System and method for an engine

Abstract

A system and method for an engine is provided, the internal combustion engine having a plurality of cylinders lubricated with engine oil. In one embodiment, a system includes: a high-speed diesel engine having a cylinder bank, each cylinder having at least one exhaust port; and a controller configured to operate the engine in at least two modes, wherein at least one mode is an exhaust port heating mode. The controller is configured to change the exhaust port heating mode based on at least one of a time function, an age of the engine, and a measured or calculated number of megawatt hours of the engine, so that for the exhaust port heating mode, the change is reduced based on one or more of: a frequency of exhaust port heating events, a duration of exhaust port heating events, a target temperature of exhaust port heating events, and an amount of fuel used by at least one cylinder during the exhaust port heating event.

Description

[0001] Priority claim

[0002] This application claims priority to Indian Application No. 202041031788 filed on July 24, 2020. Technical Field

[0003] Embodiments of the subject matter disclosed herein relate to internal combustion engines, and more particularly to heating cylinder exhaust ports. Background Art

[0004] Various engines may have a lubrication system in which pressurized oil may be used to lubricate and / or cool engine valve train components, camshaft assemblies, pistons, and related engine components. Such an oil system may provide enough oil to lubricate and cool the engine at full load.

[0005] In some engines, such as large bore engines designed to run heavily at full load, oil from the lubrication system can become lodged in grooves in the cylinder walls and eventually enter the exhaust system or engine stack. Particularly under low load conditions, unburned fuel from combustion can lead to accumulation and deposits of unburned fuel and oil in the exhaust system, especially as exhaust port temperatures decrease.

[0006] One approach to addressing such deposits involves periodic maintenance of the exhaust system. In one example, maintenance of the exhaust stack may require a maintenance personnel to climb onto the roof of the locomotive and manually clean the exhaust system. However, the frequent need to maintain the exhaust system, coupled with the complex manual operations used therein, may introduce unnecessary delays in operation. Another approach involves operating at least one donor cylinder at a cylinder load during an exhaust gas recirculation (EGR) cooler heating mode that is sufficient to increase the exhaust temperature to a level that burns local oil and fuel accumulation. However, this approach requires the use of an EGR system and does not take into account the age of the engine or the thickening (souping) of the engine during long periods of idling. Therefore, there is a fuel consumption penalty associated with this exhaust port heating method. It may be desirable to have a system and method that is different from existing systems and methods. Summary of the invention

[0007] In one embodiment, a system includes: a high speed diesel engine having a cylinder bank, each cylinder having at least one exhaust port; and a controller configured to operate the engine in at least two modes, wherein at least one mode is an exhaust port heating mode. The controller is further configured to change the exhaust port heating mode based on at least one of a time function, an age of the engine, and a measured or calculated number of megawatt hours of the engine, whereby for the exhaust port heating mode, the changed operating mode is based on reducing one or more of: a frequency of exhaust port heating events, a duration of exhaust port heating events, a target temperature of exhaust port heating events, and an amount of fuel used by at least one cylinder during an exhaust port heating event.

[0008] In one embodiment, a system includes: a high speed diesel engine having a cylinder bank, each cylinder having at least one exhaust port; and a controller. The controller is configured to operate the engine in at least two modes, wherein at least one mode is an exhaust port heating mode. The controller is further configured to reduce the operating mode of the exhaust port heating mode based at least in part on a calculated or measured engine thickening level. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 An example embodiment of a diesel-electric locomotive is shown;

[0010] Figure 2 A high level flow chart is shown which illustrates a method for an engine according to an embodiment of the present disclosure;

[0011] Figure 3 A high level flow chart is shown illustrating a routine for exhaust port heating for a high speed engine according to an embodiment of the present disclosure;

[0012] Figure 4 A high level flow chart is shown illustrating an adjustment routine that may be executed to prepare a high speed engine for a subsequent exhaust port heating procedure in accordance with an embodiment of the present disclosure;

[0013] Figure 5 shows a non-limiting example of graphical data showing that the use of Figure 3 and 4 The timing advance angle during exhaust port heating is performed according to the procedure shown; and

[0014] Figure 6 shows a non-limiting example of graphical data showing that the use of Figure 3 and 4 The procedure shown is for rail pressure during exhaust port heating. DETAILED DESCRIPTION

[0015] The engine may have a lubrication system that provides lubricating oil for lubricating the valve train, pistons, and other related engine components. During engine operation, unburned oil and / or fuel may accumulate in the engine exhaust manifold. The lubrication system may interact with the engine controlled by the engine control system to burn off the unburned oil and / or fuel, thereby reducing fouling of the engine exhaust system. Figure 1 One example of such a configuration is shown where a lubrication system interacts with a locomotive engine to provide lubrication during engine operation, and an engine controller enables scheduled exhaust maintenance.

