Ammonia vapor treatment system for ship

Abstract

A ship ammonia vapor treatment system comprises a liquid ammonia storage tank, a BOG compressor, an ammonia gas liquefier, a first throttle valve and a liquid ammonia pump, a BOG outlet of the liquid ammonia storage tank is connected with an inlet of the BOG compressor, an outlet of the BOG compressor is connected with an ammonia gas inlet of the ammonia gas liquefier, a liquid ammonia outlet of the ammonia gas liquefier is connected with an inlet of the first throttle valve, and an outlet of the first throttle valve is connected with an outlet of the liquid ammonia pump. An outlet of the first throttle valve is connected with a liquid ammonia inlet of the liquid ammonia storage tank; the liquid ammonia pump is arranged in the liquid ammonia storage tank, an outlet of the liquid ammonia pump is connected with a cooling fluid inlet of the ammonia liquefier, and a cooling fluid outlet of the ammonia liquefier is used for being connected to an ammonia fuel engine. According to the ship ammonia vapor treatment system, the ammonia vapor in the liquid ammonia storage tank can be subjected to reliquefaction treatment, so that the ammonia vapor is reused, and the waste of fuel is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of ships, in particular to a ship ammonia vapor treatment system. Background Art

[0002] As the problem of global warming intensifies, reducing greenhouse gas emissions has become one of the important tasks facing the world today. Increasing the proportion of zero-carbon or low-carbon energy in the world's energy consumption structure will help reduce greenhouse gas emissions and promote the realization of "carbon neutrality" in the global carbon cycle system. In the field of shipping, ammonia as a zero-carbon fuel has attracted widespread attention. As a ship engine fuel, ammonia is usually stored in fuel tanks in the form of liquid ammonia at -33°C. During the storage process, due to heat leakage from the environment, the liquid ammonia in the fuel tank will inevitably absorb heat and evaporate. The accumulation of ammonia vapor (boiled gas, or BOG) produced by evaporation will cause the tank pressure to increase, which is easy to cause safety accidents. Therefore, the ammonia vapor in the fuel tank needs to be treated.

[0003] At present, ammonia vapor treatment mostly adopts the method of direct absorption by an ammonia treatment device (for example, using water to absorb ammonia to form ammonia water), which will lead to fuel waste. Utility Model Content

[0004] The utility model aims to provide a ship ammonia vapor processing system, which can reliquefy the ammonia vapor in the liquid ammonia storage tank so that the ammonia vapor can be reused, thereby reducing the waste of fuel.

[0005] The utility model provides a ship ammonia vapor processing system, comprising a liquid ammonia storage tank, a BOG compressor, an ammonia liquefier, a first throttle valve and a liquid ammonia pump, wherein the BOG outlet of the liquid ammonia storage tank is connected to the inlet of the BOG compressor, the outlet of the BOG compressor is connected to the ammonia inlet of the ammonia liquefier, the liquid ammonia outlet of the ammonia liquefier is connected to the inlet of the first throttle valve, and the outlet of the first throttle valve is connected to the liquid ammonia inlet of the liquid ammonia storage tank; the liquid ammonia pump is arranged in the liquid ammonia storage tank, the outlet of the liquid ammonia pump is connected to the cooling fluid inlet of the ammonia liquefier, and the cooling fluid outlet of the ammonia liquefier is used to be connected to an ammonia fuel engine.

[0006] Furthermore, the ship ammonia vapor treatment system also includes a liquid ammonia buffer tank and a booster pump. The liquid ammonia outlet of the ammonia liquefier and the outlet of the liquid ammonia pump are both connected to the inlet of the liquid ammonia buffer tank, the liquid ammonia outlet of the liquid ammonia buffer tank is connected to the inlet of the booster pump, and the outlet of the booster pump is connected to the cooling fluid inlet of the ammonia liquefier.

[0007] Furthermore, a second throttle valve is provided on the pipeline between the liquid ammonia outlet of the ammonia liquefier and the inlet of the liquid ammonia buffer tank.

[0008] Furthermore, the ship ammonia vapor treatment system also includes a ventilation mast, which is connected to the top outlet of the liquid ammonia buffer tank, and a non-condensable gas discharge valve is provided on the pipeline between the ventilation mast and the top outlet of the liquid ammonia buffer tank.

