Ammonia recovery / discharge system and control method therefor

Abstract

The present invention relates to an ammonia recovery / discharge system and a control method therefor. The ammonia recovery / discharge system of the present invention is designed for a ship using ammonia as fuel and comprises: an ammonia tank; an engine; a fuel supply unit; a fuel recovery unit; an air supply line; an air discharge line; and a working fluid circulation unit, wherein the working fluid circulation unit comprises an ejector that supplies high-pressure working fluid to circulate air or ammonia in the working fluid circulation unit.

Description

Ammonia recovery and discharge system and control method thereof

[0001] The present invention relates to an ammonia recovery and discharge system and a control method thereof. Specifically, the present invention relates to an ammonia recovery and discharge system and a control method thereof, which safely performs ammonia dual-pipe air circulation in a vessel that uses ammonia as fuel, primarily prevents ammonia from being released into the atmosphere by dissolving ammonia gas within the pipe using fresh water when the ammonia engine is stopped, and separately separates ammonia from ammonia water for reuse.

[0002] Recently, engines using eco-friendly fuel oil are being actively applied, and ammonia is easier to store than LNG, and although its specific energy and energy density are somewhat lower than those of existing HFO, it does not emit carbon dioxide at all, making it a fuel oil that is receiving attention in the 2050 carbon dioxide reduction policy.

[0003] LPG fuel engines can be used as is, and with only a slight change in the fuel supply system, they can be used immediately. As carbon dioxide reduction policies are strengthened in the future, the level of concern will increase, and it is urgent to possess the technology for this.

[0004] Ammonia can be stored at temperatures ranging from 50°C at 20 BAR, and up to 25.7°C at 10 BAR. Therefore, it can be safely stored in a compressed tank on board a ship. The ammonia fuel stored in the compressed tank must be maintained in a liquid state by supplying it to the engine at a pressure of approximately 83 BAR through an ammonia fuel supply system, and the engine then hydraulically injects it into the nozzle at a pressure of 600 to 700 BAR to operate the engine.

[0005] At this time, if the engine is inevitably stopped while supplying ammonia as fuel, or if a trip occurs or the temperature rises and ammonia gasifies, the fuel supply must be stopped and the ammonia in the ammonia fuel supply system must be discharged to the outside.

[0006] In addition, the ammonia pipe that is supplied through the engine room and other safety areas must be constructed with a double pipe, and 30 air changes must be performed per hour using air between the inner and outer pipes. In case of ammonia leakage from the inner pipe, it must be quickly discharged to the outside and the ammonia operation of the engine must be stopped.

[0007] In order to solve the above problems, the present invention aims to provide an ammonia recovery and discharge system and method.

[0008] In addition, the purpose is to provide an ammonia recovery and discharge system and method that can significantly reduce the risk of leakage by using water (clean water) when operating the ammonia recovery and discharge system.

[0009] Specifically, the purpose is to provide an ammonia recovery and discharge system and method that can safely perform ammonia double-pipe air circulation in a ship that uses ammonia as fuel.

[0010] Additionally, the purpose is to primarily prevent ammonia from being released into the atmosphere by dissolving the ammonia gas inside the pipe using clean water when the ammonia engine is stopped.

[0011] In addition, the purpose is to separate ammonia from the ammonia water produced by dissolving ammonia gas in the above-mentioned clear water and reuse it or safely discharge it overboard.

[0012] The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0013] In order to achieve the above object, the present invention provides an ammonia recovery and discharge system for a ship that uses ammonia as fuel, the system comprising: an ammonia tank for storing liquid ammonia; an engine disposed in an engine room and operated by receiving fuel from the ammonia tank; a fuel supply unit including a fuel supply line for supplying ammonia as fuel from the ammonia tank to the engine; a fuel recovery unit including a fuel return line for recovering ammonia not consumed in the engine to the ammonia tank; an air supply line for supplying air to the fuel supply line and the fuel return line; an air discharge line for discharging air supplied to the fuel supply line and the fuel return line; and a working fluid circulation unit for circulating a working fluid to discharge air or ammonia in the fuel supply line and the fuel return line, wherein the working fluid circulation unit supplies a high-pressure working fluid to circulate the air or ammonia to the working fluid circulation unit.

[0014] Preferably, the working fluid circulation unit includes a working fluid storage tank that stores and recovers working fluid supplied to the ejector, a first venting line that discharges air supplied to the working fluid storage tank overboard, a chiller that cools the working fluid flowing into the working fluid storage tank, and an ammonia recovery unit that recovers ammonia flowing into the working fluid circulation unit. The working fluid storage tank and the ejector may be connected to a working fluid supply line, and the ejector and the working fluid storage tank may be connected to a working fluid recirculation line.

[0015] Preferably, a portion of the fuel supply line and the fuel return line are disposed within the engine room, and the fuel supply line and the fuel return line disposed within the engine room are double pipes, and an annular space formed between the inner pipe and the outer pipe of the double pipe is connected to an air supply line and an air discharge line, and the air discharge line is connected to an ejector, and includes a first ammonia sensor for measuring an ammonia concentration on the air discharge line; a pressure sensor for measuring the flow of air; and a circulation cutoff valve for controlling the circulation of air when the ammonia operation is stopped; and the air supplied to the annular space through the air supply line is supplied to the ejector through the air discharge line, and the air supplied to the ejector may be introduced into a working fluid storage tank through a working fluid recirculation line.

[0016] Preferably, the first venting line is arranged at the upper part of one end of the working fluid storage tank, a second ammonia sensor is arranged on the first venting line, and air discharged overboard through the air discharge line may have passed through a buffer plate.

[0017] Preferably, the working fluid storage tank and the ammonia water recovery unit are connected to an ammonia water supply line, and when ammonia is detected by the first ammonia sensor, the supply of ammonia fuel is stopped, the ammonia introduced through the air discharge line is supplied to the filling unit and dissolved in the working fluid, and the ammonia dissolved in the working fluid may be supplied to the ammonia water recovery unit through the lower part of the working fluid storage tank after passing through the buffer plate.

[0018] Preferably, the fuel supply system includes a liquid fuel supply system section on the fuel supply line, and includes a fuel valve train section on the fuel supply line and fuel return line at the rear end of the fuel supply system section, wherein the liquid fuel supply system section is connected to the ejector and the first ammonia recovery and discharge line, and the fuel return line is connected to the ejector and the second ammonia recovery and discharge line.

[0019] Preferably, a first double-block valve is arranged on the fuel supply line of the fuel valve train section, and a second double-block valve is arranged on the fuel return line of the fuel valve train section, wherein the first double-block valve is connected to the ejector and the third ammonia recovery and discharge line, and the second double-block valve is connected to the ejector and the fourth ammonia recovery and discharge line.

