KR20200074829A - Fuel gas supply system and ship having the same - Google Patents

Abstract

The present invention relates to a gas supply system and a ship having the same. According to one aspect of the present invention, a gas supply system comprises: a large storage tank which stores liquefied gas and has a liquefied gas transfer pump; a small fuel tank which receives the liquefied gas from the large storage tank; a gas heater which heats the liquefied gas discharged from the small fuel tank and supplies the liquefied gas to an engine; a return line which returns at least part of the liquefied gas heated in the gas heater to the small fuel tank; and a detour line which detours the small fuel tank from the large storage tank and supplies the liquefied gas to the gas heater. The gas supply system supplies the liquefied gas to the detour line through the transfer pump when the engine is initially operated, and increases the internal pressure of the small fuel tank by using the return line when the engine is normally operated, thereby supplying the liquefied gas to the engine without pumping the liquefied gas stored in the small fuel tank by using the liquefied gas transfer pump. The gas supply system can effectively increase the pressure in the fuel tank to improve the gas supply efficiency from the fuel tank to the demand.

Description

Gas supply system and ship equipped with it{FUEL GAS SUPPLY SYSTEM AND SHIP HAVING THE SAME}

The present invention relates to a gas supply system and a ship having the same.

According to recent technology development, liquefied gas such as Liquefied Natural Gas and Liquefied Petroleum Gas has been widely used to replace gasoline or diesel.

Liquefied natural gas is liquefied by cooling the methane obtained by refining natural gas collected from a gas field. It is a colorless and transparent liquid with little pollutants and high heat, making it an excellent fuel. On the other hand, liquefied petroleum gas is a fuel made of liquid by compressing gas composed mainly of propane (C3H8) and butane (C4H10) coming out of oil from the oil field at room temperature. Liquefied petroleum gas, like liquefied natural gas, is colorless and odorless, and is widely used as fuel for household, business, industrial, and automotive applications.

The liquefied gas is stored in a liquefied gas storage tank installed on the ground or in a liquefied gas storage tank provided in a ship that is a transportation means for navigating the ocean. It is reduced, and liquefied petroleum gas has the advantage of high storage efficiency because it is reduced to 1/260 of propane and 1/230 of butane by liquefaction. The temperature and pressure required to drive the engine using the liquefied gas as fuel may be different from the state of the liquefied gas stored in the tank.

The present invention was created to solve the problems of the prior art as described above, and an object of the present invention is to provide a gas supply system having improved fuel gas supply efficiency and a ship having the same.

A gas supply system according to an aspect of the present invention includes a large storage tank that stores liquefied gas and is provided with a liquefied gas transfer pump; A small fuel tank receiving liquefied gas from the large storage tank; A gas heater that heats the liquefied gas discharged from the small fuel tank and supplies it to an engine; A return line returning at least a portion of the liquefied gas heated in the gas heater to the small fuel tank; And a bypass line bypassing the small fuel tank from the large storage tank and supplying liquefied gas to the gas heater. During normal operation, the internal pressure of the small fuel tank is increased by using the return line, and liquefied gas stored in the small fuel tank is supplied to the engine without pumping by the liquefied gas transfer pump.

Specifically, the initial operation may be a state in which the internal pressure of the small fuel tank is less than the required pressure of the engine.

Specifically, the normal operation may be a state in which the internal pressure of the small fuel tank corresponds to the required pressure of the engine.

In detail, the large storage tank and the small fuel tank may be connected to and further include a transfer line provided with the liquefied gas transfer pump.

Specifically, the bypass line may diverge from the transfer line.

Specifically, an evaporation gas return line for returning evaporation gas from the small fuel tank to the large storage tank may be further included.

Specifically, a fruit heater for heating the fruit; A fruit circulation line in which the fruit circulates the fruit heater and the gas heater; And a fruit pump provided in the fruit circulation line.

Specifically, a vaporizer provided between the small fuel tank and the gas heater to vaporize the liquefied gas provided from the small fuel tank may be further included.

A ship according to another aspect of the present invention includes the gas supply system.

The gas supply system according to the present invention and a ship equipped with the same can effectively increase the pressure in the fuel tank, thereby improving the gas supply efficiency from the fuel tank to the demand destination.

Specifically, the pump for supplying liquefied gas can be omitted to reduce manufacturing and operation costs of the gas supply system.

In addition, by using the PBU only during the initial operation of the engine, and then pressurizing the fuel tank using a return line, it is possible to economically operate the gas supply system by reducing the load on the PBU and increasing the life.

In addition, the PBU and the heater can be integrated to reduce the size of the device and improve thermal efficiency.

In addition, it is possible to increase the pressurization efficiency by returning a non-condensable gas to the fuel tank.

In addition, the pressure increase efficiency can be improved by supplying fuel gas by pressing a small fuel tank provided separately.

In addition, it is possible to stably supply fuel gas continuously by alternately using a plurality of boosting tanks.

In addition, the liquefied gas pump can be omitted by transferring the fuel gas at the head pressure in a plurality of tank structures arranged up and down.

In addition, the system configuration can be simplified by integrating the PBU and the liquefied gas heater.

In addition, the two heat exchangers are provided in a configuration that backs up each other, thereby enabling stable operation of the gas supply system.

In addition, it is possible to increase the thermal efficiency and reduce the operation cost of the boiler by supplying high temperature boil-off gas to the boiler in the fuel tank.

