KR102283350B1 - Fuel cell system and marine structure having the same - Google Patents

Abstract

The present invention relates to a fuel cell system and an offshore structure having the same, comprising: a dehydrogenation reactor using LOHC as a hydrogen source and receiving LOHC to perform a dehydrogenation reaction; a fuel cell for receiving hydrogen from the dehydrogenation reactor to produce electric power and supplying it to a demand for an offshore structure; and an electric heater for supplying thermal energy to the dehydrogenation reactor, wherein the dehydrogenation reactor performs a dehydrogenation reaction of LOHC using waste heat of exhaust gas discharged from the fuel cell and thermal energy supplied from the electric heater. characterized by performing.

Description

Fuel cell system and marine structure including the same

The present invention relates to a fuel cell system and an offshore structure including the same.

In a system for supplying power or electric power such as power generation and propulsion of offshore structures, the introduction of fuel cells has been studied and applied to reduce environmental pollution compared to existing fuels.

Accordingly, the offshore structure must be provided with a means for storing hydrogen for supply to the fuel cell, and conventionally, hydrogen gas is stored in a high-pressure gas state or stored after being liquefied. When storing hydrogen gas in a high-pressure gas state, there is a risk of explosion of hydrogen gas, and there is a limit to storing and transporting in a large capacity because ultra-high pressure storage is required. In addition, since BOG is generated during storage and transportation when hydrogen gas is liquefied and stored, there is a problem that a cryogenic storage tank is required for the treatment of BOG.

Liquid organic hydrogen carrier (LOHC) is an umbrella term for organic compounds capable of storing hydrogen gas. In the unsaturated state, LOHC binds hydrogen through hydrogenation to maintain a stable state, and then releases hydrogen gas through dehydrogenation and can return to the unsaturated state. In other words, hydrogenation and dehydrogenation reactions using LOHC can occur reversibly, and LOHC is hydrogenated and stored in offshore structures, and hydrogen gas is produced through a dehydrogenation reaction before being supplied to a fuel cell, and it is separated and supplied. it could be LOHC has a superior advantage over the existing hydrogen gas storage method in that it can be stored and transported at room temperature and pressure, but the dehydrogenation reaction is an endothermic reaction, so it requires a lot of energy and costs accordingly. Therefore, in order to apply the LOHC as a hydrogen gas source for a fuel cell of an offshore structure, there is a need to develop a more efficient dehydrogenation process of the LOHC.

The present invention was created to solve the problems of the prior art as described above, and an object of the present invention is to provide a fuel cell system and an offshore structure including the same.

A fuel cell system according to an aspect of the present invention is a system using LOHC as a hydrogen source, comprising: a dehydrogenation reactor receiving LOHC and performing a dehydrogenation reaction; a fuel cell for receiving hydrogen from the dehydrogenation reactor to produce electric power and supplying it to a demand for an offshore structure; and an electric heater for supplying thermal energy to the dehydrogenation reactor, wherein the dehydrogenation reactor performs a dehydrogenation reaction of LOHC using waste heat of exhaust gas discharged from the fuel cell and thermal energy supplied from the electric heater. characterized by performing.

Specifically, the electric heater may receive power from one or more selected from the group consisting of a main engine, a power generation engine, a shaft generator, and the fuel cell of the offshore structure.

Specifically, the system further comprises a control unit for controlling the amount of thermal energy supplied to the electric heater according to any one or more of a flow rate of hydrogen supplied from the dehydrogenation reactor to the fuel cell, a temperature of the fuel cell, and an electric power requirement of the consumer. may include

Specifically, cyclohexane, methylcyclohexane, tetraline, phenylcyclohexane, 4-aminopiperine, carbazole, perhydro-dibenzeltoluene, decalin, formic acid, ammoniaborane, naphthalene, acetone, N-ethylcarbazole and 2-N-methylbenzyl pyridine may be at least one selected from the group consisting of.

Specifically, the fuel cell may have an exhaust gas temperature of 600 to 1000°C.

An offshore structure according to another aspect of the present invention is characterized in that it has the fuel cell system according to the aspect.

The fuel cell system according to the present invention is environmentally friendly because it can reduce carbon emission or not emit carbon compared to conventional fuels.

The fuel cell system according to the present invention enables stable storage and transportation at room temperature and pressure conditions by using LOHC as a hydrogen source.

The fuel cell system according to the present invention is environmentally friendly because waste heat generated from the fuel cell can be recycled.

The fuel cell system according to the present invention supplies thermal energy to the fuel cell as much as the insufficient amount of fuel in consideration of any one or more of the flow rate of hydrogen supplied to the fuel cell, the temperature of the fuel cell, and the electric power required by the demand in the offshore structure. Thus, it is possible to provide optimal fuel cell operation.

The fuel cell system according to the present invention can supply electric power generated from an offshore structure to an electric heater, and thus can utilize the surplus power of the offshore structure.

1 is a conceptual diagram of a fuel cell system according to an embodiment of the present invention.
2 is a conceptual diagram of a fuel cell system according to an embodiment of the present invention.
3 is a conceptual diagram of a fuel cell system according to an embodiment of the present invention.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In the present specification, in adding reference numbers to the components of each drawing, it should be noted that only the same components are given the same number as possible even though they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, it should be noted that high pressure, low pressure, high temperature, low temperature, high load, and low load are relative and do not represent absolute values.

Hereinafter, a fuel cell system of the present invention will be described, and the present invention includes a fuel cell system and an offshore structure including the same. In the present invention, a fuel cell refers to a high-efficiency clean power generation system that directly converts hydrogen contained in hydrocarbon-based substances such as natural gas, coal gas, and methanol and oxygen in the air into electrical energy through an electrochemical reaction. The fuel cell may be classified according to the type of electrolyte used, but the fuel cell used in the present invention may be one that generates power at a high temperature of 600 to 1000°C. In addition, the fuel cell used in the present invention may be to discharge a high-temperature exhaust gas of 600 to 1000 ℃. For example, the fuel cell of the present invention may be a solid oxide (SOFC) fuel cell or a molten carbonate fuel cell (MCFC), but preferably a solid oxide fuel cell.

Hereinafter, the rich LOHC may refer to an LOHC in which hydrogen is abundant or saturated, and the lean LOHC may refer to a LOHC in which the rich LOHC undergoes a dehydrogenation reaction and is in a hydrogen-deficient or non-hydrogen state. That is, it should be noted that LOHC is an organic compound that may or may not contain hydrogen reversibly through dehydrogenation and hydrogenation reaction, and is an expression encompassing the above two states.

Note that the above-mentioned offshore structure is an expression encompassing all of a ship carrying cargo, a merchant ship, a ship capable of producing natural gas in the ocean, a gas platform, and an offshore float. In addition, the fuel cell system of the present invention can be applied to an onshore plant.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, a fuel cell system of the present invention will be described with reference to FIGS. 1 to 3 .

1 is a view of a fuel cell system according to an embodiment of the present invention.

The fuel cell system according to this embodiment includes a fuel cell 100 and a dehydrogenation reactor 121 . Of course, in this embodiment, if necessary for driving the fuel cell and storing and supplying electric power generated from the fuel cell, various well-known components may be further added.

