KR20140091057A - Diesel engine arrangement and method for varnish build-up control - Google Patents

Abstract

A method for controlling varnish reinforcement in a variable geometry turbine of a diesel engine turbocharger is provided. According to the method, it is determined whether the operating parameter is at an established level for initiating a varnish enriched control sequence. When the operating parameter is at an established level, a varnish enrichment control sequence is initiated. The sequence includes the steps of increasing the exhaust temperature upstream of the variable shape turbine to a first exhaust temperature and increasing the exhaust temperature upstream of the variable shape turbine to a first exhaust temperature, And changing the opening size of the turbine nozzle. Diesel engine arrangements are also provided.

Description

TECHNICAL FIELD [0001] The present invention relates to a diesel engine arrangement and a method for controlling varnish reinforcement,

The present invention relates to a method for varnish enrichment control in a variable geometry turbine (VGT) of a diesel engine turbocharger and to a diesel engine arrangement.

Varnishes are unwanted, generally glossy films, which contain predominantly unburned hydrocarbons. In diesel engines with turbochargers, this condition sometimes results from incomplete combustion in relatively cold engine cylinders. Semi-fired fuel tends to cure on the turbo nozzle, causing the fuel to stick, and typically requires replacement of the turbocharger.

In conventional diesel engines, it is known to periodically cycle the variable shape turbine nozzle through the open and closed positions to facilitate removal of the reinforcing soot. It is also known to perform "heat mode" operations designed to increase the exhaust gas temperature to facilitate cleaning, regeneration, or heating of exhaust after-treatment components such as diesel oxidation catalysts and diesel particulate filters . It has also been found that it may be beneficial to heat the exhaust temperature periodically to facilitate soot removal and soot deposits to occur during an at idle expansion operation at low temperatures. However, these operations usually do not prevent or remove varnish hardening.

It is therefore desirable to provide a method for removing the varnish reinforcement. It is also desirable to provide diesel engine arrangement settings to facilitate control of varnish reinforcement.

According to one aspect of the present invention, a method for controlling varnish reinforcement in a variable geometry turbine of a diesel engine turbocharger is provided. According to the method, it is determined whether the operating parameter is at an established level for initiating a varnish enriched control sequence. When the operating parameter is at an established level, a varnish enrichment control sequence is initiated. The sequence includes the steps of increasing the exhaust temperature upstream of the variable shape turbine to a first exhaust temperature and increasing the exhaust temperature upstream of the variable shape turbine to a first exhaust temperature, And changing the opening size of the turbine nozzle.

In accordance with another aspect of the present invention, a diesel engine arrangement includes a diesel engine, a turbocharger including a variable geometry turbine downstream of the engine, an operational parameter for establishing varnish enrichment control sequences to control varnish consolidation on the variable geometry turbine, And a controller arranged to initiate a varnish enrichment control sequence when the determining means determines that the operating parameter is at an established level. The varnish enrichment control sequence includes increasing the exhaust temperature upstream of the variable geometry turbine to a first exhaust temperature and increasing the exhaust temperature to a first exhaust temperature, And changing the opening size of the first opening.

The features and advantages of the present invention will be better understood by the following detailed description when taken in conjunction with the drawings in which like numerals represent like elements.
1 is a schematic diagram of a diesel engine arrangement according to an aspect of the present invention.
2 is a flow chart illustrating the steps of a method for varnish enforcement control in accordance with another aspect of the present invention.

1 schematically shows a diesel engine arrangement 21 according to an aspect of the present invention. The arrangement 21 includes a diesel engine 23 and a turbocharger 25, which includes a variable geometry turbine 27 downstream of the engine. Means are provided for determining whether an operational parameter is present at an established level for initiating a varnish enrichment control sequence. The specific means depends on what operating parameters are. The operating parameter may be a function of several distinct parameters, such as an engine operating parameter or a parameter based on modeling, and may include some distinct parameter sensors, estimates, or decisions. The controller 29 is arranged to initiate the varnish enrichment control sequence when the determining means determines that the operating parameters are located at the established level.

