Gas supply system double-wall pipe ventilation system and LNG ship

Abstract

The utility model provides a gas supply system double-wall pipe ventilation system and an LNG ship, the LNG ship comprises an LNG tank storage cabin and a cabin, an LNG tank is arranged in the LNG tank storage cabin, and a plurality of main generator sets are arranged in the cabin; the LNG tank is communicated with the main generator set through a gas supply pipeline; the gas supply pipeline is a double-wall pipe, an inner pipe of the gas supply pipeline is used for conveying LNG gas, and an outer pipe of the gas supply pipeline is used for ventilation; the ventilation system comprises a plurality of exhaust fans, a plurality of exhaust pipelines, a plurality of air supply pipelines and a plurality of interlocking valves, inlet valves are arranged on the exhaust pipelines, the exhaust fans are communicated with the outer pipe of the air supply pipeline through the exhaust pipelines, and opening and closing of the exhaust pipelines are achieved through the inlet valves. Compared with a ventilation system in the prior art, a standby exhaust fan is saved, the number of fans is reduced by half, the ventilation system is simplified, investment cost is reduced, and equipment arrangement of the LNG ship is facilitated.

Description

TECHNICAL FIELD

[0001] The utility model relates to the ship or ocean engineering technical field of dangerous gas double-wall pipeline, especially to a kind of double-wall pipe ventilation system of gas supply system and LNG ship. BACKGROUND

[0002] The emission limit faced by global shipping industry becomes increasingly stringent, and the concept of green low-carbon, energy saving and emission reduction has been widely valued in the field of ship design and construction.

[0003] The application of clean energy to replace traditional fuel has become a general trend in the industry, and natural gas, as a representative of clean energy, has many obvious advantages such as environmental protection and economy. In particular, compared with traditional fuel oil, the application of LNG as a power fuel can effectively reduce pollution emissions: carbon dioxide emissions are reduced by about 22%, sulfur oxide emissions are reduced by nearly 100%, particulate matter emissions are reduced by nearly 100%, and nitrogen oxide emissions are reduced by about 92%.

[0004] Liquefied natural gas (LNG) has become the first choice for new environmentally friendly power for ships. Natural gas is a colorless and odorless flammable gas produced in oil and gas fields. The main component of LNG is methane (CH4), which accounts for about 80-99%. It also contains ethane, propane, total butane, total pentane, and carbon dioxide, carbon monoxide, hydrogen sulfide, total sulfur and water. At standard conditions, the boiling point is -162℃, and the density of natural gas is generally 640-750g / m3, with a relative density of 0.55-0.62 relative to air. Because LNG is flammable and explosive after vaporization, LNG transport ships or LNG power ships need to effectively release dangerous gases that may be generated during the storage, vaporization and leakage of LNG, in accordance with industry practices.

[0005] Generally, LNG is supplied to the engine at a certain temperature (room temperature) and pressure after being heated and treated. Due to the physical and chemical properties of the fuel supply, double-wall pipelines are usually used. For example, the fuel supply pipeline, the treated gas flows through the inner tube of the double-wall pipe, and the outer tube is sleeved outside the inner tube, forming a space between the two tubes. The space is filled with inert gas or negative pressure ventilation to ensure safety in case of gas leakage.

[0006] Considering the ease of negative pressure ventilation in engineering implementation, the negative pressure ventilation method is currently more widely used. The main goals of the design are: continuous negative pressure ventilation, with a ventilation frequency of not less than 30 times the space between the two tubes, negative pressure sensors and combustible gas detectors are provided to ensure the effectiveness of ventilation and alarm in case of leakage, and according to the requirements of the "Natural Gas Fuel Specification for Ships", a standby fan is required. Once the main fan fails, the standby fan needs to start immediately, and the ventilation capacity should not decrease by more than 50%.

[0007] like Figure 2 , Figure 3 As shown, taking an LNG-fueled electric propulsion ship as an example, it is equipped with four dual-fuel main generator sets and four negative pressure ventilation subsystems. When working, four main fans are running, and four backup fans are also required. For just one set of negative pressure ventilation system in the engine room, eight negative pressure exhaust fans are required. The system is complex, with many pipelines, difficult to arrange, and costly. Utility Model Content

[0008] In view of the shortcomings of the prior art described above, the technical problem to be solved by this utility model is to provide a double-walled pipe ventilation system for gas supply and LNG ships, so as to solve the problems of traditional ventilation systems being complex, having many pipes, being difficult to arrange, and being costly.