[0009] Furthermore, a spray device is provided at the top of the liquid ammonia storage tank, and the outlet of the first throttle valve is connected to the spray device.

[0010] Furthermore, the spray device includes a spray pipe and a plurality of spray heads arranged on the spray pipe, and the outlet of the first throttle valve is connected to the spray pipe.

[0011] Furthermore, the internal space of the liquid ammonia storage tank is divided into a gas phase space and a liquid phase space, the gas phase space is located above the liquid phase space, the spray device is arranged in the gas phase space, and the liquid ammonia pump is arranged in the liquid phase space.

[0012] The utility model provides a ship ammonia vapor treatment system, comprising a liquid ammonia storage tank, a BOG compressor, an ammonia liquefier, a liquid ammonia pump, a liquid ammonia buffer tank and a booster pump, wherein the BOG outlet of the liquid ammonia storage tank is connected to the inlet of the BOG compressor, the outlet of the BOG compressor is connected to the ammonia inlet of the ammonia liquefier, and the liquid ammonia outlet of the ammonia liquefier is connected to the inlet of the liquid ammonia buffer tank; the liquid ammonia pump is arranged in the liquid ammonia storage tank, the outlet of the liquid ammonia pump is connected to the inlet of the liquid ammonia buffer tank, the liquid ammonia outlet of the liquid ammonia buffer tank is connected to the inlet of the booster pump, the outlet of the booster pump is connected to the cooling fluid inlet of the ammonia liquefier, and the cooling fluid outlet of the ammonia liquefier is used to be connected to an ammonia fuel engine.

[0013] Furthermore, a second throttle valve is provided on the pipeline between the liquid ammonia outlet of the ammonia liquefier and the inlet of the liquid ammonia buffer tank.

[0014] Furthermore, the ship ammonia vapor treatment system also includes a ventilation mast, which is connected to the top outlet of the liquid ammonia buffer tank, and a non-condensable gas discharge valve is provided on the pipeline between the ventilation mast and the top outlet of the liquid ammonia buffer tank.

[0015] The ship ammonia vapor processing system provided by the utility model is provided with a BOG compressor, an ammonia liquefier, a first throttle valve and a liquid ammonia pump, and the BOG compressor is used to compress the ammonia vapor from the liquid ammonia storage tank, and then the ammonia liquefier is used to cool the ammonia vapor to condense and liquefy the ammonia vapor into liquid ammonia, and then the first throttle valve is used to throttle and cool the condensed liquid ammonia, and the throttled and cooled liquid ammonia can flow back to the liquid ammonia storage tank for re-storage and utilization, thereby reducing fuel waste, and preventing the liquid ammonia storage tank from over-temperature and over-pressure, thereby ensuring the operation safety of the liquid ammonia storage tank. Among them, the liquid ammonia pump can transport the liquid ammonia in the liquid ammonia storage tank to the ammonia liquefier, and use the low-temperature liquid ammonia in the liquid ammonia storage tank to exchange heat with the ammonia vapor in the ammonia liquefier to condense and liquefy the ammonia vapor. That is, the cooling medium of the ammonia liquefier is the liquid ammonia supplied to the ammonia fuel engine. Such an arrangement, on the one hand, makes it unnecessary to set up an additional cold source for the ammonia liquefier, simplifies the system configuration, saves equipment cost and occupied space, and on the other hand, can heat the liquid ammonia supplied to the ammonia fuel engine, thereby effectively utilizing the thermal energy of ammonia vapor and the cold energy of liquid ammonia, improving energy utilization and reducing operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of a ship ammonia vapor treatment system in the first embodiment of the utility model.

[0017] Figure 2 It is a schematic structural diagram of a ship ammonia vapor treatment system in the second embodiment of the utility model.

[0018] Figure 3 It is a schematic structural diagram of a ship ammonia vapor treatment system in the third embodiment of the utility model. DETAILED DESCRIPTION

[0019] The following is a further detailed description of the specific implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0020] The terms "first", "second", "third", "fourth" and the like (if any) in the description and claims of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0021] The directional words such as up, down, left, right, front, back, top, bottom, etc. (if any) involved in the specification and claims of the utility model are defined by the positions of the structures in the drawings and the positions of the structures relative to each other, and are only for the clarity and convenience of expressing the technical solution. It should be understood that the use of directional words should not limit the scope of protection requested by this application.