The varnish enrichment control sequence includes increasing the exhaust temperature upstream of the variable geometry turbine 27 to a first exhaust temperature and increasing the exhaust temperature upstream between the maximum opening (100%) and maximum closing (0%) opening size, Between a small opening size and a large opening size in relation to the step of increasing the exhaust temperature to the first exhaust temperature, such as by moving the vanes of the variable shape turbine between some of the positions of the variable- And changing the nozzle opening size of the variable shape turbine nozzle 33 (shown schematically in FIG. By describing the change in nozzle opening as an "associated " open size with an increase in exhaust temperature, the nozzle opening size change at different times, such as increasing temperature, or after each or every temperature increase, can be performed simultaneously , It is contemplated that there is a flexible relationship between the change in nozzle opening size and the increase in exhaust temperature, particularly with respect to the varnish enrichment control sequence.

The change in nozzle opening size and the increase in exhaust temperature executed during the "varnish enrichment control sequence " may also occur in association with each other during the engine operation, or may be a change in the nozzle opening size, which is related to one another but not to a particular sequence for varnish enrichment control And the increase in exhaust temperature. For example, the closing of the variable shape turbine nozzle opening may cause an increase in the exhaust temperature upstream of the variable shape turbine, but these two steps determine whether the operating parameter is at an established level for initiating the varnish enrichment control sequence It will not be executed in relation to each other as steps of the varnish enforcement control sequence.

Without wishing to be bound by theory, when implemented with a variable shape turbine of the type having movable vanes, the change in opening size generally has the effect of scratching the surfaces of the variable shape turbine and removing the varnish or sooty precipitate. Increasing the temperature upstream of the variable geometry turbine may facilitate combustion of the hydrocarbons of the exhaust stream, depending on the temperature, thus preventing the hydrocarbons from forming varnish deposits on components of the variable shape turbine, Lt; RTI ID = 0.0 > turbine < / RTI > components such as turbine blades. The increase in temperature may be achieved by any of the methods previously used during "heated mode" operation of the type used to heat, regenerate, or wash the diesel oxidation catalyst (DOC), diesel particulate filter (DPF), or selective catalytic reduction It can be executed using the same equipment and the same technology. A temperature rise of at least about 175 DEG C upstream of the variable geometry turbine serving to prevent varnish deposits is known to be useful and serves to remove the varnish deposits that otherwise convert or otherwise convert the precipitate to soot, Temperature increases are known to be useful.

The operating parameters at which the varnish enrichment control sequence is executed typically include one or more parameters indicating the likelihood of varnish enrichment or varnish enrichment. Examples of operating parameters include the measured level of varnish reinforcement, the actual level of varnish reinforcement, the force required to change the nozzle opening size in the variable shape turbine, the duration of engine operation, the duration of engine operation in idle, , Incomplete hardware detection, cylinder temperature, intake manifold temperature, injection pressure. The operating parameters, such as the force required to change the nozzle opening size in the variable shape turbine, may reflect the effect of the varnish enhancement and the means for determining whether the operating parameter is at an established level for initiating the varnish enriched control sequence may, for example, Such as an electrical sensor 35, such as an ammeter, a voltmeter, or other sensors conventionally used to measure the power driven by a motor while attempting to move the vanes of a variable shape turbine, . Operating parameters such as duration of engine operation, duration of engine operation in idle, ambient temperature, and engine coolant temperature may be parameters that tend to function as causes and factors related to varnish enrichment, The means for determining whether the control sequence is present at an established level for initiating the control sequence may be a thermometer or a temperature sensitive switch 39 and timers 41. The operating parameters, such as the actual level of varnish enhancement, may be based on direct observation or measurement, and the means for determining whether an operating parameter is present at an established level for initiating a varnish enriched control sequence may be used, It may be a device that allows direct or indirect measurement or observation. Operational parameters, such as the measured level of varnish enhancement, for example, may be used to calculate varnish enhancement as a function of other parameters that may be actual measured parameters, such as those that tend to cause varnish enhancement or that are related to varnish enhancement , And the means for determining whether an operating parameter is present at an established level for initiating a varnish enriched control sequence may be based on any means used to determine the level of actual parameters, , Thermometers, temperature switches, timers, sensors that provide different signals when the sensors are covered with different amounts of varnish, and / or cameras. Operating parameters, such as incomplete hardware, may include incomplete fuel injection, and those that tend to be associated with "fuel leaks" such as incomplete sensors. The operating parameters, such as the cylinder temperature, may include a determination that the cylinder is relatively cold, which may lead to a varnish or reflect a varnish. Operating parameters such as cold intake manifold and low injection pressure are also parameters that can lead to or reflect varnish.

