CN218130053U

CN218130053U - LNG cold energy is used for recovery unit that flue gas desublimated

Info

Publication number: CN218130053U
Application number: CN202222570617.XU
Authority: CN
Inventors: 丁力; 赵德泉; 陆佳
Original assignee: China International Marine Containers Group Co Ltd
Current assignee: China International Marine Containers Group Co Ltd
Priority date: 2022-09-27
Filing date: 2022-09-27
Publication date: 2022-12-27
Anticipated expiration: 2032-09-27

Abstract

The utility model provides a recovery device for condensing LNG cold energy into flue gas, which is used for recovering LNG gasification cold energy and comprises a natural gas heat exchange module, a first condensing module and a second condensing module; the gas inlet of the natural gas heat exchange module is used for combustion flue gas to enter, and the natural gas heat exchange module cools the flue gas; the gas inlet of the first desublimation module is communicated with the natural gas heat exchange module, and the gas inlet of the second desublimation module is communicated with the gas outlet of the first desublimation module so as to desublimate part of the flue gas; the gasification cold energy is respectively transmitted to the natural gas heat exchange module and the first desublimation module through the second desublimation module; the flue gas is cooled by the natural gas heat exchange module, and then is desublimated respectively by the first desublimating module and the second desublimating module, and the residual flue gas flows back to the first desublimating module by the second desublimating module, and provides gasification cold energy for the first desublimating module. The first desublimation module and the second desublimation module absorb gasification cold energy and then desublimate part of the flue gas so as to recycle the flue gas.

Description

LNG cold energy is used for recovery unit that flue gas desublimated

Technical Field

The utility model relates to a liquefied natural gas technical field, in particular to LNG cold energy is used for recovery unit of flue gas desublimation.

Background

With the development of society, natural gas is used as a clean green energy source, gradually replaces other energy sources with larger pollution, and becomes a main supply energy source for cities. LNG (Liquefied Natural Gas, LNG for short) is a low-temperature (-162 ℃) liquid mixture which is prepared by deacidifying and dehydrating low-pollution Natural Gas and freezing and liquefying the low-temperature Natural Gas through a low-temperature process, and the LNG needs to be gasified to be NG (Natural Gas, NG for short) for use. The conventional LNG gasification mode is that an air and seawater vaporizer or a combustion heater is directly adopted for gasification, so that a large amount of LNG cold energy is wasted.

The LNG is gasified and then combusted to generate a large amount of smoke, and the emission of the smoke is reduced. In the related art, there is a scheme of recovering the flue gas by using the cold energy of the LNG by using a rectifying tower, a high pressure compressor, a propane condensation circulation system, and the like. But the recovery process needs to continuously supplement materials, the recovery efficiency is low, and the recovery cost is high.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a recovery unit that LNG cold energy that flue gas recovery efficiency is high, recovery cost is low is used for flue gas desublimation.

In order to solve the technical problem, the following technical scheme is adopted in the application:

according to one aspect of the application, the application provides a recovery device for condensing flue gas by using LNG cold energy, which is used for recovering LNG gasification cold energy and comprises a natural gas heat exchange module, a first condensing module and a second condensing module; the gas inlet of the natural gas heat exchange module is used for allowing flue gas generated by combustion to enter, and the natural gas heat exchange module cools the flue gas; the gas inlet of the first desublimation module is communicated with the natural gas heat exchange module so as to desublimate part of the flue gas; the gas inlet of the second desublimation module is communicated with the gas outlet of the first desublimation module so as to desublimate part of the flue gas; the flue gas output by the gas outlet of the second desublimation module exchanges heat with the first desublimation module; the gasification cold energy is transmitted to the natural gas heat exchange module and the first desublimation module through the second desublimation module respectively; the flue gas is cooled by the natural gas heat exchange module, and then is desublimated respectively by the first desublimating module and the second desublimating module, and the residual flue gas flows back to the first desublimating module through the second desublimating module and provides gasification cold energy for the first desublimating module.

In some embodiments, the recycling device further comprises a water-cooling heat exchange module, the water-cooling heat exchange module comprises a first water-cooling unit and a second water-cooling unit, and an air inlet of the first water-cooling unit is used for flue gas generated by combustion to enter; the second water cooling unit is communicated with the first water cooling unit, and the gas outlet of the second water cooling unit is communicated with the gas inlet of the natural gas heat exchange module.

In some embodiments, the recycling device further comprises a compression unit, an air inlet of the compression unit is communicated with the first water cooling unit, and an air outlet of the compression unit is communicated with the second water cooling unit.

In some embodiments, a water removal unit is disposed between the natural gas heat exchange module gas outlet and the first desublimation module gas inlet.

In some embodiments, the second desublimation module comprises a second heat exchange tube, a second shell, and a second wiper; the second heat exchange tube is used for circulating LNG and penetrates through the second shell; two ends of the second shell are respectively provided with an opening, and the inner peripheral wall of the second shell and the outer peripheral wall of the second heat exchange tube form a second desublimation chamber; the gas inlet of the second shell is communicated with the gas outlet of the first desublimation module; the gas outlet of the second shell is used for discharging the flue gas after the LNG gasification cold energy is absorbed; the bottom of the second shell is opened for the passage of desublimated substances; the peripheral wall butt of second doctor-bar the internal perisporium of second casing, the second doctor-bar cover is located the periphery of second heat exchange tube, the second doctor-bar can be followed the extending direction of second heat exchange tube removes.

