WO2021039303A1 - Liquid injection system - Google Patents

Liquid injection system Download PDF

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Publication number
WO2021039303A1
WO2021039303A1 PCT/JP2020/029744 JP2020029744W WO2021039303A1 WO 2021039303 A1 WO2021039303 A1 WO 2021039303A1 JP 2020029744 W JP2020029744 W JP 2020029744W WO 2021039303 A1 WO2021039303 A1 WO 2021039303A1
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WIPO (PCT)
Prior art keywords
liquid
bubble
liquid injection
period
bubbles
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PCT/JP2020/029744
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French (fr)
Japanese (ja)
Inventor
慶子 柴田
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いすゞ自動車株式会社
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Publication of WO2021039303A1 publication Critical patent/WO2021039303A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20—Mixing gases with liquids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F31/00—Mixers with shaking, oscillating, or vibrating mechanisms
    • B01F31/80—Mixing by means of high-frequency vibrations above one kHz, e.g. ultrasonic vibrations
    • 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

Definitions

  • This disclosure relates to a liquid injection system.
  • the fine bubbles have the same particle size, and it is desirable that the content of the fine bubbles contained in the liquid is also constant. ..
  • An object of the present disclosure is to provide a liquid injection system that promotes fine particle formation of a liquid.
  • the liquid injection system of one aspect of the present disclosure that achieves the above object is a liquid injection system including a main tank for storing liquid and a liquid injection valve connected to the main tank, wherein the main tank and the liquid injection valve are provided.
  • a sub tank that is arranged between the main tanks and stores the liquid sent from the main tank, a bubble discharger that discharges bubbles to the liquid stored in the sub tank, and bubbles discharged from the bubble discharger.
  • An ultrasonic irradiation device for irradiating sound waves, a bubble ejector, and a control device connected to the ultrasonic irradiation device are provided, and the control device discharges bubbles from the bubble ejector and irradiates the ultrasonic waves. It is characterized in that it is configured to generate fine bubbles by irradiating ultrasonic waves from the apparatus and control the content rate of fine bubbles contained in the liquid stored in the sub tank to be adjusted within a predetermined range. ..
  • FIG. 1 is a block diagram illustrating the liquid injection system of the embodiment.
  • FIG. 2 is a block diagram illustrating the control device of FIG.
  • FIG. 3 is a relationship diagram illustrating the relationship between the number of injections of the liquid injection valve of FIG. 1 and the injection amount.
  • FIG. 4 is a relationship diagram illustrating the relationship between the passage of time in the sub-tank of FIG. 1 and the amount of liquid added, the amount of fine bubbles generated, and the content rate, respectively.
  • FIG. 5 is a relationship diagram illustrating the relationship between the passage of time in the sub tank of FIG. 1 and the disappearance amount and content of fine bubbles.
  • FIG. 6 is a first flow chart illustrating a control method in the liquid injection system of the embodiment.
  • FIG. 6 is a first flow chart illustrating a control method in the liquid injection system of the embodiment.
  • FIG. 7 is a second flow chart illustrating a control method in the liquid injection system of the embodiment.
  • FIG. 8 is a third flow chart illustrating a control method in the liquid injection system of the embodiment.
  • FIG. 9 is a fourth flow chart illustrating a control method in the liquid injection system of the embodiment.
  • the liquid injection system 10 of the present embodiment is a liquid urea water in the exhaust passage 1 on the upstream side of the selective reduction catalyst device 2 with respect to the flow of the exhaust gas G1 of an internal combustion engine mounted on a vehicle (not shown). It is a system that injects.
  • the liquid injected by the liquid injection system 10 is an injection liquid 5 in which the storage liquid 3 contains the fine bubbles 4.
  • the exhaust passage 1 is composed of a cylindrical pipe, and is a passage through which exhaust gas G1 discharged from a plurality of cylinders of an internal combustion engine (not shown) passes, and extends from a diverse exhaust pipe communicating with the plurality of cylinders to an outlet to the outside of the vehicle. It is a passage.
  • the selective reduction catalyst device 2 is arranged at an intermediate position of the exhaust passage 1.
  • the selective reduction catalyst device 2 is configured by supporting a catalyst such as zeolite on a porous ceramic carrier, and contains ammonia generated by hydrolyzing the injected urea water by the heat of the exhaust gas G1 as a reducing agent in the exhaust gas G1. It is a device that selectively reduces and purifies the nitrogen oxides produced.
  • urea water which is a liquid
  • the storage liquid 3 is urea water that does not contain fine bubbles 4
  • the injection liquid 5 is urea water that contains fine bubbles 4.
  • the bubbles are classified into fine bubbles 4 and compressed air bubbles 6.
  • the particle size of the fine bubble 4 and the bubble 6 of the compressed air are different, and the bubble 4 is a finer particle of the bubble 6 of the compressed air.
  • the fine bubble 4 is a bubble having a particle size of less than 100 micrometers.
  • the fine bubble 4 has the characteristic of staying in the liquid for a long time because the rising speed in the liquid is extremely slow, and the pressurization due to the interfacial tension increases in inverse proportion to the size of the bubble and is negatively charged and repels each other. Therefore, it is a bubble having a characteristic that it is difficult to increase the diameter.
  • the bubbles 6 of the compressed air may be fine bubbles.
  • the liquid injection system 10 includes a main tank 11, a liquid injection valve 12, a sub tank 13, a bubble discharger 14, and an ultrasonic irradiation device 15.
  • the main tank 11 and the sub tank 13 are connected by a pipe 16, and the pumping device 17 is arranged at an intermediate position thereof.
  • the liquid injection valve 12 and the sub tank 13 are connected by a pipe 18, and the flow rate adjusting device 19 is arranged at an intermediate position thereof.
  • the liquid injection system 10 includes a control device 20, a temperature sensor 21, and a NOx sensor 22.
  • the main tank 11 is a tank for storing the storage liquid 3 supplied from the outside of the vehicle.
  • the main tank 11 is configured to have a capacity capable of storing the storage liquid 3 consumed while the vehicle is running.
  • the liquid injection valve 12 is a device that injects the injection liquid 5 into the exhaust passage 1 upstream of the selective reduction catalyst device 2 with respect to the flow of the exhaust gas G1.
  • the position where the liquid injection valve 12 is arranged in the exhaust passage 1 is not limited to the downstream side with respect to the flow of the exhaust gas G1 from the turbocharger (not shown), but may be the upstream side from the turbine of the exhaust gas multi-pipe or the turbocharger.
  • the liquid injection valve 12 may be arranged on the upstream side of the turbocharger, and the selective reduction catalyst device 2 may be arranged on the downstream side of the turbocharger.
  • examples of the devices arranged on the upstream side of the liquid injection valve 12 and the downstream side of the selective reduction catalyst device 2 with respect to the flow of the exhaust gas G1 include an oxidation catalyst device, a filter device, and an ammonia adsorption catalyst device 7 (not shown). Is not particularly limited.
  • the liquid injection valve 12 may be inserted into the exhaust passage 1 and may be arranged in a space formed by recessing a part of the inner wall of the exhaust passage 1.
  • the liquid injection valve 12 is configured to periodically inject a fixed amount of the injection liquid 5, and is configured to adjust the injection amount of the injection liquid 5 by increasing or decreasing the number of injections Nx.
  • the sub tank 13 is a tank arranged between the main tank 11 and the liquid injection valve 12.
  • the sub tank 13 contains the fine bubble 4 in the storage liquid 3 inside, and the injection liquid 5 is generated. That is, the sub tank 13 is a tank for storing the storage liquid 3 sent from the main tank 11 by the pumping device 17, and is also a tank for storing the injection liquid 5 injected from the liquid injection valve 12.
  • the capacity of the sub tank 13 is smaller than the capacity of the main tank 11.
  • the storage amount Qa of the injection liquid 5 stored in the sub tank 13 is set to a constant amount in advance by experiments and tests.
  • the storage amount Qa is the average amount consumed when the vehicle equipped with the liquid injection system 10 travels for a predetermined period (for example, 500 seconds to 2000 seconds) or a predetermined distance (for example, 10 km to 30 km). Values are exemplified.
  • the bubble discharger 14 is a device that discharges bubbles 6 of compressed air into the sub tank 13.
  • the bubble discharger 14 is connected to a pump that generates compressed air (not shown) or a tank that stores compressed air, and has a needle tube 14a whose tip is arranged inside the sub tank 13.
  • the ultrasonic irradiation device 15 is a device that irradiates the bubbles 6 of the compressed air discharged from the bubble ejector 14 with ultrasonic waves.
  • the ultrasonic irradiation device 15 is connected to a battery (not shown) and has an oscillator 15a arranged inside the sub tank 13.
  • the oscillator 15a is preferably arranged vertically above the tip opening of the needle tube 14a.
  • the particle size of the generated fine bubbles 4 can be made uniform. Further, the particle size of the fine bubble 4 generated by the combination of the tube diameter of the needle tube 14a and the frequency of the ultrasonic wave can be set to an arbitrary value.
  • the particle size of the fine bubble 4 of the present embodiment is preferably 30 micrometers or less, and more preferably 10 micrometers or less. When the particle size of the fine bubble 4 is 30 micrometers or less, the atomization of the injected liquid 5 is promoted, and when the particle size is 10 micrometers or less, the atomization is further promoted. Further, the diameter of the needle tube 14a is preferably 10 times or less the diameter of the generated fine bubble 4.
  • Each of the tip opening of the needle tube 14a of the bubble discharger 14 and the vibrator 15a of the ultrasonic irradiation device 15 has a storage liquid 3 having a capacity of less than half of the storage amount Qa stored in the sub tank 13. It is preferable that it is below the surface, and it is preferable that the storage liquid 3 having a capacity of one-third or less is stored below the surface.
  • the pumping device 17 is a device for pumping the storage liquid 3 from the main tank 11 to the sub tank 13, and a pump is exemplified.
  • the pumping device 17 is configured to add the storage liquid 3 from the main tank 11 to the sub tank 13 by pumping a fixed amount of the storage liquid 3 per unit time.
  • control device 20 is a central processing unit (CPU) that performs various information processing, an internal storage device that can read and write programs and information processing results used for performing various information processing, and various interfaces. It is hardware composed of.
  • the control device 20 is electrically connected to each of the liquid injection valve 12, the bubble discharger 14, the ultrasonic irradiation device 15, the pumping device 17, and the flow rate adjusting device 19 via a signal line.
  • the control device 20 has an injection control unit 23, a liquid adjustment unit 24, and a bubble adjustment unit 25 as functional elements.
  • Each functional element is stored as a program in the internal storage device, and is executed by the central processing unit in a timely manner.
  • each functional element may be composed of a programmable controller (PLC) or an electric circuit in which each functions independently.
