Ammonia processing system and ship comprising the same

Abstract

To provide an ammonia processing system.SOLUTION: The ammonia processing system comprises: a fuel supply unit for supplying ammonia discharged from an ammonia storage tank to an engine; a fuel recovery unit for recovering excess ammonia returned from the engine; an exhaust processing unit for processing exhaust discharged from the engine; and a vent unit for discharging ammonia discharged from the fuel supply unit or the fuel recovery unit to an outside. The vent unit comprises: a low-pressure discharge drum for collecting low-pressure ammonia discharged from the ammonia storage tank or the fuel supply unit; a high-pressure discharge drum for collecting high-pressure ammonia discharged from the fuel supply unit or the fuel recovery unit; and a discharge processor for processing ammonia and delivering the processed ammonia to a vent mast. The low-pressure discharge drum or the high-pressure discharge drum delivers ammonia to the exhaust processing unit or the discharge processor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ammonia processing system and a vessel including the same. [Background technology]

[0002] Air pollution is becoming a serious problem worldwide, and climate change is being caused by it. Pollutants emitted from ships have a significant impact on air pollution, so in order to reduce air pollution, the International Maritime Organization (IMO), the European Union, the United States, and other organizations are strengthening regulations on pollutants emitted from ships.

[0003] As greenhouse gas emission regulations for ships are to be gradually strengthened at each major milestone until 2050, it is expected that it will be difficult to comply with regulations on pollutants using existing engines and fuels alone.

[0004] Therefore, as stricter greenhouse gas emission regulations for ships are applied, it is expected that the use of existing fossil fuels will become more difficult, and it is extremely urgent to find alternative fuels that can meet the stricter regulations in the future. Non-fossil fuels such as ammonia (NH3), biofuel, solar energy, and wind energy are currently being considered as alternative fuels.

[0005] Among these, ammonia is a chemical substance that can be produced, stored, transported, and supplied, and ammonia ships that use ammonia as fuel are being developed.

[0006] Existing ammonia ships store ammonia fuel as a liquid, but because ammonia has a boiling point lower than room temperature (-33°C at atmospheric pressure), the ammonia storage tank must also meet certain specifications in order to store ammonia as a liquid.In addition, because the inside of the tank must be kept at a low temperature to keep the ammonia in a liquid state, the storage tank must be cooled, and the cooling process consumes a lot of energy.

[0007] Furthermore, liquid ammonia storage tanks may generate vapors inside the tank, which may increase the internal pressure of the storage tank and cause the tank to explode. If liquid ammonia leaks out of the tank, an explosion may occur, posing a risk of loss of life due to the toxicity of ammonia.

[0008] As described above, existing ammonia ships have limitations in that they store liquid ammonia fuel and supply the ammonia fuel to the engine, resulting in reduced efficiency in terms of equipment costs and operating costs, as well as reduced safety of the facility. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made to solve the above-mentioned problems of the conventional art, and aims to provide an ammonia treatment system and a ship including the same, which ensure stable and reliable fuel supply and efficient exhaust treatment when supplying ammonia as engine fuel. [Means for solving the problem]

[0010] An ammonia treatment system according to one aspect of the present invention includes a fuel supply unit that supplies ammonia discharged from an ammonia storage tank to an engine, a fuel recovery unit that recovers excess ammonia returned from the engine, an exhaust treatment unit that treats exhaust gas discharged from the engine, and a vent unit that discharges ammonia discharged from the fuel supply unit or the fuel recovery unit to the outside, wherein the vent unit includes a low-pressure discharge drum that collects low-pressure ammonia discharged from the ammonia storage tank or the fuel supply unit, a high-pressure discharge drum that collects high-pressure ammonia discharged from the fuel supply unit or the fuel recovery unit, and an exhaust treatment machine that treats the ammonia and delivers it to a vent mast, and the low-pressure discharge drum or the high-pressure discharge drum delivers the ammonia to the exhaust treatment unit or the exhaust treatment machine.

[0011] Specifically, the exhaust treatment unit can use at least a portion of the ammonia supplied to the engine by the fuel supply unit as a reducing agent.

[0012] Specifically, the low-pressure discharge drum and the high-pressure discharge drum may transfer at least a portion of the collected ammonia to the ammonia storage tank.

[0013] Specifically, the ammonia storage tank may further include a re-liquefaction unit that re-liquefies the evaporated gas discharged from the ammonia storage tank, and the re-liquefaction unit may transfer at least a portion of the evaporated gas to the low-pressure discharge drum or the exhaust treatment unit.

[0014] Specifically, the fuel supply unit includes a low-pressure pump that transfers ammonia, a high-pressure pump that pressurizes the ammonia pressurized by the low-pressure pump to correspond to the pressure required by the engine, and a heat exchanger that adjusts the temperature of the ammonia, and the fuel recovery unit includes a cooler that cools excess ammonia discharged from the engine and transfers it from the fuel supply unit to between the low-pressure pump and the high-pressure pump, and a catch drum that is provided in parallel with the cooler and temporarily stores the ammonia.

[0015] An ammonia treatment system according to one aspect of the present invention includes a fuel supply unit that supplies ammonia discharged from an ammonia storage tank to an engine, a fuel recovery unit that recovers excess ammonia returned from the engine, an exhaust treatment unit that treats exhaust gas discharged from the engine, and a vent unit that discharges ammonia discharged from the fuel supply unit or the fuel recovery unit to the outside, wherein the exhaust treatment unit oxidizes ammonia, and the vent unit includes an exhaust treatment device that collects ammonia discharged from the ammonia storage tank, the fuel supply unit, or the fuel recovery unit, mixes the ammonia with water, and delivers the ammonia to the exhaust treatment unit.

[0016] Specifically, the vent unit may further include an exhaust drum that collects ammonia discharged from the ammonia storage tank, the fuel supply unit, or the fuel recovery unit and delivers the collected ammonia to the exhaust treatment unit or the exhaust treatment unit, and the exhaust treatment unit may collect ammonia using water and deliver ammonia water to the exhaust treatment unit.

[0017] Specifically, the fuel supply unit or the fuel recovery unit may further include a purge unit that uses a non-explosive gas to purge the fuel supply unit or the fuel recovery unit, and the purge unit may deliver the non-explosive gas to the discharge drum to adjust the pressure of the discharge drum to be higher than that of the exhaust processor or the exhaust treatment unit.

[0018] An ammonia processing system according to one aspect of the present invention includes a fuel supply unit that supplies ammonia discharged from an ammonia storage tank to an engine, a fuel recovery unit that recovers excess ammonia returned from the engine, an exhaust treatment unit that treats exhaust gas discharged from the engine, and a vent unit that releases ammonia discharged from the fuel supply unit or the fuel recovery unit to the outside, wherein the fuel supply unit includes a low-pressure pump that transfers ammonia, a high-pressure pump that pressurizes the ammonia pressurized by the low-pressure pump to a pressure corresponding to the required pressure of the engine, and a heat exchanger that adjusts the temperature of the ammonia, and the fuel recovery unit includes a cooler that cools the excess ammonia discharged from the engine and transfers it from the fuel supply unit to between the low-pressure pump and the high-pressure pump, and a pressure regulating valve that is provided downstream of the cooler and maintains the ammonia flowing from the fuel recovery unit toward the fuel supply unit at or above its saturation pressure at a corresponding temperature.

