Ship and liquid cargo tank air pressure control method

Abstract

The invention discloses a ship and a liquid cargo tank air pressure control method. The ship comprises a liquid cargo tank containment system, a cabin used for storing the liquid cargo tank containment system and an air pressure control device. The liquid cargo tank containment system comprises an insulating layer and a liquid cargo tank, and an insulating space is formed between the insulating layer and the liquid cargo tank; the outer side of the insulating layer and the interior of the cabin form a liquid cargo space; a balance hole penetrating through the insulating space and the liquid cargo tank is formed in the insulating layer; the air pressure control device controls opening or closing of the air inlet assembly of the insulation space, the air inlet assembly of the liquid cargo tank and the air outlet assembly of the liquid cargo tank according to the collected first air pressure value and second air pressure value. The liquid cargo tank air pressure control method is applied to the ship. The insulation space and the liquid cargo tank keep balance all the time, stress of the insulation layer can be reduced, and the risks of insulation layer damage and cabin hull structure deformation are effectively reduced. In addition, the introduced inert protective gas is changed into air, so that the air of the cargo tank can be simply and quickly realized.

Description

Technical Field

[0001] The present invention relates to the field of liquid cargo tanks, and in particular to a ship and a method for controlling air pressure in a liquid cargo tank. Background Art

[0002] A cargo tank is an independent compartment on a ship that is specially used to load cryogenic liquefied gas fuel tanks or cryogenic cargoes. It can be used to load cryogenic liquids such as liquefied natural gas (LNG), ethane, ethylene, and liquid ammonia. The cargo tank is covered with a thermal insulation layer, and an insulating space is formed between the cargo tank and the insulating layer, which can be used as a circulation channel in the event of a leak in the cargo tank. The cargo tank is located in the cabin of the ship, and the cabin space where the cargo tank is located is called the cargo tank space. When the ship is loaded with cryogenic liquids, the insulating space of the cargo tank and the cargo tank space are inert environments; when the cargo tank needs to be repaired, the insulating space and cabin space are converted into atmospheric environments, and people can enter the space without restriction.

[0003] Type B tank is a commonly used type of liquid cargo tank. The full name of Type B tank is Partially Secondary Contained Independent Type B Tank, abbreviated as Type B tank. Type B tank includes an insulation layer covering the outside of the liquid cargo tank, and the insulation layer is a plate structure design. The air pressure that the insulation layer can withstand is very limited, so the air pressure of the insulation space needs to be precisely controlled. The cabin space where the liquid cargo tank is located also has strict requirements on the ambient air pressure. The existing liquid cargo tank insulation structure is difficult to meet the standards and is prone to damage to the insulation structure due to overpressure. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defect in the prior art that the air pressure of the insulating space and the cabin space of the liquid cargo tank is difficult to control, which easily leads to damage of the insulation layer, and to provide a method for controlling the air pressure of a ship and a liquid cargo tank.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The present invention provides a ship, which comprises a liquid cargo tank containment system, a cabin for storing the liquid cargo tank containment system, and an air pressure control device; the liquid cargo tank containment system comprises an insulating layer and a liquid cargo tank, the insulating layer wraps the liquid cargo tank, an insulating space is formed between the insulating layer and the liquid cargo tank, and the insulating space is filled with a first inert protective gas; the outer side of the insulating layer and the inner side of the cabin form a liquid cargo tank space, and the liquid cargo tank space is filled with a second inert protective gas; the first air pressure in the insulating space is greater than the second air pressure in the liquid cargo tank space; The insulating layer is provided with a balancing hole, and the two ends of the balancing hole are respectively connected to the insulating space and the liquid cargo tank; the air pressure control device includes a first air pressure sensor, a second air pressure sensor, a control unit, an insulating space air inlet assembly, a liquid cargo tank air inlet assembly and a liquid cargo tank air outlet assembly; the insulating space air inlet assembly is in a normally open state, the liquid cargo tank air inlet assembly and the liquid cargo tank air outlet assembly are in a normally closed state, the insulating space air inlet assembly is used to supplement the first inert protective gas to the insulating space, and the liquid cargo tank air inlet assembly The liquid cargo tank is used to replenish the second inert protective gas, and the liquid cargo tank gas outlet assembly is used to discharge the second inert protective gas in the liquid cargo tank to the outside of the cabin; the first air pressure sensor is used to detect the first air pressure value in the insulating space and transmit the detection data to the control unit, and the second air pressure sensor is used to detect the second air pressure value in the liquid cargo tank and transmit the detection data to the control unit; the control unit is configured to control the insulating space air inlet assembly, the liquid cargo tank air inlet assembly and the liquid cargo tank gas outlet assembly to be opened or closed according to the first air pressure value and the second air pressure value collected; when the first air pressure value is greater than the first air pressure preset value, the control unit is used to control the insulating space air inlet assembly to be closed; when the second air pressure value is greater than the second air pressure preset value, the control unit is used to control the liquid cargo tank gas outlet assembly to be started; when the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the control unit is used to control the insulating space air inlet assembly to be closed and control the liquid cargo tank air inlet assembly to be started.

[0007] In this scheme, under normal conditions, the insulating space air intake assembly slowly and continuously delivers the first inert protective gas to the insulating space, so that the insulating space maintains an inert environment. The first inert protective gas in the insulating space flows out to the liquid cargo tank through the balance hole opened on the insulating layer to balance the air pressure between the insulating space and the liquid cargo tank. At the same time, the first air pressure preset value and the second air pressure preset value are respectively preset by the first air pressure sensor and the second air pressure sensor. When the actual air pressure value exceeds the preset air pressure value, the adjustment operation is performed: when the first air pressure sensor exceeds the first air pressure preset value, the insulating space air intake assembly is closed to suspend the air supply to the insulating space, and the air pressure in the insulating space is reduced through the balance hole; when the second air pressure sensor exceeds the second air pressure preset value, the liquid cargo tank outlet assembly is opened to discharge the excess gas in the liquid cargo tank to achieve the purpose of reducing the air pressure; when the air pressure difference between the first air pressure value and the second air pressure value is greater than the preset pressure difference value, air is supplemented to the liquid cargo tank to achieve balance. The above components are controlled by the control unit. Keeping the insulation space and the cargo tank space balanced at all times can reduce the stress on the insulation layer and effectively reduce the risk of insulation layer damage. At the same time, it avoids excessive air pressure in the cargo tank space, effectively reducing the risk of the hull structure in the cabin being compressed and deformed. In addition, the cargo tank space can be aired simply and quickly by simply replacing the inert protective gas with air.

