KR102312060B1 - Ship fuel supply system and method performing thereof - Google Patents

Abstract

The present invention is to provide a fuel supply system for a ship and an operating method thereof, which can deal with ship greenhouse gas emission regulations by using ammonia, which produces only nitrogen and water and does not generate carbon dioxide, as a fuel for a ship during a combustion reaction. According to one embodiment of the present invention, a fuel supply system for a ship comprises: a fuel supply line which provides a path for transferring liquid ammonia stored in an ammonia storage tank to a main engine; a fuel return line which provides a path for transferring the liquid ammonia returned from the main engine to the ammonia storage tank; a boil-off gas supply line which provides a path for transferring gaseous ammonia generated in the ammonia storage tank to a sub-engine; and a boil-off gas return line which provides a path for transferring the gaseous ammonia returned from the sub-engine to the ammonia storage tank.

Description

A fuel supply system for ships and a method for implementing the same

The present invention relates to a fuel supply system for a ship and a method for implementing the same, and more particularly, a fuel supply system for a ship that can respond to ship greenhouse gas emission regulations by using ammonia, which generates only nitrogen and water and does not generate carbon dioxide during a combustion reaction, and How to do it.

In terms of preparing for environmental regulations to prevent global warming and climate change, countries around the world are focusing on developing eco-friendly, low-carbon fuel-using ships due to the strengthening of international ship emission gas regulations.

In addition, the International Maritime Organization (IMO), the European Union, and the United States will significantly strengthen regulations on pollutants emitted from ships in response to global climate change and increase in air pollution.

In the meantime, the method of using liquefied natural gas (LNG) as a fuel to replace the existing fossil fuel has been considered the most influential.

Meanwhile, the ship's greenhouse gas and carbon dioxide reduction targets announced by the International Maritime Organization (IMO) are as follows.

1) Ship Greenhouse Gas Emission Reduction Goal: Compared to the 2008 GHG (Greenhouse Gas) emission of international shipping, the goal is to reduce 50% by 2050. (For reference, the gases included in greenhouse gases are methane (CH4), carbon dioxide (CO2), carbon monoxide (CO), ozone (O3), chlorofluorocarbons (CFCs), etc.)

2) Carbon Intensity Reduction Goal: Aim to reduce carbon dioxide (CO2) emissions per transport work by 40% by 2030 and 70% by 2050 compared to international shipping in 2008 are seeking with

It is expected that it will be difficult to comply with the greenhouse gas regulations with only the existing engines and fuels as the greenhouse gas emission regulations of ships will be strengthened step by step by 2050.

This is also true of LNG fuel, which is currently proven as an alternative to reducing greenhouse gas emissions from ships. LNG fuel has excellent SOx and NOx reduction efficiency, but has a disadvantage in that CO2 reduction is limited (only 15 to 25% compared to HFO). It will be difficult.

An object of the present invention is to provide a fuel supply system for a ship and a method for implementing the same, which can respond to ship greenhouse gas emission regulations by using ammonia, which produces only nitrogen and water during a combustion reaction and does not generate carbon dioxide, as a fuel for a ship.

In addition, an object of the present invention is to provide a fuel supply system for a ship and a method for implementing the same, so that it can be effectively reliquefied through an additional cooling step according to the amount of gaseous ammonia returned from the engine.

In addition, the present invention is a fuel supply system for a ship that can increase the stability of a ship without discharging ammonia into the atmosphere by dissolving ammonia in a gaseous state or in a liquid state in water to dilute the concentration of ammonia and reuse it in the SCR system, and An object of the present invention is to provide a method for implementing it.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. Moreover, it will be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

A fuel supply system for ships for achieving this purpose is a fuel supply line providing a path for transferring liquid ammonia stored in an ammonia storage tank to a main engine, and storing the ammonia in liquid state returned from the main engine. A fuel return line providing a path for transferring to the tank, a boil-off gas supply line providing a path for transferring gaseous ammonia generated in the ammonia storage tank to the sub-engine, and gaseous ammonia returned from the sub-engine and a boil-off gas return line providing a path for transport to the ammonia storage tank.

In addition, the fuel supply method for ships for achieving this object includes the steps of transferring liquid ammonia stored in an ammonia storage tank to the main engine through a fuel supply line, liquid ammonia returned from the main engine is a fuel return line transferring to the ammonia storage tank through and transferring it to the ammonia storage tank through a return line.

According to the present invention as described above, there is an advantage in that only nitrogen and water are generated during the combustion reaction, and ammonia, which does not generate carbon dioxide, can be used as a fuel of the ship to cope with the ship's greenhouse gas emission regulation.

