JP7057372B2 - Gas emission system and gas emission method for ships, and emission recycling method - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention is a residual fuel remaining in an engine and a gas valve unit (GVU) when a problem occurs in gas supply to the engine or when the engine is stopped in a ship equipped with an engine using natural gas as fuel. Regarding a gas discharge system for ships that discharges gas.

Generally, in ships such as bulk cargo ships, container ships, and passenger ships, a diesel engine system that uses heavy oil (HFO) such as bunker C oil or MGO (Marine Gas Oil) as propulsion fuel is adopted.

When burning heavy oil or the like used as fuel for the fuel supply system of these diesel engines, there is a problem that greenhouse gases and various harmful substances in the exhaust gas cause environmental pollution. Global demands for the prevention of environmental pollution are increasing, and regulations on propulsion devices that use heavy oil as fuel oil are being tightened.

In addition, if crude oil prices rise due to factors such as fossil fuel depletion and uncertainties in the international situation, there will be problems in ship management, such as soaring fuel costs for ships that use heavy oil as fuel.

Therefore, considering the use of other fuels such as the use of clean fuels such as LNG and CNG for ship propulsion, engines using different types of fuels have been developed.

The DF engine (Dual Fuel Engine), also known as a co-firing engine, is a kind of hybrid concept engine that uses gas and oil at the same time. It is a gentle engine. Since liquefied natural gas has a lower sulfur content than heavy oil, the use of such fuels can reduce the induction of air pollution.

FIG. 1 is a diagram showing a ship equipped with a gas emission system of a conventional DF engine.

With reference to FIG. 1, a gas valve unit (GVU; Gas) in which a DF engine (1) is arranged in an engine room (E / R) and controls a flow rate of an evaporative gas or a liquefied gas supplied to the DF engine (1). The Valve Unit, 2) is arranged in a separately provided gas valve unit room (G / R: Gas Valve Unit Room).

The gas valve unit room (G / R) is located behind the stern side of the engine room (E / R: Engine Room), and there is a risk of explosion due to gas leakage. It needs to be able to exhaust (Ventilation).

On the other hand, if there is a problem with the gas supply to the DF engine, if the DF engine has not been operated for a long time, or if the inside of the system is to be maintained, it remains in the DF engine (1) and gas valve unit (2). It is necessary to remove the fuel gas.

If flammable fuel gas remains in the system, there is a risk of explosion, so for the safety of the system, the residual gas must be removed.

Conventionally, the exhaust line (4) that discharges the residual gas from the DF engine (1) and the gas valve unit (2) is extended to the vent mast (Vent mast, 3) provided in the upper part of the hold, and the vent mast (3) is extended. ) Was discharged to the outside air.

In this case, even if the exhaust line (4) is connected to the vent mast (3) provided at the upper part of the hold located closest to the engine room (E / R), the engine room (E / R) and the gas valve can be connected. Since the length of the pipe of the exhaust line (4) extending from the unit room (G / R) to the vent mast (3) side reaches about 150 m, there are the following problems.

In order to discharge the residual fuel gas through the pipe reaching up to 150 m, it is necessary to provide a considerable pressure, and in order to prevent the liquid from accumulating in the pipe and the gas not being discharged, the reverse gradient is prevented. The arrangement of piping is essential.

The piping of the exhaust line (4) is generally made of stainless steel, but when the exhaust line (4) reaches 150 m, the required amount of material and cost increase, and butt welding (butt welding) The longer the length of the exhaust line (4) installed in Butt Welding), the more difficult the installation process becomes, and the more time and labor required for installation.

Nevertheless, since the fuel gas remaining in the engine (1) and the gas valve unit (2) is flammable, it is sent to the vent mast (3) side away from the engine room (E / R) by a predetermined distance. Vessels equipped with a conventional DF engine gas discharge system generally have the arrangement shown in FIG. 1 because it is safer to discharge.

There is a space at the rear end of the engine room that humans cannot approach, and it has been considered to place a gas exhaust line in this space, but a pipe that discharges gas is placed near the engine room. It has never actually been applied because it is very dangerous to do, and it is also very reluctant from the shipowner's point of view.

In order to solve the conventional problems, the present invention solves the root cause that the application of such an arrangement was impossible, that is, the problem of safety, and puts the gas exhaust line at the rear end of the engine room. By arranging it, the purpose is to significantly reduce the length of the exhaust line.

We also propose a method for recycling the gas emitted by the gas emission system of the present invention.

