JP5073328B2 - Sprinkling device for open rack type vaporizer and operation method thereof - Google Patents

Description

  The present invention relates to a watering device for an open rack type vaporizer used for vaporizing liquefied natural gas (hereinafter referred to as “LNG”) and other low-temperature liquefied gas, and an operation method thereof.

  An open rack type vaporizer is a type of heat exchanger that heats a heat transfer panel from the outside of a heat exchange panel in which a large number of heat transfer tubes are arranged in a panel, and vaporizes the low-temperature liquefied gas that passes through the heat transfer tubes. Conventionally, it is frequently used for vaporizing a low-temperature liquefied gas, particularly LNG. Seawater or circulating water is used as the heat medium, and the low-temperature liquefied gas in the heat transfer tube is vaporized by flowing this heat medium over the outer surface of the panel constituted by a large number of heat transfer tubes.

  FIG. 1 is a diagram schematically illustrating a heat exchange panel constituting a main part of an open rack type vaporizer used for vaporization of LNG and a trough containing a heat medium flowing down along both sides of the panel. (a) is a front view, (b) is an AA arrow view (partial view) of (a).

  As shown in FIG. 1, the heat exchange panel 1 is configured so that a large number of finned heat transfer tubes 2 for increasing heat exchange efficiency are arranged in the tube diameter direction, and the upper and lower portions of the heat exchange panel 1 are respectively upper portions. It is connected to a header 3 and a lower header (not shown). A large number of such panels 1 are arranged in parallel according to the capacity to constitute one open rack type vaporizer.

  The upper header 3 and the lower header of each panel 1 arranged in parallel are connected to an upper manifold and a lower manifold (not shown), respectively. Furthermore, troughs 4 for holding a heat medium (for example, circulating water) that flows down along both sides of the panel 1 are attached to both sides of each panel 1 (see FIG. 1B).

  While the LNG supplied to the lower header through the lower manifold rises in the heat transfer tube 2, as shown in FIG. 1 (b), heat exchange with water flowing down by forming a liquid film on the outer surface of the panel 1 And is led as natural gas (hereinafter referred to as “NG”) from the upper header 3 to the upper manifold. Water that has flowed down and lowered in temperature is discharged to the outside.

  In this open rack type vaporizer, for example, when the supply of water to the trough is stopped urgently due to a power failure, the water as the heat medium flowing down the outer surface of the panel is also stopped. At this time, normally, the line for supplying LNG into the panel (more precisely, in the heat transfer tube constituting the panel) is also urgently stopped. However, since extremely low temperature LNG remains in the panel, a large thermal stress is generated and the panel is deformed. When the panel is deformed due to the thermal stress in this way, the vaporizer must be stopped until the repair is completed.

  The present invention has been made in view of such a situation, and when a water supply line to the trough is brought to an emergency stop due to a power failure or other accident, it prevents or damages such as panel deformation caused by the emergency stop. An object of the present invention is to provide a water spray device that can be used in an open rack type vaporizer in the event of an emergency and a method for operating the device that can minimize the operation and enable early resumption of operation after line restoration. It is said.

  In order to achieve the above object, the present inventors have studied a method for effectively utilizing water contained in the trough. As described above, the water that flows down to the outer surface of the panel is supplied by overflowing the trough, so even if the water supply line to the trough stops urgently, the trough is full. If this large amount of water is used, it is possible to vaporize the cryogenic LNG remaining in the panel.

  For example, if a large number of small water spray holes directed toward the panel are provided in the side wall near the bottom of the trough that is used during normal operation, the supply of water to the trough stops and overflow water from the trough Even if it stops, it is possible to continue water supply and flow from the sprinkling holes near the bottom surface to the panel surface.

  In addition, a sprinkling pipe with a large number of sprinkling holes is arranged below the trough in the direction of the panel, and when the water supply line to the trough stops urgently, the water in the trough is sprinkled. LNG remaining in the panel can be sufficiently vaporized by being transferred to and discharged from the sprinkling holes. The object can also be achieved by using another trough in the lower stage of the trough instead of the sprinkling pipe and overflowing water from the lower trough.

