KR20220095417A - Fuel processor and fuel cell system including the same - Google Patents

Abstract

The present invention relates to a fuel processor and a fuel cell system including the same. The fuel processor, according to an embodiment of the present invention, comprises: a first fuel pump adjusting the flow rate of fuel gas supplied from the outside; a plurality of desulfurizers comprising an adsorbent; a reformer reforming the fuel gas; a burner burning the fuel gas to heat the reformer; a second fuel pump controlling the flow rate of the fuel gas supplied to the burner; a first valve connecting one of the first fuel pump and inlets of the plurality of desulfurizers; a second valve connecting one of the inlets of the plurality of desulfurizers to the second fuel pump; and a third valve connecting one of outlets of the plurality of desulfurizers to the reformer. Various other embodiments are possible. The present invention is capable of regenerating an adsorbent included in a desulfurizer without stopping the operation of the fuel cell system.

Description

Fuel processing device and fuel cell system including same

The present invention relates to a fuel processing apparatus and a fuel cell system including the same, and more particularly, to a fuel processing apparatus including a desulfurizer for removing sulfur compounds contained in fuel, and a fuel cell system including the same.

A fuel cell system is a power generation system that generates electric energy by electrochemically reacting hydrogen contained in hydrocarbon-based materials, for example, methanol, ethanol, natural gas, and the like, with oxygen.

A general fuel cell system includes a fuel processing device that converts and reforms fuel containing hydrogen atoms into hydrogen gas, and a fuel cell stack that generates electric energy using hydrogen gas supplied from the fuel processing device. be prepared

On the other hand, fuel supplied to the fuel processing apparatus, for example, city gas, contains an odorant made of an organic sulfur compound such as tetrahydrothiophene (THT) and tbutylmercaptan (TBM) to check for gas leakage. At this time, the odorant contained in the fuel may cause poisoning of the catalyst used in a reformer, a water-gas shift reactor, etc. provided in the fuel processing apparatus, thereby reducing the poisoning of the catalyst. In order to prevent it, the removal of sulfur compounds contained in the fuel is essential.

내외의 고온의 탈황공정을 적용하기도 하나, 연료전지 시스템의 효율을 고려하여, 흡착제를 이용하는 상온탈황방식이 탈황기에 일반적으로 적용된다. 흡착제를 이용하는 상온탈황방식은, 흡착제에 연료 가스를 통과시켜 황 화합물을 제거하는 방식이다.In general, in order to remove sulfur compounds contained in fuel, a desulfurizer is provided in the fuel processing apparatus. 300 to remove sulfur compounds

Although desulfurization processes at high temperature inside and outside are sometimes applied, in consideration of the efficiency of the fuel cell system, the room temperature desulfurization method using an adsorbent is generally applied to the desulfurizer. The room temperature desulfurization method using an adsorbent is a method of removing sulfur compounds by passing fuel gas through the adsorbent.

On the other hand, when the adsorption of the sulfur compound is saturated, the adsorbent can no longer remove the sulfur compound, so it is necessary to periodically exchange or regenerate the adsorbent to prevent poisoning of the catalyst. Conventionally, when a predetermined period has elapsed, a simple replacement of the adsorbent included in the desulfurizer, or a method of checking whether the replacement period has elapsed by adding a configuration for visually checking the inside of the desulfurizer to the desulfurizer is used. However, according to the conventional method, there is a problem in that the operation of the fuel cell system is stopped when the adsorbent is replaced, or the poisoning of the catalyst cannot be prevented because the replacement cycle is not accurately observed.

SUMMARY OF THE INVENTION The present invention aims to solve the above and other problems.

