阅读说明：本技术 一种用于海上的lng气化器及气化方法 (LNG vaporizer used on sea and vaporization method ) 是由 明红芳 张超 陈海平 黄宇 宋坤 许佳伟 郭琦 郝思佳 于 2021-01-25 设计创作，主要内容包括：本发明涉及一种用于海上的LNG气化器及气化方法,包括：箱体,所述箱体的底部设置有海水入口,所述箱体的侧壁上设置有海水出口；LNG输液管,所述LNG输液管的上端穿过所述箱体的顶部并设置有LNG入口,其下端安装在所述箱体内；NG输气管,所述NG输气管的进气口与所述LNG输液管的出气口连接,用于将气化的LNG输送至外部输气管道；鼓风管,所述鼓风管的上端穿过所述箱体的顶部并设置有空气入口,其下端安装在所述LNG输液管的下方。本发明的LNG气化器将换热部件放置于箱体中,操作灵活,结构简单紧凑,节省占地面积。(The invention relates to an LNG vaporizer and a vaporizing method used on sea, comprising the following steps: the seawater recycling device comprises a box body, a seawater inlet is formed in the bottom of the box body, and a seawater outlet is formed in the side wall of the box body; the upper end of the LNG liquid conveying pipe penetrates through the top of the box body and is provided with an LNG inlet, and the lower end of the LNG liquid conveying pipe is installed in the box body; the gas inlet of the NG gas pipe is connected with the gas outlet of the LNG liquid conveying pipe and used for conveying gasified LNG to an external gas conveying pipeline; the upper end of the blast pipe penetrates through the top of the box body and is provided with an air inlet, and the lower end of the blast pipe is arranged below the LNG liquid conveying pipe. The LNG vaporizer is provided with the heat exchange part arranged in the tank body, so that the LNG vaporizer is flexible to operate, simple and compact in structure and capable of saving floor space.)

1. An LNG vaporizer for use aboard a sea, comprising:

the seawater desalination device comprises a box body (11), wherein a seawater inlet (13) is formed in the bottom of the box body (11), and a seawater outlet (14) is formed in the side wall of the box body (11);

the upper end of the LNG liquid conveying pipe (5) penetrates through the top of the tank body (11) and is provided with an LNG inlet (7), and the lower end of the LNG liquid conveying pipe is installed in the tank body (11) and is used for conveying LNG into the tank body (11);

the gas inlet of the NG gas pipe (2) is connected with the gas outlet of the LNG liquid conveying pipe (5) and is used for conveying gasified LNG to an external gas conveying pipeline;

the LNG heat exchange device comprises a blast pipe (4), wherein the upper end of the blast pipe (4) penetrates through the top of a box body (11) and is provided with an air inlet (8), the lower end of the blast pipe is installed below an LNG (liquefied natural gas) infusion pipe (5), and a plurality of blast holes are formed in the blast pipe (4) and used for generating bubbles and accelerating the flow of seawater to improve the LNG heat exchange efficiency.

2. The LNG vaporizer for offshore use according to claim 1, further comprising:

the supporting frame (15), the said supporting frame (15) is set up in the bottom of the said container body (11);

the lower end of the LNG liquid conveying pipe (5) is divided into a plurality of heat exchange pipes (3), and the plurality of heat exchange pipes (3) are coiled into coiled pipes and are arranged in the support frame (15) side by side or are coiled into a plurality of layers of coiled pipes and are arranged in the support frame (15).

3. The LNG vaporizer for sea according to claim 2, characterized in that the NG gas pipe (2) has its gas inlet connected to the gas outlets of the heat exchange pipes (3), and the NG gas pipe (2) has its upper end passing through the top of the tank (11) and provided with an NG outlet (1) for connection to an external gas pipe.

4. LNG gasifier for offshore use according to claim 3, characterized in that the lower end of the blast pipe (4) is divided into blast legs (10), that the blast legs (10) are fixed to the bottom of the support frame (15) and located below the heat exchange pipes (3), and that the blast holes are evenly distributed in the upper pipe walls of the blast legs (10).