In addition, according to the present invention, there is an advantage that it can be effectively reliquefied through an additional cooling step according to the amount of ammonia in the gaseous state returned from the engine.

In addition, according to the present invention, by dissolving ammonia in gaseous state or liquid ammonia in water to dilute the concentration of ammonia and reuse it in the SCR system, there is an advantage that the stability of the ship can be improved without releasing ammonia to the atmosphere.

1 is a configuration diagram for explaining a fuel supply system for a ship according to an embodiment of the present invention.
2 is an exemplary view for explaining a process of supplying fuel for a ship according to an embodiment of the present invention.
3 is a flowchart for explaining an embodiment of a method for supplying fuel for a ship according to the present invention.
4 is a flowchart for explaining another embodiment of the fuel supply method for a ship according to the present invention.

The above-described objects, features and advantages will be described below in detail with reference to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

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

Referring to FIG. 1 , a fuel supply system for a ship 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 , and a filter 130 . , first Joule Thompson valve 135, first catch tank 140, second heat exchanger 145, compressor 150, cooler 155, sub-engine 160, second catch tank 165, It includes a second Joule Thompson valve 170 , a control valve 175 , 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 thereto, and a specific number of storage tanks of a suitable type may be provided according to the type or size of the vessel.

The ammonia storage tank 105 stores liquefied ammonia. On the other hand, instead of directly storing ammonia in the ammonia storage tank 105 according to an embodiment of the present invention, it may be configured in a way that stores urea and uses ammonia generated by hydrolyzing urea if necessary. .

The ammonia storage tank 105 is equipped with a sealing and insulating barrier to store liquid ammonia, but cannot completely block the heat transmitted from the outside.

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

The ammonia storage tank 105 is connected to the main engine 125 through a fuel supply line L1, and the fuel supply line L1 transfers liquid ammonia pumped through the supply pumps 100_1 and 100_2 to the main engine ( 125) is supplied.

That is, the fuel supply line L1 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 .

In the fuel supply line (L1), the first heat exchanger 110 for increasing the temperature of liquid ammonia, high-pressure pumps 115_1 and 115_2 for increasing the pressure of liquid ammonia, and liquid ammonia having increased pressure A heating device 120 for increasing the temperature is formed.

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

On the other hand, some ammonia that remains supplied to the main engine 125 or returned from the main engine 125 is cooled through the first heat exchanger 110 along the fuel return line L2 and stored in the ammonia storage tank 105 again. do.

Hereinafter, 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 formed in the fuel supply line L1 will be described.

The supply pumps 100_1 and 100_2 are installed to provide a pumping force necessary for transferring liquid ammonia to the fuel supply line L1 .

The first heat exchanger 110 is pumped by the supply pumps 100_1 and 100_2 of the ammonia storage tank 105 and then flows along the fuel supply line L1 toward the main engine 125. The temperature of ammonia in the liquid state raise the

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

Since the temperature of the liquid ammonia passing through each of the first pipe and the second pipe is different, the liquid ammonia passing through the first pipe and the second pipe through heat exchange between the first pipe and the second pipe, respectively temperature will change.

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, so it is relatively with high temperature

Accordingly, the temperature of ammonia inside the first pipe is increased through heat exchange, and ammonia inside the second pipe is decreased in temperature through heat exchange.

As described above, by increasing the temperature of liquid ammonia flowing toward the main engine 125 along the fuel supply line L1 through the first heat exchanger 110 to reduce the heat load of the heater device 120 to be described later. can

The high-pressure pumps 115_1 and 115_2 are formed at the rear end of the first heat exchanger 110 to pressurize the liquid ammonia pressure 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 pressure “10 barg” of liquid ammonia supplied from the first heat exchanger 110 to the pressure “70 barg to 80 barg” required by the main engine 125 .

The heating device 120 formed at the rear end of the high-pressure pumps 115_1 and 115_2 increases the temperature of the liquid ammonia pressurized by the high-pressure pumps 115_1 and 115_2.

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

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

On the other hand, the ammonia storage tank 105 is connected to the main engine 125 through the fuel return line (L2), the fuel return line (L2) is supplied to the main engine 125 and left or returned from the main engine 125. A path is provided for transferring liquid ammonia to the ammonia storage tank 105 .

The fuel return line L2 includes a filter 130 that removes foreign substances in the liquid ammonia returned from the main engine 125, a first heat exchanger 110 that cools the temperature of liquid ammonia, and a liquid ammonia. A first Joule Thompson valve 135 for lowering the pressure of ammonia is formed.

