Ammonia gas treatment device and treatment method

Abstract

The present invention aims to provide an ammonia gas treatment device and treatment method that can effectively treat ammonia gas volatile from cargo or remaining in the engine's fuel supply line by dissolving ammonia water in fresh water within the vessel without discharging it overboard, and eliminates the need for an additional ammonia water supply tank. This objective is achieved by converting ammonia gas remaining in the engine's (3) fuel supply line into ammonia water in a decontamination device (6), and by introducing the exhaust gas of the engine (3), urea water from the urea tank (8), and ammonia water generated in the decontamination device (6) into a selective reduction catalyst unit (17), thereby performing denitrification of the exhaust gas and detoxification of the ammonia water.

Description

Technology Field

[0001] The present invention relates to an ammonia gas treatment device and treatment method for a ship carrying liquefied ammonia as cargo or engine fuel, and specifically, to ammonia gas that volatilizes from the cargo or remains in the engine's fuel supply line, and is treated with fresh water ( The present invention relates to an ammonia gas treatment device and treatment method that can effectively treat ammonia water dissolved in ) on board without discharging it overboard, and eliminates the need for an additional ammonia water supply tank. Background Technology

[0002] As described in Patent Document 1, NO contained in the exhaust gas emitted from an engine x A urea SCR (Selective Catalytic Reduction) system is known as an exhaust gas purification device for purifying (nitrogen oxides).

[0003] The urea SCR system uses ammonia gas, generated by the hydrolysis of urea solution injected into the exhaust gas by the heat of the exhaust gas, as a reducing agent, and in the presence of an SCR catalyst, NO x It is to chemically react with ammonia gas to reduce it to nitrogen and water.

[0004] Ship's NO x Due to stricter emission regulations, urea SCR systems are being introduced on ships.

[0005] Meanwhile, due to recent global warming concerns, the use of liquefied ammonia as fuel for ship propulsion engines is anticipated. When using liquefied ammonia as fuel, the fuel supply system must be emptied to purge the fuel supply line or to ensure the fuel converges within the combustion range in the event of an abnormality. Furthermore, in tanks storing liquefied ammonia, ammonia gas known as boil-off gas is generated due to factors such as natural heat input, as the volatile nature of the ammonia causes it to be left unchecked. If left unchecked while this ammonia gas is present, the pressure inside the tank rises and exceeds the design pressure.

[0006] Furthermore, since ammonia gas is flammable and toxic, storing it as is poses a risk of affecting the human body. Therefore, it is necessary to remove the toxicity of ammonia gas using a decontamination device. As such, a device that dissolves ammonia gas in clean water to produce ammonia water is used.

[0007] In addition, since ammonia water cannot be discharged overboard under current environmental regulations, the ammonia water recovered on board must be treated on board.

[0008] In addition, since ships must install various devices and equipment in a limited space, a method that can be handled in a small space is desirable.

[0009] In Patent Document 2, denitrification treatment is performed by supplying liquefied ammonia, which is the fuel for a selective reduction catalyst device.

[0010] In Patent Document 3, residual ammonia in the fuel supply system is recovered, and as an onboard treatment of the recovered ammonia water, the recovered ammonia water is supplied to a selective catalytic reduction (SCR) device at a predetermined high concentration (e.g., tens of percent). The ammonia component is consumed in the denitrification treatment of engine exhaust gas. Prior art literature

[0011] Japanese Patent Publication No. JP 2020-045769, Japanese Patent Publication No. JP 2022-528443, Japanese Patent Publication No. JP 2022-179983 The problem to be solved

[0012] Meanwhile, since Patent Document 2 does not recover residual ammonia in the fuel supply system, no problem regarding residual ammonia recovery is presented.

[0013] In Patent Document 3, which recovers residual ammonia within a fuel supply system, denitrification treatment of engine exhaust gas is performed using the recovered ammonia water. However, since there is a concern that the concentration of the recovered ammonia water may be insufficient for denitrification treatment, an additional ammonia water supply tank is installed, and thus that much space is required.

[0014] The objective of the present invention is to provide an ammonia gas treatment device and treatment method that can effectively treat ammonia gas volatilizing from cargo or remaining in the engine's fuel supply line on board without discharging ammonia water dissolved in fresh water overboard, thereby eliminating the need for an additional ammonia water supply tank.

[0015] In addition, other problems of the present invention are clarified by the following description. means of solving the problem

[0016] The above problem is solved by each of the following inventions.

[0017] 1.

[0018] As an ammonia gas treatment device for a ship equipped with a selective reduction catalyst unit and carrying liquefied ammonia as fuel for cargo or the ship's engine,

[0019] Exhaust gas from the engine of the ship is introduced into the above-mentioned selective reduction catalyst unit, and urea solution, which is a reducing agent, can be supplied, and a selective reduction catalyst that performs denitrification treatment of the exhaust gas is arranged therein.

[0020] The vessel is equipped with a decontamination device that dissolves liquefied ammonia remaining in the fuel supply line of the vessel’s engine into vaporized ammonia gas and / or ammonia gas, or ammonia gas volatilized from the cargo, into fresh water to produce ammonia water.

[0021] An ammonia gas treatment device characterized by supplying ammonia water generated in the above-mentioned decontamination device to the above-mentioned selective reduction catalyst unit to perform harmlessness treatment of the ammonia water.

[0022] 2.

[0023] The supply path of the ammonia water to the selective reduction catalyst unit reaches the selective reduction catalyst unit independently of the supply path of the urea water to the selective reduction catalyst unit, and

[0024] The above-mentioned selective reduction catalyst unit can simultaneously supply the urea solution and the ammonia solution through a nozzle, and

[0025] The ammonia gas treatment apparatus described in 1 is characterized in that the nozzle is a three-fluid nozzle having a flow path connected to an air supply source to supply air for diffusing the urea solution and / or the ammonia solution, a flow path connected to the urea solution supply path to spray the urea solution, and a flow path connected to the ammonia solution supply path to spray the ammonia solution, and is disposed on the upstream side within the selective reduction catalyst unit.

[0026] 3.

[0027] The supply path of the ammonia water to the selective reduction catalyst unit reaches the selective reduction catalyst unit independently of the supply path of the urea water to the selective reduction catalyst unit, and

[0028] The above-mentioned selective reduction catalyst unit can simultaneously supply the urea solution and the ammonia solution through a nozzle, and

[0029] The above nozzle consists of a first nozzle and a second nozzle, and

[0030] The first nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source to supply air and a flow path connected to the urea supply path to spray the urea solution, and is disposed on the upstream side within the selective reduction catalyst unit.

[0031] The ammonia gas treatment device described in 1, characterized in that the second nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source for supplying air and a flow path connected to the ammonia water supply line for spraying the ammonia water, and is disposed upstream of the selective reduction catalyst unit.

[0032] 4.

[0033] The supply path of the ammonia water to the selective reduction catalyst unit reaches the selective reduction catalyst unit independently of the supply path of the urea water to the selective reduction catalyst unit, and

[0034] The above-mentioned selective reduction catalyst unit can simultaneously supply the urea solution and the ammonia solution through a nozzle, and

[0035] The above nozzle is composed of a first nozzle and a second nozzle, and

[0036] The first nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source to supply air and a flow path connected to the urea supply path to spray the urea solution, and is disposed on the upstream side within the selective reduction catalyst unit.

[0037] The ammonia gas treatment device described in 1, wherein the second nozzle is a two-fluid nozzle having two fluid passages, a passage connected to an air supply source to supply air and a passage connected to an ammonia water supply line to spray the ammonia water, and is disposed in an exhaust receiver through which exhaust gas passes in front of a selective reduction catalyst unit, and supplies the air and the ammonia water into the selective reduction catalyst unit through the exhaust receiver.

[0038] 5.

[0039] The supply path of the ammonia water to the selective reduction catalyst unit joins the supply path of the urea water to the selective reduction catalyst unit before reaching the selective reduction catalyst unit, and

[0040] In the above-mentioned selective reduction catalyst unit, either the urea solution or the ammonia solution is supplied through a nozzle, and

[0041] The ammonia gas treatment device described in 1 is characterized in that the nozzle is a two-fluid nozzle having two flow paths, a flow path connected to an air supply source to supply air, and a flow path where the urea solution supply path and the ammonia solution supply path are joined and connected to spray the urea solution or the ammonia solution, and is positioned on the upstream side within the selective reduction catalyst unit.

[0042] 6.

[0043] The above instrument is equipped to measure the density of the ammonia solution, and

[0044] The above urea solution and the above ammonia solution are supplied simultaneously to the above selective reduction catalyst unit, and

[0045] The density of the ammonia water measured by an instrument for measuring the density of the ammonia water is converted into a concentration of the ammonia water, and the molar equivalent of the ammonia water supplied to the selective reduction catalyst unit is calculated from this concentration.

[0046] Calculate the molar equivalent of the urea solution supplied to the selective reduction catalyst unit from the known concentration of the above urea solution, and

[0047] An ammonia gas treatment apparatus described in any one of 1 to 4, characterized by summing the molar equivalents of ammonia water and urea water supplied to the selective reduction catalyst unit, and adjusting the flow rates of the urea water and ammonia water according to the summed molar equivalents to perform denitrification treatment of the exhaust gas as the detoxification treatment.

[0048] 7.

[0049] Liquid ammonia supplied from the fuel supply device of the vessel is joined to the supply path of the ammonia water to the selective reduction catalyst unit, and the ammonia water and the liquid ammonia are mixed to become ammonia water, which is supplied to the selective reduction catalyst unit.

[0050] The apparatus is equipped with a device for measuring the density of the ammonia solution mixed with the above ammonia solution and the above liquid ammonia, and

[0051] An ammonia gas treatment apparatus described in any one of 1 to 5, characterized by calculating the molar equivalent of ammonia water supplied to the selective reduction catalyst unit from the density of the ammonia water measured by an instrument for measuring the density of the ammonia water, and adjusting the flow rate of the ammonia water according to the calculated molar equivalent to perform denitrification treatment of the exhaust gas as the detoxification treatment.

[0052] 8.

[0053] The apparatus is equipped with a device for measuring the concentration of leaked ammonia in the exhaust gas, and

[0054] Measure the exhaust gas flow rate of the above-mentioned engine, and calculate the amount of leaked ammonia from the measured exhaust gas flow rate and the leaked ammonia concentration, or from the exhaust gas flow rate and the leaked ammonia concentration calculated by load information from the output of the above-mentioned engine, and

[0055] An ammonia gas treatment apparatus described in any one of 1 to 5, characterized by controlling the flow rate of the urea solution or the ammonia solution so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit by the urea solution and / or the ammonia solution and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit, thereby performing denitrification treatment of the exhaust gas as the detoxification treatment.

