WO2005073528A1 - エンジンの排気浄化装置 - Google Patents
エンジンの排気浄化装置 Download PDFInfo
- Publication number
- WO2005073528A1 WO2005073528A1 PCT/JP2005/001530 JP2005001530W WO2005073528A1 WO 2005073528 A1 WO2005073528 A1 WO 2005073528A1 JP 2005001530 W JP2005001530 W JP 2005001530W WO 2005073528 A1 WO2005073528 A1 WO 2005073528A1
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- WIPO (PCT)
- Prior art keywords
- exhaust
- engine
- exhaust gas
- exhaust pipe
- reducing agent
- Prior art date
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
- F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/14—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having thermal insulation
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D9/04—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits concerning exhaust conduits
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/10—Adding substances to exhaust gases the substance being heated, e.g. by heating tank or supply line of the added substance
- F01N2610/102—Adding substances to exhaust gases the substance being heated, e.g. by heating tank or supply line of the added substance after addition to exhaust gases, e.g. by a passively or actively heated surface in the exhaust conduit
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2006—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating
- F01N3/2013—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating using electric or magnetic heating means
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Definitions
- the present invention relates to an engine exhaust purification device (hereinafter referred to as "exhaust exhaust device”) for reducing and purifying nitrogen oxides (NOx) in exhaust using a liquid reducing agent.
- exhaust exhaust device for reducing and purifying nitrogen oxides (NOx) in exhaust using a liquid reducing agent.
- the present invention relates to a technique for suppressing the precipitation of a solute of a liquid reducing agent in an exhaust pipe.
- Patent Document 1 As an exhaust gas purification system for purifying NOx contained in the exhaust gas of an engine, an exhaust gas purification device disclosed in Japanese Patent Application Laid-Open No. 2000-27627 (Patent Document 1) has been proposed.
- a powerful exhaust gas purification device is configured to inject a liquid reducing agent according to an engine operating state from an injection nozzle into an exhaust gas upstream of a reduction catalyst disposed in an exhaust pipe of an engine to thereby supply the exhaust gas.
- NOx and a liquid reducing agent are subjected to a catalytic reduction reaction to purify NOx into harmless components.
- the liquid reducing agent an aqueous urea solution which generates ammonia by hydrolysis, an aqueous ammonia solution, light oil mainly containing hydrocarbons, gasoline, and the like are used.
- Patent Document 1 JP-A-2000-27627
- the present invention has been developed in which the solute of the liquid reducing agent is deposited.
- the exhaust pipe that may be discharged is appropriately heated by a heater to the melting point of the solute or higher, or compressed air is injected near the injection nozzle or the exhaust flow velocity around the injection hole of the injection nozzle is increased to increase the flow rate of the liquid reducing agent. It is an object of the present invention to provide an exhaust gas purification apparatus in which the dispersion of a solute of a liquid reducing agent is suppressed by promoting dispersion.
- the exhaust purification device is provided in the engine exhaust pipe and reduces and purifies nitrogen oxides with a liquid reducing agent.
- An exhaust gas purifying apparatus is provided in an engine exhaust pipe and reduces and purifies nitrogen oxides with a liquid reducing agent, and injects and supplies a liquid reducing agent upstream of the exhaust of the reducing catalyst. It is characterized by including an injection nozzle and an air injection device for injecting compressed air at least near the injection hole of the injection nozzle.
- An exhaust gas purifying apparatus is provided on an engine exhaust pipe, a reduction catalyst for reducing and purifying nitrogen oxides with a liquid reducing agent, and a peripheral wall of an exhaust pipe located upstream of the exhaust of the reduction catalyst.
- Open injection hole force Injection nozzle that supplies liquid reducing agent toward the inside of the exhaust pipe, throttle valve that changes the flow path opening ratio of the exhaust pipe near the injection hole of the injection nozzle, and drives the throttle valve
- An actuator a flow detection device for detecting an exhaust flow rate of the engine, and an opening ratio control device for controlling a flow path opening ratio by a throttle valve via the actuator based on the exhaust flow rate detected by the flow detection device. It is characterized by comprising.