Therefore, the liquid ammonia returned from the main engine 125 passes through the filter 130 while removing foreign substances, and after passing through the first heat exchanger 110 and lowering the temperature, the first Joule Thompson valve 135 is opened. After the pressure is lowered through the ammonia storage tank 105 is stored.

Hereinafter, the filter 130 , the first heat exchanger 110 , and the first Joule Thompson valve 135 formed in the fuel return line L2 will be described.

The filter 130 removes foreign substances in the liquid ammonia discharged from the main engine 125 and provides it to the first heat exchanger 110 .

The filter 130 should be at least 10 microns. And the filter 130 is preferably installed in a double. In this case, the filter 130 is controlled to change automatically when the pressure of the differential pressure gauge (not shown) exceeds a set value.

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

The first Joule Thompson valve 135 lowers the pressure of ammonia in a liquid state whose temperature is lowered while passing through the first heat exchanger 110 so as to be stored in the ammonia storage tank 105 .

On the other hand, the ammonia storage tank 105 is connected to the sub-engine 160 through the boil-off gas supply line (L3). The boil-off gas supply line L3 provides a path for transferring ammonia in a gaseous state (ie, BOG: Boil Off Gas) naturally generated from the ammonia storage tank 105 to the sub-engine 160 .

In the boil-off gas supply line (L3), the first catch tank 140 for removing foreign substances and ammonia droplets (DROPLET) in the gaseous ammonia, and the temperature of the gaseous ammonia supplied from the first catch tank 140 A second heat exchanger 145 for raising the pressure, 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 formed.

Accordingly, the gaseous ammonia supplied from the ammonia storage tank 105 passes through the first catch tank 140 , and foreign substances and ammonia droplets DROPLET are removed therein, and the temperature while passing through the second heat exchanger 145 . rises, is compressed to the pressure required by the sub engine 160 while passing through the compressor 150, and is lowered to the temperature required by the sub engine 160 while passing through the cooler 155. is supplied

On the other hand, some gaseous ammonia that remains supplied to the sub-engine 160 or returned from the sub-engine 160 is reliquefied along the boil-off gas return line L4 and stored in the ammonia storage tank 105 again.

Hereinafter, the first catch tank 140 , the second heat exchanger 145 , the compressor 150 , and the cooler 155 formed in the boil-off gas supply line L3 will be described.

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

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

The second heat exchanger 145 passes through the first catch tank 140 and increases the temperature of gaseous ammonia flowing toward the sub-engine 160 along the boil-off gas supply line L3.

At this time, the second heat exchanger 145 is returned from the first pipe and the sub-engine 160 through which ammonia in gaseous state flowing toward the sub-engine 160 along the boil-off gas supply line L3 passes and returns the boil-off gas. and a second pipe through which gaseous ammonia flowing along line L4 towards ammonia storage tank 105 is passed.

Since the temperature of the gaseous ammonia passing through each of the first pipe and the second pipe is different, the gaseous ammonia passing through the first pipe and the second pipe through heat exchange between the first pipe and the second pipe, respectively temperature will change.

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, so the temperature is low. is high

Accordingly, the temperature of ammonia inside the first pipe is increased through heat exchange, and ammonia inside the second pipe is decreased in temperature through heat exchange.

The compressor 150 is formed at the rear end of the second heat exchanger 145 to pressurize the gaseous ammonia pressure supplied from the second heat exchanger 145 to the pressure required by the sub-engine 160 . When gaseous ammonia is compressed through the compressor 150, the pressure rises and the temperature rises at the same time.

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

On the other hand, the ammonia storage tank 105 is connected to the sub-engine 160 through the boil-off gas return line L4, and the boil-off gas return line L4 remains supplied to the sub-engine 160 or remains in the sub-engine 160. A path is provided for re-liquefying the returned gaseous ammonia to the ammonia storage tank 105 .

In the boil-off gas return line L4, a second catch tank 165 that removes foreign substances and ammonia droplets DROPLET in gaseous ammonia returned from the sub-engine 160, and the second catch tank 165 A second heat exchanger 145 for cooling the temperature of gaseous ammonia and a second Joule Thompson valve 170 for lowering the pressure of gaseous ammonia are formed.

Accordingly, the gaseous ammonia returned from the sub-engine 160 passes through the second catch tank 165 , while foreign substances and ammonia droplets are removed, and the temperature decreases while passing through the second heat exchanger 145 . After the pressure is lowered through the second Joule Thompson valve 170 and re-liquefied, it is stored in the ammonia storage tank 105 .