In some embodiments, the second desublimation module further comprises a second transmission shaft in transmission connection with the second scraping blade, a second nut fixed on the second scraping blade, and a second driving mechanism for driving the second transmission shaft to rotate, the second transmission shaft extends along the extension direction of the heat exchange tube, and the second driving mechanism drives the second transmission shaft to rotate around the rotation axis of the second transmission shaft; the second nut is sleeved on the second transmission shaft and in threaded connection with the second transmission shaft, so that the second scraping blade can move along the axis direction of the second transmission shaft.

In some embodiments, the first desublimation module comprises a first heat exchange tube, a first housing; the first heat exchange tube penetrates through the first shell, and a first desublimation chamber is formed by the inner peripheral wall of the first shell and the outer peripheral wall of the first heat exchange tube; openings are formed in two opposite ends of the first shell to be respectively communicated with the gas outlet of the natural gas heat exchange module and the gas inlet of the second shell; the first heat exchange tube is communicated with the air outlet of the second shell.

In some embodiments, a spray desublimation module is communicated between the air outlet of the second shell and the first heat exchange pipe.

In some embodiments, the spray desublimation module comprises a heat exchange tank, a spray unit arranged in the heat exchange tank, and a liquid nitrogen storage unit communicated with the spray unit; the heat exchange tank extends along the up-down direction, a spray flue gas inlet is formed in the periphery of the lower portion of the heat exchange tank and communicated with the gas outlet of the second shell, a spray desublimation substance outlet is formed in the center of the lower portion of the heat exchange tank, a spray flue gas outlet is formed in the upper portion of the heat exchange tank, and the spray flue gas outlet is communicated with the inlet of the first heat exchange pipe; the spraying unit sprays in the heat exchange tank so as to desublimate part of the flue gas.

In some embodiments, a filtering and separating unit is arranged at one end of the spray desublimation outlet, which is far away from the heat exchange tank.

According to the technical scheme, the method has at least the following advantages and positive effects:

in this application, supply apparatus burning after LNG gasification for NG. Flue gas that NG burning back produced passes through natural gas heat transfer module, first desublimation module, second desublimation module in proper order. The gasification cold energy that produces among the LNG gasification process is transmitted respectively to natural gasification hot module and first desublimation module after the second desublimation module after, and the temperature of the part flue gas in first desublimation module and the second desublimation module reaches the desublimation point, and the desublimation becomes the solid so that subsequent processing to make full use of the gasification cold energy of LNG, effectual reduction flue gas emission has improved the recovery efficiency of flue gas. And the recovery device has simple structure, no pollution to material diffusion and reduced recovery cost of the flue gas.

Drawings

Fig. 1 is a schematic view of an embodiment of the recycling device of the present invention.

Fig. 2 is a schematic structural diagram of the first desublimation module of the embodiment of the recycling device of the present invention.

Fig. 3 isbase:Sub>A cross-sectional view atbase:Sub>A-base:Sub>A of the structure shown in fig. 2.

Fig. 4 is a schematic structural diagram of a second desublimation module of the embodiment of the recycling device of the present invention.

Figure 5 is a schematic structural view of a spray desublimation module of the embodiment of the recovery device of the utility model.

FIG. 6 is a schematic view showing another example of the recovery apparatus of the present invention.

The reference numerals are explained below:

100. an LNG storage module; 200. a combustion module; 300. a water-cooling heat exchange module; 310. a first water cooling unit; 320. a second water cooling unit; 330. a compression unit; 400. a natural gas heat exchange module; 410. a water removal unit; 500. a first desublimation module; 510. a first heat exchange tube; 520. a first housing; 521. a first flue gas inlet; 522. a first flue gas outlet; 523. a first desublimation outlet; 530. a first desublimation chamber; 541. a first wiper blade; 542. a first drive shaft; 543. a first screw nut; 544. a first drive mechanism; 600. a second desublimation module; 610. a second heat exchange tube; 620. a second housing; 621. a second flue gas inlet; 622. a second flue gas outlet; 623. a second desublimated matter outlet; 630. a second desublimation chamber; 641. a second wiper blade; 642. a second drive shaft; 643. a second screw; 644. a second drive mechanism; 700. a spray desublimation module; 710. a heat exchange tank; 711. a spray flue gas inlet; 712. a spray flue gas outlet; 713. a spray desublimation outlet; 720. a spraying unit; 730. a liquid nitrogen storage unit; 740. a filtration and separation unit; 750. a pressurizing unit; 800. a desublimated matter collection module; 900. a smoke exhaust tube.

Detailed Description

Exemplary embodiments that embody the features and advantages of the present application will be described in detail in the following description. It is understood that the present application is capable of many variations in different embodiments without departing from the scope of the application, and that the description and drawings herein are to be taken as illustrative and not restrictive in character.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

LNG (Liquefied Natural Gas, LNG for short) is used as a clean energy source. The LNG is convenient to transport and store, and when the LNG is used, the LNG needs to be gasified into NG (Natural Gas, NG for short) for reuse. NG emits large amounts of nitrogen and carbon dioxide during combustion, and too much carbon dioxide is harmful to cause the greenhouse effect. Currently, in order to protect the environment, china is actively striving to reduce carbon emissions and achieve carbon neutralization.