1 is a view showing a gas supply system according to a first embodiment of the present invention.
2 is a view showing a gas supply system according to a second embodiment of the present invention.
3 is a view showing a gas supply system according to a third embodiment of the present invention.
4 is a view showing a gas supply system according to a fourth embodiment of the present invention.
5 is a view showing a gas supply system according to a fifth embodiment of the present invention.
6 is a view showing a gas supply system according to a sixth embodiment of the present invention.
7 is a view showing a gas supply system according to a seventh embodiment of the present invention.
8 is a view showing a gas supply system according to an eighth embodiment of the present invention.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments associated with the accompanying drawings. It should be noted that, in the specification, when adding reference numerals to the components of each drawing, the same components have the same number as possible, even if they are displayed on different drawings. In addition, in the description of the present invention, when it is determined that detailed descriptions of related known technologies may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

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

Hereinafter, the gas supply system of the present invention will be described, and the present invention includes a gas supply system and a ship having the same. Here, the ship may include an engine and all types of offshore structures equipped with a gas supply system for supplying liquefied gas to the engine.

Hereinafter, in the present specification, liquefied gas may be used in a sense to encompass all gas fuels that are generally stored in a liquid state, such as LNG or LPG, ethylene, ammonia, and boil-off gas (BOG) is natural vaporization or It may mean forced vaporized liquefied gas. However, the boil-off gas can be used to mean not only the gaseous boil-off gas but also liquefied boil-off gas.

1 is a view showing a gas supply system according to a first embodiment of the present invention.

1, the gas supply system 10 according to the first embodiment of the present invention includes a fuel tank 110, an engine EG, a liquefied gas supply line 120, a PBU 130, and a return line 140 ) And the evaporation gas supply line 150.

The fuel tank 110 stores liquid liquefied gas. The fuel tank 110 may be provided as a membrane type to stably store liquefied gas in a cryogenic liquid state, but is not limited thereto.

A plurality of fuel tanks 110 may be provided in the longitudinal direction of the hull, and two or more may be provided in the left and right directions of the hull. The number or arrangement of the fuel tanks 110 is not particularly limited and may be variously determined.

The fuel tank 110 may store liquefied gas at a pressure of about 1 bar or so, and the liquefied gas stored in the fuel tank 110 is discharged to the outside through the liquefied gas supply line 120 to be described later, and then the heater HT and It can be vaporized by the vaporizer (VP) and transmitted to the engine (EG).

The engine EG is an engine that receives and drives high-pressure liquefied gas from the fuel tank 110 and may provide propulsion power or internal power of the ship. Here, the pressure of the liquefied gas supplied to the engine EG may be, for example, about 10 bar to 300 bar. The engine EG may be a two-stroke diesel engine or a dual-fuel engine, or a four-stroke diesel engine or a dual-fuel engine. However, the present invention is not limited thereto, and any engine using high-pressure liquefied gas may be included.

The liquefied gas supply line 120 is provided to supply liquefied gas stored in the fuel tank 110 to the engine EG. One end of the liquefied gas supply line 120 is provided to communicate with the inside of the fuel tank 110, the other end is connected to the engine (EG).

On the liquefied gas supply line 120, a first valve V1 for regulating the flow rate of the liquefied gas, a vaporizer VP for vaporizing the liquefied gas, and a heater for heating the vaporized liquefied gas to a required temperature of the engine EG (HT) may be provided.

The vaporizer VP is provided between the fuel tank 110 and the heater HT to vaporize the liquefied gas provided from the fuel tank 110.

The heater HT heats the liquefied gas discharged from the fuel tank 110 and supplies it to the engine EG.

The vaporizer VP and the heater HT may be formed of a heat exchanger that exchanges heat with a high temperature heat medium, but is not limited thereto.

A pressure build-up unit (PBU 130) is provided in the fuel tank 110 to heat the liquefied gas stored in the fuel tank 110 and return it to the fuel tank 110. The PBU 130 may vaporize the liquefied gas to maintain the pressure in the fuel tank 110 within a predetermined section.

Specifically, when the liquefied gas is discharged from the fuel tank 110 to the outside, the pressure in the fuel tank 110 is lowered, whereby the liquefied gas may not be supplied to the vaporizer (VP), the PBU 130 is liquefied gas Is vaporized to return to the fuel tank 110 to prevent pressure drop in the fuel tank 110 as described above.

The PBU 130 of this embodiment operates only during the initial operation of the engine EG to increase the internal pressure of the fuel tank 110, and returns to be described later without operating the PBU 130 during normal operation of the engine EG. By using the line 140, the internal pressure of the fuel tank 110 is increased. More details will be described later.

The return line 140 returns at least a portion of the liquefied gas heated in the heater HT to the fuel tank 110. One end of the return line 140 is connected to the upstream of the heater HT, and the other end of the return line 140 is connected to the fuel tank 110. Here, one end of the return line 140 is branched from the liquefied gas supply line 120.

As described above, the gas supply system 10 of this embodiment increases the internal pressure of the fuel tank 110 using the PBU 130 when the engine EG is initially operated, and returns when the engine EG is normally operated By using the line 140, the internal pressure of the fuel tank 110 is increased. Here, the initial operation of the engine EG is a state in which the internal pressure of the fuel tank 110 is less than the required pressure of the engine EG, and the normal operation of the engine EG is that the internal pressure of the fuel tank 110 is of the engine EG. It can be defined as a state corresponding to the required pressure.

