JPH038352Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field] The present invention relates to an apparatus for supplying a cryogenic medium, and particularly relates to an improvement of an apparatus for supplying cryogenic LNG (liquefied natural gas) to seawater for the purpose of seawater desalination. .

[Background technology]

LNG is imported at extremely low temperatures (-161.5℃) and used after being vaporized through heat exchange with seawater.
In seawater desalination using LNG cold energy, ice is crystallized in seawater using the heat of vaporization of LNG, which is separated from seawater, washed, and
Techniques for producing fresh water by melting are already known, and various types of devices have been proposed for this purpose. Among these methods, there is a method that directly exchanges heat between LNG and seawater, one in which LNG is sprayed into the gas phase in the seawater storage canister, that is, from above the seawater surface.
It is broadly divided into liquid phase, that is, one in which LNG is directly injected into seawater.

Figure 3 shows the latter of these devices, with LNG
FIG. 3 is a drawing showing the overall configuration of an example in which the supply device A is applied to a crystal canister 1 for seawater desalination using LNG cold energy, and in FIG. contains seawater 2 as a liquid to be cooled, and a supply device A for LNG as a cryogenic medium is provided at the bottom of the crystal can 1, and this device injects LNG into the seawater 2 to turn the seawater into a jet. It is designed to exchange heat while stirring with vaporized air bubbles.

In addition, natural gas is introduced from the gas phase inside the crystal can 1 through a mist separator 3 to a natural gas return pipe 4 serving as a non-cryogenic fluid introduction pipe, and is pressurized via a compressor 5. It is designed to be supplied to a natural gas flow path 6 of an LNG supply device A shown in an enlarged scale.

and in seawater 2 at LNG supply equipment A.
The general structure of the vicinity of the tip of the nozzle 11 for jetting and injecting LNG is as follows:
The nozzle 1 is surrounded by a natural gas outlet 7 that communicates with the
The LNG jet ejected from LNG 1 is surrounded by a jet of buffer gas, that is, in a "core-sheath" shape, so that both fluids are ejected into seawater 2 at the same time.

Due to the core-sheath shape of the cryogenic medium and the buffer gas natural gas, direct contact between the LNG and seawater in the immediate vicinity of the spout 8 is prevented as they are protected by the natural gas flow. This prevents the formation of interfacial blocks (ice blocks), and then allows the seawater to effectively absorb the cold heat of the LNG through stirring contact after it leaves the spout 8.

In addition, in FIG. 3, the seawater 2 in the crystal can 1 is
When cooled by LNG, crystallization occurs and becomes a slurry in which fine ice crystal grains are suspended.
After that, it is transferred to a cleaning/melting tank (not shown). On the other hand, LNG absorbs heat from the seawater 2 and vaporizes it, and then flows into a gas heater (not shown) from the gas phase communication pipe 10. Further, seawater is supplied through a seawater injection pipe 24.

[Problems to be solved]

LNG is added to the bottom of the crystal can as explained in the above example.
In a device that injects LNG into seawater by installing a supply device A, the main structure of the conventional LNG supply device A is as shown in Fig. 4. Assemble the axis of the outlet plate 12 constituting the
In addition, it is not easy to maintain the natural gas outlet 7 concentrically during operation, and the gaps between the natural gas outlet ports 7 tend to become uneven, causing the natural gas to drift and cause an interface block near the nozzle tip. Or,
Another problem was that the jet flow caused nozzle vibration.

[Purpose of invention]

The present invention has been made to solve these problems, and includes a nozzle for spouting a cryogenic medium, particularly a non-cryogenic fluid surrounding the tip of the nozzle, in an LNG supply device. That is, it is an object of the present invention to provide a device that facilitates centering of a buffer gas made of natural gas with an outlet, securely maintains the centering, and further prevents the occurrence of nozzle vibration.

A cryogenic medium supply device according to the present invention to achieve the above object supplies a buffer gas (natural gas) around a cryogenic medium (LNG) in a liquid to be cooled 2 housed in a container 1. An outlet plate 12, which is a device that ejects water while surrounding it in a core/sheath shape, and has a spout port 8 fixed so as to be in contact with the liquid to be cooled 2.
and a nozzle mounting pipe 13 whose one end abuts on the outlet plate 12 and has a buffer gas reflux pipe 4 fixed to its side.
and a nozzle body 13a that is fitted into the nozzle attachment tube 13, and the nozzle body 13a is provided at one end of the nozzle body 13a, and has a nozzle formed with an annular gap between it and the nozzle attachment tube 13. 11 and
a collar 16 that is adjacent to the nozzle 11, located in front of the opening of the reflux pipe 4, is fitted into the inner circumferential surface of the nozzle attachment pipe 13, and has a buffer gas circulation hole 15; It is composed of an annular flow path 6 adjacent thereto for supplying the buffer gas supplied from the reflux pipe 4 to the front part of the collar 16.