In the related art, NG liquefies to LNG when the temperature reaches-161.5 ℃ at one standard atmosphere. Thus, the storage temperature of LNG is-161.5 ℃. At a standard atmospheric pressure, the carbon dioxide has a sublimation point of-78.5 ℃, and when the temperature of the gas reaches-78.5 ℃, the carbon dioxide in the gas is sublimated into dry ice. However, a large amount of nitrogen exists in the flue gas, and when the nitrogen is mixed with the carbon dioxide, the desublimation temperature of the carbon dioxide in the flue gas is continuously reduced along with the increase of the ratio of the nitrogen to the carbon dioxide. According to the calculation, after NG is combusted, the carbon dioxide desublimation temperature in the flue gas is at least lower than-100 ℃ under the normal pressure state. Nitrogen gas has a liquefaction temperature of-146.9 ℃ at one standard atmosphere, and can be liquefied into liquid nitrogen.

LNG is currently available in various industries, such as steam boilers. The vaporized LNG is burned in a steam boiler to convert chemical energy into electrical or mechanical energy, which provides energy for various devices.

Referring to fig. 1, the present application provides a recovery device for condensing the LNG cold energy in the flue gas, which is suitable for various devices using LNG as energy source. Recovery unit can be with the cold energy recycle of LNG gasification in-process release to the flue gas cooling that produces after the NG burning, thereby it is solid to make partial flue gas reach the desublimation point to desublimate. The recovery device can reduce the emission of smoke on the one hand and slow down the greenhouse effect. On the other hand, the desublimated solid can realize resource recycling, improve the energy utilization rate and reduce the production and manufacturing cost.

The LNG cold energy is used for the recovery unit of flue gas desublimation and it includes LNG storage module 100, combustion module 200, water-cooling heat transfer module 300, natural gas heat transfer module 400, first desublimation module 500 and second desublimation module 600. The LNG storage module 100 is capable of providing LNG for use by the combustion module 200. The combustion module 200 is in communication with the LNG storage module 100 and is capable of receiving the LNG-vaporized NG and combusting it. The water-cooling heat exchange module 300 is communicated with the smoke outlet of the combustion module 200 to reduce the temperature of the smoke. The natural gas heat exchange module 400 is communicated with the gas outlet of the water-cooled heat exchange module 300 to further reduce the temperature of the flue gas and enable the water vapor in the flue gas to reach a liquefaction point, and the water vapor is liquefied into water vapor. The first desublimation module 500 is communicated with the gas outlet of the natural gas heat exchange module 400 to further reduce the temperature of the flue gas, so that part of the flue gas is desublimed into solid and recycled. The second desublimation module 600 is communicated with the first desublimation module 500 to absorb the LNG gasification cold energy and further desublimate part of the flue gas.

In the process that the LNG storage module 100 delivers LNG to the combustion module 200, the LNG is gasified and releases gasified cold energy, and the gasified cold energy is transmitted to the natural gas heat exchange module 400 and the first desublimation module 500 through the second desublimation module 600; the flue gas is cooled down through water-cooling heat exchange module 300, natural gas heat exchange module 400, and after the first desublimation module 500 and the second desublimation module 600 desublimation respectively again, remaining flue gas flows back to first desublimation module 500 through second desublimation module 600 to for first desublimation module 500 provides the gasification cold energy.

The LNG storage module 100 is used for storing LNG, and an output port of the LNG storage module 100 is communicated with an input port of the combustion module 200. In the process of outputting LNG from the LNG storage module 100 to the combustion module 200, the LNG is gasified to release a large amount of cold energy, thereby recycling the resources of the flue gas generated by the combustion module 200.

The combustion module 200 is in communication with the LNG storage module 100 to receive NG and convert chemical energy of NG into thermal, mechanical, or electrical energy to drive operation of external devices. In some embodiments, the combustion module 200 is a boiler, which is suitable for use in ceramics, glass, steam demand parks, and the like. The limit on the space distance is reduced by combining the LNG gasification cold energy and the smoke emission nearby.

Referring to fig. 1, in this embodiment, the gas inlet of the water-cooling heat exchange module 300 is communicated with the smoke outlet of the combustion module 200 to cool the smoke, so that the high temperature of the smoke when the temperature of the smoke comes out from the combustion module 200 is reduced to normal temperature, thereby improving the efficiency of subsequent smoke desublimation, promoting the cold energy of LNG to be used for desublimation of the smoke as much as possible, and improving the recovery probability of the smoke. The gas outlet of the water-cooling heat exchange module 300 is communicated with the natural gas heat exchange module 400.

The water-cooling heat exchange module 300 includes a first water-cooling unit 310, a compression unit 330, and a second water-cooling unit 320. The air inlet of the first water-cooling unit 310 is communicated with the smoke outlet of the combustion module 200 to reduce the temperature of the smoke generated by combustion. The first water cooling unit 310 can reduce the temperature of the flue gas through normal temperature water flow to reduce the cooling energy required by subsequent flue gas desublimation. And the first water cooling unit 310 can also realize the cyclic utilization of the heat energy of the flue gas, and the energy utilization rate of the recovery device is improved.