That is, if the internal pressure of the fuel tank 110 is less than the required pressure of the engine EG, the PBU 130 is operated to increase the internal pressure of the fuel tank 110 to supply liquefied gas, and the internal pressure of the fuel tank 110 If it is a level corresponding to the required pressure of the engine EG, the liquefied gas heated upstream of the heater HT is recirculated to the fuel tank 110 without operating the PBU 130 to pressure in the fuel tank 110. Prevent degradation.

Thereby, the gas supply system 10 of this embodiment can supply liquefied gas to the engine EG without pumping by a separate liquefied gas pump.

The evaporation gas supply line 150 mixes the evaporation gas generated in the fuel tank 110 with the liquefied gas vaporized by the vaporizer VP. One end of the boil-off gas supply line 150 is connected to the top of the fuel tank 110, and the other end is connected to the downstream of the vaporizer (VP). The boil-off gas generated inside the fuel tank 110 may be used as a fuel gas of the engine EG by joining the liquefied gas supply line 120 through the boil-off gas supply line 150.

Additionally, a second valve V2 and a third valve V3 for adjusting the flow rate of the boil-off gas and liquefied gas may be provided on the boil-off gas supply line 150 and the return line 140, respectively. In addition, a pressure gauge (not shown) may be provided inside the fuel tank 110 to measure the internal pressure of the fuel tank 110, and the opening degree of the valves V1, V2, and V3 may be adjusted according to the measured pressure. Can.

As described above, the gas supply system 10 according to the first embodiment of the present invention can effectively increase the pressure in the fuel tank 110 to improve the gas supply efficiency from the fuel tank 110 to the customer.

Specifically, the manufacturing and operation cost of the gas supply system 10 can be reduced by omitting the pump for supplying liquefied gas.

In addition, by using the PBU 130 only during the initial operation of the engine EG, and then pressurizing the fuel tank 110 using the return line 140, the load of the PBU 130 is reduced and the life is increased to supply gas. Economical operation of the system 10 is possible.

2 is a view showing a gas supply system according to a second embodiment of the present invention.

2, the gas supply system 20 according to the second embodiment of the present invention includes a fuel tank 210, an engine EG, a PBU 220, a liquefied gas supply line 230, and a buffer fuel tank ( 240), may include a return line 250.

For the components having the same reference numbers as the aforementioned components, reference may be made to the above-mentioned disclosure unless contradictory, and duplicate description will be omitted.

The PBU 220 is provided in the fuel tank 210 to heat the liquefied gas stored in the fuel tank 210 and returns it to the fuel tank 210. The PBU 130 may vaporize the liquefied gas to maintain the pressure in the fuel tank 210 within a predetermined section.

Specifically, the PBU 220 includes a circulation line 221 for returning liquefied gas to the fuel tank 210 and a heating means 223 provided on the circulation line 221 to heat the liquefied gas. One end of the circulation line 221 is connected to the lower portion of the fuel tank 210, and the other end is connected to the upper portion of the fuel tank 210.

Then, in the circulation line 221, a liquefied gas supply line 230 to be described later is branched downstream of the heating means 223. Accordingly, the liquefied gas discharged from the fuel tank 210 passes through the heating means 223 and is partially supplied to the engine EG through the liquefied gas supply line 230, and the other part is connected to the circulation line 221. Accordingly, it is returned to the fuel tank 210.

Here, the liquefied gas returned to the fuel tank 210 along the circulation line 221 may have a lower boiling point than the liquefied gas supplied to the engine EG through the liquefied gas supply line 230. That is, the liquefied gas returned to the fuel tank 210 along the circulation line 221 may have a higher ratio of nitrogen to liquefied gas supplied to the engine EG through the liquefied gas supply line 230.

The liquefied gas supply line 230 supplies liquefied gas stored in the fuel tank 210 to the engine EG. The liquefied gas supply line 230 of the present embodiment is branched from the PBU 220, and supplies some of the liquefied gas heated by the PBU 220 and returned to the fuel tank 210 to the engine EG. At this time, the liquefied gas supply line 230 is branched downstream of the heating means 223 from the circulation line 221, and then connected to the engine EG via the heating means 223.

Thereby, the liquefied gas is first heated by the heating means 223 of the PBU 220, and secondarily heated by the heating means 223 while flowing along the liquefied gas supply line 230, and then to the engine EG. Is supplied.

Here, the heating means 223 may be provided to have a plurality of flow paths (SL1, SL2, SL3). Specifically, the heating means 223 includes a first flow path SL1 through which liquefied gas supplied from the fuel tank 210 flows, a second flow path SL2 flowing along the liquefied gas supply line 230, and a heat source (ST). It may be configured as a three-stream heat exchanger having a third flow path (SL3) through which steam flows.

The buffer fuel tank 240 is provided upstream of the heating means 223 in the liquefied gas supply line 230 to temporarily store the liquefied gas.

The return line 250 is branched from the liquefied gas supply line 230 and connected to the circulation line 221 to return the liquefied gas of the liquefied gas supply line 230 to the fuel tank 210. One end of the return line 250 is connected to the downstream of the heating means 223 in the liquefied gas supply line 230, and the other end is connected to the downstream of the heating means 223 in the circulation line 221.

In addition, the gas supply system 20 of the present embodiment is provided in the liquefied gas supply line 230, the gas valve unit 260 to adjust the pressure and flow rate of the liquefied gas supplied to the engine (EG), in the fuel tank 210 Boiler connection line 270 for supplying the boil-off gas generated in the boiler, and may further include a gas heater (HT2) provided on the boiler connection line (270).