〔Example〕

The present invention is a result of studying and improving a cryogenic medium supply device based on these objectives.
Hereinafter, the structure and operation will be explained based on drawings showing examples.

FIG. 1 is an enlarged longitudinal cross-sectional view of an improved embodiment of the LNG supply device A shown in FIG. 3, according to the present invention;
Fig. 2 is a cross-sectional view of the nozzle section K--K in Fig. 1, and Fig. 4 is a longitudinal sectional view of the main part of the conventional supply device A before improvement, shown for comparison with the nozzle section of Fig. 1. be.

First, regarding the configuration, as shown in FIG. 1, a nozzle mounting pipe 1 is installed at the bottom of a crystal can 1, which is a storage can that stores seawater as a liquid to be cooled, and which communicates between the inside and outside of the can.
A reflux tube 4 for natural gas as a non-cryogenic fluid is attached to the side of the nozzle attachment tube 13, and a support flange 14 is provided at the outer end of the can. Further, an outlet plate 12 having a spout 8 in the center is fitted into the inner end of the can of the nozzle mounting pipe 13 so as to be concentric with the axis of the nozzle mounting pipe 13, and is removably attached with a plurality of set screws. There is. Further, as shown in FIG. 2, a nozzle 11 provided with a collar 16 having a plurality of natural gas flow holes 15 (eight in this example) is inserted into the nozzle attachment pipe 13.

A nozzle body 11a having a nozzle 11 at one end has a flow hole 17 for LNG as a cryogenic medium at its axis.
A nozzle flange 18 is provided at the outer end of the can, and this nozzle body 11a is
A nozzle flange 18 is provided between the fixed flange 20 attached to the introduction pipe 19 and the support flange 14.
are held in place and tightened with a plurality of tightening bolts 21.

More specifically, in FIG. 1, a collar 16, which is provided adjacent to and orthogonally to the nozzle 11, is inserted closely into the inner wall of the nozzle attachment tube 13. The outlet plate 12 is formed with an annular protrusion, and this protrusion is fitted and fixed to the end surface of the nozzle attachment tube 13, so that the tip of the nozzle 11 and the axis of the outlet plate 12 are aligned. They are always reliably matched contrapositives. Also, this exit plate 1
2 and the nozzle 11 are preferably made of tetrafluoroethylene resin (trade name: Teflon) in order to prevent these parts from freezing.

Incidentally, FIG. 4 shows the main part configuration of a conventional supply device shown for comparison, and the nozzle portion is not provided with a collar as in the present invention.

Next, the effect of the present invention will be explained.

In Figure 1, LNG, which is a cryogenic medium, is supplied from the LNG introduction pipe 19 of LNG supply device A.
The LNG is ejected from the nozzle port 22 through the LNG distribution hole 17 toward the seawater in the crystal can 1, that is, the liquid to be cooled. On the other hand, the natural gas, that is, the buffer gas flowing back from the natural gas return pipe 4 enters the natural gas flow path 6, passes through the natural gas flow holes 15 distributed in the collar 16, and is given momentum from the natural gas outlet 7. The resulting annular jet stream surrounds the LNG spouted from the nozzle port 22 and is spouted from the spout port 8 into the seawater. At this time, the natural gas flowing out from the natural gas outlet 7 surrounds the LNG jet coming out from the nozzle 22 and is ejected from the spout 8 in the form of a core and sheath. Mouth 22
In addition, it is possible to prevent the formation of interface blocks near the jet nozzle 8.

At this time, especially since the collar 16 provided adjacent to the nozzle 11 supports the nozzle body 11a in close contact with the inner wall of the nozzle mounting tube 13, the centering of the tip of the nozzle 11 is always ensured. This suppresses bending of the nozzle caused by uneven heat of the natural gas, which is the buffer gas flowing in from the natural gas return pipe 4, and the occurrence of nozzle vibration due to high-speed jets and gas bubbles near the spout 8. do.

Further, as shown in FIG. 2, the jet velocity of the natural gas is equalized over the entire circumference of the gas outlet 7 by the gas flow hole 15 provided in the collar 16, and the outlet 7 is formed in an annular shape around the nozzle 11. Because it flows into
Even if the amount of inflow from the gas reflux pipe 4 increases, drift is difficult to occur, and the enclosing effect of the core/sheath shape on the LNG jet from the nozzle port 22 is maintained well.

