KR20230034118A - Fuel gas supply system and ship including the same - Google Patents

Abstract

A gas supply system according to the present invention may comprise: a storage tank provided on a hull and storing liquefied gas; a vaporizer for heating the liquefied gas in the storage tank and supplying the same to a customer; a PBU which heats and circulates the liquefied gas in the storage tank to the storage tank; and a buffer tank for adjusting the pressure by receiving boil-off gas of the storage tank. Therefore, the present invention can provide the gas supply system in which a line of liquefied gas and a line of the boil-off gas of liquefied gas are integrated, and the vaporizer for liquefied gas and a heater for boil-off gas of liquefied gas are integrated.

Description

Gas supply system and ship having the same {Fuel gas supply system and ship including the same}

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

A ship is a means of transportation that carries a large amount of minerals, crude oil, natural gas, or containers and navigates the ocean. .

Such a ship generates thrust by driving an engine or a gas turbine. At this time, the engine uses oil fuel such as gasoline or diesel to move a piston so that the crankshaft is rotated by the reciprocating motion of the piston, and the shaft connected to the crankshaft. is rotated to drive the propeller, while the gas turbine burns fuel together with compressed air, and generates power by rotating turbine blades through the temperature/pressure of the combustion air to transmit power to the propeller.

In addition, LNG carriers that transport liquefied natural gas, a type of liquefied gas, use LNG as fuel to drive demand sources such as engines and turbines. LNG is a clean fuel and has a large amount of reserves. Since it is also more abundant than oil, the method of using LNG as a fuel for consumers is being applied to ships other than LNG carriers.

When supplying LNG or boil-off gas of LNG to a consumer such as an engine or turbine, the boil-off gas of LNG or LNG must be heated or pressurized to meet the temperature and pressure required by the consumer. Heating means must be provided.

On the other hand, in the system for supplying liquefied natural gas to the engine, a storage tank for pressurizing and storing liquefied natural gas is provided. Since the pressure may increase, the boil-off gas should be discharged to the outside to reduce the pressure in the storage tank, or the discharged gas should be combusted through a gas burner. In this case, operation and maintenance of the pressure of the storage tank may be complicated. On the other hand, when the liquefied natural gas is discharged from the storage tank to the outside, the pressure in the storage tank decreases and the liquefied natural gas may not be supplied to the vaporizer. Therefore, in order to keep the internal pressure of the storage tank constant, the liquefied natural gas stored in the storage tank must be vaporized and the vaporized liquefied natural gas must be circulated and injected into the storage tank.

In this way, a pressurizing means and a heating means must be provided in a ship to match the temperature and pressure conditions of the customer and the temperature and pressure conditions of the storage tank. Since the installation and operating costs of the fuel supply system increase, it is necessary to configure the system so that the pressurization means and the heating means are provided with a small number.

The present invention has been created to solve the problems of the prior art as described above, and an object of the present invention is to integrate a line of liquefied gas and liquefied gas boil-off gas and supply gas that integrates a vaporizer of liquefied gas and a heater of liquefied gas boil-off gas. to provide the system.

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

A gas supply system according to the present invention includes a storage tank provided on a hull and storing liquefied gas; a vaporizer for heating the liquefied gas in the storage tank and supplying it to a customer; a PBU which heats and circulates the liquefied gas in the storage tank to the storage tank; And it may include a buffer tank for adjusting the pressure by receiving the boil-off gas of the storage tank.

Specifically, the buffer tank may be located at the front or rear of the vaporizer.

Specifically, a fruit line through which the fruit supplied to the vaporizer or the PBU circulates, and the fruit line may connect the vaporizer and the PBU in series or parallel.

Specifically, the vaporizer may be a shell and tube type heat exchanger.

Specifically, the PBU may be a shell and plate type heat exchanger.

A vessel according to the present invention may include the gas supply system.

The gas supply system of the present invention has the following effects.

The gas supply system according to the present invention integrates a line of liquefied gas and liquefied gas boil-off gas, and integrates a vaporizer of liquefied gas and a heater of liquefied gas boil-off gas to minimize system equipment costs and improve space efficiency in a ship. there is.