[0009] To achieve the above objectives, this utility model provides a double-walled pipe ventilation system for gas supply, applied to an LNG ship. The LNG ship includes an LNG tank storage compartment and an engine room. The LNG tank storage compartment contains LNG tanks, and the engine room contains several main generator sets. The LNG tanks and the main generator sets are connected via a gas supply pipeline. The gas supply pipeline is a double-walled pipe, with the inner pipe used to transport LNG fuel gas and the outer pipe used for ventilation. The ventilation system includes several exhaust fans, several exhaust pipes, several supply pipes, and several interlock valves. The exhaust pipes are equipped with inlet valves. The exhaust fans are connected to the outer pipes of the gas supply pipelines via the exhaust pipes and the inlet valves control the opening and closing of the exhaust pipes. Adjacent exhaust pipes are connected via interlock valves, which are located upstream of the inlet valves. The supply pipes are connected to the outer pipes of the gas supply pipelines to input external gas into the outer pipes of the gas supply pipelines.

[0010] Preferably, a negative pressure sensor is installed on the exhaust duct between the inlet valve and the exhaust fan. The negative pressure sensor is used to detect the negative pressure in the exhaust duct. The negative pressure sensor is communicatively connected to the inlet valve and the interlock valve.

[0011] Preferably, a gas detector is also installed on the exhaust duct between the inlet valve and the exhaust fan. The gas detector is used to detect the content of combustible gas in the exhaust duct and issue an alarm.

[0012] Preferably, the gas supply pipeline is further equipped with a main gas generator valve unit. The gas supply pipeline between the main gas generator valve unit and the LNG tank is the first gas supply pipeline, and the gas supply pipeline between the main gas generator valve unit and the main generator set is the second gas supply pipeline. The main gas generator valve unit connects the inner pipe of the first gas supply pipeline and the inner pipe of the second gas supply pipeline, and the main gas generator valve unit connects the outer pipe of the first gas supply pipeline and the outer pipe of the second gas supply pipeline. An exhaust port is provided on the main gas generator valve unit at the connection between the outer pipe of the first gas supply pipeline and the outer pipe of the second gas supply pipeline, and the exhaust port is connected to the exhaust pipeline.

[0013] Preferably, the main generator set has an exhaust port and an air inlet, the exhaust port is connected to an exhaust duct, and the air inlet is connected to an air supply duct.

[0014] Preferably, the air supply system double-walled pipe ventilation system is further provided with an air supply duct control valve group and a ventilation head. The ventilation head is located on the outer side of the deck of the engine room. The ventilation head is connected to several air supply ducts through the air supply duct control valve group. The air supply duct control valve group includes several branch control valves, which correspond one-to-one with several air supply ducts and are used to control the opening and closing of the air supply ducts.

[0015] Preferably, a ventilation system consists of an exhaust fan, an inlet valve, a first gas supply pipe, a second gas supply pipe, a main gas valve unit, a main generator set, two exhaust pipes, three air supply pipes, and a ventilation head; one end of the three air supply pipes is connected to the same ventilation head through three branch control valves, and the other end of the three air supply pipes is connected to the outer pipe of the first gas supply pipe, the outer pipe of the second gas supply pipe, and the main generator set, respectively.

[0016] Preferably, the ventilation system consists of four sets, and the number of interlock valves is three. The exhaust pipes of two adjacent sets of ventilation systems are connected by interlock valves.

[0017] To achieve the above or other objectives, this utility model also discloses an LNG ship, including the aforementioned gas supply system and double-walled pipe ventilation system.