  In this case, if the transfer pipe is provided with a valve that opens when the supply of the heat medium to the trough is stopped, the transfer of water in the trough to the water sprinkling pipe or lower trough is automatically performed. Can be done automatically.

  The present invention has been made on the basis of such ideas and examination results. The gist of the present invention lies in the watering device of the open rack type vaporizer (1) below and the method of operating the watering device (2).

(1) A low-temperature liquefied gas that passes through the heat transfer tube by flowing a heat medium along both sides of the panel from troughs arranged on both sides of the upper part of the heat exchange panel in which a plurality of heat transfer tubes are arranged in a panel shape In the watering device used in the open rack type vaporizer that vaporizes the heat medium, when the supply of the heat medium into the trough is stopped, the heat medium in the trough or the heat medium supply pipe flows down along both sides of the panel, And a means for vaporizing the low-temperature liquefied gas remaining in the trough, wherein the means for flowing down the heat medium in the trough has a connection pipe for transferring the heat medium from the trough. apparatus. However, this embodiment is an invention as a reference example of the present invention.

  As the “heat medium” applied to the watering device of the open rack type vaporizer of the present invention, seawater and water (industrial water) are mainly used.

In the watering device of the present invention, when the supply of the heat medium into the trough is stopped, the heat medium in the trough or the heat medium supply pipe flows down along both sides of the panel to vaporize the low-temperature liquefied gas remaining in the heat transfer pipe. A means for lowering the trough, and a sprinkling pipe for flowing down the heat medium transferred from the trough along both sides of the panel, and a connection for transferring the heat medium in the trough into the sprinkling pipe It is also possible to employ a watering device having a pipe (this is referred to as “Embodiment 1 ”).

In the watering device of the present invention, when the supply of the heat medium into the trough is stopped, the heat medium in the trough or the heat medium supply pipe flows down along both sides of the panel, and the low-temperature liquefied gas remaining in the heat transfer pipe The vaporizing means is disposed below the sprinkling pipe for introducing the heat medium into the trough, and the sprinkling pipe for flowing the heat medium along both sides of the panel and the heat medium in the trough or the sprinkling pipe are arranged. It is also possible to employ a watering device having a connection pipe for transferring into the watering pipe (this is referred to as “Embodiment 2 ”).

Further, in the watering device of the present invention, when the supply of the heat medium into the trough is stopped, the heat medium in the trough or the heat medium supply pipe flows down along both sides of the panel, and the low-temperature liquefied gas remaining in the heat transfer pipe Is disposed below the trough, overflows the heat medium transferred from the trough, and flows down along both sides of the panel, and the heat medium in the trough in the lower trough It is also possible to employ a watering device having a connection pipe for transporting to the water (this is referred to as “Embodiment 3 ”).

Each of the watering devices of the first to third embodiments is a device that causes the heat medium to flow down along both sides of the panel when the supply of the heat medium into the trough is stopped. A heat medium is supplied to the lower trough. For the purpose of shutting off the supply of the heat medium to the water sprinkling pipe or the lower trough during normal operation, all of the “connection piping for transporting” common to the water sprinkling apparatus of the first to third embodiments is transported. A shut-off valve for shutting off may be attached.

In the watering device of the first to third embodiments, if the closing valve is a valve that is “open” when the supply of the heat medium into the trough is stopped, the valve is immediately operated when the supply of the heat medium is stopped. This is desirable because

  (2) The operation method of the watering device of the open rack type vaporizer according to (1), wherein when the supply of the heat medium into the trough is stopped, the heat medium in the trough flows down along both sides of the panel. The operation method of the watering device of the open rack type vaporizer characterized by vaporizing the low-temperature liquefied gas which remains in the heat exchanger tube.

  If the water spraying device of the open rack type vaporizer of the present invention is used, the heat medium in the trough is effectively used when the supply line of water (heat medium) to the trough stops due to a power failure or other accident. Thus, it is possible to vaporize a low-temperature liquefied gas such as a very low temperature LNG remaining in the panel, and it is possible to reduce or prevent the deformation of the panel by reducing the thermal stress generated in the panel. In addition, it is not necessary to stop the vaporizer to repair the deformation of the panel and the like, and the operation can be restarted quickly after the recovery.

