KR20230061660A - Fuel Supplying System For Ammonia Fueled Ship - Google Patents

Abstract

Disclosed is an ammonia fuel supply system for a ship which can effectively process eco-friendly fuel such as ammonia in a ship. The ammonia fuel supply system for a ship comprises: a fuel supply line provided in a ship and connected from an ammonia storage tank storing ammonia to an engine in the ship; a transport pump provided on the fuel supply line and transporting ammonia to be supplied to the engine; a compression pump compressing ammonia transported by the transport pump to a pressure required by the engine; a fuel heater provided on the rear end of the compression pump and heating ammonia to a temperature required by the engine; and a return line recovering ammonia which is not consumed by the engine to the fuel supply line between the compression pump and the transport pump. The ammonia which is not consumed by the engine is recovered in a liquid state through the return line to be re-circulated along the fuel supply line.

Description

Ammonia fuel supply system for ships {Fuel Supplying System For Ammonia Fueled Ship}

The present invention relates to an ammonia fuel supply system for a ship, and more particularly, to a ship's ammonia fuel capable of re-liquefying and treating boil-off gas generated from ammonia without discharging it into the atmosphere while supplying ammonia as fuel to an engine on board a ship. It's about the supply system.

Efforts are being made to reduce greenhouse gas emissions worldwide as the global warming phenomenon intensifies, and as the Kyoto Protocol in 1997, which contained the obligations of developed countries to reduce greenhouse gases, expired in 2020, the conference was held in Paris, France in December 2015. According to the Paris Climate Change Accord, which was adopted in the 21st United Nations Framework Convention on Climate Change and entered into force in November 2016, the 195 Parties participating in the agreement are making various efforts to reduce 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 has increased and various technologies have been developed as pollution-free energy that can replace fossil fuels and nuclear power. are losing

Although LNG is evaluated as an eco-friendly fuel compared to other fossil fuels, it still generates carbon dioxide when burned, and ships that use it as fuel emit carbon dioxide during operation.

Several studies have been conducted on eco-friendly fuels capable of reducing carbon dioxide emissions during ship operation, and recently, technologies related to ship engines capable of using hydrogen, ammonia, etc. as fuel have been developed.

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

According to EEDI (Energy Efficiency Design Index), a compulsory carbon dioxide reduction regulation applied by IMO to new ships, in the initial EEDI announcement, CO2 emissions in 2015 were reduced by 10% based on the CO2 emissions from 2013 to 2015 EEDI Phase 1 was applied, and it was scheduled to apply Phase 3 in 2025 by strengthening and applying one step every 5 years. As international interest in climate change and greenhouse gas emissions grows, ships ordered after 2030 decide to reduce carbon emissions by 40% compared to ships ordered in 2008 and by 50% by 2050. As regulations on fuel are rapidly strengthening, the need for alternative fuels is increasing.

In particular, if the standards of Phase 4 (40% reduction in carbon dioxide emissions) or higher are applied in the future, it may be difficult to achieve the carbon dioxide emission regulations with ships using current LNG or LPG as fuel. Since it is inevitable to replace fuel with carbon-neutral fuel, it is necessary to further accelerate the development and application of technology for eco-friendly ship fuel to actual ships.

Among carbon-neutral fuels, ammonia (NH ₃ ) is a substance in which 3 hydrogen atoms are bonded to 1 nitrogen. It can form strong hydrogen bonds between molecules, making it easy to liquefy. is °C. Ammonia is particularly easy to store and transport, easy to mass-produce through the Haber-Bosch method, and has excellent economic feasibility compared to other carbon-neutral fuels, so research and development for using ammonia as a ship fuel are being actively conducted.

In the case of applying an eco-friendly fuel such as ammonia as a fuel for a ship engine, the present invention effectively supplies ammonia fuel to the engine while taking into account the characteristics of not being able to discharge boil-off gas and vent gas into the atmosphere due to toxicity, corrosiveness, etc. We would like to propose a fuel supply system that can effectively handle

According to one aspect of the present invention for solving the above problems, a fuel supply line provided in a ship and connected to an inboard engine from an ammonia fuel tank for storing ammonia;

a transfer pump provided in the fuel supply line and transferring ammonia to be supplied to the engine;

a compression pump for compressing the ammonia transferred from the transfer pump to a pressure required by the engine;

a fuel heater provided at a rear end of the compression pump and heating ammonia to a temperature required by the engine; and

A return line for recovering ammonia not consumed in the engine to a fuel supply line between the transfer pump and the compression pump;

Ammonia not consumed in the engine is recovered through the return line in a liquid state and recirculated along the fuel supply line.

