KR102153302B1 - Lng vaporization apparatus and gas lubrication system for ship using lng, and operation method of ship using lng - Google Patents

Abstract

(Task) Provide an LNG vaporization device and a gas lubrication system for ships using LNG capable of reducing energy consumption for supplying gas to an outlet formed in the hull, and a method of operating a ship using LNG.
(Solution) The LNG vaporization device for ships using LNG is formed on a gas supply line for supplying gas to an outlet formed in the hull, and flows through an LNG line connected to an LNG tank of an LNG carrier, and a gas supply line. And a heat exchanger configured to heat exchange the gas flowing therethrough.

Description

LNG vaporization system and gas lubrication system for ships using LNG, and operation method of ships using LNG {LNG VAPORIZATION APPARATUS AND GAS LUBRICATION SYSTEM FOR SHIP USING LNG, AND OPERATION METHOD OF SHIP USING LNG}

The present disclosure relates to an LNG vaporization device for vaporizing LNG in a ship using LNG, a gas lubrication system for taking out gas from the hull of a ship, and a method of operating a ship using LNG.

As a type of ship sailing using the output from an engine, an LNG carrier carrying LNG, which is a low-temperature liquid fuel, or an LNG fuel ship using vaporized LNG, is known. For example, in an LNG carrier, a boil-off gas (BOG) in a tank storing LNG is used as fuel for the engine. In particular, in a dual fuel engine, when the engine output is increased, the amount of fuel supplied to the engine is increased by using the vaporized gas generated by forcibly evaporating part of the LNG stored in the tank in addition to the boil-off gas.

By the way, as a technique for reducing the frictional resistance acting on the hull during navigation, there is known a gas lubrication system that covers the outer surface of the hull with bubbles by ejecting gas from an outlet formed in the hull. For example, Patent Literature 1 discloses a gas lubrication system capable of uniformizing the amount of air blown out from the outlet even when an inclination occurs in the hull due to rolling during navigation. In addition, Patent Document 2 discloses a gas lubrication system capable of controlling the amount of air taken out from the outlet according to the amount of change in the case where the draft is changed depending on the amount of loading on the ship.

Japanese Unexamined Patent Publication No. 2012-166704 Japanese Patent Application Publication No. 2013-091376

When the gas lubrication system as described above is applied to a ship with a large draft, the water pressure at the outlet from which the gas is taken out increases, and thus the energy consumption for discharging the gas by resisting the water pressure increases. As a result, there is a concern that it becomes difficult to sufficiently enjoy the energy saving effect by reducing the frictional resistance by the gas lubrication system.

At least one embodiment of the present invention has been made in view of the above-described circumstances, and includes an LNG vaporization device and a gas lubrication system for ships using LNG capable of reducing energy consumption for supplying gas to an outlet formed in the hull, and LNG. The purpose of this is to provide a method of operating a vessel used.

(1) In order to solve the above problems, the LNG vaporization apparatus for ships using LNG according to at least one embodiment of the present invention,

As an LNG vaporization device for ships using LNG to vaporize LNG,

Heat exchange configured to heat exchange the LNG flowing through the LNG line connected to the LNG tank of the ship and the gas flowing through the gas supply line formed on a gas supply line for supplying gas to an outlet formed in the ship's hull It has a flag.

According to the configuration of the above (1), when LNG flowing through the LNG line in the heat exchanger is vaporized, the gas flowing through the gas supply line is cooled by heat exchange with LNG. As the temperature of the gas flowing through the gas supply line decreases in this way, energy consumption for supplying the gas to the outlet formed in the hull of the ship is reduced.

(2) In some embodiments, in the configuration of (1),

It has an LNG forced evaporation line formed in parallel with the gas supply line,

The heat exchanger,

Between the gas flowing through the gas supply line and the heat medium flowing through the LNG forced evaporation line, the medium exchanged with the LNG flowing through the LNG line can be switched.

According to the configuration of (2), even when the flow of gas from the gas supply line toward the outlet is stopped by exchanging heat between the LNG flowing through the LNG line and the heating medium flowing through the forced evaporation line, the vaporization of LNG can be continued.

(3) In some embodiments, in the configuration of (2),

A circulation device formed in the LNG forced evaporation line and for circulating the heat medium;

It is formed in the LNG forced evaporation line, and includes a heater for heating the heat medium.

According to the configuration of the above (3), in the forced evaporation line, the heat medium heated by the heater is circulated by the circulation device. Thereby, when LNG flowing through the LNG line is heat-exchanged with the heat medium flowing through the forced evaporation line, heat energy can be continuously and stably supplied from the heat medium flowing through the forced evaporation line, whereby LNG can be reliably vaporized.