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

1 is a conceptual diagram illustrating a gas supply system according to an embodiment of the present invention.
2 is a conceptual diagram illustrating a gas supply system according to another embodiment of the present invention.
3 is a conceptual diagram illustrating a gas supply system according to another embodiment of the present invention.

Objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In adding reference numerals to components of each drawing in this specification, it should be noted that the same components have the same numbers as much as possible, even if they are displayed on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

Hereinafter, in the present specification, liquefied gas may be used to encompass all gaseous fuels generally stored in a liquid state, such as liquefied natural gas (LNG) or liquefied petroleum gas (LPG), ethylene, and ammonia. (Liquefied Natural Gas), and when it is not in a liquid state by heating or pressurization, etc., it can be expressed as liquefied gas for convenience. This can be applied to boil-off gas as well.

In the following, it should be noted that high pressure (HP), low pressure (LP), high temperature and low temperature are relative and do not represent absolute values.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a conceptual diagram showing a gas supply system according to an embodiment of the present invention, and FIG. 2 is a conceptual diagram showing a gas supply system according to another embodiment of the present invention.

1 is a conceptual diagram showing a gas supply system 1 according to an embodiment of the present invention.

Referring to FIG. 1, a gas supply system 1 according to the present invention includes a storage tank 10, a carburetor 20, a PBU 30, an engine 40, and a buffer tank 50, and includes a heterogeneous fuel engine. It can be used for floating structures such as ships using floating, production, storage and offloading (FPSO). Here, the heterogeneous fuel engines include all engines using heterogeneous fuels regardless of engine type, such as a low-pressure gas injection type or a high-pressure gas injection type.

The storage tank 10 stores liquefied gas at atmospheric pressure inside, and allows an increase in internal pressure due to the generation of boil-off gas. For this purpose, it may be made of a material and structure to allow an increase in internal pressure, In addition to being made of a material to sufficiently withstand the cryogenic temperature of the liquefied gas, an insulation member may be installed to block heat input and output.

A plurality of storage tanks 10 may be provided, and the storage tanks 10 may be connected to each other through pipes through which liquefied gas or boil-off gas may move. In order to minimize the risk of gas leakage by blocking contact with the outside, the storage tank 10 and the pipe connecting the storage tank 10 to each other may be surrounded by a tank connection portion (not shown) forming a gas tight space. Pipes connecting the storage tanks 10 to each other are surrounded by tank connection parts (not shown), so that the risk of gas leakage from the gas supply system 1 can be minimized even if a double wall pipe is not applied.

In general, in order to prevent damage to the hull when liquefied gas leaks in the liquefied gas pipe, the vaporizer 20 is composed of a skid, and the skid is a fuel supply system (FGSS) room It is disposed in a room or a room that can replace it, and a drip tray (not shown) may be installed along the path in which the pipe is installed. In the present invention, the storage tank 10 and the pipe connecting the storage tank 10 to each other are surrounded by a tank connection portion (not shown) to replace the fuel supply system room and the drip tray, thereby simplifying the system.

The gas supply system 1 is provided with a steam line (not shown) connecting the storage tanks 10 to each other so that the boil-off gas can move between the storage tanks 10, so that the pressure of a specific storage tank 10 increases rapidly or , can prevent the lowering. Moreover, it is possible to secure operational diversity of the storage tank 10 by controlling one storage tank 10 to be filled with 100% of the liquefied gas or controlling two storage tanks 10 to be filled with 50% of the liquefied gas. there is.

The vaporizer 20 receives the liquefied gas delivered to the PBU 30 through the liquefied gas supply line L1 and vaporizes the liquefied gas, or boil off gas (BOG) through the boil-off gas supply line L2. ) is received, and the boil-off gas is heated so that the boil-off gas meets the temperature conditions of the engine 40. The boil-off gas supply line (L2) joins the liquefied gas supply line (L1) upstream of the vaporizer (20) to supply both the liquefied gas and boil-off gas to the vaporizer (20), the vaporizer (20) Boiled gas can be heated.

The shell-and-plate heat exchanger uses a vortex effect. When the shell-and-plate heat exchanger is used to supply fuel to an engine, pressure fluctuations may occur in vaporized fuel. Therefore, in the case of the vaporizer 20 used before supplying the engine, a shell-and-tube type heat exchanger is used.

