CN117211939A - Design method of exhaust aftertreatment device of old special vehicle - Google Patents
Design method of exhaust aftertreatment device of old special vehicle Download PDFInfo
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- CN117211939A CN117211939A CN202311114207.7A CN202311114207A CN117211939A CN 117211939 A CN117211939 A CN 117211939A CN 202311114207 A CN202311114207 A CN 202311114207A CN 117211939 A CN117211939 A CN 117211939A
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- 238000013461 design Methods 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims abstract description 25
- 238000011282 treatment Methods 0.000 claims abstract description 28
- 230000003584 silencer Effects 0.000 claims abstract description 26
- 230000008929 regeneration Effects 0.000 claims abstract description 22
- 238000011069 regeneration method Methods 0.000 claims abstract description 22
- 230000003197 catalytic effect Effects 0.000 claims abstract description 20
- 230000030279 gene silencing Effects 0.000 claims abstract description 18
- 238000011065 in-situ storage Methods 0.000 claims abstract description 15
- 230000008030 elimination Effects 0.000 claims abstract description 14
- 238000003379 elimination reaction Methods 0.000 claims abstract description 14
- 239000011943 nanocatalyst Substances 0.000 claims abstract description 7
- 238000009434 installation Methods 0.000 claims abstract description 6
- 238000000746 purification Methods 0.000 claims abstract description 4
- 230000001629 suppression Effects 0.000 claims abstract description 4
- 239000003054 catalyst Substances 0.000 claims description 22
- 230000003647 oxidation Effects 0.000 claims description 21
- 238000007254 oxidation reaction Methods 0.000 claims description 21
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 16
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 14
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 13
- 229910052802 copper Inorganic materials 0.000 claims description 13
- 239000010949 copper Substances 0.000 claims description 13
- 239000002808 molecular sieve Substances 0.000 claims description 13
- 239000002245 particle Substances 0.000 claims description 13
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 claims description 13
- 238000004088 simulation Methods 0.000 claims description 11
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 8
- 238000004364 calculation method Methods 0.000 claims description 8
- 229910052697 platinum Inorganic materials 0.000 claims description 8
- 238000005457 optimization Methods 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 7
- 230000008859 change Effects 0.000 claims description 5
- 239000000779 smoke Substances 0.000 claims description 5
- 238000010521 absorption reaction Methods 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 4
- 229910052763 palladium Inorganic materials 0.000 claims description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 238000007084 catalytic combustion reaction Methods 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims 1
- 238000003912 environmental pollution Methods 0.000 abstract description 3
- 239000007789 gas Substances 0.000 description 59
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 13
- 239000004215 Carbon black (E152) Substances 0.000 description 10
- 230000005540 biological transmission Effects 0.000 description 10
- 229930195733 hydrocarbon Natural products 0.000 description 10
- 150000002430 hydrocarbons Chemical class 0.000 description 8
- 238000012360 testing method Methods 0.000 description 6
- 239000011159 matrix material Substances 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
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- 239000000919 ceramic Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 239000007800 oxidant agent Substances 0.000 description 2
- 239000013618 particulate matter Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
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- 238000001914 filtration Methods 0.000 description 1
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- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 150000002940 palladium Chemical class 0.000 description 1
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- 150000003057 platinum Chemical class 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001743 silencing effect Effects 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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- Exhaust Gas After Treatment (AREA)
Abstract
The application discloses a design method of an exhaust aftertreatment device of an old special vehicle, which belongs to the technical field of exhaust aftertreatment of diesel engines, and comprises the following steps of S1, obtaining the installation structure and the size parameter of an original silencer installed on the old special vehicle; s2, setting a through wall flow nano catalytic purifying and silencing system with a purifying and silencing integrated structure by taking 'noise suppression + pollution elimination + continuous regeneration' as a target; s3, the through-wall flow nano catalytic purification noise elimination system is divided into three parts, namely a nano catalyst continuous regeneration system design, a catalytic muffler structure design and an interface design; s4, designing an old special vehicle tail gas aftertreatment device capable of replacing the original silencer in situ. The application designs a tail gas post-treatment device which can be used for a compact and airtight power cabin and is used for replacing an old silencer in situ so as to reduce the discharge of harmful tail gas of an old special vehicle, reduce environmental pollution and improve riding comfort in the vehicle.