(4) In order to solve the above problem, the gas lubrication system for ships using LNG according to at least one embodiment of the present invention,

The gas supply line extending to the outlet by passing through the inside of the heat exchanger of the LNG vaporization device of any one of the above (1) to (3),

And a first blower formed between the heat exchanger and the outlet on the gas supply line.

According to the configuration of the above (4), the gas flowing through the gas supply line passing through the inside of the heat exchanger is cooled by heat exchange with LNG flowing through the LNG line. As a result, since the temperature of the gas supplied to the first blower formed between the heat exchanger and the outlet (i.e., downstream of the heat exchanger) on the gas supply line is lowered, energy consumption in the first blower can be effectively reduced. .

(5) In some embodiments, in the configuration of (4),

A discharge line branched from the gas supply line on a downstream side of the heat exchanger and communicated with a discharge port formed at a lower pressure side than the discharge port is provided.

According to the configuration of the above (5), the gas flowing through the gas supply line is discharged from the discharge port through the discharge line, so that the ejection of the gas from the discharge port can be stopped. Since the discharge port is formed on the lower pressure side than the discharge port, the consumption energy required to take out gas is less than that of the discharge port. Therefore, energy consumption can be suppressed even under a situation in which the ejection of gas from the outlet is stopped.

(6) In some embodiments, in the configuration of (5),

A parallel line formed in parallel with the gas supply line upstream of the branch point of the gas supply line with the discharge line,

A second blower is installed on the parallel line and has a lower output than the first blower.

According to the configuration of the above (6), the discharge of gas through the discharge line can be performed by the second blower formed on the parallel line. Since the second blower has a smaller output than the first blower, the energy consumption required for discharge can be lowered.

(7) In some embodiments, in any of the configurations (4) to (6),

And a bypass line formed in parallel with the gas supply line and bypassing the heat exchanger.

According to the configuration of the above (7), the pressure loss occurring when the gas passes through the heat exchanger can be avoided by inducing the gas flowing through the gas supply line to the bypass line. By allowing the gas to flow so as to bypass the heat exchanger by such a bypass line, energy consumption when operating the gas lubrication system while stopping the vaporization of LNG in the LNG vaporizer can be suppressed to a low level.

(8) In some embodiments, in any of the configurations (4) to (7),

And a cooling gas supply line branching from a downstream side of the heat exchanger among the gas supply lines and communicating with at least one of an intake passage of an engine mounted on the LNG carrier or an engine room in which the engine is accommodated.

According to the configuration (8) above, the gas cooled by heat exchange with LNG in the heat exchanger is supplied to at least one of the engine intake passage or the engine room through the cooling gas supply line. Thereby, it becomes possible to reduce engine power by cooling the intake air of the engine, or to reduce power for cooling the engine room.

(9) In some embodiments, in any of the configurations (4) to (8),

The gas supply line is configured to supply the exhaust of an engine mounted on the LNG carrier as the gas toward the outlet.

According to the configuration of (9) above, exhaust from the engine is supplied to the gas supply line. As a result, since exhaust with high temperature and pressure is introduced into the heat exchanger, LNG can be vaporized efficiently and downsizing of the heat exchanger is possible. Further, by introducing high-pressure exhaust into the gas supply line, energy consumption required for ejecting the gas from the air outlet can be reduced.

(10) In order to solve the above problems, the method of operating a ship using LNG according to at least one embodiment of the present invention,

A step of flowing gas through the gas supply line toward the outlet formed at the hull of the LNG carrier;

Vaporizing the LNG flowing through the LNG line connected to the LNG tank of the LNG carrier by heat exchange with the gas flowing through the gas supply line;

At least, there is provided a step of operating the engine of the LNG carrier by using the vaporized gas obtained by vaporizing the LNG as fuel.

According to the method of (10) above, by flowing gas through the gas supply line toward the discharge port formed in the hull of the ship, air bubbles covering the outer surface of the ship body are generated by the gas ejected from the discharge port, and friction of the ship body during navigation Resistance can be reduced. On the other hand, LNG flowing through the LNG line becomes vaporized gas by heat exchange with the gas flowing through the gas supply line, and is supplied to the engine. At this time, since the gas flowing through the gas supply line is cooled by heat exchange with LNG to lower the temperature, energy consumption for supplying the gas to the outlet formed in the ship's hull can be reduced.

(11) In some embodiments, in the method of (10),

And a step of vaporizing the LNG by heat exchange between the heat medium flowing through the LNG forced evaporation line formed in parallel with the gas supply line and the LNG when the supply of the gas to the outlet is stopped.

