KR20160027550A - A Fuel Gas Supply System of Liquefied Natural Gas - Google Patents

Abstract

The present invention relates to an LNG fuel supply system. The LNG fuel supply system includes: a fuel supply line connected from an LNG storage tank to an engine; an auxiliary storage tank storing LNG discharged from the LNG storage tank; a boosting pump pressurizing the LNG discharged from the auxiliary storage tank; a high pressure pump pressurizing the LNG discharged from the boosting pump at a high pressure; a heat exchange device heating the LNG of the high pressure supplied from the high pressure pump; a collection line connected between the high pressure pump and the heat exchange device and raising an inner pressure of the auxiliary storage tank by collecting a part of the LNG of the high pressure in the auxiliary storage tank; and a detour line supplying the LNG of the high pressure discharged from the auxiliary storage tank in which the inner pressure rises, by the high pressure pump. According to the present invention, the LNG fuel supply system raises the inner pressure of the auxiliary storage tank by collecting the LNG of the high pressure in the auxiliary storage tank through the collection line connected between the high pressure pump and the heat exchange device and directly supplies the LNG of the high pressure from the auxiliary storage tank by the high pressure pump through the detour line connected between the auxiliary storage tank and the high pressure tank. The LNG fuel supply system can smoothly supply the LNG of a required fluid rate to the high pressure pump when a boosting pump cannot be normally operated. Therefore, a vessel can be operated in an emergency situation in which the boosting pump is not operated.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an LNG fuel supply system,

The present invention relates to an LNG fuel supply system.

A ship is a means of transporting large quantities of minerals, crude oil, natural gas, or several thousand containers. It is made of steel and buoyant to float on the water surface. The thrust generated by rotation of the propeller ≪ / RTI >

Such a vessel generates thrust by driving the engine. In this case, the engine uses gasoline or diesel to move the piston so that the crankshaft is rotated by the reciprocating movement of the piston, so that the shaft connected to the crankshaft is rotated to drive the propeller It was common.

In recent years, however, LNG fuel supply systems for driving an engine using LNG as a fuel have been used in an LNG carrier carrying Liquefied Natural Gas (LNG) It is also applied to other ships.

Generally, it is known that LNG is a clean fuel and its reserves are more abundant than petroleum, and its usage is rapidly increasing as mining and transfer technology develops. This LNG is generally stored in a liquid state at a temperature of -162 ° C. or below under 1 atm. The volume of liquefied methane is about one sixth of the volume of methane in a gaseous state, The specific gravity is 0.42, which is about one half of that of crude oil.

However, the temperature and pressure required to drive the engine may be different from the state of the LNG stored in the tank. Therefore, in recent years, research and development have been made on the technology of controlling the temperature and pressure of the LNG stored in the liquid state and supplying the engine to the engine.

Specifically, the LNG fuel supply system converts LNG stored in the LNG storage tank into an LNG fuel supply system composed of a boosting pump, a high-pressure pump, a heat exchanger, etc., can do.

The booster pump removes the LNG from the LNG storage tank and pressurizes the LNG within a few to several tens of bar to ensure that a sufficient amount of LNG is continuously supplied to the high pressure pump to prevent cavitation of the high pressure pump do. Thus, the booster pump is one of the important components of the LNG fuel supply system.

However, if the booster pump for constantly adjusting the required flow rate of the high-pressure pump is shut down due to a failure or the like, the operation of the LNG fuel supply system must be stopped, thereby preventing the engine from being stopped, There is a problem such as a situation occurs.

It is an object of the present invention to provide an LNG fuel supply system capable of smoothly supplying a required flow amount of LNG to a high pressure pump even when the boosting pump can not normally operate, .