  • PLC programmable controller
  • the injection control unit 23 receives the temperature Tx of the exhaust gas G1 acquired by the temperature sensor 21 and determines whether or not the temperature Tx is equal to or higher than the preset injection temperature Ta, and the temperature Tx becomes equal to or higher than the injection temperature Ta. It is a functional element that controls the liquid injection valve 12 to inject the injection liquid 5 when it is determined that the temperature has increased. At this time, the injection control unit 23 also controls to adjust the number of injections Nx based on the nitrogen oxide content of the exhaust gas G1 acquired by the NOx sensor 22.
  • the injection control unit 23 has a counter 26, counts the number of injections Nx of the liquid injection valve 12, and when the counted number of injections Nx reaches a preset additional number Na, the liquid adjustment unit 24 and the bubble adjustment unit 24 It is also a functional element that issues additional commands to each of the 25.
  • the injection amount of the injected liquid 5 is injected. It has a positive relationship with the number of times Nx. Therefore, the additional amount ⁇ Qa for the injected injection liquid 5 is a value set in advance by experiments and tests, and is set to an amount less than half of the storage amount Qa of the storage liquid 3 in the sub tank 13. The additional amount ⁇ Qa is set so that the difference from the stored amount Qa, that is, the liquid level of the remaining amount is higher than the tip opening of the needle tube 14a of the bubble discharger 14 and the vibrator 15a of the ultrasonic irradiation device 15. ..
  • the additional amount ⁇ Qa is the amount when the number of injections Nx reaches the number of additional injections Na.
  • the injection control unit 23 may acquire the injection amount, and may use the total injection time of the liquid injection valve 12 instead of the injection count Nx, and the injection amount based on the acquired value of the NOx sensor 22. May be used.
  • the liquid adjusting unit 24 is a functional element that drives the pressure feeding device 17 to pump the storage liquid 3 from the main tank 11 to the sub tank 13 and controls to add the amount injected from the liquid injection valve 12.
  • the liquid adjusting unit 24 drives the pumping device 17 by an additional command from the injection control unit 23, counts the period tx in which the pumping device 17 is driven by the pumping timer 27, and the counted period tx is the preset pumping period ta. When it reaches, the drive of the pumping device 17 is stopped.
  • the liquid adjusting unit 24 adjusts the pumping device 17 so that the amount of the storage liquid 3 added to the sub tank 13 becomes constant per unit time, so that the sub tank 13 is used.
  • the amount of storage liquid 3 added to has a positive relationship with respect to the period tx.
  • the additional amount ⁇ Qa is the amount when the period tx reaches the pumping period ta.
  • the bubble adjusting unit 25 drives the bubble ejector 14 and the ultrasonic irradiation device 15 to generate fine bubbles 4 inside the sub tank 13, and determines the content X of the fine bubbles 4 contained in the injection liquid 5 in advance. It is a functional element that controls the adjustment to the range A.
  • the content rate X indicates the volume percentage, and indicates the volume ratio of the fine bubble 4 in the injection liquid 5. It is desirable that the range A is set in advance in a range in which the atomization of the injection liquid 5 can be promoted by experiments and tests, and the performance of the internal combustion engine on which the liquid injection system 10 is mounted and the reduction rate of the selective reduction catalyst device 2 The appropriate range differs depending on the type. In the present embodiment, the range A is a range determined based on the case where the capacity of the fine bubble 4 contained in the stored amount Qa becomes the content Ra.
  • the bubble adjusting unit 25 drives the bubble discharger 14 and the ultrasonic wave irradiation device 15 by an additional command from the injection control unit 23, and the period ty during which the bubble discharger 14 and the ultrasonic wave irradiation device 15 are driven by the generation timer 28.
  • the counted period ty reaches a preset generation period tb, the operation of the bubble ejector 14 and the ultrasonic irradiation device 15 is stopped.
  • the production amount ⁇ Ra is the amount when the period ty reaches the production period tb.
  • the production amount ⁇ Ra is set based on the additional amount ⁇ Qa of the storage liquid 3.
  • the production amount ⁇ Ra is set so that the storage liquid 3 having the additional amount ⁇ Qa contains the fine bubbles 4 having the production amount ⁇ Ra, and the content rate X of the fine bubbles 4 in the injection liquid 5 is within the preset range A.
  • the value is set to be the upper limit of the range A.
  • the bubble adjusting unit 25 generates fine bubbles 4 inside the auxiliary tank 13 so as to replenish the fine bubbles 4 that disappear with the passage of time, and preliminarily sets the content X of the fine bubbles 4 contained in the injection liquid 5. It is also a functional element that controls adjustment to a defined range A.
  • the bubble adjusting unit 25 counts the period tz by the disappearance timer 29, and drives the bubble ejector 14 and the ultrasonic irradiation device 15 when the counted period tz reaches a preset disappearance period tk.
  • the bubble adjusting unit 25 counts the period ty in which the bubble discharger 14 and the ultrasonic irradiation device 15 are driven by the generation timer 28, and discharges bubbles when the counted period ty reaches the preset replenishment period td. Stop driving the device 14 and the ultrasonic irradiation device 15.
  • the disappearance period tc is a period in which the amount of fine bubble 4 disappeared becomes the disappearance amount ⁇ Rb.
  • the amount of fine bubbles 4 generated is relative to the period ty. It becomes a positive relationship.
  • the replenishment period td is the period required to replenish the fine bubbles 4 for the amount of disappearance ⁇ Rb.
  • control method of the liquid injection system 10 will be described as a function of the control device 20.
  • This control method is timed control, and 1 second is used as the control cycle in this embodiment.
  • the control cycle is not limited to 1 second, and may be shorter than 1 second.
  • the injection liquid 5 having a stored amount of Qa is stored in the sub tank 13, and the content rate X of the fine bubbles 4 contained in the injection liquid 5 is the upper limit value of the range A. Shall be.
  • control flow performed by the injection control unit 23 is repeatedly performed at predetermined cycles while the internal combustion engine is operating, and ends when the operation of the internal combustion engine is stopped. In the control flow, it is assumed that one cycle elapses when the return returns to the start.
  • the injection control unit 23 determines whether or not the temperature Tx of the exhaust gas G1 acquired by the temperature sensor 21 is equal to or higher than the injection temperature Ta (S110).
  • the injection temperature Ta is set to a value at which it is possible to determine the situation in which urea water is hydrolyzed to produce ammonia.
  • the injection control unit 23 adjusts the liquid injection valve 12 to periodically inject a constant amount of the injection liquid 5 (S120). In this step, it is preferable that the number of injections Nx is set according to the content of nitrogen oxides contained in the exhaust gas G1 acquired by the NOx sensor 22.
  • the control flow returns and returns to the start.
  • the injection control unit 23 counts the number of injections Nx at which the injection liquid 5 is injected from the liquid injection valve 12 by the counter 26 (S130).
  • the injection control unit 23 determines whether or not the counted number of injections Nx has reached the additional number Na (S140).
  • the injection control unit 23 issues an additional command to the liquid adjusting unit 24 and the bubble adjusting unit 25 (S150).
  • the injection control unit 23 returns the number of injections Nx counted by the counter 26 to zero (S160), returns the control flow, and returns to the start.
  • the control flow returns and returns to the start.
  • control flow performed by the liquid adjusting unit 24 is started by an additional command from the injection control unit 23 and ends when all the steps are completed.
  • the liquid adjusting unit 24 Upon receiving the additional command from the injection control unit 23, the liquid adjusting unit 24 adjusts the drive of the pumping device 17 to pump a fixed amount of the storage liquid 3 per unit time from the main tank 11 to the sub tank 13. Add (S210). Next, the liquid adjusting unit 24 counts the period tx in which the pumping device 17 is driven by the pumping timer 27 (S220). Next, the liquid adjusting unit 24 determines whether or not the period tx counted by the pumping timer 27 has reached the pumping period ta (S230).
  • the liquid adjusting unit 24 stops driving the pumping device 17 (S240). Next, the liquid adjusting unit 24 returns the period tx counted by the pumping timer 27 to zero (S250), and the control flow ends. On the other hand, when it is determined that the period tx is less than the pumping period ta (S230: NO), the driving of the pumping device 17 is continued and the addition of the storage liquid 3 to the sub tank 13 is continued.
  • control flow performed by the bubble adjusting unit 25 is started by an additional command from the injection control unit 23 and ends when all the steps are completed. This control flow is performed at the same time as the control flow shown in FIG. 7 described above.
  • the bubble adjusting unit 25 Upon receiving the additional command from the injection control unit 23, the bubble adjusting unit 25 discharges the bubbles 6 of the compressed air from the bubble ejector 14 and irradiates the ultrasonic waves from the ultrasonic irradiation device 15 to generate fine bubbles 4 ( S310). Next, the bubble adjusting unit 25 drives the bubble ejector 14 and the ultrasonic irradiation device 15 by the generation timer 28 to count the period ty during which the fine bubble 4 is generated (S320). Next, the bubble adjusting unit 25 determines whether or not the period ty counted by the generation timer 28 has reached the generation period tb (S330).
  • the bubble adjusting unit 25 stops driving the bubble ejector 14 and the ultrasonic irradiation device 15 to stop the generation of the fine bubble 4 (S340). .. Next, the bubble adjusting unit 25 returns the period ty counted by the generation timer 28 to zero (S350), and the control flow ends. On the other hand, when it is determined that the period ty is less than the generation period tb (S330: NO), the operation of the bubble ejector 14 and the ultrasonic irradiation device 15 is continued, and the generation of the fine bubbles 4 in the sub tank 13 is continued. ..
  • control flow performed by the bubble adjusting unit 25 is repeatedly performed at predetermined cycles while the internal combustion engine is operating, and ends when the operation of the internal combustion engine is stopped. In the control flow, it is assumed that one cycle elapses when the return returns to the start.
  • the bubble adjusting unit 25 counts the period tz by the disappearance timer 29 (S410). Next, the bubble adjusting unit 25 determines whether or not the counted period tz has reached the disappearance period tk (S420). When it is determined that the period tz is less than the disappearance period tk (S420: NO), the control flow returns and returns to the start.
  • the bubble adjusting unit 25 discharges the bubbles 6 of the compressed air from the bubble ejector 14 and irradiates the ultrasonic waves from the ultrasonic irradiation device 15. Fine bubble 4 is generated (S430).
  • the bubble adjusting unit 25 drives the bubble ejector 14 and the ultrasonic irradiation device 15 by the generation timer 28 to count the period ty during which the fine bubble 4 is generated (S440).
  • the bubble adjusting unit 25 determines whether or not the period ty counted by the generation timer 28 has reached the replenishment period td (S450).
  • the bubble adjusting unit 25 stops driving the bubble ejector 14 and the ultrasonic irradiation device 15 to stop the generation of the fine bubble 4 (S460). .. Next, the bubble adjusting unit 25 returns the period ty counted by the generation timer 28 and the period tz counted by the disappearance timer 29 to zero (S470), and the control flow returns and returns to the start.