According to the method (11), even when the supply of gas to the outlet is stopped, the vaporization of LNG can be continued by exchanging heat between the LNG flowing through the LNG line and the heat medium flowing through the forced evaporation line.

(12) In some embodiments, in the method of (10) or (11),

A step of discharging the gas heat-exchanged with the LNG to an outlet formed at a lower pressure side than the outlet through an outlet line branched from the gas supply line when the ejection of the gas from the outlet is stopped. .

According to the method of (12), when the ejection of gas from the outlet is stopped, the gas exchanged with LNG is discharged from the outlet through the discharge line. Since the discharge port is formed on the lower pressure side than the discharge port, the consumption energy required to take out gas is minimal compared to the discharge port.

(13) In some embodiments, in any one of the above (10) to (12),

And supplying the gas heat-exchanged with the LNG to at least one of an intake passage of an engine mounted on the ship or an engine room in which the engine is accommodated.

According to the method of (13), the gas cooled by heat exchange with LNG in the heat exchanger is supplied to at least one of the engine intake passage or the engine room. Thereby, it becomes possible to reduce engine power by cooling the intake air of the engine, or to reduce power for cooling the engine room.

(14) In some embodiments, in any one of the above (10) to (13),

And a step of flowing exhaust from the engine of the ship as the gas in the gas supply line.

According to the method of (14) above, exhaust from the engine is supplied to the gas supply line. As a result, since exhaust with high temperature and pressure is introduced into the heat exchanger, LNG can be vaporized efficiently and downsizing of the heat exchanger is possible. Further, by introducing high-pressure exhaust into the gas supply line, energy consumption required for ejecting the gas from the air outlet can be reduced.

(15) In some embodiments, in any one of the above (10) to (14),

And a step of ejecting the gas heat-exchanged with the LNG from the outlet by a first blower formed in the gas supply line on a downstream side of a heat exchanger in which heat exchange between the LNG and the gas is performed.

According to the method of (15) above, the gas cooled by heat exchange with LNG is ejected from the air outlet by the first blower formed in the gas supply line downstream from the heat exchanger. Thereby, since the temperature of the gas supplied to the first blower is lowered, energy consumption in the first blower can be effectively reduced.

(16) In some embodiments, in any one of the above (10) to (15),

When the engine is operated using only the boil-off gas from the LNG tank as fuel, a step of bypassing a heat exchanger for performing heat exchange between the LNG and the gas, and supplying the gas to the outlet.

According to the method (16) above, when the engine is operated using only the boil-off gas from the LNG tank as fuel, the vaporization of LNG flowing through the LNG line is stopped. In this case, the gas flowing through the gas supply line bypasses the heat exchanger and is guided to the outlet. Thereby, since the pressure loss generated when the gas flowing through the gas supply line passes through the heat exchanger can be avoided, energy consumption can be lowered.

According to at least one embodiment of the present invention, an LNG vaporization device and a gas lubrication system for ships using LNG capable of reducing energy consumption for supplying gas to an outlet formed in the hull, and a method of operating a ship using LNG are provided. I can.

1 is a schematic diagram showing the internal structure of an LNG carrier including an LNG vaporization device according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing a method of operating the LNG carrier of FIG. 1 for each process.
Fig. 3 is a schematic diagram showing the internal structure of an LNG carrier including an LNG vaporizing device according to a second embodiment of the present invention.
4 is a flowchart showing a method of operating the LNG carrier of FIG. 3 for each process.
Fig. 5 is a schematic diagram showing the internal structure of an LNG carrier including an LNG vaporization device according to a third embodiment of the present invention.
6 is a flowchart showing a method of operating the LNG carrier of FIG. 5 for each process.
Fig. 7 is a schematic diagram showing the internal structure of an LNG carrier including an LNG vaporization device according to a fourth embodiment of the present invention.
8 is a flow chart showing the operation method of the LNG carrier of FIG. 7 for each process.
Fig. 9 is a schematic diagram showing the internal structure of an LNG carrier including an LNG vaporization device according to a fifth embodiment of the present invention.
Fig. 10 is a schematic diagram showing the internal structure of an LNG carrier including an LNG vaporization device according to a sixth embodiment of the present invention.
Fig. 11 is a schematic diagram showing the internal structure of an LNG carrier equipped with an LNG vaporization device according to a reference technology.

Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, dimensions, materials, shapes, relative arrangements, etc. of constituent parts described as embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, but are merely illustrative examples.

For example, expressions representing relative or absolute arrangements such as “in which direction”, “along which direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly related to It is assumed that not only the same arrangement is shown, but also a state in which the tolerance is relatively displaced by an angle or distance such that the same function can be obtained.