[0019] Specifically, the fuel recovery unit may further include a mixer that mixes excess ammonia discharged from the engine with ammonia between the low-pressure pump and the high-pressure pump in the fuel supply unit, and the pressure regulating valve may be provided between the cooler and the mixer.

[0020] Specifically, the cooler may include a first cooler that cools the ammonia using a medium provided separately from the ammonia, and a second cooler that is provided downstream or upstream of the first cooler and uses the ammonia from the fuel supply unit.

[0021] Specifically, the heat exchanger includes a first heat exchanger provided between the low-pressure pump and the high-pressure pump, and a second heat exchanger provided between the high-pressure pump and the engine, and the first heat exchanger is provided between the mixer and the high-pressure pump, and the second heat exchanger is provided between the second cooler and the engine.

[0022] A ship according to one aspect of the present invention includes the above-described ammonia treatment system. [Effects of the Invention]

[0023] The ammonia processing system and the ship including the same according to the present invention can not only efficiently supply ammonia to the ammonia engine, but also exhibit excellent performance in venting, purging, exhaust treatment, etc. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a conceptual diagram of an ammonia treatment system according to a first embodiment of the present invention. [Figure 2] 1 is a conceptual diagram of an ammonia treatment system according to a first embodiment of the present invention. [Figure 3] 1 is a conceptual diagram of an ammonia treatment system according to a first embodiment of the present invention. [Figure 4] 1 is a conceptual diagram of an ammonia treatment system according to a first embodiment of the present invention. [Figure 5] FIG. 1 is a conceptual diagram of an ammonia treatment system according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a conceptual diagram of an ammonia treatment system according to a third embodiment of the present invention. [Figure 7] FIG. 10 is a conceptual diagram of an ammonia treatment system according to a fourth embodiment of the present invention. [Figure 8] FIG. 10 is a conceptual diagram of an ammonia treatment system according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The objects, particular advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In this specification, when referring to components in each drawing, please note that the same components are numbered as much as possible even if they appear in different drawings. Furthermore, when describing the present invention, if a detailed description of related prior art is deemed to unnecessarily obscure the gist of the present invention, such a detailed description will be omitted.

[0026] The present invention includes a ship equipped with an ammonia processing system described below. Here, the term "ship" is a concept that includes all ammonia carriers, commercial ships carrying cargoes other than ammonia or passengers, FSRUs, FPSOs, bunkering vessels, offshore plants, etc.

[0027] Although not shown in the drawings of the present invention, pressure sensors (PT), temperature sensors (TT), flow rate sensors (FT), etc. may be installed at any suitable location without limitation, and the measurement values ​​from each sensor may be used in various ways without limitation in the operation of the configuration described below.

[0028] Also, the straight lines in the drawings of the present invention represent flow paths through which various fluids such as ammonia, heat transfer media, and non-explosive gases move, and can be interpreted as pipelines.

[0029] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] 1 to 4 are conceptual diagrams of an ammonia treatment system according to a first embodiment of the present invention.

[0031] 1 to 4, an ammonia treatment system 1 according to a first embodiment of the present invention includes an ammonia storage tank 10, a fuel supply unit 20, a fuel recovery unit, an exhaust treatment unit 40, a vent unit 50, a re-liquefaction unit 60, a drain treatment unit 70, and a purge unit 80.

[0032] The ammonia storage tank 10 stores ammonia. The ammonia is used as fuel to be consumed by the engine E. In this case, the engine E may be an ammonia-only engine E or an ammonia-mixed combustion engine E. Of course, the engine E in this specification is an engine that consumes ammonia to obtain energy, and is interpreted as including a turbine, etc.

[0033] The ammonia storage tank 10 stores ammonia in a liquid phase, and therefore, thermal insulation may be applied to at least one of the inside and outside of the ammonia storage tank 10. Alternatively, the ammonia storage tank 10 may store ammonia at high pressure to prevent the ammonia from liquefying, in which case the low-pressure pump 21 of the fuel supply unit 20, which will be described later, may be reduced in size or omitted.

[0034] The ammonia storage tank 10 may be installed inside the ship to form a cargo hold, or may be a fuel tank installed separately inside or on the deck of the ship. One or more ammonia storage tanks 10 may be installed, and when multiple ammonia storage tanks 10 are installed, ammonia may be consumed alternatively or simultaneously.

[0035] A bunkering unit 11 is connected to the ammonia storage tank 10. The bunkering unit 11 transfers ammonia from an external oil source to the ammonia storage tank 10. The external oil source may be a land-based ammonia supply source or an ammonia bunkering vessel at sea.

[0036] The bunkering unit 11 can connect the ammonia storage tank 10 to an oil supply source using a manifold, a loading arm, etc., and the oil supply source delivers ammonia at a constant pressure to the ammonia storage tank 10. However, as ammonia evaporates in the ammonia storage tank 10, evaporated gas may be generated, which increases the internal pressure of the ammonia storage tank 10, resulting in a situation where the pressure of the ammonia storage tank 10 is higher than that of the oil supply source.

[0037] At this time, the oil supply source consumes a large load when supplying ammonia to the ammonia storage tank 10, so the bunkering unit 11 can use a bunkering compressor (not shown) to resolve this situation. The bunkering compressor compresses the evaporated gas generated in the ammonia storage tank 10 and transmits it to the oil supply source, thereby increasing the pressure of the oil supply source and ensuring a pressure difference between the oil supply source and the ammonia storage tank 10. As a result, the bunkering unit 11 can smoothly supply ammonia from the oil supply source to the ammonia storage tank 10.

[0038] The bunkering compressor can use the evaporated gas generated in the oil source in addition to the evaporated gas from the ammonia storage tank 10. Alternatively, the bunkering compressor can use a gas other than ammonia to increase the pressure of the oil source, and in this case, the oil source can have a structure that delivers only ammonia to the ammonia storage tank 10.

[0039] The ammonia storage tank 10 may be provided with a pressure regulator 12. The pressure regulator 12 may be a PBU (Pressure Build-up Unit) that heats or vaporizes the ammonia discharged from the ammonia storage tank 10 and then injects it into the ammonia storage tank 10 to increase the internal pressure of the ammonia storage tank 10, or may be a supercooler that cools / supercools the ammonia and returns it.

[0040] Alternatively, the pressure adjusting unit 12 may be a re-liquefaction unit 60, and the pressure adjusting unit 12 can increase or decrease the internal pressure of the ammonia storage tank 10 to ensure the stability of the ammonia fuel supply.

[0041] The fuel supply unit 20 supplies ammonia from the ammonia storage tank 10 to the engine E. The fuel supply unit 20 can supply liquid-phase ammonia from the ammonia stored in the ammonia storage tank 10 to the engine E. In particular, taking into consideration the specifications of the engine E that currently consumes ammonia, the fuel supply unit 20 is configured to supply liquid-phase ammonia to the engine E. The fuel supply unit 20 can also adjust the state of ammonia in various ways in response to changes in the specifications of the engine E.

[0042] The fuel supply unit 20 may be divided into a low-pressure section and a high-pressure section, and the low-pressure section and the high-pressure section may be configured as skids. Also, the skid on which the low-pressure section is provided (LP skid) and the skid on which the high-pressure section is provided (HP skid) may be provided separately or may have a structure that allows them to be connected to each other.

