JP2008275002A - Liquefied gas receiving storage facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquefied gas receiving storage facility for holding a portion of a receiving pipe in which liquefied gas is not filled, at a low temperature. <P>SOLUTION: The liquefied gas receiving storage facility 10 comprises a storage tank 3 for storing liquefied gas received from a predetermined liquefied gas supply source, and the receiving pipe 5 for feeding the liquefied gas from the liquefied gas supply source into the storage tank 3. Herein, a filling device 11 is provided for filling the liquefied gas into the receiving pipe portion in which the liquefied gas is not filled, during a period when the liquefied gas is not fed through the receiving pipe 5 from the liquefied gas supply source into the storage tank 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquefied gas receiving and storing facility comprising a storage tank for receiving and storing liquefied gas from a liquefied gas supply source such as an LNG ship tank, and a receiving pipe for sending the liquefied gas from the liquefied gas supply source to the storage tank. About.

  The liquefied gas receiving and storing facility is, for example, an LNG receiving facility that receives and stores LNG from a tank of an LNG ship that has transported LNG (liquefied Natural Gas). The LNG receiving facility is described in FIG. 1 of Patent Document 1 below, for example. FIG. 2 is a diagram illustrating a configuration of the LNG receiving facility.

  The LNG receiving facility includes a loading arm 21, a receiving pipe 5, a storage tank 3, a return gas pipe 23, a return gas blower 25, a vaporizer 7, a gas feed pipe 27, a BOG compressor 29, and a BOG pipe 31.

  The loading arm 21 is for connecting to an LNG ship that has transported LNG. LNG in the LNG ship tank 33 is fed into the loading arm 21 by a cargo pump. The receiving pipe 5 receives the LNG of the LNG ship tank 33 through the loading arm 21. The storage tank 3 stores LNG fed from the LNG ship tank 33 through the receiving pipe 5. The return gas pipe 23 and the return gas blower 25 are for returning BOG (Boil Off Gas) to the LNG ship tank 33 whose pressure has decreased when LNG is received. The vaporizer 7 generates vaporized gas from the liquefied gas supplied from the storage tank 3. The gas supply pipe 27 is for supplying the vaporized gas from the vaporizer 7 as a combustion gas (for example, city gas) to a predetermined demand point.

  If the receiving pipe 5 is left in the period until the LNG acceptance into the storage tank 3 is finished and then the next LNG is accepted, the temperature of the receiving pipe 5 rises to room temperature due to heat input to the receiving pipe 5. End up. In this case, when a predetermined amount of low-temperature LNG flows into the receiving pipe 5 at the time of the next LNG reception, the LNG evaporates and a large amount of BOG is generated. Therefore, the receiving pipe 5 is cooled during a standby period from the end of LNG reception until the next LNG reception.

  There is a circulation cooling method as a receiving pipe cooling method. This method is described in, for example, Patent Document 1 below, page 1, right lower orchid, lines 15 to 18. In the circulation cooling method, during the standby period, the LNG in the storage tank 3 is circulated through the receiving pipe 5 to keep the receiving pipe 5 cooled at all times. FIG. 3 is an explanatory diagram of such a circulating cooling method. As shown in FIG. 3, LNG is circulated using a circulation pump 35.

  However, in order to circulate LNG, a considerably large capacity circulation pump 35 is required, so that the equipment cost increases and the running cost also increases.

  Therefore, there is an LNG filling and holding method as a receiving pipe cooling method that does not use the circulation pump 35. This method is described, for example, in the following page 13 in the lower right orchid line 13 to 15 of Patent Document 1. In this method, the LNG is always filled in the receiving pipe 5 by supplying LNG intermittently from the storage tank 3 into the receiving pipe 5 during the standby period. In order to perform such an LNG filling and holding method, for example, the configuration of FIG. 4 can be assumed. As shown in FIG. 4, a part of the LNG discharged from the storage tank 3 by the pump 3 a is intermittently supplied into the receiving pipe 5 through the pipe 36.

