JP2014145359A - Internal combustion operating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new operating method of an internal combustion engine.SOLUTION: In the method, at least one turbine (3) is arranged in an internal combustion engine (1), and exhaust gas leaving the internal combustion engine (1) can be supplied to the turbine for expansion. Energy obtained at that time is used for driving at least one compressor (2) or at least one power generator, and at least one catalyst-type exhaust gas purification device (6) is arranged in the internal combustion engine (1), and the expanded exhaust gas can be supplied to the catalyst type exhaust gas purification device or each turbine (3) for cleaning. Or, to make a quick heating process of each catalyst type exhaust gas purification device (6) sure, an adjusting variable relating to influences of a waist gate, and/or an adjusting variable relating to influences of a turbine geometry of each turbine (3) are determined according to a temperature setting value relating to exhaust gas temperature existing before each turbine (3).

Description

  The present invention relates to a method for operating an internal combustion engine according to the preamble of claim 1.

  It is known from practice that a turbine is placed after an internal combustion engine, the exhaust gas of the internal combustion engine is expanded, and the energy obtained when the exhaust gas expands is used to drive a compressor or a generator. Furthermore, it is known from practice to clean the exhaust gas of an internal combustion engine using at least one catalytic exhaust gas purification device, the exhaust gas being expanded in one or each turbine and then one or each catalytic exhaust gas. Supplied to the purification device.

  In order to ensure effective exhaust gas cleaning and concomitant minimization of exhaust gas emissions, the catalytic exhaust gas purification device must be operated at a fixed temperature. When starting the operation of the internal combustion engine that has been stopped until then, the catalytic exhaust gas purification device must be heated. The heating process for one or each catalytic exhaust gas purification device should be performed in the shortest possible time, thereby ensuring effective exhaust gas cleaning as soon as possible.

  In internal combustion engines known from practice, one or each turbine is bypassed by the influence of the wastegate of the wastegate valve in order to ensure a rapid heating process of one or each catalytic exhaust gas purification device. In the case of a turbine having a variable turbine geometry, it is common to supply exhaust gas to each catalytic exhaust gas purifier under the influence of the turbine geometry of one or each turbine.

  Here, according to practice, the adjustment variables for the influence of the wastegate (Stellgroesse) and / or the influence of the turbine geometry are determined by the controller for the heating process, i.e. one or each of the already expanded exhaust gases. It is determined according to the temperature setpoint (Sollwert) relating to the exhaust gas temperature present after the turbine.

  With the above as a starting point, an object of the present invention is to provide a new operating method of an internal combustion engine.

  This problem is solved by the operation method of the internal combustion engine according to claim 1. According to the invention, in order to ensure a rapid heating process of one or each catalytic exhaust gas purification device, there are adjustment variables relating to the influence of the waste gate and / or adjustment variables relating to the influence of the turbine geometry of one or each turbine. , Depending on the temperature setpoint for the exhaust gas temperature that is present in front of one or each turbine of the exhaust gas that has not yet expanded.

  In accordance with the present invention, in order to ensure a rapid heating process of one or each catalytic exhaust gas purification device, the adjustment variables relating to the influence of the wastegate and / or the adjustment variables relating to the influence of the turbine geometry are set to the exhaust gas that has not yet expanded It is proposed for the first time to determine in dependence on the temperature setpoint for the exhaust gas temperature present in front of one or each turbine. This has the advantage over one known from practice that one or each catalytic exhaust gas purification device can be heated to its defined operating temperature faster. Therefore, the catalytic exhaust gas purification device can be used more quickly for cleaning the exhaust gas. The wastegate valve can be closed earlier and / or the turbine geometry can be affected earlier so that more power is obtained earlier in one or each turbine. . Overall, this makes it possible to increase the overall efficiency of the internal combustion engine.