Further, in order to achieve the above object, another embodiment of the present invention includes an engine that uses gas as fuel, a gas supply unit that supplies fuel gas to the engine, and fuel gas from the gas supply unit to the engine. A gas valve unit (GVU) provided on the gas supply line to control the flow rate of the fuel gas supplied to the engine, connected to the engine and the gas valve unit, and gas from the engine and the gas valve unit. A fuel gas discharge line that branches from the exhaust line and is connected to the gas supply unit and transfers fuel gas discharged from the engine and the gas valve unit to the gas supply unit is provided. Provided is a gas discharge system for a ship, which transfers fuel gas remaining inside the engine and the gas valve unit to the gas supply unit via the exhaust line and the fuel gas discharge line and recycles the fuel gas.

The marine gas discharge system according to another embodiment of the present invention further includes a second ejector installed on the fuel gas discharge line, and discharges fuel gas remaining inside the engine or the gas valve unit. The second ejector is operated to provide pressure for transferring fuel gas to the gas supply unit via the exhaust line and the fuel gas discharge line.

The marine gas discharge system according to another embodiment of the present invention is installed at a branch point where the fuel gas discharge line branches from the exhaust line, and the opening and closing of the exhaust line or the pipe on the fuel gas discharge line side is selected. A three-way valve that controls the fuel gas and an inert gas separator that is installed on the exhaust line downstream of the three-way valve and separates the fuel gas and the inert gas from the mixed gas of the fuel gas and the inert gas. A branch line that joins the fuel gas separated by the inert gas separator to the fuel gas discharge line side, an inert gas discharge line that discharges the inert gas separated by the inert gas separator, and the above. Further provided with an inert gas supply unit for storing the inert gas discharged via the inert gas discharge line.

The marine gas discharge system according to another embodiment of the present invention further includes a first ejector installed on the inert gas discharge line to eliminate fuel gas remaining inside the engine or the gas valve unit. When purging with active gas and discharging, only the pipe leading from the exhaust line to the inert gas discharge line is opened by the three-way valve, and the first ejector is operated to operate the fuel gas and the inert gas. The pressure for transferring the mixed gas to the inert gas separator via the exhaust line, and the inert gas separated by the inert gas separator through the inert gas discharge line. Provides pressure for transfer to the supply section.

The marine gas discharge system in another embodiment of the present invention further comprises a second ejector installed on the fuel gas discharge line to branch the fuel gas separated by the inert gas separator. It provides pressure for transfer to the gas supply unit via a line and a fuel gas discharge line.

The first driving gas (g1) for driving the first ejector is supplied from the inert gas supply unit, and the second driving gas for driving the second ejector is the gas supply unit. It is supplied via a drive gas line that branches off from the gas supply line that supplies fuel gas to the engine.

A first purge line that supplies an inert gas (g2) to the engine is connected to the engine, and a second purge line that supplies an inert gas (g2) to the gas valve unit is connected to the gas valve unit. Then, when the residual fuel gas of the engine or the gas valve unit is purged with an inert gas and discharged, the inert gas (g2) is discharged through the first purge line and the second purge line of the engine and the gas valve. By supplying each unit, in addition to the pressure formed by the first ejector, an additional pressure for discharging the gas is supplied.

The first driving gas (g1) supplied to the first ejector and the inert gas (g2) supplied to the engine and the gas valve unit can be nitrogen gas ( _N2 ).

In the exhaust gas recycling method of the gas exhaust system for ships in another embodiment of the present invention, the exhaust line connected to the engine and the gas valve unit is opened to remove the fuel gas remaining inside the engine and the gas valve unit. An inert gas (g2) is supplied to the exhaust step to be discharged and the engine and the gas valve unit , and the residual fuel gas remaining inside the engine and the gas valve unit is sent to the gas supply unit via the exhaust line. It includes a purge step of replacing the fuel gas remaining inside the engine and the gas valve unit with the inert gas (g2) by supplying a pressure for discharging.

In the exhaust step, only the fuel gas discharge line branched from the exhaust line and connected to the gas supply unit is opened, and the fuel gas remaining inside the engine and the gas valve unit is discharged to the exhaust line and the gas valve unit. Transferred to the gas supply unit via the fuel gas discharge line, the purge step opens only the pipe leading from the exhaust line to the inert gas discharge line, and separates the inert gas installed on the exhaust line. After separating the mixed gas of the fuel gas and the inert gas discharged from the engine and the gas valve unit by the device, the separated fuel gas is merged with the fuel gas discharge line through the branch line to supply the gas. It is transferred to the unit, and the separated inert gas is transferred to the inert gas supply unit via the inert gas discharge line.

