Engine system and ship comprising same

Abstract

The present invention relates to an engine system comprising: an engine using ammonia fuel; a gas receiver, which is disposed at the rear end of the engine and receives the exhaust gas generated in the engine; and a connection part, which connect the engine and the gas receiver so that the exhaust gas generated in the engine is discharged to the gas receiver, wherein the connection part has a catalyst layer provided at a portion through which the exhaust gas passes, and the catalyst layer is a selective catalytic reduction (SCR) layer in which ammonia in the exhaust gas acts as a reducing agent so as to cause SCR, thereby removing nitrogen oxides, or, in a condition in which ammonia and nitrogen oxides are included in the exhaust gas, ammonia in the exhaust gas acts as a reducing agent so as to cause SCR, thereby removing the nitrogen oxides, and, in a condition in which nitrogen oxides are not included in the exhaust gas, ammonia in the exhaust gas can be oxidized and removed.

Description

Engine system and vessel including same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0098116, filed July 27, 2023, Korean Patent Application No. 10-2023-0142169, filed October 23, 2023, and Korean Patent Application No. 10-2024-0052169, filed April 18, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to an exhaust gas aftertreatment system and an engine system in which a selective catalytic reduction reaction occurs. Furthermore, the present invention relates to a vessel including such an exhaust gas aftertreatment system and engine system.

[0005] When fuel is burned in an engine, exhaust gas is generated. Exhaust gas contains harmful substances such as nitrogen oxides, methane, and sulfur oxides, and regulations on these substances are becoming increasingly stringent. Therefore, research is being conducted on exhaust gas aftertreatment systems that remove harmful substances contained in exhaust gas to meet the emission levels required by these regulations.

[0006] As an example of an aftertreatment system, a Selective Catalytic Reduction (SCR) device reduces nitrogen oxides in exhaust gas into nitrogen and water by reacting them with a reducing agent and a denitrification catalyst. Another example is an ammonia oxidation catalyst (AOC) that oxidizes and removes ammonia.

[0007] When ammonia is used as a fuel, unburned ammonia, or ammonia slip, is produced. Consequently, exhaust gas from an ammonia-fueled engine contains both nitrogen oxides and ammonia. Based on these characteristics of ammonia fuel, engine systems and exhaust gas aftertreatment systems can be improved.

[0008] The present invention aims to efficiently remove nitrogen oxides and ammonia contained in exhaust gas generated from an engine that uses ammonia as fuel.

[0009] In addition, the present invention seeks to primarily remove nitrogen oxides and ammonia contained in exhaust gas generated from an engine that uses ammonia as fuel within an engine system.

[0010] In addition, the present invention aims to efficiently supply a reducing agent required for a selective catalytic reduction device that treats exhaust gas generated from an engine that uses ammonia as fuel.

[0011] In addition, it is an object of the present invention to provide a vessel including an engine system and an exhaust gas aftertreatment system.

[0012] An engine system according to one embodiment of the present invention comprises: an engine using ammonia fuel; a gas receiver disposed at a rear end of the engine and receiving exhaust gas generated from the engine; and a connecting portion connecting the engine and the gas receiver so that exhaust gas generated from the engine is discharged to the gas receiver, wherein a catalyst layer is provided in a portion through which the exhaust gas passes, and the catalyst layer is a selective catalytic reduction layer in which ammonia in the exhaust gas acts as a reducing agent to cause a selective catalytic reduction (SCR) reaction to remove nitrogen oxides, or in a condition in which the exhaust gas contains ammonia and nitrogen oxides, ammonia in the exhaust gas acts as a reducing agent to cause a selective catalytic reduction (SCR) reaction to remove nitrogen oxides, and in a condition in which the exhaust gas does not contain nitrogen oxides, ammonia in the exhaust gas can be oxidized and removed.

[0013] In one example, the method may further include a nitrogen oxide concentration sensor for measuring the nitrogen oxide concentration of the exhaust gas received in the gas receiver; and a control unit for controlling supply of a reducing agent for a selective catalytic reduction reaction to the catalyst layer when the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor exceeds a predetermined reference value.

[0014] In one example, the control unit may be controlled to additionally supply ammonia to the engine through the fuel supply unit of the engine during an exhaust process in which fuel combustion does not occur during the operation of the engine, when the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor exceeds a predetermined reference value.

