KR101903763B1 - System for supplying fuel gas in ships - Google Patents

Abstract

A fuel gas supply system for a ship according to the present invention comprises: a storage tank for storing liquefied gas; A pressurization supply line extending from the storage tank to a high-pressure consumer and having a first compression unit and a second compression unit sequentially connected to compress the evaporation gas generated in the storage tank toward the high-pressure consumer; A vaporization supply line extending from the storage tank to the high-pressure consumer and provided with a high-pressure pump for pressurizing the liquefied gas in the storage tank at a set pressure; A mixed supply line branched downstream of the high pressure pump of the vaporization supply line and extending toward the low pressure demand side; An ejector provided in the mixed supply line; And a suction line extending from the storage tank to the ejector and supplying the evaporation gas to the ejector.

Description

SYSTEM FOR SUPPLYING FUEL GAS IN SHIPS

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel gas supply system for a ship which stably supplies fuel gas to various devices for operating a ship.

As IMO regulations on the emission of greenhouse gases and various air pollutants are strengthened, shipbuilding and marine industries are replacing the use of heavy fuel oil and diesel oil, In many cases.

Natural gas, which is widely used and regarded as an important resource in fuel gas, is mainly composed of methane and is usually cooled to about -162 degrees Celsius for ease of storage and transportation, thereby reducing the volume to 1/600 (Liquefied Natural Gas) to manage and operate it.

The liquefied gas is stored and transported in a storage tank which is installed in a heat insulation treatment on the hull, and the engine of the ship is driven by supplying liquefied gas or boiled off gas to the fuel gas. At this time, the liquefied gas or the evaporated gas is subjected to processing such as compression and vaporization, and is supplied to meet the requirements of the engine.

Today, xenon fuel engines are widely used for ship propulsion or ship power generation. In particular, X-DF engines capable of combusting with medium-pressure fuel gas have been developed and used. Such an X-DF engine generates an output by supplying an evaporative gas on the gas as fuel gas.

On the other hand, when laden voyage is filled with liquefied gas in a storage tank, since the amount of evaporated gas generated is large, it is possible to easily generate the output by supplying the fuel gas to the X-DF engine. However, after the liquefied gas is unloaded In the ballast voyage in which the liquefied gas is not stored in the storage tank, the amount of evaporation gas is greatly reduced, and it is difficult to generate the output of the X-DF engine constantly.

Accordingly, there is a need for a method capable of efficiently utilizing the fuel gas while stably generating the output of the X-DF engine regardless of the capacity of the liquefied gas.

Korean Unexamined Patent Application Publication No. 10-2010-0035223 (Published Apr. 5, 2010)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fuel gas supply system for a ship having an improved performance efficiency while stably supplying fuel and reducing facility investment costs. .

According to an aspect of the present invention, there is provided a storage tank for storing a liquefied gas and an evaporated gas of the liquefied gas; A pressurization supply line extending from the storage tank to a high-pressure consumer and having a first compression unit and a second compression unit sequentially connected to compress the evaporation gas stored in the storage tank and supply the compressed gas to the high-pressure consumer; A vaporization supply line extending from the storage tank to the high-pressure consumer and having a high-pressure pump for pressurizing and discharging the liquefied gas stored in the storage tank; A mixed supply line branching at a downstream side of the high pressure pump of the vaporization supply line and extending to the low pressure consumer, and having an ejector; And a suction line extending from the storage tank to the ejector and supplying the evaporator gas stored in the storage tank to the ejector.

The apparatus may further include a first connection line branched from the first compression unit and the second compression unit of the pressurization supply line and extending to an ejector downstream of the mixed supply line.

The apparatus may further include a second connection line branched from the first compression unit and the second compression unit of the pressurization supply line and extending to the suction line, wherein the second connection line is provided with a regulating valve for regulating a pressure or a flow rate.

The apparatus may further include a third connection line extending downstream of the second compression section of the pressurization supply line and downstream of the ejector of the mixed supply line, wherein the third connection line is provided with a regulating valve for regulating a pressure or a flow rate.

The fuel gas supply system for a ship according to the present invention is characterized in that the ejector is provided on the mixed feed line and the mixed feed line to reduce the power consumption by using the ejector in place of the first compressed part during the cruise, Redundancy can be controlled.

It is also possible to provide a first connection line extending between the first compression section and the second compression section of the multistage and toward the mixing supply line and a second connection line extending between the first compression section and the second compression section toward the suction line , The first compression unit, the second compression unit, or the ejector can be flexibly selected depending on the navigation mode.

