WO2013176413A1

WO2013176413A1 - Nitrogen generation, storage, and supply system for tanker ships, and method for controlling same

Info

Publication number: WO2013176413A1
Application number: PCT/KR2013/003789
Authority: WO
Inventors: 이경우; 김만응; 천강우; 남연우
Original assignee: 사단법인 한국선급
Priority date: 2012-05-21
Filing date: 2013-05-02
Publication date: 2013-11-28
Also published as: KR101200100B1

Abstract

The nitrogen generation, storage, and supply system according to the present invention includes: a cargo tank for storing cargo oil therein and having an inert gas injection inlet through which nitrogen and air are injected, and a cargo oil inlet and outlet through which the cargo oil flows in and out; a nitrogen generator for producing nitrogen having a first purity and a second purity which is lower than the first purity in response to a control signal from a control unit; a nitrogen storage unit for storing the nitrogen having the first purity; an air suction unit suctioning air from outside the cargo tank; a mixing device mixing the nitrogen having the first purity stored in the nitrogen storage unit, the nitrogen having the second purity generated by the nitrogen generator, and the external air suctioned by the air suction unit; and a valve unit, the opening and closing of which are controlled by the control unit so as to control the purity of the nitrogen supplied to the cargo tank.

Description

Nitrogen generation, storage and supply system for tanker ships and its control method

The present invention relates to a nitrogen generation, storage and supply system and a control method thereof installed on a tanker ship for storing and transporting cargo oil.

Tanker ships carry cargo oil (crude oil, petroleum products, chemicals, etc.). Since the cargo oil is mostly flammable materials, the cargo tank containing the flammable liquid may contain a large amount of flammable gas evaporated from the cargo oil. When such flammable gas comes into contact with an ignition source at a certain level of oxygen concentration (depending on the type of cargo oil, but generally 13% or more), it may lead to an explosion accident, which may cause a lot of life loss and environmental pollution.

In order to prevent such explosions, the International Maritime Organization (IMO) shall, when loading or unloading cargo oil (including purging), for cargo tankers of 20,000 DWT or more deadweight tonnage. In order to maintain the oxygen concentration in the tank below 8%, it is mandatory to install a device on the ship that can fill the inside of the cargo tank containing the cargo oil with an inert gas.

In addition, apart from IMO mandates, large oil companies such as Exxon, British Petroleum (BP), Shell, etc., are responsible for monitoring the concentration of oxygen in the cargo tanks for ships carrying their cargo. It is required to keep it below 5%, and since the large oil companies make up the share of the world's cargo volume, all tankers above 20,000 DWT are equipped with related facilities to keep the oxygen concentration below 5%.

Recently, however, the IMO has been discussing mandatory ships with inert gas production equipment for small tanker ships of less than 20,000 DWT in order to reduce the impact of explosions on small tankers. As a result, from 2015 onwards, relevant tankers are expected to be applied to all tankers above 8,000 DWT.

Inert gas manufacturing apparatus for ships is typically used inert gas system (IGS) or inert gas generator (IGG).

IGS uses a boiler installed on a tanker ship and operates the burner of the boiler in an incomplete combustion state (supplying a small amount of air compared to the supplied fuel) to produce exhaust gas with an oxygen concentration of 5% or less. It is a facility that cleans exhaust gas through seawater scrubber and supplies it to the cargo tank as inert gas. At this time, the exhaust gas is known to have 81 to 83% of nitrogen, 12 to 14% of CO2, and 2 to 4% of oxygen. IGG uses a dedicated combustion plant to produce inert gas instead of a boiler, the rest of which is the same as IGS.

IGS and IGG are operated under incomplete combustion conditions to reduce the oxygen concentration of exhaust gas below 5%, and large amounts of combustion oxides (Soot, PM, etc.) are generated during incomplete combustion. In order to clean the vessel using seawater scrubber, a considerable amount of combustion oxide is introduced into the cargo tank. In addition, because IGG uses high quality fuel oil (usually MDO) compared to IGS by using a dedicated combustion facility, less combustion oxides are emitted than IGS. However, even when IGG is used, a considerable amount of combustion is performed. Oxides enter the cargo tanks.

However, large tanker ships of 20,000 DWT or more are mainly ships carrying large quantities of relatively inexpensive cargoes such as crude oil and petroleum products. This is very small compared to the amount of cargo, and most of the additional refining process is not a problem.

