JP2013533422A - Method and apparatus relating to temperature limitation of HC charging unit in exhaust system - Google Patents

Abstract

  The present invention is an HC charging system for purifying exhaust gas from an engine (150), which is located in thermal contact with the exhaust system (250) of the engine and is connected to an exhaust duct (240) of the exhaust system. With respect to a method associated with an HC input system comprising an input unit for supplying fuel, the method includes determining (s340) whether an undesired temperature level of the input unit (250) exists. The method also includes a step (s360) of limiting the temperature of the exhaust duct (240) by controlling operation of the engine if the undesirable temperature level is found to exist. The invention also relates to a computer program product comprising program code (P) for a computer (200; 210; 400) for carrying out the method according to the invention. The invention also relates to a device and a motor vehicle (100) comprising this device.

Description

  The present invention is an HC charging system for purifying exhaust gas from an engine, and is a charging unit for supplying fuel to an exhaust duct of the exhaust system, located in thermal contact with the exhaust system of the engine To a method related to an HC injection system comprising: The invention also relates to a computer program product comprising program code for a computer for carrying out the method according to the invention. The present invention also relates to an apparatus of an HC charging system for exhaust purification for an engine and an automobile provided with the HC charging system.

  In today's vehicles, diesel fuel is used as fuel in DPF (diesel exhaust particulate filter) systems with particle filters. The particle filter is configured to capture, for example, diesel exhaust particles and soot. During active regeneration of the particulate filter, diesel fuel is supplied to an exhaust pipe downstream of the engine and directed to an oxidation catalyst, also called DOC. In the oxidation catalyst, the diesel fuel burns, and the temperature of the exhaust system rises. Therefore, active regeneration of the particle filter located on the downstream side of the oxidation catalyst can be realized.

  One type of DPF system includes a container for diesel fuel. The DPF system also draws the diesel fuel from this vessel via a suction hose and connects it via a pressure hose to a dosing unit located adjacent to the exhaust system of the vehicle, for example adjacent to an exhaust pipe of the exhaust system. There may be a pump configured to supply the leverage. The charging unit is configured to inject a required amount of diesel fuel into the exhaust pipe upstream of the particle filter in accordance with the operating routine stored in the vehicle control unit. In order to facilitate pressure regulation when zero or only a small amount is charged, the system also includes a return hose that returns from the pressure side of the system back to the container. This configuration allows the charging unit to be cooled by the diesel fuel, and this fuel flows from the container through the pump and the charging unit during cooling and back to the container. This realizes active cooling of the dosing unit. The flow back from the input valve to the container is generally substantially constant.

  Since the dosing unit is generally located adjacent to the exhaust system of the vehicle that becomes warm during operation of the vehicle, for example, depending on the engine load, there is a risk that the dosing valve will overheat. Overheating of the charging unit leads to a decrease in the function of this unit, and in some cases impairs its performance.

  The input unit generally includes an electrical component, and a circuit card is provided in a part of the component. The circuit card may be configured, for example, to control the injection of diesel fuel into the vehicle exhaust system. For various reasons, these electrical components are susceptible to high temperatures. If the temperature of the dosing unit becomes too high, it will result in deterioration of the electrical components, and in some cases, will pay expensive repair costs at the service factory. Furthermore, if the temperature is too high, the diesel fuel present in the dosing unit will at least partially change to a solid, possibly leading to failure of the dosing unit. According to one example, the diesel fuel undergoes pyrolysis in the dosing unit and thereby at least partially changes to coke. Accordingly, at least a portion of the diesel fuel may be carbonized. Therefore, it is most important that the temperature of the input unit of the DPF system must not exceed a critical level.

  Therefore, there is a need to improve current HC input systems to reduce or eliminate the above disadvantages.

  One object of the present invention is to propose a new and advantageous method for improving the performance of an HC injection system.

  One object of the present invention is to propose a new and advantageous method for improving the performance of an HC charging system when the charging unit has insufficient cooling flow or no cooling flow at all.

  Another object of the present invention is to propose a new advantageous apparatus of the HC injection system and a new advantageous computer program for improving the performance of the HC injection system.

  Another object of the present invention is to improve the performance of the HC input system when the HC input system has a new and advantageous device and when the input unit has insufficient or no cooling flow. It is to propose a new and advantageous computer program.

  Another object of the present invention is a method associated with an HC injection system, whereby the risk of undesirable functional degradation of the components of the HC injection system and / or failure of the components of the HC injection system with respect to fuel. It is to propose a method for reducing the risk, for example the failure risk of the input unit.