Further, for example, an expression indicating a shape such as a square shape or a cylindrical shape not only indicates a shape such as a square shape or a cylindrical shape in a geometrical strict sense, but also includes an uneven portion or a chamfered portion within the range in which the same effect is obtained. The shape to be included is also shown.

On the other hand, the expression "have", "have", "have", "include", or "have" one component is not an exclusive expression excluding the existence of another component.

<Reference technology>

In this specification, before describing a specific embodiment of the present invention, a reference technique that is premised will be described. 11 is a schematic diagram showing the internal structure of an LNG carrier 1 which is an example of a ship using LNG equipped with an LNG vaporization device 10 according to a reference technology.

In addition, in the following description, an LNG carrier 1 is described as an example of a ship using LNG, but at least one embodiment of the present invention is similar to other ships using LNG, for example, LNG fuel ships, etc. Applicable.

The LNG carrier 1 is a ship for conveying LNG which is a low temperature liquid fuel. The LNG carrier 1 is equipped with an LNG tank 2 capable of storing LNG as a transport object, and LNG is stored in a high-pressure liquid state in the LNG tank 2. The LNG tank 2 has a substantially spherical shape, and the liquid level of the liquid LNG stored therein is filled with a boil-off gas 4 obtained by evaporating LNG.

The LNG carrier 1 is equipped with an engine 6 that uses LNG vaporized gas as a fuel as a power source for navigation. On the intake side of the engine 6, a boil-off gas supply line 8 connected to the upper part of the LNG tank 2 is connected, and the boil-off gas in the LNG tank 2 can be supplied to the engine 6 as fuel. Is structured.

The engine 6 is a dual fuel engine, and in the case of raising the engine power, in addition to the boil-off gas supplied through the boil-off gas supply line 8, part of the LNG stored in the LNG tank 2 is added as needed. It is configured to be able to supply vaporized gas generated by forcibly evaporating. Specifically, by the LNG line 12 connected to the lower part of the LNG tank 2, a part of the LNG stored in the LNG tank 2 is introduced into the LNG vaporization apparatus 10, and the LNG vaporization apparatus 10 The vaporized gas of LNG generated by this is configured to be able to be supplied to the intake side of the engine 6 via the vaporized gas supply line 14.

In the following description, a dual fuel engine is exemplified as the engine 6, but the engine 6 can include the whole engine using vaporized LNG as fuel.

The LNG vaporization device 10 includes a heat medium flowing through the LNG forced evaporation line 16 and a heat exchanger 18 configured to allow heat exchange of LNG flowing through the LNG line 12. On the LNG forced evaporation line 16, a pump 20 which is a circulation device for circulating the heat medium in a closed circuit, and a heater 22 for heating the heat medium are provided. In the LNG vaporization apparatus 10, the heat medium heated by the heater 22 circulates the LNG forced evaporation line 16 by the pump 20, so that LNG flowing through the LNG line 12 in the heat exchanger 18 By heating the vaporized gas is generated.

Further, on the intake side of the engine 6, a compressor 24 for compressing the boil-off gas supplied through the boil-off gas supply line 8 and the vaporized gas supplied from the vaporized gas supply line 14 is disposed. Has been.

Further, the LNG carrier 1 is equipped with a gas lubrication system 26 for reducing frictional resistance acting on the hull during navigation. The gas lubrication system 26 ejects gas from an outlet 28 formed in the hull (not shown) of the LNG carrier 1 into the water, thereby covering the outer surface of the hull with air bubbles, thereby acting on the hull during navigation. Reduce resistance.

In addition, the position of the outlet 28 in the hull of the LNG carrier 1 may be arbitrary, but the outlet 28 is formed at the bottom of the ship, for example.

The gas lubrication system 26 has a gas supply line 30 for supplying gas to the air outlet 28. The gas supply line 30 communicates with an inlet 32 for injecting gas and an outlet 28 formed in the hull. In the present embodiment, the intake port 32 is formed so as to be open to the inside of a ship or deck at atmospheric pressure, and is configured to allow air in the atmosphere to be blown as a gas that can be blown out from the outlet port 28.

Further, in the gas supply line 30, a first blower 34 is provided as a blower for conveying the gas blown into the gas supply line 30. The first blower 34 is a blowing device capable of being driven by electric power supplied from an electric power supply source (not shown). When the first blower 34 is driven, gas (air from the atmosphere) is blown from the inlet 32, and the gas flows through the gas supply line 30 toward the outlet 28.