[0043] In the case of a low pressure skid (LP Skid), an ammonia storage tank 10 may be provided in addition to the configuration of the fuel supply unit 20. On the other hand, in the case of a high pressure skid (HP Skid), in addition to the configuration of the fuel supply unit 20, a configuration of a fuel recovery unit, which will be described later, may be provided together.

[0044] 4, the low-pressure portion of the fuel supply unit 20 includes a low-pressure pump 21. The low-pressure pump 21 serves to draw ammonia stored in the ammonia storage tank 10 to the outside, and may be a fixed displacement type or a variable displacement type (VFD), etc.

[0045] The low-pressure pump 21 may be disposed downstream of the ammonia storage tank 10 as shown in the figure, but it may also be disposed inside the ammonia storage tank 10. Furthermore, as described above, the low-pressure pump 21 may be omitted depending on the type and internal pressure of the ammonia storage tank 10.

[0046] Unlike the drawing, a plurality of low-pressure pumps 21 may be provided to form a structure capable of backing up each other, and a plurality of low-pressure pumps 21 may be provided to operate simultaneously to share the load. Alternatively, a plurality of low-pressure pumps 21 may be provided in series to utilize a multi-stage pressurization method.

[0047] A constant flow rate of ammonia must be continuously supplied to the low-pressure pump 21, which is essential for stable operation of the low-pressure pump 21. This flow rate is called the net positive suction head (NPSHr), and a flow rate greater than the net positive suction head is supplied to the low-pressure pump 21.

[0048] However, since the flow rate required by the engine E may be less than the effective suction head, a flow path for returning ammonia to the ammonia storage tank 10 may be provided downstream of the low-pressure pump 21. In this case, the return flow path connected to the ammonia storage tank 10 downstream of the low-pressure pump 21 may be connected to the pressure adjustment unit 12.

[0049] 4 again, the high-pressure section of the fuel supply unit 20 includes a high-pressure pump 22 and a heat exchanger 23. The high-pressure pump 22 pressurizes the ammonia pressurized by the low-pressure pump 21 to a pressure corresponding to the pressure required by the engine E. As with the low-pressure pump 21, one or more high-pressure pumps 22 may be provided in series or in parallel.

[0050] The high-pressure pump 22 may be provided as a variable displacement pump, and the load can be varied according to the measurement value of a flow meter that can be provided between the low-pressure pump 21 and the high-pressure pump 22. In this case, the flow meter may be provided at a position that reflects the flow rate of the excess ammonia recovered by the fuel recovery unit.

[0051] The fuel recovery unit described below can transfer excess ammonia discharged from the engine E to the high-pressure pump 22, but due to the specifications of the high-pressure pump 22, it is not desirable for gas phase ammonia to flow in. Therefore, it is required that the ammonia upstream of the high-pressure pump 22 exists only in the liquid phase, and therefore the temperature and pressure upstream of the high-pressure pump 22 can be effectively controlled.

[0052] As an example, the ammonia recovered by the fuel recovery section can be cooled and the pressure of the ammonia upstream of the high pressure pump 22 can be kept high to increase the boiling point of the ammonia and inhibit vaporization.

[0053] As described for the low-pressure pump 21, the high-pressure pump 22 continuously receives a minimum flow rate to satisfy the effective suction head, and in case of an excess, a return line is provided downstream of the high-pressure pump 22. The return line circulates the excess over the flow rate supplied to the engine E from downstream to upstream of the high-pressure pump 22, and may be connected to a mixer 33 in the fuel recovery section.

[0054] The heat exchanger 23 adjusts the temperature of the ammonia. The heat exchanger 23 may be provided between the low-pressure pump 21 and the high-pressure pump 22, or may be disposed on the high-pressure skid. The heat exchanger 23 can adjust the temperature of the ammonia to correspond to the temperature required by the engine E by using a heat medium such as glycol water GW.

[0055] The heat exchanger 23 may be a heater that heats ammonia. Normally, the temperature required by the engine E is higher than the storage temperature of the ammonia storage tank 10 (which is equal to or lower than the boiling point of ammonia at atmospheric pressure), and the temperature rise that occurs when the low-pressure pump 21 and the high-pressure pump 22 pressurize the ammonia is not enough to meet the temperature required by the engine E, so the heat exchanger 23 may be used.

[0056] However, the heat exchanger 23 is provided upstream of the high-pressure pump 22 and can appropriately adjust the temperature of the ammonia so that the ammonia vapor does not flow into the high-pressure pump 22. At this time, the heat exchanger 23 controls the heating temperature of the ammonia in consideration of the recovery of ammonia by the fuel recovery unit.

[0057] The fuel supply unit 20 includes a heat medium supply unit 25 for supplying a heat medium to the heat exchanger 23. The heat medium supply unit 25 can circulate a heat medium such as glycol water to the heat exchanger 23, and the heat medium can be replenished or discharged from the heat medium circulation path as needed. Alternatively, the heat medium supply unit 25 may be provided in a form that continuously supplies new heat medium through the heat exchanger 23.

[0058] The heat medium supplying unit 25 can heat or cool the temperature of the heat medium to appropriately match the temperature of the ammonia that is heat exchanged with the heat medium in the heat exchanger 23. To this end, the heat medium supplying unit 25 can include both a heat medium heater 251 and a heat medium cooler 252.

[0059] The heat medium heater 251 is configured to heat the heat medium with a heat source such as steam, and can sufficiently increase the temperature of the heat medium after the heat medium is cooled by ammonia in the heat exchanger 23 and before it flows back into the heat exchanger 23. At this time, the heating temperature of the heat medium can be adjusted by at least a portion of the heat medium bypassing the heat medium heater 251.

[0060] The heat transfer medium cooler 252 is configured to heat a heat transfer medium with a cold source such as fresh water, and when the high-temperature ammonia recovered by the fuel recovery unit is in a relatively large amount during operation, the temperature of the heat transfer medium can be lowered to appropriately match the temperature of the ammonia flowing into the high-pressure pump 22. Alternatively, the heat transfer medium cooler 252 can cool the heat transfer medium heated by the cooler 31 of the fuel recovery unit, which will be described below. The cooling of the heat transfer medium cooler 252 can also be controlled by using partial bypass of the heat transfer medium, similar to the heat transfer medium heater 251.

[0061] The heat transfer medium cooler 252 and the heat transfer medium heater 251 may be installed in parallel or in series and operated alternatively. The arrangement and operation of the heat transfer medium cooler 252 and the heat transfer medium heater 251 can be modified in various ways to efficiently adjust the temperature of the heat transfer medium.

[0062] The fuel supply unit 20 includes a valve for adjusting the supply flow rate of ammonia immediately before the engine E, and in this case, such a valve can be called a fuel supply valve train SVT.

[0063] The fuel recovery unit recovers excess ammonia returned from engine E. Ammonia engine E, which is currently developed or under development, receives and consumes ammonia in the liquid phase, but is structured to further receive a surplus supply in order to stably receive the required flow rate.

[0064] At this time, the excess ammonia can be discharged from the engine E after passing through at least a part of the engine E, but in this case, the ammonia may be mixed with the lubricating oil used in the engine E. Therefore, the excess ammonia discharged from the engine E is in a contaminated state, and it is not desirable for it to be returned to the ammonia storage tank 10.

