KR102600606B1 - Fuel Supply System And Method For Ship - Google Patents

Abstract

A ship fuel supply system and method are disclosed. The fuel supply system for a ship of the present invention includes a plurality of power generation engines provided on a ship and producing electric power; An ammonia storage tank provided on the ship and storing ammonia; A liquefied gas storage tank provided on the ship and storing liquefied gas; and an oil fuel tank provided on the ship and storing marine oil fuel, wherein all or part of the power generation engine is an ammonia dual fuel that is selectively supplied with ammonia from the ammonia storage tank and the marine oil fuel. It is provided as a power generation engine, and the power produced by the ammonia dual fuel power generation engine is characterized in that it can be supplied to the propulsion propeller of the ship.

Description

Fuel supply system and method for ship {Fuel Supply System And Method For Ship}

The present invention relates to a fuel supply system and method for ships, and more specifically, to supply ammonia as fuel for ships' engines, thereby meeting regulatory standards set by international conventions and increasing the efficiency of ship engine operation systems. It's about the supply system.

As the global warming phenomenon intensifies, efforts are being made to reduce greenhouse gas emissions around the world, and as the 1997 Kyoto Protocol, which included obligations for developed countries to reduce greenhouse gases, expires in 2020, the event held in Paris, France in December 2015 The 195 parties participating in the Paris Climate Change Accord, which was adopted at the 21st United Nations Framework Convention on Climate Change and came into effect in November 2016, are making various efforts with the goal of reducing greenhouse gases.

Along with this global trend, interest in renewable energy (or renewable energy) such as wind power, solar power, solar heat, bioenergy, tidal power, and geothermal heat as a pollution-free energy that can replace fossil fuels and nuclear power is increasing, and various technologies are being developed. I'm losing.

Liquefied gases, including liquefied natural gas, can remove or reduce air pollutants during the liquefaction process, so they can be viewed as eco-friendly fuels that emit fewer air pollutants during combustion. Accordingly, the consumption of liquefied gas such as liquefied natural gas (LNG) has recently been rapidly increasing worldwide. Liquefied gas, which is made by liquefying gas at low temperature, has a much smaller volume than gas, so it has the advantage of increasing storage and transportation efficiency.

Liquefied natural gas is a colorless and transparent liquid obtained by liquefying natural gas containing methane as a main component by cooling it to about -162°C, and has a volume of about 1/600 of that of natural gas. Therefore, when natural gas is liquefied and transported, it can be transported very efficiently.

The liquefaction temperature of liquefied petroleum gas varies depending on its composition, but in the case of petroleum gas containing propane as the main ingredient, it is liquefied at a low temperature of about -42℃ at normal pressure, and at a temperature of about 45℃ at 18 bar, and at 20℃ at 7 bar. It can be saved as a state.

Meanwhile, conventional LPG carriers, etc., adopt a fuel supply system that uses relatively inexpensive heavy oil such as bunker C oil as propulsion fuel for ships. This heavy oil fuel supply system has the international exhaust gas emissions associated with the use of heavy oil fuel. Due to strengthened regulations, a separate low-sulfur heavy fuel fuel tank (LSHFO tank) had to be installed, and the demand for an eco-friendly fuel supply system that meets international environmental regulation standards has increased.

Recently, the application of fuel supply systems that use LPG or LNG and boil-off gas generated therefrom as propulsion fuel has been increasing in LPG or LNG carriers, and in accordance with the strengthening of international exhaust gas emission regulations, in addition to LPG or LNG carriers, general ships also use LNG. The number of ships using propulsion fuel is increasing.

IMO (International Maritime Organization), a UN specialized organization established to internationally unify shipping routes, traffic rules, port facilities, etc., also plans to reduce greenhouse gases by 50% in 2050 compared to 2008 and reduce greenhouse gases by 100% by 2100. % reduction (GHG Zero Emission) is proposed as the goal, and regulations in each country and region are expected to be strengthened accordingly.

LNG and LPG, which have recently been widely used as ship fuels, are evaluated as eco-friendly fuels compared to other fossil fuels previously used as ship fuels, but they still produce carbon dioxide when burned, and ships that use them as fuel emit carbon dioxide during operation. .

According to EEDI (Energy Efficiency Design Index), a mandatory carbon dioxide reduction regulation applied by IMO to new ships, the initial EEDI announcement called for a 10% reduction in carbon dioxide emissions in 2015 based on carbon dioxide emissions from 2013 to 2015. EEDI Phase 1 was applied, and it was planned to apply Phase 3 in 2025 by strengthening and applying one step every five years. However, for LPG carriers, EEDI Phase 3 will be applied early from 2022, two years after applying EEDI Phase 2. As international interest in climate change and greenhouse gas emissions grows, regulations on carbon dioxide emissions for ships are being rapidly strengthened, and when standards above Phase 4 (40% reduction in carbon dioxide emissions) are applied in the future, current LNG or LPG It may be difficult to meet carbon dioxide emission regulations for ships that use carbon dioxide as fuel.