Another object of the present invention is to provide a fuel processing apparatus capable of regenerating an adsorbent contained in a desulfurizer without stopping the operation of the fuel cell system, and a fuel cell system including the same.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a fuel processing apparatus according to an embodiment of the present invention includes: a first fuel pump for controlling a flow rate of fuel gas supplied from the outside; a plurality of desulfurizers comprising an adsorbent; a reformer for reforming the fuel gas; a burner that burns the fuel gas to heat the reformer; a second fuel pump for controlling a flow rate of the fuel gas supplied to the burner; a first valve connecting the first fuel pump and any one of the inlet sides of the plurality of desulfurizers; a second valve connecting one of the inlet sides of the plurality of desulfurizers to the second fuel pump; and a third valve connecting any one of the outlet sides of the plurality of desulfurizers to the reformer.

In order to achieve the above object, a fuel cell system according to an embodiment of the present invention includes: a fuel processing device for generating hydrogen by reforming fuel gas; and a stack generating electric energy using the hydrogen and oxygen, wherein the fuel processing apparatus includes: a first fuel pump for controlling a flow rate of the fuel gas supplied from the outside; a plurality of desulfurizers comprising an adsorbent; a reformer for reforming the fuel gas; a burner that burns the fuel gas to heat the reformer; a second fuel pump for controlling a flow rate of the fuel gas supplied to the burner; a first valve connecting the first fuel pump and any one of the inlet sides of the plurality of desulfurizers; a second valve connecting one of the inlet sides of the plurality of desulfurizers to the second fuel pump; and a third valve connecting one of the outlets of the plurality of desulfurizers to the reformer.

The details of other embodiments are included in the detailed description and drawings.

According to various embodiments of the present invention, sulfur compounds can be separated from the adsorbent without applying high-temperature heat without replacing the adsorbent, so that the adsorbent can be regenerated without structural deformation.

In addition, according to various embodiments of the present invention, by periodically changing the flow direction of the fuel gas passing through the plurality of desulfurizers, it is possible to regenerate the adsorbent without stopping the operation of the fuel cell system.

In addition, according to various embodiments of the present invention, the user can effectively regenerate the adsorbent without directly replacing and regenerating the adsorbent included in the desulfurizer, thereby improving user convenience.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a schematic diagram of a configuration of a fuel cell system according to an embodiment of the present invention.
2 is a diagram illustrating a configuration of a fuel processing apparatus according to an embodiment of the present invention.
3 and 4 are diagrams referred to for explanation of the operation of the fuel processing apparatus of FIG. 2 .

Hereinafter, the present invention will be described in detail with reference to the drawings. In the drawings, in order to clearly and briefly describe the present invention, the illustration of parts irrelevant to the description is omitted, and the same reference numerals are used for the same or extremely similar parts throughout the specification.

The suffixes “module” and “part” for the components used in the following description are given simply in consideration of the ease of writing the present specification, and do not impart a particularly important meaning or role by themselves. Accordingly, the terms “module” and “unit” may be used interchangeably.

In the present application, terms such as “comprises” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence of, or addition of, elements, numbers, steps, operations, components, parts, or combinations thereof.

Also, in this specification, terms such as first and second may be used to describe various elements, but these elements are not limited by these terms. These terms may only be used to distinguish one element from another.

1 is a schematic diagram of a configuration of a fuel cell system according to an embodiment of the present invention.

Referring to FIG. 1 , a fuel cell system 1 may include a fuel processing device 10 and/or a stack 20 .

The fuel processing apparatus 10 may include a desulfurizer 110 , a reformer 120 , a burner 130 , a first reactor 140 , and/or a second reactor 150 .

The desulfurizer 110 may perform a desulfurization process for removing sulfur compounds contained in the fuel gas. For example, the desulfurizer 110 may include an adsorbent therein. At this time, the sulfur compound contained in the fuel gas passing through the inside of the desulfurizer 110 may be adsorbed to the adsorbent.

The adsorbent may be composed of metal oxide, zeolite, activated carbon, or the like.

The desulfurizer 110 may further include a filter for removing foreign substances contained in the fuel gas.

The reformer 120 may perform a reforming process of generating hydrogen gas from the fuel gas from which the sulfur compound has been removed by using a catalyst. For example, hydrocarbon-based fuel gas and water vapor may be supplied to the reformer 120 , and hydrogen gas may be generated by a reforming reaction between the fuel gas and water vapor in the reformer 120 .