[0016] In one embodiment, the engine controller can switch the engine between different operating modes. Examples of operating modes may include normal operating mode, low load, high load, high heat mode, starting mode, oxygen limited mode, etc. Under normal operating conditions, oil used to lubricate the pistons is carried into the combustion chamber and into the exhaust system. During extended periods of low load mode, the exhaust temperature is not high enough to burn off the residual oil. Residue, thickening and / or excessive smoke production may cause wet oil or smoke in the exhaust system to be deposited near the engine, such as on the engine casing and / or returned to the intake system via EGR (if applicable). In one embodiment, the technical effect may include using exhaust port heating to alleviate oil carryover. Exhaust port heating may be achieved, for example, by over-fueling one or more cylinders to increase the exhaust temperature and locally burn off any accumulated oil before the oil can flow downstream to the exhaust port. As Figure 2 , Figure 3 and Figure 4 As further described in , in contrast to current methods, a control routine may be implemented to initiate exhaust port heating without EGR cooler regeneration, wherein exhaust port heating is gradually reduced over time and the heating is weighted by the age / richness level of the engine. In this way, the fuel consumption penalty associated with cylinder exhaust port heating may be minimized by taking advantage of the reduced richness over time as the engine breaks in.

[0017] In one embodiment, a system may include: a high-speed diesel engine having a cylinder bank, each cylinder having at least one exhaust port; and a controller capable of operating the engine in at least two modes, at least one of which is an exhaust port heating mode. The controller may switch to the exhaust port heating mode based on one or more triggers. Suitable triggers may include a time function, an age of the engine, and a measured or calculated megawatt (MW) hours (hrs) of the engine, such that for the exhaust port heating mode, the changed operation is based on reducing one or more of the following: the frequency of exhaust port heating events, the duration of exhaust port heating events, the target temperature of the exhaust port heating events, and the amount of fuel used by at least one cylinder during the exhaust port heating event. The maximum power output of the high-speed diesel engine may be about 5 MW. As a non-limiting example, the high-speed engine may be used to drive a vehicle, a truck, a bus, a car, a yacht, a ship, a compressor, a pump, and / or a generator.

[0018] In another embodiment, a system includes: a high speed diesel engine having a cylinder bank, each cylinder having at least one exhaust port; and a controller. The controller is configured to operate the engine in at least two modes, wherein at least one mode is an exhaust port heating mode. The controller is further configured to reduce the operating mode of the exhaust port heating mode based at least in part on a calculated or measured engine thickening level. Figure 5 and Figure 6 The following table shows the normal operation and the use of Figure 3 and Figure 4 An example graphical representation of the difference between advance angle timing and rail fuel pressure during exhaust port heating of the described routine.

[0019] The methods described herein can be used in various engine types, sizes and speeds and in various engine-driven systems. Some of these systems may be fixed, while other systems may be on semi-mobile or mobile platforms. Semi-mobile platforms can be relocated during operation, such as when mounted on a flatbed trailer. Mobile platforms include self-propelled vehicles. Such vehicles may include road transport vehicles (such as automobiles), mining equipment, ships, rail vehicles and other off-highway vehicles (OHVs). Locomotives are provided as examples of mobile platforms that support systems that include embodiments of the present disclosure. Suitable non-vehicle applications may include power station generators.

[0020] In one embodiment, a platform for an engine disposed in a vehicle is disclosed. Figure 11 is a block diagram of an example vehicle system with a rail vehicle. In the illustrated embodiment, the vehicle is described as a locomotive 100 having a main engine housing 102 that can travel on a track 104. In addition, the locomotive is a diesel electric vehicle that operates a diesel engine 106 located in the engine housing. In alternative embodiments, suitable engines can consume or utilize various fuels and oils other than diesel and lubricating oil. Suitable other fuels may include gasoline, kerosene, alcohol, natural gas, biodiesel, and mixtures of two or more thereof. The engine may include a plurality of cylinders 107. In one example, the engine may include twelve cylinders (two rows of cylinders, each row having six cylinders). In addition, the plurality of cylinders in the engine may include various cylinder sets and subsets, such as a first subset of cylinders 109a and a second subset of cylinders 109b, and in some embodiments, each subset of cylinders may include one or more donor cylinders and one or more non-donor cylinders. For example, in other embodiments, the first subset of cylinders may include only donor cylinders, while the second subset of cylinders may include only non-donor cylinders. Various sets and subsets of cylinders may include one or more cylinder banks for selected operating modes, as described herein.In alternative embodiments, alternative engine configurations may be employed, such as a gasoline engine or a biodiesel or natural gas engine.

