KR20160085589A - Fuel Gas Supply System And Method - Google Patents

Abstract

A fuel supply system and a method for a ship are disclosed. According to the present invention, the fuel supply system for a ship, wherein an engine for propulsion and another engine for generating power are provided, comprises: a vaporizer vaporizing LNG to be supplied to the engine for propulsion; a fuel gas heater heating fuel gas to be supplied to the engine for generating power; a heat source supply line supplying a heat source to be heat exchanged with the LNG in the vaporizer; and a branch line branched from the heat source supply line to supply the heat source to the fuel gas heater. Therefore, the vaporizer and the fuel gas heater are supplied with the same heat source.

Description

Technical Field [0001] The present invention relates to a fuel supply system and method for a ship,

The present invention relates to a system and method for supplying fuel to a ship, and more particularly, to a ship having a propulsion engine and a power generation engine, a vaporizer for vaporizing the LNG to be supplied to the propulsion engine, A fuel gas heater for heating the gas, a heat source supply line for supplying a heat source to be heat-exchanged with the LNG in the vaporizer, and a branching line branched from the heat source supply line for supplying a heat source to the fuel gas heater, And more particularly, to a fuel supply system and method of a ship supplying the same heat source.

In recent years, consumption of liquefied gas such as LNG (Liquefied Natural Gas) and LPG (Liquefied Petroleum Gas) has been rapidly increasing worldwide.

Particularly, Liquefied Natural Gas (hereinafter, referred to as "LNG") is an eco-friendly fuel having a low emission of air pollutants during combustion, and is increasingly used in various fields. Liquefied natural gas is a colorless transparent liquid obtained by cooling methane-based natural gas to about -162 ° C and liquefying it, and has a volume of about 1/600 of that of natural gas. Therefore, it can be transported very efficiently when liquefied by LNG for transporting natural gas.

As international standards for vessels and regulatory standards for each country become increasingly complicated, interest in eco-friendly and highly efficient fuels is growing. One of them is the mixing of natural gasified or forced vaporized gas from LNG into diesel fuel DFDE (Dual Fuel Diesel Engine), which is a heterogeneous fuel engine used, has been developed and used.

Japanese Patent Application Laid-Open No. 10-2008-0057421 (published on June 25, 2008)

Liquefied natural gas includes methane as well as ethane and propane, and the composition varies depending on the place of production. In order to fuel the engine such as DFDE by forcibly vaporizing the liquefied natural gas, the methane number and temperature conditions required by the engine You have to supply them together.

By using the characteristics of heavy hydrocarbons, which have higher liquefaction point than methane, it removes the heavy hydrocarbons contained in the natural gas which is vaporized and adjusts the methane gas to supply to the engine such as DFDE. The natural gas to be supplied to the engine after the methane adjustment should be further heated to the required temperature of the engine.

The present invention proposes a fuel supply system that can economically and effectively supply fuel according to the methane price and the required temperature of each engine when a plurality of engines are provided in the ship.

According to an aspect of the present invention, in a fuel supply system for a ship having a propulsion engine and a power generation engine,

A vaporizer for vaporizing the LNG to be supplied to the propulsion engine;

A fuel gas heater for heating the fuel gas to be supplied to the power generation engine;

A heat source supply line for supplying a heat source to be heat-exchanged with the LNG in the vaporizer; And

And a branch line branched from the heat source supply line and supplying a heat source to the fuel gas heater,

Wherein the vaporizer and the fuel gas heater are supplied with the same heat source.

Preferably, the heat source may be waste heat exhausted from the propulsion engine.

Preferably, the heat source may be a heat medium heated by the exhaust gas discharged from the propulsion engine and recovered from waste heat.

Preferably, the heat source supply line is provided with a heat medium heater for heating the heat medium by heat exchange with the exhaust gas, and a heat medium heater which is discharged after heat exchange through the vaporizer or the fuel gas heater through the heat source supply line or branch line And a heat medium supply pump for supplying the heat medium from the heat medium storage tank to the heat medium heater may be provided.

Preferably, a fuel supply pump provided in the LNG storage tank of the vessel for pumping LNG, a forced vaporizer for vaporizing the LNG pumped from the fuel supply pump, and an HHC (Heavy Further comprising an LNG supply line for supplying the LNG pumped from the fuel supply pump to the upstream side of the vaporizer from the upstream side of the forced vaporizer, wherein the LNG supply line removes the liquid HHC from the separator, The fuel gas can be supplied to the fuel gas heater by adjusting the methane number required by the engine for power generation.

