JP2000240894A - Tank equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To discharge liquefied gas without using a pump in a tank facility, and to greatly reduce facility costs and maintenance costs. Kind Code: A1 A tank facility for discharging a stored liquefied gas, comprising: a main tank connected to a liquefied gas supply line for storing the liquefied gas; and a pressurized tank disposed below the main tank. 12, a connection line 14 for connecting the upper part of the pressurized tank and the lower part of the main tank via a check valve 13 which can only flow to the pressurized tank side, and the upper part of the pressurized tank and the upper part of the main tank. Is connected via a first on-off valve 15, and a second
A pressurized gas line 18 connected through an on-off valve 17 for supplying pressurized gas into the pressurized tank, and a liquefied liquid in the pressurized tank connected to a lower portion of the pressurized tank via a third on-off valve 19 A liquid discharge line 20 for discharging gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tank facility for storing liquefied gas such as LNG and discharging the gas as appropriate.

[0002]

2. Description of the Related Art Conventionally, when a liquefied gas such as LNG is discharged from a tank storing the liquefied gas, as shown in FIG.
For example, in the tank facility 1 for dispensing LNG, the liquid draining drum 3 for storing LNG 4 supplied from the supply line 2
Is connected to the pump P, and the pump P is driven to discharge the LNG4. The tank equipment 1 is connected to the upper part of the draining drum 3 to discharge the BOG in the draining drum 3 by the compressor C, and to cool the internal LNG 4 connected to the draining drum 3 for cooling. A cooling liquid line 6 for supplying LNG for cooling.

[0003]

However, the above-mentioned conventional tank equipment has the following problems. In other words, the pump must be connected to and installed on the liquid draining drum in order to discharge the LNG, which increases the equipment cost, and requires a periodic inspection of the pump, thereby increasing the cost of the inspection. there were.

[0004] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a tank facility capable of discharging a liquefied gas without using a pump and greatly reducing equipment costs and maintenance costs. Aim.

[0005]

The present invention has the following features to attain the object mentioned above. That is, in the tank facility according to claim 1, the tank facility for discharging the stored liquefied gas is connected to a liquefied gas supply line, and is disposed below the main tank. Pressurized tank, a connection line connecting the upper part of the pressurized tank and the lower part of the main tank via a check valve that can only flow to the pressurized tank side, A pressure equalizing line connecting the upper part of the main tank via a first opening / closing valve, and a pressure equalizing line connected to the upper part of the pressurizing tank via a second opening / closing valve to supply a pressurized gas into the pressurizing tank. A technique including a pressurized gas line and a liquid discharge line connected to a lower portion of the pressurized tank via a third on-off valve to discharge the liquefied gas in the pressurized tank is employed.

[0006] Since this tank equipment includes a pressurized tank disposed below the main tank, when the liquefied gas is sent from the main tank to the pressurized tank, the first on-off valve is opened to open the main tank. And the pressurized tank are equalized, and the liquefied gas falls from the main tank to the lower pressurized tank,
Inflow. When discharging the liquefied gas in the pressurized tank, the first on-off valve is closed and the second and third valves are closed.
By opening the open / close valve, the inside of the pressurized tank is pressurized with the pressurized gas, and the liquefied gas is discharged from the liquid discharge line.

In the tank facility according to the second aspect, the first aspect is provided.
The tank facility according to claim 1, further comprising a gas discharge line connected to an upper portion of the main tank and discharging a gas in which the liquefied gas is vaporized by a compressor, wherein the pressurized gas line is connected to the gas discharge line. A technique of supplying at least a part of the gas flowing through the pressure tank to the pressurized tank as the pressurized gas is adopted.

In this tank equipment, the pressurized gas line is connected to the gas discharge line and supplies at least a part of the gas flowing through the gas discharge line to the pressurized tank as the pressurized gas. There is no need to provide a source.

In the tank equipment according to the third aspect, the first aspect is provided.
Or the tank equipment according to 2, wherein a first switch for opening and closing the first on-off valve in accordance with a level of the liquefied gas in the main tank, and the second on-off valve and the third on-off valve are provided. A technique including a second switch that opens and closes according to the liquid level of the liquefied gas in the pressurized tank is employed.

