Membrane separation device and engine exhaust device

Abstract

The invention relates to the technical field of environmental protection, and discloses a membrane separation device and an engine exhaust device.A first-stage separation membrane assembly comprises a first cylindrical membrane and a first cylindrical membrane arranged in the first cylindrical membrane, the inner diameter side of the first cylindrical membrane and the axial inner side of the first cylindrical membrane are first spaces, and the first spaces are air inlet spaces; the axial outer side of the first cylindrical film is a third space, and the outer diameter side of the first cylindrical film is a second space; the secondary separation membrane assembly comprises a second cylindrical membrane and a second cylindrical membrane arranged in the second cylindrical membrane, the axial inner side of the second cylindrical membrane and the axial inner side of the second cylindrical membrane are third spaces, the outer diameter side of the second cylindrical membrane is a second space, the axial outer side of the second cylindrical membrane is a fourth space, and the axial outer side of the second cylindrical membrane is a fifth space; and the fourth space and the fifth space are exhaust spaces. Four circulation paths can be formed from the gas inlet space to the gas exhaust space and used for circulation of different gas components, and finally gas to be separated is separated out.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection, and in particular to a membrane separation device and an engine exhaust device. Background Art

[0002] In the field of global transportation, with the rapid development of economy and the continuous growth of population, the number of vehicles has exceeded one billion. Although the carbon emissions generated by the engine of each vehicle when running alone are relatively small, due to the large number of vehicles, the overall carbon emissions are extremely significant, causing serious impacts on the global climate and environment. Therefore, how to effectively control and reduce carbon emissions in the field of transportation has become an important issue that needs to be solved urgently.

[0003] For CO 2 There are many methods for capturing emissions that have been studied and applied, including solvent absorption, cryogenic separation, membrane separation technology and adsorption separation.

[0004] The solvent absorption method utilizes the difference in solubility of different solutes in solvents to separate and purify the target by selecting a suitable solvent. However, this method may face challenges in solvent selection, recovery and treatment in practical applications.

[0005] Low temperature separation, also known as cryogenic separation, is based on the difference in boiling points of different substances. It uses low temperature liquefaction and separation distillation to purify and recover CO in the mixed gas. 2 However, this method has high energy consumption and equipment cost, and is difficult to achieve large-scale mass production, which limits its widespread application.

[0006] Membrane separation technology is based on the different permeability of each component in the mixture through the membrane to achieve separation. With the continuous development of membrane synthesis technology, membrane separation has become increasingly popular in CO 2 It has shown broad application prospects in capture. 2 Gas separation membrane materials include organic membranes such as polyethylene oxide, polyphenylene ether, etc., and composite materials such as MOFs (Metal-Organic Frameworks), carbon membranes, mixed matrix membranes, etc. However, issues such as the performance, stability and cost of membrane materials still need further research and resolution.

[0007] Adsorption separation method is to use the difference in the intensity of the action between the adsorbent and the mixed gas under different operating conditions to achieve separation and purification. According to different operating conditions, adsorption separation method can be divided into temperature swing adsorption (TSA) and pressure swing adsorption (PSA). Among them, pressure swing adsorption has been widely used in the gas adsorption and separation industry due to its advantages such as low energy demand, simple operation process and short adsorbent regeneration cycle. For example, in the flue gas separation process, CO 2The capture is mostly done by pressure swing adsorption separation process.

[0008] However, currently these CO 2 The capture method is mainly used in coal-fired power plants and other places with large fossil fuel consumption and CO 2 For large-scale energy equipment with large concentrated emissions. For mobile and decentralized energy equipment, such as vehicles and other transportation vehicles, due to the complexity and diversity of their operating environments, there is no effective CO 2 Capture technology involves this field. Especially in the control of engine carbon emissions, the current focus is on the combustion and utilization of fossil fuels, while the post-combustion CO 2 Technological research and development in the exhaust emission stage is still blank. Summary of the invention

[0009] The purpose of the present invention is to provide a membrane separation device and an engine exhaust device to solve the problems existing in the above-mentioned prior art. Four flow paths can be formed from the intake space to the exhaust space. Multiple flow paths can be used to circulate different gas components and finally separate the gas to be separated.