In some embodiments, the first water cooling unit 310 includes a flue gas channel (not shown) and a water flow channel (not shown) disposed at the periphery of the flue gas channel. The water flow in the water flow channel can exchange heat energy with the flue gas in the flue gas channel. In other embodiments, the water flow channel comprises a plurality of water flow pipes, and the plurality of water flow pipes penetrate through the flue gas channel to improve the heat exchange efficiency.

The air inlet of the compression unit 330 is communicated with the air outlet of the first water-cooling unit 310, and the air outlet of the compression unit 330 is communicated with the air inlet of the second water-cooling unit 320. The flue gas output from the gas outlet of the first water-cooling unit 310 is compressed by the compression unit 330 and then input to the gas inlet of the second water-cooling unit 320. The compression unit 330 compresses the flue gas to improve the power of the flue gas, so as to overcome the resistance of the subsequent flue gas flowing through the natural gas heat exchange module 400, the first desublimation module 500 and the second desublimation module 600. In some embodiments, the compression unit 330 has less compression power, and it does not need to compress the flue gas into liquid for recycling, which is less costly. In addition, the compression unit 330 only needs to pressurize the flue gas to gauge pressure of 0.2 bar-0.5 bar, and the power of the compression unit 330 is lower than that of a compressor in a method for removing carbon dioxide by using a membrane method, a thermokalite method or an amine method in the market, so that the power consumption is low, and the overall energy consumption of the recovery device is obviously lower than that of other methods in the market. The method for removing carbon dioxide by using a membrane method or an ammonia method needs to pressurize the flue gas, the pressure is far more than 0.2 bar-0.5 bar, and the power consumption is far more than that of the device. For a specific method for removing carbon dioxide by using a membrane method, a thermokalite method or an amine method, reference is made to related technologies, which are not described herein.

The gas inlet of the second water cooling unit 320 is communicated with the gas outlet of the compression unit 330, and the gas outlet of the second water cooling unit 320 is communicated with the gas inlet of the natural gas heat exchange module 400. The second water cooling unit 320 absorbs the heat energy of the flue gas output by the compression unit 330, reduces the temperature of the flue gas, and improves the condensing efficiency of the flue gas. The second water cooling unit 320 can also realize the heat energy recycling of the flue gas, and improve the energy multistage utilization of the recovery device.

In this embodiment, the gas inlet of the natural gas heat exchange module 400 is communicated with the gas outlet of the second water cooling unit 320 to receive the flue gas output by the second water cooling unit 320, and absorb the cold energy generated by the LNG gasification to cool the flue gas. On one hand, the water vapor in the flue gas is liquefied into water vapor, so that the water vapor in the flue gas can be conveniently removed; on the other hand, the cooling energy required by the first desublimation module 500 and the second desublimation module 600 to desublimate the flue gas is reduced, and the flue gas desublimation efficiency of the first desublimation module 500 and the second desublimation module 600 is improved.

The natural gas heat exchange module 400 includes a natural gas heat exchange channel (not shown), a flue gas flow pipe (not shown), and a water removal unit 410. The two ends of the natural gas heat exchange channel are respectively communicated with the LNG storage module 100 and the combustion module 200, so that the gasified NG of the LNG can circulate in the natural gas heat exchange channel. The both ends of flue gas flow tube communicate the gas outlet of second water cooling unit 320 and the income gas port of first desublimation module 500 respectively to make the intraductal flue gas of flue gas flow can absorb LNG's gasification cold energy, thereby reduce the temperature of flue gas, make the vapor liquefaction in the flue gas be steam, so that dewatering unit 410 absorbs steam, thereby go out the steam in the flue gas.

In some embodiments, the natural gas heat exchange channel comprises a plurality of natural gas heat exchange tubes (not shown in the figures), and the plurality of natural gas heat exchange tubes penetrate through the flue gas flow tube, so that the flue gas can sufficiently absorb the gasification cold energy of the LNG in the natural gas heat exchange channel.

The gas inlet of the water removal unit 410 is communicated with the gas outlet of the flue gas circulation pipe in the natural gas heat exchange module 400, and the gas outlet of the water removal unit 410 is communicated with the inlet of the flue gas of the first desublimation module 500. After the flue gas flowing through the flue gas circulating pipe absorbs the gasification cold energy of the LNG in the natural gas heat exchange channel, part of steam in the flue gas is gasified into water vapor. After the flue gas flows into the water removal unit 410 from the flue gas flow pipe, the water removal unit 410 absorbs water in the flue gas to remove water molecules in the flue gas, so as to improve the quality of the solid in subsequent flue gas desublimation. In some embodiments, the water removal unit 410 is a reusable desiccant. The drying agent can use the heat energy of the subsequent smoke to realize recycling.

Fig. 2 is a schematic structural diagram of the first desublimation module of the embodiment of the recycling device of the present invention. Fig. 3 isbase:Sub>A cross-sectional view atbase:Sub>A-base:Sub>A of the structure shown in fig. 2.