  It is a further object of the present invention to propose an alternative method associated with the HC injection system, an alternative computer program associated with the HC injection system, and an alternative device for the HC injection system.

  These objects are achieved by a method according to claim 1 relating to an HC input system for exhaust purification for an engine.

  One aspect of the present invention is an HC injection system for purifying exhaust gas from an engine, for supplying fuel to an exhaust duct of the exhaust system located in thermal contact with the engine exhaust system. In connection with an HC charging system comprising a charging unit, a method is proposed comprising determining whether an undesired temperature level of the charging unit is present. The method also includes the step of limiting the temperature of the exhaust duct by controlling operation of the engine if the undesirable temperature level is found to be present.

  If the charging unit is not sufficiently cooled and, as a result, the temperature of the charging unit rises to an undesirable level, the temperature of the exhaust gas in the exhaust system may be controlled by affecting the operation of the engine. As a result, it is advantageous to reduce the risk of the temperature of the dosing unit becoming too high. This prevents the charging unit from being permanently damaged or prevents fuel from becoming an obstacle in the charging unit as a result of carbonization.

  The temperature limitation may be achieved by reducing the maximum available torque on the engine output shaft. For this reason, neither the driver nor the stored operating routine should request torques that exceed this maximum available torque. By reducing the maximum available torque, the temperature of the exhaust gas in the exhaust duct will be reduced. Said reduction of the maximum available torque may be achieved with a gentle slope or in discrete steps. Said reduction in the maximum available torque may be based on the temperature of the exhaust gas in the exhaust duct, which is detected or calculated by a stored model. Alternatively, the reduction in the maximum available torque may be based on the temperature of the dosing unit, which is measured or calculated by a stored model.

  Said limit of temperature may be achieved by affecting the EGR content of the engine. By affecting the contents of the EGR, it is possible to actively adjust the temperature of the exhaust gas in the exhaust duct to a desired predetermined level. By changing the contents of the EGR, the temperature of the exhaust gas in the exhaust duct can be actively lowered to a desired predetermined level. Improved cooling of the dosing unit is thus possible.

  Said temperature limitation may be achieved by affecting the fuel injection time of at least one cylinder of the engine or the ignition time of at least one cylinder of the engine. Actively adjusting the temperature of the exhaust gas in the exhaust duct to a desired predetermined level by changing the injection time of at least one cylinder of the diesel engine or the ignition time of at least one cylinder of the Otto engine Is possible. By shifting the injection time or ignition time, the temperature of the exhaust gas in the exhaust duct can be actively reduced to a desired predetermined level. Improved cooling of the dosing unit is thus possible.

  The undesirable temperature level may be set based on characteristics of the fuel. Specifically, the temperature level may be set based on a temperature at which the fuel starts to have an adverse effect and / or a temperature at which the fuel becomes unstable. The temperature level may be in the range of 80 to 130 degrees Celsius. The temperature level may be a temperature higher than 130 degrees Celsius. According to one example, the temperature level may be in the range of 60-90 degrees Celsius when using highly sensitive fuels.

The step of determining whether an undesired temperature level of the dosing unit is present comprises the following steps:
-Directly measuring the temperature of the dosing unit;
Measuring the temperature of the exhaust stream in the exhaust duct;
It may be based on at least one of the steps of calculating the temperature of the dosing unit by means of a calculation model.

  By directly measuring the temperature of the dosing unit, an accurate measurement of the current temperature at this dosing unit is realized.

  By measuring the temperature of the exhaust flow in the exhaust duct, or the temperature of the components of the exhaust system of the HC input system, such as the temperature of the exhaust duct, the current temperature of the input unit can be indicated. Measuring the temperature of the exhaust flow in the exhaust duct is a good complement to or alternative to the direct measurement of the temperature of the input unit.

  Calculating the temperature of the input unit with a calculation model is a variant that does not require physical sensors adjacent to the input unit and / or the exhaust duct (exhaust system). Thus, calculating in this way is a cost-effective variant for determining the temperature of the dosing unit.

  To supply fuel to the exhaust duct by determining (measuring or calculating) the temperature of the charging unit, corresponding to the temperature of the charging unit, or determining (measuring or calculating) the temperature of some other component of the HC charging system It becomes possible to detect that an undesirable temperature level of the configured dosing unit has occurred.