[0008] Preferably, the insulating layer is further provided with an air inlet hole, the two ends of which are respectively connected to the insulating space and the liquid cargo tank; the insulating space air inlet assembly comprises a first air source component, an insulating space air inlet pipeline and an insulating space air inlet valve, the first air source component is communicated with the insulating space air inlet pipeline, the insulating space air inlet pipeline is connected to the air inlet hole, the insulating space air inlet valve is arranged on the insulating space air inlet pipeline and is electrically connected to the control unit; the liquid cargo tank air inlet assembly comprises a second air source component, a liquid cargo tank air inlet pipeline and a liquid cargo tank air inlet valve. The second air source is connected to the air inlet pipe of the insulating space, the air inlet pipe of the liquid cargo tank is connected to the cabin, the air inlet valve of the liquid cargo tank is arranged on the air inlet pipe of the liquid cargo tank and is electrically connected to the control unit; the air outlet assembly of the liquid cargo tank comprises an air outlet pipe of the liquid cargo tank and an air outlet valve of the liquid cargo tank, the two ends of the air outlet pipe of the liquid cargo tank are connected to the interior of the cabin and the exterior of the cabin respectively, and the air outlet valve of the liquid cargo tank is arranged on the air outlet pipe of the liquid cargo tank and is electrically connected to the control unit.

[0009] In this solution, the insulating space air inlet assembly, the cargo tank space and the cargo tank space air outlet assembly are respectively composed of pipeline and valve structures. The opening and closing of the insulating space air inlet assembly, the cargo tank space and the cargo tank space air outlet assembly can be easily realized by controlling the opening and closing of each valve through the control unit.

[0010] Preferably, the balancing hole is arranged at the upper part of the insulating layer, and the air inlet hole is arranged at the bottom of the insulating layer; the first air pressure sensor is arranged in the air inlet duct of the insulating space; and / or the second air pressure sensor is arranged in the air inlet duct of the liquid cargo tank.

[0011] In this solution, the air intake assembly of the insulating space supplies air into the insulating space through the air intake hole at the bottom of the insulating layer, and the air overflows from the balance hole at the top of the insulating layer. Such a structure facilitates the diffusion of the first inert protective gas and fills the entire insulating space. By arranging the first air pressure sensor and the second air pressure sensor on the air intake pipe of the insulating space and the air intake pipe of the cargo tank respectively, it is convenient to detect the air pressure values ​​of the insulating space and the cargo tank, realize the precise control function of the environmental pressure, have a high degree of automation, and avoid the risks caused by human operation errors.

[0012] Preferably, the air pressure control device also includes a first safety protection device, which includes an insulating space air pressure safety valve and a first safety protection pipe, wherein both ends of the insulating space air pressure safety valve are respectively connected to the insulating space air intake pipe and the first safety protection pipe, and the other end of the first safety protection pipe is connected to the outside of the cabin; the insulating space air pressure safety valve can be set to a first safety air pressure preset value, and when the first air pressure value is greater than the first safety air pressure preset value, the insulating space air pressure safety valve automatically opens; and / or, the air pressure control device also includes a second safety protection device, which includes an air pressure safety valve in a liquid cargo tank and a second safety protection pipe, wherein both ends of the air pressure safety valve in a liquid cargo tank are respectively connected to the liquid cargo tank and the second safety protection pipe, and the other end of the second safety protection pipe is connected to the outside of the cabin; the air pressure safety valve in a liquid cargo tank can be set to a second safety air pressure preset value, and when the second air pressure value is greater than the second safety air pressure preset value, the air pressure safety valve in a liquid cargo tank automatically opens.

[0013] In this solution, if the air pressure in the insulating space exceeds the first preset safety air pressure value, it may be that the air inlet component of the insulating space is faulty. The first safety protection device is turned on to ensure that air will not be supplied to the insulating space, so that the air pressure in the insulating space will not continue to rise, and the balance will be restored after the excess gas overflows from the balance hole. If the air pressure in the cargo tank exceeds the second preset safety air pressure value, it may be that the air outlet component of the cargo tank is faulty. The second safety protection device is turned on to ensure that the gas in the cargo tank is discharged in time, so that the air pressure in the cargo tank will not continue to rise, and the balance will be restored after the excess gas is discharged from the second safety protection pipeline.

[0014] Preferably, the air pressure control device also includes a pressure difference sensor, and the first air pressure sensor and the second air pressure sensor are both electrically connected to the pressure difference sensor, and the pressure difference sensor is used to detect the pressure difference between the first air pressure value and the second air pressure value and transmit the detection data to the control unit.

[0015] In this solution, the differential pressure sensor can monitor the air pressure difference, provide data support, and ensure the normal operation of the air pressure control device.

[0016] Preferably, the ship also includes a gas detection device and an alarm, the detection end of the gas detection device is arranged close to the balancing hole, the gas detection device is electrically connected to the alarm, and the gas detection device is used to detect combustible gas at the balancing hole.

[0017] In this solution, when a liquid cargo tank leaks, the flammable gas in the liquid cargo tank evaporates into the insulating space and escapes from the balancing hole along with the first inert protective gas. The gas detection device arranged near the balancing hole can detect the flammable gas leakage in time and sound an alarm.

[0018] The present invention also provides a liquid cargo tank air pressure control method, which is applied to the ship as described above, and the liquid cargo tank air pressure control method comprises: using the first air pressure sensor to detect the first air pressure value in the insulating space, and using the second air pressure sensor to detect the second air pressure value in the liquid cargo tank; judging whether the first air pressure value exceeds the first air pressure preset value; if so, closing the insulating space air inlet component through the control unit; if not, keeping the insulating space air inlet component normally open; judging whether the second air pressure value exceeds the second air pressure preset value; if so, opening the liquid cargo tank air outlet component through the control unit; if not, keeping the liquid cargo tank air outlet component normally closed; judging whether the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, if so, controlling the insulating space air inlet component to be closed and controlling the liquid cargo tank air inlet component to be started through the control unit; if not, keeping the insulating space air inlet component normally open and the liquid cargo tank air inlet component normally closed.