[0015] In one example, the method further includes a reducing agent supply unit for supplying a reducing agent for a selective catalytic reduction reaction to the catalyst layer, and the control unit can control to supply a reducing agent for a selective catalytic reduction reaction to the catalyst layer through the reducing agent supply unit when the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor exceeds a predetermined reference value.

[0016] An engine system according to one embodiment of the present invention may include an engine using ammonia fuel; and a control unit that controls to additionally supply ammonia to the engine through a fuel supply unit of the engine during an exhaust process in which fuel combustion does not occur during the operation of the engine.

[0017] A vessel may include an engine system according to one embodiment of the present invention.

[0018] According to the present invention, nitrogen oxides and ammonia contained in exhaust gas generated from an engine that uses ammonia as fuel can be efficiently removed.

[0019] According to the present invention, nitrogen oxides and ammonia contained in exhaust gas generated from an engine using ammonia as fuel can be primarily removed within the engine system, thereby reducing the need for a selective catalytic reduction device at the rear end of the engine system.

[0020] In addition, the present invention can efficiently supply a reducing agent required for a selective catalytic reduction device that treats exhaust gas generated from an engine that uses ammonia as fuel.

[0021] FIG. 1 is a drawing showing an exhaust gas aftertreatment system according to a first embodiment of the present invention.

[0022] FIG. 2 is a drawing showing an engine system according to a second embodiment of the present invention.

[0023] FIG. 3 is a drawing showing an exhaust gas aftertreatment system according to a third embodiment of the present invention.

[0024] FIG. 4 is a drawing showing an exhaust gas aftertreatment system according to a fourth embodiment of the present invention.

[0025] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given the same reference numerals, even if they appear in different drawings. Furthermore, when describing embodiments of the present invention, detailed descriptions of known components or functions will be omitted if they are deemed to hinder understanding of the embodiments of the present invention.

[0026] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present invention. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms. When it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but another component may also be "connected," "coupled," or "connected" between each component.

[0027] In this specification, the forward / backward, left / right, and up / down directions are referred to for convenience of explanation and may be orthogonal to each other. However, these directions are determined relatively, and the up / down direction does not necessarily imply a vertical direction.

[0028]

[0029] <Example 1>

[0030] FIG. 1 is a drawing showing an exhaust gas aftertreatment system according to a first embodiment of the present invention.

[0031] Referring to FIG. 1, an exhaust gas aftertreatment system (10) according to a first embodiment of the present invention is an exhaust gas aftertreatment system (10) for aftertreatment of exhaust gas generated from an engine (20) that uses ammonia as fuel, and includes a plurality of catalyst layers, and the plurality of catalyst layers include at least one composite ammonia purification layer, and in the composite ammonia purification layer, under conditions in which the exhaust gas contains ammonia and nitrogen oxides, ammonia in the exhaust gas acts as a reducing agent to cause a selective catalytic reduction reaction to remove nitrogen oxides, and under conditions in which the exhaust gas does not contain nitrogen oxides, ammonia in the exhaust gas can be oxidized and removed. Hereinafter, each component will be described in detail.

[0032] Exhaust gas generated from an engine (20) that uses ammonia as fuel contains not only nitrogen oxides but also ammonia that is not combusted in the engine. To remove nitrogen oxides and ammonia, an exhaust gas aftertreatment system (10) is provided at the rear end of the engine.

[0033] The exhaust gas post-treatment system (10) includes multiple catalyst layers, and the multiple catalyst layers may be configured in multiple stages. Accordingly, even if nitrogen oxides and ammonia in the exhaust gas are not completely removed by the preceding catalyst layer, they can be gradually removed by passing through the subsequent catalyst layer. This can increase the removal efficiency of nitrogen oxides and ammonia.

[0034] The plurality of catalyst layers may include at least one composite ammonia purification layer. Existing ammonia purification catalysts only have the function of removing ammonia by oxidizing it. However, the composite ammonia purification catalyst can function as an ammonia purification catalyst or as a catalyst for a selective reduction reaction, depending on the conditions. Specifically, under conditions where both ammonia and nitrogen oxides are present in the exhaust gas, the composite ammonia purification catalyst functions to reduce nitrogen oxides to nitrogen and remove them by using ammonia as a reducing agent. Alternatively, under conditions where ammonia is present in the exhaust gas but nitrogen oxides are absent, the composite ammonia purification catalyst functions to remove ammonia by oxidizing it.