  • the liquid injection system 10 of the present disclosure is fine so as to adjust the content rate X to a certain range A with respect to the storage liquid 3 stored in the sub tank 13 separate from the main tank 11.
  • Generate bubble 4. Therefore, it becomes possible to inject the injection liquid 5 containing the fine bubbles 4 having the same particle size at a constant content X, and it is possible to promote the atomization of the injection liquid 5.
  • This is advantageous for increasing the efficiency of ammonia production and improving the agitation property when the liquid is urea water, reducing the consumption of urea water and increasing the aeration resistance by eliminating the need for a stirring mixer. It is possible to obtain effects such as suppression and suppression of precipitation of white products caused by urea water adhering in a liquid or droplet state.
  • the particle sizes of the contained fine bubbles 4 are not uniform and the content rate X Is not stable.
  • the storage liquid 3 is stored in the sub tank 13, and the fine bubble 4 is stored in the stored liquid 3 by the bubble ejector 14 and the ultrasonic irradiation device 15. Is contained.
  • the content ratio X is set to a certain range A. It is also advantageous to fit.
  • the liquid injection system 10 can keep the content rate X of the fine bubbles 4 contained in the injection liquid 5 within a certain range A by the timed control that controls the operation of each device based on the elapsed time of each timer. In this way, by adjusting the content rate X of the fine bubble 4 by timed control, it becomes unnecessary to install a sensing device related to the control amount as compared with the feedback control and the feedforward control using the content rate X as the control amount, and the control It is possible to reduce the calculation load related to. In the liquid injection system 10 of the present disclosure, by adding a sensing device related to the content rate X, the content rate X can be kept within a certain range A by using feedback control or feedforward control using the content rate X as a control amount. You can also.
  • step S330 determines whether or not the period ty counted by the generation timer 28 has reached the period obtained by adding the replenishment period td to the generation period tb. It may be configured.
  • the control illustrated in FIG. 9 can also be applied as a control for counting the period of stoppage while the vehicle or the internal combustion engine is stopped and replenishing the fine bubble 4 that disappeared during the stoppage period. Further, regarding this control, a control may be added to reduce the amount of the storage liquid 3 stored in the sub tank 13 so that the content rate X can be quickly kept within a certain range A when the internal combustion engine is started.
  • the pumping device 17 may be configured to reversely operate and return from the sub tank 13 to the main tank 11.
  • the generation period tb is longer than the additional period ta, but the additional period ta can be set to the same period as the generation period tb by setting.
  • the configuration in which the liquid injection system 10 injects urea water as a liquid into the exhaust passage 1 of the internal combustion engine has been described as an example, but the liquid injected by the liquid injection system 10 is not limited to urea water. ..
  • the liquid injected by the droplet injection system 10 of the present disclosure includes a cleaning liquid that is injected into a filter device arranged in the exhaust passage 1 and backwashes non-combustible combustion products (also referred to as ash) accumulated in the filter device, an internal combustion engine.
  • the liquid injection system 10 is not limited to the one mounted on the vehicle. Examples of the liquid injection system 10 include a system for injecting lubricating oil or cooling oil to parts on a production line, a system for injecting cleaning water to parts, and a system for injecting coating liquid to parts.
  • the liquid injection system of the present disclosure is useful in that it is possible to inject a liquid containing fine bubbles having a uniform particle size at a constant content rate, and it is possible to promote fine particle formation of the liquid.

Abstract

A liquid injection system (10) including a main tank (11) and a liquid injection valve (12) comprises a sub tank (13), a bubble discharger (14), an ultrasonic irradiation device (15), and a control device (20), wherein the control device (20) is configured to perform control such that compressed air bubbles (6) are discharged from the bubble ejector (14) and irradiated by ultrasonic waves from the ultrasonic irradiation device (15) to generate fine bubbles (4), and the content rate X of the fine bubbles (4) contained in an injection liquid (5) stored in the sub tank (13) is adjusted to a predetermined range A.

Description

液体噴射システムLiquid injection system
　本開示は、液体噴射システムに関する。 This disclosure relates to a liquid injection system.
　気泡が含有された尿素水を噴射させることで、噴射された尿素水の微粒子化の促進に有利になることが知られている。これに関して、尿素水噴射弁から噴射する必要量の尿素水を尿素水タンクから超音波照射槽に送り、超音波によりキャビテーションによる気泡を発生させる装置が提案されている（例えば、特許文献１参照）。 It is known that by injecting urea water containing bubbles, it is advantageous to promote the atomization of the injected urea water. In this regard, a device has been proposed in which a required amount of urea water injected from a urea water injection valve is sent from a urea water tank to an ultrasonic irradiation tank to generate bubbles due to cavitation by ultrasonic waves (see, for example, Patent Document 1). ..
日本国特開２００７－１８２８０３号公報Japanese Patent Application Laid-Open No. 2007-182803
　ところで、尿素水などの液体の微粒子化を促進させるためには、粒径が揃ったファインバブルであることが望ましく、また、液体に含有されるそのファインバブルの含有率も一定であることが望ましい。 By the way, in order to promote the atomization of a liquid such as urea water, it is desirable that the fine bubbles have the same particle size, and it is desirable that the content of the fine bubbles contained in the liquid is also constant. ..
　特許文献１に記載の開示のように単純に尿素水に気泡を含有させるだけでは、粒径が大きい気泡が含まれるおそれがあり、尿素水に含有される気泡の粒径が不揃いになる。また、尿素水に含有される気泡の含有率も不定である。このように、特許文献１に記載の開示を単純に利用しても液体の微粒子化を促進する有効な解決策とはならない。 If the urea water is simply contained with bubbles as disclosed in Patent Document 1, there is a possibility that bubbles having a large particle size may be contained, and the particle size of the bubbles contained in the urea water becomes uneven. In addition, the content of bubbles contained in urea water is also indefinite. As described above, simply using the disclosure described in Patent Document 1 does not provide an effective solution for promoting the atomization of the liquid.
　本開示の目的は、液体の微粒子化を促進させる液体噴射システムを提供することである。 An object of the present disclosure is to provide a liquid injection system that promotes fine particle formation of a liquid.
　上記の目的を達成する本開示の一態様の液体噴射システムは、液体を貯留する主タンクとこの主タンクに接続された液体噴射弁とを備える液体噴射システムにおいて、前記主タンクおよび前記液体噴射弁の間に配置されて前記主タンクから送られた液体を貯留する副タンクと、この副タンクに貯留された液体に気泡を吐出する気泡吐出器と、この気泡吐出器から吐出された気泡に超音波を照射する超音波照射装置と、前記気泡吐出器および前記超音波照射装置に接続された制御装置と、を備え、前記制御装置により、前記気泡吐出器から気泡を吐出させるとともに前記超音波照射装置から超音波を照射させてファインバブルを生成し、前記副タンクに貯留された液体に含有されたファインバブルの含有率を予め定めた範囲に調節する制御を行う構成にしたことを特徴とする。 The liquid injection system of one aspect of the present disclosure that achieves the above object is a liquid injection system including a main tank for storing liquid and a liquid injection valve connected to the main tank, wherein the main tank and the liquid injection valve are provided. A sub tank that is arranged between the main tanks and stores the liquid sent from the main tank, a bubble discharger that discharges bubbles to the liquid stored in the sub tank, and bubbles discharged from the bubble discharger. An ultrasonic irradiation device for irradiating sound waves, a bubble ejector, and a control device connected to the ultrasonic irradiation device are provided, and the control device discharges bubbles from the bubble ejector and irradiates the ultrasonic waves. It is characterized in that it is configured to generate fine bubbles by irradiating ultrasonic waves from the apparatus and control the content rate of fine bubbles contained in the liquid stored in the sub tank to be adjusted within a predetermined range. ..
　本開示の一態様によれば、粒径が揃ったファインバブルを一定の含有率で含有させた液体を噴射することが可能になり、液体の微粒子化を促進することができる。 According to one aspect of the present disclosure, it is possible to inject a liquid containing fine bubbles having a uniform particle size at a constant content rate, and it is possible to promote fine particle formation of the liquid.
図１は、実施形態の液体噴射システムを例示する構成図である。FIG. 1 is a block diagram illustrating the liquid injection system of the embodiment. 図２は、図１の制御装置を例示するブロック図である。FIG. 2 is a block diagram illustrating the control device of FIG. 図３は、図１の液体噴射弁の噴射回数と噴射量との関係を例示する関係図である。FIG. 3 is a relationship diagram illustrating the relationship between the number of injections of the liquid injection valve of FIG. 1 and the injection amount. 図４は、図１の副タンクにおける時間経過と液体の追加量、ファインバブルの生成量、及び含有率のそれぞれとの関係を例示する関係図である。FIG. 4 is a relationship diagram illustrating the relationship between the passage of time in the sub-tank of FIG. 1 and the amount of liquid added, the amount of fine bubbles generated, and the content rate, respectively. 図５は、図１の副タンクにおける時間経過とファインバブルの消失量及び含有率のそれぞれとの関係を例示する関係図である。FIG. 5 is a relationship diagram illustrating the relationship between the passage of time in the sub tank of FIG. 1 and the disappearance amount and content of fine bubbles. 図６は、実施形態の液体噴射システムにおける制御方法を例示する第一のフロー図である。FIG. 6 is a first flow chart illustrating a control method in the liquid injection system of the embodiment. 図７は、実施形態の液体噴射システムにおける制御方法を例示する第二のフロー図である。FIG. 7 is a second flow chart illustrating a control method in the liquid injection system of the embodiment. 図８は、実施形態の液体噴射システムにおける制御方法を例示する第三のフロー図である。FIG. 8 is a third flow chart illustrating a control method in the liquid injection system of the embodiment. 図９は、実施形態の液体噴射システムにおける制御方法を例示する第四のフロー図である。FIG. 9 is a fourth flow chart illustrating a control method in the liquid injection system of the embodiment.
　以下に、本開示における液体噴射システムの実施形態について説明する。図中において、白抜き矢印が排ガスＧ１を示し、矢印が液体を示し、一点鎖線が信号線を示すものとする。 The embodiment of the liquid injection system in the present disclosure will be described below. In the figure, it is assumed that the white arrow indicates the exhaust gas G1, the arrow indicates the liquid, and the alternate long and short dash line indicates the signal line.
　図１に例示するように、本実施形態の液体噴射システム１０は図示しない車両に搭載された内燃機関の排ガスＧ１の流れに関して選択的還元触媒装置２の上流側の排気通路１で液体として尿素水を噴射するシステムである。この液体噴射システム１０が噴射する液体は、貯留用液体３にファインバブル４を含有させた噴射用液体５である。 As illustrated in FIG. 1, the liquid injection system 10 of the present embodiment is a liquid urea water in the exhaust passage 1 on the upstream side of the selective reduction catalyst device 2 with respect to the flow of the exhaust gas G1 of an internal combustion engine mounted on a vehicle (not shown). It is a system that injects. The liquid injected by the liquid injection system 10 is an injection liquid 5 in which the storage liquid 3 contains the fine bubbles 4.