  In principle, the heating process of the catalytic exhaust gas purification device can be performed selectively or in combination, for example with additional actuators, such as actuating elements, to bypass one or each turbine at high or low temperatures (cooled). In the form of jetting the supply air into the exhaust gas, or in the form of a high or low temperature (cooled) engine bypass from the supply air into the exhaust gas, or in the high or low temperature (cooled) compressor bypass In form, it is influenced. It has not yet been claimed here to apply the control strategy to the actuator as well, as explained with respect to the effects of wastegate and / or turbine geometry.

  According to a first advantageous further configuration, a load-dependent temperature setpoint is used for the exhaust gas temperature present in front of one or each turbine. This temperature set value is compared with the corresponding measured temperature value, and the controller adjusts the waste gate effect and / or turbine geometry effect variable depending on the difference between the temperature set value and the measured temperature value. To decide.

  By using a temperature set value that depends on the load, it becomes possible to implement the present invention by complying with the exhaust gas dust allowable limit value and complying with the maximum component temperature using a particularly simple means. The load-dependent temperature setpoint curve in relation to the exhaust gas temperature present in front of one or each turbine can be parameterized with little effort.

  According to a second alternative advantageous further configuration, a load independent temperature setpoint relating to the exhaust gas temperature present in front of one or each turbine is used together with the exhaust gas dust setpoint or lambda setpoint, Is compared with the actual measured temperature value, and the exhaust gas dust set value is compared with the exhaust gas dust actual value, or the lambda set value is compared with the lambda actual measured value, and the controller depends on the corresponding difference. An adjustment variable for wastegate effects and / or an adjustment variable for turbine geometry effects is determined.

  In addition, if there is an exhaust gas sensor or lambda sensor, it is also possible to use a temperature setpoint that does not depend on the load, by using the measured value of the exhaust gas dust sensor and / or by using the measured value of the lambda sensor. Compliance with the exhaust gas dust tolerance limits can be ensured.

  Preferably, when the measured temperature of the catalytic exhaust gas purification device of one or each catalytic exhaust gas purification device reaches the set temperature of the catalytic exhaust gas purification device, the temperature setting value relating to the exhaust gas temperature existing in front of one or each turbine From dependent control, control is switched to temperature-dependent control over the exhaust gas temperature present after one or each turbine. When the catalytic exhaust gas purification device reaches the set temperature of the catalytic exhaust gas purification device, the heating process ends.

  The invention further relates to a controller for an internal combustion engine having means for carrying out the method according to the invention.

  Preferred further configurations of the invention will become apparent from the subclaims and the following description. Embodiments of the present invention will be described in detail with reference to the drawings, but are not limited thereto. The following figure is shown.

It is the schematic of the internal combustion engine provided with exhaust gas supercharging and exhaust gas cleaning. 1 is a diagram for clarifying the method according to the invention for operating an internal combustion engine.

  FIG. 1 is a schematic block diagram of an internal combustion engine 1 equipped with exhaust gas supercharging and exhaust gas cleaning. The internal combustion engine 1 has a plurality of cylinders 2 in which the fuel mixture burns. The exhaust gas leaving the internal combustion engine 2 can be supplied to the turbine 3 of the exhaust gas turbocharger 4, and the exhaust gas expands in the turbine 3. The energy obtained at this time is used to drive the compressor 5 of the exhaust gas turbocharger 4, whereby the supply air to be supplied to the internal combustion engine 1 is compressed.

  In addition to the exhaust gas supercharging provided by the exhaust gas turbocharger 4, the internal combustion engine shown in FIG. 1 includes exhaust gas cleaning, and the internal combustion engine has a catalytic exhaust gas purification device 6 for this purpose. The catalytic exhaust gas purification device 6 can be supplied with the exhaust gas expanded in the turbine 3 of the exhaust gas turbocharger 4 for cleaning.

  According to FIG. 1, the exhaust gas leaving the internal combustion engine 1 passes by the side of the turbine 3 through the bypass 7. That is, depending on the opening position of the waste gate valve 8 incorporated in the bypass 7. When the waste gate valve 8 is closed, the entire exhaust gas is guided to the internal combustion engine 1 through the turbine 3 of the exhaust gas turbocharger 4.