[0065] However, since such excess ammonia can be consumed by the engine E, the fuel recovery unit transfers the excess ammonia discharged from the engine E to the fuel supply unit 20. Specifically, the fuel recovery unit can transfer the excess ammonia from the fuel supply unit 20 to the high-pressure pump 22, and includes a cooler 31, a catch drum 32, a mixer 33, and the like as shown in FIG.

[0066] The cooler 31 cools the excess ammonia discharged from the engine E. Since the excess ammonia has passed through the engine E, it may be in a heated state due to the heat generated by the engine E, and if it is returned as is and flows into the high-pressure pump 22, it may induce the inflow of gas phase ammonia into the high-pressure pump 22. Therefore, the cooler 31 cools the excess ammonia with fresh water or the like and transfers it between the low-pressure pump 21 and the high-pressure pump 22 in the fuel supply unit 20, thereby preventing the inflow of ammonia gas into the high-pressure pump 22.

[0067] The cooler 31 can utilize the heat medium of the heat exchanger 23. That is, the heat medium circulation flow path of the heat medium supply unit 25 may be provided to pass through the cooler 31, and the cooler 31 may be disposed downstream of the heat exchanger 23 based on the flow of the heat medium.

[0068] Therefore, the heat medium is cooled while heating ammonia in the heat exchanger 23, and then heated while cooling excess ammonia in the cooler 31. Thereafter, the heat medium is again introduced into the heat exchanger 23, and at this time, the temperature of the heat medium introduced into the heat exchanger 23 can be appropriately adjusted by the heat medium heater 251 and / or the heat medium cooler 252.

[0069] Catch drum 32 is provided in parallel with cooler 31 and temporarily stores ammonia. Catch drum 32 may be configured to separate excess ammonia into gas and liquid to prevent the gas phase from flowing into high-pressure pump 22. Catch drum 32 may also be provided to remove lubricating oil contained in excess ammonia.

[0070] Unlike the drawing, the catch drum 32 may have a structure including a gas-liquid separator and a knock-out drum. In this case, excess ammonia first flows into the gas-liquid separator to separate the gas phase, and at least a portion of the liquid excess ammonia flows into the knock-out drum to separate the lubricant. That is, although the separation of the gas phase and the lubricant can be performed using separate components, for convenience, the components that realize these functions can be collectively referred to as the catch drum 32.

[0071] Mixer 33 mixes excess ammonia discharged from engine E with ammonia between low-pressure pump 21 and high-pressure pump 22 in fuel supply unit 20. Mixer 33 allows ammonia that has passed through cooler 31 or catch drum 32 to be mixed with ammonia in fuel supply unit 20, and may be provided as a container-type mixer, an in-line mixer, or the like.

[0072] The fuel recovery section is provided with a valve for adjusting the return flow rate of ammonia immediately after the engine E, and in this case, the valve can be called a fuel return valve train RVT.

[0073] The exhaust treatment unit 40 treats the exhaust gas emitted from the engine E. The exhaust gas from the engine E may contain various particles and environmental pollutants such as nitrogen oxides (NOx), and the exhaust treatment unit 40 can appropriately treat the pollutants in the exhaust gas by using filtering, chemical reactions, etc.

[0074] For example, the exhaust treatment device 40 may be a selective catalytic reduction device (SCR) or a scrubber, etc. However, in this embodiment, the exhaust treatment device 40 may be configured to include at least an SCR, and ammonia, etc. may be used as a reducing agent.

[0075] The reducing agent used by the exhaust treatment unit 40 may be supplied separately from the outside, or may be delivered from the fuel supply unit 20, etc. That is, the fuel supply unit 20 can deliver a portion of the ammonia flowing toward the engine E from at least a portion of the low-pressure portion or the high-pressure portion to the exhaust treatment unit 40. Therefore, the exhaust treatment unit 40 can use at least a portion of the ammonia delivered to the engine E by the fuel supply unit 20 as a reducing agent. However, the ammonia in the high-pressure portion of the fuel supply unit 20 can be delivered to the exhaust treatment unit 40 after its pressure is reduced using a valve, etc.

[0076] The exhaust treatment unit 40 can also purify nitrogen oxides and the like contained in the exhaust gas of the engine E by using ammonia transferred from a vent unit 50 (described later) as a reducing agent.

[0077] The engine E of this embodiment is an engine E that consumes ammonia, and some ammonia may be mixed into the exhaust gas (ammonia slip). In this case, the exhaust treatment unit 40 can oxidize and purify the ammonia contained in the exhaust gas.

[0078] The oxidation of ammonia may be performed by SCR, which reduces nitrogen oxides using ammonia, and the exhaust treatment device 40 can oxidize ammonia by causing ammonia and nitrogen oxides contained in the exhaust gas to interact with each other.

[0079] Alternatively, ammonia oxidation may be performed separately from the SCR. In this case, ammonia oxidation may be a reaction in which ammonia reacts with oxygen to produce nitrogen oxides and water (4NH3 + 5O2 → 4NO + 6H2O), and the nitrogen oxides produced at this time can be purified by the SCR described above. However, in this case, it is preferable that ammonia oxidation be performed before reduction by the SCR.

[0080] Therefore, the exhaust treatment device 40 may be equipped with only a nitrogen oxide reduction device (not shown) that is an SCR, thereby simultaneously implementing ammonia oxidation and nitrogen oxide reduction, or the exhaust treatment device 40 may include a nitrogen oxide reduction device (not shown) and an ammonia oxidation device (not shown).

[0081] In the latter case, the ammonia oxidation unit is placed upstream of the nitrogen oxide reduction unit, and ammonia slip converts the ammonia mixed in the exhaust gas into nitrogen oxides and water.The nitrogen oxide reduction unit then uses ammonia as a reducing agent to convert the nitrogen oxides into nitrogen and water (4NO + 4NH3 + O2 -> 2N2 + 3H2O), ensuring that the ratio of ammonia and nitrogen oxides in the exhaust gas falls within the standard range.

[0082] Of course, the exhaust treatment unit 40 may include an ammonia filter (not shown) that filters out ammonia mixed in the exhaust, and ammonia other than the ammonia in the exhaust may be used as a reducing agent for the nitrogen oxide reduction unit, or the ammonia oxidation unit may be minimized or omitted.

[0083] The exhaust treatment unit 40 can sufficiently purify the exhaust gas from the engine E before discharging it into the atmosphere. The exhaust gas purified by the exhaust treatment unit 40 is discharged to the outside through a funnel having a certain height and treated so as not to cause any harm to people.

[0084] The vent unit 50 releases to the outside the ammonia discharged from the fuel supply unit 20. The vent unit 50 serves to remove ammonia from the system in an abnormal situation, such as when an ammonia leak is detected or the system is shut down due to a stoppage of the engine E.

[0085] The vent unit 50 may be provided to discharge ammonia discharged from the ammonia storage tank 10, the fuel recovery unit, etc., in addition to the fuel supply unit 20. That is, the vent unit 50 is connected to the parts of the entire system where ammonia is stored or flows, ensuring quick and safe discharge of ammonia.