Accordingly, various studies are being conducted on eco-friendly marine fuels that can reduce carbon dioxide emissions, and recently, technology for marine engines that can use ammonia as fuel along with fuels such as LNG or LPG is being developed.

Ammonia (NH ₃ ) is a substance in which three hydrogens are bonded to one nitrogen. It can form strong hydrogen bonds between molecules, making it easy to liquefy. It has a boiling point of -33.34°C and a melting point of -77.73°C at normal pressure.

The present invention seeks to propose a method that can respond to the gradual strengthening of regulatory standards set by international conventions by reducing greenhouse gas emissions from ships equipped with engines, while increasing the efficiency of the engine operation system.

According to one aspect of the present invention for solving the above-described problem, a plurality of power generation engines provided on a ship and producing electric power;

An ammonia storage tank provided on the ship and storing ammonia;

A liquefied gas storage tank provided on the ship and storing liquefied gas; and

An oil fuel tank provided on the ship and storing marine oil fuel,

All or part of the power generation engine is provided as an ammonia dual fuel power generation engine that is selectively supplied with ammonia from the ammonia storage tank and the marine oil fuel,

A fuel supply system for a ship is provided, wherein the power produced by the ammonia dual fuel power generation engine can be supplied to the propeller for propulsion of the ship.

Preferably, among the power generation engines, the rest that are not ammonia dual fuel power generation engines are dual fuel engines supplied with the liquefied gas and marine oil fuel, and the ammonia boil-off gas generated in the ammonia storage tank is supplied to the dual fuel engine. The liquefied gas can be re-liquefied by cold heat and returned to the ammonia storage tank.

Preferably, an ammonia pump transporting ammonia from the ammonia storage tank to the ammonia dual fuel power generation engine; And an ammonia heater that heats the ammonia transferred from the ammonia pump and supplies it to the ammonia dual-fuel power generation engine.

Preferably, a propulsion engine provided on the ship and connected to the propulsion propeller by a shaft; A liquefied gas supply line connected from the liquefied gas storage tank to the propulsion engine to supply liquefied gas; And a shaft generator motor unit connected to a shaft connecting the propulsion engine and the propulsion propeller to produce power, wherein the shaft generator motor unit operates an electric motor using surplus power of the power generation engine as driving power. Power can be provided to the propulsion engine.

Preferably, a variable frequency drive connected to the shaft generator motor unit; And a transformer connected to the variable frequency drive, wherein the transformer is connected to the main switchboard of the ship, so that surplus power of the power generation engine is supplied to the shaft generator motor unit and used in the propulsion engine, The surplus output of the propulsion engine can be used to generate electricity from the shaft generator motor unit and supply it to the ship's power generation power source.

Preferably, an exhaust discharge line that discharges exhaust gases generated from the propulsion engine and the power generation engine overboard and is provided with a selective catalytic reduction unit for denitrification; a reducing agent heater that heats ammonia from the ammonia storage tank and supplies it to the selective catalytic reduction unit; a reducing agent valve that controls ammonia supplied from the reducing agent heater to the selective catalytic reduction unit; an exhaust analyzer provided in the exhaust discharge line to analyze the concentration of nitrogen oxides in the exhaust gas; and an unreacted ammonia analyzer provided in the exhaust discharge line to analyze the concentration of unreacted ammonia in the exhaust gas, wherein the reducing agent valve determines the nitrogen oxide concentration and unreacted ammonia concentration in the exhaust gas analyzed by the exhaust analyzer and the unreacted ammonia analyzer. The ammonia supplied to the selective catalytic reduction unit can be adjusted depending on the reaction ammonia concentration.

Preferably, a buffer tank provided in the liquefied gas supply line and temporarily storing the liquefied gas transferred from the liquefied gas storage tank; A liquefied gas pump that receives liquefied gas from the buffer tank and compresses it; And a heater for heating the liquefied gas compressed in the liquefied gas pump, wherein the liquefied gas may be LPG.

Preferably, a generator provided in the power generation engine to generate power; A propulsion motor connected to the rotation shaft of the propulsion propeller to drive the propulsion propeller; A frequency converter connected to the propulsion motor; A switchboard that distributes electricity produced by the generator; And it may further include a transformer that converts the electricity distributed from the switchboard to suit the propulsion motor and supplies it to the frequency converter.

An exhaust discharge line that discharges exhaust gas generated from the power generation engine overboard and is provided with a selective catalytic reduction unit for denitrification; a reducing agent heater that heats ammonia from the ammonia storage tank and supplies it to the selective catalytic reduction unit; a reducing agent valve that controls ammonia supplied from the reducing agent heater to the selective catalytic reduction unit; An exhaust analyzer provided in the exhaust discharge line to analyze the concentration of nitrogen oxides in the exhaust gas; and an unreacted ammonia analyzer provided in the exhaust discharge line to analyze the concentration of unreacted ammonia in the exhaust gas, wherein the reducing agent valve determines the nitrogen oxide concentration and unreacted ammonia concentration in the exhaust gas analyzed by the exhaust analyzer and the unreacted ammonia analyzer. The ammonia supplied to the selective catalytic reduction unit can be adjusted depending on the reaction ammonia concentration.