An LNG fuel supply system according to an aspect of the present invention includes a fuel supply line connected from an LNG storage tank to an engine; An auxiliary storage tank for storing the LNG discharged from the LNG storage tank; A boosting pump for pressurizing the LNG discharged from the auxiliary storage tank; A high pressure pump that pressurizes the LNG discharged from the boosting pump to a high pressure; A heat exchanger for heating the high-pressure LNG supplied from the high-pressure pump; A recovery line connected between the high-pressure pump and the heat exchanger for recovering a portion of high-pressure LNG to the auxiliary storage tank to raise the internal pressure of the auxiliary storage tank; And a bypass line for supplying the high pressure pump with high pressure LNG discharged from the auxiliary storage tank in which the internal pressure is increased.

Specifically, the boosting pump may pressurize the LNG discharged from the LNG storage tank from 1 bar to 25 bar, and the high-pressure pump may pressurize the LNG from 200 bar to 400 bar.

Specifically, the auxiliary storage tank may include a suction drum for separating the evaporative gas from the LNG discharged from the LNG storage tank.

A flow control valve installed on the fuel supply line between the high-pressure pump and the heat exchanger and connected to one end of the recovery line; A bypass valve installed on the fuel supply line between the auxiliary storage tank and the boosting pump and connected to one end of the bypass line; And a reverse flow shutoff valve disposed on the fuel supply line at a downstream end of the boosting pump.

Specifically, when the booster pump is normally operating, the flow control valve is opened and closed to supply the LNG from the high-pressure pump to the heat exchanger at a high pressure. When the booster pump can not be operated due to failure, And a part of the high-pressure LNG supplied from the high-pressure pump to the heat exchanger is regulated to be supplied to the auxiliary storage tank through the recovery line.

Specifically, the bypass valve is opened to supply the LNG from the auxiliary storage tank to the boosting pump when the boosting pump is normally operating, and when the boosting pump can not be operated due to failure, Blocking the supply of LNG from the tank to the boosting pump and opening the LNG to be supplied directly to the high pressure pump from the auxiliary storage tank.

Specifically, the backflow shutoff valve is opened to supply the LNG from the boosting pump to the high-pressure pump when the boosting pump is normally operating, and when the boosting pump can not be operated due to failure, The LNG supplied to the high-pressure pump may be back-flowed to the booster pump.

A first transmitter provided in the fuel supply line at a front end or a rear end of the booster pump, for checking whether or not the booster pump is abnormal; And a second transmitter provided in the fuel supply line at a front end of the high pressure pump for checking the flow rate or pressure of the LNG supplied to the high pressure pump from the auxiliary storage tank.

Specifically, when the abnormality is detected in the booster pump, the first transmitter adjusts the opening of the flow control valve so that a portion of the LNG supplied to the heat exchanger from the high-pressure pump is recovered to the auxiliary storage tank The bypass valve is opened and closed so that the LNG of the auxiliary storage tank is directly supplied to the high pressure pump and the LNG supplied to the high pressure pump from the auxiliary storage tank is prevented from flowing back to the booster pump, Closing of the shut-off valve may be effected.

Specifically, the second transmitter checks the flow rate or pressure when the LNG of the auxiliary storage tank is supplied to the high-pressure pump, and controls the flow rate of the LNG to be supplied to the high- And allowing the opening to be finely tuned.

The LNG fuel supply system according to the present invention increases the internal pressure of the auxiliary storage tank by allowing the high pressure LNG to be recovered to the auxiliary storage tank through the recovery line connected between the high pressure pump and the heat exchanger, Pressure LNG is directly supplied from the auxiliary storage tank to the high-pressure pump through the bypass line connected between the high-pressure pump and the high-pressure pump, so that the LNG can be supplied smoothly to the high-pressure pump even when the boosting pump can not normally operate. It is possible to operate the ship even in the emergency situation of interruption.

1 is a conceptual diagram of a conventional LNG fuel supply system.
2 is a conceptual diagram of an LNG fuel supply system according to an embodiment of the present invention.
3 is a cross-sectional view of an LNG storage tank in an LNG fuel supply system according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram of a conventional LNG fuel supply system.