[0010] To achieve the above object, the present invention provides the following solutions:

[0011] The present invention provides a membrane separation device, comprising a primary separation membrane assembly and a secondary separation membrane assembly, wherein the primary separation membrane assembly comprises a first tubular membrane and a first columnar membrane, wherein the first columnar membrane is arranged on the inner diameter side of the first tubular membrane and close to the end, the inner diameter side of the first tubular membrane and the axial inner side of the first columnar membrane are a first space, the first space is an air intake space, the axial outer side of the first columnar membrane is a third space, and the outer diameter side of the first tubular membrane is a second space; the secondary separation membrane assembly comprises a second tubular membrane and a second columnar membrane, wherein the second columnar membrane is arranged on the inner diameter side of the second tubular membrane, the axial inner side of the second tubular membrane and the axial inner side of the second columnar membrane are the third space, the outer diameter side of the second tubular membrane is the second space, the axial outer side of the second tubular membrane is a fourth space, the axial outer side of the second columnar membrane is a fifth space, and the fourth space and the fifth space are exhaust spaces.

[0012] In one embodiment, the radial inner surface of the first cylindrical membrane is modified to be hydrophilic. 2 O-type surface layer, radial outer surface modified to hydrophobic H 2 O surface layer; the first cylindrical film axial inner surface modified to be hydrophobic H 2 O-like surface layer, the axial outer surface is modified to be CO-philic 2 The axial inner surface of the second cylindrical membrane is modified to be pro-H 2The axial inner surface of the second columnar film is modified to be CO-philic 2 The radial side surface is modified to be CO-philic 2 Sexual surface layer.

[0013] In one embodiment, the radial inner surface of the first tubular membrane is made of modified nano-silica, and the radial outer surface is made of modified graphite nanomaterial; the axial inner surface of the first columnar membrane is made of modified graphite nanomaterial, and the axial outer surface is made of modified graphene nanomaterial; the axial inner surface of the second tubular membrane is made of modified nano-silica; the axial inner surface of the second columnar membrane is made of modified graphene nanomaterial, and the radial side surface is made of modified graphene nanomaterial.

[0014] In one embodiment, the inner diameter of the first tubular membrane, the outer diameter of the first cylindrical membrane, and the outer diameter of the second tubular membrane are equal.

[0015] In one embodiment, the end surfaces of the second tubular membrane and the second cylindrical membrane are flush, and the axial length of the second tubular membrane is equal to the axial length of the second cylindrical membrane.

[0016] In one embodiment, it includes a main shell, which includes an outer shell and an inner shell that are nested with each other, the inner diameter side of the inner shell is the third space, the inner wall of the outer shell and the outer wall of the inner shell are between the second space, the inlet end of the outer shell is provided with the first space, and the outlet end of the outer shell is provided with the fourth space and the fifth space.

[0017] In one embodiment, an outlet pipe is further included, and the outlet pipe includes an inner pipe and an outer pipe which are nested with each other, the inner diameter side of the inner pipe is the fifth space, and the space between the inner wall of the outer pipe and the outer wall of the inner pipe is the fourth space.

[0018] In one embodiment, it also includes a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor and a fifth pressure sensor, the first pressure sensor is arranged in the first space, the second pressure sensor is arranged in the second space, the third pressure sensor is arranged in the third space, the fourth pressure sensor is arranged in the fourth space, and the fifth pressure sensor is arranged in the fifth space.

[0019] In one embodiment, the first temperature sensor and the second temperature sensor are further included, wherein the first temperature sensor is disposed in the first space, and the second temperature sensor is disposed in the fourth space and / or the fifth space.

[0020] The present invention provides an engine exhaust device, comprising an exhaust pipe for connecting to the engine and the membrane separation device as described above, wherein the first space is connected to the exhaust pipe.