The controller 29 may be arranged to increase the exhaust temperature to a first exhaust temperature by one or more techniques. The controller 29 can reduce the opening size of the variable shape turbine nozzle or delay the fuel injection timing so that the fuel injection nozzle 45 can control the operation of the fuel injection nozzle 45, By reducing the fuel injection pressure that controls the operation, the exhaust temperature can be increased by increasing the speed of the engine 23 and injecting it through the seventh injector 49.

The varnish enforcement control sequence is used for the purpose of reducing or eliminating the varnish enhancement generated, or for the purpose of preventing varnish enhancement, or for the purpose of reducing or eliminating the varnish enrichment generated and for preventing varnish enrichment Function. The varnish enrichment control sequence, which may be implemented to prevent varnish enrichment, includes increasing the exhaust temperature upstream of the variable geometry turbine 27 to a different first exhaust temperature, and adjusting the varnish enrichment, which may be performed to reduce or eliminate varnish enrichment The opening size of the variable shape turbine nozzle between a small opening size and a large opening size with respect to increasing the exhaust temperature to a first exhaust temperature for different degrees, different ratios, or different numbers of strokes than the control sequence And < / RTI > Consequently, under some circumstances, a varnish hardening may occur despite the operation of the varnish hardening control sequence intended to prevent varnish hardening, in which case the varnish hardening, which is intended to reduce or eliminate varnish hardening, It may be necessary to initiate an enhanced control sequence.

To this end, a determining means such as the electric sensor 35 can continuously monitor the force required to change the opening size of the nozzle 33 in the variable shape turbine 27. [ The controller 29 is configured to control the exhaust temperature from a second, lower exhaust temperature through a sufficient number of temperature cycles, which may include maintaining the exhaust temperature at a first exhaust temperature for a predetermined length during each cycle, The number of nozzles of the variable shape turbine 27 between the small opening size and the large opening size in a sufficient number of times so that the force required to change the nozzle opening size in the variable shape turbine is present below the predetermined value 33). ≪ / RTI > Nevertheless, for events exceeding a predetermined value, where the force required to change the nozzle opening size in the variable shape turbine 27 may be the result of a varnish enhancement, the varnish enrichment control sequence may function as an enhancement reduction or removal mechanism can do. In the intensification reduction or elimination mode, the controller 29 determines a first exhaust temperature and a sufficient number of temperature cycles, which may be the first exhaust temperature, which is the highest of the first temperature at which the exhaust gas is raised to attempt to prevent varnish buildup Between a small opening size and a large opening size in sufficient number of times so that the force required to change the nozzle opening size in the variable shape turbine is present below a predetermined value, And a change in the opening size of the nozzle of the variable shape turbine.

Figure 2 is a flow chart illustrating the basic steps in a method for controlling varnish consolidation in a variable geometry turbine 27 of a diesel engine turbocharger 25. The first step 100 includes determining whether the operational parameter is at an established level for initiating a varnish enriched control sequence. If the operating parameter is not at an established level (i.e., "NO"), the operating parameter is monitored continuously or periodically to determine whether the operating parameter is changed and is present at the established level do. The second step 200 includes initiating a varnish enforcement control sequence in response to determining that an operational parameter is present at the established level. The sequence includes a step of increasing the exhaust temperature upstream of the variable geometry turbine 27 to a first exhaust temperature and a step of increasing the exhaust temperature to the first exhaust temperature, And changing the nozzle opening size of the nozzle 33. In response, the operating parameters at which the varnish enrichment control sequence is executed are generally determined from the measured level of varnish enrichment, the actual level of varnish enrichment, the force required to change the nozzle opening size in the variable shape turbine, the duration of the engine operation, One or more parameters that indicate the likelihood of varnish enrichment or varnish enrichment such as one or more of the duration of operation, ambient temperature, and engine coolant temperature.

