JP2018091423A - Carburetor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carburetor capable of detecting gas leakage from an introduction chamber to a heat exchanger chamber.SOLUTION: A carburetor 1 includes: a plurality of heat transfer pipes 10; a casing 20 capable of flowing a heat source medium so that the heat source medium contacts with an outer peripheral surface of each heat transfer pipe 10; a heat exchange chamber side pipe plate 42 configured to form a heat exchange chamber S1 where heat exchange is performed between the heat source medium and low-temperature liquefied gas; a pipe chamber side pipe plate 44 configured to section a space opposite to a heat exchange chamber S1 with a heat exchange chamber side pipe plate 42 as reference, of a casing 20 into a pipe chamber having an introduction chamber S2 into which the low-temperature liquefied gas is introduced, and a detection chamber S4 capable of storing gas between the pipe chamber and the heat exchange chamber S1; and a detection unit 50 configured to detect gas leakage from the introduction chamber S2 to the detection chamber S4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vaporizer.

  Conventionally, a vaporizer that vaporizes a low-temperature liquefied gas such as liquefied natural gas (LNG) using a heat source medium (seawater or the like) is known. For example, Patent Document 1 discloses heat exchange including a plurality of cooling pipes, a casing (a trunk plate and a side cover) that accommodates the plurality of cooling pipes, and a pair of tube plates that support the cooling pipes in the casing. A vessel is disclosed. Each tube sheet supports each end of each cooling tube in the casing. The end of each cooling pipe is fixed to the tube sheet by brazing or expanding. A heat exchange chamber in which heat is exchanged between the fluid flowing in each cooling pipe and the fluid flowing in the casing while being in contact with the outer peripheral surface of each cooling pipe is formed between the tube plates in the casing. A tube chamber is formed outside the one tube plate in the casing, and a turn-back chamber is formed outside the other tube plate in the casing. The pipe chamber includes an introduction chamber that introduces fluid into a part of the plurality of cooling pipes, a discharge chamber that discharges fluid that has flowed out from the remainder of the plurality of cooling pipes to the outside of the casing, and a partition wall that partitions the introduction chamber and the discharge chamber And have. The folding chamber is a chamber for guiding the fluid flowing out from a part of the plurality of cooling pipes to the remaining part of the plurality of cooling pipes.

JP-A-6-294591

  When a heat exchanger as described in Patent Document 1 is used as a vaporizer that vaporizes a low-temperature liquefied gas (the fluid introduced into each cooling pipe is a low-temperature liquefied gas such as LNG, and the outer circumference of each cooling pipe When the fluid supplied into the casing so as to come into contact with the surface is a heat source medium such as seawater), there are the following problems. That is, since the temperature difference between the temperature of the low-temperature liquefied gas and the temperature of the heat source medium is very large, a crack or the like occurs in the connection portion between the tube plate and the cooling tube due to the thermal stress generated in the tube plate. There is a possibility that gas leaks from the introduction chamber, the discharge chamber, or the turn-back chamber to the heat exchange chamber through the cracks. In particular, since a very low-temperature low-temperature liquefied gas is introduced into the introduction chamber, that is, thermal stress generated in a portion of the tube plate that partitions the introduction chamber is increased, cracks or the like are likely to occur in the portion. When gas leaks into the heat exchange chamber, the gas is discharged out of the casing together with the heat source medium, so that the occurrence of gas leak (cracking etc. at the connection between the tube plate and the cooling pipe) is detected. Difficult to do.

  An object of the present invention is to provide a vaporizer capable of detecting a gas leak from an introduction chamber to a heat exchange chamber.

  As means for solving the above problems, the present invention includes a plurality of heat transfer tubes each capable of flowing a low-temperature liquefied gas, the plurality of heat transfer tubes, and a heat source medium in contact with the outer peripheral surface of each heat transfer tube. And a heat exchange that supports the plurality of heat transfer tubes and forms a heat exchange chamber for exchanging heat between the low-temperature liquefied gas and the heat source medium in the casing. A chamber-side tube plate and a portion of the plurality of heat transfer tubes located on the opposite side of the heat exchange chamber side with respect to the heat exchange chamber-side tube plate as a reference, and the heat exchange chamber in the casing A space on the opposite side of the heat exchange chamber side with respect to the side tube sheet is formed between a tube chamber including an introduction chamber into which the low temperature liquefied gas is introduced, and the low temperature liquefaction between the tube chamber and the heat exchange chamber. That gas is vaporized A vaporizer comprising: a detection chamber capable of storing generated gas; a tube-side tube plate that is partitioned; and a detection unit that detects leakage of the gas from the introduction chamber to the detection chamber. I will provide a.