The gas discharge system is installed on the inert gas discharge line to provide a pressure for transferring the gas, and is installed on the fuel gas discharge line to transfer the gas. It is equipped with a second ejector that provides pressure, and in the exhaust step, the second ejector is operated, and in the purge step, the first ejector and the second ejector are all operated.

The gas exhaust system according to the present invention needs to extend the exhaust line to the vent mast by extending the exhaust line to the space at the rear end of the engine room and discharging the gas directly from the stern side. The length of the exhaust line can be significantly reduced as compared with the conventional one.

In addition, by forming a high exhaust pressure with the ejector installed on the exhaust line, the fuel gas can be discharged more quickly through the exhaust line, and the fuel remaining in the engine and gas valve unit by creating a vacuum. It does not matter because the gas can be removed more completely and the gas can be pushed out with sufficient pressure even if a reverse gradient is formed from the exhaust line.

Further, since the residual fuel gas discharged through the exhaust line has sufficient pressure when mixed with the inert gas, it can be discharged to seawater from the stern side.

Further, in one embodiment of the present invention, the fuel gas discharged through the gas discharge system can be recycled without being discharged to the outboard.

The figure which showed the ship equipped with the gas discharge system of the conventional DF engine. The figure for demonstrating the gas discharge system which concerns on 1st Embodiment of this invention. The figure for demonstrating the gas discharge system which concerns on 2nd Embodiment of this invention.

In order to fully understand the present invention, the operational advantages of the present invention, and the object achieved by the practice of the present invention, examples of the present invention will be described with reference to the accompanying drawings and the contents described in the attached drawings. The same reference numeral presented in each drawing indicates the same member.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Further, the following examples can be changed to other embodiments, and the scope of the present invention is not limited to the following examples.

The gas emission system according to the present invention can be applied to a ship equipped with an engine that uses natural gas as fuel, and can also be applied to, for example, an LNGC (LNG Carrier) that uses LNG as a propulsion fuel.

FIG. 2 is a diagram for explaining a gas emission system according to the first embodiment of the present invention.

With reference to FIG. 2, the gas exhaust system according to the first embodiment of the present invention is located in the engine room (100) in which the engine (10) is arranged and behind the stern side of the engine room (100). A gas valve unit room (200) in which a gas valve unit (GVU, 20) is arranged, an exhaust line (30) for discharging residual fuel gas from the engine (10) and the gas valve unit (20), and an exhaust line (30). It is equipped with an ejector (40) installed on top. The exhaust line (30) extends from the engine (10) and the gas valve unit (20) to the rear end space on the stern side of the engine room (100) to allow residual fuel gas from the stern side to seawater or side safety of the hull. Discharge to the area.

As the engine (10) arranged in the engine room (100), a DF engine (Duel Fuel Engine) that uses different types of fuel is used. However, the type of the engine (10) is not limited, and the present invention can be applied to an engine using natural gas as a fuel, such as an ME-GI engine and an X-DF engine.

The gas valve unit (20) is installed on a fuel supply line that supplies evaporative gas or natural gas to the engine (10), controls the flow rate of the evaporative gas or natural gas supplied to the engine (10), and controls the flow rate of the evaporative gas or natural gas to the engine room (10). It is arranged inside a gas valve unit room (200) provided separately from 100).

The gas valve unit room (200) is located behind the stern side of the engine room (100) and is isolated from the engine room (100). Further, in the gas valve unit room (200), an exhaust fan (210) for constantly ventilating is installed.

The exhaust line (30) extends from the engine (10) or the gas valve unit (20) to the rear end space on the stern side of the engine room (100), and the fuel gas remaining in the engine (10) and the gas valve unit (20). Is discharged from the stern side to seawater or a safe area on the side of the hull.

By extending the exhaust line (30) to the rear end space on the stern side of the engine room (100) and discharging the gas directly to the stern side, the exhaust line (30) is compared with the conventional one. 30) The length can be significantly reduced. This is because it is not necessary to extend the exhaust line to the vent mast as in the conventional one.

The exhaust line (30) includes a first exhaust line (31) for discharging the residual gas of the engine (10), a second exhaust line (32) for discharging the residual gas of the gas valve unit (20), and a first exhaust line. A third exhaust line (33) at which the (31) and the second exhaust line (32) meet is provided.