[0022] First embodiment

[0023] like Figure 1 As shown, the ship ammonia vapor processing system provided by the first embodiment of the utility model comprises a liquid ammonia storage tank 1, a BOG (ammonia vapor, Boil-Off Gas) compressor 2, an ammonia liquefier 3, a first throttle valve 81 and a liquid ammonia pump 4, the BOG outlet of the liquid ammonia storage tank 1 is connected to the inlet of the BOG compressor 2, the outlet of the BOG compressor 2 is connected to the ammonia inlet of the ammonia liquefier 3, the liquid ammonia outlet of the ammonia liquefier 3 is connected to the inlet of the first throttle valve 81, and the outlet of the first throttle valve 81 is connected to the liquid ammonia inlet of the liquid ammonia storage tank 1. The liquid ammonia pump 4 is arranged in the liquid ammonia storage tank 1, the outlet of the liquid ammonia pump 4 is connected to the cooling fluid inlet of the ammonia liquefier 3, and the cooling fluid outlet of the ammonia liquefier 3 is used to be connected to an ammonia fuel engine (not shown), so as to supply fuel to the ammonia fuel engine.

[0024] Among them, the liquid ammonia storage tank 1 is used to store liquid ammonia; the BOG compressor 2 is used to compress the ammonia vapor output from the liquid ammonia storage tank 1; the ammonia liquefier 3 is used to cool the compressed ammonia vapor to condense the ammonia vapor into liquid ammonia; the first throttle valve 81 is used to throttle and cool the condensed liquid ammonia (the first throttle valve 81 expands, decompresses and cools the liquid ammonia), and the cooled liquid ammonia is returned to the liquid ammonia storage tank 1 for re-storage and utilization. The liquid ammonia pump 4 is used to transport the liquid ammonia in the liquid ammonia storage tank 1 to the ammonia liquefier 3, and the low-temperature liquid ammonia in the liquid ammonia storage tank 1 is used to exchange heat with the ammonia vapor in the ammonia liquefier 3 to condense and liquefy the ammonia vapor, and the liquid ammonia after heat exchange with the ammonia vapor is supplied to the ammonia fuel engine.

[0025] The ship ammonia vapor processing system provided by the embodiment of the utility model is provided with a BOG compressor 2, an ammonia liquefier 3, a first throttle valve 81 and a liquid ammonia pump 4. The BOG compressor 2 is used to compress the ammonia vapor from the liquid ammonia storage tank 1, and then the ammonia liquefier 3 is used to cool the ammonia vapor to condense and liquefy the ammonia vapor into liquid ammonia. Then, the first throttle valve 81 is used to throttle and cool the condensed liquid ammonia. The throttled and cooled liquid ammonia can flow back to the liquid ammonia storage tank 1 for re-storage and utilization, thereby reducing fuel waste and preventing the liquid ammonia storage tank 1 from over-temperature and over-pressure, thereby ensuring the operating safety of the liquid ammonia storage tank 1. Among them, the liquid ammonia pump 4 can transport the liquid ammonia in the liquid ammonia storage tank 1 to the ammonia liquefier 3, and use the low-temperature liquid ammonia in the liquid ammonia storage tank 1 to exchange heat with the ammonia vapor in the ammonia liquefier 3 (the temperature of the liquid ammonia is lower than the temperature of the ammonia vapor) to condense and liquefy the ammonia vapor, that is, the cooling medium (cold source) of the ammonia liquefier 3 is the liquid ammonia supplied to the ammonia fuel engine. Such an arrangement, on the one hand, makes it unnecessary to set up an additional cold source for the ammonia liquefier 3, simplifies the system configuration, saves equipment cost and occupies space, and on the other hand, can heat the liquid ammonia supplied to the ammonia fuel engine, thereby effectively utilizing the thermal energy of ammonia vapor and the cold energy of liquid ammonia (the temperature of the liquid ammonia in the liquid ammonia storage tank 1 is generally around -33°C, and the supply temperature of the ammonia fuel engine is generally around 25°C to 45°C), thereby improving energy utilization and reducing operating costs.

[0026] Furthermore, if Figure 1 As shown, in this embodiment, the ammonia liquefier 3 is a heat exchanger, a heat exchange tube 31 is provided in the ammonia liquefier 3, the outlet of the liquid ammonia pump 4 is connected to the cooling fluid inlet of the heat exchange tube 31, and the cooling fluid outlet of the heat exchange tube 31 is used to be connected to the ammonia fuel engine.