[0086] The vent section 50 includes discharge drums 51 and 52, a discharge processor 53, and a vent mast 54. The discharge drums 51 and 52 collect ammonia discharged from the ammonia storage tank 10, the fuel supply section 20, or the fuel recovery section.

[0087] Discharge drums 51 and 52 are container-shaped and receive ammonia from fuel supply unit 20 or the like. At this time, the ammonia transferred to discharge drums 51 and 52 may be in a gas phase or liquid phase, but may be mainly in a gas phase.

[0088] The discharge drums 51 and 52 can capture ammonia using water. That is, water may be stored in the discharge drums 51 and 52, and the ammonia flowing into the discharge drums 51 and 52 dissolves in the water to produce ammonia water.

[0089] The ammonia flowing into the discharge drums 51 and 52 may be delivered to the discharge processor 53, which will be described later, or may be delivered to the exhaust treatment unit 40. That is, the ammonia water in the discharge drums 51 and 52 may be supplied to the exhaust treatment unit 40 and used as a reducing agent in the exhaust treatment unit 40, or may be oxidized in the exhaust treatment unit 40.

[0090] The discharge drums 51, 52 are divided into a low-pressure discharge drum 51 and a high-pressure discharge drum 52. The low-pressure discharge drum 51 collects ammonia discharged from the low-pressure section, and the high-pressure discharge drum 52 collects ammonia discharged from the high-pressure section. That is, the low-pressure discharge drum 51 collects low-pressure ammonia discharged from the ammonia storage tank 10 or the low-pressure pump 21 of the fuel supply unit 20, etc., and the high-pressure discharge drum 52 can collect high-pressure ammonia discharged from the heat exchanger 23 of the fuel supply unit 20, the high-pressure pump 22, the cooler 31 of the fuel recovery unit, the catch drum 32, etc.

[0091] As described above, the low-pressure discharge drum 51 and the high-pressure discharge drum 52 can deliver ammonia to the exhaust processor 53 or to the exhaust treatment unit 40. In the former case, the ammonia is delivered to the exhaust processor 53 in a gaseous state, and in the latter case, the ammonia is delivered to the exhaust treatment unit 40 in the form of ammonia water to be used as a reducing agent or to be oxidized.

[0092] Alternatively, the low-pressure discharge drum 51 and the high-pressure discharge drum 52 can transfer at least a portion of the collected ammonia to the ammonia storage tank 10 or the like. That is, the low-pressure discharge drum 51 or the like has a structure capable of separating ammonia, and only the ammonia can be recovered in the ammonia storage tank 10.

[0093] Instead of the low-pressure discharge drum 51 separating ammonia and delivering it to the ammonia storage tank 10, the low-pressure discharge drum 51 delivers a fluid mixture of ammonia and water to the ammonia storage tank 10, and a filter (not shown) for filtering out substances other than ammonia may be used along the way.

[0094] That is, the discharge drums 51 and 52 recover the collected ammonia in the ammonia storage tank 10, and if recovery is difficult, the ammonia can be transferred to the exhaust treatment unit 40. In addition, the gaseous ammonia in the discharge drums 51 and 52 can be sent to the exhaust treatment unit 53 for treatment.

[0095] The low-pressure discharge drum 51 can directly deliver ammonia to the ammonia storage tank 10 or the discharge processor 53, while the high-pressure discharge drum 52 has a larger internal pressure difference compared to the ammonia storage tank 10, etc., so the ammonia in the high-pressure discharge drum 52 can be decompressed using a valve, etc. before being delivered to the ammonia storage tank 10, etc.

[0096] Conversely, if the pressure in the discharge drums 51, 52 is insufficient, the internal pressure of the discharge drums 51, 52 can be increased using the purge unit 80. The purge unit 80, which will be described later, is configured to purge the fuel supply unit 20 and / or the fuel recovery unit using a non-explosive gas such as nitrogen, and if it is necessary to increase the pressure in the discharge drums 51, 52, the purge unit 80 can inject the non-explosive gas into the discharge drums 51, 52.

[0097] Therefore, the internal pressure of the discharge drums 51 and 52 can be sufficiently increased by the purge unit 80, and thus the ammonia stored in the discharge drums 51 and 52 can be smoothly transferred to the ammonia storage tank 10, the discharge processor 53, or the exhaust gas treatment unit 40 without any additional pressurization or compression.

[0098] The discharge processor 53 processes the ammonia and delivers it to the vent mast 54. The discharge processor 53 collects the ammonia delivered from the discharge drums 51 and 52, and delivers the ammonia to the vent mast 54 within a certain level (e.g., 30 ppm).

[0099] The discharge processor 53 is configured to capture ammonia using water, and may be a water tank that dissolves ammonia in water or a water scrubber that injects water into ammonia. In this case, the substances transferred from the discharge drums 51 and 52 to the vent mast 54 via the discharge processor 53 may mainly be nitrogen.

[0100] The discharge processor 53 may deliver ammonia water, which is generated by mixing ammonia with water, to the exhaust treatment unit 40. That is, the ammonia collected by the discharge processor 53 may be used as a reducing agent in the exhaust treatment unit 40, and in this case, a discharge pump 531 may be used.

[0101] However, the discharge processor 53 can adjust the ratio of ammonia to water depending on the operating state of the exhaust treatment unit 40. That is, the discharge processor 53 can adjust the inflow of ammonia water, which is a mixture of ammonia and water, so that the exhaust treatment unit 40 can operate normally. At this time, the discharge processor 53 and the exhaust treatment unit 40 can mutually control the delivery of ammonia water through appropriate sensors and signal transmission.

[0102] For example, the exhaust treatment unit 40 may be provided with a sensor for measuring pollutants in the exhaust gas being discharged, and the specifications of the ammonia water that the exhaust treatment unit 53 delivers to the exhaust treatment unit 40 may be adjusted according to the sensor's measurement value. And / or the temperature, pressure, flow rate, etc. of the exhaust gas flowing into the exhaust treatment unit 40 may be used as control variables for the exhaust treatment unit 53.

[0103] The re-liquefaction unit 60 re-liquefies the evaporated gas discharged from the ammonia storage tank 10. The re-liquefaction unit 60 can re-liquefy ammonia using a separate refrigerant other than ammonia (indirect type). In this case, the refrigerant may be nitrogen, a mixed refrigerant, etc.

[0104] Alternatively, the re-liquefaction unit 60 may be a direct type that re-liquefies ammonia using heat exchange between ammonia. For example, the re-liquefaction unit 60 may compress and cool ammonia, and then depressurize and liquefy a portion of the ammonia and liquefy the remaining ammonia, using the ammonia as a refrigerant.

[0105] The method by which the re-liquefaction unit 60 re-liquefies ammonia can be implemented using various known re-liquefaction devices, and therefore detailed description thereof will be omitted.

[0106] The reliquefaction unit 60 can transmit at least a portion of the evaporated gas to the low-pressure discharge drum 51 or the exhaust treatment unit 40. The reliquefaction unit 60 is equipped with a compressor (not shown) to improve the liquefaction performance of the evaporated gas, and the evaporated gas compressed by the compressor of the reliquefaction unit 60 can be transmitted to the low-pressure discharge drum 51 to help increase the internal pressure of the low-pressure discharge drum 51. Alternatively, the reliquefaction unit 60 can compress and transmit the evaporated gas to supplement the pressure of ammonia transmitted from the discharge drums 51, 52 or the exhaust treatment unit 53 to the exhaust treatment unit 40.

