JP3239000U - Marine fuel supply system - Google Patents

Abstract

Kind Code: A1 A marine fuel supply system that can comply with greenhouse gas emission regulations for ships is provided. A marine fuel supply system includes a first fuel supply line (L1) for transferring liquid ammonia from an ammonia storage tank (105) to a main engine (125), and liquid ammonia returned from the main engine to the ammonia storage tank. a fuel return line L2 for transfer, an evaporative gas supply line L3 for transferring gaseous ammonia from the ammonia storage tank to the sub-engine 160, and a second fuel supply line L8 for further supplying gaseous ammonia to the evaporative gas supply line. , an evaporative gas return line L4 for transferring the gaseous ammonia returned from the sub-engine to the ammonia storage tank, only nitrogen and water are produced during the combustion reaction, and no carbon dioxide is produced. [Selection drawing] Fig. 1

Description

The present invention relates to a marine fuel supply system that uses ammonia, which generates only nitrogen and water during a combustion reaction and does not generate carbon dioxide, so that it can comply with greenhouse gas emission regulations from ships.

Due to the tightening of international regulations on ship exhaust gas from the standpoint of preparing for environmental regulations to prevent global warming and climate change, countries around the world are focusing on the development of environmentally friendly low-carbon fuel ships.

As climate change and air pollution increase worldwide, the International Maritime Organization (IMO), the European Union, the United States, and other countries are planning to significantly strengthen regulations on pollutants discharged from ships. be.

So far, the method of using liquefied natural gas (LNG) as a fuel to replace conventional fossil fuels has been most influentially studied.
Meanwhile, the International Maritime Organization (IMO) announced the ship greenhouse gas and carbon dioxide reduction targets as follows.

1) Greenhouse Gas Emissions Reduction Target from Ships: Pursue a 50% reduction by 2050 compared to 2008 GHG emissions from international shipping. (Incidentally, greenhouse gases include methane (CH ₄ ), carbon dioxide (CO ₂ ), carbon monoxide (CO), ozone (O ₃ ), chlorofluorocarbons (CFCs), and the like. ).

2) Carbon intensity reduction target: 40% reduction in carbon dioxide ( _CO2 ) emissions per transport work by 2030 compared to international shipping in 2008; The goal is to achieve a 70% reduction by 2050.

In the future, it is expected that it will be difficult to comply with greenhouse gas regulations with conventional engines and fuel alone, as the regulations on greenhouse gas emissions from ships will be tightened step by step by 2050 at each major starting point. .

This is also the case with LNG fuel, which has been proven as an alternative for reducing greenhouse gas emissions on current ships. Although LNG fuel is highly efficient in reducing SOx and NOx, it has the disadvantage of being limited in reducing _CO2 (only 15 to 25% compared to HFO). As with other fuels, it will be difficult to comply with greenhouse gas regulations for ships.

The present invention is a marine fuel supply system that can comply with greenhouse gas emission regulations from ships by using ammonia as fuel for ships, which produces only nitrogen and water during the combustion reaction and does not generate carbon dioxide. intended to provide

It is also an object of the present invention to provide a marine fuel supply system that is capable of effectively re-liquefying the amount of gaseous ammonia returned from the engine through an additional cooling step. aim.

In addition, the present invention dissolves gaseous ammonia or liquid ammonia in water to dilute the concentration of ammonia, and reuses this in the SCR system, thereby stabilizing the ship without releasing ammonia into the atmosphere. It is an object of the present invention to provide a marine fuel supply system capable of improving efficiency.

A marine fuel supply system for achieving the above objects includes a first fuel supply line that provides a path for transferring ammonia in a liquid state stored in an ammonia storage tank to a main engine, and a fuel supply line that returns from the main engine. a fuel return line providing a path for transferring liquid ammonia to the ammonia storage tank; an evaporative gas supply line providing a path for transferring gaseous ammonia produced in the ammonia storage tank to the sub-engine; providing a path for transferring liquid ammonia stored in an ammonia storage tank to the sub-engine, wherein gaseous ammonia supplied to the sub-engine through the evaporative gas supply line meets the demand of the sub-engine; If it is insufficient, it provides a second fuel supply line for further supplying gaseous ammonia to the evaporative emission supply line, and a path for transferring gaseous ammonia returned from the sub-engine to the ammonia storage tank. and an evaporative emission return line.