  Further, FIG. 1 shows a temperature sensor 9 disposed in the catalytic exhaust gas purification device 6, and the measured temperature of the catalytic exhaust gas purification device 6 can be grasped using the temperature sensor.

  The internal combustion engine 1 shown in FIG. 1 further includes a temperature sensor 10 located upstream of the turbine 3 of the exhaust gas turbocharger 4, thereby measuring the exhaust gas that has not yet expanded upstream of the turbine 3. The temperature is grasped.

  Further, the internal combustion engine 1 shown in FIG. 1 is provided with a temperature sensor 12 located downstream of the turbine 3 of the exhaust gas turbocharger 4, thereby grasping the actually measured temperature of the expanded exhaust gas downstream of the turbine 3. Is done.

  It has already been pointed out here that the internal combustion engine 1 shown in FIG. 1 is an example.

  Unlike the illustrated embodiment, the internal combustion engine may have a multi-stage exhaust gas supercharger equipped with at least two exhaust gas turbochargers.

  Furthermore, a turbine in which the exhaust gas of the internal combustion engine expands can drive a generator for generating electrical energy.

  In the illustrated embodiment, the turbine 3 of the exhaust gas turbocharger 4 is a turbine 3 having a turbine geometry that cannot be changed. On the other hand, it is also possible to use a turbine 3 with a changeable turbine geometry.

  For the catalytic exhaust gas purification device 6 of the internal combustion engine 1 shown in FIG. 1, a heating phase to the operating temperature in the shortest possible time is ensured, so that, for example, after the internal combustion engine 1 is started, the catalyst In order to ensure that the exhaust gas purification device 6 can ensure effective exhaust gas cleaning in as short a time as possible, the adjustment relating to the influence of the wastegate is made according to the temperature setting value relating to the exhaust gas temperature existing in front of the turbine 3 It is proposed to determine a variable, preferably an adjustment variable relating to the influence of the opening position of the wastegate valve 8.

  Accordingly, FIG. 1 shows a controller 11 that receives the measured value of the temperature sensor 10. The temperature sensor 10 grasps the measured temperature of the exhaust gas that has not yet expanded before the turbine 3. The controller 11 determines an adjustment variable for the wastegate valve 8 according to the measured temperature of the exhaust gas upstream of the turbine 3 and according to the corresponding temperature setting in the embodiment of FIG. The heating process of the catalytic exhaust gas purification device 6 as fast as possible is ensured.

  If the turbine 3 has a changeable turbine geometry, the controller 11 can alternatively or additionally determine a corresponding tuning variable for the influence of the turbine geometry of the turbine 3. That is, according to the actual temperature value calculated by the temperature sensor 10 and according to the temperature setting value stored in the controller 11 regarding the exhaust gas temperature upstream of the turbine 3.

  When the catalytic exhaust gas purification device 6 reaches its operating temperature, that is, when the measured temperature of the catalytic exhaust gas purification device matches the set temperature of the catalytic exhaust gas purification device, the temperature related to the exhaust gas temperature existing in front of the turbine 3 The control depending on the set value is switched to the control depending on the temperature set value relating to the exhaust gas temperature existing after one or each turbine 3.

  FIG. 2 illustrates this in a time diagram. That is, FIG. 2 shows different temperature transitions T over time t. The temperature transition T10 corresponds to the actually measured temperature of the exhaust gas before the turbine 3 measured using the temperature sensor 10, and T-SOLL10 corresponds to the corresponding temperature setting value. The temperature transition T12 corresponds to the actually measured exhaust gas temperature after the turbine 3 measured using the temperature sensor 12, and the T-SOLL 12 corresponds to the corresponding temperature setting value. The temperature transition T9 corresponds to the actually measured temperature of the catalytic exhaust gas purification device 6 measured using the temperature sensor 9, and T-SOLL9 corresponds to the set temperature of the catalytic exhaust gas purification device.

  Before the time point t1, that is, the time point when the catalytic exhaust gas purification device 6 is heated, the control relating to the exhaust gas temperature upstream of the turbine 3 is performed. The controller 11 determines an adjustment variable related to the waste gate valve 8 according to the exhaust gas measured temperature T10 before the turbine and the corresponding set value T-SOLL10.