[0018] As described above, the gas supply system double-walled pipe ventilation system and LNG carrier involved in this utility model have the following beneficial effects:

[0019] The present invention relates to a double-walled pipe ventilation system for gas supply and an LNG carrier, which is equipped with an interlock valve. When a certain exhaust fan fails to work, the interlock valve can be opened to allow two adjacent exhaust pipes to share the same exhaust fan. Compared with the ventilation system in the prior art, this saves the need for a spare exhaust fan, reduces the number of fans by half, simplifies the ventilation system, reduces investment costs, and facilitates the equipment layout of the LNG carrier. Attached Figure Description

[0020] Figure 1 This is a flowchart of the double-walled pipe ventilation system of the gas supply system involved in this utility model;

[0021] Figure 2 This is a typical diagram of a traditional double-walled tube negative pressure exhaust system in existing technology;

[0022] Figure 3 This is a typical diagram of a branch in a traditional double-walled tube negative pressure exhaust system in existing technology.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. LNG tank storage compartment; 2. Engine room; 3. First gas supply pipeline; 301. Inner pipe of the first gas supply pipeline; 302. Outer pipe of the first gas supply pipeline; 303. Interval space of the first gas supply pipeline; 4. Second gas supply pipeline; 401. Inner pipe of the second gas supply pipeline; 402. Outer pipe of the second gas supply pipeline; 403. Interval space of the second gas supply pipeline; 5. Main generator gas valve unit; 501. Exhaust vent; 6. Main generator set; 601. Unit exhaust vent; 602. Unit air inlet; 7. First exhaust duct; 701. Second exhaust duct; 8. Inlet valve; 9. Interlock valve; 10. Ventilation head; 11. Gas detector; 12. Negative pressure sensor; 13. Exhaust fan; 14. First air supply duct; 15. Second air supply duct; 16. Third air supply duct; 17. First branch control valve; 18. Second branch control valve; 19. Third branch control valve. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0026] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0027] like Figure 1As shown, this utility model provides a double-walled pipe ventilation system for gas supply, applied to an LNG ship. The LNG ship includes an LNG tank storage compartment 1 and an engine room 2. The LNG tank storage compartment 1 contains LNG tanks, and the engine room 2 contains several main generator sets 6. The LNG tanks and the main generator sets 6 are connected by a gas supply pipeline. The gas supply pipeline is a double-walled pipe, with the inner pipe used to transport LNG fuel gas and the outer pipe used for ventilation. The ventilation system includes several exhaust fans 13, several exhaust pipes, several supply pipes, and several interlock valves 9. An inlet valve 8 is installed on the exhaust pipe. The exhaust fans 13 are connected to the outer pipe of the gas supply pipeline through the exhaust pipe and the inlet valve 8 enables the opening and closing of the exhaust pipe. Adjacent exhaust pipes are connected by interlock valves 9, which are located upstream of the inlet valve 8. Several supply pipes are connected to the outer pipes of several gas supply pipes for inputting external gas into the outer pipes of the gas supply pipelines.

[0028] This utility model relates to a double-walled pipe ventilation system for gas supply. An inlet valve 8 is installed on the exhaust duct, and adjacent exhaust ducts are connected by an interlock valve 9. If the exhaust fan 13 on one of the exhaust ducts malfunctions and cannot perform exhaust, the inlet valve 8 on that duct closes, and the interlock valve 9 opens. Air then flows through the interlock valve 9 into the adjacent exhaust duct, achieving timely exhaust and preventing the danger caused by the leakage and accumulation of combustible gas.

[0029] Preferred, such as Figure 1 As shown, a negative pressure sensor 12 is installed on the exhaust duct between the inlet valve 8 and the exhaust fan 13. The negative pressure sensor 12 is used to detect the negative pressure in the exhaust duct. The negative pressure sensor 12 is communicatively connected to the inlet valve 8 and the interlock valve 9.

[0030] Preferred, such as Figure 1 As shown, a gas detector 11 is also installed on the exhaust duct between the inlet valve 8 and the exhaust fan 13. The gas detector 11 is used to detect the content of combustible gas in the exhaust duct and issue an alarm. The purpose of installing the gas detector 11 is to detect and alarm for possible gas leaks. In addition, the negative pressure sensor 12 can also have an alarm function. The alarm of the negative pressure sensor 12 can be distinguished from the alarm of the gas detector 11.