  Below, the watering apparatus of the open rack type vaporization apparatus of this invention and the operating method of the watering apparatus are demonstrated concretely with reference to drawings.

The water spray device of the open rack type vaporizer of the present invention is an open rack type vaporizer configured as described above, and when the supply of the heat medium into the trough is stopped, the heat medium in the trough or the heat medium supply pipe Means for causing the heat medium to flow down on both sides of the panel using the gas to vaporize the low-temperature liquefied gas remaining in the heat transfer tube , and means for causing the heat medium in the trough to flow down from the trough. a sprinkler system that have a connection pipe for transferring.

  The above-mentioned “when the supply of the heat medium into the trough is stopped” refers to a case where the supply of water (heat medium) to the trough is urgently stopped due to a power failure or other accident. In this case, since the heat medium flowing down the outer surface of the panel is also stopped, normally, a line for supplying a low-temperature liquefied gas such as LNG into the panel is also urgently stopped.

  A feature of the watering device of the present invention is that in such an emergency, the heat generated in the panel is generated by vaporizing a low-temperature liquefied gas such as LNG having a very low temperature remaining in the panel using a heat medium in the trough and the watering pipe. The point is to reduce the stress.

The heat medium in the trough is caused to flow down along both sides of the panel by some means. However, as long as a connection pipe for transferring the heat medium from the trough is provided, the means is not limited. In the embodiment of the present invention to be described later, a specific method of using the heat medium in the trough is illustrated, but other than those watering devices, the heat medium flows down along both sides of the panel and remains in the heat transfer tube. Any device capable of vaporizing liquefied gas can be employed as the watering device of the open rack type vaporizer of the present invention.

The watering device according to the first embodiment includes a watering pipe that is disposed below the trough as means for flowing down the heat medium in the trough, and for flowing down the heat medium transferred from the trough along both sides of the panel. A watering device having a connection pipe for transferring a heat medium in the trough into the watering pipe.

FIG. 2 is a diagram illustrating a schematic configuration of the watering device of the first embodiment. As shown in the figure, this apparatus has a watering pipe 8 disposed below the trough and a connection pipe 9 for transferring the heat medium in the trough 4 into the watering pipe 8. The sprinkling pipe 8 is provided with a large number of small holes 10 directed toward the panel surface. At this time, as shown in FIG. 2 , the connection pipe 9 is not attached with a shut-off valve, but can be attached.

  The water sprinkling pipe generally has a circular cross section, but the purpose of allowing the heat medium to flow down along both sides of the panel and evaporating the low-temperature liquefied gas remaining in the heat transfer tube is achieved. If it is, it will not be limited to this. The number, size, angle, and the like of the small holes provided in the watering pipe may be determined in advance so as to achieve this purpose according to the size of the trough or the panel.

  In addition, the connection pipe also has a function of transferring the heat medium in the trough into the pipe at an appropriate flow rate corresponding to the size of the watering pipe when the stop valve is in the “open” state. What is necessary is just a thing and the shape does not ask | require.

The operation of the watering apparatus of the first embodiment is started after the supply of the heat medium into the trough 4 is stopped. That is, when a stop valve is attached to the connection pipe 9 after the supply of the heat medium is stopped, the close valve attached to the connection pipe 9 is immediately opened. Since the water sprinkling pipe 8 is arranged below the trough 4, the heat medium in the trough 4 is transferred into the water sprinkling pipe 8 via the connection pipe 9, and is passed through the numerous small holes 10 of the water sprinkling pipe 8 to the panel. It flows down along both sides. Thereby, the cryogenic LNG remaining in the panel can be vaporized, and the thermal stress generated in the panel can be reduced.

  If the shutoff valve attached to the pipe is automatically opened when the supply of heat medium to the trough is stopped, immediately turn off the valve when the supply of heat medium to the trough is stopped. Operate and respond quickly.