  In this vaporizer, a detection chamber is formed between the introduction chamber and the heat exchange chamber in the casing by the heat exchange chamber side tube plate and the tube chamber side tube plate. The leaking gas can be detected by the detection unit in the detection chamber before the gas reaches the heat exchange chamber.

  In this case, the casing has a nozzle connected to the detection chamber so as to allow communication between the detection chamber and the outside of the casing, and the detection unit emits gas exhausted outside the casing through the nozzle. It is preferable to detect.

  In this way, gas leakage can be easily detected outside the casing.

  Furthermore, in this case, it is preferable that the detection unit includes a connection channel that connects the nozzle and a recovery unit that recovers the gas, and a detection unit that detects a gas flowing through the connection channel.

  In this way, it is possible to detect a gas leak while collecting the gas leaked into the detection chamber without being released to the atmosphere by the collection unit.

  Specifically, the detection unit preferably detects a combustible gas.

  In this way, the gas detection accuracy is further increased.

  In the vaporizer, the detection unit may include an on-off valve provided in the connection flow path, and a valve adjustment unit that opens the on-off valve when the pressure in the detection chamber is equal to or higher than a set pressure. preferable.

  If it does in this way, it will be avoided that a detection chamber becomes more than preset pressure (it becomes too high pressure).

  Moreover, it is preferable that the vaporizer further includes a cold insulation agent that is filled in the detection chamber and has cold insulation properties and air permeability.

  In this way, it is possible to achieve both suppression of gas leakage from the introduction chamber to the detection chamber and detection of gas leaked into the detection chamber. Specifically, the temperature difference between the surface temperature on the introduction chamber side of the tube chamber side tube sheet and the surface temperature on the detection chamber side (temperature difference generated in the tube chamber side tube plate) is caused by filling the detection chamber with the cooling agent. Since it is reduced, generation | occurrence | production of the crack etc. to the connection part of a tube chamber side tube sheet and a heat exchanger tube is suppressed. In addition, since the cooling agent has air permeability, it is possible to effectively detect the gas leaked into the detection chamber.

  As described above, according to the present invention, it is possible to provide a vaporizer capable of detecting gas leakage from the introduction chamber toward the heat exchange chamber.

It is a figure which shows the outline of a structure of the vaporizer | carburetor of one Embodiment of this invention. It is a figure which shows the outline of the modification of the vaporizer | carburetor shown in FIG. It is a figure which shows the outline of the modification of the vaporizer | carburetor shown in FIG.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a vaporizer 1 according to an embodiment of the present invention. The vaporizer 1 can obtain natural gas (NG) by vaporizing liquefied natural gas (LNG), which is a low-temperature liquefied gas. The vaporizer 1 is not limited to liquefied natural gas, and can vaporize a low-temperature liquefied gas such as ethylene, liquefied oxygen, and liquefied nitrogen.

  The vaporizer 1 includes a plurality of heat transfer tubes 10, a casing 20, a heat exchange chamber side tube plate 42, a tube chamber side tube plate 44, and a detection unit 50.

  LNG is introduced into each heat transfer tube 10. In this embodiment, each heat exchanger tube 10 is formed in a U shape.

  Casing 20 accommodates a plurality of heat transfer tubes 10 and allows the heat source medium to flow so that the heat source medium (seawater or the like) contacts the outer peripheral surface of each heat transfer tube 10. Specifically, the casing 20 has an inlet (not shown) that allows the heat source medium to flow into the casing 20 from the outside of the casing 20, and an outlet that allows the heat source medium to flow out of the casing 20 to the outside of the casing 20. (Not shown).

  The heat exchange chamber side tube sheet 42 supports the plurality of heat transfer tubes 10 in the casing 20. In this embodiment, the site | part supported by the heat exchange chamber side tube sheet 42 among each heat exchanger tube 10 is expanded. The heat exchange chamber side tube sheet 42 is connected to the casing 20 so as to be in close contact with the casing 20. Thereby, the heat exchange chamber side tube sheet 42 forms a heat exchange chamber S <b> 1 in the casing 20. In other words, the casing 20 has the main body 22 that forms the heat exchange chamber S1 together with the heat exchange chamber side tube sheet 42. The heat exchange chamber S1 is a room that exchanges heat between the LNG and the heat source medium via the heat transfer tubes 10. That is, in the heat exchange chamber S <b> 1, the LNG flowing in each heat transfer tube 10 is heated by the heat source medium that contacts the outer peripheral surface of the heat transfer tube 10. Thereby, LNG becomes NG. A baffle plate (not shown) that supports each heat transfer tube 10 may be provided in the heat exchange chamber S1.

