell assembly. Which is a cut-away section of the second end 92. The gas flows in a gas channel formed between the two membrane electrodes, namely, the gas flows in a normal phase direction of the cross section in a blank area between the two membrane electrodes. Preferably, the load device is arranged on the side surface of the catalytic cell assembly, and the arrangement and connection of the pipelines at the two ends of the catalytic cell assembly are not influenced. The membrane electrode 8 of the present invention includes at least a proton exchange membrane 81, an anode a, and a cathode C. The anode a and the cathode C are respectively disposed on both sides of the proton exchange membrane 81. Preferably, a metal complex having a catalytic function, such as a platinum complex, is disposed between the anode a, the cathode C, and the proton exchange membrane 81. Under the catalytic action of the platinum complex, the activation energy is reduced, so that hydrogen and oxygen in the air are contacted at normal temperature and undergo chemical reaction, water is directly generated, and a large amount of heat is released. When hydrogen and oxygen are present in the gas passages in which the anode a and the cathode C are located, respectively, a potential difference exists between the anode a and the cathode C. When the load device 4 is turned on, electric charges move to form electric current, and an electrochemical reaction occurs to generate water.

As shown in fig. 1 to 3, at least one anode a and at least one cathode C of the plurality of membrane electrodes 8 are conducted through the load device 4 to form a catalytic structure capable of catalyzing a chemical reaction or an electrochemical reaction between hydrogen and oxygen in the air. Based on the limitations demonstrated by the cross-sectional views, the cross-sectional structural view of the present invention, while capable of showing the load device at the second end 92 of the catalytic cell assembly, does not represent the load device being mounted at the second end 92. For example, the anode a and the cathode C of the same membrane electrode are conducted through the load device 4. For example, the anode a of one membrane electrode is in electrical communication with the cathode C of the other membrane electrode via the load device 4. The load device 4 and/or the power generation device are connected to the control device 7 and are controlled by the control device 7. The load device 4 includes a resistor, a light-emitting device, and an electrical device, which consumes electric energy generated by a chemical reaction or an electrochemical reaction between hydrogen in the catalytic cell assembly and oxygen in the air. Preferably, all the anodes a and all the cathodes C are conducted through the load device 4 with adjustable resistance values by a connection mode of combining series connection and parallel connection, so that current transmission between the anode a and the cathode C between any two membrane electrodes is met.

Because the hydrogen content in the tail gas of the fuel cell is less, the electric energy generated by the catalytic cell assembly is less, less electric energy can be reasonably consumed by adopting the load device, higher heat can not be generated, and the safety of the fuel cell is improved. Moreover, the load device not only has the function of consuming electric energy, but also has the function of monitoring the hydrogen consumption content through the data characteristics, light characteristics and temperature characteristics of heat, light, current and the like generated by the electric energy, and is used for reflecting the hydrogen content of tail gas in the catalytic battery pack. I.e. the energy consuming state of the load means 4, is related to the hydrogen content of the exhaust gas in the catalytic cell assembly 3. Whether the content of hydrogen in the tail gas in the catalytic battery assembly 3 is reduced to a specified range is judged based on the energy consumption state of the load device 4.

The catalytic cell assembly can eliminate hydrogen in gas in various ventilation modes, has no limitation and requirement on the mode of inputting the gas, and simplifies the arrangement mode of the ventilation pipeline. In the invention, no matter the hydrogen and the air are input into the catalytic cell assembly in a mixed input mode or a separate input mode, the hydrogen can be oxidized and consumed, thereby greatly improving the efficiency of hydrogen removal and leading the content of the hydrogen in the discharged gas to be reduced and even approach to zero.

First, as shown in fig. 1, hydrogen and air form a mixed air and pass into the first end 91 of the catalytic cell assembly. The mixed air enters the plurality of gas passages simultaneously. Under the catalytic action of the anode A and the cathode C in the gas channel, the hydrogen and the oxygen in the air generate chemical reaction, directly generate water and release a large amount of heat energy. In this process, no electric charge flows between the anode a and the cathode C on both sides of the membrane electrode, and no current is generated.

Under the condition that hydrogen and air are uniformly mixed according to the chemical reaction proportion, the electric potential of each gas channel is uniform and the same.

