JP7078204B2 - Liquefied gas fuel ship - Google Patents

Description

The present invention relates to a liquefied gas fuel ship that uses liquefied gas as a fuel for a main engine or the like.

In recent years, the International Maritime Organization has been gradually advancing SOx emission regulations for ships in each sea area. Since the amount of SOx emitted is proportional to the sulfur concentration of the fuel oil, the SOx emission regulation is regulated by the sulfur concentration of the fuel oil (mass percent (%)). The regulation value of the sulfur concentration of fuel oil in the sea area designated by ECA) is 0.1%, and the regulation value in the general sea area outside the emission regulation sea area is 3.5%. To comply with such SOx emission regulations for each sea area, a dual fuel-fired diesel engine is adopted for the main engine, and heavy oil and sulfur, which have a high sulfur content but high loading efficiency, are used as the fuel for the main engine in each sea area. It is conceivable to maintain transportation efficiency and operating costs by switching between natural gas, which has a low component concentration but low loading efficiency.

However, after 2020 or 2025, the regulation value of the sulfur concentration of fuel oil in general sea areas (entire sea area) will be tightened to 0.5%, so it cannot be dealt with by switching fuels. In the future, it will be necessary to use fuel oil that does not contain sulfur or fuel oil that has a sulfur concentration of less than the specified value as fuel for the main engine and power generation engine, such as LNG, liquefied ethane, and LPG that do not contain sulfur. Liquefied gas fuels, alternative fuels such as methanol and ethanol, or low sulfur fuels must be used. Since low-sulfur fuel oil is expensive and may be in short supply, the use of sulfur-free LNG, liquefied ethane, LPG and other liquefied gas fuels and alternative fuels such as methanol and ethanol is being considered. ..

On the other hand, in order to store liquefied gas fuel, it is necessary to keep the inside of the tank at low temperature and high pressure. A self-supporting tank of shape is used. Therefore, the liquefied gas fuel tank cannot be arranged in the gap of the hull structure like the conventional fuel oil tank, and the space used as the conventional cargo compartment is occupied by the liquefied gas fuel tank, and the cargo loading capacity is increased. Is significantly reduced. In particular, LNG and the like have a small specific gravity, so a large volume fuel tank is required, and the cargo space becomes even narrower. To solve such a problem, a configuration has been proposed in which the liquefied gas fuel tank is arranged on the exposed deck above the engine room (see Patent Document 1).

Special Table 2016-508916 Gazette

However, if the liquefied gas fuel ship is a car carrier, RO-RO ship, or passenger ship, the upper part of the engine room is used as cargo space, and for other ship types, there is a living quarter on the exposed deck above the engine room. There is an engine casing, and the area that can be used as a fuel tank installation space is limited. Therefore, it is still necessary to secure a large space for the liquefied gas fuel tank under the exposed deck, and it cannot be said that a sufficient cargo compartment can be secured. Further, when co-firing a liquid fuel (for example, fuel oil) and a liquefied gas fuel, it is necessary to arrange tanks for both the liquid fuel and the liquefied gas fuel, and the cargo compartment is further reduced.

The present invention is a liquefied gas fuel that can secure a wide cargo compartment while reducing SOx emissions as compared with the case where both liquefied gas fuel and liquid fuel are mounted and co-combusted to burn liquid fuel such as fuel oil alone. The purpose is to provide a ship.

The liquefied gas fuel ship of the present invention includes a liquid fuel tank for storing liquid fuel, a liquefied gas fuel tank for storing liquefied gas fuel, an engine that can be operated by co-firing liquid fuel and liquefied gas fuel, and a liquid fuel for the engine. It is provided with a fuel supply means for supplying and / or liquefied gas fuel in a desired ratio, and is characterized in that a liquid fuel tank is arranged along the ship side and / or the bottom of the ship.

The liquefied gas fuel tank has a cylindrical shape with a radius r, and at least one of the liquid fuel tanks is inside the position separated by a radius r from the outer shell of the liquefied gas fuel tank, and the liquefied gas fuel tank and the ship side. It is preferably located in the space between the outer panel.