5. The LNG vaporizer of claim 4, further comprising a chlorine gas pipe (6), wherein the upper end of the chlorine gas pipe (6) penetrates through the top of the tank body (11) and is provided with a chlorine gas inlet (9), and the lower end of the chlorine gas pipe (6) is in air flow communication connection with the blast pipe (4).

6. The LNG vaporizer of claim 5, further comprising an overflow weir (12), wherein the overflow weir (12) is a cylindrical structure with an upper and lower opening, and is fixed at the bottom of the supporting frame (15) and located at the periphery of the plurality of heat exchange tubes (3) for enabling the liquid in the whole tube bundle region to flow sufficiently for heat exchange.

7. LNG vaporizer according to claim 6, characterized in that several heat exchanger tubes (3) are arranged in isosceles triangle to enhance the bubble breaking effect, so that the number of bubbles with relatively small diameter is increased, and the liquid is disturbed and the heat transfer effect is enhanced under the same air input.

8. LNG vaporizer according to claim 7, characterized in that it further comprises a filter screen (16), which filter screen (16) is arranged at the seawater inlet (13) for filtering large-particle silt and marine organisms.

9. LNG-gasifier according to claim 8, characterized in that the LNG-inlet (7), the air-inlet (8) and the chlorine-inlet (9) are provided with flanges, the material of which comprises austenitic stainless steel.

10. A method of vaporizing an LNG vaporizer according to any one of claims 1 to 9, comprising the steps of:

placing the LNG vaporizer on a sea level or a semi-submersible offshore platform, opening the seawater inlet (13) and the seawater outlet (14), and immersing the heat exchange tube (3) after seawater is primarily filtered by the filter screen (16), wherein the seawater is in a static state; turning on a blower to be in a working state, enabling air to enter the LNG vaporizer through the air inlet (8), conveying the air to the blower pipe (4), finally dispersing the air to the blower branch pipe (10) at the bottom of the LNG vaporizer, ascending in the form of bubbles through the blower holes of the blower branch pipe (10), and enabling seawater inside the LNG vaporizer to flow under the action of the rising force of the bubbles; meanwhile, the chlorine inlet (9) is opened, chlorine is injected through the chlorine gas conveying pipe (6), and the chlorine and air are mixed and then enter the LNG gasifier to play a role in killing marine organisms; LNG enters from the LNG inlet (7), enters the heat exchange tube (3) through the LNG infusion tube (5), and forms convection with seawater flowing outside the tube, so that the purpose of heat exchange and gasification is achieved; the gasified natural gas reaches the NG outlet (1) through the NG gas pipe (2) and is then conveyed out through an external pipeline; after heat exchange, the fluid is discharged through the seawater outlet (14).

Technical Field

The invention relates to an LNG vaporizer used on the sea and a vaporizing method, belonging to the technical field of LNG transportation and distribution.

Background

Conventional LNG gasifiers used on land, i.e., Open Rack gasifiers (ORV), Submerged Combustion gasifiers (SCV), Intermediate Fluid gasifiers (IFV), and Air temperature gasifiers (AAV), are suitable for different operating conditions, and have respective advantages, but also have many disadvantages. With the development of offshore LNG, the novel LNG vaporizer applicable to the sea is provided by combining the offshore geographic position, the natural condition and the seawater condition and taking the function and the demand as design starting points, so as to overcome the limitation of the existing vaporizer, namely the problem that the existing offshore LNG is urgently needed to be solved.