According to the present invention, there is an advantage that it is possible to comply with greenhouse gas emission regulations from ships by using ammonia as fuel for ships, which generates only nitrogen and water during the combustion reaction and does not generate carbon dioxide. .

Another advantage of the present invention is that depending on the amount of gaseous ammonia returned from the engine, it can be effectively re-liquefied through an additional cooling step.

Further, according to the present invention, gaseous ammonia or liquid ammonia is dissolved in water to dilute the concentration of ammonia, and this is reused in the SCR system, so that the vessel can be discharged without releasing ammonia into the atmosphere. has the advantage of being able to improve the stability of

1 is a configuration diagram for explaining a marine fuel supply system according to an embodiment of the present invention; FIG.

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a configuration diagram for explaining a marine fuel supply system according to one embodiment of the present invention.

Referring to FIG. 1, the marine fuel supply system includes supply pumps 100_1 and 100_2, an ammonia storage tank 105, a first heat exchanger 110, a heating device 120, a main engine 125, a filter 130, a first Joule-Thomson valve 135, First catch tank 140, second heat exchanger 145, compressor 150, cooler 155, flow control valve 215, vaporizer 220, sub-engine 160, second catch tank 165, second Joule-Thomson valve 170, control valve 175, It includes a third heat exchanger 180 , a dilution tank 185 and an SCR system 190 .

One or more ammonia storage tanks 105 may be provided on the ship. Although one ammonia storage tank 105 is provided in the drawing, it is not limited to this, and a specific number of storage tanks of a suitable type may be provided according to the type and size of the ship. .

The ammonia storage tank 105 stores liquefied ammonia. Meanwhile, the ammonia storage tank 105 according to an embodiment of the present invention stores urea instead of directly storing ammonia, and uses ammonia generated by hydrolyzing urea as needed. may consist of

The ammonia storage tank 105 is equipped with a sealing and heat insulating barrier so that ammonia in a liquid state can be stored, but cannot completely block heat transferred from the outside.

Accordingly, gaseous ammonia is generated in the ammonia storage tank 105, and the gaseous ammonia in the ammonia storage tank 105 is discharged in order to maintain the pressure of the gaseous ammonia at a proper level.

The ammonia storage tank 105 is connected to the main engine 125 through a first fuel supply line L1, and the first fuel supply line L1 supplies the main engine 125 with liquid ammonia pumped through supply pumps 100_1 and 100_2. supply.

That is, the first fuel supply line L<b>1 provides a path for transferring liquid ammonia supplied from the ammonia storage tank 105 by driving the supply pumps 100_1 and 100_2 to the main engine 125 .

The first fuel supply line L1 includes a first heat exchanger 110 for increasing the temperature of the liquid ammonia, high-pressure pumps 115_1 and 115_2 for increasing the pressure of the liquid ammonia, and liquid ammonia with increased pressure. A heating device 120 is provided to increase the temperature.

Therefore, the liquid ammonia stored in the ammonia storage tank 105 increases in temperature while passing through the first heat exchanger 110, and is heated to the pressure required by the main engine 125 while passing through the high-pressure pumps 115_1 and 115_2. The fuel is pressurized and heated while passing through the heating device 120 and supplied to the main engine 125 .

On the other hand, a portion of the ammonia remaining after being supplied to the main engine 125 or returned from the main engine 125 is cooled along the fuel return line L2 through the first heat exchanger 110 and returned to the ammonia storage tank 105. Stored.

The supply pumps 100_1 and 100_2, the first heat exchanger 110, the high pressure pumps 115_1 and 115_2, and the heating device 120 provided in the first fuel supply line L1 will be described below.

The supply pumps 100_1 and 100_2 are installed to provide the pumping power required to transfer liquid ammonia to the first fuel supply line L1.

