WO2014080846A1 - Capteur de concentration gazeuse et son procédé de chauffage - Google Patents

Capteur de concentration gazeuse et son procédé de chauffage Download PDF

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Publication number
WO2014080846A1
WO2014080846A1 PCT/JP2013/080912 JP2013080912W WO2014080846A1 WO 2014080846 A1 WO2014080846 A1 WO 2014080846A1 JP 2013080912 W JP2013080912 W JP 2013080912W WO 2014080846 A1 WO2014080846 A1 WO 2014080846A1
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WO
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Prior art keywords
temperature
detection element
determination value
sensor
gas concentration
Prior art date
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PCT/JP2013/080912
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English (en)
Japanese (ja)
Inventor
正信 嶺澤
真 尼ヶ崎
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いすゞ自動車株式会社
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Publication of WO2014080846A1 publication Critical patent/WO2014080846A1/fr

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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
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/04—Introducing corrections for particular operating conditions
    • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
    • F02D41/062—Introducing corrections for particular operating conditions for engine starting or warming up for starting
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1493—Details
    • F02D41/1494—Control of sensor heater
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/04—Introducing corrections for particular operating conditions
    • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
    • F02D41/062—Introducing corrections for particular operating conditions for engine starting or warming up for starting
    • F02D41/064—Introducing corrections for particular operating conditions for engine starting or warming up for starting at cold start
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/146—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration
    • F02D41/1461—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration of the exhaust gases emitted by the engine
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/4067—Means for heating or controlling the temperature of the solid electrolyte