[0056] 9.

[0057] An ammonia slip catalyst is disposed within the above-mentioned selective reduction catalyst unit, and

[0058] An ammonia gas treatment apparatus described in any one of 1 to 5, characterized by performing a harmless treatment of ammonia water supplied to the selective reduction catalyst unit by the ammonia slip catalyst.

[0059] 10.

[0060] A method for treating ammonia gas in a vessel equipped with a selective reduction catalyst unit and carrying liquefied ammonia as fuel for cargo or the vessel's engine,

[0061] Exhaust gas from the engine of the vessel is introduced into the above-mentioned selective reduction catalyst unit, and urea solution as a reducing agent can be supplied, and a selective reduction catalyst that performs denitrification treatment of the exhaust gas is installed.

[0062] Liquid ammonia remaining in the fuel supply line of the engine of the vessel is vaporized ammonia gas and / or ammonia gas, or ammonia gas volatilized from the cargo, by a decontamination device and dissolved in fresh water to produce ammonia water, and

[0063] A method for treating ammonia gas characterized by supplying ammonia water generated by the above-mentioned decontamination device to the above-mentioned selective reduction catalyst unit to perform harmlessness treatment of the ammonia water.

[0064] 11.

[0065] The above urea solution and the above ammonia solution are supplied simultaneously to the above selective reduction catalyst unit, and

[0066] The density of the ammonia water is measured, the measured density of the ammonia water is converted into a concentration of the ammonia water, and the molar equivalent of the ammonia water to be supplied to the selective reduction catalyst unit is calculated from this concentration.

[0067] Calculate the molar equivalent of the urea solution supplied to the selective reduction catalyst unit from the concentration of the above-mentioned urea solution of the base, and

[0068] A method for treating ammonia gas described in 10, characterized by summing the molar equivalents of ammonia water and urea water supplied to the selective reduction catalyst unit, adjusting the flow rates of the urea water and ammonia water according to the summed molar equivalents, and performing denitrification treatment of the exhaust gas as the detoxification treatment.

[0069] 12.

[0070] Liquid ammonia supplied from the fuel supply device of the vessel is added to the supply path of the ammonia water to the selective reduction catalyst unit, and the ammonia water and the liquid ammonia are mixed to form ammonia water and supplied to the selective reduction catalyst unit.

[0071] The density of the ammonia solution mixed with the above ammonia solution and the above liquid ammonia is measured, and

[0072] A method for treating ammonia gas described in 10, characterized by calculating the molar equivalent of ammonia water to be supplied to the selective reduction catalyst unit from the density of the measured ammonia water, adjusting the flow rate of the ammonia water according to the calculated molar equivalent, and performing denitrification treatment of the exhaust gas as the detoxification treatment.

[0073] 13.

[0074] An instrument for measuring the concentration of leaked ammonia in the exhaust gas is installed, and

[0075] Measure the exhaust gas flow rate of the above-mentioned engine, and calculate the amount of leaked ammonia from the measured exhaust gas flow rate and the leaked ammonia concentration, or from the exhaust gas flow rate and the leaked ammonia concentration calculated by load information from the output of the above-mentioned engine, and

[0076] A method for treating ammonia gas described in 10, characterized by controlling the flow rate of the urea solution or the ammonia solution so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit by the urea solution and / or the ammonia solution and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit, thereby performing denitrification treatment of the exhaust gas as the detoxification treatment.

[0077] 14.

[0078] An ammonia slip catalyst is installed within the above-mentioned selective reduction catalyst unit, and

[0079] Ammonia gas treatment method described in 10, characterized by performing a harmless treatment of ammonia water supplied to the selective reduction catalyst unit by the ammonia slip catalyst. Effects of the invention

[0080] According to the present invention, ammonia gas volatilized from cargo or remaining in the engine's fuel supply line can be effectively treated on board without discharging ammonia water dissolved in fresh water overboard, and an ammonia gas treatment device and treatment method can be provided that eliminate the need for an additional ammonia water supply tank. Brief explanation of the drawing

[0081] FIG. 1 is a block diagram showing the configuration of a fuel supply device of a ship to which the ammonia gas treatment device of the present invention is applied. FIG. 2 is a block diagram showing the configuration of an ammonia gas treatment device of a first embodiment of the present invention. FIG. 3 is a block diagram showing the configuration of an ammonia gas treatment device of a second embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing the first structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the present invention. FIG. 5 is a block diagram showing the configuration of an ammonia gas treatment device of a third embodiment of the present invention. FIG. 6 is a block diagram showing the configuration of an ammonia gas treatment device of the fourth embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing the second structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the present invention. FIG. 8 is a schematic cross-sectional view showing the third structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the present invention. FIG. 9 is a schematic cross-sectional view showing the fourth structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the present invention. FIG. 10 is a schematic cross-sectional view showing the fifth structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the present invention. Specific details for implementing the invention

[0082] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The various features presented in each of the embodiments shown below can be combined with one another.

[0083] The present invention relates to an ammonia gas treatment device for a ship carrying liquefied ammonia as fuel for cargo or the ship's engine, and an ammonia gas treatment method performed in such an ammonia gas treatment device.

[0084] [Composition of the Ship's Fuel Supply System]

[0085] FIG. 1 is a block diagram showing the configuration of a fuel supply device for a ship to which the ammonia gas treatment device of the present invention is applied. In FIG. 1, the liquid flow path is indicated by a solid line, and the gas flow path is indicated by a dotted line.

[0086] As shown in FIG. 1, the fuel supply unit of the ship is equipped with a selective catalytic reduction (SCR) unit (17). A selective catalytic reduction (SCR) is installed inside the selective catalytic reduction unit (17), and denitrification treatment is performed by reacting NOx and ammonia gas in the engine exhaust gas by the selective catalytic reduction (SCR).

[0087] The selective reduction catalyst unit (17) is connected to the exhaust duct of the engine (3), which is the engine of the ship, and the engine exhaust gas is introduced. Additionally, urea solution, which is a reducing agent stored in the urea solution tank (8), is supplied to the selective reduction catalyst unit (17).

[0088] Meanwhile, in the exhaust duct of the engine (3), although not shown in the drawing, a device (ammonia gas concentration meter) for measuring the concentration of leaked ammonia in the engine exhaust gas may be installed, and a device (gas flow meter) for measuring the gas flow rate of the engine exhaust gas may also be installed.

[0089] The urea solution stored in the urea solution tank (8) is supplied to the selective reduction catalyst unit (17) by the urea solution pump (15a) via the urea solution transport pipe (15), which serves as the urea solution supply path. The urea solution is hydrolyzed within the high-temperature selective reduction catalyst unit (17) to generate ammonia gas. The engine exhaust gas is denitrified by this ammonia gas. The denitrified exhaust gas is discharged into the atmosphere.

[0090] Meanwhile, in this fuel supply device, liquefied ammonia fuel is supplied from the liquefied ammonia tank (1) to the engine (3) via the fuel supply line (fuel supply device (2) and fuel piping (4)). The engine (3) is driven by burning the liquefied ammonia fuel.

[0091] And, in this fuel supply device, the liquefied ammonia introduced from the fuel supply line, the vaporized ammonia gas and / or ammonia gas (residual gas), the liquefied ammonia remaining in the fuel supply device (2), the vaporized ammonia gas and / or ammonia gas, or the ammonia gas introduced from a cargo ammonia tank not shown in the drawing (boil-off gas) are decontaminated by the decontamination device (6).

[0092] The fuel supply line consists of a fuel supply device (2) and a fuel pipe (4), and is a path through which liquefied ammonia fuel is supplied to the engine (3) via the fuel pipe (4) by means of a compressor, pump, heat exchanger, etc., of the fuel supply device (2). Meanwhile, the fuel supply device (2) may not be installed if it is not required. Additionally, the fuel pipe (4) may be composed of a supply pipe that supplies ammonia gas from the fuel supply device (2) to the engine (3), and a return pipe that returns excess ammonia gas from the engine (3) to the fuel supply device (2). Although not shown in the drawing, an opening and closing valve capable of closing the section between the liquefied ammonia tank (1) side of the fuel supply device (2) and the engine (3) side of the fuel pipe (4) may be installed on the liquefied ammonia tank (1) side of the fuel supply device (2) and the engine (3) side of the fuel pipe (4).

[0093] A liquid ammonia tank (1) stores ammonia, which is used as fuel for engines (3), etc. Inside the liquid ammonia tank (1), the ammonia is stored in a liquid ammonia state. To maintain the liquid state of the liquid ammonia, the liquid ammonia tank (1) maintains the interior at high pressure or low temperature. When a large amount of liquid ammonia is loaded onto a ship for long voyages, etc., a full-pressure type (atmospheric pressure type) or semi-pressure type (semi-pressurized type), which is thin and easy to process, is mainly used as the liquid ammonia tank (1). Inside the liquid ammonia tank (1), there is a suction pump (1a), and through this suction pump (1a), the liquid ammonia stored is sent to the piping for the fuel supply device (2).

[0094] An unincorporated cargo ammonia tank stores liquid ammonia as cargo rather than as fuel used in engines (3), etc. Similar to the liquid ammonia tank (1), the cargo ammonia tank is maintained at high pressure or low temperature inside to maintain the liquid state of the liquid ammonia inside the cargo ammonia tank. When loading a large amount of liquid ammonia onto a ship, a full-pressure type (atmospheric pressure type) or semi-pressure type (semi-pressurized type) is mainly used as the cargo ammonia tank, as it is thin and easy to process.

[0095] Liquid ammonia fuel is supplied to the engine (3) from the liquid ammonia tank (1) via the fuel supply device (2). Additionally, pilot fuel may be supplied to the engine (3) from a heavy oil tank not shown. The pilot fuel is burned together with the ammonia fuel at the start of combustion to raise the temperature inside the combustion chamber, thereby allowing the ammonia fuel to burn smoothly. The supply of pilot fuel may be stopped when the temperature inside the combustion chamber rises to a state where combustion is possible with only the ammonia fuel. Furthermore, if the engine (3) is capable of combustion with only the ammonia fuel from the start, the pilot fuel is unnecessary.

[0096] In addition, the engine (3) can also be a dual-fuel engine using liquid ammonia fuel and fossil fuels such as heavy oil. In a dual-fuel engine, the engine can selectively switch between a mode in which liquid ammonia fuel is used as the main fuel and fossil fuels such as heavy oil are supplied as an ignition source, and a fossil fuel mode in which only fossil fuels are used.