- the exhaust gas purification apparatus of the first invention a part of the liquid reducing agent injected and supplied to the exhaust gas upstream of the reduction catalyst adheres to the inner wall of the exhaust pipe, and the solvent evaporates due to the exhaust heat, solute Even if is deposited, the deposited solute can be heated and dissolved by operating a heater disposed around the exhaust pipe including the portion where the liquid reducing agent adheres. Therefore, by properly controlling the operation of the heater, the solute of the liquid reducing agent precipitates in the exhaust pipe. Therefore, it is possible to reliably prevent a reduction in fuel consumption and output due to an increase in exhaust resistance.
- the heater does not operate when the exhaust pipe temperature is equal to or higher than the melting point of the solute of the liquid reducing agent. And unnecessary energy can be prevented from being consumed.
- the heater is operated only when the engine is in an idle state, the amount of heat that loses the heater power by the exhaust gas is reduced, and the precipitated solute can be efficiently dissolved and removed.
- the operation of the heater is prohibited while the engine is warming up or various auxiliary machines are operating, it is possible to prevent the engine operation from becoming unstable due to the load fluctuation of the alternator.
- the heater is operated for a predetermined time to dissolve and remove the solute even if the solute is deposited in the exhaust pipe. can do. For this reason, when the engine is restarted, it is possible to reliably prevent a decrease in fuel consumption and output immediately after the start of the engine, in which solute precipitation in which an increase in exhaust resistance is a problem occurs. Further, whether or not the solute of the liquid reducing agent has precipitated in the exhaust pipe is determined, for example, by determining the differential pressure in the exhaust pipe sandwiching the portion where the heater is provided, and operating the heater as necessary. Is also good. With this configuration, the heater operates only when the solute of the liquid reducing agent precipitates in the exhaust pipe, so that unnecessary energy consumption can be prevented.
- the heat insulating material around the heater, the heat generated by the heater is suppressed from diffusing to the outside of the exhaust pipe, and the exhaust pipe can be efficiently heated. . For this reason, it is possible to heat the exhaust pipe to a temperature equal to or higher than the melting point of the solute of the liquid reducing agent using the minimum necessary energy, and it is possible to suppress the consumption of the vehicle-mounted battery.
- the liquid reducing agent injected and supplied from the injection nozzle is compressed by the compressed air. Diffusion is promoted, and solutes can be prevented from depositing on the inner wall of the injection hole and the exhaust pipe located downstream of the exhaust hole.
- the injection nozzlelka enables the injection and supply of the liquid reducing agent according to the operating state of the engine. NOx can be appropriately reduced and purified.
- the compressed air is injected in a conical shape, the compressed air is diffused over the entire cross section of the exhaust pipe, and the mixing of the liquid reducing agent with the exhaust gas can be promoted.
- the compressed air is injected from the upstream or downstream of the exhaust nozzle toward the vicinity of the injection hole, the liquid reducing agent injected and supplied from the injection nozzle can be diffused, and the compressed nozzle can be diffused. And solute deposition in the exhaust pipe located downstream of the solute.
- the exhaust downstream force of the injection nozzle also injects compressed air, the liquid reducing agent injected and supplied from the injection nozzle is once returned to the upstream side against the exhaust flow. And promotes diffusion mixing.
- the air injection device includes an air reservoir that stores compressed air, an on-off valve that opens and closes an air flow path of an air pipe extending from the air reservoir, and an air nozzle that injects compressed air that has passed through the on-off valve into an exhaust pipe.
- the compressed air injection mechanism can be simplified.
- the injection control of the compressed air can be easily performed by opening the on-off valve. At this time, it is desirable to detect the exhaust flow rate indirectly from the engine speed.
- the flow rate is increased or decreased in accordance with the exhaust flow rate of the exhaust pipe near the injection hole of the injection nozzle.
- the flow velocity increases, and good dispersion of the liquid reducing agent injected and supplied from the injection nozzle can be obtained. Therefore, the amount of the liquid reducing agent adhering to the inner wall of the exhaust pipe is drastically reduced, and the deposition of the solute on the exhaust pipe can be suppressed. Also, by improving the dispersion of the liquid reducing agent, it is intended to improve the transient response during acceleration and deceleration and to improve the use efficiency of the liquid reducing agent.