In the case where hydrogen and air are not uniformly mixed, hydrogen remains in a part of the gas passages and oxygen remains in a part of the gas passages after the chemical reaction. At this time, when the anode a and the cathode C of the two gas channels are conducted through the load device, the hydrogen and the oxygen are electrochemically reacted, and charges are generated on the anode a and the cathode C of the membrane electrode respectively to form locally uneven potentials, so that voltage increase or voltage decrease changes occur between the cathode and the anode. An electrical current is generated at the load device and converted to heat or other energy for consumption. The connection of the load device between the anode A and the cathode C also reduces the activation energy, so that the hydrogen and the oxygen can be subjected to electrochemical reaction quickly, and the hydrogen consumption efficiency is improved. In the practical process, in the same gas channel, the contact area between the cathode or the anode of the membrane electrode and the gas is large, the local three-dimensional hydrogen and the oxygen are subjected to chemical reaction under the catalytic action of the cathode or the anode, and the local hydrogen and the oxygen in the other channel are subjected to electrochemical reaction under the action of the cathode and the anode. I.e. the chemical reaction and the electrochemical reaction are carried out simultaneously. Obviously, regardless of whether the hydrogen and air are mixed proportionally or uniformly, the catalytic cell assembly of the present invention can rapidly consume the hydrogen under sufficient air charge, so that the hydrogen content in the exhaust gas is rapidly reduced or even approaches zero.

Second, as shown in fig. 4, in the case where hydrogen and air are introduced into different gas channels through separate pipes, respectively, a first gas channel to which hydrogen is introduced and a second gas channel to which air is introduced electrochemically react, a potential difference exists between an anode/cathode of a membrane electrode of the first gas channel and a cathode/anode of a membrane electrode of the second gas channel and an electric current is generated on a load device while generating heat.

Third, as shown in fig. 5, hydrogen and air can be simultaneously fed in both directions from both ends of the catalytic cell assembly. Hydrogen and air can also be fed to different gas channels in both directions. The hydrogen and the air are subjected to chemical reaction at normal temperature under the catalytic action of the metal catalyst in the same gas channel to directly generate water and release a large amount of heat. Or, in the case that the load device communicates the corresponding cathode and anode, the hydrogen and air electrochemically react in different gas channels to generate water. Preferably, in the case of two-way ventilation, the catalytic cell assembly is also provided with a discharge conduit for discharging the mixture 2 of water, hydrogen and oxygen.

The load device of the present invention may be a rated resistor. The electric energy generated by the catalytic cell assembly 3 can cause the rated resistance to generate heat. When the current suddenly increases, the heat suddenly increases, which is not favorable for the stable emission of heat. The load device 4 according to the invention is therefore preferably an adjustable resistor with an adjustable resistance. The adjusting end of the adjustable resistor is connected with the control device 7. When the current of the catalytic battery assembly 3 becomes large, the control device can adaptively adjust the adjusting end of the adjustable resistor, so that the current of the adjustable resistor is maintained within a limited range, the heat sudden increase of the adjustable resistor is avoided, and the stability of the heat dissipation of the adjustable resistor is maintained.

Preferably, when the load device is a light-emitting device, such as an LED lamp, the light-emitting device can display the amount of electric energy generated by the catalytic battery assembly 3 through a change in light-emitting intensity while consuming energy, so as to indirectly reflect a change in the amount of hydrogen consumed in the exhaust gas.

Preferably, the load device may be a combination of an adjustable resistor, a light emitting device and other components in parallel or in series. By adjusting the resistance and the change in the light emission intensity of the light-emitting device, it is possible to adjust the change in the current between the cathode and the anode of the catalytic cell module 3 to maintain the stability of heat dissipation, and to observe the change in the amount of hydrogen consumed in the exhaust gas.

The invention enables the fuel cell to be mounted on equipment or devices in a closed space under the condition that the catalytic cell assembly of the invention quickly reduces the hydrogen in the fuel cell tail gas to approach zero.

Example 2

This embodiment is a further improvement of the foregoing embodiment, and repeated contents are not described again.

This embodiment enables to further reduce the hydrogen content in the gas, even to zero.

The catalytic cell module 3 of the invention is connected to at least one catalytic device 5 via a discharge line, so that the mixture of water, hydrogen and oxygen discharged from the discharge line enters the catalytic device for further catalysis. The temperature control assembly 53 on the surface of the catalytic device 5 is connected with the control device 7 for temperature regulation and control.

