KR20240043478A - Purging system and method for a ship - Google Patents

Abstract

A purging system that purges the combustion device with inert gas on a ship equipped with a combustion device that receives fuel gas through the fuel supply system and combusts it, and a vent mast to discharge the remaining fuel gas in the fuel supply system into the atmosphere when necessary. A method is provided. According to the purging system and method, the combustion device is purged by supplying inert gas toward the combustion device, and after the purge of the combustion device is completed, the inert gas is supplied toward the vent mast to purge the vent mast. can be carried out.

Description

Purging system and method for ships {PURGING SYSTEM AND METHOD FOR A SHIP}

The present invention relates to a purging system and method for preventing fuel gas from remaining in the fuel gas vent line even when a boiler used in a ship is located above the vent mast.

Traditionally, combustion devices such as engines, boilers, and turbines installed on various ships used oil such as MDO (Marine Diesel Oil) and HFO (Heavy Fuel Oil, i.e. Bunker C) as fuel. However, using fuel gas such as LNG (Liquefied Natural Gas) or LPG (Liquified Petroleum Gas) as fuel can reduce the emission of environmental pollutants, gradually reducing the amount of fuel oil used and using fuel gas instead. Methods are being developed.

To this end, research and development are continuing to install a combustion device installed in a ship with specifications that can use fuel oil and fuel gas together or alternately as fuel.

If the combustion device installed on the ship is of a specification that can use fuel gas as fuel together with or alternately with fuel oil, the fuel gas remaining inside the combustion device and the fuel gas vent line, etc. after the combustion device has stopped operating. A purging system to discharge must be installed.

As a combustion device that can use fuel oil and fuel gas together or alternately as fuel, for example, it is a type of DF (Dual Fuel) boiler with an oil fired section and an exhaust gas section. A composite boiler with an integrated structure can be applied. At this time, the installation location of the boiler may be limited to the rear end of the SCR (selective catalytic reduction) system, and the installation location of the boiler may be set near the top of the stack.

In other words, in the case of a composite steam boiler including an exhaust gas combustion zone, it is configured to generate steam using the heat of the exhaust gas of the main engine, and for this purpose, its installation location is set around the exhaust pipe. Accordingly, the principle for combined steam boilers is to install an engine room casing. In addition, when the SCR system is applied, the exhaust gas supplied to the combined steam boiler must be supplied after nitrogen oxides (NOx) have been treated, so the installation location of the combined steam boiler is limited to the rear end of the SCR equipment. Because of this, the installation position of the boiler can be set to a position near the top of the stack.

Meanwhile, a vent mast must be installed on a ship to discharge evaporation gas in the fuel gas tank or residual fuel gas in the fuel supply system into the atmosphere when necessary. These vent masts must secure a safety area around them in accordance with relevant regulations. Therefore, when determining the installation location of the vent mast in accordance with relevant regulations during design, the design may be made so that it is installed at a location lower than the height at which the boiler is installed.

When the installation position of the vent mast is designed to be lower than the installation position of combustion devices such as boilers, a purging system is required to discharge combustible gases such as fuel gas trapped in the vent pipe extending to the vent mast into the atmosphere. The purging system may utilize an inert gas, such as nitrogen gas.

According to relevant regulations, a Double Block and Bleed (DBB) valve device must be installed in the inert gas supply line to prevent combustible gas from flowing back within the purging system. In other words, according to the existing boiler system logic, it is configured to purge the burner using nitrogen gas itself when the burner is stopped. However, since there is a possibility that the flammable gas may flow back within the purging system, in order to prevent this, A DBB valve device must be installed. Therefore, according to the existing boiler system, the design becomes complicated due to the DBB valve device and there is an inconvenience of having to secure installation space for the DBB valve device.

As seen above, when a ship is equipped with a combustion device that can use fuel gas as fuel, a purging system must be installed to purge fuel gas when necessary, and to simplify operation and increase deployment space utilization, There is a continuing need to develop fuzzing systems.