However, small tankers of less than 20,000 DWT mainly carry very expensive small cargoes, such as pharmaceutical raw materials and cosmetic raw materials, so when the combustion oxide from IGS or IGG flows into the cargo tank, There is a problem that can be contaminated.

Therefore, in case IMO enforces a requirement to install inert gas production equipment for all tankers of more than 8,000 DWT, it is necessary to develop inert gas production equipment suitable for small tankers. In particular, the inert gas manufacturing apparatus for ships that can replace the IGS and IGG, and can prevent the contamination of the cargo by the combustion oxide, the nitrogen generator is the only situation.

Nitrogen generator is divided into membrane type using membrane and Pressure Swing Adsorption using adsorbent. However, ships mainly use membrane type in consideration of small facility installation space and smooth maintenance. .

The membrane method utilizes the difference in permeation rate of various gases in the membrane, and supplies the compressed air at about 8-12 bar to the membrane module, and shows the permeation rate of various molecules (mostly nitrogen and oxygen) of the compressed air inside the membrane. By using the difference of 95% or more purity of nitrogen is produced. At this time, the purity of the nitrogen produced in the membrane may vary slightly depending on the type of membrane, but can be adjusted to 95 ~ 99.9%, and in general, as the purity of nitrogen increases, the amount of nitrogen produced in the nitrogen generator tends to decrease. Has

However, the nitrogen generator has the advantage that it can produce nitrogen having a purity of 95% or more while preventing contamination of the cargo by the combustion oxide, there is a problem that the power required to produce nitrogen is relatively large.

In addition, since a large capacity nitrogen generator is not easy to install in view of the narrow space of a ship, it may be difficult to apply the nitrogen generator directly to a small tanker of less than 20,000 DWT.

The present invention has been made in view of the above problems, to provide a system for producing, storing and supplying nitrogen injected into a cargo tank in a ship to prevent an explosion accident in a tanker ship carrying cargo oil. For that purpose.

Another object of the present invention is to provide an improved method for producing and supplying nitrogen so that even a small tanker of less than 20,000 DWT can use a nitrogen generator with limited power.

Nitrogen production and supply system according to the present invention is a cargo tank containing a cargo oil is stored therein, the inert gas and nitrogen inlet gas inlet and the inlet gas inlet and vent pipe and the cargo tank including a cargo oil inlet and outlet; A nitrogen generator for producing nitrogen to have a second purity having a first purity and a purity lower than the first purity according to a control signal of the controller; A nitrogen storage unit storing nitrogen of the first purity; An air suction unit for sucking air outside the cargo tank; A mixing device for mixing the nitrogen of the first purity stored in the nitrogen storage unit, the nitrogen of the second purity generated by the nitrogen generator, and the outside air sucked from the air suction unit; And a valve unit for controlling opening and closing by the control unit to adjust the purity of nitrogen supplied to the cargo tank.

According to a preferred embodiment of the present invention, the valve unit, the first valve for opening and closing the flow path between the nitrogen generator and the nitrogen storage; A second valve for opening and closing a flow path between the nitrogen storage part and the mixing device; A third valve for opening and closing a flow path between the nitrogen generator and the mixing device; A fourth valve for opening and closing a flow path between the air suction unit and the mixing device; And a fifth valve for opening and closing a flow path between the mixing device and the cargo tank.

In this case, when the first valve is opened, the second to fourth valves are preferably closed, and the second to fourth valves are individually opened according to the oxygen concentration of the gas mixed in the mixing device. It is desirable to be controlled.

On the other hand, the mixing device and the oxygen concentration meter for measuring the oxygen concentration inside the cargo tank; further comprising, the fifth valve is preferably controlled to open or close according to the measured value of the oxygen concentration meter.

The first concentration is 99 to 99.9% concentration, the second concentration may be provided to 92 to 95% concentration.

The nitrogen generation, storage and supply control method for the tanker ship according to the present invention comprises the steps of: determining whether the tanker ship is in operation; When the tanker is in operation, producing nitrogen at a concentration of 99 to 99.9% with a nitrogen generator, and storing the produced high purity nitrogen in a nitrogen storage unit; When the tanker is not in operation, producing a large amount of 92 to 95% nitrogen with a nitrogen generator, and mixing it with high purity nitrogen stored in the nitrogen storage unit and the outside air in a mixing apparatus; And supplying a gas in which nitrogen of different purity is mixed to the cargo tank, and performing dropping or unloading of the cargo oil.