The method generally includes circulating between a first exhaust temperature and a second, lower exhaust temperature through a plurality of temperature cycles. The first exhaust temperature is typically the temperature that is currently selected to be at least about 175 degrees Celsius, the temperature selected for the purpose of preventing varnish deposition, or the temperature of at least about 3505 degrees Celsius, so that the varnish deposit changes into soot pieces The temperature may be selected for the purpose. A second, low exhaust temperature is generally produced through certain engine operations that are problematic under certain ambient conditions, such as engine operation under heavy engine load or idling, and / or high or low ambient temperature and pressure. Lt; / RTI > The exhaust temperature may be controlled by equipment conventionally used to perform "heating mode" operations used to heat, regenerate, or clean engine exhaust aftertreatment components, or other techniques known as ≪ / RTI >

The length of time that the temperature is maintained at the first temperature and the length of time at the second low temperature between any successive cycles is the time required for effective varnish enrichment control in a given engine operation in a particular mode of operation, Lt; RTI ID = 0.0 > length. ≪ / RTI > The effect of any heat cycle on other exhaust equipment or engine operation will also generally be considered in selecting the length of time the temperature is maintained at the first or second temperature.

The open size of the nozzles 33 of the variable shape turbine 27 may be varied between the temperature cycles, after circulating the exhaust temperature through a plurality of temperature cycles, or between a small opening size and a large opening size can be changed. The open size of the nozzle 33 can be cycled between a small opening size and a large opening size through a plurality of development opening and closing cycles. The open size of the nozzle 33 of the variable shape turbine 27 can be varied between 0% and 100% open size, although the open size may be changed to some other open sizes smaller than full close or full open (And, if appropriate, come back).

The varnish enrichment control sequence, which is known to be particularly effective in preventing varnish enhancement, includes maintaining the open size of the nozzle 33 at a predetermined open size when the engine coolant temperature is above a predetermined engine coolant temperature. For example, in certain types of engines, the variable geometry turbine may be configured such that the coolant temperature reaches the maximum temperature (such as 80 DEG C) to facilitate warm-up of the engine when the coolant temperature is above 60 DEG C It may remain open until. However, particularly at cold ambient temperatures, with variable turbine openings, the cooling water temperature may reach little or no reaching high temperatures and the exhaust temperatures may be relatively low, which tends to cause formation of varnish deposits Can be. The inventors of the present invention have found that it is useful to maintain the open size of the nozzle in such vehicles at an open size of 3.6% of the maximum open size when the coolant temperature is higher than 60 DEG C and lower than 80 DEG C to facilitate prevention of varnish hardening I found the fact. It is anticipated that the most useful opening size and coolant temperature for preventing varnish hardening will vary depending on different engine types, operating modes, and ambient operating conditions.

Another varnish enriched control sequence, which is known to be particularly effective in preventing varnish enhancement, is a combination of an ambient temperature at a predetermined ambient temperature or an ambient temperature lower than a predetermined ambient temperature, and a period of operation or a predetermined period of time at a predetermined length of time Lt; RTI ID = 0.0 > length of operation. ≪ / RTI > For example, it has been observed that operation of certain organ shapes at ambient temperatures of about 15 DEG C for extended periods of time has caused varnish hardening. The inventors of the present invention have found that it is useful to initiate a varnish enrichment control sequence after operation at these low temperatures after a certain length of time, such as four hours. The varnish enrichment control sequence may include circulating the exhaust temperature between a first exhaust temperature and a second, low exhaust temperature through a plurality of temperature cycles.

Another varnish enriched control sequence known to be particularly effective in preventing varnish enrichment includes operational parameters that include the actuation of the engine in extended revolutions for a predetermined length of time. For example, the inventors of the present invention have found that, for certain organ types, it may be useful to prevent varnish consolidation by initiating a varnish enrichment control sequence when determining that an organ is to operate in extended orbit for half an hour . In contrast, for this same type of engine, the algorithm automatically initiates variable shape turbine circulation (without increasing temperature) after one hour of extended idle as a soot tightening control strategy.

