KR20230060845A - Ventilation System for LNG Fueled Ship - Google Patents

Abstract

A ventilation system of a liquefied natural gas (LNG) fueled ship is disclosed. In a ship equipped with a plurality of engines that can be driven using LNG as fuel, by configuring a fuel gas supply line consisting of double pipes and a fan to perform ventilation for a gas valve unit provided as ED type for dual use depending on the engine's operation mode, it is possible to implement a ventilation system by installing one fan per engine. Therefore, it has the effect of 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 vessel, and more particularly, to a ventilation system for an LNG fueled vessel equipped with an ED type gas valve unit for controlling the flow rate and pressure of LNG supplied as engine fuel. It is about.

Recently, clean fuels such as liquefied natural gas (LNG), which have low content of sulfur oxides and nitrogen oxides, are in the limelight as an alternative to conventional fuel oil as an energy source for ships, and both fuel oil and natural gas can be used. A dual fuel engine has been developed and applied to ships.

In an LNG carrier (LNGC), which is already built for the purpose of transporting large amounts of LNG, a technology is applied to produce the propulsion power and power of the ship by supplying LNG stored in the cargo hold as fuel for the engine. Recently, air pollution regulations have been applied As the use of LNG fuel is gradually strengthened, the use of LNG fuel is gradually being applied to ships other than LNGC.

On the other hand, LNG fueled ships (LFS: LNG Fueled Ships) that use LNG as fuel use LNG fuel by forcibly vaporizing LNG or using BOG (Boil-Off Gas) naturally generated from LNG as engine fuel. A fuel gas supply line for supplying fuel gas from the tank to the engine must be provided.

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

In addition, the IGF Code for safety standards related to LNG ships stipulates that outside air, not internal air of the engine room, should be brought in or air from the cargo area should be suctioned and used as air for ventilation of the double pipe.

However, when outside air is brought in for air circulation of the double pipe, since the double pipe is formed with a considerable length of about 70 m or more, it is a key whether smooth air exchange by a ventilation fan can be performed.

Meanwhile, a gas valve unit (GVU) for controlling pressure and flow rate of fuel gas is installed on a fuel gas supply line for supplying fuel gas from an LNG fuel tank to an engine. Such a gas valve unit is inevitably exposed to the risk of gas leakage at all times due to the nature of being composed of valve devices that handle gas.

According to the classification rules prescribed in consideration of this risk, the gas valve unit is provided in an enclosed type (encolsed type, also referred to as 'ED type') airtightly surrounded by a housing, so that periodic ventilation for the enclosed space is performed. When equipped in 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 the gas valve unit is provided as an ED type, it is common that a ventilation line and a ventilation fan for performing ventilation of the gas valve unit are independently configured. This is because air balancing is difficult when the capacity of the ventilation fan is small.

However, the prior art as described above is subject to additional facilities or constraints due to the single configuration of the ventilation line and ventilation fan for performing ventilation of the gas valve unit.

Specifically, the prior art is a redundancy concept so that the other one can be operated when one of the fans for performing ventilation for the double pipe of the ED type gas valve unit and the fuel gas supply line fails. Therefore, two units must be installed per engine, and two gas detectors must be installed for each engine to detect gas leaks in the inner tube of the double tube. For example, when a ship is provided with three engines driven by using LNG as fuel, a total of six fans and six gas detectors are required.

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

An object of the present invention proposed to solve the above conventional problems is to use a fan for performing ventilation for a gas valve unit provided in an ED type and a double pipe of a fuel gas supply line in an engine operation mode. ), to provide a ventilation system for an LNG fueled ship that enables the application of one fan and a gas sensor per engine.

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 mounted in the engine room and capable of driving using LNG as fuel; A fuel gas supply line provided in plurality to correspond to the plurality of engines as a pipe supplying fuel gas to the engine, and a pipe disposed inside the engine room 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 the fuel gas supplied to the engine, provided in an ED type sealed with a housing and disposed in the engine room; an air suction line for suctioning external air and supplying it to the double pipe in order to ventilate the double pipe of the fuel gas supply line and the gas valve unit; a vent line connected to the double pipe of each of the fuel gas supply lines and discharging air inside the double pipe to the outside; connection lines connecting the plurality of vent lines to each other; And a ventilation system of an LNG fueled ship including a fan installed on each of the vent lines at the rear end of the point connected by the linkage line to form a discharge pressure of air may be provided.