[0097] Nitrogen gas is supplied to the fuel pipe (4) from the nitrogen gas supply device (51) via the purge gas supply valve (50). This nitrogen gas is also supplied to the fuel supply device (2) via the fuel pipe (4). This nitrogen gas is an inert gas that purges the vaporized ammonia gas and / or ammonia gas from the liquefied ammonia remaining inside the fuel pipe (4) and the fuel supply device (2) during the starting, stopping, and emergency stopping of the engine (3).

[0098] In the fuel piping (4), when the engine (3) starts, stops, or stops in an emergency, the remaining liquid ammonia vaporized ammonia gas and / or ammonia gas flows into the decontamination device (6) via the gas-liquid separator (4a) and the purge gas discharge valve (5). Additionally, in the fuel supply device (2), when the engine (3) starts, stops, stops in an emergency, or stops in an emergency, or during maintenance, the remaining liquid ammonia vaporized ammonia gas and / or ammonia gas is introduced into the decontamination device (6) via the opening / closing valve (2a). Meanwhile, inside the fuel supply device (2), a gas-liquid separator is installed at the outlet of the remaining liquid ammonia vaporized ammonia gas and / or ammonia gas, along with a pump, etc.

[0099] Additionally, the gas introduced from the fuel pipe (4) and the fuel supply device (2) to the decontamination device (6) is a gas mixed with ammonia gas and purge gas, such as nitrogen. In this embodiment, treatment is performed on the ammonia component in the mixed gas.

[0100] When ammonia gas is introduced into the decontamination device (6), the section between the liquefied ammonia tank (1) side of the fuel supply device (2) and the engine (3) side of the fuel piping (4) is closed by an opening / closing valve. Additionally, ammonia gas (boil-off gas) is introduced into the decontamination device (6) from the cargo ammonia tank. Meanwhile, the nitrogen gas for purging is discharged into the atmosphere through the decontamination device (6).

[0101] In the decontamination device (6), fresh water generated, for example by a desalination unit on board and stored in a fresh water tank (22) is introduced by a water supply pump (22a). Here, fresh water is, for example, distilled water, ion-exchanged water, filtered water, etc., which does not contain impurities and additives as much as possible.

[0102] The pollution removal device (6) is configured to include a water seal tank and a scrubber tank. A mixture of ammonia gas and nitrogen introduced into the pollution removal device (6) flows into the water seal tank and the scrubber tank.

[0103] In the water seal tank or scrubber tank, a mixture of introduced ammonia gas and nitrogen is passed through clean water, or clean water is sprayed from the top to dissolve the ammonia component in the clean water, thereby producing ammonia water. The nitrogen gas for purging is released into the atmosphere from the decontamination device (6).

[0104] It is preferable to use a water seal tank or a scrubber tank as the pollution removal device (6).

[0105] When using a water-sealed tank, ammonia gas is introduced from the bottom of the tank and absorbed by the clean water stored in it, becoming ammonia water.

[0106] In addition, when a scrubber is used, ammonia gas flows in from the bottom of the scrubber and comes into contact with the clean water sprayed from the top, thereby being absorbed into the clean water and becoming ammonia water.

[0107] More preferably, a water seal tank and a scrubber tank are installed together to introduce the ammonia gas that has evaporated from the ammonia water generated in the water seal tank and the ammonia gas that was not absorbed in the water seal tank into the lower part of the scrubber tank. In the scrubber tank, it is desirable to further absorb the ammonia gas that has evaporated from the ammonia water and the unabsorbed ammonia gas by circulating the ammonia water accumulated inside the scrubber tank by spraying it from the upper part of the scrubber tank. By installing the water seal tank and the scrubber tank together, ammonia gas can be reliably absorbed, and the overboard release of ammonia gas can be reliably prevented.

[0108] In addition, even when only a water seal tank is used as a pollution removal device (6), a circulation mechanism is provided to introduce the ammonia gas volatilized from the ammonia water and the ammonia gas that was not absorbed by the clean water back into the bottom of the water seal tank, thereby ensuring that the ammonia gas is reliably absorbed and that the out-of-ship discharge of ammonia gas is reliably prevented.

[0109] In addition, even when only a scrubber tank is used as a pollution removal device (6), a circulation mechanism is provided to spray the ammonia water accumulated in the scrubber tank from the top of the scrubber tank again to further absorb the ammonia gas volatilized from the ammonia water and the ammonia gas that was not absorbed by the clean water, thereby ensuring that the ammonia gas is reliably absorbed and that the out-of-ship discharge of ammonia gas is reliably prevented.

[0110] The wastewater (ammonia water) from the decontamination device (6) is sent to the ammonia water tank (7) by gravity and is primarily stored in the ammonia water tank (7). Meanwhile, the ammonia water tank (7) is a sealed pressurized tank, and it is desirable to prevent ammonia gas from volatilizing from the contained ammonia water. If the ammonia water tank (7) is not a sealed pressurized tank, it is desirable to return the ammonia gas volatilizing from the contained ammonia water to the decontamination device (6) (water seal tank and / or scrubber tank).

[0111] The ammonia water stored in the ammonia water tank (7) is rendered harmless by performing denitrification treatment in the selective reduction catalyst unit (17). The ammonia water stored in the ammonia water tank (7) can be supplied to the selective reduction catalyst unit (17) by the ammonia water pump (18a) via the ammonia water transport pipe (18), which serves as the ammonia water supply path. The ammonia water generates ammonia gas within the high-temperature selective reduction catalyst unit (17), and this ammonia gas [removes NO] from the engine exhaust gas x It is neutralized by reacting with. Or, ammonia gas generated within the selective reduction catalyst unit (17) is neutralized by an ammonia slip catalyst (ASC) installed within the selective reduction catalyst unit (17).

[0112] In addition, denitrification treatment in the selective reduction catalyst unit (17) is performed in either the operating mode using liquefied ammonia fuel as the main fuel or the fossil fuel mode.

[0113] The ammonia water supply path from the ammonia water tank (7) to the selective reduction catalyst unit (17) and the urea water supply path from the urea water tank (8) to the selective reduction catalyst unit (17) will be described in each embodiment described below.

[0114] In addition, the structure of the selective reduction catalyst unit (17) and the structure of the nozzle that supplies urea solution and ammonia solution to the selective reduction catalyst unit (17) will also be described later.

[0115] [First embodiment]

[0116] FIG. 2 is a block diagram showing the configuration of an ammonia gas treatment device according to a first embodiment of the present invention. An ammonia gas treatment method according to a first embodiment of the present invention is carried out in such an ammonia gas treatment device.

[0117] In the ammonia gas treatment device of the present embodiment, the liquid level of the urea stored in the urea tank (8) is measured by the LIT (8a) (hereinafter referred to as the "liquid level gauge (8a)"), and the urea is discharged from the urea tank (8) to the urea transport pipe (15) by the urea pump (15a).

[0118] The urea solution discharged from the urea solution tank (8) can be supplied to the selective reduction catalyst unit (17) via the first shut-off valve (16), the urea solution flow control valve (19), and the FT (20) (hereinafter referred to as the "urea solution flow meter (20)") installed in the urea solution transport pipe (15). The urea solution flow control valve (19) is operated according to the measurement result of the urea solution flow meter (20).

[0119] The urea transport pipe (15) is branched between the urea pump (15a) and the urea flow control valve (19), and the branch pipe returns to the urea tank (8) through the urea circulation valve (21). The urea circulation valve (21) is a back pressure valve (regulator). The urea circulation valve (21) opens when the pressure inside the urea transport pipe (15) exceeds a predetermined pressure, thereby limiting the pressure inside the urea transport pipe (15) to a predetermined pressure or lower. Meanwhile, the urea circulation valve (21) may also be used as a pressure reducing valve.

[0120] The urea water transport pipe (15) joins the ammonia water transport pipe (18), which serves as an ammonia water supply line, before reaching the selective reduction catalyst unit (17). The piping after the urea water transport pipe (15) and the ammonia water transport pipe (18) join becomes the urea water or ammonia water transport pipe (28).

[0121] The ammonia water stored in the ammonia water tank (7) has its liquid level measured by the LIT (7a) (hereinafter referred to as the "liquid level gauge (7a)"), and is discharged from the ammonia water tank (7) to the ammonia water transport pipe (18) by the ammonia water pump (18a).

[0122] Ammonia water discharged from the ammonia water tank (7) is supplied to the selective reduction catalyst unit (17) via the second shut-off valve (9) installed in the ammonia water transport pipe (18), the FD (10) (hereinafter referred to as the "flow rate / density meter (10)"), the FT (11) (hereinafter referred to as the "ammonia water flow rate meter (11)"), and the third shut-off valve (12), which are instruments for measuring the density of the ammonia water. The flow rate / density meter (10) is a Coriolis flow meter and can measure the flow rate and density of the ammonia water.

[0123] The ammonia water transport pipe (18) is branched between the flow rate / density meter (10) and the ammonia water flow meter (11), and the branch pipe returns to the ammonia water tank (7) through the ammonia water circulation valve (14). The ammonia water circulation valve (14) is a back pressure valve (regulator). The ammonia water circulation valve (14) opens when the pressure inside the ammonia water transport pipe (18) exceeds a predetermined pressure, thereby limiting the pressure inside the ammonia water transport pipe (18) to a predetermined pressure or lower. Meanwhile, the ammonia water circulation valve (14) may also be used as a pressure reducing valve.

[0124] The ammonia water transport pipe (18) joins the urea water transport pipe (15) before reaching the selective reduction catalyst unit (17). The piping after the urea water transport pipe (15) and the ammonia water transport pipe (18) join becomes the urea water or ammonia water transport pipe (28).

[0125] Air is supplied to the urea or ammonia water transport pipe (28) along with the urea or ammonia water from the air supply source (25) into the selective reduction catalyst unit (17). The pressure inside the urea or ammonia water transport pipe (28) is measured by a PT (24) (hereinafter referred to as "pressure gauge (24)"). The temperature inside the selective reduction catalyst unit (17) is measured by a TT (26) (hereinafter referred to as "thermometer (26)").

[0126] Additionally, the ammonia water circulation valve (14) and the urea water circulation valve (21) may be used as flow control valves that operate according to the measurement results of the pressure gauge (24). Furthermore, the flow control of the urea water and ammonia water may be performed by adjusting the rotational speed of the pump using an inverter according to the load of the engine (3).

[0127] Air and urea solution, or air and ammonia solution, are supplied into the selective reduction catalyst unit (17) through the nozzle (13). The structure of the selective reduction catalyst unit (17) and the shape of the nozzle (13) will be described later.