A regasification gas supply line that vaporizes the liquefied gas in the liquefied gas storage tank and supplies it to land; A recondenser provided in the regasification gas supply line; A boil-off gas supply line that transfers the boil-off gas generated in the liquefied gas storage tank to the recondenser; A compressor provided in the boil-off gas supply line to compress the boil-off gas to be transferred to the recondenser; A compression pump provided downstream of the recondenser of the regasification gas supply line to compress the liquefied gas; And it may further include a forced vaporizer provided in the regasification gas supply line to force vaporize the liquefied gas compressed in the compression pump.

According to another aspect of the present invention, an ammonia storage tank for storing ammonia on a ship, a liquefied gas storage tank for storing low-temperature liquefied gas, and an oil fuel tank for storing marine oil fuel are provided,

All or part of the plurality of power generation engines that produce electric power on a ship are provided as ammonia dual fuel power generation engines that are selectively supplied with ammonia from the ammonia storage tank and the marine oil fuel, and the ammonia dual fuel power generation engines are provided as fuel. The remaining power generation engines are equipped with dual fuel engines supplied with the liquefied gas and marine oil fuel,

A fuel supply method for a ship is provided, characterized in that the power produced by the ammonia dual fuel power generation engine can be supplied to the propulsion propeller of the ship.

In the present invention, all or part of the marine power generation engine is provided as an ammonia dual fuel power generation engine that is selectively supplied with ammonia and marine oil fuel, and the power produced by the ammonia dual fuel power generation engine is supplied to the ship's propulsion propeller. make it possible Through this, by using ammonia, an eco-friendly fuel, as fuel for ship engines, greenhouse gas emissions can be reduced and regulatory standards set by international agreements can be met. In addition, ammonia is supplied as fuel for power generation engines instead of propulsion engines, which require large fuel supply facilities such as storage tanks and compressors to supply fuel because the fuel supply pressure is generally higher than that of power generation engines and fuel consumption is high, making it an eco-friendly fuel. It can contribute to securing space on board by reducing the cost of adopting an engine and reducing the size of additional facilities required for fuel supply.

In particular, by gradually increasing the proportion of ammonia dual-fuel power generation engines among power generation engines, we can flexibly respond to the gradual strengthening of greenhouse gas emission standards, meeting the needs of ship owners and increasing the sales competitiveness of ships.

Furthermore, in the present invention, a shaft generator motor unit is provided on the shaft of a propulsion engine in a ship to supply power produced by an ammonia dual-fuel power generation engine to a propulsion propeller, or a generator is provided to the propulsion motor and power generation engine that drives the propulsion propeller. This allows ships to operate using electricity produced from eco-friendly fuel. In addition, the surplus power of the power generation engine can be used to provide power to the propulsion engine, and the surplus output of the propulsion engine can be supplied to the ship's power generation power, thereby increasing the flexibility and efficiency of the operating system by operating the ship's propulsion engine and power generation engine in an integrated manner when operating the ship. You can.

Figure 1 schematically shows a fuel supply system for a ship according to a first embodiment of the present invention.
Figure 2 schematically shows a fuel supply system for a ship according to a second embodiment of the present invention.
Figure 3 schematically shows a fuel supply system for a ship according to a third embodiment of the present invention.
Figure 4 schematically shows a fuel supply system for a ship according to a fourth embodiment of the present invention.
Figure 5 schematically shows a fuel supply system for a ship according to a fifth embodiment of the present invention.

In order to fully understand the operational advantages of the present invention and the objectives achieved by practicing the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the structure and operation of a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Here, in adding reference numerals to components in each drawing, it should be noted that identical components are indicated with the same reference numerals as much as possible, even if they are shown in different drawings.

Hereinafter, the ships in the present invention may include ships with self-propulsion capabilities, as well as offshore structures floating on the sea but without propulsion capabilities, for example, ammonia carriers, LNG carriers, and liquid hydrogen. It may be a carrier, Arctic LNGC, LNG RV (Regasification Vessel), FPSO (Floating Production Storage Offloading), FSRU (Floating Storage Regasification Unit), etc.

1 to 5 schematically show a fuel supply system for a ship according to the first to fifth embodiments of the present invention, respectively.

As shown in Figures 1 to 5, the fuel supply system of the present embodiments includes an ammonia storage tank (NT) for storing liquid ammonia, a liquefied gas storage tank (LT) for storing liquefied gas such as LNG or LPG, and HFO. , LSFO, MGO, MDO, ULSFO, etc. are equipped with an oil fuel tank (OT) to store marine oil fuel, and it is a fuel supply system for supplying fuel to engines in ships equipped with multiple power generation engines.