Due to the rapid and efficient catalysis of the catalytic cell assembly on hydrogen, the content of hydrogen discharged by the catalytic cell assembly 3 is low. For example, less than 0.5%. The catalytic device 5 is used for further hydrogen consumption of the gas with a low hydrogen content discharged from the catalytic cell assembly 3, so that the hydrogen content in the gas discharged from the catalytic device 5 approaches zero.

The advantage of using the catalytic device 5 for removing trace amounts of hydrogen is also that the loss of the metal catalyst in the catalytic device can be reduced, the service life of the catalytic device can be prolonged, and the use cost of the catalytic device can be reduced.

As shown in fig. 8 to 9, the catalytic device 5 at least includes a catalytic layer 51 and a catalytic outer layer 52. The catalyst outer layer 52 is provided outside the catalyst layer 51 so as to cover the catalyst layer 51. The catalytic layer 51 is a metal structure having a porous structure. Preferably, the catalyst layer 51 is a rare metal such as platinum having a porous structure. After the mixture 2 discharged from the catalytic cell assembly enters the catalytic layer 51, the catalytic layer further catalytically oxidizes the hydrogen in the mixture 2 to directly generate water. The catalytic reaction is an exothermic reaction, and a large amount of heat is released to cause the temperature of the catalytic layer to increase. Preferably, the catalytic layer 51 has a good catalytic activity at 200 to 800 ℃. The catalytic outer layer 52 is a porous layer. Wherein, the pore density of the catalytic outer layer 52 is less than that of the catalytic layer 1, so that the catalytic reaction of the mixed gas in the catalytic outer layer 52 is less. The catalytic outer layer 52 functions to lower the temperature of the catalytic layer 51, and prevent the temperature of the catalytic device 5 from being excessively high and exceeding a defined temperature, so that the catalytic layer 51 is maintained in a better catalytic activity state.

As shown in fig. 9, the surface of the catalytic outer layer 52 is provided with at least one temperature control component 53 capable of monitoring temperature change and temperature reduction. The temperature control component 53 is distributed on the surface of the catalytic outer layer 52 in a patch manner, a film material manner, or the like, and can be coated on the surface of the catalytic outer layer 52 in a coating manner. The temperature control unit 53 is connected to the control device 7 by a wire. In the case where the control device 7 monitors that the temperature of the catalytic outer layer 52 exceeds the defined temperature, the control device 7 adjusts the temperature of the catalytic device 5 to the defined range by controlling the temperature control assembly 53 to decrease the temperature. The limited range is preferably 100-800 ℃. The temperature control member 53 may be, for example, a graphite hydrocarbon patch having a temperature adjusting function.

Preferably, the catalytic cell assembly 3 and the catalytic device 5 may be integrally provided. Because the hydrogen content in the first tail gas discharged by the catalytic battery assembly is trace, the catalyst in the catalytic device is less in loss, the service life of the catalytic device is longer, and frequent replacement is not needed, the catalytic battery assembly and the catalytic device 5 can be integrally arranged. The integral type is provided with and does benefit to the stability that improves the pipeline between catalysis battery pack and the catalytic unit, reduces because the pipeline fracture, the not hard up scheduling problem of interface that the shock environment formed.

The catalytic cell assembly 3 and the catalytic device 5 can also be arranged in a split manner. Namely, the catalytic cell assembly 3 and the catalytic device 5 are detachably assembled. The split arrangement facilitates replacement of the catalytic device or catalytic battery assembly when damaged.

Example 3

This embodiment is through the series connection or the parallel arrangement of a plurality of catalytic cell subassemblies for the electric energy that hydrogen oxidation in the tail gas produced can be through the audio-visual prediction hydrogen content of the change of the power consumption state of load, thereby can be at input catalytic unit 5 when the content of hydrogen reduces to the specified range in tail gas, exhaust with the whole catalysis of realization catalytic unit 5 with hydrogen, realize the near zero release of hydrogen, realize the zero release of hydrogen even.