The first connection line, the second connection line and the third connection line may be provided so that the evaporation gas or the forced evaporation gas is supplied to each customer through three paths, i.e., the pressurization supply line, the vaporization supply line, The methane number (MN) of the liquefied gas can be easily controlled by supplying the fuel gas directly or by mixing.

1 shows a fuel gas supply system for a ship according to an embodiment of the present invention.
2 shows a first operational example of a fuel gas supply system for a ship according to an embodiment of the present invention.
3 shows a second operation example of a fuel gas supply system for a ship according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided to fully convey the spirit of the present invention to a person having ordinary skill in the art to which the present invention belongs. The present invention is not limited to the embodiments shown herein but may be embodied in other forms. For the sake of clarity, the drawings are not drawn to scale, and the size of the elements may be slightly exaggerated to facilitate understanding.

1 shows a fuel gas supply system for a ship according to an embodiment of the present invention. The fuel gas supply system for a ship according to an embodiment of the present invention includes a storage tank 1 and a storage tank 1 for compressing the evaporation gas G2 generated by the storage tank 1 toward the high pressure consumer 2 A vaporizing and supplying line 20 for vaporizing the liquefied gas G1 of the storage tank 1 and supplying the liquefied gas G1 to the high pressure consumer 2, a vaporizer 22 of the vaporizing and supplying line 20, An ejector 31 provided in the mixed supply line 30 and an ejector 31 extending from the storage tank 1 to the ejector 31, , And a suction line (40) for supplying the evaporator gas (G2) to the ejector (31).

Hereinafter, the liquefied gas (G1) and the evaporation gas generated therefrom are described as an example to help understand the present invention. However, the present invention is not limited thereto, and various liquefied gases such as liquefied ethane gas and liquefied hydrocarbon gas, The same technical idea should be equally understood when the evolving gas is applied.

The storage tank 1 is provided to receive and store the liquefied gas G1 and the evaporation gas G2 generated therefrom. The storage tank 1 may be provided with a membrane-type cargo window which is heat-treated so as to minimize vaporization of the liquefied gas G1 due to external heat penetration. The storage tank 1 receives and stores the liquefied gas G1 from the production site of natural gas or the like, and stably stores the liquefied gas G1 until it arrives at the destination and unloads it. The liquefied gas G1 stored in the storage tank 1 may be used as a fuel gas for a propulsion engine, a power generation engine and a GCU of a ship as described later.

At this time, the fuel gas is a gas which can be used as fuel in the high-pressure consumer 2 or the low-pressure consumer 3, and includes a vaporized gas G2 compressed by pressurization and a vaporized gas G3 vaporized by the liquefied gas G1 do. This fuel gas can be divided into a high-pressure fuel gas and a low-pressure fuel gas in accordance with the required pressure in the high-pressure consumer 2 and the low-pressure consumer 3.

Since the storage tank 1 is generally installed with heat insulation, it is substantially difficult to completely block the heat penetration from the outside. Therefore, in the storage tank 1, the evaporation gas generated by natural vaporization of the liquefied gas G1 G2). This evaporation gas G2 is required to be removed from the storage tank 1 because it raises the internal pressure of the storage tank 1 and poses a risk of deformation and explosion of the storage tank 1.

The evaporation gas G2 can be used as the fuel gas to the high pressure consumer 2 or the low pressure consumer 3 through the pressurization supply line 10 to be described later. Also, although not shown in the drawing, a vent mast (not shown) may be provided in the storage tank 1 to treat or consume excessive evaporation gas G2. On the other hand, since the evaporation gas G2 has a large carbon content, the liquefied gas G1 may show a considerable difference in the carbon content ratio from the vaporized gas G3 which is forcedly vaporized.

The high pressure consumer 2 receives the gaseous fuel gas composed of the evaporation gas G2 or the vaporization gas G3 or the like through the pressurization supply line 10 and the vaporization supply line 20 to generate the propulsion force of the ship . For example, the engine may be an X-DF engine capable of generating an output by receiving a fuel gas of a medium pressure, specifically about 15 to 17 bar, but not limited thereto, And includes various types of engines if they can generate and generate output.

The low pressure consumer 3 is a DFG engine or a GCU (Gas Combustion Unit) which supplies extra fuel gas not supplied to the engine among the fuel gas supplied through the pressurization supply line 10 and the vaporization supply line 20 Or can supply and consume extra fuel gas from the mixed supply line 30 to be described later. At this time, if the low pressure consumer 3 is a GCU, it can be supplied with evaporative gas or fuel gas at a level of about 1 to 6.5 bar to be incinerated forcibly.