  According to an example, the future temperature of the dosing unit may be predicted by a stored calculation model. According to an example, for example, the current load on the engine of the HC injection system may be taken into account. It is well known that the increase in exhaust temperature associated with an increase in engine load is accompanied by a certain time lag. Therefore, the future temperature of the charging unit may be predicted based on the current load on the engine of the HC charging system or a change in the load.

  The fuel may be diesel fuel or some other hydrocarbon based fuel.

  The method may further include manually stopping the step of controlling the operation of the engine to limit the temperature of the exhaust duct. While the input unit is in an insufficiently cooled operating state, automatic control of the engine control is initiated and the temperature of the exhaust flow is lowered in a desirable manner. If the HC injection system is attached to a rescue vehicle, such as a fire engine, a driver or some other member of the vehicle may choose to actively stop the control of engine operation. . This leads to an undesirable result, for example, that the temperature is too high and the dosing unit is destroyed, so that the vehicle may emit an undesirably large amount of emissions. However, in the case of emergency rescue, innovative methods may be disabled to preferentially increase vehicle speed and increase available engine torque. The stoppage of the innovative method may be performed with a push button attached to the driver's seat of the vehicle and signal-connected to the control unit of the vehicle.

  This method is easy to implement on existing vehicles. Software related to the HC injection system for engine exhaust purification according to the present invention may be installed in the vehicle control unit during vehicle manufacture. Thus, the purchaser of the vehicle may be able to select the function of this method as an option. Alternatively, software including program code for applying an innovative method related to the HC injection system for engine exhaust purification may be installed in the vehicle control unit when upgrading at a service station. Well, in such cases, the software may be loaded into a memory in the control unit. Therefore, it is cost-effective to implement this innovative method, since no further components or subsystems need to be provided in the vehicle. Related hardware is generally already provided in the vehicle. The present invention thus presents a cost-effective solution to the aforementioned problems.

One aspect of the present invention is an apparatus for an HC injection system for purifying exhaust gas from an engine, which is located in thermal contact with the exhaust system of the engine and supplies fuel to an exhaust duct of the exhaust system. HC charging system device comprising a charging unit for
Means for determining whether an undesired temperature level of the dosing unit exists;
-Proposing a device further comprising means for limiting the temperature of the exhaust duct by controlling the operation of the engine if it is found that the undesirable temperature level is present.

  The apparatus may comprise means for reducing the maximum available torque of the engine output shaft to achieve the temperature limit.

  The apparatus may comprise means for influencing the content of the engine's EGR to perform the temperature limitation. Said temperature limitation may be achieved by affecting the fuel injection time of at least one cylinder of the engine or the ignition time of at least one cylinder of the engine.

This device comprises the following means:
-Means for directly measuring the temperature of the dosing unit;
Means for measuring the temperature of the exhaust stream in the exhaust duct;
It may comprise at least one of means for calculating the temperature of the dosing unit by means of a calculation model.

  The above object is also realized in a motor vehicle comprising the features of the device described herein of an HC injection system. The vehicle may be a truck, a bus, or a passenger car.

  One aspect of the present invention proposes a computer program related to an HC injection system for exhaust purification for an engine. The computer program is stored on a computer readable medium for causing the electronic control unit or another computer connected to the electronic control unit to execute the steps according to any one of claims 1-7. Program code.

  One aspect of the present invention proposes a computer program related to an HC injection system for exhaust purification for an engine. The computer program includes program code for causing the electronic control unit or another computer connected to the electronic control unit to execute the steps according to any one of claims 1 to 7.

  One aspect of the present invention is for executing the method steps according to any one of claims 1 to 7 when the program is executed on an electronic control unit or another computer connected to the electronic control unit. A computer program product comprising program code stored on a computer readable medium is proposed.

  Software that includes program code related to the HC injection system for exhaust purification for engines is easy to update or replace. Further, various portions of software including program code associated with an HC injection system for engine exhaust purification may be replaced independently of each other. This modular configuration is advantageous from a maintenance point of view.

  Further objects, advantages, and novel features of the present invention will become apparent to those skilled in the art from the following details and upon practice of the invention. Although the invention is described below, it is noted that the invention is not limited to the specific details described. Additional uses, modifications, and other areas of incorporation within the scope of the present invention will be appreciated by those skilled in the art who can utilize the teachings herein.

  For a fuller understanding of the present invention, as well as further objects and advantages of the present invention, read the detailed description set forth below in connection with the accompanying drawings. In the accompanying drawings, like reference numerals designate like items in the various views.