Description
Technical Field
The application relates to the technical field of diesel engine tail gas treatment, in particular to a design method of an exhaust gas aftertreatment device of an old special vehicle.
Background
The old special vehicle has no special harmful gas filter unit and only has silencer to eliminate noise.
The emission level of the old special vehicle is national one, and the exhaust gas after diesel engine combustion is directly discharged after passing through the muffler and the exhaust pipeline, so that the harmful gas is more and the noise is larger. The current general tail gas treatment equipment has cylindrical structural dimensions, and the diameter of the tail gas treatment equipment meeting the performance requirement is larger than that of the original silencer, so that the tail gas treatment equipment cannot be installed on special vehicles with narrow and compact power cabins; the performance of the tail gas treatment equipment with small diameter cannot meet the performance requirement of a special vehicle, and in-situ replacement cannot be realized.
In view of this disadvantage, there is a need to develop a special vehicle exhaust aftertreatment device to solve the above-mentioned problems.
Disclosure of Invention
The application aims to solve the technical problem of providing a design method of an exhaust aftertreatment device of an old special vehicle, which is characterized in that an old silencer of the old special vehicle is replaced by the exhaust aftertreatment device in situ under the condition that the output power of an engine and the appearance of the whole vehicle are not influenced, namely, an original vehicle exhaust silencer is detached, and the original vehicle exhaust silencer is directly replaced by the exhaust aftertreatment device in situ, so that the installation structure and the dimensional parameters of the exhaust aftertreatment device are completely consistent with those of the exhaust silencer of the old special equipment vehicle, the great change of the whole vehicle structure and the appearance is not caused, and the exhaust aftertreatment device has good interchangeability.
In order to solve the technical problems, the application adopts the following technical scheme:
the design method of the old special vehicle tail gas aftertreatment device comprises the following steps:
s1, acquiring the installation structure and the size parameter of an original silencer installed on an old special vehicle;
s2, setting a through wall flow nano catalytic purifying and silencing system with a purifying and silencing integrated structure by taking 'noise suppression + pollution elimination + continuous regeneration' as a target;
s3, the through-wall flow nano catalytic purification noise elimination system is divided into three parts, namely a nano catalyst continuous regeneration system design, a catalytic muffler structure design and an interface design;
s4, designing an old special vehicle tail gas aftertreatment device capable of replacing the original silencer in situ.
The technical scheme of the application is further improved as follows: s3, specifically comprising:
s31, the nano catalyst continuous regeneration system adopts an oxidation unit, a trapping unit and a silencing unit to oxidize and decompose harmful substances in the tail gas of the diesel engine and physically trap particulate matters, and realizes continuous regeneration through catalytic combustion so as to achieve the aim of eliminating smoke;
s32, on the structural design of the catalytic muffler, respectively performing simulation calculation and optimization design on an exhaust flow field and acoustics of an exhaust aftertreatment device structure;
s33, adopting the same interface as the original silencer in the interface design, so that the silencer can be replaced to the old special vehicle in situ.
The technical scheme of the application is further improved as follows: s31 specifically includes:
the oxidation unit adopts a DOC carrier with an asymmetric section, and a nano palladium-based catalyst is coated on the surface of the DOC carrier to convert CO and HC compounds into harmless H 2 O and CO 2 Conversion of NO to NO 2 ；
The capturing unit adopts a POC copper-based molecular sieve carrier with a split-flow structure, and a catalyst is coated on the surface of the POC copper-based molecular sieve carrier to realize continuous catalytic regeneration of particles;
the noise elimination unit optimizes the internal flow field result through the design of the resistive muffler and the resistive sound absorption material, reduces turbulence caused by the structure of the post-treatment device, combines the dynamic flow field collaborative optimization during the variable working condition of the engine, reduces the exhaust flow velocity, changes the noise fluctuation frequency characteristic and realizes the impedance noise elimination target.