The fuel cell 100 may generate electric power by electrochemically reacting hydrogen as a fuel and oxygen in the air.

In this case, hydrogen as the fuel may be separated from various compounds including hydrogen through a physical or chemical reaction and used as the fuel of the fuel cell 100 . Preferably, the hydrogen may be separated from various compounds including hydrogen through a chemical reaction. The chemical reaction may be to separate hydrogen from the compound by reforming or thermal decomposition of a compound containing hydrogen. Preferably, the compound may be a Liquid Organic Hydrogen Carrier (LOHC). Examples of the LOHC include cyclohexane, methylcyclohexane, tetraline, phenylcyclohexane, 4-aminopiperine, carbazole, perhydro-dibenzeltoluene, decalin, formic acid, ammoniaborane, naphthalene, acetone, It may be at least one selected from the group consisting of N-ethylcarbazole and 2-N-methylbenzyl pyridine, but is not limited thereto. Preferably, the LOHC may be methylcyclohexane.

More specifically, when the LOHC is methylcyclohexane, the methylcyclohexane may be referred to as a hydrogen-rich LOHC. The marine structure having the fuel cell system according to the present embodiment can dehydrogenate the amount of methylcyclohexane required for power generation while storing methylcyclohexane in a storage tank. When methylcyclohexane is dehydrogenated, three hydrogen molecules and toluene are generated, and the generated hydrogen is supplied to a fuel cell to generate electricity through an electrochemical reaction, and toluene becomes LOHC lacking hydrogen and stores LOHC separately. It can be stored in part (E). Lean LOHC lacking hydrogen can be stored in the LOHC storage unit (E), unloaded, and converted into hydrogen-rich LOHC through a hydrogenation reaction, which can be used again for dehydrogenation. In other words, the LOHC can be used for power generation through reversible dehydrogenation and hydrogenation reactions, and at the same time can provide easy storage and transport.

In addition, the fuel cell 100 according to the present embodiment may be supplied with hydrogen, natural gas, ammonia, or a combination thereof to generate electric power through an electrochemical reaction. Natural gas and ammonia can be used to generate electricity through an electrochemical reaction with oxygen. Alternatively, at least a portion of the natural gas or ammonia may be reformed by meeting steam in the fuel cell 100 to generate hydrogen gas. In this case, the steam may be generated by an electrochemical reaction of hydrogen in the fuel cell 100 . Alternatively, the steam may be supplied from a steam supply unit N, which will be described later. This reforming reaction is an endothermic reaction, and heat generated when electric power is generated due to the electrochemical reaction of hydrogen as described above may be used. In this case, it is possible to prevent the fuel cell 100 from being excessively heated due to the electrochemical reaction of hydrogen in the fuel cell 100 , so that it is not necessary to separately cool the fuel cell 100 .

Hereinafter, when the fuel cell 100 generates electric power using ammonia, the ammonia may react with steam to generate hydrogen gas. In the present invention, such a reaction may be referred to as reforming or pyrolysis of ammonia.

The fuel cell 100 is connected to any one or more of an ammonia supply unit (A), a natural gas supply unit (B), a compressed air supply unit (C), and a LOHC supply unit (D), which will be described later, to provide materials necessary for the electrochemical reaction of the fuel cell. can be supplied.

In this embodiment, the fuel cell 100 may be driven at 600 to 1000°C. Preferably, the fuel cell 100 may have a temperature of 600 to 1000° C. of the exhaust gas discharged after the internal electrochemical reaction is completed. More preferably, the fuel cell may have an exhaust gas temperature of 600 to 800°C.

The fuel cell 100 may discharge exhaust gas generated as a result of the electrochemical reaction through the fuel cell exhaust gas line L113 .

The fuel cell exhaust gas line L113 may transfer waste heat of the exhaust gas to a dehydrogenation reactor 121 to be described later. Additionally, the fuel cell exhaust gas line L113 may transfer waste heat of the exhaust gas to the LOHC preheater 120 and the ammonia vaporizer 111 to be described later.

The dehydrogenation reactor 121 may receive the LOHC from the LOHC supply unit D and provide a place for performing the dehydrogenation reaction of the LOHC. Since the dehydrogenation reaction of the LOHC is an endothermic reaction, the dehydrogenation reactor 121 may supply a sufficient heat source for the dehydrogenation reaction of the LOHC.

The dehydrogenation reactor 121 according to the present embodiment may perform the dehydrogenation reaction of the LOHC using waste heat of the exhaust gas discharged from the fuel cell 100 . Specifically, the dehydrogenation reactor 121 may perform the LOHC dehydrogenation reaction using waste heat of the exhaust gas at a temperature of 600 to 1000° C. discharged from the fuel cell 100 .

If the dehydrogenation reactor 121 uses the exhaust gas waste heat of the fuel cell 100 and is not supplied with a separate heat source, the dehydrogenation reactor 121 may use the total amount of hydrogen required by the fuel cell 100 or the 40 to 60% of the total energy required for dehydrogenation of hydrogen can be covered. In order to obtain the remaining 40 to 60% of hydrogen, additional energy may be supplied to the dehydrogenation reactor 121 or a separate energy source may be supplied to the fuel cell. For example, the fuel cell system according to an embodiment of the present invention may supply natural gas or ammonia as an additional fuel.

The fuel cell system according to an embodiment of the present invention may further include an ammonia supply unit (A).

The ammonia supply unit A is a means for storing and supplying liquid ammonia as an additional fuel for the fuel cell system. Therefore, the ammonia supply unit (A) can maintain a suitable temperature and internal pressure for storing ammonia in a liquid state.

The ammonia supply unit A may supply ammonia to the fuel cell 100 through the ammonia supply line L110. In this case, on the ammonia supply line L110, a pump 110 for pumping liquid ammonia, an ammonia vaporizer 111 for vaporizing liquid ammonia, a fuel mixer 112, and the like may be further provided.

The pump 110 pressurizes liquid ammonia from the ammonia supply unit A to flow ammonia through the ammonia supply line L110. The pump 110 may adjust the flow rate of ammonia supplied from the ammonia supply unit A, and the flow rate may be controlled by the control unit 102 to be described later.

The ammonia vaporizer 111 may supply ammonia in a gaseous state to the fuel cell 100 through the ammonia supply line L110 by vaporizing liquid ammonia. Accordingly, ammonia supplied to the fuel cell 100 is reformed into a gaseous state to generate hydrogen. The ammonia vaporizer 111 may vaporize liquid ammonia using waste heat of the exhaust gas of the fuel cell 100 flowing along the fuel cell exhaust gas line L113, which will be described later.

For example, the ammonia vaporizer 111 is provided on the fuel cell exhaust gas line L113 and may be provided at the rear end of the dehydrogenation reactor 121 and the LOHC preheater 120 based on the fuel cell 100 . . That is, the exhaust gas of the fuel cell 100 may sequentially supply waste heat to the dehydrogenation reactor 121 , the LOHC preheater 120 , and the ammonia vaporizer 111 .

In this case, the exhaust gas of the fuel cell 100 that has passed through the ammonia vaporizer 111 may be supplied to the exhaust gas post-processing device 114 to undergo a process of removing nitrogen oxides (NOx) in the exhaust gas. The exhaust gas aftertreatment device 114 may be, for example, a selective catalytic reduction (SCR), but is not limited as long as it is a means that can be used to reduce nitrogen oxides as known in the art.