In addition, the ventilation system of an LNG fueled ship according to an aspect of the present invention is installed between the front end of the point connected by the linkage line on each of the vent lines and the vent line adjacent to each other on the linkage line, A plurality of isolation valves that are flexibly controlled according to the number of operating engines may be further included.

The capacity of each fan may be designed to cover the ventilation of the two engines.

The number of fans provided in plurality is determined according to the number of operating units in gas mode using LNG as fuel among the plurality of engines, and one of the plurality of fans may be on standby for conversion in case of emergency.

A ventilation system for an LNG fueled ship according to an aspect of the present invention includes an integrated line for finally discharging air by integrating a plurality of the vent lines into one; and a plurality of gas detectors respectively installed on the integrated line and in front of the point where the isolation valve is installed on each of the vent lines, and detecting leakage of the fuel gas by analyzing components of the circulating air. .

Individual fuel gas leakage detection for the plurality of engines is possible by the gas detector installed on the vent line.

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

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

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

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

Among the plurality of switchboards, general switchboards other than the emergency switchboard receive power generated from at least two of the plurality of engines, and the emergency switchboard receives power from the general switchboard and in case of an emergency, power generated by the emergency generator. can be supplied.

The ventilation system of the LNG fuel ship according to the present invention integrates ventilation for the gas valve unit provided in the ED type and the double pipe of the fuel gas supply line, thereby reducing costs through reduction in the volume required for ventilation. It has effects and design advantages.

Specifically, for example, when a ship is provided with three engines that can be driven by using LNG as fuel, conventionally, two fans were required for each engine, so a total of six fans had to be provided, but the present invention provides a total of three It is possible to implement a ventilation system for three engines with only one fan, and thus, there is an effect of reducing costs by reducing the number of installed ventilation fans.

In addition, according to the present invention, as the capacity of the fan for performing ventilation is reduced, power consumption is also reduced, resulting in OPEX and CAPEX savings, and flexibility in design arrangement of various piping and equipment for performing ventilation. has an enhancing effect.

That is, the present invention, in constructing a ventilation system for a ship using LNG as an engine fuel, satisfies the classification requirements, secures economic feasibility and stability, and greatly improves the ship's dryness and productivity through layout optimization. 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 view schematically showing a ventilation system for an LNG fuel ship according to the present invention.

In order to fully understand the present invention and the operational advantages of the present invention and the objects and effects achieved by the practice of 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 represented in the drawings accompanying this specification may be somewhat different from the form actually implemented as a schematic drawing to easily explain the embodiments of the present invention, and the size of each component shown in the drawings is for explanation. They may be exaggerated or reduced and are not meant to be of actual size.

In addition, terms used in this specification are only used to describe specific embodiments and are not intended to limit the present invention. For example, in the present specification, 'including' a certain component means that other components may be further included, rather than excluding other components unless otherwise stated.

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

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. 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 thereby.

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

Referring to FIG. 1 , a ventilation system of an LNG fueled ship according to the present invention includes a plurality of engines 11 to 13 mounted in an engine room and driven by using LNG as fuel; Fuel gas supply lines SL1 to SL3 for supplying LNG as fuel to the engines 11 to 13; An air suction line (which suctions outside air and supplies it to the double pipe of the fuel gas supply line (SL1 to SL3) to perform ventilation (air circulation) for the pipe composed of double pipes among the fuel gas supply lines (SL1 to SL3). AL1 to AL3); and a plurality of vent lines VL1 to VL3 connected to the outer tube of the double pipe of the fuel gas supply lines SL1 to SL3 to discharge air inside the outer tube.

The plurality of engines (11 to 13) may include a propulsion engine (also referred to as 'main engine') that produces the propulsion power of the ship and a power generation engine that produces the necessary power in the ship, and MDO, HFO fuel oil and natural gas It can be provided as a dual fuel engine that can be driven by using both as fuel.

Preferably, the engines 11 to 13 of the present invention may be provided as power generation engines that generate power by power generation and supply it to various demand places in the ship, for example, DFGE (Dual Fuel GEnerator), DFDG (Dual Fuel Diesel Generator), DFDE (Dual Fuel Diesel Electric Engine) may be provided.

Hereinafter, although a preferred embodiment is described in which a total of three engines 11 to 13 are provided in a ship, 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 logarithm can be increased or decreased according to .