[0019] In this solution, the insulating space air intake assembly slowly and continuously delivers the first inert protective gas into the insulating space, so that the insulating space maintains an inert environment, and balances the air pressure of the insulating space and the liquid cargo tank through the balance hole opened on the insulating layer. At the same time, the first air pressure preset value and the second air pressure preset value are respectively preset by the first air pressure sensor and the second air pressure sensor, and when the actual air pressure value exceeds the preset air pressure value, the adjustment operation is performed: when the first air pressure sensor exceeds the first air pressure preset value, the insulating space air intake assembly is closed to suspend the air supply to the insulating space, and the air pressure in the insulating space is reduced through the balance hole; when the second air pressure sensor exceeds the second air pressure preset value, the liquid cargo tank outlet assembly is opened to discharge the excess gas in the liquid cargo tank to achieve the purpose of reducing the air pressure; when the pressure difference between the first air pressure value and the second air pressure value is greater than the preset pressure difference value, the liquid cargo tank is replenished with air to achieve balance, and the above components are controlled by the control unit.

[0020] Preferably, when the first air pressure value exceeds the first air pressure preset value, the step of closing the insulating space air inlet component by the control unit specifically includes: the control unit controls the insulating space air inlet component to be closed until the first air pressure value satisfies less than or equal to the first air pressure preset value, and the control unit controls the insulating space air inlet component to be opened; and / or, when the second air pressure value exceeds the second air pressure preset value, the step of opening the liquid cargo tank air outlet component by the control unit specifically includes: the control unit controls the liquid cargo tank air outlet component to be opened until the second air pressure value satisfies less than or equal to the second air pressure preset value. When the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the control unit controls the closing of the air outlet assembly of the liquid cargo tank; and / or, when the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the steps of controlling the closing of the insulating space air intake assembly and starting the air intake assembly of the liquid cargo tank by the control unit specifically include: the control unit controls the closing of the insulating space air intake assembly and controls the starting of the air intake assembly of the liquid cargo tank until the pressure difference between the first air pressure value and the second air pressure value is less than or equal to the preset pressure difference value, and the control unit controls the opening of the insulating space air intake assembly and controls the closing of the air intake assembly of the liquid cargo tank.

[0021] In this solution, the air inlet assembly of the insulating space is closed until the first air pressure value satisfies less than or equal to the first air pressure preset value, and the control unit controls the air inlet assembly of the insulating space to open to ensure that the first inert protective gas is supplied immediately after the air pressure value of the insulating space reaches the first air pressure preset value, thereby preventing the concentration of the first inert protective gas in the inert environment from being too low. The air outlet assembly of the cargo tank is opened until the second air pressure value satisfies less than or equal to the second air pressure preset value, and the control unit controls the air outlet assembly of the cargo tank to close to ensure that the excess gas in the cargo tank is closed in time after being discharged, thereby preventing the second inert protective gas in the cargo tank from being discharged excessively, resulting in too low air pressure and gas waste. When the pressure difference between the first air pressure value and the second air pressure value is less than or equal to the preset pressure difference value, the control unit controls the air inlet assembly of the insulating space to open and controls the air inlet assembly of the cargo tank to close to prevent excessive gas replenishment to the insulating space or the cargo tank from destroying the air pressure balance.

[0022] Preferably, in the step of determining whether the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the pressure difference between the first air pressure value and the second air pressure value is acquired by a pressure difference sensor.

[0023] In this solution, the differential pressure sensor can monitor the air pressure difference, provide data support, and ensure the normal operation of the air pressure control device.

[0024] Preferably, in the step of judging whether the first air pressure value exceeds the first air pressure preset value; if so, in the step of closing the insulating space air intake assembly by the control unit, the insulating space air pressure safety valve is set to a first safety air pressure preset value, if after the control unit closes the insulating space air intake assembly, the first air pressure value is greater than the first safety air pressure preset value, the insulating space air pressure safety valve automatically opens until the first air pressure value satisfies less than or equal to the first safety air pressure preset value; and / or, in the step of judging whether the second air pressure value exceeds the second air pressure preset value; if so, in the step of opening the liquid cargo tank air outlet assembly by the control unit, the liquid cargo tank air pressure safety valve is set to a second safety air pressure preset value, if after the control unit opens the liquid cargo tank air outlet assembly, the second air pressure value is greater than the second safety air pressure preset value, the liquid cargo tank air pressure safety valve opens until the second air pressure value satisfies less than or equal to the second safety air pressure preset value.

[0025] In this solution, if the air pressure in the insulating space exceeds the first preset safety air pressure value, it may be that the air inlet component of the insulating space is faulty. The first safety protection device is turned on to ensure that air will not be supplied to the insulating space, so that the air pressure in the insulating space will not continue to rise, and the balance will be restored after the excess gas overflows from the balance hole. If the air pressure in the cargo tank exceeds the second preset safety air pressure value, it may be that the air outlet component of the cargo tank is faulty. The second safety protection device is turned on to ensure that the gas in the cargo tank is discharged in time, so that the air pressure in the cargo tank will not continue to rise, and the balance will be restored after the excess gas is discharged from the second safety protection pipeline.