1, a conventional LNG fuel supply system 1 includes an LNG storage tank 10, an engine 20, a pump 30, and a heat exchanger 60. [ At this time, the pump 30 may include a boosting pump 31 and a high pressure pump 32. In the present specification, LNG can be used to encompass both NG, which is a liquid state, and NG, which is a supercritical state, for the sake of convenience.

The conventional LNG fuel supply system 1 is configured such that the boosting pump 31 pressurizes the LNG discharged from the LNG storage tank 10 to several to several tens of bar and then the high pressure pump 32 The LNG is pressurized by pressure (for example, 200 bar to 400 bar) and supplied to the heat exchanger 60. The heat exchanger 60 can increase the temperature of the LNG supplied from the pump 30 to be supplied to the engine 20. At this time, the LNG supplied to the engine 20 has a pressure of 200 to 400 bar and may be in a supercritical state having a temperature of 30 to 60 degrees.

At this time, a constant flow rate of LNG should be supplied to the high-pressure pump 32, and a flow demanded by the high-pressure pump 32 is represented by NPSHr (Net Positive Suction Head). If a certain amount of LNG is not introduced into the high-pressure pump 32, cavitation may occur and the high-pressure pump 32 may be damaged. Therefore, it is very important to satisfy the required flow rate of the high-pressure pump 32.

Therefore, in order to continuously satisfy the required flow rate of the high-pressure pump 32, the boosting pump 31 is disposed at the front end of the high-pressure pump 32 and the boosting pump 31 is discharged from the LNG storage tank 10 The LNG is pressurized and then delivered to the high-pressure pump 32, thereby preventing the high-pressure pump 32 from being damaged.

However, when the booster pump 31 for keeping the required flow rate of the high-pressure pump 32 at a constant level is stopped due to failure or the like, there is no other means for supplying the LNG to the high-pressure pump 32 in the related art. There is a problem that the operation of the supply system 1 itself must be interrupted, thereby causing the situation that the engine 20 is stopped and the ship can not be operated.

FIG. 2 is a conceptual diagram of an LNG fuel supply system according to an embodiment of the present invention, and FIG. 3 is a sectional view of an LNG storage tank in an LNG fuel supply system according to an embodiment of the present invention.

2, an LNG fuel supply system 2 according to an embodiment of the present invention includes an LNG storage tank 10, an engine 20, a pump 30, a recovery line 41, (42) an auxiliary storage tank (50), and a heat exchanger (60). The LNG storage tank 10, the engine 20, the pump 30, the heat exchanger 60 and the like in the embodiment of the present invention are denoted by the same reference numerals as those in the conventional LNG fuel supply system 1 But it does not necessarily refer to the same configuration.

The LNG storage tank 10 stores the LNG to be supplied to the engine 20. The LNG storage tank 10 must store the LNG in a liquid state, and the LNG storage tank 10 may have a pressure tank form.

3, the LNG storage tank 10 includes an outer tank 11, an inner tank 12, and a heat insulating portion 13. As shown in Fig. The outer tank 11 is formed as an outer wall of the LNG storage tank 10, and may be formed of steel, and may have a polygonal cross section.

The tanks 12 are provided inside the tanks 11 and can be supported and supported inside the tanks 11 by means of a support 14. At this time, the support 14 may be provided at the lower end of the inner tank 12, and may be provided at the side of the inner tank 12 in order to suppress the lateral movement of the inner tank 12. [

The bath tank 12 may be made of stainless steel and designed to withstand a pressure of 5 bar to 10 bar (for example 6 bar). The reason why the inner tank 12 is designed to withstand such a constant pressure is that the inner pressure of the inner tank 12 can be raised as the LNG provided in the inner tank 12 is evaporated to generate the evaporation gas Because.

A baffle 15 may be provided in the inner tank 12. [ The baffle 15 means a plate in the form of a lattice and the baffle 15 is installed so that the pressure inside the tank 12 can be evenly distributed to prevent the tank 12 from being subjected to concentrated pressure .