When ammonia is used as an additional fuel in the fuel cell system according to an embodiment of the present invention, nitrogen oxides may be generated in the fuel cell. Nitrogen oxide may be reduced through the exhaust gas post-treatment device 114 as described above.

The exhaust gas that has passed through the exhaust gas post-treatment device 114 may be delivered to the vent unit L through the vent line L114 to be vented.

The fuel mixer 112 may be a means for receiving gas from any one or more of the ammonia supply line L110 and the natural gas supply line L111, and for receiving and mixing steam from the steam supply unit N.

Ammonia and steam are mixed inside the fuel mixer 112 , and reforming or thermal decomposition of ammonia may occur, and hydrogen gas produced through this may be supplied to the fuel cell 100 .

Natural gas may be reformed by steam in the fuel mixer 112 , and hydrogen gas produced through this may be supplied to the fuel cell 100 .

Additionally, the fuel mixer 112 may receive hydrogen gas from a hydrogen line L122 to be described later and mix it with ammonia, natural gas, or a combination thereof. That is, the fuel mixer 112 may supply a gas mixture including hydrogen gas to the fuel cell 100 .

The fuel cell system according to an embodiment of the present invention may further include a natural gas supply unit (B).

The natural gas supply (B) is a means for storing and supplying natural gas as an additional fuel for the fuel cell system. For example, the natural gas supply unit (B) may be connected to a fuel gas supply system (FGSS) that supplies natural gas, which is a fuel, from various conventional offshore structures to a demand such as a propulsion means.

The natural gas supply unit B may supply natural gas to the fuel cell 100 through the natural gas supply line L111. In this case, a natural gas control valve 113 for controlling the flow rate of natural gas, a fuel mixer 112, and the like may be further provided on the natural gas supply line L111.

The natural gas control valve 113 may adjust the flow rate of natural gas supplied from the natural gas supply unit B, and the flow rate may be controlled by the control unit 102 to be described later.

The fuel cell system according to an embodiment of the present invention may further include a steam supply unit (N).

The steam supply unit N is a means for supplying water required to produce hydrogen gas by reforming natural gas in the fuel cell 100 . Accordingly, the steam supply unit N may be provided at a position for supplying steam to natural gas. For example, the steam supply unit N may be connected to the fuel mixer 112 to supply steam to enable smooth reforming of natural gas.

The fuel cell system according to an embodiment of the present invention may further include a compressed air supply unit (C).

The compressed air supply unit C is a means for supplying the fuel cell 100 by compressing air containing oxygen required for an electrochemical reaction with hydrogen. For example, compressed air may contain oxygen of higher purity than general air.

The fuel cell system according to an embodiment of the present invention may further include a LOHC supply unit (D).

The LOHC supply (D) is a means for storing and supplying hydrogen-rich rich LOHC.

The LOHC supply unit D may supply LOHC to the dehydrogenation reactor 121 through the LOHC supply line L120 . In this case, the LOHC preheater 120 for preheating the LOHC may be further provided on the LOHC supply line L120 .

The LOHC preheater 120 preheats the hydrogen-rich rich LOHC and supplies it to the dehydrogenation reactor 121 , thereby helping the dehydrogenation reaction proceed more smoothly in the dehydrogenation reactor 121 . As described above, the LOHC preheater 120 may preheat the LOHC using waste heat of the exhaust gas of the fuel cell 100 flowing through the fuel cell exhaust gas line L113.

The LOHC supplied to the dehydrogenation reactor 121 may be discharged in the form of a mixture of hydrogen gas and lean LOHC by performing a dehydrogenation reaction. A mixture of hydrogen gas and lean LOHC discharged from the dehydrogenation reactor 121 may be introduced into the gas-liquid separator 122 through the hydrogen and lean LOHC line L121.

The gas-liquid separator 122 may receive a mixture of hydrogen gas and lean LOHC from the hydrogen and lean LOHC line L121 to perform gas-liquid separation.

At least a portion of the separated hydrogen gas may be supplied to the fuel mixer 112 through the hydrogen line L122. The hydrogen gas may be supplied to the fuel cell 110 in a state of being mixed with any one or more of ammonia and natural gas in the fuel mixer 112 .

Additionally, at least a portion of the separated hydrogen gas may be stored in the hydrogen tank 124 through the hydrogen line L123. In this case, a compressor 135 for compressing hydrogen may be further provided on the hydrogen line L123. Accordingly, the hydrogen tank 124 may store pressurized hydrogen gas.

As such, the hydrogen tank 124 may store at least a portion of hydrogen gas produced through the dehydrogenation reaction of the LOHC, and may be supplied to the fuel cell 100 through a hydrogen line (not shown) only when necessary. .

Additionally, the hydrogen tank 124 may supply hydrogen to the hydrogen line L122 that supplies hydrogen from the gas-liquid separator 122 to the fuel mixer 112 through the hydrogen line L124. The hydrogen line L124 may further include a hydrogen control valve 125 for controlling a flow rate of supplied hydrogen. The hydrogen control valve 125 may have a flow rate controlled by the control unit 102 to be described later.

The lean LOHC in the liquid state separated by the gas-liquid separator 122 may be transferred to the LOHC storage unit E through the lean LOHC line L125. The LOHC storage unit (E) may be provided so as to be detachable from the offshore structure, through which it can be easily unloaded from the offshore structure. The recovered lean LOHC can be converted into rich LOHC through a hydrogenation reaction and stored in the LOHC supply unit (D) for use.

The fuel cell system according to an embodiment of the present invention may further include a control unit 102 .

The control unit 102 controls the flow rate of hydrogen gas supplied from the dehydrogenation reactor 121 to the fuel cell 100 , the temperature of the fuel cell 100 according to the electrochemical reaction of the fuel cell 100 , and a demand destination of the marine structure. It is possible to control the natural gas supply amount of the natural gas supply unit (B), the ammonia supply amount of the ammonia supply unit (A), or both according to any one or more of the power requirements required in the .

For example, when the flow rate of the hydrogen gas supplied from the dehydrogenation reactor 121 to the fuel cell 100 is less than a predetermined standard, or when the generated power is less than the power required by the demand, the control unit 102 can increase the supply of natural gas, ammonia or both.

For example, when the temperature of the fuel cell 100 is higher than a predetermined reference, the controller 102 may increase the supply amount of natural gas, ammonia, or both.

Specifically, the control unit 102 may control the driving of the fuel cell system by controlling the flow rate of one or more selected from the group consisting of the ammonia pump 110 , the natural gas control valve 113 , and the hydrogen control valve 125 . there is.

The fuel cell system according to an embodiment of the present invention may be connected to a main switchboard SWBD.

The fuel cell 100 may supply power to various consumers of offshore structures through the main switchboard. The demand includes a variety of means that can use electric power in offshore structures, such as a hotel load (G), a cargo pump (H), a ballast pump (I), and a service load (J).

Accordingly, the main switchboard may further include a wire connected to each demand, a switchgear, an overcurrent protector, or an instrument.

