Marine ammonia fuel release device system and release method

Abstract

The invention provides a release device system and a release method for marine ammonia fuel. The release device system comprises a suction buffer tank, a compression device, a cooling device and a discharge buffer tank which are connected in sequence, and a heating device is arranged in the suction buffer tank. The marine ammonia fuel relief device system provided by the invention is simple in structure and low in equipment arrangement space requirement; and the collected liquid ammonia can be recycled, so that energy waste is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of ship design, and in particular relates to a discharge device system and a discharge method for marine ammonia fuel. Background Art

[0002] As the greenhouse effect becomes increasingly serious, a global wave of carbon emission reduction has been set off. In the shipping industry, clean energy has also developed rapidly and will gradually replace fossil energy as the main energy source for future ships. Ammonia is an easily available and easy-to-store chemical product. Its combustion emissions do not produce carbon. It has gradually entered the ship fuel industry and become one of the most promising clean fuels for ships. Therefore, the shipping industry has gradually increased its research on ammonia fuel.

[0003] Ammonia is a toxic substance. Considering the safety of ships, the classification society has given clear regulations on ammonia emissions from ammonia fuel systems: ammonia generated by the ammonia fuel system cannot be discharged directly into the atmosphere, and must be treated by ammonia treatment equipment before being discharged. After discharge, the ammonia concentration must not be higher than 30pm at any location on the ship. At the same time, according to the requirements of the classification society, the ammonia treatment system must operate for a long time or be able to start automatically when ammonia is discharged. Ammonia emissions from ships are characterized by low temperature and high concentration. At present, ammonia treatment technologies include ammonia absorption, ammonia combustion, ammonia catalytic oxidation and ammonia air dilution technology. Ammonia combustion and ammonia catalytic oxidation technologies have high operating costs and are not currently suitable for ship ammonia treatment. Ammonia absorption has the characteristics of simple principle, safety and reliability, and is suitable for ship ammonia treatment.

[0004] CN 204275768U discloses an ammonia absorption device and provides an ammonia absorption method generated in an ammonia water storage tank. The method uses a hydraulic jet pump to mix ammonia with ammonia water in the storage tank, and uses a plate heat exchanger to take away the heat generated during the ammonia absorption process to reduce the temperature of the ammonia water and improve the ammonia absorption rate. In this method, high-concentration ammonia water is used as an absorbent, which has a great influence on the ammonia absorption efficiency. Therefore, it is necessary to deeply cool the ammonia water after absorbing ammonia to ensure that the ammonia is not desorbed. The plate heat exchanger used for ammonia water cooling has a large pressure loss, which will lead to a high back pressure at the outlet of the hydraulic jet pump, affecting the efficiency of the jet pump. At the same time, the method does not need to consider the situation of incomplete ammonia absorption when using this patent, so the method cannot be directly applied to the working conditions of ammonia emission treatment.

[0005] In addition, in order to deal with the release of ammonia during fuel switching on ships, some tanks are usually required, such as anti-shock cabinets at the machine end, anti-shock cabinets at the fuel supply system end, recovery cabinets, water seal cabinets, etc. The released ammonia will evaporate into ammonia gas due to the reduction in pressure. The ammonia gas passes through the impact cabinet and then flows to the water seal cabinet. It is absorbed by fresh water using the property of ammonia being easily soluble in water. If the ammonia solution is saturated and cannot absorb ammonia gas, the ammonia gas will be discharged into the atmosphere through the vent mast. This method has the following disadvantages: (1) More tanks need to be designed during the ammonia absorption process, which will take up more space; (2) The released ammonia cannot be used and can only be absorbed by water, resulting in waste; (3) The obtained ammonia water is not allowed to be discharged into the sea, and a storage tank needs to be set up on the ship to store the saturated ammonia water; and the ammonia water is easily evaporated by heat and discharged into the atmosphere, increasing pollution.

[0006] In summary, it is necessary to provide a discharge device which has a simple structure, low space requirements for equipment installation, and can recycle ammonia. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention aims to provide a discharge device system and a discharge method for marine ammonia fuel. The discharge device system for marine ammonia fuel has a simple structure and low space requirements for equipment installation; and the collected liquid ammonia can be recycled to avoid energy waste.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a discharge device system for marine ammonia fuel, the discharge device system comprising a suction buffer tank, a compression device, a cooling device and a discharge buffer tank connected in sequence;

[0010] A heating device is arranged inside the suction buffer tank.

[0011] In the present invention, the ammonia fuel discharged is ensured to be in gaseous state by means of an intake buffer tank equipped with a heating device, and then the gaseous ammonia is converted into liquid ammonia and transported to a discharge buffer tank through compression and cooling in sequence, and the obtained liquid ammonia can be transported to an ammonia storage tank, thus avoiding the waste of liquid ammonia resources.