[0021] Compared with the prior art, the present invention has achieved the following technical effects:

[0022] The present invention utilizes a primary separation membrane assembly and a secondary separation membrane assembly to separate into a first space, a second space, a third space, a fourth space, and a fifth space. Four flow paths can be formed from the air intake space to the exhaust space, namely, sequentially from the first space, the second space to the fourth space, sequentially from the first space, the second space to the fifth space, sequentially from the first space, the third space to the fourth space, and sequentially from the first space, the third space to the fifth space. Multiple flow paths can be used to circulate different gas components, and ultimately the gas to be separated (for example, CO 2 ) separated.

[0023] The present invention can be applied to CO2 emission from mobile and distributed energy equipment such as transportation vehicles. 2 Capture is of great significance for effectively controlling and reducing carbon emissions in the transportation sector. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the overall structure of the engine exhaust device in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of a membrane separation device in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of a first cylindrical membrane in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of a first cylindrical membrane in an embodiment of the present invention;

[0029] Figure 5 Schematic diagram of the second cylindrical membrane in an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of a second cylindrical membrane in an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of a membrane separation device in an embodiment of the present invention;

[0032] Among them, 1. exhaust pipe; 2. first tubular membrane; 21. first hydrophobic layer; 22. first hydrophilic layer; 3. first columnar membrane; 31. second hydrophobic layer; 32. first carbon dioxide affinity layer; 4. second tubular membrane; 41. second hydrophilic layer; 5. second columnar membrane; 51. second carbon dioxide affinity layer; 52. third carbon dioxide affinity layer; 6. fourth space; 7. fifth space; 8. third space; 9. second space; 10. first space; 11. first pressure sensor; 12. second pressure sensor; 13. third pressure sensor; 14. fourth pressure sensor; 15. fifth pressure sensor; 16. first temperature sensor; 17. second temperature sensor; 18. outer shell; 19. inner shell; 23. pollutant emission control system; 24. outer tube; 25. inner tube; 26. engine; 110. primary separation membrane assembly; 120. secondary separation membrane assembly. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The purpose of the present invention is to provide a membrane separation device and an engine exhaust device to solve the problems existing in the prior art. Four flow paths can be formed from the intake space to the exhaust space. Multiple flow paths can be used to circulate different gas components and finally separate the gas to be separated.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figure 1 to Figure 7As shown, the present invention provides a membrane separation device, including a primary separation membrane assembly 110 and a secondary separation membrane assembly 120, wherein the primary separation membrane assembly 110 includes a first tubular membrane 2 and a first columnar membrane 3, wherein the first tubular membrane 2 can be a separation membrane of a cylindrical structure, and the first columnar membrane 3 can be a separation membrane of a cylindrical structure, wherein the first columnar membrane 3 is arranged on the inner diameter side of the first tubular membrane 2 and close to the end, thereby forming a first space 10 on the inner diameter side of the first tubular membrane 2 and the axial inner side of the first columnar membrane 3, wherein the first space 10 is an intake space, and is used to connect the exhaust pipe 1 of the engine 26 to wait for the gas source to be processed. It should be noted that the axial inner side mentioned here and in the following text refers to the side close to the intake space, and the axial outer side refers to the side close to the exhaust space. The axial outer side of the first columnar membrane 3 is the third space 8, and the outer diameter side of the first tubular membrane 2 is the second space 9. The secondary separation membrane assembly 120 includes a second cylindrical membrane 4 and a second columnar membrane 5. The second cylindrical membrane 4 can be a separation membrane with a cylindrical structure, and the second columnar membrane 5 can be a separation membrane with a cylindrical structure. The second columnar membrane 5 is arranged on the inner diameter side of the second cylindrical membrane 4. The axial inner side of the second cylindrical membrane 4 and the axial inner side of the second columnar membrane 5 are the third space 8, the outer diameter side of the second cylindrical membrane 4 is the second space 9, the axial outer side of the second cylindrical membrane 4 is the fourth space 6, and the axial outer side of the second columnar membrane 5 is the fifth space 7. The fourth space 6 and the fifth space 7 are exhaust spaces.