The supplying the mixed gas to the cargo tank may include closing a first valve for opening and closing a flow path between the nitrogen generator and the nitrogen storage unit; A second valve for opening and closing the flow path between the nitrogen storage unit and the mixing device, and a third valve for opening and closing the flow path between the nitrogen generator and the mixing device; And a fourth valve for opening and closing a flow path between the air suction unit and the mixing device. Detecting the oxygen concentration inside the mixing device, when the composition of the inert gas of a suitable level that can be supplied to the cargo tank, opening the fifth valve to supply a nitrogen center inert gas to the cargo tank; can do.

According to the present invention as described above, while improving the control method of the nitrogen generator, by providing a nitrogen storage unit that can store high-purity nitrogen, while producing a small capacity while sailing the tanker ship, it produces high-purity nitrogen and stores it in the nitrogen storage unit It is a large capacity at the time of loading and unloading cargo oil, but produces low-purity nitrogen, and supplies high-purity nitrogen stored during voyage with low-purity nitrogen produced at the time of loading and unloading cargo, and supplies it to the cargo tank. Therefore, a relatively small capacity nitrogen generator can supply inert gas (nitrogen) required for the cargo tank.

Therefore, if the present invention is applied to the inert gas generation and supply apparatus suitable for tanker ships less than 20,000 DWT difficult to apply IGS or IGG due to the risk of cargo contamination due to the combustion oxide produced in IGS or IGG Nitrogen generator can be installed and operated.

1 is a view showing a cargo oil loading and unloading operation sequence of the tanker ship,

2 is a view showing the concept of nitrogen production, storage and supply apparatus according to an embodiment of the present invention,

3 is a control block diagram of a nitrogen production, storage and supply apparatus according to an embodiment of the present invention, and

4 is a control flowchart of the nitrogen production, storage and supply apparatus according to an embodiment of the present invention.

Hereinafter, the nitrogen generation, storage and supply system for tanker ship according to an embodiment of the present invention will be described with the drawings.

1 is a view showing a cargo oil loading and unloading operation sequence of the tanker ship, Figure 2 is a view showing the concept of nitrogen production, storage and supply apparatus according to an embodiment of the present invention, Figure 3 is a preferred embodiment of the present invention Control block diagram of the nitrogen production, storage and supply apparatus according to an embodiment, and Figure 4 is a control flow diagram of the nitrogen production, storage and supply apparatus according to an embodiment of the present invention.

1 is a view illustrating a process in which a tanker ship loads and unloads cargo.

As shown, step (a) is a purging step, in which the oxygen concentration in the cargo tank 10 is increased to 5 to prevent explosions before the vessel without loading the cargo loads the cargo. It shows the process of lowering below 8%. To this end, the inert gas inlet 11 of the cargo tank 10 is opened, and the inert gas 100 of the nitrogen center generated by the nitrogen generator 200 to be described later is injected into the cargo tank 10. At this time, by opening the vent pipe 12 installed in the cargo tank 10, it is good to discharge the air containing oxygen in the cargo tank 10 to the outside.

When the oxygen concentration of the internal space of the cargo tank 10 is lowered to the required level or less in the above step (a), as shown in step (b), the cargo oil 20 is moved to the cargo oil inlet and outlet 13. Drop through

On the other hand, during the dropping of the cargo oil 20 in the step (b), since the oxygen concentration inside the cargo tank 10 may increase while the outside air is introduced, the cargo oil 20 is a process of dropping the cargo oil 20. During the step (c), the inert gas inlet 11 may be opened to further replenish the inert gas 100 of the nitrogen center. That is, while loading of the cargo oil 20 is carried out, the inert gas 100 of the nitrogen center, which is an inert gas in the cargo tank 10, is discharged to the outside of the cargo tank 10 by the amount of the cargo oil 20 dropped. Because it becomes. In general, when the dripping of the cargo oil 20 is completed, only about 5-10% of the volume of the cargo tank 10 is finally filled with the inert gas 100 of the nitrogen center which is an inert gas.