An engine room in which a 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 zone, and safety from the gas danger zone must be secured. According to the classification rules, direct access from the gas dangerous area to the gas safe area is prohibited (air-lock installation if necessary), and the gas piping passing through the gas safe area must be composed of a double pipe or completely closed by a duct. do.

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

The LNG fuel tank may include an appropriate level of insulation and sealing system to accommodate LNG liquefied at a cryogenic temperature. An independent type tank that can be mounted independently can be used freely without restrictions on the type.

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 engines 11 to 13, and for this purpose, the LNG or BOG extracted from the LNG fuel tank is delivered to the fuel gas supply system After being subjected to a series of treatments including compression and heating, it is supplied to the engines 11 to 13. When the LNG in the LNG fuel tank is directly extracted and used as fuel, a process of forcibly vaporizing the LNG may be further involved. In order to perform this treatment, the fuel gas supply system may include equipment such as a high-pressure pump (HP pump), a vaporizer (vaporizer), a compressor (compressor) and a heater (heater).

LNG fuel processed by the fuel gas supply system (hereinafter referred to as 'fuel gas') may be supplied to the engines 11 to 13 along the fuel gas supply lines SL1 to SL3. At this time, since the operating conditions 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 the respective engines 11 to 13. Can be connected individually.

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

Since the fuel gas supply lines SL1 to SL3 are gas pipes through which fuel gas with a risk of explosion flows, the fuel gas supply lines SL1 to SL3 disposed in the engine room classified as a gas safety zone are configured as double pipes. Referring to the drawings, it can be seen that the fuel gas supply lines SL1 to SL3 from the weather deck leading into the engine room 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 pressure and flow rate of fuel gas supplied to each engine 11 to 13.

Specifically, on the first fuel gas supply line (SL1), the first gas valve unit 21 for controlling the pressure and flow rate of the fuel gas supplied to the first engine 11, the second fuel gas supply line (SL2) On the second gas valve unit 22 for controlling 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 for controlling the pressure and flow rate of gas may be installed, respectively.

The gas valve units 21 to 23 are a group of valves that control the pressure and flow rate of fuel gas supplied to the engines 11 to 13, and the pressure of the fuel gas supplied to the engines 11 to 13 is controlled by the engine. It is a device that quickly controls according to the load and cuts off the supply of fuel gas quickly and reliably as needed.

These gas valve units 21 to 23 are devices for controlling the flow of fuel gas with a risk of explosion. When located in a gas safety area, they are provided in an ED type sealed with a housing to provide periodic ventilation , when it is to be equipped with an OD type, it must be placed in a gas dangerous area where ventilation is always performed.

However, when the engines 11 to 13 of the present invention are provided as a power generation engine, the power generation engine receives a relatively low pressure fuel gas compared to the main engine, and has a characteristic in that the flow rate of the fuel gas required according to the load is flexibly changed. Therefore, if the gas valve units 21 to 23 are disposed far from the engines 11 to 13, it is difficult to adequately cope with load fluctuations of the engines 11 to 13.

In consideration of the above characteristics, the present invention configures the gas valve units 21 to 23 as an 'ED type' that seals them with a housing and arranges them in an engine room so that they can be positioned close to the engines 11 to 13.

On the other hand, in the present invention, the fuel gas supply lines (SL1 to SL3) and the gas valve units (21 to 23) composed of double pipes flow or control the flow of fuel gas having a risk of explosion, and are cycled according to classification rules. It is required that proper ventilation be performed.

In order to satisfy the classification rules, the present invention is an air suction line (AL1 to AL3) for supplying air to the outer tube 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 outer tube, and the fuel gas supply line is supplied through the air suction line (AL1 to AL3) and discharged through the vent line (VL1 to VL3). (SL1 ~ SL3) of the double pipe and gas valve units (21 ~ 23) configure the system so that ventilation is performed.

The air suction lines (AL1 to AL3) suction outside air and supply it to the outer tubes of the fuel gas supply lines (SL1 to SL3). At this time, the air suction lines (AL1 to AL3) can suction and supply outside air or air in the cargo area, not the air inside the engine room. When humid outside air is sucked, an electric heater 60 for heating the air suction lines AL1 to AL3 may be additionally provided to prevent condensation from occurring.