[0107] At this time, reliquefaction unit 60 can adjust the load of the compressor based on the internal pressure of discharge drums 51 and 52. That is, reliquefaction unit 60 can operate the compressor exclusively for reliquefaction when reliquefaction of ammonia evaporated gas is required, and can operate the compressor for ammonia transmission when transmission of ammonia evaporated gas is required. In this case, reliquefaction unit 60 can be provided with one or more compressors, one of which can be used for reliquefaction and the other for ammonia transmission.

[0108] Of course, the re-liquefaction unit 60 can also transfer the ammonia discharged from the ammonia storage tank 10 to the discharge drums 51, 52, the exhaust treatment unit 40, etc. in an uncompressed state. In this case, the load on the compressor can be reduced as part of the evaporated gas discharged from the ammonia storage tank 10 is transferred to the discharge drums 51, 52, etc.

[0109] The drain treatment device 70 recovers ammonia drained from the fuel supply device 20, the fuel recovery device, etc., into the ammonia storage tank 10. That is, the drain treatment device 70 collects ammonia remaining in the low-pressure section, high-pressure section, fuel supply valve train, fuel recovery device, fuel return valve train, etc. of the fuel supply device 20, thereby minimizing the amount of ammonia traveling from the fuel supply device 20 to the discharge processor 53 via the discharge drums 51 and 52.

[0110] The drain treatment unit 70 can recover ammonia drained when the engine E is stopped and the ammonia remaining in the fuel supply unit 20 must be recovered, or when the system is purged. That is, draining can be performed separately from purging or during purging.

[0111] The drain treatment unit 70 may be structurally disposed below the fuel supply unit 20 so that the liquid phase ammonia can be smoothly drained, and the drained ammonia can be returned to the ammonia storage tank 10 as needed. Such a drain treatment unit 70 may include a drain drum 71, a drain pump 72, and a drain valve 73 as shown in FIG.

[0112] Drain drum 71 collects ammonia drained from fuel supply unit 20. Drain drum 71 is provided in a container shape and can collect a certain amount of ammonia. However, since non-explosive gas from purge unit 80 can be injected into fuel supply unit 20 to ensure smooth drainage of fuel supply unit 20, etc., the ammonia flowing into drain drum 71 may contain non-explosive gas.

[0113] Drain drum 71 is provided with a liquid detector 711. Liquid detector 711 detects liquid droplets in drain drum 71, and since ammonia or non-explosive gas flows into drain drum 71 as described above, when liquid detector 711 detects liquid droplets, it can be assumed that draining has been performed. Therefore, when ammonia drainage is detected, the ammonia in drain drum 71 can be recovered by drain pump 72, which will be described later.

[0114] Drain pump 72 transfers the ammonia in drain drum 71 to ammonia storage tank 10. When liquid detector 711 detects that ammonia has flowed into drain drum 71, drain pump 72 can pump the ammonia in drain drum 71. At this time, liquid detector 711 detects ammonia at a certain level in drain drum 71, so that drain pump 72 can be operated when the amount of drained ammonia reaches a certain amount or more.

[0115] However, in some cases, it may be preferable from an operational standpoint to immediately recover the drained ammonia in the ammonia storage tank 10 rather than continuously storing it in the drain drum 71. Therefore, the drain pump 72 may be of a type that is not affected by the inflow of gas.

[0116] For example, the drain pump 72 may be a low-speed pump that uses nitrogen or instrument air as a driving force, considering that gas may be contained in the fluid that flows in. Therefore, the drain pump 72 may not be impaired in function even if gas flows into it.

[0117] The drain pump 72 may be of a type that is driven by, for example, the non-explosive gas of the purge unit 80. Therefore, the drain treatment unit 70 recovers ammonia into the ammonia storage tank 10 using the non-explosive gas of the purge unit 80 as a driving source, and thus does not use combustible materials during drain treatment, thereby minimizing risk.

[0118] The drain valve 73 is installed in parallel with the drain pump 72 to transfer the ammonia in the drain drum 71 to the ammonia storage tank 10. The drain valve 73 can be used instead of the drain pump 72 when the internal pressure of the drain drum 71 is high.

[0119] The drain valve 73 is a non-return valve that opens when high-pressure fluid flows into the drain drum 71, allowing ammonia to be recovered in the ammonia storage tank 10 by utilizing the differential pressure between the drain drum 71 and the ammonia storage tank 10 without operating the drain pump 72.

[0120] Of course, the operation of the drain valve 73 and the drain pump 72 are linked, so that when the drain valve 73 is opened, the inflow of ammonia into the drain pump 72 is blocked, and conversely, when the drain pump 72 is operated, the drain valve 73 can be closed.

[0121] A filter 74 may be provided downstream of the drain pump 72 and the drain valve 73. The filter 74 is for removing impurities present inside the ammonia, and a known membrane filter or the like can be used.

[0122] The purge unit 80 uses a non-explosive gas such as nitrogen to purge the fuel supply unit 20, the fuel recovery unit, etc. The purge unit 80 operates when it is necessary to empty the ammonia flow path in the system, and can purge the ammonia flow path using a non-explosive gas such as nitrogen as a purging gas.

[0123] 2, the purge unit 80 can deliver non-explosive gas to the discharge drums 51 and 52. If the internal pressure of the discharge drums 51 and 52 is insufficient, this embodiment uses the purge unit 80 to inject nitrogen or the like into the discharge drums 51 and 52 to increase the internal pressure of the discharge drums 51 and 52, thereby smoothly adjusting the flow of ammonia from the discharge drums 51 and 52 to the discharge processor 53, etc.

[0124] 3, the purge unit 80 may supply a non-explosive gas as a driving source for the drain treatment unit 70 to recover ammonia into the ammonia storage tank 10. For example, the purge unit 80 may supply a non-explosive gas to the drain pump 72 to operate the drain pump 72, or may inject a non-explosive gas into the drain drum 71 to transfer ammonia through the drain valve 73.

[0125] That is, considering that the purge unit 80 is configured to supply a non-explosive gas that is not dangerous, it not only performs the basic function of purging the ammonia flow path but also performs the additional function of assisting the operation of the vent unit 50, the drain treatment unit 70, etc.

[0126] As described above, this embodiment can provide an environmentally friendly fuel supply system by stably implementing venting, draining, and oxidation treatment of ammonia while supplying ammonia as fuel to the engine E.

[0127] In addition, in this embodiment, ammonia that is suddenly discharged during system operation is primarily collected using discharge drums 51 and 52, and the remaining ammonia is secondarily treated through the exhaust treatment unit 40, thereby minimizing unnecessary venting of ammonia and ensuring safe system operation.

[0128] FIG. 5 is a conceptual diagram of an ammonia treatment system according to a second embodiment of the present invention.

[0129] The following description will focus on the differences between this embodiment and the above-described embodiment, and the parts that will not be described will be replaced with the above content. This also applies to the other embodiments described below.