The pressurization supply line 10 is provided to supply the evaporation gas G2 generated naturally to the storage tank 1 as a fuel gas to the high pressure consumer 2 or the low pressure consumer 3. [ To this end, the pressurization supply line 10 may be arranged such that the inlet side end of the pressurization supply line 10 can be located inside the respective storage tanks 1 so that the evaporation gas G2 in the storage tank 1 can be easily supplied, The end may be in the form of an extension to the high pressure consumer 2. The pressurization supply line 10 may be provided with compressing units 11 and 12 having a plurality of compressors so that the evaporation gas G2 can be supplied according to the pressure and temperature conditions required by the high pressure consumer 2 .

The compressing sections 11 and 12 may include a compressor for compressing the evaporation gas G2 and a cooler (not shown) for cooling the evaporation gas G2 heated while being compressed. At this time, the first compression section 11 and the second compression section 12 may have the same compression performance so as to sequentially pressurize the evaporation gas G2 from 1 bar to 8 bar and from 8 bar to 16 bar, respectively. In FIG. 1, the compression units 11 and 12 are two-stage compression units including the first compression unit 11 and the second compression unit 12, but the present invention is not limited thereto.

The vaporization supply line 20 can supply the liquefied gas G1 stored in the storage tank 1 to the high-pressure consumer 2 as fuel gas. The vaporization supply line 20 may be provided as a means for supplying fuel to the high pressure consumer 2 when the pressurization supply line 10 is unavailable, that is, at the time of repair or replacement.

The vaporization supply line 20 may be connected at one end to the interior of the storage tank 1 and at the other end to the high pressure consumer 2 by joining with the pressure supply line 10. The vaporization supply line 20 is provided with a pump 21 for sending and pressurizing the liquefied gas G1 in the storage tank 1 and a vaporizer for vaporizing the liquefied gas G1 delivered and pressurized by the pump 21 (22) may be provided.

The pump 21 may be provided at the inlet side end of the vaporization supply line 20 in the storage tank 1 and adjacent to the bottom surface of the inside of the storage tank 1 so as to improve the operation efficiency. The pump 21 discharges the liquefied gas G1 stored in the storage tank 1 to the vaporization supply line 20 and simultaneously supplies the liquefied gas G1 to the vaporization supply line 20 at a pressure level corresponding to the pressure condition of the fuel gas required by the high- The gas G1 can be pressurized. For example, when the high pressure consumer 2 is an X-DF engine, the pump 21 can pressurize the liquefied gas G1 to about 15 to 17 bar and send it to the vaporizer 22 side.

The vaporizer 22 is provided to forcibly vaporize the pressurized liquefied gas G1 supplied by the pump 21 and supply it as fuel gas to the high pressure consumer 2. [ The vaporizer 22 may be a heat exchanger that performs heat exchange with glycol water or the like to heat and vaporize the pressurized liquefied gas G1. However, the vaporizer 22 is not limited thereto, If possible, a device of various types.

The control valve 23 is provided between the downstream of the vaporizer 22 and the high pressure consumer 2 and can control the pressure or the flow rate of the fluid flowing through the vaporization supply line 20. [ For this purpose, the control valve 23 may be, for example, a pressure reducing valve. When the fuel gas passing through the carburetor 22 exceeds the pressure condition required by the high pressure consumer 2, the regulating valve 23 reduces the pressure of the fuel gas to meet the specific conditions.

The mixed supply line 30 may be provided in a form branched from the vaporization supply line 20 and extended to the low pressure consumer 3. The mixed supply line 30 is provided with an ejector 31 and a suction line 40 connecting the storage tank 1 and the mixed supply line 30 to supply the fuel gas to the low pressure consumer 3 . A three-way valve is provided at a point where the mixed supply line 30 is branched from the vaporization supply line 20 so that the flow of the fuel gas supplied to the mixed supply line 30 Can be adjusted.

The ejector 31 can serve to convert the relatively high-pressure vaporized gas G3 into a low-pressure state fuel gas required by the low-pressure consumer 3. Pressure evaporation gas G2 contained in the storage tank 1 is sucked to the suction line 40 by using the vaporized gas G3 in the high pressure state as the driving force Motive of the ejector 31, And the vaporized gas G3 and the vaporized gas G2 in the high-pressure state are mixed with each other in the mixed supply line 30 to be discharged toward the low-pressure consumer 3 side. The vaporized gas G3 in the high-pressure state is a pressure of about 15 to 17 ba, the fuel gas in the low-pressure state may be in the range of about 5 to 7 bar, and the evaporated gas G2 in the storage tank 1 being sucked is approximately Can be from 0 to 1 bar. A high pressure gas vapor G3, a low pressure fuel gas gas, and a vapor gas G2.