For example, at least a pair of liquefied gas fuel tanks are provided in the width direction of the ship, and at least one of the liquid fuel tanks is arranged between the pair of liquefied gas fuel tanks. The liquid fuel tank is located above, for example, the deck on which the support structure for the liquefied gas fuel tank is installed. Further, the liquid fuel tank is located below the center of the liquefied gas fuel tank, for example. A part of the liquid fuel tank is adjacent to, for example, a part from the front end to the rear end of the liquefied gas fuel tank.

The liquefied gas fuel tank has a cylindrical shape, and the side wall of the liquid fuel tank facing the liquefied gas fuel tank has an inclined surface along the cylindrical surface of the liquefied gas fuel tank. The liquid fuel is, for example, fuel oil.

When the sulfur concentration of the liquid fuel is S1 [%], the specific gravity is γ1, the sulfur concentration of the liquefied gas fuel is S2 [%], the specific gravity is γ2, and the sulfur concentration as the emission target is S [%]. It is preferable that the volume ratio of the liquid fuel tank to the volume of the liquefied gas fuel tank is ((S—S2) / γ1) :( (S1-S) / γ2). Further, the ratio of the volume of the liquefied gas fuel tank to the volume of the liquid fuel tank (liquefied gas fuel tank volume / liquid fuel tank volume) is preferably in the range of 2 to 13.

According to the present invention, both liquefied gas fuel and liquid fuel are mounted and co-firing, and liquefaction that can secure a wide cargo compartment while reducing SOx emissions as compared with the case where liquid fuel such as fuel oil is burned alone. Can provide gas fueled ships.

It is a block diagram which shows the structure of the fuel supply system of the liquefied gas fuel ship which is one Embodiment of this invention. It is a side view (a), a cross-sectional view (b), and a plan view (c) of the liquefied gas fuel ship of this embodiment. It is an enlarged view of FIG. 2 (b). It is a modification of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing a configuration of a fuel supply system of a liquefied gas fuel ship according to an embodiment of the present invention.

The liquefied gas fuel ship 10 (see FIG. 2) of the present embodiment is, for example, under an exposed deck such as an automobile carrier, a container ship, a RO-RO ship, a cargo ship, a passenger ship, etc., which adopts a dual fuel-fired diesel engine in the main engine 12. It is a ship with a large space for arranging cargo and personnel in a closed area. The fuel of the main engine 12 includes a liquid fuel such as fuel oil (for example, light oil, heavy oil A to C, etc.) as the first fuel (fuel that is liquid at room temperature) and a liquefied gas (LNG, liquefied ethane, LPG) as the second fuel. A liquefied gas fuel such as) is used, and the liquid fuel and / or the liquefied gas fuel is supplied to the main engine 12 through the fuel supply system 11.

The fuel oil is stored in the fuel oil tank (first fuel tank) 14, and the fuel oil stored in the fuel oil tank 14 is sent to the fuel oil heater 18 by the fuel supply pump 16 in the fuel oil heater 18. After being warmed up, it is injected from the fuel oil injection valve 20 into each cylinder of the main engine 12 at a predetermined timing. On the other hand, the liquefied gas fuel is stored in the liquefied gas fuel tank (second fuel tank) 22, and the liquefied gas in the liquefied gas fuel tank 22 is pressurized and vaporized in the gas fuel supply system 24 and passed through the gas valve train 26. Then, the gas fuel is injected from the gas fuel injection valve 28 into each cylinder of the main engine 12 at a predetermined timing.

The fuel injection time of the fuel oil injection valve 20 and the gas fuel injection valve 28 is controlled by the fuel supply control unit 30, whereby the amount of fuel oil and liquefied gas fuel supplied to the main engine 12 X, Y [kg / h]. Are controlled respectively. That is, the fuel supply control unit 30 has a main engine required value Z [kJ / h], a sulfur content concentration S1 [%] of the fuel oil, a calorific value A [kJ / kg], and a sulfur content concentration S2 of the liquefied gas fuel. Fuel supply amounts X and Y are calculated based on [%], calorific value B [kJ / kg], and target sulfur concentration S [%], respectively, and the fuel oil injection valve 20 and gas fuel injection are calculated based on the same values. The fuel injection time of the valve 28 is controlled. The sulfur concentration here is a mass percent.