　排気通路１は円筒管で構成されて、図示しない内燃機関の複数の気筒から排出される排ガスＧ１が通過する通路であり、複数の気筒に連通する排気多岐管から車両の外部への出口までの通路である。選択的還元触媒装置２は排気通路１の中途位置に配置される。選択的還元触媒装置２は多孔質セラミック担体にゼオライト等の触媒を担持して構成され、噴射された尿素水が排ガスＧ１の熱により加水分解されて生成されたアンモニアを還元剤として排ガスＧ１に含有される窒素酸化物を選択的に還元浄化する装置である。 The exhaust passage 1 is composed of a cylindrical pipe, and is a passage through which exhaust gas G1 discharged from a plurality of cylinders of an internal combustion engine (not shown) passes, and extends from a diverse exhaust pipe communicating with the plurality of cylinders to an outlet to the outside of the vehicle. It is a passage. The selective reduction catalyst device 2 is arranged at an intermediate position of the exhaust passage 1. The selective reduction catalyst device 2 is configured by supporting a catalyst such as zeolite on a porous ceramic carrier, and contains ammonia generated by hydrolyzing the injected urea water by the heat of the exhaust gas G1 as a reducing agent in the exhaust gas G1. It is a device that selectively reduces and purifies the nitrogen oxides produced.
　本開示において、液体である尿素水は貯留用液体３と噴射用液体５とに区別される。貯留用液体３はファインバブル４を含有させていない尿素水であり、噴射用液体５はファインバブル４を含有させた尿素水である。 In the present disclosure, urea water, which is a liquid, is classified into a storage liquid 3 and a jet liquid 5. The storage liquid 3 is urea water that does not contain fine bubbles 4, and the injection liquid 5 is urea water that contains fine bubbles 4.
　また、気泡はファインバブル４と圧縮空気の気泡６とに区別される。ファインバブル４と圧縮空気の気泡６とは粒径が異なり、圧縮空気の気泡６をさらに微細化した気泡がファインバブル４である。ファインバブル４は粒径が１００マイクロメートル未満の気泡である。ファインバブル４は、液体中の上昇速度が極めて遅いことから液体中で長時間滞在するという特性や、気泡の大きさに反比例して界面張力による加圧が大きくなるとともに負に帯電して互いに反発することから大径化しにくいという特性を有する気泡である。なお、圧縮空気の気泡６がファインバブルであってもよい。 Further, the bubbles are classified into fine bubbles 4 and compressed air bubbles 6. The particle size of the fine bubble 4 and the bubble 6 of the compressed air are different, and the bubble 4 is a finer particle of the bubble 6 of the compressed air. The fine bubble 4 is a bubble having a particle size of less than 100 micrometers. The fine bubble 4 has the characteristic of staying in the liquid for a long time because the rising speed in the liquid is extremely slow, and the pressurization due to the interfacial tension increases in inverse proportion to the size of the bubble and is negatively charged and repels each other. Therefore, it is a bubble having a characteristic that it is difficult to increase the diameter. The bubbles 6 of the compressed air may be fine bubbles.
　液体噴射システム１０は主タンク１１、液体噴射弁１２、副タンク１３、気泡吐出器１４、および、超音波照射装置１５を備える。主タンク１１と副タンク１３とが配管１６により接続されてその中途位置に圧送装置１７が配置される。液体噴射弁１２と副タンク１３とが配管１８により接続されてその中途位置に流量調節装置１９が配置される。また、液体噴射システム１０は制御装置２０、温度センサ２１、および、ＮＯｘセンサ２２を備える。 The liquid injection system 10 includes a main tank 11, a liquid injection valve 12, a sub tank 13, a bubble discharger 14, and an ultrasonic irradiation device 15. The main tank 11 and the sub tank 13 are connected by a pipe 16, and the pumping device 17 is arranged at an intermediate position thereof. The liquid injection valve 12 and the sub tank 13 are connected by a pipe 18, and the flow rate adjusting device 19 is arranged at an intermediate position thereof. Further, the liquid injection system 10 includes a control device 20, a temperature sensor 21, and a NOx sensor 22.
　主タンク１１は車両の外部から供給される貯留用液体３を貯留するタンクである。主タンク１１は車両の走行中に消費される貯留用液体３を貯留可能な容量を有して構成される。 The main tank 11 is a tank for storing the storage liquid 3 supplied from the outside of the vehicle. The main tank 11 is configured to have a capacity capable of storing the storage liquid 3 consumed while the vehicle is running.
　液体噴射弁１２は排ガスＧ１の流れに関して選択的還元触媒装置２よりも上流の排気通路１の内部に噴射用液体５を噴射する装置である。排気通路１における液体噴射弁１２が配置される位置は図示しないターボチャージャよりも排ガスＧ１の流れに関して下流側に限定されずに、排気多岐管やターボチャージャのタービンよりも上流側でもよく、ターボチャージャの上流側に液体噴射弁１２が配置され、ターボチャージャの下流側に選択的還元触媒装置２が配置されてもよい。また、排ガスＧ１の流れに関して液体噴射弁１２の上流側や選択的還元触媒装置２の下流側に配置される装置としては、図示しない酸化触媒装置やフィルタ装置、アンモニア吸着触媒装置７が例示されるが特に限定されるものではない。加えて、液体噴射弁１２は、排気通路１に挿通されていればよく、排気通路１の一部の内壁を窪ませて形成した空間に配置されてもよい。 The liquid injection valve 12 is a device that injects the injection liquid 5 into the exhaust passage 1 upstream of the selective reduction catalyst device 2 with respect to the flow of the exhaust gas G1. The position where the liquid injection valve 12 is arranged in the exhaust passage 1 is not limited to the downstream side with respect to the flow of the exhaust gas G1 from the turbocharger (not shown), but may be the upstream side from the turbine of the exhaust gas multi-pipe or the turbocharger. The liquid injection valve 12 may be arranged on the upstream side of the turbocharger, and the selective reduction catalyst device 2 may be arranged on the downstream side of the turbocharger. Further, examples of the devices arranged on the upstream side of the liquid injection valve 12 and the downstream side of the selective reduction catalyst device 2 with respect to the flow of the exhaust gas G1 include an oxidation catalyst device, a filter device, and an ammonia adsorption catalyst device 7 (not shown). Is not particularly limited. In addition, the liquid injection valve 12 may be inserted into the exhaust passage 1 and may be arranged in a space formed by recessing a part of the inner wall of the exhaust passage 1.
　液体噴射弁１２は一定量の噴射用液体５を周期的に噴射するように構成され、噴射用液体５の噴射量を噴射回数Ｎｘの増減により調節するように構成される。 The liquid injection valve 12 is configured to periodically inject a fixed amount of the injection liquid 5, and is configured to adjust the injection amount of the injection liquid 5 by increasing or decreasing the number of injections Nx.
　副タンク１３は主タンク１１および液体噴射弁１２の間に配置されたタンクである。副タンク１３は内部で貯留用液体３にファインバブル４が含有されて噴射用液体５が生成される。つまり、副タンク１３は主タンク１１から圧送装置１７により送られた貯留用液体３を貯留するタンクであり、液体噴射弁１２から噴射される噴射用液体５を貯留するタンクでもある。 The sub tank 13 is a tank arranged between the main tank 11 and the liquid injection valve 12. The sub tank 13 contains the fine bubble 4 in the storage liquid 3 inside, and the injection liquid 5 is generated. That is, the sub tank 13 is a tank for storing the storage liquid 3 sent from the main tank 11 by the pumping device 17, and is also a tank for storing the injection liquid 5 injected from the liquid injection valve 12.
　副タンク１３の容量は主タンク１１の容量よりも小さい。副タンク１３に貯留する噴射用液体５の貯留量Ｑａは予め実験や試験により一定量に設定される。この貯留量Ｑａとしては、液体噴射システム１０を搭載した車両が所定の期間（例えば、５００秒～２０００秒）や所定の距離（例えば、１０ｋｍ～３０ｋｍ）を走行した場合に消費される量の平均値が例示される。 The capacity of the sub tank 13 is smaller than the capacity of the main tank 11. The storage amount Qa of the injection liquid 5 stored in the sub tank 13 is set to a constant amount in advance by experiments and tests. The storage amount Qa is the average amount consumed when the vehicle equipped with the liquid injection system 10 travels for a predetermined period (for example, 500 seconds to 2000 seconds) or a predetermined distance (for example, 10 km to 30 km). Values are exemplified.
　気泡吐出器１４は副タンク１３の内部に圧縮空気の気泡６を吐出する装置である。気泡吐出器１４は図示しない圧縮空気を生成するポンプや圧縮空気を貯留するタンクに接続されて、副タンク１３の内部に先端が配置されたニードル管１４ａを有して構成される。 The bubble discharger 14 is a device that discharges bubbles 6 of compressed air into the sub tank 13. The bubble discharger 14 is connected to a pump that generates compressed air (not shown) or a tank that stores compressed air, and has a needle tube 14a whose tip is arranged inside the sub tank 13.
　超音波照射装置１５は気泡吐出器１４から吐出された圧縮空気の気泡６に超音波を照射する装置である。超音波照射装置１５は図示しないバッテリに接続されて、副タンク１３の内部に配置された振動子１５ａを有して構成される。振動子１５ａはニードル管１４ａの先端開口の鉛直直上に配置されることが好ましい。 The ultrasonic irradiation device 15 is a device that irradiates the bubbles 6 of the compressed air discharged from the bubble ejector 14 with ultrasonic waves. The ultrasonic irradiation device 15 is connected to a battery (not shown) and has an oscillator 15a arranged inside the sub tank 13. The oscillator 15a is preferably arranged vertically above the tip opening of the needle tube 14a.
　気泡吐出器１４から吐出された圧縮空気の気泡６に超音波照射装置１５から超音波を照射してファインバブル４を生成することで、生成されたファインバブル４の粒径を揃えることができる。また、ニードル管１４ａの管径や超音波の周波数の組み合わせにより生成されるファインバブル４の粒径を任意の値に設定することができる。本実施形態のファインバブル４の粒径としては３０マイクロメートル以下が好ましく、１０マイクロメートル以下がより好ましい。ファインバブル４の粒径が３０マイクロメートル以下になると噴射された噴射用液体５の微粒子化が促進され、１０マイクロメートル以下になると微粒子化がより促進される。また、ニードル管１４ａの管径は生成されるファインバブル４の粒径に対して１０倍以下の長さにすることが好ましい。 By irradiating the bubbles 6 of the compressed air discharged from the bubble ejector 14 with ultrasonic waves from the ultrasonic irradiation device 15 to generate fine bubbles 4, the particle size of the generated fine bubbles 4 can be made uniform. Further, the particle size of the fine bubble 4 generated by the combination of the tube diameter of the needle tube 14a and the frequency of the ultrasonic wave can be set to an arbitrary value. The particle size of the fine bubble 4 of the present embodiment is preferably 30 micrometers or less, and more preferably 10 micrometers or less. When the particle size of the fine bubble 4 is 30 micrometers or less, the atomization of the injected liquid 5 is promoted, and when the particle size is 10 micrometers or less, the atomization is further promoted. Further, the diameter of the needle tube 14a is preferably 10 times or less the diameter of the generated fine bubble 4.