[0020] Preferably, the system further includes an ammonia dilution unit for diluting ammonia introduced into the working fluid storage tank, wherein the ammonia dilution unit is disposed between the working fluid storage tank and the first venting line, and the ammonia dilution unit may include an ammonia dilution chamber for receiving and diluting ammonia, and a dilution pan for diluting ammonia in the ammonia dilution chamber.

[0021] Preferably, the ammonia recovery unit may include an ammonia water tank that receives ammonia water from the working fluid storage tank and evaporates ammonia to separate it into ammonia and working fluid, a steam separator disposed above the ammonia water tank and separating the evaporated working fluid and ammonia, an ammonia compressor that compresses the ammonia separated in the steam separator, and a combustion unit that receives the compressed ammonia and combusts it to reuse it as fuel oil.

[0022] Preferably, the ammonia recovery unit further includes a cooler, and the cooler operates the chiller to cool the ammonia, and when the ammonia compressed in the ammonia compressor is in a gaseous state, it is supplied to the cooler to liquefy it, and the liquefied ammonia is supplied to the combustion unit.

[0023] Preferably, the working fluid storage tank and the ammonia water tank are connected to an ammonia water supply line formed by branching from the working fluid supply line, an ammonia water transfer selection valve is disposed on the ammonia water supply line, and the ammonia water tank and the ejector are connected to a working fluid recovery line, and a working fluid recovery valve may be disposed on the working fluid recovery line.

[0024] In addition, according to another aspect of the present invention for achieving the above-described object, a method for controlling an ammonia recovery and discharge system is provided, comprising: a fuel supply step of supplying ammonia fuel from an ammonia tank to an engine through a fuel supply unit including a fuel supply line; a working fluid circulation step of supplying and circulating high-pressure working fluid to an ejector provided in a working fluid circulation unit when the fuel supply step is performed; and an ammonia recovery step of recovering ammonia from an ammonia recovery unit when the fuel supply step is stopped.

[0025] Preferably, the working fluid circulation step includes an air circulation step of supplying air to the fuel supply line and the fuel return line and discharging the supplied air; the air circulation step may include an air supply step of supplying air to a circulation space of the fuel supply line and the fuel return line formed as a double pipe, and an air discharge step of supplying the air introduced into the circulation space to an ejector, the air supplied to the ejector being introduced into a working fluid storage tank through a working fluid recirculation line, and the air introduced into the working fluid storage tank passing through a buffer plate and being discharged to the outside through the upper portion.

[0026] Preferably, the method further comprises an ammonia leak detection step, wherein the ammonia leak detection step may include a first ammonia leak detection step for detecting whether there is an ammonia leak from the inner pipe to the outer pipe of the double pipe, and a second ammonia leak detection step for detecting whether there is an ammonia leak from the working fluid storage tank.

[0027] Preferably, the first ammonia leak detection step may include a first ammonia recovery step of supplying ejected ammonia fuel to an engine in which a gas leak has been detected and performing an ammonia recovery step when an ammonia leak is detected by the first ammonia sensor, and recovering the ammonia fuel present in the fuel supply line and the fuel return line, and a second ammonia recovery step of supplying nitrogen to the fuel supply line to recover the ammonia remaining in the fuel supply line and the fuel return line.

[0028] Preferably, ammonia recovered by ejection through the first ammonia recovery step is introduced into a working fluid storage tank, ammonia introduced into the working fluid storage tank is supplied to a filler unit, ammonia supplied to the filler unit is dissolved in the working fluid, and ammonia dissolved in the working fluid is recovered by passing through a buffer plate and supplied to an ammonia recovery unit through the lower part of the working fluid storage tank.

[0029] Preferably, the ammonia water supplied to the ammonia recovery unit is separated into a working fluid and ammonia, and may include the steps of: supplying the ammonia water to an ammonia water tank; heating the ammonia water tank to a temperature at which ammonia can evaporate; supplying the evaporated ammonia from the ammonia water tank to a water separator and separating it into ammonia and a working fluid; supplying the separated ammonia to a compressor and compressing it; and supplying the compressed ammonia to a combustion unit and combusting it so that it can be reused as fuel oil.

[0030] Preferably, the second ammonia leak detection step includes a cooling step of operating a chiller to cool a working fluid (ammonia water) in which ammonia is dissolved in a working fluid storage tank so that the concentration of ammonia measured by the second ammonia sensor becomes 20 ppm or less when an ammonia leak is detected by the second ammonia sensor; and after performing the cooling step, if the ammonia concentration is 20 ppm or less, the cooling temperature of the chiller may be controlled to gradually increase and the working fluid in which ammonia is dissolved in the working fluid storage tank may be supplied to the ammonia water recovery unit.

[0031] Preferably, if the ammonia concentration in the second ammonia sensor is 20 ppm or more after performing the cooling step, an ammonia dilution step is performed to dilute ammonia in the ammonia dilution chamber by operating a dilution fan, and if the ammonia concentration is 20 ppm or less after performing the cooling step or the ammonia dilution step, the cooling temperature of the chiller is controlled to gradually increase, and the working fluid in which ammonia is dissolved in the working fluid storage tank can be supplied to the ammonia recovery unit.

[0032] According to the present invention, which is accomplished as described above, there is an effect of providing an ammonia recovery and discharge system and a control method thereof.

[0033] Additionally, by using water (clean water) when operating the ammonia recovery and discharge system, the risk of leakage can be significantly reduced.

[0034] Additionally, it has the effect of preventing ammonia from being released into the atmosphere.

[0035] Additionally, ammonia can be dissolved in water (clean water) and slowly discharged in accordance with external discharge regulations.

[0036] In addition, to prevent ammonia from being released into the atmosphere, it has the effect of reusing ammonia or safely discharging it overboard by separating ammonia from the ammonia water produced by dissolving the released ammonia gas.

[0037] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0038] Figure 1 is a schematic diagram showing an ammonia recovery and discharge system according to one embodiment of the present invention.

[0039] Figure 2 is a schematic diagram showing an ammonia recovery and discharge system according to another embodiment of the present invention.

[0040] The purpose and technical configuration of the present invention and the resulting operation and effects will be more clearly understood through a detailed description based on the drawings attached to the specification of the present invention.

[0041] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. For example, when a component is referred to as "including" herein, unless specifically stated otherwise, it does not exclude other components but rather implies that other components may be included. Furthermore, when a component is referred to as "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to the other component, other components may also be present in between.

[0042] Hereinafter, the present invention will be described in detail by describing preferred embodiments thereof with reference to the attached drawings. The embodiments described below are provided to facilitate the technical concept of the present invention for those skilled in the art to understand, and should not be construed as limiting the present invention. It should be understood that the embodiments of the present invention can have various applications to those skilled in the art.

[0043] Ammonia is an environmentally friendly fuel that emits no carbon dioxide, making it a highly sought-after fuel in the 2050 carbon dioxide reduction policy. It can be used in LPG-fueled engines, requiring only minor changes to the fuel supply system. As carbon dioxide reduction policies become more stringent, interest in ammonia is expected to grow, and securing the necessary technology is urgent.