Preferably, a high-pressure pump for compressing the LNG at a high pressure of 50 to 350 bar may be provided upstream of the vaporizer in the LNG supply line.

Preferably, the HHC separated from the separator may be re-stored in the LNG storage tank.

Preferably, the HHC separated from the separator may be supplied upstream of the high-pressure pump of the LNG supply line.

Preferably, the HHC separated from the separator may be supplied to the fuel gas heater and supplied to the power generation engine.

According to another aspect of the present invention, there is provided a fuel supply method for a ship having a propulsion engine and a power generation engine,

The LNG storage tank of the ship is pumped with LNG to supply the fuel for the propulsion engine and the power generation engine,

The pumping LNG is compressed and fed to the propulsion engine by heat exchange,

Wherein the power generation engine is supplied with the fuel gas by vaporizing the pumped LNG and separating the HHC by heat exchange,

Wherein the fuel to be supplied to the propulsion engine and the power generation engine is heat-exchanged with the same heat source.

Preferably, the heat source may be waste heat exhausted from the propulsion engine.

Preferably, the heat source may be a heat medium heated by the exhaust gas discharged from the propulsion engine and recovered from waste heat.

In the fuel supply system and method of the present invention, the same heat source can be supplied to the vaporizer for vaporizing the LNG to be supplied to the propulsion engine and the fuel gas heater for heating the fuel gas to be supplied to the power generation engine, This is compact.

Especially, by supplying the heat source to the carburetor and the fuel gas heater by the exhaust gas waste heat of the engine for propulsion other than steam, the oil fuel consumption of the auxiliary boiler using the oil fuel can be reduced, and the energy efficiency of the ship can be improved.

  In addition, an engine requiring methane control can be prevented from abnormal combustion phenomena such as knocking of the engine and the resulting device abnormality by removing and supplying the heavy hydrocarbon component contained in the forced vaporized natural gas.

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

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

FIG. 1 schematically shows a fuel supply system of a ship according to an embodiment of the present invention, and FIG. 2 schematically shows a fuel supply system of a ship according to another embodiment of the present invention.

As shown in FIGS. 1 and 2, the fuel supply system for a ship of the present embodiment is a fuel supply system for a ship having a propulsion engine (PE) and a power generation engine (GE) A fuel gas heater 200 for heating a fuel gas in which the LNG to be supplied to the power generation engine GE is forcibly vaporized and a heat source to be heat-exchanged with the LNG in the vaporizer 100 And a branch line HLa branched from the heat source supply line HL and supplying a heat source to the fuel gas heater 200 so that the vaporizer 100 and the fuel gas heater 200, Is supplied with the same heat source.

In this embodiment, the propulsion engine (PE) of the ship supplied with the LNG as fuel may be ME-GI engine and the power generation engine GE may be a dual fuel diesel engine (DFDE) diesel generator. Valve units VU1 and VU2 for regulating fuel supply may be provided upstream of the propulsion engine PE and the power generation engine GE, respectively.

1, in the first embodiment of the present invention, a heat source supplied to the vaporizer 100 and the fuel gas heater 200 is a heat source that is discharged from a propelling engine (PE) And may be a heated heat medium.

In the case of heating by heat exchange with steam as in the conventional fuel supply system, especially in the case of DFDG, since the amount of liquefied natural gas supplied as fuel is small, excessive heat energy is supplied more than necessary, And generate steam through a boiler using oil fuel, there is a cost problem and an environmental pollution problem due to the use of oil fuel.

In this embodiment, the heating of the fuel supplied to the propelling engine (PE) is performed by supplying a part of the heat source from the heat source supply line (HL) to the fuel gas heater (200) through the branch line (HLa) In particular, the residual heat of the exhaust gas discharged from the propulsion engine (PE) is utilized to increase the energy efficiency and reduce the fuel cost. The exhaust gas discharged from the propulsion engine (PE) is heated to a temperature of about 170 to 180 DEG C even after passing through a waste heat recovery apparatus (HR) such as an economizer, and is supplied to the propulsion engine (PE) Since the temperature of the fuel is about 45 ° C or so, it is possible to sufficiently supply the heat source necessary for the carburetor 100 and the fuel gas heater 200 by using the residual heat of the exhaust passed through the waste heat recovery apparatus HR.

In this embodiment, the heating medium circulating through the heat source supply line HL and the branch line HLa and used as a medium for heat exchange may be GW (Glycol Water). Glycol water is a kind of antifreeze such as ethylene glycol ). Ethylene glycol is a viscous, colorless liquid having a molecular weight of 62.07, a freezing point of -12.6 ° C, a boiling point of 197.7 ° C and a specific gravity of 1.1131.