The technical scheme of the application is further improved as follows: the capture unit is divided into an oxidation section and a capture section, wherein a nano platinum-based catalyst is coated on a POC copper-based molecular sieve carrier of the oxidation section, and a nano platinum-based particle regenerated catalyst is coated on a POC copper-based molecular sieve carrier of the capture section.
The technical scheme of the application is further improved as follows: s32 specifically includes:
a first cavity serving as a front cavity is arranged behind an air inlet pipe connected with a tail gas exhaust pipe of an old special vehicle so as to slow down the flow of tail gas and reduce the turbulence change intensity;
a second cavity serving as an oxidation unit is arranged behind the first cavity so as to reduce CO, HC, VOF harmful substances;
a third cavity serving as a trapping unit is arranged behind the second cavity so as to accurately identify and trap carbon deposit quantity and intelligently implement active regeneration;
a fourth cavity serving as a silencing unit is arranged behind the third cavity, and the impedance silencer reduces exhaust noise;
and an exhaust pipe is arranged behind the fourth cavity.
The technical scheme of the application is further improved as follows: the cross sections of the first cavity, the second cavity, the third cavity and the fourth cavity are consistent in size; a front end cover is arranged at the joint of the air inlet pipe and the first cavity; a rear end cover is arranged at the joint of the fourth cavity and the exhaust pipe; the cross section of the first cavity is larger than that of the air inlet pipe; the cross section of the fourth cavity is larger than that of the exhaust pipe.
The technical scheme of the application is further improved as follows: and the first cavity and the second cavity, the second cavity and the third cavity and the fourth cavity are all connected through a cavity connecting flange.
The technical scheme of the application is further improved as follows: a first pressure sensor interface is arranged at the upper end of the joint of the second cavity and the third cavity; a second pressure sensor interface is arranged at the upper end of the joint of the third cavity and the fourth cavity; the first pressure sensor interface and the second pressure sensor interface are respectively provided with a first pressure sensor and a second pressure sensor which are interlocked with the EUC of the vehicle, and the service condition of the tail gas aftertreatment device is displayed on an instrument panel.
The technical scheme of the application is further improved as follows: a first temperature sensor interface is arranged at the bottom end of the joint of the air inlet pipe and the first cavity; a second temperature sensor interface is arranged at the bottom end of the joint of the second cavity and the third cavity; a third temperature sensor interface is arranged at the bottom end of the joint of the third cavity and the fourth cavity; the first temperature sensor interface, the second temperature sensor interface and the third temperature sensor interface are respectively provided with a first temperature sensor, a second temperature sensor and a third temperature sensor which are interlocked with the EUC of the vehicle, and the service condition of the tail gas aftertreatment device is displayed on an instrument panel.
The technical scheme of the application is further improved as follows: the cross sections of the first cavity, the second cavity, the third cavity and the fourth cavity are all in the shape consisting of an upper semicircle, a cuboid and a lower semicircle, and the cross sections of the air inlet pipe and the air outlet pipe are all round.
By adopting the technical scheme, the application has the following technical progress:
1. the application designs the exhaust aftertreatment device of the old special vehicle, which is used for purifying the exhaust with HC, CO, VOF and other harmful substances discharged by the old special vehicle, and can be replaced in situ into the old special vehicle with a narrow and compact power cabin, so that the discharge of the harmful exhaust of the existing old special vehicle is reduced, the environmental pollution is reduced, and the riding comfort in the vehicle is improved.
2. After the muffler of the old special vehicle is replaced by the tail gas post-treatment device designed by the application in situ, the dynamic property of the vehicle is not reduced through a subsequent sports car test, the tail gas emission is obviously reduced, the noise is obviously reduced, and the pollution of the existing old special vehicle to the environment is effectively reduced.