Disclosure of Invention

In view of the above-mentioned problems, the present invention provides a vaporizer for LNG at sea and a method for vaporizing the LNG, which is installed in an offshore open water area or a seawater semi-submersible platform, and can directly vaporize LNG carried on an LNG carrier and transport the LNG in a pipeline, thereby effectively saving the cost for transporting LNG and seawater to an onshore LNG receiving station and improving economic efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme:

the present invention provides in a first aspect an LNG vaporizer for use at sea, comprising:

the seawater recycling device comprises a box body, a seawater inlet is formed in the bottom of the box body, and a seawater outlet is formed in the side wall of the box body;

the upper end of the LNG liquid conveying pipe penetrates through the top of the box body and is provided with an LNG inlet, and the lower end of the LNG liquid conveying pipe is installed in the box body and is used for conveying LNG into the box body;

the gas inlet of the NG gas pipe is connected with the gas outlet of the LNG liquid conveying pipe and used for conveying gasified LNG to an external gas conveying pipeline;

the upper end of the blast pipe penetrates through the top of the box body and is provided with an air inlet, the lower end of the blast pipe is installed below the LNG liquid conveying pipe, and the blast pipe is provided with a plurality of blast holes for generating bubbles and accelerating the flow of seawater to improve the LNG heat exchange efficiency.

The LNG vaporizer for sea preferably further comprises:

the supporting frame is arranged at the bottom of the box body;

the lower end of the LNG liquid conveying pipe is divided into a plurality of heat exchange pipes, and the plurality of heat exchange pipes are coiled into coiled pipes and arranged in the support frame side by side or coiled into a plurality of layers of coiled pipes and arranged in the support frame.

The LNG vaporizer for the sea is preferably characterized in that an air inlet of the NG air conveying pipe is connected with a plurality of air outlets of the heat exchange pipes, and the upper end of the NG air conveying pipe penetrates through the top of the box body and is provided with an NG outlet for being connected with an external air conveying pipeline.

Preferably, the lower end of the blast pipe is divided into a plurality of blast branch pipes, the plurality of blast branch pipes are fixed at the bottom of the support frame and located below the plurality of heat exchange pipes, and the plurality of blast holes are uniformly distributed on the upper pipe walls of the plurality of blast branch pipes.

The LNG vaporizer, preferably, still include the chlorine gas-supply pipe, the upper end of chlorine gas-supply pipe passes the top of box and is provided with the chlorine entry, the lower extreme of chlorine gas-supply pipe with blast pipe air current switch on is connected.

The LNG vaporizer preferably further comprises an overflow weir, wherein the overflow weir is of a cylindrical structure with an upper opening and a lower opening, is fixed at the bottom of the support frame and is positioned at the periphery of the plurality of heat exchange tubes, and is used for enabling liquid in the whole tube bundle area to fully flow for heat exchange.

Preferably, the plurality of heat exchange tubes are arranged in an isosceles triangle manner and used for enhancing the bubble breaking effect, so that the number of bubbles with relatively small diameters is increased, liquid is disturbed and enhanced under the condition of the same air inflow, and the heat transfer effect is enhanced.

The LNG vaporizer, preferably, still include the filter screen, the filter screen set up in the sea water entrance for filter large granule silt and marine organism.

Preferably, the LNG vaporizer is provided with flanges at the LNG inlet, the air inlet and the chlorine inlet, and the flanges are made of austenitic stainless steel.

The second aspect of the present invention further provides a method for gasifying the LNG vaporizer, including the steps of:

placing the LNG vaporizer on a sea level or a semi-submersible offshore platform, opening the seawater inlet and the seawater outlet, and immersing the heat exchange tube after seawater is primarily filtered by the filter screen, wherein the seawater is in a static state; turning on a blower to enable the blower to be in a working state, enabling air to enter the LNG vaporizer through the air inlet, conveying the air to the blower pipe, finally dispersing the air to the blower branch pipe at the bottom of the LNG vaporizer, enabling the air to rise in the form of bubbles through the blower holes of the blower branch pipe, and enabling seawater inside the LNG vaporizer to flow under the action of bubble rising force; meanwhile, the chlorine inlet is opened, chlorine is injected through the chlorine gas conveying pipe, and the chlorine and air are mixed and then enter the LNG gasifier to play a role in killing marine organisms; LNG enters from the LNG inlet, enters the heat exchange tube through the LNG liquid conveying tube and forms convection with seawater flowing outside the tube, so that the purpose of heat exchange and gasification is achieved; the gasified natural gas reaches the NG outlet through the NG gas pipe and is then conveyed out through an external pipeline; and after heat exchange, the fluid is discharged through the seawater outlet.