[0027] Furthermore, if Figure 1 As shown, in this embodiment, the ship ammonia vapor treatment system also includes a liquid ammonia buffer tank 5 and a booster pump 6. The liquid ammonia outlet of the ammonia liquefier 3 and the outlet of the liquid ammonia pump 4 are both connected to the inlet of the liquid ammonia buffer tank 5, the liquid ammonia outlet of the liquid ammonia buffer tank 5 is connected to the inlet of the booster pump 6, and the outlet of the booster pump 6 is connected to the cooling fluid inlet of the ammonia liquefier 3 (specifically connected to the cooling fluid inlet of the heat exchange tube 31).

[0028] Specifically, by setting up a liquid ammonia buffer tank 5 and a booster pump 6, the liquid ammonia condensed by the ammonia liquefier 3 and the liquid ammonia output by the liquid ammonia pump 4 can be transported to the liquid ammonia buffer tank 5 and mixed, so that the ammonia vapor mixed in the liquid ammonia from the ammonia liquefier 3 can be further condensed and liquefied (limited by the heat exchange efficiency of the ammonia liquefier 3, a small amount of ammonia vapor in the ammonia liquefier 3 is not liquefied), thereby increasing the proportion of ammonia vapor re-liquefaction; the mixed liquid ammonia in the liquid ammonia buffer tank 5 is then pressurized by the booster pump 6 and transported to the ammonia liquefier 3 for heat exchange with ammonia vapor, and then supplied to the ammonia fuel engine. With this arrangement, the liquid ammonia liquefied by the ammonia liquefier 3 can be selectively refluxed to the liquid ammonia storage tank 1, and can also provide fuel supply for the ammonia fuel engine through the liquid ammonia buffer tank 5 and the booster pump 6.

[0029] At the same time, the liquid ammonia buffer tank 5 can also play the role of buffering and gas-liquid separation. The condensed liquid ammonia and the unliquefied ammonia vapor can be separated into gas and liquid in the liquid ammonia buffer tank 5. On the one hand, it can ensure that the medium entering the booster pump 6 is pure liquid ammonia. On the other hand, when the amount of gas in the liquid ammonia buffer tank 5 (the gas includes unliquefied ammonia vapor and the non-condensable gas described below) gradually increases, the pressure in the liquid ammonia buffer tank 5 gradually increases, which can further liquefy the ammonia vapor in the liquid ammonia buffer tank 5, thereby increasing the liquefaction ratio of the ammonia vapor. Specifically, the liquid ammonia buffer tank 5 is provided with monitoring instruments such as a pressure sensor (not shown), a temperature sensor and a liquid level sensor. When the liquid level in the liquid ammonia buffer tank 5 reaches a certain height, the liquid ammonia is discharged through the booster pump 6. On the one hand, it can ensure that the medium entering the booster pump 6 is pure liquid ammonia. On the other hand, it can increase the pressure in the liquid ammonia buffer tank 5 (holding pressure), thereby further liquefying the ammonia vapor in the liquid ammonia buffer tank 5.

[0030] Furthermore, if Figure 1 As shown, in this embodiment, a second throttle valve 82 is provided on the pipeline between the liquid ammonia outlet of the ammonia liquefier 3 and the inlet of the liquid ammonia buffer tank 5, and the second throttle valve 82 is used to throttle and cool the condensed liquid ammonia (the second throttle valve 82 expands, decompresses and cools the liquid ammonia; the set pressures of the first throttle valve 81 and the second throttle valve 82 may be different).

[0031] Furthermore, in this embodiment, control valves (not shown) are respectively provided between the liquid ammonia outlet of the ammonia liquefier 3 and the inlet of the first throttle valve 81 and the inlet of the second throttle valve 82, and the flow direction of the liquid ammonia in the ammonia liquefier 3 is controlled by opening / closing the corresponding control valves.

[0032] Furthermore, if Figure 1 As shown, in this embodiment, the ship ammonia vapor treatment system also includes a ventilation mast 7, which is connected to the top outlet of the liquid ammonia buffer tank 5, and a non-condensable gas discharge valve 71 is provided on the pipeline between the ventilation mast 7 and the top outlet of the liquid ammonia buffer tank 5.