The burner 130 may supply heat to the reformer 120 to promote a reforming reaction in the reformer 120 . For example, a mixed gas in which fuel gas and oxygen are mixed in a predetermined ratio may be supplied to the burner 130 , and the burner 130 may generate combustion heat by burning the supplied mixed gas.

In this case, the internal temperature of the reformer 120 may be maintained at an appropriate temperature (eg, 800° C.) by the heat supplied from the burner 130 .

The first reactor 140 may reduce carbon monoxide generated by the reforming reaction among components included in the gas discharged from the reformer 120 . For example, carbon monoxide included in the gas discharged from the reformer 120 may react with water vapor in the reactor 140 to generate carbon dioxide and hydrogen.

In this case, the internal temperature of the first reactor 140 may be lower than the internal temperature of the reformer 120 and higher than the room temperature (eg, 200° C.).

The first reactor 140 may be referred to as a shift reactor.

The second reactor 150 may reduce carbon monoxide remaining among components included in the gas discharged from the first reactor 140 . For example, a selective oxidation (PROX) reaction in which carbon monoxide included in the gas discharged from the first reactor 140 reacts with oxygen inside the second reactor 150 may occur.

On the other hand, in the case of the selective oxidation reaction, since a large amount of oxygen is required, an additional supply of air is required, and hydrogen is diluted by the additionally supplied air, so that the concentration of hydrogen supplied to the stack decreases. Therefore, in order to overcome this disadvantage, a selective methanation reaction in which carbon monoxide and hydrogen are reacted may be utilized.

The stack 20 may generate electric energy by causing an electrochemical reaction in the reformed gas supplied from the fuel processing device 10 .

The stack 20 may be configured by stacking single cells in which an electrochemical reaction occurs.

A single cell may include a membrane electrode assembly (MEA), a separator, and the like, in which an anode and a cathode are disposed around an electrolyte membrane. At the anode of the membrane-electrode assembly, hydrogen is separated into hydrogen ions and electrons by a catalyst to generate electricity, and at the cathode of the membrane-electrode assembly, hydrogen ions and electrons combine with oxygen to produce water.

The stack 20 may further include a heat exchanger (not shown) for dissipating heat generated in the electrochemical reaction process.

2 is a diagram illustrating a configuration of a fuel processing apparatus according to an embodiment of the present invention.

Referring to FIG. 2 , the fuel processing device 10 includes a plurality of desulfurizers 110a and 110b, a reformer 120 , a burner 130 , a first reactor 140 and/or a second reactor 150 . may include

The fuel processing apparatus 10 may further include a plurality of fuel pumps 161 and 163 and/or a plurality of valves 171 , 173 and 175 . At this time, the plurality of valves (171, 173, 175) may be configured as a three-way valve (three-way valve).

The first fuel pump 161 may flow the hydrocarbon-based fuel gas supplied from the outside to the first valve 171 .

The first fuel pump 161 may adjust the flow rate of the fuel gas flowing to the first valve 171 . For example, when the flow rate of the fuel gas flowing to the first valve 171 increases, the pressure of the fuel gas flowing into the first valve 171 may increase.

The first valve 171 may be connected to the first fuel pump 161 and the first and second inflow passages 181 and 183 . The first valve 171 may operate so that the fuel gas delivered from the first fuel pump 161 flows into any one of the first and second inflow passages 181 and 183 . At this time, the fuel gas flowing into the first valve 171 flows into the first desulfurizer 110a through the first inflow passage 181 , or into the second desulfurizer 110b through the second inflow passage 183 . ) can flow.

The second valve 173 includes a first branch passage 182 branching from the first inflow passage 181 , a second branch passage 183 branching in the second inflow passage 183 , and a second fuel pump ( 163) can be connected.

The second valve 173 may operate so that the fuel gas flowing in any one of the first and second branch flow paths 182 and 184 flows to the second fuel pump 163 .