[0128] Additionally, the decontamination device (6), the ammonia water tank (7), and the urea water tank (8) are installed outside the engine room of the ship, and the selective reduction catalyst unit (17) is installed inside the engine room of the ship.

[0129] In this embodiment, urea solution is supplied to the selective reduction catalyst unit (17) to perform denitrification treatment in the Tier 3 regulation area of ​​exhaust gas regulations for marine diesel engines, and ammonia water is supplied to the selective reduction catalyst unit (17) to perform ammonia water detoxification treatment in the Tier 2 regulation area. In the ammonia water detoxification treatment, nitrogen oxides (NO) in the engine exhaust gas x The entire amount of ) does not need to be denitrified.

[0130] When supplying ammonia water to the selective reduction catalyst unit (17), the concentration of ammonia water is calculated from the density of the ammonia water measured by the flow rate / density meter (10), and the output of the ammonia water pump (18a) is adjusted according to this concentration. Through this, the concentration of the ammonia water supplied to the selective reduction catalyst unit (17) can be managed, and the entire amount of ammonia water supplied from the selective reduction catalyst unit (17) can be treated to be harmless.

[0131] The supply of urea solution and / or ammonia solution in such ammonia gas treatment devices is carried out, for example, as follows.

[0132] (1) Supply in Tier 3 regulated waters

[0133] In the ammonia gas treatment device of the present embodiment, in the Tier 3 regulated area, the engine (3) is started, and when the temperature inside the selective reduction catalyst unit (17) measured by the thermometer (26) is sufficiently high, a reducing agent is supplied to the selective reduction catalyst unit (17) to perform denitrification treatment.

[0134] As for the reducing agent, if ammonia water generated by the decontamination device (6) is stored, it is preferable to supply such ammonia water, and if the ammonia water is insufficient, to supply urea water. By performing ammonia water treatment first, the consumption of urea water can be reduced. In addition, the capacity of the urea water tank can be reduced.

[0135] The adjustment of the ammonia water supply volume is performed by measuring the density of the ammonia water in the ammonia water transport pipe (18) with a flow rate / density meter (10), converting it into an ammonia water concentration, and operating the third opening / closing valve (12) according to this ammonia water concentration.

[0136] In addition, the concentration and flow rate of the supplied ammonia water and nitrogen oxides (NO₂) in the engine exhaust gas x The relationship with the throughput of ) is known in advance.

[0137] When the ammonia water level of the ammonia water tank (7) is above a low level (L), the ammonia water pump (18a) is activated and the second shut-off valve (9) and the third shut-off valve (12) are opened to supply ammonia water.

[0138] The amount of ammonia water supplied to the selective reduction catalyst unit (17) is calculated from the molar equivalent of the ammonia water, and the flow rate of the ammonia water is adjusted so that it is a sufficient amount for denitrification treatment in the selective reduction catalyst unit (17).

[0139] In addition, in the operating mode where liquid ammonia fuel is the main fuel, leaked ammonia (leaked ammonia) in the engine exhaust gas enters the selective reduction catalyst unit (17), so the amount of ammonia water supplied is the amount after deducting the leaked ammonia.

[0140] In this case, it is desirable to provide an instrument (ammonia gas concentration meter) for measuring the concentration of leaked ammonia in the engine exhaust gas. That is, the amount of leaked ammonia is calculated from the exhaust gas flow rate calculated from the output of the engine (3) by load information and the leaked ammonia concentration measured by the instrument. Load information refers to the relationship between the output of the engine (3) and the exhaust gas flow rate, which is determined in advance. Based on this load information, the exhaust gas flow rate is calculated from the output of the engine (3). Meanwhile, since the load information varies depending on whether the operating mode is a mode using liquid ammonia fuel as the main fuel or a fossil fuel mode, and whether the navigation area is Tier 3 or Tier 2, it is determined for each case.

[0141] Alternatively, an instrument (gas flow meter) for measuring the exhaust gas flow rate of the engine (3) may be installed to calculate the amount of leaked ammonia from the exhaust gas flow rate and leaked ammonia concentration measured by the instrument.

[0142] When urea solution and ammonia solution are supplied simultaneously, the amount of leaked ammonia is subtracted from the amount of ammonia supplied into the selective reduction catalyst unit (17) by the ammonia solution, and the flow rate of the ammonia solution is adjusted so that this amount of ammonia is supplied by the ammonia solution. Then, the shortfall in the amount of ammonia required for exhaust gas denitrification treatment in the selective reduction catalyst unit (17) is supplemented by the ammonia supplied by the urea solution. Meanwhile, the supply of ammonia by the urea solution refers to the urea solution being hydrolyzed by the heat of the exhaust gas within the selective reduction catalyst unit (17) to produce ammonia.

[0143] That is, when urea solution and ammonia solution are supplied simultaneously, the flow rate of the ammonia solution is adjusted so that the sum of the amount of ammonia supplied to the selective reduction catalyst unit (17) by the urea solution and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit (17), thereby performing denitrification treatment of the exhaust gas as a detoxification treatment.

[0144] In the case where only urea solution is supplied, the amount of leaked ammonia is subtracted from the amount of ammonia supplied into the selective reduction catalyst unit (17) by the urea solution, and the flow rate of the urea solution is adjusted so that this amount of ammonia is supplied by the urea solution. By adjusting the flow rate in this way, the amount of ammonia supplied into the selective reduction catalyst unit (17) is made to be a sufficient amount of ammonia necessary for the denitrification treatment of exhaust gas.

[0145] That is, when only urea solution is supplied, the flow rate of the urea solution is adjusted so that the sum of the amount of ammonia supplied to the selective reduction catalyst unit (17) by the urea solution and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit (17), thereby performing denitrification treatment of the exhaust gas.

[0146] In addition, nitrogen oxides (NOx) in engine exhaust gas x It is also possible to measure the amount of ) and adjust the flow rate of the ammonia water according to the measurement results.

[0147] When the ammonia water level in the ammonia water tank (7) falls below the lowest level (LL), the ammonia water pump (18a) is stopped to stop the supply of ammonia water.

[0148] In this embodiment, when supplying urea solution, the ammonia water pump (18a) is stopped, the urea solution pump (15a) is started, the first shut-off valve (16) is opened, and the supply of urea solution is started. The flow rate of the urea solution is adjusted so that the amount of urea solution supplied is sufficient for denitrification treatment in the selective reduction catalyst unit (17) calculated from the molar equivalent of the urea solution.

[0149] Since the concentration of the urea solution is known, the molar equivalent of the urea solution supplied according to this concentration can be calculated. That is, the amount of urea solution supplied can be controlled by adjusting the urea solution flow control valve (19) while measuring the flow rate of the urea solution in the urea solution transport pipe (15) by the urea solution flow meter (20) according to the molar equivalent of the urea solution in the urea solution transport pipe (15).

[0150] In addition, nitrogen oxides (NOx) in engine exhaust gas x It is also possible to measure the amount of ) and adjust the urea flow rate control valve (19) according to the measurement result.

[0151] (2) Supply in Tier 2 regulated areas

[0152] In Tier 2 regulated waters, only ammonia water is supplied to perform detoxification or denitrification treatment. That is, in Tier 2 regulated waters, the urea pump (15a) is stopped and the supply of urea is interrupted.

[0153] When the ammonia water level in the ammonia water tank (7) is above a low level (L), the ammonia water pump (18a) is started, and the second shut-off valve (9) and the third shut-off valve (12) are opened to supply ammonia water.

[0154] The amount of ammonia water supplied to the selective reduction catalyst unit (17) is adjusted so that the amount of ammonia water supplied is less than or equal to the amount required for denitrification treatment in the selective reduction catalyst unit (17), calculated from the molar equivalent of the ammonia water.

[0155] In addition, in the operating mode where liquefied ammonia fuel is used as the main fuel, leaked ammonia (leaked ammonia) in the engine exhaust gas is introduced into the selective reduction catalyst unit (17), so the amount of ammonia water supplied is the amount after deducting the leaked ammonia.

[0156] In this case, it is preferable to provide an instrument (ammonia gas concentration meter) for measuring the concentration of leaked ammonia in the engine exhaust gas. That is, the amount of leaked ammonia is calculated from the exhaust gas flow rate calculated from the output of the engine (3) based on load information and the leaked ammonia concentration measured by the device. Alternatively, an additional instrument (gas flow meter) for measuring the exhaust gas flow rate of the engine (3) may be installed, and the amount of leaked ammonia may be calculated from the exhaust gas flow rate measured by the device and the leaked ammonia concentration.

[0157] In Tier 2 regulated waters, only ammonia water is supplied, so the amount of leaked ammonia is subtracted from the amount of ammonia supplied into the selective reduction catalyst unit (17) by the ammonia water, and the flow rate of the ammonia water is adjusted so that this amount of ammonia is supplied by the ammonia water. Through this flow rate adjustment, the amount of ammonia supplied into the selective reduction catalyst unit (17) is set to an amount of ammonia within the denitrification treatment capacity of the selective reduction catalyst unit (17).

[0158] That is, the flow rate of the ammonia water is adjusted so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit (17) by the ammonia water and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit (17), thereby performing denitrification treatment of the exhaust gas as a detoxification treatment.

[0159] In addition, when the ammonia slip catalyst (ASC) (17c) described later is used in combination, the flow rate of the ammonia water is adjusted so that the amount of ammonia water supplied to the selective reduction catalyst unit (17) is less than or equal to the processing capacity of the ammonia slip catalyst (ASC) (17c) calculated from the molar equivalent of the ammonia water.

[0160] As described above, the adjustment of the ammonia water supply volume is performed by converting the density of the ammonia water in the ammonia water transport pipe (18), measured by the flow rate / density meter (10), into an ammonia water concentration, and by measuring the flow rate of the ammonia water flowing through the ammonia water transport pipe (18) by the flow rate / density meter (10), and by operating the third opening / closing valve (12) according to the ammonia water concentration. In addition, the concentration and flow rate of the supplied ammonia water and the nitrogen oxides (NO₂) in the engine exhaust gas x The relationship with the throughput of ) is known in advance.

[0161] When the level of ammonia water in the ammonia water tank (7) falls below the lowest level (LL), the ammonia water pump (18a) is stopped to stop the supply of ammonia water.

[0162] [Second embodiment]

[0163] FIG. 3 is a block diagram showing the configuration of an ammonia gas treatment device according to a second embodiment of the present invention. An ammonia gas treatment method according to a second embodiment of the present invention is carried out in such an ammonia gas treatment device.