Drawings
For a clearer description of embodiments of the application or of the solutions of the prior art, the drawings that are used in the description of the embodiments or of the prior art will be briefly described, it being obvious that the drawings in the description below are some embodiments of the application, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art;
FIG. 1 is a schematic diagram of an integrated purifying and silencing design of a special vehicle tail gas aftertreatment device;
FIG. 2 is a schematic diagram of a special vehicle exhaust aftertreatment device according to the present application;
FIG. 3 is a schematic diagram of the exhaust aftertreatment device for a special vehicle and an old special vehicle;
FIG. 4 is a schematic cross-sectional view of an oxidation unit support according to the present application;
FIG. 5 is a schematic view of a trap unit carrier structure in accordance with the present application;
FIG. 6 is a graph of transmission loss obtained by simulation in the present application;
FIG. 7 is a graph of backpressure simulation results in the present application;
1, an air inlet pipe; 2. a first cavity; 3. a second cavity; 4. a third cavity; 5. a fourth cavity; 6. an exhaust pipe; 7. a front end cover; 8. a cavity connecting flange; 9. a rear end cover; p1, a first pressure sensor interface; p2, a second pressure sensor interface; t1, a first temperature sensor interface; t2, a second temperature sensor interface; t3, a third temperature sensor interface; 10. a smoke exhaust pipe; 11. a vehicle side panel.
Detailed Description
In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.
The terms first, second and the like in the description and in the claims and in the above-described figures, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The application is described in further detail below with reference to the attached drawings and examples:
as shown in fig. 1-3, a design method of an exhaust aftertreatment device of an old-fashioned special vehicle comprises the following steps:
s1, acquiring the installation structure and the size parameter of an original silencer installed on an old special vehicle;
s2, setting a through wall flow nano catalytic purifying and silencing system with a purifying and silencing integrated structure by taking 'noise suppression + pollution elimination + continuous regeneration' as a target;
s3, the through-wall flow nano catalytic purification noise elimination system is divided into three parts, namely a nano catalyst continuous regeneration system design, a catalytic muffler structure design and an interface design; the method specifically comprises the following steps:
s31, the nano catalyst continuous regeneration system adopts an oxidation unit, a trapping unit and a silencing unit to oxidize and decompose harmful substances in the tail gas of the diesel engine and physically trap particulate matters, and realizes continuous regeneration through catalytic combustion so as to achieve the aim of eliminating smoke;
in particular, as shown in FIG. 4The oxidation unit adopts a DOC carrier with an asymmetric section, and a nano palladium-based catalyst is coated on the surface of the DOC carrier to convert CO and HC compounds into harmless H 2 O and CO 2 Conversion of NO to NO 2 ；
The capturing unit adopts a POC copper-based molecular sieve carrier with a split-flow structure, and a catalyst is coated on the surface of the POC copper-based molecular sieve carrier to realize continuous catalytic regeneration of particles;
further, the trapping unit is divided into an oxidation section and a trapping section, wherein a nano platinum-based catalyst is coated on a POC copper-based molecular sieve carrier of the oxidation section, and a nano platinum-based particle regenerated catalyst is coated on a POC copper-based molecular sieve carrier of the trapping section.
Compared with the traditional noble metal oxide, the nano-scale palladium-based, platinum-based and platinum-based particle regenerated catalyst with smaller diameter is used as the catalyst, so that the contact area between the catalyst and the particles is increased, the catalyst activity and the light-off characteristic of the catalyst are improved, and the regenerated temperature window is widened.
DOC is an abbreviation for diesel oxidationcatalyst, chinese paraphrasing is diesel oxidation catalyst. DOC generally uses metal or ceramic as a catalyst carrier, and the main active components in the coating are noble metals and rare metals such as platinum series, palladium series and the like. When the tail gas of the diesel engine passes through the catalyst, hydrocarbon (HC), carbon monoxide (CO) and the like can quickly react with oxygen in the tail gas at a lower temperature to generate pollution-free H2O and CO2, and the DOC achieves the aim of purifying HC and CO in the tail gas.
POC is an abbreviation for particle oxidationcatalyst, and chinese paraphrasing is a particulate catalytic oxidizer. The working principle of POC is that the particulate matters are grabbed up and then burnt out by the high temperature (250 ℃ -500 ℃) of the tail gas, so as to achieve the purpose of reducing PM (particulate matters).