[0033] Specifically, there will be some impurity gases in the liquid ammonia storage tank 1 (such as nitrogen, which generally remain in the liquid ammonia storage tank 1 when the liquid ammonia storage tank 1 is purged with nitrogen, filled with liquid ammonia, etc.), and the condensation temperature of these impurity gases is lower than the temperature of liquid ammonia (for example, the condensation temperature of nitrogen is -196°C, while the storage temperature of liquid ammonia is generally around -33°C), so these impurity gases will always exist in the liquid ammonia storage tank 1 in a gaseous state, that is, form non-condensable gases, and mix with the ammonia vapor in the liquid ammonia storage tank 1. When the non-condensable gases follow the ammonia vapor into the liquid ammonia buffer tank 5, if these non-condensable gases are not discharged, they will accumulate in the liquid ammonia buffer tank 5, causing the liquid ammonia buffer tank 5 to be over-pressurized, reducing the efficiency of reliquefaction.

[0034] Therefore, in this embodiment, by providing the vent mast 7 and the non-condensable gas discharge valve 71, when the pressure in the liquid ammonia buffer tank 5 rises to a certain value (the more non-condensable gas in the liquid ammonia buffer tank 5, the greater the pressure), the ammonia vapor in the liquid ammonia buffer tank 5 is further liquefied, and at this time, most of the gas in the gas phase space in the liquid ammonia buffer tank 5 is non-condensable gas; then the non-condensable gas discharge valve 71 is opened to discharge the non-condensable gas in the liquid ammonia buffer tank 5 through the vent mast 7, thereby improving the reliquefaction processing efficiency of the system. Of course, in other embodiments, the vent mast 7 and the non-condensable gas discharge valve 71 may not be provided.

[0035] Furthermore, if Figure 1 As shown, in this embodiment, a spray device 11 is provided at the top of the liquid ammonia storage tank 1, and the outlet of the first throttle valve 81 is connected to the spray device 11. The spray device 11 is used to spray the cooled liquid ammonia into the liquid ammonia storage tank 1, so that the ammonia vapor in the liquid ammonia storage tank 1 is condensed and liquefied into liquid ammonia (that is, the sprayed low-temperature liquid ammonia can exchange heat with the ammonia vapor in the liquid ammonia storage tank 1, so that the ammonia vapor is cooled and liquefied), thereby improving the reliquefaction efficiency of the ammonia vapor.

[0036] Furthermore, if Figure 1 As shown, in this embodiment, the spray device 11 includes a spray pipe 111 and a plurality of spray heads 112 disposed on the spray pipe 111. The plurality of spray heads 112 are disposed at intervals on the spray pipe 111. The outlet of the first throttle valve 81 is connected to the spray pipe 111, so that low-temperature liquid ammonia can be uniformly sprayed through the spray pipe 111 through the plurality of spray heads 112, thereby improving the reliquefaction efficiency of ammonia vapor. Of course, in other embodiments, the spray device 11 can also have other structures.

[0037] Furthermore, if Figure 1As shown, in this embodiment, the internal space of the liquid ammonia storage tank 1 is divided into a gas phase space 10A and a liquid phase space 10B, the gas phase space 10A is located above the liquid phase space 10B, the liquid ammonia in the liquid ammonia storage tank 1 is stored in the liquid phase space 10B, and the ammonia vapor in the liquid ammonia storage tank 1 is concentrated in the gas phase space 10A. The spray device 11 is arranged in the gas phase space 10A, so that the ammonia vapor in the gas phase space 10A can be sprayed; the liquid ammonia pump 4 is arranged in the liquid phase space 10B, so that the liquid ammonia in the liquid phase space 10B can be sucked.

[0038] Furthermore, if Figure 1 As shown, in this embodiment, the main working process of the ship ammonia vapor treatment system is as follows:

[0039] The ammonia vapor in the liquid ammonia storage tank 1 is concentrated in the gas phase space 10A at the top of the liquid ammonia storage tank 1. The ammonia vapor in the liquid ammonia storage tank 1 enters the BOG compressor 2 and is compressed. After being compressed and heated, the ammonia vapor enters the ammonia liquefier 3 and exchanges heat with the liquid ammonia supplied to the ammonia fuel engine, so that the ammonia vapor is condensed and liquefied into liquid ammonia. The condensed liquid ammonia can be expanded, depressurized and cooled by the first throttle valve 81, and then sprayed into the liquid ammonia storage tank 1 through the spray device 11, so that the ammonia vapor in the liquid ammonia storage tank 1 is condensed and liquefied into liquid ammonia, so as to further reduce the temperature and pressure in the liquid ammonia storage tank 1; the condensed liquid ammonia can also be expanded, depressurized and cooled by the second throttle valve 82, and then enter the liquid ammonia buffer tank 5 to mix with the liquid ammonia output by the liquid ammonia pump 4. The liquid ammonia in the liquid ammonia buffer tank 5 is pressurized by the booster pump 6 and transported to the ammonia liquefier 3 to exchange heat with the ammonia vapor, and then supplied to the ammonia fuel engine. When a certain amount of non-condensable gas is accumulated in the liquid ammonia buffer tank 5 , the non-condensable gas discharge valve 71 is opened to discharge the non-condensable gas in the liquid ammonia buffer tank 5 through the vent mast 7 .

[0040] The ship ammonia vapor processing system provided by the embodiment of the utility model is provided with a BOG compressor 2, an ammonia liquefier 3, a first throttle valve 81 and a liquid ammonia pump 4. The BOG compressor 2 is used to compress the ammonia vapor from the liquid ammonia storage tank 1, and then the ammonia liquefier 3 is used to cool the ammonia vapor to condense and liquefy the ammonia vapor into liquid ammonia. Then, the first throttle valve 81 is used to throttle and cool the condensed liquid ammonia. The throttled and cooled liquid ammonia can flow back to the liquid ammonia storage tank 1 for re-storage and utilization, thereby reducing fuel waste and preventing the liquid ammonia storage tank 1 from over-temperature and over-pressure, thereby ensuring the operating safety of the liquid ammonia storage tank 1. Among them, the liquid ammonia pump 4 can transport the liquid ammonia in the liquid ammonia storage tank 1 to the ammonia liquefier 3, and use the low-temperature liquid ammonia in the liquid ammonia storage tank 1 to exchange heat with the ammonia vapor in the ammonia liquefier 3 to condense and liquefy the ammonia vapor. That is, the cooling medium of the ammonia liquefier 3 is the liquid ammonia supplied to the ammonia fuel engine. Such an arrangement, on the one hand, makes it unnecessary to set up an additional cold source for the ammonia liquefier 3, simplifies the system configuration, saves equipment cost and occupied space, and on the other hand, can heat the liquid ammonia supplied to the ammonia fuel engine, thereby effectively utilizing the thermal energy of ammonia vapor and the cold energy of liquid ammonia, improving energy utilization and reducing operating costs.

[0041] Second embodiment

[0042] like Figure 2 As shown, the ship ammonia vapor treatment system provided by the second embodiment of the utility model is substantially the same as the first embodiment, except that the liquid ammonia buffer tank 5, the booster pump 6 and the second throttle valve 82 (and the air-permeable mast 7 and the non-condensable gas discharge valve 71) are not provided in this embodiment, and the outlet of the liquid ammonia pump 4 is directly connected to the cooling fluid inlet of the ammonia liquefier 3, so that the liquid ammonia supplied to the ammonia fuel engine is used to provide a cold source for the ammonia liquefier 3. With such a configuration, the liquid ammonia condensed and liquefied by the ammonia liquefier 3 can only flow back to the liquid ammonia storage tank 1 after passing through the first throttle valve 81.

[0043] The other structures and functions of this embodiment are the same or similar to those of the first embodiment and are not described in detail here.

[0044] Third embodiment

[0045] like Figure 3 As shown, the ship ammonia vapor treatment system provided by the third embodiment of the utility model is substantially the same as the first embodiment, except that the flow direction of the reliquefied liquid ammonia is different.

[0046] Specifically, the ship ammonia vapor treatment system provided by the embodiment of the utility model comprises a liquid ammonia storage tank 1, a BOG compressor 2, an ammonia liquefier 3, a liquid ammonia pump 4, a liquid ammonia buffer tank 5 and a booster pump 6. The BOG outlet of the liquid ammonia storage tank 1 is connected to the inlet of the BOG compressor 2, the outlet of the BOG compressor 2 is connected to the ammonia inlet of the ammonia liquefier 3, and the liquid ammonia outlet of the ammonia liquefier 3 is connected to the inlet of the liquid ammonia buffer tank 5. The liquid ammonia pump 4 is arranged in the liquid ammonia storage tank 1, the outlet of the liquid ammonia pump 4 is connected to the inlet of the liquid ammonia buffer tank 5, the liquid ammonia outlet of the liquid ammonia buffer tank 5 is connected to the inlet of the booster pump 6, the outlet of the booster pump 6 is connected to the cooling fluid inlet of the ammonia liquefier 3, and the cooling fluid outlet of the ammonia liquefier 3 is used to be connected to an ammonia fuel engine (not shown) to supply fuel to the ammonia fuel engine.