Here, the sulfur content concentration S1 [%] and calorific value A [kJ / kg] of the fuel oil and the sulfur content concentration S2 [%] and calorific value B [kJ / kg] of the liquefied gas fuel are obtained at the time of purchasing each fuel. The target sulfur content concentration S [%] is a value set by a regulation value for each sea area or the like. These values are set, for example, in the fuel supply control unit 30 before the operation of the main engine. Further, the main engine required value Z [kJ / h] is a value determined from the output of the main engine 12 in the main engine control, and is input from the control unit of the main engine 12, for example.

The output of the main engine 12 is the calorific value per unit time supplied by the fuel oil: A [kJ / kg] · X [kg / h] and the calorific value per unit time supplied by the liquefied gas fuel: B [kJ]. It is the sum of / kg] and Y [kg / h]. Therefore, in order to satisfy the main engine required value Z [kJ / h] by supplying both fuels, the fuel oil supply amount X and the liquefied gas fuel supply amount Y must satisfy the following equation (1).
Z = A ・ X + B ・ Y (1)

Further, in order to satisfy the target sulfur concentration S [%], which is the regulation value, in the output corresponding to the main engine required value Z [kJ / h], the fuel oil supply amount X and the liquefied gas fuel supply amount Y must be satisfied. , It is necessary to satisfy the following equation (2).
S ≧ (Mass of mixed fuel sulfur) / (Mass of mixed fuel total)
≧ (S1 ・ X + S2 ・ Y) / (X + Y) (2)

Here, if S2 <S <S1, then from equations (1) and (2),
X ≦ Z ・ (S—S2) / (B ・ (S1-S) + A ・ (S—S2)) (3)
Y ≧ Z ・ (S1-S) / (B ・ (S1-S) + A ・ (S—S2)) (4)
Will be.

For example, when the equal sign holds in the equations (3) and (4), that is, when the sulfur concentration is set to the limit of the regulation value, the supply amount ratio X: Y of the fuel oil and the liquefied gas fuel is.
X: Y = SS2: S1-S
Will be. Further, the volume ratio V1: V2 of the fuel oil and the liquefied gas fuel required at this time is
V1: V2 = ((S—S2) / γ1): ((S1-S) / γ2) (5)
Will be. Here, γ1 is the specific gravity of the fuel oil, and γ2 is the specific gravity of the liquefied gas fuel.
When the volume ratio of the fuel oil tank and the liquefied gas fuel tank is set to the equation (5), the volumes of both tanks are the optimum ratios for both fuels.

For example, when equation (5) is used and the target sulfur concentration is 0.5%, the optimum volume ratio between the fuel oil tank and the liquefied gas fuel tank is as follows. A fuel oil tank that can load heavy oil (density about 980 kg / m ³ , sulfur concentration 3.5%) and a liquefied gas fuel tank that can load LNG fuel (density about 450 kg / m ³ , sulfur concentration 0%). The optimum volume ratio is about 1:13. In addition, a tank that can load heavy oil (density about 900 kg / m ³ , sulfur concentration 1.0%) and a liquefied gas fuel tank that can load LNG fuel (density about 450 kg / m ³ , sulfur concentration 0%). The optimum volume ratio is about 1: 2. From these facts, it is preferable that the ratio of "liquefied gas fuel tank volume" to "fuel oil tank volume (liquefied gas fuel tank volume / fuel oil tank volume) is generally in the range of 2 to 13.

Next, with reference to FIG. 2, the arrangement and volume of the fuel oil tank 14 and the liquefied gas fuel tank 22 will be described. 2A and 2B are a side view (FIG. 2A), a cross-sectional view (FIG. 2B), and a plan view (FIG. 2C) of the liquefied gas fuel ship 10. 2 (b) is a cross-sectional view taken along the line II of FIG. 2 (a) passing through the substantially center of the liquefied gas fuel tank 22, and FIG. 2 (c) is FIG. 2 (a) passing through the substantially center of the liquefied gas fuel tank 22. It is a plan view of the II-II cross section of). An enlarged view of FIG. 2B is shown in FIG. Further, FIG. 4 shows a modified example.