[0026] The positive and progressive effects of the present invention are:

[0027] The ship and liquid cargo tank air pressure control method of the present invention, under normal conditions, the insulating space air intake component slowly and continuously transports the first inert protective gas into the insulating space, so that the insulating space maintains an inert environment, and the first inert protective gas in the insulating space flows out to the liquid cargo tank through the balance hole opened on the insulating layer to balance the air pressure between the insulating space and the liquid cargo tank. At the same time, the first air pressure preset value and the second air pressure preset value are respectively preset by the first air pressure sensor and the second air pressure sensor, and when the actual air pressure value exceeds the preset air pressure value, the adjustment operation is performed: when the first air pressure sensor exceeds the first air pressure preset value, the insulating space air intake component is closed to suspend the air supply to the insulating space, and the air pressure in the insulating space is reduced through the balance hole; when the second air pressure sensor exceeds the second air pressure preset value, the liquid cargo tank outlet component is opened to discharge the excess gas in the liquid cargo tank to achieve the purpose of reducing the air pressure; when the air pressure difference between the first air pressure value and the second air pressure value is greater than the preset pressure difference value, air is supplemented to the liquid cargo tank to achieve balance, and the above components are controlled by the control unit. Keeping the insulation space and the cargo tank space balanced at all times can reduce the stress on the insulation layer and effectively reduce the risk of insulation layer damage. At the same time, it avoids excessive air pressure in the cargo tank space, effectively reducing the risk of the hull structure in the cabin being compressed and deformed. In addition, the cargo tank space can be aired simply and quickly by simply replacing the inert protective gas with air. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a liquid cargo tank according to an embodiment of the present invention

[0029] Figure 2 A partial structural diagram of a liquid cargo tank according to an embodiment of the present invention

[0030] Figure 3 Flow chart of the liquid cargo tank gas pressure control method according to an embodiment of the present invention

[0031] Description of reference numerals:

[0032] Cargo tank containment system1

[0033] Cabin 2

[0034] Air pressure control device 3

[0035] Insulation layer 4

[0036] Cargo tank 5

[0037] Insulation space 6

[0038] Cargo tank space 7

[0039] Balance hole 8

[0040] Air Inlet 9

[0041] First air pressure sensor 10

[0042] Second air pressure sensor 11

[0043] Control unit 12

[0044] Differential pressure sensor 13

[0045] Insulation space air intake assembly 14

[0046] Air intake assembly for cargo tank space 15

[0047] Gas outlet assembly for cargo tank space 16

[0048] First safety protection device 17

[0049] Second safety protection device 18

[0050] Gas detection device 19 DETAILED DESCRIPTION

[0051] A preferred embodiment is given below, and the present invention is described more clearly and completely in conjunction with the accompanying drawings.

[0052] This embodiment provides a ship, such as Figure 1 and Figure 2 As shown, it includes a liquid cargo tank containment system 1, a compartment 2 for storing the liquid cargo tank containment system 1, and an air pressure control device 3; the liquid cargo tank containment system 1 refers to a device for storing fuel including a liquid cargo tank joint, and is used to safely store and transport liquefied gas at extremely low temperatures. The liquid cargo tank containment system 1 includes an insulation layer 4 and a liquid cargo tank 5.

[0053] The cargo tank 5 is a partially secondary shielded independent cargo tank (Partially Secondary Contained Independent Type B Tank), referred to as a Type B tank. The insulation layer 4 wraps the cargo tank 5, and an insulation space 6 is formed between the insulation layer 4 and the cargo tank 5, and the insulation space 6 is filled with a first inert protective gas; the outer side of the insulation layer 4 and the inside of the cabin 2 form a cargo tank space 7, and the cargo tank space 7 is filled with a second inert protective gas; the first gas pressure in the insulation space 6 is greater than the second gas pressure in the cargo tank space 7.

[0054] A balancing hole 8 is provided on the insulating layer 4, and both ends of the balancing hole 8 are respectively connected to the insulating space 6 and the liquid cargo tank space 7; the air pressure control device 3 includes a first air pressure sensor 10, a second air pressure sensor 11, a control unit 12, an insulating space air inlet assembly 14, a liquid cargo tank space air inlet assembly 15 and a liquid cargo tank space air outlet assembly 16; the insulating space air inlet assembly 14 is in a normally open state, the liquid cargo tank space air inlet assembly 15 and the liquid cargo tank space air outlet assembly 16 are in a normally closed state, the insulating space air inlet assembly 14 is used to supplement the first inert protective gas to the insulating space 6, the liquid cargo tank space air inlet assembly 15 is used to supplement the second inert protective gas to the liquid cargo tank space 7, and the liquid cargo tank space air outlet assembly 16 is used to discharge the second inert protective gas in the liquid cargo tank space 7 to the outside of the cabin 2.

[0055] The first air pressure sensor 10 is used to detect a first air pressure value in the insulating space 6 and transmit the detection data to the control unit 12, and the second air pressure sensor 11 is used to detect a second air pressure value in the liquid cargo tank space 7 and transmit the detection data to the control unit 12; the control unit 12 is configured to control the opening or closing of the insulating space air inlet component 14, the liquid cargo tank space air inlet component 15 and the liquid cargo tank space air outlet component 16 according to the collected first air pressure value and the second air pressure value.

[0056] When the first air pressure value is greater than the first air pressure preset value, the control unit 12 is used to control the insulating space air intake component 14 to close; when the second air pressure value is greater than the second air pressure preset value, the control unit 12 is used to control the liquid cargo tank air outlet component 16 to start; when the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the control unit 12 is used to control the insulating space air intake component 14 to close and control the liquid cargo tank air intake component 15 to start.

[0057] In this way, under normal conditions, the insulating space air intake assembly 14 slowly and continuously transports the first inert protective gas into the insulating space 6 to maintain an inert environment in the insulating space 6. The first inert protective gas in the insulating space 6 flows out to the liquid cargo tank space 7 through the balancing hole 8 opened on the insulating layer 4 to balance the air pressure between the insulating space 6 and the liquid cargo tank space 7. At the same time, the first air pressure preset value and the second air pressure preset value are preset by the first air pressure sensor 10 and the second air pressure preset value, respectively. When the actual air pressure value exceeds the preset air pressure value, an adjustment operation is performed: when the first air pressure sensor 10 exceeds the first air pressure preset value, the insulating space air inlet assembly 14 is closed to suspend the air supply to the insulating space 6, and the air pressure in the insulating space 6 is reduced through the balance hole 8; when the second air pressure sensor 11 exceeds the second air pressure preset value, the liquid cargo tank location air outlet assembly 16 is opened to discharge the excess gas in the liquid cargo tank location 7 to achieve the purpose of reducing the air pressure; when the air pressure difference between the first air pressure value and the second air pressure value is greater than the preset pressure difference value, air is supplemented to the liquid cargo tank location 7 to achieve balance, and the above components are controlled by the control unit 12. The insulating space 6 and the liquid cargo tank location 7 are kept balanced at all times, which can reduce the stress on the insulating layer 4 and effectively reduce the risk of damage to the insulating layer 4. At the same time, the air pressure in the liquid cargo tank location 7 is avoided to be too high, and the risk of the hull structure of the cabin 2 being compressed and deformed is effectively reduced. Furthermore, the cargo tank space 7 can be aired simply and quickly by simply replacing the inert protective gas introduced with air.