In this way, in the LNG carrier 1 related to the reference technology, the LNG vaporization device 10 and the gas lubrication system 26 are mounted as mutually independent systems (different systems). In such an LNG carrier 1, when the energy (power) consumed by the first blower 34 increases when operating the gas lubrication system 26, energy due to reduction of frictional resistance by the gas lubrication system 26 There is a fear that it becomes difficult to fully enjoy the saving effect. In particular, in a ship with a large draft such as the LNG carrier 1, the water pressure in the outlet 28 from which the gas is taken out increases, so that the energy consumption for taking out the gas against the water pressure is likely to increase.

The problem in such a reference technique can be suitably solved in each embodiment described below. In addition, in each of the embodiments described below, a common reference numeral is assigned to a configuration corresponding to the above-described reference description, and overlapping descriptions are omitted unless otherwise specified.

<First embodiment>

1 is a schematic diagram showing the internal structure of an LNG carrier 1 including an LNG vaporizing device 10 according to a first embodiment of the present invention.

The LNG vaporization device 10 includes a heat exchanger 36 configured to allow heat exchange between gas flowing through the gas supply line 30 of the gas lubrication system 26 and LNG flowing through the LNG line 12. In the above-described reference technique, the gas supply line 30 of the gas lubrication system 26 and the LNG line 12 of the LNG vaporization device 10 were configured as mutually independent systems (different systems). In the form, the gas supply line 30 of the gas lubrication system 26 and the LNG line 12 of the LNG vaporization device 10 are mounted on a common heat exchanger 36 to constitute an integrated heat exchange system. In short, the heat exchanger 36 includes the gas supply line 30 of the gas lubrication system 26 and the LNG line 12 of the LNG vaporization device 10. In other words, the gas supply line 30 passes through the inside of the heat exchanger 36 of the LNG vaporization device 10 and extends to the outlet 28.

As described above, in the present embodiment, the LNG vaporization device 10 and the gas lubrication system 26 are constructed as a substantially integrated system, and the LNG forced evaporation line 16 and the pump ( 20) and the heater 22 can be made unnecessary. Therefore, the system size may be small, and good design freedom is obtained.

FIG. 2 is a flowchart showing a method of operating the LNG carrier 1 of FIG. 1 for each process.

In the LNG carrier 1, in accordance with the operating state of the gas lubrication system 26, gas flows through the gas supply line 30 toward the air outlet 28 formed in the hull (step S10). The flow of gas in such a gas supply line 30 is formed by operating the first blower 34 formed in the gas supply line 30. The gas flowing through the gas supply line 30 is ejected into the water from the air outlet 28 as necessary, thereby covering the outer surface of the hull with air bubbles and reducing frictional resistance acting on the hull during navigation.

In the LNG line 12, in accordance with the output state of the engine 6, the LNG introduced from the LNG tank 2 to the LNG vaporization device 10 is passed through the gas supply line 30 in the heat exchanger 36. It is vaporized by heat exchange with flowing gas (step S11). That is, in the heat exchanger 36, the LNG flowing through the LNG line 12 is heated by the gas flowing through the gas supply line 30, thereby generating a vaporized gas.

In the heat exchange of step S11, the gas flowing through the gas supply line 30 is cooled by the LNG flowing through the LNG line 12. Since the gas cooled by the heat exchanger 36 is conveyed to the first blower 34 in this way, energy consumption in the first blower 34 is reduced.

The vaporized gas generated by the heat exchanger 36 is conveyed to the engine 6 through the vaporized gas supply line 14 according to the output state of the engine 6. The vaporized gas transferred to the engine 6 is supplied as fuel to the intake side of the engine 6 together with the boil-off gas transferred through the boil-off gas supply line 8, and the engine 6 is operated. It becomes (step S12).

As described above, according to the first embodiment, when LNG flowing through the LNG line 12 in the heat exchanger 36 is vaporized, the gas flowing through the gas supply line 30 is cooled by heat exchange with LNG. As the temperature of the gas flowing through the gas supply line 30 decreases in this way, energy consumption for supplying the gas to the outlet 28 formed at the hull of the LNG carrier 1 is reduced.

<2nd embodiment>

3 is a schematic diagram showing an internal structure of an LNG carrier 1 including an LNG vaporization device 10 according to a second embodiment of the present invention.

In this embodiment, compared with the first embodiment described above, the LNG forced evaporation line 16 is provided in parallel with the gas supply line 30. The LNG forced evaporation line 16 has the same configuration as the reference technology, and on the LNG forced evaporation line 16, a pump 20 which is a circulation device for circulating the heat medium in a closed circuit, and a heater for heating the heat medium (22) is installed.