Referring to fig. 1 to 3, in the present embodiment, the gas inlet of the flue gas of the first desublimation module 500 is communicated with the gas outlet of the flue gas circulation pipe in the water removal unit 410, and the first desublimation module 500 can absorb the gasification cold energy of the LNG to desublimate part of the flue gas into solid, thereby reducing the discharge amount of the flue gas. The gas outlet of the flue gas of the first desublimation module 500 is communicated with the gas inlet of the flue gas of the second desublimation module 600.

The first desublimation module 500 includes a first heat exchange pipe 510, a first housing 520, and first scrapers 541; the first heat exchange pipe 510 penetrates the first casing 520, and the first heat exchange pipe 510 is used for releasing the gasified cold energy of the LNG into the first casing 520. A first flue gas inlet 521, a first flue gas outlet 522 and a first desublimation substance outlet 523 are arranged in the first shell 520, the first flue gas inlet 521 and the first flue gas outlet 522 are positioned at two opposite ends of the first shell 520, the first flue gas inlet 521 is communicated with the gas outlet of the natural gas heat exchange module 400, and the first flue gas outlet 522 is communicated with the gas inlet of the flue gas of the second desublimation module 600. The inner peripheral wall of the first shell 520 is hermetically connected with the outer peripheral wall of the first heat exchange tube 510 to form a first desublimation chamber 530, and part of the flue gas is desublimated in the first desublimation chamber 530 to be solid. The first heat exchange pipe 510 communicates with the gas outlet of the flue gas of the second casing 620. The flue gas flowing through the first desublimation chamber 530 absorbs the cold energy of the flue gas discharged by the second desublimation module 600, so that the temperature of the flue gas in the first desublimation chamber 530 is reduced, and part of the flue gas is desublimed into solid. The flue gas discharged from the second desublimation module 600 flows through the first heat exchange pipe 510 and is discharged to the outside. The first scraping blade 541 is accommodated in the first casing 520, an outer peripheral wall of the first scraping blade 541 abuts against an inner peripheral wall of the first casing 520, and the first scraping blade 541 is sleeved on an outer periphery of the first heat exchange tube 510. The first wiper 541 can move along the extending direction of the first heat exchanging pipe 510 to wipe off the flue gas desublimation, and the hung flue gas desublimation is discharged through the first desublimation outlet 523.

Referring to fig. 1 to 3, in the present embodiment, the recycling apparatus further includes a smoke exhaust pipe 900, and the smoke exhaust pipe 900 is communicated with the outlet of the first heat exchange pipe 510, so that the smoke in the first heat exchange pipe 510 is exhausted to the outside through the smoke exhaust pipe 900.

In some embodiments, the point of desublimation of carbon dioxide in the flue gas is below-100 ℃, the substance desublimed by the first desublimation module 500 is carbon dioxide in the flue gas, and the desublimation is dry ice. On the one hand, the LNG gasification cold energy is recycled. On the other hand, the emission of carbon dioxide in the flue gas is reduced, and the greenhouse effect is slowed down.

In some embodiments, the first heat exchange pipe 510 is plural, and the plural first heat exchange pipes 510 extend in the same direction. The plurality of first heat exchange pipes 510 penetrate through the first housing 520, and the contact area between the first heat exchange pipes 510 and the flue gas is increased, so that the cold energy absorption efficiency of the first desublimation module 500 is improved, and the gasified cold energy of the LNG is fully absorbed. The first scraping blades 541 correspond to the openings of the plurality of first heat exchange tubes 510 to accommodate the plurality of first heat exchange tubes 510, so that the first scraping blades 541 move to hang the dry ice on the outer peripheries of the plurality of first heat exchange tubes 510 and the inner peripheral wall of the first housing 520.

Referring to fig. 1 to 3, the first desublimation module 500 further includes a first transmission shaft 542, a first nut 543, and a first driving mechanism 544; the first transmission shaft 542 extends in the extending direction of the first heat exchange pipe 510, both ends of the first transmission shaft 542 are now positioned on the first housing 520, and the first transmission shaft 542 can rotate about its own rotation axis. The first scraping blade 541 is sleeved on the first transmission shaft 542, the first scraping blade 541 is threadedly connected to the first transmission shaft 542 through a first nut 543, and the first transmission shaft 542 rotates to enable the first scraping blade 541 to move along the extending direction of the first transmission shaft 542. The first driving mechanism 544 is drivingly connected to the first transmission shaft 542 to drive the first transmission shaft 542 to rotate around its axis.

Referring to fig. 1 and 4, in this embodiment, the flue gas inlet of the second desublimation module 600 is communicated with the gas outlet of the flue gas circulation pipe in the first desublimation module 500, and the first desublimation module 500 can absorb the gasification cold energy of LNG to desublimate part of the flue gas into solid, thereby reducing the amount of flue gas emission. After the flue gas in the second desublimation module 600 is desublimated, the flue gas outlet of the second desublimation module 600 is communicated with the gas inlet of the first heat exchange tube 510 of the first desublimation module 500.