Incidentally, as shown in FIG. 5, the receiving pipe 5 often has a rising portion 5a. For example, when the side surface of the storage tank 3 is a concrete wall, the rising portion 5a is provided to connect the receiving pipe 5 to the upper portion of the storage tank 3 that is not covered with the concrete wall.
Japanese Patent Application Laid-Open No. 1-120500 "Precooling holding method for LNG receiving pipe"

  When such a rising portion 5a exists, in the LNG filling and holding method, it is necessary to take a receiving portion where the LNG is not filled and the LNG does not exist between the rising portion 5a and the storage tank 3 according to the height. . Therefore, the temperature of this part rises, and a large amount of BOG may be generated in this part at the time of receiving the next LNG. Therefore, it is desirable to be able to cool and hold the receiving pipe portion that is not filled with LNG.

Further, in the above LNG filling and holding method, if the rising portion 5a is held in a state where LNG is filled, a problem of Geisering occurs. Geisering is an abrupt phase transition oscillation phenomenon between the liquid phase and the gas phase that occurs when the liquefied gas is overheated by heat input. If Geisering occurs at the rising part 5a, if the liquid level of the rising part 5a is high, the bubbles will be lifted up and the bubbles will fall out, and then the liquid will drop, causing abnormal noise and vibration, which will damage the equipment. There is a possibility that. Therefore, there is a possibility that Geisering may occur due to the temperature rise of the rising portion 5a while LNG is not supplied to the storage tank 3 in the LNG filling and holding method.
In order to reliably prevent Geisering at the rising portion 5a, the liquid level of the rising portion 5a is lowered. For example, as shown in FIG. 5, at the end of the LNG reception or at the end of the supply of the cooling holding LNG to the reception pipe 5, the on-off valve 37 is opened to send the liquefied gas to the liquid draining drum 39, whereby the rising portion 5a Lower the liquid level. The liquefied gas sent to the liquid draining drum 39 is sent to the storage tank 3 by the liquid draining drum pump 41.
In this case, the portion where LNG is not filled in the receiving pipe is further increased. Therefore, it is further desirable to be able to cool and hold the receiving pipe portion that is not filled with LNG.

  Then, this invention is providing the liquefied gas reception storage equipment which can hold | maintain the receiving pipe part which is not satisfy | filled with liquefied gas at low temperature.

  To achieve the above object, according to the present invention, a storage tank that receives and stores liquefied gas from a predetermined liquefied gas supply source, and a receiving pipe for sending liquefied gas from the liquefied gas supply source to the storage tank; An injection device for injecting liquefied gas into a receiving pipe portion not filled with liquefied gas during a period when liquefied gas is not sent from the liquefied gas supply source to the storage tank through the receiving pipe. A liquefied gas receiving and storing facility is provided.

  In the above configuration, the injection device injects the liquefied gas into the receiving pipe portion that is not filled with the liquefied gas during the period in which the liquefied gas is not sent to the storage tank. Can be cooled. Therefore, for example, by intermittently injecting the liquefied gas, the receiving pipe portion can be kept at a low temperature.

According to a preferred embodiment of the present invention, the receiving pipe has a rising portion that extends upward from below while being extended to the storage tank side,
The position where the injection device injects the liquefied gas into the receiving pipe is the receiving pipe position between the top of the rising portion and the storage tank.

  The temperature rise is remarkable in the receiving pipe part between the top of the rising part and the storage tank. Since the injection device injects the liquefied gas into the receiving pipe position between the top of the rising portion and the storage tank, it is possible to cool the receiving pipe portion where the temperature rises remarkably.

  According to a preferred embodiment of the present invention, when the temperature value detected by the temperature sensor provided in the receiving pipe portion to be cooled by the liquefied gas from the injection device becomes the injection start temperature value, the injection device is liquefied. And a control device for controlling the injection device so as to start the gas injection.

  In the above configuration, the control device controls the injection device so that the injection device injects the liquefied gas into the receiving pipe when the temperature detection value reaches the injection start temperature. It can be kept below the starting temperature.

  According to a preferred embodiment of the present invention, the control device controls the injection device so that the injection device stops the injection of the liquefied gas when the temperature value detected by the temperature sensor reaches the injection stop temperature value. The injection stop temperature is lower than the injection start temperature.

  In the above configuration, the control device controls the injection device so that the injection device stops the injection of the liquefied gas when the detected temperature reaches the injection stop temperature, and the injection stop temperature is lower than the injection start temperature. The injection apparatus does not always need to perform liquefied gas injection. Accordingly, the amount of liquefied gas used for cooling can be suppressed and the cooling can be efficiently performed, and the temperature of the receiving pipe can be maintained in a low temperature range from the injection stop temperature to the injection start temperature.