　気泡吐出器１４のニードル管１４ａの先端開口と超音波照射装置１５の振動子１５ａのそれぞれは、副タンク１３に貯留量Ｑａの半分以下の容量の貯留用液体３が貯留された状態でその液面下になることが好ましく、三分の一以下の容量の貯留用液体３が貯留された状態でその液面下になることが好ましい。このようにファインバブル４の発生場所を副タンク１３の下端側に配置することで、貯留用液体３が所定の容量になるまでファインバブル４が生成できない状態を回避するには有利になる。 Each of the tip opening of the needle tube 14a of the bubble discharger 14 and the vibrator 15a of the ultrasonic irradiation device 15 has a storage liquid 3 having a capacity of less than half of the storage amount Qa stored in the sub tank 13. It is preferable that it is below the surface, and it is preferable that the storage liquid 3 having a capacity of one-third or less is stored below the surface. By arranging the place where the fine bubble 4 is generated on the lower end side of the sub tank 13 in this way, it is advantageous to avoid a state in which the fine bubble 4 cannot be generated until the storage liquid 3 reaches a predetermined capacity.
　圧送装置１７は主タンク１１から副タンク１３へ貯留用液体３を圧送する装置であり、ポンプが例示される。圧送装置１７は単位時間あたりで一定量の貯留用液体３を圧送することで主タンク１１から副タンク１３へ貯留用液体３を追加するように構成される。 The pumping device 17 is a device for pumping the storage liquid 3 from the main tank 11 to the sub tank 13, and a pump is exemplified. The pumping device 17 is configured to add the storage liquid 3 from the main tank 11 to the sub tank 13 by pumping a fixed amount of the storage liquid 3 per unit time.
　図２に例示するように、制御装置２０は各種情報処理を行う中央演算装置（ＣＰＵ）、その各種情報処理を行うために用いられるプログラムや情報処理結果を読み書き可能な内部記憶装置、及び各種インターフェースなどから構成されるハードウェアである。制御装置２０は液体噴射弁１２、気泡吐出器１４、超音波照射装置１５、圧送装置１７、および、流量調節装置１９のそれぞれに信号線を介して電気的に接続される。 As illustrated in FIG. 2, the control device 20 is a central processing unit (CPU) that performs various information processing, an internal storage device that can read and write programs and information processing results used for performing various information processing, and various interfaces. It is hardware composed of. The control device 20 is electrically connected to each of the liquid injection valve 12, the bubble discharger 14, the ultrasonic irradiation device 15, the pumping device 17, and the flow rate adjusting device 19 via a signal line.
　制御装置２０は機能要素として噴射制御部２３と液体調節部２４と気泡調節部２５とを有する。各機能要素は、プログラムとして内部記憶装置に記憶されていて、適時、中央演算装置により実行されている。なお、各機能要素としては、プログラムの他にそれぞれが独立して機能するプログラマブルコントローラ（ＰＬＣ）や電気回路で構成されてもよい。 The control device 20 has an injection control unit 23, a liquid adjustment unit 24, and a bubble adjustment unit 25 as functional elements. Each functional element is stored as a program in the internal storage device, and is executed by the central processing unit in a timely manner. In addition to the program, each functional element may be composed of a programmable controller (PLC) or an electric circuit in which each functions independently.
　噴射制御部２３は温度センサ２１が取得した排ガスＧ１の温度Ｔｘが入力されて、その温度Ｔｘが予め設定された噴射温度Ｔａ以上になったか否かを判定し、温度Ｔｘが噴射温度Ｔａ以上になったと判定した場合に液体噴射弁１２に噴射用液体５を噴射させる制御を行う機能要素である。このとき、噴射制御部２３はＮＯｘセンサ２２が取得した排ガスＧ１の窒素酸化物の含有量に基づいて噴射回数Ｎｘを調節する制御も行う。 The injection control unit 23 receives the temperature Tx of the exhaust gas G1 acquired by the temperature sensor 21 and determines whether or not the temperature Tx is equal to or higher than the preset injection temperature Ta, and the temperature Tx becomes equal to or higher than the injection temperature Ta. It is a functional element that controls the liquid injection valve 12 to inject the injection liquid 5 when it is determined that the temperature has increased. At this time, the injection control unit 23 also controls to adjust the number of injections Nx based on the nitrogen oxide content of the exhaust gas G1 acquired by the NOx sensor 22.
　また、噴射制御部２３はカウンタ２６を有し、液体噴射弁１２の噴射回数Ｎｘを数え、数えたその噴射回数Ｎｘが予め設定した追加回数Ｎａに達したときに液体調節部２４および気泡調節部２５のそれぞれに追加指令を出す機能要素でもある。 Further, the injection control unit 23 has a counter 26, counts the number of injections Nx of the liquid injection valve 12, and when the counted number of injections Nx reaches a preset additional number Na, the liquid adjustment unit 24 and the bubble adjustment unit 24 It is also a functional element that issues additional commands to each of the 25.
　図３に例示するように、噴射制御部２３が一定量の噴射用液体５を周期的に噴射させるように液体噴射弁１２を調節することで、噴射された噴射用液体５の噴射量は噴射回数Ｎｘに対して正の関係になる。そこで、噴射された噴射用液体５の分の追加量ΔＱａは予め実験や試験により設定された値であり、副タンク１３の貯留用液体３の貯留量Ｑａの半分以下の量に設定される。追加量ΔＱａは貯留量Ｑａとの差分、つまり、残量の液面が気泡吐出器１４のニードル管１４ａの先端開口と超音波照射装置１５の振動子１５ａよりも上になるように設定される。本実施形態で、追加量ΔＱａは噴射回数Ｎｘが追加回数Ｎａに達したときの量とする。なお、噴射制御部２３は噴射量を取得可能であればよく、噴射回数Ｎｘの代わりに、液体噴射弁１２の噴射時間の合計を用いてもよく、ＮＯｘセンサ２２の取得値に基づいた噴射量を用いてもよい。 As illustrated in FIG. 3, by adjusting the liquid injection valve 12 so that the injection control unit 23 periodically injects a constant amount of the injection liquid 5, the injection amount of the injected liquid 5 is injected. It has a positive relationship with the number of times Nx. Therefore, the additional amount ΔQa for the injected injection liquid 5 is a value set in advance by experiments and tests, and is set to an amount less than half of the storage amount Qa of the storage liquid 3 in the sub tank 13. The additional amount ΔQa is set so that the difference from the stored amount Qa, that is, the liquid level of the remaining amount is higher than the tip opening of the needle tube 14a of the bubble discharger 14 and the vibrator 15a of the ultrasonic irradiation device 15. .. In the present embodiment, the additional amount ΔQa is the amount when the number of injections Nx reaches the number of additional injections Na. The injection control unit 23 may acquire the injection amount, and may use the total injection time of the liquid injection valve 12 instead of the injection count Nx, and the injection amount based on the acquired value of the NOx sensor 22. May be used.
　液体調節部２４は圧送装置１７を駆動させて主タンク１１から副タンク１３へ貯留用液体３を圧送し、液体噴射弁１２から噴射された分を追加する制御を行う機能要素である。液体調節部２４は噴射制御部２３からの追加指令により圧送装置１７を駆動させ、圧送用タイマ２７により圧送装置１７を駆動させた期間ｔｘを数え、数えたその期間ｔｘが予め設定した圧送期間ｔａに達したときに圧送装置１７の駆動を停止する。 The liquid adjusting unit 24 is a functional element that drives the pressure feeding device 17 to pump the storage liquid 3 from the main tank 11 to the sub tank 13 and controls to add the amount injected from the liquid injection valve 12. The liquid adjusting unit 24 drives the pumping device 17 by an additional command from the injection control unit 23, counts the period tx in which the pumping device 17 is driven by the pumping timer 27, and the counted period tx is the preset pumping period ta. When it reaches, the drive of the pumping device 17 is stopped.
　図４の点線で例示するように、液体調節部２４が副タンク１３に追加される貯留用液体３の量を単位時間あたりで一定になるように圧送装置１７を調節することで、副タンク１３に追加される貯留用液体３の量は期間ｔｘに対して正の関係になる。本実施形態で、追加量ΔＱａは期間ｔｘが圧送期間ｔａに達したときの量とする。 As illustrated by the dotted line in FIG. 4, the liquid adjusting unit 24 adjusts the pumping device 17 so that the amount of the storage liquid 3 added to the sub tank 13 becomes constant per unit time, so that the sub tank 13 is used. The amount of storage liquid 3 added to has a positive relationship with respect to the period tx. In the present embodiment, the additional amount ΔQa is the amount when the period tx reaches the pumping period ta.
　気泡調節部２５は気泡吐出器１４および超音波照射装置１５を駆動させて副タンク１３の内部にファインバブル４を生成し、噴射用液体５に含有されたファインバブル４の含有率Ｘを予め定めた範囲Ａに調節する制御を行う機能要素である。 The bubble adjusting unit 25 drives the bubble ejector 14 and the ultrasonic irradiation device 15 to generate fine bubbles 4 inside the sub tank 13, and determines the content X of the fine bubbles 4 contained in the injection liquid 5 in advance. It is a functional element that controls the adjustment to the range A.
　本実施形態において含有率Ｘは容量百分率を示し、噴射用液体５におけるファインバブル４の容量比率を示す。範囲Ａは予め実験や試験により噴射用液体５の微粒化が促進可能な範囲に設定されることが望ましく、液体噴射システム１０が搭載される内燃機関の性能や選択的還元触媒装置２の還元率により適切な範囲が異なる。本実施形態で、範囲Ａは貯留量Ｑａに対して含有したファインバブル４の容量が含有量Ｒａとなった場合を基準として定められた範囲である。 In the present embodiment, the content rate X indicates the volume percentage, and indicates the volume ratio of the fine bubble 4 in the injection liquid 5. It is desirable that the range A is set in advance in a range in which the atomization of the injection liquid 5 can be promoted by experiments and tests, and the performance of the internal combustion engine on which the liquid injection system 10 is mounted and the reduction rate of the selective reduction catalyst device 2 The appropriate range differs depending on the type. In the present embodiment, the range A is a range determined based on the case where the capacity of the fine bubble 4 contained in the stored amount Qa becomes the content Ra.