- the flow path opening ratio of the exhaust pipe by the throttle valve can be changed.
- a butterfly valve as the throttle valve, it can be rotated to easily change the aperture ratio.
- the butterfly valve heated by exhaust heat heats the liquid reducing agent. Vaporization and diffusion can be promoted.
- the butterfly valve has a slit formed at an edge of a portion which is close to the injection hole of the injection nozzle when the opening ratio of the exhaust pipe is narrowed, or a through hole is formed in a plate surface of the valve body. Since the turbulent flow is generated in the exhaust gas by the slits or the through-holes by forming scattered dots, the dispersion of the liquid reducing agent injected and supplied from the injection nozzle can be further promoted.
- FIG. 1 is a configuration diagram of an exhaust gas purification device embodying the first invention.
- FIG. 2 is a partially enlarged view near an injection nozzle.
- FIG. 3 is a flowchart showing control contents of an electric heater.
- FIG. 4 is a configuration diagram of an exhaust gas purification device embodying the second invention.
- FIG. 5 is a flowchart showing control contents of an on-off valve.
- FIG. 6 is a partially enlarged view showing another configuration of the air injection device.
- FIG. 7 is a configuration diagram of an exhaust gas purification device embodying the third invention.
- FIG. 8 is an enlarged sectional view of a main part of the above.
- FIG. 9 is a detailed view of a butterfly valve.
- FIG. 10 is a flowchart showing the control contents of an actuator.
- FIG. 11 is an explanatory diagram of a control map.
- FIG. 12 is a detailed view showing another embodiment of the butterfly valve.
- FIG. 13 is a detailed view showing still another embodiment of the butterfly valve.
- FIG. 1 shows a configuration of an exhaust gas purification device embodying the first invention.
- the exhaust gas of the engine 10 is discharged from the exhaust manifold 12 into the atmosphere through an exhaust pipe 16 provided with a NOx reduction catalyst 14.
- a urea aqueous solution as a liquid reducing agent according to the operating state of the engine is injected and supplied to the exhaust gas upstream of the NOx reduction catalyst 14 together with compressed air from a reducing agent supply device 18 via a pipe 20 and an injection nozzle 22. That is, as shown in FIG. 2, the exhaust pipe 16 located upstream of the NOx reduction catalyst 14 is provided with a flange 24 to which the injection nozzle 22 is connected so as to close the opening 16A opened on the peripheral wall thereof. Removably fastened by 26.
- the reducing agent supply device 18 and the injection nozzle 22 are connected to each other by a pipe 20.
- the temperature of the urea is reduced by at least the melting point of urea (A electric heater 28 capable of heating to 132 ° C. or higher, a heat insulating material 30 for suppressing the heat generated by the electric heater 28 from being diffused outside, and a force S are arranged in this order.
- a rotation speed sensor 32 As a control system of the reducing agent supply device 18 and the electric heater 28, a rotation speed sensor 32, a load sensor 34, and an electric heating heater 28 for detecting the rotation speed Ne and the load Q of the engine 10, respectively, are provided.
- Temperature sensor 36 Temperature detection device
- a differential pressure sensor 38 Differential pressure
- a detecting device A detecting device
- an auxiliary switch 40 for outputting an ON signal when various auxiliary machines are operating
- a water temperature sensor 42 for detecting a cooling water temperature Tw.
- a fuel injection amount, an accelerator pedal opening, a throttle valve opening, an intake flow rate, an intake negative pressure, and the like can be used as the load Q of the engine 10.
- Each output signal of the rotation speed sensor 32, load sensor 34, temperature sensor 36, differential pressure sensor 38, auxiliary switch 40 and water temperature sensor 42 is input to a control unit 44 with a built-in computer, and its ROM (Read Only Memory)
- the reducing agent supply device 18 and the electric heater 28 are respectively controlled by the control program stored in the storage device.
- the temperature sensor 36 may be configured to indirectly detect the exhaust pipe temperature Te from the exhaust temperature instead of directly detecting the exhaust pipe temperature Te.