Additionally, a battery (not shown) or a capacitor (not shown) capable of temporarily storing the surplus power generated by the fuel cell 100 may be further provided.

As described above, the fuel cell system according to an embodiment of the present invention is a system for supplying hydrogen obtained by dehydrogenating LOHC to the fuel cell 100 to produce electricity, and LOHC can be used instead of hydrogen, which is difficult to store and handle. and waste heat of exhaust gas discharged from the fuel cell 100 can be used for the dehydrogenation reaction, which is environmentally friendly. In addition, when hydrogen supplied through dehydrogenation is insufficient, it can be compensated by supplying natural gas or ammonia as an additional fuel. In this case, the reforming reaction of natural gas or ammonia and the electrochemical reaction of hydrogen gas may occur simultaneously in the same space of the fuel cell 100 . Since the reforming reaction of natural gas or ammonia is an endothermic reaction, and the electrochemical reaction of hydrogen gas is an exothermic reaction, separate cooling is not required when the fuel cell is driven.

With continued reference to FIG. 1, a fuel cell system according to another embodiment of the present invention will be described.

A fuel cell system according to an embodiment of the present invention includes a fuel cell 100 , a dehydrogenation reactor 121 , and an electric heater 126 . In this embodiment, if necessary for driving the fuel cell and storing and supplying electric power generated from the fuel cell, various known components may be further added.

Hereinafter, the present embodiment will be mainly described on the points that are different from the previous embodiment, and the parts omitted from the description will be replaced with the previous content.

The dehydrogenation reactor 121 may perform a dehydrogenation reaction of the LOHC using waste heat of the exhaust gas discharged from the fuel cell 100 .

If the dehydrogenation reactor 121 uses the exhaust gas waste heat of the fuel cell 100 and is not supplied with a separate heat source, the dehydrogenation reactor 121 may use the total amount of hydrogen required by the fuel cell 100 or the 40 to 60% of the total energy required for dehydrogenation of hydrogen can be covered. In order to obtain the remaining 40 to 60% of hydrogen, additional energy may be supplied to the dehydrogenation reactor 121 or a separate energy source may be supplied to the fuel cell. For example, the fuel cell system according to an embodiment of the present invention may include an electric heater 126 to supply additional energy to the dehydrogenation reactor 121 .

The electric heater 126 may supply thermal energy to the dehydrogenation reactor 121 by receiving power generated from the offshore structure.

For example, the electric heater 126 may receive power from the power generation unit K of the offshore structure. Preferably, the electric heater 126 may be supplied with surplus power of the offshore structure to supply insufficient energy to the dehydrogenation reactor 121 .

The power generation unit K may mean a main engine, a power generation engine, a shaft generator, and the like. The shaft generator may be a type of power take-off device or power take-off (PTO) that is connected to a power source such as an engine and generates power using a portion of power produced by the power source.

The electric heater 126 may receive power from the marine structure through the main switchboard.

Additionally, the electric heater 126 may receive power from the fuel cell 100 or a fuel cell provided separately from the fuel cell 100 in addition to the power generation unit K.

The control unit 102 controls the flow rate of hydrogen gas supplied from the dehydrogenation reactor 121 to the fuel cell 100 , the temperature of the fuel cell 100 according to the electrochemical reaction of the fuel cell 100 , and a demand destination of the marine structure. The amount of thermal energy supplied to the electric heater 126 may be controlled according to any one or more of the required amount of power.

For example, when the flow rate of the hydrogen gas supplied from the dehydrogenation reactor 121 to the fuel cell 100 is less than a predetermined standard, or when the generated power is less than the power required by the demand, the control unit 102 may increase the power supplied to the electric heater 126 to increase the amount of thermal energy supplied to the electric heater 126 .

As described above, the fuel cell system according to an embodiment of the present invention is a system for supplying hydrogen obtained by dehydrogenating LOHC to the fuel cell 100 to produce electricity, and LOHC can be used instead of hydrogen, which is difficult to store and handle. and waste heat of exhaust gas discharged from the fuel cell 100 can be used for the dehydrogenation reaction, which is environmentally friendly. In addition, when hydrogen supplied through dehydrogenation is insufficient, heat energy may be supplied to the dehydrogenation reactor 121 through the electric heater 126 to supply hydrogen. In this case, it is possible to utilize the surplus power of the offshore structure.

With continued reference to FIG. 1, a fuel cell system according to another embodiment of the present invention will be described.

A fuel cell system according to an embodiment of the present invention includes a fuel cell 100 , an electrolysis cell 101 , and a dehydrogenation reactor 121 . In this embodiment, if necessary for driving the fuel cell and the electrolysis cell and storing and supplying electric power generated from the fuel cell, various known components may be further added.

Hereinafter, the present embodiment will be mainly described on the points that are different from the previous embodiment, and the parts omitted from the description will be replaced with the previous content.

The electrolysis cell 101 receives water and power to produce hydrogen gas and oxygen gas. That is, the electrolysis cell 101 may electrolyze the supplied water to produce hydrogen gas and oxygen gas. In this case, the electrolysis cell 101 may be to produce hydrogen gas of higher purity than the dehydrogenation reactor 121 .

At this time, the water is preferably fresh water, but is not limited thereto. The electrolysis cell 101 may receive steam generated from seawater supplied from a seawater supply unit F to be described later and electrolyze it. Additionally, the electrolysis cell 101 may receive steam contained in the exhaust gas of the fuel cell 100 and electrolyze it.

The electrolysis cell 101 may receive electric power generated from an offshore structure and electrolyze water.

For example, the electrolytic cell 101 may receive power from the power generation unit K of the offshore structure. Preferably, the electrolysis cell 101 can be used by receiving the surplus power of the offshore structure.

The electrolytic cell 101 may receive power from the marine structure through the main switchboard.

Additionally, the electrolytic cell 101 may receive power from the fuel cell 100 or a fuel cell provided separately from the fuel cell 100 in addition to the power generation unit K.

Hydrogen gas and steam produced in the electrolysis cell 101 may be supplied to the hydrogen tank 124 through the hydrogen and steam line L133 or may be supplied to the fuel cell 100 .

Specifically, a vaporizer 133 may be provided on the hydrogen and steam line L133 , and hydrogen and steam may be supplied to the gas-liquid separator 134 .

The vaporizer 133 may vaporize water supplied from the water tank 131 , which will be described later, using the hydrogen gas and steam supplied through the hydrogen and steam line L133 at high temperature. Steam generated through the vaporizer 133 may be supplied to the electrolysis cell 101 .

The gas-liquid separator 134 may receive hydrogen gas and steam from the hydrogen and steam line L133 and perform gas-liquid separation. Specifically, the gas-liquid separator 134 may separate only hydrogen gas from a mixture of hydrogen gas and steam, and the steam may be liquefied and discharged. The separated hydrogen gas may be supplied to the hydrogen tank 124 through the hydrogen line L134. In this case, a compressor 135 for compressing hydrogen may be further provided on the hydrogen line L134.

The water separated in the gas-liquid separator 134 may be returned to a water tank 131 to be described later.

Oxygen gas produced in the electrolysis cell 101 may be discharged through the oxygen line (L132).