[0012] As a preferred technical solution of the present invention, an ammonia fuel discharge and delivery pipeline is provided on the side wall of the suction buffer tank.

[0013] Preferably, a remote control valve is provided on the ammonia fuel discharge and delivery pipeline.

[0014] As a preferred technical solution of the present invention, the heating device includes a heating coil.

[0015] As a preferred technical solution of the present invention, the compression device includes a two-stage compressor or a three-stage compressor.

[0016] As a preferred technical solution of the present invention, a liquid level switch is provided on the side wall of the discharge buffer tank.

[0017] Preferably, the discharge outlet of the discharge buffer tank is connected to an ammonia storage tank.

[0018] It is worth noting that when the liquid ammonia level in the discharge buffer tank is low, the liquid level switch on the discharge buffer tank automatically opens to discharge other gases (such as nitrogen) in the liquid ammonia, thereby preventing other impurities except liquid ammonia from entering the ammonia storage tank;

[0019] In addition, a BOG conveying pipeline is also provided on the side wall of the suction buffer tank of the present invention.

[0020] In a second aspect, the present invention provides a method for discharging ammonia fuel for ships, and the discharging method is performed using the discharging device system for ammonia fuel for ships provided in the first aspect.

[0021] As a preferred technical solution of the present invention, the discharge method comprises the following steps:

[0022] (1) using a suction buffer tank to heat and pressurize the released ammonia fuel to obtain ammonia gas;

[0023] (2) using a compression device to pressurize the ammonia gas obtained in step (1), and then using a cooling device to cool it to obtain liquid ammonia;

[0024] (3) The liquid ammonia obtained in step (2) is transported to a discharge buffer tank.

[0025] As a preferred technical solution of the present invention, the temperature of the heating treatment in step (1) is 10-20°C, for example, it can be 10°C, 12°C, 14°C, 16°C, 18°C ​​or 20°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the terminal pressure of the pressurization treatment in step (1) is 1 to 5 bar, for example, 1 bar, 2 bar, 3 bar, 4 bar or 5 bar, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0027] As a preferred technical solution of the present invention, the terminal pressure of the pressurization treatment in step (2) is 16 to 20 bar, for example, it can be 16 bar, 16.5 bar, 17 bar, 17.5 bar, 18 bar, 18.5 bar, 19 bar, 19.5 bar or 20 bar, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0028] Preferably, the temperature of the cooling treatment in step (2) is 30-40°C, for example, 30°C, 32°C, 34°C, 36°C, 38°C or 40°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] As a preferred technical solution of the present invention, the discharge method provided in the second aspect of the present invention using the discharge device system for marine ammonia fuel provided in the first aspect comprises the following steps:

[0030] (1) using a suction buffer tank to heat the released ammonia fuel at 10 to 20° C. and a pressure of 1 to 5 bar to obtain ammonia gas;

[0031] (2) using a compression device to pressurize the ammonia gas obtained in step (1) to 16 to 20 bar, and then using a cooling device to cool the ammonia gas to 30 to 40° C. to obtain liquid ammonia;

[0032] (3) The liquid ammonia obtained in step (2) is transported to a discharge buffer tank.

[0033] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The system structure of the marine ammonia fuel discharge device provided by the present invention is simple and the space requirement for equipment installation is low;

[0036] (2) The liquid ammonia collected by the discharge device system for marine ammonia fuel provided by the present invention can be recycled, thus avoiding the waste of energy;

[0037] (3) The discharge device system for marine ammonia fuel provided by the present invention does not need to set up an ammonia storage tank. The device system is easy to arrange, has no risk of re-evaporation, and reduces pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the structure of the discharge device system for marine ammonia fuel provided by the present invention;

[0039] Among them, 1 is a suction buffer tank, 2 is a heating device, 3 is a compression device, 4 is a cooling device, 5 is a discharge buffer tank, 6 is a remote control valve, and 7 is a liquid level switch. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0041] In one specific embodiment, the present invention provides a discharge device system for marine ammonia fuel, such as Figure 1 As shown, the discharge device system includes a suction buffer tank 1, a compression device 3, a cooling device 4 and a discharge buffer tank 5 which are connected in sequence;

[0042] A heating device 2 is provided inside the suction buffer tank 1 .

[0043] The side wall of the suction buffer tank is provided with an ammonia fuel discharge and delivery pipeline; the ammonia fuel discharge and delivery pipeline is provided with a remote control valve 6;

[0044] The heating device comprises a heating coil; the compression device comprises a two-stage compressor or a three-stage compressor;

[0045] A liquid level switch 7 is provided on the side wall of the discharge buffer tank; the discharge outlet of the discharge buffer tank is connected to the ammonia storage tank.