1 is a schematic view of a vehicle according to an embodiment of the present invention. FIG. 2 is a schematic view of the vehicle subsystem shown in FIG. 1 according to an embodiment of the present invention. 2 is a schematic flow diagram of a method according to an embodiment of the invention. 4 is a more detailed schematic flow diagram of a method according to an embodiment of the invention. 1 is a schematic diagram of a computer according to an embodiment of the present invention. FIG.

  FIG. 1 shows a side portion of the vehicle 100. The illustrated vehicle 100 includes a tractor unit 110 having an engine 150 and a trailer 112. This vehicle may be a heavy vehicle, such as a truck or a bus. Alternatively, the vehicle may be a passenger car.

  It should be noted that the present invention is applicable to any suitable HC injection system and is therefore not limited to automotive DPF systems. The innovative method and innovative apparatus according to one aspect of the present invention is well suited for other platforms having HC input systems other than automobiles, such as ships. The vessel may be of any type, for example a motor boat, a steamer, a ferry or a large vessel.

  The innovative method and the innovative apparatus according to one aspect of the present invention are also well suited, for example, to systems with general purpose engines and / or industrial robots powered by engines.

  The innovative method and the innovative apparatus according to one aspect of the present invention are also well suited for various types of power plants, for example power plants with diesel generators.

  The innovative method associated with the HC injection system and the innovative device of the HC injection system are well suited for any engine system comprising an engine and an HC injection system, for example on a locomotive or some other platform .

  The innovative method and innovative apparatus are well suited for any system that includes a particle generator (eg, a combustion engine) and an HC input system.

  The innovative method and the innovative apparatus are also well suited for any kind of system that generates exhaust gas with particles and any system that has a filter that accumulates particles, Burned during filter regeneration, especially during active regeneration of the filter.

  As used herein, the term “link” refers to a communication link that may be a physical connection, such as an optoelectronic communication line, or a non-physical connection, such as a wireless connection, eg, a radio link or a microwave link.

  As used herein, the term “line” refers to a passage for holding and transporting a fluid, eg, a liquid fuel. The line may be any suitable size pipe. The line may be made from any suitable material, such as plastic, rubber, or metal.

  As used herein, the term “fuel” refers to an agent used for active regeneration of a particle filter of an HC input system. The fuel according to one version is diesel fuel. Of course, other types of hydrocarbon-based fuels such as synthetic fuels may be used. Diesel fuel is mentioned here as an example of fuel, but the innovative method and the innovative device are required adaptations in the control algorithm for executing the software code by this innovative method. Those skilled in the art will appreciate that other types of fuels are possible, for example, subject to adaptation to the appropriate carbonization temperature for the fuel employed.

  Although the term “HC dosing system” is used herein to denote a particle filter system, the present invention is not limited to the use of a diesel particle filter. On the contrary, other types of particle filters may be used in accordance with the present invention. Those skilled in the art will understand what type of fuel is most suitable for regenerating the particulate filter employed.

  FIG. 2 shows a subsystem 299 of the vehicle 100. Subsystem 299 is located within tractor unit 110. Subsystem 299 may form part of the HC input system. According to this example, subsystem 299 is comprised of a container 205 configured to store fuel. The container 205 is configured to store an appropriate amount of fuel and be refillable as needed. This container can contain, for example, 200 liters or 1500 liters of fuel.

  The first line 271 is configured to guide fuel from the container 205 to the pump 230. Pump 230 may be any suitable pump. The pump 230 may be a diaphragm pump provided with at least one filter. The pump 230 is configured to be driven by an electric motor. The pump 230 is configured to draw fuel from the container 205 via the first line 271 and supply it to the input unit 250 via the second line 272. The input unit 250 comprises an electrically controlled input valve for controlling the flow of fuel added to the exhaust system. The pump 230 is configured to pressurize the fuel in the second line 272. The charging unit 250 is provided with a throttle unit, and the pressure of the fuel increases in the subsystem 299 with respect to the throttle unit.

  The input unit 250 is configured to supply the fuel to an exhaust system (not shown) of the vehicle 100. More specifically, the input unit 250 is configured to supply an appropriate amount of fuel to the exhaust system of the vehicle 100 in a controlled manner. According to this version, a particle filter (not shown), such as a DPF, is located downstream of where the fuel supply is performed in the exhaust system. The amount of fuel supplied to the exhaust system is that used in the normal manner in the HC input system for active regeneration of the particle filter.

