KR102600609B1 - Ventilation System for LNG Fueled Ship - Google Patents

Abstract

The ventilation system of an LNG fuel ship is disclosed. The present invention is a ship equipped with a plurality of engines that can be driven using LNG as fuel, and the engine uses a fan to perform ventilation for a fuel gas supply line composed of a double pipe and a gas valve unit provided of the ED type. By configuring it for dual use depending on the operation mode, it is possible to implement a ventilation system by installing one fan per engine, thereby reducing the amount required for ventilation and reducing costs.

Description

Ventilation system for LNG fueled ship {Ventilation System for LNG Fueled Ship}

The present invention relates to a ventilation system for an LNG-fueled ship, and more specifically, to a ventilation system for an LNG-fueled ship equipped with an ED type gas valve unit for controlling the flow rate and pressure of LNG supplied as engine fuel. It's about.

Recently, clean fuels such as liquefied natural gas (LNG), which has low sulfur oxide and nitrogen oxide content, are in the spotlight as an energy source for ships, replacing existing fuel oil. Both fuel oil and natural gas can be used. Dual fuel engines have been developed and are being applied to ships.

LNG carriers (LNGC: LNG Carrier), which are already built for the purpose of transporting large quantities of LNG, are using technology to produce propulsion power and electric power by supplying LNG stored in the cargo hold as fuel for the engine, and recent air pollution regulations have been applied. As LNGC is gradually strengthened, the use of LNG fuel is gradually being applied to ships other than LNGC.

Meanwhile, LNG-fueled ships (LFS: LNG Fueled Ship) that use LNG as fuel either forcefully vaporize LNG or use boil-off gas (BOG: Boil-Off Gas) naturally generated from LNG as fuel for the engine. A fuel gas supply line must be provided to supply fuel gas from the tank to the engine.

This fuel gas supply line is a gas pipe through which fuel gas with the risk of explosion flows. If it passes through an area classified as a gas safety zone, such as the engine room, it must be prepared for LNG leakage. Therefore, it must be composed of a double pipe, and ventilation must be performed to ensure 30 air exchanges per hour in the space between the inner pipe and the outer pipe of the double pipe.

In addition, the IGF Code on safety standards related to LNG ships stipulates that the air for ventilation of double pipes must be used by bringing in outside air rather than the inside air of the engine room or by suctioning air from the cargo area.

However, when bringing in outside air for air circulation in a double pipe, the key is whether smooth air exchange can be performed by a ventilation fan because the double pipe is formed to a considerable length of approximately 70 m or more.

Meanwhile, a gas valve unit (GVU: Gas Valve Unit) that controls the pressure and flow rate of fuel gas is installed on the fuel gas supply line that supplies fuel gas from the LNG fuel tank to the engine. Due to the nature of these gas valve units consisting of valve-type devices that handle gas, they are always exposed to the risk of gas leakage.

According to the classification rules established in consideration of these risks, the gas valve unit is provided as an enclosed type (also known as 'ED type') airtightly surrounded by a housing, and periodic ventilation of the enclosed space is performed. It is required, and if it is provided as an open type (also called 'OD type') without a separate housing, it must be placed in a gas danger zone where ventilation is always performed.

Conventionally, when a gas valve unit was provided as an ED type, it was common to have a separate ventilation line and a ventilation fan for ventilation of the gas valve unit. The reason is that air balancing is difficult when the capacity of the ventilation fan is small.

However, the above-described prior art requires additional equipment or restrictions due to the sole configuration of a ventilation line and a ventilation fan to perform ventilation of the gas valve unit.

Specifically, the prior art uses a redundancy concept so that when one of the fans to perform ventilation for the ED type gas valve unit and the double pipe of the fuel gas supply line fails, the other one can be operated. Two gas detectors must be installed per engine, and two gas detectors must be installed per engine to detect gas leaks from the inner pipe of the double pipe. For example, if a ship is equipped with three engines powered by LNG as fuel, a total of six fans and six gas detectors are required.

In addition, in gas mode, where the engine is operated using LNG as fuel, ventilation of the double pipe and gas valve unit of the fuel gas supply line corresponding to the relevant engine must be performed, and all of the ship's engines are operated in gas mode. When operating as a fan, the number of fans corresponding to the number of engines must be operated simultaneously, and therefore, there is a problem that power consumption increases due to the simultaneous operation of many ventilation fans.

The purpose of the present invention, which is proposed to solve the above conventional problems, is to provide a fan for ventilation of the ED type gas valve unit and the double pipe of the fuel gas supply line in the operation mode of the engine. ), the purpose is to provide a ventilation system for LNG-fueled ships that enables the application of one fan and gas detector per engine by configuring it for dual use.