[0046] In another specific embodiment, the present invention provides a discharge method using the above-mentioned discharge device system for marine ammonia fuel, and the discharge method comprises the following steps:

[0047] (1) using a suction buffer tank to heat the released ammonia fuel at 10 to 20° C. and a pressure of 5 to 10 bar to obtain ammonia gas;

[0048] (2) using a compression device to pressurize the ammonia gas obtained in step (1) to 16 to 20 bar, and then using a cooling device to cool the ammonia gas to 30 to 40° C. to obtain liquid ammonia;

[0049] (3) The liquid ammonia obtained in step (2) is transported to a discharge buffer tank.

[0050] Example 1

[0051] This embodiment provides a release device system for marine ammonia fuel, such as Figure 1 As shown, the discharge device system includes a suction buffer tank 1, a compression device 3, a cooling device 4 and a discharge buffer tank 5 which are connected in sequence;

[0052] A heating device 2 is provided inside the suction buffer tank 1 .

[0053] The side wall of the suction buffer tank is provided with an ammonia fuel discharge and delivery pipeline; the ammonia fuel discharge and delivery pipeline is provided with a remote control valve 6;

[0054] The heating device comprises a heating coil; the compression device is a single-stage or two-stage compressor;

[0055] A liquid level switch 7 is provided on the side wall of the discharge buffer tank; the discharge outlet of the discharge buffer tank is connected to the ammonia storage tank.

[0056] Example 2

[0057] This embodiment provides a discharge device system for marine ammonia fuel, and the difference between the discharge device system for marine ammonia fuel and embodiment 1 is only that:

[0058] In this embodiment, the liquid level switch 7 arranged on the side wall is omitted.

[0059] Comparative Example 1

[0060] This embodiment provides a discharge device system for marine ammonia fuel, and the difference between the discharge device system for marine ammonia fuel and embodiment 1 is only that:

[0061] In this comparative example, the heating device 2 disposed inside the suction buffer tank 1 is omitted.

[0062] Comparative Example 2

[0063] This embodiment provides a discharge device system for marine ammonia fuel, and the difference between the discharge device system for marine ammonia fuel and embodiment 1 is only that:

[0064] The compression device is omitted in this comparative example.

[0065] Application Example 1

[0066] This application example provides a method for discharging ammonia fuel for ships using the discharging device system provided in Example 1. The discharging method comprises the following steps:

[0067] (1) Using a suction buffer tank to heat the released ammonia fuel at 15°C and a pressure of 3 bar to obtain ammonia gas;

[0068] (2) using a compression device to pressurize the ammonia gas obtained in step (1) to 18 bar, and then using a cooling device to cool the ammonia gas to 35° C. to obtain liquid ammonia;

[0069] (3) The liquid ammonia obtained in step (2) is transported to a discharge buffer tank.

[0070] Application Example 2

[0071] This application example provides a method for discharging ammonia fuel for ships using the discharging device system provided in Example 1. The discharging method comprises the following steps:

[0072] (1) Using a suction buffer tank to heat the released ammonia fuel at 10°C and a pressure of 1 bar to obtain ammonia gas;

[0073] (2) using a compression device to pressurize the ammonia gas obtained in step (1) to 16 bar, and then using a cooling device to cool the ammonia gas to 30° C. to obtain liquid ammonia;

[0074] (3) The liquid ammonia obtained in step (2) is transported to a discharge buffer tank.

[0075] Application Example 3

[0076] This application example provides a method for discharging ammonia fuel for marine use using the discharging device system provided in Example 1. The discharging method comprises the following steps:

[0077] (1) Using a suction buffer tank to heat the released ammonia fuel at 20°C and pressurize it to 5 bar to obtain ammonia gas;

[0078] (2) using a compression device to pressurize the ammonia gas obtained in step (1) to 20 bar, and then using a cooling device to cool it to 40° C. to obtain liquid ammonia;

[0079] (3) The liquid ammonia obtained in step (2) is transported to a discharge buffer tank.

[0080] A comprehensive analysis of application examples 1-3 shows that the process of releasing ammonia fuel using the device system provided by the present invention is simple, and reusable liquid ammonia can be directly obtained without causing waste of resources.

[0081] Application Example 4

[0082] This application example provides a discharge method using the discharge device system for marine ammonia fuel provided in Example 1. The difference between the discharge method and Application Example 1 is that:

[0083] In this application example, the final pressure of the pressurization treatment in step (2) is adjusted to 10 bar.

[0084] Compared with Application Example 1, the terminal pressure of the compression device in this application example is relatively low, which will cause the ammonia gas to be unable to condense into liquid ammonia, resulting in the loss of ammonia gas and further causing a waste of ammonia resources.