[0130] 5, in an ammonia processing system 1 according to a second embodiment of the present invention, the arrangement of the heat exchanger 23 in the fuel supply unit 20 and the mixer 33 in the fuel recovery unit is changed compared to the above-described embodiments. In the first embodiment, the mixer 33 is arranged downstream of the heat exchanger 23 based on the ammonia flow in the fuel supply unit 20, but in this embodiment, the heat exchanger 23 can be arranged downstream of the mixer 33.

[0131] In addition, a backflow prevention valve is provided upstream of the mixer 33 on the ammonia flow path of the fuel supply unit 20 to prevent ammonia mixed with lubricating oil from being transmitted to the ammonia storage tank 10 via the engine E.

[0132] The heat exchanger 23 installed downstream of the mixer 33 can heat or cool the ammonia. When the engine E is operating at a low load, the amount of ammonia recirculated increases, and at this time, the ammonia in the mixer 33 becomes relatively hot. Therefore, the heat exchanger 23 cools the ammonia between the mixer 33 and the high-pressure pump 22, thereby preventing gas from flowing into the high-pressure pump 22.

[0133] On the other hand, when the load of the engine E increases, the flow rate of the excess ammonia decreases, and the ammonia in the mixer 33 becomes relatively cold, so that the heat exchanger 23 can heat the ammonia and transfer it to the high-pressure pump 22.

[0134] That is, the heat exchanger 23 can heat or cool the ammonia according to the load of the engine E. For example, a sufficient amount of heat medium at a constant temperature can be continuously supplied to the heat exchanger 23, so that the ammonia flowing into the heat exchanger 23 can be heated or cooled according to the temperature of the heat medium.

[0135] FIG. 6 is a conceptual diagram of an ammonia treatment system according to a third embodiment of the present invention.

[0136] Referring to FIG. 6, the ammonia processing system 1 according to the third embodiment of the present invention may further include a return heat exchanger 24 compared to the first embodiment.

[0137] The return heat exchanger 24 adjusts the temperature of the ammonia returned from downstream of the high-pressure pump 22 to upstream of the high-pressure pump 22. As described above, a return line is provided downstream of the high-pressure pump 22, and the return heat exchanger 24 is provided in the return line to cool the ammonia transferred from the high-pressure pump 22 to the mixer 33.

[0138] When the engine E is not using ammonia as fuel (when the engine E is stopped or when the engine E is operating on a fuel other than ammonia) and the high-pressure pump 22 and the like are running, the ammonia is heated while passing through the high-pressure pump 22, but circulates along the return line without flowing into the engine E.

[0139] In this case, there is a risk that the heat generated by the high-pressure pump 22 will vaporize the ammonia, so the heat generated by the high-pressure pump 22 must be removed. Therefore, in this embodiment, a return heat exchanger 24 is provided in the return line, and the ammonia can be cooled using a refrigerant such as fresh water, seawater, or glycol water. Therefore, the return heat exchanger 24 can also be called a return cooler 31.

[0140] In addition, the return heat exchanger 24 can use a heat medium circulated and supplied by the heat medium supply unit 25. In this case, the heat medium cooled by ammonia while passing through the heat exchanger 23 in the upstream stage of the high-pressure pump 22 can be used.

[0141] Therefore, in this embodiment, although the high-pressure pump 22 is operating, ammonia is not supplied from the high-pressure pump 22 to the engine E, and therefore, in a case where ammonia downstream of the high-pressure pump 22 is continuously circulated upstream of the high-pressure pump 22, the circulating ammonia can be cooled to suppress ammonia evaporation in the high-pressure pump 22, etc.

[0142] FIG. 7 is a conceptual diagram of an ammonia treatment system according to a fourth embodiment of the present invention.

[0143] 7, in the ammonia treatment system 1 according to the fourth embodiment of the present invention, the heat exchanger 23 of the fuel supply unit 20 may include a first heat exchanger 231 and a second heat exchanger 232. The first heat exchanger 231 may be installed between the low-pressure pump 21 and the high-pressure pump 22, for example, between the mixer 33 and the high-pressure pump 22. In this case, the first heat exchanger 231 may perform heating or cooling, as described in the second embodiment.

[0144] The second heat exchanger 232 is provided between the high-pressure pump 22 and the engine E. The second heat exchanger 232 can heat or cool the ammonia pressurized by the high-pressure pump 22 according to the temperature required by the engine E.

[0145] As will be described later, in this embodiment, a second cooler 312 is provided downstream of the high-pressure pump 22 to allow heat exchange between excess ammonia and ammonia downstream of the high-pressure pump 22. In this case, however, there is a risk that the temperature of the ammonia pressurized by the high-pressure pump 22 and then heat exchanged in the second cooler 312 may not be constant. Therefore, in this embodiment, a second heat exchanger 232 is provided between the second cooler 312 and the engine E to adjust the temperature of the ammonia flowing into the engine E to be constant.

[0146] The cooler 31 of the fuel recovery unit of this embodiment may include a first cooler 311 and a second cooler 312. The first cooler 311 cools the ammonia using a medium provided separately from the ammonia, and in this case, the medium may be the heat medium used in the heat exchanger 23.

[0147] The first cooler 311 may have a configuration similar to the cooler 31 in the first embodiment described above, and is provided in parallel with the catch drum 32 to cool the excess ammonia and transfer it to the mixer 33.

[0148] The second cooler 312 is installed downstream or upstream of the first cooler 311 and uses ammonia from the fuel supply unit 20. That is, the second cooler 312 is configured to realize heat exchange between ammonia, and can mutually exchange heat between excess ammonia and ammonia downstream of the high-pressure pump 22.

[0149] From the viewpoint of fuel supply, the ammonia pressurized by the high-pressure pump 22 has its temperature changed by the second cooler 312 before being supplied to the engine E, and as mentioned above, the second heat exchanger 232 can be used to adjust the temperature to the required temperature of the engine E.

[0150] Meanwhile, from the viewpoint of fuel recovery, the excess ammonia discharged from the engine E is primarily cooled in the first cooler 311 and then secondarily cooled in the second cooler 312, which can sufficiently prevent gas generation when circulating to the high-pressure pump 22. Furthermore, the fuel recovery unit can prevent vaporization by using the pressure regulating valve 34 to maintain the ammonia at or above the saturation pressure at the corresponding temperature.

[0151] The pressure regulating valve 34 is provided downstream of the cooler 31 based on the flow of excess ammonia, and can be disposed, for example, between the second cooler 312 and the mixer 33. The pressure regulating valve 34 can maintain the ammonia flowing from the fuel recovery unit toward the fuel supply unit 20 at a pressure equal to or higher than the saturation pressure at the corresponding temperature (for example, 15 bar or higher), thereby allowing the excess ammonia passing through the second cooler 312 to be maintained in a liquid phase.

[0152] The pressure regulating valve 34 can maintain the excess ammonia in the second cooler 312 in a liquid phase, thereby increasing the cooling efficiency of the excess ammonia in the second cooler 312. Of course, the ammonia downstream of the pressure regulating valve 34 can be reduced in pressure to below its saturation pressure, but since the excess ammonia is sufficiently cooled by the second cooler 312, there is little possibility that a gas phase will be generated downstream of the pressure regulating valve 34, and some additional cooling during decompression can also be expected.