In the forced evaporation line 16, the heat medium heated by the heater 22 circulates by the pump 20. In this way, when LNG flowing through the LNG line 12 is heat-exchanged with the heating medium flowing through the forced evaporation line 16, heat energy is continuously and stably supplied from the heating medium flowing through the forced evaporation line 16, thereby ensuring the vaporization of LNG. It becomes possible to implement.

The heat exchanger 36 is configured to be capable of switching between the gas flowing through the gas supply line 30 and the heat medium flowing through the LNG forced evaporation line 16, the medium to be heat-exchanged with the LNG flowing through the LNG line 12. Such a switching operation is performed, for example, by manually or automatically controlling a flow path switching valve (not shown). In short, in this embodiment, when the LNG flowing through the LNG line 12 is vaporized, the LNG forced evaporation line 16 replaces the gas flowing through the gas supply line 30 similar to the first embodiment as a heat exchange object with LNG. ) It is composed to be able to use the heating medium flowing through.

4 is a flow chart showing a method of operating the LNG carrier 1 of FIG. 3 for each process.

In accordance with the state of the LNG carrier 1, it is judged whether or not the supply of gas to the outlet 28 is stopped (step S20). When it is determined that the supply of gas to the air outlet 28 is stopped (step S20: YES), the flow of gas in the gas supply line 30 is stopped by stopping the first blower 34 (step S21). . Thereby, the gas lubrication system 26 is brought to a standstill.

Subsequently, the target for heat exchange with the LNG line 12 in the heat exchanger 36 is switched from the gas supply line 30 to the LNG forced evaporation line 16 (step S22). In the heat exchanger 36, the heat medium flowing through the LNG forced evaporation line 16 and the LNG flowing through the LNG line 12 are heat-exchanged to vaporize LNG (step S23).

As described above, in this embodiment, even when the supply of gas to the outlet 28 is stopped, LNG flowing through the LNG line 12 can be vaporized by heat exchange with the heat medium flowing through the forced evaporation line 16. In the forced evaporation line 16, since the heat medium heated by the heater 22 circulates by the pump 20, heat energy is continuously and stably supplied from the heat medium flowing through the forced evaporation line 16, thereby evaporating LNG. It can be done with certainty.

In addition, when it is determined that the supply of gas to the outlet 28 is not stopped (step S20: NO), the LNG flowing through the LNG line 12 is the gas supply line 30 as in the first embodiment described above. It is vaporized by heat exchange with the gas flowing through the air.

<3rd embodiment>

5 is a schematic diagram showing the internal structure of an LNG carrier 1 including an LNG vaporization device 10 according to a third embodiment of the present invention.

In this embodiment, a discharge line 38 branched from the gas supply line 30 on the downstream side of the heat exchanger 36 is provided. The discharge line 38 communicates with the discharge port 40 formed on the lower pressure side than the discharge port 28, and is configured to be able to switch the connection state to the gas supply line 30 by a switching valve (not shown). Here, the outlet 40 is a hole capable of blowing gas into a space having a lower pressure than the outlet 28, for example, may be formed on the outer surface of the hull or on the deck above the outlet 28, and the outlet 28 ), it may be formed in a space filled with the atmosphere (such as a cabin) inside the ship. In addition, the pressure in the outlet 40 may be lower than the water pressure in the outlet 28, but may be atmospheric pressure, for example.

When the ejection of gas from the outlet 28 is stopped (regardless of the operating state of the LNG vaporization device 10), the gas in the gas supply line 30 passes through the discharge line 38 as described above. 40) can be discharged from. Since the discharge port 40 is formed on the lower pressure side than the discharge port 28, the consumption energy required to take out gas is minimal compared to the discharge port 28.

Further, a parallel line 46 formed in parallel with the gas supply line 30 is formed on the upstream side of the gas supply line 30 from the branch point 44 with the discharge line 38. On the parallel line 46, a second blower 48 having a smaller output than the first blower 34 is provided. The parallel line 46 is configured to be able to switch the connection state to the gas supply line 30 by a flow path switching valve not shown.

When the gas in the gas supply line 30 is discharged from the outlet 40, the flow path switching valve is controlled so that the parallel line 46 communicates with the gas supply line 30, and on the parallel line 46 The second blower 48 may be operated. Thereby, since the gas can be discharged by the operation of the second blower 48, which has a smaller output than the first blower 34, the energy consumption required for discharge can be lowered.

6 is a flow chart showing a method of operating the LNG carrier 1 of FIG. 5 for each process.