As described above, the gas supply system 20 according to the second embodiment of the present invention can reduce the manufacturing and operation cost of the gas supply system 20 by omitting the pump for supplying liquefied gas.

In addition, the PBU 220 and the heater can be integrated to reduce the size of the device and improve thermal efficiency.

In addition, it is possible to increase the pressurization efficiency by returning the non-condensable gas to the fuel tank 210.

In addition, by supplying high temperature boil-off gas to the boiler in the fuel tank 210 to increase the thermal efficiency, it is possible to reduce the operating cost of the boiler.

3 is a view showing a gas supply system according to a third embodiment of the present invention.

3, the gas supply system 30 according to the third embodiment of the present invention includes a fuel tank 310, an engine EG, a PBU 320, a liquefied gas supply line 330, and a heater 340. It may include.

For the components having the same reference numbers as the aforementioned components, reference may be made to the above-mentioned disclosure unless contradictory, and duplicate description will be omitted.

The PBU 320 is provided in the fuel tank 310 to heat the liquefied gas stored in the fuel tank 310 and returns it to the fuel tank 310. The PBU 130 may vaporize the liquefied gas to maintain the pressure in the fuel tank 310 within a predetermined section.

Specifically, the PBU 320 includes a circulation line 321 for returning liquefied gas to the fuel tank 310 and a heating means 323 provided on the circulation line 321 to heat the liquefied gas. One end of the circulation line 321 is connected to the lower portion of the fuel tank 310, and the other end is connected to the upper portion of the fuel tank 310.

Then, in the circulation line 321, a liquefied gas supply line 330 to be described later is branched downstream of the heating means 323. Accordingly, the liquefied gas discharged from the fuel tank 310 passes through the heating means 323, and a part is supplied to the engine EG through the liquefied gas supply line 330, and the other part is connected to the circulation line 321. Accordingly, it is returned to the fuel tank 310.

Here, the liquefied gas returned to the fuel tank 310 along the circulation line 321 may have a lower boiling point than the liquefied gas supplied to the engine EG through the liquefied gas supply line 330. That is, the liquefied gas returned to the fuel tank 310 along the circulation line 321 may have a higher ratio of nitrogen to liquefied gas supplied to the engine EG through the liquefied gas supply line 330.

In this embodiment, the heating means 323 of the PBU 320 includes a first flow path SL1 through which liquefied gas supplied from the fuel tank 310 flows, and a second flow path SL2 through which steam flows from the heat source ST. It can be configured as a two-stream heat exchanger.

The liquefied gas supply line 330 supplies liquefied gas stored in the fuel tank 310 to the engine EG. The liquefied gas supply line 330 of the present embodiment is branched from the PBU 320 and supplies a portion of the liquefied gas heated by the PBU 320 and returned to the fuel tank 310 to the engine EG. At this time, the liquefied gas supply line 330 is branched downstream of the heating means 323 from the circulation line 321, and then connected to the engine EG via a heater 340, which will be described later.

Thereby, the liquefied gas is first heated by the heating means 323 of the PBU 320, flows along the liquefied gas supply line 330, and secondly heated by the heater 340, and then supplied to the engine EG. do.

The heater 340 is provided on the liquefied gas supply line 330 and may share a flow path through which steam flows to the heating means 323 of the PBU 320. Specifically, the heater 340 may be configured as a two-stream heat exchanger having a second flow path SL2 through which steam flows from the heat source ST and a third flow path SL3 flowing along the liquefied gas supply line 330. .

Additionally, the gas supply system 30 of the present embodiment is provided upstream of the heating means 323 from the liquefied gas supply line 330 to the buffer fuel tank 350 and the liquefied gas supply line 330 for temporarily storing liquefied gas. Prepared to control the pressure and flow rate of the liquefied gas supplied to the engine (EG) gas valve unit 360, the boiler connection line 370 to supply the boil-off gas generated in the fuel tank 310 to the boiler, and the boiler connection The gas heater HT2 provided on the line 370 may be further included.

As described above, the gas supply system 30 according to the third embodiment of the present invention can reduce the manufacturing and operation cost of the gas supply system 30 by omitting the pump for supplying liquefied gas.

In addition, it is possible to improve the thermal efficiency by providing the same heat source to the PBU 320 and the heater 340.

In addition, it is possible to increase the pressurization efficiency by returning a non-condensable gas to the fuel tank 310.

4 is a view showing a gas supply system according to a fourth embodiment of the present invention.

4, the gas supply system 40 according to the fourth embodiment of the present invention is a large storage tank 410, a small fuel tank 420, a liquefied gas supply line 430, a gas heater 440, It may include a return line 450, a bypass line 460 and an evaporative gas return line 470.

For the components having the same reference numbers as the aforementioned components, reference may be made to the above-mentioned disclosure unless contradictory, and duplicate description will be omitted.

The large storage tank 410 stores liquefied gas and a liquefied gas transfer pump 411 is provided therein. Since the large storage tank 410 is substantially the same as the fuel tank of the above-described embodiments, a detailed description is omitted.

The small fuel tank 420 receives liquefied gas from the large storage tank 410. The small fuel tank 420 is smaller than the large storage tank 410 and supplies liquefied gas to the engine EG through the liquefied gas supply line 430, which will be described later.

The large storage tank 410 and the small fuel tank 420 are connected to a transfer line 412, and in the transfer line 412, a liquefied gas transfer pump 411 is provided on the large storage tank 410 side.