The residual gas of the engine (10) discharged through the first exhaust line (31) merges with the residual gas of the gas valve unit (20) discharged via the second exhaust line (32), and the third exhaust gas is exhausted. It is discharged outboard via the line (33).

A first exhaust valve (11) that opens and closes the first exhaust line (31) is on the first exhaust line (31), and a second exhaust line (32) is opened and closed on the second exhaust line (32). 2 Exhaust valves (21) are installed.

The opening and closing of the first exhaust valve (11) and the second exhaust valve (21) are controlled by the control unit (60) so as to discharge the fuel gas remaining in the engine (10) and the gas valve unit (20), respectively. ..

Further, as in the present invention, in order to reduce the length of the exhaust line (30) as compared with the conventional one, the residual fuel gas of the engine (10) and the gas valve unit (20) is used in the engine room (100). It is necessary to discharge in the vicinity of the fuel gas, and it is essential to eliminate the risk of explosion of the residual fuel gas discharged through the exhaust line (30) to ensure safety.

In the first embodiment of the present invention, an ejector (40) is installed on the exhaust line (30) in order to eliminate the risk of explosion of the residual fuel gas discharged through the exhaust line (30). ..

Further, it is preferable to install the ejector (40) on the third exhaust line (33), which is a line in which the first and second exhaust lines (31, 32) are integrated.

Since a known ejector (40) can be used in the present invention, detailed description of the configuration and operation of the ejector (40) will be omitted, and the description will be focused on the parts related to the present invention.

The ejector (40) is a type of pump that utilizes the Venturi effect. It uses the pressure energy of the high-pressure driving fluid to create a vacuum, and easily discharges the intake fluid (Inlet fluid) at a high discharge pressure. do.

In the present invention, the driving gas supplied to the ejector (40) via the driving gas supply line (41) acts as a driving fluid, and the gas discharged through the exhaust line (30) is sucked. It acts as an inlet fluid.

In the present invention, the non-explosive inert gas (g1) can be used as the driving gas, and it is particularly preferable to use the nitrogen gas ( _N2 ) which is indispensably produced in the LNGC ship.

A drive gas supply line (41) for supplying the drive gas to the ejector (40) is connected to one side of the ejector (40), and the supply of the drive gas is controlled on the drive gas supply line (41). A drive gas control valve (42) is installed.

When the driving gas control valve (42) is opened and the inert gas (g1) is supplied to the ejector (40) via the driving gas supply line (41), the ejector (40) operates and the ejector (40) operates. ), The inert gas (g1) is supplied to the exhaust line (30).

Therefore, the residual fuel gas discharged from the engine (10) and the gas valve unit (20) is mixed with a large amount of the inert gas (g1) supplied by the ejector (40) to be in a non-explosive state. It is not necessary to send the mixed gas of the residual fuel gas and the inert gas (g1) to the vent mast, and the mixed gas can be discharged via the exhaust line (30) in the vicinity of the engine room (100).

Further, the residual fuel gas discharged through the exhaust line (30) is mixed with the inert gas (g1) to have a sufficient pressure, and can be discharged to seawater from the stern side.

The ejector (40) not only has a role of supplying the inert gas (g1) to the exhaust line (30), but also forms an exhaust pressure by the ejector effect, so that the fuel gas makes the exhaust line (30). The fuel gas remaining in the engine (10) and the gas valve unit (20) can be more completely removed to assist the quicker discharge through and to create a vacuum.

Since the ejector (40) does not have an electrical configuration, maintenance and repair are hardly required, and when applied to the gas emission system according to the present invention, the safety becomes very high.

Further, in the gas discharge system according to the first embodiment of the present invention, the fuel gas remaining in the engine (10) and the gas valve unit (20) is discharged through the exhaust line (30), and then the engine (10) and the gas valve are discharged. A Purging step is performed to remove the residual fuel gas of the unit (20) more completely.

The gas discharge system according to the first embodiment of the present invention comprises a first purge line (51) connected to one side of the engine (10) to supply purge gas to the engine (10), and a gas valve unit (20). A second purge line (52) connected to one side to supply purge gas to the gas valve unit (20) is further provided.

In the present invention, it is preferable to use a non-explosive inert gas (g2) such as nitrogen gas ( _N2 ) as the purge gas, similarly to the driving gas. The inert gas (g1) used as the driving gas of the ejector (40) and the inert gas (g2) used as the purge gas are nitrogen gas ( _N2 ), and are nitrogen gas generators installed in the ship. Supplied from (not shown).