[0035] The exhaust gas generated from an engine (20) that uses ammonia as fuel contains unburned ammonia. In the composite ammonia purification layer, since the ammonia in the exhaust gas acts as a reducing agent in the selective catalytic reduction reaction, the ammonia contained in the exhaust gas can be removed by the composite ammonia purification catalyst in the process of removing nitrogen oxides by acting as a reducing agent. When the nitrogen oxides contained in the exhaust gas are all removed in the composite ammonia purification layer at the front, a reaction occurs in the composite ammonia purification layer at the rear, in which the ammonia in the exhaust gas is oxidized and removed. Consequently, the exhaust gas emitted from the engine (20) can be subjected to both nitrogen oxides and ammonia removal by passing through the exhaust gas aftertreatment system (10) including the composite ammonia purification layer.

[0036] In addition, the plurality of catalyst layers may include a selective catalytic reduction layer in addition to the composite ammonia purification layer. The composite ammonia purification catalyst used in the composite ammonia purification layer can perform the roles of both an ammonia purification catalyst and a selective catalytic reduction catalyst, but is relatively expensive. Therefore, instead of making all of the catalyst layers composite ammonia purification layers, some of them may be made into selective catalytic reduction catalyst layers, thereby reducing costs. However, it is preferable that the composite ammonia purification layer be arranged downstream of the selective catalytic reduction layer. This is because if the composite ammonia purification layer is arranged upstream and all nitrogen oxides are removed upstream, no reaction occurs in the selective catalytic reduction layer downstream. The following describes an exhaust gas aftertreatment system including three catalyst layers as an example.

[0037] The exhaust gas post-treatment system (10) according to the first embodiment of the present invention may include a first catalyst layer (11), a second catalyst layer (12), and a third catalyst layer (13). Hereinafter, the configuration of each catalyst layer will be described by way of example.

[0038] Each catalyst layer may be composed of, for example, a first catalyst layer (11) that removes nitrogen oxides through a selective catalytic reduction reaction, as illustrated in FIG. 1(a); a second catalyst layer (12) that is provided at the rear end of the first catalyst layer (11) and removes nitrogen oxides through a selective catalytic reduction reaction; and a third catalyst layer (13) that is provided at the rear end of the second catalyst layer (12) and is a composite ammonia purification layer.

[0039] In this case, in the first catalyst layer (11) and the second catalyst layer (12), ammonia contained in the exhaust gas acts as a reducing agent to remove nitrogen oxides. In the third catalyst layer (13), nitrogen oxides that were not removed in the first catalyst layer (11) and the second catalyst layer (12) are removed, and if all nitrogen oxides are removed, ammonia can be oxidized and removed.

[0040] In addition, as illustrated in FIG. 1(b), each catalyst layer may be composed of, for example, a first catalyst layer (11) that removes nitrogen oxides through a selective catalytic reduction reaction; a second catalyst layer (12) that is provided at the rear end of the first catalyst layer (11) and is a composite ammonia purification layer; and a third catalyst layer (13) that is provided at the rear end of the second catalyst layer (12) and is a composite ammonia purification layer.

[0041] In this case, in the first catalyst layer (11), ammonia contained in the exhaust gas acts as a reducing agent to remove nitrogen oxides. In the second catalyst layer (12) and the third catalyst layer (13), nitrogen oxides that were not removed in the first catalyst layer (11) are removed, and if all nitrogen oxides are removed, ammonia can be oxidized and removed.

[0042] In addition, as illustrated in FIG. 1(c), each catalyst layer may be composed of, for example, a first catalyst layer (11) which is a composite ammonia purification layer; a second catalyst layer (12) which is provided at the rear end of the first catalyst layer (11) and is a composite ammonia purification layer; and a third catalyst layer (13) which is provided at the rear end of the second catalyst layer (12) and is a composite ammonia purification layer.

[0043] In this case, nitrogen oxides are first removed in the first catalyst layer (11), the second catalyst layer (12), and the third catalyst layer (13), and if all nitrogen oxides are removed, ammonia is oxidized and removed.

[0044] Although the exhaust gas post-treatment system (10) having three catalyst layers was described as an example, this is only an example, and catalyst layers may be of different numbers or different combinations depending on considerations such as nitrogen oxide reduction and economic efficiency.

[0045]

[0046] <Example 2>

[0047] FIG. 2 is a drawing showing an engine system according to a second embodiment of the present invention.