  According to a preferred embodiment of the present invention, a temperature sensor provided in a receiving pipe portion to be cooled by liquefied gas from an injection device, and when the temperature value detected by the temperature sensor reaches an injection stop temperature, And a control device that controls the injection device so that the injection device stops the injection of the liquefied gas.

  In the above configuration, when the liquefied gas injection is automatically started at the timing when the injection device is set, or when the liquefied gas injection of the injection device is started by the operation of the operator, the receiving pipe is set to the desired injection stop temperature. The temperature can be adjusted.

  According to a preferred embodiment of the present invention, the apparatus includes a vaporizer that vaporizes the liquefied gas supplied from the storage tank, and the injection device sends a part of the liquefied gas sent from the storage tank to the vaporizer to the receiving pipe. inject.

  In the said structure, the receiving pipe part with which liquefied gas is not satisfy | filled can be cooled using a part of liquefied gas withdrawn to the vaporizer.

  According to the present invention described above, it is possible to keep a portion of the receiving pipe not filled with the liquefied gas at a low temperature.

  The best mode for carrying out the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a configuration diagram of a liquefied gas receiving and storing facility according to an embodiment of the present invention. As shown in FIG. 1, the liquefied gas receiving and storing facility 10 includes a storage tank 3, a receiving pipe 5, a vaporizing device 7, a BOG pipe 31, a dispensing pipe 9, and an injecting device 11. The storage tank 3, the vaporizer 7, and the BOG pipe 31 are the same as the storage tank 3, the vaporizer 7, and the BOG pipe 31 described with reference to FIG. The discharge pipe 9 is a pipe that supplies the LNG delivered from the storage tank 3 by the pump 3 a to the vaporizer 7, and extends from the storage tank 3 to the vaporizer 7. The receiving pipe 5 is the same as the receiving pipe 5 described with reference to FIG. 2, and has a rising portion 5 a that extends in the vertical direction from the lower side to the upper side while extending to the storage tank 3 side. In addition, the code | symbol 8 has shown the on-off valve, and is open at the time of LNG reception.

  The injecting device 11 is configured so that the LNG in the receiving pipe 5 is not filled with LNG during a period in which the liquefied gas is not sent from the liquefied gas supply source (in this example, the LNG ship tank) to the storage tank 3 through the receiving pipe 5. Inject. In this embodiment, the injection device 11 injects a part of LNG sent from the storage tank 3 to the vaporizer 7 into the receiving pipe 5. In the example of FIG. 1, the injection device 11 includes a liquefied gas supply pipe 11a, an on-off valve 11b, and a pump 3a. The liquefied gas supply pipe 11 a extends from the storage tank 3 and is connected to the LNG injection position x into the receiving pipe 5. In the example of FIG. 1, the liquefied gas supply pipe 11 a includes a part of the discharge pipe 9 extending to a midpoint from the storage tank 3 toward the vaporizer 7, and an injection pipe extending from this midpoint of the discharge pipe 9 to the LNG injection position x. 11a-1. The on-off valve 11b is provided in the injection pipe 11a-1. The pump 3 a is mainly for sending LNG from the storage tank 3 to the vaporizer 7, but has a sufficient ability to send LNG to the liquefied gas supply pipe 11 a and is provided in the storage tank 3. .

  Further, according to the present embodiment, the LNG injection position x by the injection device 11 is a receiving pipe position between the top of the rising portion 5 a and the storage tank 3. In the example of FIG. 1, the LNG injection position x is an intermediate position between the top of the rising portion 5a, the storage tank 3, and the like. Preferably, the LNG injected into the receiving tube 5 in a spray form flows toward the rising portion 5a. For this purpose, for example, the receiving pipe portion from the top of the rising portion 5a to the LNG injection position x may be inclined so that the height of the top of the rising portion 5a is lower than the height of the LNG injection position x. When the injection device 11 injects LNG into the receiving pipe 5 in a spray form, an appropriate mechanism / device for injecting LNG in a spray form such as a spray nozzle or a sprayer may be provided at the injection location.