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

According to one aspect of the present invention for achieving the above object, a plurality of engines are mounted in the engine room and can be driven using LNG as fuel; A fuel gas supply line that supplies fuel gas to the engine and is provided in plural pipes to correspond to the plurality of engines, and the pipe disposed inside the engine room is composed of a double pipe; a gas valve unit installed on each of the fuel gas supply lines to control the pressure and flow rate of fuel gas supplied to the engine, provided as an ED type sealed with a housing, and disposed in the engine room; An air suction line that suctions external air and supplies it to the double pipe of the fuel gas supply line to perform ventilation for the gas valve unit and the double pipe of the fuel gas supply line; A vent line connected to the double pipe of each fuel gas supply line to discharge the air inside the double pipe to the outside; A connection line connecting the plurality of vent lines to each other; A ventilation system for an LNG fuel ship may be provided, including a fan installed at a rear end of a point connected by the connection line on each of the vent lines to generate air discharge pressure.

In addition, the ventilation system of an LNG fuel ship according to an aspect of the present invention is installed between a front end of each vent line connected by the connection line and adjacent vent lines on the connection line, It may further include a plurality of isolation valves that are flexibly controlled according to the number of operating engines.

The capacity of each fan may be designed to have a capacity that can cover the ventilation of the two engines.

The number of the plurality of fans provided is determined depending on the number of the plurality of engines operating in gas mode using LNG as fuel, and one of the plurality of fans may be put on standby for switching in an emergency.

The ventilation system of an LNG fuel ship according to one aspect of the present invention includes an integrated line that integrates the plurality of vent lines into one and finally discharges air; And it may further include a plurality of gas detectors, which are respectively installed in front of the point where the isolation valve is installed on each of the vent lines and on the integrated line, and detect leakage of fuel gas by analyzing the components of the circulating air. .

The gas detector installed on the vent line enables individual fuel gas leak detection for the plurality of engines.

When one of the plurality of engines is gas tripped, one of the plurality of fans operates independently to exhaust the gas leaked between the double pipes, and may be operated until the GAS LEL of the gas detector returns to the normal range.

The air suction lines are provided in plural numbers to correspond to the plurality of engines and are connected to each engine, and the air sucked through the air suction line can be supplied to the double pipe of the fuel gas supply line through the inside of the engine. .

The ventilation system of an LNG fuel ship according to one aspect of the present invention may further include an orifice valve installed on each air suction line to perform air balancing.

Meanwhile, the plurality of fans are operated by receiving electricity from different distribution boards, and one of the plurality of distribution boards may be provided as an emergency distribution board.

Among the plurality of switchboards, except for the emergency switchboard, the remaining general switchboards are supplied with power produced by at least two of the plurality of engines, and the emergency switchboard distributes power from the general switchboard and, in an emergency, power produced by an emergency generator. can be supplied.

The ventilation system for an LNG fuel ship according to the present invention provides integrated ventilation for the ED type gas valve unit and the double pipe of the fuel gas supply line, thereby reducing costs by reducing the volume required for ventilation. It has effectiveness and design advantages.

Specifically, for example, if a ship is equipped with three engines that can be driven using LNG as fuel, conventionally, two fans were needed for each engine, so a total of six fans had to be provided, but the present invention requires a total of three fans. A ventilation system for three engines can be implemented with only one fan, thereby reducing costs by reducing the number of ventilation fans installed.

In addition, according to the present invention, as the capacity of the fan for ventilation is reduced, power consumption is also reduced, which has the effect of reducing OPEX and CAPEX, and provides flexibility in the design of various piping and equipment for ventilation. There is an improving effect.

In other words, in constructing a ventilation system for a ship that uses LNG as engine fuel, the present invention satisfies class requirements, secures economy and stability, and at the same time greatly improves the buildability and productivity of the ship through layout optimization. You can contribute.

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

1 is a diagram schematically showing the ventilation system of an LNG fuel ship according to the present invention.

In order to fully understand the present invention, its operational advantages, and the purposes and effects achieved by practicing the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Matters expressed in the drawings attached to this specification may be somewhat different from the form actually implemented in schematic drawings to easily explain the embodiments of the present invention, and the sizes of each component shown in the drawings are for explanatory purposes. It can be exaggerated or reduced and does not mean the size that is actually applied.

Additionally, the terms used herein are merely used to describe specific embodiments and are not intended to limit the invention. For example, in this specification, “including” a certain component does not mean excluding other components, but may further include other components, unless specifically stated to the contrary.