[0031] Preferred, such as Figure 1As shown, a main gas supply valve unit 5 is also installed on the gas supply pipeline. The gas supply pipeline between the main gas supply valve unit 5 and the LNG tank is the first gas supply pipeline 3, and the gas supply pipeline between the main gas supply valve unit 5 and the main generator set 6 is the second gas supply pipeline 4. The main gas supply valve unit 5 connects the inner pipe 301 of the first gas supply pipeline and the inner pipe 401 of the second gas supply pipeline, and connects the outer pipe 302 of the first gas supply pipeline and the outer pipe 402 of the second gas supply pipeline. An exhaust port 501 is provided on the main gas supply valve unit 5 at the connection between the outer pipe 302 of the first gas supply pipeline and the outer pipe 402 of the second gas supply pipeline, and the exhaust port 501 is connected to the exhaust pipeline. In this embodiment, the main gas supply valve unit 5 is equipped with a gas supply pipeline, a main gas supply control valve, and safety components, etc. The gas supply pipeline connects the first gas supply pipeline 3 and the second gas supply pipeline 4, and the main gas supply control valve is used to realize the opening and closing of the gas between the first gas supply pipeline 3 and the second gas supply pipeline 4. The main gas valve unit 5 can be abbreviated as GVU.

[0032] Preferred, such as Figure 1 As shown, the main generator set 6 has a unit exhaust port 601 and a unit air inlet 602. The unit exhaust port 601 is connected to the exhaust duct, and the unit air inlet 602 is connected to the supply duct.

[0033] In this embodiment, the main generator set 6 has an inner layer and an outer layer, with a unit cavity space between them. The inner layer is connected to the inner pipe 401 of the second gas supply pipeline, and the outer layer is connected to the outer pipe 402 of the second gas supply pipeline. The unit exhaust port 601 and the unit air inlet 602 are both connected to the outer layer of the main generator set 6 to achieve ventilation in the unit cavity space. The space between the inner pipe 301 and the outer pipe 302 of the first gas supply pipeline is the first gas supply pipeline cavity space 303, and the space between the inner pipe 401 and the outer pipe 402 of the second gas supply pipeline is the second gas supply pipeline cavity space 403. The first gas supply pipeline cavity space 303, the second gas supply pipeline cavity space 403, and the main generator gas valve unit 5 are considered as a whole.

[0034] Furthermore, in this embodiment, the exhaust duct includes a first exhaust duct 7 and a second exhaust duct 701. The first exhaust duct 7 is connected to the exhaust port 501 and is used to achieve ventilation in the first gas supply duct wall space 303, the second gas supply duct wall space 403, and the main gas generator valve unit 5. One end of the second exhaust duct 701 is connected to the unit exhaust port 601, and the other end of the second exhaust duct 701 is connected to the first exhaust duct 7, used to achieve ventilation in the unit wall space.

[0035] Preferred, such as Figure 1As shown, the air supply system double-walled pipe ventilation system is also equipped with an air supply duct control valve group and a ventilation head 10. The ventilation head 10 is located on the outer side of the deck of the engine room 2. The ventilation head 10 is connected to several air supply ducts through the air supply duct control valve group. The air supply duct control valve group includes several branch control valves, which correspond one-to-one with several air supply ducts and are used to control the opening and closing of the air supply ducts.

[0036] In this embodiment, there are three air supply ducts and three branch control valves. The three air supply ducts are the first air supply duct 14, the second air supply duct 15, and the third air supply duct 16. The three branch control valves are the first branch control valve 17, the second branch control valve 18, and the third branch control valve 19. The first branch control valve 17 is installed on the first air supply duct 14, the second branch control valve 18 is installed on the second air supply duct 15, and the third branch control valve 19 is installed on the third air supply duct 16.

[0037] The first air supply duct 14 is connected to the space 303 between the first air supply duct and the main generator set 6, supplying outside air into the space 303. The third air supply duct 16 is connected to the space 403 between the second air supply duct and the main generator set 6, supplying outside air into the space 403. One ventilator 10 is responsible for supplying air to the three air supply ducts.

[0038] Preferred, such as Figure 1 As shown, an exhaust fan 13, an inlet valve 8, a first gas supply pipe 3, a second gas supply pipe 4, a main gas valve unit 5, a main generator set 6, two exhaust pipes, three air supply pipes, and a ventilator 10 constitute a ventilation system; one end of the three air supply pipes is connected to the same ventilator 10 through three branch control valves, and the other end of the three air supply pipes are respectively connected to the first gas supply pipe cavity space 303, the second gas supply pipe cavity space 403, and the generator set cavity space.

[0039] Preferred, such as Figure 1 As shown, there are four sets of ventilation systems and three interlock valves 9. The exhaust pipes of two adjacent sets of ventilation systems are connected by interlock valves 9.