The ultimate goal of the varnish enrichment control sequence for controlling the varnish in the variable shape turbine is that the proper operation of the variable shape turbine, especially the ability of the vanes in the variable shape turbine to open and close the nozzle, is not affected by varnish reinforcement. In a given situation, the varnish enrichment control sequence typically includes circulating the exhaust temperature between the first exhaust temperature and the second, low exhaust temperature through a sufficient number of temperature cycles and changing the nozzle opening size in the variable shape turbine Changing the opening size of the nozzle (33) of the variable shape turbine (27) between a small opening size and a large opening size in sufficient number of times so that the required force is below a predetermined value will be. This includes measuring the required force, such as by electrical sensors 35, and initiating the varnish enrichment control sequence as the required force rises above the normal level, and as part of the varnish enforcement prevention scheme Repeating the heating and / or opening size change cycle until the force to restore the normalized level to the normal level, or initiating the varnish enrichment control sequence when the required force rises above an acceptable level, And repeating the heating and / or opening size change cycle until the required force is recovered to an acceptable level as part of the removal mode.

In the context of the present application, the use of terms such as " including "is intended to be broadly open and is intended to have the same meaning as the term "comprising" and does not exclude the presence of other structures, . Similarly, the use of terms such as " can or may "are intended to be inclusive and open-ended and to reflect things that structural materials or actions are not necessarily required, It is not intended to reflect what actions are necessary. To some extent, such structures, materials, or actions are now considered essential and are thus identified. While the present invention has been shown and described with respect to preferred embodiments, it should be understood that variations and modifications may be made therein without departing from the scope of the invention as set forth in the claims.

21: Diesel Engine Arrangement
23: Diesel engine
25: Turbocharger
27: Variable shape turbine
29:
33: Variable shape turbine nozzle
35: Electric sensor
39: Temperature Sensitive Switch
41: Timer
43: Camera
45: Fuel injection nozzle
47: Fuel injection pump
49: Seventh Injector

Claims (20)