The present invention was made in consideration of the above-described needs, and provides a purging system and method that can effectively discharge combustible gas captured in the vent line into the atmosphere while eliminating the DBB valve device that requires separate installation space. This is what we want to provide.

According to one aspect of the present invention for achieving the above object, a combustion device that receives fuel gas through a fuel supply system and combusts it, and a vent mast for discharging the remaining fuel gas in the fuel supply system into the atmosphere when necessary. In a ship, a purging method of purging the combustion device with an inert gas includes the steps of supplying an inert gas toward the combustion device to purge the combustion device; After purging the combustion device is completed, purging the vent mast by supplying an inert gas toward the vent mast; A purging method for ships may be provided, including.

According to one embodiment, in the ship, the combustion device is installed at a higher position than the vent mast, and the step of purging the vent mast is performed by using a device extending from a position lower than the combustion device to the vent mast. The vent line can be purged by supplying an inert gas to the vent line.

According to one embodiment, the ship includes a fuel gas supply line that supplies fuel gas to the combustion device, a vent line that branches off from the fuel gas supply line and extends to the vent mast, and is connected to the fuel gas supply line. and an inert gas supply line that supplies an inert gas, and may include closing the fuel gas supply line and opening the inert gas supply line before purging the combustion device. You can.

According to another aspect of the present invention, in a ship equipped with a combustion device for receiving fuel gas through a fuel supply system and combustion, and a vent mast for discharging the remaining fuel gas in the fuel supply system into the atmosphere when necessary, the combustion device A purging system for purging with an inert gas, comprising: a fuel gas supply line supplying fuel gas to the combustion device; a vent line branching from the fuel gas supply line and extending to the vent mast; an inert gas supply line connected to the fuel gas supply line to supply an inert gas; A gas valve unit installed at a front end of the combustion device on the fuel gas supply line to control the supply of fuel gas through the fuel gas supply line and the supply of inert gas through the inert gas supply line; A purging system for ships may be provided, including a.

According to one embodiment, in the ship, the combustion device and the gas valve unit may be installed at a higher position than the vent mast.

According to one embodiment, the combustion device may be a DF (Dual Fuel) boiler that can use fuel oil and fuel gas as fuel.

According to one embodiment, the marine purging system further includes a connection line branched from the inert gas supply line and connected to the vent line, and a three-way valve is installed at the point where the connection line branches from the inert gas supply line. It can be.

According to the present invention, a purging system and method can be provided that can effectively discharge combustible gas trapped in a vent line extending to a vent mask into the atmosphere.

According to the purging system and method according to the present invention, after purging the burner of the boiler, purging is also performed on the vent line, thereby eliminating the DBB valve device that requires a separate installation space and simultaneously eliminating combustibles trapped in the vent line. Gas can be effectively discharged into the atmosphere, simplifying operation, and reducing the space required to install equipment, piping, etc. required for purging, contributing to increased space utilization.

1 is a schematic configuration diagram of a purging system for a ship according to an embodiment of the present invention.
Figure 2 is a diagram showing a portion of the hull of a ship on which a purging system according to an embodiment of the present invention is installed.
Figures 3 and 4 are diagrams showing a state in which a purging operation is performed by the purging system shown in Figure 1.
Figure 5 is a diagram for explaining a purging method according to an embodiment of the present invention.

Hereinafter, a purging system for ships according to a preferred embodiment of the present invention will be described in detail with reference to the drawings.

Figure 1 shows a schematic configuration diagram of a purging system for a ship according to an embodiment of the present invention, and Figure 2 shows a diagram showing a portion of the hull of a ship on which a purging system according to an embodiment of the present invention is installed. .

A purging system according to an embodiment of the present invention is installed on a ship to perform a purging operation using an inert gas for a combustion device that can be mounted on the ship.

In this specification, a ship refers not only to a ship in the general sense, that is, a marine floating body such as an oil tanker, LNG carrier, container ship, various merchant ships, and passenger ships that can sail on their own, but also to oil used by being moored at sea for a certain period of time. This concept includes all offshore plants such as FPSO, LNG FPSO, and LNG FSRU.