The oxygen line L132 may be connected to the oxygen tank 136 through the dehydrogenation reactor 121 . Since the oxygen gas discharged from the electrolysis cell 101 is also relatively high compared to the LOHC, the dehydrogenation reactor 121 may perform the dehydrogenation reaction of the LOHC using the waste heat of the oxygen gas.

The oxygen tank 136 may store oxygen gas and, when necessary for driving the fuel cell 100 , mix it with compressed air and supply it to the fuel cell 100 through the compressed air supply line L112 .

The fuel cell system according to an embodiment of the present invention may further include a seawater supply unit (F).

The seawater supply unit F may store seawater from the outside of the marine structure and supply it to the system. For example, the seawater supply unit (F) may be a sea chest.

The seawater supply unit F may supply seawater to the desalination unit 130 through the water supply line L130 .

The desalination unit 130 desalinates the supplied seawater to produce fresh water and supplies it to the water tank 131 . Desalination through desalination may be accomplished by conventional means known in the art.

The water tank 131 may store fresh water supplied from the desalination unit 130 and supply water when the electrolysis cell 101 is driven. The water tank 131 may supply water to the vaporizer 133 through the water supply line L130 . A pump 132 for pumping water may be further provided on the water supply line L130. As described above, the water supplied to the vaporizer 133 is vaporized due to the heat of hydrogen and steam discharged from the electrolysis cell 101 to become steam. The generated steam may be supplied to the electrolysis cell 101 through a steam line L131.

As described above, the electrolysis cell 101 may produce hydrogen gas and supply it to the fuel cell 100 .

In this case, the fuel cell system according to the present embodiment may further include a control unit 102 , wherein the control unit 102 controls the flow rate of hydrogen gas supplied from the dehydrogenation reactor 121 to the fuel cell 100 , The hydrogen gas supply amount of the electrolytic cell 101 may be controlled according to any one or more of the temperature of the fuel cell 100 according to the electrochemical reaction of the fuel cell 100 and the amount of power required by the demand for offshore structures.

For example, when the flow rate of the hydrogen gas supplied from the dehydrogenation reactor 121 to the fuel cell 100 is less than a predetermined standard, or when the generated power is less than the power required by the demand, the control unit 102 may increase the hydrogen gas supply amount of the electrolysis cell 101 .

Specifically, the control unit 102 may increase the hydrogen gas supply amount by adjusting the opening degree of the hydrogen control valve 125 .

As described above, the fuel cell system according to an embodiment of the present invention includes a fuel cell 100 for producing electric power using hydrogen obtained by dehydrogenating LOHC, and an electrolysis for producing hydrogen and oxygen using water and electric power. cell 101 . This fuel cell system is eco-friendly because it can be used for the dehydrogenation reaction of the LOHC using the waste heat of the fuel cell 100 and the electrolysis cell 101 . In addition, when hydrogen supplied through dehydrogenation is insufficient, high-purity hydrogen gas produced from the electrolysis cell 101 may be used. In this case, it is possible to minimize the use of additional fuels such as natural gas and ammonia, or not to use the additional fuels.

2 is a diagram of a fuel cell system according to an embodiment of the present invention.

The fuel cell system according to the present embodiment includes a fuel cell 100 and an ammonia reformer 200 . Of course, in this embodiment, if necessary for driving the fuel cell and storing and supplying electric power generated from the fuel cell, various well-known components may be further added.

The fuel cell 100 may generate electric power by electrochemically reacting hydrogen as a fuel and oxygen in the air.

In this case, hydrogen as the fuel may be separated from various compounds including hydrogen through a physical or chemical reaction and used as the fuel of the fuel cell 100 . Preferably, the hydrogen may be separated from various compounds including hydrogen through a chemical reaction. The chemical reaction may be to separate hydrogen from the compound by reforming or thermal decomposition of a compound containing hydrogen. Preferably, the compound may be ammonia.

The fuel cell 100 according to the present embodiment may be supplied with hydrogen gas obtained by reforming or thermally decomposing ammonia to generate electric power through an electrochemical reaction.

In addition, the fuel cell 100 according to the present embodiment may receive hydrogen and ammonia to generate electric power through an electrochemical reaction. Ammonia and oxygen may be producing electricity through an electrochemical reaction. Alternatively, at least a portion of the ammonia may be reformed or thermally decomposed with steam in the fuel cell 100 to generate hydrogen gas. In this case, the steam may be generated by an electrochemical reaction of hydrogen in the fuel cell 100 . This reforming or thermal decomposition reaction is an endothermic reaction, and heat generated when electric power is generated due to the electrochemical reaction of hydrogen as described above may be used. In this case, it is possible to prevent the fuel cell 100 from being excessively heated due to the electrochemical reaction of hydrogen in the fuel cell 100 , so that it is not necessary to separately cool the fuel cell 100 .

The fuel cell 100 may receive ammonia from an ammonia supply unit A, which will be described later.

In this embodiment, the fuel cell 100 may be driven at 600 to 1000°C. Preferably, the fuel cell 100 may have a temperature of 600 to 1000° C. of the exhaust gas discharged after the internal electrochemical reaction is completed. More preferably, the fuel cell may have an exhaust gas temperature of 600 to 800°C.

The fuel cell 100 may discharge exhaust gas generated as a result of the electrochemical reaction through the fuel cell exhaust gas line L202 .

The fuel cell exhaust gas line L202 may transfer waste heat of the exhaust gas to the ammonia reformer 200 to be described later. Additionally, the fuel cell exhaust gas line L202 may transfer waste heat of the exhaust gas to the ammonia vaporizer 111 and the economizer 210 to be described later.

The fuel cell system according to an embodiment of the present invention may further include an ammonia supply unit (A).

The ammonia supply unit A is a means for storing and supplying liquid ammonia as an additional fuel for the fuel cell system. Therefore, the ammonia supply unit (A) can maintain a suitable temperature and internal pressure for storing ammonia in a liquid state.

The ammonia supply unit A may supply liquid ammonia to the ammonia vaporizer 111 through the ammonia supply line L110. In this case, a pump 110 for pumping liquid ammonia may be further provided on the ammonia supply line L110.

The ammonia vaporizer 111 may supply ammonia in a gaseous state to the ammonia reformer 200 through the ammonia supply line L110 by vaporizing liquid ammonia. The ammonia vaporizer 111 may vaporize liquid ammonia using waste heat of the exhaust gas of the fuel cell 100 flowing along the fuel cell exhaust gas line L202 .

For example, the ammonia vaporizer 111 is provided on the fuel cell exhaust gas line L202 and may be provided at the rear end of the ammonia reformer 200 to be described later based on the fuel cell 100 . That is, the exhaust gas of the fuel cell 100 may sequentially supply waste heat to the ammonia reformer 200 and the ammonia vaporizer 111 . Additionally, the exhaust gas passing through the ammonia vaporizer 111 may supply waste heat to the economizer 210 to be described later.

The ammonia reformer 200 may provide a place for reforming or pyrolyzing at least a portion of the vaporized ammonia supplied from the ammonia vaporizer 111 .

The ammonia reformer 200 according to the present embodiment may perform a pyrolysis reaction of ammonia using waste heat of the exhaust gas discharged from the fuel cell 100 . Specifically, the ammonia reformer 200 may perform reforming or thermal decomposition of ammonia by using waste heat of the exhaust gas at 600 to 1000° C. discharged from the fuel cell 100 .