The noise elimination unit optimizes the internal flow field result through the design of the resistive muffler and the resistive sound absorption material, reduces turbulence caused by the structure of the post-treatment device, combines the dynamic flow field collaborative optimization during the variable working condition of the engine, reduces the exhaust flow velocity, changes the noise fluctuation frequency characteristic and realizes the impedance noise elimination target. The carriers of the oxidation unit and the trapping unit also have silencing effect
S32, on the structural design of the catalytic muffler, respectively performing simulation calculation and optimization design on an exhaust flow field and acoustics of an exhaust aftertreatment device structure;
simulation calculation:
(1) Sound field
The silencing unit designs a perforated pipe expansion cavity structure and a foam ceramic carrier matrix structure. The influence of the round angle and the flange structure on the analysis result is not considered in the acoustic simulation calculation, the boundary of the wall surface is assumed to be a rigid wall surface, and the sound absorption condition of the wall surface is not considered. By setting reasonable sound field boundary conditions, a transmission loss curve of the purified base unit and the non-purified base unit is obtained through simulation, as shown in fig. 6.
Simulation results show that in the region of the transmission loss curve graph I, the transmission loss of the tail gas treatment device is obviously improved when the tail gas treatment device has a purifying substrate and is basically the same as that of the tail gas treatment device without the purifying substrate. In the region of the transmission loss curve graph II, the transmission loss obvious frequency band of the tail gas treatment device with the purifying matrix is widened compared with that of the tail gas treatment device without the purifying matrix, and the silencing trough disappears. In the area of the transmission loss curve graph III, the transmission loss of the tail gas treatment device with the purifying matrix is greatly improved compared with that without the purifying matrix, but the curve rule is not obvious. The average transmission loss of the resistant tail gas treatment device is 14.7db when the purifying unit is not provided, and the average transmission loss of the tail gas treatment device is increased to 37.6db when the purifying unit is provided, so that the device meets the requirement (more than 15 db) on the noise reduction amount in the design requirement.
(2) Flow field
Because the tail gas treatment device has a relatively complex resistant silencing structure, the section mutation of the tail gas flowing in the pipeline is easy to cause turbulence, and therefore, a proper turbulence calculation formula is selected to calculate the turbulence. And the porosity, the flow resistance, the permeability and the inlet speed of the tail gas of the carrier material are adjusted in the simulation calculation, parameters are optimized, and the result of the optimal calculation is determined: the new increase of the exhaust system of the original machine is not more than 5 kpa, thereby meeting the design requirement. As shown in fig. 7.
And (3) testing: through the earlier stage fluid analysis and aftertreatment matching, the aftertreatment system of 3 different technical routes is initially determined, including the application and matching of DPF, DOC, POC different aftertreatment devices, the selection and coating of catalysts and the like, through simulation and bench test verification, the DOC+POC structural form is finally determined as a final aftertreatment system through 2 rounds of tests, the appearance is designed according to the appearance and interface size of a special vehicle silencer, the special carrier is developed to adapt to the existing structural size, the optimal treatment system is achieved, and through test verification, the free acceleration method tests the light absorption coefficient to be 1.3-1.6 on the premise of meeting the power requirement, and the design requirement is met.
The DPF is an abbreviation of diesel particulate filter (DieselParticulate Filter), and is installed in an exhaust system, and PM (particulate matter) in the exhaust gas can be filtered and captured by the DPF, so that PM (particulate matter) in the exhaust gas can be reduced, and the filtering effect can reach 70% -90% in general.
(II) optimization design
As shown in fig. 2, the exhaust aftertreatment device for the old-fashioned special vehicle specifically includes:
a first cavity 2 serving as a front cavity is arranged behind an air inlet pipe 1 connected with a tail gas exhaust pipe of an old special vehicle so as to slow down the flow of tail gas and reduce the turbulence change intensity;
a second chamber 3 is provided as an oxidation unit after the first chamber 2 to reduce CO, HC, VOF (the soluble organic fraction is sometimes also referred to as the volatile organic fraction) of harmful substances;
a third cavity 4 serving as a trapping unit is arranged behind the second cavity 3 so as to accurately identify and trap the carbon deposit quantity and intelligently implement active regeneration;
a fourth cavity 5 serving as a silencing unit is arranged behind the third cavity 4, and the impedance silencer reduces exhaust noise;
an exhaust pipe 6 is provided behind the fourth chamber 5.