  The input unit 250 is located adjacent to an exhaust pipe that itself is configured to, for example, guide exhaust gas from the combustion engine 150 of the vehicle 100 to the particle filter. The input unit 250 is in a position in thermal contact with the exhaust system of the vehicle 100. This means, for example, that the heat energy stored in the exhaust pipe, silencer, particle filter and SCR catalyst can be directed to the dosing unit 250 in this way.

  The input unit 250 includes an electronic control card configured to handle communication with the control unit 200. The dosing unit 250 also includes plastic and / or rubber components, but these components may melt or otherwise be adversely affected if they become too hot.

  The dosing unit 250 is affected by a specific value, for example, a temperature exceeding 120 degrees Celsius. For example, when the temperature of the exhaust pipe, the silencer, and the particle filter of the vehicle 100 exceeds this value, there is a risk that the charging unit 250 may be overheated during or after operation of the vehicle if cooling is not performed. .

  Note that the fuel present in the dosing unit 250 may be adversely affected by temperatures significantly lower than the aforementioned 120 degrees Celsius. For example, at temperatures above 70 degrees Celsius, the fuel may become unstable and at somewhat higher temperatures may carbonize, thus potentially causing failure of the dosing unit 250.

  A third line 273 is between the dosing unit 250 and the container 205. The third line 273 is configured to return a certain amount of fuel supplied to the input valve 250 to the container 205. With this configuration, it is advantageous to achieve cooling of the dosing unit 250. Therefore, when fuel is pumped from the pump 230 to the container 205 via the charging unit 250, the charging unit 250 is cooled by this fuel flow.

  The first control unit 200 is configured to communicate with the first temperature sensor 220 via the link 221. The first temperature sensor 220 is configured to detect the current temperature of the dosing unit 250. The first temperature sensor 220 is configured to continuously send a signal including information about the current first temperature T 1 of the dosing unit 250 to the first control unit 200.

  The first control unit 200 is configured to communicate with the pump 230 via the link 231. The first control unit 200 is configured to control the operation of the pump 230 to regulate, for example, fuel flow within the subsystem 299. The first control unit 200 is configured to control the operating power of the pump 230 by adjusting the associated electric motor.

  The first control unit 200 is arranged to communicate with the second temperature sensor 280 via the link 281. The second temperature sensor 280 is configured to detect the current temperature of the exhaust duct 240. The second temperature sensor 280 is configured to continuously send a signal including information about the current temperature of the exhaust duct 240 to the first control unit 200.

  The first control unit 200 is configured to calculate the estimated current temperature Test of the dosing unit 250 based on the signal received from the second temperature sensor 280.

  The first control unit 200 is arranged to communicate with the input unit 250 via the link 251. The first control unit 200 is configured to control the operation of the charging unit 250 to adjust the fuel supply to the exhaust system of the vehicle 100, for example. According to an example, the first control unit 200 is configured to control the operation of the dosing unit 250 to adjust, for example, the return of fuel supply to the container 205.

  According to one version, the first control unit 200 provides a basis for limiting the temperature of the exhaust duct by controlling the operation of the engine, if necessary, according to one aspect of an innovative method. , Configured to use signals received from the first temperature sensor 220 and / or the second temperature sensor 280.

  Specifically, according to one version, the first control unit 200 reduces the maximum available torque of the engine output shaft, if necessary, and / or affects the EGR content of the engine. Is configured to use signals received from the first temperature sensor 220 and / or the second temperature sensor 280.

  According to one version, the first control unit 200 influences the fuel injection time of at least one cylinder of the engine, if necessary, according to one aspect of the innovative method, or at least one of the engine. It is configured to use signals received from the first temperature sensor 220 and / or the second temperature sensor 280 as a basis for affecting the ignition time of one cylinder. This can also be performed in combination with reducing the maximum available torque of the engine output shaft and / or affecting the content of the engine's EGR.

  The second control unit 210 is arranged to communicate with the first control unit 200 via the link 201. The second control unit 210 may be detachably connected to the first control unit 200. The second control unit 210 may be a control unit outside the vehicle 100. The second control unit 210 may be configured to perform innovative method steps according to the present invention. The second control unit 210 may be used to cross-load software, particularly software for using innovative methods, into the first control unit 200. Alternatively, the second control unit 210 may be arranged to communicate with the first control unit 200 via an internal network of the vehicle. The second control unit 210 has a function substantially similar to that of the first control unit 200, for example, whether there is an undesirable temperature level of the dosing unit 250 configured to supply fuel to the exhaust duct. And determining if the undesirable temperature level is present and limiting the temperature of the exhaust duct by controlling operation of the engine. The innovative method may be applied to the first control unit 200 or the second control unit 210, or both the first control unit 200 and the second control unit 210.