All ammonia supplied to the ammonia reformer 200 may be reformed or pyrolyzed to form a mixture of hydrogen gas and nitrogen gas. When a part of ammonia is reformed or pyrolyzed, a mixture of hydrogen gas, nitrogen gas and ammonia gas is formed.

The gas separator 201 may separate hydrogen gas and supply it to the fuel cell 100 through the hydrogen line L201. Separating the hydrogen gas by the gas separator 201 may use a pressure swing adsorption (PSA), a hydrogen adsorption column, or the like, but is not limited as long as it is a means capable of separating hydrogen gas as known in the art. In this case, since only hydrogen gas is supplied to the fuel cell 100 through the gas separator 201 , nitrogen oxide is not generated according to the power generation of the fuel cell 100 .

The nitrogen gas separated from the gas separator 201 may be delivered to the economizer 210 to be described later through the nitrogen line L203. The economizer 210 may produce steam by using the waste heat of the nitrogen gas.

When only a part of ammonia is reformed or pyrolyzed, hydrogen gas, nitrogen gas, and ammonia gas may be supplied to the gas separator 201 through the hydrogen and nitrogen line L200.

Alternatively, the system may not include the gas separator 201, and as only a part of the ammonia is reformed or pyrolyzed, hydrogen gas, nitrogen gas and ammonia gas are supplied to the fuel cell 100 through the hydrogen and nitrogen line L200. can

In this case, hydrogen gas in the fuel cell 100 is used to generate electric power through an electrochemical reaction, and heat produced through the electrochemical reaction may be used to reform ammonia gas. Meanwhile, heat generated through the electrochemical reaction of the hydrogen gas is absorbed by the unreacted ammonia gas and used for thermal decomposition of ammonia, thereby providing a cooling effect to the fuel cell 100 . At this time, the generated nitrogen oxides may be supplied to an exhaust gas post-treatment device (not shown) to undergo a treatment for removing nitrogen oxides in the exhaust gas.

The economizer 210 may generate steam from water by receiving heat from the outside. The economizer 210 is a type of a waste heat recovery unit (WHRU) and is used as a means for recycling waste heat of the fuel cell system in this embodiment.

The economizer 210 may use surplus water generated inside the marine structure, and may produce steam using water supplied from the outside of the marine structure or produced by desalination of seawater. The fuel cell system according to the present embodiment may further include a water tank 220 for supplying water to the economizer 210, but is not limited thereto.

For example, the economizer 210 may receive exhaust gas from the fuel cell 100 through the fuel cell exhaust gas line L202 and use waste heat of the exhaust gas to produce steam. In this case, as described above, the fuel cell exhaust gas line L202 may be connected to the economizer 210 after passing through the ammonia reformer 200 or the ammonia reformer 200 and the ammonia vaporizer 111 . The exhaust gas used for steam production may be delivered to the vent part L through the vent line L204 to be vented. The vent line L204 may further include an exhaust gas post-treatment device (not shown) to remove nitrogen oxides in the exhaust gas and then discharge the exhaust gas. When ammonia gas is supplied to the fuel cell 100 , nitrogen oxide may be generated in the fuel cell. As described above, nitrogen oxides can be reduced through an exhaust gas aftertreatment device.

For example, the economizer 210 may receive nitrogen gas from the gas separator 201 through the nitrogen line L203, and use waste heat of the nitrogen gas to produce steam. The nitrogen gas used for steam production may be delivered to the vent part L through the vent line L204 to be vented. Alternatively, only nitrogen gas may be recovered and supplied to a separate consumer.

The steam produced by the economizer 210 may be supplied to the steam demander M through the steam line L205.

The fuel cell system according to an embodiment of the present invention may be connected to a main switchboard SWBD.

The fuel cell 100 may supply power to various consumers of offshore structures through the main switchboard. The demand includes a variety of means that can use electric power in offshore structures, such as a hotel load (G), a cargo pump (H), a ballast pump (I), and a service load (J).

Accordingly, the main switchboard may further include a wire connected to each demand, a switchgear, an overcurrent protector, or an instrument.

Additionally, a battery (not shown) or a capacitor (not shown) capable of temporarily storing the surplus power generated by the fuel cell 100 may be further provided.

As described above, the fuel cell system according to an embodiment of the present invention may reform some or all of ammonia to produce hydrogen gas and supply it to the fuel cell. In the case of partially reforming ammonia, the reforming or thermal decomposition reaction of ammonia and the electrochemical reaction of hydrogen gas may occur simultaneously in the same space of the fuel cell 100 . The reforming or thermal decomposition reaction of ammonia is an endothermic reaction, and the electrochemical reaction of hydrogen gas is an exothermic reaction, so that no separate cooling is required when the fuel cell is driven. When all ammonia is reformed, only hydrogen gas is separated and supplied to the fuel cell 100 to produce electric power. The fuel cell system may include a WHRU such as the economizer 210, and the economizer 210 produces steam using waste heat from exhaust gas of the fuel cell 100, waste heat from nitrogen gas, or a combination thereof to produce steam. can be supplied to

3 is a diagram of a fuel cell system according to an embodiment of the present invention.

The fuel cell system according to the present embodiment includes a reversible fuel cell 300 and a dehydrogenation reactor 121 . Of course, in this embodiment, if necessary for driving the reversible fuel cell and storing and supplying electric power and hydrogen gas produced from the reversible fuel cell, various known configurations may be further added.

The reversible fuel cell 300 includes a fuel cell mode (FC mode) in which electricity is produced by electrochemically reacting hydrogen and oxygen in the air as a fuel source, and an electrolytic cell mode (FC mode) in which water and power are supplied to produce hydrogen gas and oxygen gas ( EC mode).

For example, the reversible fuel cell 300 is configured by integrating a fuel cell and an electrolysis cell, and may be provided to drive or reverse drive one system, or may be provided to simultaneously produce electric power and hydrogen gas.

In addition, the reversible fuel cell 300 may be driven in the fuel cell mode when the offshore structure requires high load operation, and driven in the electrolytic cell mode when the offshore structure requires low load operation.

For example, the reversible fuel cell 300 may be driven in the electrolytic cell mode to produce and store hydrogen gas because the amount of power required by the demand for the offshore structure is reduced when the offshore structure is stopped or anchored. The reversible fuel cell 300 is driven in the fuel cell mode because the amount of power required by the demanding party increases during driving or operation of the offshore structure to generate power and supply it to the demanding part of the offshore structure.

In the present embodiment, the reversible fuel cell 300 may be supplied with hydrogen obtained by dehydrogenating LOHC in the fuel cell mode to generate electric power.

In addition, it may be to produce hydrogen and oxygen from the steam supplied in the electrolysis cell mode and the power supplied from the power generation unit.

The same description as in the above-described embodiment with respect to the fuel cell, the electrolytic cell, and the LOHC is replaced with the description of the previous embodiment.

The dehydrogenation reactor 121 may receive the LOHC from the LOHC supply unit D and provide a place for performing the dehydrogenation reaction of the LOHC. Since the dehydrogenation reaction of the LOHC is an endothermic reaction, the dehydrogenation reactor 121 may supply a sufficient heat source for the dehydrogenation reaction of the LOHC.