The first heat exchanger 110 raises the temperature of the liquid ammonia flowing toward the main engine 125 along the first fuel supply line L1 after being pumped by the supply pumps 100_1 and 100_2 of the ammonia storage tank 105. .

At this time, after the first heat exchanger 110 is pumped by the supply pumps 100_1 and 100_2 of the ammonia storage tank 105, the ammonia flowing toward the main engine 125 along the first first fuel supply line L1 passes through. A first pipe and a second pipe through which liquid ammonia that remains after being supplied to the main engine 125 or is returned from the main engine 125 and flows toward the ammonia storage tank 105 along the fuel return line L2 passes. ,including.

Due to the difference in temperature of the liquid ammonia passing through the first pipe and the second pipe respectively, through the heat exchange between the first pipe and the second pipe, it passes through the first pipe and the second pipe respectively. The temperature of the liquid state ammonia changes.

That is, since the liquid ammonia passing through the first pipe is supplied from the ammonia storage tank 105, the temperature is low, and the liquid ammonia passing through the second pipe is supplied from the main engine 125. Because it is a thing, the temperature is relatively high.

Therefore, the temperature of ammonia inside the first pipe increases through heat exchange, and the temperature of ammonia inside the second pipe decreases through heat exchange.

As described above, by increasing the temperature of the liquid state ammonia flowing toward the main engine 125 along the first fuel supply line L1 via the first heat exchanger 110, the heat of the heating device 120, which will be described later, is increased. load can be reduced.

The high-pressure pumps 115_1 and 115_2 are installed after the first heat exchanger 110 and pressurize the liquid ammonia supplied from the first heat exchanger 110 to the pressure required by the main engine 125 .

For example, the high-pressure pumps 115_1 and 115_2 pressurize the liquid ammonia supplied from the first heat exchanger 110 and having a pressure of '10 barg' to a pressure of '70-80 barg' required by the main engine 125 .

A heating device 120 provided downstream of the high-pressure pumps 115_1 and 115_2 raises the temperature of liquid ammonia pressurized by the high-pressure pumps 115_1 and 115_2.

In one embodiment, the heating device 120 can increase the temperature of the liquid state ammonia through heat exchange with thermal oil.

In another embodiment, the heating device 120 can increase the temperature of liquid ammonia through a heating means (eg, a heater).

On the other hand, the ammonia storage tank 105 is connected to the main engine 125 via a fuel return line L2, and the fuel return line L2 stores liquid ammonia remaining after being supplied to the main engine 125 or returned from the main engine 125. Provides a path for transport to the ammonia storage tank 105 .

The fuel return line L2 includes a filter 130 for removing foreign substances in the liquid ammonia returned from the main engine 125, a first heat exchanger 110 for cooling the temperature of the liquid ammonia, and a liquid ammonia. A first Joule-Thomson valve 135 is provided to drop the pressure of the ammonia.

Therefore, the ammonia in the liquid state returned from the main engine 125 passes through the filter 130 to remove foreign matter, passes through the first heat exchanger 110 and is cooled, and then passes through the first Joule-Thomson valve 135. After the pressure drops through the ammonia storage tank 105, it is stored.

The filter 130, the first heat exchanger 110, and the first Joule-Thomson valve 135 provided in the fuel return line L2 will be described below.

The filter 130 removes contaminants from liquid ammonia discharged from the main engine 125 and provides the first heat exchanger 110 with the contaminants.

Filter 130 should be 10 microns or greater. Also, it is preferable that the filter 130 is installed doubly. In this case, the filter 130 is controlled to automatically change when the pressure of the differential pressure gauge (not shown) exceeds the set value.

The first heat exchanger 110 cools the liquid ammonia returning from the main engine 125 and flowing toward the ammonia storage tank 105 along the fuel return line L2. The operating principle of the first heat exchanger 110 is as described above.

The first Joule-Thomson valve 135 reduces the pressure of the liquid state ammonia whose temperature has decreased while passing through the first heat exchanger 110 so that the ammonia is stored in the ammonia storage tank 105 .