Definitions

  • the present invention relates to a gas concentration sensor including a heater (heating device) for activating an element of a gas concentration sensor capable of detecting the concentration of a gas such as NOx and a method for raising the temperature.
  • an LNT catalyst lean-NOx-trap catalyst; NOx occlusion reduction catalyst, etc.
  • a urea SCR catalyst urea selective catalytic reduction catalyst
  • a NOx sensor gas concentration sensor for detecting the NOx concentration in the exhaust gas discharged from the engine.
  • This NOx sensor exhibits a detection function at the operating temperature of the sensor in which the detection element is activated. Therefore, when detecting the NOx concentration, it is necessary to pass the current through an electric heater (heating device) attached to the NOx sensor and raise the temperature of the NOx sensor in advance to the operating temperature of the sensor (for example, , See Patent Document 1).
  • water drops may accumulate in the exhaust pipe.
  • the water droplets may adhere to the NOx sensor.
  • the NOx sensor includes a detection element into which a concentration detection target gas is introduced and a heater that raises the temperature of the detection element. Both the detection element and the heater are made of ceramic. In the unlikely event that water droplets adhere to the detection element or heater after the temperature rise, the detection element or heater is broken due to a temperature gradient. Therefore, the temperature rise by the heater must be started in a state where there are no water droplets around the detection element, that is, in a state where the NOx sensor is completely dry. However, it is difficult to directly detect the presence or absence of water droplets.
  • the amount of heat stored in the NOx sensor is calculated by multiplying the amount of heat of the exhaust gas by the heat balance coefficient in the NOx sensor, and when the amount of stored heat is larger than a preset drying judgment value, the temperature rise by the heater is permitted.
  • an apparatus for example, refer to Patent Document 2.
  • step S10 for starting preheating of the heater is performed.
  • step S20 for determining whether or not the estimated heat quantity Qx is larger than the drying determination value Qn is performed.
  • the estimated heat amount Qx here is the amount of heat stored in the NOx sensor calculated by multiplying the heat balance coefficient k in the NOx sensor by the heat amount of the exhaust gas (a value calculated from the exhaust gas temperature and the exhaust gas flow rate). is there.
  • the heat balance coefficient k is a value calculated from the heat balance map, and the maximum value is 1 and the minimum value is 0.
  • the heat balance coefficient k is set large in a region where the outside air temperature is high and the vehicle speed is low, and small in a region where the outside air temperature is low and the vehicle speed is high.
  • step S30 is performed to continue preheating of the heater.
  • step S40 for performing temperature increase by the heater is performed, and this method for increasing the temperature of the NOx sensor is completed.
  • this device By calculating the amount of heat stored in the NOx sensor from the exhaust gas temperature as described above, this device reliably determines the drying of the NOx sensor, and the detection element and the heater break due to the temperature rise by the heater. It is preventing.
  • the temperature of the exhaust gas is low and a post-treatment such as a catalyst for purifying the exhaust gas. Since the device is not warmed, the temperature of the detection element of the NOx sensor may be lower than that during normal operation.
  • the temperature of the detection element When the temperature of the detection element is low, it takes a longer time than in a normal state until no water droplets are attached to the NOx sensor, that is, until the NOx sensor is completely dry.
  • the present invention has been made in view of the above problems, and its object is to detect in a state where the detection element may be wet when the temperature of the detection element is low, such as during a cold start of an internal combustion engine. It is an object of the present invention to provide a gas concentration sensor capable of preventing cracking of a detection element or a heating device by avoiding temperature rise of the element, and a method for raising the temperature.
  • a gas concentration sensor of the present invention includes a detection element that detects a gas concentration in an internal combustion engine, a heating device that raises the detection element to a predetermined operating temperature, An element temperature sensor for detecting temperature, and a normal temperature raising means for raising the temperature of the detection element by the heating device when an estimated heat quantity in the gas concentration sensor becomes larger than a predetermined drying determination value
  • a predetermined element temperature determination value When the first temperature of the detection element at the start of the internal combustion engine detected by the element temperature sensor is equal to or less than a predetermined element temperature determination value, Using the temperature of the detection element detected by the element temperature sensor as the drying judgment value, the timing for heating the detection element by the heating device is delayed compared to the normal temperature raising means. It is corrected to value, when the estimated quantity of heat is larger than the correction drying judgment value, configured with a low-temperature TokiNoboru raising means for raising the temperature of the sensing element in the heating device.
  • the internal combustion engine is corrected by correcting the dryness determination value used in the conventional gas concentration sensor.
  • the temperature of the sensing element is low, such as during a cold start, the time until the temperature of the sensing element is adjusted is adjusted to avoid the temperature rise of the sensing element in the presence of water around the sensing element. The crack of an element or a heating device can be prevented.
  • the controller determines the drying determination value from the first temperature. 1 correction value and the corrected drying determination value obtained from the second correction value obtained from the second temperature of the detection element detected by the element temperature sensor when the gas temperature is equal to or higher than a predetermined gas temperature determination value. It is preferable to include a dry determination value correction unit that corrects to the above.