The second desublimation module 600 comprises a second heat exchange pipe 610, a second shell 620 and a second wiper 641; the second heat exchange pipe 610 penetrates the second casing 620, and the second heat exchange pipe 610 is used for releasing the gasified cold energy of the LNG into the second casing 620. A second flue gas inlet 621, a second flue gas outlet 622 and a second desublimation outlet 623 are arranged in the second shell 620, the second flue gas inlet 621 and the second flue gas outlet 622 are located at two opposite ends of the second shell 620, the second flue gas inlet 621 is communicated with the first flue gas outlet, and the second flue gas outlet 622 is communicated with the gas inlet of the first heat exchange tube 510. The inner peripheral wall of the second casing 620 is hermetically connected with the outer peripheral wall of the second heat exchange tube 610 to form a second desublimation chamber 630, and part of the flue gas is desublimated into a solid in the second desublimation chamber 630. The second heat exchange pipe 610 is internally used for circulating LNG and NG. The flue gas flowing through the second desublimation chamber 630 absorbs the gasification cold energy in the second heat exchange tube 610, thereby reducing the temperature of the flue gas in the second desublimation chamber 630 and desublimating part of the flue gas into solid. The flue gas discharged from the second desublimation chamber 630 through the second flue gas outlet 622 flows through the first heat exchange pipe 510 and is discharged to the outside. The second scraping blade 641 is accommodated in the second casing 620, an outer peripheral wall of the second scraping blade 641 abuts against an inner peripheral wall of the second casing 620, and the second scraping blade 641 is sleeved on an outer periphery of the second heat exchange tube 610. The second wiper 641 is movable in the extending direction of the second heat exchanging pipe 610 to wipe off the flue gas desublimation, and the hung off flue gas desublimation is discharged through the second desublimation outlet 623.

In some embodiments, the desublimated substance of the second desublimation module 600 is carbon dioxide in the flue gas and the desublimation is dry ice. On the one hand, the LNG gasification cold energy is recycled. On the other hand, the emission of carbon dioxide in the flue gas is reduced, and the greenhouse effect is slowed down.

In some embodiments, the second heat exchange pipe 610 is plural, and the plural second heat exchange pipes 610 extend in the same direction. The second shell 620 is penetrated by the second heat exchange tubes 610, so that the contact area between the second heat exchange tubes 610 and the flue gas is increased, and the cold energy absorption efficiency of the second desublimation module 600 is improved. The second scraping blades 641 are opened corresponding to the plurality of second heat exchange tubes 610 to receive the plurality of second heat exchange tubes 610, so that the second scraping blades 641 hang the dry ice on the outer peripheries of the plurality of second heat exchange tubes 610 and the inner peripheral wall of the second housing 620 when moving.

The second desublimation module 600 further comprises a second transmission shaft 642, a second screw 643 and a second driving mechanism 644; the second transmission shaft 642 extends along the extending direction of the second heat exchanging pipe 610, both ends of the second transmission shaft 642 are now positioned on the second housing 620, and the second transmission shaft 642 can rotate around its own rotation axis. The second scraper 641 is sleeved on the second transmission shaft 642, the second scraper 641 is screwed on the second transmission shaft 642 through a second screw 643, and the second transmission shaft 642 rotates to enable the second scraper 641 to move along the extending direction of the second transmission shaft 642. The second driving mechanism 644 is drivingly connected to the second transmission shaft 642 for driving the second transmission shaft 642 to rotate around its axis.

In this embodiment, the natural gas heat exchange channel is in communication with the second heat exchange tube 610 to form a transfer conduit for the LNG storage module 100 to the combustion module 200. An inlet of the second heat exchange pipe 610 is communicated with an outlet of the LNG storage module 100, an outlet of the second heat exchange pipe 610 is communicated with an inlet of the natural gas heat exchange channel, and an outlet of the natural gas heat exchange channel is communicated with the combustion module 200. The temperature of second heat exchange tube 610 department is less than the temperature of natural gas heat transfer passageway to make second heat exchange tube 610 be used for the desublimation of flue gas, the natural gas heat transfer passageway is used for the cooling of flue gas, in order to realize the multistage utilization of LNG gasification cold energy, improves the utilization efficiency of LNG gasification cold energy.

In this embodiment, the recovery apparatus for flue gas desublimation using LNG cold energy further includes a desublimation collection module, and the desublimation collection module is respectively communicated with the first desublimation outlet 523 of the first desublimation module 500 and the second desublimation outlet 623 of the second desublimation module 600.

In some embodiments, it is calculated that after the flue gas sequentially passes through the first water cooling unit 310, the second water cooling unit 320, the natural gas heat exchange module 400, the first desublimation module 500 and the second desublimation module 600, the recovery rate of carbon dioxide in the flue gas is 35%. At this time, the temperatures inside the first heat exchange pipe 510 and the second heat exchange pipe 610 are both lower than-120 ℃ to sufficiently desublimate the carbon dioxide.

Fig. 5 is a schematic structural view of the spray desublimation module of the embodiment of the recovery device of the present invention.

Referring to fig. 1, fig. 4 and fig. 5, in this embodiment, in order to further reduce the content of carbon dioxide in the flue gas, the recovery apparatus for flue gas desublimation using LNG cold energy further includes a spraying desublimation module 700, an air inlet of the spraying desublimation module 700 is communicated with the second flue gas outlet 622, and an air outlet of the spraying desublimation module 700 is communicated with an inlet of the first heat exchange pipe 510. The spraying module can further reduce the temperature of the flue gas, thereby further reducing the carbon dioxide in the flue gas.