[0040] In this embodiment, the inlet valve 8, interlock valve 9, and branch control valve are all remote-controlled valves. After receiving relevant signals, they can be opened and closed as needed. Automatic control can be achieved by setting logic to ensure safety.

[0041] In this embodiment, a control component is also provided in the ventilation system. The negative pressure sensor 12 is communicatively connected to the inlet valve 8 and the interlock valve 9 through the control component. When the exhaust fan 13 on a certain exhaust duct malfunctions, the negative pressure sensor 12 cannot detect the negative pressure in the exhaust duct and will send a signal to the control component. Then, the control component receives the signal and closes the inlet valve 8 on the exhaust duct, while opening the interlock valve 9 to connect the exhaust duct to the adjacent exhaust duct.

[0042] To achieve the above or other objectives, this utility model also discloses an LNG ship, including the aforementioned gas supply system and double-walled pipe ventilation system.

[0043] The working principle of the gas supply system double-walled pipe ventilation system and LNG ship involved in this utility model is as follows:

[0044] First, the operator follows the instructions in the appendix. Figure 1 The above description describes the assembly of the various components.

[0045] Then, when the main generator set 6 needs to work, the combustible gas in the LNG tank enters the inner layer of the main generator set 6 through the inner pipe 301 of the first gas supply pipeline, the main generator gas valve unit 5, and the inner pipe 401 of the second gas supply pipeline to generate electricity for the main generator set 6.

[0046] Simultaneously, the exhaust fan 13 operates, drawing air from the first gas supply pipe cavity 303, the main generator gas valve unit 5, and the second gas supply pipe cavity 403 through the first exhaust pipe 7, and drawing air from the main generator set 6's cavity through the second exhaust pipe 701. As the exhaust fan 13 operates, outside air enters the first air supply pipe 14, the second air supply pipe 15, and the third air supply pipe 16 through the ventilation head 10. The first air supply pipe 14 delivers outside air into the first gas supply pipe cavity 303, the second air supply pipe 15 delivers outside air into the main generator set 6's cavity, and the third air supply pipe 16 delivers outside air into the second gas supply pipe cavity 403, achieving ventilation and preventing the leakage of combustible gas from the inner pipes of the gas supply pipes and the inner layer of the main generator set 6, thus avoiding potential safety hazards.

[0047] When the exhaust fan 13 is working, the inlet valve 8 on the first exhaust duct 7 is opened, and the interlock valve 9 between adjacent first exhaust ducts 7 is closed. Both the negative pressure sensor 12 and the gas detector 11 are working. The negative pressure sensor 12 detects the negative pressure in the first exhaust duct 7 to determine whether the exhaust fan 13 is working normally; the gas detector 11 detects whether there is combustible gas in the first exhaust duct 7 to determine whether there is a leak.

[0048] When the negative pressure sensor 12 fails to detect negative pressure in the first exhaust duct 7, or when the negative pressure in the first exhaust duct 7 is below standard, it indicates that the exhaust fan 13 on the first exhaust duct 7 is malfunctioning and cannot guarantee normal ventilation. In this case, the negative pressure sensor 12 sends feedback information to the control component. The control component receives the information and closes the inlet valve 8, while simultaneously opening the interlock valve 9. This connects the first exhaust duct 7 to the adjacent first exhaust duct 7, and ventilation is achieved through the adjacent exhaust fan 13. It should be noted that in this embodiment, the capacity of the exhaust fan 13 is relatively... Figure 2 , Figure 3 The capacity of the central exhaust fan has been slightly increased.

[0049] This utility model relates to a double-walled pipe ventilation system for gas supply and an LNG carrier. The ventilation system has been optimized, reducing the number of exhaust fans 13 by half. Figure 2 , Figure 3 The existing ventilation system in China has a total of eight exhaust fans 13, which are divided into four main exhaust fans and four backup exhaust fans. In this application, only four exhaust fans 13 need to be designed as main exhaust fans. The ventilation system is simplified, investment costs are reduced, and it is easier to arrange on board. It has broad prospects for promotion and application.