[0085] Application Example 5

[0086] This application example provides a discharge method using the discharge device system for marine ammonia fuel provided in Example 1. The difference between the discharge method and Application Example 1 is that:

[0087] In this application example, the temperature of the cooling treatment in step (2) is adjusted to 50°C.

[0088] Compared with Application Example 1, the cooling treatment temperature of the cooler in this application example is relatively high, which will result in the need for a heating medium with a higher temperature, wasting energy;

[0089] In addition, higher temperatures cannot condense all ammonia into liquid form, resulting in a waste of resources.

[0090] Application Example 6

[0091] This application example provides a discharge method using the discharge device system for marine ammonia fuel provided in Example 2, and the discharge method is the same as that in Application Example 1.

[0092] Compared with Application Example 1, the liquid level switch is omitted in the device system used in this application example, which will cause nitrogen to accumulate in the discharge buffer tank, reduce the liquid ammonia level, and eventually the liquid ammonia level will be lower than the discharge port, and nitrogen will enter the ammonia storage tank.

[0093] Comparative application example 1

[0094] This comparative application example provides a discharge method using the discharge device system for marine ammonia fuel provided in Comparative Example 1, and the discharge method is the same as that in Application Example 1.

[0095] Compared with Application Example 1, the heating device is omitted in the device system used in this comparative application example, which will result in the presence of liquid ammonia in the suction buffer tank and the compressor is at risk of sucking in liquid ammonia, affecting the normal operation of the compressor.

[0096] Comparative Application Example 2

[0097] This comparative application example provides a discharge method using the discharge device system for marine ammonia fuel provided in Comparative Example 2, and the discharge method is the same as that in Application Example 1.

[0098] Compared with Application Example 1, the compression device is omitted in the device system used in this comparative application example, which will cause most of the released ammonia to vaporize due to its low pressure and enter the ammonia storage tank, thereby increasing its pressure and possibly causing ammonia emissions.

[0099] In summary, the discharge device system for marine ammonia fuel provided by the present invention has a simple structure and low space requirements for equipment installation; and the collected liquid ammonia can be recycled, avoiding energy waste.

[0100] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A discharge device system for marine ammonia fuel, characterized in that: The discharge device system includes a suction buffer tank, a compression device, a cooling device and a discharge buffer tank which are connected in sequence; A heating device is arranged inside the suction buffer tank.

2. The release device system of marine ammonia fuel according to claim 1, characterized in that: The side wall of the suction buffer tank is provided with an ammonia fuel discharge and delivery pipeline; Preferably, a remote control valve is provided on the ammonia fuel discharge and delivery pipeline.

3. The release device system of marine ammonia fuel according to claim 1 or 2, characterized in that: The heating device comprises a heating coil.

4. The marine ammonia fuel discharge device system according to any one of claims 1 to 3, characterized in that: The compression device comprises a two-stage compressor or a three-stage compressor.

5. The marine ammonia fuel discharge device system according to any one of claims 1 to 4, characterized in that: A liquid level switch is provided on the side wall of the discharge buffer tank; Preferably, the discharge outlet of the discharge buffer tank is connected to an ammonia storage tank.

6. A method for releasing marine ammonia fuel, characterized in that: The discharge method is carried out using the discharge device system for marine ammonia fuel according to any one of claims 1 to 5.

7. The discharge method according to claim 6, characterized in that: The release method comprises the following steps: (1) using a suction buffer tank to heat the released ammonia fuel to obtain ammonia gas; (2) using a compression device to pressurize the ammonia gas obtained in step (1), and then using a cooling device to cool it to obtain liquid ammonia; (3) The liquid ammonia obtained in step (2) is transported to a discharge buffer tank.

8. The discharge method according to claim 7, characterized in that: The temperature of the heating treatment in step (1) is 10-20°C; Preferably, the pressure in step (1) is 1 to 5 bar.

9. The discharge method according to claim 7 or 8, characterized in that: The terminal pressure of the pressurization treatment in step (2) is 16 to 20 bar; Preferably, the temperature of the cooling treatment in step (2) is 30-40°C.

10. The discharge method according to any one of claims 7 to 9, characterized in that: The release method comprises the following steps: (1) using a suction buffer tank to heat the released ammonia fuel at 10 to 20° C. and a pressure of about 1 to 5 bar to obtain ammonia gas; (2) using a compression device to pressurize the ammonia gas obtained in step (1) to 16 to 20 bar, and then using a cooling device to cool the ammonia gas to 30 to 40° C. to obtain liquid ammonia; (3) The liquid ammonia obtained in step (2) is transported to a discharge buffer tank.

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