[0044] Ammonia can be stored at temperatures up to approximately 50°C at 20 BAR, and up to 25.7°C at 10 BAR. Therefore, it can be safely stored in compressed tanks on ships. In this case, it must be supplied to the engine at a pressure of approximately 83 BAR to maintain its liquid state, and the engine is hydraulically injected into the nozzle at a pressure of 600 to 700 BAR to operate the engine.

[0045] Meanwhile, in the ammonia supply system, if the engine operation is inevitably stopped, a trip occurs, or the temperature rises and ammonia gasifies, the fuel supply system must be stopped and the ammonia in the system must be discharged to the outside.

[0046] In addition, the ammonia pipes supplied through the engine room and other safety areas must be constructed as double pipes, and air must be changed 30 times per hour between the inner and outer pipes using air. In the event of ammonia leakage from the inner pipe, it must be quickly discharged to the outside and the engine's ammonia operation must be stopped.

[0047] Accordingly, the present invention will describe in detail an ammonia recovery and discharge system and a control method thereof.

[0048] Hereinafter, the term "ship" in the present invention refers to all types of ships that are equipped with engines capable of using ammonia as fuel for the onboard engine, and may include ships with self-propulsion capabilities such as LPG carriers, LNG carriers, liquid hydrogen carriers, and ammonia carriers, as well as offshore structures that do not have propulsion capabilities but are floating on the sea.

[0049] An engine supplied with ammonia as fuel includes an engine supplied with other marine fuels such as LNG, LPG, and HFO as well as an engine supplied with ammonia as fuel alone, and includes both propulsion engines and power generation engines of ships.

[0050] An ammonia recovery and discharge system according to one embodiment of the present invention may be an ammonia recovery and / or discharge system.

[0051] Figure 1 is a schematic diagram showing an ammonia recovery and discharge system according to one embodiment of the present invention.

[0052] Referring to FIG. 1, a ship using ammonia as fuel is configured to include an ammonia tank (100) for storing liquid ammonia, an engine (E) that is placed in the engine room and operates by receiving fuel from the ammonia tank (100), a fuel supply unit including a fuel supply line (FSL), a fuel recovery unit including a fuel return line (FRL), and a working fluid circulation unit in which working fluid circulates to discharge air or ammonia in the fuel supply line and the fuel return line.

[0053] The above ammonia tank (100) stores liquid ammonia supplied to the ship's engine, and can store ammonia in liquid form by pressurizing gaseous ammonia or lowering the internal temperature of the tank. For example, ammonia can be stored in a liquid state by setting the internal pressure of the ammonia tank (100) to approximately 18 bar.

[0054] The above engine (E) is placed in the engine room (E / R) and can be equipped with one or more engines, and the number of engines can be adjusted as needed. The engine (E) is operated by receiving fuel from an ammonia tank, and can be connected to an SCR system (600) and an exhaust gas discharge line (EL1) to discharge exhaust gas generated while operating the engine (E).

[0055] The above fuel supply unit supplies fuel gas from the ammonia tank (100) to the engine (E), and the fuel supply unit may include a fuel supply line (FSL).

[0056] In detail, the fuel supply line (FSL) connects the ammonia tank (100) and the engine (E), and a low-pressure pump (1), a high-pressure pump (2), a temperature controller (4), and a filter (5) can be arranged on the fuel supply line (FSL).

[0057] The above low-pressure pump (1) supplies liquid ammonia stored in the ammonia tank (100) to the engine (E), and it is preferable that the above high-pressure pump (2, compression pump) compresses the ammonia transferred from the low-pressure pump (1) to the pressure required by the engine and supplies it.

[0058] It is preferable that the above temperature controller (4) heats or cools the ammonia fuel compressed by the high-pressure pump (2) to the temperature required by the engine (E) and supplies it to the filter (5).

[0059] The above filter (5) can filter out foreign substances contained in the fuel to protect the engine (E) before supplying compressed ammonia, the temperature of which is controlled through the temperature controller (4), to the engine (E).

[0060] At this time, the high pressure pump (2), temperature controller (4) and filter (5) are part of a liquid fuel supply system (LFSS). The pressure of the ammonia fuel compressed in the high pressure pump (2) of the liquid fuel supply system is 83 bar, and it is preferable that cooling or heating is continuously performed.

[0061] The fuel recovery unit recovers ammonia that has been supplied to the engine (E) but not consumed, and the fuel recovery unit may include a fuel return line (FRL).

[0062] In detail, the fuel return line (FRL) connects the engine (E) and the ammonia tank (100), and the fuel can be recovered to the ammonia tank (100) through the fuel return line (FRL).

[0063] At this time, a part of the fuel supply line (FSL) and the fuel return line (FRL) is arranged inside the engine room, and in order to prevent leakage of liquid ammonia, the fuel supply line (FSL) and the fuel return line (FRL) arranged inside the engine room are preferably provided as a double pipe including an inner pipe (IP1, IP2) through which ammonia moves and an outer pipe (OP1, OP2) that surrounds the outer surface of the inner pipe.

[0064] The above inner pipes (IP1, IP2) are closed by outer pipes (OP1, OP2) or ducts, so that even if ammonia gas leaks from the inner pipes (IP1, IP2), the gas can be prevented from being released into the engine room.

[0065] In addition, the empty space formed between the inner tubes (IP1, IP2) and the outer tubes (OP1, OP2) of the double tube is an annular space, into which air can be continuously injected by an exhaust ventilation device, and the injected air can be discharged into the atmosphere depending on the ammonia concentration level in the air.

[0066] For example, air can be injected into the annulus space through a ventilation air inlet. Specifically, the end point of the double-pipe section of the fuel return line or fuel supply line and the exhaust inlet are connected to an air supply line (AL1), so that air can be injected into the annulus space.

[0067] The air injected through the exhaust inlet is discharged to the outside through the working fluid circulation unit (300). The point where the double pipe portion of the fuel supply line or fuel return line begins and the working fluid circulation unit are connected to an air discharge line (AL2), and it is preferable that the air circulated in the annulus space is discharged to the outside through the air discharge line (AL2).

[0068] For example, if the point where the double pipe portion of the fuel return line ends and the exhaust inlet are connected to the air supply line (AL1), it is preferable that the point where the double pipe portion of the fuel supply line begins and the working fluid circulation section are connected to the air discharge line (AL2), and if the point where the double pipe portion of the fuel supply line begins and the exhaust inlet are connected to the air supply line (AL1), it is preferable that the point where the double pipe portion of the fuel return line ends and the working fluid circulation section are connected to the air discharge line (AL2). That is, the positions where the air supply line (AL1) and the air discharge line (AL2) are connected can be changed, and it is preferable that they are connected so that air circulation can occur.