Combustion devices may be, for example, various engines, boilers, turbines, GCUs (Gas Combustion Units), etc. that can be mounted on ships for propulsion, power generation, steam generation, evaporation gas treatment, etc. The engine may be a DF (Dual Fuel) engine configured to burn fuel oil and fuel gas together or separately. The boiler may be a DF boiler configured to burn fuel oil and fuel gas together or separately. The GCU burns and discharges evaporative gas generated from the fuel gas storage tank or fuel gas remaining in the pipe. It may simply have a gas combustion function or may have an integrated function as an inert gas generator.

For example, nitrogen gas may be used as an inert gas used to perform the purging operation. Fuel oil may be MDO (Marine Diesel Oil), HFO (Heavy Fuel Oil, i.e. Bunker C), etc., and fuel gas may be LNG, CNG, LPG, etc.

As a fuel gas storage tank (not shown) for storing fuel gas, any storage tank of any structure and type can be used as long as it can store liquefied gas, which must be maintained at a very low temperature in order to exist in a liquid state. Alternatively, the fuel gas storage tank may be a pressurized tank that can withstand high pressure of tens to hundreds of bars.

Hereinafter, the description will be made by taking as an example the purging operation using nitrogen gas for a boiler mounted on a ship, but this is only an example and the present invention is not limited to this.

As shown in Figures 1 and 2, the purging system according to an embodiment of the present invention is stored in a boiler 30 as a combustion device capable of burning fuel gas and a fuel gas storage tank (not shown). A fuel gas supply line (L12) for supplying the remaining fuel gas to the boiler (30), a vent mast (40), and a fuel gas supply line for discharging the remaining fuel gas in the fuel gas supply line (L12) into the atmosphere. It includes a vent line (L16) branching from (L12) and extending to the vent mast (40), and an inert gas supply line (L22) connected to the fuel gas supply line (L12) to supply inert gas.

The purging system uses a gas valve unit (GVU) (20) to control the supply of fuel gas through the fuel gas supply line (L12) and the supply of inert gas through the inert gas supply line (L22) and vent line (L16). ) may include. The gas valve unit 20 may include various valves 22, 24, 26, and 28 that open and close various fuel gas supply lines (L12), inert gas supply lines (L22), and vent lines (L16). Figure 1 shows a state in which fuel gas is supplied to the boiler 30 through the fuel gas supply line (L12). At this time, the valves 22 and 24 are opened. The operation of the valves 22, 24, 26, and 28 included in the gas valve unit 20 will be described later with reference to FIGS. 3 and 4.

As described above, the boiler 30 illustrated as a combustion device may be a DF (Dual Fuel) boiler that can use fuel oil and fuel gas together or alternately as fuel. Additionally, the boiler 30 may be a composite boiler with a structure in which an oil fired section and an exhaust gas section are integrated without a separate exhaust gas section. For example, the boiler 30 includes a burner section 32 as a combustion section that generates heat by burning fuel such as gas fuel, and a heating section 34 as an exhaust gas section that heats water with the generated heat. can do. Exhaust gas may be discharged from the boiler 30 to the outside through the exhaust line (L14).

The installation location of such a boiler may be limited to the rear end of the SCR (selective catalytic reduction) system, and as shown in FIG. 2, the installation location of the gas valve unit 20 and boiler 30 is of the stack 14. It can be set to a position near the top.

On the other hand, the vent mast (40), which must be installed to discharge boil-off gas in the fuel gas tank or residual fuel gas in the fuel supply system into the atmosphere when necessary, is installed in the boiler (30) in accordance with relevant regulations that require securing a safety area around the boiler (30). ) can be designed to be installed at a lower location than the installed height. Figure 2 illustrates that the vent mast 40 is installed at a lower height than the boiler 30 above the upper deck 12 by a required distance from the stack 14.

The position of the vent mast 40 is not limited to that shown in FIG. 2 as long as it is set lower than the installation position of the boiler 30. The vent mast 40 may be installed on the bow or stern side of the hull with respect to the funnel 14, or may be installed on either or both the port and starboard sides of the funnel 14.