A pressure build-up unit (PBU) 30 is provided in the PBU line L3 connected to the storage tank 10 to heat the liquefied gas stored in the storage tank 10 to vaporize the liquefied gas and return it to the storage tank 10 let it The PBU 30 may transfer the vaporized liquefied gas to the storage tank 10 and maintain it within a certain pressure range in the storage tank 10 .

When the liquefied gas is discharged from the storage tank 10 to the outside, the pressure in the storage tank 10 is lowered, and as a result, the liquefied gas may not be supplied to the vaporizer 20, but the PBU 30 vaporizes the liquefied gas By returning to the storage tank 10, the pressure drop in the storage tank 10 is prevented, and the supply of liquefied gas to the vaporizer 20 can be smoothly performed.

In this way, the liquefied gas in the storage tank 10 can be delivered to the PBU 30 only by the head pressure of the storage tank 10 . When the PBU 30 heats the liquefied gas and transfers it to the storage tank 10 to pressurize the storage tank 10, the liquefied gas in the storage tank 10 is supplied to the vaporizer 20 and vaporized through the vaporizer 20. The evaporated gas may be supplied to the engine 40.

When the PBU 30 is a shell & tube type, in the case of a single path type, the price is high and maintainability is remarkably low, so it is often a two path type. If the vaporization path is two-pass, there is a possibility of a vapor pocket, and because of the U-shaped tube, there is a possibility of a vapor pocket occurring when the ship is tilted vertically / horizontally. In the gas supply system 1 of the present invention, it is preferable that the PBU 30 is a single-pass shell-and-plate heat exchanger. Moreover, the shell-and-plate type heat exchanger has a relatively compact design and is easy to arrange in a ship and to secure a required head.

Gas supply system 1 according to the present invention, the first block valve 60 on the liquefied gas supply line (L1), the second block valve 61 and the PBU line (L3) on the boil-off gas supply line (L2) ) may be provided with a third block valve 62 on. The block valves 60, 61, and 62 are valves for blocking flow, and may be butterfly valves, ball valves, or gate valves.

In particular, when the third block valve 62 is a valve that controls flow, such as a throttle valve, the differential pressure generated in the valve becomes excessive in the low flow region, so that liquefied gas may not flow to the PBU 30, so that the third block valve 62 may not flow. Block valve 62 is preferably a valve for blocking the flow. A flow blocking valve is provided at the front end of the PBU 30 instead of a flow control valve, and the flow is controlled in an on/off manner to reduce pressure loss in the pipe when the PBU 30 operates, thereby lowering the required head level of the PBU 30. .

In addition, the gas supply system 1 according to the present invention may include a fuel gas press control valve (PCV) 70 on the liquefied gas supply line L1 at the front of the vaporizer 20, or A pressure control valve 70 may be provided on the rear end of the carburetor 20 and on the engine line L4.

When the pressure control valve 70 is provided at the rear end of the vaporizer 20, gaseous fuel passes through the pressure control valve 70, so the pressure control valve 70 processes the gaseous fuel The pressure control valve 70 may be made smaller. Therefore, compared to the pressure control valve 70 provided at the front end of the vaporizer 20, when the pressure control valve 70 is provided at the rear end of the vaporizer 20, the size of the pressure control valve 70 is reduced and the equipment It can reduce cost and increase space efficiency in a ship. Therefore, it is preferable that the pressure control valve 70 is provided at the rear end of the vaporizer 20.

In addition, the gas supply system 1 according to the present invention may include both a shut-off valve 80 and a check valve 81 on the boil-off gas supply line L2. The flow of the boil-off gas supply line (L2) is controlled by the shut-off valve 80, and when the liquefied gas flows in the boil-off gas supply line (L2), the check valve 81 can prevent the back flow of the liquefied gas. there is. In addition, a check valve (not shown) may be provided in the liquefied gas supply line L1, and a reverse flow of the liquefied gas may be prevented by the check valve.

In addition, the gas supply system 1 according to the present invention may include a heat medium supply line (L5), and a 3-way valve (90) and a heat medium tank ( 100), a heat pump 110 and a heat heat heater 120 may be provided. The heat medium moves along the fruit supply line (L5), and after the fruit is heated in the heat medium heater 120, the vaporizer 20 and the PBU 30 pass through the vaporizer 20 and the PBU 30. ) can heat liquefied gas or boil-off gas.