The second fuel pump 163 may flow the fuel gas discharged from the second valve 173 to the burner 130 . The second fuel pump 163 may adjust the flow rate of the fuel gas discharged from the second valve 173 .

The plurality of desulfurizers 110a and 110b may have an inlet side connected to the first and second inflow passages 181 and 183, respectively, and an outlet side connected to the first and second discharge passageways 185 and 186, respectively. have.

The plurality of desulfurizers 110a and 110b may include adsorbents 115a and 115b disposed on the inlet side.

The fuel processing apparatus 10 may further include a bypass passage 187 connecting the first and second discharge passages 185 and 186 to each other.

The third valve 175 may be connected to the reformer 120 and the first and second discharge passages 185 and 186 . The third valve 175 may operate so that the fuel gas flowing in any one of the first and second discharge passages 185 and 186 flows to the reformer 120 .

The fuel processing apparatus 10 may further include a control unit (not shown) for controlling the overall operation of each component.

The controller may include at least one processor, and may control the overall operation of the gas engine heat pump 10 by using the processor included therein. Here, the processor may be a general processor such as a central processing unit (CPU). Of course, the processor may be a dedicated device such as an ASIC or other hardware-based processor.

The control unit of the fuel processing apparatus 10 includes a plurality of valves 171, 173, so that the desulfurization process is performed in any one of the plurality of desulfurizers 110a and 110b and the adsorbent is regenerated in the other according to a predetermined cycle. 175) can be controlled. In this regard, it will be described with reference to FIGS. 3 and 4 .

Referring to FIG. 3 , the fuel processing apparatus 10 may drive the first fuel pump 161 so that the fuel gas supplied from the outside flows to the first valve 171 .

In this case, the fuel processing device 10 includes a first valve 171 such that the fuel gas delivered from the first fuel pump 161 flows to the first desulfurizer 110a through the first inflow passage 181 . operation can be controlled.

The sulfur compound included in the fuel gas flowing into the first desulfurizer 110a may be adsorbed by the first adsorbent 115a disposed at the inlet side of the first desulfurizer 110a.

When the flow rate of fuel gas flowing into the inlet side of the first desulfurizer 110a increases by the operation of the first fuel pump 161, the interior of the first desulfurizer 110a corresponds to the increase in the flow rate of the fuel gas. pressure may increase. At this time, in proportion to the increase in the internal pressure of the first desulfurizer 110a, the amount of the sulfur compound adsorbed to the first adsorbent 115a disposed on the inlet side of the first desulfurizer 110a may increase.

The fuel processing apparatus 10 controls the operation of the third valve 175 so that at least a portion of the fuel gas discharged from the first desulfurizer 110a flows to the reformer 120 through the first discharge passage 185 . can be controlled

The remaining portion of the fuel gas discharged from the first desulfurizer 110a may flow toward the outlet side of the second desulfurizer 110b through the bypass passage 187 and the second discharge passage 186 .

The fuel processing apparatus 10 may drive the second fuel pump 163 to supply fuel gas to the burner 130 . In this case, the fuel processing device 10 may control the operation of the second valve 173 so that the fuel gas flowing in the second branch flow path 184 flows to the second fuel pump 163 .

On the other hand, the internal pressure of the second branch flow path 184 may be decreased by the operation of the second fuel pump 163 , and the second desulfurizer 110b corresponds to the decrease in the internal pressure of the second branch flow path 184 . ) can also decrease the internal pressure.

At this time, in proportion to the decrease in the internal pressure of the second desulfurizer 110b, the sulfur compound adsorbed to the second adsorbent 115b disposed on the inlet side of the second desulfurizer 110b is removed from the second adsorbent 115b. The sulfur compound may be separated, and the sulfur compound separated from the second adsorbent 115b may be discharged to the second branch flow path 184 together with the fuel gas.