Through the above (a) to (c) step, when the cargo oil 20 is dropped into the cargo tank 10, the inert gas inlet 11, vent pipe 12 and the cargo oil inlet and outlet 13 In closed state, move tanker ship and drive. On the other hand, after the dropping of the cargo oil 20 is completed to sail to the place for unloading the cargo oil 20, while the tanker ship sails due to the external heat source (solar heat, etc.) inside the cargo tank vent Since the pipe 12 is installed to continuously discharge and inhale gas, in order to lower the oxygen concentration in the gaseous phase in the cargo tank 10 to a required level, the inert gas 100 of the nitrogen center is sailed even while sailing. You need to replenish it constantly. This nitrogen supplement is called padding.

On the other hand, in the (d) step of unloading the cargo oil 20, during the process of unloading the cargo oil 20 through the cargo oil inlet and outlet 13, as in the (c) step, the outside air inflow In order to suppress the increase in the oxygen concentration according to, it is good to carry out the step of unloading the cargo oil 20 while continuing to replenish nitrogen through the inert gas inlet (11). That is, when arriving at the port for unloading the cargo oil 20 and unloading the cargo oil, in order to prevent structural damage (buckling) and explosion of the cargo tank 10, as much as the amount of cargo oil to be unloaded This is because it is necessary to supply nitrogen from the outside. Such additional supply of the nitrogen-based inert gas 100 needs to be made continuously until the unloading of the cargo oil 20 is completed.

And when the unloading of the cargo oil 20 is completed, as shown in step (e), the inert gas 100 of the nitrogen center filled in the internal space of the cargo tank 10 through the vent pipe 12, The outside air (A) is sucked to fill the cargo tank 10 with air. That is, when the unloading of the cargo oil 20 is completed, the oxygen concentration in the cargo tank 10 to about 20% level so that the work force can enter the cargo tank for cleaning work in the cargo tank 10. Because you have to raise. Meanwhile, as described above, the step of discharging the oil vapor of the cargo oil 20 existing in the cargo tank 10 to the outside of the cargo tank and filling the air in the cargo tank 10 may be performed in a gas free manner. ). After the gas free, the tanker ship that has completed the work inside the cargo tank unloads the cargo again, and then starts the purging step (a).

2 is a view schematically showing the configuration of the nitrogen generating device 200 for generating a nitrogen-based inert gas 100 used to control the oxygen concentration of the cargo tank (10).

As shown, the nitrogen generating apparatus 200 according to the preferred embodiment of the present invention includes a nitrogen generator 210, nitrogen storage unit 220, mixing device 230 and the air suction unit 240, These may be selectively connected to a valve unit 250 composed of a plurality of valves.

Nitrogen generator 210 is a device for producing a nitrogen-centered inert gas 100 is supplied to the inside of the cargo tank (10). On the other hand, in order to apply the nitrogen generator 210 to tankers of various sizes, the nitrogen generating capacity of the nitrogen generator 210 dropping or unloading the cargo oil 20 with respect to the total volume of the cargo tank 10 of the tanker ship It is necessary to be configured to be able to supply a nitrogen-based inert gas 100 during the time that is made.

For example, the total volume of the cargo tank of the 20,000 DWT tanker ship is typically about 30,000 m 3, and the time required for loading or unloading the cargo is about 24 hours, so the nitrogen production capacity of the nitrogen generator 210 is about 1,250 m 3 / h. Should be

In addition, since the inert gas 100 of the nitrogen center corresponding to at least three times the volume of the cargo tank 10 should be supplied to the purging step, considering the amount of nitrogen lost in the purging step, the nitrogen generator 210 It should be capable of supplying at least 3,750 m3 / h of nitrogen. In particular, in the case of applying the separation membrane method, considering that the general nitrogen discharge pressure is 8bar, even if the volume ratio of 8bar and 0bar (atmospheric pressure) at 45 ℃ is about 8.9 times, about 421㎥ / h class nitrogen generator When considering that the separator-type nitrogen generator needs 1 ~ 1.5kW of power per 1㎥ / h, it can be seen that the power of 420 ~ 630kW class is required. This, 420 ~ 630kW of power is a big power close to the output of one generator installed in the tanker ship.

However, in the case of the nitrogen generating apparatus 200 according to the present invention, the nitrogen generator 210 is selectively operated during the dropping and unloading and discharging and operating steps of the cargo oil 20 of the tanker ship, and the inert gas 100 of the nitrogen center is 100. There is a feature of the invention that the power required for the production of sigma is greatly reduced. The control method of the nitrogen generator 210 will be described later with a flowchart.