The liquefied gas stored in the large storage tank 410 is transferred to the small fuel tank 420 and temporarily stored, and then supplied from the small fuel tank 420 to the engine EG. The liquefied gas transfer pump 411 may operate to transfer liquefied gas when the storage amount of liquefied gas in the small fuel tank 420 decreases.

The liquefied gas supply line 430 is provided to supply the liquefied gas stored in the small fuel tank 420 to the engine EG. One end of the liquefied gas supply line 430 is provided to communicate inside the small fuel tank 420, and the other end is connected to the engine EG.

On the liquefied gas supply line 430, a vaporizer (VP) for vaporizing the liquefied gas and a heater 440 for heating the vaporized liquefied gas to a required temperature of the engine EG are provided.

The vaporizer VP is provided between the small fuel tank 420 and the gas heater 440 to vaporize the liquefied gas provided from the small fuel tank 420.

The gas heater 440 heats the liquefied gas discharged from the small fuel tank 420 and supplies it to the engine EG. The vaporizer VP and the gas heater 440 may be formed of a heat exchanger that exchanges heat with a high temperature heat medium, but is not limited thereto.

The return line 450 returns at least a portion of the liquefied gas heated by the gas heater 440 to the small fuel tank 420. One end of the return line 450 is connected to the upstream of the gas heater 440, and the other end of the return line 450 is connected to the small fuel tank 420. Here, one end of the return line 450 is branched from the liquefied gas supply line 430.

The return line 450 recirculates the liquefied gas heated upstream of the gas heater 440 to the small fuel tank 420 to prevent a pressure drop in the small fuel tank 420. Accordingly, the small fuel tank 420 can supply liquefied gas to the engine EG without pumping by a separate liquefied gas pump.

The bypass line 460 bypasses the small fuel tank 420 from the large storage tank 410 to supply liquefied gas to the gas heater 440. One end of the bypass line 460 is connected to the upstream of the liquefied gas transfer pump 411 in the transfer line 412, the other end is connected to the downstream of the vaporizer (VP) in the liquefied gas supply line (430). That is, the bypass line 460 is branched from the transfer line 412.

The gas supply system 40 of the present embodiment supplies liquefied gas to the bypass line 460 through the transfer pump 411 when the engine EG is initially operated, and the return line 450 when the engine EG is normally operated By increasing the internal pressure of the small fuel tank 420 by using, it is possible to supply the liquefied gas to the engine EG without pumping the liquefied gas stored in the small fuel tank 420 by the liquefied gas transfer pump 411. Here, the initial operation of the engine EG is a state where the internal pressure of the small fuel tank 420 is less than the required pressure of the engine EG, and the normal operation of the engine EG is the internal pressure of the small fuel tank 420 is the engine (EG) ) May be defined as a state corresponding to the required pressure.

That is, if the internal pressure of the small fuel tank 420 is less than the required pressure of the engine EG, the transfer line 412 is cut off and the liquefied gas transfer pump 411 is operated to supply liquefied gas to the bypass line 460. . A portion of the liquefied gas that has passed through the vaporizer (VP) and the gas heater 440 is returned to the small fuel tank 420 through the return line 450 to increase the internal pressure of the small fuel tank 420. Thus, when the internal pressure of the small fuel tank 420 reaches a level corresponding to the required pressure of the engine EG, even if the bypass line 460 is blocked and the liquefied gas transfer pump 411 is stopped, the small fuel tank ( Liquefied gas stored in 420) may be supplied to the engine (EG).

The boil-off gas return line 470 returns the boil-off gas from the small fuel tank 420 to the large storage tank 410. One end of the boil-off gas return line 470 is connected to the top of the small fuel tank 420, and the other end is connected to the top of the large storage tank 410. The boil-off gas generated inside the small fuel tank 420 is supplied to the large storage tank 410 through the evaporation gas return line 470 to prevent the pressure drop of the large storage tank 410.

Meanwhile, the gas supply system 40 of the present embodiment may further include a heat exchanger system that heats the vaporizer VP and the gas heater 440. Specifically, the fruit circulation system is provided on a fruit heater 480 for heating a fruit, a fruit circulation line 481 for circulating a fruit heater 480 and a gas heater 440, and a fruit circulation line 481 It may include a fruit pump 483 to circulate the fruit. Here, the heat medium heater 480 may be configured as a heat exchanger performing heat exchange by receiving steam from the heat source (ST). Further, the fruit may be glycol water, but is not particularly limited.

As described above, the gas supply system 40 according to the fourth embodiment of the present invention can improve the internal pressure rise efficiency by supplying fuel gas by pressing a small fuel tank 420 provided separately.

In addition, by using the liquefied gas transfer pump 411 only during the initial operation of the engine EG, and then pressurizing the small fuel tank 420 using the return line 450, the load of the liquefied gas transfer pump 411 is increased. By reducing and increasing the lifespan, economical operation of the gas supply system 40 is possible.

In addition, it is possible to omit the PBU provided in the fuel tank to increase the internal pressure.

5 is a view showing a gas supply system according to a fifth embodiment of the present invention.

5, the gas supply system 50 according to the fifth embodiment of the present invention includes a storage tank 510, a buffer tank 520, a plurality of boosting tanks 531 and 532, and a plurality of PBUs 541, 542), a fuel transmission line 550, a liquefied gas supply line 560, a return line 570 and an evaporation gas supply line 580 may be included.

