CN106382145B - A kind of exhaust treatment system and control method based on NTP technology - Google Patents

Abstract

The invention provides a tail gas treatment system and a control method based on NTP technology. The system includes an aftertreatment device, a first NTP injection system, a second NTP injection system, a power supply device, an NTP generator cooling system and a control system. The first NTP injection system uses air as a gas source to generate active substances, oxidize the carbon deposits deposited in the DPF, and realize off-line regeneration of the DPF. The second NTP injection system utilizes N ₂ as a gas source to generate active gas to reduce NO _x adsorbed in the NO _x adsorber, thereby realizing desorption of the NO _x adsorber. The invention utilizes the DPF and the _NOx adsorber to purify and treat the exhaust gas of the diesel engine, effectively reduces PM and _NOx in the exhaust gas of the diesel engine, and can realize the simultaneous removal of both. Two sets of NTP injection systems can be used to realize the regeneration of DPF and the desorption of NO _x adsorber respectively, thereby realizing the efficient recycling of DPF and NO _x adsorber. NO _x is converted into N ₂ after being processed by this system, which is non _- toxic and harmless, and can meet the increasingly strict emission regulations.

Description

A kind of exhaust treatment system and control method based on NTP technology

Technical field

The present invention relates to the post-processing fields of diesel engine, more particularly, to a kind of vent gas treatment system based on NTP technology System and control method.

Background technique

Diesel engine its because of excellent dynamic property, economy be widely used in the fields such as communications and transportation and farm machinery.Bavin Harmful components in oil machine exhaust mainly have carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO_x), particulate matter (Particulate matter, PM) and sulfide etc..Compared to gasoline engine, diesel engine uses the average air-fuel ratio of gaseous mixture It is larger, therefore its CO and HC is discharged and is significantly lower than gasoline engine, but diesel engine NO_xIt is higher with the discharge of PM.Diesel oil is reduced at present Machine NO_xCommon exhaust aftertreatment technology will lead to PM discharge and increase, and which increase diesel engine NO_xWith the control difficulty of PM discharge. Therefore, seek to reduce NO simultaneously_xBecome a major tasks in Exhaust Control for Diesel Engine technical research with the method for PM discharge.

Currently, diesel particulate trap (DPF) is to reduce one of most effective technology of diesel PM emissions, arresting efficiency Up to 90% or more.But with deposition of the PM in DPF, DPF can be blocked, and exhaust back pressure is caused to increase, and oil consumption increases, into And influence the normal operation of engine.

Zeolite is to NO_xThere is good adsorption cleaning function.There is natural zeolite oxygen-octahedron and aluminum-oxygen tetrahedron to be formed Skeleton structure, spatially will form bug hole abundant and duct, there is very strong adsorption capacity.Norton Co's zeolite Molecular sieve handles the NO in nitric plant's tail gas_x, content can be made to drop to 20ul/L by 2500ml/L.

Low temperature plasma (NTP) technology is high by treatment effeciency, device is simple, low energy consumption, particle-resistant interference performance is strong The advantages that, there is apparent advantage in terms of the exhaust emissions of processing diesel engine, is the research hotspot of field of exhaust gas purification in recent years. A kind of vehicle-mounted water cooling formula NTP generating system is described in patent CN105251323A, which is realized using NTP generator The highly efficient regeneration of DPF, while during the active gases for generating NTP generator sprays into exhaust, realize NO_xOxidation. But this method has certain problems: NO_xMajor oxidation product be NO₂, it is discharged into the NO of atmosphere₂It is dirty to will cause acid rain, photochemistry Dye.If being exposed to NO for a long time₂Among, the probability of respiratory tract infection just will increase.When situation is serious, NO₂Result even in lung Permanent lesion.

Summary of the invention

To solve the above problems, the present invention provides a kind of exhaust treatment system based on NTP technology, DPF and NO are utilized_xIt inhales Adnexa reduces PM and NO in diesel engine vent gas_xDischarge, and pass through the regeneration of NTP technology realization DPF and NO_xThe solution of absorber It inhales.