  • the means for calculating the first correction value from the first temperature and the second correction value from the second temperature is calculated here using a map based on the change amount of the gas temperature and the detection element temperature. . Therefore, the first correction value increases as the first temperature of the detection element decreases, and the second correction value increases as the second temperature decreases and the difference between the first temperature and the second temperature decreases. Value.
  • a method for raising the temperature of the gas concentration sensor of the present invention for solving the above-described object is provided by a gas concentration sensor that raises the temperature of a detection element for detecting a gas concentration in an internal combustion engine with a heating device to a predetermined operating temperature.
  • the temperature raising method when the first temperature of the detection element at the start of the internal combustion engine is larger than a predetermined element temperature determination value, the estimated heat amount in the gas concentration sensor becomes larger than a predetermined drying determination value.
  • the drying determination value is determined using the temperature of the detection element.
  • the timing for raising the temperature of the detection element is corrected to a corrected drying determination value that is slower than when the first temperature is higher than the element temperature determination value, and the estimated heat amount is greater than the corrected drying determination value.
  • the drying determination value is a first correction value obtained from the first temperature and the gas temperature is equal to or higher than a predetermined gas temperature determination value
  • the correction dryness determination value is corrected with a second correction value obtained from the second temperature of the detection element.
  • the temperature of the detection element when the temperature of the detection element is low, such as when the internal combustion engine is cold-started, the temperature of the detection element is avoided in a state where the detection element may be wetted. It is possible to prevent the device from cracking.
  • FIG. 1 is a diagram showing a configuration of a gas concentration sensor according to an embodiment of the present invention.
  • FIG. 2 is a flowchart showing a method for raising the temperature of the gas concentration sensor according to the embodiment of the present invention.
  • FIG. 3 is a flowchart showing a method for raising the temperature of a conventional gas concentration sensor.
  • a gas concentration sensor and a temperature raising method according to an embodiment of the present invention will be described with reference to the drawings.
  • a NOx sensor provided in the exhaust pipe of a diesel engine will be described as an example of the gas concentration sensor.
  • the present invention is not limited to the NOx sensor, and the detection element is raised by a heater (heating device). Any sensor that warms can be used. Note that the dimensions of the drawings are changed so that the configuration can be easily understood, and the ratios of the thicknesses, widths, lengths, and the like of the respective members and parts do not necessarily match the ratios of actually manufactured parts.
  • the NOx sensor (gas concentration sensor) 1 is a sensor that is provided in the exhaust pipe 3 of the engine (internal combustion engine) 2 and detects the NOx concentration in the exhaust gas.
  • This NOx sensor 1 houses a detection element 5 made of ceramic in a metal housing 4 and opens at least an inlet of the detection element 5 into the exhaust pipe 3 to take in exhaust gas into the detection element 5. It is out.
  • the NOx sensor 1 is composed of a ceramic heater 6 (heating device). And an element temperature sensor 7 for controlling the temperature rise of the detection element 5 by the heater 6.
  • the heater 6 is, for example, an electric heater, and raises the temperature of the detection element 5 when an electric current is passed.
  • the heater 6 itself can be preheated (hereinafter referred to as preheating) before the detection element 5 is heated.
  • the element temperature sensor 7 is a well-known sensor that detects the temperature of the detection element 5.
  • the NOx sensor 1 of the present invention includes a control device 8 that controls the heater 6 in accordance with the temperature of the detection element 5 detected by the element temperature sensor 7 in addition to the above-described conventional configuration.
  • the control device 8 includes an element temperature determination means C1 for determining whether or not the temperature of the detection element 5 at the start of the engine 2 is equal to or lower than a predetermined element temperature determination value, a normal temperature increase means C2, and a low temperature increase temperature. And a temperature means C3.
  • the control device 8 is provided in the exhaust pipe 3 in the same manner as the NOx sensor 1, and includes an exhaust gas temperature sensor 9 that detects the exhaust gas temperature, and an exhaust gas flow rate calculation device 10 that outputs an exhaust gas flow rate calculated from various operating conditions. It is connected to the.
  • the exhaust gas temperature sensor 9 and the exhaust gas flow rate calculation device 10 are provided in order to describe the NOx sensor 1 that detects the NOx concentration in the exhaust gas. It may be replaced with a sensor or a calculation device.
  • control device 8 is disposed as a single unit.
  • control device 8 is a control device called an engine control unit, and is a micro that comprehensively performs electrical control in charge of controlling the engine 2 by an electric circuit.
  • ECU which is a controller, DCU etc. which control injection of urea water provided in an SCR catalyst system.
  • exhaust gas flow rate calculation device 10 may be incorporated in the control device 8 and integrally formed.
  • the element temperature determination means C1 provided in the control device 8 is a means for determining whether or not the detection element 5 is in a cold state when the engine 2 is started, such as when the engine 2 is cold started. It is means for determining whether or not the detected first temperature T1 is equal to or lower than a predetermined element temperature determination value Tn.
  • the element temperature determination value Tn can be set to an arbitrary numerical value, but it is preferable to set it based on the temperature of the detection element 5 when the engine 2 is cold-started.
  • the temperature state of the detection element 5 is determined using the element temperature determination means C1, but a means for determining a cold start of the engine 2 may be used instead.