At the time of purging, the inert gas (g2) is supplied to the engine (10) and the gas valve unit (20) via the first purge line (51) and the second purge line (52), respectively, and the residual fuel gas remains. Is extruded into the inert gas (g2) and discharged through the exhaust line (30).

Supplying the inert gas (g2) to each engine (10) and gas valve unit (20) via the first and second purge lines (51, 52) is an addition for discharging the fuel gas outboard. This is to supply pressure.

In addition, the ejector (40) can be operated even during purging, and by forming the exhaust pressure with the ejector (40), the purging can be performed more quickly, and the ejector (40) is evacuated. Then, the inert gas (g2) supplied to the engine (10) and the gas valve unit (20) via the first and second purge lines (51, 52) is also all outboard via the exhaust line (30). Can be discharged.

The gas discharge system according to the first embodiment of the present invention further includes a control unit (60). The control unit (60) controls to discharge the residual fuel gas of the engine (10) and the gas valve unit (20) when a problem occurs in the gas supply to the engine (10).

Therefore, the control unit operates the ejector (40) by opening and closing the first exhaust valve (11) and the second exhaust valve (21), opening and closing the drive gas control valve (42), and the first and second purge lines (1st and 2nd purge lines). The supply of the inert gas (g2) to the engine (10) and the gas valve unit (20) via 51, 52) is controlled.

Next, with reference to FIG. 2, a gas discharge method for a ship according to the first embodiment of the present invention will be described.

If there is a problem with the gas supply to the engine (10) such as the trip phenomenon of the engine (10), or if the engine (10) has not been operated for a long time or if the inside of the system is to be maintained, the engine It is necessary to discharge the fuel gas remaining in (10) and the gas valve unit (20). The process of discharging gas is roughly divided into two steps, a blow-off step and a purging step.

In the exhaust (Blow-off) step, the fuel gas remaining in the engine (10) and the gas valve unit (20) is discharged as it is at atmospheric pressure.

In the exhaust step, the first exhaust valve (11) and the second exhaust valve (21) are opened, and the fuel gas remaining in the engine (10) and the gas valve unit (20) is discharged outboard via the exhaust line (30). Exhaust to. The first and second exhaust valves (11, 21) are opened by the control unit (60).

In the exhaust step, the ejector (40) can be activated to assist the exhaust of fuel gas. When the drive gas control valve (42) is opened and the ejector (40) is operated, the inert gas (g1) is supplied from the drive gas supply line (41) to the exhaust line (30), and the exhaust line (30) is supplied. The fuel gas discharged through the gas is mixed with a large amount of the inert gas (g1) and discharged outboard in a state where the explosiveness is removed.

The exhaust step is performed in a time-delay manner. As an example, the first and second exhaust valves (11, 21) are opened, gas discharge is started through the exhaust line (30), and after a set t time, the first and second exhaust valves (11, 21) is controlled to be closed automatically.

In the Purging step, the residual gas remaining in the engine (10) and the gas valve unit (20) is replaced with the inert gas, so that the residual gas is more reliably removed.

In the purge step, the first and second purge lines (51, 52) supply the engine (10) and the gas valve unit (20) with the inert gas (g2), respectively.

The inert gas (g2) supplied to the engine (10) and the gas valve unit (20) via the first and second purge lines (51, 52) is the engine (10) and the gas valve unit (20), respectively. By supplying additional pressure for discharging the residual fuel gas outboard, all the residual fuel gas is pushed out through the discharge line (30) and reliably purged.

Also in the purge step, the purge can be performed more quickly by operating the ejector (40) to form the discharge pressure.

When all the residual fuel gas of the engine (10) and the gas valve unit (20) is discharged, all the existing residual fuel gas is replaced with the inert gas (g2), and the first and second purge lines (1st and 2nd purge lines) The supply of the inert gas (g2) to the engine (10) and the gas valve unit (20) via 51, 52) is interrupted.

Therefore, the substituted inert gas (g2) is present in the engine (10) and the gas valve unit (20), and the inert gas (g2) present in the engine (10) and the gas valve unit (20) is present. ) Is discharged outboard by the discharge pressure formed by the ejector (40), similarly to the exhaust step, and the purge step is completed.