In particular, in the present embodiments, all or part of the power generation engines (GE, NGE) are provided as ammonia dual fuel power generation engines (NGE) that are selectively supplied with ammonia from an ammonia storage tank and marine oil fuel. Ammonia (NH ₃ ) is a substance that combines 3 hydrogens with 1 nitrogen. When used as fuel and completely burned, only nitrogen and water are produced, so it is attracting attention as an eco-friendly fuel that does not generate carbon dioxide. In these embodiments, ammonia is selectively supplied as fuel to the ammonia dual-fuel power generation engine. For example, the power generation engine selectively supplies ammonia and marine oil fuel such as HFO, LSFO, MGO, MDO, and ULSFO. It could be a Dual Fuel engine that you can get. In this case, ammonia and marine oil fuel can be selected and supplied as fuel to the ammonia dual fuel power generation engine depending on the vessel's operating sea area, operating conditions, and carbon dioxide emission regulation standards to be applied to the vessel.

Among the power generation engines, the remaining power generation engines that are not ammonia dual fuel power generation engines are dual fuel engines supplied with liquefied gas such as LNG or LPG stored in a liquefied gas storage tank and marine oil fuel stored in an oil fuel tank. Among power generation engines, the composition ratio of ammonia dual fuel power generation engines and dual fuel engines may change. For example, the composition ratio of ammonia dual fuel power generation engines may be gradually increased according to the carbon dioxide emission regulation standards to be applied to ships, or all power generation engines may be converted to ammonia dual fuel power generation engines. It can be used as a power generation engine to supply ammonia, an eco-friendly fuel.

Depending on the type of ship, a separate propulsion engine may be provided in addition to the power generation engine, and each embodiment schematically shows a more specific fuel supply system configuration according to various ships, engine types, liquefied gas fuel types, etc.

First, the first embodiment system of FIG. 1 schematically shows the fuel supply system of a ship equipped with a high-pressure two-stroke engine that stores LNG in a liquefied gas storage tank and receives LNG and oil fuel through a propulsion engine (ME). It is shown as .

As shown in Figure 1, there are multiple 4-stroke power generation engines (GE, NGE), some of which are ammonia dual fuel power generation engines (NGE) supplied with LNG, oil fuel, and ammonia. , the remaining power generation engine (GE) is a dual-fuel engine supplied with existing LNG and oil fuel.

An ammonia storage tank (NT) to store ammonia, a liquefied gas storage tank (LT) to store LNG, and an oil fuel tank (OT) to store marine oil fuel are each provided. A liquefied gas supply line (LL) is provided to supply LNG from the liquefied gas storage tank to the propulsion engine and power generation engine, and an ammonia supply line (NL) is connected from the ammonia storage tank to the ammonia dual-fuel power generation engine, and an oil fuel tank. Oil supply lines (OL1, OL2) are connected to the propulsion engine and the power generation engine. The boil-off gas generated from the LNG in the liquefied gas storage tank can be discharged to the outside of the tank through the boil-off gas supply line (GL) and re-liquefied (300) or supplied as fuel for the propulsion engine and power generation engine through the compressor (310).

For example, in a propulsion engine (ME), LNG at about 25 to 45°C and 300 bar through a liquefied gas pump and vaporizer through a liquefied gas supply line, or 5 to 20 bar, 25 to 25 bar, from an oil fuel tank through an oil supply line. Oil fuel with a temperature of around 45℃ can be supplied as fuel.

In the ammonia dual-fuel power generation engine (NGE), ammonia is delivered from the oil fuel tank (OL1) at 5 to 80 bar and 25 to 45°C through the ammonia supply line (NL) and the ammonia pump and ammonia heater (200). Oil fuel at 5 to 20 bar, or LNG at 5 to 20 bar and 25 to 45°C can be selectively supplied as fuel, and 5 to 20 bar delivered from the oil fuel tank to power generation engines (GE) other than ammonia dual fuel power generation engines. Oil fuel at a temperature of 20 to 20 bar, or LNG at a temperature of 5 to 20 bar and 25 to 45° C. may be supplied as fuel.

As such, in this embodiment, greenhouse gas emissions can be reduced by using ammonia, an eco-friendly fuel, as fuel for ship engines. In general, propulsion engines have higher fuel supply pressures and higher fuel consumption than power generation engines, and the calorific value of ammonia is lower than that of LNG, LPG or diesel. To supply ammonia as the main fuel for propulsion engines, fuel supply facilities such as fuel tanks and compressors are required. There is a problem of increasing scale. However, in these embodiments, ammonia is supplied first as fuel for the power generation engine instead of the propulsion engine, thereby reducing the cost of adopting an engine for eco-friendly fuel and reducing the size of additional facilities required for fuel supply, which contributes to securing space on board and deploying equipment efficiently. You can. Furthermore, while reducing greenhouse gas emissions, priority is given to supplying existing proven fuel to propulsion engines, thereby lowering the risk that may occur during operation and providing competitiveness to conservative ship owners. In addition, if emission standards are strengthened in the future, power generation engines can be supplied as needed. By replacing all engines with engines that can receive ammonia fuel, it is possible to respond to strengthened emission standards and enable more flexible operation.