[0047] Among them, the liquid ammonia storage tank 1 is used to store liquid ammonia; the BOG compressor 2 is used to compress the ammonia vapor output from the liquid ammonia storage tank 1; the ammonia liquefier 3 is used to cool the compressed ammonia vapor to condense the ammonia vapor into liquid ammonia; the liquid ammonia pump 4 is used to transport the liquid ammonia in the liquid ammonia storage tank 1 to the liquid ammonia buffer tank 5, and the liquid ammonia condensed by the ammonia liquefier 3 and the liquid ammonia output by the liquid ammonia pump 4 can be transported to the liquid ammonia buffer tank 5 and mixed, so that the ammonia vapor mixed in the liquid ammonia from the ammonia liquefier 3 can be further condensed and liquefied, thereby increasing the proportion of ammonia vapor re-liquefaction; the mixed liquid ammonia in the liquid ammonia buffer tank 5 is then pressurized by the booster pump 6 and transported to the ammonia liquefier 3 for heat exchange with the ammonia vapor, and then supplied to the ammonia fuel engine. In this way, the liquid ammonia condensed and liquefied by the ammonia liquefier 3 can only provide fuel supply for the ammonia fuel engine through the liquid ammonia buffer tank 5 and the booster pump 6.

[0048] Furthermore, if Figure 3 As shown, in this embodiment, a second throttle valve 82 is provided on the pipeline between the liquid ammonia outlet of the ammonia liquefier 3 and the inlet of the liquid ammonia buffer tank 5, and the second throttle valve 82 is used to throttle and cool the condensed liquid ammonia.

[0049] Furthermore, if Figure 3 As shown, in this embodiment, the ship ammonia vapor treatment system further includes a vent mast 7, which is connected to the top outlet of the liquid ammonia buffer tank 5, and a non-condensable gas discharge valve 71 is provided on the pipeline between the vent mast 7 and the top outlet of the liquid ammonia buffer tank 5. Of course, in other embodiments, the vent mast 7 and the non-condensable gas discharge valve 71 may not be provided.

[0050] The ship ammonia vapor treatment system provided in this embodiment provides fuel supply for the ammonia fuel engine by condensing and liquefying the ammonia vapor in the liquid ammonia storage tank 1 into liquid ammonia, thereby reducing fuel waste, and preventing the liquid ammonia storage tank 1 from overheating and overpressure, thereby ensuring the operating safety of the liquid ammonia storage tank 1. At the same time, this embodiment uses the low-temperature liquid ammonia in the liquid ammonia storage tank 1 to exchange heat with the ammonia vapor in the ammonia liquefier 3, that is, the cooling medium of the ammonia liquefier 3 is the liquid ammonia supplied to the ammonia fuel engine. Such a setting, on the one hand, makes it unnecessary to set up an additional cold source for the ammonia liquefier 3, and on the other hand, it can heat up the liquid ammonia supplied to the ammonia fuel engine, thereby effectively utilizing the heat energy of ammonia vapor and the cold energy of liquid ammonia, improving energy utilization, and reducing operating costs. At the same time, since the condensed liquid ammonia does not need to flow back to the liquid ammonia storage tank 1, there is no need to set up a spray device 11 in the liquid ammonia storage tank 1, nor is there a need to set up a first throttle valve 81.

[0051] The other structures and functions of this embodiment are the same or similar to those of the first embodiment and are not described in detail here.