In addition, it should be understood that saying that a component is 'connected' to another component includes direct connection as well as indirect connection, and that other components may exist between the two components. Singular expressions may be interpreted to include plural expressions unless the context clearly indicates otherwise.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings. The embodiments described below are provided so that those skilled in the art can easily understand the technical idea of the present invention, and the present invention is not limited thereto.

1 is a diagram schematically showing the ventilation system of an LNG fuel ship according to the present invention.

Referring to Figure 1, the ventilation system of an LNG fuel ship according to the present invention includes a plurality of engines 11 to 13 mounted in the engine room and capable of being driven using LNG as fuel; Fuel gas supply lines (SL1 to SL3) for supplying LNG as fuel to the engines (11 to 13); In order to perform ventilation (air circulation) for the pipes composed of double pipes among the fuel gas supply lines (SL1~SL3), the air suction line (air suction line) suctions external air and supplies it to the double pipes of the fuel gas supply lines (SL1~SL3). AL1~AL3); And it may be configured to include a plurality of vent lines (VL1 to VL3) that are connected to the outer pipe of the double pipe of the fuel gas supply line (SL1 to SL3) and discharge the air inside the outer pipe.

The plurality of engines (11 to 13) may include a propulsion engine (also called 'main engine') that produces the ship's propulsion power and a power generation engine that produces the power needed within the ship, and fuel oil and natural gas of MDO and HFO It can be equipped as a dual-fuel engine that can be driven by using all of the fuel as fuel.

Preferably, the engines 11 to 13 of the present invention may be equipped as power generation engines that produce power through power generation and supply it to various demand sources on board, such as DFGE (Dual Fuel GEnerator), DFDG (Dual Fuel Diesel Generator), It can be prepared with a DFDE (Dual Fuel Diesel Electric Engine), etc.

Below, it is described as a preferred embodiment that the ship is equipped with a total of three engines (11 to 13), but the number of engines (11 to 13) is not limited or limited thereto, and the required load level of the ship It is natural that the number can increase or decrease depending on.

The engine room where the plurality of engines 11 to 13 are mounted may be partitioned at the stern of the LNG fuel ship according to the present invention. The engine room is a space classified as a gas safety area, and safety from gas hazard areas must be ensured. According to the classification rules, direct entry from the gas hazardous area to the gas safe area is prohibited (install an air-lock if necessary), and the gas pipe passing through the gas safe area must be composed of a double pipe or completely enclosed by a duct. do.

Meanwhile, although not shown in the drawing, the LNG fuel ship according to the present invention includes an LNG fuel tank for storing LNG to be used as fuel for the engines 11 to 13, and LNG stored in the LNG fuel tank or inside the LNG fuel tank. A fuel gas supply system (FGSS) may be provided that properly processes naturally occurring BOG and supplies it as fuel for the engines 11 to 13.

The LNG fuel tank may include an appropriate level of insulation and sealing system to accommodate LNG liquefied at extremely low temperatures, and may be a membrane type tank manufactured using the inner wall of the hull, as well as a membrane type tank manufactured separately from the hull to be used on the ship. Independent type tanks that can be mounted independently can be freely used without type restrictions.

In order for the LNG stored in the LNG fuel tank to be used as fuel, it must meet the conditions such as pressure and temperature required by the engine (11 to 13). To this end, the LNG or BOG extracted from the LNG fuel tank is delivered to the fuel gas supply system. After going through a series of processes including compression and heating, it is supplied to the engines 11 to 13. If the LNG inside the LNG fuel tank is directly extracted and used as fuel, an additional processing process of forcibly vaporizing the LNG may be involved. To perform this treatment, the fuel gas supply system may include equipment such as a high pressure pump (HP pump), vaporizer, compressor, and heater.

LNG fuel (hereinafter referred to as 'fuel gas') processed by the fuel gas supply system can be supplied to the engines 11 to 13 along the fuel gas supply lines (SL1 to SL3). At this time, since the operating status and required fuel gas conditions of the plurality of engines 11 to 13 may be different from each other, the fuel gas supply lines SL1 to SL3 are provided as a plurality of lines corresponding to each engine 11 to 13. Can be connected individually.

Specifically, the first fuel gas supply line (SL1) supplies fuel gas from the fuel gas supply system to the first engine 11, and the second fuel gas supply line SL1 supplies fuel gas from the fuel gas supply system to the second engine 12. A fuel gas supply line (SL2) and a third fuel gas supply line (SL3) that supply fuel gas from the fuel gas supply system to the third engine 13 are provided.