In this embodiment, the power produced by the ammonia dual-fuel power generation engine (NGE) can be supplied to drive the ship's propulsion propeller (P), thereby improving the flexibility and efficiency of the operating system of ship engines such as power generation engines and propulsion engines. and lay the foundation for a green energy propulsion system for ship propulsion power.

For this purpose, a shaft generator motor unit (SGM) is provided that is connected to the shaft (S) that connects the propulsion engine (ME) and the ship's propulsion propeller (P) to produce power. The shaft generator motor unit (SGM) can provide power to the propulsion engine by operating an electric motor using the surplus power of the power generation engine as driving power.

The system of this embodiment is provided with a variable frequency drive (VFD) connected to the shaft generator motor, and a transformer (TR) connected to the variable frequency drive, and the transformer is installed on the main switchboard (SWBD) of the ship. connected.

The shaft generator motor unit (SGM) is a type of power take-off device that is mechanically connected to the shaft (S) of the propulsion engine (ME) and can produce electricity by extracting part of the power supplied from the propulsion engine. Power generation is generated by the propulsion engine. In the possible RPM range, it acts as a generator. The shaft generator motor unit of the present embodiments has the function of being driven by an electric motor when surplus power within the ship produced by the power generation engine is used as driving power. Additionally, in these embodiments, devices such as the shaft generator motor unit (SGM), variable frequency drive (VFD), transformer (TR), and main switch board (SWBD) are configured to operate in both directions.

Through this, power can be produced in the shaft generator motor unit (SGM) with the surplus output of the propulsion engine (ME) to provide additional power to the propulsion engine or as power generation power on board the ship, and conversely, surplus power of the power generation engine (GE) can be generated. It is supplied to the shaft generator motor unit (SGM) through the main switch board (SWBD) and is driven by an electric motor as driving power, so it can be operated in two directions to provide additional power to assist the output of the propulsion engine (ME).

In this way, when operating a ship, the flexibility and efficiency of the operating system can be increased by operating the ship's propulsion engine and power generation engine in an integrated manner. By operating the SGM at the maximum efficiency point of the propulsion engine, fuel consumption is reduced while surplus output is used to supply power within the ship. By doing so, the frequency of use of power generation engines can be reduced, thereby reducing greenhouse gases and carbon emissions during ship operation. In addition, we will lay the foundation for a green energy propulsion system for ship propulsion power, eliminate or reduce operational disruptions due to unexpected risks by using eco-friendly fuel, and respond flexibly when EEDI emission standards are gradually strengthened. It can be operated while gradually reducing carbon dioxide emissions.

Meanwhile, liquid ammonia in the ammonia storage tank (NT) can be stored at around -34°C, and evaporation gas is generated from the liquid ammonia being stored. In this embodiment, boil-off gas generated from stored ammonia can be re-liquefied using LNG cold heat. For this purpose, a heat exchanger (110) capable of exchanging heat with the ammonia boil-off gas is provided between the pump of the liquefied gas supply line and the vaporizer, and the ammonia boil-off gas is re-liquefied with the cold heat of the LNG to be supplied to the propulsion engine and power generation engine. It can be recovered to the ammonia storage tank (RL1). A separate ammonia re-liquefaction unit 250 may be additionally provided to discharge ammonia boil-off gas from the storage tank, re-liquefy it, and then return it to the tank (RL2).

Exhaust gas generated from the propulsion engine and power generation engine is discharged overboard through the exhaust discharge line (EL), and a selective catalytic reduction unit 400 is provided in the exhaust discharge line to denitrify the exhaust gas. When ammonia is supplied as engine fuel, the exhaust gas may contain more nitrogen oxides than when using LPG or oil as fuel, and nitrogen oxides are also substances whose emissions are regulated by the IMO.

In this embodiment, in order to remove this, a selective catalytic reduction unit 400 is provided in the exhaust discharge line EL, and nitrogen oxides are reduced through a reduction reaction. Urea aqueous solution ((NH ₂ ) ₂ CO) is often used as a reducing agent in the selective catalytic reduction unit, but urea reacts with nitrogen oxides and decomposes into ammonia and carbon dioxide, producing carbon dioxide, and the aqueous solution When stored as is, the service life decreases over time and a constant temperature must be maintained, so there is a problem of installation space and installation cost.

In this embodiment, ammonia is used directly as a reducing agent in the selective catalytic reduction unit instead of urea, and a reducing agent supply line (AL) is provided to supply liquid ammonia from the ammonia storage tank to the selective catalytic reduction unit to denitrify the exhaust gas to the selective catalytic reduction unit. Ammonia is supplied as a reducing agent for .

The reducing agent supply line is provided with a reducing agent heater 410 that heats the ammonia to be supplied to the selective catalytic reduction unit, and a reducing agent valve (AV) that opens and closes the reducing agent supply line downstream of the reducing agent heater. Ammonia injected into the SCR Reactor of the selective catalytic reduction unit through a reducing agent heater reacts with NOx in the presence of a catalyst and changes into N ₂ and H ₂ O, reducing the NOx content in the exhaust. The reaction formula is as follows.