[0058] The first inert protective gas and the second inert protective gas can be different gases, such as helium, argon and nitrogen. Different inert protective gases will not chemically react with each other. In this embodiment, the first inert protective gas and the second inert protective gas are both nitrogen.

[0059] In this embodiment, the insulating layer 4 is further provided with an air inlet hole 9, the two ends of which are respectively connected to the insulating space 6 and the liquid cargo tank 7; the insulating space air inlet assembly 14 includes a first air source component, an insulating space 6 air inlet pipe and an insulating space 6 air inlet valve, the first air source component is communicated with the insulating space 6 air inlet pipe, the insulating space 6 air inlet pipe is connected to the air inlet hole 9, the insulating space 6 air inlet valve is arranged on the insulating space 6 air inlet pipe and is electrically connected to the control unit 12; the liquid cargo tank air inlet assembly 15 includes a second air source component, a liquid cargo tank air inlet The gas pipeline and the gas inlet valve of the liquid cargo tank space, the second gas source component is communicated with the gas inlet pipeline of the insulating space, the gas inlet pipeline of the liquid cargo tank space is connected to the cabin 2, the gas inlet valve of the liquid cargo tank space is arranged on the gas inlet pipeline of the liquid cargo tank space and is electrically connected to the control unit 12; the gas outlet assembly 16 of the liquid cargo tank space includes the gas outlet pipeline of the liquid cargo tank space and the gas outlet valve of the liquid cargo tank space, the two ends of the gas outlet pipeline of the liquid cargo tank space are respectively communicated with the inside of the cabin 2 and the outside of the cabin 2, the gas outlet valve of the liquid cargo tank space is arranged on the gas outlet pipeline of the liquid cargo tank space and is electrically connected to the control unit 12.

[0060] The insulating space air inlet assembly 14 supplies air into the insulating space 6 through the air inlet hole 9 provided at the bottom of the insulating layer 4, and the air overflows from the balance hole 8 at the top of the insulating layer 4. Such a structure facilitates the diffusion of the first inert protective gas and fills the entire insulating space 6. At the same time, the insulating space air inlet assembly 14, the cargo tank space 7 and the cargo tank space air outlet assembly 16 are respectively composed of pipes and valve structures. The control unit 12 controls the opening and closing of each valve to facilitate the opening and closing of the insulating space air inlet assembly 14, the cargo tank space 7 and the cargo tank space air outlet assembly 16.

[0061] The first gas source and the second gas source may be the same gas source. In this embodiment, the first gas source and the second gas source are the same gas source, which is connected to the nitrogen system carried by the ship itself. The nitrogen system is usually a permanent device of a dual-fuel ship or a liquid cargo ship.

[0062] Specifically, the balance hole 8 is arranged at the upper part of the insulating layer 4, and the air inlet hole 9 is arranged at the bottom of the insulating layer 4; the two air pressure sensors can be arranged in the following three ways: first, the first air pressure sensor 10 is arranged in the air inlet pipe of the insulating space; second, the second air pressure sensor 11 is arranged in the air inlet pipe of the liquid cargo tank; third, the first air pressure sensor 10 is arranged in the air inlet pipe of the insulating space, and the second air pressure sensor 11 is arranged in the air inlet pipe of the liquid cargo tank. The third arrangement is preferred.

[0063] In this way, by respectively arranging the first air pressure sensor 10 and the second air pressure sensor 11 on the air intake pipe of the insulating space and the air intake pipe of the liquid cargo tank, it is convenient to detect the air pressure values ​​of the insulating space 6 and the liquid cargo tank 7, thereby realizing the precise control function of the environmental pressure with a high degree of automation, avoiding the risks caused by human operating errors.

[0064] Specifically, the air pressure control device 3 also includes a first safety protection device 17, the first safety protection device 17 includes an insulating space air pressure safety valve and a first safety protection pipeline, the two ends of the insulating space air pressure safety valve are respectively connected to the insulating space air intake pipeline and the first safety protection pipeline, and the other end of the first safety protection pipeline is connected to the outside of the cabin 2; when the first air pressure value is greater than the first safety air pressure preset value for a preset time, the insulating space air pressure safety valve automatically opens; or, the air pressure control device 3 also includes a second safety protection device 18, the second safety protection device 18 includes a liquid cargo tank space air pressure safety valve and a second safety protection pipeline, the two ends of the liquid cargo tank space air pressure safety valve are respectively connected to the liquid cargo tank space 7 and the second safety protection pipeline, and the other end of the second safety protection pipeline is connected to the outside of the cabin 2; when the second air pressure value is greater than the second safety air pressure preset value for a preset time, the liquid cargo tank space air pressure safety valve automatically opens. Alternatively, the air pressure control device 3 includes a first safety protection device 17 and a second safety protection device 18.

[0065] Among them, the first safety air pressure preset value is greater than the first air pressure preset value and less than the air pressure value of the pressure borne by the insulation layer 4; the second safety air pressure preset value is greater than the second air pressure preset value and less than the air pressure value of the pressure borne by the structure of the cabin 2. The insulation space air pressure safety valve and the liquid cargo tank air pressure safety valve are commonly used air pressure safety valves for ships, which belong to the prior art and are not discussed in detail in this patent.

[0066] In this way, if the gas pressure of the insulating space 6 exceeds the first preset safety gas pressure value, it may be that the insulating space air inlet assembly 14 is faulty, and the first safety protection device 17 is opened to ensure that gas will not be supplied to the insulating space 6, so that the gas pressure of the insulating space 6 will not continue to rise, and the balance will be restored after the excess gas overflows from the balance hole 8. If the gas pressure of the cargo tank space 7 exceeds the second preset safety gas pressure value, it may be that the cargo tank space gas outlet assembly 16 is faulty, and the second safety protection device 18 is opened to ensure that the gas in the cargo tank space 7 is discharged in time, so that the gas pressure of the cargo tank space 7 will not continue to rise, and the balance will be restored after the excess gas is discharged from the second safety protection pipeline.