Further, the cross sections of the first cavity 2, the second cavity 3, the third cavity 4 and the fourth cavity 5 are consistent in size; a front end cover 7 is arranged at the joint of the air inlet pipe 1 and the first cavity 2; a rear end cover 9 is arranged at the joint of the fourth cavity 5 and the exhaust pipe 6; the cross section of the first cavity 2 is larger than that of the air inlet pipe 1; the cross section of the fourth chamber 5 is larger than the cross section of the exhaust pipe 6.
Further, the first cavity 2 and the second cavity 3, the second cavity 3 and the third cavity 4 and the fourth cavity 5 are all connected through a cavity connecting flange 8.
Further, a first pressure sensor interface P1 is arranged at the upper end of the joint of the second cavity 3 and the third cavity 4; a second pressure sensor interface P2 is arranged at the upper end of the joint of the third cavity 4 and the fourth cavity 5; the first pressure sensor interface P1 and the second pressure sensor interface P2 are respectively provided with a first pressure sensor and a second pressure sensor, which are interlocked with the vehicle EUC, and the service condition of the exhaust gas aftertreatment device is displayed on the instrument panel.
Further, a first temperature sensor interface T1 is arranged at the bottom end of the joint of the air inlet pipe 1 and the first cavity 2; a second temperature sensor interface T2 is arranged at the bottom end of the joint of the second cavity 3 and the third cavity 4; a third temperature sensor interface T3 is arranged at the bottom end of the joint of the third cavity 4 and the fourth cavity 5; the first temperature sensor interface T1, the second temperature sensor interface T2 and the third temperature sensor interface T3 are respectively provided with a first temperature sensor, a second temperature sensor and a third temperature sensor which are interlocked with the EUC of the vehicle, and the service condition of the tail gas aftertreatment device is displayed on an instrument panel.
Further, the cross sections of the first cavity 2, the second cavity 3, the third cavity 4 and the fourth cavity 5 are all in a shape formed by an upper semicircle, a cuboid and a lower semicircle, and the cross sections of the air inlet pipe 1 and the air outlet pipe 6 are all round.
S33, adopting the same interface as the original silencer in the interface design, so that the silencer can be replaced to an old special vehicle in situ;
s4, designing an old special vehicle tail gas aftertreatment device capable of replacing the original silencer in situ.
As shown in fig. 3, the exhaust gas post-treatment device of the special vehicle and the old special vehicle are installed in a schematic diagram, the exhaust muffler originally installed on the side plate 11 of the old special vehicle is disassembled under the condition that the output power of the engine and the appearance of the whole vehicle are not affected, and the exhaust gas post-treatment device designed by the application is directly assembled on the exhaust pipe 10 in an in-situ complete set, and the installation structure and the dimensional parameters of the exhaust gas post-treatment device are completely consistent with those of the exhaust muffler device of the old special equipment vehicle, so that the great change is not brought to the structure and the appearance of the whole vehicle, and the exhaust gas post-treatment device has good interchangeability;
the specific use process is as follows:
(1) After entering the air inlet pipe 1 from the smoke exhaust pipe 10, the tail gas of the diesel engine flows through the first cavity 2, the flow rate of the tail gas is reduced, and then the tail gas enters the second cavity 3, and in the process that the tail gas passes through all pore channels in the catalytic oxidizer carrier, under the action of a catalyst, CO and HC are oxidized into CO 2 And H 2 O, and wherein NO is converted to NO 2 Make NO 2 Concentration is increased due to NO 2 Oxidative ratio O at lower temperature conditions 2 The device is strong, is favorable for the oxidation combustion of soot particles in the normal exhaust temperature range of the diesel engine, improves the exhaust temperature due to the oxidation combustion of CO and HC, and ensures the continuous regeneration of the particles trapped by the trapping unit in the normal working condition range of the diesel engine;
(2) If the engine is in a specific severe working condition of low-load operation for a long time, the exhaust temperature is obviously lower, continuous regeneration of particles in the POC copper-based molecular sieve carrier of the trapping unit is difficult to carry out, the ECU utilizes the pressures of an inlet and an outlet of the device of the exhaust gas detected in real time by the first pressure sensor and the second pressure sensor, and carries out alarming when the back pressure value of the exhaust gas reaches a set value according to the detected data, and intelligently reminds a driver to carry out maintenance operation: the first way is optional: increasing the working load of the diesel engine to increase the temperature of tail gas and promote the oxidation combustion of particles; a second way is also optional: and (3) reversely purging the tail gas treatment device by compressed air. Thereby avoiding the blockage of the tail gas treatment device and further monitoring the service condition of the tail gas treatment device.