Meanwhile, the exhaust discharge line is provided with an exhaust analyzer 420 that analyzes the concentration of nitrogen oxides in the exhaust gas, and an unreacted ammonia analyzer 430 that analyzes the concentration of unreacted ammonia in the exhaust gas.

Unreacted ammonia contained in the exhaust gas can also be used as a reducing agent in the selective catalytic reduction unit 400.

Accordingly, the valve (AV) of the reducing agent supply line (AL) is opened and closed according to the concentration of nitrogen oxides and unreacted ammonia in the exhaust gas analyzed by the exhaust analyzer 420 and the unreacted ammonia analyzer 430 to discharge the ammonia from the ammonia storage tank. The ammonia supplied to the selective catalytic reduction unit can be controlled.

The ship to which this embodiment system is applied may be equipped with an air lubrication system (ALS) that sprays air on the outer bottom surface of the hull to reduce frictional resistance when the hull moves. The air lubrication system injects air into the outer bottom surface of the hull to continuously form an air layer between the hull and the seawater, thereby reducing the frictional resistance between the seawater and the hull as the ship moves, thereby improving the ship's fuel efficiency. The air lubrication system can be supplied with power produced by power generation engines (NGE, GE).

In this way, by configuring the air lubrication system, the frictional resistance during ship operation is reduced, improving fuel efficiency, and by driving it with a power generation engine using ammonia, an eco-friendly fuel, the effect of reducing greenhouse gas emissions during ship operation can be further increased.

Next, looking at the second embodiment system of FIG. 2, the second embodiment system supplies LNG as the main fuel of the propulsion engine like the first embodiment described above, but LNG is supplied at a fuel supply pressure of about 15 to 20 bar. This is a system in which a low-pressure two-stroke engine such as the ME-GA or X-DF engine is provided as the propulsion engine (ME). The fuel supply pressure of the propulsion engine is lower than that of the first embodiment described above, and LNG and boil-off gas are propelled from devices such as the pump 100 and compressor 310 of the liquefied gas supply line (LL) and boil-off gas supply line (GL). In accordance with the fuel supply conditions of the engine, compression is performed at a lower pressure than in the first embodiment. Since other configurations are similar to the above-described first embodiment, duplicate descriptions will be omitted.

Next, let's look at the third embodiment system of FIG. 3. Descriptions that overlap with the above-described first embodiment will be omitted.

The third embodiment system in Figure 3 is a fuel supply system for electric motor propulsion ships such as Arctic LNGC. The ship does not have a separate 2-stroke propulsion engine, but generates power from a 4-stroke power generation engine (GE, NGE). It supplies power to the electric motor that drives the propulsion propeller (P).

As shown in Figure 3, all or part of the power generation engines are ammonia dual-fuel power generation engines (NGE) supplied with LNG, oil fuel, and ammonia, and the remainder (GE) is a dual fuel power generation engine supplied with existing LNG and oil fuel. It is equipped with a fuel engine.

Each power generation engine is equipped with a generator (G) for power generation, and the electricity produced by the generator is distributed through a switchboard (SB). The rotating shaft of the propulsion propeller (P) is connected to the propulsion motor (PM). The electricity distributed from the switchboard (SB) is converted to suit the propulsion motor through a transformer (TR) and supplied to the frequency converter (CV). Then, through the frequency converter, it is supplied to the propulsion motor (PM) for propulsion use. The driving propeller (P) is driven by the driving of the motor.

In this way, by replacing/operating all or part of the power generation engine in an electric motor propulsion type ship with an ammonia dual fuel power generation engine, the basis for a green energy propulsion system is laid for ship propulsion power and greenhouse gas and carbon emissions are reduced during ship operation. You can.

The fourth embodiment of the system in FIG. 4 is a case of a Floating Storage Regasification Unit (FSRU) that regasifies LNG at sea and supplies it to land (SH).

As shown in Figure 4, for this purpose, facilities for LNG regasification are provided on the upper part of the hull, and a regasification gas supply line (LL2) that vaporizes liquefied gas from the liquefied gas storage tank (LT) and supplies it to land (SH). This is prepared. The regasification gas supply line LL2 is provided with a recondenser 500, a compression pump 510 for compressing the liquefied gas, and a forced vaporizer 520 for forcibly vaporizing the compressed liquefied gas. A boil-off gas supply line (GL) is provided to transfer the boil-off gas generated from the liquefied gas storage tank (LT) to the recondenser, and a compressor 350 is provided in the boil-off gas supply line to compress the boil-off gas to be transferred to the recondenser. , the boil-off gas compressed in the compressor can be mixed with liquefied gas in the recondenser, condensed, and then supplied to land (SH) through a compression pump and forced vaporizer through a re-gas supply line.

In the fourth embodiment of the system of FIG. 4, like the third embodiment described above, a separate two-stroke propulsion engine is not provided, but electricity is generated from a four-stroke power generation engine (GE, NGE) to drive the propulsion propeller (P). Power can be supplied to the motor.