　気泡調節部２５は噴射制御部２３からの追加指令により気泡吐出器１４および超音波照射装置１５を駆動させ、生成用タイマ２８により気泡吐出器１４および超音波照射装置１５を駆動させた期間ｔｙを数え、数えたその期間ｔｙが予め設定した生成期間ｔｂに達したときに気泡吐出器１４および超音波照射装置１５の駆動を停止する。 The bubble adjusting unit 25 drives the bubble discharger 14 and the ultrasonic wave irradiation device 15 by an additional command from the injection control unit 23, and the period ty during which the bubble discharger 14 and the ultrasonic wave irradiation device 15 are driven by the generation timer 28. When the counted period ty reaches a preset generation period tb, the operation of the bubble ejector 14 and the ultrasonic irradiation device 15 is stopped.
　図３の実線で例示するように、気泡調節部２５が生成されるファインバブル４の量を単位時間あたりで一定になるように気泡吐出器１４および超音波照射装置１５を調節すると、生成されるファインバブル４の量は期間ｔｙに対して正の関係となる。本実施形態で生成量ΔＲａは期間ｔｙが生成期間ｔｂに達したときの量とする。 As illustrated by the solid line in FIG. 3, it is generated when the bubble ejector 14 and the ultrasonic irradiation device 15 are adjusted so that the amount of fine bubbles 4 generated by the bubble adjusting unit 25 is constant per unit time. The amount of fine bubbles 4 has a positive relationship with respect to the period ty. In the present embodiment, the production amount ΔRa is the amount when the period ty reaches the production period tb.
　生成量ΔＲａは貯留用液体３の追加量ΔＱａに基づいて設定される。生成量ΔＲａは、追加量ΔＱａの貯留用液体３に生成量ΔＲａのファインバブル４を含有させて、噴射用液体５におけるファインバブル４の含有率Ｘが予め設定した範囲Ａとなるように設定されることが好ましく、範囲Ａの上限値となるように設定されることがより好ましい。範囲Ａの上限値となるように設定することで、時間経過とともにファインバブル４が消失しても、含有率Ｘが範囲Ａの下限値を下回ることを回避するには有利になる。 The production amount ΔRa is set based on the additional amount ΔQa of the storage liquid 3. The production amount ΔRa is set so that the storage liquid 3 having the additional amount ΔQa contains the fine bubbles 4 having the production amount ΔRa, and the content rate X of the fine bubbles 4 in the injection liquid 5 is within the preset range A. It is preferable that the value is set to be the upper limit of the range A. By setting the upper limit value of the range A, even if the fine bubble 4 disappears with the passage of time, it is advantageous to prevent the content rate X from falling below the lower limit value of the range A.
　また、気泡調節部２５は時間経過とともに消失するファインバブル４を補充するように副タンク１３の内部にファインバブル４を生成し、噴射用液体５に含有されるファインバブル４の含有率Ｘを予め定めた範囲Ａに調節する制御を行う機能要素でもある。気泡調節部２５は消失用タイマ２９により期間ｔｚを数え、数えたその期間ｔｚが予め設定した消失期間ｔｃに達したときに気泡吐出器１４および超音波照射装置１５を駆動させる。次いで、気泡調節部２５は生成用タイマ２８により気泡吐出器１４および超音波照射装置１５を駆動させた期間ｔｙを数え、数えたその期間ｔｙが予め設定した補充期間ｔｄに達したときに気泡吐出器１４および超音波照射装置１５の駆動を停止する。 Further, the bubble adjusting unit 25 generates fine bubbles 4 inside the auxiliary tank 13 so as to replenish the fine bubbles 4 that disappear with the passage of time, and preliminarily sets the content X of the fine bubbles 4 contained in the injection liquid 5. It is also a functional element that controls adjustment to a defined range A. The bubble adjusting unit 25 counts the period tz by the disappearance timer 29, and drives the bubble ejector 14 and the ultrasonic irradiation device 15 when the counted period tz reaches a preset disappearance period tk. Next, the bubble adjusting unit 25 counts the period ty in which the bubble discharger 14 and the ultrasonic irradiation device 15 are driven by the generation timer 28, and discharges bubbles when the counted period ty reaches the preset replenishment period td. Stop driving the device 14 and the ultrasonic irradiation device 15.
　図５に例示するように、生成されたファインバブル４の含有量Ｒａは時間経過とともにファインバブル４が消失することで減少する。消失期間ｔｃはファインバブル４が消失した量が消失量ΔＲｂとなる期間である。 As illustrated in FIG. 5, the content Ra of the generated fine bubbles 4 decreases as the fine bubbles 4 disappear over time. The disappearance period tc is a period in which the amount of fine bubble 4 disappeared becomes the disappearance amount ΔRb.
　気泡調節部２５が生成されるファインバブル４の量を単位時間あたりで一定になるように気泡吐出器１４および超音波照射装置１５を調節すると、生成されるファインバブル４の量は期間ｔｙに対して正の関係となる。本実施形態で補充期間ｔｄは消失量ΔＲｂの分のファインバブル４を補充するのに要する期間となる。 When the bubble ejector 14 and the ultrasonic irradiation device 15 are adjusted so that the amount of fine bubbles 4 generated by the bubble adjusting unit 25 is constant per unit time, the amount of fine bubbles 4 generated is relative to the period ty. It becomes a positive relationship. In the present embodiment, the replenishment period td is the period required to replenish the fine bubbles 4 for the amount of disappearance ΔRb.
　図６～図９に例示するように、液体噴射システム１０の制御方法を制御装置２０の機能として説明する。この制御方法は時限制御であり、本実施形態において制御周期として１秒を用いた。なお、制御周期は１秒に限定されず、１秒よりも短い時間でもよい。また、制御の開始時において副タンク１３には貯留量Ｑａの噴射用液体５が貯留され、その噴射用液体５に含有されたファインバブル４の含有率Ｘは範囲Ａの上限値となっているものとする。 As illustrated in FIGS. 6 to 9, the control method of the liquid injection system 10 will be described as a function of the control device 20. This control method is timed control, and 1 second is used as the control cycle in this embodiment. The control cycle is not limited to 1 second, and may be shorter than 1 second. Further, at the start of control, the injection liquid 5 having a stored amount of Qa is stored in the sub tank 13, and the content rate X of the fine bubbles 4 contained in the injection liquid 5 is the upper limit value of the range A. Shall be.
　図６に例示するように、噴射制御部２３により行われる制御フローは内燃機関が運転している間は所定の周期ごとに繰り返し行われ、内燃機関の運転が停止したときに終了する。なお、制御フローにおいてはリターンでスタートに戻ると一周期が経過するものとする。 As illustrated in FIG. 6, the control flow performed by the injection control unit 23 is repeatedly performed at predetermined cycles while the internal combustion engine is operating, and ends when the operation of the internal combustion engine is stopped. In the control flow, it is assumed that one cycle elapses when the return returns to the start.
　噴射制御部２３は温度センサ２１が取得した排ガスＧ１の温度Ｔｘが噴射温度Ｔａ以上になったか否かを判定する（Ｓ１１０）。噴射温度Ｔａは尿素水が加水分解してアンモニアが生成される状況を判定可能な値に設定される。温度Ｔｘが噴射温度Ｔａ以上になったと判定すると（Ｓ１１０：ＹＥＳ）、噴射制御部２３は液体噴射弁１２を調節して一定量の噴射用液体５を周期的に噴射させる（Ｓ１２０）。このステップでは、ＮＯｘセンサ２２が取得した排ガスＧ１に含有される窒素酸化物の含有量に応じて噴射回数Ｎｘが設定されることが好ましい。一方、温度Ｔｘが噴射温度Ｔａ未満であると判定すると（Ｓ１１０：ＮＯ）、制御フローがリターンしてスタートへ戻る。 The injection control unit 23 determines whether or not the temperature Tx of the exhaust gas G1 acquired by the temperature sensor 21 is equal to or higher than the injection temperature Ta (S110). The injection temperature Ta is set to a value at which it is possible to determine the situation in which urea water is hydrolyzed to produce ammonia. When it is determined that the temperature Tx is equal to or higher than the injection temperature Ta (S110: YES), the injection control unit 23 adjusts the liquid injection valve 12 to periodically inject a constant amount of the injection liquid 5 (S120). In this step, it is preferable that the number of injections Nx is set according to the content of nitrogen oxides contained in the exhaust gas G1 acquired by the NOx sensor 22. On the other hand, when it is determined that the temperature Tx is lower than the injection temperature Ta (S110: NO), the control flow returns and returns to the start.
　次いで、噴射制御部２３はカウンタ２６により液体噴射弁１２から噴射用液体５を噴射させた噴射回数Ｎｘを数える（Ｓ１３０）。次いで、噴射制御部２３は数えた噴射回数Ｎｘが追加回数Ｎａに到達したか否かを判定する（Ｓ１４０）。噴射回数Ｎｘが追加回数Ｎａに到達したと判定すると（Ｓ１４０：ＹＥＳ）、噴射制御部２３は液体調節部２４と気泡調節部２５とに追加指令を出す（Ｓ１５０）。次いで、噴射制御部２３はカウンタ２６で数えた噴射回数Ｎｘを零に戻し（Ｓ１６０）、制御フローがリターンしてスタートへ戻る。一方、噴射回数Ｎｘが追加回数Ｎａに到達していないと判定すると（Ｓ１４０：ＮＯ）、制御フローがリターンしてスタートへ戻る。 Next, the injection control unit 23 counts the number of injections Nx at which the injection liquid 5 is injected from the liquid injection valve 12 by the counter 26 (S130). Next, the injection control unit 23 determines whether or not the counted number of injections Nx has reached the additional number Na (S140). When it is determined that the number of injections Nx has reached the number of additional times Na (S140: YES), the injection control unit 23 issues an additional command to the liquid adjusting unit 24 and the bubble adjusting unit 25 (S150). Next, the injection control unit 23 returns the number of injections Nx counted by the counter 26 to zero (S160), returns the control flow, and returns to the start. On the other hand, when it is determined that the number of injections Nx has not reached the additional number Na (S140: NO), the control flow returns and returns to the start.
　図７に例示するように、液体調節部２４により行われる制御フローは噴射制御部２３からの追加指令により開始されて、全てのステップが完了すると終了するものとする。 As illustrated in FIG. 7, the control flow performed by the liquid adjusting unit 24 is started by an additional command from the injection control unit 23 and ends when all the steps are completed.
　噴射制御部２３からの追加指令を受け取ると、液体調節部２４は圧送装置１７の駆動を調節して、単位時間あたりで一定量の貯留用液体３を圧送して主タンク１１から副タンク１３に追加する（Ｓ２１０）。次いで、液体調節部２４は圧送用タイマ２７により圧送装置１７を駆動させた期間ｔｘを数える（Ｓ２２０）。次いで、液体調節部２４は圧送用タイマ２７により数えた期間ｔｘが圧送期間ｔａに達したか否かを判定する（Ｓ２３０）。 Upon receiving the additional command from the injection control unit 23, the liquid adjusting unit 24 adjusts the drive of the pumping device 17 to pump a fixed amount of the storage liquid 3 per unit time from the main tank 11 to the sub tank 13. Add (S210). Next, the liquid adjusting unit 24 counts the period tx in which the pumping device 17 is driven by the pumping timer 27 (S220). Next, the liquid adjusting unit 24 determines whether or not the period tx counted by the pumping timer 27 has reached the pumping period ta (S230).