That is, the sulfur compound contained in the fuel gas supplied from the outside is adsorbed to the first adsorbent 115a disposed on the inlet side of the first desulfurizer 110a while the fuel gas passes through the first desulfurizer 110a. can be In addition, the sulfur compound adsorbed on the second adsorbent 115b disposed on the inlet side of the second desulfurizer 110b is separated from the second adsorbent 115b and flows into the outlet side of the second desulfurizer 110b. Together with the fuel gas, it may be discharged to the inlet side of the second desulfurizer 110b.

Through this, while the first adsorbent 115a included in the first desulfurizer 110a performs a desulfurization process of removing sulfur compounds included in the fuel gas, the second adsorbent included in the second desulfurizer 110b 115b can be reproduced.

Meanwhile, referring to FIG. 4 , the fuel processing apparatus 10 may drive the first fuel pump 161 so that the fuel gas supplied from the outside flows to the first valve 171 .

In this case, the fuel processing device 10 includes a first valve 171 so that the fuel gas delivered from the first fuel pump 161 flows to the second desulfurizer 110b through the second inflow passage 183 . operation can be controlled.

The sulfur compound included in the fuel gas flowing into the second desulfurizer 110b may be adsorbed by the second adsorbent 115b disposed at the inlet side of the second desulfurizer 110b.

When the flow rate of fuel gas flowing into the inlet side of the second desulfurizer 110b increases by the operation of the first fuel pump 161, the interior of the second desulfurizer 110b corresponds to the increase in the flow rate of the fuel gas. pressure may increase. At this time, in proportion to the increase in the internal pressure of the second desulfurizer 110b, the amount of the sulfur compound adsorbed to the second adsorbent 115b disposed on the inlet side of the second desulfurizer 110b may increase.

The fuel processing apparatus 10 controls the operation of the third valve 175 so that at least a portion of the fuel gas discharged from the second desulfurizer 110b flows to the reformer 120 through the second discharge passage 186 . can be controlled

The remaining portion of the fuel gas discharged from the second desulfurizer 110b may flow toward the outlet side of the first desulfurizer 110a through the bypass passage 187 and the first discharge passage 185 .

The fuel processing apparatus 10 may drive the second fuel pump 163 to supply fuel gas to the burner 130 . In this case, the fuel processing apparatus 10 may control the operation of the second valve 173 so that the fuel gas flowing in the first branch flow path 182 flows to the second fuel pump 163 .

On the other hand, the internal pressure of the first branch flow path 182 may be decreased by the operation of the second fuel pump 163 , and the first desulfurizer 110a in response to the decrease of the internal pressure of the first branch flow path 182 . ) can also decrease the internal pressure.

At this time, in proportion to the decrease in the internal pressure of the first desulfurizer 110a, the sulfur compound adsorbed to the first adsorbent 115a disposed on the inlet side of the first desulfurizer 110a is removed from the first adsorbent 115a. The sulfur compound may be separated, and the sulfur compound separated from the first adsorbent 115a may be discharged to the first branch flow path 182 together with the fuel gas.

That is, the sulfur compound contained in the fuel gas supplied from the outside is adsorbed to the second adsorbent 115b disposed on the inlet side of the second desulfurizer 110b while the fuel gas passes through the second desulfurizer 110b. can be In addition, the sulfur compound adsorbed on the first adsorbent 115a disposed on the inlet side of the first desulfurizer 110a is separated from the first adsorbent 115a and flows into the outlet side of the first desulfurizer 110a. Together with the fuel gas, it may be discharged to the inlet side of the first desulfurizer 110a.

Through this, while the second adsorbent 115b included in the second desulfurizer 110b performs a desulfurization process of removing sulfur compounds included in the fuel gas, the first adsorbent included in the first desulfurizer 110a 115a can be reproduced.

As described above, according to various embodiments of the present invention, by periodically changing the flow direction of the fuel gas passing through the plurality of desulfurizers 110a and 110b, desulfurization without stopping the operation of the fuel cell system 1 The adsorbents 115a and 115b included in the groups 110a and 110b may be regenerated.