A kind of exhaust treatment system based on NTP technology, which is characterized in that including after-treatment device, the first NTP injection system System, the 2nd NTP spraying system, power supplier, NTP generator cooling system and control system,

The after-treatment device includes the connected exhaust branch of main exhaust, main exhaust, is connected on main exhaust DPF and NO_xAbsorber, the DPF are installed on the NO_xThe upstream of absorber；

The first NTP spraying system includes the first NTP generator, the first mass flow controller, gas supply blower, first Injection line and first jet, the gas supply blower through first mass flow controller and the first NTP generator into Port is connected, and the first NTP generator exports are connected through first injection line with first jet, the first jet position In the upstream DPF, active gases can be sprayed into the DPF；

The 2nd NTP spraying system includes the 2nd NTP generator, the second mass flow controller, air pump, N₂Gas source, Second injection line and second nozzle, the N₂Gas source is connected with air pump, and the air pump is through the second mass flow controller and institute The 2nd NTP generator to be stated to be connected, the 2nd NTP generator exports are connected through the second injection line with second nozzle, and described the Two nozzles are located at NO_xAbsorber upstream, can be to the NO_xActive gases is sprayed in absorber；

The power supplier includes vehicle power supply, inversion boosting device, the first relay and the second relay, the vehicle It is the first NTP generator, the power supply of the 2nd NTP generator, the first relay and the second relay that power supply, which is carried, by inversion boosting device It is separately positioned on the power supply circuit of the first NTP generator, the 2nd NTP generator；

The NTP generator cooling system includes water tank, the first water pump and the second water pump, and the water tank passes through first respectively Water pump and the second water pump provide cooling water for the first NTP generator, the 2nd NTP generator；

The control system includes control module, is arranged in DPF and NO_xThe first control on main exhaust between absorber Valve processed, the second control valve being arranged on exhaust branch, the third control valve door being arranged in the first injection line, setting The 4th control valve in the second injection line, is arranged in NO the differential pressure pickup that the both ends DPF are arranged in_xAbsorber downstream NO_xSensor and O₂Sensor, first control valve, the second control valve, third control valve door, the 4th control valve, Differential pressure pickup, NO_xSensor and O₂Sensor is connected with control module；

The NO_xSensor and the O₂Sensor is for monitoring the NO_xNO in absorber backend gas_xAnd O₂Contain Amount；

The differential pressure pickup is used to monitor the pressure difference at the both ends DPF；

The control module is according to differential pressure pickup, NO_xSensor and O₂The data and control strategy control of sensor detection First control valve, the second control valve, third control valve door, the 4th control valve, the first relay and the second relay It opens and closes, and the work of gas supply blower, air pump, the first water pump and the second water pump.

Preferably, the first jet is threadingly attached in first injection line, apart from the upstream DPF At 100mm；The second nozzle is threadingly attached in second injection line, apart from the NO_xAbsorber upstream At 100mm.

Preferably, the NO_xAbsorber is by substrate, porous plate and NO_xAdsorbent composition；The NO_xAdsorbent in absorber For zeolite, two blocks of stainless steel porous plates are mounted in substrate both ends, the NO_xAdsorbent addition is on the substrate in absorber.

Preferably, the first NTP generator and the 2nd NTP generator are dielectric barrier discharge type, using stainless steel Pipe is located at stone as high-field electrode, the stainless steel tube as block media, thin wire gauze as low-field electrode, quartz glass tube In English glass tube and coaxial with quartz glass tube, the thin wire gauze is wrapped on the quartz glass tube.

Preferably, the DPF is made of honeycomb ceramic filter material, and hole density is 100cpsi, diameter 144mm, mother Wire length 152mm.

Preferably, exhaust branch is located at the DPF and the NO_xBetween absorber.

The control method of the exhaust treatment system based on NTP technology, which comprises the steps of:

Step 1: rating test is carried out to diesel exhaust systems, determines the upper limit value of the both ends DPF pressure difference under different operating conditions ΔP_mWith regeneration target value Δ P_nAnd NO in air exit_xThe upper limit value C of content_m, and by pressure difference upper limit value Δ P_m, regeneration target It is worth Δ P_nAnd NO_xThe upper limit value C of content_mIt is stored in control module；

Step 2: when engine is run, the both ends DPF pressure differential deltap P is monitored by differential pressure pickup, to judge whether it needs It is regenerated；Pass through NO_xSensor monitors main exhaust exit NO_xContent C_NOx, to judge NO_xWhether absorber, which needs, solves It inhales；

Step 3: when control module monitoring detects that the both ends DPF pressure differential deltap P is greater than upper limit value Δ P_mOr NO in air exit_x Content C_NOxGreater than NO_xThe upper limit value C of content_m, engine stopping signal is detected, when control module detects that engine shuts down letter Number, control module closes the first control valve, opens the second control valve；