The liquefied gas receiving and storing facility 10 further includes a temperature sensor 13 and a control device 15.
The temperature sensor 13 is provided in a receiving pipe portion to be cooled by LNG from the injection device 11. The temperature sensor 13 is attached to the outer surface of the receiving pipe 5 and detects the temperature of the receiving pipe 5. In the example of FIG. 1, the temperature sensor 13 is provided near the top of the rising portion 5a.
The control device 15 receives the temperature value detected by the temperature sensor 13, and controls the injection device 11 so that the injection device 11 starts injection of LNG when the temperature value reaches the injection start temperature value. In the example of FIG. 1, the injection device 11 performs control to open the on-off valve 11b. The pump 3a is always operating. The injection start temperature is a temperature higher than the boiling point of LNG -162 ° C, and may be set to -100 ° C, for example. Further, the control device 15 controls the injection device 11 so that the injection device 11 stops the injection of LNG when the temperature value detected by the temperature sensor 13 becomes the injection stop temperature value. In the example of FIG. 1, the injection device 11 performs control to close the on-off valve 11b. The injection stop temperature is lower than the injection start temperature, and may be set to −150 ° C., for example. Note that the on-off valve 8 is open during the LNG injection.

When the length of the receiving pipe part to be cooled by the injection device 11 is 50 m, and the temperature of the receiving pipe part is lowered by 50 ° C., the required amount of LNG is estimated.
When the receiving pipe 5 is composed of piping metal and urethane which is a heat insulating material covering the piping metal, the specific heat amount of the piping metal is 19 (kJ / kg), and the specific heat of urethane is 1.673 (kJ / kg ° C.). Suppose that It is assumed that the weight of the pipe metal per receiving pipe unit length is 139.1 (kg / m) and the weight of the urethane per receiving pipe unit length is 18.37 (kg / m).
In this case, the amount of cooling heat required to cool the pipe metal is
139.1 (kg / m) × 50 (m) × 19 (kJ / kg) = 132145 (kJ),
The amount of cooling heat required to cool urethane is
18.37 (kg / m) × 50 (m) × 1.674 (kJ / kg ° C.) × 50 (° C.) = 76879 (kJ).
Therefore, the amount of cooling heat required to cool the 50 m receiving pipe portion is
132145 (kJ) +76879 (kJ) = 209024 (kJ).
When the 50 m receiving pipe portion is cooled at 50 ° C. at a rate of 20 (° C./h), the amount of LNG required per unit time is 531 (kJ / kg) when the heat of vaporization of LNG is 531
{209024 (kJ) / 531 (kJ / kg)} × {20 (° C./h)/50 (° C.)} = 157.5 kg / h.

  According to the liquefied gas receiving and storing facility 10 according to the above-described embodiment, the injection device 11 injects LNG into the receiving pipe portion that is not filled with LNG during the period in which LNG is not sent to the storage tank 3. The receiving pipe portion can be cooled by LNG. Therefore, it is possible to keep the receiving pipe portion that is not filled with LNG at a low temperature.

Further, according to the liquefied gas receiving and storing facility 10 according to the above-described embodiment, the following effects can also be obtained.
(1) The temperature rises remarkably in the receiving pipe portion between the top of the rising portion 5a and the storage tank 3, and the injection device 11 injects LNG into the receiving pipe position, so that this receiving pipe portion can be cooled. it can.
(2) Furthermore, the control device 15 controls the injection device 11 so that the injection device 11 injects LNG into the reception pipe 5 when the temperature detection value of the temperature sensor 13 reaches the injection start temperature. The portion to be cooled of the tube 5 can be kept below the desired injection start temperature.
(3) Further, the control device 15 controls the injection device 11 so that the injection device 11 stops the injection of LNG when the temperature detection value reaches the injection stop temperature, and the injection stop temperature is higher than the injection start temperature. Since it is low, the injection device 11 does not always have to perform LNG injection. As a result, the amount of LNG used for cooling can be suppressed and the cooling can be efficiently performed, and the temperature of the receiving pipe 5 is set to a low temperature range (for example, a range of −100 ° C. to −150 ° C.) from the injection stop temperature to the injection start temperature. Can hold.
(4) By using a part of LNG discharged from the storage tank 3 to the vaporizer 7, the receiving pipe portion that is not filled with LNG can be cooled.

  The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.