[0069] The above working fluid circulation unit (300) includes an ejector (200), a working fluid storage tank (310) that stores and recovers working fluid supplied to the ejector (200), and the working fluid storage tank (310) and the ejector (200) are connected to a working fluid supply line, the ejector (200) and the working fluid storage tank (310) are connected to a working fluid recirculation line, and the ejector (200) is connected to a point where a double pipe portion of the fuel supply line begins and an air discharge line (AL2).

[0070] In addition, by arranging an ejector pump (210) on the working fluid supply line, the ejector pump is operated to form pressure in the working fluid supply line, and as high-pressure working fluid is supplied to the ejector, a high flow rate is generated, and as the flow rate increases, a low pressure is formed to create a vacuum state, and the air injected into the annulus space through the air supply line (AL1) is sucked in to circulate the air. At this time, one or more ejector pumps (210) may be arranged, and when one of them breaks down, a STANDBY pump can be operated to ensure safety.

[0071] At this time, the working fluid supply line includes a first working fluid supply line in which an air cooler (240) is arranged and a second working fluid supply line in which an air cooler is not arranged, and an air cooler selection valve (250) is arranged at the front end of the ejector pump (210) so that the working fluid can be selected to be supplied to the first working fluid supply line or the second working fluid supply line.

[0072] For example, when the ejector pump (210) is operated, heat is generated in the ejector pump (210). In order to reduce the heat generated in the ejector pump (210), the working fluid can be supplied through the first working fluid supply line.

[0073] As the working fluid is supplied through the first working fluid supply line, the working fluid is cooled through an air cooler (240) and supplied to the ejector pump (210), and the heat of the ejector pump can be lowered by the cooling heat of the working fluid.

[0074] At this time, the air cooler (240) may be of the air tube type, and can prevent bubbles from forming on the ejector pump (210) side as it is supplied after cooling.

[0075] In addition, a flow sensor or pressure sensor (230) is placed on the air discharge line (AL2), so that it is possible to measure whether air is flowing well in the annular space of the double pipe through the flow sensor or pressure sensor (230).

[0076] The interior of the above-described working fluid storage tank (310) may be configured to include a filling material portion (320) and a buffer plate (330). At this time, the filling material portion (320) is arranged to be connected to the working fluid recirculation line, and it is preferable that the working fluid passing through the ejector (200) is supplied to the filling material portion (320).

[0077] In addition, it is preferable that the air passing through the filling material (320) and flowing into the working fluid storage tank (310) pass through the buffer plate (330) and then be discharged to the outside through the first venting line (L1).

[0078] At this time, it is preferable that the first venting line (L1) is arranged at the upper part of one end of the working fluid storage tank, and it is preferable that the second ammonia sensor is arranged on the first venting line (L1).

[0079] In detail, an ammonia dilution unit for diluting ammonia is further included between the upper portion of the working fluid storage tank (310) and the first venting line (L1), and the ammonia dilution unit includes an ammonia dilution chamber (370) for receiving and diluting ammonia, and a dilution fan (380) for diluting ammonia in the ammonia dilution chamber.

[0080] At this time, the first venting line (L1) is arranged at the upper part of the ammonia dilution chamber (370), so that only air can be discharged overboard without ammonia being discharged.

[0081] In addition, it is preferable that the working fluid storage tank (310) is provided with a level sensor (340) disposed at the bottom of the working fluid storage tank (310) to prevent the working fluid from evaporating, and that a working fluid supplement valve (350) is disposed to automatically inject the working fluid to maintain a certain level according to the value measured by the level sensor (340). At this time, it is preferable that the working fluid is fresh water, and that the fresh water is injected through the working fluid supplement valve (350).

[0082] Meanwhile, a first ammonia sensor (220) and a circulation cutoff valve (260) are arranged on the air discharge line (AL2). When ammonia is measured by the first ammonia sensor (220), it is determined that ammonia has leaked from the inner pipe (IP1, IP2) of the double pipe, and operation of the engine (E) is stopped and supply of ammonia fuel to the engine (E) is stopped.

[0083] At this time, it is preferable to block the circulation cutoff valve (260) after confirming that the ammonia concentration measured by the first ammonia sensor (220) becomes 0.

[0084] That is, it is desirable to perform ammonia water recovery within the system and air circulation through the double pipe (double pipe ventilation) simultaneously, and then close the circulation cutoff valve (260) when the ammonia concentration measured by the first ammonia sensor (220) becomes 0.

[0085] It is preferable that the ammonia fuel contained in the above system be supplied to the ammonia recovery unit (500) and discharged.

[0086] In detail, the ejector (200) in the ammonia recovery discharge system is connected to the fuel supply unit and the first ammonia recovery discharge line (VL1), and can be connected to the fuel recovery unit and the second ammonia recovery discharge line (VL2).

[0087] In detail, the ejector (200) is connected to the liquid fuel supply system (LFSS) of the fuel supply unit and the first ammonia recovery discharge line (VL1), and is connected to the fuel return line (FRL) and the second ammonia recovery discharge line (VL2), and it is preferable that a first venting valve (VV1) is arranged on the first ammonia recovery discharge line (VL1), and a second venting valve (VV2) is arranged on the second ammonia recovery discharge line (VL2).

[0088] In addition, it is preferable that a fuel valve train (FVT) section be included on the fuel supply line (FSL) and the fuel return line (FRL) at the rear end of the fuel supply system section, and that a double shut-off valve be arranged on the fuel supply line (FSL) and the fuel return line (FRL) within the fuel valve train section.

[0089] The above double block and bleed valve is installed in a fuel pipe to effectively block the fuel supply. By installing double valves on the pipe and branching a vent pipe between the valves, the fuel supply device and the engine can be effectively blocked.

[0090] In detail, it is preferable that a first double shut-off valve (DV1) is arranged on a fuel supply line (FSL) of the fuel valve train (FVT) section, and that the first double shut-off valve (DV1) is connected to the ejector (200) and a third ammonia recovery discharge line (VL3), and that the second double shut-off valve (DV2) is connected to the ejector (200) and a fourth ammonia recovery discharge line (VL4).

[0091] That is, it is preferable that the ammonia fuel in each zone within the above system is supplied to the ejector (200) through the first ammonia recovery discharge line (VL1), the second ammonia recovery discharge line (VL2), the third ammonia recovery discharge line (VL3), and the fourth ammonia recovery discharge line (VL4), and that the ammonia supplied to the ejector (200) is introduced into the working fluid storage tank (310) through the working fluid recirculation line together with the working fluid.

[0092] At this time, the working fluid containing the ammonia is supplied to the filling material unit (320) in the working fluid storage tank (310), and the ammonia supplied to the filling material unit (320) is dissolved in the working fluid, and the ammonia (ammonia water) dissolved in the working fluid is preferably supplied to the ammonia recovery unit (500) through the ammonia water supply line formed at the bottom after passing through the buffer plate (330).