[0153] Therefore, in this embodiment, the heat transfer medium is cooled using low-temperature ammonia upstream of the high-pressure pump 22 (first heat exchanger 231), and the cooled heat transfer medium is used to cool the excess ammonia (first cooler 311). The pressure control valve 34 maintains the pressure of the excess ammonia high to increase the cooling efficiency (second cooler 312), thereby effectively suppressing evaporation of the excess ammonia when it flows into the high-pressure pump 22.

[0154] FIG. 8 is a conceptual diagram of an ammonia treatment system according to a fifth embodiment of the present invention.

[0155] Referring to FIG. 8, an ammonia processing system 1 according to a fifth embodiment of the present invention includes a housing 35 in which the fuel supply section 20 and the fuel recovery section surround at least a portion of the ammonia flow path.

[0156] The ammonia flow path may be a pipeline as described above, and the housing 35 surrounds the outer periphery of the pipeline, thereby forming a double-pipe structure for the ammonia flow path. Therefore, the housing 35 prevents ammonia from immediately permeating into the external space when ammonia leaks from the ammonia flow path, and the housing 35 can be filled with a non-explosive gas.

[0157] For example, non-explosive gas may be supplied to the housing 35 through the purge unit 80 or the vent unit 50, and the non-explosive gas circulated through the housing 35 may be released into the atmosphere. Hereinafter, a case where non-explosive vent gas is introduced into the housing 35 through the vent unit 50 will be described.

[0158] The vent unit 50 injects vent gas into one side of the housing 35 and collects the vent gas from the other side of the housing 35. For example, the vent unit 50 can inject vent gas into one side of the fuel recovery unit housing 35 adjacent to the engine E, and collect the vent gas from the other side of the housing 26 of the fuel supply unit 20 adjacent to the engine E after passing through the cooler 31 or catch drum 32 and the high-pressure pump 22. Therefore, the vent gas can circulate through most of the high-pressure portion.

[0159] At this time, since there is a risk that ammonia may be mixed into the vent gas recovered from the housing 35 of the fuel supply unit 20 due to a leak in the ammonia flow path, the vent unit 50 can store the vent gas recovered from the housing 26 in a vent drum 55 instead of immediately releasing it into the atmosphere.

[0160] The vent drum 55 uses water to capture ammonia contained in the vent gas. That is, the vent drum 55 may be a water tank, and the vent gas can be passed through water to dissolve ammonia that may be mixed into the vent gas.

[0161] At this time, a pH sensor 551 is provided in the vent drum 55. The pH sensor 551 measures the pH of the water stored in the vent drum 55, thereby making it possible to confirm whether ammonia has entered the vent drum 55.

[0162] The vent gas flowing into the vent drum 55 may be released into the atmosphere through an outlet line, and a gas detector 552 may be installed at the portion where the vent gas is discharged from the vent drum 55.

[0163] If the vent gas contains ammonia, the ammonia can dissolve in the water as the vent gas passes through the water in the vent drum 55, but the ammonia that does not dissolve in the water can be discharged to the outside of the vent drum 55.

[0164] To prepare for this, the vent unit 50 can primarily detect the inflow of ammonia into the vent drum 55 using a pH sensor 551, and can secondarily detect the presence or absence of ammonia through a gas detector 552 at the discharge portion of the vent drum 55.

[0165] At this time, the release of vent gas into the atmosphere from vent drum 55 can be blocked according to the detection value of gas detector 552. This makes it possible to sufficiently suppress the risk of ammonia leakage even if vent gas is discharged into the atmosphere.

[0166] For reference, the vent unit 50 may use a vent fan 56 that forcibly recovers vent gas from the housing 35 of the fuel supply unit 20 to the vent drum 55. This can be utilized when the flow of vent gas does not reach a desired level due to insufficient pressure of the vent gas flowing into the fuel recovery unit housing 35. Of course, when high-pressure vent gas is injected into the fuel recovery unit housing 35, the vent fan 56 may be minimized or omitted.

[0167] In this way, in this embodiment, in case of ammonia leakage from the ammonia flow path, pH and gas detection is implemented in the vent drum 55, thereby ensuring that ammonia is released into the atmosphere at a safe level.

[0168] In addition to the above-mentioned embodiments, the present invention encompasses all embodiments that are generated by combining the above-mentioned embodiments with known techniques.

[0169] The present invention has been described in detail above with reference to specific examples. However, these examples are for the purpose of specifically explaining the present invention, and the present invention is not limited thereto. It is clear that modifications and improvements can be made by those skilled in the art within the technical spirit of the present invention.

[0170] Any simple variations or modifications of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be made clear by the appended claims. [Explanation of symbols]

[0171] 1. Ammonia treatment system E-Engine 10. Ammonia storage tank 11 Bunkering Department 12 Pressure adjustment section 20 Fuel supply section 21 Low-pressure pump 22 High-pressure pump 23 Heat exchanger 231 1st heat exchanger 232 Second heat exchanger 24 Return heat exchanger 25 Heat medium supply section 251 Heat medium heater 252 Heat Transfer Cooler 26 Housing 30 Fuel recovery section 31 Cooler 311 No. 1 Cooler 312 Second Cooler 32 Catch Drum 33 Mixer 34 Pressure Regulating Valve 35 Housing 40 Exhaust treatment section 50 Vent 51 Low pressure discharge drum 52 High-pressure discharge drum 53 Discharge Processing Machine 531 Discharge Pump 54 Bent Mast 55 Bent Drum 551 pH sensor 552 Gas Detector 56 Vent fan 60 Reliquefaction section 70 Drain treatment section 71 Drain drum 711 Liquid Detector 72 Drain pump 73 Drain valve 74 filters 80 Purge section

Claims

1. a fuel supply unit that supplies ammonia discharged from the ammonia storage tank to the engine; a fuel recovery unit that recovers excess ammonia returned from the engine; an exhaust treatment unit that treats exhaust gas discharged from the engine; a vent portion that releases ammonia discharged from the fuel supply portion or the fuel recovery portion to the outside, The exhaust treatment unit includes: Ammonia is oxidized, The vent section is an exhaust treatment device that collects ammonia discharged from the ammonia storage tank, the fuel supply unit, or the fuel recovery unit, mixes the ammonia with water, and delivers the ammonia to the exhaust treatment unit; and an ammonia treatment system comprising: an exhaust treatment device that collects ammonia discharged from the ammonia storage tank, the fuel supply unit, or the fuel recovery unit, mixes the ammonia with water, and delivers the ammonia to the exhaust treatment unit.

2. The vent section is The ammonia storage tank, the fuel supply unit, or the fuel recovery unit may further include an exhaust drum for collecting the ammonia discharged from the ammonia storage tank, the fuel supply unit, or the fuel recovery unit, and then transferring the ammonia to the exhaust treatment device or the exhaust treatment unit; The discharge processor is 2. The ammonia treatment system according to claim 1, wherein the ammonia is captured using water, and the ammonia water is delivered to the exhaust treatment unit.

3. The fuel supply system further includes a purge unit that purges the fuel supply unit or the fuel recovery unit using a non-explosive gas, The purge section is 3. The ammonia treatment system according to claim 2, wherein a non-explosive gas is delivered to the discharge drum to adjust the pressure of the discharge drum to be higher than the pressure of the discharge processor or the exhaust treatment unit.

4. A marine vessel comprising the ammonia processing system of claim 1.

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