In addition, an orifice valve (OV) may be installed on each of the air suction lines AL1 to AL3. The orifice valve (OV) facilitates air balancing so that each line can be exchanged 30 times per hour when ventilation of two or more lines among a plurality of fuel gas supply lines (SL1 to SL3) is performed at the same time. play a role

In the present invention, the air suction lines (AL1 to AL3) may 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 outer tube of (SL1 ~ SL3). A double pipe for supplying fuel gas is also configured 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 the respective engines 11 to 13 and may be individually connected to the respective engines 11 to 13. If there is an engine operating in gas mode among a plurality of engines (11 to 13), external air is supplied through the air suction lines (AL1 to AL3) corresponding to the engine to supply fuel gas involved in the supply of fuel gas to the engine. Ventilation must be performed for the double pipe of the lines (SL1 to SL3) and the gas valve units (21 to 23).

The vent lines (VL1 to VL3) are for discharging the air inside the external pipe of the fuel gas supply lines (SL1 to SL3) to the outside, and each fuel gas supply line (SL1 to SL3) has a vent line (VL1 to VL3), respectively. can be connected Specifically, the first vent line (VL1) is connected to the outer pipe of the first fuel gas supply line (SL1), the second vent line (VL2) is connected to the outer 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 of the vent lines VL1 to VL3 to generate pressure for discharging air inside the double pipe of the fuel gas supply lines 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 may be designed to cover ventilation for two engines 11 to 13. As will be described later, the present invention enables ventilation to be performed 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 (11 to 13) are operated in the gas mode, the system is configured such 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 so that the fuel on the engine side Ventilation must be performed for the double pipe of the fuel gas supply lines (SL1 to SL3) and the gas valve units (21 to 23) involved in gas supply.

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

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 with each other. am. In the present invention, each of the fans 31 to 33 is a ventilator of the fuel gas supply lines SL1 to SL3 directly connected as well as other fuel gas supply lines SL1 to SL3 indirectly connected by the connection line LL. 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 needs to be operated.

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

On the other hand, the present invention is to solve the design inefficiency problem of the prior art in which two fans had to be installed per engine, and the gas valve units (21 to 23) and fuel gas supply lines (SL1 to SL1 to ED) provided in the ED type It has been previously revealed that the purpose of reducing the quantity required for ventilation is by integrating the ventilation for the double pipe of SL3).

To this end, the present invention provides a connection line (LL) for connecting a plurality of vent lines (VL1 to VL3) connected to the double pipe of the fuel gas supply line (SL1 to SL3) for supplying fuel gas to the engines (11 to 13). Including further, the system can be configured so that the fans 31 to 33 installed in each of the vent lines VL1 to VL3 can operate as a backup to each other. Here, 'connecting' means configuring the piping systems to be connected (communicated) or separated (blocked).

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

In addition, in order to realize the connection of the 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 the vent lines VL1 to VL3 adjacent to each other. An isolation valve serves to connect or separate connected piping systems from each other by opening and closing a flow path at an installed point.

According to the configuration of the present invention as described above, regardless of which line the first to third fans 31 to 33 are connected to, they can be involved in performing ventilation of all fuel gas supply lines SL1 to SL3. . 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 of another line. Therefore, one fan per engine (11 to 13) Even if only the fans 31 to 33 are installed, it is sufficient.

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

A. In case all 3 engines (11~13) 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 form the exhaust pressure for ventilation, and the remaining one is on standby in preparation for an emergency. by) to wait. At this time, all of the first to fifth isolation valves 41 to 45 are opened.

As described above, since the capacity of each fan 31 to 33 forming the discharge pressure for ventilation has a capacity to cover the ventilation of two engines 11 to 13, three engines 11 ~13), it is possible to perform ventilation with only two fans even when all are operated in gas mode. This comes as an effect of reducing the number and capacity of the ventilation fan in comparison with the prior art.

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

B. In case 2 of multiple engines (11~13) 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 the exhaust pressure for ventilation, and one of the other two is in standby wait in a state

At this time, an isolation valve installed on a vent line connected to an external pipe of a fuel gas supply line for supplying fuel gas to an engine operating in a gas mode among the plurality of engines 11 to 13 is opened. In addition, the connection line connecting the vent line where the fan to be operated and the vent line to be standby are installed is opened so that it can be quickly converted to a standby fan in case of an emergency, and it is connected to an engine that does not operate in gas mode to provide ventilation. The passage leading to the fuel gas supply line side, which is not required to be performed, is blocked. The flow path may be blocked by closing an isolation valve installed on a connection line or an isolation valve installed on a vent line corresponding to an engine not operated in gas mode.