The watering device of the second embodiment is arranged below the watering pipe for introducing the heat medium into the trough as means for flowing down the heat medium in the trough, and the heat medium flows down along both sides of the panel. It is a watering apparatus which has a watering pipe for carrying out, and connection piping for transferring the trough or the heat medium in a watering pipe into a watering pipe.

FIG. 3 is a diagram illustrating a schematic configuration of the watering device of the second embodiment. As shown in the figure, this apparatus has a watering pipe 8 and a connection pipe 12 for transferring the heat medium in the trough 4 into the watering pipe 8 via the watering pipe 5. As described above, the stop valve 11 can be attached to the connection pipe 12. In addition, the watering pipe 8 is the same as the watering pipe 8 attached to the watering apparatus of Embodiment 1 , and is provided with many small holes directed to the panel surface.

About the shape of the watering pipe in the watering device of this Embodiment 2 , the number of the small holes provided in it, a dimension, an angle, the shape of a piping, the flow, etc., it is the same as that of the case of the watering device of the said Embodiment 1. .

When operating the watering device of the second embodiment, the stop valve 11 is immediately opened after the supply of the heat medium is stopped. Since the sprinkling pipe 8 is disposed below the sprinkling pipe 5, the heat medium in the trough 4 is transferred into the sprinkling pipe 8 via the sprinkling pipe 5 and the connection pipe 12 due to the head difference, and the sprinkling pipe 8. Flow down along both sides of the panel through a number of small holes. Thereby, the cryogenic LNG remaining in the panel can be vaporized.

  Also in this case, if the shutoff valve attached to the pipe is a valve that is automatically “opened” when the supply of the heat medium into the trough is stopped, it can be operated immediately.

Sprinkler system according to the third embodiment of the above, as means for flowing down the heat medium in Trough, arranged below the trough, the heat medium is transferred from the trough to overflow, to flow down along the side of the panel It is a watering apparatus which has the lower stage trough for this, and the connection piping for transferring the heat medium in a trough into the said lower stage trough.

Figure 4 is a diagram exemplifying a schematic configuration of a sprinkler system in the third embodiment, a (a) is a front view, (b) is taken along line B-B view of (a) (partial view). As shown in the figure, this apparatus has a lower trough 13 and a connection pipe 14 for transferring the heat medium in the trough 4 to the lower trough 13.

  The shape, particularly the depth, of the lower trough is not limited, but is desirably as shallow as possible as long as the function of overflowing the heat medium and flowing down along both sides of the panel is not impaired. This is because the heat medium in the trough can be utilized to the maximum extent. The connecting pipe may be any pipe that can transfer the heat medium into the trough at an appropriate flow rate corresponding to the size of the lower trough.

When operating the watering device of the third embodiment, if a closing valve is attached to the connection pipe 14, immediately after the supply of the heat medium is stopped, the closing valve of the connection pipe 14 is opened. Since the lower trough 13 is disposed below the trough 4, the heat medium in the trough 4 is transferred into the lower trough 13 through the connecting pipe 14, overflows from the lower trough 13, and runs along both sides of the panel. Flow down. Thereby, the cryogenic LNG remaining in the panel can be vaporized.

  The operation method of the watering device used in the open rack type vaporizer of the present invention is the operation method of the watering device of the present invention described above, and when the supply of the heat medium into the trough is stopped, the operation in the trough (and the watering pipe) is performed. This is a method of operating a watering device of an open rack type vaporizer that causes a heat medium to flow down along both sides of a panel and vaporizes a low-temperature liquefied gas remaining in a heat transfer tube.

  That is, the operation method of the present invention is an emergency operation method in which the supply of the heat medium into the trough is stopped, and uses a large amount of heat medium held in the trough, and this is applied to both sides of the panel. It is characterized by flowing down along. There is no limitation on the method of flowing down.

  According to the water spray device of the open rack type vaporizer of the present invention and its operation method, when the supply line of the heat medium to the trough is stopped urgently, it remains in the panel using the heat medium in the trough. It is possible to vaporize a low-temperature liquefied gas such as a very low temperature LNG and to prevent or minimize the deformation of the panel caused by the thermal stress. As a result, it is possible to avoid stopping the vaporizer for repairing deformation or the like of the panel.