In this tank facility, a first switch for opening and closing the first on-off valve according to the level of the liquefied gas in the main tank, and a second on-off valve and a third on-off valve in the pressurized tank are connected. And a second switch that opens and closes in accordance with the level of the liquefied gas in the main tank. When the liquefied gas in the main tank exceeds an upper limit level, the first switch opens the first on-off valve to open the main tank. Liquefied gas is dropped from
When the liquefied gas in the main tank falls below the lower limit level, the first switch closes the first on-off valve to stop the liquefied gas from falling. When the liquefied gas in the pressurized tank exceeds the upper limit level, the second switch opens the second and third on-off valves to discharge the liquefied gas from the pressurized tank, and the liquefied gas in the pressurized tank is opened. Is lower than the lower limit level, the second switch closes the second and third on-off valves to stop discharging the liquefied gas.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the tank equipment according to the present invention will be described below with reference to FIG. In these figures, 10 is a tank facility, 11 is a draining drum,
12 is a pressure drum.

As shown in FIG. 1, a tank facility 10 according to the present embodiment is a facility for discharging stored LNG (liquefied gas) 4 and is connected to a supply line 2 of LNG 4 and is connected to an LNG supply line 2.
A liquid discharging drum (main tank) 11 for storing NG 4, a pressure drum (pressure tank) 12 disposed below the liquid discharging drum 11, an upper part of the pressure drum 12 and a lower part of the liquid discharging drum 11 And a connection line 14 connecting the upper part of the pressure drum 12 and the upper part of the liquid draining drum 11 to each other via a check valve 13 that can only flow to the pressure drum 12 side. ) A pressure equalizing line 16 connected via 15
And a pressurizing valve (second on-off valve) 1 above the pressurizing drum 12.
A pressurized gas line 18 connected to the pressurized drum 12 for supplying pressurized gas into the pressurized drum 12, and a pressurized drum connected to a lower portion of the pressurized drum 12 via a discharge valve (third on-off valve) 19 A liquid discharge line 20 for discharging the LNG 4 from the inside 12 and a BO connected to the upper part of the liquid draining drum 11 and the LNG 4 being vaporized.
A gas discharge line 21 for discharging G (boil-off gas) by the compressor C;

The pressure equalizing line 16 is connected to the liquid draining drum 11 via the supply line 2, and the pressurized gas line 18 is connected via the connecting line 14 downstream from the check valve 13. 12 is connected. In addition, the tank equipment 10 sets the equalizing valve 15 to LNG in the liquid draining drum 11.
4, a first level switch (first switch) 22 that opens and closes according to the liquid level, and a second switch that opens and closes the pressurizing valve 17 and the discharge valve 19 according to the liquid level of the LNG 4 in the pressurizing drum 12.
A level switch (second switch) 23.

The first level switch 22 senses the liquid level of the LNG 4 in the liquid draining drum 11, and when the liquid level exceeds a predetermined upper limit level, opens the pressure equalizing valve 15 and sets the liquid level of the LNG 4 to a predetermined level. It is set so that the pressure equalizing valve 15 is closed when it falls below the lower limit level. The second level switch 23 senses the liquid level of the LNG 4 in the pressurizing drum 12 and, when the liquid level exceeds a predetermined upper limit level, pressurizes the pressurizing valve 17.
When the liquid level of the LNG 4 drops below a predetermined lower limit level, the pressurizing valve 17 and the discharging valve 19 are opened.
Is set to close.

The pressurized gas line 18 is connected to the middle of the gas discharge line 21 (downstream of the compressor C) and supplies a part of the BOG flowing through the gas discharge line 21 to the pressurized drum 12 as a pressurized gas. It is set as follows.
The tank equipment 1 includes a cooling liquid line 6 connected to the liquid draining drum 11 and supplying a cooling LNG for cooling the internal LNG 4. BOG not sent to the pressurized gas line 18 is sent to a gas sending line (not shown) by the gas exhaust line 21.

Next, a method of dispensing LNG 4 in the tank facility 1 of the present embodiment will be described.

First, LNG 4 is supplied to the liquid draining drum 11 from a supply line 2 connected to an LNG tank (not shown). At this time, the LNG 4 is stored via a mist separator (not shown) installed in the liquid draining drum 11. When the LNG 4 in the liquid drain drum 11 exceeds a predetermined upper limit level, the first level switch 22 switches the pressure equalizing valve 15
Is opened, and the liquid draining drum 11 and the pressure drum 12 are equalized by the equalizing line 16. At this time, the LNG 4 in the liquid draining drum 11 drops via the connection line 14 due to the head difference to the lower pressure drum 12 and flows into the pressure drum 12. Then, L in the draining drum 11
When NG4 falls below a predetermined lower limit level, the pressure equalizing valve 15 is closed by the first level switch 22.