Meanwhile, the ammonia storage tank 105 is connected to the sub-engine 160 via an evaporative gas supply line L3. Evaporation gas supply line L3 provides a path for transferring naturally occurring gaseous ammonia (ie, BOG: Boil Off Gas) from ammonia storage tank 105 to sub-engine 160 .

The evaporative gas supply line L3 is provided with a first catch tank 140 for removing foreign matter and ammonia droplets (DROPLET) in gaseous ammonia, and increasing the temperature of the gaseous ammonia supplied from the first catch tank 140. A second heat exchanger 145, a compressor 150 for increasing the pressure of gaseous ammonia, and a cooler 155 for cooling the temperature of the gaseous ammonia with increased pressure are provided.

Therefore, gaseous ammonia supplied from the ammonia storage tank 105 passes through the first catch tank 140 to remove internal foreign substances and ammonia droplets (DROPLET), and passes through the second heat exchanger 145 to increase the temperature. rises, passes through the compressor 150 and is compressed to the pressure required by the sub-engine 160, passes through the cooler 155 and drops to the temperature required by the sub-engine 160, and is supplied to the sub-engine 160.

On the other hand, some gaseous ammonia remaining after being supplied to the sub-engine 160 or returned from the sub-engine 160 is re-liquefied along the evaporative gas return line L4 and stored in the ammonia storage tank 105 again. .

The first catch tank 140, the second heat exchanger 145, the compressor 150 and the cooler 155 provided in the evaporative gas supply line L3 will be described below.

The first catch tank 140 removes foreign matter and ammonia droplets (DROPLET) inside gaseous ammonia supplied from the ammonia storage tank 105, and for this purpose, a filter may be installed therein.

The gaseous ammonia that has passed through the first catch tank 140 is supplied to the second heat exchanger 145 through the evaporative gas supply line L3, and the liquid ammonia is supplied to the ammonia storage tank 105 again.

The second heat exchanger 145 raises the temperature of gaseous ammonia that passes through the first catch tank 140 and flows toward the sub-engine 160 along the evaporative gas supply line L3.

At this time, the second heat exchanger 145 includes a first pipe through which gaseous ammonia flowing toward the sub-engine 160 along the evaporative gas supply line L3 passes, and an evaporative gas return line returning from the sub-engine 160. a second pipe through which ammonia in gaseous state flows along L4 towards the ammonia storage tank 105;

Since the temperature of gaseous ammonia passing through the first pipe and the second pipe is different, it passes through the first pipe and the second pipe respectively through heat exchange between the first pipe and the second pipe. The temperature of ammonia in gaseous state changes.

That is, since the gaseous ammonia passing through the first pipe is supplied from the ammonia storage tank 105, the temperature is low, and the gaseous ammonia passing through the second pipe is supplied from the sub-engine 160. temperature is high.

Therefore, the temperature of ammonia inside the first pipe increases through heat exchange, and the temperature of ammonia inside the second pipe decreases through heat exchange.

The compressor 150 is provided after the second heat exchanger 145 and pressurizes the gaseous ammonia supplied from the second heat exchanger 145 to the pressure required by the sub-engine 160 . Compressing the gaseous ammonia through the compressor 150 increases the pressure as well as the temperature.

The cooler 155 cools down the temperature of gaseous ammonia, which has been raised while passing through the compressor 150 , to a temperature required by the sub-engine 160 , and then supplies the ammonia to the sub-engine 160 .

Meanwhile, the ammonia storage tank 105 is also connected to the sub-engine 160 via the second fuel supply line L8. The second fuel supply line L8 provides a path for transferring liquid ammonia stored in the ammonia storage tank 105 to the sub-engine 160, and ultimately supplies it to the sub-engine 160 via the evaporative gas supply line L3. If the amount of gaseous ammonia to be supplied is insufficient compared to the amount required by the sub-engine 160, the appropriate amount of gaseous ammonia is further supplied to the evaporative gas supply line L3.