[0048] Referring to FIG. 2, the engine (20) using ammonia fuel; a gas receiver (40) disposed at the rear end of the engine (20) and receiving exhaust gas generated from the engine (20); and a connecting portion (30) connecting the engine (20) and the gas receiver (40) so that exhaust gas generated from the engine (20) is discharged to the gas receiver (40), and a catalyst layer (35) is provided in a portion through which the exhaust gas passes, and the catalyst layer (35) is a selective catalytic reduction layer in which ammonia in the exhaust gas acts as a reducing agent to cause a selective catalytic reduction reaction to remove nitrogen oxides, or in a condition in which the exhaust gas contains ammonia and nitrogen oxides, ammonia in the exhaust gas acts as a reducing agent to cause a selective catalytic reduction reaction to remove nitrogen oxides, and in a condition in which the exhaust gas does not contain nitrogen oxides, ammonia in the exhaust gas can be oxidized and removed. Each component will be described in detail below.

[0049] Exhaust gas generated from an engine (20) using ammonia fuel may contain nitrogen oxides and unburned ammonia, i.e., ammonia slip. The gas receiver (40) collects exhaust gas emitted from the engine (20) and supplies it to the turbocharger. This is to stabilize the exhaust gas before supplying it to the turbocharger. In FIG. 2, one engine (20) is connected to the gas receiver (40), but multiple engines (20) may be connected to the gas receiver (40) to collect exhaust gas.

[0050] The connecting portion (30) connecting the engine (20) and the gas receiver (40) serves as a passage through which exhaust gas discharged from the engine (20) moves to the gas receiver (40). One end of the connecting portion (30) is connected to the engine (20), and the other end of the connecting portion (30) is connected to the gas receiver (40).

[0051] A catalyst layer (35) may be provided in the connection portion (30) through which exhaust gas passes. The catalyst layer (35) can reduce and remove nitrogen oxides contained in the exhaust gas through a selective catalytic reduction reaction. In addition, the catalyst layer (35) may be a composite ammonia purification layer.

[0052] When diesel fuel is used, since the exhaust gas does not contain ammonia, even if a catalyst layer (35) is placed in the connection portion (30), nitrogen oxides are not removed because there is no reducing agent for the selective catalytic reduction reaction. However, when ammonia fuel is used, since the exhaust gas contains ammonia, nitrogen oxides in the exhaust gas can be removed as ammonia acts as a reducing agent for the selective catalytic reduction reaction in the catalyst layer (35). Therefore, since nitrogen oxides in the exhaust gas are primarily removed in the catalyst layer (35) in the connection portion (30), the amount of nitrogen oxides contained in the exhaust gas entering the selective catalytic reduction device that can be placed in the rear end of the engine system (100) is reduced, and thus the size of the selective catalytic reduction device in the rear end can be reduced.

[0053] The nitrogen oxide concentration sensor (130) can measure the nitrogen oxide concentration of the exhaust gas received in the gas receiver (40). The control unit (140) can control to supply a reducing agent for the selective catalytic reduction reaction to the catalyst layer (35) when the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor (130) exceeds a predetermined standard value.

[0054] If the amount of ammonia slipped from the engine (20), i.e., the amount of reducing agent required for the selective catalytic reduction reaction, is small and the selective catalytic reduction reaction does not sufficiently occur in the catalyst layer (35), the nitrogen oxide concentration may be measured high in the nitrogen oxide concentration sensor (130). In this case, by supplying more reducing agent to the catalyst layer (35) to promote the selective catalytic reduction reaction in the catalyst layer (35), the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor (130) can be lowered. Hereinafter, a method of supplying a reducing agent for the selective catalytic reduction reaction to the catalyst layer (35) will be described.

[0055] For example, if the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor (130) exceeds a predetermined reference value, the control unit (140) can control to additionally supply ammonia to the engine (20) through the fuel supply unit (110) of the engine (20) during an exhaust process in which fuel combustion does not occur during the operation of the engine (20). The cycle of the engine (20) using ammonia fuel operates very similarly to a diesel cycle. The diesel cycle generates power by combusting fuel through a compression and ignition process, and exhaust gas is discharged during the exhaust process. Therefore, if ammonia is supplied through the fuel supply unit (110) of the engine (20) during the exhaust process, the ammonia is not burned but is discharged together with the exhaust gas as it is. As a result, ammonia as a reducing agent can be additionally supplied to the catalyst layer (35).