As a more specific example, a case where the first engine 11 and the second engine 12 are operated in the 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 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 may be on standby. First, the first fan ( It is assumed that 31) is running and the second fan 32 is on standby. At this time, the third fan 33 is not operated.

In this case, the first vent line VL1 and the second vent line VL2 should communicate with each other so that the second fan 32 can be quickly switched to 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 passage toward the third fuel gas supply line SL3.

Meanwhile, it may be assumed that the first fan 31 is operating 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 for switching to the standby fan 33 in case of emergency, 45) should all be open. Accordingly, in this case, blocking of the passage toward the third fuel gas supply line SL3 may be accomplished by closing the third isolation valve 43 .

In addition, as a number of other cases, it may be assumed that one of the second fan 32 and the third fan 33 is operated and the other is standby, and in this case, the isolation valves 41 are similar to those described above. ~ 45) can be controlled to set the flow path to which discharge pressure will be provided and the flow path to which it will not be provided.

That is, the present invention relates to three isolation valves 41 to 43 installed on each previous vent line VL1 to VL3 not connected by the linking line LL and two isolation valves installed on the linking line LL ( 44, 45), it is possible to connect or disconnect the piping system of the first to third vent lines (VL1 to VL3), and appropriately control a total of 5 isolation valves (41 to 45) to open the necessary passages and avoid unnecessary The system is configured so that the flow path is blocked.

C. In case 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 the exhaust pressure for ventilation, and the remaining two are prepared in case of an emergency. It is the same as 'B' case discussed above that one unit must be put on standby.

Therefore, in this case, control can be performed in a similar manner to case 'B' 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 explanations are omitted.

As described in the above embodiment, the plurality of fans 31 to 33 and the isolation valves 41 to 45 provided in the 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 of the vent lines VL1 to VL3 is finally integrated into one integrated line CL to discharge air to the outside. On the vent line (VL1 to VL3) between the point where the fans (31 to 33) are installed and the point where the integrated line (CL) is integrated, a flame screen (71) to prevent flames from spreading to other places in the event of an explosion accident ) can be installed.

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

First to third gas detectors 51 to 53 may be installed on each of the vent lines VL1 to VL3 before being connected by the connection line LL to detect leakage of fuel gas, and the first to third gas detectors 51 to 53 may be installed. A fourth gas detector 54 for detecting leakage of fuel gas may be installed on the integrated line CL in which the three vent lines VL1 to VL3 are integrated. The first to fourth gas detectors 51 to 54 may detect leakage of fuel gas by analyzing components of air exchanged during ventilation.

In addition, the present invention generates an alarm (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 side of 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) exceeds 20% at the same time The system can be configured to perform a gas trip of

As described above, according to the present invention in which the discharge ends of the first to third vent lines VL1 to VL3 are integrated into one line and the fourth gas detector 54 is additionally configured on the integrated line CL, In contrast, there is an effect of reducing the number of gas detectors.

Specifically, in the prior art, two gas detectors were installed at the front end of the ventilation fan, so a total of six gas detectors were required. One is configured on the integrated line (CL), so the number can be reduced as a total of four.

In addition, in the present invention, it is possible to estimate which side of the engine (11 to 13) the leakage of fuel gas has 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 in that only the gas trip of the engine in which the fuel gas leak occurs can be performed.

When one of the engines 11 to 13 is gas tripped, one of the plurality of fans 31 to 33 operates independently for the tripped engine to discharge the gas leaked between the double pipes, and the gas detector 51 The fan can 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 tripped engine and a normal engine.

On the other hand, since the plurality of fans 31 to 33 provided in this system are operated by receiving electricity, smooth operation should be performed even if a switchboard (SWBD) supplying electricity to the fans 31 to 33 fails. .

To this end, according to the present invention, a system may be configured such that each of the fans 31 to 33 receives electricity from different distribution boards 81 to 83. Specifically, the first fan 31 receives electricity from the first switchboard 81, the second fan 32 receives electricity from the second switchboard 82, and the third fan 33 receives electricity from the third switchboard 83. According to this system configuration, even if any one of the first to third switchboards 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 generated by the first engine 11 and the third engine 13, and the second switchboard 82 receives power from the second engine 12 and the third engine 13. can be supplied with electricity generated by In addition, the third switchboard 83 is an emergency switchboard (Emergency SWBD) capable of supplying power even in an emergency such as blackout, and receives power from the first switchboard 81 and the second switchboard 82, and an emergency generator in case of an emergency. It can be configured to receive power from (Emergency Generator).