In one embodiment, the second fuel supply line L8 is bypassed from the first fuel supply line L1 at its beginning before the first heat exchanger 110 of the first fuel supply line L1 and ends at the evaporative gas supply. It may be configured to merge before the sub-engine 160 in line L3.

The second fuel supply line L8 includes a flow control valve 215 for controlling the amount of liquid ammonia required to drive the sub-engine 160, and a vaporizer for phase-changing liquid ammonia into gaseous ammonia. can be configured.

Accordingly, the liquid state ammonia bypassing the first fuel supply line L1 and flowing along the second fuel supply line L8 passes through the flow rate control valve 215, and then passes through the vaporizer 220 to become gaseous state. It is phase-converted into ammonia and supplied to sub-engine 160 .

The flow control valve 215 and the carburetor 220 provided in the second fuel supply line L8 will be described below.

When the amount of gaseous ammonia supplied to the sub-engine 160 through the evaporative gas supply line L3 is insufficient compared to the required amount of the sub-engine 160, the flow control valve 215 provides an appropriate amount of gaseous ammonia to the evaporative gas supply line L3. The amount of liquid ammonia flowing through the second fuel supply line L8 is adjusted so that more ammonia can be supplied.

The vaporizer 220 phase-converts liquid ammonia into gaseous ammonia, raises the temperature, and supplies the ammonia to the sub-engine 160 .

In one embodiment, the vaporizer 220 can phase-convert liquid state ammonia to gaseous state ammonia via heat exchange of thermal oil.

In another embodiment, the vaporizer 220 can phase-change ammonia in a liquid state into ammonia in a gaseous state through a heating means (eg, a heater).

Therefore, according to the present invention, when the amount of gaseous ammonia supplied to the sub-engine 160 along the evaporative gas supply line L3 is insufficient for the amount of fuel for the sub-engine 160, the second fuel supply line L8 is used. By supplying an appropriate amount of additional gaseous ammonia to the sub-engine 160, overall system stability can be ensured.

On the other hand, the ammonia storage tank 105 is connected to the sub-engine 160 via the evaporative gas return line L4, and the evaporative gas return line L4 is the gaseous state that remains after being supplied to the sub-engine 160 or is returned from the sub-engine 160. Provides a path for the ammonia to be re-liquefied and transferred to the ammonia storage tank 105 .

The evaporative gas return line L4 includes a second catch tank 165 for removing foreign matter and ammonia droplets (DROPLET) in gaseous ammonia returned from the sub-engine 160, and A second heat exchanger 145 is provided to cool the temperature of the gaseous ammonia and a second Joule-Thompson valve 170 is provided to drop the pressure of the gaseous ammonia.

Therefore, the gaseous ammonia returned from the sub-engine 160 passes through the second catch tank 165 to remove foreign matter and ammonia droplets (DROPLET), and passes through the second heat exchanger 145 to lower its temperature. After that, the ammonia is stored in the ammonia storage tank 105 after the pressure is lowered through the second Joule-Thomson valve 170 and re-liquefied.

The second catch tank 165, the second heat exchanger 145, and the second Joule-Thomson valve 170 provided in the evaporative gas return line L4 will be described below.

The second catch tank 165 removes foreign matter and ammonia droplets (DROPLET) inside gaseous ammonia returned from the sub-engine 160, and for this purpose, a filter may be installed therein.

The gaseous ammonia that has passed through the second catch tank 165 is supplied to the second heat exchanger 145 through the evaporative gas return line L4, and the liquid ammonia is supplied to the ammonia storage tank 105 again.

The second heat exchanger 145 cools the gaseous ammonia that has passed through the second catch tank 165 .

The operating principle of the second heat exchanger 145 is as described above.

On the other hand, the surplus evaporative gas return line L5 is arranged in a branched form in the evaporative gas return line L4. The surplus evaporated gas return line L5 provides a path for re-liquefying gaseous ammonia that has passed through the second catch tank 165 and transferring it to the ammonia storage tank 105 .

A control valve 175 for controlling the supply of gaseous ammonia that has passed through the second catch tank 165 and the temperature of the gaseous ammonia supplied through the control valve 175 is cooled in the surplus evaporative gas return line L5. A third heat exchanger 180 is provided.