Step 4: when control module detects that the both ends DPF pressure differential deltap P is greater than upper limit value Δ P_m, and NO in air exit_x's Content C_NOxLess than upper limit value C_mWhen, control module open third control valve door, and transmit a signal to vehicle power supply, gas supply blower, First mass flow controller, the first relay and the first water pump open the first NTP spraying system；First NTP spraying system produces Raw active material is sprayed through the first injection line by first jet, the particulate matter deposited in DPF is aoxidized, then by exhaust branch Discharge, realizes the regeneration of DPF；When detect the both ends DPF pressure differential deltap P be less than or equal to regeneration target value Δ P_nWhen, close the first NTP Spraying system closes the second control valve, third control valve door, opens the first control valve；

When control module detects NO in air exit_xContent be greater than upper limit value, and the both ends DPF pressure differential deltap P be less than it is upper Limit Δ P_m, control module opens the 4th control valve, and transmits a signal to vehicle power supply, air pump, the control of the second mass flow Device, the second relay and the second water pump open the 2nd NTP spraying system；The active material that 2nd NTP spraying system generates is through the Two injection lines spray into NO by second nozzle_xIn absorber, gone out by main exhaust, realizes NO_xThe desorption of absorber；Work as O₂Sensing Device detects NO_xO in absorber backend gas₂When content is 0, show NO_xWithout NO in absorber_xCan with N radical reaction, NO_xDesorption is completed in absorber, and control module closes the 2nd NTP spraying system, closes the second control valve, the 4th control valve Door opens the first control valve；

When control module detects that the both ends DPF pressure differential deltap P is greater than upper limit value Δ P_m, and NO in air exit_xContent be greater than Upper limit value C_mWhen, control module opens third control valve door, the 4th control valve, and transmits a signal to vehicle power supply, gas supply wind Machine, the first mass flow controller, the first relay and the first water pump, air pump, the second mass flow controller, the second relay With the second water pump, the first NTP spraying system, the 2nd NTP spraying system are opened；The regeneration of DPF, NO_xThe desorption of absorber, when The both ends DPF pressure differential deltap P is less than or equal to regeneration target value Δ P_nWhen, the first NTP spraying system is closed, NO is worked as_xAbsorber backend gas Middle O₂When content is 0, the 2nd NTP spraying system is closed, until being less than or equal to regeneration target value Δ P to the both ends DPF pressure differential deltap P_n、 NO_xO in absorber backend gas₂When content is 0, the first NTP spraying system and the 2nd NTP spraying system are all turned off, and control mould Block closes the second control valve, third control valve door and the 4th control valve, opens the first control valve.

Preferably, the first mass flow controller and the second mass flow controller control gas source and flow amount are 5L/min.

The present invention utilizes DPF and NO_xAbsorber realizes the purified treatment of diesel engine Tail Gas, and diesel engine can be effectively reduced PM and NO in tail gas_xDischarge.After a shutdown, DPF is regenerated using non-thermal plasma trap (NTP), while to NO_xIt inhales Adnexa is desorbed, and then is realized to DPF and NO_xThe efficient circulation of absorber utilizes.NO_xIt is converted into after system processing N₂, compared to patent CN105251323A by NO_xIt is oxidized to NO₂, N₂It is nontoxic, more it is able to satisfy increasingly strict emission regulation.

Detailed description of the invention

Fig. 1 is for realizing the exhaust treatment system schematic diagram of the invention based on NTP technology.

Fig. 2 is the structural schematic diagram of the NTP generator of designed, designed.

Fig. 3 is the schematic diagram of control module control method.

Description of symbols:

101: main exhaust；102: exhaust branch；103:DPF；104:NO_xAbsorber；1041: porous plate；1042:NO_xIt inhales Attached dose；1043: substrate；201: the one NTP generators；202: the first mass flow controllers；203: gas supply blower；204: the first Injection line；205: first jet；301: the two NTP generators；302: the second mass flow controllers；303: air pump；304: N₂Gas source；305: the second injection lines；306: second nozzle；401: vehicle power supply；402: inversion boosting device；403: the first relays Device；404: the second relays；501: water tank；502: the first water pumps；503: the second water pumps；601: control module: 602: the first controls Valve processed；603: the second control valves；604: third control valve door；605: the four control valves；606: differential pressure pickup；607: NO_xSensor；608:O₂Sensor；700: diesel engine；801: cooling water inlet；802: cooling water outlet；803: stainless steel tube； 804: quartz glass tube；805: thin wire gauze；806:NTP generator inlet；807:NTP generator exports；

Specific embodiment

Present invention will be further explained with reference to the attached drawings and specific examples, but protection scope of the present invention is simultaneously It is without being limited thereto.