As shown in FIG. 2, when the installation position of the vent mast 40 is designed to be lower than the installation position of the boiler 30, the vent line (L16) extending from the gas valve unit 20 to the vent mast 40 There is a problem with fuel gas remaining inside. The present invention provides a purging system and method for effectively discharging combustible gas trapped in a vent line into the atmosphere while eliminating a DBB valve device that requires separate installation space.

A purging system according to an embodiment of the present invention includes an inert gas tank (not shown) storing inert gas such as nitrogen gas to be used during purging work, and an inert gas compressor (not shown) that compresses the inert gas to an appropriate pressure. It may further include the like.

Nitrogen as an inert gas used in the purging operation may be produced, for example, by a nitrogen generator (not shown). The nitrogen produced in the nitrogen generator can be stored in a pressurized state in an inert gas tank.

The purging system according to an embodiment of the present invention may further include a connection line (L24) branched from the inert gas supply line (L22) and connected to the vent line (L16). The connection line (L24) may have all or part of its length installed within the gas valve unit (20). A valve 28 may be installed at the point where the connection line L24 branches off from the inert gas supply line L22, and this valve 28 may be a three-way valve.

FIGS. 3 and 4 are diagrams for explaining the state of performing a purging operation by the purging system according to an embodiment of the present invention shown in FIG. 1. In FIG. 3, the gas supplied through the inert gas supply line (L22) is shown. A state in which purging work is performed while the inert gas is supplied to the boiler 30 is shown, and in FIG. 4, the purging work is performed while the inert gas supplied through the inert gas supply line (L22) is supplied to the vent mast 40. The state is shown.

As shown in FIG. 3, in order to perform a purging operation while supplying the inert gas supplied through the inert gas supply line (L22) toward the boiler 30, the valves 22 and 24 installed on the fuel gas supply line (L12) are used. ) is closed, and the valve 26 installed in the inert gas supply line (L22) is opened. Additionally, the three-way valve 28 installed in the inert gas supply line L22 is switched to allow the inert gas to flow toward the boiler 30.

As shown in FIG. 4, in order to perform a purging operation while the inert gas supplied through the inert gas supply line (L22) is supplied toward the vent mast (40) along the vent line (L16), the fuel gas supply line (L12) ) are closed, and the valve 26 installed on the inert gas supply line (L22) is opened. Additionally, the three-way valve 28 installed in the inert gas supply line L22 is switched to allow the inert gas to flow toward the vent mast 40.

Hereinafter, a method of performing a purging operation using the purging system according to an embodiment of the present invention as described above will be described with reference to FIG. 5.

As shown in FIG. 5, first, when the user or controller stops the boiler (step S10), the valves 22 and 24 installed in the fuel gas supply line L12 are closed, thereby allowing gas to be discharged through the fuel gas supply line L12. The supply of fuel gas is blocked (step S20), and the valve 26 installed in the inert gas supply line L22 is opened to open the inert gas (nitrogen gas) supply line (step S30).

Then, the valve (3-way valve) 28 installed in the inert gas supply line (L22) is switched to allow the flow of inert gas toward the boiler 30, and the inert gas is supplied to the boiler 30. A purging operation is performed for a predetermined time (step S40). Through this, the fuel gas remaining inside the fuel gas supply line (L12) between the gas valve unit 20 and the boiler 30 can be removed. Additionally, gas remaining inside the boiler 30, that is, the burner portion 32 of the boiler and the exhaust line L14, can also be removed.

When purging toward the boiler 30 is completed by performing a purging operation for a predetermined time, the valve 28 is switched (step S50) to allow the flow of inert gas toward the vent mast 40, and the vent mast ( 40), an inert gas is supplied and purging is performed for a predetermined time (step S60). Through this, the gas remaining inside the vent line (L16) between the gas valve unit 20 and the vent mast 40 can be removed.

When purging toward the vent mast 40 is completed by performing the purging operation for a predetermined time, the valve 26 is closed to close the inert gas supply line L22 (step S70).