Due to the adoption of the technical scheme, the invention has the following advantages:

the LNG vaporizer is placed in seawater at the offshore location, LNG on an LNG transport ship can be directly vaporized and then transported from a pipeline, and therefore the cost of transporting LNG and seawater to a receiving station by the onshore LNG vaporizer is effectively saved. Air is injected by the air blower and rises in the form of bubbles through the vent holes, seawater outside the heat exchange pipe flows under the action of bubble rising force, and the purpose of exchanging heat with LNG in the pipe to gasify the seawater is achieved, so that power of a water pump is replaced. The LNG vaporizer places the heat exchange part in the tank body, is flexible to operate, simple and compact in structure and saves the occupied area.

Drawings

Fig. 1 is a schematic diagram illustrating an overall structure of an offshore LNG vaporizer according to an embodiment of the present invention;

fig. 2 is another perspective view of the offshore LNG vaporizer according to the embodiment of the present invention;

fig. 3 is a bottom plan view of an offshore LNG vaporizer according to the embodiment of the present invention;

fig. 4 is a schematic view of an operation state of an offshore LNG vaporizer according to the embodiment of the present invention;

fig. 5 is a practical structural view of an offshore LNG vaporizer according to the embodiment of the present invention;

the reference numerals in the figures are as follows:

1-NG outlet; 2-NG gas transmission pipe; 3, heat exchange tubes; 4-a blast pipe; 5-LNG transfer lines; 6-chlorine gas conveying pipe; 7-LNG inlet; 8-an air inlet; 9-a chlorine inlet; 10-blast branch pipes; 11-a box body; 12-an overflow weir; 13-seawater inlet; 14-a seawater outlet; 15-a support frame; 16-a filter screen.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention are described clearly and completely below, and it is obvious that the described embodiments are some, not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

As shown in fig. 1 to 3, the present invention provides an LNG vaporizer for use at sea, comprising:

the seawater desalination device comprises a box body 11, wherein a seawater inlet 13 is formed in the bottom of the box body 11, and a seawater outlet 14 is formed in the side wall of the box body 11;

the support frame 15, the support frame 15 is set up in the bottom of the container body 11;

the LNG transfer pipe 5, the upper end of the LNG transfer pipe 5 passes through the top of the box body 11 and is provided with an LNG inlet 7, the lower end of the LNG transfer pipe 5 is divided into a plurality of heat exchange pipes 3, and the heat exchange pipes 3 are coiled into coiled pipes and are arranged in the support frame 15 side by side or coiled into a plurality of layers of coiled pipes and are arranged in the support frame 15;

the lower end of the NG gas pipe 2 is connected with the other ends of the heat exchange pipes 3, and the upper end of the NG gas pipe 2 penetrates through the top of the box body 11 and is provided with an NG outlet 1 which is used for being connected with an external gas pipe;

the upper end of the blast pipe 4 penetrates through the top of the box body 11 and is provided with an air inlet 8, the lower end of the blast pipe 4 is divided into a plurality of blast branch pipes 10, the plurality of blast branch pipes 10 are fixed at the bottom of the support frame 15 and are positioned below the plurality of heat exchange pipes 3, and a plurality of blast holes are formed in the upper pipe walls of the plurality of blast branch pipes 10;

the upper end of the chlorine gas conveying pipe 6 penetrates through the top of the box body 11 and is provided with a chlorine gas inlet 9, and the lower end of the chlorine gas conveying pipe 6 is in airflow communication connection with the blast pipe 4.

In this embodiment, it is preferable that the evaporator further comprises an overflow weir 12, and the overflow weir 12 is a cylindrical structure with an upper opening and a lower opening, and is fixed at the bottom of the support frame 15 and located at the periphery of the plurality of heat exchange tubes 3, and is used for enabling the liquid in the whole tube bundle region to flow sufficiently for heat exchange.

In this embodiment, the diameter of the blowing hole is preferably 15 to 25 mm.