Further, when the LNG 4 in the pressurizing drum 12 exceeds a predetermined upper limit level by dropping from the liquid draining drum 11, the pressurizing valve 17 and the discharging valve 19 are opened by the second level switch 23. At this time, pressurized gas line 1
The inside of the pressure drum 12 is pressurized by the pressurized gas (part of BOG) from 8, and the LNG 4 is discharged from the liquid discharge line 20 via the discharge valve 19. Then, when the LNG 4 in the pressure drum 12 falls below a predetermined lower limit level, the pressure valve 17 and the discharge valve 19 are closed by the second level switch 23.

Therefore, the tank equipment 10 of the present embodiment is
Then, when dispensing the LNG 4, since the pressurizing drum 12 is dispensed under pressure, a pump is not required, so that the equipment cost can be lower than the case where the pump is provided, and the maintenance cost can be greatly reduced. it can. Also, since the pressure drum 12 is separately installed, the original liquid draining drum 1
1 does not limit its own operation. Further, since the BOG in the liquid draining drum 11 pressurized by the compressor C is used as the pressurized gas, the cost can be reduced by simpler equipment. Since the first level switch 22 and the second level switch 23 are provided, an automatic payout operation is also possible.

[0020]

According to the present invention, the following effects can be obtained. (1) In the tank equipment according to the first aspect, a pressurizing tank disposed below the main tank, and a pressure equalizing line connecting an upper portion of the pressurizing tank and an upper portion of the main tank via a first on-off valve. And a pressurized gas line connected to the upper part of the pressurized tank via a second on-off valve to supply pressurized gas into the pressurized tank. And the liquefied gas is dropped into the pressurized tank, and the pressurized gas is sent to the pressurized tank to discharge the liquefied gas. That is, since the dispensing can be easily performed only by pressurizing the pressurizing tank without using the pump, the facility cost and the maintenance cost can be significantly reduced.

(2) In the tank facility according to the second aspect, the pressurized gas line is connected to the gas discharge line and supplies at least a part of the gas flowing through the gas discharge line to the pressurized tank as the pressurized gas. In addition, there is no need to provide a separate pressurized gas supply source, the pressurizing line can be configured with a simpler configuration, and the equipment cost can be further reduced.

(3) In the tank equipment according to the third aspect, the first switch for opening and closing the first on-off valve in accordance with the liquid level of the liquefied gas in the main tank, the second on-off valve and the third on-off valve A second switch for opening and closing the on-off valve in accordance with the level of the liquefied gas in the pressurized tank is provided, so that the liquid level in the main tank and the pressurized tank can be sensed and the dispensing operation can be performed automatically. it can. That is, a reliable and efficient payout operation can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a tank facility according to the present invention.

FIG. 2 is a schematic configuration diagram showing a conventional example of a tank facility according to the present invention.

[Explanation of symbols]

 2 supply line 4 LNG (liquefied gas) 10 tank equipment 11 liquid draining drum (main tank) 12 pressurizing drum (pressurizing tank) 13 check valve 14 connection line 15 equalizing valve (first on-off valve) 16 equalizing line Reference Signs List 17 pressure valve (second on-off valve) 18 pressurized gas line 19 discharge valve (third on-off valve) 20 liquid discharge line 21 gas discharge line 22 first level switch (first switch) 23 second level switch ( 2nd switch) C compressor

Claims (3)

[Claims] 1. A tank facility (10) for discharging a stored liquefied gas (4), comprising: a main tank (11) connected to a liquefied gas supply line (2) for storing the liquefied gas; Pressurized tank (12) located below the tank
A connection line (14) for connecting an upper part of the pressurized tank and a lower part of the main tank via a check valve (13) that can only flow to the pressurized tank side; Pressure equalizing line (16) connecting the upper part of the main tank and the main tank via a first on-off valve (15)
A pressurized gas line (18) connected to the upper part of the pressurized tank via a second on-off valve (17) to supply pressurized gas into the pressurized tank; 3. A tank facility comprising: a liquid discharge line (20) connected through the on-off valve (19) for discharging the liquefied gas in the pressurized tank. 2. The tank facility according to claim 1, further comprising a gas discharge line (21) connected to an upper portion of the main tank (11) for discharging gas vaporized from the liquefied gas (4) by a compressor (C). Tank equipment, wherein the pressurized gas line (18) is connected to the gas exhaust line and supplies at least a part of gas flowing through the gas exhaust line to the pressurized tank as the pressurized gas. . 3. The tank equipment according to claim 1, wherein the first on-off valve (15) is opened and closed according to a liquid level of the liquefied gas (4) in the main tank (11). A switch (22), the second on-off valve (17) and the third on-off valve (1
9) a second switch (23) that opens and closes according to the level of the liquefied gas in the pressurized tank (12).