The purge step, like the exhaust step, is performed in a time-delay manner, or a gas detector (not shown) is installed in the engine (10) or gas valve unit (20) to provide residual fuel gas. Is continued until is no longer detected.

The ejector (40) can be used in all processes of forming the exhaust pressure of the gas, and can be maintained in an operating state from the exhaust step to the completion of the purge step.

FIG. 3 is a diagram for explaining a gas emission system according to a second embodiment of the present invention.

The gas discharge system according to the second embodiment shown in FIG. 3 has the same configuration for gas discharge as the gas discharge system according to the first embodiment shown in FIG. 2, and the exhaust gas is recycled. Configuration is added.

Therefore, in the following, the configuration added in the gas discharge system according to the first embodiment will be mainly described, and the detailed description regarding the same members as the gas discharge system according to the first embodiment described above will be omitted.

Further, for convenience of explanation, the ejector (40) of the first embodiment is referred to as the first ejector (40) in the second embodiment.

With reference to FIG. 3, the gas discharge system according to the second embodiment of the present invention includes all the components of the first embodiment, and further branches from the exhaust line (30) to the gas supply unit (300). Further, a fuel gas discharge line (310) to be connected and a three-way valve (320) installed at a branch point where the fuel gas discharge line (310) branches from the exhaust line (30) are further provided.

Further, the gas discharge system according to the second embodiment of the present invention is installed on the exhaust line (30) downstream of the three-way valve (320), and is inactive with the fuel gas from the mixed gas of the fuel gas and the inert gas. An inert gas separator (410) that separates the gas from each other, an inert gas discharge line (420) that discharges the inert gas separated by the inert gas separator (410), and an inert gas separator ( A branch line (430) that merges the fuel gas separated in 410) with the fuel gas discharge line (310), and an inert gas supply that stores the inert gas discharged via the inert gas discharge line (420). A unit (400) is further provided.

The gas supply unit (300) supplies fuel gas to the engine (10). The fuel gas is supplied from the gas supply unit (300) to the engine (10) via the gas valve unit (20) via the gas supply line (330).

The fuel gas discharge line (310) branches from the exhaust line (30) and is connected to the gas supply unit (300). A second ejector (311) is installed on the fuel gas discharge line (310) to transfer the gas inside the exhaust line (30) and the fuel gas discharge line (310) to the gas supply unit (300). Provide pressure.

The second ejector (311) utilizes the ejector effect described in the first embodiment to provide a pressure for transferring gas through the pipe.

The drive gas for driving the second ejector (311) is via a drive gas line (331) branched from the gas supply line (330) that supplies fuel gas from the gas supply unit (300) to the engine (10). Will be supplied.

An air separator (312) is installed upstream of the gas supply unit (300) of the fuel gas discharge line (310). Since the residual fuel gas initially released may be mixed with air in the piping in the process of being transferred to the gas supply unit (300), the gas is supplied after the air is removed by the air separator (312). It is sent to the department (300).

The three-way valve (320) is installed at a branch point where the fuel gas discharge line (310) branches from the exhaust line (30). Whether the gas transferred from the engine (10) and the gas valve unit (20) is sent to the fuel gas discharge line (310) side or the inert gas separator (410) side by the three-way valve (320). Is determined. The control of the three-way valve (320) is performed by the control unit (60).

The Inactive Gas Separator (410) is installed on the exhaust line (30) downstream of the three-way valve (320). The inert gas separator (410) separates the fuel gas and the inert gas from the mixed gas of the fuel gas and the inert gas, respectively. The separated inert gas is discharged via the inert gas discharge line (420), and the separated fuel gas joins the fuel gas discharge line (310) via the branch line (430) and joins the gas supply unit (gas supply unit (310). Transferred to 300).

As the inert gas separator (410), a membrane filter, a cyclone, a gas centrifuge, or a vortex tube can be used.

The first ejector (40) is installed on the inert gas discharge line (420), and the gas inside the exhaust line (30) and the inert gas discharge line (420) is transferred to the inert gas supply unit (400). Provides pressure for transfer.

The first ejector (40) utilizes the ejector effect described in the first embodiment to provide a pressure for transferring gas through the pipe.

The Inactive gas supply unit (400) stores the Inactive gas discharged via the Inactive gas discharge line (420). The inert gas stored in the inert gas supply unit (400) is used as the driving gas (g1) of the first ejector (40), or the purge gas supplied to the engine (10) and the gas valve unit (20). It is used as (g2) or used at the demand destination in the ship.