  According to this version, a compressed air source 260 is provided for supplying compressed air to the dosing unit 250 via the line 261. The input unit 250 is configured to finely divide the input fuel using the compressed air supply. Compressed air may also be used, at least in part, to cause the input unit to input the fuel into the exhaust duct. Compressed air may also be used, for example, from the input unit 250 to blow out any fuel that may be present inside. This may be performed during operation of the engine 150 or after the engine 150 has stopped.

  According to one version, the container 205 may be a vehicle fuel tank, in which case parts of the vehicle's existing fuel system according to the invention are utilized. According to another example, the container may be a separate container. That is, the container may not be the same as the vehicle fuel tank.

  According to one version, the input unit 250 is located immediately next to the exhaust duct of the HC input system. According to another example, the input unit 250 is provided with a passive nozzle that directly inputs the fuel into the exhaust duct through the exhaust duct.

  According to one version, the pump 230 is the same pump that normally produces fuel pressure for the injection system of the engine 150. According to another example, the pump 230 is a separate pump. That is, it is not the same pump that normally produces fuel pressure for the injection system.

  According to one example, a pre-catalyst and / or an oxidation catalyst is mounted in series with the particle filter and upstream of the particle filter.

  In accordance with one embodiment of the present invention, FIG. 3a is an HC charging system for purifying exhaust gas from the engine 150, located in thermal contact with the engine exhaust system 250. 2 is a schematic flow diagram of a method associated with an HC input system comprising an input unit for supplying fuel to an exhaust duct 240. The method includes a first step s310. Method step s301 determines whether there is an undesired temperature level of the dosing unit 250, and if it is found that the undesired temperature level exists, the exhaust duct 240 is controlled by controlling the operation of the engine. Step s360 for limiting the temperature of. The method ends after step s301.

  In accordance with one embodiment of the present invention, FIG. 3b is an HC charging system for purifying exhaust gas from the engine 150, located in thermal contact with the engine exhaust system 250, the exhaust system. 2 is a schematic flow diagram of a method associated with an HC input system comprising an input unit for supplying fuel to the exhaust duct 240 of FIG.

  The method includes a first step s310. Method step s310 includes determining the current temperature of dosing unit 250. This is done by directly measuring the current temperature adjacent to the dosing unit 250. Step s310 measures a first temperature value T1 representing the current temperature of the dosing unit 250. Following step s310, control proceeds to step s320.

  Method step s320 includes indirectly determining the estimated current temperature Test of the dosing unit 250. This is done by measuring the current temperature T2 adjacent to some other component of the HC input system other than the input unit 250. Step s310 measures the second temperature value T2 of some other component other than the dosing unit 250. The measured temperature T2 may be used to determine (calculate) the first estimated current temperature T1est of the dosing unit 250. An alternative option is to determine (calculate) the second estimated current temperature T2est of the input unit 250 by means of a calculation model with some other parameter as input value other than the temperature of one component of the HC input system. It may be. Such an input parameter may be the current load on engine 150, for example. It should also be noted that according to one version, it is possible to use only the measured temperature T1 of the dosing unit 250 to determine the maximum temperature value Tmax as follows. In some cases, it is advantageous to use both the measured temperature T1 and at least one of the estimated current temperatures T1est and T2est to determine the maximum temperature value Tmax as follows: As a result, a more robust method can be realized. Note that steps s310 and s320 may be performed substantially simultaneously or in reverse order. Following step s320, control proceeds to step s330.

  Method step s330 includes comparing the determined first temperature T1 to at least one of the estimated current temperatures T1est and T2est of the dosing unit 250. Following step s330, the process moves to step s340.

  Method step s340 includes the determined first temperature T1 and at least one estimated current temperature (T1est, T2est) of the input unit 250 as a basis for selecting the highest value among the compared values. Using the result of the comparison between This maximum temperature value is also called Tmax. Step 340 also includes determining whether an undesired temperature level of the input unit exists if the input unit is configured to supply fuel to the exhaust duct. This is done by comparing a predetermined temperature value, for example a limit value Tth such as 70 degrees Celsius or 100 degrees, depending on what type of fuel is used in the HC charging system. If Tmax is higher than or equal to Tth, it may be understood that there is an undesirable temperature level of the dosing unit. If Tmax is lower than Tth, it may be understood that there are no undesirable temperature levels in the dosing unit 250.