[0050] In summary, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0051] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A double-walled pipe ventilation system for gas supply, applied to an LNG ship; the LNG ship includes an LNG tank storage compartment (1) and an engine room (2), wherein the LNG tank storage compartment (1) is equipped with LNG tanks, and the engine room (2) is equipped with a plurality of main generator sets (6); the LNG tanks and the main generator sets (6) are connected by a gas supply pipeline; the gas supply pipeline is a double-walled pipe, wherein the inner pipe of the gas supply pipeline is used to transport LNG fuel gas, and the outer pipe of the gas supply pipeline is used for ventilation; characterized in that: The ventilation system includes several exhaust fans (13), several exhaust ducts, several air supply ducts, and several interlock valves (9). An inlet valve (8) is provided on the exhaust duct. The exhaust fan (13) is connected to the outer pipe of the air supply duct through the exhaust duct and the exhaust duct is opened and closed through the inlet valve (8). Two adjacent exhaust ducts are connected through the interlock valve (9). The interlock valve (9) is located on the upstream side of the inlet valve (8). Several air supply ducts are connected to several gas supply ducts, which are used to input external gas into the gas supply ducts.

2. The air supply system with double-walled pipe ventilation system according to claim 1, characterized in that: A negative pressure sensor (12) is installed on the exhaust pipe between the inlet valve (8) and the exhaust fan (13). The negative pressure sensor (12) is used to detect the negative pressure in the exhaust pipe. The negative pressure sensor (12) is communicatively connected to the inlet valve (8) and the interlock valve (9).

3. The air supply system with double-walled pipe ventilation system according to claim 1, characterized in that: A gas detector (11) is also installed on the exhaust pipe between the inlet valve (8) and the exhaust fan (13). The gas detector (11) is used to detect the content of combustible gas in the exhaust pipe and issue an alarm.

4. The air supply system with double-walled pipe ventilation system according to claim 1, characterized in that: The gas supply pipeline is also equipped with a main gas valve unit (5). The gas supply pipeline between the main gas valve unit (5) and the LNG tank is the first gas supply pipeline (3), and the gas supply pipeline between the main gas valve unit (5) and the main generator set (6) is the second gas supply pipeline (4). The main gas valve unit (5) connects the inner pipe (301) of the first gas supply pipeline and the inner pipe (401) of the second gas supply pipeline. The main gas valve unit (5) also connects the outer pipe (302) of the first gas supply pipeline and the outer pipe (402) of the second gas supply pipeline. An exhaust port (501) is provided on the main gas valve unit (5) at the connection between the outer pipe (302) of the first gas supply pipeline and the outer pipe (402) of the second gas supply pipeline. The exhaust port (501) is connected to the exhaust pipeline.

5. The air supply system with double-walled pipe ventilation system according to claim 4, characterized in that: The main generator set (6) is provided with a generator set exhaust port (601) and a generator set air inlet (602). The generator set exhaust port (601) is connected to the exhaust pipe, and the generator set air inlet (602) is connected to the air supply pipe.

6. The air supply system with double-walled pipe ventilation system according to claim 4, characterized in that: It is also equipped with an air supply duct control valve group and a ventilation head (10). The ventilation head (10) is located on the outer side of the deck of the engine room (2). The ventilation head (10) is connected to several air supply ducts through the air supply duct control valve group. The air supply duct control valve group includes several branch control valves, which correspond one-to-one with several air supply ducts and are used to control the opening and closing of the air supply ducts.

7. The air supply system with double-walled pipe ventilation system according to claim 6, characterized in that: A ventilation system consists of an exhaust fan (13), an inlet valve (8), a first gas supply pipe (3), a second gas supply pipe (4), a main gas valve unit (5), a main generator set (6), two exhaust pipes, three air supply pipes, and a ventilation head (10). One end of each of the three air supply pipes is connected to the same ventilation head (10) via three branch control valves, and the other end of each of the three air supply pipes is connected to the outer pipe of the first air supply pipe (302), the outer pipe of the second air supply pipe (402), and the main generator set (6), respectively.

8. The air supply system with double-walled pipe ventilation system according to claim 7, characterized in that: The ventilation system consists of four sets, and the number of interlock valves (9) is three. The exhaust pipes of two adjacent sets of ventilation systems are connected by interlock valves (9).

9. An LNG carrier, characterized in that: The gas supply system includes the double-walled pipe ventilation system as described in any one of claims 1-8.

Images