The heat insulating portion 13 is provided between the inner tank 12 and the outer tank 11 and can prevent the external heat energy from being transmitted to the inner tank 12. [ At this time, the heat insulating portion 13 may be in a vacuum state. By forming the adiabatic portion 13 in a vacuum, the LNG storage tank 10 can more efficiently withstand higher pressures as compared to a conventional tank. For example, the LNG storage tank 10 may sustain a pressure of 5 to 20 bar through the vacuum insulation 13.

As described above, the present embodiment uses the pressure tank LNG storage tank 10 having the vacuum insulation unit 13 between the outer tank 11 and the inner tank 12 to minimize the generation of the evaporated gas And it is possible to prevent the LNG storage tank 10 from being damaged even if the internal pressure is increased.

The engine 20 is driven through the LNG supplied from the LNG storage tank 10 to generate thrust. At this time, the engine 20 may be a MEGI engine or a dual fuel engine.

When the engine 20 is a dual fuel engine, LNG and oil may be selectively supplied without being mixed with the LNG. This is to prevent the mixture of two materials having different combustion temperatures from being mixed and to prevent the efficiency of the engine 20 from being lowered.

As the piston 20 (not shown) in the cylinder (not shown) reciprocates due to the combustion of the LNG, the engine 20 rotates the crank shaft (not shown) connected to the piston, (Not shown) can be rotated. Therefore, as the propeller (not shown) connected to the shaft finally rotates when the engine 20 is driven, the hull is moved forward or backward.

Of course, in the present embodiment, the engine 20 may be an engine 20 for driving a propeller, but it may be an engine 20 for generating electricity or an engine 20 for generating other power. That is, the present embodiment does not specifically limit the type of the engine 20. However, the engine 20 may be an internal combustion engine that generates a driving force by combustion of the LNG.

A fuel supply line 21 for transferring LNG can be installed between the LNG storage tank 10 and the engine 20. A pump 30, an auxiliary storage tank 50, a heat exchanger (60) and the like so that the LNG can be supplied to the engine (20).

At this time, the fuel supply line 21 is provided with a fuel supply valve (not shown) so that the supply amount of the LNG can be adjusted according to the opening degree adjustment of the fuel supply valve.

The pump 30 is provided on the fuel supply line 21 and pressurizes the LNG discharged from the LNG storage tank 10 to a high pressure. The pump 30 includes a boosting pump 31 and a high-pressure pump 32.

The boosting pump 31 may be provided on the fuel supply line 21 between the auxiliary storage tank 50 and the high pressure pump 32 to be described later or in the LNG storage tank 10, So that cavitation of the high-pressure pump 32 is prevented. Also, the boosting pump 31 can extract the LNG from the auxiliary storage tank 50 to pressurize the LNG within a few to several tens of bar, and the LNG through the boosting pump 31 can be pressurized to 1 to 25 bar.

The LNG stored in the auxiliary storage tank 50 is in a liquid state. At this time, the boosting pump 31 may pressurize the LNG discharged from the auxiliary storage tank 50 to slightly increase the pressure and the temperature, and the LNG pressurized by the boosting pump 31 may still be in a liquid state.

The boosting pump 31 continuously satisfies the required flow rate of the high-pressure pump 32 so that the high-pressure pump 32 can be smoothly driven, and also the important It plays a role.

However, if the booster pump 31 stops its operation due to a failure or the like, it can not play its essential role and eventually must stop the operation of the LNG fuel supply system 1, In this embodiment, the LNG of the required flow rate is continuously supplied to the high-pressure pump 32 through the recovery line 41 and the bypass line 42, So that there is no disruption to the operation of the vehicle. This will be described later.