1, the heat source supply line HL is provided with a heat medium heater 300 that heats the heat medium by heat exchange with the exhaust gas and a heat medium heater 300 through a heat source supply line HL or a branch line HLa A heating medium storage tank 310 for storing a heating medium heater 300 discharged after heat exchange through the fuel gas heater 200 or a heating medium supply unit 310 for supplying a heating medium from the heating medium storage tank 310 to the heating medium heater 300, A pump 320 may be provided.

On the other hand, a fuel supply pump P for pumping LNG is provided in the LNG storage tank T of the vessel for supplying fuel to the propulsion engine PE and the power generation engine GE. The fuel supply pump (P) is provided as a pump type among liquids so as to be locked to the LNG inside the tank.

The pumped LNG is supplied to the outside of the tank via the main supply line (ML).

A forced vaporizer 210 for vaporizing the LNG pumped from the fuel supply pump P for supplying fuel to the power generation engine GE such as a DF engine, A separator 220 for removing HHC (Heavy Hydrocarbon) is provided. The liquid HHC is removed from the separator 220 so that the fuel gas can be supplied to the fuel gas heater 200 by adjusting the methane number required by the engine GE for power generation.

In addition to methane, natural gas includes hydrocarbons having a plurality of hydrocarbons such as ethane, propane, butane, and pentane, and inert gas components such as nitrogen and carbon dioxide. The composition ratio varies depending on the place of production. Methane number indicates the composition ratio of methane in natural gas. If fuel that does not meet the methane required by the engine is supplied, knocking phenomenon in the engine or explosion and combustion of the piston before top dead center An abnormal combustion phenomenon may occur. Such an abnormal combustion phenomenon may cause wear of the engine piston, and may cause problems such as deterioration of engine efficiency and device failure. The DF engine generally requires methane over 80, which may range from about 70 to about 70, depending on the country of production, so methane regulation is required to feed the fuel gas, which is forced vaporized from LNG, to the DF engine.

Ethane, propane, butane, etc. contained in the forced vaporized fuel gas have higher liquefaction point than methane. Therefore, in the separator 220, the methane gas of the liquefied natural gas is removed to a level required by the engine by removing the liquefied heavy hydrocarbons at a temperature at which the heavy hydrocarbons (HHC) such as propane and butane can be liquefied while maintaining the gas state . The vaporization temperature of the LNG heated in the forced vaporizer is from -80 to -120 ° C., and the vaporization temperature can be controlled within the above range in consideration of different compositions depending on the LNG production site.

The methane gas may be regulated to 80 or more, preferably 90 or more, more preferably 95 or more, through the separator 220. As the methane gas is regulated, the lower heating value (LHV) is higher than before the separator 220 is passed.

For example, in the case of General LNG (C1: 89.6%, N2: 0.6%), the methane level before separation is 71.3 and the lower heating value at that time is 48,872.8 kJ / kg (1 atm, saturated vapor basis) 7 bara, the mixture is heated to -120.degree. C. By vaporizing and separating the liquid through the separator 220, the methane gas is changed to 95.5 and the LHV is changed to 49,265.6 kJ / kg. When heating at -120 ° C. based on General LNG, about 25% of the mass of the total incoming LNG is removed from the separator 220.

On the other hand, the LNG pumped in the fuel supply pump P is supplied from the upstream side of the forced vaporizer 210 to the propelling engine PE through the LNG supply line L 1 connected to the upstream of the vaporizer 100. To this end, the main supply line ML includes a high-pressure pump LNG supply line L1 connected to the propulsion engine PE via a high-pressure pump upstream of the forced vaporizer 210, To a line (L2) connected to the engine (GE).

A propelling engine (PE), such as an ME-GI engine, is supplied with high pressure gas as fuel. To compress the LNG at this pressure, LNG is introduced into the LNG supply line upstream of the carburetor 100 at a high pressure of 50 to 350 bar A high-pressure pump 110 for compressing the refrigerant can be provided.