[0056] However, the control unit (140) that controls to additionally supply ammonia to the engine (20) through the fuel supply unit (110) of the engine (20) during the exhaust process in which fuel combustion does not occur during the operation of the engine (20) is a configuration that can be applied only to an engine (20) that uses ammonia as fuel. Therefore, even if the nitrogen oxide concentration sensor (130) or the catalyst layer (35) described above is omitted, it can be independently applied to an engine (20) that uses ammonia as fuel. The ammonia supplied here can be used as a reducing agent in a selective catalytic reduction device arranged at the rear end of the engine system (100).

[0057] A reducing agent supply unit (120) for supplying a reducing agent for a selective catalytic reduction reaction to the catalyst layer (35) may be further included. The reducing agent supply unit (120) may be connected to the connection unit (30) from the outside in the form of a nozzle. However, the present invention is not limited thereto, and may be installed in another form capable of supplying a reducing agent for a selective catalytic reduction reaction to the catalyst layer (35).

[0058] The control unit (140) can control to supply a reducing agent for a selective catalytic reduction reaction to the catalyst layer (35) through the reducing agent supply unit (120) when the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor (130) exceeds a predetermined standard value. The reducing agent may include, but is not limited to, ammonia, ammonia water, and urea water.

[0059] In addition, the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor (130) can be utilized not only to control the supply of reducing agent to the catalyst layer (35), but also to control the selective catalytic reduction device that can be placed at the rear end of the engine system (100).

[0060]

[0061] <Example 3>

[0062] FIG. 3 is a drawing showing an exhaust gas aftertreatment system according to a third embodiment of the present invention.

[0063] Referring to FIG. 3, an exhaust gas aftertreatment system (200) according to a third embodiment of the present invention may include a selective catalytic reduction device (210) that is disposed at the rear end of an engine (20) that uses ammonia fuel and removes nitrogen oxides in exhaust gas generated from the engine (20) by a selective catalytic reduction reaction; a sensor (220, 230) that measures the concentration of at least one of ammonia and nitrogen oxides contained in the exhaust gas; and a control unit (240) that adjusts the type and amount of a reducing agent supplied to the selective catalytic reduction device (210) according to the concentrations of nitrogen oxides and ammonia measured by the sensors (220, 230).

[0064] Previously, the reducing agent required for the selective catalytic reduction reaction was separately injected into the selective catalytic reduction device (210) through equipment such as a nozzle. However, since exhaust gas emitted from an engine (20) using ammonia as fuel may contain unburned ammonia, efficiency can be increased by controlling the type and amount of the reducing agent injected separately. Hereinafter, the control of the reducing agent supply will be described in detail.

[0065] The front sensor (220) is arranged between the engine (20) and the selective catalytic reduction device (210) and can measure the concentration of ammonia and nitrogen oxides contained in the exhaust gas emitted from the engine (20). The control unit (240) can control to increase the supply amount of reducing agent when the amount of ammonia measured by the front sensor (220) is less than the amount of ammonia required to maximally remove nitrogen oxides. In addition, when the amount of ammonia measured by the front sensor (220) is sufficient to maximally remove nitrogen oxides, the control unit (240) can control to decrease the supply amount of reducing agent.

[0066] The rear sensor (230) is positioned at the rear end of the selective catalytic reduction device (210) and can measure the concentration of nitrogen oxides contained in the exhaust gas that has passed through the selective catalytic reduction device (210). The control unit (240) can control to increase the supply amount of reducing agent when it is determined that the catalytic reaction has not been maximally performed within the selective catalytic reduction device (210) based on the concentration of ammonia and the concentration of nitrogen oxides measured by the rear sensor (230). In addition, when the concentration of ammonia measured by the rear sensor (230) is higher than a predetermined value, the control unit (240) can control to reduce the supply amount of reducing agent.

[0067] By utilizing both the concentrations of ammonia and nitrogen oxides measured by the front sensor (220) and the rear sensor (230), the difference in the concentrations of ammonia and nitrogen oxides between the front and rear ends of the selective catalytic reduction device (210) can be known, and information on how much reaction has occurred in the selective catalytic reduction device (210) can be obtained. The control unit (240) can control to increase the supply amount of reducing agent if it is determined that the reaction has not occurred sufficiently in the selective catalytic reduction device (210). In addition, if it is determined that the reaction has occurred sufficiently in the selective catalytic reduction device (210), it can control to decrease the supply amount of reducing agent.