Fig. 1 illustrates the exhaust treatment system of the present invention based on NTP technology, which includes after-treatment device, One NTP spraying system, the 2nd NTP spraying system, power supplier, NTP generator cooling system and control system.After described Processing unit includes main exhaust 101, DPF 103, NO_xAbsorber 104 and exhaust branch 102.The first NTP spraying system Including the first NTP generator 201, the first mass flow controller 202, gas supply blower 203, the first injection line 204 and first Nozzle 205.The 2nd NTP spraying system includes the 2nd NTP generator 301, the second mass flow controller 302, air pump 303、N₂Gas source 304, the second injection line 305 and second nozzle 306.The power supplier includes vehicle power supply 401, inverse Become booster 402, the first relay 403 and the second relay 404.The NTP generator cooling system includes water tank 501, One water pump 502 and the second water pump 503.The control system includes control module 601, the first control valve 602, the second control valve Door 603, third control valve door 604, the 4th control valve 605, differential pressure pickup 606, NOx sensor 607 and O₂Sensor 608。

The gas supply blower 203 is through first mass flow controller 202 and 201 air inlet of the first NTP generator Mouthful it is connected, the gas supply blower 203 receives after 601 signal of control module to the first NTP generator 201 offer gas Source.The N₂Gas source 304 is connected with the air pump 303, and the air pump 303 is through the second mass flow controller 302 and described the Two NTP generators 301 are connected.It is sprayed through first injection line 204 by described first first NTP generator 201 outlet Mouth 205 sprays active gases to the DPF 103.The 2nd NTP generator 301 outlet is through the second injection line 305, by the Two nozzles 306 are to the NO_xAbsorber 104 sprays active gases.The first jet 205 is threadingly attached to described first On 204 tube wall of injection line, at the 103 upstream 100mm of DPF.The second nozzle 306 is threadingly attached to institute It states on 305 tube wall of the second injection line, apart from the NO_xAt 104 upstream 100mm of absorber.

The DPF 103 and NO_xAbsorber 104 is mounted on the main exhaust 101 using concatenated mode, institute It states DPF 103 and is installed on the NO_xBefore absorber 104.The NO_xAbsorber 104 is by substrate 1043, porous plate 1041 and NO_x Adsorbent 1042 forms.The NO_xThe material of adsorbent 1042 is mainly zeolite in absorber 104, and zeolite adsorbs NO_xProcess For physical process, no chemical reaction occurs.The NO_x104 both ends of absorber are equipped with two blocks of stainless steel porous plates 1041.The NO_x The addition of adsorbent 1042 is on the substrate 1043 in absorber.In the DPF 103 and NO_xRow between absorber 104 An exhaust branch 102 is drawn in air pipe, bypassed exhaust gas when closing for the first control valve 602.Diesel engine works normally When, the first control valve 602 is opened, and the second control valve 603 is closed, and tail gas is through the DPF 103 and NO_xAbsorber 104 are discharged from main exhaust 101.NTP restores NO_xEffect is preferable in the case where oxygen deprivation or anaerobic, NO_xAbsorber 104 needs When desorption, the first control valve 602 is closed.During dpf regeneration, the carbon distribution in active gases and the DPF 103 occurs Chemical reaction, reaction product are discharged from the exhaust branch 102.

First control valve 602 is installed in the main exhaust 101, is located at the NO_x104 front end of absorber； The second control valve 603 is installed in 102 entrance of exhaust branch；Third is installed in first injection line 204 Control valve 604；The 4th control valve 605 is installed in second injection line 305.First control valve 602, Second control valve 603, the third control valve door 604 and the 4th control valve 605 all with the control module 601 are connected, and are opened or closed according to the signal of control module 601.When engine is run, first control valve 602 is opened, Second control valve 603, third control valve door 604 and the 4th control valve 605 are closed.103 both ends DPF are equipped with The differential pressure pickup 606 is connected with the control module 601.The NOx sensor 607 and the O₂Sensor 608 and institute It states control module 601 to be connected, is mainly used for monitoring and flows through the DPF 103 and NO_xNO in tail gas after absorber 104_xAnd O₂ Content.Control module 601 receives the pressure differential deltap P and NO transmitted from differential pressure pickup 606_xThe gas that sensor 607 transmits is dense Spend C_NOx, Δ P is more than or equal to Δ P_mOr C_NOxMore than or equal to C_mWhen, control module 601 controls the opening and closing of four control valves, and passes The number of delivering letters gives vehicle power supply 401, the first relay 403, the second relay 404, the first water pump 502, the second water pump 503, first Mass flow controller 202, the second mass flow controller 302, gas supply blower 203 and air pump 303, open NTP spraying system, DPF is regenerated, to NO_xAbsorber is desorbed.