Preferably, an emergency discharge line branched from the return line and connected to the ammonia fuel tank; And a first pressure reducing valve provided in the emergency discharge line to reduce the ammonia to be recovered to the ammonia fuel tank; Thus, it can be discharged to the ammonia fuel tank.

Preferably, a compression unit for receiving and compressing the boil-off gas generated in the ammonia fuel tank; a condensing unit that receives and cools the boil-off gas compressed by the compression unit; a phase separation tank receiving the evaporation gas cooled in the condensing unit and performing gas-liquid separation thereon; and a liquid line for transferring the liquid separated from the phase separation tank to the ammonia fuel tank.

Preferably, a second pressure reducing valve provided in the liquid line to reduce the pressure of the liquid separated in the phase separation tank; and a level sensor for detecting a liquid level inside the phase separation tank, and the second pressure reducing valve may discharge the liquid from the phase separation tank according to the liquid level detected by the level sensor.

Preferably, a BOG manifold supplying the gas separated in the phase separation tank and the ammonia vent gas discharged from the engine to the ammonia fuel tank; and a third pressure reducing valve for reducing the ammonia gas separated from the phase separation tank and transferred to the BOG manifold.

Preferably, a heat medium circulation line through which a heat medium supplied to the fuel heater for heating ammonia is circulated; and a heat medium supply unit provided in the heat medium circulation line and configured to heat the heat medium, wherein the fuel heater heats the ammonia and the cooled heat medium may be returned to the heat medium supply unit through the condensation unit.

Preferably, the ammonia fuel tank may be provided as an IMO-B type tank or a membrane type tank.

In the present invention, ammonia, which is an eco-friendly fuel, is supplied as fuel for a ship engine to reduce greenhouse gas emissions during ship operation and to meet the strengthened greenhouse gas emission regulation standards set by international agreements.

In addition, ammonia that is not consumed in the engine is sent to the fuel supply line for recycling, and the evaporation gas generated from ammonia and the vent gas discharged from the engine are re-liquefied or circulated as fuel without emitting ammonia to the atmosphere, thereby reducing toxicity and corrosiveness such as ammonia. When applying eco-friendly fuel, which is difficult to discharge to the outside through a vent mast, as a ship engine fuel, boil-off gas and vent gas can be effectively treated inside the ship.

1 schematically shows an ammonia fuel supply system for a ship according to an embodiment of the present invention.

In order to fully understand the operational advantages of the present invention and the objects achieved by the practice of 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 configuration and operation of a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components are marked with the same numerals as much as possible, even if they are displayed on different drawings.

Hereinafter, the ship in the present invention refers to all types of ships in which an engine capable of using ammonia as a fuel for an inboard engine is installed, and is representative of an LPG carrier, an LNG carrier, a liquid hydrogen carrier, and a liquid hydrogen carrier. Carriers, ammonia carriers, container carriers, crude oil carriers, bulk carriers such as minerals or grains, ships with self-propelled capabilities such as Ro-Ro (Roll on/Roll off) ships, etc. Offshore structures under construction may also be included.

An engine supplied with ammonia as a fuel of an engine means to be supplied as fuel together with other marine fuel such as LNG, LPG, HFO, and Diesel Oil, and to be supplied with ammonia alone as fuel, and is used for propulsion of a ship. Includes both engines and engines for power generation.

1 schematically shows an ammonia fuel supply system for a ship according to an embodiment of the present invention.

As shown in FIG. 1, the fuel supply system of this embodiment is for supplying ammonia fuel to the engine in a ship equipped with an engine E receiving ammonia as fuel, and storing ammonia to be supplied as engine fuel. It includes a fuel tank (FT) and a fuel supply line (FL) for supplying liquid ammonia to the engine as fuel.

Ammonia is stored in a liquid state in the ammonia fuel tank (FT), and is supplied to the engine in a liquid state along a fuel supply line. The ammonia fuel tank may be provided as an independent IMO-B type tank on the upper or lower deck or as a membrane tank on the lower deck.

In order to supply ammonia according to the pressure and temperature conditions required by the engine, the fuel supply line (FL) has a transfer pump 100 that transfers ammonia to be supplied to the engine, and compresses the ammonia transferred from the transfer pump to the pressure required by the engine. A compression pump 110 for heating, and a fuel heater 120 for heating the ammonia compressed by the compression pump to a temperature required by the engine are provided.