For the components having the same reference numbers as the aforementioned components, reference may be made to the above-mentioned disclosure unless contradictory, and duplicate description will be omitted.

The storage tank 510 stores liquefied gas. The storage tank 510 may be provided in a B type or a membrane type.

The buffer tank 520 is provided between the storage tank 510 and the boosting tanks 531 and 532 to be described later, and temporarily stores the liquefied gas transmitted from the storage tank 510. The buffer tank 520 has a smaller capacity than the storage tank 510 and may be located at the bottom of the storage tank 510 so that liquefied gas can be supplied by head pressure.

A first valve V1 for controlling flow rate may be provided between the storage tank 510 and the buffer tank 520.

The boosting tanks 531 and 532 temporarily store liquefied gas delivered from the buffer tank 520 and are provided with two or more. In this embodiment, the boosting tanks 531 and 532 include a first boosting tank 531 having a first PBU 541 and a second boosting tank 532 having a second PBU 542. . However, the boosting tanks 531 and 532 may be provided in three or more.

The boosting tanks 531 and 532 have a smaller capacity than the buffer tank 520 and may be provided side by side in parallel. In addition, the boosting tanks 531 and 532 may be located at the bottom of the buffer tank 520 so that liquefied gas can be supplied by head pressure. That is, the fuel may be sequentially delivered from the storage tank 510 to the boosting tanks 531 and 532 via the buffer tank 520 by the head pressure.

The first PBU 541 is provided in the first boosting tank 531 to heat the liquefied gas stored in the first boosting tank 531 and returns to the first boosting tank 531. The first PBU 541 may vaporize the liquefied gas to maintain the pressure in the first boosting tank 531 within a predetermined section.

The second PBU 542 is provided in the second boosting tank 532 to heat the liquefied gas stored in the second boosting tank 532 and returns to the second boosting tank 532. The second PBU 542 may vaporize the liquefied gas to maintain the pressure in the second boosting tank 532 within a predetermined section.

The fuel delivery line 550 supplies fuel from the buffer tank 520 to the first boosting tank 531 and the second boosting tank 532. One end of the fuel delivery line 550 is connected to the buffer tank 520, and the other end is branched in parallel to be connected to the first boosting tank 531 and the second boosting tank 532, respectively. At this time, the two other ends of the fuel transmission line 550 are connected to the first PBU 541 and the second PBU 542, respectively.

In addition, a high-temperature gas delivery line 555 that is branched from the fuel delivery line 550 and returns high-temperature gas generated in the boosting tank that has stopped fuel supply to the buffer tank 520 is provided. One end of the hot gas delivery line 555 is connected to the fuel delivery line 550, and the other end is connected to the buffer tank 520.

A plurality of valves for controlling the liquefied gas flow rate may be provided on the fuel delivery line 550. Specifically, a third valve V3 is provided downstream of the buffer tank 520, and a fourth valve V4 and a fifth valve V5 are provided in each of the lines where the fuel delivery line 550 is branched in parallel. Can be. In addition, a sixth valve V6 is provided downstream of the first PBU 541 connected to the fuel delivery line 550, and a seventh valve downstream of the second PBU 542 connected to the fuel delivery line 550 ( V7) may be provided.

The liquefied gas supply line 560 is provided to supply the liquefied gas stored in the first boosting tank 531 and the second boosting tank 532 to the engine EG. One end of the liquefied gas supply line 560 is branched in parallel and connected to the first boosting tank 531 and the second boosting tank 532, respectively, and the other end is connected to the engine EG.

A liquefied gas supply line 560 may be provided with a vaporizer (VP) for vaporizing the liquefied gas, a heater (HT) for heating the vaporized liquefied gas to the required temperature of the engine (EG).

In addition, a plurality of valves for controlling the flow rate of liquefied gas may be provided on the liquefied gas supply line 560. Specifically, a ninth valve V9 and a tenth valve V10 are provided downstream of the first boosting tank 531, and an eighth valve V and an eleventh valve (downstream of the second boosting tank 532) V11) may be provided. Here, a line branched between the ninth valve V9 and the tenth valve V10 is connected to the first PBU 541, and a line branched between the eighth valve V and the eleventh valve V11. It may be connected to the second PBU 542.

The return line 570 returns the evaporated gas from the buffer tank 520 to the storage tank 510. One end of the return line 570 is connected to the buffer tank 520, and the other end is connected to the storage tank 510. At this time, a branch line may be connected to the storage tank 510 in the middle of the return line 570, and a second valve V2 may be provided in the branch line.

The evaporation gas supply line 580 mixes the evaporation gas of the buffer tank 520 with the liquefied gas vaporized by the vaporizer (VP). One end of the boil-off gas supply line 580 may be connected to the return line 570, and the other end may be connected to the liquefied gas supply line 560. One end of the boil-off gas supply line 580 may be branched from the return line 570.

The fuel of the storage tank 510 is transmitted to the first boosting tank 531 and the second boosting tank 532 by the head pressure, and the first boosting tank 531 and the second boosting tank 532 alternately engine (EG) to supply fuel. When the first boosting tank 531 supplies fuel, the second boosting tank 532 waits, and when the second boosting tank 532 supplies fuel, the first boosting tank 531 recharges fuel.

Hereinafter, the fuel supply method of the gas supply system 50 according to the fifth embodiment will be described in detail.

First, when the first valve V1 is opened, fuel is transferred from the storage tank 510 to the buffer tank 520.