[0037] The present invention utilizes a primary separation membrane assembly 110 and a secondary separation membrane assembly 120 to separate into a first space 10, a second space 9, a third space 8, a fourth space 6 and a fifth space 7, wherein the first space 10 is used as an intake space, and the fourth space 6 and the fifth space 7 are used as exhaust spaces. Four flow paths can be formed from the intake space to the exhaust space, namely, sequentially from the first space 10, the second space 9 to the fourth space 6, sequentially from the first space 10, the second space 9 to the fifth space 7, sequentially from the first space 10, the third space 8 to the fourth space 6, and sequentially from the first space 10, the third space 8 to the fifth space 7. Under the action of the primary separation membrane assembly 110 and the secondary separation membrane assembly 120, multiple flow paths can be used to circulate different gas components, and finally the gas to be separated (for example, CO 2 ) separated.

[0038] In one embodiment, after the membrane separation device of the present invention is installed in the pollutant emission control system 23 provided in the exhaust pipe 1 of the engine 26, the emissions at this time are mainly: N 2 , O 2 , H 2 O、CO 2 Table 1 shows the CO 2 Table 2 shows the physical properties of CO 2From Tables 1 and 2, we can see that the physical and chemical properties of these emissions, such as their molecular dynamics diameters, are significantly different. Let the molecular dynamics diameters be d N2 d O2 d H2O d CO2 Indicates that there is d H2O <d CO2 <d N2 <d O2 .H 2 O is a polar molecule, N 2 , O 2 , CO 2 It is a non-polar molecule. 2 There is a triple bond N≡N in the molecule, N 2 The molecule is the most stable diatomic molecule known. 2 The molecule has a lower energy level of empty orbital and a higher electron affinity, so it is relatively easier to accept electrons. Based on this, a separation membrane with corresponding functions can be designed. The engine 26 with the proposed two-stage separation membrane structure in series can emit CO 2 Separation technology, in the exhaust pipe 1, CO 2 From N 2 , O 2 , H 2 O、CO 2 Separate out.

[0039] Table 1CO 2 Physical properties

[0040]

[0041]

[0042] Table 2CO 2 Equimolecular diameter /

[0043] He <![CDATA[H 2 ]]> <![CDATA[CO 2 ]]> <![CDATA[O 2 ]]> <![CDATA[N 2 ]]> <![CDATA[CH 4 ]]> <![CDATA[C 2 H 4 ]]> <![CDATA[C 3 H 6 ]]> Kinetic diameter 2.60 2.89 3.30 3.46 3.64 3.80 3.9 4.5 Collision diameter 2.58 2.92 4.00 3.43 2.68 3.82 4.42 5.06 Effective diameter 2.59 2.90 3.63 3.44 3.66 3.81 / /

[0044] In one embodiment, the radially inner surface of the first cylindrical membrane 2 is modified to be hydrophilic. 2 The hydrophilic surface layer, i.e., the first hydrophilic layer 22, has its radially outer surface modified to be hydrophobic. 2 The first columnar film 3 has a hydrophobic surface layer, namely, a first hydrophobic layer 21. The axial inner surface of the first columnar film 3 is modified to be hydrophobic. 2 O-like surface layer, i.e., the second hydrophobic layer 31, the axial outer surface is modified to be CO-philic 2 The axial inner surface of the second tubular membrane 4 is modified to be carbon dioxide-philic. 2The axial inner surface of the second columnar membrane 5 is modified to be CO-philic. 2 The radial side surface is modified to be CO2-philic. 2 The third carbon dioxide-philic layer 52 is a surface layer.

[0045] In one embodiment, the radial inner surface of the first tubular membrane 2 is made of modified nano-silicon dioxide, and the radial outer surface is made of modified graphite nano-material. The axial inner surface of the first cylindrical membrane 3 is made of modified graphite nano-material, and the axial outer surface is made of modified graphene nano-material. The axial inner surface of the second tubular membrane 4 is made of modified nano-silicon dioxide. The axial inner surface of the second cylindrical membrane 5 is made of modified graphene nano-material, and the radial side surface is made of modified graphene nano-material.