[0093] At this time, the purpose of the filling material (320) is to maximize the reaction area of ​​ammonia to increase the reaction speed and reaction efficiency with the working fluid (clean water) and to ensure good dissolution. It is preferable to fill the filling material with a material that is resistant to ammonia.

[0094] In addition, it is preferable that ammonia leaking from the inner pipe (IP1, IP2) of the double pipe and flowing into the ejector is recovered to the ammonia recovery unit (500) together with the recovered ammonia.

[0095] Additionally, the system may further include a nitrogen supply unit for supplying nitrogen to completely remove ammonia within the system.

[0096] In detail, the nitrogen is supplied to the system through a nitrogen supply line (NL), and it is preferable that the nitrogen supply line (NL) is connected to the rear end of the first double shut-off valve (DV1). At this time, it is preferable that the supplied nitrogen is supplied to the ejector through the second ammonia recovery discharge line (VL2) after passing through the inner pipes (IP1, IP2) of the double pipe.

[0097] The ammonia recovery and discharge system according to the present invention may be configured to further include a control unit (not shown). The control unit controls the operation of the ammonia recovery and discharge system, and preferably controls the flow of fuel gas and the operation mode of the engine using temperature and ammonia concentration information measured by detectors and sensors within the system.

[0098] FIG. 2 is a schematic diagram showing an ammonia recovery and discharge system according to another embodiment of the present invention. Except for the configuration described below, the configuration of the ammonia recovery and discharge system described above with reference to FIG. 1 can be applied as is.

[0099] Therefore, the configuration of the ammonia recovery and discharge system described above in Fig. 1 is omitted.

[0100] Referring to FIG. 2, the ammonia water recovery unit recovers ammonia (ammonia water) dissolved in the working fluid that flows into the working fluid storage tank (310), and may be configured to include an ammonia water tank (700), a water separator (740), an ammonia compressor (750), and a combustion unit (800).

[0101] The above ammonia water tank (700) is connected to the working fluid storage tank (310) and the ammonia water supply line. It is preferable that the ammonia water supply line be formed by branching from the working fluid supply line, and it is preferable that an ammonia water transfer valve (not shown) is placed at the branching point.

[0102] The above ammonia water tank (700) is configured to separate ammonia water supplied from the working fluid storage tank (310) into ammonia and working fluid, and includes an electric heater (710) and a temperature sensor (720).

[0103] The above ammonia water is separated by utilizing the fact that the evaporation temperatures of ammonia and working fluid are different, and by heating the ammonia water to a certain temperature using an electric heater (710), it is separated into working fluid and ammonia evaporation gas (ammonia in a gaseous state).

[0104] At this time, the ammonia is evaporated, and the working fluid is heated to a temperature at which it does not evaporate, but a small amount of the working fluid may also evaporate together. Accordingly, it is preferable to place a working fluid catcher (water catcher) within the ammonia water tank (700) to separate the small amount of working fluid from the ammonia evaporation gas.

[0105] In addition, a small amount of working fluid that is not separated in the working fluid catcher is supplied to the steam separator (740) together with the ammonia vaporization gas, and it is preferable that the ammonia vaporization gas and the working fluid are secondarily separated in the steam separator (740).

[0106] At this time, it is preferable that the separated working fluid is supplied to the ejector (200) through the working fluid recovery line (WRL), and the working fluid supplied to the ejector (200) is recovered to the working fluid storage tank (310).

[0107] The above ammonia compressor (750) compresses the ammonia vapor gas separated from the above steam separator (740), and it is preferable to compress it to 8 bar to 10 bar.

[0108] At this time, the ammonia pressurized in the compressor (750) can be supplied to the cooler (760) to be liquefied or supplied to the combustion unit (800).

[0109] In detail, when supplying the pressurized ammonia to the cooler (760), the ammonia is cooled and liquefied, and it is preferable to cool the pressurized ammonia by operating the chiller (400). At this time, it is preferable that the cooler (760) liquefies the ammonia by dropping it to about 10°C using the chiller (400).

[0110] The above combustion unit (800) receives ammonia from the ammonia compressor (750) or the cooler (760) and combusts it to reuse it as fuel oil. It is preferable that a boiler or an incinerator be arranged in the combustion unit.

[0111] At this time, depending on the type of boiler placed in the combustion unit (800), liquefied ammonia or gaseous ammonia is fluidly supplied. When liquefied ammonia is supplied to the combustion unit, the pressurized ammonia is supplied to the cooler (760) to be liquefied and then supplied to the combustion unit (800). When gaseous ammonia is supplied, it is preferable to supply it to the combustion unit (800) without passing through the cooler (760).

[0112]

[0113] Hereinafter, a control method of an ammonia recovery and discharge system according to an embodiment of the present invention will be described with reference to an ammonia recovery and discharge system according to an embodiment of the present invention described above.

[0114] The control method of the above ammonia recovery and discharge system includes a fuel supply step of supplying ammonia fuel from an ammonia tank (100) to an engine (E) through a fuel supply unit including a fuel supply line (FSL), a working fluid circulation step of supplying high-pressure working fluid to an ejector (200) provided in a working fluid circulation unit (300) when the fuel supply step is performed, and an ammonia recovery step of recovering ammonia from an ammonia recovery unit when the fuel supply step is stopped.

[0115] The above fuel supply step is to supply liquid ammonia stored in the ammonia tank (100) to the engine (E) by driving the low-pressure pump (1), and it is preferable to supply the ammonia transferred from the low-pressure pump (1) by compressing it to the pressure required by the engine using the high-pressure pump (2).

[0116] At this time, some of the ammonia compressed in the high-pressure pump (2) is recovered to the ammonia storage tank (100) and can be resupplied to the high-pressure pump (2).

[0117] In addition, the ammonia fuel compressed in the high-pressure pump (2) is supplied to the temperature controller (4) to heat or cool it and adjust it to the temperature required by the engine (E), and can be supplied to the filter (5) to remove foreign substances contained in the compressed ammonia whose temperature is adjusted. At this time, if ammonia in a liquid state is used, a vaporizer is not necessary, and the liquid ammonia is pressurized to about 83 bar by the pump and reaches the temperature range (25°C to 55°C) required by the engine (E) through the heat exchanger, so that it can be supplied to the engine.

[0118] At this time, the fuel supply step can be performed together with the fuel recovery step, and ammonia that is not consumed in the engine (E) while the fuel supply step is performed can be recovered back to the ammonia tank (100) through the fuel return line (FRL).

[0119] While the above fuel supply step is performed, the above working fluid circulation step is performed simultaneously, and the working fluid circulation step includes a working fluid supply step of supplying working fluid from the working fluid storage tank (310) to the ejector (200) and a working fluid recirculation step of recirculating the working fluid that has passed through the ejector (200) to the working fluid storage tank (310).