The special vehicle tail gas post-treatment device designed by the application can be used for tail gas post-treatment equipment of a compact and airtight power cabin, and is used for replacing an old silencer in situ so as to reduce the discharge of harmful tail gas of the old special vehicle, reduce environmental pollution and improve the riding comfort in the vehicle.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.
Claims (10)
1. The design method of the exhaust aftertreatment device of the old special vehicle is characterized by comprising the following steps of:
s1, acquiring the installation structure and the size parameter of an original silencer installed on an old special vehicle;
s2, setting a through wall flow nano catalytic purifying and silencing system with a purifying and silencing integrated structure by taking 'noise suppression + pollution elimination + continuous regeneration' as a target;
s3, the through-wall flow nano catalytic purification noise elimination system is divided into three parts, namely a nano catalyst continuous regeneration system design, a catalytic muffler structure design and an interface design;
s4, designing an old special vehicle tail gas aftertreatment device capable of replacing the original silencer in situ.
2. The method for designing an exhaust aftertreatment device for an old-fashioned special vehicle according to claim 1, wherein in S3, specifically:
s31, the nano catalyst continuous regeneration system adopts an oxidation unit, a trapping unit and a silencing unit to oxidize and decompose harmful substances in the tail gas of the diesel engine and physically trap particulate matters, and realizes continuous regeneration through catalytic combustion so as to achieve the aim of eliminating smoke;
s32, on the structural design of the catalytic muffler, respectively performing simulation calculation and optimization design on an exhaust flow field and acoustics of an exhaust aftertreatment device structure;
s33, adopting the same interface as the original silencer in the interface design, so that the silencer can be replaced to the old special vehicle in situ.
3. The method for designing an exhaust aftertreatment device for an old-fashioned special vehicle according to claim 2, wherein in S31, specifically comprising:
the oxidation unit adopts a DOC carrier with an asymmetric section, and a nano palladium-based catalyst is coated on the surface of the DOC carrier to convert CO and HC compounds into harmless H 2 O and CO 2 Conversion of NO to NO 2 ；
The capturing unit adopts a POC copper-based molecular sieve carrier with a split-flow structure, and a catalyst is coated on the surface of the POC copper-based molecular sieve carrier to realize continuous catalytic regeneration of particles;
the noise elimination unit optimizes the internal flow field result through the design of the resistive muffler and the resistive sound absorption material, reduces turbulence caused by the structure of the post-treatment device, combines the dynamic flow field collaborative optimization during the variable working condition of the engine, reduces the exhaust flow velocity, changes the noise fluctuation frequency characteristic and realizes the impedance noise elimination target.
4. The method for designing an exhaust aftertreatment device for an old-fashioned special vehicle according to claim 3, wherein the trapping unit is divided into an oxidation section and a trapping section, a nano platinum-based catalyst is coated on a POC copper-based molecular sieve carrier of the oxidation section, and a nano platinum-based particle regenerated catalyst is coated on a POC copper-based molecular sieve carrier of the trapping section.