Since the fuel gas supply lines (SL1~SL3) are gas pipes through which fuel gas with the risk of explosion flows, the fuel gas supply lines (SL1~SL3) located in the engine room classified as a gas safety area are composed of double pipes. Referring to the drawing, it can be seen that the fuel gas supply lines (SL1 to SL3) from the part entering the engine room from the weather deck to the engines 11 to 13 are composed of double pipes.

Gas valve units 21 to 23 may be installed on each fuel gas supply line (SL1 to SL3) to control the pressure and flow rate of fuel gas supplied to each engine (11 to 13).

Specifically, a first gas valve unit 21 that controls the pressure and flow rate of fuel gas supplied to the first engine 11 is installed on the first fuel gas supply line (SL1), and a second fuel gas supply line (SL2) On the top, there is a second gas valve unit 22 that controls the pressure and flow rate of the fuel gas supplied to the second engine 12, and on the third fuel gas supply line SL3, the fuel supplied to the third engine 13 A third gas valve unit 23 that controls the pressure and flow rate of gas may be installed, respectively.

The gas valve units 21 to 23 are devices that group valves that control the pressure and flow rate of fuel gas supplied to the engines 11 to 13. The gas valve units 21 to 23 control the pressure of the fuel gas supplied to the engines 11 to 13 to the engine. It is a device that quickly controls depending on the load and quickly and stably cuts off the supply of fuel gas when necessary.

These gas valve units (21 to 23) are devices that control the flow of fuel gas that has the risk of explosion. When located in a gas safety area, they are provided as an ED type sealed with a housing and must be periodically ventilated. , if it is to be equipped with an OD type, it must be placed in a gas hazard area where ventilation is always performed.

However, when the engines (11 to 13) of the present invention are equipped as power generation engines, the power generation engine is supplied with fuel gas at a relatively low pressure compared to the main engine, and the required fuel gas flow rate varies flexibly depending on the load. Therefore, if the gas valve units 21 to 23 are placed far from the engines 11 to 13, it is difficult to properly cope with load changes of the engines 11 to 13.

In consideration of the above characteristics, the present invention is configured as an 'ED type' in which the gas valve units (21 to 23) are sealed with a housing and placed in the engine room so that they can be located close to the engines (11 to 13).

Meanwhile, in the present invention, the fuel gas supply lines (SL1 to SL3) and the gas valve units (21 to 23), which are composed of double pipes, flow or control the flow of fuel gas with a risk of explosion, and are required according to classification rules. It is required that adequate ventilation be carried out.

In order to satisfy classification rules, the present invention is an air suction line (AL1 to AL3) that supplies air to the external pipe of the fuel gas supply line (SL1 to SL3) composed of a double pipe and a fuel gas supply line (SL1 to SL3). A vent line (VL1 to VL3) is provided to discharge the air inside the external pipe, and the fuel gas supply line is supplied through the supply of air by the air suction line (AL1 to AL3) and the discharge of air by the vent line (VL1 to VL3). Configure the system so that ventilation is performed on the double pipes (SL1~SL3) and gas valve units (21~23).

The air suction line (AL1~AL3) suctions external air and supplies it to the external pipe of the fuel gas supply line (SL1~SL3). At this time, the air suction lines (AL1 to AL3) can suction and supply air from the outside air or cargo area rather than the air inside the engine room. When suctioning humid outdoor air, an electric heater 60 that heats the air suction lines (AL1 to AL3) may be additionally provided to prevent condensation.

Additionally, an orifice valve (OV) may be installed on each air suction line (AL1 to AL3). The orifice valve (OV) facilitates air balancing to satisfy 30 air exchanges per hour for each line when ventilation is performed simultaneously on two or more lines among multiple fuel gas supply lines (SL1 to SL3). It plays a role.

In the present invention, the air suction lines (AL1 to AL3) can be connected to the engines (11 to 13), and the air suctioned through the air suction lines (AL1 to AL3) passes through the inside of the engines (11 to 13) to the fuel gas supply line. It can be supplied to the external pipe of (SL1~SL3). A double pipe for supplying fuel gas is also formed inside the engines (11 to 13), and ventilation is performed together.

The air suction lines (AL1 to AL3) are provided as a plurality of lines to correspond to each engine (11 to 13) and can be individually connected to each engine (11 to 13). If there is an engine operating in gas mode among the plurality of engines (11 to 13), external air is supplied through the air suction lines (AL1 to AL3) corresponding to the engine, thereby contributing to the fuel gas supply to the engine. Ventilation must be performed on the double pipes of the lines (SL1~SL3) and the gas valve units (21~23).