[0067] Specifically, the air pressure control device 3 also includes a pressure difference sensor 13 , the first air pressure sensor 10 and the second air pressure sensor 11 are both electrically connected to the pressure difference sensor 13 , and the pressure difference sensor 13 is used to detect the pressure difference between the first air pressure value and the second air pressure value and transmit the detection data to the control unit 12 .

[0068] In this way, the pressure difference sensor 13 can monitor the air pressure difference, provide data support, and ensure the normal operation of the air pressure control device 3.

[0069] In this embodiment, the differential pressure sensor 13 may be integrated into the control unit 12 .

[0070] Specifically, the ship also includes a gas detection device 19 and an alarm. The detection end of the gas detection device 19 is arranged close to the balancing hole 8. The gas detection device 19 is electrically connected to the alarm. The gas detection device 19 is used to detect the combustible gas at the balancing hole 8.

[0071] In this way, when a liquid cargo tank leaks, the combustible gas in the liquid cargo tank 5 evaporates into the insulating space 6 and escapes from the balancing hole 8 along with the first inert protective gas. The gas detection device 19 arranged near the balancing hole 8 can detect the combustible gas leakage in time and sound an alarm.

[0072] In this embodiment, the gas detection device 19 may also be simultaneously arranged in the gas outlet pipeline of the liquid cargo tank space, so as to detect the combustible gas at the gas outlet pipeline of the liquid cargo tank space.

[0073] This embodiment also provides a method for controlling the gas pressure in a liquid cargo tank. The method for controlling the gas pressure in a liquid cargo tank is applied to the above-mentioned ship. Figure 3 As shown, the cargo tank gas pressure control method includes:

[0074] A first air pressure sensor 10 is used to detect a first air pressure value in the insulating space 6, and a second air pressure sensor 11 is used to detect a second air pressure value in the cargo tank space 7;

[0075] Determine whether the first air pressure value exceeds the first air pressure preset value; if so, close the insulating space air intake component 14 through the control unit 12; if not, keep the insulating space air intake component 14 normally open;

[0076] Determine whether the second air pressure value exceeds the second air pressure preset value; if so, open the liquid cargo tank gas outlet component 16 through the control unit 12; if not, keep the liquid cargo tank gas outlet component 16 normally closed;

[0077] Determine whether the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value. If so, the control unit 12 controls the insulation space air intake component 14 to be closed and the liquid cargo tank air intake component 15 to be started; if not, keep the insulation space air intake component 14 normally open and keep the liquid cargo tank air intake component 15 normally closed.

[0078] In this way, the insulating space air inlet assembly 14 slowly and continuously delivers the first inert protective gas to the insulating space 6, so that the insulating space 6 maintains an inert environment, and balances the air pressure of the insulating space 6 and the liquid cargo tank space 7 through the balance hole 8 provided on the insulating layer 4. At the same time, the first air pressure preset value and the second air pressure preset value are respectively preset through the first air pressure sensor 10 and the second air pressure sensor 11, and when the actual air pressure value exceeds the preset air pressure value, the adjustment operation is performed: when the first air pressure sensor 10 exceeds the first air pressure preset value, the insulating space air inlet assembly 14 is closed to suspend the air supply to the insulating space 6, and the air pressure in the insulating space 6 is reduced through the balance hole 8; when the second air pressure sensor 11 exceeds the second air pressure preset value, the liquid cargo tank space air outlet assembly 16 is opened to discharge the excess gas in the liquid cargo tank space 7 to achieve the purpose of reducing the air pressure; when the air pressure difference between the first air pressure value and the second air pressure value is greater than the preset pressure difference value, air is supplemented to the liquid cargo tank space 7 to achieve balance, and the above components are controlled by the control unit 12.

[0079] Specifically, the specific steps of comparing the first air pressure value with the first air pressure preset value, the second air pressure value with the second air pressure preset value, and the pressure difference with the preset pressure difference value are as follows:

[0080] The first one is that when the first air pressure value exceeds the first air pressure preset value, the step of closing the insulating space air intake component 14 by the control unit 12 specifically includes: the control unit 12 controls the insulating space air intake component 14 to close until the first air pressure value satisfies less than or equal to the first air pressure preset value, and the control unit 12 controls the insulating space air intake component 14 to open;

[0081] The second method is to open the gas outlet assembly 16 of the cargo tank space by the control unit 12 when the second gas pressure value exceeds the second gas pressure preset value, and the control unit 12 controls the gas outlet assembly 16 of the cargo tank space to open until the second gas pressure value satisfies the second gas pressure preset value, and then controls the gas outlet assembly 16 of the cargo tank space to close.

[0082] The third type, when the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the steps of controlling the insulating space air intake component 14 to close and controlling the liquid cargo tank air intake component 15 to start by the control unit 12 specifically include: the control unit 12 controls the insulating space air intake component 14 to close and controls the liquid cargo tank air intake component 15 to start until the pressure difference between the first air pressure value and the second air pressure value is less than or equal to the preset pressure difference value, and the control unit 12 controls the insulating space air intake component 14 to open and controls the liquid cargo tank air intake component 15 to close.

[0083] The fourth method is preferred, and the above three methods are implemented simultaneously.

[0084] In this way, when the insulating space air inlet assembly 14 is closed until the first air pressure value satisfies less than or equal to the first air pressure preset value, the control unit 12 controls the insulating space air inlet assembly 14 to open to ensure that the first inert protective gas is supplied after the air pressure value of the insulating space 6 reaches the first air pressure preset value, thereby preventing the concentration of the first inert protective gas in the inert environment from being too low. When the cargo tank location air outlet assembly 16 is opened until the second air pressure value satisfies less than or equal to the second air pressure preset value, the control unit 12 controls the cargo tank location air outlet assembly 16 to close to ensure that the excess gas in the cargo tank location 7 is closed in time after being discharged, thereby preventing the second inert protective gas in the cargo tank location 7 from being discharged excessively, causing low air pressure and gas waste. When the pressure difference between the first air pressure value and the second air pressure value is less than or equal to the preset pressure difference value, the control unit 12 controls the insulating space air inlet assembly 14 to open and controls the cargo tank location air inlet assembly 15 to close to prevent excessive gas replenishment to the insulating space 6 or the cargo tank location 7 from destroying the air pressure balance.

