KR102285470B1 - Fuel gas supply system - Google Patents

Abstract

Disclosed is a fuel supply system. A fuel supply system according to an embodiment of the present invention includes a storage tank for storing liquefied gas and boil-off gas of the liquefied gas; A compression unit including a first compressor for compressing the boil-off gas to a first pressure, and a second compressor for compressing the boil-off gas to a second pressure greater than the first pressure; a first supply line connecting the storage tank, the compression unit, and the engine, and supplying boil-off gas compressed by the compression unit to the engine; a branch line branching from between the first compressor and the second compressor of the first supply line and supplying boil-off gas compressed to a first pressure; a condensing unit receiving the liquefied gas supplied from the storage tank and the boil-off gas compressed to a first pressure, and condensing the boil-off gas compressed to the first pressure using the liquefied gas; a pressure pump for pressurizing the fluid passing through the condensing unit; a vaporizer for vaporizing the pressurized fluid; and a second supply line connecting the storage tank, the condensing unit, the pressure pump and the vaporization unit, and joining the vaporized fluid to the rear end of the compression unit of the first supply line.

Description

Fuel supply system {FUEL GAS SUPPLY SYSTEM}

The present invention relates to a fuel supply system.

As the International Maritime Organization (IMO)'s regulations on the emission of greenhouse gases and various air pollutants are strengthened, the shipbuilding and shipping industry replaces the existing fuels such as heavy oil and diesel oil, and uses natural gas, a clean energy source, as a fuel gas for ships. is being used more and more.

Natural gas, which is widely used among fuel gas, has methane as its main component, and is stored and transported after being changed to a liquefied gas state, which is usually reduced in volume by 1/600.

The liquefied gas carrier has a storage tank insulated to store liquefied gas. The engine of such a ship uses as fuel by forcibly vaporizing the liquefied gas in the storage tank, or uses Boiled Off Gas naturally occurring in the storage tank as a fuel.

On the other hand, during laden voyage with full liquefied gas in the storage tank, the amount of naturally generated boil-off gas is large, so it is possible to easily satisfy the fuel amount required by the engine.

However, during ballast voyage in which a large amount of liquefied gas is not accommodated in the storage tank, the amount of naturally occurring BOG is greatly reduced, so it is difficult to meet the amount of fuel required by the engine. Moreover, in order to process a small amount of BOG, since a high-pressure compressor must be continuously used, inefficient operation may be made.

Please refer to Korean Patent Publication No. 10-2012-0103421 (published on September 19, 2012) as a related prior art.

Korean Patent Publication No. 10-2012-0103421 (published on September 19, 2012)

An embodiment of the present invention is to provide a fuel supply system that can effectively supply a flow rate according to the amount of fuel required by the engine.

According to an aspect of the present invention, a storage tank for storing liquefied gas and boil-off gas of the liquefied gas; a compression unit including a first compressor for compressing the boil-off gas to a first pressure, and a second compressor for compressing the boil-off gas to a second pressure greater than the first pressure; a first supply line connecting the storage tank, the compression unit, and the engine, and supplying the boil-off gas compressed by the compression unit to the engine; a branch line branching from between the first compressor and the second compressor of the first supply line to supply the boil-off gas compressed to the first pressure; a condensing unit receiving the liquefied gas supplied from the storage tank and the boil-off gas compressed to the first pressure, and condensing the boil-off gas compressed to the first pressure using the liquefied gas; a pressure pump for pressurizing the fluid passing through the condensing unit; a vaporizer for vaporizing the pressurized fluid; and a second supply line connecting the storage tank, the condensing unit, the pressurization pump and the vaporization unit, and joining the vaporized fluid to the rear end of the compression unit of the first supply line; .

A third supply line branched from the branch line and connected to a consumer, and supplying a portion of the boil-off gas compressed to the first pressure to the consumer, a first on/off valve provided in the third supply line, and the third A first pressure measuring unit for measuring the pressure of the boil-off gas compressed to the first pressure supplied to the consumer through a supply line, a second on-off valve provided in the branch line, and the flow rate of the liquid stored in the condensing unit A second pressure that is provided between a level measuring unit for measuring, a third on/off valve provided in the second supply line, a junction of the second supply line and the engine, and measuring the pressure of the fluid supplied to the engine. It may further include a measurement unit, a fourth on-off valve provided between the branch point of the branch line and the second compressor, and a controller for controlling at least one of the first on-off valve to the fourth on-off valve.

The control unit may include at least one of the first on/off valve to the third on/off valve based on a value measured by at least one of the first pressure measuring unit, the level measuring unit, and the second pressure measuring unit during full sailing. by controlling the flow rate supplied to one or more of the confluence of the demand destination, the condensing unit, and the second supply line.