In addition, according to various embodiments of the present invention, the user does not directly replace and regenerate the adsorbents 115a and 115b included in the desulfurizers 110a and 110b, and the adsorbents 115a and 115b included in the (110a, 110b). ) can be effectively reproduced, improving user convenience.

The accompanying drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed herein is not limited by the accompanying drawings, and all changes and equivalents included in the spirit and scope of the present invention It should be understood to include water or substitutes.

Likewise, although acts are depicted in the figures in a particular order, it should not be construed that such acts must be performed in that particular order or sequential order shown, or that all depicted acts must be performed in order to achieve desirable results. can In certain cases, multitasking and parallel processing may be advantageous.

In addition, although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention as claimed in the claims In addition, various modifications are possible by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

Claims (10)

In the fuel processing device,
a first fuel pump for controlling a flow rate of fuel gas supplied from the outside;
a plurality of desulfurizers comprising an adsorbent;
a reformer for reforming the fuel gas;
a burner that burns the fuel gas to heat the reformer;
a second fuel pump for controlling a flow rate of the fuel gas supplied to the burner;
a first valve connecting the first fuel pump and any one of the inlet sides of the plurality of desulfurizers;
a second valve connecting one of the inlet sides of the plurality of desulfurizers to the second fuel pump; and
and a third valve connecting one of the outlets of the plurality of desulfurizers to the reformer. According to claim 1,
The fuel processing apparatus further comprising a bypass pipe connecting the outlet sides of the plurality of desulfurizers to each other. According to claim 1,
The adsorbent included in the plurality of desulfurizers is disposed adjacent to the inlet side of the plurality of desulfurizers. According to claim 1,
The first to third valves are fuel processing apparatus, characterized in that it is a three-way valve (three-way valve). 3. The method of claim 2,
further comprising a control unit,
The control unit is
According to a predetermined period, the fuel gas flows from the inlet side to the outlet side of any one of the plurality of desulfurizers and flows from the outlet side of the other one of the plurality of desulfurizers to the inlet side, the first to third Fuel processing device, characterized in that for controlling the valve. 6. The method of claim 5,
The control unit, for a time corresponding to the predetermined period,
controlling the first valve so that the fuel gas discharged from the first fuel pump flows toward an inlet side of a first desulfurizer among the plurality of desulfurizers;
controlling the second valve so that the fuel gas discharged from the inlet side of a second desulfurizer among the plurality of desulfurizers flows to the second fuel pump,
and controlling the third valve so that the fuel gas discharged from the outlet side of the first desulfurizer flows to the reformer. 7. The method of claim 6,
The control unit, when the time corresponding to the predetermined period has elapsed,
controlling the first valve so that the fuel gas discharged from the first fuel pump flows toward the inlet side of the second desulfurizer;
controlling the second valve so that the fuel gas discharged from the inlet side of the first desulfurizer flows to the second fuel pump,
and controlling the third valve so that the fuel gas discharged from the outlet side of the second desulfurizer flows to the reformer. According to claim 1,
The plurality of desulfurizers may further include a filter for removing foreign substances contained in the fuel gas. In the fuel cell system,
a fuel processing device for generating hydrogen by reforming fuel gas; and
A stack for generating electrical energy using the hydrogen and oxygen,
The fuel processing device,
a first fuel pump for controlling a flow rate of the fuel gas supplied from the outside;
a plurality of desulfurizers comprising an adsorbent;
a reformer for reforming the fuel gas;
a burner that burns the fuel gas to heat the reformer;
a second fuel pump for controlling a flow rate of the fuel gas supplied to the burner;
a first valve connecting the first fuel pump and any one of the inlet sides of the plurality of desulfurizers;
a second valve connecting one of the inlet sides of the plurality of desulfurizers to the second fuel pump; and
and a third valve connecting one of the outlets of the plurality of desulfurizers to the reformer. 10. The method of claim 9,
The fuel processing device, the fuel cell system, characterized in that it further comprises a bypass pipe connecting the outlet sides of the plurality of desulfurizers to each other.

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