In this embodiment, it is preferable that the seawater desalination device further includes a filter screen 16, and the filter screen 16 is disposed at the seawater inlet 13 and is used for filtering large-particle silt and marine organisms.

In this embodiment, it is preferable that flanges are disposed at the inlets of the LNG inlet 7, the air inlet 8, and the chlorine inlet 9, and the material of the flanges includes austenitic stainless steel.

In this embodiment, preferably, the plurality of heat exchange tubes 3 and the LNG liquid transfer tube 5 are made of an aluminum alloy + Al — Zn coating.

In this embodiment, preferably, the NG gas pipe 2, the blast pipe 4, the chlorine gas pipe 6, and the plurality of blast branch pipes 10 are made of aluminum alloy + Al — Zn coating.

In this embodiment, the material of the box 11, the support frame 15 and the overflow weir 12 preferably includes austenitic stainless steel.

In this embodiment, preferably, the plurality of heat exchange tubes 3 are arranged in an isosceles triangle manner to enhance the bubble breaking effect, so that the number of bubbles with relatively small diameters is increased, and under the condition of the same air inflow, the liquid is disturbed to enhance and the heat transfer effect is enhanced.

In this embodiment, preferably, the heat exchange tubes 3 are arranged in an isosceles triangle, the tube bundle distribution structure is compact, and gas-liquid two-phase flow flows around each heat exchange tube 3, so that the bubble breaking effect is enhanced, the number of bubbles with relatively small diameters is increased, and under the condition of the same air inflow, the liquid is disturbed and enhanced, and the heat transfer effect is enhanced.

Based on the LNG vaporizer, the present invention further provides a method for vaporizing the LNG vaporizer, as shown in fig. 4 and 5, including the following steps:

placing the LNG vaporizer on a sea level or a semi-submersible offshore platform, opening a seawater inlet 13 and a seawater outlet 14, and immersing the heat exchange tube 3 after seawater is primarily filtered by a filter screen 16, wherein the seawater is in a static state; the air blower is turned on to be in a working state, air enters the LNG vaporizer through the air inlet 8, is conveyed to the air blowing pipe 4 and is finally dispersed to the air blowing branch pipe 10 at the bottom of the LNG vaporizer, the air rises in a bubble mode through the air blowing holes of the air blowing branch pipe 10, and seawater in the LNG vaporizer flows under the action of bubble rising force; meanwhile, a chlorine inlet 9 is opened, chlorine is injected through a chlorine gas delivery pipe 6, and the chlorine and air are mixed and then enter the LNG gasifier to play a role in killing marine organisms; LNG enters from an LNG inlet 7, enters the heat exchange tube 3 through an LNG liquid conveying tube 5, and forms convection with seawater flowing outside the tube, so that the purpose of heat exchange and gasification is achieved; the gasified natural gas reaches an NG outlet 1 through an NG gas pipe 2 and is then conveyed out through an external pipeline; after heat exchange, the fluid is discharged through a seawater outlet 14.

The overflow weir 12 is arranged, so that air can shuttle between the pipe walls to a greater extent, liquid in the whole pipe bundle area can fully flow for heat exchange, and the heat exchange effect is better; in the process that air passes through the tube bundle transversely, large bubbles are subjected to the interference effect of the tube bundle and are broken into a plurality of small bubbles, so that the liquid disturbance is enhanced, and the heat exchange is enhanced.

With the increase of the aperture of the blast hole, the convective heat transfer coefficient of the shell-side fluid has a trend of increasing and then decreasing. When the aperture of the blast hole is about 20mm, the convection heat transfer coefficient reaches the maximum. The aperture of the blast hole is not suitable to be too large, when the aperture of the blast hole is too large, the diameter of the formed initial bubble is relatively large, and the coalescence rate among the bubbles is increased within a certain hole spacing range, so that the gas-liquid two-phase flow near the LNG gasifier is in block flow, and the heat exchange between the gas-liquid two-phase flow and the tube bundle is not facilitated, therefore, the aperture of the LNG gasifier is selected to be 20 mm.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.