Hereinafter, the second catch tank 165 , the second heat exchanger 145 , and the second Joule Thompson valve 170 formed in the boil-off gas return line L4 will be described.

The second catch tank 165 removes foreign substances and ammonia droplets in the gaseous ammonia returned from the sub-engine 160 , and for this purpose, a filter may be formed therein.

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

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 evaporative gas return line (L4) is disposed in a branched surplus BOG return line (L5). The excess boil-off gas return line L5 provides a path for re-liquefying the gaseous ammonia that has passed through the second catch tank 165 and transferring it to the ammonia storage tank 105 .

In the surplus boil-off gas return line L5, a control valve 175 for controlling the supply of gaseous ammonia that has passed through the second catch tank 165 and a gaseous ammonia supplied through the control valve 175 A third heat exchanger 180 for cooling the temperature is formed.

The reason for providing the excess boil-off gas return line L5 as described above is as follows. When the amount of ammonia in gaseous state supplied to the sub-engine 160 and remaining or returned from the sub-engine 160 is large, it may be difficult to cool a large amount of ammonia with only the second heat exchanger 145 at once.

Accordingly, in this case, by opening the control valve 175 and supplying a portion of ammonia to the third heat exchanger 180 , the amount of ammonia that the second heat exchanger 145 has to bear can be reduced. Gas ammonia cooled while passing through the third heat exchanger 180 is reliquefied while passing through the second Joule Thompson valve 170 and is finally stored in the ammonia storage tank 105 . In the present invention, the control valve 175 is selectively opened and closed when necessary.

Hereinafter, the control valve 175 and the third heat exchanger 180 formed in the surplus BOG return line L5 will be described.

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

If the amount of ammonia in the gaseous state returned from the sub-engine 160 is less than or equal to the set value and thus the control valve 175 maintains the closed state, the ammonia does not flow into the surplus BOG return line L5.

Conversely, if the amount of ammonia in the gaseous state returned from the sub-engine 160 is greater than or equal to the set value and thus the control valve 175 is maintained in the open state, a portion of the ammonia is branched and flows into the surplus BOG return line L5. and a portion flows through the boil-off gas return line (L4) as it is.

If a part of ammonia is introduced into the surplus BOG return line L5, the ammonia passes through the third heat exchanger 180 of the surplus BOG return line L5 and after the temperature is lowered, the second Joule Thompson valve After the pressure is lowered through 170 and reliquefied, it is stored in the ammonia storage tank 105 .

Meanwhile, the third heat exchanger 180 includes a first pipe through which ammonia in gaseous state introduced into the excess boil-off gas return line L5 passes, and a second pipe through which seawater passes.

Since the temperature of the gaseous ammonia and seawater passing through each of the first and second pipes is different, the gaseous state passing through the first pipe and the second pipe through heat exchange between the first pipe and the second pipe, respectively temperature of ammonia and seawater will change.

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

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

On the other hand, the ammonia storage tank 105 and several lines are connected to the dilution tank 185 through the ammonia supply line (L6). The ammonia supply line L6 provides a path for moving the ammonia storage tank 105 and gas or liquid ammonia in various lines to the dilution tank 185 .

The reason for providing the ammonia supply line L6 as described above is as follows. When the amount of ammonia in the gaseous state inside the ammonia storage tank 105 increases, the pressure of the ammonia storage tank 105 increases. Also, the pressure inside the fuel supply line L1 or the fuel return line L2 may rapidly increase due to an unexpected situation. However, when the pressure of the ammonia storage tank 105 or the various lines L1 and L2 is excessively increased as described above, there is a risk of ammonia leaking or explosion.

Therefore, in this case, the safety valve 195 is opened to partially extract gaseous ammonia from the ammonia storage tank 105 or liquid ammonia from the fuel supply line L1 or the fuel return line L2 to extract the ammonia supply line L6 ) by supplying the dilution tank 185 through the excessive increase in pressure can be reduced.

Additionally, ammonia in a liquid state that has passed through the first catch tank 140 or the second catch tank 165 may also be supplied to the dilution tank 185 , and may join the fuel supply line L1 if necessary.

Hereinafter, the safety valve 195 formed in the ammonia supply line L6 will be described.

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

In addition, the safety valve 195 maintains a closed state when the pressure of the fuel supply line L1 or the fuel return line L2 is equal to or less than a set value, and maintains an open state when the pressure of the fuel supply line L1 or the fuel return line L2 is equal to or greater than the set value. If the pressure of the fuel supply line L1 or the fuel return line L2 is below the set value and the safety valve 195 is maintained in the closed state, the liquid ammonia does not flow into the ammonia supply line L6. . Conversely, when the pressure of the fuel supply line L1 or the fuel return line L2 is higher than the set value and the safety valve 195 is maintained in an open state, the liquid ammonia flows into the ammonia supply line L6 and the dilution tank (185).