Fig. 2 is the structural schematic diagram of NTP generator.The first NTP generator 201 and the 2nd NTP generator 301 are same One type generator.The NTP generator is dielectric barrier discharge type, is used as low-field electrode, quartzy glass using stainless steel tube 803 Glass pipe 804 is used as block media, and thin wire gauze 805 is used as high-field electrode.The stainless steel tube 803 is located at quartz glass tube 804 In, and it is coaxial with quartz glass tube 804, the thin wire gauze 805 is wrapped on the quartz glass tube 804.NTP spraying system After unlatching, vehicle power supply 401 provides electric energy, the first relay 403 and the second relay to NTP generator through inversion boosting device 402 Device 404 receives the opening and closing of control circuit after the signal of control module 601.First mass flow controller 202 and the second quality stream The gas source and flow amount that the control of amount controller 302 enters NTP generator is 5L/min.The first NTP generator 201 and described second NTP generator 301 is water-cooled NTP generator.Cooling device includes water tank 501, the first water pump 502 and the second water pump 503. After the water pump receives the signal of control module 601, recirculated cooling water is extracted from the water tank 501, flows through NTP generator Stainless steel tube 803 realizes the cooling to NTP generator.

Fig. 3 is the flow chart for describing control module 601 and executing illustrative steps.Firstly, being carried out to diesel exhaust systems Rating test, the upper limit value and NO of diesel engine DPF pressure difference under different operating conditions_xThe upper limit value of content is different, first passes through calibration in advance Test the pressure difference upper limit value Δ P for determining diesel engine under different operating conditions_mWith lower limit value Δ P_nAnd NO_xThe upper limit value C of content_m, and By pressure difference upper limit value Δ P_m, regeneration target value Δ P_nAnd NO_xThe upper limit value C of content_mIt is stored in control module 601.

The diesel engine 700 is once start, then control process starts, and control module 601 is first according to differential pressure pickup 606 The pressure differential deltap P for obtaining 103 front and back end DPF, according to NO_xSensor 607 obtains NO_xNO in 104 rear end tail gas of absorber_xContent C_NOx。

Rate-determining steps enter 902, and control module 601 calls corresponding Δ P according to the operating condition of diesel engine 700_mAnd C_m, And the Δ P and C that will acquire_NOxWith Δ P_mAnd C_mIt is compared, if Δ P is more than or equal to Δ P_mOr C_NOxMore than or equal to C_m, then control Step processed enters 903, otherwise return step 901.In step 903, control module 601 detects stop sign.The present invention be Regeneration and the NO of DPF 103 are carried out when diesel engine stop to it_xThe desorption of absorber 104, offline active material utilization is higher, Keep exhaust treatment system more economical, efficient.In step 904, control module 601 detects stopping signal, if so, entering control Step 905 processed, otherwise return step 903.In rate-determining steps 905, control module 601 is closed the first control valve 602 and is opened Open the second control valve 603.NO_xThe desorption of absorber 104 better effect under conditions of oxygen deprivation or anaerobic, otherwise NO_xEasily by oxygen Turn to NO₂, so closing the first control valve 602.When dpf regeneration, product is discharged from exhaust branch 102.

Exhaust treatment system of the invention, using two sets of NTP spraying systems, the regeneration of DPF and NO_xThe desorption of absorber point Processing is opened, this system economy is higher.During processing, it may appear that three kinds of actual conditions, situation one: only DPF needs again It is raw, NO_xAbsorber is also working normally.Situation two: only NO_xAbsorber needs to desorb, and DPF is still being worked normally.Situation three: DPF needs to regenerate NO simultaneously_xAbsorber is also required to desorb.In rate-determining steps 906, control module 601 judges pressure differential deltap P and NO_x Content C_NOxWhether upper limit value is simultaneously greater than.If so, showing DPF and NO_xAbsorber needs to carry out the processing of NTP, i.e. feelings simultaneously Condition three opens the third control valve door 604 and the second injection line 305 in the first injection line 204 into rate-determining steps 918 In the 4th control valve 605.Conversely, showing that only one needs the processing of NTP, into rate-determining steps 907, further judge DPF needs to regenerate or NO_xAbsorber needs to desorb.In step 907, if pressure differential deltap P is greater than upper limit value P_m, show that DPF is needed It regenerates, NO_xAbsorber is working normally, i.e. situation one, then enters step 908, opens the third in the first injection line 204 Control valve 604.Conversely, showing NO_xAbsorber needs to desorb, and DPF is still being worked normally, i.e. situation two, then enters step 913, open the 4th control valve 605 in the second injection line 305.