  For example, in the above-described embodiment, the LNG injection is started when the temperature value detected by the temperature sensor 13 reaches the injection start temperature, but the present invention is not limited to this. That is, the injection device 11 automatically starts the LNG injection at a set timing (may be a plurality of timings with a time interval), or the LNG injection of the injection device 11 is started by the operation of the operator. You may make it do. In such a case, the injection stop of the injection device 11 is performed by the control device 15 controlling the injection device 11 when the temperature value from the temperature sensor 13 reaches the injection stop temperature as in the above-described embodiment. May be stopped.

  In the above embodiment, the LNG injection point x is between the top of the rising portion 5a and the storage tank 3, but the injection device 11 can inject LNG into other receiving pipe portions where the temperature rise is significant. Good. For example, when the temperature rise of the rising part 5a becomes significant, the injection device 11 may inject LNG into the rising part 5a. Moreover, the injection device 11 may inject LNG into the receiving pipe 5 at a plurality of locations instead of at one location.

  In the embodiment described above, the injection device 11 uses LNG flowing through the payout pipe 9, but LNG supplied from another location may be injected into the receiving pipe 5. For example, the injection pipe 11a-1 may be connected to other piping through which LNG flows, and the control device 15 may open the on-off valve 11b to perform LNG injection using LNG flowing through the other piping.

  The liquefied gas receiving and storing facility of the present invention may be used in combination with the above LNG filling and holding method. Further, the liquefied gas receiving and storing facility of the present invention may be used in combination with a circulating cooling method. For example, if the receiving pipe 5 has the rising part 5a and the circulating cooling method also does not fill the receiving pipe part between the top of the rising part 5a and the storage tank 3 with LNG during the waiting period, You may use together.

  In the embodiment described above, the liquefied gas receiving and storing facility 10 receives and stores LNG. However, the liquefied gas receiving and storing facility 10 may receive and store other liquefied gases such as LPG.

It is a block diagram of the liquefied gas reception storage equipment by embodiment of this invention. It is a general block diagram of LNG receiving equipment. It is a figure for demonstrating the circulation cooling method. It is a figure for demonstrating the LNG filling and holding method. It is a figure in case a rising part exists in a receiving pipe.

Explanation of symbols

3 storage tank, 3a pump, 5 receiving pipe 5a rising part, 7 vaporizer, 9 discharge pipe 10 liquefied gas receiving storage equipment, 11 injecting apparatus 11a liquefied gas supply pipe, 11b on-off valve 11a-1 injecting pipe, 13 temperature sensor, 15 Control device

Claims (6)

A liquefied gas receiving and storing facility comprising a storage tank for receiving and storing liquefied gas from a predetermined liquefied gas supply source, and a receiving pipe for sending liquefied gas from the liquefied gas supply source to the storage tank,
A liquefied gas receiving characterized by comprising an injection device for injecting the liquefied gas into a receiving pipe portion not filled with the liquefied gas during a period when the liquefied gas is not sent from the liquefied gas supply source to the storage tank through the receiving pipe. Storage facilities. The receiving pipe has a rising portion extending upward from below in the middle of extending to the storage tank side,
2. The liquefied gas receiving and storing equipment according to claim 1, wherein a position where the injecting device injects the liquefied gas into the receiving pipe is a receiving pipe position between the top of the rising portion and the storage tank.   Injection is performed so that the injection device starts injecting the liquefied gas when the temperature value detected by the temperature sensor provided in the receiving pipe portion to be cooled by the liquefied gas from the injection device reaches the injection start temperature value. The liquefied gas receiving and storing facility according to claim 1, further comprising: a control device that controls the device. The control device controls the injection device so that the injection device stops the injection of the liquefied gas when the temperature value detected by the temperature sensor becomes the injection stop temperature value,
The liquefied gas receiving and storing equipment according to claim 3, wherein the injection stop temperature is lower than the injection start temperature. A temperature sensor provided in the receiving pipe portion to be cooled by the liquefied gas from the injection device;
2. A control device that controls the injection device so that the injection device stops the injection of the liquefied gas when the temperature value detected by the temperature sensor reaches the injection stop temperature. The liquefied gas receiving storage facility described in 1. Comprising a vaporizer for vaporizing liquefied gas supplied from the storage tank;
The liquefied gas receiving and storing equipment according to claim 1, wherein the injection device injects a part of the liquefied gas sent from the storage tank to the vaporizer into the receiving pipe.

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