First, depending on the state of the LNG carrier 1, it is determined whether or not the ejection of the gas from the outlet 28 is stopped (step S30). When it is determined that the ejection of the gas from the outlet 28 is stopped (step S30: YES), the exhaust line 38 is communicated with the gas supply line 30 by switching control of a flow path switching valve (not shown) (step S30: YES). S31).

Thereafter, the parallel line 46 is communicated with the gas supply line 30 by switching control of the flow path switching valve (not shown) (step S32). Then, while stopping the first blower 34 (step S33), the second blower 48 on the parallel line 46 is operated (step S34). Thereby, the gas in the gas supply line 30 is discharged through the discharge line 38 without being blown out from the outlet 28. Since the second blower 48 has a smaller output than the first blower 34 as described above, the discharge using the second blower 48 requires minimal energy consumption.

<4th embodiment>

7 is a schematic diagram showing the internal structure of an LNG carrier 1 including an LNG vaporization device 10 according to a fourth embodiment of the present invention.

In this embodiment, a bypass line 50 formed in parallel with the gas supply line 30 and bypassing the heat exchanger 36 is provided. The bypass line 50 is configured to connect the upstream side and the downstream side of the heat exchanger 36 among the gas supply lines 30, and at least one of both ends thereof is provided with a flow path switching valve for switching a flow path. Has been. The flow path switching valve is configured so that the gas flowing through the gas supply line 30 can bypass the heat exchanger 36 by being operated manually or by a control signal from a controller (not shown).

FIG. 8 is a flowchart showing the operation method of the LNG carrier 1 of FIG. 7 for each process.

First, according to the state of the LNG carrier 1, it is judged whether or not vaporization of LNG in the LNG vaporization apparatus 10 is stopped (step S40). When it is determined that the vaporization of LNG in the LNG vaporization device 10 is stopped (step S40: YES), the gas flowing through the gas supply line 30 is transferred to the bypass line 50 by switching and controlling the flow path switching valve (not shown). ), the flow path is switched (step S41). Thereby, the gas flowing through the gas supply line 30 does not pass through the heat exchanger 36 but is guided to the air outlet 28 through the bypass line 50. As a result, since the pressure loss generated when the gas flowing through the gas supply line 30 passes through the heat exchanger 36 can be avoided, energy consumption is reduced. Thus, in this embodiment, even in the state where vaporization of LNG in the LNG vaporization device 10 is stopped, the operation of the gas lubrication system 26 can be continued while suppressing energy consumption.

<Fifth Embodiment>

9 is a schematic diagram showing an internal structure of an LNG carrier 1 including an LNG vaporization device 10 according to a fifth embodiment of the present invention.

In the present embodiment, the gas supply line 30 branches from the downstream side of the heat exchanger 36, and the intake passage of the engine 6 mounted on the LNG carrier 1 or the engine room in which the engine 6 is accommodated ( A cooling gas supply line 54 communicating with at least one of 52) is provided. Therefore, the gas cooled by heat exchange with LNG in the heat exchanger 36 is supplied to at least one of the intake passage of the engine 6 or the engine room 52 via the cooling gas supply line 54. Thereby, the engine power can be reduced by cooling the intake air of the engine 6, or the power for cooling the engine room 52 can be reduced.

<Sixth Embodiment>

Fig. 10 is a schematic diagram showing the internal structure of an LNG carrier 1 including an LNG vaporization device 10 according to a sixth embodiment of the present invention.

In the present embodiment, the gas supply line 30 is configured to supply exhaust gas from the engine 6 mounted on the LNG carrier 1 toward the air outlet 28 as gas. In short, the exhaust passage of the engine 6 is connected to the inlet 32 of the gas supply line 30 through the exhaust supply line 56, so that the exhaust of the engine 6 is connected to the gas supply line 30. It is made available for supply. Thereby, since exhaust with high temperature and pressure is introduced into the heat exchanger 36, the vaporization of LNG can be performed more efficiently in the heat exchanger 36, and the downsizing of the heat exchanger 36 becomes possible. . In addition, since high-pressure exhaust is introduced into the gas supply line 30, energy consumption required for ejecting the gas from the air outlet 28 can also be reduced.

As described above, according to at least one embodiment of the present invention, the LNG vaporization device 10 and the gas lubrication system for an LNG carrier 1 capable of reducing energy consumption for supplying gas to the outlet 28 formed in the hull 26) And, it is possible to provide a method of operating an LNG carrier (1).

Further, various operations relating to the LNG carrier 1 described above may be performed manually or may be performed automatically and controlled by a controller (not shown). In the latter case, the controller is configured by, for example, an electronic computing device such as a computer, and a program related to the control contents is installed, so that various controls can be performed. Further, such a program may be recorded on a recording medium, or the controller may be configured by reading the recording medium by an electronic computing device.