[0068] The types of reducing agents mentioned above may include ammonia, ammonia water, and urea water. Since the components and concentrations contained in each type of reducing agent vary, the amount of reducing agent injected to remove nitrogen oxides may vary. Accordingly, the control unit (240) can control the supply amount of reducing agent differently depending on the type of reducing agent, even when removing the same amount of nitrogen oxides. Furthermore, the type of reducing agent may be changed depending on the amount of unburned ammonia.

[0069]

[0070] <Example 4>

[0071] FIG. 4 is a drawing showing an exhaust gas aftertreatment system according to a fourth embodiment of the present invention.

[0072] A plurality of selective catalytic reduction devices (210) are respectively arranged at the rear ends of a plurality of engines (20) that use different fuels and remove nitrogen oxides in exhaust gas generated from the engines (20) by a selective catalytic reduction reaction; and a control unit (250) that adjusts the type and amount of reducing agent supplied to the plurality of selective catalytic reduction devices (210) that are respectively arranged at the rear ends of the plurality of engines (20) according to the type of fuel of the plurality of engines (20).

[0073] Depending on the type of fuel injected into the engine (20), the type and ratio of substances contained in the exhaust gas generated from each engine (20) may vary. Specifically, even with the same engine load or the same amount of fuel, if the type of fuel is different, the amount of nitrogen oxides contained in the exhaust gas, whether ammonia is contained, etc. may vary. Accordingly, the control unit (250) may control the amount and type of reducing agent supplied to the selective catalytic reduction device (210) arranged at the rear end of each engine (20) to vary depending on the type of fuel supplied to the engine (20).

[0074] The control unit (250) calculates the amount of nitrogen oxides or ammonia emitted according to the type of fuel supplied, the amount of fuel, the load of the engine (20), etc., and the amount of reducing agent required to reduce nitrogen oxides accordingly, and can automatically control the type and amount of reducing agent supplied to the selective catalytic reduction device (210) according to the fuel supply status of each engine (20).

[0075]

[0076] Additionally, the vessel may include an engine system (100) and an exhaust gas aftertreatment system (10, 200) according to one embodiment of the present invention.

[0077]

[0078] The above description is merely an illustrative illustration of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. Engines using ammonia fuel; A gas receiver positioned at the rear end of the engine and receiving exhaust gas generated from the engine; and A connection part is included to connect the engine and the gas receiver, and exhaust gas generated from the engine is discharged to the gas receiver. In the above connecting portion, a catalyst layer is provided in the portion through which the exhaust gas passes. The above catalyst layer is a selective catalytic reduction layer in which ammonia in the exhaust gas acts as a reducing agent to cause a selective catalytic reduction (SCR) reaction to remove nitrogen oxides, or An engine system having a composite ammonia purification layer in which, under conditions in which the exhaust gas contains ammonia and nitrogen oxides, the ammonia in the exhaust gas acts as a reducing agent to cause a selective catalytic reduction (SCR) reaction to remove nitrogen oxides, and, under conditions in which the exhaust gas does not contain nitrogen oxides, the ammonia in the exhaust gas is oxidized and removed.

2. In claim 1, A nitrogen oxide concentration sensor for measuring the nitrogen oxide concentration of the exhaust gas received in the gas receiver; and An engine system further comprising a control unit that controls supply of a reducing agent for a selective catalytic reduction reaction to the catalyst layer when the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor exceeds a predetermined reference value.

3. In claim 2, The above control unit is an engine system that controls to additionally supply ammonia to the engine through the fuel supply unit of the engine during an exhaust process in which fuel combustion does not occur during the operation of the engine when the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor exceeds a predetermined reference value.

4. In claim 2, It further includes a reducing agent supply unit for supplying a reducing agent for a selective catalytic reduction reaction to the above catalyst layer, The above control unit is an engine system that controls to supply a reducing agent for a selective catalytic reduction reaction to the catalyst layer through the reducing agent supply unit when the nitrogen oxide concentration measured by the nitrogen oxide concentration sensor exceeds a predetermined reference value.

5. Engines using ammonia fuel; and An engine system including a control unit that controls to additionally supply ammonia to the engine through a fuel supply unit of the engine during an exhaust process in which fuel combustion does not occur during the operation of the engine.

6. A vessel comprising an engine system according to any one of claims 1 to 5.

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