Next, when the first valve V1 is blocked and the third to fifth valves V3, V4, and V5 are opened, the first boosting tank 531 and the second boosting tank 532 in the buffer tank 520 are opened. Fuel is delivered.

Next, the first PBU 541 and the second PBU 542 are operated to increase the internal pressures of the first boosting tank 531 and the second boosting tank 532. At this time, the third to fifth valves (V3, V4, V5) are closed and the sixth to ninth valves (V6, V7, V8, V9) are opened.

Next, when the tenth valve V10 is opened and the eleventh valve V11 is blocked, fuel is supplied from the first boosting tank 531 to the engine EG, and the second boosting tank 532 is in a high pressure state. To wait.

Next, when the first valve V1 is opened, fuel is transferred from the storage tank 510 to the exhausted buffer tank 520.

Next, when the tenth valve V10 is blocked and the eleventh valve V11 is opened, fuel is supplied from the second boosting tank 532 to the engine EG.

Next, when the fourth valve (V4) is opened, the high pressure gas of the first boosting tank (531) in the state that the internal pressure of the first boosting tank (531) is greater than the internal pressure of the buffer tank (520) It is provided to the buffer tank 520 through 555).

When the internal pressure of the buffer tank 520 increases, fuel is transferred from the buffer tank 520 to the first boosting tank 531 in which fuel is exhausted. At this time, the second valve V2 may be opened to return a portion of the evaporation gas in the buffer tank 520 to the storage tank 510.

While fuel is supplied from the second boosting tank 532 to the engine EG, the first PBU 541 is activated to increase the internal pressure of the first boosting tank 531, and the first boosting tank 531 is high pressure Stand by.

Next, when the first valve V1 is opened, fuel is transferred from the storage tank 510 to the exhausted buffer tank 520.

Next, when the tenth valve V10 is opened and the eleventh valve V11 is blocked, fuel is supplied from the first boosting tank 531 to the engine EG.

Next, when the fifth valve (V5) is opened, the high pressure gas of the second boosting tank (532) in the state that the internal pressure of the second boosting tank (532) is greater than the internal pressure of the buffer tank (520) It is provided to the buffer tank 520 through 555).

When the internal pressure of the buffer tank 520 rises, fuel is transferred from the buffer tank 520 to the second boosting tank 532 in which fuel is exhausted. At this time, the second valve V2 may be opened to return a portion of the evaporation gas in the buffer tank 520 to the storage tank 510.

While fuel is supplied from the first boosting tank 531 to the engine EG, the second PBU 542 is activated to increase the internal pressure of the second boosting tank 532, and the second boosting tank 532 is high pressure Stand by.

As described above, the gas supply system 50 according to the fifth embodiment of the present invention can reduce the manufacturing and operation cost of the gas supply system 50 by omitting a pump for supplying liquefied gas.

In addition, it is possible to stably supply fuel gas continuously by using a plurality of boosting tanks 531 and 532 alternately.

In addition, it is possible to omit the liquefied gas pump from all the tanks by transferring the fuel gas at the head pressure in a plurality of tank structures arranged up and down.

6 is a view showing a gas supply system according to a sixth embodiment of the present invention.

Referring to FIG. 6, the gas supply system 60 according to the sixth embodiment of the present invention includes a fuel tank 610, a supply line 620, a plurality of heat exchangers 631 and 632, and a plurality of return lines ( 641, 642).

For the components having the same reference numbers as the aforementioned components, reference may be made to the above-mentioned disclosure unless contradictory, and duplicate description will be omitted.

The supply line 620 is connected from the fuel tank 610 to the engine EG, and at least a portion is provided in parallel. In this embodiment, the supply line 620 may include a first supply line 621 and a second supply line 622 that are branched downstream of the fuel tank 610 and are provided in parallel with each other.

The plurality of heat exchangers 631 and 632 are respectively installed at portions provided in parallel in the supply line 620. Specifically, the first heat exchanger 631 is provided on the first supply line 621, and the second heat exchanger 632 is provided on the second supply line 622.

The first heat exchanger 631 and the second heat exchanger 632 heat the liquefied gas to different temperatures. At this time, any one heat exchanger that heats to a relatively low temperature is used as a PBU heater for increasing the internal pressure of the fuel tank 610 by allowing the heated liquefied gas to be returned to the fuel tank 610, and heating to a relatively high temperature Another heat exchanger, which supplies the heated liquefied gas to the engine EG.

For example, when the heating temperature of the first heat exchanger 631 is lower than the heating temperature of the second heat exchanger 632, liquefied gas passing through the first heat exchanger 631 is returned to the fuel tank 610, 2 The liquefied gas passing through the heat exchanger 632 is supplied to the engine EG.

In addition, the heat flow rate supplied to any one of the first heat exchanger 631 and the second heat exchanger 632 used as a PBU heater may be set smaller than the heat flow rate supplied to the other.

The plurality of return lines 641 and 642 are provided to return to the fuel tank 610 downstream of each of the first heat exchanger 631 and the second heat exchanger 632. Specifically, the plurality of return lines 641 and 642 are provided at the downstream of the first heat exchanger 631 and the first return line 641 returned to the fuel tank 610 and downstream of the second heat exchanger 632. A second return line 642 returned to the fuel tank 610 may be included.

Additionally, return valves RV1 and RV1 that maintain the pressure of the fuel tank 610 constant may be provided in each of the first return line 641 and the second return line 642. In one embodiment, the return valves RV1 and RV1 may be self-regulating valves.