The high-pressure pump 32 pressurizes the LNG discharged from the boosting pump 31 to a high pressure so that the LNG is supplied to the engine 20. The LNG is discharged from the auxiliary storage tank 50 at a pressure of about 10 bar and then primarily pressurized by the boosting pump 31. The high pressure pump 32 is supplied with the LNG that is pressurized by the boosting pump 31 And is supplied to the heat exchanger 60 to be described later.

At this time, the high-pressure pump 32 may pressurize the LNG to the engine 20 at a pressure required by the engine 20, for example, 200 to 400 bar, thereby causing the engine 20 to produce thrust through the LNG .

The high pressure pump 32 is capable of phase-changing the LNG discharged from the boosting pump 31 to a supercritical state having a higher temperature and a higher pressure than the LNG at a high pressure have. At this time, the temperature of the supercritical LNG may be lower than -20 ° C, which is relatively higher than the critical temperature.

Or the high-pressure pump 32 can pressurize the LNG in a liquid state to a super-cooled liquid state by pressurizing it with a high pressure. Here, the LNG in the subcooled liquid state is a state in which the pressure of the LNG is higher than the critical pressure and the temperature is lower than the critical temperature.

Specifically, the high-pressure pump 32 pressurizes the liquid LNG discharged from the boosting pump 31 to a high pressure of 200 to 400 bar so that the temperature of the LNG becomes lower than the critical temperature, Phase change. Here, the temperature of the LNG in the subcooled liquid state may be -140 캜 to -60 캜, which is relatively lower than the critical temperature.

In the above description, the function of the high-pressure pump 32 when the boosting pump 31 is normally operated has been described. Even in the case where the boosting pump 31 is stopped due to failure or the like, in this embodiment, The high pressure pump 32 can be operated normally by performing the function of the boosting pump 31 for supplying the LNG at the required flow rate to the high pressure pump 32 through the bypass line 41 and the bypass line 42 have. This will be described later.

The recovery line 41 is connected to a flow control valve 71 which will be described later provided in the fuel supply line 21 between the high pressure pump 32 and the heat exchanger 60 and the other end is connected to the auxiliary storage tank 50 so that the LNG can be recovered to the auxiliary storage tank 50.

The bypass line 42 is connected to a bypass valve 72 to be described later which is provided in the fuel supply line 21 between the auxiliary storage tank 50 and the booster pump 31 to be described later and the other end is connected to the booster pump 31 To the fuel supply line 21 between the high pressure pump 32 and the high pressure pump 32 so that the LNG discharged from the auxiliary storage tank 50 can be supplied to the high pressure pump 32.

In the present embodiment, when the boosting pump 31 can not supply the required flow rate to the high-pressure pump 32 due to a failure or the like, the engine 20 may have to be stopped.

Therefore, in this embodiment, a part of the LNG of high pressure (for example, 200 bar to 400 bar) discharged from the high-pressure pump 32 through the recovery line 41 connected between the high-pressure pump 32 and the heat exchanger 60, So that the auxiliary tank 50 can be used as the booster pump 31 and the auxiliary pressure of the auxiliary tank 50 can be increased The required amount of LNG can be supplied to the high pressure pump 32 through the bypass line 42 connected to the storage tank 50 so that the engine 20 can be continuously operated without depending on the boosting pump 31 Let's do it.

The auxiliary storage tank 50 is provided on the fuel supply line 21 downstream of the LNG storage tank 10 and receives the high pressure LNG discharged from the high pressure pump 32 through the recovery line 41, The LNG can be returned to the high-pressure pump 32 through the bypass line 42 in a state where the pressure is increased. Accordingly, the present embodiment can supply the required amount of LNG to the high-pressure pump 32 even if the boosting pump 31 is difficult to operate due to failure or the like.

The auxiliary storage tank 50 may be a suction drum for separating the evaporated gas from the LNG discharged from the LNG storage tank 10. That is, the auxiliary storage tank 50 is disposed on the fuel supply line 21 connected to the boosting pump 31 from the LNG storage tank 10, separates the evaporated gas from the LNG, (31) to prevent cavitation from occurring in the boosting pump (31). The auxiliary storage tank 50 temporarily stores the LNG when the internal pressure of the LNG storage tank 10 rises excessively and an abnormal amount of the LNG is transferred toward the booster pump 31, It is possible to prevent an overload of the motor.