Vent lines (VL1~VL3) are used to discharge the air inside the external pipe of the fuel gas supply lines (SL1~SL3) to the outside. Each fuel gas supply line (SL1~SL3) has a vent line (VL1~VL3). can be connected Specifically, the first vent line (VL1) is connected to the external pipe of the first fuel gas supply line (SL1), and the second vent line (VL2) is connected to the external pipe of the second fuel gas supply line (SL2). , the third vent line (VL3) may be connected to the external pipe of the third fuel gas supply line (SL3).

Fans 31 to 33 may be installed on each vent line (VL1 to VL3) to create pressure to discharge the air inside the double pipe of the fuel gas supply line (SL1 to SL3) to the outside. Specifically, the first fan 31 is on the first vent line (VL1), the second fan 32 is on the second vent line (VL2), and the third fan 33 is on the third vent line (VL3). Each of these can be installed.

The capacity of each fan (31 to 33) can be designed to cover ventilation for two engines (11 to 13). As will be described later, the present invention makes it possible to perform ventilation by operating only two of the plurality of fans (31 to 33) when all three engines (11 to 13) are operated in gas mode, and the three engines When two of the fans (11 to 13) are operated in gas mode, the system is configured so that ventilation can be performed by operating only one of the plurality of fans (31 to 33).

When at least one of the plurality of engines 11 to 13 is operated in a gas mode using LNG as fuel, at least one of the first to third fans 31 to 33 must be operated to fuel the engine. Ventilation must be performed on the double pipe of the fuel gas supply line (SL1~SL3) and the gas valve unit (21~23) involved in gas supply.

At this time, whether the first to third fans 31 to 33 for ventilation are operated is not determined by the operating state of the directly connected engines 11 to 13. That is, when the first engine 11 is operated in gas mode, the first fan 31 does not necessarily have to be operated, and the same applies to the others.

This is because, as will be described later, the system of the present invention is configured so that the plurality of fans (31 to 33) can back up each other by the connection line (LL) that connects the plurality of vent lines (VL1 to VL3) to each other. am. In the present invention, each fan (31 to 33) is connected directly to the fuel gas supply line (SL1 to SL3) as well as the ventilator of other fuel gas supply lines (SL1 to SL3) indirectly connected by the connection line (LL). ration may also be involved, and therefore, when at least one of the plurality of engines 11 to 13 is operated in gas mode, at least one unspecified one of the plurality of fans 31 to 33 may be operated.

When performing ventilation, the existing air existing in the external pipe of the fuel gas supply line (SL1 to SL3) and the gas valve unit (21 to 23) is discharged from the vent line ( It is discharged to the outside through VL1~VL3) and is replaced by new air supplied through air suction lines (AL1~AL3).

Meanwhile, the present invention is intended to solve the inefficient design problem of the prior art, which required two fans to be installed per engine, and includes gas valve units (21 to 23) and fuel gas supply lines (SL1 to SL1) provided as ED type. It was previously revealed that the purpose is to reduce the amount required for ventilation by implementing ventilation for the double pipe of SL3) in an integrated manner.

For this purpose, the present invention provides a connection line (LL) that connects a plurality of vent lines (VL1 to VL3) connected to the double pipes of the fuel gas supply lines (SL1 to SL3) that supply fuel gas to the engines (11 to 13). In addition, the system can be configured so that the fans 31 to 33 installed in each vent line (VL1 to VL3) can be operated as backup to each other. Here, ‘connecting’ means configuring the piping systems to be connected (connected) or separated (blocked) from each other.

As shown, the connection line (LL) may be configured to connect the front end points of the fans (31 to 33) in each vent line (VL1 to VL3), and each vent line (VL1 to VL3) is connected to the connection line ( LL), so that discharge pressure can be provided from any of the plurality of fans (31 to 33).

In addition, in order to implement connection of a plurality of vent lines (VL1 to VL3), first to third isolation valves (41 to 43) are installed on each vent line (VL1 to VL3) before being connected by the connection line (LL). may be installed, and the fourth and fifth isolation valves 44 and 45 may be installed on the connection line LL connecting neighboring vent lines VL1 to VL3. Isolation valves serve to connect or separate connected piping systems from each other by opening and closing the flow path at the installed point.

According to the configuration of the present invention as described above, the first to third fans (31 to 33) can participate in the ventilation of all fuel gas supply lines (SL1 to SL3) regardless of which line they are connected to. . This means that even if one of the plurality of fans (31 to 33) fails, the remaining fans (31 to 33) can back up and perform ventilation for other lines. Therefore, one fan per engine (11 to 13) Even if only fans (31 to 33) are installed, it is sufficient.

The control logic of the fans 31 to 33 according to the operation mode of the engines 11 to 13 may be configured as follows.