The nitrogen storage unit 220 stores inert gas 100 of high purity nitrogen center among the nitrogen center inert gas 100 generated by the nitrogen generator 210, as shown in FIG. 2. The first valve 251 may be connected to the nitrogen generator 210 and the outlet may be connected to the second valve 220.

Mixing device 230 is a large-capacity low-purity nitrogen center inert gas 100 generated during the dropping and unloading of the cargo oil 20 of the nitrogen-centered inert gas 100 generated by the nitrogen generator 210 As shown, the inlet is connected to the nitrogen storage unit 220 by the second valve 252, the nitrogen generator 210 by the third valve 253, and the fourth valve. 254 is connected to the air suction unit 240, the outlet may be connected to the cargo tank 10 by a fifth valve (255). Therefore, in the mixing device 230, the inert gas 100 of the high purity nitrogen center, the inert gas 100 of the high purity and low purity nitrogen center, and air (A) are mixed to open and close the fifth valve 255. It can be supplied to the cargo tank 10 by.

On the other hand, as shown in Figure 3, the nitrogen generator 210, the air suction unit 240 and the valve unit 250 is preferably controlled by a predetermined control unit (C).

That is, the oxygen concentration meter 15 for detecting the oxygen concentration in the cargo tank 10 outputs the measured oxygen concentration value to the controller C. Then, the controller C determines that the inert gas 100 of the nitrogen center needs to be added to the inside of the cargo tank 10 according to the oxygen concentration value measured by the oxygen concentration meter 15. While operating the 210, the valve unit 250 is controlled to form the nitrogen-centered inert gas 100 at a concentration level required by the mixing apparatus 230, and the fifth valve 255 is formed. In accordance with the opening and closing operation, the inert gas 100 of the nitrogen center generated by the nitrogen generator 210 may be supplied into the cargo tank 10.

In addition, according to a preferred embodiment of the present invention, the control unit (C) controls the operating method of the nitrogen generator 210 differently, according to the current state of the tanker ship. That is, as described above, during the dripping and unloading of the cargo oil 20, the large-scale low-purity nitrogen-based inert gas 100 is controlled to be produced, and the high-purity nitrogen-based inert gas 100 is produced during ship operation. By doing so, the nitrogen storage unit 220 may be controlled to be stored in advance.

For example, the cargo tank volume of the 20,000 DWT tanker ship is about 30,000 m3, and the loading and unloading time is 24 hours, the operating period from the place of departure to the place of arrival is 3 days, and the nitrogen generator installed can produce nitrogen as described above. If the purity of 99.5 ~ 95%, the nitrogen generator 210 during the voyage to produce and store 99.5% purity nitrogen, and when loading or unloading the cargo oil 20 to a relatively low 95% purity To produce and store a high-purity nitrogen-centered inert gas (100) generated and stored during sailing and the low-purity nitrogen-centered inert gas (100) produced at the time of dropping or unloading and air to be supplied to the cargo tank. Can be. Then, the power required for the nitrogen generator 210 can be significantly reduced compared to the conventional.

Of course, in order to store the high-purity nitrogen-centered inert gas 100 produced during sailing, a cost, installation space, and power required in addition to the nitrogen storage unit 220 including a pressure vessel and a compressor are required. However, when the high-purity nitrogen center inert gas 100 is compressed and stored at a high pressure of 30 bar or more, the space required for the storage container can be minimized, and the compressor used at this time is inexpensive and requires less reciprocating compressor. Alternatively, the screw type compressor can be used, so the power required is not large.

Such a method of controlling the nitrogen generator according to the nitrogen generation, storage and supply system for the tanker according to the present invention will be described with the flowchart of FIG.

As shown in FIG. 4, the controller C determines whether the tanker ship is currently in operation (S10), and if it is determined that the tanker ship is in operation, operates the nitrogen generator 210 to the maximum. , To produce a high purity nitrogen center inert gas 100 (S20), the produced high purity nitrogen center inert gas 100 opens only the first valve 251, the second to fourth valves (252 ~) 254 is closed, and stores the produced high purity nitrogen-centered inert gas 100 in the nitrogen storage unit 220 provided with a compression vessel or the like. The steps S10 to S30 continue in a closed loop, and may be configured to stop when the nitrogen storage unit 220 is filled with high purity nitrogen.