Even if excessive pressure increase occurs in the fuel supply system for the same reason as described above, the pressure increase can be prevented by extracting ammonia in gaseous or liquid state. risk can be prevented in advance.

The dilution tank 185 is connected to the SCR system 190 through a reducing agent supply line L7. The reducing agent supply line L7 provides a path for transferring the ammonia water discharged from the dilution tank 185 to the SCR system 190 .

In the dilution tank 185, ammonia is diluted with water and temporarily stored in the form of ammonia water, and the ammonia water is supplied to the SCR system 190 through the reducing agent supply line L7 whenever necessary. The SCR system 190 removes nitrogen oxides (NOx) from the exhaust gas using ammonia water. At this time, the SCR system 190 may adjust the amount of ammonia water according to the concentration of nitrogen oxide (NOx).

As described above, the dilution tank 185 serves as a buffer means for reducing the risk that the fuel supply system will explode due to leakage of ammonia, and at the same time supplies ammonia to the SCR system 190 (when the SCR system is operating) or It serves as a supply and storage means to temporarily store unused ammonia (when the SCR system is not in operation).

2 is an exemplary view for explaining a process of supplying fuel for a ship according to an embodiment of the present invention.

The fuel supply line L1 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 .

First, the liquid ammonia stored in the ammonia storage tank 105 passes through the first heat exchanger 110 and the temperature rises.

For example, as shown in reference number (a), the pressure of ammonia in the liquid state input to the first heat exchanger 110 is 10.5 barg and the temperature is -30°C, but as shown in reference number (b), the first heat exchanger ( 110), the pressure of ammonia in the liquid state is 10 barg and the temperature is raised to -28°C.

Thereafter, the liquid ammonia that has passed through the first heat exchanger 110 is pressurized to a pressure required by the main engine 125 while passing through the high-pressure pumps 115_1 and 115_2 .

For example, as shown in reference number (b), the pressure of ammonia in liquid state input to the high pressure pumps 115_1 and 115_2 is 10 barg and the temperature is -28 ° C., but as shown in reference number (c), the high pressure pumps 115_1, The pressure of liquid ammonia discharged from 115_2) is 81 barg and the temperature is converted to -10°C.

After that, the liquid ammonia discharged from the high-pressure pumps 115_1 and 115_2 passes through the heating device 120 and is raised to a temperature required by the main engine 125 .

For example, as shown in reference number (c), the pressure of ammonia in the liquid state input to the heating device 120 is 81 barg and the temperature is -10°C, but it passes through the heating device 120 as shown in reference number (d). The pressure of ammonia in a liquid state is 80 barg and the temperature is converted to 40-50 °C.

Ammonia in a liquid state that has passed through the heating device 120 is supplied to the main engine 125, and the ammonia returned from the main engine 125 is cooled through the first heat exchanger 110 along the fuel return line L2. Again stored in the ammonia storage tank (105).

That is, the fuel return line L2 provides a path for transferring the liquid ammonia which is supplied to the main engine 125 and left or returned from the main engine 125 to the ammonia storage tank 105 .

More specifically, as shown in reference numeral (e), the pressure of ammonia in the liquid state returned from the main engine 125 is 80 barg and the temperature is 40-50°C.

This liquid ammonia is removed from foreign substances while passing through the filter 130 , and after the temperature is lowered while passing through the first heat exchanger 110 , the pressure is lowered through the first Joule Thompson valve 135 and then the ammonia storage tank is stored in (105).

For example, as shown in reference number (e), the pressure of ammonia in the liquid state input to the first heat exchanger 110 is 80 barg and the temperature is 40-50 °C, but as shown in reference number (f), the first heat exchanger The pressure of ammonia in the liquid state discharged through the 110 and the first Joule Thompson valve 135 is 1 to 2 barg and the temperature is lowered to -30°C.

On the other hand, the ammonia storage tank 105 is connected to the sub-engine 160 through the boil-off gas supply line (L3). The boil-off gas supply line L3 provides a path for transferring ammonia in a gaseous state (ie, BOG: Boil Off Gas) naturally generated from the ammonia storage tank 105 to the sub-engine 160 .