  According to an alternative version, as described above, it is possible to determine whether there is an undesirable temperature level of the dosing unit 250 based solely on the measured temperature T1 of the dosing unit, and as a result, one aspect of the present invention. A relatively simple method can be realized.

  Following step s340, control proceeds to step s350.

  Method step s350 includes using the selected value Tmax as a basis for determining the maximum allowable exhaust temperature Tem. The maximum allowable exhaust temperature Tem may be determined by a reference data consultation process, which associates the selected value Tmax with the maximum allowable exhaust temperature Tem, for example in tabular form. Alternatively, the maximum allowable exhaust temperature Tem may be determined by a calculation model in which the selected value Tmax is an input value. Following step s350, control proceeds to step s360.

Method step s360 includes using the determined maximum allowable exhaust temperature Tem as a basis for employing at least one measurement that affects the temperature of the exhaust flow in the exhaust duct 240. According to one version, the at least one measurement is determined by the following steps:
-Reducing the maximum available torque of the engine output shaft;
-The steps that affect the EGR content of the engine;
Affecting the fuel injection time of at least one cylinder of the engine or affecting the ignition time of at least one cylinder of the engine;
One or more dampers, for example selected from among the steps affecting the air flow of the engine by means of a throttle on the inlet side and / or outlet side of the engine.
The method ends after step s360.

  FIG. 4 is a version of the device 400. The control units 200 and 210 described with reference to FIG. 2 comprise an apparatus 400 in one version. The device 400 comprises a non-volatile memory 420, a data processing unit 410, and a read / write memory 450. The nonvolatile memory 420 includes a first memory element 430 in which a computer program for controlling the function of the device 200, for example, an operating system is stored. The apparatus 400 further includes a bus controller, a serial communication port, an I / O means, an A / D converter, a date / time input / transfer unit, an event counter, and an interrupt controller (not shown). The nonvolatile memory 420 also has a second memory element 440.

  The proposed computer program P has an undesired temperature level of the dosing unit 250 that is located in thermal contact with the engine exhaust system 250 and configured to supply fuel to the exhaust duct 240 of the exhaust system. And a routine for limiting the temperature of the exhaust duct by controlling the operation of the engine in an innovative manner if the undesirable temperature level is found to exist. Including.

  Program P includes routines to reduce the maximum available torque on the engine output shaft, if necessary, to achieve exhaust duct 240 temperature limits.

  Program P includes routines to influence the EGR content of engine 150 as needed to achieve exhaust duct 240 temperature limits.

  Program P may be used to achieve a temperature limit for exhaust duct 240, as needed, to influence the fuel injection time of at least one cylinder of engine 150, or to at least one cylinder of engine 150. Includes routines to affect ignition time.

  Program P may be stored in memory 460 and / or read / write memory 450 in executable or compressed form.

  If the data processing unit 410 is described as performing a particular function, the data processing unit 410 may be a particular part of a program stored in the memory 460 or a program stored in the read / write memory 450. Means to perform certain parts of.

  Data processor 410 can communicate with data port 499 via data bus 415. The nonvolatile memory 420 communicates with the data processing unit 410 via the data bus 412. A separate memory 460 communicates with the data processing unit 410 via the data bus 411. Read / write memory 450 is configured to communicate with data processing unit 410 via data bus 414. The data port 499 includes, for example, links 201, 221, 231, 251 and 281, which are connected to the data port 499 (see FIG. 2).

  As data is received at the data port 499, it is temporarily stored in the second memory element 440. When the received input data is temporarily stored, the data processing unit 410 executes code execution as described above. According to one version, the signal received at the data port 499 includes information about the current temperature of the input unit 250. According to one version, the signal received at data port 499 includes information about the current temperature of the exhaust flow in exhaust duct 240. According to an alternative version, the signal received at the data port 499 is the current temperature of the appropriate component of the subsystem 299, eg, the current temperature of the exhaust duct, the current temperature of the particle filter, or the HC input system. Contains information about the current temperature of the silencer. Such a signal may be used to calculate the current temperature of the dosing unit 250 according to a calculation model stored in the memory 460. The signal received at the data port 499 is used by the device 400 to determine if there is an undesirable temperature of the exhaust flow in the exhaust duct 240 and based on that determination, the desired temperature of the exhaust flow is achieved. It may affect the operation of engine 150 to be able to do so.