  • the cold start of the engine 2 is determined from parameters such as the ambient temperature, the engine cooling water temperature, or the temperature of the catalyst provided in the exhaust pipe, and in the case of the cold start, even if it is determined that the temperature of the detection element 5 is low. Good.
  • the normal temperature raising means C2 is a means for raising the temperature of the detection element 5 of the NOx sensor 1 when the temperature of the detection element 5 is not low and is started from a somewhat high temperature.
  • the temperature raising means for example, a known means described in Patent Document 2 (Japanese Patent Laid-Open No. 2012-21457) may be used.
  • the heat balance coefficient k in the NOx sensor 1 by multiplying the heat balance coefficient k in the NOx sensor 1 by the amount of heat of the exhaust gas, for example, the amount of heat (heat flow rate) calculated from the exhaust gas temperature and the exhaust gas flow rate when the vehicle is stopped and the outside air temperature is constant, An estimated heat quantity Qx in which heat from the exhaust gas is accumulated in the NOx sensor 1 is calculated.
  • the heater 6 It is determined whether or not the calculated estimated heat quantity Qx is larger than a predetermined drying determination value Qn. If the estimated heat quantity Qx is equal to or less than the drying determination value Qn, the heater 6 does not raise the temperature, while the estimated heat quantity When Qx is larger than the dry determination value Qn, the temperature of the heater 6 is increased.
  • the low temperature temperature raising means C3 is a means for raising the temperature of the detection element 5 of the NOx sensor 1 when the temperature of the detection element 5 is low.
  • the temperature of the detection element 5 is low, for example, when the engine 2 is cold-started, the engine 2 cannot obtain the original output performance, but also the post-treatment such as an EGR system or a catalyst provided in the exhaust pipe 3
  • the apparatus is also in a state where it does not function sufficiently, and the NOx sensor 1 is easily exposed to condensed water (or also referred to as condensed water).
  • the detection element 5 When the engine 2 is cold started, if the temperature of the detection element 5 is increased by the normal temperature increase means C2 as in the conventional case, the detection is performed by the heater 6 in a state where a large amount of water (or moisture) exists around the detection element 5. There is a possibility that the temperature of the element 5 is raised, and it is preferable to perform more accurate DewPoint control to avoid this. Therefore, when the detection element 5 is at a low temperature, such as when the engine 2 is cold started, the detection element 5 and the heater 6 are cracked by adjusting the time until the detection element 5 is heated by the low temperature heating means C3. To prevent.
  • it is means for raising the temperature of the detection element 5 in a normal heating state.
  • the low temperature temperature raising means C3 includes a first correction value calculating means C4 for calculating a first correction value Q1 from the first temperature T1 of the detection element 5 detected by the element temperature sensor 7 when the engine 2 is started.
  • the second correction value calculation means C5 for calculating the second correction value Q2 from T2, and the correction dryness determination obtained by correcting the dryness determination value Qn used in the normal temperature raising means C2 with the first correction value Q1 and the second correction value Q2.
  • a dry determination value correcting means C6 for calculating the value Qn ′.
  • the first correction value calculation unit C4 and the second correction value calculation unit C5 are configured to calculate the first correction value Q1 corresponding to the first temperature T1 and the first correction value from the map based on the change amount of the exhaust gas temperature and the temperature of the detection element. This is a means for calculating the second correction value Q2 corresponding to the two temperatures T2. In this embodiment, the calculation is performed from the map, but it is only necessary that the first correction value Q1 corresponding to the first temperature T1 and the second correction value Q2 corresponding to the second temperature can be calculated. It is not limited to.
  • the dry determination value correction means C6 adds the first correction value Q1 and the second correction value Q2 to the dry determination value Qn used in the normal temperature increase means C2, and the heater 6 increases the temperature of the detection element 5 Is means for calculating a corrected drying determination value Qn ′ that is later than the timing at which the temperature of the detection element 5 is raised by the heater 6 of the normal temperature raising means C2.
  • the temperature raising method of the NOx sensor 1 is started when an ignition key (not shown) is turned on.
  • the element temperature determination means C1 determines that the first temperature T1 of the detection element 5 at the start of the engine 2 is a predetermined element temperature.
  • Step S100 for determining whether or not the value is equal to or less than the determination value is performed.
  • the first temperature T1 of the detection element 5 at the start of the engine 2 is When the temperature is equal to or lower than a predetermined element temperature determination value Tn, it is determined that the detection element 5 is at a low temperature.
  • This step S100 only needs to be able to determine that the detection element 5 is at a low temperature.
  • the engine 2 can be cold-started from parameters such as the ambient temperature, the engine cooling water temperature, or the temperature of the catalyst provided in the exhaust pipe. In the case of a cold start, it may be determined that the temperature of the detection element 5 is low. The determination may be made using a timer or the like that measures the stop time of the engine 2.
  • step S100 If it is determined in step S100 that the temperature of the detection element 5 is not low, then the normal temperature raising means C2 raises the temperature by the same method as the conventional NOx sensor temperature raising method shown in FIG. .
  • the low temperature temperature raising means C3 starts to raise the temperature of the low temperature detection element 5.
  • the first correction value calculation means C4 calculates the first correction value Q1 from the first temperature T1 of the detection element 5 at the start of the engine 2 detected by the element temperature sensor 7. I do.
  • the first correction value Q1 corresponding to the first temperature T1 is calculated from the map based on the exhaust gas temperature obtained in advance and the change amount of the temperature of the detection element 5,