A. When all three engines (11 to 13) are operated in gas mode

When all three engines (11 to 13) are operated in gas mode, two of the three fans (31 to 33) are operated to create exhaust pressure for ventilation, and the remaining fan is on standby in case of an emergency. by) status. At this time, the first to fifth isolation valves (41 to 45) are all opened.

As described above, the capacity of each fan (31 to 33) that forms the discharge pressure for ventilation has a capacity to cover the ventilation of two engines (11 to 13), so three engines (11) Even when all ~13) are operated in gas mode, ventilation can be performed with only two fans. This has the effect of reducing the number and capacity of ventilation fans in operation compared to the prior art.

In addition, the present invention facilitates air balancing because when all three engines (11 to 13) are operated in gas mode, the margin can be larger than the air exchange capacity actually required by operating two fans. , having the remaining fan as a standby fan has the effect of enabling stable operation of the system.

B. When two of multiple engines (11 to 13) are operated in gas mode

When two of the plurality of engines (11 to 13) are operated in gas mode, one of the plurality of fans (31 to 33) is operated to form exhaust pressure for ventilation, and one of the remaining two fans is on standby. Put it on standby.

At this time, the isolation valve installed on the vent line connected to the external pipe of the fuel gas supply line that supplies fuel gas to the engine operating in gas mode among the plurality of engines 11 to 13 is opened. In addition, the connection line connecting the vent line with the fan to be operated and the vent line with the fan to be on standby is opened to enable quick switching to the standby fan in an emergency, and is connected to the engine not operating in gas mode to provide ventilation. Block the flow path to the fuel gas supply line that does not require operation. Blocking of the flow path can be accomplished by closing the isolation valve installed on the connection line or the isolation valve installed on the vent line corresponding to the engine not operating in gas mode.

As a more specific example, a case where the first engine 11 and the second engine 12 are operated in gas mode will be described. In this case, in order to perform ventilation of the first fuel gas supply line (SL1) and the second fuel gas supply line (SL2) involved in the supply of fuel gas to the first engine 11 and the second engine 12, the first fuel gas supply line (SL1) and the second fuel gas supply line (SL2) are The first isolation valve 41 installed on the vent line (VL1) and the second isolation valve 42 installed on the second vent line (VL2) are opened.

In addition, in order to perform ventilation according to the gas mode operation of the first and second engines 11 and 12, one of the plurality of fans 31 to 33 may be operated and one fan may be on standby. First, the first fan ( It is assumed that 31) is operated and the second fan 32 is on standby. At this time, the third fan 33 does not operate.

In this case, the first vent line (VL1) and the second vent line (VL2) must communicate with each other so that the fan can quickly switch to the second fan (32) when the first fan (31) fails. Accordingly, the fourth isolation valve 44 installed on the connection line LL connecting the first vent line VL1 and the second vent line VL2 is opened. Another isolation valve installed on the connection line LL, that is, the fifth isolation valve 45, is closed to block the flow path to the third fuel gas supply line SL3.

Meanwhile, it may be assumed that the first fan 31 is running and the third fan 33 is on standby. In this case, the fourth and fifth isolation valves (44) installed on the connection line (LL) between the first vent line (VL1) and the third vent line (VL3) to switch to the standby fan (33) in an emergency. 45) must all be open. Therefore, in this case, blocking the flow path to the third fuel gas supply line (SL3) can be achieved by closing the third isolation valve (43).

In addition, as another case, it may be assumed that one of the second fan 32 and the third fan 33 is operating and the other is on standby. In this case, the isolation valves 41 are operated in a similar manner as described above. By controlling ~45), the flow path in which discharge pressure is provided and the flow path in which discharge pressure is not provided can be set.

That is, the present invention includes three isolation valves (41 to 43) installed on each vent line (VL1 to VL3) that are not connected by the connection line (LL) and two isolation valves ( 44, 45), it is possible to connect or disconnect the piping system of the first to third vent lines (VL1 to VL3), and a total of five isolation valves (41 to 45) are properly controlled to open necessary flow paths and remove unnecessary ones. The system is configured to block unused flow paths.

C. When one of multiple engines (11 to 13) is operated in gas mode

When only one of the plurality of engines (11 to 13) is operated in gas mode, one of the plurality of fans (31 to 33) is operated to form exhaust pressure for ventilation, and one of the remaining two fans (31 to 33) is operated in preparation for an emergency. The need to put one unit on standby is the same as the 'B' case seen above.

Therefore, in this case, control can be performed in a similar manner to the 'B' case, except that one more isolation valve installed on the vent line connected to the external pipe of the fuel gas supply line where ventilation is not performed is blocked. , detailed description is omitted.