5. The method for designing an exhaust aftertreatment device for an old-fashioned special vehicle according to claim 2, wherein in S32, specifically comprising:
a first cavity (2) serving as a front cavity is arranged behind an air inlet pipe (1) connected with a tail gas exhaust pipe of an old special vehicle so as to slow down the flow of tail gas and reduce the turbulence change intensity;
a second cavity (3) serving as an oxidation unit is arranged behind the first cavity (2) so as to reduce CO, HC, VOF harmful substances;
a third cavity (4) serving as a trapping unit is arranged behind the second cavity (3) so as to accurately identify and trap carbon deposit quantity and intelligently implement active regeneration;
a fourth cavity (5) serving as a silencing unit is arranged behind the third cavity (4), and the impedance silencer reduces exhaust noise;
an exhaust pipe (6) is arranged behind the fourth cavity (5).
6. The design method of the exhaust aftertreatment device for the old special vehicle according to claim 5, wherein the cross sections of the first cavity (2), the second cavity (3), the third cavity (4) and the fourth cavity (5) are consistent in size; a front end cover (7) is arranged at the joint of the air inlet pipe (1) and the first cavity (2); a rear end cover (9) is arranged at the joint of the fourth cavity (5) and the exhaust pipe (6); the cross section of the first cavity (2) is larger than that of the air inlet pipe (1); the cross section of the fourth cavity (5) is larger than that of the exhaust pipe (6).
7. The design method of the old special vehicle exhaust aftertreatment device according to claim 5, wherein the first cavity (2) and the second cavity (3), the second cavity (3) and the third cavity (4) and the fourth cavity (5) are connected through a cavity connecting flange (8).
8. The design method of the old special vehicle tail gas aftertreatment device according to claim 5, wherein a first pressure sensor interface (P1) is arranged at the upper end of the joint of the second cavity (3) and the third cavity (4); a second pressure sensor interface (P2) is arranged at the upper end of the joint of the third cavity (4) and the fourth cavity (5); the first pressure sensor interface (P1) and the second pressure sensor interface (P2) are respectively provided with a first pressure sensor and a second pressure sensor which are interlocked with the EUC of the vehicle, and the service condition of the tail gas aftertreatment device is displayed on an instrument panel.
9. The design method of the exhaust aftertreatment device for the old special vehicle according to claim 5 is characterized in that a first temperature sensor interface (T1) is arranged at the bottom end of the joint of the air inlet pipe (1) and the first cavity (2); a second temperature sensor interface (T2) is arranged at the bottom end of the joint of the second cavity (3) and the third cavity (4); a third temperature sensor interface (T3) is arranged at the bottom end of the joint of the third cavity (4) and the fourth cavity (5); the first temperature sensor interface (T1), the second temperature sensor interface (T2) and the third temperature sensor interface (T3) are respectively provided with a first temperature sensor, a second temperature sensor and a third temperature sensor which are interlocked with the EUC of the vehicle, and the service condition of the tail gas aftertreatment device is displayed on an instrument panel.
10. The design method of the exhaust aftertreatment device for the old special vehicle according to claim 5 is characterized in that the cross sections of the first cavity (2), the second cavity (3), the third cavity (4) and the fourth cavity (5) are all in a shape consisting of an upper semicircle, a cuboid and a lower semicircle, and the cross sections of the air inlet pipe (1) and the air outlet pipe (6) are all round.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311114207.7A CN117211939A (en) | 2023-08-31 | 2023-08-31 | Design method of exhaust aftertreatment device of old special vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311114207.7A CN117211939A (en) | 2023-08-31 | 2023-08-31 | Design method of exhaust aftertreatment device of old special vehicle |
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| Publication Number | Publication Date |
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| CN117211939A true CN117211939A (en) | 2023-12-12 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311114207.7A Pending CN117211939A (en) | 2023-08-31 | 2023-08-31 | Design method of exhaust aftertreatment device of old special vehicle |
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| Country | Link |
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| CN (1) | CN117211939A (en) |
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2023
- 2023-08-31 CN CN202311114207.7A patent/CN117211939A/en active Pending
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