Further, when the boosting pump 31 can not be operated due to a failure or the like, the auxiliary pressure in the auxiliary storage tank 50 is raised by the high pressure LNG recovered through the recovery line 41, and the bypass line 42 The LNG can be supplied to the high- That is, the auxiliary storage tank 50 can perform not only the above-mentioned function but also the role of the booster pump 31 in the present embodiment.

The heat exchanger 60 is provided on the fuel supply line 21 between the engine 20 and the pump 30 and heats the LNG supplied from the pump 30. The pump 30 for supplying the LNG to the heat exchanger 60 may be the high pressure pump 32 and the heat exchanger 60 may be configured to supply the LNG in the supercooled liquid state or the supercritical state to the high pressure pump 32 Heated to 200 to 400 bar, converted into LNG in a supercritical state of 30 to 60 degrees, and then supplied to the engine 20.

The heat exchanger 60 can heat the LNG using the steam supplied through the boiler (not shown) or the glycol water supplied from the glycol heater (not shown), or can heat the LNG using electric energy, Or the waste heat generated from a generator or other equipment provided on the ship can be used to heat the LNG.

The flow rate control valve 71 is installed on the fuel supply line 21 between the high pressure pump 32 and the heat exchanger 60 and is connected to one end of the recovery line 41. The boosting pump 31 is normally operated The opening degree of the LNG is controlled so that the LNG is supplied from the high pressure pump 32 to the heat exchanger 60 at a pressure of 200 to 400 bar so that the engine 20 can be normally operated.

The flow rate control valve 71 in the present embodiment can not normally operate due to failure or the like and the boosting pump 31 can not supply the required flow rate directly to the high pressure pump 32 by the boosting pump 31, Pressure LNG supplied from the high-pressure pump 32 to the heat exchanger 60 may be supplied to the auxiliary storage tank 50 through the recovery line 41. In this case, Thereby increasing the internal pressure of the auxiliary storage tank 50 so that the LNG can be supplied to the high-pressure pump 32 through the bypass line 42 again. The LNG capable of normally operating the engine 20 can be supplied to the heat exchanger 60 even if the flow control valve 71 is opened so that a part of the LNG can be supplied to the auxiliary storage tank 50 to be. That is, the opening control of the flow control valve 71 is controlled by controlling the opening degree of the high-pressure pump 32 from the boosting pump 31 to such an extent that the internal pressure of the auxiliary storage tank 50 can replace the role of the boosting pump 31, The amount of LNG supplied to the heat exchanger 60 from the high-pressure pump 32 (the amount of LNG recovered to the auxiliary storage tank) can be reduced by about 1 bar to about 25 bar. It does not affect normal operation. The opening control of the flow control valve 71 may be performed by the first and second transmitters 81 and 82 to be described later.

The bypass valve 72 is provided on the fuel supply line 21 between the auxiliary storage tank 50 and the boosting pump 31 and is connected to one end of the bypass line 42. The boosting pump 31 is normally operated The LNG can be supplied from the auxiliary storage tank 50 to the boosting pump 31. [

The bypass valve 72 in this embodiment can not operate normally due to failure or the like in the booster pump 31 and can not supply the required flow rate directly to the high-pressure pump 32 by the boosting pump 31, The LNG supply from the auxiliary storage tank 50 to the boosting pump 31 is blocked and the LNG is supplied directly from the auxiliary storage tank 50 to the high pressure pump 32 Is opened. At this time, the auxiliary storage tank 50 in which the internal pressure is raised by the high-pressure LNG recovered through the recovery line 41 can serve as the boosting pump 31, and the high-pressure pump 32 does not cause a problem in the high-pressure pump 32 even if LNG is supplied. The opening and closing of the bypass valve 72 can be controlled by the first transmitter 81 described later.