The control unit may close the fourth opening/closing valve during collinear sailing so that the boil-off gas in the storage tank supplied through the first supply line is supplied toward the condensing unit through the branch line.

The fuel supply system according to an embodiment of the present invention can effectively supply a flow rate according to the amount of fuel required by the engine.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 shows a fuel supply system according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration for controlling the fuel supply system of FIG. 1 .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those of ordinary skill in the art to which the present invention pertains. The present invention is not limited to the embodiments described below and may be embodied in other forms. In order to clearly explain the present invention, parts irrelevant to the description are omitted from the drawings, and in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numerals refer to like elements throughout.

1 and 2 , a fuel supply system 100 according to an embodiment of the present invention includes a storage tank 110 for storing liquefied gas and boil-off gas of the liquefied gas, and evaporation supplied from the storage tank 110 . A compression unit 120 including a first compressor 121 for compressing the gas to a first pressure and a second compressor 122 for compressing the boil-off gas to a second pressure greater than the first pressure, and a storage tank 110 . , a first supply line (L1) connecting the compression unit 120, and the engine E1, and supplying boil-off gas compressed by the compression unit 120 to the engine E1, and a first supply line L1 ) branching from between the first compressor 121 and the second compressor 122 and supplying the boil-off gas compressed to the first pressure (L2), and the liquefied gas supplied from the storage tank 110 and the first The condensing unit 130 that receives the boil-off gas compressed to the first pressure by the compressor 121 and condenses the boil-off gas compressed to the first pressure using the liquefied gas, and the condensing unit 130 A pressurizing pump 140 for pressurizing the fluid, a vaporizing unit 150 and a storage tank 110 for vaporizing the fluid pressurized by the pressurizing pump 140, a condensing unit 130, a pressurizing pump 140, and a vaporizing unit A second supply line (L3) connecting the 150 and joining the fluid vaporized by the above-described vaporization unit 150 to the rear end of the compression unit 120 of the first supply line (L1) is included.

In addition, the fuel supply system 100 is branched from the branch line L2 and connected to the consumer E2, and a third supply line L4 that supplies a portion of the boil-off gas compressed to the first pressure to the consumer E2. And, the first on/off valve V1 provided in the third supply line L4, and the first pressure measuring unit 161 for measuring the pressure of the boil-off gas supplied to the consumer E2 through the third supply line L4 ), a second on/off valve V2 provided in the branch line L2, a level measuring unit 162 for measuring the flow rate of the liquid stored in the condensing unit 130, and a second opening/closing valve V2 provided in the second supply line L3. The third on-off valve V3 and the second pressure measuring unit 163 provided between the junction of the second supply line L3 and the engine E1 and measuring the pressure of the fluid supplied to the engine E1; , the fourth on-off valve (V4) provided between the branch point (A2) of the branch line (L2) and the second compressor 122, and at least one of the first on-off valves (V1) to the fourth on-off valve (V4) It may include a control unit 170 to control. The demand E2 may include a boiler, a turbine, and the like.

Such a fuel supply system 100 is various liquefied fuel carriers, liquefied fuel RV (Regasification Vessel), container ship, general merchant ship, LNG FPSO (Floating, Production, Storage and Off-loading), LNG FSRU (Floating Storage and Regasification Unit) It can be applied to ships including etc.

The liquefied gas stored in the above-described storage tank 10 may be any one of LNG (Liquefied Natural Gas), LPG (Liquefied Petroleum Gas), DME (Dimethylether), and ethane that can be stored in a liquefied state, but is limited thereto it is not

The storage tank 10 may include a membrane type tank, an SPB type tank, and the like for storing fuel in a liquefied state while maintaining a thermal insulation state. BOG of the liquefied gas stored in the storage tank 10 is supplied to the engine E1 through the first supply line L1. Here, the engine E1 may be, for example, a high-pressure gas injection engine such as an ME-GI engine, but is not limited thereto, and may be, for example, a low-pressure or medium-pressure gas injection engine.

The compression unit 120 includes a first compressor 121 for compressing the boil-off gas supplied from the storage tank 110 to a first pressure, and a second compressor 122 for compressing the boil-off gas to a second pressure greater than the first pressure. ), and coolers 124 and 125 are provided at the rear end of each compressor 121 and 122 . Although FIG. 1 shows that the three-stage compressor and the cooler are alternately arranged, more may be provided, and a higher pressure is formed as the BOG supplied from the storage tank 110 passes through each compressor. Hereinafter, the first compressor 121 and the second compressor 122 will be mainly described.

The condensing unit 130 receives the liquefied gas from the storage tank 110 through the second supply line L3, and receives the boil-off gas compressed to the first pressure through the branch line L2. Then, the boil-off gas compressed to the first pressure is condensed using the liquefied gas.