The fuel heater 120 is provided with a heating medium circulation line HL through which a heating medium supplied to heat ammonia is circulated, and a heating medium supply unit 300 for heating the heating medium is provided in the heating medium circulation line.

An engine receiving ammonia may be, for example, an ME-LGIP engine of MAN Diesel & Turbo. In addition to LPG, methanol and ethanol, the ME-LGIP engine can be supplied with liquefied gas such as ammonia as fuel. , the engine is operated by spraying it to the nozzle at a pressure of 600 to 700 bar with hydraulic pressure from the engine. In the case of ammonia, it can be supplied to the engine at around 50 to 85 bar and 24 to 45 ° C through a fuel heater and a compression pump.

On the other hand, when an incompressible fluid having little or no change in volume even when pressure is applied, that is, liquid fuel is supplied to the engine, excess fuel is supplied to the engine in order to respond to engine load fluctuations and prevent cavitation. Among the fuel supplied to the engine, the remaining fuel after being consumed as fuel is recovered upstream of the engine.

To this end, in the system of this embodiment, a return line (RTL) for recovering ammonia not consumed in the engine from the engine to the front end of the compression pump of the fuel supply line (FL), that is, between the transfer pump 100 and the compression pump 110 is connected. . In the case of ammonia, it can be recovered and recycled from the engine to the front end of the compression pump 110 through the return line (RTL) at around 30 bar and 60 ° C.

In addition, an emergency discharge line (RTLa) branching from the return line (RTL) and transferring ammonia recovered from the engine to the ammonia fuel tank is connected, and a first pressure reducing valve (RV) for reducing ammonia is provided in the emergency discharge line . Ammonia, which was recovered from the engine and recirculated to the engine through the return line, goes to the first pressure reducing valve (RV) through the emergency discharge line (RTLa) when the engine is switched to fuel mode, when entering a port, or when an emergency situation occurs, such as purging in the engine. It can be reduced and recovered to the ammonia fuel tank (FT).

Meanwhile, boil-off gas generated from ammonia stored in the ammonia fuel tank FT may be re-liquefied by discharging it from the tank along the re-liquefaction line RL. In the re-liquefaction line, a compression unit 200 receives and compresses the boil-off gas from the ammonia fuel tank, a condenser unit 210 receives and cools the boil-off gas compressed from the compression unit, and receives the cooled boil-off gas from the condenser to gas-liquid. A phase separation tank 220 for separation is provided.

The compression unit 200 may be provided as a multi-stage compressor including a plurality of compressors 200a and 200b as needed, or may be composed of a single compressor. The evaporation gas compressed in the compression unit 200 is condensed while being cooled by a heat medium in the condensation unit 210 and moved to the phase separation tank 220 .

The condenser 210 may pass through the fuel heater 120 and cool boil-off gas to be re-liquefied by receiving the heat medium of the heat medium circulation line that exchanges heat with ammonia to be supplied as engine fuel. That is, the heat medium supplied from the heat medium supply unit 300 to the fuel heater 120 along the heat medium circulation line HL converts pressurized ammonia from the ammonia fuel tank FT through the transfer pump 100 and the compression pump 110. The heat medium heated and supplied to the engine E and cooled while heating ammonia is returned to the heat medium supply unit 300 through the condensing unit 210. The evaporation gas of the reliquefaction line compressed in the compression unit by the heat medium supplied from the fuel heater to the condensing unit along the heating medium circulation line is supplied with cold heat and condensed. The heat medium of the heat medium circulation line (HL) may be, for example, glycol, and this glycol is heated in the heat medium supply unit 300 and supplied to the fuel heater 120, and is cooled while heating ammonia and supplied to the condensation unit 210 , Ammonia evaporation gas is introduced into the condensing unit 210 through the compression unit 200 and is condensed while being cooled through heat exchange with the heating medium.

The ammonia condensed through the condensation unit 210 is gas-liquid separated in the phase separation tank 220, and the separated liquid is decompressed through the second pressure reducing valve 230 along the liquid line LL and then returned to the ammonia fuel tank. .

A level sensor (LC) for detecting the liquid level inside the tank is provided in the phase separation tank 220, and the second pressure reducing valve 230 is controlled according to the liquid level detected by the level sensor so that the ammonia fuel tank FT is discharged from the phase separation tank. Ammonia in liquid state can be released.