As shown in FIGS. 6 to 7, one embodiment of the catalytic cell assembly of the present invention is shown. Several catalytic cell assemblies are combined in series to form a catalytic cell assembly with N-stage catalysis. The primary catalytic battery assembly 31 performs primary catalysis on a mixture of hydrogen and air in the input tail gas to consume a large amount of hydrogen, and the generated primary mixture 21 is input into the subsequent secondary catalytic battery assembly 32 through a discharge pipeline to perform secondary catalysis to continue to consume hydrogen. The secondary mixture 22 which is subjected to secondary catalysis and then further reduces the hydrogen content is input into the tertiary catalytic battery assembly, the tertiary catalysis is carried out to continue consuming the hydrogen, and the rest is done in the same way until the N-1-level mixture is input into the N-level catalytic battery assembly, and the hydrogen content of the generated N-level mixture approaches zero. Wherein, the second-level catalysis battery component to the N-level catalysis battery component 3N can also be provided with an air inlet pipeline for supplementing air, so as to avoid the shortage of oxygen. Preferably, the water produced by each catalytic cell assembly can be discharged through the arranged water discharge pipeline, and can also be discharged through the discharge pipeline in the N-stage catalytic cell assembly.

The advantage of having several catalytic cell assemblies connected in series is that the total heat generated by the load device 4 of each catalytic cell assembly or the luminous intensity of the power generation device will change, and as the hydrogen content decreases step by step, the total heat or luminous intensity of the load device will also decrease or weaken accordingly. Therefore, in the series connection mode, the load device can reflect the variation trend of the hydrogen content and whether the hydrogen content is consumed to the specified range. For example, when the electrical energy generated by the exhaust gas in one of the catalytic cell assemblies 3 in the catalytic cell combination cannot generate enough heat, current, or the load device cannot emit light, the hydrogen content in the exhaust gas has been reduced to an extremely low level, or to within a specified range. Even if the hydrogen and the air are uniformly mixed, and all the gas channels have chemical reaction of the hydrogen and the oxygen under the extreme condition of no current generation, the control device 7 can judge the reduction range of the hydrogen content by monitoring the level change of the sequentially generated temperature of a plurality of serially connected catalytic cell components, and then discharge the mixture to obtain tail gas with the hydrogen content approaching zero.

Moreover, in the pipeline between two catalytic battery modules 3 connected in series, the mixed gas discharged from each gas channel of the catalytic battery module at the previous stage can be remixed in the pipeline, so that the proportion of hydrogen and air is changed, and the defect of insufficient hydrogen or air in a local gas channel is overcome. In a catalytic cell combination with N catalytic cell modules 3 connected in series, there are N-1 channels, i.e. the gas can be mixed up to N-1 times.

Preferably, the catalytic cell assembly is connected with the catalytic device 5 through a pipeline, and the mixture with the hydrogen content reaching the specified range after the N-level catalytic dehydrogenation is discharged into the catalytic device 5 for further dehydrogenation, so that zero tail gas emission is realized.

For example, when one of the catalytic cell assemblies in the catalytic cell assembly consumes hydrogen in the exhaust gas to a degree insufficient to make the light-emitting device emit light, or when the catalytic cell assembly in the catalytic cell assembly consumes hydrogen in the exhaust gas to a degree insufficient to make the resistor emit heat to a specified temperature, it indicates that the hydrogen in the gas is reduced to a specified range, and at this time, the mixture 2 is discharged to the catalytic device 5 for further catalytic dehydrogenation, so as to obtain a safe exhaust gas with extremely low hydrogen content, even without hydrogen. The invention determines the range of the hydrogen content in the tail gas through the change of the load device, thereby ensuring that the hydrogen in the tail gas entering the catalytic device 5 can be completely removed in the catalytic device and obtaining the tail gas 6 with the hydrogen content approaching zero.

Preferably, each of the plurality of catalytic cell modules in the catalytic cell assembly is connectable to the gas inlet of the catalytic device 5 through an exhaust duct provided with a valve. The valve is electrically connected to the control device 7. Under the condition that the heat of the resistor of one of the catalytic battery assemblies does not reach the preset temperature or the light-emitting device cannot emit light, the control device 7 controls the valve corresponding to the catalytic battery assembly to be opened, and the mixture discharged from the discharge pipeline of the catalytic battery assembly is input into the catalytic device 5 for catalysis and does not enter the next catalytic battery assembly. The advantage of such an arrangement is that after the hydrogen content in the mixture is reduced to a specified range, no meaningless chemical or electrochemical reaction needs to be carried out on the next-stage catalytic cell assembly, and the direct catalytic device catalysis is more beneficial to saving energy and improving catalytic efficiency.