On the other hand, if it is determined that the tanker ship is not in operation in step S10, this is a dropping or unloading step of the cargo oil 20, in this case using a nitrogen generator 210 inert gas 100 of large-capacity low purity nitrogen center To produce). If the purity of nitrogen in the previous step S20 is 99% or more, the purity of nitrogen in this step is about 95% is sufficient (S40).

When the nitrogen generator 210 produces a large-capacity low-purity nitrogen-centered inert gas 100 in step S40, the produced nitrogen is inert of the high-purity nitrogen center stored in the nitrogen storage unit 220 in the mixing device 230. The gas 100 may be mixed with air in the outside atmosphere sucked from the air suction unit 240 and injected into the cargo tank 10. At this time, it is preferable that the second to fourth valves 252 to 254 are connected to the inlet of the mixing device 230. Each of the valves 252 to 254 has a required concentration of oxygen (5 to 8%). You can adjust the amount of gas that is properly introduced so that For example, the high purity nitrogen-centered inert gas 100 supplied from the nitrogen storage unit 220 to the mixing device 230 connects the second valve 252 with the oxygen concentration meter 15 to the second valve ( 252) can automatically adjust the opening and closing degree (S50).

Whether the composition of the inert gas of the appropriate concentration is completed in the step S50 can be confirmed through the oxygen concentration meter 15, as shown in Figure 2, through the value measured in the oxygen concentration meter 15 If it is determined that the composition of the inert gas of the nitrogen center generated in step S50 is suitable to supply to the cargo tank 10, the control unit (C) is opened to open the fifth valve 255, the inert While filling the gas into the internal space of the cargo tank 10 through the nitrogen inlet 11, the cargo oil 20 can be safely loaded and unloaded into the cargo tank 10 (S60).

According to the present invention as described above, the cargo tank volume of the 20,000 DWT tanker ship is 30,000 m 3, the time required for purging, unloading and unloading, respectively, 24 hours, the operating period from the place of departure to the port of arrival 3 days, The purity of nitrogen that can be produced by the installed separator nitrogen method is 99.5 ~ 95% at 8 bar discharge pressure, the nitrogen discharge flow rate at 95% purity and the nitrogen discharge flow rate at purity 99.5% is 3.5 times similar to the general nitrogen generator. In this case, if the nitrogen generator is operated only at the time of loading (including purging) and unloading the cargo as before, as described above, to supply 3,750 m 3 / h of nitrogen at atmospheric pressure of 45 ° C., the level of 420 m 3 / h Nitrogen generator is required, and power of 420 ~ 630kW is required.

However, if the method proposed in the present invention is applied, the power required for the nitrogen generator can be significantly reduced. That is, since air (A) in the atmosphere is composed of 79% nitrogen and 21% oxygen, in order to make 100 m3 of air (A) at 5% oxygen concentration, nitrogen having a purity of 99.5% (nitrogen 99.5%, oxygen 0.5%) 355.6 m 3 should be mixed, and the inert gas produced at this time may be produced by installing about 203 m 3 / h class nitrogen generator 210 at 45 ° C. 8 bar discharge pressure. This is only 48.3% of capacity and pressure compared to conventional methods. Detailed calculation results are shown in Table 1 below.

Table 1

Required Inert Gas Flow Rate (㎥ / h)	Air flow rate (㎥ / h)	99.5% nitrogen supply (㎥ / h)	Inert gas with 99.5% nitrogen (㎥ / h)	95% Nitrogen Generator Production (㎥ / h)	8bar discharge generator 95% nitrogen flow rate (㎥ / h)	8 bar discharge 99.5% nitrogen flow rate (㎥ / h)	Quantity required for 24 hours 99.5% Nitrogen content (㎥)	8 bar discharge condition The amount of 99.5% nitrogen required for 24 hours (㎥ / h)	99.5% Time required for nitrogen production (h)
(A)	(B)	(C = B * 3.556)	(D = B + C)	(E = AD)	(F = E / 8.9)	(G = F / 3.5)	(H = C * 24)	(I = H / 8.9)	(J = I / G)
3,750	450.0	1,600.0	2,050	1,700.0	191.0	54.6	38,401.1	4,314.7	79,1
3,750	439.0	1,561.0	2,000	1,750.0	196.6	56.2	37,464.4	4,209.5	74.9
3,750	428.0	1,522.0	1,950	1,800.0	202.2	57.8	36,527.8	4,104.3	71.0
3,750	417.0	1,483.0	1,900	1,850.0	207.9	59.4	35,591.2	3,999.0	67.3
3,750	406.1	1,443.9	1,850	1,900.0	213.5	61.0	34,654.6	3,893.8	63.8

In the above described as an example of the inert gas, but the nitrogen was described as an example, not limited to this, any equipment that can generate an inert gas can be used.