As seen in the above embodiment, a plurality of fans (31 to 33) and isolation valves (41 to 45) provided in this system can be operated in conjunction with each other flexibly according to the number of operating engines (11 to 13), It can be automatically linked and controlled by the ship's control system.

Meanwhile, in the present invention, each vent line (VL1 to VL3) is finally integrated into one integrated line (CL) to discharge air to the outside. On the vent lines (VL1 to VL3) between the point where the fan (31 to 33) is installed and the point that is integrated into the integrated line (CL), a flame screen (71) is installed to prevent flames from spreading elsewhere in the event of an explosion. ) can be installed.

The flow switch (72) installed between the check valve installed at the rear of the fans (31-33) and the flame screen (71) is a device that detects whether the air flow is smooth. As a result, when the air flow is smooth, a signal that gas mode operation of the engines 11 to 13 is possible can be given.

First to third gas detectors 51 to 53 may be installed on each vent line (VL1 to VL3) before being connected by the connection line (LL), and the first to third gas detectors 51 to 53 may be installed to detect leakage of fuel gas. A fourth gas detector 54 to detect leakage of fuel gas may be installed on the integrated line (CL) where three vent lines (VL1 to VL3) are integrated. The first to fourth gas detectors 51 to 54 can detect fuel gas leakage by analyzing the components of air exchanged when ventilation is performed.

In addition, the present invention generates an alarm when the GAS LEL (gas content) measured by the first to third gas detectors (51 to 53) installed on each vent line (VL1 to VL3) exceeds 20%. , Engines (11 to 13) connected to the vent line (VL1 to VL3) where an alarm is generated when the GAS LEL measured by the fourth gas detector (54) installed on the integrated line (CL) simultaneously exceeds 20%. The system can be configured to perform a gas trip.

According to the present invention, the discharge ends of the first to third vent lines (VL1 to VL3) are integrated into one line as described above, and a fourth gas detector 54 is additionally configured on the integrated line (CL). This has the effect of reducing the number of gas detectors.

Specifically, conventionally, two gas detectors were installed at the front of the ventilation fan, requiring a total of six gas detectors. However, in the present invention, one gas detector is installed on each vent line (VL1 to VL3) and one at the rear end. One unit can be configured on the integrated line (CL), reducing the number of units to a total of four.

In addition, the present invention makes it possible to estimate which side of the engine (11 to 13) the fuel gas leak occurred by using the first to third gas detectors (51 to 53) installed on each vent line (VL1 to VL3). Therefore, there is an advantage that only the gas trip of the engine in which the fuel gas leak occurred can be performed.

When any one of the engines (11 to 13) has a gas trip, one of the plurality of fans (31 to 33) operates independently for the tripped engine to exhaust the gas leaked between the double pipes, and the gas detector (51) The fan can be run until the GAS LEL of ~54) returns to the normal range. The aforementioned isolation valves 41 to 45 are also controlled to distinguish between a gas trip engine and a normal engine.

Meanwhile, since the plurality of fans (31 to 33) provided in this system are operated by receiving electricity, smooth operation must be achieved even if the switchboard (SWBD) that supplies electricity to the fans (31 to 33) fails. .

To this end, the present invention can configure the system so that each fan (31 to 33) receives electricity from different distribution boards (81 to 83). Specifically, the first fan 31 draws electricity from the first distribution board 81, the second fan 32 draws electricity from the second distribution board 82, and the third fan 33 draws electricity from the third distribution board 83. It is configured to receive supply, and according to this system configuration, even if any one of the first to third distribution boards (81 to 83) is damaged, at least two of the plurality of fans (31 to 33) can be operated at any time.

In addition, the first switchboard 81 receives power produced by the first engine 11 and the third engine 13, and the second switchboard 82 receives the power produced by the second engine 12 and the third engine 13. You can receive power generated from . In addition, the third switchboard 83 is an emergency switchboard (Emergency SWBD) that can supply power even in an emergency such as a blackout. It distributes power from the first switchboard 81 and the second switchboard 82, and in case of an emergency, it uses an emergency generator. It can be configured to receive power from an (Emergency Generator).

As described above, the present invention is a system that takes into account all emergency situations such as failure of the fans 31 to 33, failure of the switchboards 81 to 83, or power supply and demand problems of the ship, and has excellent stability.

In the above, the present invention is described as being applied to ships using LNG as fuel, but in addition to LNG, which is the most representative liquefied gas, the present invention also applies to LPG (Liquefied Petroleum Gas), LEG (Liquefied Ethane Gas), and Liquefied Ethylene Gas. It can be applied to ships that use various liquefied gases as fuel, such as gas and liquefied propylene gas, which can be liquefied at low temperature, stored and transported, and can be used as fuel for engines in a vaporized state.