　期間ｔｘが圧送期間ｔａに達したと判定すると（Ｓ２３０：ＹＥＳ）、液体調節部２４は圧送装置１７の駆動を停止する（Ｓ２４０）。次いで、液体調節部２４は圧送用タイマ２７により数えた期間ｔｘを零に戻し（Ｓ２５０）、制御フローが終了する。一方、期間ｔｘが圧送期間ｔａに満たないと判定すると（Ｓ２３０：ＮＯ）、圧送装置１７の駆動は継続されて副タンク１３への貯留用液体３の追加が継続される。 When it is determined that the period tx has reached the pumping period ta (S230: YES), the liquid adjusting unit 24 stops driving the pumping device 17 (S240). Next, the liquid adjusting unit 24 returns the period tx counted by the pumping timer 27 to zero (S250), and the control flow ends. On the other hand, when it is determined that the period tx is less than the pumping period ta (S230: NO), the driving of the pumping device 17 is continued and the addition of the storage liquid 3 to the sub tank 13 is continued.
　図８に例示するように、気泡調節部２５により行われる制御フローは噴射制御部２３からの追加指令により開始されて、全てのステップが完了すると終了するものとする。なお、この制御フローは前述した図７に示す制御フローと同時に行われる。 As illustrated in FIG. 8, the control flow performed by the bubble adjusting unit 25 is started by an additional command from the injection control unit 23 and ends when all the steps are completed. This control flow is performed at the same time as the control flow shown in FIG. 7 described above.
　噴射制御部２３からの追加指令を受け取ると、気泡調節部２５は気泡吐出器１４から圧縮空気の気泡６を吐出させるとともに超音波照射装置１５から超音波を照射させてファインバブル４を生成する（Ｓ３１０）。次いで、気泡調節部２５は生成用タイマ２８により気泡吐出器１４および超音波照射装置１５を駆動させてファインバブル４を生成した期間ｔｙを数える（Ｓ３２０）。次いで、気泡調節部２５は生成用タイマ２８により数えた期間ｔｙが生成期間ｔｂに達したか否かを判定する（Ｓ３３０）。 Upon receiving the additional command from the injection control unit 23, the bubble adjusting unit 25 discharges the bubbles 6 of the compressed air from the bubble ejector 14 and irradiates the ultrasonic waves from the ultrasonic irradiation device 15 to generate fine bubbles 4 ( S310). Next, the bubble adjusting unit 25 drives the bubble ejector 14 and the ultrasonic irradiation device 15 by the generation timer 28 to count the period ty during which the fine bubble 4 is generated (S320). Next, the bubble adjusting unit 25 determines whether or not the period ty counted by the generation timer 28 has reached the generation period tb (S330).
　期間ｔｙが生成期間ｔｂに達したと判定すると（Ｓ３３０：ＹＥＳ）、気泡調節部２５は気泡吐出器１４および超音波照射装置１５の駆動を停止させてファインバブル４の生成を停止する（Ｓ３４０）。次いで、気泡調節部２５は生成用タイマ２８により数えた期間ｔｙを零に戻し（Ｓ３５０）、制御フローが終了する。一方、期間ｔｙが生成期間ｔｂに満たないと判定すると（Ｓ３３０：ＮＯ）、気泡吐出器１４および超音波照射装置１５の駆動は継続されて副タンク１３でのファインバブル４の生成が継続される。 When it is determined that the period ty has reached the generation period tb (S330: YES), the bubble adjusting unit 25 stops driving the bubble ejector 14 and the ultrasonic irradiation device 15 to stop the generation of the fine bubble 4 (S340). .. Next, the bubble adjusting unit 25 returns the period ty counted by the generation timer 28 to zero (S350), and the control flow ends. On the other hand, when it is determined that the period ty is less than the generation period tb (S330: NO), the operation of the bubble ejector 14 and the ultrasonic irradiation device 15 is continued, and the generation of the fine bubbles 4 in the sub tank 13 is continued. ..
　図９に例示するように、気泡調節部２５により行われる制御フローは内燃機関が運転している間は所定の周期ごとに繰り返し行われ、内燃機関の運転が停止したときに終了する。なお、制御フローにおいてはリターンでスタートに戻ると一周期が経過するものとする。 As illustrated in FIG. 9, the control flow performed by the bubble adjusting unit 25 is repeatedly performed at predetermined cycles while the internal combustion engine is operating, and ends when the operation of the internal combustion engine is stopped. In the control flow, it is assumed that one cycle elapses when the return returns to the start.
　気泡調節部２５は消失用タイマ２９により期間ｔｚを数える（Ｓ４１０）。次いで、気泡調節部２５は数えた期間ｔｚが消失期間ｔｃに達したか否かを判定する（Ｓ４２０）。期間ｔｚが消失期間ｔｃに満たないと判定すると（Ｓ４２０：ＮＯ）、制御フローがリターンしてスタートへ戻る。 The bubble adjusting unit 25 counts the period tz by the disappearance timer 29 (S410). Next, the bubble adjusting unit 25 determines whether or not the counted period tz has reached the disappearance period tk (S420). When it is determined that the period tz is less than the disappearance period tk (S420: NO), the control flow returns and returns to the start.
　一方、期間ｔｚが消失期間ｔｃに達したと判定すると（Ｓ４２０：ＹＥＳ）、気泡調節部２５は気泡吐出器１４から圧縮空気の気泡６を吐出させるとともに超音波照射装置１５から超音波を照射させてファインバブル４を生成する（Ｓ４３０）。次いで、気泡調節部２５は生成用タイマ２８により気泡吐出器１４および超音波照射装置１５を駆動させてファインバブル４を生成した期間ｔｙを数える（Ｓ４４０）。次いで、気泡調節部２５は生成用タイマ２８により数えた期間ｔｙが補充期間ｔｄに達したか否かを判定する（Ｓ４５０）。 On the other hand, when it is determined that the period tz has reached the disappearance period tk (S420: YES), the bubble adjusting unit 25 discharges the bubbles 6 of the compressed air from the bubble ejector 14 and irradiates the ultrasonic waves from the ultrasonic irradiation device 15. Fine bubble 4 is generated (S430). Next, the bubble adjusting unit 25 drives the bubble ejector 14 and the ultrasonic irradiation device 15 by the generation timer 28 to count the period ty during which the fine bubble 4 is generated (S440). Next, the bubble adjusting unit 25 determines whether or not the period ty counted by the generation timer 28 has reached the replenishment period td (S450).
　期間ｔｙが補充期間ｔｄに達したと判定すると（Ｓ４５０：ＹＥＳ）、気泡調節部２５は気泡吐出器１４および超音波照射装置１５の駆動を停止させてファインバブル４の生成を停止する（Ｓ４６０）。次いで、気泡調節部２５は生成用タイマ２８により数えた期間ｔｙと消失用タイマ２９により数えた期間ｔｚとを零に戻し（Ｓ４７０）、制御フローがリターンしてスタートへ戻る。一方、期間ｔｙが補充期間ｔｄに満たないと判定すると（Ｓ４５０：ＮＯ）、気泡吐出器１４および超音波照射装置１５の駆動は継続されて副タンク１３でのファインバブル４の生成が継続される。 When it is determined that the period ty has reached the replenishment period td (S450: YES), the bubble adjusting unit 25 stops driving the bubble ejector 14 and the ultrasonic irradiation device 15 to stop the generation of the fine bubble 4 (S460). .. Next, the bubble adjusting unit 25 returns the period ty counted by the generation timer 28 and the period tz counted by the disappearance timer 29 to zero (S470), and the control flow returns and returns to the start. On the other hand, when it is determined that the period ty is less than the replenishment period td (S450: NO), the operation of the bubble ejector 14 and the ultrasonic irradiation device 15 is continued, and the generation of the fine bubbles 4 in the sub tank 13 is continued. ..
　以上のように、本開示の液体噴射システム１０は、主タンク１１とは別体の副タンク１３に貯留された貯留用液体３に対して含有率Ｘを一定の範囲Ａに調節するようにファインバブル４を生成する。それ故、粒径が揃ったファインバブル４を一定の含有率Ｘで含有させた噴射用液体５を噴射することが可能になり、噴射用液体５の微粒子化を促進することができる。これにより、液体が尿素水である場合にアンモニアの生成効率を高めるとともに撹拌性も向上させるには有利になり、尿素水の消費量の低減、撹拌ミキサを不要とすることによる通気抵抗の増加の抑制、液状や液滴の状態で付着した尿素水に起因する白色生成物の析出の抑制といった効果を得ることができる。 As described above, the liquid injection system 10 of the present disclosure is fine so as to adjust the content rate X to a certain range A with respect to the storage liquid 3 stored in the sub tank 13 separate from the main tank 11. Generate bubble 4. Therefore, it becomes possible to inject the injection liquid 5 containing the fine bubbles 4 having the same particle size at a constant content X, and it is possible to promote the atomization of the injection liquid 5. This is advantageous for increasing the efficiency of ammonia production and improving the agitation property when the liquid is urea water, reducing the consumption of urea water and increasing the aeration resistance by eliminating the need for a stirring mixer. It is possible to obtain effects such as suppression and suppression of precipitation of white products caused by urea water adhering in a liquid or droplet state.
　例えば、主タンク１１と液体噴射弁１２との間に気液剪断方式によりファインバブル４を発生させる発生器を介在させた構成では、含有されるファインバブル４の粒径が揃わずに含有率Ｘも安定しない。これに対して、本開示の液体噴射システム１０は副タンク１３に貯留用液体３を貯留し、貯留した状態の貯留用液体３に対して気泡吐出器１４および超音波照射装置１５によりファインバブル４を含有させる。これにより、液体噴射システム１０によれば、従来技術のファインバブル４の発生器に比して、生成したファインバブル４の粒径を揃えるには有利になるとともに含有率Ｘを一定の範囲Ａに収めるにも有利になる。 For example, in a configuration in which a generator that generates fine bubbles 4 by a gas-liquid shearing method is interposed between the main tank 11 and the liquid injection valve 12, the particle sizes of the contained fine bubbles 4 are not uniform and the content rate X Is not stable. On the other hand, in the liquid injection system 10 of the present disclosure, the storage liquid 3 is stored in the sub tank 13, and the fine bubble 4 is stored in the stored liquid 3 by the bubble ejector 14 and the ultrasonic irradiation device 15. Is contained. As a result, according to the liquid injection system 10, it is advantageous to make the diameters of the generated fine bubbles 4 uniform as compared with the generator of the fine bubbles 4 of the prior art, and the content ratio X is set to a certain range A. It is also advantageous to fit.