[0052] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A ship ammonia vapor treatment system, characterized in that: The invention comprises a liquid ammonia storage tank (1), a BOG compressor (2), an ammonia liquefier (3), a first throttle valve (81) and a liquid ammonia pump (4); the BOG outlet of the liquid ammonia storage tank (1) is connected to the inlet of the BOG compressor (2); the outlet of the BOG compressor (2) is connected to the ammonia inlet of the ammonia liquefier (3); the liquid ammonia outlet of the ammonia liquefier (3) is connected to the inlet of the first throttle valve (81); the outlet of the first throttle valve (81) is connected to the liquid ammonia inlet of the liquid ammonia storage tank (1); the liquid ammonia pump (4) is arranged in the liquid ammonia storage tank (1); the outlet of the liquid ammonia pump (4) is connected to the cooling fluid inlet of the ammonia liquefier (3); and the cooling fluid outlet of the ammonia liquefier (3) is used to be connected to an ammonia fuel engine.

2. The ship ammonia vapor treatment system according to claim 1, characterized in that: The ship ammonia vapor treatment system also includes a liquid ammonia buffer tank (5) and a booster pump (6); the liquid ammonia outlet of the ammonia liquefier (3) and the outlet of the liquid ammonia pump (4) are both connected to the inlet of the liquid ammonia buffer tank (5); the liquid ammonia outlet of the liquid ammonia buffer tank (5) is connected to the inlet of the booster pump (6); and the outlet of the booster pump (6) is connected to the cooling fluid inlet of the ammonia liquefier (3).

3. The ship ammonia vapor treatment system according to claim 2, characterized in that: A second throttle valve (82) is provided on the pipeline between the liquid ammonia outlet of the ammonia liquefier (3) and the inlet of the liquid ammonia buffer tank (5).

4. The ship ammonia vapor treatment system according to claim 2, characterized in that: The ship ammonia vapor treatment system also includes a ventilation mast (7), which is connected to the top outlet of the liquid ammonia buffer tank (5), and a non-condensable gas discharge valve (71) is provided on the pipeline between the ventilation mast (7) and the top outlet of the liquid ammonia buffer tank (5).

5. The ship ammonia vapor treatment system according to any one of claims 1 to 4, characterized in that: A spray device (11) is provided at the top of the liquid ammonia storage tank (1), and an outlet of the first throttle valve (81) is connected to the spray device (11).

6. The ship ammonia vapor treatment system according to claim 5, characterized in that: The spray device (11) comprises a spray pipe (111) and a plurality of spray heads (112) arranged on the spray pipe (111); the outlet of the first throttle valve (81) is connected to the spray pipe (111).

7. The ship ammonia vapor treatment system according to claim 5, characterized in that: The internal space of the liquid ammonia storage tank (1) is divided into a gas phase space (10A) and a liquid phase space (10B), the gas phase space (10A) is located above the liquid phase space (10B), the spray device (11) is arranged in the gas phase space (10A), and the liquid ammonia pump (4) is arranged in the liquid phase space (10B).

8. A ship ammonia vapor treatment system, characterized in that: The invention comprises a liquid ammonia storage tank (1), a BOG compressor (2), an ammonia liquefier (3), a liquid ammonia pump (4), a liquid ammonia buffer tank (5) and a booster pump (6), wherein the BOG outlet of the liquid ammonia storage tank (1) is connected to the inlet of the BOG compressor (2), the outlet of the BOG compressor (2) is connected to the ammonia inlet of the ammonia liquefier (3), and the liquid ammonia outlet of the ammonia liquefier (3) is connected to the inlet of the liquid ammonia buffer tank (5); the liquid ammonia pump (4) is arranged in the liquid ammonia storage tank (1), the outlet of the liquid ammonia pump (4) is connected to the inlet of the liquid ammonia buffer tank (5), the liquid ammonia outlet of the liquid ammonia buffer tank (5) is connected to the inlet of the booster pump (6), the outlet of the booster pump (6) is connected to the cooling fluid inlet of the ammonia liquefier (3), and the cooling fluid outlet of the ammonia liquefier (3) is used to be connected to an ammonia fuel engine.

9. The ship ammonia vapor treatment system according to claim 8, characterized in that: A second throttle valve (82) is provided on the pipeline between the liquid ammonia outlet of the ammonia liquefier (3) and the inlet of the liquid ammonia buffer tank (5).

10. The ship ammonia vapor treatment system according to claim 8, characterized in that: The ship ammonia vapor treatment system also includes a ventilation mast (7), which is connected to the top outlet of the liquid ammonia buffer tank (5), and a non-condensable gas discharge valve (71) is provided on the pipeline between the ventilation mast (7) and the top outlet of the liquid ammonia buffer tank (5).

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