  • the method is not particularly limited as long as the first correction value Q1 based on the first temperature T1 can be calculated. Since the first correction value Q1 calculated in step S120 is based on the first temperature T1, the lower the first temperature T1 of the detection element 5 at the start of the engine 2, the higher the value. .
  • step S110 when the temperature of the detection element 5 at the time of starting the engine 2 is low, that is, when the first temperature T1 is low, the timing of raising the temperature by the heater 6 can be delayed.
  • the temperature can be raised in a state where there is no condensed water around 5.
  • step S130 is performed to determine whether or not the exhaust gas temperature Tg detected by the exhaust gas temperature sensor 9 is equal to or higher than a predetermined exhaust gas temperature determination value Tm.
  • the exhaust gas temperature determination value Tm in step S130 can be set to an arbitrary value, but preferably the exhaust gas temperature when the engine 2 is sufficiently warmed up is good. Further, in the case of using the urea SCR catalyst, it is necessary to detect the NOx concentration in the exhaust gas with the NOx sensor 1 before starting the injection of the urea water, so that it is lower than the threshold value for starting the injection of the urea water.
  • the exhaust gas temperature judgment value may be set to 40 ° C. to 100 ° C.
  • step S130 If it is determined in step S130 that the exhaust gas temperature Tg is equal to or higher than the predetermined exhaust gas temperature determination value Tm, then the second correction value calculation means C5 causes the exhaust gas temperature Tg to be equal to or higher than the predetermined exhaust gas temperature determination value Tm.
  • step S140 which calculates the 2nd correction value Q2 from the 2nd temperature T2 detected with element temperature sensor 7 is performed.
  • step S140 is a second correction value corresponding to the second temperature T2 from the map based on the exhaust gas temperature obtained in advance and the amount of change in the temperature of the detection element 5, as in step S110.
  • Q2 is calculated as long as the second correction value Q2 based on the second temperature T2 can be calculated, and the method is not particularly limited.
  • the exhaust gas temperature Tg is preliminarily set.
  • the second temperature T2 of the detection element 5 when the exhaust gas temperature determination value Tm is equal to or higher than the predetermined exhaust gas temperature determination value Tm is lower and the temperature difference between the second temperature T2 and the first temperature T1 is smaller.
  • step S140 the state around the NOx sensor 1 is not sufficiently warmed by the exhaust gas temperature Tg, that is, the second temperature T2 is low, or the temperature difference between the second temperature T2 and the first temperature T1 is small.
  • the timing of raising the temperature by the heater 6 can be delayed, the temperature can be raised in the absence of condensed water around the detection element 5.
  • Step S150 for calculating Qn ′ is performed.
  • the correction drying determination value Qn ′ is detected by the heater 6 when the temperature of the detection element 5 is increased by the heater 6 when the temperature of the detection element 5 is low. It can be set so as to be later than the temperature rising timing of the element 5.
  • the temperature raising means C3 at low temperature performs a temperature raising method in which the drying judgment value Qn of the temperature raising method performed by the normal temperature raising means C2 is replaced with a corrected drying judgment value Qn ′.
  • step S160 for starting preheating of the heater 6 is performed. By preheating the heater 6, the temperature of the detection element 5 can be quickly raised when it is determined that the NOx sensor 1 is sufficiently dry.
  • step S170 is performed to determine whether or not the estimated heat quantity Qx of the NOx sensor 1 is larger than the corrected drying determination value Qn '. If the estimated heat quantity Qx is equal to or less than the corrected drying determination value Qn ′ in step S170, step S180 for continuing the preheating of the heater 6 is performed, and step S170 is performed again. On the other hand, if the estimated heat quantity Qx is larger than the corrected drying determination value Qn ′ in step S170, next, step S190 for starting the temperature increase by the heater 6 is performed, and this temperature increase method is completed.
  • the NOx sensor 1 when the detection element 5 is at a low temperature, such as when the engine 2 is cold-started, the NOx sensor 1 is in a state where condensed water is present. Correction is performed with a first correction value Q1 calculated from the first temperature T1 of the detection element 5 and a second correction value Q2 calculated from the second temperature T2 of the detection element 5 when the exhaust gas temperature Tg rises.
  • accurate DewPoint control can be performed. Specifically, the detection element 5 and the heater 6 can be prevented from cracking by delaying the time until the temperature of the detection element 5 is raised when the temperature of the detection element 5 is low, such as during a cold start. Can do.
  • the temperature of the detection element 5 is low at the time of cold start of the engine 2 and the condensed water is present in the NOx sensor 1, a new sensor is not added, and the heater 6 of the NOx sensor 1 has.
  • the determination can be easily made only with the control element temperature sensor 7, the exhaust gas temperature sensor 9, and the exhaust gas flow rate calculation device 10.
  • the accumulated amount in the NOx sensor is calculated by multiplying the heat quantity of the exhaust gas by the heat balance coefficient k in the NOx sensor 1 of the exhaust gas disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 2012-21457).
  • the amount of heat Qx was calculated, and the estimated amount of heat Qx was compared with a predetermined drying determination value Qn to determine the dry state in the NOx sensor 1.
  • the present invention is not limited to the above method, as long as the determination value used at the normal time is corrected and the timing for raising the temperature of the heater 6 can be delayed from the normal time when the detection element 5 is at a low temperature.
  • the gas concentration sensor according to the present invention avoids the temperature rise of the detection element when the temperature of the detection element is low when the internal combustion engine is cold-started. Since cracking of the apparatus can be prevented, it can be used particularly for a NOx sensor for detecting NOx concentration in exhaust gas.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)
  • Measuring Oxygen Concentration In Cells (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