According to the present invention, by performing the purging operation in this way, all remaining gas in the passage from the gas valve unit 20 to the boiler 30 and the passage from the gas valve unit 20 to the vent mast 40 are removed. It can be.

The step (S10) of stopping the operation of the boiler 30 is performed not only when the user stops the normally operating boiler 30, but also when an abnormality occurs in the boiler during operation when fuel gas is supplied to the boiler. This may include cases where the controller manually or automatically stops the operation of the boiler. The step of stopping the boiler operation should be considered to include both cases where the user manually stops the boiler operation or the controller automatically stops the boiler operation.

In addition, it has been explained above that purging work is performed when the operation of the boiler 30 is stopped, but when the type of fuel for the boiler 30 is changed, for example, when fuel oil must be supplied to the boiler instead of fuel gas. Fuzzing can also be performed on the back. The decision on whether to perform such a purge can be done manually by the user, or automatically by a controller that monitors the operating status of combustion devices such as boilers, and the user confirms the status monitored by this controller. It can also be performed semi-automatically.

In addition, the opening/closing control of the valves 22, 24, and 26 or the switching control of the valve 28 performed in each step described above may be performed manually by the user or automatically performed by the controller.

According to another embodiment of the present invention, instead of controlling the flow path by installing one three-way valve 28 at the connection position between the inert gas supply line (L22) and the connection line (L24), the inert gas supply line A change can be made to perform flow control by installing three open/close valves adjacent to the connection position between (L22) and the connection line (L24).

It will be apparent to those skilled in the art that the present invention is not limited to the above-mentioned embodiments, and that it can be implemented with various modifications or variations without departing from the technical gist of the present invention. will be.

12: upper deck, 14: stack, 20: gas valve unit, 22, 24, 26: valve, 28: valve (3-way valve), 30: boiler as combustion device, 32: burner unit, 34: heating unit, 40 : Vent mast, L12: Fuel gas supply line, L14: Exhaust line, L16: Vent line, L22: Inert gas supply line, L24: Connection line.

Claims (7)

In a ship equipped with a combustion device that receives fuel gas through a fuel supply system and combusts it, and a vent mast to discharge the remaining fuel gas in the fuel supply system into the atmosphere when necessary, purging is where the combustion device is purged with an inert gas. As a method,
purging the combustion device by supplying an inert gas toward the combustion device;
After purging the combustion device is completed, purging the vent mast by supplying an inert gas toward the vent mast;
Including, purging method for ships. In claim 1,
In the ship, the combustion device is installed at a higher position than the vent mast,
The step of purging the vent mast is purging the vent line by supplying an inert gas to the vent line extending from a position lower than the combustion device to the vent mast. In claim 1,
The ship has a fuel gas supply line that supplies fuel gas to the combustion device, a vent line that branches off from the fuel gas supply line and extends to the vent mast, and is connected to the fuel gas supply line to supply inert gas. Includes an inert gas supply line,
A purging method for a ship, including closing the fuel gas supply line and opening the inert gas supply line before purging the combustion device. In a ship equipped with a combustion device that receives fuel gas through a fuel supply system and combusts it, and a vent mast to discharge the remaining fuel gas in the fuel supply system into the atmosphere when necessary, purging is where the combustion device is purged with an inert gas. As a system,
a fuel gas supply line that supplies fuel gas to the combustion device;
a vent line branching from the fuel gas supply line and extending to the vent mast;
an inert gas supply line connected to the fuel gas supply line to supply an inert gas;
A gas valve unit installed at a front end of the combustion device on the fuel gas supply line to control the supply of fuel gas through the fuel gas supply line and the supply of inert gas through the inert gas supply line;
Including, a purging system for ships. In claim 4,
In the ship, the combustion device and the gas valve unit are installed at a higher position than the vent mast. In claim 4,
The combustion device is a purging system for ships, which is a DF (Dual Fuel) boiler that can use fuel oil and fuel gas as fuel. In claim 4,
It further includes a connection line branched from the inert gas supply line and connected to the vent line,
A purging system for ships in which a three-way valve is installed at a point where the connection line branches off from the inert gas supply line.

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