There is situation for the moment, into after rate-determining steps 908, open third control valve door, after being finished, is walked into control Rapid 909, open the first NTP spraying system.Control module transmits a signal to vehicle power supply 401, inversion boosting device 402, the first water The 502, first relay 403, the first mass flow controller 202 and gas supply blower 203 are pumped, the first NTP spraying system is opened, it is right DPF is regenerated.In rate-determining steps 910, control module 601 is real-time monitored to the pressure differential deltap P and pressure difference at 103 both ends DPF Lower limit value Δ P_nIt is compared.If Δ P is less than or equal to Δ P_n, show that dpf regeneration has been completed, into rate-determining steps 911, instead It, return step 909.After step 911 close the first spraying system, 912 are entered step, second, third control valve is closed, Start the first control valve.DPF 103 regenerates finished

When there is situation two, into after rate-determining steps 913, the 4th control valve is opened, after being finished, is walked into control Rapid 914, open the 2nd NTP spraying system.Control module transmits a signal to vehicle power supply 401, inversion boosting device 402, the second water The 503, second relay 404, the second mass flow controller 302 and air pump 303 are pumped, the 2nd NTP spraying system is opened, to NO_x Absorber is desorbed.In rate-determining steps 915,601 real-time monitoring NO of control module_xO in absorber backend gas₂Content, When content is 0, show NO_xDesorption is completed in absorber, into rate-determining steps 916, conversely, return step 914.In step After 916 close the second spraying system, 917 are entered step, closes the second, the 4th control valve, starts the first control valve.NO_x The desorption of absorber 104 is finished.

When there is situation three, into after rate-determining steps 918, third, the 4th control valve are opened, after being finished, is entered Rate-determining steps 919 open the first, second NTP spraying system.Control module transmits a signal to vehicle power supply 401, inversion boosting device 402, the first water pump 502, the first mass flow controller 202, gas supply blower 203, the second water pump 503, the second mass flow control Device 302, air pump 303, the first relay 403 and the second relay 404 processed open the first, second NTP spraying system.It is controlling In step 910, the pressure differential deltap P and NO at 103 both ends 601 real-time monitoring DPF of control module_xO in absorber backend gas₂Contain Amount, if Δ P is less than lower limit value Δ P_nAnd oxygen content C_O2It is 0, then shows that regeneration and NO is completed in DPF_xSolution is completed in absorber It inhales, into rate-determining steps 529, closes the first NTP spraying system and the 2nd NTP spraying system, the regeneration of DPF and NO_xAbsorber Desorption be fully completed.Conversely, into rate-determining steps 921, if Δ P is less than lower limit value Δ P_n, show that regeneration is completed in DPF, NO_xAbsorber also not desorption completely, into rate-determining steps 922.Conversely, into rate-determining steps 926.If DPF first completes to regenerate, In step 922, the first NTP spraying system is closed, the 2nd NTP spraying system is continued starting.923 are entered step, if control module Monitor NO_xThe O of absorber rear end₂Content is zero, shows NO_xThe desorption of absorber is also completed, and enters step 924, closes the Two NTP spraying systems, conversely, return step 922.If NO_xAbsorber is first completed to regenerate, and enters step 926, closes the 2nd NTP Spraying system opens the first NTP spraying system.927 are entered step, if the pressure difference at the both ends DPF is less than lower limit value Δ P_n, show Regeneration is completed in DPF, into rate-determining steps 928, closes the first NTP spraying system.Conversely, return step 926.When DPF is complete At regeneration and NO_xDesorption is completed in absorber, into rate-determining steps 925, close second, third, the 4th control valve, open the One control valve.So far, a whole set of NTP regeneration and NO_xThe desorption of absorber, which has been carried out, to be finished.

The embodiment is a preferred embodiment of the present invention, but present invention is not limited to the embodiments described above, not In the case where substantive content of the invention, any conspicuous improvement that those skilled in the art can make, replacement Or modification all belongs to the scope of protection of the present invention.