- At least one of the rotation speed sensor 32, the load sensor 34, the auxiliary switch 40, and the water temperature sensor 42 constitutes a power operation state detection device.
- An operation control device is realized by the control unit 44 that executes the control program.
- step 1 based on the differential pressure ⁇ detected by the differential pressure sensor 38, it is determined whether or not urea has precipitated on the inner wall of the exhaust pipe 16. judge. That is, if urea is deposited to some extent on the inner wall of the exhaust pipe 16, the area force of the exhaust flow path becomes smaller, so that a pressure loss occurs, and the pressure difference before and after the urea increases. Therefore, it is possible to indirectly detect the precipitation of urea via whether or not the pressure difference ⁇ ⁇ is equal to or greater than the predetermined value ⁇ .
- the If urea is deposited the process proceeds to step 2 (Yes), while if urea is not deposited, the process waits (No).
- step 2 based on the rotation speed Ne detected by the rotation speed sensor 32, it is determined whether or not the engine 10 is operating, in other words, whether or not the engine 10 has stopped. If the engine 10 is operating, the process proceeds to step 3 (Yes), while if the engine 10 is not operating, it is determined that the engine 10 has stopped and the process proceeds to step 8 (No).
- step 3 it is determined based on the rotational speed Ne and the load Q detected by the rotational speed sensor 32 and the load sensor 34, whether or not the engine 10 is idle. That is, when the rotation speed Ne is substantially the idle rotation speed and the load Q is equal to or less than the predetermined value Q,
- the engine 10 can be determined to be in the idle state.
- the intake system is provided with a throttle valve, it may be determined whether or not a force such as a throttle opening sensor or an idle switch is in an idle state. If the engine 10 is in the idle state, the process proceeds to step 4 (Yes), and if not, the process returns to step 1 (No).
- step 4 based on the cooling water temperature Tw detected by the water temperature sensor 42, it is determined whether or not the warming-up of the engine 10 is completed, in other words, whether or not the engine 10 is being warmed up. If the warm-up is completed, the process proceeds to step 5 (Yes), while if the warm-up is being performed, the process returns to step 1 (No).
- step 5 based on the ONZOFF signal from the auxiliary switch 40, it is determined whether or not various auxiliary machines are operating. If the various accessories are not operating, the process proceeds to step 6 (Yes), while the various accessories are operated! /, And if it is, the process returns to step 1 (No).
- step 6 when the exhaust pipe temperature Te detected by the temperature sensor 36 is less than the predetermined value T,
- the predetermined value T is such that urea deposited on the inner wall of the exhaust pipe 16 is dissolved.
- the melting temperature is set to be equal to or higher than the melting point of urea. If the exhaust pipe temperature Te is lower than the predetermined value T, the process proceeds to Step 7 (Yes), and the precipitated urea is heated to a temperature equal to or higher than the melting point.
- the electric heater 28 for dissolving and removing is operated for a predetermined time. On the other hand, if the exhaust pipe temperature Te is equal to or higher than the predetermined value T, urea is dissolved and removed spontaneously, thereby preventing unnecessary power consumption.
- step 8 processing after the engine 10 is stopped is performed. That is, whether the exhaust pipe temperature Te detected by the temperature sensor 36 is less than the predetermined value T, in other words, whether the exhaust pipe temperature
- the electric heater 28 for heating and dissolving is operated for a predetermined time. On the other hand, if the exhaust pipe temperature Te is equal to or higher than the predetermined value T, urea is dissolved and removed spontaneously, and unnecessary power consumption is reduced.
- the process is terminated without operating the electric heater 28 to prevent cost (No).
- the exhaust of the engine 10 is introduced into the NOx reduction catalyst 14 through the exhaust manifold 12 and the exhaust pipe 16. Further, the urea aqueous solution injected and supplied from the injection nozzle 22 is hydrolyzed by exhaust heat and water vapor in the exhaust gas to form ammonia, and is introduced into the NOx reduction catalyst 14 by riding on the exhaust gas flow. Then, in the NOx reduction catalyst 14, NOx in the exhaust gas is converted into water (H 2 O) and harmless gas (N) by a reduction reaction using ammonia to purify the NOx.