The gas separated from the phase separation tank is decompressed in the third pressure reducing valve (VV) through the gas line (VL) and then returned to the ammonia fuel tank (FT) through the BOG manifold (BM).

The vent gas, including ammonia, emitted from the engine (E) is not emitted to the atmosphere, but is collected in the knockout drum inside the engine, and discharged from the engine in emergency situations such as fuel change or purging in the engine to supply ammonia fuel through the BOG manifold (BM). It is recovered to the tank FT.

The ammonia gas recovered in the ammonia fuel tank FT may be sent to the reliquefaction line RL and re-liquefied through devices such as the compression unit 200, the condensation unit 210, and the phase separation tank 220.

As described above, in this embodiment, the ammonia not consumed by the engine is sent to the fuel supply line to be recycled to the engine, and the boil-off gas generated from the ammonia stored in the fuel tank and the vent gas discharged from the engine are re-liquefied without being released into the atmosphere. By recovering it to the ammonia fuel tank, it is possible to effectively treat boil-off gas and vent gas in the ship when eco-friendly fuels such as ammonia, which are difficult to discharge to the outside through the vent mast due to toxicity and corrosiveness, are applied as ship engine fuel.

The present invention is not limited to the above embodiments, and it can be practiced with various modifications or variations within a range that does not deviate from the technical gist of the present invention to those skilled in the art to which the present invention belongs. It is self-evident.

E: engine
FT: Ammonia Fuel Tank
FL: fuel supply line
RL: reliquefaction line
RTL: return line
RTLa: emergency discharge line
HL: heat medium circulation line
LL: Liquidline
100: transfer pump
110: compression pump
120: fuel heater
200: compression unit
210: condensation unit
220: phase separation tank
300: heat medium supply unit

Claims (7)

A fuel supply line provided in the ship and connected to the inboard engine from the ammonia fuel tank for storing ammonia;
a transfer pump provided in the fuel supply line and transferring ammonia to be supplied to the engine;
a compression pump for compressing the ammonia transferred from the transfer pump to a pressure required by the engine;
a fuel heater provided at a rear end of the compression pump and heating ammonia to a temperature required by the engine; and
A return line for recovering ammonia not consumed in the engine to a fuel supply line between the transfer pump and the compression pump;
Ammonia fuel supply system of a ship, characterized in that the ammonia not consumed in the engine is recovered through the return line in a liquid state and recycled along the fuel supply line. According to claim 1,
an emergency discharge line branched from the return line and connected to the ammonia fuel tank; and
A first pressure reducing valve provided in the emergency discharge line to reduce the ammonia to be recovered to the ammonia fuel tank;
Ammonia fuel supply system of a ship, characterized in that the ammonia recovered to the front end of the compression pump through the return line is depressurized through the emergency discharge line in case of emergency and discharged to the ammonia fuel tank. According to claim 2,
a compression unit for receiving and compressing the boil-off gas generated from the ammonia fuel tank;
a condensing unit that receives and cools the boil-off gas compressed by the compression unit;
a phase separation tank receiving the evaporation gas cooled in the condensing unit and performing gas-liquid separation thereon; and
The ship's ammonia fuel supply system further comprising: a liquid line for transferring the liquid separated from the phase separation tank to the ammonia fuel tank. According to claim 3,
a second pressure reducing valve provided in the liquid line to reduce the pressure of the liquid separated from the phase separation tank; and
Further comprising a level sensor for detecting the liquid level inside the phase separation tank,
Ammonia fuel supply system of a ship, characterized in that the second pressure reducing valve discharges the liquid from the phase separation tank according to the liquid level sensed by the level sensor. According to claim 4,
a BOG manifold supplying gas separated in the phase separation tank and ammonia vent gas discharged from the engine to the ammonia fuel tank; and
A third pressure reducing valve for reducing the ammonia gas separated from the phase separation tank and transferred to the BOG manifold: Ship's ammonia fuel supply system further comprising. According to claim 5,
a heat medium circulation line through which heat medium supplied to the fuel heater for heating ammonia is circulated; and
Further comprising: a heat medium supply unit provided in the heat medium circulation line to heat the heat medium,
Ammonia fuel supply system for a ship, characterized in that the heat medium cooled by heating the ammonia in the fuel heater is recovered to the heat medium supply unit through the condensation unit. According to any one of claims 1 to 6,
The ammonia fuel tank is an ammonia fuel supply system for ships, characterized in that provided as an IMO-B type tank or a membrane type tank.

Images