[0164] In this embodiment, as shown in FIG. 3, a mixer (29) for mixing additional liquid ammonia into the ammonia water transferred from the contaminant removal device (6) in the first embodiment (Fig. 2) and an instrument FD (10b) (hereinafter referred to as "second flow rate / density meter (10b)") for measuring the density of the ammonia water are installed. The second flow rate / density meter (10b) is a Coriolis flow meter and can measure the flow rate and density of the ammonia water after the additional liquid ammonia is mixed.

[0165] In this ammonia gas treatment device, liquefied ammonia supplied from the fuel supply device (2) joins the ammonia water at a downstream position of the third shut-off valve (12) of the ammonia water transport pipe (18). The liquefied ammonia is supplied from the fuel supply device (2) to the ammonia water transport pipe (18) via the liquefied ammonia back pressure valve (regulator) (31) and the liquefied ammonia flow meter (32).

[0166] Ammonia water mixed with liquefied ammonia is supplied to the mixer (29), and the liquefied ammonia and ammonia water are mixed to form ammonia water. Cooling water is supplied to the mixer (29) to cool the ammonia water transport pipe (18) from the outside, so that mixing is performed smoothly through cooling. The ammonia water transport pipe (18), through which the ammonia water that has passed through the mixer (29) is supplied, passes through the second flow / density meter (10b) and the check valve (30) and joins the urea water transport pipe (15). The piping after the urea water transport pipe (15) and the ammonia water transport pipe (18) join becomes the urea water or ammonia water transport pipe (28).

[0167] A check valve (33) is installed downstream of the urea flow meter (20) installed in the urea transport pipe (15).

[0168] In this embodiment, in a Tier 3 regulation area for exhaust gas regulations of marine diesel engines, urea solution or ammonia water is supplied to a selective reduction catalyst unit (17) to perform denitrification treatment, and in a Tier 2 regulation area, ammonia water is supplied to a selective reduction catalyst unit (17) to perform ammonia water detoxification treatment. In the ammonia water detoxification treatment, nitrogen oxides (NO) in the engine exhaust gas x The entire amount of ) does not need to be denitrified.

[0169] When the concentration and / or flow rate of the ammonia water is insufficient during denitrification treatment, the pressure of the liquefied ammonia discharged from the fuel supply device (2) is increased, and the liquefied ammonia is added to the ammonia water through the liquefied ammonia back pressure valve (31) and the liquefied ammonia flow meter (32). The amount of liquefied ammonia supplied is adjusted by measuring the flow rate of the liquefied ammonia by the liquefied ammonia flow meter (32), measuring the flow rate and density of the upstream and downstream ammonia water of the mixer (29) by the flow rate / density meter (10) and the second flow rate / density meter (10b), adjusting the pressure of the liquefied ammonia discharged from the fuel supply device (2), and adjusting the flow rate passing through the liquefied ammonia back pressure valve (31). As the liquefied ammonia is mixed, the ammonia water supplied to the selective reduction catalyst unit (17) becomes sufficiently concentrated to perform denitrification treatment.

[0170] In this case, the consumption of urea solution can be reduced.

[0171] The supply of urea solution and / or ammonia solution in such ammonia gas treatment devices is carried out, for example, as follows.

[0172] (1) Supply in Tier 3 regulated waters

[0173] In the ammonia gas treatment device of this embodiment, the supply of a reducing agent in the Tier 3 regulated area is the same as in the first embodiment (Fig. 2).

[0174] However, in this embodiment, when the concentration of ammonia water generated by the decontamination device (6) is insufficient, additional liquefied ammonia is mixed by the mixer (29).

[0175] In this embodiment, as a reducing agent, if ammonia water generated by the decontamination device (6) is stored, it is preferable to supply such ammonia water, and if such ammonia water is insufficient, to add liquefied ammonia or supply urea water. By performing ammonia water treatment first, the consumption of urea water can be reduced. In addition, the capacity of the urea water tank can be reduced.

[0176] The density of the ammonia water mixed with added liquid ammonia is measured by the second flow rate / density meter (10b).

[0177] That is, the adjustment of the ammonia water supply amount is performed by calculating the amount of liquefied ammonia to be added from the density of the ammonia water in the ammonia water transport pipe (18) measured by the flow rate / density meter (10), measuring the density of the ammonia water in the ammonia water transport pipe (18) after addition with the second flow rate / density meter (10b) to convert it into an ammonia water concentration, and operating the third opening / closing valve (12) according to this ammonia water concentration.

[0178] In this embodiment, when supplying urea solution in a Tier 3 regulated area, the adjustment of the urea solution supply amount is the same as in the first embodiment (Fig. 2).

[0179] (2) Supply in Tier 2 regulated areas

[0180] In this embodiment, only ammonia water is supplied in the Tier 2 regulated area, and the adjustment of the ammonia water supply amount is the same as in the first embodiment (Fig. 2).

[0181] In this case, since the addition of liquid ammonia is not performed, the adjustment of the ammonia water supply amount to the selective reduction catalyst unit (17) can be performed by calculating the concentration of the ammonia water from the density of the ammonia water measured by the flow rate / density meter (10), as in the first embodiment (Fig. 2), and adjusting the output of the ammonia water pump (18a) according to this concentration.

[0182] [Structure of nozzle and selective reduction catalyst unit (1)]

[0183] FIG. 4 is a schematic cross-sectional view showing the first structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the first embodiment (Fig. 2) and the second embodiment (Fig. 3).

[0184] As shown in FIG. 4, exhaust gas from the engine (3) is introduced into the selective reduction catalyst unit (17) from the combustion chamber (3a) of the engine (3) through the exhaust receiver (27). The exhaust gas passing through the exhaust receiver (27) rotates the turbine of the supercharger (52) and is exhausted into the atmosphere. The intake air compressed by the turbine of the supercharger (52) is supplied to the combustion chamber (3a). Inside the selective reduction catalyst unit (17), two-stage selective reduction catalysts (SCR) (17a, 17b) are arranged on the upstream side (inlet side) and downstream side (exhaust side). By configuring the selective reduction catalysts in multiple stages, it becomes easier to divide the roles of each catalyst, and a sufficient reaction area can be secured without making the selective reduction catalyst unit (17) larger. Meanwhile, the selective reduction catalysts do not need to be configured in multiple stages.

[0185] Inside the selective reduction catalyst unit (17), the nozzle (13) that supplies urea solution or ammonia solution with air is a two-fluid nozzle having two flow paths: a flow path connected to an air supply source (25) to supply air, and a flow path connected to a urea solution or ammonia solution transport pipe (28) to spray urea solution or ammonia solution.

[0186] These nozzles (13) supply air from upstream of the upstream selective reduction catalyst (17a) through an air supply channel, and at the same time spray urea solution or ammonia solution from upstream of the upstream selective reduction catalyst (17a) through a spraying channel.

[0187] In this nozzle (13), not only ammonia water but also urea water can be sprayed along the central axis of the selective reduction catalyst unit (17), so it can be uniformly diffused. In addition, since one nozzle (13) is sufficient for placement within the selective reduction catalyst unit (17), the structure is simplified.

[0188] [Third Embodiment]

[0189] FIG. 5 is a block diagram showing the configuration of an ammonia gas treatment device according to a third embodiment of the present invention. An ammonia gas treatment method according to a third embodiment of the present invention is carried out in such an ammonia gas treatment device.

[0190] In this embodiment, as shown in FIG. 5, the urea water transport pipe (15) and the ammonia water transport pipe (18) in the first embodiment (Fig. 2) are not combined, and each is connected independently to the nozzle (13).

[0191] In this ammonia gas treatment device, the urea solution flow control valve (19) is operated according to the measurement results of the urea solution flow meter (20) and the flow density meter (10). This is to make the sum of the molar equivalent of the supplied urea solution and the molar equivalent of the ammonia solution equal to the molar equivalent when only urea solution is supplied. The molar equivalent when only urea solution is supplied is a molar equivalent that is necessary and sufficient for denitrification treatment in the selective reduction catalyst unit (17).

[0192] In this embodiment, the pressure gauge (24) measures the pressure in the urea solution transport pipe (15). The pressure in the ammonia solution transport pipe (18) is measured by the PT (23) (hereinafter referred to as the "ammonia solution pressure gauge (23)").

[0193] The air supply source (25) supplies air supplied to the urea solution transport pipe (15) along with the urea solution within the selective reduction catalyst unit (17), and supplies air supplied to the ammonia solution transport pipe (18) along with the ammonia solution within the selective reduction catalyst unit (17).

[0194] Additionally, the air supply source (25) may be configured to supply air directly to the nozzle (13) through a single pipe, rather than through the urea water transport pipe (15) and the ammonia water transport pipe (18). The same applies to the fourth embodiment (Fig. 6) described later.

[0195] In this embodiment, it is possible to supply urea solution and ammonia solution simultaneously and spray them simultaneously. In this embodiment, in a Tier 3 regulation area for marine diesel engine exhaust gas regulations, urea solution and / or ammonia solution are supplied to a selective reduction catalyst unit (17) to perform denitrification treatment, and in a Tier 2 regulation area, ammonia solution is supplied to a selective reduction catalyst unit (17) to perform ammonia solution detoxification treatment. In the ammonia solution detoxification treatment, nitrogen oxides (NO) in the engine exhaust gas x The entire amount of ) does not need to be denitrified.

[0196] When supplying ammonia water to the selective reduction catalyst unit (17), the concentration of ammonia water is calculated from the density of the ammonia water measured by the flow rate / density meter (10), and by adjusting the output of the ammonia water pump (18a) according to this concentration, the concentration of the ammonia water supplied to the selective reduction catalyst unit (17) can be managed, and the entire amount of ammonia water supplied from the selective reduction catalyst unit (17) can be treated to be harmless.

[0197] The supply of urea solution and / or ammonia solution in such ammonia gas treatment devices is carried out, for example, as follows.

[0198] (1) Supply in Tier 3 regulated waters

[0199] In the ammonia gas treatment device of this embodiment, denitrification treatment can be performed in Tier 3 regulated waters by simultaneously supplying urea solution and ammonia solution.

[0200] In this embodiment, if ammonia water generated by the decontamination device (6) is stored as a reducing agent, it is preferable to supply such ammonia water, and if such ammonia water is insufficient, to supply urea water simultaneously. By performing ammonia water treatment first, the consumption of urea water can be reduced. In addition, the capacity of the urea water tank can be reduced.

[0201] In this embodiment, the urea solution pump (15a) and the ammonia solution pump (18a) are started to supply urea solution and ammonia solution simultaneously. The flow rates of the urea solution and ammonia solution are adjusted so that the total supply amount of urea solution and ammonia solution supplied to the selective reduction catalyst unit (17) becomes a sufficient supply amount necessary for denitrification treatment in the selective reduction catalyst unit (17), calculated from the total molar equivalent of the urea solution and ammonia solution.