In other words, the ejector 31 uses the fluid delivery system by momentum transfer to apply the momentum of the vaporization gas G3 in the high pressure state to the evaporation gas G2, which is sucked through the suction line 40, Can be provided. At this time, the suction line 40 may serve to transfer the evaporation gas G2 in the storage tank 1 to the ejector 31. [ The ejector 31 ejects water, air, or steam having pressure from the jet port at a high speed to attract the fluid in the vicinity of the ejector 31, and may be a kind of pump.

On the other hand, although not shown, the suction line 40 may be provided with a regulating valve for regulating the internal flow rate or pressure. The control valve (not shown) may be a flow control valve or a pressure control valve so that the evaporation gas G2 passing through the suction line 40 can be supplied to the ejector 31 at a constant pressure or flow rate.

FIG. 2 shows a first operation example of a fuel gas supply system for a ship according to an embodiment of the present invention, and FIG. 3 shows a second operation example of a fuel gas supply system for a ship according to an embodiment of the present invention. Here, in the first operation example, the operation of the first compression portion 11 is stopped when the operation is stopped due to repair or failure. In the second operation example, the operation is stopped for maintenance of the ejector 31 Respectively. ≪ / RTI >

When the operation of a part of the pressurization supply line 10 is stopped to perform the maintenance of the first compression portion 11 as in the first operation example, the evaporation gas G2 is continuously And the internal pressure of the storage tank 1 may rise excessively. In addition, even when the amount of evaporation gas G2 generated in the storage tank 1 is larger than the amount of evaporation gas G2 supplied through the pressurization supply line 10, the evaporation gas G2 is excessively accumulated in the storage tank 1 The internal pressure of the storage tank 1 can be excessively increased. Therefore, it is necessary to treat and consume the evaporated gas in the storage tank 1 when the first compressed portion 11 is maintained or when the internal pressure rises excessively over a certain range due to a large amount of evaporated gas generated.

The first connection line 50 solves this problem by allowing the ejector 31 to replace the role of the first compression section 11 on the pressurization supply line 10. [ So that the fuel gas injected into the second compression section (12) is pressurized through the ejector (31). Thus, the first connection line 50 can be used instead of the first compression unit 11, thereby reducing the power consumption of the first compression unit 11 and reducing the power consumption of the first compression unit 11 ) Can be easily adjusted. At this time, the first connection line 50 may extend toward the downstream side of the ejector 31 between the first compression section 11 and the second compression section 12.

On the other hand, in the second operation example of Fig. 3, the first compression portion 11 can be used for maintenance of the ejector 31. [ The first connection line 50 may allow fuel gas to flow from the pressurized feed line 10 to the mixed feed line 30. The fuel gas is supplied to the low-pressure consumer 3 via the first compression unit 11 instead of the ejector 31. [ Thus, the first compression unit 11 and the ejector 31 can be complementarily used through the first connection line 50.

The second connection line 60 may serve to return a part of the fuel gas flowing downstream of the ejector 31 together with the first connection line 50 when the evaporation gas G2 in the storage tank 1 is small have. As shown in FIG. 2, the ejection port side of the ejector 31 is connected to the suction line 40 so that the gas can be sufficiently supplied to the ejector 31. This solves the problem that the amount of evaporation gas generated during the ballast voyage is greatly reduced, making it difficult to constantly generate the output of the X-DF engine. To this end, the second connection line 60 may extend toward the suction line 40 between the first compression section 11 and the second compression section 12.

In addition, the second connection line 60 may be provided with a control valve 61 for controlling the pressure or the flow rate of the flowing fluid. Here, the regulating valve may be a regulating valve. The fuel gas in a low pressure state that has passed through the ejector 31 has a pressure of about 8 bar and the evaporation gas G2 is in a pressure state of about 1 bar. So as to supply the reduced pressure.

On the other hand, when supplying the fuel gas to the high-pressure consumer 2 or the low-price consumer 3, it is important to appropriately adjust the value of the MN (Metan Number) contained in the fuel gas, that is, the methane price. Here, the MN value of the evaporation gas (G2) is generally larger than that of the vaporization gas (G3) in general.

The fuel gas supply system according to an embodiment of the present invention is characterized in that the fuel gas supplied to the high-pressure consumer 2 is supplied to the mixed supply line 30, the first connection line 50 and the second compression unit 12 in sequence So that it has the appropriate MN value required by the high-pressure consumer (2). The ejector 31 mixes the evaporated gas G2 and the vaporized gas G3 to generate a fuel gas having an appropriate MN value required by the high pressure consumer 2. [ At this time, since the fuel gas supplied to the low-pressure consumer 3 also passes through the ejector 31, it has an appropriate MN value.