As described above, the present invention is a system that takes into consideration not only the failure of the fans 31 to 33 but also the failure of the switchboards 81 to 83 and emergency situations such as power supply and demand problems of the ship, and thus has excellent stability.

In the above, it has been described that the present invention is applied to a ship using LNG as fuel, but in addition to LNG, which is the most representative liquefied gas, the present invention includes LPG (Liquefied Petroleum Gas), LEG (Liquefied Ethane Gas), and liquefied ethylene gas (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 temperatures to be stored and transported, and can be used as fuel for engines in a vaporized state.

In addition, in the present invention, 'ship' may be interpreted as a concept including all types of vessels using various liquefied gases as engine fuel. Representatively, ships with self-propelled power 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) are also suitable for the concept of the ship of the present invention. can 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. Therefore, such modifications or variations should fall within the scope of the claims of the present invention.

11: first engine
12: second engine
13: 3rd engine
21: first gas valve unit
22: second gas valve unit
23: third gas valve unit
31: first fan
32: second fan
33: 3rd 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: 4th gas detector
60: electric heater
71: flame screen
72: flow switch
81: first switchboard
82: second switchboard
83: third switchboard
SL1: first fuel gas supply line
SL2: second fuel gas supply line
SL3: 3rd fuel gas supply line
AL1: first air suction line
AL2: 2nd air suction line
AL3: 3rd air suction line
VL1: first vent line
VL2: second vent line
VL3: third vent line
LL: linkage line
CL: integrated line
OV: orifice valve

Claims (11)

A plurality of engines mounted in the engine room and capable of driving using LNG as fuel;
A fuel gas supply line provided in plurality to correspond to the plurality of engines as a pipe supplying fuel gas to the engine, and a pipe disposed inside the engine room 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 the fuel gas supplied to the engine, provided in an ED type sealed with a housing and disposed in the engine room;
an air suction line for suctioning external air and supplying it to the double pipe in order to ventilate the double pipe of the fuel gas supply line and the gas valve unit;
a vent line connected to the double pipe of each of the fuel gas supply lines and discharging air inside the double pipe to the outside;
connection lines connecting the plurality of vent lines to each other; and
Including a fan installed at the rear end of the point connected by the linkage line on each of the vent lines to form a discharge pressure of air,
Ventilation system for LNG fueled ships. The method of claim 1,
A plurality of isolation valves are installed between the front end of the point connected by the linkage line on each vent line and the vent line adjacent to each other on the linkage line, and are flexibly controlled according to the number of operating engines. including,
Ventilation system for LNG fueled ships. The method of claim 2,
Characterized in that the capacity of each fan is designed to cover the ventilation of the two engines.
Ventilation system for LNG fueled ships. The method of claim 3,
The number of fans provided in plurality is determined according to the number of gas mode operating units using LNG as fuel among the plurality of engines, and one of the plurality of fans is standby for conversion in case of emergency. Characterized in that,
Ventilation system for LNG fueled ships. The method of claim 2,
an integrated line for finally discharging air by integrating the plurality of vent lines into one; and
Further comprising a plurality of gas detectors installed on each of the integrated lines and in front of the point where the isolation valve is installed on each of the vent lines and detecting leakage of fuel gas by analyzing components of circulating air,
Ventilation system for LNG fueled ships. The method of 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. The method of claim 6,
When one of the plurality of engines is gas tripped, one of the plurality of fans is operated independently to discharge the gas leaked between the double pipes, and operates until the GAS LEL of the gas detector returns to the normal range. doing,
Ventilation system for LNG fueled ships. The method of claim 2,
The air suction line is provided in plurality to correspond to the plurality of engines and is 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 do,
Ventilation system for LNG fueled ships. The method of claim 8,
Further comprising an orifice valve installed on each of the air suction lines to perform air balancing,
Ventilation system for LNG fueled ships. The method of claim 2,
Characterized in that 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. The method of claim 10,
Among the plurality of switchboards, except for the emergency switchboard, the rest of the switchboards receive power generated from at least two of the plurality of engines,
Characterized in that the emergency switchboard receives power from the general switchboard and receives power generated by an emergency generator in case of an emergency.
Ventilation system for LNG fueled ships.

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