The pressure pump 140 pressurizes the fluid that has passed through the condensing unit 130 , and the vaporization unit 150 vaporizes the fluid pressurized by the pressurization pump 140 . The compressors 121 and 122 and the pressure pump 140 included in the above-described compression unit 120 may include a reciprocating pump.

When the control unit 170 is full sail, the first on/off valve ( V1) to control one or more of the third on-off valve (V3) to control the flow rate supplied to one or more of the demand destination (E2), the condensing unit 130, and the junction point (A1) of the second supply line (L3) do.

For example, when the consumer E2 consumes a large amount of fuel (evaporated gas), the pressure of the fluid measured by the first pressure measuring unit 161 is low. In this case, the control unit 170 may adjust the first on/off valve V1 so that a larger amount of fuel is provided through the third supply line L4.

In addition, when the flow rate of the liquid stored in the condensing unit 130 measured by the level measuring unit 162 is lower than the set value, the control unit 170 adjusts the second opening/closing valve V2 provided in the branch line L2. to meet the required flow rate.

In addition, when the amount of fuel consumed by the engine E1 exceeds the set value, the pressure of the fluid measured by the second pressure measuring unit 163 is low. In this case, the control unit 170 supplies more fuel to the engine E1 by controlling one or more of the first on/off valve V1 to the third on/off valve V3, and the amount of fuel required by the engine E1. can satisfy

In addition, the control unit 170 closes the fourth on-off valve (V4) during the ballistic voyage so that the boil-off gas in the storage tank 110 supplied through the first supply line (L1) passes through the branch line (L2) to the condensing unit ( 130) can be supplied. Through this, condensation using liquefied gas is made through the condensing unit 130 , and the fluid that has passed through the condensing unit 130 is supplied as fuel, so that sailing is possible without using the compressor 122 that compresses to a high pressure.

In the above, specific embodiments have been shown and described. However, the present invention is not limited to the above embodiments, and those of ordinary skill in the art to which the invention pertains may make various changes without departing from the spirit of the invention described in the claims below. will be able

110: storage tank 120: compression unit
130: condensing unit 140: pressure pump
150: vaporization unit 161: first pressure measuring unit
162: level measurement unit 163: second pressure measurement unit
170: control unit E1: engine
E2: Demander L1: 1st supply line
L2: branch line L3: second supply line
L4: 3rd supply line V1~V4: on/off valve

Claims (4)

a storage tank for storing liquefied gas and boil-off gas of the liquefied gas;
a compression unit including a first compressor for compressing the boil-off gas to a first pressure, and a second compressor for compressing the boil-off gas to a second pressure greater than the first pressure;
a first supply line connecting the storage tank, the compression unit, and the engine, and supplying the boil-off gas compressed by the compression unit to the engine;
a branch line branching from between the first compressor and the second compressor of the first supply line and supplying boil-off gas compressed to the first pressure;
a condensing unit receiving the liquefied gas supplied from the storage tank and the boil-off gas compressed to the first pressure, and condensing the boil-off gas compressed to the first pressure using the liquefied gas;
a pressure pump for pressurizing the fluid passing through the condensing unit;
a vaporizer for vaporizing the pressurized fluid;
a second supply line connecting the storage tank, the condensing unit, the pressure pump, and the vaporization unit, and joining the vaporized fluid to a rear end of the compression unit of the first supply line;
a third supply line branched from the branch line and connected to a consumer, and supplying a portion of the boil-off gas compressed to the first pressure to the consumer;
a first opening/closing valve provided in the third supply line; and
Includes; a first pressure measuring unit for measuring the pressure of the boil-off gas compressed to the first pressure supplied to the demand through the third supply line;
When the pressure value measured by the first pressure measuring unit is lower than a set value, the fuel supply system for increasing the flow rate supplied to the demand by the third supply line by adjusting the first on-off valve. According to claim 1,
a second on-off valve provided in the branch line;
a level measuring unit for measuring the flow rate of the liquid stored in the condensing unit;
a third on-off valve provided in the second supply line;
a second pressure measuring unit provided between the junction of the second supply line and the engine and measuring the pressure of the fluid supplied to the engine;
a fourth on-off valve provided between the branch point of the branch line and the second compressor;
The fuel supply system further comprising a control unit for controlling at least one of the first on-off valve to the fourth on-off valve. 3. The method of claim 2,
The control unit may include at least one of the first on/off valve to the third on/off valve based on a value measured by at least one of the first pressure measuring unit, the level measuring unit, and the second pressure measuring unit during full sailing. A fuel supply system for controlling the flow rate supplied to at least one of the junction of the demand destination, the condensing unit, and the second supply line by controlling the . 3. The method of claim 2,
The control unit closes the fourth opening/closing valve during collinear sailing so that the boil-off gas in the storage tank supplied through the first supply line is supplied to the condensing unit through the branch line.

Images