As described above, the gas supply system 60 according to the sixth embodiment of the present invention can simplify the system configuration by integrating the PBU and the liquefied gas heater.

In addition, two heat exchangers are provided in a configuration to back up each other, thereby enabling stable operation of the gas supply system 60.

7 is a view showing a gas supply system according to a seventh embodiment of the present invention.

Referring to FIG. 7, the gas supply system 70 according to the seventh embodiment of the present invention includes a fuel tank 710, a baffle structure 715, a liquefied gas supply line 720, a PBU 730, and a return line ( 740) and the boil-off gas supply line (750).

In this embodiment, since the configuration other than the fuel tank 710 is substantially the same as those of the first embodiment described above, a duplicate description will be omitted.

The liquefied gas is heated in the PBU 730 and injected into the gas phase portion of the fuel tank 710. When the surface area of the received liquefied gas surface is large, pressurization efficiency is reduced.

Therefore, the fuel tank 710 of this embodiment can be configured in a vertical type to reduce the surface area of the water surface. Accordingly, the pressurization efficiency of the fuel tank 710 may be improved.

In addition, by installing a baffle (Baffle) structure 715 inside the fuel tank 710, it is possible to prevent sloshing. The baffle structure 715 is a plurality of spaced apart in the height direction inside the fuel tank 710, each of which is alternating from both sides, so that the liquefied gas can flow in a zigzag form.

8 is a view showing a gas supply system according to an eighth embodiment of the present invention.

Referring to FIG. 8, the gas supply system 80 according to the eighth embodiment of the present invention includes a plurality of fuel tanks 811 and 812, a plurality of connection pipes 821, 822 and 823, and a liquefied gas supply line 830. ), PBUs 841 and 842, a return line 850, and an evaporation gas supply line 860.

For the components having the same reference numbers as the aforementioned components, reference may be made to the above-mentioned disclosure unless contradictory, and duplicate description will be omitted.

The fuel tanks 811 and 812 of this embodiment are configured side by side in two or more. PBUs 841 and 842 are provided in each of the fuel tanks 811 and 812 to increase the internal pressure. Only a part of the fuel tanks 811 and 812 may operate the PBU to supply liquefied gas, or the whole may operate the PBU to supply liquefied gas.

The fuel tanks 811 and 812 may be configured in a vertical type so that the pressurization efficiency is improved. In addition, the fuel tanks 811 and 812 may be interconnected with connection pipes 821, 822, and 823. The connecting pipes 821, 822, and 823 may be vertically disposed along the height direction of the fuel tanks 811, 812.

When the liquefied gas is supplied by alternately switching the fuel tanks 811 and 812, a pressure fluctuation may occur, but the fuel tanks 811 and 812 of this embodiment are connected to each other by connecting pipes 821, 822, and 823. Pressure fluctuations between the fuel tanks 811 and 812 can be reduced. Also, in case of emergency, the fuel tanks 811 and 812 can back up each other.

In addition to the above-described embodiments, the present invention encompasses all of the embodiments generated by a combination of at least one embodiment and a known technique, or a combination of at least two or more embodiments.

The present invention has been described in detail through specific examples, but this is for specifically describing the present invention, and the present invention is not limited to this, and by a person skilled in the art within the technical spirit of the present invention. It will be apparent that the modification or improvement is possible.

All simple modifications or changes of the present invention belong to the scope of the present invention, and the specific protection scope of the present invention will be clarified by the appended claims.

10: gas supply system EG: engine
110: fuel tank 120: liquefied gas supply line
HT: Heater VP: Carburetor
130: PBU 140: return line
150: evaporation gas supply line

Claims (9)

A large storage tank that stores liquefied gas and is provided with a liquefied gas transfer pump;
A small fuel tank receiving liquefied gas from the large storage tank;
A gas heater that heats the liquefied gas discharged from the small fuel tank and supplies it to an engine;
A return line returning at least a portion of the liquefied gas heated in the gas heater to the small fuel tank; And
A bypass line for supplying liquefied gas to the gas heater by bypassing the small fuel tank in the large storage tank,
Liquefied gas stored in the small fuel tank by supplying liquefied gas to the bypass line through the transfer pump during the initial operation of the engine and raising the internal pressure of the small fuel tank using the return line during normal operation of the engine For the gas supply system, characterized in that for supplying the liquefied gas to the engine without pumping by the liquefied gas transfer pump. The method of claim 1, wherein the initial operation,
Gas supply system, characterized in that the internal pressure of the small fuel tank is less than the required pressure of the engine. The method of claim 1, wherein the normal operation,
Gas supply system, characterized in that the internal pressure of the small fuel tank corresponds to the required pressure of the engine. According to claim 1,
Gas supply system characterized in that it further comprises a transfer line equipped with the liquefied gas transfer pump connecting the large storage tank and the small fuel tank. The method of claim 4,
Gas supply system characterized in that the bypass line is branched from the transfer line. According to claim 1,
A gas supply system further comprising an evaporation gas return line from which the evaporation gas returns from the small fuel tank to the large storage tank. According to claim 1,
A fruit heater for heating the fruit;
A fruit circulation line in which the fruit circulates the fruit heater and the gas heater; And
Gas supply system characterized in that it further comprises a fruit pump provided in the fruit circulation line. According to claim 1,
A gas supply system provided between the small fuel tank and the gas heater, further comprising a vaporizer for vaporizing liquefied gas provided from the small fuel tank. A ship characterized by having the gas supply system according to any one of claims 1 to 8.

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