The reason for providing the surplus evaporated gas return line L5 as described above is as follows. When a large amount of gaseous ammonia remains after being supplied to the sub-engine 160 or is returned from the sub-engine 160, it is difficult to cool a large amount of ammonia at once using only the second heat exchanger 145.

Therefore, in this case, by opening the control valve 175 and supplying part of the ammonia to the third heat exchanger 180, the amount of ammonia that the second heat exchanger 145 should withstand can be reduced. The gaseous ammonia cooled while passing through the third heat exchanger 180 is re-liquefied while passing through the second Joule-Thomson valve 170 and finally stored in the ammonia storage tank 105 . In the present invention, the control valve 175 is selectively opened and closed as required.

The control valve 175 and the third heat exchanger 180 provided in the surplus evaporated gas return line L5 will be described below.

The control valve 175 remains open or closed depending on the amount of gaseous ammonia returned from the sub-engine 160 . The control valve 175 maintains an open state when the amount of gaseous ammonia returned from the sub-engine 160 is greater than or equal to a set value, and maintains a closed state when the amount is less than or equal to the set value.

If the amount of gaseous ammonia returned from the sub-engine 160 is below the set value and the control valve 175 remains closed, no ammonia will flow into the surplus evaporative gas return line L5.

Conversely, when the amount of gaseous ammonia returned from the sub-engine 160 is equal to or greater than the set value and the control valve 175 is kept open, part of the ammonia branches and flows into the surplus evaporative gas return line L5. , part of which flows directly through the evaporative gas return line L4.

If part of the ammonia flows into the excess evaporated gas return line L5, the ammonia passes through the third heat exchanger 180 of the excess evaporated gas return line L5 and then passes through the second Joule-Thomson valve 170. After being depressurized and re-liquefied, it is stored in the ammonia storage tank 105 .

On the other hand, the third heat exchanger 180 includes a first pipe through which gaseous ammonia flowing into the surplus evaporative gas return line L5 passes, and a second pipe through which seawater passes.

Since the temperature of gaseous ammonia and the temperature of seawater that pass through the first pipe and the second pipe are different, through heat exchange between the first pipe and the second pipe, the first pipe and the second pipe The temperature of gaseous ammonia and sea water passing through the two pipes respectively changes.

That is, since gaseous ammonia passing through the first pipe is supplied from the sub-engine 160, the temperature of the seawater passing through the second pipe is relatively low.

Therefore, the temperature of ammonia inside the first pipe is lowered through heat exchange, and the temperature of seawater inside the second pipe is raised through heat exchange.

Meanwhile, the ammonia storage tank 105 and the plurality of lines are connected to the dilution tank 185 through the ammonia supply line L6. Ammonia supply line L 6 provides a path for ammonia storage tank 105 and multiple lines of gaseous or liquid ammonia to dilute tank 185 .

The reason for providing the ammonia supply line L6 as described above is as follows. When the amount of gaseous ammonia in the ammonia storage tank 105 increases, the pressure in the ammonia storage tank 105 increases. Also, due to unexpected circumstances, the pressure inside the first fuel supply line L1 or the fuel return line L2 may suddenly increase. However, if the pressure in the ammonia storage tank 105 or the plurality of lines L1, L2 becomes excessively high in this way, there is a risk that the ammonia will leak or explode.

Therefore, in this case, the safety valve 195 is opened to partially extract the gaseous ammonia in the ammonia storage tank 105 or the liquid ammonia in the first fuel supply line L1 or the fuel return line L2 and supply it through the ammonia supply line L6. By feeding the dilution tank 185, excessive pressure build-up can be reduced.

Furthermore, the liquid ammonia that has passed through the first catch tank 140 or the second catch tank 165 can also be supplied to the dilution tank 185 and can join the first fuel supply line L1 as necessary.

The safety valve 195 provided in the ammonia supply line L6 will be described below.