  When the temperature T9 of the catalytic exhaust gas purification device 6 reaches the operating temperature or the set value T-SOLL9 at the time point t1, the control is switched, and the exhaust gas measured temperature T12 after the turbine and the corresponding time start from the time point t1. Control based on temperature set value T-SOLL12 is performed.

  According to a first advantageous further configuration of the invention, the controller 11 stores a temperature setpoint T-SOLL 10 depending on the load for the heating process of the catalytic exhaust gas purification device 6. Depending on the load when the internal combustion engine 1 is driven during the heating process, the controller 11 stores a temperature setpoint T-SOLL10 depending on the corresponding load relating to the exhaust gas temperature T10 present in front of the turbine 3. Has been. This temperature set value T-SOLL10 is compared with the measured actual temperature value T10, and the controller 11 determines the waste according to the difference between the load-dependent temperature setpoint T-SOLL10 and the measured actual temperature value T10. An adjustment variable relating to the influence of the waste gate of the gate valve 8 is determined.

  At this time, the controller 9 stores a temperature setpoint curve which is determined empirically, preferably depending on the load. The following table is an exemplary load-dependent temperature setpoint curve. From this table, it is understood that the same temperature set value T-SOLL10 is stored when the engine load is 45% or more of the total load. Therefore, the temperature setpoint curve depending on the load relating to the exhaust gas temperature T10 existing upstream of the turbine 3 can be parameterized with little effort and determined empirically with little effort. This is because the same temperature setting value T-SOLL10 is used for an engine load of 45% or more of the total engine load.

  By determining the temperature setting value depending on the load, the exhaust gas dust allowable limit value is observed and the component allowable maximum temperature is observed with a small amount of parameterization effort. It is possible to ensure the heating process.

  By means of the present invention, high efficiency of the internal combustion engine can be ensured by simple means. Since the catalytic exhaust gas purification device 6 can be efficiently heated to the operating temperature in a short time, effective exhaust gas cleaning in a short time is ensured. Since the catalytic exhaust gas purification device 6 is heated to the operating temperature in a short time, the waste gate valve 8 is closed relatively early, and more exhaust gas is passed through the turbine 3 of the exhaust gas turbocharger 4 to increase efficiency. Can be guided to do.

  In the alternative further configuration of the present invention, it is particularly easy and preferable to have the controller 11 memorize the load-dependent temperature setpoint for the heating process of the catalytic exhaust gas purification device 6. The controller 11 can also store a temperature set value T-SOLL 10 that does not depend on the load, regarding the exhaust gas temperature upstream of the turbine 3. In this case, preferably an exhaust gas sensor is installed downstream of the catalytic exhaust gas purification device 6 and / or a lambda sensor is installed in the region of the internal combustion engine 1, whereby the exhaust gas dust measured value and / or Lambda actual measurement value is grasped. The actual exhaust gas dust value can be compared with the exhaust gas dust set value stored in the controller 11 and / or the actual lambda actual value can be compared with the lambda set value stored in the controller. The controller 11 is configured according to a control deviation between the actual temperature measured value and the temperature set value, and between the actual lambda measured value and the lambda set value, or between the actual exhaust gas dust measured value and the exhaust gas dust set value. The control variable relating to the influence of the waste gate valve 8 is determined according to the control deviation.

  As already mentioned, the invention can also be used when the wastegate valve 8 is not present and a turbine 3 having a changeable turbine geometry is used. In this case, the controller 11 determines a control variable relating to the influence of the turbine geometry.

  Similarly, it is possible to determine control variables related to wastegate effects in addition to turbine geometry effects. Here, a turbine 3 having a changeable turbine geometry is used with a wastegate valve 8.