[0120] In addition, the working fluid circulation step includes an air circulation step of supplying air to the fuel supply line and the fuel return line and discharging the supplied air, and the air circulation step preferably includes an air supply step of supplying air to a circulation space of the fuel supply line and the fuel return line formed as a double pipe, and an air discharge step of supplying the air introduced into the circulation space to an ejector (200), and the air supplied to the ejector (200) is introduced into a working fluid storage tank (310) through a working fluid recirculation line, and the air introduced into the working fluid storage tank (310) passes through a buffer plate and is discharged to the outside through the upper portion.

[0121] In detail, the air discharge step supplies air to the annulus space and discharges the supplied air overboard, and air is injected through an air supply line (AL1) connected to the end point of the double pipe portion of the fuel return line, and the air injected into the annulus space can be supplied to the working fluid circulation unit (300) through the air discharge line (AL2).

[0122] At this time, in order to discharge the air injected into the annulus space to the outside, it is preferable to operate the ejector pump (210) to circulate the working fluid.

[0123] In detail, as the ejector pump (210) is operated, pressure is formed in the working fluid supply line, and the working fluid becomes high pressure. As the high pressure working fluid is supplied to the ejector (200), a high flow rate is generated, and as the flow rate increases, a low pressure is formed, resulting in a vacuum state. As the vacuum state is formed, air supplied to the annular space can be introduced into the ejector (200) through the air discharge line (AL2).

[0124] The above air circulation stage is a prerequisite for the engine to operate when driving with ammonia, and ammonia operation is only performed when flow is detected through a pressure sensor or flow sensor (230).

[0125] At this time, it is determined that a flow is being formed where a vacuum is formed below a certain pressure, and if an excessive vacuum or a weak vacuum is formed, it is determined that the annular space of the double pipe is blocked or the flow rate is insufficient, and the ammonia operation is stopped.

[0126] For example, in the case of the above flow sensor or pressure sensor (230), the vacuum level can be measured to determine how much flow is measured. If the vacuum level is measured to be higher than the designed value, it is considered that the pressure drop is increasing due to foreign substances in the pipe. In addition, if the vacuum level is measured to be lower than the designed value, it is considered that the pressure drop is decreasing due to low flow, and it is determined that a problem has occurred, so the ammonia operation is stopped.

[0127] Meanwhile, the control method of the ammonia recovery and discharge system may further include an ammonia leak detection step. Preferably, the ammonia leak detection step is performed in real time while supplying ammonia fuel to operate the engine.

[0128] In detail, the ammonia leak detection step may include a first ammonia leak detection step for detecting ammonia leak from an inner pipe (IP1, IP2) of a double pipe, and a second ammonia leak detection step for detecting ammonia leak from a working fluid storage tank.

[0129] The above first ammonia leak detection step detects whether there is a gas leak from the inner pipe (IP1, IP2) of the double pipe to the outer pipe (OP1, OP2). If ammonia is detected by the first ammonia sensor (220), it is determined that ammonia gas has leaked.

[0130] At this time, if it is determined that the ammonia gas has leaked, the engine operation and the ammonia fuel supply are stopped, and the first double shut-off valve (DV1) and the second double shut-off valve (DV2) are shut off and an ammonia recovery step is performed. The ammonia recovery step may include a first ammonia recovery step of primarily recovering ammonia fuel existing in the fuel supply line (FSL) and the fuel return line (FRL) through an ammonia recovery unit, and a second ammonia recovery step of secondarily recovering ammonia remaining in the fuel supply line (FSL) and the fuel return line (FRL) by supplying nitrogen to the fuel supply line (FSL).

[0131] In detail, the first ammonia recovery step recovers and discharges ammonia in a liquid fuel supply system (LFSS) and a fuel return line (FRL) through the ammonia recovery unit (500). It is preferable that ammonia generated in the liquid fuel supply system (LFSS) is recovered to the ammonia recovery unit (500) through a first ammonia recovery discharge line (VL1), and ammonia in the fuel return line (FRL) is recovered to the ammonia recovery unit (500) through a second ammonia recovery discharge line (VL2).

[0132] In addition, it is preferable that the ammonia not recovered in the fuel supply line (FSL) and the fuel return line (FRL) is recovered in the ammonia recovery unit through the third ammonia recovery discharge line (VL3) and the fourth ammonia recovery discharge line (VL4) as the first double shut-off valve (DV1) and the second double shut-off valve (DV2) are blocked.

[0133] That is, ammonia recovered through the first ammonia recovery discharge line (VL1), the second ammonia recovery discharge line (VL2), the third ammonia recovery discharge line (VL3), and the fourth ammonia recovery discharge line (VL4) is supplied to the ejector (200) and mixed with the working fluid, and is supplied to the filling unit (320) together with the working fluid.

[0134] Ammonia supplied to the above-mentioned filling unit (320) is dissolved in the working fluid (clean water) by the above-mentioned filling unit (320), and it is preferable that the ammonia (ammonia water) dissolved in the working fluid pass through the buffer plate (330) and then be recovered to the ammonia recovery unit (500) through the lower part of the working fluid storage tank.

[0135] In addition, the second ammonia recovery step is preferably performed by supplying nitrogen to recover ammonia for the second time after the first recovery of ammonia is completed, and by pushing out and recovering the residual ammonia remaining in the fuel supply line and fuel return line within the system. At this time, the pressure of the supplied nitrogen is preferably 5 BAR to 6 BAR, and the ammonia recovered for the second time is also supplied to the ejector (200), and the ammonia supplied to the ejector (200) is preferably supplied to the ammonia recovery unit.

[0136] At this time, it is preferable that the ammonia is dissolved in the working fluid and the nitrogen is discharged overboard through the upper portion of the working fluid storage tank after passing through the buffer plate (330).

[0137] The above second ammonia leak detection step detects ammonia that has flowed into the working fluid storage tank (310) through the air discharge line after detecting a leak in the first ammonia leak detection step so that it does not leak out of the ship. It is preferable to measure the ammonia concentration through the second ammonia sensor (360) while discharging the air that has flowed into the working fluid storage tank (310) to the outside.

[0138] At this time, it is preferable to set the second ammonia sensor (360) to maintain the ammonia concentration below 20 PPM, and to operate the chiller (400) so that ammonia can be dissolved in the working fluid (clean water) when the ammonia concentration exceeds 20 PPM.

[0139] For example, when the ammonia concentration measured by the second ammonia sensor (360) exceeds 20 PPM, the chiller (400) is operated to cool the working fluid and improve the solubility of ammonia, thereby maintaining the ammonia concentration measured by the second ammonia sensor (360) at 20 PPM or less.

[0140] In addition, when the concentration of ammonia measured by the second ammonia sensor (360) is 20 PPM or higher while the chiller (400) is being operated to cool the working fluid, it is preferable to operate the dilution fan to dilute the ammonia through the ammonia dilution chamber (370) to 20 PPM or lower.