The dehydrogenation reactor 121 according to the present embodiment may perform the dehydrogenation reaction of the LOHC using waste heat of the exhaust gas or oxygen gas discharged from the reversible fuel cell 300 . Specifically, the dehydrogenation reactor 121 uses waste heat to dehydrogenate the LOHC by using waste heat from the exhaust gas at 600 to 1000° C. delivered through the fuel cell exhaust gas line L301 in the fuel cell mode of the reversible fuel cell 300 . can be performed. The dehydrogenation reactor 121 may perform the LOHC dehydrogenation reaction using waste heat of oxygen gas transferred through the oxygen line L325 in the electrolytic cell mode of the reversible fuel cell 300 .

The reversible fuel cell system according to an embodiment of the present invention may further include a compressed air supply unit (C).

The compressed air supply unit C is a means for supplying the reversible fuel cell 300 by compressing the air containing oxygen required for an electrochemical reaction with hydrogen. For example, compressed air may contain oxygen of higher purity than general air.

The compressed air supply unit C may supply compressed air to the reversible fuel cell 300 through the compressed air supply line L300 . An air preheater 301 may be further provided on the compressed air supply line L300.

The air preheater 301 may preheat compressed air by using waste heat from the exhaust gas transferred through the exhaust gas line L301 in the fuel cell mode. The air preheater 301 may preheat compressed air using waste heat of oxygen gas transferred through the oxygen line L325 in the electrolysis cell mode.

The reversible fuel cell system according to an embodiment of the present invention may further include a LOHC supply unit (D).

The LOHC supply (D) is a means for storing and supplying hydrogen-rich rich LOHC.

The LOHC supply unit D may supply LOHC to the dehydrogenation reactor 121 through the LOHC supply line L310. In this case, the LOHC preheater 120 for preheating the LOHC may be further provided on the LOHC supply line L310 .

The LOHC preheater 120 preheats the hydrogen-rich rich LOHC and supplies it to the dehydrogenation reactor 121 , thereby helping the dehydrogenation reaction proceed more smoothly in the dehydrogenation reactor 121 . The LOHC preheater 120 may preheat the LOHC using waste heat from the exhaust gas transferred through the exhaust gas line L301 in the fuel cell mode. The LOHC preheater 120 may preheat the LOHC using waste heat of oxygen gas transferred through the oxygen line L325 in the electrolytic cell mode.

As such, the fuel cell exhaust gas line L301 that delivers the exhaust gas discharged when the reversible fuel cell 300 is in the fuel cell mode is sequentially connected to the dehydrogenation reactor 121 , the LOHC preheater 120 and the air preheater 301 . Waste heat can be supplied. The exhaust gas supplied with the waste heat may be transferred to the vent unit L to be vented.

When the reversible fuel cell 300 is in the electrolysis cell mode, the oxygen line L325 through which the oxygen gas is discharged may sequentially supply waste heat to the dehydrogenation reactor 121, the LOHC preheater 120, and the air preheater 301. . Oxygen gas supplied with waste heat may be transferred to and stored in the oxygen tank 136 . The oxygen tank 136 may supply oxygen to the compressed air supply line L300 through the oxygen line L326 when the reversible fuel cell 300 is driven in the fuel cell mode while storing oxygen.

The LOHC supplied to the dehydrogenation reactor 121 may be discharged in the form of a mixture of hydrogen gas and lean LOHC by performing a dehydrogenation reaction. A mixture of hydrogen gas and lean LOHC discharged from the dehydrogenation reactor 121 may be introduced into the gas-liquid separator 122 through the hydrogen and lean LOHC line L311.

The gas-liquid separator 122 may receive a mixture of hydrogen gas and lean LOHC from the hydrogen and lean LOHC line L311 to perform gas-liquid separation. At least a portion of the separated hydrogen gas may be supplied to the reversible fuel cell 300 through the hydrogen line L312.

Additionally, at least a portion of the separated hydrogen gas may be stored in the hydrogen tank 124 through the hydrogen line L313 . In this case, a compressor 123 for compressing hydrogen may be further provided on the hydrogen line L123. Accordingly, the hydrogen tank 124 may store pressurized hydrogen gas.

As such, the hydrogen tank 124 may store at least a portion of the hydrogen gas produced through the dehydrogenation reaction of the LOHC. Specifically, the hydrogen tank 124 stores surplus power generated when the reversible fuel cell 300 is driven in the fuel cell mode, and is reversible when the reversible fuel cell 300 is driven in the electrolytic cell mode. Hydrogen gas may be supplied to the fuel cell 300 through the hydrogen supply line L314.

The lean LOHC in the liquid state separated by the gas-liquid separator 122 may be transferred to the LOHC storage unit E through the lean LOHC line L315. The LOHC storage unit (E) may be provided so as to be detachable from the offshore structure, through which it can be easily unloaded from the offshore structure. The recovered lean LOHC can be converted into rich LOHC through a hydrogenation reaction and stored in the LOHC supply unit (D) for use.

The reversible fuel cell system according to an embodiment of the present invention may further include a seawater supply unit (F).

The seawater supply unit F may store seawater from the outside of the marine structure and supply it to the system. For example, the seawater supply unit (F) may be a sea chest.

The seawater supply unit F may supply seawater to the desalination unit 130 through the water supply line L320 .

The desalination unit 130 desalinates the supplied seawater to produce fresh water and supplies it to the water tank 131 . Desalination through desalination may be accomplished by conventional means known in the art.

The water tank 131 may store fresh water supplied from the desalination unit 130 and supply water in the electrolytic cell mode of the reversible fuel cell 300 . The water tank 131 may supply water to the vaporizer 133 through the water supply line L320 . A pump 132 for pumping water may be further provided on the water supply line L320. The water supplied to the vaporizer 133 is vaporized due to the heat of hydrogen and steam discharged from the reversible fuel cell 300 in the electrolytic cell mode to become steam. The generated steam may be supplied to the reversible fuel cell 300 through a steam line L321.

A mixture of hydrogen gas and steam generated in the electrolysis cell mode of the reversible fuel cell 300 may be discharged through the hydrogen and steam line L322. As described above, the mixture of hydrogen gas and steam may be supplied to the gas-liquid separator 134 after being used to generate steam in the vaporizer 133 .

The gas-liquid separator 134 separates hydrogen gas from a mixture of hydrogen gas and steam and delivers it to the hydrogen tank 124 through a hydrogen line L324, and the steam is separated in the form of water through a water return line L323. It can return to the water tank 131 . A compressor 135 for compressing hydrogen gas may be further provided on the hydrogen line L324.

The reversible fuel cell system according to an embodiment of the present invention may be connected to a main switchboard SWBD.

When the reversible fuel cell 300 is driven in the fuel cell mode, the reversible fuel cell 300 may supply power to various consumers of marine structures through the main switchboard. The demand includes a variety of means that can use electric power in offshore structures, such as a hotel load (G), a cargo pump (H), a ballast pump (I), and a service load (J).

Accordingly, the main switchboard may further include a wire connected to each demand, a switchgear, an overcurrent protector, or an instrument.