In the fruit heater 120, the fruit may be heated by steam, jacket cooling water (JCW, engine cooling water), or electricity. The fruit heater 120 may be provided in plural, and both the fruit heater 120 for heating the fruit using jacket cooling water and the heat fruit heater 120 for heating the fruit using electricity may be provided.

In addition, since the safety of the gas supply system 1 may decrease when the temperature of the heat medium is adjusted by adjusting the load of the heat medium heater 120, the flow in the direction of the heat medium heater 120 is adjusted according to the temperature of the heat medium. A three-way valve 90 capable of adjusting the temperature of the fruit in the fruit supply line (L5) may be provided in the fruit supply line (L5). The diesel line L6 may be branched from the 3-way valve 90.

2 is a conceptual diagram illustrating a gas supply system according to another embodiment of the present invention.

The gas supply system 1 according to the present invention may include a buffer tank 50 at a rear end of the vaporizer 20 . Since the buffer tank 50 can accommodate boil-off gas by providing an empty space therein, it is possible to reduce pressure fluctuations in the downstream line of the vaporizer 20. Of course, as shown in FIG. 1 , the gas supply system 1 according to the present invention may include a buffer tank 50 in front of the vaporizer 20 .

3 is a conceptual diagram illustrating a gas supply system according to another embodiment of the present invention.

Referring to FIG. 3, in the gas supply system 1 according to the present invention, the heat supply line L5 is connected to the vaporizer 20, the vaporizer heat transfer line L7, and the PBU heat transfer line connected to the PBU 30 ( L8), the carburetor fruit line (L7) and the PBU fruit line (L8) may be connected in parallel. Of course, as in FIG. 1, in the gas supply system 1, the carburetor heat transfer line (L7) and the PBU heat transfer line (L8) in FIG. 3 may be connected in series as in the heat supply line (L5) in FIG. there is.

As such, the gas supply system 1 according to an embodiment of the present invention integrates a line of liquefied natural gas and liquefied natural gas evaporation gas, and integrates a vaporizer of liquefied natural gas and a heater of liquefied natural gas evaporation gas to form a system. It can minimize facility cost and improve space efficiency in the ship.

Of course, the present invention is not limited to the above-described embodiment, and may include a combination of the above embodiments or a combination of at least one of the above embodiments and known technology as another embodiment.

In the above, the present invention has been described centering on the embodiments of the present invention, but these are only examples and do not limit the present invention, and those skilled in the art to which the present invention belongs do not deviate from the essential technical content of the present embodiment. It will be appreciated that various combinations or modifications and applications not exemplified in the embodiments are possible within the range. Therefore, technical contents related to modifications and applications that can be easily derived from the embodiments of the present invention should be construed as being included in the present invention.

1: gas supply system 10: storage tank
20: vaporizer 30: PBU
40: engine 50: buffer tank
60, 61, 62: block valve 70: pressure control valve
80: shutoff valve 81: check valve
90: three-way valve 100: fruit tank
110: fruit pump 120: fruit heater
L1: liquefied gas supply line L2: boil-off gas supply line
L3: PBU line L4: engine line
L5: fruit line L6: diesel line
L7: carburetor fruit line L8: PBU fruit line

Claims (6)

A storage tank provided on the hull and storing liquefied gas;
a vaporizer for heating the liquefied gas in the storage tank and supplying it to a customer;
a PBU which heats and circulates the liquefied gas in the storage tank to the storage tank; and
A gas supply system comprising a buffer tank for receiving the boil-off gas of the storage tank and adjusting the pressure. According to claim 1,
The buffer tank is a gas supply system located at the front or rear of the vaporizer. According to claim 1,
A fruit line in which the fruit supplied to the vaporizer or the PBU circulates,
The heat transfer line connects the vaporizer and the PBU in series or parallel. According to claim 1,
The vaporizer is a shell-and-tube type heat exchanger gas supply system. According to claim 1,
The PBU is a shell and plate type heat exchanger gas supply system. A vessel equipped with the gas supply system according to any one of claims 1 to 5.

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