That is, according to the second embodiment of the present invention, the residual fuel gas inside the engine (10) and the gas valve unit (20) is transferred to the gas supply unit (300) via the fuel gas discharge line (310). The inert gas used for purging the residual fuel gas inside the engine (10) and the gas valve unit (20) was separated from the fuel gas by the inert gas separator (410). After that, it can be recycled by transferring it to the inert gas supply unit (400) and storing it.

Next, a method for recycling exhaust gas according to the second embodiment of the present invention will be described with reference to FIG.

The gas discharge system according to the second embodiment of the present invention discharges the residual fuel gas of the engine (10) and the gas valve unit (20) in the same manner as in the first embodiment.

However, in the second embodiment, the residual fuel gas is not discharged to the outboard through the exhaust line (30), but the exhaust gas is recycled by using the additional configuration of the second embodiment.

The exhaust gas recycling method according to the second embodiment of the present invention differs depending on the exhaust (Blow-off) step and the purging (Purging) step.

In the exhaust (Blow-off) step, the first exhaust valve (11) and the second exhaust valve (21) are opened, and the fuel gas remaining in the engine (10) and the gas valve unit (20) is discharged, so that the exhaust line is exhausted. The only gas transferred via (30) is fuel gas.

At this time, the pipe connected to the inert gas separator (410) side from the exhaust line (30) is closed by the three-way valve (320), and only the pipe connected to the fuel gas discharge line (310) is opened. do. Therefore, all the fuel gas remaining in the engine (10) and the gas valve unit (20) is transferred from the exhaust line (30) to the fuel gas discharge line (310).

At this time, by driving the second ejector (311) installed on the fuel gas discharge line (310) to create a vacuum, the fuel gas remaining in the engine (10) and the gas valve unit (20) is discharged to the exhaust line. Pressure is provided for easy transfer to the gas supply unit (300) via (30) and the fuel gas discharge line (30).

The fuel gas transferred to the gas supply unit (300) via the fuel gas discharge line (310) was surely removed by the air separator (312) installed upstream of the gas supply unit (300). After that, it is stored in the gas supply unit (300).

In the Purging step, the fuel gas discharged from the engine (10) and the gas valve unit (20) is replaced with the inert gas to remove the fuel gas remaining in the engine (10) and the gas valve unit (20). A mixed gas of the inert gas and the inert gas is transferred via the exhaust line (30).

At this time, the pipe connected to the fuel gas discharge line (310) is closed by the three-way valve (320), and the pipe connected to the inert gas separator (410) is opened to prevent the fuel gas. The mixed gas with the active gas is transferred to the inert gas separator (410) side.

The mixed gas is separated into a fuel gas and an inert gas by an inert gas separator (410), and then the separated inert gas is transferred to the inert gas supply unit (400) and stored. The separated fuel gas joins the fuel gas discharge line (310) via the branch line (430) and is transferred to the gas supply unit (300).

A check valve (431) is installed on the branch line (430), and the fuel gas separated by the inert gas separator (410) is transferred from the inert gas separator (410) to the fuel gas discharge line (310). It flows only in the direction you are heading.

The fuel gas and the inert gas are transferred to the gas supply unit (300) and the inert gas supply unit (400), respectively, stored, and then recycled.

At this time, the pressure at which the fuel gas and the inert gas are transferred through the exhaust line (30) and the pressure at which the inert gas is transferred through the inert gas discharge line (420) are the first ejectors ( The pressure provided by 40) and the fuel gas being transferred through the fuel gas discharge line (310) is provided by the second ejector (311).

In the above, the specific embodiments of the present invention have been mainly described. The above description and drawings do not limit the technical idea of the present invention and should be construed as exemplifying the present invention.

Claims (10)