[0046] In one embodiment, the primary separation membrane assembly 110 and the secondary separation membrane assembly 120 have the following characteristics:

[0047] Primary separation membrane assembly 110: The first cylindrical membrane 2 is a microporous membrane that follows the molecular sieving mechanism. Its main function is to convert CO 2 With N 2 , O 2 , H 2 O separation, according to d O2 The size of the molecular sieve material ZSM-5 is selected The pore size of the molecular sieve membrane is d a The radial inner surface is modified with nano-silica to be H-philic. 2 O-type surface layer, the radial outer surface is modified by graphite nanomaterials to be H-free 2 O-type surface layer, the modification process of the membrane surface is completed by dipping method, there are: d H2O <d CO2 <d N2 <d O2 <d a The first columnar membrane 3 is a microporous membrane that follows the molecular sieving mechanism and also has some functions of an adsorption membrane. Its main function is to convert CO 2 With H 2 O separation, while N 2 , O 2 The membrane blocks it, according to d CO2 The size of the LTA zeolite is selected + Molecular sieve membrane made of exchanged A-type molecular sieve (commercially known as Na-A type) material The aperture size is d b It indicates that the graphite nanomaterial on the inner axial surface is modified to be hydrophobic 2O-like surface layer, and the axial outer surface is modified to be CO-philic using graphene nanomaterials 2 The modification process of the membrane surface is completed by the dipping method. On the membrane surface there are: H2O <d CO2 <d b <d N2 <d O2 .

[0048] Secondary separation membrane assembly 120: The second cylindrical membrane 4 is a microporous membrane that follows the molecular sieving mechanism. Its main function is to convert CO 2 With H 2 O separation, and N 2 , O 2 , H 2 O is separated and the molecular sieve material ZSM-5 is selected The pore size of the molecular sieve membrane is d c Indicates that there are: d H2O <d CO2 <d N2 <d O2 <d c The inner axial surface is modified with nano-silica to be H-philic. 2 O-type surface layer, the modification process of the membrane surface is completed by impregnation method, in the 2 O surface layer, should be d H2O <d CO2 <d c <d N2 <d O2 The second columnar membrane 5 is a microporous membrane that follows the molecular sieving mechanism and also has some functions of an adsorption membrane. Its main function is to convert CO 2 With H 2 O separation, according to d CO2 The size of the LTA zeolite is selected + Molecular sieve membrane made of exchanged A-type molecular sieve (commercially known as Na-A type) material The aperture size is d d The inner axial surface is modified with graphene nanomaterials to be CO-philic. 2 The radial side surface is modified with graphene nanomaterials to be CO-philic. 2 The modification process of the membrane surface is completed by the dipping method. On the membrane surface there are: H2O <d CO2 <d d <d N2 <d O2 .

[0049] In one embodiment, the inner diameter of the first cylindrical membrane 2, the outer diameter of the first cylindrical membrane 3 and the outer diameter of the second cylindrical membrane 4 are equal. The first cylindrical membrane 3 is embedded in the first cylindrical membrane 2 from one end and is flush with the end surface of the exhaust space. This facilitates the connection of the first cylindrical membrane 3 and the second cylindrical membrane 5 with the exhaust pipe 1 and can form the first space 10.

[0050] In one embodiment, the end surfaces of the second tubular membrane 4 and the second cylindrical membrane 5 are flush, and the axial length of the second tubular membrane 4 is equal to the axial length of the second cylindrical membrane 5, so as to facilitate the division of the fourth space 6 and the fifth space 7 on the axial outer side.

[0051] For the size of the first cylindrical membrane 2, the inner diameter is r 1 , radial wall thickness is δ 1 , axial height is δ 2 For the size of the first cylindrical membrane 3, the diameter is r 1 , axial height is δ 3 For the size of the second cylindrical membrane 4, the outer diameter is r 1 , inner diameter is r 3 , axial height is δ 4 For the size of the second cylindrical membrane 5, the axial height is δ 4 , diameter is r 3 . Each size can be designed and adjusted according to actual needs.

[0052] In one embodiment, the main housing includes an outer housing 18 and an inner housing 19 which are sleeved together. The diameter of the outer housing 18 is represented by r. 2 Indicates that the diameter of the inner shell 19 is approximately equal to r 1 The inner diameter side of the inner shell 19 is the third space 8, which is a cylindrical space. The inner wall of the outer shell 18 and the outer wall of the inner shell 19 are the second space 9, which is an annular space. The inlet end of the outer shell 18 is provided with a first space 10, which is a cylindrical space. The outlet end of the outer shell 18 is provided with a fourth space 6 and a fifth space 7, which is an annular space and the fifth space 7 is a cylindrical space.