The spray desublimation module 700 includes a heat exchange tank 710, a spray unit 720 disposed in the heat exchange tank 710, and a liquid nitrogen storage unit 730 communicated with the spray unit 720. The heat exchange tank 710 extends in the up-down direction, the spraying flue gas inlet 711 is formed in the peripheral side of the bottom of the heat exchange tank 710, and the spraying flue gas inlet 711 is communicated with the second flue gas outlet 622 of the second shell 620. The lower part of the heat exchange tank 710 is provided with a spray desublimation outlet 713. The upper part of the heat exchange tank 710 is provided with a spraying flue gas outlet 712, and the spraying flue gas outlet 712 is communicated with the inlet of the first heat exchange pipe 510. The spraying unit 720 sprays in the heat exchange tank 710, and the cold energy of the sprayed liquid nitrogen is conveyed into the flue gas, so that the temperature of the flue gas is reduced, part of the flue gas is desublimated into dry ice, and the content of carbon dioxide in the flue gas is reduced. In some embodiments, the bottom of the heat exchange tank 710 is a hemispherical shape with an upward opening, and the spray desublimation outlet 713 is located at the center of the hemispherical shape to facilitate the delivery of dry ice to the desublimation collection module 800.

One end of the spray desublimation outlet 713, which is far away from the heat exchange tank 710, is communicated with a filtering and separating unit 740, and the filtering and separating unit 740 is communicated with the liquid nitrogen storage unit 730 and the desublimation collection module. The mixture in the heat exchange tank 710 is delivered to the filtering separation unit 740 through the spray desublimation outlet 713. The filtering separation unit 740 can separate liquid nitrogen and dry ice. The liquid nitrogen is recovered to the liquid nitrogen storage unit 730. The dry ice is recovered into a desublimated matter collecting module. In some embodiments, the residual liquid nitrogen on the dry ice can be directly discharged to the outside after being gasified into nitrogen gas, and no pollution is caused.

In some embodiments, a pressurizing unit 750 is further disposed between the liquid nitrogen storage unit 730 and the spraying unit 720, and the pressurizing unit 750 strengthens the pressure of the liquid nitrogen to increase the spraying speed of the spraying unit 720, so as to achieve sufficient heat exchange between the flue gas and the liquid nitrogen, and enable the recycling rate of carbon dioxide in the flue gas to reach 100%.

Referring to fig. 1 to 5, in the present embodiment, LNG in the LNG storage module 100 is transferred to the combustion module 200, where the LNG releases cold energy to be gasified into NG, and the NG is inputted to the combustion module 200 to be combusted to generate flue gas.

The flue gas generated by the combustion module 200 is delivered to the first water cooling unit 310 from the flue gas outlet to be cooled. The flue gas after being cooled is conveyed to the compression unit 330, and the flue gas is conveyed to the second water cooling unit 320 for cooling after being compressed by the compression unit 330. The flue gas is cooled by the second water cooling unit 320 and then conveyed into the flue gas flow pipe. The flue gas in the flue gas flow tube absorbs the gasification cold energy of NG in the natural gas heat exchange channel, thereby further reducing the temperature of the flue gas and liquefying water molecules in the flue gas into water vapor. The flue gas in the flue gas flow pipe absorbs the gasification cold energy and then is conveyed into the water removal unit 410 to remove the water vapor in the flue gas.

The flue gas in the water removal unit 410 enters the first desublimation chamber 530 through the first flue gas inlet 521, and the flue gas absorbs the gasification cold energy of the NG in the first heat exchange tube 510 in the first desublimation chamber 530, so that part of the flue gas is desublimed into dry ice. The dry ice is conveyed to the first desublimated substance outlet 523 by the first scraper 541, and conveyed to the desublimated substance collection module 800 through the first desublimated substance outlet 523.

Residual flue gas in the first desublimation chamber 530 is input into the second desublimation chamber 630 through the first flue gas outlet 522 and the second flue gas inlet 621. The flue gas absorbs the cold of the second heat exchange tube 610 in the second desublimation chamber 630, so that the carbon dioxide in the flue gas is further desublimed into dry ice. The dry ice in the second desublimation chamber 630 is output to the desublimation collection module 800 through the second desublimation outlet 623.

The residual flue gas in the second desublimation chamber 630 absorbs the gasification cold energy and then is further cooled, and is conveyed into the first heat exchange tube 510 through the second flue gas outlet 622, so that the flue gas in the first desublimation chamber 530 absorbs the gasification cold energy of the flue gas in the first heat exchange tube 510. Part of the flue gas in the first desublimation chamber 530 absorbs the gasification cold energy and then is desublimated into dry ice. After the flue gas in the first heat exchange tube 510 exchanges heat with the flue gas in the first desublimation chamber 530, the flue gas in the first heat exchange tube 510 is input into the exhaust pipe 900 and is discharged to the outside through the exhaust pipe 900.

Referring to fig. 2, 3, 4 and 6, in another embodiment of the present application, the recovery apparatus for flue gas desublimation of LNG cold energy includes only an LNG storage module 100, a combustion module 200, a natural gas heat exchange module 400, a first desublimation module 500, a second desublimation module 600, a desublimation collection module 800 and a chimney 900.