  As already mentioned, the present invention is preferably used to drive an internal combustion engine, in particular a marine diesel internal combustion engine driven by heavy oil. The catalytic exhaust gas purification device 6 is preferably an SCR-catalyst exhaust gas purification device. The operating temperature of the catalytic exhaust gas purification device 6 is such that the urea aqueous solution is used for cleaning the exhaust gas in the SCR-catalyst exhaust gas purification device. Corresponds to the temperature that can be introduced.

  In contrast, the present invention can also be used in stationary internal combustion engines, particularly when exhaust gas flow is used to generate electrical energy through a generator driven by a turbine 3.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder 3 Turbine 4 Exhaust gas turbocharger 5 Compressor 6 Catalytic exhaust gas purification device 7 Bypass 8 Waste gate valve 9 Temperature sensor 10 Temperature sensor 11 Controller 12 Temperature sensor

Claims (8)

A method for operating an internal combustion engine (1), comprising:
The internal combustion engine (1) is provided with at least one turbine (3), and the turbine can be supplied with exhaust gas leaving the internal combustion engine (1) in order to expand the exhaust gas. Yes,
The energy obtained at this time is used to drive at least one compressor (2) or at least one generator,
The internal combustion engine (1) is provided with at least one catalytic exhaust gas purification device (6). The catalytic exhaust gas purification device expands in the turbine (3) for cleaning exhaust gas. Exhaust gas can be supplied,
In order to ensure a rapid heating process of the catalytic exhaust gas purification device (6), the influence of the wastegate bypasses the turbine (3) and / or the influence of the turbine geometry of the turbine (3) In response, the exhaust gas is supplied to each of the catalytic exhaust gas purification devices (6),
In order to ensure a rapid heating process of the catalytic exhaust gas purification device (6), an adjustment variable relating to the influence of the wastegate and / or an adjustment variable relating to the influence of the turbine geometry of the turbine (3) may be applied to the turbine (3 ) Is determined according to the temperature setpoint (T-SOLL10) relating to the exhaust gas temperature present before. A load-dependent temperature setpoint (T-SOLL10) is used for the exhaust gas temperature present in front of the turbine (3),
The temperature setting value (T-SOLL10) is compared with the corresponding temperature measurement value (T10), and the controller (11) determines the difference between the temperature setting value (T-SOLL10) and the temperature measurement value (T10). The method according to claim 1, further comprising determining an adjustment variable related to the influence of the wastegate and / or an adjustment variable related to the influence of the turbine geometry.   3. A method according to claim 2, characterized in that the load-dependent temperature setpoint curve is determined empirically. For the exhaust gas temperature present in front of the turbine (3), a temperature independent setpoint (T-SOLL10) independent of the load is used together with the exhaust gas dust setpoint or lambda setpoint,
The temperature set value (T-SOLL10) is compared with the temperature measured value (T10), and the exhaust gas dust set value is compared with the exhaust gas dust measured value, or the lambda set value is compared with the lambda measured value,
The method of claim 1, wherein the controller determines an adjustment variable for the wastegate effect and / or an adjustment variable for the turbine geometry effect in response to a corresponding difference.   In particular, when the catalytic exhaust gas purification device measured temperature (T9) of the catalytic exhaust gas purification device (6) reaches the catalytic exhaust gas purification device set temperature (T-SOLL9), it exists before the turbine (3). The exhaust gas temperature is switched from the control depending on the temperature set value (T-SOLL10) to the control depending on the temperature set value (T-SOLL12) regarding the exhaust gas temperature existing after the turbine (3). The method according to any one of claims 1 to 4. The method is used for operating an internal combustion engine (1), in particular a marine diesel internal combustion engine driven by heavy oil,
The turbine (3) is a component of at least one exhaust gas turbocharger (4);
The energy obtained in the turbine (3) is used to drive the compressor (5) of each exhaust gas turbocharger (4) and thereby the combustion air to be supplied to the internal combustion engine (1). The method according to any one of claims 1 to 5, characterized in that the supply pressure increases. The method is used to operate a stationary internal combustion engine,
6. The energy obtained in the turbine is used to drive at least one generator, thereby generating electrical energy. Method.   A controller for an internal combustion engine comprising means for carrying out the method according to any one of the preceding claims.