In FIG. 2, a car carrier will be described as an example of the liquefied gas fuel ship 10. As shown in FIG. 2, in the automobile carrier 10, an engine room 34 in which the main engine 12 is installed is provided below the freeboard deck 32 at the stern, and the hull section 36A above the freeboard deck 32. The 36B and the hull compartment 36C in front of the liquefied gas fuel tank 22 are almost all used as the automobile mounting compartment 36. In addition, a living area 38 is arranged on the bow side of the uppermost part of the hull. In addition to the main engine 12, equipment such as a power generation engine and a boiler that consume fuel oil and / or liquefied gas as fuel is arranged in the engine room 34.

The liquefied gas fuel tank 22 is arranged, for example, in a section 40 on the bow side adjacent to the engine room 34, and is arranged symmetrically with respect to the hull in FIG. For each liquefied gas fuel tank 22, for example, a cylindrical tank having a radius r is adopted. On the other hand, the fuel oil tank 14 (141, 142) is shown in the space between the liquefied gas fuel tank 22 and the void space (or cofadam) 42 provided along the ship side outer plate, or in the modified example of FIG. It is arranged in the space between the pair of liquefied gas fuel tanks 22 so as to be. That is, the fuel oil tanks 141 arranged on the left and right sides of the hull as shown in FIG. 3 are arranged diagonally below the left and right liquefied gas fuel tanks 22 along the sides of both ships near the bilge, and are arranged in the center of the hull as shown in FIG. The fuel oil tank 142 to be arranged is arranged between the liquefied gas fuel tanks 22 along the bottom of the ship. It should be noted that both the fuel oil tank 141 of FIG. 3 and the fuel oil tank 142 of FIG. 4 may be provided together.

As shown in FIG. 3, the left and right fuel oil tanks 141 are inside the position separated by a radius r from the outer shell of the liquefied gas fuel tank 22, and the liquefied gas fuel tank 22 and the ship side outer plate are located. It is desirable to be located in the space between them. Further, as shown in FIGS. 3 and 4, the left, right, and center fuel oil tanks 141 and 142 are both located above the deck on which the support structure 44 of the liquefied gas fuel tank 22 is installed, and the liquefied gas. It is desirable to be located below the center of the fuel tank 22. Further, a part of the fuel oil tank 14 is adjacent to a part of the liquefied gas fuel tank 22 from the front end to the rear end. Further, by making the side wall of the fuel oil tank 14 facing the liquefied gas fuel tank 22 an inclined surface along the cylindrical surface of the liquefied gas fuel tank 22, the volumes of the fuel oil tanks 141 and 142 are expanded, and the space is further effective. It can be used.

For example, heavy oil (HFO) (calorific value 40.6 MJ / kg, density about 980 kg / m ³ , sulfur concentration 3.5%) has been used as fuel, and about 4,000 m ³ of heavy oil has been required for round-trip voyages so far. If all of this is replaced with LNG fuel (calorific value 50 MJ / kg, density approx. 450 kg / m ³ , sulfur concentration 0%), which is a liquefied gas fuel, it is approximately 7,100 m ³ (4000 [m ³ ] x 40). A tank capacity of .6 [MJ / kg] / 50 [MJ / kg] x 980 [kg / m ³ ] / 450 [kg / m ³ ]) is required. However, when the fuel oil and the liquefied gas fuel are co-fired as in the present embodiment, for example, heavy oil (DO) (calorific value 42.7 MJ / kg, density about 980 kg / m ³ , sulfur content concentration 1.0) is used as the fuel oil. %), And when this is mixed with the above LNG fuel (calorific value 50 MJ / kg, density about 450 kg / m ³ , sulfur concentration 0%) at a ratio of approximately 1: 1, the exhaust sulfur concentration is 0.5%. At this time, the volume required for the fuel oil tank 14 is about 1,900 m ³ , and the volume required for the liquefied gas fuel tank 22 is about 3,800 m ³ .