Similarly, all or part of the power generation engines are ammonia dual fuel power generation engines (NGE) supplied with LNG, oil fuel and ammonia, and the remaining power generation engines (GE) are dual fuel engines supplied with existing LNG and oil fuel. do. The electricity produced by the generator (G) of the power generation engine (GE, NGE) is distributed through the switchboard (SB), and the electricity distributed from the switchboard is converted to suit the propulsion motor through a transformer (TR) and then converted to a frequency converter (CV). ) and then supplied to the propulsion motor (PM) to drive the propulsion propeller (P) by driving the propulsion motor.

Next, looking at the fifth embodiment system of FIG. 5, the fifth embodiment system is a two-stroke LPG dual-fuel propulsion engine that stores LPG in a liquefied gas storage tank and is supplied with oil and LPG as fuel by a propulsion engine (ME). This is the fuel supply system when adopted.

The liquefied gas supply line (LL) connected to the propulsion engine (ME) and power generation engine (GE, NGE) is equipped with a buffer tank (BT) to temporarily store the liquefied gas transferred from the liquefied gas storage tank, and the liquefied gas from the buffer tank is provided. A liquefied gas pump 100 that receives gas and compresses it, and a heater 120 that heats the liquefied gas compressed in the liquefied gas pump are provided.

For example, the propulsion engine (ME) may be a high-pressure two-stroke engine supplied as fuel with LPG at a temperature of 5 to 80 bar and 25 to 45 ℃ or oil fuel at a temperature of about 5 to 20 bar, and a liquefied gas storage tank (LT). LPG is stored at around -53°C and can be transferred to the buffer tank (BT) and supplied to the propulsion engine through the liquefied gas pump (100) and heater (!20).

The power generation engine is a low-pressure 4-stroke engine, all or part of which is an ammonia dual-fuel power generation engine (NGE), and passes through the ammonia pump and ammonia heater 200 through the ammonia supply line (NL) at 5 to 80 bar, 25 to 45 bar. Ammonia at around ℃, oil fuel at 5 to 20 bar transferred from an oil fuel tank (OT), or LPG at 5 to 50 bar and 25 to 45℃ can be selectively supplied as fuel. A power generation engine (GE) other than an ammonia dual fuel power generation engine may be supplied with oil fuel at 5 to 20 bar delivered from an oil fuel tank, or LPG at 5 to 50 bar and around 25 to 45°C as fuel.

As in the first and second embodiment systems described above, a shaft generator motor unit (SGM) is provided on the shaft (S) connecting the propulsion engine (ME) and the ship's propulsion propeller (P), and the shaft generator motor When the ship's surplus power produced by the power generation engine is used as driving power, the unit has the function of being driven by an electric motor, and includes a shaft generator motor unit (SGM), variable frequency drive (VFD), transformer (TR), and main switch board (SWBD). ), etc. devices are configured to operate in both directions.

With the excess output of the propulsion engine (ME), power is produced in the shaft generator motor unit (SGM) to provide additional power to the propulsion engine or as power generation power on board the ship, or, conversely, the surplus power of the power generation engine (GE) is transferred to the main switchboard ( It can be operated to supply additional power to the shaft generator motor unit (SGM) through SWBD and to assist the output of the propulsion engine.

In this way, when operating a ship, the ship's propulsion engine and power generation engine are operated in an integrated manner to increase the flexibility and efficiency of the operating system, and to lay the foundation for a green energy propulsion system for ship propulsion power, flexibly responding to the gradual strengthening of greenhouse gas emission standards. make it possible

It is obvious to those skilled in the art that the present invention is not limited to the above-mentioned embodiments, and that it can be implemented with various modifications or variations without departing from the technical gist of the present invention. It was done.

ME: propulsion engine
GE: power generation engine
NGE: Ammonia dual-fuel power generation engine
NT: Ammonia storage tank
LT: Liquefied gas storage tank
OT: Oil fuel tank
P: propeller for propulsion

Claims (11)