The safety valve 195 maintains a closed state when the pressure of the ammonia storage tank 105 is equal to or less than the set value, and maintains an open state when the pressure is equal to or greater than the set value. If the pressure in the ammonia storage tank 105 is below the set value and the safety valve 195 remains closed, gaseous ammonia will not flow into the ammonia supply line L6. Conversely, when the pressure in the ammonia storage tank 105 is equal to or higher than the set value and the safety valve 195 remains open, gaseous ammonia flows into the ammonia supply line L6 and moves to the dilution tank 185 .

Further, the safety valve 195 maintains the closed state if the pressure in the first fuel supply line L1 or the fuel return line L2 is equal to or lower than the set value, and maintains the open state if the pressure is equal to or higher than the set value. If the pressure in the first fuel supply line L1 or the fuel return line L2 is below the set value and the safety valve 195 remains closed, no liquid ammonia will flow into the ammonia supply line L6. Conversely, when the pressure in the first fuel supply line L1 or the fuel return line L2 is equal to or higher than the set value and the safety valve 195 is kept open, liquid ammonia flows into the ammonia supply line L6 and into the dilution tank 185. Moving.

For the above reasons, even if excessive pressure increases occur in the fuel supply system, gaseous or liquid ammonia can be extracted to prevent the pressure increase, and the extracted ammonia is released into the atmosphere. By temporarily storing it in the dilution tank 185 instead of throwing it away, it is possible to prevent danger such as explosion in advance.

Dilution tank 185 is connected to SCR system 190 via reducing agent supply line L7. The reducing agent supply line L7 provides a route for transferring the aqueous ammonia discharged from the dilution tank 185 to the SCR system 190.

Ammonia is diluted with water and temporarily stored in the dilution tank 185 in the form of ammonia water, and the ammonia water is supplied to the SCR system 190 through the reducing agent supply line L7 as needed. The SCR system 190 uses aqueous ammonia to remove nitrogen oxides (NOx) from the exhaust gas. At this time, the SCR system 190 can adjust the amount of ammonia water according to the concentration of nitrogen oxides (NOx).

As described above, the dilution tank 185 supplies ammonia to the SCR system 190 (when the SCR system is in operation) while serving as a buffer that reduces the risk of the fuel supply system exploding due to ammonia leakage. It serves as a supply and storage means for temporarily storing unused ammonia (when the SCR system is not in operation).

100_1, 100_2 supply pump 105 ammonia storage tank 110 first heat exchanger 115_1, 115_2 high pressure pump 120 heating device 125 main engine 130 filter 135 first Joule-Thomson valve 140 first catch tank 145 second heat exchanger 150 compressor 155 Cooler 160 Sub-engine 165 Second catch tank 170 Second Joule-Thomson valve 175 Control valve 180 Third heat exchanger 185 Dilution tank 190 SCR system 195 Safety valve 215 Flow control valve 220 Vaporizer L1 First fuel supply line L2 Fuel return line L3 Evaporated gas supply line L4 Evaporated gas return line L5 Surplus evaporated gas return line L6 Ammonia supply line L7 Reducing agent supply line L8 Second fuel supply line

Claims (20)