  Each portion of the method described herein may be performed by apparatus 400 using a data processing unit 410 that stores a program stored in memory 460 or read / write memory 450. Run. When the device 400 is executing a program, the methods described herein are performed.

  The foregoing description of preferred embodiments of the present invention is for purposes of illustration and description. This previous description is not exhaustive and does not limit the invention to the variations described. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. Each embodiment has been chosen and described in order to best illustrate the principles of the invention and the actual application of the invention, which makes it suitable for various embodiments and for the intended use. With various modifications, the expert will be able to understand the present invention.

Claims (18)

An HC charging system for purifying exhaust gas from an engine (150), which is located in thermal contact with the exhaust system (250) of the engine and supplies fuel to an exhaust duct (240) of the exhaust system A method related to an HC input system comprising an input unit for supplying,
Determining whether an undesired temperature level of the dosing unit (250) exists (s340)
Including
-Limiting the temperature of the exhaust duct (240) by controlling the operation of the engine if it is found that the undesirable temperature level exists (s360)
A method characterized by.   The method of claim 1, wherein the limitation of the temperature is achieved by reducing a maximum available torque of an output shaft of the engine (150).   The method of claim 1 or 2, wherein the limitation of the temperature is achieved by affecting the content of EGR of the engine (150).   The limitation of the temperature is achieved by affecting the fuel injection time of at least one cylinder of the engine (150) or by affecting the ignition time of at least one cylinder of the engine (150). 4. The method according to any one of claims 1 to 3, wherein:   The method of any one of claims 1 to 4, wherein the undesirable temperature level is set based on characteristics of the fuel. Determining whether an undesired temperature level of the dosing unit (250) is present comprises the following steps:
Directly measuring the temperature (T1) of the dosing unit (250);
Measuring the temperature of the exhaust stream in the exhaust duct (240);
Method according to any one of the preceding claims, based on at least one of the following: calculating the temperature of the dosing unit (250) by means of a calculation model.   7. A method according to any one of the preceding claims, wherein the fuel is diesel fuel or some other hydrocarbon based fuel. An HC charging system device for purifying exhaust gas from an engine (150), located in thermal contact with the exhaust system (250) of the engine and connected to an exhaust duct (240) of the exhaust system It has a dosing unit for supplying fuel,
Means for determining whether an undesired temperature level of the dosing unit (250) exists (200; 210; 400)
Further comprising
Means (200; 210; 400) for limiting the temperature of the exhaust duct (240) by controlling the operation of the engine if the undesirable temperature level is found to be present
A device characterized by.   The apparatus of claim 8, comprising means (200; 210; 400) for reducing the maximum available torque of the output shaft of the engine (150) to achieve the limit of the temperature.   10. Apparatus according to claim 8 or 9, comprising means for influencing the EGR content of the engine (150) to achieve the limit of the temperature.   The limitation of the temperature is achieved by affecting the fuel injection time of at least one cylinder of the engine (150) or by affecting the ignition time of at least one cylinder of the engine (150). 11. The device according to any one of claims 8 to 10, wherein:   12. Apparatus according to any one of claims 8 to 11, wherein the undesirable temperature level is set based on characteristics of the fuel. The following means:
-Means (220) for directly measuring the temperature of the dosing unit;
Means for measuring the temperature of the exhaust stream in the exhaust duct;
Device according to any one of claims 8 to 12, comprising at least one of means (200; 210; 400) for calculating the temperature of the dosing unit by means of a calculation model.   14. The apparatus according to any one of claims 8 to 13, wherein the fuel is diesel fuel or some other hydrocarbon based fuel.   A motor vehicle (100; 110) comprising the device according to any one of claims 8 to 14.   The automobile (100; 110) according to claim 15, which is one of a truck, a bus or a passenger car.   A computer program (P) associated with an HC injection system for purifying exhaust gas from an engine (150), comprising an input unit (250) for supplying fuel to an exhaust duct (240), the electronic control Program code for causing a unit (200; 400) or another computer (210; 400) connected to the electronic control unit (200; 400) to execute the steps according to any one of claims 1 to 7. Including a computer program (P).   When the computer program is executed on an electronic control unit (200; 400) or another computer (210; 400) connected to the electronic control unit (200; 400), any one of claims 1 to 7 A computer program product comprising program code stored on a computer readable medium for performing the method steps of claim.

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