The backflow shutoff valve 73 is provided on the fuel supply line 21 at the rear end of the boosting pump 31 and is connected to the high pressure pump 32 from the boosting pump 31 when the boosting pump 31 is normally operating So that the LNG can be supplied.

The backflow shutoff valve 73 in the present embodiment can not supply the required flow rate to the high-pressure pump 32 directly from the boosting pump 31 because the boosting pump 31 is difficult to normally operate due to failure or the like, The LNG supplied to the high pressure pump 32 is prevented from flowing back to the boosting pump 31 through the bypass line 42 and the LNG is smoothly supplied to the high pressure pump 32 I will. The opening / closing control of the backflow shutoff valve 73 can be performed by the first transmitter 81 described later.

The first transmitter 81 may be provided in the fuel supply line 21 at the front end or the rear end of the boosting pump 31. The first transmitter 81 may check the abnormality of the boosting pump 31 through the flow rate, (71), bypass valve (72) and backflow shutoff valve (73).

Particularly, when an abnormality is detected in the boosting pump 31, the first transmitter 81 can recover a portion of the LNG supplied from the high-pressure pump 32 to the heat exchanger 60 to the auxiliary storage tank 50 So that the bypass valve 72 can be opened and closed so that the LNG of the auxiliary storage tank 50 can be directly supplied to the high-pressure pump 32, The opening / closing control of the backflow shutoff valve 73 can be controlled so that the LNG supplied from the tank 50 to the high pressure pump 32 does not flow back to the boosting pump 31.

All the valves 71, 72 and 73 are connected by the first transmitter 81 so that the LNG of the auxiliary storage tank 50 can be continuously supplied to the engine 20 through the high-pressure pump 32 and the heat exchanger 60 It is preferable that the flow control valve 71, the bypass valve 72 and the reverse flow shutoff valve 73 are operated in order for more stable supply.

The second transmitter 82 may be provided in the fuel supply line 21 at the upstream of the high pressure pump 32 and checks the flow rate or pressure of the LNG supplied from the auxiliary storage tank 50 to the high pressure pump 32 So that the flow control valve 71 can be operated.

Specifically, the second transmitter 82 is configured such that the first transmitter 81 is initially connected to the auxiliary storage tank 50 so that a portion of the LNG supplied from the high-pressure pump 32 to the heat exchanger 60 can be recovered to the auxiliary storage tank 50. [ It is possible to check the flow rate or pressure when the LNG of the auxiliary storage tank 50 is supplied to the high pressure pump 32 and to supply the LNG from the boosting pump 31 at the normal time The opening degree of the flow control valve 71 is finely adjusted so that the LNG can be supplied under the optimum conditions required by the high pressure pump 32. [

The LNG of high pressure is recovered to the auxiliary storage tank 50 through the recovery line 41 connected between the high-pressure pump 32 and the heat exchanger 60, Pressure LNG is supplied from the auxiliary storage tank 50 directly to the high-pressure pump 32 through the bypass line 42 connected between the auxiliary storage tank 50 and the high-pressure pump 32 , It is possible to smoothly supply the LNG of the required flow rate to the high-pressure pump 32 even when the booster pump 31 can not normally operate, so that the booster pump 31 can operate the ship even in the emergency situation of shutdown.

Accordingly, in the present embodiment, when the booster pump for keeping the required flow rate of the high-pressure pump at a constant level is stopped due to a failure or the like, the operation of the LNG fuel supply system must be stopped, It is possible to solve all the conventional problems such as the occurrence of an emergency situation in which the vehicle can not be operated.