The LNG in the LNG storage module 100 releases the cold energy of gasification and then is converted into NG, and the NG is delivered to the combustion module 200 to be combusted to generate flue gas containing a large amount of nitrogen, carbon dioxide and the like. The flue gas is delivered into the natural gas heat exchange module 400 through the flue gas outlet of the combustion module 200 to liquefy the water vapor and dry it. The dried flue gas is discharged to the outside after being desublimated by the first desublimation module 500 and the second desublimation module 600.

While the present application has been described with reference to several exemplary embodiments, it is understood that the terminology used is intended to be in the nature of words of description and illustration, rather than of limitation. As the present application may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.

Claims

1. The utility model provides a LNG cold energy is used for recovery unit of flue gas desublimation, its gasification cold energy that is used for retrieving LNG, its characterized in that includes:

the gas inlet of the natural gas heat exchange module is used for allowing flue gas generated by combustion to enter, and the natural gas heat exchange module cools the flue gas;

the gas inlet of the first desublimation module is communicated with the natural gas heat exchange module so as to desublimate part of the flue gas;

the gas inlet of the second desublimation module is communicated with the gas outlet of the first desublimation module so as to desublimate part of the flue gas; the flue gas output by the gas outlet of the second desublimation module exchanges heat with the first desublimation module;

the gasification cold energy is transmitted to the natural gas heat exchange module and the first desublimation module through the second desublimation module respectively; the flue gas warp the cooling of natural gas heat transfer module, the warp again first desublimation module reaches the second desublimation module is desublimed the back respectively, remains the flue gas warp the second desublimation module flows back to first desublimation module, and does first desublimation module provides the gasification cold energy.

2. The recycling device according to claim 1, further comprising a water-cooling heat exchange module, wherein the water-cooling heat exchange module comprises a first water-cooling unit and a second water-cooling unit, and an air inlet of the first water-cooling unit is used for flue gas generated by combustion to enter; the second water cooling unit is communicated with the first water cooling unit, and the gas outlet of the second water cooling unit is communicated with the gas inlet of the natural gas heat exchange module.

3. The recycling apparatus according to claim 2, further comprising a compression unit, wherein an air inlet of the compression unit is communicated with the first water cooling unit, and an air outlet of the compression unit is communicated with the second water cooling unit.

4. The recycling apparatus according to claim 1, wherein a water removal unit is arranged between the gas outlet of the natural gas heat exchange module and the gas inlet of the first desublimation module.

5. The recovery device of claim 1, wherein the second desublimation module comprises a second heat exchange tube, a second housing, and a second wiper; the second heat exchange tube is used for circulating LNG and penetrates through the second shell; two ends of the second shell are respectively provided with an opening, and the inner peripheral wall of the second shell and the outer peripheral wall of the second heat exchange tube form a second desublimation chamber; the gas inlet of the second shell is communicated with the gas outlet of the first desublimation module; the gas outlet of the second shell is used for discharging the flue gas after the LNG gasification cold energy is absorbed; the bottom of the second shell is opened for the passage of desublimated substances; the peripheral wall butt of second doctor-bar the internal perisporium of second casing, the second doctor-bar cover is located the periphery of second heat exchange tube, the second doctor-bar can be followed the extending direction of second heat exchange tube removes.

6. The recycling device according to claim 5, wherein the second desublimation module further comprises a second transmission shaft in transmission connection with the second scraping blade, a second nut fixed on the second scraping blade, and a second driving mechanism for driving the second transmission shaft to rotate, the second transmission shaft extends along the extending direction of the heat exchange tube, and the second driving mechanism drives the second transmission shaft to rotate around the rotation axis thereof; the second nut is sleeved on the second transmission shaft and in threaded connection with the second transmission shaft, so that the second scraping blade can move along the axis direction of the second transmission shaft.

7. The recycling apparatus according to claim 5, wherein said first desublimation module comprises a first heat exchange tube, a first housing; the first heat exchange tube penetrates through the first shell, and a first desublimation chamber is formed by the inner peripheral wall of the first shell and the outer peripheral wall of the first heat exchange tube; the two opposite ends of the first shell are opened to be respectively communicated with the gas outlet of the natural gas heat exchange module and the gas inlet of the second shell; the first heat exchange tube is communicated with the air outlet of the second shell.

8. The recycling device according to claim 7, wherein a spray desublimation module is communicated between the gas outlet of the second shell and the first heat exchange tube.

9. The recycling device according to claim 8, wherein the spray desublimation module comprises a heat exchange tank, a spray unit arranged in the heat exchange tank and a liquid nitrogen storage unit communicated with the spray unit; the heat exchange tank extends along the up-down direction, a spray flue gas inlet is formed in the periphery of the lower portion of the heat exchange tank and communicated with the gas outlet of the second shell, a spray desublimation substance outlet is formed in the center of the lower portion of the heat exchange tank, a spray flue gas outlet is formed in the upper portion of the heat exchange tank, and the spray flue gas outlet is communicated with the inlet of the first heat exchange pipe; the spraying unit sprays in the heat exchange tank so as to desublimate part of the flue gas.

10. The recycling apparatus according to claim 9, wherein the end of the spray desublimation outlet away from the heat exchange tank is provided with a filtration and separation unit.