[0202] The total molar equivalent of sufficient urea solution and ammonia solution required for denitrification treatment in the selective reduction catalyst unit (17) is the same as the molar equivalent of urea solution that must be supplied when only urea solution is supplied to the selective reduction catalyst unit (17).

[0203] In addition, the total supply amount of the supplied urea solution and ammonia solution may be zero (no supply) for either the urea solution or the ammonia solution. If the urea solution and ammonia solution are not sprayed simultaneously, the supply amount of either the urea solution or the ammonia solution is set to zero (no supply).

[0204] When the ammonia water supply amount is set to 0 (no supply), the ammonia water pump (18a) is stopped and only urea water is supplied, and in this case, the adjustment of the urea water supply amount is the same as in the first embodiment (Fig. 2).

[0205] When the urea solution supply amount is set to 0 (no supply), the urea solution pump (15a) is stopped and only ammonia solution is supplied, and in this case, the adjustment of the ammonia solution supply amount is the same as in the first embodiment (Fig. 2).

[0206] (2) Supply in Tier 2 regulated areas

[0207] In this embodiment, only ammonia water is supplied in the Tier 2 regulated area, and the adjustment of the ammonia water supply amount is the same as in the first embodiment (Fig. 2).

[0208] [Fourth embodiment]

[0209] FIG. 6 is a block diagram showing the configuration of an ammonia gas treatment device according to a fourth embodiment of the present invention. An ammonia gas treatment method according to a fourth embodiment of the present invention is carried out in such an ammonia gas treatment device.

[0210] In this embodiment, as shown in FIG. 6, a mixer (29) and a second flow rate / density meter (10b) are installed to mix additional liquid ammonia into the ammonia water sent from the decontamination device (6) in the third embodiment (Fig. 5), just as in the second embodiment (Fig. 3). The second flow rate / density meter (10b) is a Coriolis flow meter and can measure the flow rate and density of the ammonia water after the additional liquid ammonia is mixed.

[0211] In this ammonia gas treatment device, liquefied ammonia is supplied from a fuel supply device (2) to a downstream position of the third shut-off valve (12) of the ammonia water transport pipe (18) and joins the ammonia water. The liquefied ammonia is supplied from the fuel supply device (2) to the ammonia water transport pipe (18) via a liquefied ammonia back pressure valve (regulator) (31) and a liquefied ammonia flow meter (32).

[0212] Ammonia water mixed with liquid ammonia is supplied to the mixer (29), and the liquid ammonia and ammonia water are mixed to form ammonia water. Cooling water is supplied to the mixer (29) to cool the ammonia water transport pipe (18) from the outside. The ammonia water that has passed through the mixer (29) is supplied to the nozzle (13) through the check valve (30).

[0213] A check valve (33) is installed downstream of the urea flow meter (20) installed in the urea transport pipe (15).

[0214] In this embodiment, simultaneous spraying of urea solution and ammonia solution is possible. In this embodiment, urea solution and / or ammonia solution are supplied to a selective reduction catalyst unit (17) in a Tier 3 regulation area for exhaust gas regulations of a marine diesel engine to perform denitrification treatment, and ammonia solution is supplied to a selective reduction catalyst unit (17) in a Tier 2 regulation area to perform detoxification treatment or denitrification treatment of ammonia solution.

[0215] When the concentration and / or flow rate of the ammonia water is insufficient during denitrification treatment, the pressure of the liquefied ammonia discharged from the fuel supply device (2) is increased, and the liquefied ammonia is added to the ammonia water through the liquefied ammonia back pressure valve (31) and the liquefied ammonia flow meter (32). The amount of liquefied ammonia supplied is adjusted by measuring the flow rate of the liquefied ammonia by the liquefied ammonia flow meter (32), measuring the flow rate and density of the ammonia water by the flow rate and density meter (10), adjusting the pressure of the liquefied ammonia discharged from the fuel supply device (2), and adjusting the flow rate passing through the liquefied ammonia back pressure valve (31). As the liquefied ammonia is mixed, the ammonia water supplied to the selective reduction catalyst unit (17) becomes sufficiently concentrated to perform denitrification treatment.

[0216] In this case, the consumption of urea solution can be reduced.

[0217] The supply of urea solution and / or ammonia solution in such ammonia gas treatment devices is carried out, for example, as follows.

[0218] (1) Supply in Tier 3 regulated waters

[0219] In this embodiment, when urea solution and ammonia solution are supplied simultaneously in a Tier 3 regulated area, the adjustment of the supply amounts of urea solution and ammonia solution is the same as in the third embodiment (Fig. 5).

[0220] However, the adjustment of the ammonia water supply amount for the selective reduction catalyst unit (17) is performed by calculating the ammonia water concentration from the density of the ammonia water measured by the second flow rate / density meter (10b) rather than the flow rate / density meter (10), and adjusting the output of the ammonia water pump (18a) according to this concentration. This is because there are cases where liquefied ammonia is added.

[0221] In this embodiment, if ammonia water generated by the decontamination device (6) is stored as a reducing agent, it is preferable to supply such ammonia water, and if such ammonia water is insufficient, to add liquefied ammonia and / or simultaneously supply urea water. By performing the treatment of ammonia water first, the consumption of urea water can be reduced. In addition, the capacity of the urea water tank can be reduced.

[0222] In this embodiment, when only urea solution is supplied in a Tier 3 regulated area, the adjustment of the urea solution supply amount is the same as in the first embodiment (Fig. 2).

[0223] In this embodiment, when only ammonia water is supplied in a Tier 3 regulated area, the adjustment of the ammonia water supply amount is the same as in the second embodiment (Fig. 3). This is because liquid ammonia may be added.

[0224] (2) Supply in Tier 2 regulated areas

[0225] In this embodiment, only ammonia water is supplied in the Tier 2 regulated area, and the adjustment of the ammonia water supply amount is the same as in the second embodiment (Fig. 3).

[0226] In this case, since the addition of liquid ammonia is not performed, the adjustment of the ammonia water supply amount to the selective reduction catalyst unit (17) can be performed by calculating the concentration of the ammonia water from the density of the ammonia water measured by the flow rate / density meter (10), as in the first embodiment (Fig. 2), and adjusting the output of the ammonia water pump (18a) according to this concentration.

[0227] [Structure of nozzle and selective reduction catalyst unit (2)]

[0228] FIG. 7 is a schematic cross-sectional view showing the second structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the third embodiment (Fig. 5) and the fourth embodiment (Fig. 6).

[0229] As shown in FIG. 7, the nozzle (13) may be a three-fluid nozzle having three flow paths: a flow path connected to an air supply source (25) to supply air, a flow path connected to an ammonia water transport pipe (18) to supply ammonia water, and a flow path connected to a urea water transport pipe (15) to supply urea water. In this structural example, the air supply flow path is used for both the diffusion of ammonia water and the diffusion of urea water.

[0230] These nozzles (13) supply diffusion air from upstream of the upstream selective reduction catalyst (17a) through an air channel, spray ammonia water from upstream of the upstream selective reduction catalyst (17a) through an ammonia water channel, and spray urea water from upstream of the upstream selective reduction catalyst (17a) through a urea water channel.

[0231] In this nozzle (13), both ammonia water and urea water can be sprayed along the central axis of the selective reduction catalyst unit (17), so they can be uniformly diffused. In addition, since one nozzle (13) is sufficient for placement within the selective reduction catalyst unit (17), the structure is simplified.

[0232] In these nozzles (13), urea solution and ammonia solution are sprayed through dedicated paths, so even if there is a large difference between the amount of ammonia solution to be sprayed and the amount of urea solution to be sprayed, it can be handled.

[0233] In a selective reduction catalyst unit (17) using such a nozzle (13), urea solution and / or ammonia solution is sprayed in Tier 3 regulated areas, which are exhaust gas regulations for marine diesel engines, and ammonia solution is sprayed in Tier 2 regulated areas.

[0234] When performing ammonia water spraying in Tier 3 regulated waters, it is necessary to manage the concentration of the ammonia water to secure a sufficient amount of ammonia components required for denitrification treatment.

[0235] In such nozzles (13), the flow path for urea solution can be set to a high flow rate flow path, and the flow path for ammonia solution can be set to a low flow rate flow path. The air flow rate is controlled by a flow meter-equipped control valve according to a signal indicating whether it is a mode for spraying urea solution or a mode for spraying ammonia solution.

[0236] By using such a nozzle (13), a low-flow mode for treating ammonia water in Tier 2 waters can be implemented. In this case, simultaneous spraying of urea solution and ammonia water is not performed.

[0237] In the example of the nozzle (13) structure described above, the air supply path for ammonia water diffusion and urea water diffusion was shared, but it is not limited to this, and the air supply path for ammonia water diffusion and the air supply path for urea water diffusion may be installed separately.

[0238] That is, as a nozzle (13), it may be a three-fluid nozzle having four flow paths, such as a flow path connected to a urea water transport pipe (15) to spray urea water, a flow path connected to an ammonia water transport pipe (18) to spray ammonia water, a flow path connected to an air supply source (25) to supply air that diffuses urea water, and a flow path connected to an air supply source (25) to supply air that diffuses ammonia water.

[0239] These nozzles (13) supply air for ammonia diffusion and ammonia water from upstream of the upstream selective reduction catalyst (17a) through the air path for ammonia water diffusion and the ammonia water receiving path, and spray air for urea diffusion and urea water from upstream of the upstream selective reduction catalyst (17a) through the air path for urea water diffusion and the urea water receiving path.

[0240] By using such a nozzle (13), the supply amount of air and ammonia water for ammonia water diffusion and the supply amount of air and urea water for urea water diffusion can be changed according to the load of the engine (3).

[0241] [Structure of nozzle and selective reduction catalyst unit (3)]

[0242] FIG. 8 is a schematic cross-sectional view showing the third structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the third embodiment (Fig. 5) and the fourth embodiment (Fig. 6).

[0243] As shown in FIG. 8, the nozzle may be composed of a first nozzle (13a) and a second nozzle (13b).

[0244] The first nozzle (13a) is a two-fluid nozzle having two fluid paths: a path connected to an air supply source (25) to supply air, and a path connected to a urea transport pipe (15) to spray urea solution.

[0245] The second nozzle (13b) is a two-fluid nozzle having two fluid paths, a path connected to an air supply source (25) to supply air, and a path connected to an ammonia water transport pipe (18) to spray ammonia water.