[0085] In this embodiment, in the step of determining whether the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the pressure difference between the first air pressure value and the second air pressure value is obtained by the pressure difference sensor 13. The pressure difference sensor 13 can monitor the air pressure difference, provide data support, and ensure the normal operation of the air pressure control device 3.

[0086] Specifically, the control methods of the air pressure safety valve of the insulating space and the air pressure safety valve of the liquid cargo tank space include the following three methods:

[0087] The first method is to determine whether the first air pressure value exceeds the first air pressure preset value; if so, in the step of closing the insulating space air intake component 14 through the control unit 12, the insulating space air pressure safety valve is set to the first safety air pressure preset value, and if the first air pressure value is greater than the first safety air pressure preset value after the control unit 12 closes the insulating space air intake component 14, the insulating space air pressure safety valve is automatically opened to ensure that there is no overpressure in the insulating space 6;

[0088] The second method is to determine whether the second air pressure value exceeds the second air pressure preset value; if so, in the step of opening the gas outlet component 16 in the cargo tank space by the control unit 12, the air pressure safety valve in the cargo tank space is set to the second safety air pressure preset value, and if the second air pressure value is greater than the second safety air pressure preset value after the control unit 12 opens the gas outlet component 16 in the cargo tank space, the air pressure safety valve in the cargo tank space is opened to ensure that the cargo tank space 7 will not be over-pressurized.

[0089] The third method is preferred, and the above two methods are implemented simultaneously.

[0090] In this way, if the gas pressure of the insulating space 6 exceeds the first preset safety gas pressure value, it may be that the insulating space air inlet assembly 14 is faulty, and the first safety protection device 17 is opened to ensure that gas will not be supplied to the insulating space 6, so that the gas pressure of the insulating space 6 will not continue to rise, and the balance will be restored after the excess gas overflows from the balance hole 8. If the gas pressure of the cargo tank space 7 exceeds the second preset safety gas pressure value, it may be that the cargo tank space gas outlet assembly 16 is faulty, and the second safety protection device 18 is opened to ensure that the gas in the cargo tank space 7 is discharged in time, so that the gas pressure of the cargo tank space 7 will not continue to rise, and the balance will be restored after the excess gas is discharged from the second safety protection pipeline.

[0091] Specifically, when the liquid cargo tank is filled for the first time, the gas in the insulating space 6 is first dried and inerted, the insulating space air inlet assembly 14 is opened to introduce nitrogen from the air inlet hole 9, and the air in the insulating space 6 is discharged from the balance pipe.

[0092] The beneficial effect of the present invention is that the existing nitrogen system on board can be used to provide the requirements for environmental pressure suitable for different application scenarios, ensure the inert environment of the insulating space 6 and the liquid cargo tank 7 and the safety of the operators, and have the function of precise control of environmental pressure, with a high degree of automation, avoiding the risks caused by human operation errors. At the same time, the flammable gas composition in the environment can be monitored in real time and an alarm can be issued. When the liquid cargo tank 5 needs to be inspected and aerated, the liquid cargo tank 7 can be aerated simply and quickly by replacing the inert protective gas introduced with air. The present invention can be applied to dual-fuel ships with liquid cargo tanks as fuel tanks, and can also be applied to gas transport ships with liquid cargo tanks as cargo tanks.

[0093] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A ship, characterized in that: The ship comprises a liquid cargo tank containment system, a compartment for storing the liquid cargo tank containment system, and an air pressure control device; The liquid cargo tank containment system comprises an insulating layer and a liquid cargo tank, wherein the insulating layer wraps the liquid cargo tank, an insulating space is formed between the insulating layer and the liquid cargo tank, and the insulating space is filled with a first inert protective gas; the outer side of the insulating layer and the inner side of the cabin form a liquid cargo tank space, and the liquid cargo tank space is filled with a second inert protective gas; the first gas pressure in the insulating space is greater than the second gas pressure in the liquid cargo tank space; The insulating layer is provided with a balancing hole, and two ends of the balancing hole are respectively connected to the insulating space and the liquid cargo tank space; The air pressure control device comprises a first air pressure sensor, a second air pressure sensor, a control unit, an insulating space air inlet assembly, a liquid cargo tank air inlet assembly and a liquid cargo tank air outlet assembly; the insulating space air inlet assembly is in a normally open state, the liquid cargo tank air inlet assembly and the liquid cargo tank air outlet assembly are in a normally closed state, the insulating space air inlet assembly is used to replenish the first inert protective gas to the insulating space, the liquid cargo tank air inlet assembly is used to replenish the second inert protective gas to the liquid cargo tank, and the liquid cargo tank air outlet assembly is used to discharge the second inert protective gas in the liquid cargo tank to the outside of the cabin; The first air pressure sensor is used to detect a first air pressure value in the insulating space and transmit the detection data to the control unit, and the second air pressure sensor is used to detect a second air pressure value in the cargo tank space and transmit the detection data to the control unit; the control unit is configured to control the opening or closing of the insulating space air inlet assembly, the cargo tank space air inlet assembly and the cargo tank space air outlet assembly according to the first air pressure value and the second air pressure value collected; When the first air pressure value is greater than the first air pressure preset value, the control unit is used to control the insulating space air intake assembly to close; when the second air pressure value is greater than the second air pressure preset value, the control unit is used to control the liquid cargo tank air outlet assembly to start; when the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the control unit is used to control the insulating space air intake assembly to close and control the liquid cargo tank air intake assembly to start.