As a result, the fuel oil tank 14 is reduced to about 1,900 m ³ from the conventional 4,000 m ³ that uses only heavy oil, which is less than half, and the liquefied gas fuel tank 22 is also about 7,100 m when only LNG is used. It will be about half from ³ to about 3,800 m ³ . In addition, the total volume of the fuel tank 14 including the fuel oil tank 14 and the liquefied gas fuel tank 22 is about 5,700 m ³ (= about 1,900 m ³ + about 3,800 m ³ ), which is about more than when only LNG is used. 1,400m ³ smaller.

That is, when only LNG is used as the fuel, a tank capacity about twice that of the liquefied gas fuel tank 22 in FIG. 2 is required. Therefore, a pair of cylindrical liquefied gas fuels are further placed on the bow side of the liquefied gas fuel tank 22. In addition to arranging the tanks, it is necessary to increase the diameter of the cylindrical tank on the stern side corresponding to the liquefied gas fuel tank 22 (the bow side is narrower than the stern side, and a tank with a larger diameter cannot be installed on the stern side). .. In FIG. 2, sections 36B and 36C indicate sections that cannot be used as cargo sections due to the increasing number of liquefied gas fuel tanks when only liquefied gas is used as fuel.

In the example of FIG. 2, by adopting the co-firing of fuel oil and liquefied gas fuel, the volume of the liquefied gas fuel tank is reduced to less than half, and the liquefied gas fuel tank 22 is arranged only on the stern side. The hull section 36C in front of the tank is secured as an automobile loading section (cargo section), and by further reducing the diameter of the liquefied fuel tank 22, the hull section 36B above the tank is also secured as a car loading section (cargo section). ing. Further, in the present embodiment, the volume of the fuel oil tank is halved as compared with the conventional ship using only heavy oil as fuel, so that a space for the liquefied gas fuel tank 22 can be easily secured. Since the fuel oil is liquid at room temperature, there are no restrictions on the shape and arrangement of the fuel oil tank 14, and since it can be made of the same material as the hull, it can be placed in an empty space inside the hull. It is easy to secure a large cargo compartment.

As described above, in the liquefied gas fuel ship of the present embodiment, the liquid fuel having a relatively high volume efficiency and a high sulfur concentration and the liquefied gas fuel having a relatively low volume efficiency and a low sulfur concentration are co-fired. By using it, it is possible to secure a wide cargo compartment while suppressing the sulfur emission concentration below the SOx emission regulation value.

In addition, by controlling the supply amount of liquid fuel and the supply amount of liquefied gas fuel, it is possible to match the required value of the main engine, and further, by co-firing the liquid fuel and liquefied gas fuel, the total sulfur part concentration is specified. It can be less than or equal to the (target) value. Further, according to the present embodiment, by arranging the liquid fuel tank along the liquefied gas fuel tank between the cylindrical liquefied gas fuel tank and the hull structure, the empty space can be reduced as much as possible. Further, in the present embodiment, only the fuel oil loaded in the fuel oil tank can be used until the above-mentioned SOx emission regulation is started.

In the present embodiment, the LNG fuel has been described as an example of the liquefied gas fuel as the second fuel, but instead, an alternative fuel such as methanol or ethanol may be used as the second fuel. Further, in the present embodiment, one type of liquid fuel and one type of liquefied gas fuel are used, but two or more types of fuel can be adopted for each, and some of the three or more types of fuel can be used. It is also possible to use multiple types simultaneously and selectively. For example, by loading both low-sulfur fuel oil and high-sulfur fuel oil, it is possible to preferentially use cheaper fuel.

Further, in the present invention, the operation of the fuel injection device such as the fuel oil injection valve and the gas fuel injection valve is automatically controlled by the fuel supply control unit, but the control parameters of each fuel injection device are output to an output device such as a display. , The worker who refers to the same output sets the control parameters of each fuel injection device, and inputs the fuel ratio of fuel oil or liquefied gas fuel to the engine control device according to the fuel ratio obtained by calculation. It can also be configured.

In the present embodiment, the liquefied gas fuel tank has been described as a cylindrical tank, but the tank is not limited to a cylinder, and may be a multi-cylinder tank. Further, the liquefied gas fuel tank may be arranged away from the engine chamber, and in that case, a fuel oil tank or a cargo compartment may be arranged between the liquefied gas fuel tank and the engine chamber.