[0246] The first nozzle (13a) supplies air from upstream of the upstream selective reduction catalyst (17a) through an air passage and sprays urea solution from upstream of the upstream selective reduction catalyst (17a) through an urea solution passage.

[0247] The second nozzle (13b) supplies air from upstream of the upstream selective reduction catalyst (17a) through an air passage and sprays ammonia water from upstream of the upstream selective reduction catalyst (17a) through an ammonia water passage.

[0248] The first nozzle (13a) and the second nozzle (13b) are both positioned near the center axis of the selective reduction catalyst unit (17), but they may be positioned with the center axis as the Z-axis, with the X-axis and Z-axis directions being the same and only the Y-axis direction being different, or with the Y-axis and Z-axis directions being the same and only the X-axis direction being different.

[0249] When using these first nozzles (13a) and second nozzles (13b), urea solution and ammonia solution are sprayed from dedicated first nozzles (13a) and second nozzles (13b), respectively, so that urea solution and ammonia solution can be sprayed simultaneously, and even if there is a large difference between the amount of ammonia solution to be sprayed and the amount of urea solution to be sprayed, it can be accommodated.

[0250] The amount of urea solution sprayed and the amount of ammonia solution sprayed can be adjusted according to the operating condition of the engine (3).

[0251] In the selective reduction catalyst unit (17) using such nozzles (13), urea solution and / or ammonia solution is sprayed in Tier 3 regulated areas, which are exhaust gas regulations for marine diesel engines, and ammonia solution is sprayed in Tier 2 regulated areas.

[0252] When performing ammonia water spraying in Tier 3 regulated waters, it is necessary to manage the concentration of the ammonia water to secure a sufficient amount of ammonia components required for denitrification treatment.

[0253] [Structure of nozzle and selective reduction catalyst unit (4)]

[0254] FIG. 9 is a schematic cross-sectional view showing the fourth structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the third embodiment (Fig. 5) and the fourth embodiment (Fig. 6).

[0255] As shown in FIG. 9, the nozzle is composed of a first nozzle (13a) and a second nozzle (13b), and the second nozzle (13b) may be placed inside the exhaust receiver (27).

[0256] The first nozzle (13a) is a two-fluid nozzle having two fluid paths: a path connected to an air supply source (25) to supply air, and a path connected to a urea transport pipe (15) to spray urea solution.

[0257] The second nozzle (13b) is a two-fluid nozzle having two fluid paths, a path connected to an air supply source (25) to supply air, and a path connected to an ammonia water transport pipe (18) to spray ammonia water.

[0258] The first nozzle (13a) supplies air from upstream of the upstream selective reduction catalyst (17a) through an air passage and sprays urea solution from upstream of the upstream selective reduction catalyst (17a) within the selective reduction catalyst unit (17) through an urea solution passage.

[0259] The second nozzle (13b) supplies air from upstream of the upstream selective reduction catalyst (17a) through an air passage and sprays ammonia water into the exhaust receiver (27) through an ammonia water passage.

[0260] In these first nozzle (13a) and second nozzle (13b), not only ammonia water but also urea water can be sprayed along the central axis of the selective reduction catalyst unit (17), so that it can be uniformly diffused.

[0261] When using these first nozzles (13a) and second nozzles (13b), urea solution and ammonia solution are sprayed from dedicated first nozzles (13a) and second nozzles (13b), respectively, so that urea solution and ammonia solution can be sprayed simultaneously, and even if there is a large difference between the amount of urea solution to be sprayed and the amount of ammonia solution to be sprayed, it can be accommodated.

[0262] The amount of urea solution sprayed and the amount of ammonia solution sprayed can be adjusted according to the operating condition of the engine (3).

[0263] When using these first nozzle (13a) and second nozzle (13b), the outlet temperature of the exhaust receiver (27) is higher than the inlet temperature of the selective reduction catalyst unit (17), so the temperature drop of the exhaust gas can be suppressed even if the ammonia water is low concentration and the spray volume is high.

[0264] These first nozzle (13a) and second nozzle (13b) are suitable when the amount of ammonia water sprayed is about 1 / 10 or less of the amount of urea water sprayed.

[0265] In a selective reduction catalyst unit (17) using such a nozzle (13), urea solution and / or ammonia solution is sprayed in Tier 3 regulated areas of marine diesel engines, and ammonia solution is sprayed in Tier 2 regulated areas.

[0266] When performing ammonia water spraying in Tier 3 regulated waters, it is necessary to manage the concentration of the ammonia water to secure a sufficient amount of ammonia components required for denitrification treatment.

[0267] In addition, the first nozzle (13a) for spraying urea solution can also be placed in the exhaust receiver (27) just like the second nozzle (13b).

[0268] [Structure of nozzle and selective reduction catalyst unit (5)]

[0269] FIG. 10 is a schematic cross-sectional view showing the fifth structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the third embodiment (Fig. 5) and the fourth embodiment (Fig. 6).

[0270] As shown in FIG. 10, the nozzle is composed of a first nozzle (13a) and a second nozzle (13b), and the second nozzle (13b) may be placed upstream of an ammonia slip catalyst (ASC) (17c) installed instead of a downstream selective reduction catalyst (17b).

[0271] The first nozzle (13a) is a two-fluid nozzle having two fluid paths: a path connected to an air supply source (25) to supply air, and a path connected to a urea transport pipe (15) to spray urea solution.

[0272] The second nozzle (13b) is a two-fluid nozzle having two fluid paths, a path connected to an air supply source (25) to supply air, and a path connected to an ammonia water transport pipe (18) to spray ammonia water.

[0273] The first nozzle (13a) supplies air from upstream of the upstream selective reduction catalyst (17a) through an air passage and sprays urea solution from upstream of the upstream selective reduction catalyst (17a) within the selective reduction catalyst unit (17) through an urea solution passage.

[0274] The second nozzle (13b) supplies air from upstream of the upstream selective reduction catalyst (17a) through an air passage and sprays ammonia water from downstream of the upstream selective reduction catalyst (17a) and upstream of the ammonia slip catalyst (ASC) (17c) installed in place of the downstream selective reduction catalyst (17b) within the selective reduction catalyst unit (17) through an ammonia water passage.

[0275] In these first nozzle (13a) and second nozzle (13b), not only ammonia water but also urea water can be sprayed along the central axis of the selective reduction catalyst unit (17), so that it can be uniformly diffused.

[0276] When using these first nozzles (13a) and second nozzles (13b), urea solution and ammonia solution are sprayed from dedicated first nozzles (13a) and second nozzles (13b), respectively, so that urea solution and ammonia solution can be sprayed simultaneously, and even if there is a large difference between the amount of ammonia solution to be sprayed and the amount of urea solution to be sprayed, it can be accommodated.

[0277] The amount of urea solution sprayed and the amount of ammonia solution sprayed can be adjusted according to the operating condition of the engine (3).

[0278] When using these first nozzle (13a) and second nozzle (13b), the nitrogen oxide reduction treatment is completed solely by the upstream selective reduction catalyst (17a), and the downstream ammonia slip catalyst is specialized for ammonia water treatment.

[0279] These first nozzle (13a) and second nozzle (13b) are suitable when the amount of ammonia water sprayed is about 1 / 10 or less of the amount of urea water sprayed.

[0280] Additionally, the second nozzle (13b) of these nozzles can also be configured to spray ammonia water upstream of the upstream selective reduction catalyst (17a) within the selective reduction catalyst unit (17). In this case, when there is excess ammonia gas from the denitrification treatment in the selective reduction catalyst (17a), this ammonia gas is neutralized by the downstream ammonia slip catalyst.

[0281] In the selective reduction catalyst unit (17) using such nozzles (13), urea solution and ammonia solution are sprayed in Tier 3 regulated areas of marine diesel engines, and ammonia solution is sprayed in Tier 2 regulated areas.

[0282] In a selective reduction catalyst unit (17) using such a nozzle (13), since the ammonia water is not related to denitrification treatment, there is no need to manage the concentration, but concentration management may be performed to confirm that the amount of ammonia component is less than or equal to the treatment capacity of the ammonia slip catalyst (ASC) (17c).

[0283] As described above, in this ammonia gas treatment device and treatment method, in Tier 3 emission gas regulation areas for marine diesel engines, not only can regulations be met by reliably performing denitrification treatment in the selective reduction catalyst unit (17) using urea solution, but onboard treatment of ammonia gas generated on the ship is also made possible. Since the ammonia solution is consumed in the detoxification treatment and an additional ammonia solution supply tank is unnecessary, the capacity of the ammonia solution tank can be reduced.

[0284] In addition, in a method that utilizes ammonia water generated from a decontamination device for denitrification treatment, by performing denitrification treatment using ammonia water in Tier 2 regulated areas where denitrification treatment is not strictly required, it is possible to provide a clean vessel that emits clean exhaust gas with reduced nitrogen oxides in all areas. Explanation of the symbols

[0285] 1 liquefied ammonia tank 1a Suction pump 2 fuel supply unit 2a Ammonia discharge valve 3 engines 3a Combustion chamber 4 Fuel Piping 4a Gas-Liquid Separator 5 Purge gas release valve 6. Contamination removal device 7 Ammonia water tank 7a Face value meter 8 AdBlue tanks 9 Second shut-off valve 10 Flowmeter / Density Meter (Coriolis Flowmeter) 10b Second flow / density meter (Coriolis flow meter) 11 Ammonia water flow meter 12 Third shut-off valve 13 nozzles 13a First nozzle 13b Second nozzle 14 Ammonia water circulation valve (back pressure valve) 15 AdBlue transport pipe 15a AdBlue Pump 16 First shut-off valve 17 Selective Reduction Catalytic Unit 17a Selective Catalytic Reduction (SCR) 17b Selective Catalytic Reduction (SCR) 17c Ammonia Slip Catalyst (ASC) 18 Ammonia water transport pipe 18a Ammonia water pump 19. AdBlue Flow Control Valve 20 urea flow meter 21 AdBlue Circulation Valve (Back Pressure Valve) 22 fresh water tank 22a Water supply pump 23 Ammonia pressure gauge 24 pressure gauge 25 air supply sources 26 thermometers 27 Exhaust Receiver 28 Urea or ammonia water transport pipe 29 Mixer 30 check valve 31 Liquefied ammonia back pressure valve 32 Liquid Ammonia Flow Meter 33 Check valve 50 purge gas supply valve 51 Nitrogen gas supply device 52 Supercharger