2. The vessel according to claim 1, characterized in that: The insulating layer is also provided with an air inlet hole, and both ends of the air inlet hole are respectively connected to the insulating space and the liquid cargo tank space; The insulating space air intake assembly comprises a first air source component, an insulating space air intake pipeline and an insulating space air intake valve, wherein the first air source component is in communication with the insulating space air intake pipeline, the insulating space air intake pipeline is connected to the air intake hole, and the insulating space air intake valve is arranged on the insulating space air intake pipeline and is electrically connected to the control unit; The cargo tank air intake assembly comprises a second air source, a cargo tank air intake pipe and a cargo tank air intake valve, wherein the second air source is in communication with the insulating space air intake pipe, the cargo tank air intake pipe is connected to the cabin, and the cargo tank air intake valve is arranged on the cargo tank air intake pipe and is electrically connected to the control unit; The cargo tank gas outlet assembly comprises a cargo tank gas outlet pipe and a cargo tank gas outlet valve, the two ends of the cargo tank gas outlet pipe are respectively connected to the interior of the cabin and the exterior of the cabin, and the cargo tank gas outlet valve is arranged on the cargo tank gas outlet pipe and is electrically connected to the control unit.

3. The ship according to claim 2, characterized in that: The balancing hole is arranged at the upper part of the insulating layer, and the air inlet hole is arranged at the bottom of the insulating layer; The first air pressure sensor is arranged in the air intake duct of the insulating space; And / or, the second air pressure sensor is arranged in the air intake pipe of the liquid cargo tank.

4. The ship according to claim 2, characterized in that: The air pressure control device also includes a first safety protection device, which includes an insulating space air pressure safety valve and a first safety protection pipeline, wherein the two ends of the insulating space air pressure safety valve are respectively connected to the insulating space air intake pipeline and the first safety protection pipeline, and the other end of the first safety protection pipeline is connected to the outside of the cabin; the insulating space air pressure safety valve can be set to a first safety air pressure preset value, and when the first air pressure value is greater than the first safety air pressure preset value, the insulating space air pressure safety valve automatically opens; And / or, the air pressure control device also includes a second safety protection device, the second safety protection device includes an air pressure safety valve in the liquid cargo tank and a second safety protection pipe, both ends of the air pressure safety valve in the liquid cargo tank are respectively connected to the liquid cargo tank and the second safety protection pipe, and the other end of the second safety protection pipe is connected to the outside of the cabin; the air pressure safety valve in the liquid cargo tank can be set to a second safety air pressure preset value, and when the second air pressure value is greater than the second safety air pressure preset value, the air pressure safety valve in the liquid cargo tank automatically opens.

5. The ship according to claim 1, characterized in that: The air pressure control device also includes a pressure difference sensor, the first air pressure sensor and the second air pressure sensor are both electrically connected to the pressure difference sensor, and the pressure difference sensor is used to detect the pressure difference between the first air pressure value and the second air pressure value and transmit the detection data to the control unit.

6. The ship according to claim 1, characterized in that: The ship also includes a gas detection device and an alarm. The detection end of the gas detection device is arranged close to the balancing hole. The gas detection device is electrically connected to the alarm. The gas detection device is used to detect the combustible gas at the balancing hole.

7. A method for controlling gas pressure in a liquid cargo tank, characterized in that: The cargo tank gas pressure control method is applied to the ship according to any one of claims 1 to 6, and the cargo tank gas pressure control method comprises: Using the first air pressure sensor to detect a first air pressure value in the insulating space, and using the second air pressure sensor to detect a second air pressure value in the liquid cargo tank space; Determine whether the first air pressure value exceeds the first air pressure preset value; if so, close the insulating space air intake component through the control unit; if not, keep the insulating space air intake component normally open; Determine whether the second air pressure value exceeds the second air pressure preset value; if so, open the gas outlet component of the liquid cargo tank through the control unit; if not, keep the gas outlet component of the liquid cargo tank normally closed; Determine whether the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value. If so, control the insulating space air intake assembly to be closed and control the liquid cargo tank air intake assembly to be started through the control unit; if not, keep the insulating space air intake assembly normally open and keep the liquid cargo tank air intake assembly normally closed.

8. The method for controlling gas pressure in a liquid cargo tank according to claim 7, characterized in that: When the first air pressure value exceeds the first air pressure preset value, the step of closing the insulating space air intake component by the control unit specifically includes: The control unit controls the insulating space air intake component to be closed until the first air pressure value is less than or equal to the first air pressure preset value, and the control unit controls the insulating space air intake component to be opened; And / or, when the second air pressure value exceeds the second air pressure preset value, the step of opening the air outlet component in the cargo tank by the control unit specifically includes: the control unit controls the air outlet component in the cargo tank to open until the second air pressure value satisfies less than or equal to the second air pressure preset value, and the control unit controls the air outlet component in the cargo tank to close; And / or, when the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the step of controlling the insulating space air intake assembly to be closed and the liquid cargo tank air intake assembly to be started by the control unit specifically includes: the control unit controls the insulating space air intake assembly to be closed and controls the liquid cargo tank air intake assembly to be started until the pressure difference between the first air pressure value and the second air pressure value is less than or equal to the preset pressure difference value, and the control unit controls the insulating space air intake assembly to be opened and controls the liquid cargo tank air intake assembly to be closed.

9. The method for controlling gas pressure in a liquid cargo tank according to claim 7, characterized in that: In the step of determining whether the pressure difference between the first air pressure value and the second air pressure value exceeds the preset pressure difference value, the pressure difference between the first air pressure value and the second air pressure value is acquired by a pressure difference sensor.

10. The method for controlling gas pressure in a liquid cargo tank according to claim 7, characterized in that: In determining whether the first air pressure value exceeds the first air pressure preset value; if so, in the step of closing the insulating space air intake component by the control unit, the insulating space air pressure safety valve is set to a first safety air pressure preset value, and if the first air pressure value is greater than the first safety air pressure preset value after the control unit closes the insulating space air intake component, the insulating space air pressure safety valve is automatically opened until the first air pressure value satisfies a value less than or equal to the first safety air pressure preset value; And / or, in determining whether the second air pressure value exceeds the second air pressure preset value; if so, in the step of opening the gas outlet component in the cargo tank by the control unit, the air pressure safety valve in the cargo tank is set to the second safety air pressure preset value, if after the control unit opens the gas outlet component in the cargo tank, the second air pressure value is greater than the second safety air pressure preset value, the air pressure safety valve in the cargo tank is opened until the second air pressure value satisfies a condition that is less than or equal to the second safety air pressure preset value.

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