At least one embodiment of the present invention is applicable to an LNG vaporization device for vaporizing LNG in a ship using LNG, a gas lubrication system for taking out gas from the hull of a ship using LNG, and a method of operating an LNG carrier. .

1: LNG carrier
2: LNG tank
4: Boil-off gas
6: engine
8: Boil-off gas supply line
10: LNG vaporizer
12: LNG line
14: vaporized gas supply line
16: forced evaporation line
18, 36: heat exchanger
20: pump
22: heater
24: compressor
26: gas lubrication system
28: outlet
30: gas supply line
32: inlet
34: first blower
38: discharge line
40: outlet
44: branch point
46: parallel line
48: 2nd blower
50: bypass line
52: engine room
54: cooling gas supply line
56: exhaust supply line

Claims (16)

As a gas lubrication system for ships using LNG,
A gas supply line for supplying gas to an outlet formed in the hull of the ship,
A heat exchanger formed on the gas supply line and configured to heat exchange the LNG flowing through the LNG line connected to the LNG tank of the LNG carrier and the gas flowing through the gas supply line,
The gas supply line passes through the inside of the heat exchanger of the LNG vaporization device for vaporizing LNG and extends to the outlet,
The gas supply line is provided with a first blower formed between the heat exchanger and the outlet on the gas supply line, a gas lubrication system for ships using LNG. The method of claim 1,
It has an LNG forced evaporation line formed in parallel with the gas supply line,
The heat exchanger,
A gas lubrication system for ships using LNG, configured to be capable of switching between the gas flowing through the gas supply line and a heat medium flowing through the LNG forced evaporation line. The method of claim 2,
A circulation device formed in the LNG forced evaporation line and for circulating the heat medium;
A gas lubrication system for ships using LNG, provided in the LNG forced evaporation line and provided with a heater for heating the heat medium. The method of claim 1,
A gas lubrication system for ships using LNG, comprising a discharge line branching from the gas supply line on a downstream side of the heat exchanger and communicating with an outlet formed on a lower pressure side than the outlet. The method of claim 4,
A parallel line formed in parallel with the gas supply line upstream of the branch point of the gas supply line with the discharge line,
A gas lubrication system for ships using LNG, comprising a second blower installed on the parallel line and having a smaller output than the first blower. The method of claim 1,
A gas lubrication system for ships using LNG, which is formed in parallel with the gas supply line and includes a bypass line that bypasses the heat exchanger when vaporization of the LNG is stopped. The method of claim 1,
For ships using LNG having a cooling gas supply line branching from the downstream side of the heat exchanger among the gas supply lines and communicating with at least one of the intake passage of the engine mounted on the ship or the engine room in which the engine is accommodated Gas lubrication system. The method of claim 1,
The gas supply line is configured to supply the exhaust of an engine mounted on the ship toward the outlet as the gas, and a gas lubrication system for a ship using LNG. A step of flowing gas through a gas supply line toward an outlet formed in the hull of a ship using LNG;
Vaporizing the LNG flowing through the LNG line connected to the LNG tank of the LNG carrier by heat exchange with the gas flowing through the gas supply line;
At least, a method of operating a ship using LNG, comprising a step of operating the engine of the ship by using the vaporized gas obtained by vaporizing the LNG as fuel. The method of claim 9,
LNG comprising a step of vaporizing the LNG by heat exchange between the LNG and a heat medium flowing through an LNG forced evaporation line formed in parallel with the gas supply line when the supply of the gas to the outlet is stopped. How to drive the ship you use. The method of claim 9 or 10,
A step of discharging the gas heat-exchanged with the LNG to an outlet formed at a lower pressure side than the outlet through an outlet line branched from the gas supply line when the ejection of the gas from the outlet is stopped. , How to operate a ship using LNG. The method of claim 9,
And supplying the gas heat-exchanged with the LNG to at least one of an intake passage of an engine mounted on the LNG carrier or an engine room in which the engine is accommodated. The method of claim 9,
A method of operating a ship using LNG, comprising the step of causing exhaust from an engine of the LNG carrier to flow as the gas to the gas supply line. The method of claim 9,
A ship using LNG having a step of ejecting the gas heat-exchanged with the LNG from the outlet by a first blower formed in the gas supply line on a downstream side of a heat exchanger in which heat exchange between the LNG and the gas is performed Way of driving. The method of claim 9,
When the engine is operated using only the boil-off gas from the LNG tank as fuel, the LNG is provided with a step of supplying the gas to the outlet by bypassing a heat exchanger for performing heat exchange between the LNG and the gas. How to drive the ship you use. delete

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