Additionally, in the present invention, 'ship' can be interpreted as a concept that includes all types of ships that use various liquefied gases as engine fuel. Representatively, ships with self-propulsion, such as LNGC and LFS, as well as offshore structures floating on the sea, such as LNG FPSO (Floating Production Storage Offloading) and LNG FSRU (Floating Storage Regasification Unit), can be used in the concept of the ship of the present invention. may be included.

It is obvious to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. Accordingly, such modifications or variations should be considered to fall within the scope of the claims of the present invention.

11: 1st engine
12: Second engine
13: Third engine
21: First gas valve unit
22: Second gas valve unit
23: Third gas valve unit
31: first fan
32: second fan
33: Third fan
41: first isolation valve
42: Second isolation valve
43: Third isolation valve
44: Fourth isolation valve
45: Fifth isolation valve
51: First gas detector
52: Second gas detector
53: Third gas detector
54: Fourth gas detector
60: Electric heater
71: Flame screen
72: Flow switch
81: 1st switchboard
82: Second switchboard
83: Third switchboard
SL1: 1st fuel gas supply line
SL2: Second fuel gas supply line
SL3: Third fuel gas supply line
AL1: 1st air suction line
AL2: 2nd air suction line
AL3: Third air suction line
VL1: 1st vent line
VL2: Second vent line
VL3: Third vent line
LL: Link line
CL: integrated line
OV: Orifice valve

Claims (11)

Multiple engines mounted in the engine room and capable of being driven using LNG as fuel;
A fuel gas supply line that supplies fuel gas to the engine and is provided in plural pipes to correspond to the plurality of engines, and the pipe disposed inside the engine room is composed of a double pipe;
a gas valve unit installed on each of the fuel gas supply lines to control the pressure and flow rate of fuel gas supplied to the engine, provided as an ED type sealed with a housing, and disposed in the engine room;
An air suction line that suctions external air and supplies it to the double pipe of the fuel gas supply line to perform ventilation for the gas valve unit and the double pipe of the fuel gas supply line;
A vent line connected to the double pipe of each fuel gas supply line to discharge the air inside the double pipe to the outside;
A connection line connecting the plurality of vent lines to each other;
A fan installed at a rear end of each vent line at a point connected by the connection line to generate air discharge pressure; and
Each of the vent lines is installed between a front end of a point connected by the connection line and adjacent vent lines on the connection line, and includes a plurality of isolation valves that are flexibly controlled according to the number of operating units of the plurality of engines. do,
The capacity of each fan is designed to cover the ventilation of the two engines,
The number of the plurality of fans provided is determined according to the number of gas mode operation using LNG as fuel among the plurality of engines, and at least one of the plurality of fans is on standby for switching in an emergency.
Ventilation system for LNG fueled ships. delete delete delete In claim 1,
An integrated line that integrates the plurality of vent lines into one and finally discharges the air; and
It is installed in front of the point where the isolation valve is installed on each of the vent lines and on the integrated line, and further includes a plurality of gas detectors that detect leakage of fuel gas by analyzing components of circulating air,
Ventilation system for LNG fueled ships. In claim 5,
Characterized in that individual fuel gas leak detection for the plurality of engines is possible by the gas detector installed on the vent line,
Ventilation system for LNG fueled ships. In claim 6,
When one of the plurality of engines is gas tripped, one of the plurality of fans is independently operated to exhaust the gas leaked between the double pipes, and is operated until the GAS LEL of the gas detector returns to the normal range. doing,
Ventilation system for LNG fueled ships. In claim 1,
The air suction line is provided in plurality to correspond to the plurality of engines and connected to each engine, and the air sucked through the air suction line is supplied to the double pipe of the fuel gas supply line through the inside of the engine. to,
Ventilation system for LNG fueled ships. In claim 8,
Further comprising an orifice valve installed on each air suction line to perform air balancing,
Ventilation system for LNG fueled ships. In claim 1,
The plurality of fans are operated by receiving electricity from different switchboards, and one of the plurality of switchboards is provided as an emergency switchboard.
Ventilation system for LNG fueled ships. In claim 10,
Among the plurality of switchboards, the remaining general switchboards, excluding the emergency switchboard, are supplied with power produced by at least two of the plurality of engines,
The emergency switchboard is characterized in that it distributes power from the general switchboard and receives power produced by an emergency generator in the event of an emergency.
Ventilation system for LNG fueled ships.