- the entire amount of the urea aqueous solution injected and supplied from the injection nozzle 22 is not necessarily hydrolyzed to ammonia, and a part thereof adheres to the inner wall of the exhaust pipe 16. If the exhaust gas temperature is high and the exhaust pipe temperature Te is equal to or higher than the melting point of urea, the urea is dissolved and removed spontaneously even if the water in the urea aqueous solution attached to the inner wall of the exhaust pipe 16 evaporates and urea precipitates. This is not a problem.
- the electric heating heater 28 disposed around the exhaust pipe 16 including at least a portion to which the aqueous urea solution adheres for a predetermined time By operating the electric heating heater 28 disposed around the exhaust pipe 16 including at least a portion to which the aqueous urea solution adheres for a predetermined time, the deposited urea is heated to a melting point or higher, and the urea is melted and removed. it can.
- the electric heater 28 is operated only when the engine 10 is in an idle state, the amount of heat taken from the electric heater 28 by the exhaust gas having a relatively high flow rate is reduced, and the deposited urea is efficiently removed. Can be.
- the engine operation tends to be unstable. Therefore, the operation of the electric heater 28 is prohibited, and the engine is turned on in response to the load fluctuation of the alternator (AC generator). Prevents unstable operation.
- the heat insulating material 30 is provided around the electric heater 28, the thermal power generated by the electric heater 28 is suppressed from being diffused to the outside of the exhaust pipe 16, and the exhaust pipe is efficiently exhausted. 16 can be heated. Therefore, it is possible to heat the exhaust pipe temperature Te to a temperature equal to or higher than the melting point of urea using the minimum necessary energy, and it is possible to suppress the consumption of the vehicle-mounted battery.
- FIG. 4 shows a configuration of an exhaust gas purification device embodying the second invention. Note that the same components as those of the exhaust gas purification apparatus according to the first invention are denoted by the same reference numerals, and description thereof will be omitted (the same applies hereinafter).
- An air injection device 46 that injects compressed air at least near the injection hole of the injection nozzle 22 is provided upstream of the exhaust of the injection nozzle 22.
- the air injection device 46 includes an air reservoir 48 for storing compressed air, an air pipe 50 for forming an air flow path extending from the air lizano 48, and a normally-closed electromagnetic on-off valve (hereinafter referred to as an on-off valve) interposed in the air pipe 50. 52) and an air nozzle 54 connected to the tip of the air pipe 50.
- the air nozzle 54 discharges air so that the upstream exhaust force of the injection nozzle 22 also injects compressed air toward the vicinity of the injection hole. It is detachably fastened to the peripheral wall of the trachea 16 via a flange 56.
- the air nozzle 54 is configured so as to be able to jet compressed air in a conical shape as shown in FIG.
- an exhaust pipe 16 located upstream of the NOx reduction catalyst 14, specifically, between the injection nozzle 22 and the NOx reduction catalyst 14, has an exhaust gas temperature Tg.
- An exhaust temperature sensor 58 exhaust temperature detecting device for detecting the temperature is provided.
- the output signals of the rotation speed sensor 32 and the exhaust temperature sensor 58 are input to the control unit 44, and the on-off valve 52 is controlled by a control program stored in the ROM.
- control unit 44 that executes the control program implements an on-off valve control device.
- step 11 the exhaust gas temperature Tg detected by the exhaust gas temperature sensor 58 is lower than a predetermined value T.
- the predetermined value T is the injection nozzle 22 and its exhaust downstream.
- step 12 the rotation speed Ne detected by the rotation speed sensor 32 is equal to or less than the predetermined value N.
- the predetermined value N is such that the exhaust flow rate of the engine 10 is small.
- step 14 If higher than the predetermined value N, proceed to step 14 (No).
- the exhaust flow rate is, for example,
- the rotation speed sensor 32 corresponds to the rotation speed detection device
- the rotation speed sensor 32 or the flow rate sensor corresponds to the flow rate detection device.
- the on-off valve 52 is energized to open. When the on-off valve 52 opens, the compressed air stored in the air lizano 48 is supplied to the air nozzle 54 through the air pipe 50 and is injected toward the vicinity of the injection hole from the exhaust upstream of the injection nozzle 22. .