[0141] At this time, the ammonia diluted in the ammonia dilution chamber (370) is recovered to the working fluid storage tank (310), and it is preferable that the ammonia recovered to the working fluid storage tank (310) be dissolved in the working fluid and recovered to the ammonia recovery unit (500).

[0142] For example, when the ammonia concentration measured by the second ammonia sensor (360) exceeds 20 PPM, the chiller (400) is operated to cool the working fluid and improve the solubility of ammonia, thereby maintaining the ammonia concentration measured by the second ammonia sensor (360) at 20 PPM or less.

[0143] At this time, if the concentration of ammonia measured by the second ammonia sensor (360) is 20 ppm or more, it is preferable to operate the dilution fan to dilute the ammonia in the ammonia dilution chamber (370) to 20 ppm or less.

[0144] Thereafter, when the concentration of ammonia measured by the second ammonia sensor (360) becomes 20 ppm or less, the cooling temperature of the chiller (400) is controlled to gradually increase the temperature of the working fluid in the working fluid storage tank (310), and when the concentration of ammonia measured by the second ammonia sensor (360) becomes lower than 20 ppm, it is preferable to continuously discharge the working fluid (ammonia water) in which ammonia is dissolved to the ammonia recovery unit (500). Through this, the ammonia content of the working fluid in the working fluid storage tank (310) is reduced, and it is possible to maintain it in a saturated ammonia water state at room temperature. At this time, it is preferable to perform the process of discharging ammonia water from the working fluid storage tank (310) to the ammonia recovery unit (500) until the ammonia concentration measured by the second ammonia sensor (360) becomes 0 ppm.

[0145] The ammonia water supplied to the ammonia water recovery unit may be separated into a working fluid and ammonia, and may include a step of supplying the ammonia water to an ammonia water tank (700), a step of heating the ammonia water tank (700) to a temperature at which ammonia can evaporate, a step of supplying the evaporated ammonia from the ammonia water tank (700) to a steam separator (740) to separate it into ammonia and a working fluid, a step of supplying the separated ammonia to an ammonia compressor (750) to compress it, and a step of supplying the compressed ammonia to a combustion unit (800) to combust it so that it can be reused as fuel oil.

[0146] The ammonia water supplied to the ammonia water tank (700) is preferably separated into ammonia evaporation gas and working fluid by heating the ammonia water tank (700) so that only the ammonia can evaporate, and setting the electric heater (710) to a temperature of about 80°C or lower.

[0147] At this time, in order to separate the evaporated working fluid together with the ammonia evaporation gas, a working fluid catcher (clean water catcher) is placed in the ammonia water tank (700), and it is preferable to first separate the evaporated working fluid through the working fluid catcher.

[0148] If the evaporated working fluid is not separated even after the first separation, it is preferable to supply the ammonia evaporated gas and the evaporated working fluid to the steam separator (740) and perform the second separation.

[0149] At this time, it is preferable that the separated working fluid is supplied to the ejector (200) through the working fluid recovery line (WRL), and the working fluid supplied to the ejector (200) is recovered to the working fluid storage tank (310).

[0150] The ammonia vapor gas separated in the above-mentioned gas separator (740) is supplied to the ammonia compressor (750), and it is preferable to compress it to 8 bar to 10 bar.

[0151] At this time, the ammonia compressed in the ammonia compressor (750) may be supplied as compressed ammonia in a gaseous state, depending on the boiler type of the combustion unit (800), or may be supplied to a cooler (760) to be liquefied and then supplied as liquefied ammonia.

[0152] At this time, when liquefying the pressurized ammonia, it is preferable to supply the pressurized ammonia to the cooler (760) and operate the chiller (400) to cool it to 10°C and liquefy it.

[0153] It is preferable that the ammonia that has passed through the ammonia compressor (750) or cooler (760) is supplied to the combustion unit (800), and the ammonia supplied to the combustion unit (800) is combusted and reused as fuel oil.

[0154] Meanwhile, after supplying the ammonia water in the working fluid storage tank (310) to the ammonia recovery unit (500), it is preferable to open the working fluid supplement valve (350) to supply the working fluid to the working fluid storage tank (310). At this time, the working fluid is stored in the working fluid storage tank (310) through the filling unit (320), and it is preferable to keep the ammonia present in the filling unit (320) to a minimum and to keep the ammonia that is dissolved and vaporized to a minimum and to keep it in the working fluid (clean water) as much as possible.

[0155] As described above, the present invention has the effect of providing an ammonia recovery and discharge system and method.

[0156] Additionally, by using water (clean water) when operating the ammonia recovery and discharge system, the risk of leakage can be significantly reduced.

[0157] Additionally, it has the effect of preventing ammonia from being released into the atmosphere.

[0158] In addition, to prevent ammonia from being released into the atmosphere, it has the effect of reusing ammonia or safely discharging it overboard by separating ammonia from the ammonia water produced by dissolving the released ammonia gas.

[0159] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications, changes, and substitutions may be made without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical idea of ​​the present invention, but rather to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments and the accompanying drawings. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. For ships that use ammonia as fuel, Ammonia tank for storing liquid ammonia; An engine placed in an engine room and driven by receiving fuel from the ammonia tank; A fuel supply unit including a fuel supply line for supplying ammonia as fuel to the engine from the ammonia tank; A fuel recovery unit including a fuel return line for recovering ammonia not consumed in the engine to an ammonia tank; An air supply line that supplies air to the above fuel supply line and fuel return line; An air discharge line for discharging air supplied to the fuel supply line and fuel return line; and A working fluid circulation unit in which working fluid circulates to discharge air or ammonia in the fuel supply line and the fuel return line; An ammonia recovery and discharge system, wherein the above working fluid circulation unit includes an ejector that supplies high-pressure working fluid to circulate air or ammonia into the working fluid circulation unit.

2. In paragraph 1, The above working fluid circulation unit includes a working fluid storage tank that stores and recovers working fluid supplied to the ejector; A first venting line for discharging air supplied to the above working fluid storage tank to the outside; A chiller that cools the working fluid flowing into the working fluid storage tank; and It comprises an ammonia recovery unit for recovering ammonia introduced into the above working fluid circulation unit; The above working fluid storage tank and the above ejector are connected to a working fluid supply line, An ammonia recovery and discharge system, wherein the above ejector and working fluid storage tank are connected to a working fluid recirculation line.

3. In paragraph 1, A portion of the fuel supply line and fuel return line are placed within the engine room, The fuel supply line and fuel return line placed inside the engine room are double pipes. The annular space formed between the inner and outer pipes of the above double pipe is connected to the air supply line and the air exhaust line, The above air supply line and air discharge line are connected to the ejector, A first ammonia sensor for measuring the ammonia concentration on the air exhaust line; a pressure sensor that measures the flow of air; and Includes a circulation cutoff valve that controls the circulation of air when ammonia operation is stopped; An ammonia recovery and discharge system in which air supplied to the annular space through the above air supply line is supplied to an ejector through an air discharge line, and the air supplied to the ejector is introduced into a working fluid storage tank through a working fluid recirculation line.