La présente invention concerne un capteur de concentration gazeuse qui est doté d'un élément de détection (5) permettant de détecter la concentration d'un gaz dégagé par un moteur (2), d'un élément chauffant (6) permettant de chauffer l'élément de détection (5) à une température de fonctionnement prédéfinie, et d'un capteur de température d'élément (7) permettant de détecter la température de l'élément de détection (5). Un dispositif de commande (8) utilise une première température (T1) et une seconde température (T2) de l'élément de détection (5) pour corriger une valeur seuil de séchage (Qn) sur une valeur seuil de séchage corrigée (Qn') à laquelle l'élément de détection (5) est chauffé par l'élément chauffant (6) plus tard qu'un moyen de chauffage (C2) à l'état normal lorsque la première température (T1) de l'élément de détection (5) détectée par le capteur de température d'élément (7) est inférieure ou égale à une valeur seuil de température d'élément (Tn) prédéfinie ; et est conçu de façon à être doté d'un moyen de chauffage (C3) à l'état basse température qui réchauffe l'élément de détection (5) par le biais de l'élément chauffant (6) lorsqu'une quantité estimée de chaleur (Qx) est supérieure à la valeur seuil de séchage corrigée (Qn'). Ainsi, lorsque la température de l'élément de détection (5) est basse, notamment lorsque le moteur (2) démarre à froid, l'élément de détection (5) ou l'élément chauffant (6) peut éviter de se fissurer si l'on évite de chauffer l'élément de détection (5) lorsque ce dernier est couvert d'eau.
PCT/JP2013/080912 2012-11-21 2013-11-15 Capteur de concentration gazeuse et son procédé de chauffage WO2014080846A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012255321A JP2014102196A (ja) 2012-11-21 2012-11-21 ガス濃度センサとその昇温方法
JP2012-255321 2012-11-21

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WO2014080846A1 true WO2014080846A1 (fr) 2014-05-30

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113006906A (zh) * 2021-03-31 2021-06-22 奇瑞汽车股份有限公司 尾气加热装置、尾气加热方法和汽车
US11359527B2 (en) 2018-04-24 2022-06-14 Scania Cv Ab Method and system for control of an activation of at least one liquid sensitive sensor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009168759A (ja) * 2008-01-18 2009-07-30 Denso Corp 排出ガスセンサのヒータ制御装置
JP2012021457A (ja) * 2010-07-14 2012-02-02 Isuzu Motors Ltd ＮＯｘセンサ昇温装置

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009168759A (ja) * 2008-01-18 2009-07-30 Denso Corp 排出ガスセンサのヒータ制御装置
JP2012021457A (ja) * 2010-07-14 2012-02-02 Isuzu Motors Ltd ＮＯｘセンサ昇温装置

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11359527B2 (en) 2018-04-24 2022-06-14 Scania Cv Ab Method and system for control of an activation of at least one liquid sensitive sensor
CN113006906A (zh) * 2021-03-31 2021-06-22 奇瑞汽车股份有限公司 尾气加热装置、尾气加热方法和汽车

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