a first fuel supply line providing a path for transferring liquid ammonia stored in the ammonia storage tank to the main engine;
a fuel return line providing a path for transferring liquid ammonia returned from the main engine to the ammonia storage tank;
an evaporative gas supply line providing a path for transferring gaseous ammonia generated in the ammonia storage tank to the sub-engine;
providing a path for transferring the liquid ammonia stored in the ammonia storage tank to the sub-engine, and supplying gaseous ammonia to the sub-engine through the evaporative gas supply line to meet the demand of the sub-engine; a second fuel supply line for further supplying ammonia in a gaseous state to the evaporative emission supply line when the amount is insufficient compared to
and an evaporative gas return line that provides a path for transferring gaseous ammonia returned from the sub-engine to the ammonia storage tank. According to the amount of gaseous ammonia connected to the evaporative gas return line and remaining after being supplied to the sub-engine or returned from the sub-engine, when part of the ammonia is branched and inflowed, 2. The marine fuel supply system according to claim 1, further comprising a surplus evaporative gas return line providing a path for transferring gaseous ammonia to the ammonia storage tank after cooling the temperature thereof. The first fuel supply line and the fuel return line are
A first heat exchange between liquid ammonia pumped from the ammonia storage tank and flowing toward the main engine and liquid ammonia returning from the main engine and flowing toward the ammonia storage tank. 2. A marine fuel supply system according to claim 1, comprising a heat exchanger. The evaporative gas supply line and the evaporative gas return line are
Second heat for heat exchange between gaseous ammonia generated in the ammonia storage tank and flowing toward the sub-engine and gaseous ammonia returning from the sub-engine and flowing toward the ammonia storage tank. 2. A marine fuel supply system according to claim 1, comprising an exchanger. 2. The marine fuel supply system according to claim 1, wherein the fuel return line includes a filter for removing contaminants in liquid ammonia returned from the main engine. 2. The method of claim 1, wherein the evaporative gas supply line includes a first catch tank that removes foreign matter and ammonia droplets (DROPLET) in gaseous ammonia supplied from the ammonia storage tank. Marine fuel supply system. 2. The ship according to claim 1, wherein the evaporative gas return line includes a second catch tank for removing foreign matter and ammonia droplets (DROPLET) in gaseous ammonia returned from the sub-engine. fuel supply system. The surplus evaporative gas return line is maintained in an open state or a closed state according to the amount of gaseous ammonia returned from the sub-engine so that part of the gaseous ammonia branches and flows in. 3. A marine fuel supply system according to claim 2, comprising a control valve for When the amount of gaseous ammonia returned from the sub-engine reaches or exceeds a set value, the control valve is opened so that part of the gaseous ammonia branches and flows into the surplus evaporated gas return line. 9. The marine fuel supply system according to claim 8, characterized in that: The control valve is closed when the amount of gaseous ammonia returned from the sub-engine falls below a set value, thereby preventing the gaseous ammonia from flowing into the surplus evaporated gas return line. The marine fuel supply system according to claim 8, wherein 3. The marine fuel according to claim 2, wherein the surplus evaporative gas return line includes a third heat exchanger for cooling the gaseous ammonia when a portion of the gaseous ammonia flows thereinto. supply system. 12. The marine fuel supply system according to claim 11, wherein the third heat exchanger cools the gaseous ammonia using cold heat of seawater. 2. The marine fuel supply system according to claim 1, further comprising an ammonia supply line providing a path for supplying gaseous ammonia generated in the ammonia storage tank to the dilution tank. The ammonia supply line is
A safety valve that maintains an open state or a closed state according to the pressure of the ammonia storage tank and allows gaseous ammonia stored in the ammonia storage tank to flow into the dilution tank. 14. A marine fuel supply system according to Item 13. The safety valve is opened when the pressure of the ammonia storage tank reaches or exceeds a set value, and allows gaseous ammonia stored in the ammonia storage tank to flow into the dilution tank. 15. A marine fuel supply system according to Item 14. The safety valve is closed when the pressure of the ammonia storage tank becomes equal to or less than a set value, thereby preventing gaseous ammonia stored in the ammonia storage tank from flowing into the dilution tank. 15. A marine fuel supply system according to Item 14. 14. The marine fuel supply system according to claim 13, further comprising a reducing agent supply line for supplying ammonia water in the dilution tank to the SCR system. 18. The marine fuel supply system according to claim 17, wherein the SCR system removes nitrogen oxides (NOx) from the exhaust gas using aqueous ammonia flowing through the reducing agent supply line. The second fuel supply line is configured such that one end is bypassed from the first fuel supply line and the other end is joined to the preceding stage of the sub-engine of the evaporative gas supply line. 2. The marine fuel supply system according to . The second fuel supply line is
a flow control valve for adjusting the amount of liquid ammonia required to drive the sub-engine;
2. The marine fuel supply system according to claim 1, further comprising a vaporizer for phase-changing the liquid ammonia that has passed through the flow control valve into gaseous ammonia and raising the temperature.

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