Additionally, a battery (not shown) or a capacitor (not shown) capable of temporarily storing the surplus power generated by the reversible fuel cell 300 may be further provided.

When the reversible fuel cell 300 is driven in the electrolytic cell mode, the reversible fuel cell 300 may receive power from the power generation unit K through the main switchboard. Preferably, the reversible fuel cell 300 may be supplied with surplus power from the offshore structure to drive the electrolytic cell mode. The power generation unit K may encompass a main engine, a power generation engine, a shaft generator, and the like. The shaft generator may be a power take-off device or a type of power take-off (PTO) that is connected to a power source such as an engine and generates power using a portion of power produced by the power source.

The reversible fuel cell system according to an embodiment of the present invention may further include an electric heater 302 .

The electric heater 302 may supply thermal energy required for driving the reversible fuel cell 300 . Power required for driving the electric heater 302 may be supplied from the main switchboard of the marine structure.

The reversible fuel cell system according to an embodiment of the present invention may further include a control unit 303 .

The control unit 303 controls the flow rate of hydrogen gas supplied from the dehydrogenation reactor 121 to the reversible fuel cell 300 , the temperature of the reversible fuel cell 300 according to the electrochemical reaction of the reversible fuel cell 300 , and the ocean. Mode driving of the reversible fuel cell 300 may be controlled according to any one or more of the amount of power required by the demand of the structure.

Accordingly, the controller 303 may control the power production according to the fuel cell mode of the reversible fuel cell 300 . More specifically, the controller 303 may control the amount of power produced according to the fuel cell mode by adjusting the amount of hydrogen supplied to the hydrogen tank 124 .

Also, the controller 303 may control the amount of thermal energy supplied by the electric heater 302 to the reversible fuel cell 300 .

As described above, the reversible fuel cell system according to an embodiment of the present invention includes a fuel cell mode for producing electric power using hydrogen obtained by dehydrogenating LOHC, and a method for producing hydrogen gas and oxygen gas using water and electricity. A reversible fuel cell 300 capable of operating in an electrolytic cell mode is provided. When the reversible fuel cell 300 is driven in the fuel cell mode, the exhaust gas waste heat of the reversible fuel cell 300 can be used for the dehydrogenation reaction, and when the reversible fuel cell 300 is driven in the electrolytic cell mode, the dehydrogenation reaction is performed using waste heat of oxygen gas. It is eco-friendly in that it can be used for Hydrogen gas produced in the electrolytic cell mode can be used when the fuel cell mode is driven, and the power generated in the fuel cell mode can be used when the electrolytic cell mode is driven. Accordingly, it is possible to optimally operate the reversible fuel cell 300 through mode control according to the amount of power required according to circumstances such as operation and anchoring of offshore structures. In this case, it is possible to minimize the use of additional fuels such as natural gas and ammonia, or not to use the additional fuels.

It goes without saying that the present invention is not limited to the embodiments described above, and a combination of the above embodiments or a combination of at least one of the embodiments and a known technology may be included as another embodiment.

In the above, the present invention has been described focusing on the embodiments of the present invention, but this is merely an example and does not limit the present invention, and those of ordinary skill in the art to which the present invention pertains without departing from the essential description of the present embodiment. It will be appreciated that various combinations or modifications and applications not illustrated in the embodiments are possible within the scope. Accordingly, descriptions related to variations and applications that can be easily derived from the embodiments of the present invention should be interpreted as being included in the present invention.

A: Ammonia supply B: Natural gas supply
C: compressed air supply D: LOHC supply
E: LOHC reservoir F: seawater supply
G: Hotel Road H: Cargo Pump
I: ballast pump J: service load
K: Power generation unit L: Vent unit
M: Steam demand N: Steam supply
100: fuel cell 101: electrolytic cell
102: control unit 110: pump
111: ammonia vaporizer 112: fuel mixer
113: natural gas control valve 114: exhaust gas aftertreatment device
L110: Ammonia supply line L111: Natural gas supply line
L112: compressed air supply line L113: fuel cell exhaust gas line
L114: vent line
120: LOHC preheater 121: dehydrogenation reactor
122: gas-liquid separator 123: compressor
124 hydrogen tank 125 hydrogen control valve
126: electric heater
L120: LOHC Supply Line L121: Hydrogen and Lean LOHC Line
L122, 123, 124: Hydrogen line L125: Lean LOHC line
130: desalination unit 131: water tank
132: pump 133: carburetor
134: gas-liquid separator 135: compressor
136: oxygen tank
L130: water supply line L131: steam line
L132: oxygen line L133: hydrogen and steam line
L134: hydrogen line L135: water return line
200: ammonia reformer 201: gas separator
210: economizer 220: water tank
L200: hydrogen and nitrogen lines L201: hydrogen lines
L202: fuel cell exhaust gas line L203: nitrogen line
L204: vent line L205: steam line
300: reversible fuel cell 301: air preheater
302: electric heater 303: control unit
L300: compressed air supply line L301: fuel cell exhaust gas line
L310: LOHC Supply Line L311: Hydrogen and Lean LOHC Line
L312, 313, 314: Hydrogen line L315: Lean LOHC line
L320: water supply line L321: steam line
L322: Hydrogen and Steam Lines L323: Water Return Lines
L324: hydrogen line L325, 326: oxygen line

Claims (6)

As a fuel cell system using LOHC (Liquid Organic Hydrogen Carrier) as a hydrogen source,
a dehydrogenation reactor receiving LOHC and performing a dehydrogenation reaction;
an ammonia vaporizer for vaporizing liquid ammonia supplied from the ammonia supply unit;
a fuel cell for producing electric power from hydrogen supplied from the dehydrogenation reactor and ammonia supplied from the ammonia vaporizer and supplying it to a demand for offshore structures; and
Including an electric heater for supplying thermal energy to the dehydrogenation reactor by receiving power from one or more selected from the group consisting of a main engine, a power generation engine and a shaft generator of the marine structure,
The dehydrogenation reactor is
performing the dehydrogenation reaction of LOHC using waste heat of exhaust gas discharged from the fuel cell and heat energy supplied from the electric heater,
The ammonia vaporizer,
A fuel cell system, characterized in that the ammonia is vaporized using waste heat and thermal energy used in the dehydrogenation reaction in the dehydrogenation reactor. delete The method of claim 1, wherein the system comprises:
Fuel, characterized in that it further comprises a control unit for controlling the amount of supply of thermal energy to the electric heater according to any one or more of the flow rate of hydrogen supplied from the dehydrogenation reactor to the fuel cell, the temperature of the fuel cell, and the electric power required by the demander. battery system. The method of claim 1, wherein the LOHC is
Cyclohexane, methylcyclohexane, tetraline, phenylcyclohexane, 4-aminopiperine, carbazole, perhydro-dibenzeltoluene, decalin, formic acid, ammoniaborane, naphthalene, acetone, N-ethylcarbazole and 2- A fuel cell system, characterized in that at least one selected from the group consisting of N-methylbenzyl pyridine. According to claim 1, wherein the fuel cell,
The fuel cell system, characterized in that the temperature of the exhaust gas is 600 to 1000 ℃. An offshore structure, characterized in that it has the fuel cell system according to any one of claims 1 to 5.

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