First, the gaseous ammonia stored in the ammonia storage tank 105 passes through the first catch tank 140 , and foreign substances and ammonia droplets are removed therein, and the temperature while passing through the second heat exchanger 145 . is raised

For example, as shown in reference number (g), the pressure of gaseous ammonia input to the second heat exchanger 145 is 1 to 2 barg and the temperature is -25°C, but as shown in reference number (h), the second heat exchange The pressure of gaseous ammonia that has passed through the group 145 and the compressor 150 is 6-8 barg, and the temperature is converted to 55°C.

Thereafter, the gaseous ammonia discharged from the compressor 150 passes through the cooler 155 and is lowered to a temperature required by the sub-engine 160 , and then is supplied to the sub-engine 160 .

For example, as shown in reference number (h), the pressure of ammonia in gaseous state input to the cooler 155 is 6 to 8 barg and the temperature is 55°C, but it is discharged from the cooler 155 as shown in reference number (j). The pressure of gaseous ammonia supplied to the sub-engine 160 is 6-8 barg, and the temperature is converted to 45°C.

On the other hand, the ammonia storage tank 105 is connected to the sub-engine 160 through the boil-off gas return line L4, and the boil-off gas return line L4 remains supplied to the sub-engine 160 or remains in the sub-engine 160. A path is provided for reliquefying the returned gaseous ammonia to the ammonia storage tank 105 .

The gaseous ammonia returned from the sub-engine 160 passes through the second catch tank 165 to remove foreign substances and ammonia droplets (DROPLET), and passes through the second heat exchanger 145 after the temperature is lowered. 2 The pressure is lowered through the Joule Thompson valve 170 and re-liquefied and then stored in the ammonia storage tank 105 .

For example, as shown in reference number (k), the pressure of ammonia in gaseous state returned from the sub-engine 160 is 6-8 barg and the temperature is 45°C, but as shown in reference number (m), the second heat exchanger 145 ), the pressure of gaseous ammonia passing through it is 5~7 barg and the temperature is converted to 30℃.

Meanwhile, the boil-off gas return line L4 is connected to the excess boil-off gas return line L5 . The surplus boil-off gas return line L5 opens the control valve 175 when the amount of ammonia in the gaseous state remaining after being supplied to the sub-engine 160 or returning from the sub-engine 160 is large, so that a portion of the ammonia is transferred to the third heat exchanger. By supplying at 180, the amount of ammonia that the second heat exchanger 145 has to bear can be reduced.

Gas ammonia cooled while passing through the third heat exchanger 180 is reliquefied while passing through the second Joule Thompson valve 170 and is finally stored in the ammonia storage tank 105 .

For example, as shown in reference number (k), the pressure of ammonia in the gaseous state returned from the sub-engine 160 is 6 to 8 barg and the temperature is 45°C, but as shown in reference number (l), the third heat exchanger 180 ), the pressure of gaseous ammonia passing through it is 5-7 barg, and the temperature is converted to 30°C.

The functions and actions of the ammonia supply line (L6) and the reducing agent supply line (L7) are as described above.

3 is a flowchart for explaining an embodiment of a method for supplying fuel for a ship according to the present invention.

Referring to FIG. 3 , in step S310, gaseous ammonia generated in the ammonia storage tank is transferred to the sub-engine through the boil-off gas supply line.

In step S320, the gaseous ammonia returned from the sub-engine is transferred to the ammonia storage tank through the boil-off gas return line.

In step S330, some of the gaseous ammonia returned from the sub-engine is introduced into the surplus BOG return line according to the amount of gaseous ammonia returned from the sub-engine.

That is, the control valve formed in the surplus BOG return line is changed to an open state or a closed state according to the amount of gaseous ammonia returned from the sub-engine, so that some of the gaseous ammonia returned from the sub-engine is partially converted to excess BOG. It can flow into the return line.

More specifically, when the control valve changes from the closed state to the open state when the amount of gaseous ammonia returned from the sub-engine is equal to or greater than the set value, some of the gaseous ammonia returned from the sub-engine is transferred to the surplus BOG return line will be introduced into

In step S340, the partially gaseous ammonia is cooled and then transferred to the ammonia storage tank through the surplus BOG return line.

4 is a flowchart for explaining another embodiment of the fuel supply method for a ship according to the present invention.

Referring to FIG. 4 , in step S410, gaseous ammonia stored in the ammonia storage tank is transferred to the dilution tank through an ammonia supply line according to the pressure of the ammonia storage tank.

In one embodiment for step S410, the safety valve maintains an open state or a closed state according to the pressure of the ammonia storage tank to control the introduction of gaseous ammonia stored in the ammonia storage tank into the dilution tank.