The embodiments of the present invention described above and illustrated in the drawings should not be construed as limiting the technical idea of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention, as will be apparent to those skilled in the art.

In tanker ships carrying cargo oil, it can be applied to the system to produce, store and supply nitrogen injected into the cargo tank in ships to prevent explosion accident.

In addition, even a small tanker of less than 20,000 DWT can provide a technology that can use the nitrogen generator with limited power.

Claims

A cargo tank having a cargo oil stored therein and including an inert gas inlet and a vent pipe and a cargo oil inlet and outlet through which inert gas and nitrogen are injected, the main component of which is nitrogen;

A nitrogen generator for producing nitrogen to have a second purity having a first purity and a purity lower than the first purity according to a control signal of the controller;

A nitrogen storage unit storing nitrogen of the first purity;

An air suction unit for sucking air outside the cargo tank;

A mixing device for mixing the nitrogen of the first purity stored in the nitrogen storage unit, the nitrogen of the second purity generated by the nitrogen generator, and the outside air sucked from the air suction unit; And

Opening and closing is controlled by the control unit, the valve unit for adjusting the purity of the nitrogen supplied to the cargo tank; nitrogen generating, storage and supply system for a tanker comprising a.
The method of claim 1, wherein the valve unit,

A first valve for opening and closing a flow path between the nitrogen generator and the nitrogen storage unit;

A second valve for opening and closing a flow path between the nitrogen storage part and the mixing device;

A third valve for opening and closing a flow path between the nitrogen generator and the mixing device;

A fourth valve for opening and closing a flow path between the air suction unit and the mixing device; And

Nitrogen generation, storage and supply system for a tanker including a; 5th valve for opening and closing the flow path between the mixing device and the cargo tank.
The method of claim 2,

When the first valve is open, the second to fourth valve is closed nitrogen generating, storage and supply system for the tanker.
The method of claim 2,

The second to fourth valves, the nitrogen generation, storage and supply system for tanker ships, the open amount is individually controlled in accordance with the oxygen concentration of the gas mixed in the mixing device.
The method of claim 2,

Oxygen concentration meter for measuring the oxygen concentration in the cargo tank further comprises;

The fifth valve is a nitrogen generation, storage and supply system for the tanker vessel is opened or closed according to the measured value of the oxygen concentration meter.
The method of claim 1,

Wherein the first concentration is from 99 to 99.9% concentration and the second concentration is from 92 to 95% concentration.
Determining whether the tanker ship is in operation;

When the tanker is in operation, producing nitrogen at a concentration of 99 to 99.9% with a nitrogen generator, and storing the produced high purity nitrogen in a nitrogen storage unit;

When the tanker is not in operation, producing a large amount of nitrogen having a concentration of 95% or less with a nitrogen generator, and mixing it with high purity nitrogen stored in the nitrogen storage unit and outside air in a mixing apparatus; And

A method for controlling nitrogen generation, storage and supply system for a tanker, comprising the step of: supplying a mixture of nitrogen with different purity to a cargo tank to perform loading or unloading of cargo oil.
The method of claim 7, wherein supplying the mixed gas to the cargo tank,

Closing a first valve for opening and closing a flow path between the nitrogen generator and the nitrogen storage unit;

A second valve for opening and closing the flow path between the nitrogen storage unit and the mixing device, and a third valve for opening and closing the flow path between the nitrogen generator and the mixing device; And a fourth valve for opening and closing a flow path between the air suction unit for sucking external air and the mixing device. And

Detecting the oxygen concentration inside the mixing device, when the composition of the inert gas of a suitable level that can be supplied to the cargo tank is completed, by supplying a nitrogen center inert gas to the cargo tank by opening the fifth valve; Method of controlling nitrogen generation, storage and supply system for tanker ships