In gas emission systems for ships
Engines that use gas as fuel;
Gas supply unit that supplies fuel gas to the engine;
A gas valve unit (GVU) provided on a gas supply line for supplying fuel gas to the engine from the gas supply unit and controlling the flow rate of the fuel gas supplied to the engine;
An exhaust line connected to the engine and the gas valve unit to exhaust gas from the engine and the gas valve unit; and branched from the exhaust line and connected to the gas supply unit and discharged from the engine and the gas valve unit. A fuel gas discharge line that transfers the fuel gas to the gas supply unit;
A gas discharge system for ships that transfers fuel gas remaining inside the engine and the gas valve unit to the gas supply unit via the exhaust line and the fuel gas discharge line for recycling. Further equipped with an ejector installed on the fuel gas discharge line;
When discharging the fuel gas remaining inside the engine or the gas valve unit, the pressure for operating the ejector to transfer the fuel gas to the gas supply unit via the exhaust line and the fuel gas discharge line is applied. The gas emission system for a ship according to claim 1 , characterized in that it is provided. A three-way valve installed at a branch point where the fuel gas discharge line branches from the exhaust line and selectively controls the opening and closing of the exhaust line or the piping on the fuel gas discharge line side;
An inert gas separator installed on the exhaust line downstream of the three-way valve to separate the fuel gas and the inert gas from the mixed gas of the fuel gas and the inert gas, respectively;
A branch line that joins the fuel gas separated by the inert gas separator to the fuel gas discharge line side;
Further provided is an inert gas discharge line for discharging the inert gas separated by the inert gas separator; and an inert gas supply unit for storing the inert gas discharged through the inert gas discharge line. The gas discharge system for a ship according to claim 1 , characterized in that. Further equipped with a first ejector installed on the inert gas discharge line;
When the fuel gas remaining inside the engine or the gas valve unit is purged with an inert gas and discharged, only the pipe leading from the exhaust line to the inert gas discharge line is opened by the three-way valve, and the said. The pressure for operating the first ejector to transfer the mixed gas of the fuel gas and the inert gas to the inert gas separator via the exhaust line, and the inert gas separated by the inert gas separator. The gas discharge system for a ship according to claim 3 , wherein the pressure for transferring the gas to the inert gas supply unit via the inert gas discharge line is provided. Further equipped with a second ejector installed on the fuel gas discharge line;
The fourth aspect of claim 4 , wherein the fuel gas separated by the inert gas separator is provided with a pressure for transferring the fuel gas to the gas supply unit via the branch line and the fuel gas discharge line. Gas emission system for ships. The first driving gas for driving the first ejector is supplied from the inert gas supply unit.
The second drive gas for driving the second ejector is supplied from the gas supply unit via a drive gas line branched from a gas supply line for supplying fuel gas to the engine. The gas discharge system for a ship according to claim 5 . The engine is connected to a first purge line that supplies the engine with an inert gas.
A second purge line for supplying the inert gas to the gas valve unit is connected to the gas valve unit.
When the residual fuel gas of the engine or the gas valve unit is purged with the inert gas and discharged, the inert gas is supplied to the engine and the gas valve unit via the first purge line and the second purge line, respectively. The gas discharge system for a ship according to claim 4 , wherein an additional pressure for discharging the gas is supplied in addition to the pressure formed by the first ejector. The seventh aspect of claim 7 , wherein the first driving gas supplied to the first ejector and the inert gas supplied to the engine and the gas valve unit are nitrogen gas (N ₂ ). Gas emission system for ships. In the exhaust gas recycling method of the gas emission system for ships
An exhaust step that opens the exhaust line connected to the engine and the gas valve unit to exhaust the fuel gas remaining inside the engine and the gas valve unit; and supplies an inert gas to the engine and the gas valve unit. By supplying a pressure for discharging the fuel gas remaining inside the engine and the gas valve unit to the gas supply unit via the exhaust line , the fuel gas remaining inside the engine and the gas valve unit can be removed . Including a purge step of replacing and discharging the inert gas;
The exhaust step opens only the fuel gas discharge line branched from the exhaust line and connected to the gas supply unit, and the fuel gas remaining inside the engine and the gas valve unit is discharged to the exhaust line and the gas valve unit. Transferred to the gas supply section via the fuel gas discharge line,
In the purge step, only the pipe leading from the exhaust line to the inert gas discharge line is opened, and the fuel gas discharged from the engine and the gas valve unit by the inert gas separator installed on the exhaust line. After separating the mixed gas with the inert gas, the separated fuel gas is merged with the fuel gas discharge line via the branch line and transferred to the gas supply unit, and the separated inert gas is transferred to the inert gas. A method of recycling exhaust gas from a gas discharge system for ships, which is transferred to the inert gas supply section via a discharge line. The gas emission system is
A first ejector installed on the Inactive Gas Emission Line that provides pressure to transfer gas; and a second ejector installed on the Fuel Gas Emission Line that provides pressure to transfer gas. Equipped with an ejector;
In the exhaust step, the second ejector is operated.
The exhaust gas recycling method for a ship gas discharge system according to claim 9 , wherein in the purge step, the first ejector and the second ejector are all operated.

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