　液体噴射システム１０は各タイマの経過時間に基づいて各機器の動作を制御する時限制御により、噴射用液体５に含有したファインバブル４の含有率Ｘを一定の範囲Ａに収めることができる。このように、ファインバブル４の含有率Ｘを時限制御により調節することで、含有率Ｘを制御量とするフィードバック制御やフィードフォワード制御に比して制御量に関するセンシング機器の設置が不要となり、制御に関する演算負荷を低減することができる。なお、本開示の液体噴射システム１０は含有率Ｘに関するセンシング機器を追加することで、含有率Ｘを制御量とするフィードバック制御やフィードフォワード制御を用いて含有率Ｘを一定の範囲Ａに収めることもできる。 The liquid injection system 10 can keep the content rate X of the fine bubbles 4 contained in the injection liquid 5 within a certain range A by the timed control that controls the operation of each device based on the elapsed time of each timer. In this way, by adjusting the content rate X of the fine bubble 4 by timed control, it becomes unnecessary to install a sensing device related to the control amount as compared with the feedback control and the feedforward control using the content rate X as the control amount, and the control It is possible to reduce the calculation load related to. In the liquid injection system 10 of the present disclosure, by adding a sensing device related to the content rate X, the content rate X can be kept within a certain range A by using feedback control or feedforward control using the content rate X as a control amount. You can also.
　既述した実施形態において、図６～図８に例示する制御と、図９に例示する制御とが同じタイミングで発生することもある。その場合は、図６～図８に例示する制御を図９に例に例示する制御よりも優先度を高くして先に処理するように構成してもよい。また、二つの制御が同じタイミングで発生した場合に、ステップＳ３３０を、生成用タイマ２８により数えた期間ｔｙが生成期間ｔｂに補充期間ｔｄを加えた期間に達したか否かを判定するように構成してもよい。 In the above-described embodiment, the control illustrated in FIGS. 6 to 8 and the control illustrated in FIG. 9 may occur at the same timing. In that case, the control illustrated in FIGS. 6 to 8 may be configured to have a higher priority than the control illustrated in FIG. 9 for processing first. Further, when the two controls occur at the same timing, step S330 determines whether or not the period ty counted by the generation timer 28 has reached the period obtained by adding the replenishment period td to the generation period tb. It may be configured.
　図９に例示する制御は、車両や内燃機関の停止中に停止した期間を数え、停止した期間分で消失したファインバブル４を補充する制御としても適用可能である。また、この制御に関して、内燃機関の始動時に迅速に含有率Ｘを一定の範囲Ａに収められるように、副タンク１３に貯留した貯留用液体３の量を減らす制御を追加してもよい。例えば、圧送装置１７を逆転動作させて副タンク１３から主タンク１１に戻すように構成してもよい。 The control illustrated in FIG. 9 can also be applied as a control for counting the period of stoppage while the vehicle or the internal combustion engine is stopped and replenishing the fine bubble 4 that disappeared during the stoppage period. Further, regarding this control, a control may be added to reduce the amount of the storage liquid 3 stored in the sub tank 13 so that the content rate X can be quickly kept within a certain range A when the internal combustion engine is started. For example, the pumping device 17 may be configured to reversely operate and return from the sub tank 13 to the main tank 11.
　既述した実施形態では、追加期間ｔａよりも生成期間ｔｂが長いが、設定により追加期間ｔａを生成期間ｔｂと同じ期間にすることも可能である。 In the above-described embodiment, the generation period tb is longer than the additional period ta, but the additional period ta can be set to the same period as the generation period tb by setting.
　既述した実施形態では、液体噴射システム１０が内燃機関の排気通路１の内部に液体として尿素水を噴射する構成を一例として説明したが、液体噴射システム１０が噴射する液体は尿素水に限定されない。本開示の液滴噴射システム１０が噴射する液体としては、排気通路１に配置されたフィルタ装置に噴射されてフィルタ装置に溜まった不燃燃焼生成物（アッシュともいう）を逆洗する洗浄液、内燃機関の筒内や吸気通路へ噴射されて筒内で燃焼する燃料、排気通路１の内部に噴射されて酸化触媒装置で酸化燃焼される燃料、車両のフロントガラス、ヘッドライト、または、ミラーに噴射されてそれらを洗浄するウォッシャー液、駆動部品へ噴射される潤滑油や冷却油が例示される。また、液体噴射システム１０は車両に搭載されるものに限定されない。液体噴射システム１０としては、製造ラインで部品に潤滑油や冷却油を噴射するシステム、部品に洗浄水を噴射するシステム、部品に塗装液を噴射するシステムが例示される。 In the above-described embodiment, the configuration in which the liquid injection system 10 injects urea water as a liquid into the exhaust passage 1 of the internal combustion engine has been described as an example, but the liquid injected by the liquid injection system 10 is not limited to urea water. .. The liquid injected by the droplet injection system 10 of the present disclosure includes a cleaning liquid that is injected into a filter device arranged in the exhaust passage 1 and backwashes non-combustible combustion products (also referred to as ash) accumulated in the filter device, an internal combustion engine. Fuel that is injected into the cylinder or intake passage and burns in the cylinder, fuel that is injected inside the exhaust passage 1 and oxidatively burned by the oxidation catalyst device, is injected into the windshield, headlight, or mirror of the vehicle. Examples include a washer fluid that cleans them, and a lubricating oil or a cooling oil that is injected into a driving component. Further, the liquid injection system 10 is not limited to the one mounted on the vehicle. Examples of the liquid injection system 10 include a system for injecting lubricating oil or cooling oil to parts on a production line, a system for injecting cleaning water to parts, and a system for injecting coating liquid to parts.
　本出願は、2019年8月29日付で出願された日本国特許出願（特願2019-156838）に基づくものであり、その内容はここに参照として取り込まれる。 This application is based on a Japanese patent application (Japanese Patent Application No. 2019-156838) filed on August 29, 2019, the contents of which are incorporated herein by reference.
　本開示の液体噴射システムは、粒径が揃ったファインバブルを一定の含有率で含有させた液体を噴射することが可能になり、液体の微粒子化を促進することができる点において有用である。 The liquid injection system of the present disclosure is useful in that it is possible to inject a liquid containing fine bubbles having a uniform particle size at a constant content rate, and it is possible to promote fine particle formation of the liquid.
１　排気通路
３　貯留用液体
４　ファインバブル
５　噴射用液体
６　圧縮空気の気泡
１０　液体噴射システム
１１　主タンク
１２　液体噴射弁
１３　副タンク
１４　気泡吐出器
１５　超音波照射装置
２０　制御装置 1 Exhaust passage 3 Storage liquid 4 Fine bubble 5 Injection liquid 6 Compressed air bubbles 10 Liquid injection system 11 Main tank 12 Liquid injection valve 13 Sub tank 14 Bubble discharger 15 Ultrasonic irradiation device 20 Control device

Claims (4)

  1. 　液体を貯留する主タンクとこの主タンクに接続された液体噴射弁とを備える液体噴射システムにおいて、
    　前記主タンクおよび前記液体噴射弁の間に配置されて前記主タンクから送られた液体を貯留する副タンクと、この副タンクに貯留された液体に気泡を吐出する気泡吐出器と、この気泡吐出器から吐出された気泡に超音波を照射する超音波照射装置と、前記気泡吐出器および前記超音波照射装置に接続された制御装置と、を備え、
    　前記制御装置により、前記気泡吐出器から気泡を吐出させるとともに前記超音波照射装置から超音波を照射させてファインバブルを生成し、前記副タンクに貯留された液体に含有されたファインバブルの含有率を予め定めた範囲に調節する制御を行う構成にしたことを特徴とする液体噴射システム。     In a liquid injection system including a main tank for storing liquid and a liquid injection valve connected to the main tank.
    An auxiliary tank arranged between the main tank and the liquid injection valve to store the liquid sent from the main tank, a bubble discharger for discharging bubbles to the liquid stored in the sub tank, and the bubble discharge. It is provided with an ultrasonic irradiation device that irradiates ultrasonic waves to bubbles discharged from the device, and a control device connected to the bubble discharger and the ultrasonic irradiation device.
    The control device discharges bubbles from the bubble ejector and irradiates ultrasonic waves from the ultrasonic irradiation device to generate fine bubbles, and the content of fine bubbles contained in the liquid stored in the sub tank. A liquid injection system characterized in that it is configured to control to adjust to a predetermined range.
  2. 　前記調節する制御は前記主タンクから前記副タンクに液体が追加されたときに行われて、前記主タンクから前記副タンクに送られた液体の追加量に基づいて設定された追加期間で行われる請求項１に記載の液体噴射システム。 The adjusting control is performed when liquid is added from the main tank to the sub tank, and is performed for an additional period set based on the additional amount of liquid sent from the main tank to the sub tank. The liquid injection system according to claim 1.
  3. 　前記調節する制御は予め定めた消失期間が経過したときに行われて、前記消失期間に基づいて設定された補充期間で行われる請求項１または２に記載の液体噴射システム。 The liquid injection system according to claim 1 or 2, wherein the control to be adjusted is performed when a predetermined disappearance period has elapsed, and is performed in a replenishment period set based on the disappearance period.
  4. 　前記液体が尿素水であり、前記液体噴射弁が内燃機関の排ガスが通過する排気通路の中途位置に配置される請求項１～３のいずれか１項に記載の液体噴射システム。 The liquid injection system according to any one of claims 1 to 3, wherein the liquid is urea water, and the liquid injection valve is arranged at a position in the middle of an exhaust passage through which exhaust gas of an internal combustion engine passes.
PCT/JP2020/029744 2019-08-29 2020-08-04 Liquid injection system WO2021039303A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006214310A (en) * 2005-02-02 2006-08-17 Denso Corp Nox removing device for vehicle
JP2007089710A (en) * 2005-09-27 2007-04-12 Matsushita Electric Works Ltd Shower apparatus
JP2007182803A (en) * 2006-01-06 2007-07-19 Hino Motors Ltd Exhaust emission control device
JP2010077902A (en) * 2008-09-26 2010-04-08 Ud Trucks Corp Engine exhaust emission control device
JP2014037789A (en) * 2012-08-13 2014-02-27 Isuzu Motors Ltd Exhaust gas post-processing device and internal combustion engine mounted with the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006214310A (en) * 2005-02-02 2006-08-17 Denso Corp Nox removing device for vehicle
JP2007089710A (en) * 2005-09-27 2007-04-12 Matsushita Electric Works Ltd Shower apparatus
JP2007182803A (en) * 2006-01-06 2007-07-19 Hino Motors Ltd Exhaust emission control device
JP2010077902A (en) * 2008-09-26 2010-04-08 Ud Trucks Corp Engine exhaust emission control device
JP2014037789A (en) * 2012-08-13 2014-02-27 Isuzu Motors Ltd Exhaust gas post-processing device and internal combustion engine mounted with the same

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