Claims

Claim 1 A ship equipped with a selective reduction catalyst unit and carrying liquefied ammonia as cargo or engine fuel, wherein exhaust gas from the ship's engine is introduced into the selective reduction catalyst unit, urea solution as a reducing agent is supplied, and a selective reduction catalyst that performs denitrification treatment of the exhaust gas is arranged therein, and a decontamination device is provided to dissolve liquefied ammonia remaining in the ship's engine fuel supply line into vaporized ammonia gas and / or ammonia gas, or ammonia gas volatilized from the cargo, in fresh water to form ammonia water, and an ammonia gas treatment device is provided to supply the ammonia water generated by the decontamination device to the selective reduction catalyst unit to perform detoxification treatment of the ammonia water, wherein the supply path of the ammonia water to the selective reduction catalyst unit reaches the selective reduction catalyst unit independently of the supply path of the urea solution to the selective reduction catalyst unit, and the urea solution and the ammonia water can be supplied simultaneously to the selective reduction catalyst unit through a nozzle, and the nozzle is connected to an air supply source to supply the urea solution and / or the An ammonia gas treatment device characterized by having a three-fluid nozzle having a flow path for supplying air to diffuse ammonia water, a flow path connected to the urea water supply path for spraying the urea water, and a flow path connected to the ammonia water supply path for spraying the ammonia water, and positioned upstream of the selective reduction catalyst unit. Claim 2 A ship equipped with a selective reduction catalyst unit and carrying liquefied ammonia as cargo or engine fuel, wherein exhaust gas from the ship's engine is introduced into the selective reduction catalyst unit, urea solution as a reducing agent is supplied, and a selective reduction catalyst that performs denitrification treatment of the exhaust gas is arranged therein, and a decontamination device is provided to dissolve liquefied ammonia remaining in the ship's engine fuel supply line into ammonia water by dissolving vaporized ammonia gas and / or ammonia gas, or ammonia gas volatilized from the cargo, in fresh water, and an ammonia gas treatment device that supplies the ammonia water generated by the decontamination device to the selective reduction catalyst unit to perform detoxification treatment of the ammonia water, wherein the supply path of the ammonia water to the selective reduction catalyst unit reaches the selective reduction catalyst unit independently of the supply path of the urea solution to the selective reduction catalyst unit, and the urea solution and the ammonia water can be supplied simultaneously to the selective reduction catalyst unit through a nozzle, wherein the nozzle is composed of a first nozzle and a second nozzle, and the first An ammonia gas treatment device characterized in that the nozzle is a two-fluid nozzle having two flow paths—a flow path connected to an air supply source for supplying air and a flow path connected to an ammonia water supply line for spraying the ammonia water—and is disposed on the upstream side within the selective reduction catalyst unit, and the second nozzle is a two-fluid nozzle having two flow paths—a flow path connected to an air supply source for supplying air and a flow path connected to an ammonia water supply line for spraying the ammonia water—and is disposed on the upstream side within the selective reduction catalyst unit. Claim 3 A ship equipped with a selective reduction catalyst unit and carrying liquefied ammonia as cargo or engine fuel, wherein exhaust gas from the ship's engine is introduced into the selective reduction catalyst unit, urea solution as a reducing agent is supplied, and a selective reduction catalyst that performs denitrification treatment of the exhaust gas is disposed therein, and a decontamination device is provided to convert liquefied ammonia remaining in the ship's engine fuel supply line into ammonia water by dissolving vaporized ammonia gas and / or ammonia gas, or ammonia gas volatilized from the cargo, in fresh water, and an ammonia gas treatment device is provided that supplies the ammonia water generated by the decontamination device to the selective reduction catalyst unit to perform detoxification treatment of the ammonia water, wherein the supply path of the ammonia water to the selective reduction catalyst unit reaches the selective reduction catalyst unit independently of the supply path of the urea solution to the selective reduction catalyst unit, and the urea solution and the ammonia water can be supplied simultaneously to the selective reduction catalyst unit through a nozzle, and the nozzle is composed of a first nozzle and a second nozzle. An ammonia gas treatment device characterized by the first nozzle being a two-fluid nozzle having two flow paths—a flow path connected to an air supply source for supplying air and a flow path connected to an urea supply line for spraying the urea solution—and being disposed upstream within the selective reduction catalyst unit, and the second nozzle being a two-fluid nozzle having two flow paths—a flow path connected to an air supply source for supplying air and a flow path connected to an ammonia water supply line for spraying the ammonia water—and being disposed within an exhaust receiver through which the exhaust gas passes in front of the selective reduction catalyst unit, and supplying the air and the ammonia water into the selective reduction catalyst unit through this exhaust receiver. Claim 4 A ship equipped with a selective reduction catalyst unit and carrying liquefied ammonia as cargo or engine fuel, wherein exhaust gas from the ship's engine is introduced into the selective reduction catalyst unit, urea solution as a reducing agent is supplied, and a selective reduction catalyst that performs denitrification treatment of the exhaust gas is arranged therein, and a decontamination device is provided to dissolve liquefied ammonia remaining in the ship's engine fuel supply line into vaporized ammonia gas and / or ammonia gas, or ammonia gas volatilized from the cargo, in fresh water to form ammonia water, and an ammonia gas treatment device that supplies the ammonia water generated by the decontamination device to the selective reduction catalyst unit to perform detoxification treatment of the ammonia water, wherein the supply path of the ammonia water to the selective reduction catalyst unit joins the supply path of the urea solution to the selective reduction catalyst unit before reaching the selective reduction catalyst unit, and either the urea solution or the ammonia water is supplied to the selective reduction catalyst unit through a nozzle, and the nozzle is connected to two flow paths—air supply sources—to supply air An ammonia gas treatment device characterized by having a two-fluid nozzle having a supply path and a path in which the urea solution supply path and the ammonia solution supply path are joined and connected to spray the urea solution or the ammonia solution, and positioned on the upstream side within the selective reduction catalyst unit. Claim 5 An ammonia gas treatment apparatus according to any one of claims 1 to 3, comprising: providing a device for measuring the density of the ammonia water; simultaneously supplying the urea water and the ammonia water to the selective reduction catalyst unit; converting the density of the ammonia water measured by the device for measuring the density of the ammonia water into a concentration of the ammonia water; calculating the molar equivalent of the ammonia water supplied to the selective reduction catalyst unit from this concentration; calculating the molar equivalent of the urea water supplied to the selective reduction catalyst unit from a known concentration of the urea water; summing the molar equivalent of the ammonia water and the molar equivalent of the urea water supplied to the selective reduction catalyst unit; and adjusting the flow rates of the urea water and the ammonia water according to the summed molar equivalent to perform denitrification treatment of the exhaust gas as the detoxification treatment. Claim 6 An ammonia gas treatment device according to any one of claims 1 to 4, wherein liquefied ammonia supplied from a fuel supply device of the ship is combined in the supply path of the ammonia water to the selective reduction catalyst unit, the ammonia water and the liquefied ammonia are mixed to form ammonia water and supplied to the selective reduction catalyst unit, and a device for measuring the density of the ammonia water mixed with the ammonia water and the liquefied ammonia is provided, and the molar equivalent of the ammonia water supplied to the selective reduction catalyst unit is calculated from the density of the ammonia water measured by the device for measuring the density of the ammonia water, and the flow rate of the ammonia water is adjusted according to the calculated molar equivalent to perform denitrification treatment of the exhaust gas as the detoxification treatment. Claim 7 An ammonia gas treatment device according to any one of claims 1 to 4, comprising: a device for measuring the concentration of leaked ammonia in the exhaust gas; measuring the exhaust gas flow rate of the engine; calculating the amount of leaked ammonia from the measured exhaust gas flow rate and the leaked ammonia concentration, or from the exhaust gas flow rate and the leaked ammonia concentration calculated by load information from the output of the engine; and adjusting the flow rate of the urea solution or the ammonia solution so that the sum of the amount of ammonia supplied to the selective reduction catalyst unit by the urea solution and / or the ammonia solution and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit, thereby performing denitrification treatment of the exhaust gas as the detoxification treatment. Claim 8 An ammonia gas treatment apparatus characterized in that, in any one of claims 1 to 4, an ammonia slip catalyst is disposed within the selective reduction catalyst unit, and the ammonia water supplied to the selective reduction catalyst unit is treated to be harmless by the ammonia slip catalyst. Claim 9 A method for treating ammonia gas in a vessel equipped with a selective reduction catalyst unit and carrying liquefied ammonia as fuel for cargo or the vessel's engine, wherein exhaust gas from the vessel's engine is introduced into the selective reduction catalyst unit and urea solution, which is a reducing agent, is supplied, and a selective reduction catalyst is installed to perform denitrification treatment of the exhaust gas; wherein, by means of a pollution removal device, the liquefied ammonia remaining in the fuel supply line of the vessel's engine is dissolved in fresh water to form ammonia water, and / or ammonia gas, or ammonia gas volatilized from the cargo, and the ammonia water generated by the pollution removal device is supplied to the selective reduction catalyst unit to perform detoxification treatment of the ammonia water, wherein liquefied ammonia supplied from the vessel's fuel supply device is combined with the supply path of the ammonia water to the selective reduction catalyst unit, the ammonia water and the liquefied ammonia are mixed to form ammonia water and supplied to the selective reduction catalyst unit, and the ammonia water and the liquefied ammonia A method for treating ammonia gas characterized by measuring the density of mixed ammonia water, calculating the molar equivalent of ammonia water to be supplied to the selective reduction catalyst unit from the measured density of the ammonia water, and controlling the flow rate of the ammonia water according to the calculated molar equivalent to perform denitrification treatment of the exhaust gas as the detoxification treatment. Claim 10 A method for treating ammonia gas according to claim 9, wherein an instrument for measuring the concentration of leaked ammonia in the exhaust gas is installed, the exhaust gas flow rate of the engine is measured, the amount of leaked ammonia is calculated from the measured exhaust gas flow rate and the leaked ammonia concentration, or from the exhaust gas flow rate and the leaked ammonia concentration calculated by load information from the output of the engine, and the flow rate of the urea solution or the ammonia solution is adjusted so that the sum of the amount of ammonia supplied to the selective reduction catalyst unit by the urea solution and / or the ammonia solution and the amount of leaked ammonia is the amount of ammonia treated in the selective reduction catalyst unit, thereby performing denitrification treatment of the exhaust gas as the detoxification treatment. Claim 11 A method for treating ammonia gas according to claim 9 or 10, characterized in that an ammonia slip catalyst is installed in the selective reduction catalyst unit, and the ammonia water supplied to the selective reduction catalyst unit is treated to be harmless by the ammonia slip catalyst. Claim 12 delete Claim 13 delete Claim 14 delete

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