Claims (8)

1. A tail gas treatment system based on NTP technology, characterized in that it comprises a post-processing device, a first NTP injection system, a second NTP injection system, a power supply device, an NTP generator cooling system and a control system, The aftertreatment device comprises a main exhaust pipe (101), an exhaust branch (102) connected with the main exhaust pipe (101), a DPF (103) and _NOx connected in series on the main exhaust pipe (101) an adsorber (104), the DPF (103) being installed upstream of the _NOx adsorber (104); The first NTP injection system comprises a first NTP generator (201), a first mass flow controller (202), an air supply fan (203), a first injection pipeline (204) and a first nozzle (205), The air supply fan (203) is connected to the air inlet of the first NTP generator (201) via the first mass flow controller (202), and the outlet of the first NTP generator (201) passes through the The first injection pipeline (204) is connected with the first nozzle (205), the first nozzle (205) is located upstream of the DPF (103), and can inject active gas into the DPF (103); The second NTP injection system includes a second NTP generator (301), a second mass flow controller (302), an air pump (303), an N ₂ gas source (304), a second injection pipeline (305) and a first _Two nozzles (306), the N gas source (304) is connected to an air pump (303), and the air pump (303) is connected to the second NTP generator (301) via a second mass flow controller (302) , the outlet of the second NTP generator (301) is connected to a second nozzle (306) through a second injection line (305), the second nozzle (306) is located upstream of the _NOx adsorber (104) and can be directed to the Injecting reactive gas into the _NOx adsorber (104); The power supply device includes a vehicle power supply (401), an inverter booster (402), a first relay (403) and a second relay (404), and the vehicle power supply (401) passes through the inverter booster (402). ) supplies power to the first NTP generator (201) and the second NTP generator (301), and the first relay (403) and the second relay (404) are respectively arranged in the first NTP generator (201), the second NTP generator on the power supply circuit of the device (301); The NTP generator cooling system includes a water tank (501), a first water pump (502) and a second water pump (503), and the water tank (501) is the first water pump (502) and the second water pump (503) respectively for the first water pump (502) and the second water pump (503). An NTP generator (201) and a second NTP generator (301) provide cooling water; The control system includes a control module (601), a first control valve (602) arranged on the main exhaust pipe (101) between the DPF (103) and the _NOx adsorber (104), a first control valve (602) arranged in the exhaust branch The second control valve (603) on the road (102), the third control valve (604) provided on the first injection line (204), the fourth control valve provided on the second injection line (305) (605), a differential pressure sensor (606) arranged at both ends of the DPF (103), a _NOx sensor (607) and an _O2 sensor (608) arranged downstream of the _NOx adsorber (104), the first control valve (602), the second control valve (603), the third control valve (604), the fourth control valve (605), the differential pressure sensor (606), the _NOx sensor (607) and the _O2 sensor (608) are all connected with The control module (601) is connected; The _NOx sensor (607) and the _O2 sensor (608) are used to monitor the _NOx and _O2 content in the back-end gas of the _NOx adsorber (104); The differential pressure sensor (606) is used to monitor the differential pressure across the DPF (103); The control module (601) controls the first control valve (602) and the second control valve (603) according to the data detected by the differential pressure sensor (606), the _NOx sensor (607) and the _O2 sensor (608) and the control strategy , the third control valve (604), the fourth control valve (605), the opening and closing of the first relay (403) and the second relay (404), as well as the opening and closing of the air supply fan (203), the air pump (303), the first Operation of the water pump (502) and the second water pump (503). 2. The exhaust gas treatment system based on NTP technology according to claim 1, characterized in that, the first nozzle (205) is connected to the first injection pipeline (204) by a thread, and the first nozzle (205) is Upstream of the DPF (103), at a distance of 100mm from the DPF (103); the second nozzle (306) is connected to the second injection pipeline (305) through threads, upstream of the _NOx adsorber (104), 100mm from the _NOx adsorber (104). 3. The exhaust gas treatment system based on NTP technology according to claim 1, wherein the _NOx adsorber (104) is composed of a substrate (1043), a porous plate (1041) and a _NOx adsorbent (1042) ; the _NOx adsorbent (1042) in the _NOx adsorber (104) is zeolite, two stainless steel porous plates (1041) are mounted on both ends of the substrate (1043), and the _NOx adsorbent (1042) is added to the adsorption on the substrate (1043) in the device. 4. The exhaust gas treatment system based on NTP technology according to claim 1, wherein the first NTP generator (201) and the second NTP generator (301) are both dielectric barrier discharge type, using stainless steel pipes (803) as a low-voltage electrode, a quartz glass tube (804) as a blocking medium, a fine wire mesh (805) as a high-voltage electrode, the stainless steel tube (803) is located in the quartz glass tube (804), and is connected with the quartz glass tube (804) Coaxially, the fine wire mesh (805) is wrapped on the quartz glass tube (804). 