  Therefore, the water spray device of the open rack type vaporizer of the present invention, the operation method thereof, particularly in the open rack type vaporizer used for vaporization of LNG, when the supply of water to the trough is stopped urgently, It can be suitably used.

It is a figure which illustrates typically the trough containing the heat carrier which flows down along both sides of a heat exchange panel and the panel which constitute the principal part of the open rack type vaporizer used for vaporization of LNG, (a) A front view and (b) are the AA arrow directional views (partial drawing) of (a). It is a figure which illustrates schematic structure of the watering apparatus of Embodiment 1 of this invention. It is a figure which illustrates schematic structure of the watering apparatus of Embodiment 2 of this invention. It is a figure which illustrates schematic structure of the watering apparatus of Embodiment 3 of this invention.

1: Heat exchange panel 2: Heat transfer pipe 3: Upper header 4: Trough 5: Sprinkling pipe 8: Sprinkling pipe 9: Connection pipe 10: Small hole 11: Shut-off valve 12: Connection pipe 13: Lower trough 14: Connection pipe

Claims (5)

  A low-temperature liquefied gas passing through the heat transfer tube is vaporized by causing a heat medium to flow along both sides of the panel from troughs disposed on both upper sides of the heat exchange panel in which a plurality of heat transfer tubes are arranged in a panel shape. In the watering device used in the open rack type vaporizer, when the supply of the heat medium into the trough is stopped, the heat medium in the trough or the heat medium supply pipe flows down along both sides of the panel and remains in the heat transfer pipe. A water spray pipe comprising means for vaporizing a low-temperature liquefied gas, and means for flowing down the heat medium in the trough are arranged below the trough, and the heat medium transferred from the trough flows down along both sides of the panel And a sprinkling device for an open rack type vaporizer characterized by having a connecting pipe for transferring the heat medium in the trough into the sprinkling pipe.   A low-temperature liquefied gas passing through the heat transfer tube is vaporized by causing a heat medium to flow along both sides of the panel from troughs disposed on both upper sides of the heat exchange panel in which a plurality of heat transfer tubes are arranged in a panel shape. In the watering device used in the open rack type vaporizer, when the supply of the heat medium into the trough is stopped, the heat medium in the trough or the heat medium supply pipe flows down along both sides of the panel and remains in the heat transfer pipe. Means for vaporizing the low-temperature liquefied gas, and means for flowing down the heat medium in the trough is disposed below the sprinkler pipe for introducing the heat medium into the trough, and the heat medium is disposed along both sides of the panel. A watering device for an open rack type vaporizer, comprising a watering pipe for flowing down and a connecting pipe for transferring a trough or a heat medium in the watering tube into the watering pipe.   A low-temperature liquefied gas passing through the heat transfer tube is vaporized by causing a heat medium to flow along both sides of the panel from troughs disposed on both upper sides of the heat exchange panel in which a plurality of heat transfer tubes are arranged in a panel shape. In the watering device used in the open rack type vaporizer, when the supply of the heat medium into the trough is stopped, the heat medium in the trough or the heat medium supply pipe flows down along both sides of the panel and remains in the heat transfer pipe. A means for vaporizing the low-temperature liquefied gas is provided, and the means for flowing down the heat medium in the trough is arranged below the trough to overflow the heat medium transferred from the trough and flow down along both sides of the panel A sprinkler for an open rack type vaporizer, comprising: a lower trough for the above and a connection pipe for transferring a heat medium in the trough into the lower trough. The water sprinkling device for an open rack type vaporizer according to any one of claims 1 to 3 , wherein a valve that is "open" when the supply of the heat medium into the trough is stopped is attached to the connection pipe. . The operation method of the watering device according to any one of claims 1 to 4 , wherein when the supply of the heat medium into the trough is stopped, the heat medium in the trough is caused to flow down along both sides of the panel, and into the heat transfer tube. An operation method of a watering device of an open rack type vaporizer characterized by vaporizing remaining low-temperature liquefied gas.

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