Determining if an operational parameter is present at an established level for initiating a varnish enforcement control sequence; And
And when the operating parameter is at an established level, initiating the varnish enrichment control sequence, wherein the operating parameter includes: increasing the exhaust temperature upstream of the variable turbine to a first exhaust temperature, And changing the opening size of the variable shape turbine nozzle between a small opening size and a large opening size with respect to increasing the exhaust temperature upstream of the variable shape turbine to a first exhaust temperature Wherein the method comprises the steps of: providing a turbocharger with a variable geometry turbine;
2. The method of claim 1 wherein the operating parameters include at least one of a measured level of varnish enhancement, an actual level of varnish enhancement, a force required to change a nozzle opening size in the variable shape turbine, a duration of the engine operation, Wherein the method comprises one or more of: ambient temperature and engine coolant temperature; detection of incomplete hardware; cylinder temperature; intake manifold temperature; injection pressure.
The method of any one of claims 1 to 2, comprising circulating the exhaust temperature between the first exhaust temperature and a second, low exhaust temperature through a plurality of temperature cycles / RTI >
4. The method according to any one of claims 1 to 3, comprising changing the opening size of the variable shape turbine nozzle between the small opening size and the large opening size after circulation of the exhaust temperature through a plurality of temperature cycles Wherein the method further comprises the steps of:
5. The method according to any one of claims 1 to 4, comprising changing the opening size of the variable shape turbine nozzle between the small opening size and the large opening size through a plurality of nozzle opening and closing circulation Gt; to < / RTI >
A method for controlling varnish reinforcement according to any one of claims 1 to 5, wherein the first exhaust temperature is a temperature sufficient to cause the enriched varnish on the variable shape turbine to turn into soot pieces .
7. A method according to any one of claims 1 to 6, wherein the first exhaust temperature is about 175 DEG C or higher.
8. A method according to any one of claims 1 to 7, wherein the first exhaust temperature is about 350 占 폚 or higher.
8. A method according to any one of claims 1 to 8, comprising maintaining the exhaust temperature at the first exhaust temperature for a predetermined length of time.
A method according to any one of claims 1 to 9, comprising changing the opening size of the variable shape turbine nozzle between 0% and 100% open size.
11. A varnish reinforcement according to any one of claims 1 to 10, characterized in that it comprises the step of maintaining said open size of said variable shape turbine nozzle to a predetermined opening size when said engine cooling water temperature is above a predetermined engine cooling water temperature / RTI >
12. The method according to any one of the preceding claims, wherein the operating parameter is selected from the group consisting of an ambient temperature at a predetermined ambient temperature or an ambient temperature lower than a predetermined ambient temperature, and a period of operation or a predetermined period of time at a predetermined length of time Wherein the varnish enrichment control sequence comprises circulating the exhaust temperature between the first exhaust temperature and the second, low exhaust temperature through a plurality of temperature cycles Gt; to < / RTI >
13. A method according to any one of claims 1 to 12, wherein the operating parameter comprises the actuation of the engine in extended idle, wherein the varnish enrichment control sequence is configured such that the engine is open in extended idle for a predetermined length of time And wherein the initialization is initiated upon determination.
14. A method according to any one of claims 1 to 13, characterized in that it comprises the steps of: reducing the variable geometry turbine nozzle opening size, retarding the injection timing, reducing the fuel injection pressure, increasing the engine speed, And increasing the exhaust temperature to the first exhaust temperature. ≪ Desc / Clms Page number 17 >
15. A method according to any one of claims 1 to 14, comprising circulating the exhaust temperature between the first exhaust temperature and a second, low exhaust temperature through a sufficient number of temperature cycles, And changing the opening size of the variable shape turbine nozzle between the small opening size and the large opening size with sufficient times so that the force required to change the size is below a predetermined value Wherein the method further comprises the steps of:
diesel;
A turbocharger comprising a variable shape turbine downstream of the engine;
Means for determining whether an operating parameter is present at an established level for initiating a varnish enrichment control sequence to control varnish reinforcement on the variable shape turbine; And
And a controller arranged to initiate the varnish enrichment control sequence when the determining means determines that an operating parameter is present at an established level, wherein the varnish enrichment control sequence comprises: determining an exhaust temperature upstream of the variable turbine to a first exhaust temperature And changing the opening size of the variable shape turbine nozzle between a small opening size and a large opening size with respect to increasing the exhaust temperature upstream of the variable shape turbine to a first exhaust temperature. And a controller.
17. The method of claim 16, wherein the operating parameters include at least one of a measured level of varnish enhancement, an actual level of varnish enhancement, a force required to change a nozzle opening size in the variable shape turbine, a duration of the engine operation, Ambient temperature, and engine coolant temperature. ≪ RTI ID = 0.0 > [0002] < / RTI >
17. The method of any one of claims 16 to 17, wherein the controller is configured to reduce the variable geometry turbine nozzle opening size, retard injection timing, decrease fuel injection pressure, increase engine speed, And to increase the exhaust temperature to the first exhaust temperature by one or more of the first and second exhaust temperatures.
19. A turbine nozzle according to any one of claims 16 to 18, wherein the determining means determines whether the force required to change the open size of the variable shape turbine nozzle exceeds a predetermined value, To an exhaust temperature between the first exhaust temperature and a second, low exhaust temperature, and a force required to change the nozzle opening size in the variable shape turbine to a value sufficient to change below a predetermined value, Wherein the at least one of the plurality of turbine nozzles is disposed for at least one of changing the open size of the variable shape turbine nozzle between the open size and the large open size.
19. The method of any one of claims 16 to 19, wherein the controller is configured to increase the exhaust temperature between the first exhaust temperature and a second, lower exhaust temperature through a sufficient number of temperature cycles, A change in the opening size of the variable shape turbine nozzle between the small opening size and the large opening size in a sufficient number of times to maintain the force required to change the nozzle opening size below a predetermined value Features diesel engine arrangement.

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