[0053] In one embodiment, an outlet pipe is also included, which includes an inner pipe 25 and an outer pipe 24 which are nested with each other, the inner diameter side of the inner pipe 25 is a fifth space 7, and the inner wall of the outer pipe 24 and the outer wall of the inner pipe 25 are between the fourth space 6.

[0054] In one embodiment, the first pressure sensor 11, the second pressure sensor 12, the third pressure sensor 13, the fourth pressure sensor 14 and the fifth pressure sensor 15 are further included. The first pressure sensor 11 is arranged in the first space 10, the second pressure sensor 12 is arranged in the second space 9, the third pressure sensor 13 is arranged in the third space 8, the fourth pressure sensor 14 is arranged in the fourth space 6, and the fifth pressure sensor 15 is arranged in the fifth space 7. By arranging each pressure sensor in each space, the pressure state of each space is monitored, and P is used respectively. 1 , P 2 , P 3 , P 4 , P 5 Indicates the pressure of each space and is fed back to the ECU (electronic control unit) of the engine 26 to monitor the pressure conditions on both sides of the membrane during operation and ensure that the primary separation membrane assembly 110 and the secondary separation membrane assembly 120 operate under appropriate pressure conditions. 2 , O 2 , H 2 O、CO 2 The successful separation leads to: P 1 >P 2 >P 3 >P 4 >P 5 .

[0055] In one embodiment, a first temperature sensor 16 and a second temperature sensor 17 are further included. The first temperature sensor 16 is arranged in the first space 10, and the second temperature sensor 17 is arranged in the fourth space 6 and / or the fifth space 7. The membrane operates within a certain temperature range. Too high a temperature may damage the structure of the membrane material. The first temperature sensor 16 and the second temperature sensor 17 are respectively arranged at the inlet and outlet of the membrane separation device to monitor the temperature T of the inlet of the first separation membrane assembly 110 and the outlet of the second separation membrane assembly 120. 1 , T 2 , and fed back to the ECU of the engine 26 to monitor the temperature of the membrane during operation and ensure that the primary separation membrane assembly 110 and the secondary separation membrane assembly 120 operate under a suitable temperature environment.

[0056] The working principle of the membrane separation device of the present invention is as follows:

[0057] like Figure 7 As shown, N 2 , O 2 , H 2 O、CO 2 The molecular weight is expressed as m N2 、m O2、m H2O 、m CO2 The axial flow velocity and radial flow velocity components after the pollutant emission control system 23 of the engine 26 are represented by v d 、v r The pressure is represented by P, and the axial momentum and radial momentum components are represented by M respectively. d 、M r The force and resistance on the membrane surface are represented by F and f respectively. Therefore, (1) v d >v r ; (2) According to the momentum definition formula M = (1 / 2) mv 2 , M d >M r .

[0058] Working process of the primary separation membrane assembly 110:

[0059] (1) Due to v d >v r Therefore, CO 2 With N 2 , O 2 , H 2 O first mainly interacts with the first columnar membrane 3. H2O <d CO2 <d b <d N2 <d O2 , N 2 , O 2 The membrane will block the main 2 , H 2 O acts on the first cylindrical membrane 3. Due to the hydrophobicity of the axial inner surface, the force F acting on the surface by water is H2O , the force (resistance) of the surface on the water H2O Between: F H2O <f H2O , so even though d H2O <d b , the first space 10 and the third space 8 on both sides of the membrane have P 1 >P 3 , but H 2 O will fail completely or mostly; let H 2 The axial momentum of the O molecule is M dH2O , due to v d Larger, M dH2O is also larger, making F H2O >f H2O , so some H 2 O passes through the separation membrane and enters the third space 8 from the first space 10. 2 The molecules have no fCO2 The effect of d CO2 <d b , P 1 >P 3 , M dCO2 Larger, with a CO-friendly axial outer surface 2 The graphene nanomaterials are easily heated, so CO 2 It will mainly separate from the first cylindrical membrane 3 and enter the third space 8 from the first space 10 .