The third connection line 70 connects the high pressure consumer 2 and the inlet side of the low pressure consumer 3. When the flow rate to be supplied to the high pressure consumer 2 is excessive or the MN value contained in the fuel gas to be introduced into the low pressure consumer 3 is not suitable, So that the fuel gas can be supplied to the low-pressure consumer 3. To this end, the third connection line 70 may be provided with a regulating valve 71 comprising a regulator valve such as a Joule-Thomson valve.

The control unit controls the supply of the fuel gas through the pressurization supply line 10 and the vaporization supply line 20 based on the capacity of the liquefied gas G1 of the storage tank 1 or the capacity of the evaporation gas G2 of the storage tank 1 May be provided.

The control unit may include a level sensor for sensing the capacity of the liquefied gas G1 in the storage tank 1 or a pressure sensor for sensing the amount of evaporation gas G2 generated in the storage tank 1, It is possible to detect and measure any one of the capacity of the liquefied gas G1 of the storage tank 1 or the amount of the evaporation gas G2 generated in the storage tank 1 so that the supply of the fuel gas through the pressurization supply line 10 Or the supply of the fuel gas through the vaporization feed line 20 may be selectively implemented.

Concretely, when the laden voyage in which the capacity of the liquefied gas (G1) is sufficient in the storage tank 1, the evaporation gas generation amount is also sufficient. On the basis of this, when the level sensor senses that the liquefied gas capacity of the storage tank 1 is in a certain range or more, or when the pressure sensor senses that the evaporation gas generation amount of the storage tank 1 is above a certain range, the capacity of the evaporation gas G2 It is possible to increase the supply of the fuel gas to the high-pressure consumer 2 and the low-pressure consumer 3 via the pressurizing supply line 10 while reducing or stopping the supply of the fuel gas through the vaporizing supply line 20 The inefficient consumption of the liquefied gas G1 can be suppressed.

The fuel gas supply system for a ship according to an embodiment of the present invention includes the mixer 30 and the first and second compressors 11, It is possible to reduce the power consumption and easily control the redundancy of the compression section.

A first connection line 50 extending between the first compression section 11 and the second compression section 12 of the multistage to the mixing supply line 30 and a second connection line 50 extending between the first compression section 11 and the second compression section 12. [ A second connection line 60 extending between the first and second compression units 11 and 12 toward the suction line 40 may be provided so that the first compression unit 11, It can be used flexibly.

It is also possible to supply the fuel gas directly to or mixed with each customer through three paths, i.e., the pressurizing supply line 10, the vaporizing supply line 20, and the mixed supply line 30, (Metan Number) can be easily controlled

G1: Liquefied gas G2: Evaporation gas
G3: vaporized gas 1: storage tank
2: high pressure consumer 3: low pressure consumer
10: pressure supply line 11: first compression section
12: second compression section 20: vaporization supply line
21: pump 22: vaporizer
23: Control valve 30: Mixed feed line
31: Ejector 40: Suction line
50: first connection line 60: second connection line
61: regulating valve 70: third connecting line
71: Regulating valve

Claims (4)

A storage tank for storing a liquefied gas and an evaporation gas of the liquefied gas;
A pressurization supply line extending from the storage tank to a high-pressure consumer and having a first compression unit and a second compression unit sequentially connected to compress the evaporation gas stored in the storage tank and supply the compressed gas to the high-pressure consumer;
A vaporization supply line extending from the storage tank to the high-pressure consumer and having a high-pressure pump for pressurizing and discharging the liquefied gas stored in the storage tank;
A mixed supply line branched at the downstream of the high pressure pump of the vaporization supply line and extending to the low pressure consumer, and having an ejector;
A first connection line branching between the first compression section and the second compression section of the pressurization supply line and extending to the downstream of the ejector of the mixed supply line;
A second connection line branched from the first compression section and the second compression section of the pressurization supply line and extending to the suction line, the regulation valve being provided for regulating pressure or flow rate;
A third connection line extending downstream of the second compression section of the pressurization supply line and downstream of the ejector of the mixed supply line and having a regulating valve for regulating a pressure or a flow rate; And
And a suction line extending from the storage tank to the ejector and supplying the evaporator gas stored in the storage tank to the ejector,
The ejector is used by stopping the use of the first compression portion at the time of a full voyage and allowing the flow of the fluid to the mixed supply line instead,
Wherein the first compression unit, the second compression unit, or the ejector can be selectively used according to the navigation mode. delete delete delete

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