- step 14 the energization of the on-off valve 52 is stopped as necessary, and the valve is closed.
- the exhaust gas of the engine 10 is introduced into the NOx reduction catalyst 14 through the exhaust manifold 12 and the exhaust pipe 16. Further, the urea aqueous solution injected and supplied from the injection nozzle 22 is hydrolyzed by exhaust heat and water vapor in the exhaust gas to form ammonia, and is introduced into the NOx reduction catalyst 14 by riding on the exhaust gas flow. In the NOx reduction catalyst 14, NOx in the exhaust gas is converted into water and harmless gas and purified by a reduction reaction using ammonia.
- the on-off valve 52 is opened, and the compressed air is also injected toward the vicinity of the injection hole with the exhaust upstream force of the injection nozzle 22.
- the urea aqueous solution injected and supplied from the injection nozzle 22 is promoted to diffuse by the compressed air, and it is possible to suppress the deposition of urea on the injection hole and the inner wall of the exhaust pipe 16 located downstream of the exhaust hole. .
- the precipitation of urea is suppressed, it is possible to supply the aqueous urea solution from the injection nozzle 22 in accordance with the operating state of the engine, so that NOx in the exhaust gas can be appropriately reduced and purified.
- the compressed air is injected in a conical shape, so that mixing of the urea aqueous solution with the exhaust gas can be promoted. For this reason, hydrolysis of the urea aqueous solution is promoted, and ammonia is introduced into the NOx reduction catalyst 14 substantially uniformly.
- the exhaust purification function of the exhaust purification device is maintained and maintained. This can be optimized.
- the on-off valve 52 is closed.
- the diffusion of the urea aqueous solution is promoted by the exhaust gas itself instead of the compressed air having a high flow velocity. Therefore, when the possibility of urea precipitation is small, by not injecting the compressed air, it is possible to suppress unnecessary consumption of the compressed air.
- the air injection device 46 may also inject the compressed air toward the vicinity of the injection hole with the exhaust downstream force of the injection nozzle 22 as well. By doing so, the urea aqueous solution injected and supplied from the injection nozzle 22 is returned to the upstream side against the exhaust gas flow, and therefore, the time required to reach the NOx reduction catalyst 14 is increased, and the hydrolysis thereof is performed. And the diffusion mixing of the ammonia.
- FIG. 7 and FIG. 8 show a configuration of an exhaust gas purification device embodying the third invention.
- the injection nozzle 22 is also configured such that the injection hole opening on the peripheral wall of the exhaust pipe 16 located upstream of the NOx reduction catalyst 14 exhausts the urea aqueous solution toward the inside of the exhaust pipe 16. It is arranged to supply injection.
- the exhaust pipe 16 is provided as a throttle valve that increases or decreases the flow path opening ratio of the exhaust pipe 16 near the injection hole of the injection nozzle 22 at a position where the aqueous urea solution injected and supplied from the injection nozzle 22 collides.
- the butterfly valve 60 is rotatably disposed.
- the butterfly valve 60 has a disc-shaped valve body 60 A having substantially the same shape as the inner surface of the cross section of the exhaust pipe 16, and is integrally formed so as to pass through substantially the center thereof.
- the valve shaft 60B As shown in FIG. 8, the butterfly valve 60 is provided on the peripheral wall of the exhaust pipe 16 so as to be rotatable around a horizontal axis orthogonal to the exhaust flow direction A, at least to positions B and C in FIG.
- the shaft 60B is supported.
- an actuator 62 such as an electric motor for rotating the valve body 60A is connected to the valve shaft 60B. It is desirable to use a stepping motor as the actuator 62 that facilitates the rotation control of the butterfly valve 60.
- an intake air temperature sensor 64 for detecting an intake air temperature Ti is provided in addition to the rotational speed sensor 32, the load sensor 34, and the exhaust gas temperature sensor 58.
- the output signals of the rotation speed sensor 32, the load sensor 34, the exhaust gas temperature sensor 58, and the intake air temperature sensor 64 are input to the control unit 44 and stored in the ROM.