The HHC separated from the separator 220 can be restored to the LNG storage tank T. The LNG storage tank T of the present embodiment may be a stand-alone tank, for example, an IMO C type tank. A line may be provided to supply a boil-off gas (BOG) generated in the LNG storage tank T to a propulsion engine (PE) or a power generation engine (GE). In this case, BOG is mostly composed of methane, The line BL for supplying the BOG can be joined to the fuel supply line L2 supplied from the main supply line ML to the power generation engine GE at the downstream of the separator 220. [

On the other hand, the ME-GI engine does not require methane control, so instead of restoring it to the LNG storage tank T, the HHC separated from the separator 220 is supplied to the upstream of the high-pressure pump 110 of the LNG supply line And can be supplied to a propulsion engine (PE). When the power generation engine (GE) can use the HHC as fuel, the separated HHC can be supplied to the fuel gas heater (200) and supplied to the power generation engine (GE). Alternatively, the separated HHC may be stored in a specific tank so as not to mix with LNG, and may be transported offshore and treated separately.

2, the heat source supplied to the carburetor 100 and the fuel gas heater 200 may be exhausted from the propelling engine (PE) to be a waste heat recovered exhaust gas have. The other parts are constituted in the same manner as in the above embodiment, and the exhaust gas having passed through the waste heat recovery apparatus HR such as an economizer after discharge from the propulsion engine PE is supplied to the heat source supply line HL and the branch line, 100 and the fuel gas heater 200. In this case,

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Accordingly, such modifications or variations are intended to fall within the scope of the appended claims.

T: LNG storage tank
P: fuel supply pump
PE: Propulsion engine
GE: Engines for power generation
HR: waste heat recovery device
ML: main supply line
L1: High pressure pump LNG supply line
L2: Fuel gas heater LNG supply line
HL: Heat source supply line
HLa: Branch line
100: vaporizer
110: high pressure pump
200: Fuel gas heater
210: forced vaporizer
220: Separator
300: Heat medium heater
310: heating medium storage tank
320: heat medium supply pump

Claims (12)

A fuel supply system for a ship having a propulsion engine and an engine for power generation,
A vaporizer for vaporizing the LNG to be supplied to the propulsion engine;
A fuel gas heater for heating the fuel gas to be supplied to the power generation engine;
A heat source supply line for supplying a heat source to be heat-exchanged with the LNG in the vaporizer; And
And a branch line branched from the heat source supply line and supplying a heat source to the fuel gas heater,
Wherein the vaporizer and the fuel gas heater are supplied with the same heat source. The method according to claim 1,
Wherein the heat source is exhaust gas discharged from the propulsion engine and recovered from waste heat. The method according to claim 1,
Wherein the heat source is a heat medium heated by the exhaust gas discharged from the propulsion engine and recovered from waste heat. 4. The apparatus according to claim 3, wherein the heat source supply line
A heating medium heater for heating the heating medium by heat exchange with the exhaust gas;
A heating medium storage tank in which a heating medium heater which is discharged after heat exchange through the vaporizer or the fuel gas heater through the heat source supply line or the branch line is stored; And
And a heating medium supply pump for supplying the heating medium from the heating medium storage tank to the heating medium heater. The method according to claim 2 or 3,
A fuel supply pump provided in the LNG storage tank of the ship to pump the LNG;
A forced vaporizer for vaporizing the LNG pumped from the fuel supply pump;
A separator for removing HHC (Heavy Hydrocarbon) contained in the fuel gas vaporized in the forced vaporizer; And
Further comprising an LNG supply line for supplying the LNG pumped in the fuel supply pump from the upstream side of the forced vaporizer to the upstream side of the vaporizer,
Wherein the separator separates the HHC in liquid form into a methane number required by the power generation engine to supply the fuel gas to the fuel gas heater. 6. The method of claim 5,
And a high-pressure pump for compressing LNG at a high pressure of 50 to 350 bar is provided upstream of the carburetor in the LNG supply line. The method according to claim 6,
And the HHC separated from the separator is restored to the LNG storage tank. The method according to claim 6,
And the HHC separated from the separator can be supplied upstream of the high-pressure pump of the LNG supply line. The method according to claim 6,
And the HHC separated from the separator can be supplied to the fuel gas heater and supplied to the power generation engine. 1. A fuel supply method for a ship having a propulsion engine and an engine for power generation,
The LNG storage tank of the ship is pumped with LNG to supply the fuel for the propulsion engine and the power generation engine,
The pumping LNG is compressed and fed to the propulsion engine by heat exchange,
Wherein the power generation engine is supplied with the fuel gas by vaporizing the pumped LNG and separating the HHC by heat exchange,
Wherein the fuel to be supplied to the propulsion engine and the power generation engine is heat-exchanged with the same heat source. 11. The method of claim 10,
Wherein the heat source is exhaust gas discharged from the propulsion engine and recovered from waste heat. 11. The method of claim 10,
Wherein the heat source is a heat medium heated by the exhaust gas discharged from the propulsion engine and recovered from waste heat.

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