That is, when the pressure of the ammonia storage tank exceeds the set value, the safety valve is opened and gaseous ammonia stored in the ammonia storage tank flows into the dilution tank.

In step S420, the dilution tank prepares ammonia water by dissolving the gaseous ammonia introduced through the ammonia supply line in water.

In step S430, the ammonia water in the dilution tank is transferred to the SCR system through a reducing agent supply line.

In step S440, the SCR system removes nitrogen oxides (NOx) from the exhaust gas using ammonia water.

Although it has been described with reference to the limited embodiments and drawings, the present invention is not limited to the above embodiments, and various modifications and variations are possible from these descriptions by those skilled in the art to which the present invention pertains. Accordingly, the spirit of the present invention should be understood only by the claims described below, and all equivalents or equivalent modifications thereof will fall within the scope of the spirit of the present invention.

100_1, 100_2: feed 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 Thompson valve
140: first catch tank
145: second heat exchanger
150: compressor
155: cooler
160: sub engine
165: second catch tank
170: second Joule Thompson valve
175: control valve
180: third heat exchanger
185: dilution tank
190: SCR system
195: safety valve
L1: fuel supply line
L2: fuel return line
L3: boil-off gas supply line
L4: Evaporative gas return line
L5: surplus boil-off gas return line
L6: ammonia supply line
L7: reducing agent supply line

Claims (34)