5 . The exhaust gas treatment system based on NTP technology according to claim 1 , wherein the DPF ( 103 ) is made of a wall-flow honeycomb ceramic material, the pore density is 100 cpsi, the diameter is 144 mm, and the busbar length is 152 mm. 6 . 6. The exhaust gas treatment system based on NTP technology according to claim 1, characterized in that, an exhaust branch (102) is located between the DPF (103) and the _NOx adsorber (104). 7. the control method of the tail gas treatment system based on NTP technology according to claim 1, is characterized in that, comprises the steps: Step 1: Carry out a calibration test on the diesel engine exhaust system, and determine the upper limit value _{ΔPm of the pressure difference across the DPF (103) and the regeneration target value ΔPn and the upper limit value Cm of the NOx} content in the exhaust outlet under different working conditions , and store the pressure difference upper limit value ΔP _m , the regeneration target value ΔP _n and the upper limit value C _m of the NO _x content into the control module (601); Step 2: When the engine is running, the pressure difference ΔP across the DPF (103) is monitored by the differential pressure sensor (606) to determine whether it needs to be regenerated; the _NOx sensor (607) is used to monitor the outlet of the main exhaust pipe (101). The content of _NOx , _CNOx , to determine whether the _NOx adsorber (104) needs to be desorbed; Step 3: When the control module (601) monitors and detects that the pressure difference ΔP across the DPF (103) is greater than the upper limit ΔP _m or the _NOx content C _NOx in the exhaust outlet is greater than the _NOx content upper limit C _m , detect Engine stop signal, when the control module (601) detects the engine stop signal, the control module (601) closes the first control valve (602) and opens the second control valve (603); Step 4: When the control module (601) detects that the pressure difference ΔP across the DPF (103) is greater than the upper limit _{ΔPm, and the NOx content C NOx in the exhaust outlet is less than the upper limit Cm , the control} module (601) ) opens the third control valve (604), and transmits signals to the vehicle power supply (401), the air supply fan (203), the first mass flow controller (202), the first relay (403) and the first water pump (502) , the first NTP injection system is turned on; the active substances produced by the first NTP injection system are ejected from the first nozzle (205) through the first injection pipeline (204) to oxidize the particles deposited in the DPF (103), and then discharged by the exhaust gas The branch (102) is discharged to realize the regeneration of the DPF (103); when it is detected that the pressure difference ΔP between the two ends of the DPF (103) is less than or equal to the regeneration target value ΔP _n , the first NTP injection system is closed, and the second control valve (603) ), the third control valve (604), and the first control valve (602) is opened; When the control module (601) detects that the _NOx content in the exhaust outlet is greater than the upper limit _Cm , and the pressure difference ΔP across the DPF (103) is smaller than the upper limit _ΔPm , the control module (601) opens the fourth control valve (605), and transmit a signal to the vehicle-mounted power supply (401), the air pump (303), the second mass flow controller (302), the second relay (404) and the second water pump (503) to turn on the second NTP injection system; The active substances produced by the second NTP injection system are injected into the _NOx adsorber (104) from the second nozzle (306) through the second injection pipe (305), and then discharged from the main exhaust pipe (101) to realize _NOx adsorption When the O ₂ sensor ( 608 ) detects that the O ₂ content in the back-end gas of the NO _x adsorber ( 104 ) is 0, it indicates that there is no NO _x in the NO _x adsorber ( 104 ) that can interact with N The free radical reaction, the _NOx adsorber (104) has been desorbed, the control module (601) closes the second NTP injection system, closes the second control valve (603), the fourth control valve (605), and opens the first control valve ( 602); When the control module (601) detects that the pressure difference ΔP across the DPF (103) is greater than the upper limit ΔPm, and the _NOx content in the exhaust outlet is greater than the upper limit _Cm , the control module (601) _starts the third control A valve (604), a fourth control valve (605), and transmit signals to the vehicle power supply (401), the air supply fan (203), the first mass flow controller (202), the first relay (403) and the first water pump (502), air pump (303), second mass flow controller (302), second relay (404) and second water pump (503), turn on the first NTP injection system and the second NTP injection system; DPF (103) Regeneration and desorption of the _NOx adsorber (104), when the pressure difference ΔP between the two ends of the DPF (103) is less than or equal to the regeneration target value _ΔPn , the first NTP injection system _is closed. When the O ₂ content in the medium is 0, the second NTP injection system is closed until the pressure difference ΔP between the two ends of the DPF (103) is less than or equal to the regeneration target value ΔP _n , and the O ₂ content in the back-end gas of the _NOx adsorber (104) is 0 When the first NTP injection system and the second NTP injection system are closed, the control module (601) closes the second control valve (603), the third control valve (604) and the fourth control valve (605), and opens the first Control valve (602). 8. The control method of the exhaust gas treatment system based on NTP technology according to claim 7, wherein the first mass flow controller (202) and the second mass flow controller (302) control the gas source flow to be 5L/ min.