- the actuator 62 is controlled by the control program.
- control unit 44 that executes the control program implements a flow rate detection device and an aperture ratio control device, respectively.
- step 21 the rotation speed Ne, the load Q, the exhaust temperature Tg, and the intake temperature Ti are read from the rotation speed sensor 32, the load sensor 34, the exhaust temperature sensor 58, and the intake temperature sensor 64, respectively.
- step 22 the exhaust flow rate of the engine 10 is estimated and calculated based on the rotation speed Ne, the load Q, the exhaust gas temperature Tg, and the intake air temperature Ti.
- an exhaust flow rate sensor provided in the exhaust pipe 16 may be used to directly detect the exhaust flow rate.
- the exhaust flow rate sensor corresponds to the flow rate detection device.
- step 23 the opening ratio (flow passage opening ratio) of the butterfly valve corresponding to the exhaust flow rate is calculated with reference to the control map shown in FIG.
- the control map shows that the opening ratio is fully open (100%) when the exhaust flow rate is equal to or greater than the predetermined value Q.
- the correlation between the exhaust flow rate and the aperture ratio is set so that the aperture ratio gradually increases nonlinearly when the value is less than zero.
- Step 24 a control signal corresponding to the flow path opening ratio is output to the actuator 62.
- the exhaust gas of the engine 10 is introduced into the NOx reduction catalyst 14 through the exhaust manifold 12 and the exhaust pipe 16. Further, the urea aqueous solution injected and supplied from the injection nozzle 22 is hydrolyzed by exhaust heat and water vapor in the exhaust gas to form ammonia, and is introduced into the NOx reduction catalyst 14 by riding on the exhaust gas flow. In the NOx reduction catalyst 14, NOx in the exhaust gas is converted into water and harmless gas and purified by a reduction reaction using ammonia.
- the rotation of the valve body 60A is controlled to a position C substantially parallel to the exhaust gas flow direction A as shown in FIG.
- the urea aqueous solution injected and supplied from the injection nozzle 22 has a high exhaust flow velocity near the injection hole of the injection nozzle 22. Is atomized due to enhanced diffusion. For this reason, the urea aqueous solution adhering to the inner wall of the exhaust pipe 16 is drastically reduced, and the deposition of urea on the exhaust pipe 16 can be suppressed.
- the urea precipitated in the exhaust pipe 16 dissolves when the exhaust gas temperature becomes equal to or higher than its melting point. Therefore, even if a small amount of urea is precipitated, a problem caused by the urea does not occur.
- the rotation of the valve body 60A is controlled to a predetermined opening degree in the direction of the B position.
- the opening rate of the butterfly valve 60 decreases, so that the exhaust flow velocity flowing through the exhaust pipe 16 increases, and the diffusion of the urea aqueous solution injected and supplied from the injection nozzle 22 is promoted. Atomize. Therefore, even when the exhaust gas flow rate is small, the amount of the urea aqueous solution adhering to the inner wall of the exhaust pipe 16 is drastically reduced, and the deposition of urea on the exhaust pipe 16 can be suppressed.
- the urea aqueous solution injected and supplied from the injection nozzle 22 collides with the plate surface of the valve body 60A of the inclined butterfly valve 60. At this time, since the butterfly valve 60 is heated by the exhaust heat, hydrolysis of the colliding aqueous urea solution is promoted, and ammonia can be generated efficiently.
- FIG. 12 shows another embodiment of the butterfly valve 60. That is, the butterfly valve 60 has a configuration in which a slit 60C is formed at an edge of a portion close to the injection hole of the injection nozzle 22 when the flow path opening ratio of the exhaust pipe 16 is reduced. By doing so, turbulence is generated in the exhaust gas by the slit 60C, so that the dispersion of the urea aqueous solution injected and supplied from the injection nozzle 22 can be further promoted.
- FIG. 13 shows still another embodiment of the butterfly valve 60. That is, the butterfly valve 60 has a configuration in which the through-holes 60D are formed in a scattered shape on the plate surface of the valve body 60A. Like this For example, similarly to the slit 60C, a turbulent flow is generated in the exhaust gas by the through hole 60D, so that the dispersion of the urea aqueous solution injected and supplied from the injection nozzle 22 can be further promoted.