[0060] (2) Due to the influence of the first columnar film 3, near the surface of the first columnar film 3, the N 2 , O 2 and some CO 2 , H 2 O, there is v d <v r For the first cylindrical membrane 2, the first space 10 and the second space 9 on both sides of the membrane have P 1 >P 2 , the relationship between the molecular dynamics diameter and the membrane pore size is: d H2O <d CO2 <d N2 <d O2 <d a , so that all N 2 , O 2 And some H 2 O、CO 2 Through the separation membrane, H enters the second space 9 from the first space 10. 2 O molecules, due to the radial inner surface of the first cylindrical membrane 2 being H- 2 O-resistance and repellency of radial outer surface 2 O, make H 2 O molecules are adsorbed by the force f on the radial inner surface of the first cylindrical membrane 2 H2O The effect of H 2 O molecules are repelled by the force f on the radially outer surface of the first cylindrical film 2 H2O It is easier to separate from the surface of the membrane.

[0061] Working process of the secondary separation membrane assembly 120:

[0062] (1) In the third space 8, CO mainly exists 2 , including a small amount of H 2 O.CO 2 It mainly acts on the second cylindrical membrane 5, and on the third space 8 and the fifth space 7 on both sides of the second cylindrical membrane 5. 3 >P 5 , due to the affinity of the second columnar membrane 5 for CO 2The surface layer makes CO 2 The adsorption force f CO2 The effect of graphene nanomaterials makes it easier to enter the membrane pores, and graphene nanomaterials are easily heated, making CO 2 Enter the fifth space 7 from the third space 8, complete CO 2 A small amount of H 2 O Since the axial inner surface of the second cylindrical film 4 is close to H 2 O, make H 2 O molecules are adsorbed by the force f on the radial inner surface of the second cylindrical membrane 4 H2O The effect of P makes it easier to enter the membrane hole, and the third space 8 and the fourth space 6 on both sides of the second cylindrical membrane 4 have P 3 >P 4 , so H 2 O will separate from the third space 8 and enter the fourth space 6.

[0063] (2) In the second space 9, there are mainly N 2 , O 2 , H 2 O, and a small amount of CO 2 For the second cylindrical membrane 4, there is d H2O <d CO2 <d N2 <d O2 <d c , and P 2 >P 4 , so N 2 , O 2 , H 2 O is separated from the second space 9 and enters the fourth space 6; while CO 2 Since the CO affinity of the second columnar membrane 5 2 The surface layer makes CO 2 The adsorption force f CO2 The effect of graphene nanomaterials makes it easier to enter the membrane pores, and graphene nanomaterials are easily heated, making CO 2 Enter the fifth space 7 from the second space 9, complete CO 2 separation.

[0064] In summary, after the working process of the primary separation membrane assembly 110 and the secondary separation membrane assembly 120, N 2 , O 2 Separated through the first space 10, the second space 9, and the fourth space 6; H 2 O is mainly separated out through the first space 10, the second space 9, and the fourth space 6, and a small part is separated out through the first space 10, the third space 8, and the fourth space 6; while CO 2It is mainly separated through the first space 10, the third space 8 and the fifth space 7, and a small part is separated through the first space 10, the second space 9 and the fifth space 7.

[0065] Reference again Figure 1 to Figure 7 As shown, the present invention provides an engine exhaust device, including an exhaust pipe 1 for connecting to an engine 26 and a membrane separation device as described above, the membrane separation device adopts a two-stage separation membrane structure (a primary separation membrane assembly 110 and a secondary separation membrane assembly 120) connected in series, the first space 10 is connected to the exhaust pipe 1, and a pollutant emission control system 23, such as a three-way catalytic converter, etc., can be arranged between the first space 10 and the exhaust pipe 1. It is composed of the exhaust pipe 1, the primary separation membrane assembly 110, and the secondary separation membrane assembly 120, and is divided into five areas of the first space 10, the second space 9, the third space 8, the fourth space 6, and the fifth space 7 with different pressures, forming N 2 , O 2 , H 2 O and CO 2 After separation by the primary separation membrane assembly 110 and the secondary separation membrane assembly 120, the discharged CO can be collected in the fifth space 7. 2 gas.