4. In paragraph 3, The above first venting line is arranged at the upper part of one end of the working fluid storage tank, A second ammonia sensor is placed on the first venting line, The air discharged overboard through the above air discharge line passes through the buffer plate. Ammonia recovery and discharge system.

5. In paragraph 4, The above working fluid storage tank and the ammonia recovery unit are connected to an ammonia water supply line, When ammonia is detected by the above first ammonia sensor, the supply of ammonia fuel is stopped, Ammonia introduced through the above air discharge line is supplied to the filling unit and dissolved in the working fluid. An ammonia recovery and discharge system in which ammonia dissolved in the above working fluid is supplied to an ammonia recovery unit through the lower part of the working fluid storage tank after passing through a buffer plate.

6. In paragraph 1, Including a liquid fuel supply system section on the above fuel supply line, Including a fuel valve train area on the fuel supply line and fuel return line at the rear end of the above fuel supply system section, The above fuel supply line is connected to the ejector and the first ammonia recovery line, An ammonia recovery discharge system, wherein the above fuel return line is connected to the ejector and the second ammonia recovery line.

7. In paragraph 6, A first double-block valve is arranged on the fuel supply line of the above fuel valve train section, and a second double-block valve is arranged on the fuel return line of the above fuel valve train section. The above first double shut-off valve is connected to the ejector and the third ammonia recovery discharge line, An ammonia recovery discharge system, wherein the second double shut-off valve is connected to the ejector and the fourth ammonia recovery discharge line.

8. In paragraph 2, It further includes an ammonia dilution unit for diluting ammonia introduced into the above-mentioned working fluid storage tank; The ammonia dilution unit is arranged between the working fluid storage tank and the first venting line. The above ammonia dilution unit is an ammonia dilution chamber that supplies ammonia and dilutes it; and An ammonia recovery and discharge system, comprising a dilution pan for diluting ammonia in the ammonia dilution chamber.

9. In paragraph 2, The above ammonia recovery unit recovers ammonia dissolved in the working fluid that flows into the working fluid storage tank. An ammonia water tank that receives ammonia water from the above-mentioned working fluid storage tank, evaporates the ammonia, and separates it into ammonia and working fluid; A steam separator positioned at the top of the ammonia water tank to separate the evaporated working fluid and ammonia; An ammonia compressor for compressing ammonia separated from the above-mentioned steam separator; and An ammonia recovery and discharge system comprising a combustion unit that receives the compressed ammonia and combusts it to reuse it as fuel oil.

10. In paragraph 9, The above ammonia recovery unit further includes a cooler; The above cooler operates the chiller to cool, An ammonia recovery and discharge system in which ammonia compressed in the above ammonia compressor is supplied to a cooler to liquefy the compressed ammonia in a gaseous state, and the liquefied ammonia is supplied to the combustion unit.

11. In paragraph 9, The above working fluid storage tank and the ammonia water tank are connected to an ammonia water supply line formed by branching from the working fluid supply line, and an ammonia water transfer selection valve is arranged on the ammonia water supply line. An ammonia recovery and discharge system, wherein the ammonia water tank and ejector are connected to a working fluid recovery line, and a working fluid recovery valve is arranged on the working fluid recovery line.

12. A fuel supply step for supplying ammonia fuel from an ammonia tank to an engine through a fuel supply unit including a fuel supply line; When the above fuel supply step is performed, a working fluid circulation step is performed by supplying and circulating high-pressure working fluid to an ejector provided in the working fluid circulation section; A control method for an ammonia recovery and discharge system, comprising: performing an ammonia recovery step for recovering ammonia to an ammonia recovery unit when the above fuel supply step is interrupted.

13. In paragraph 12, The above working fluid circulation step includes an air circulation step of supplying air to the fuel supply line and the fuel return line and discharging the supplied air; The above air circulation step is an air supply step that supplies air to the annular space of the fuel supply line and fuel return line formed by a double pipe; and A control method for an ammonia recovery and discharge system, comprising: an air discharge step in which air introduced into the above-mentioned circulation space is supplied to an ejector, the air supplied to the ejector is introduced into a working fluid storage tank through a working fluid recirculation line, and the air introduced into the working fluid storage tank passes through a buffer plate and is discharged to the outside through the upper portion.

14. In paragraph 12, further comprising an ammonia leak detection step; The above ammonia leak detection step includes a first ammonia leak detection step for detecting whether there is an ammonia leak from the inner pipe of the double pipe to the outer pipe; and A control method for an ammonia recovery and discharge system, comprising a second ammonia leak detection step for detecting whether there is an ammonia leak from the above-mentioned working fluid storage tank.

15. In paragraph 14, The above first ammonia leak detection step is to stop the operation and ammonia fuel supply of the engine in which the gas leak is detected and perform the ammonia recovery step when the first ammonia sensor detects an ammonia leak. A first ammonia recovery step for recovering ammonia fuel existing in the fuel supply line and fuel return line to an ammonia recovery unit; and, A second ammonia recovery step for supplying nitrogen to the fuel supply line and recovering ammonia remaining in the fuel supply line and fuel return line; Control method of an ammonia recovery and discharge system.

16. In paragraph 15, The ammonia recovered by ejection through the above first ammonia recovery step is introduced into the working fluid storage tank. Ammonia flowing into the above working fluid storage tank is supplied to the filling unit, Ammonia supplied to the above filling material is dissolved in the working fluid, A control method for an ammonia recovery and discharge system, wherein ammonia (ammonia water) dissolved in the above working fluid passes through a buffer plate and is supplied to an ammonia recovery unit through the lower part of the working fluid storage tank for recovery.

17. In paragraph 16, The ammonia water supplied to the above ammonia water recovery unit is separated into working fluid and ammonia. A step of supplying the above ammonia water to an ammonia water tank; Step of heating the above ammonia water tank to a temperature at which ammonia can evaporate: A step of supplying evaporated ammonia from the ammonia water tank to a water separator and separating it into ammonia and working fluid; A step of supplying the separated ammonia to a compressor and compressing it; and A control method for an ammonia recovery and discharge system, comprising: a step of supplying the compressed ammonia to a combustion unit and combusting it to reuse it as fuel oil; 18. In paragraph 14, The above second ammonia leak detection step includes a cooling step of operating a chiller to cool the working fluid (ammonia water) in which ammonia is dissolved in the working fluid storage tank so that the concentration of ammonia measured by the second ammonia sensor becomes 20 ppm or less when an ammonia leak is detected by the second ammonia sensor; A control method for an ammonia recovery and discharge system, wherein if the ammonia concentration is 20 ppm or less after performing the above cooling step, the cooling temperature of the chiller is controlled to gradually increase and the working fluid in which ammonia is dissolved in the working fluid storage tank is supplied to the ammonia recovery unit.

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