10 Liquefied gas fuel ship 11 Fuel supply system 12 Main engine 14 Fuel oil tank (first fuel tank)
16 Fuel supply pump 20 Fuel oil injection valve 22 Liquefied gas fuel tank (second fuel tank)
24 Gas fuel supply system 26 Gas valve train 28 Gas fuel injection valve 30 Fuel supply control unit 32 Free board deck 34 Engine room 36 Car mounting section (cargo section)
38 Residential Area 42 Void Space (or Cofadam)

Claims (9)

A liquid fuel tank that stores liquid fuel and
A liquefied gas fuel tank that stores liquefied gas fuel,
An engine that can be operated by co-firing the liquid fuel and the liquefied gas fuel,
The engine is provided with a fuel supply means for supplying the liquid fuel and / or the liquefied gas fuel at a desired ratio.
The liquid fuel tank is placed along the ship side and / or the bottom of the ship.
The liquefied gas fuel tank has a cylindrical shape with a radius r, and at least one of the liquid fuel tanks is inside the position separated by the radius r from the outer shell of the liquefied gas fuel tank, and the liquefaction is performed. Located in the space between the gas fuel tank and the outer panel on the ship side
A liquefied gas fueled ship characterized by that. A liquid fuel tank that stores liquid fuel and
A liquefied gas fuel tank that stores liquefied gas fuel,
An engine that can be operated by co-firing the liquid fuel and the liquefied gas fuel,
The engine is provided with a fuel supply means for supplying the liquid fuel and / or the liquefied gas fuel at a desired ratio.
The liquid fuel tank is placed along the ship side and / or the bottom of the ship.
The liquefied gas fuel tank has a cylindrical shape, and the side wall of the liquid fuel tank facing the liquefied gas fuel tank has an inclined surface along the cylindrical surface of the liquefied gas fuel tank.
A liquefied gas fueled ship characterized by that. A liquid fuel tank that stores liquid fuel and
A liquefied gas fuel tank that stores liquefied gas fuel,
An engine that can be operated by co-firing the liquid fuel and the liquefied gas fuel,
The engine is provided with a fuel supply means for supplying the liquid fuel and / or the liquefied gas fuel at a desired ratio.
The liquid fuel tank is placed along the ship side and / or the bottom of the ship.
When the sulfur content concentration of the liquid fuel is S1 [%], the specific gravity is γ1, the sulfur content concentration of the liquefied gas fuel is S2 [%], the specific gravity is γ2, and the sulfur content concentration as the emission target is S [%]. , The volume ratio of the liquid fuel tank to the volume of the liquefied gas fuel tank is ((S—S2) / γ1) :( (S1-S) / γ2).
A liquefied gas fueled ship characterized by that. A liquid fuel tank that stores liquid fuel and
A liquefied gas fuel tank that stores liquefied gas fuel,
An engine that can be operated by co-firing the liquid fuel and the liquefied gas fuel,
The engine is provided with a fuel supply means for supplying the liquid fuel and / or the liquefied gas fuel at a desired ratio.
The liquid fuel tank is placed along the ship side and / or the bottom of the ship.
The ratio of the volume of the liquefied gas fuel tank to the volume of the liquid fuel tank is in the range of 2 to 13.
A liquefied gas fueled ship characterized by that. Any of claims 1 to 4 , wherein at least a pair of the liquefied gas fuel tanks are provided in the width direction of the ship, and at least one of the liquid fuel tanks is arranged between the pair of liquefied gas fuel tanks. The liquefied gas fuel ship described in paragraph 1. The liquefied gas fuel ship according to any one of claims 1 to 5 , wherein the liquid fuel tank is located above a deck on which a support structure for the liquefied gas fuel tank is installed. The liquefied gas fuel ship according to any one of claims 1 to 6 , wherein the liquid fuel tank is located below the center of the liquefied gas fuel tank. The liquefied gas fuel ship according to any one of claims 1 to 7 , wherein a part of the liquid fuel tank is adjacent to a part of the liquefied gas fuel tank from the front end to the rear end. The liquefied gas fuel ship according to any one of claims 1 to 8 , wherein the liquid fuel is fuel oil.

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