- at least one of the slit 60C and the through hole 60D may be formed in the valve body 60A of the butterfly valve 60.
- an aqueous ammonia solution, light oil containing hydrocarbon as a main component, gasoline, or the like may be used as the liquid reducing agent.
- the NOx reduction catalyst 14 a catalyst having a property of reducing and purifying NOx in exhaust gas using a liquid reducing agent or a substance generated therefrom as a reducing agent may be used. Further, by appropriately combining the respective inventions, it is possible to more effectively suppress the deposition of the solute of the liquid reducing agent in the exhaust pipe 16.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Exhaust Gas After Treatment (AREA)
Abstract
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JP2004025785A JP4290027B2 (ja) | 2004-02-02 | 2004-02-02 | 排気浄化装置 |
JP2004-025785 | 2004-02-02 | ||
JP2004-089882 | 2004-03-25 | ||
JP2004089882A JP4408051B2 (ja) | 2004-03-25 | 2004-03-25 | エンジンの排気浄化装置 |
JP2004-107183 | 2004-03-31 | ||
JP2004107183A JP4290056B2 (ja) | 2004-03-31 | 2004-03-31 | エンジンの排気浄化装置 |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007146810A (ja) * | 2005-11-30 | 2007-06-14 | Toyota Motor Corp | 内燃機関の排気システム |
DE102006059507A1 (de) * | 2006-12-14 | 2008-06-19 | J. Eberspächer GmbH & Co. KG | Abgasanlage mit Injektor |
DE102009021616A1 (de) * | 2009-05-15 | 2010-11-18 | Makon Engineering Gmbh | Schiffabgasnachbehandlungsvorrichtung |
WO2011120838A1 (de) * | 2010-04-01 | 2011-10-06 | Emitec Gesellschaft Für Emissionstechnologie Mbh | Verfahren zum betrieb einer abgasbehandlungsvorrichtung |
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0598953A (ja) * | 1991-10-01 | 1993-04-20 | Mitsubishi Electric Corp | 電気ヒータ付触媒の制御装置 |
JPH07279650A (ja) * | 1994-04-05 | 1995-10-27 | Niigata Eng Co Ltd | 排煙脱硝装置の還元剤噴霧装置 |
JPH0921310A (ja) * | 1995-07-04 | 1997-01-21 | Honda Motor Co Ltd | 内燃機関の排気ガス浄化装置 |
JPH11294145A (ja) * | 1998-04-06 | 1999-10-26 | Toyota Motor Corp | 内燃機関の排気浄化装置 |
JP2002030927A (ja) * | 2000-07-17 | 2002-01-31 | Toyota Motor Corp | 内燃機関の排気浄化装置 |
JP2002038942A (ja) * | 2000-07-24 | 2002-02-06 | Toyota Motor Corp | 内燃機関の排気浄化装置 |
-
2005
- 2005-02-02 WO PCT/JP2005/001530 patent/WO2005073528A1/ja active Application Filing
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0598953A (ja) * | 1991-10-01 | 1993-04-20 | Mitsubishi Electric Corp | 電気ヒータ付触媒の制御装置 |
JPH07279650A (ja) * | 1994-04-05 | 1995-10-27 | Niigata Eng Co Ltd | 排煙脱硝装置の還元剤噴霧装置 |
JPH0921310A (ja) * | 1995-07-04 | 1997-01-21 | Honda Motor Co Ltd | 内燃機関の排気ガス浄化装置 |
JPH11294145A (ja) * | 1998-04-06 | 1999-10-26 | Toyota Motor Corp | 内燃機関の排気浄化装置 |
JP2002030927A (ja) * | 2000-07-17 | 2002-01-31 | Toyota Motor Corp | 内燃機関の排気浄化装置 |
JP2002038942A (ja) * | 2000-07-24 | 2002-02-06 | Toyota Motor Corp | 内燃機関の排気浄化装置 |
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DE102006059507A1 (de) * | 2006-12-14 | 2008-06-19 | J. Eberspächer GmbH & Co. KG | Abgasanlage mit Injektor |
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