a 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;
a boil-off gas supply line providing a path for transferring the gaseous ammonia generated in the ammonia storage tank to the sub-engine;
a boil-off gas return line providing a path for transferring gaseous ammonia returned from the sub-engine to the ammonia storage tank; and
It is connected to the boil-off gas return line and is supplied to the sub-engine, and when a part of the ammonia is branched and introduced according to the amount of gaseous ammonia remaining or returned from the sub-engine, the temperature of the introduced gaseous ammonia is cooled. and an surplus boil-off gas return line that provides a path for transferring to the ammonia storage tank after
Marine fuel supply system.
delete According to claim 1,
The fuel supply line and the fuel return line are
and a first heat exchanger for exchanging heat between liquid ammonia pumped from the ammonia storage tank and flowing toward the main engine and liquid ammonia returned from the main engine and flowing toward the ammonia storage tank.
Marine fuel supply system.
According to claim 1,
The boil-off gas supply line and the boil-off gas return line are
and a second heat exchanger for exchanging 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.
Marine fuel supply system.
According to claim 1,
The fuel return line is
and a filter for removing foreign substances in the liquid ammonia returned from the main engine.
Marine fuel supply system.
According to claim 1,
The boil-off gas supply line is
It characterized in that it comprises a first catch tank for removing foreign substances and ammonia droplets (DROPLET) in the gaseous ammonia supplied from the ammonia storage tank.
Marine fuel supply system.
According to claim 1,
The boil-off gas return line is
and a second catch tank for removing foreign substances and ammonia droplets in the gaseous ammonia returned from the sub-engine.
Marine fuel supply system.
According to claim 1,
The surplus boil-off gas return line is
and a control valve that maintains an open or closed state according to the amount of gaseous ammonia returned from the sub-engine so that a part of the gaseous ammonia is branched and introduced.
Marine fuel supply system.
9. The method of claim 8,
the control valve
When the amount of ammonia in the gaseous state returned from the sub-engine is greater than or equal to a set value, it is in an open state so that a part of the ammonia in the gaseous state is branched and introduced into the surplus BOG return line.
Marine fuel supply system.
9. The method of claim 8,
the control valve
When the amount of ammonia in the gaseous state returned from the sub-engine becomes less than or equal to a set value, it is in a closed state to prevent the ammonia in the gaseous state from flowing into the surplus BOG return line.
Marine fuel supply system.
According to claim 1,
The surplus boil-off gas return line is
and a third heat exchanger for cooling the gaseous ammonia when a part of the gaseous ammonia is introduced
Marine fuel supply system.
12. The method of claim 11,
The third heat exchanger
Cooling the gaseous ammonia using the cooling heat of seawater, characterized in that
Marine fuel supply system.
According to claim 1,
An ammonia supply line providing a path for supplying gaseous ammonia generated in the ammonia storage tank to the dilution tank, characterized in that it further comprises
Marine fuel supply system.
14. The method of claim 13,
The ammonia supply line is
and a safety valve that maintains an open or closed state according to the pressure of the ammonia storage tank so that gaseous ammonia stored in the ammonia storage tank flows into the dilution tank.
Marine fuel supply system.
15. The method of claim 14,
the safety valve
When the pressure of the ammonia storage tank exceeds a set value, the ammonia storage tank is opened to allow gaseous ammonia stored in the ammonia storage tank to flow into the dilution tank.
Marine fuel supply system.
15. The method of claim 14,
the safety valve
When the pressure of the ammonia storage tank becomes less than a set value, the closed state prevents gaseous ammonia stored in the ammonia storage tank from flowing into the dilution tank.
Marine fuel supply system.
14. The method of claim 13,
It characterized in that it further comprises a reducing agent supply line for supplying the ammonia water of the dilution tank to the SCR system.
Marine fuel supply system.
18. The method of claim 17,
The SCR system is
It characterized in that the nitrogen oxide (NOx) of the exhaust gas is removed by using the ammonia water introduced through the reducing agent supply line.
Marine fuel supply system.
transferring liquid ammonia stored in the ammonia storage tank to the main engine through a fuel supply line;
transferring liquid ammonia returned from the main engine to the ammonia storage tank through a fuel return line;
transferring gaseous ammonia generated in the ammonia storage tank to a sub-engine through a boil-off gas supply line;
transferring gaseous ammonia returned from the sub-engine to the ammonia storage tank through a boil-off gas return line;
A portion of the gaseous ammonia is branched and introduced into an surplus BOG return line according to the amount of gaseous ammonia supplied to the sub-engine and remaining or returned from the sub-engine; and
The gaseous ammonia introduced into the surplus boil-off gas return line is cooled and then transferred to the ammonia storage tank.
Methods of supplying fuel for ships.
delete 20. The method of claim 19,
The steps of transferring liquid ammonia stored in the ammonia storage tank to the main engine through a fuel supply line and transferring liquid ammonia returned from the main engine to the ammonia storage tank through a fuel return line
and a first heat exchanger exchanging heat with liquid ammonia pumped from the ammonia storage tank and flowing toward the main engine with liquid ammonia returning from the main engine and flowing toward the ammonia storage tank. to do
Methods of supplying fuel for ships.
20. The method of claim 19,
transferring gaseous ammonia generated in the ammonia storage tank to a sub-engine through a boil-off gas supply line, and transferring gaseous ammonia returned from the sub-engine to the ammonia storage tank through a boil-off gas return line Is
and a second heat exchanger exchanging heat with 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. to do
Methods of supplying fuel for ships.
20. The method of claim 19,
The step of transferring liquid ammonia returned from the main engine to the ammonia storage tank through a fuel return line
A filter comprising the step of removing foreign substances in the liquid ammonia returned from the main engine
Methods of supplying fuel for ships.
20. The method of claim 19,
The step of transferring the gaseous ammonia generated in the ammonia storage tank to the sub-engine through the boil-off gas supply line
A first catch tank comprising the step of removing foreign substances and ammonia droplets (DROPLET) in the gaseous ammonia supplied from the ammonia storage tank
Methods of supplying fuel for ships.
20. The method of claim 19,
The step of transferring the gaseous ammonia returned from the sub-engine to the ammonia storage tank through the boil-off gas return line
A second catch tank comprising the step of removing foreign substances and ammonia droplets (DROPLET) in the gaseous ammonia returned from the sub-engine
Methods of supplying fuel for ships.
20. The method of claim 19,
The step in which a part of the gaseous ammonia is branched and introduced into the surplus boil-off gas return line is
The control valve formed in the surplus BOG return line maintains an open state or a closed state depending on the amount of gaseous ammonia returned from the sub-engine to control that a part of the gaseous ammonia is branched and introduced. characterized by including
Methods of supplying fuel for ships.
27. The method of claim 26,
The step in which a part of the gaseous ammonia is branched and introduced into the surplus boil-off gas return line is
When the amount of ammonia in the gaseous state returned from the sub-engine is greater than or equal to a set value, the control valve enters an open state so that a part of the ammonia in the gaseous state is branched and introduced into the surplus BOG return line characterized by
Methods of supplying fuel for ships.
27. The method of claim 26,
The step in which a part of the gaseous ammonia is branched and introduced into the surplus boil-off gas return line is
and the control valve enters a closed state when the amount of gaseous ammonia returned from the sub-engine becomes less than or equal to a set value so as to prevent the gaseous ammonia from flowing into the surplus BOG return line.
Methods of supplying fuel for ships.
20. The method of claim 19,
The step of transferring the gaseous ammonia introduced into the surplus BOG return line to the ammonia storage tank after cooling
and cooling, by a third heat exchanger formed in the surplus BOG return line, gaseous ammonia introduced into the surplus BOG return line by using the cooling heat of seawater.
Methods of supplying fuel for ships. delete delete delete delete delete

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