[0066] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A membrane separation device, characterized in that: include: A first-stage separation membrane assembly, the first-stage separation membrane assembly comprises a first tubular membrane and a first columnar membrane, the first columnar membrane is arranged on the inner diameter side of the first tubular membrane and close to the end, the inner diameter side of the first tubular membrane and the axial inner side of the first columnar membrane are a first space, the first space is an air intake space, the axial outer side of the first columnar membrane is a third space, and the outer diameter side of the first tubular membrane is a second space; And a secondary separation membrane assembly, the secondary separation membrane assembly includes a second tubular membrane and a second columnar membrane, the second columnar membrane is arranged on the inner diameter side of the second tubular membrane, the axial inner side of the second tubular membrane and the axial inner side of the second columnar membrane are the third space, the outer diameter side of the second tubular membrane is the second space, the axial outer side of the second tubular membrane is the fourth space, the axial outer side of the second columnar membrane is the fifth space, and the fourth space and the fifth space are exhaust spaces.

2. The membrane separation device according to claim 1, characterized in that: The radial inner surface of the first tubular membrane is modified into a H2O-philic surface layer, and the radial outer surface is modified into a H2O-phobic surface layer; the axial inner surface of the first columnar membrane is modified into a H2O-phobic surface layer, and the axial outer surface is modified into a CO2-philic surface layer; the axial inner surface of the second tubular membrane is modified into a H2O-philic surface layer; the axial inner surface of the second columnar membrane is modified into a CO2-philic surface layer, and the radial side surface is modified into a CO2-philic surface layer.

3. The membrane separation device according to claim 2, characterized in that: The radial inner surface of the first tubular membrane is made of modified nano-silicon dioxide, and the radial outer surface is made of modified graphite nanomaterial; the axial inner surface of the first columnar membrane is made of modified graphite nanomaterial, and the axial outer surface is made of modified graphene nanomaterial; the axial inner surface of the second tubular membrane is made of modified nano-silicon dioxide; the axial inner surface of the second columnar membrane is made of modified graphene nanomaterial, and the radial side surface is made of modified graphene nanomaterial.

4. The membrane separation device according to claim 1, characterized in that: The inner diameter of the first tubular membrane, the outer diameter of the first cylindrical membrane, and the outer diameter of the second tubular membrane are equal.

5. The membrane separation device according to claim 1, characterized in that: The end surfaces of the second tubular membrane and the second cylindrical membrane are flush, and the axial length of the second tubular membrane is equal to the axial length of the second cylindrical membrane.

6. The membrane separation device according to claim 1, characterized in that: It includes a main shell, which includes an outer shell and an inner shell that are nested with each other, the inner diameter side of the inner shell is the third space, the inner wall of the outer shell and the outer wall of the inner shell are between the second space, the inlet end of the outer shell is provided with the first space, and the outlet end of the outer shell is provided with the fourth space and the fifth space.

7. The membrane separation device according to claim 5, characterized in that: It also includes an outlet pipe, which includes an inner pipe and an outer pipe which are nested with each other, the inner diameter side of the inner pipe is the fifth space, and the space between the inner wall of the outer pipe and the outer wall of the inner pipe is the fourth space.

8. The membrane separation device according to claim 1, characterized in that: It also includes a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor and a fifth pressure sensor. The first pressure sensor is arranged in the first space, the second pressure sensor is arranged in the second space, the third pressure sensor is arranged in the third space, the fourth pressure sensor is arranged in the fourth space, and the fifth pressure sensor is arranged in the fifth space.

9. The membrane separation device according to claim 1, characterized in that: It also includes a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is arranged in the first space, and the second temperature sensor is arranged in the fourth space and / or the fifth space.

10. An engine exhaust device, characterized in that: It comprises an exhaust pipe for connecting to an engine and the membrane separation device according to any one of claims 1 to 9, wherein the first space is connected to the exhaust pipe.

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