Note that the support flange 14 and the nozzle flange 18
The aperture of the natural gas outlet 7 can be arbitrarily set by adjusting the gap size between the outlet plate 12 and the tip of the nozzle 11 by adjusting a shim between the outlet plate 12 and the nozzle 11 .

In addition, the non-cryogenic fluid is not limited to the method of using natural gas by circulating it, but depending on the operational balance conditions, for example, a pipe such as pipe line 23 in Fig. 3 in which a fluid such as heated water is provided separately may be used. It may also be used by being supplied from the system.

[Effect of idea]

The cryogenic medium supply device according to the present invention is a device that spouts the cryogenic medium into a liquid to be cooled housed in a storage can while surrounding the cryogenic medium in a core/sheath shape with a buffer gas, which comprises: An outlet plate having an ejection port fixed to be in contact with the liquid to be cooled, a nozzle mounting pipe having one end in contact with the outlet plate and a buffer gas return pipe fixed to the side, and a nozzle fitting pipe fitted into the nozzle mounting pipe. a nozzle body provided at one end thereof and formed with an annular gap between the nozzle body and the nozzle mounting pipe; and a nozzle body adjacent to the nozzle and in front of the reflux pipe. Located in
a collar fitted to the inner circumferential surface of the nozzle attachment pipe and having a buffer gas circulation hole; adjacent to the collar;
and an annular flow path for supplying the buffer gas supplied from the reflux pipe to the front part of the collar.

Therefore, since the nozzle is supported by a collar located adjacent to the nozzle and in front of the opening of the buffer gas return pipe, there is no space between the nozzle and the spout of the outlet plate provided facing the storage can. can be easily and reliably centered. Furthermore, it is possible to prevent the eccentricity of the nozzle during operation and the occurrence of vibrations due to the jet stream.

In addition, a large number of buffer gas flow holes are formed in the brim, and a buffer gas outlet is formed between the outlet plate and the nozzle in an annular shape surrounding the nozzle, so that this buffer gas can flow. It is evenly distributed at the outlet, surrounds LNG, which is a cryogenic medium, in a core/sheath shape and is ejected into the liquid phase of the container containing the liquid to be cooled, so that an interface block may occur near the nozzle tip. Since nozzle vibration due to the jet flow does not occur, it is possible to improve the operating performance and reliability of the entire device, and to further improve the cooling energy utilization efficiency.

[Brief explanation of the drawing]

Figures 1 and 2 are drawings showing one embodiment of the present invention, in which Figure 1 is a vertical sectional view of the main part configuration of the LNG supply device, and Figure 2 is a cross-sectional view of the nozzle section K--K in Figure 1. A top view, FIG. 3 is an explanatory view of the overall configuration of an example in which the LNG supply device is applied to a crystal can for seawater desalination, and FIG. 4 is a vertical sectional view of the main part of a conventional device. A... LNG supply device, 1... Crystal can, 2...
Seawater, 4... Natural gas circulation pipe, 5... Compressor, 6
...Natural gas flow path, 7...Natural gas outlet, 8...
...Ejection port, 9... Slurry outlet pipe, 10... Gas phase communication pipe, 11... Nozzle, 12... Outlet plate, 13... Nozzle mounting pipe, 15... Natural gas distribution hole, 16... Collar, 17...LNG distribution hole, 1
9... LNG introduction pipe, 22... Nozzle port, 24...
...Seawater injection pipe.

Claims (1)

[Scope of utility model registration request] A device that spouts a cryogenic medium into a liquid to be cooled housed in a storage can while surrounding it with a buffer gas in a core/sheath shape, and the spout is fixed so as to be in contact with the liquid to be cooled. The nozzle body consists of an outlet plate having an outlet plate, a nozzle mounting pipe whose one end is in contact with the outlet plate, and a buffer gas reflux pipe fixed to the side thereof, and a nozzle body fitted into the nozzle mounting pipe. , a nozzle provided at one end thereof and formed with an annular gap between it and the nozzle mounting pipe, and a nozzle located adjacent to the nozzle and in front of the reflux pipe, and an inner circumferential surface of the nozzle mounting pipe. a collar that is fitted into the collar and has a buffer gas flow hole; and an annular flow path adjacent to the collar for supplying the buffer gas supplied from the reflux pipe to the front part of the collar. Low temperature medium supply device.