  The tube chamber side tube sheet 44 supports a portion of the plurality of heat transfer tubes 10 that is located on the opposite side of the heat exchange chamber S1 side with respect to the heat exchange chamber side tube plate 42 as a reference. In the present embodiment, the tube chamber side tube sheet 44 supports the end of each heat transfer tube 10. The end of each heat transfer tube 10 is expanded. The end of each heat transfer tube 10 is fixed to the tube chamber side tube plate 44 by welding or the like.

  The tube chamber side tube plate 44 divides a space on the opposite side of the heat exchange chamber S1 side with respect to the heat exchange chamber side tube plate 42 in the casing 20 into a tube chamber and a detection chamber S4. In other words, the casing 20 forms the detection chamber S4 together with the tube chamber forming portion 24 that forms the tube chamber together with the tube chamber side tube plate 44, and both the heat exchange chamber side tube plate 42 and the tube chamber side tube plate 44. And a detection chamber forming unit 26. The tube chamber side tube plate 44 is fixed at a position spaced from the heat exchange chamber side tube plate 42 in the thickness direction of the heat exchange chamber side tube plate 42. The tube chamber side tube sheet 44 is in close contact with the tube chamber forming portion 24 and the detection chamber forming portion 26.

  The tube chamber has an introduction chamber S2 into which LNG is introduced, a discharge chamber S3 that discharges NG, and a partition wall 28 that partitions the introduction chamber S2 and the discharge chamber S3. One end portion of each heat transfer tube 10 communicates with the introduction chamber S2, and the other end portion of each heat transfer tube 10 communicates with the discharge chamber S3.

  The detection chamber S4 is formed between the tube chamber and the heat exchange chamber S1. The detection chamber S4 accommodates NG leaking from the tube chamber (particularly the introduction chamber S2) toward the heat exchange chamber S1 through the gap between each heat transfer tube 10 and the tube chamber side tube plate 44. Note that the detection chamber S4 is maintained at 0.3 MPa, for example. The casing 20 has a nozzle 29 connected to the detection chamber S4 (detection chamber forming portion 26) so as to communicate the inside of the detection chamber S4 and the outside of the casing 20. In the present embodiment, the detection chamber S4 is filled with a cold-retaining agent (foaming material such as foamed urethane) having cold-retaining properties and air permeability. Note that the cryogen is supplied through the nozzle 29.

  The detection unit 50 detects that NG is leaking from the tube chamber to the detection chamber S4. Specifically, the detection unit 50 includes a connection channel 52 connected to the nozzle 29, a tank 53 provided in the connection channel 52, a detection unit 54 that detects NG, a pressure sensor 55, and a connection channel. The on-off valve V provided in 52 and the valve adjustment part 56 which adjusts the opening degree of the on-off valve V are provided.

  The connection flow path 52 connects the nozzle 29 and the recovery unit 100 that recovers NG. Examples of the recovery unit 100 include a diffusion tower, a low-pressure gas holder, and a booster compressor.

  The tank 53 stores NG flowing out from the detection chamber S4 through the nozzle 29. In the present embodiment, the tank 53 is provided with a detection unit 54 and a pressure sensor 55. The detection unit 54 can detect a combustible gas such as NG. The pressure sensor 55 detects the pressure in the tank 53.

  The valve adjustment unit 56 adjusts the opening degree of the on-off valve V so that the pressure in the tank 53 (detected value of the pressure sensor 55) is maintained below the set pressure. Specifically, when the pressure in the tank 53 becomes larger than the set pressure, the valve adjustment unit 56 generates an alarm and increases the opening degree of the on-off valve V.

  As described above, in the vaporizer 1 of the present embodiment, the heat exchange chamber side tube plate 42 and the tube chamber side tube plate 44 detect between the tube chamber and the heat exchange chamber S1 in the casing 20. Since the chamber S4 is formed, the gas leaking from the introduction chamber S2 to the heat exchange chamber S1 can be automatically detected by the detection unit 50 in the detection chamber S4 before the gas reaches the heat exchange chamber S1.

  Specifically, the detection unit 50 detects gas discharged out of the casing 20 through the nozzle 29. For this reason, gas leakage can be easily detected outside the casing 20.

  Further, the detection unit 50 includes a detection unit 54 that detects a gas flowing through a connection flow path 52 that connects the nozzle 29 and the recovery unit 100. For this reason, it is possible to detect a gas leak while collecting the gas leaked into the detection chamber S4 by the collection unit 100 without releasing it to the atmosphere.

  Further, the detection unit 50 includes a valve adjustment unit 56 that opens the on-off valve V when the pressure in the detection chamber S4 is equal to or higher than a set pressure. For this reason, it is avoided that detection chamber S4 becomes more than a setting pressure (it becomes too high pressure).