1: conventional LNG fuel supply system 2: LNG fuel supply system of the present invention
10: LNG storage tank 11: outer tank
12: inner tank 13:
14: Support 15: Baffle
20: engine 21: fuel supply line
30: Pump 31: Boosting pump
32: high pressure pump 41: recovery line
42: bypass line 50: auxiliary storage tank
60: Heat Exchanger 71: Flow Control Valve
72: Bypass valve 73: Reverse flow shutoff valve
81: first transmitter 82: second transmitter

Claims (10)

A fuel supply line connected from the LNG storage tank to the engine;
An auxiliary storage tank for storing the LNG discharged from the LNG storage tank;
A boosting pump for pressurizing the LNG discharged from the auxiliary storage tank;
A high pressure pump that pressurizes the LNG discharged from the boosting pump to a high pressure;
A heat exchanger for heating the high-pressure LNG supplied from the high-pressure pump;
A recovery line connected between the high-pressure pump and the heat exchanger for recovering a portion of high-pressure LNG to the auxiliary storage tank to raise the internal pressure of the auxiliary storage tank; And
And a bypass line for supplying high-pressure LNG discharged from the auxiliary storage tank with the internal pressure raised to the high-pressure pump. The method according to claim 1,
The booster pump pressurizes the LNG discharged from the LNG storage tank at 1 to 25 bar,
Wherein the high-pressure pump pressurizes the LNG from 200 bar to 400 bar. The apparatus according to claim 1, wherein the auxiliary storage tank
And a suction drum for separating the evaporated gas from the LNG discharged from the LNG storage tank. The method according to claim 1,
A flow control valve installed on the fuel supply line between the high-pressure pump and the heat exchanger and connected to one end of the recovery line;
A bypass valve installed on the fuel supply line between the auxiliary storage tank and the boosting pump and connected to one end of the bypass line; And
Further comprising a reverse flow shut-off valve provided on the fuel supply line at a downstream end of the boosting pump. The flow control valve according to claim 4,
And the opening degree of the LNG is controlled to be supplied from the high-pressure pump to the heat exchanger at a high pressure when the boosting pump is normally operated,
Wherein the high pressure LNG supplied from the high pressure pump to the heat exchanger is regulated to be supplied to the auxiliary storage tank through the recovery line when the boosting pump can not be operated due to failure. . 5. The apparatus according to claim 4,
Wherein when the boosting pump is normally operating, the auxiliary storage tank is opened to supply the LNG to the boosting pump,
Wherein when the booster pump can not be operated due to failure, the supply of LNG from the auxiliary storage tank to the booster pump is blocked and the LNG is supplied directly from the auxiliary storage tank to the high-pressure pump. LNG fuel supply system. 5. The backflow prevention valve according to claim 4,
When the boosting pump is operating normally, the boosting pump is opened to supply the LNG from the boosting pump to the high-pressure pump,
And when the boosting pump can not be operated due to failure, the LNG supplied to the high-pressure pump through the bypass line is prevented from flowing back to the boosting pump. The method according to claim 1,
A first transmitter provided in the fuel supply line at a front end or a rear end of the boosting pump, for checking whether or not the boosting pump is abnormal; And
Further comprising a second transmitter provided in the fuel supply line at a front end of the high pressure pump for checking the flow rate or pressure of the LNG supplied from the auxiliary storage tank to the high pressure pump. 9. The transmitter according to claim 4 or 8, wherein the first transmitter comprises:
If an abnormality is detected in the booster pump,
The opening degree of the flow control valve is adjusted so that a portion of the LNG supplied from the high-pressure pump to the heat exchanger is returned to the auxiliary storage tank,
The opening and closing of the bypass valve is controlled so that the LNG of the auxiliary storage tank is directly supplied to the high-pressure pump,
Wherein the opening and closing of the backflow shutoff valve is controlled so that the LNG supplied from the auxiliary storage tank to the high pressure pump does not flow back to the boosting pump. 9. The transmitter according to claim 4 or 8, wherein the second transmitter comprises:
And controls the flow rate or pressure of the LNG supplied to the high pressure pump to adjust the opening of the flow control valve so that the LNG is supplied under the conditions required by the high pressure pump LNG fuel supply system.

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