Multiple power generation engines provided on the ship and producing electric power;
An ammonia storage tank provided on the ship and storing ammonia;
A liquefied gas storage tank provided on the ship and storing liquefied gas; and
An oil fuel tank provided on the ship and storing marine oil fuel,
All or part of the power generation engine is provided as an ammonia dual fuel power generation engine that is selectively supplied with ammonia from the ammonia storage tank and the marine oil fuel,
The power produced by the ammonia dual-fuel power generation engine can be supplied to the ship's propulsion propeller,
Among the power generation engines, the remaining ones that are not ammonia dual fuel power generation engines are dual fuel engines supplied with the liquefied gas and marine oil fuel, but are characterized in that they can be replaced with ammonia dual fuel power generation engines in accordance with carbon dioxide emission regulation standards. fuel supply system. According to clause 1,
A ship's fuel supply system, characterized in that the ammonia boil-off gas generated in the ammonia storage tank is re-liquefied by the cold heat of the liquefied gas supplied to the dual fuel engine and returned to the ammonia storage tank. According to clause 2,
An ammonia pump that transfers ammonia from the ammonia storage tank to the ammonia dual fuel power generation engine; and
A fuel supply system for a ship further comprising an ammonia heater that heats the ammonia transferred from the ammonia pump and supplies it to the ammonia dual fuel power generation engine. According to clause 3,
A propulsion engine provided on the ship and connected to the propulsion propeller by a shaft;
A liquefied gas supply line connected from the liquefied gas storage tank to the propulsion engine to supply liquefied gas; and
It further includes a shaft generator motor unit connected to the shaft connecting the propulsion engine and the propulsion propeller to produce power,
A fuel supply system for a ship, characterized in that the shaft generator motor unit operates an electric motor using surplus power of the power generation engine as driving power to provide power to the propulsion engine. According to clause 4,
A variable frequency drive connected to the shaft generator motor unit; and
It further includes a transformer connected to the variable frequency drive,
The transformer is connected to the main switchboard of the ship, and the surplus power of the power generation engine is supplied to the shaft generator motor unit and used in the propulsion engine, and the surplus output of the propulsion engine produces power in the shaft generator motor unit to be used in the ship. A ship's fuel supply system characterized in that it can be supplied with generated power. According to clause 5,
An exhaust discharge line that discharges exhaust gases generated from the propulsion engine and the power generation engine overboard and is provided with a selective catalytic reduction unit for denitrification;
a reducing agent heater that heats ammonia from the ammonia storage tank and supplies it to the selective catalytic reduction unit;
a reducing agent valve that controls ammonia supplied from the reducing agent heater to the selective catalytic reduction unit;
an exhaust analyzer provided in the exhaust discharge line to analyze the concentration of nitrogen oxides in the exhaust gas; and
It further includes an unreacted ammonia analyzer provided in the exhaust discharge line to analyze the concentration of unreacted ammonia in the exhaust gas,
The reducing agent valve is a ship's fuel supply system characterized in that it adjusts the ammonia supplied to the selective catalytic reduction unit according to the concentration of nitrogen oxides and unreacted ammonia in the exhaust gas analyzed by the exhaust analyzer and the unreacted ammonia analyzer. According to clause 6,
A buffer tank provided in the liquefied gas supply line and temporarily storing the liquefied gas transferred from the liquefied gas storage tank;
A liquefied gas pump that receives liquefied gas from the buffer tank and compresses it; and
It further includes a heater for heating the liquefied gas compressed in the liquefied gas pump,
A fuel supply system for a ship, characterized in that the liquefied gas is LPG. According to clause 3,
A generator provided in the power generation engine to generate power;
A propulsion motor connected to the rotation shaft of the propulsion propeller to drive the propulsion propeller;
A frequency converter connected to the propulsion motor;
A switchboard that distributes electricity produced by the generator; and
A ship's fuel supply system further comprising: a transformer that converts the electricity distributed from the switchboard to suit the propulsion motor and supplies it to the frequency converter. According to clause 8,
An exhaust discharge line that discharges exhaust gas generated from the power generation engine overboard and is provided with a selective catalytic reduction unit for denitrification;
a reducing agent heater that heats ammonia from the ammonia storage tank and supplies it to the selective catalytic reduction unit;
a reducing agent valve that controls ammonia supplied from the reducing agent heater to the selective catalytic reduction unit;
an exhaust analyzer provided in the exhaust discharge line to analyze the concentration of nitrogen oxides in the exhaust gas; and
It further includes an unreacted ammonia analyzer provided in the exhaust discharge line to analyze the concentration of unreacted ammonia in the exhaust gas,
The reducing agent valve is a ship's fuel supply system characterized in that it adjusts the ammonia supplied to the selective catalytic reduction unit according to the concentration of nitrogen oxides and unreacted ammonia in the exhaust gas analyzed by the exhaust analyzer and the unreacted ammonia analyzer. According to clause 8,
A regasification gas supply line that vaporizes the liquefied gas in the liquefied gas storage tank and supplies it to land;
A recondenser provided in the regasification gas supply line;
A boil-off gas supply line that transfers the boil-off gas generated in the liquefied gas storage tank to the recondenser;
A compressor provided in the boil-off gas supply line to compress the boil-off gas to be transferred to the recondenser;
A compression pump provided downstream of the recondenser of the regasification gas supply line to compress the liquefied gas; and
A ship's fuel supply system further comprising: a forced vaporizer provided in the regasification gas supply line to force vaporize the liquefied gas compressed in the compression pump. An ammonia storage tank for storing ammonia on a ship, a liquefied gas storage tank for storing low-temperature liquefied gas, and an oil fuel tank for storing oil fuel for ships are provided,
All or part of a plurality of power generation engines that produce power on a ship are provided with an ammonia dual fuel power generation engine that is selectively supplied with ammonia from the ammonia storage tank and the marine oil fuel,
The power produced by the ammonia dual-fuel power generation engine can be supplied to the ship's propulsion propeller,
The remaining power generation engines other than the ammonia dual fuel power generation engine are provided as dual fuel engines supplied with the liquefied gas and marine oil fuel, but are characterized in that they can be replaced with ammonia dual fuel power generation engines in accordance with carbon dioxide emission regulation standards. Fuel supply method.

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