  Further, the vaporizer 1 of the present embodiment has a cooling agent filled in the detection chamber S4. For this reason, for example, it is possible to achieve both suppression of gas leakage from the introduction chamber S2 to the detection chamber S4 and detection of gas leaked into the detection chamber S4. Specifically, the detection chamber S4 is filled with a cold insulating agent, whereby the temperature difference between the surface temperature on the introduction chamber S2 side of the tube chamber side tube plate 44 and the surface temperature on the detection chamber S4 side (tube chamber side tube plate 44). Therefore, the occurrence of cracks or the like at the connection portion between the tube chamber side tube sheet 44 and the heat transfer tube 10 is suppressed. Further, since the cold insulator has air permeability, it is possible to effectively detect the gas leaked into the detection chamber S4.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, the detection unit 50 may determine that NG is leaking when the pressure sensor 55 becomes equal to or greater than a predetermined value. Further, the connection channel 52, the tank 53, and the on-off valve V may be omitted, and the detection unit 50 may detect NG flowing out from the nozzle 29 by the detection unit 54.

  Moreover, as FIG.2 and FIG.3 shows, the structure of each heat exchanger tube 10 and the casing 20 can be variously changed. For example, as shown in FIG. 2, each heat transfer tube 10 is formed in a straight line, and the casing 20 has a folding chamber S <b> 5 provided on the side opposite to the tube chamber side in the longitudinal direction of the heat transfer tube 10. May be. Alternatively, as shown in FIG. 3, each heat transfer tube 10 is formed linearly, and an introduction chamber S <b> 2 is provided on one end side of each heat transfer tube 10 in the longitudinal direction of the heat transfer tube 10, and the other end of each heat transfer tube 10. A discharge chamber S3 may be provided on the side. 2 and 3, the detection chambers S4 are formed on both sides of the heat exchange chamber S1 in the longitudinal direction of the heat transfer tube 10 (another heat exchange chamber side tube plate 43 and another tube). It is preferable that the chamber side tube sheet 45 is provided).

  Moreover, in the example shown by FIGS. 1-3, the position of introduction chamber S2 and discharge chamber S3 can be changed suitably. The introduction chamber S2 and the discharge chamber S3 may be arranged so as to be aligned in an arbitrary direction (vertical direction or horizontal direction).

DESCRIPTION OF SYMBOLS 1 Vaporizer 10 Heat transfer tube 20 Casing 29 Nozzle 42 Heat exchange chamber side tube plate 44 Tube chamber side tube plate 50 Detection unit 52 Connection flow path 53 Tank 54 Detection part 55 Pressure sensor 56 Valve adjustment part S1 Heat exchange room S2 Introduction room S3 Discharge chamber S4 Detection chamber V Open / close valve

Claims (6)

A plurality of heat transfer tubes each capable of flowing a low-temperature liquefied gas;
A casing capable of containing the plurality of heat transfer tubes and allowing the heat source medium to flow so that the heat source medium contacts the outer peripheral surface of each heat transfer tube;
A heat exchange chamber side tube plate that supports the plurality of heat transfer tubes and forms a heat exchange chamber in the casing for heat exchange between the low-temperature liquefied gas and the heat source medium;
While supporting the site | part located in the opposite side to the said heat exchange chamber side on the basis of the said heat exchange chamber side tube sheet among the said several heat exchanger tubes, on the basis of the said heat exchange chamber side tube sheet in the said casing By the vaporization of the low-temperature liquefied gas between the tube chamber including the introduction chamber into which the low-temperature liquefied gas is introduced and the tube chamber and the heat exchange chamber in the space opposite to the heat exchange chamber side A detection chamber capable of containing the generated gas;
A vaporizer comprising: a detection unit that detects leakage of the gas from the introduction chamber to the detection chamber. The vaporizer according to claim 1, wherein
The casing has a nozzle connected to the detection chamber so as to allow communication between the detection chamber and the outside of the casing.
The said detection unit is a vaporizer which detects the gas discharged | emitted out of the said casing through the said nozzle. The vaporizer according to claim 2, wherein
The detection unit is
A connection flow path for connecting the nozzle and a recovery unit for recovering the gas;
A vaporizer comprising: a detector that detects gas flowing through the connection flow path. The vaporizer according to claim 3, wherein
The said detection part is a vaporizer which detects combustible gas. The vaporizer according to claim 3 or 4,
The detection unit is
An on-off valve provided in the connection flow path;
A carburetor comprising: a valve adjustment unit that opens the on-off valve when the pressure in the detection chamber is equal to or higher than a set pressure. The vaporizer according to any one of claims 1 to 5,
A vaporizer that is filled in the detection chamber and further includes a cold-retaining agent having cold-retaining properties and breathability.

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