It should be noted that the above-mentioned embodiments are exemplary, and that those skilled in the art, having benefit of the present disclosure, may devise various arrangements that are within the scope of the present disclosure and that fall within the scope of the invention. It should be understood by those skilled in the art that the present specification and figures are illustrative only and are not limiting upon the claims. The scope of the invention is defined by the claims and their equivalents.

Claims

1. A fuel cell stack comprising at least a fuel cell main body composed of a membrane electrode, a cathode gas channel and an anode gas channel,

at least one catalytic cell assembly (3) is arranged downstream of the flow passage of the fuel cell main body exhaust gas,

the catalytic cell assembly (3) comprises at least one gas channel which is formed by at least one membrane electrode (8) in such a way that an anode (A) and an anode (C) are arranged in parallel, and at least one load device (4) is arranged between at least one anode (A) of one gas channel and a cathode (C) of at least one other gas channel.

2. The fuel cell stack according to claim 1, characterized in that at least one catalytic device (5) is arranged downstream of the flow path of the mixture discharged from at least one catalytic cell module (3), said catalytic device (5) being connected to said control device (7),

the catalytic device (5) is used for carrying out catalytic oxidation on hydrogen in the mixture discharged by the catalytic battery component (3) so as to discharge the catalyzed gas in a state that the hydrogen content approaches zero hydrogen.

3. A device for removing hydrogen from the tail gas of a fuel cell, the device comprising at least one catalytic cell assembly (3),

the catalytic cell component (3) comprises at least one membrane electrode (8) which is arranged in parallel with an anode (A) and an anode (C) at intervals to form at least one gas channel, at least one load device (4) is arranged between at least one anode (A) of one gas channel and a cathode (C) of at least one other gas channel,

the load device (4) circulates a current generated by a potential difference between the anode and the cathode.

4. The device for removing hydrogen from the tail gas of the fuel cell according to claim 3, wherein the catalytic cell assembly (3) is connected with the control device (7), the load device is connected with the control device (7),

the control device (7) adjusts the load current based on the operating state of the load device and/or the catalytic battery assembly (3).

5. The device for removing hydrogen from the exhaust gas of the fuel cell according to claim 4, wherein the device comprises at least one catalytic device (5) connected to the catalytic cell assembly (3), and the catalytic device (5) catalytically oxidizes the hydrogen in the mixture discharged from the catalytic cell assembly (3) until the hydrogen content approaches zero.

6. The device for removing hydrogen from the tail gas of the fuel cell according to any one of the claims 3 to 5, characterized in that at least two catalytic cell modules (3) form a catalytic cell combination in series and/or in parallel, the load device of at least one catalytic cell module (3) is connected with the control device (7),

7. The device for removing hydrogen from the tail gas of the fuel cell according to any one of claims 3 to 5, wherein the load device (4) is an adjustable resistor, and an adjusting end of the adjustable resistor is connected with the control device (7).

8. The device for removing hydrogen from fuel cell tail gas according to claim 7, characterized in that at least one catalytic device (5) is arranged in the flow path of the discharged mixture of the catalytic cell assembly,

the catalytic device (5) comprises at least a catalytic layer (51) and a catalytic outer layer (52),

the catalytic outer layer (52) is provided on the surface of the catalytic layer (51) in a covering manner so as to reduce the temperature of the catalytic layer (51).

9. A method for removing hydrogen in the apparatus for removing hydrogen from the exhaust gas of a fuel cell according to any one of claims 3 to 5, wherein the method comprises:

arranging at least one membrane electrode (8) in such a way that an anode (A) and a cathode (C) are arranged in parallel to form at least one gas channel of the catalytic cell assembly (3), arranging at least one load device (4) between the at least one anode and the at least one cathode of the catalytic cell assembly (3),

an electric current generated by a potential difference between the anode and the cathode flows through the load device (4).

10. A method of making a fuel cell stack according to claims 1-2, the method comprising: the fuel cell main body is constituted by a membrane electrode, a cathode gas passage and an anode gas passage, characterized in that the method further comprises:

at least one membrane electrode (8) is arranged in a way that an anode (A) and an anode (C) are arranged in parallel to form a catalytic cell component (3) comprising a plurality of gas channels,

at least one load device (4) is arranged between at least one anode (A) of one gas channel and a cathode (C) of at least one other gas channel.