[0021] Operators and electronic components involved in vehicle system control and management may be housed within the locomotive cab 108. In one example, the controller 110 may include a computer control system and / or an engine control system. The locomotive control system may have a computer readable storage medium that includes code for enabling on-board monitoring and control of locomotive operations. The controller may oversee vehicle system control and management and may receive signals from various sources to estimate vehicle operating parameters. The controller may be connected to a display (not shown) to provide a user interface to the vehicle operator. In one embodiment, the controller may be configured to operate with an automatic engine start / stop (AESS) control system on an idling vehicle 100, so that the vehicle engine is automatically started and stopped when the AESS criteria managed by the AESS control routine are met.

[0022] The engine can be started using an engine starting system. In one example, a generator start can be performed, wherein the electrical energy generated by the generator or alternator 116 can be used to start the engine. In addition, the engine starting system can use a motor to start the engine. Suitable motors can include electric starter motors and compressed air motors. The engine can be started using energy from an energy storage device (e.g., a battery) or other suitable energy source.

[0023] The diesel engine produces torque, which is transmitted to the alternator 116 along a drive shaft (not shown). The torque generated is used by the alternator to generate electricity for subsequent transmission of the vehicle. The electricity generated in this manner can be referred to as prime mover power. The electricity can be transmitted to various downstream electrical components along the power bus 117. Based on the nature of the power output generated, the power bus can be a direct current (DC) bus (as shown) or an alternating current (AC) bus. Various power electronic components can be used to manage the current.

[0024] The engine may be operated at multiple load levels and / or multiple engine speeds. These load levels may range from idle at a low end point to peak engine output at a high end point. Low engine load may include operation at the low end point of the engine load range. Medium engine load may include operation at a mid-level engine load range above low load. High engine load may include operation at a higher end point of the engine load range above medium engine load. Although the engine may be operated at a given engine load, each cylinder may have a variable cylinder load. These cylinder loads may range from cylinder low load to cylinder high load. In some cases, the engine load and cylinder load may coincide, and in other cases not. For example, the engine as a whole may be operated at a low load, however, some cylinders may be operated at essentially no load (e.g., deactivated) while other cylinders are operated at medium to high loads, depending on the number of cylinders operating at different loads. In addition, the cylinder fuel injection amount may set the load of the cylinder. For example, a cylinder operating without fuel injection may be considered to be deactivated (in which case it may be referred to as skip ignition operation, which will be referred to as skip ignition operation). Figure 2 ), while cylinders operating with low fuel injection can be considered to be operating at low load.

[0025] The alternator may be connected in series to a power electronics device having one or more rectifiers (not shown) that convert the electrical output of the alternator into DC electrical energy before transmitting along the DC bus. Based on the configuration of the downstream electrical components that receive power from the DC bus, one or more inverters 118 may be configured to convert power from the power bus before powering the downstream components. In one embodiment, a single inverter may provide AC power to multiple components from a DC power bus. In another embodiment, each of a plurality of different inverters may supply power to different components. The vehicle may include one or more inverters connected to a switch that may be controlled to selectively provide power to different components connected to the switch.

[0026] The traction motor 120 mounted on the truck 122 below the main engine housing can receive power from the AC generator via a DC bus to provide traction power to propel the vehicle. As described herein, the traction motor can be an AC motor. Therefore, the inverter paired with the traction motor can convert the DC input into an appropriate AC input, such as a three-phase AC input, for subsequent use by the traction motor. In an alternative embodiment, the traction motor can be a DC motor that directly uses the output of the AC generator after rectification and transmission along the DC bus. An example vehicle configuration may include a pair of inverters / traction motors for each pair of axles 124. As described herein, six pairs of inverters / traction motors are shown for each of the six pairs of axles of the vehicle. In an alternative embodiment, the vehicle may have four inverter / traction motor pairs. In an alternative embodiment, a single inverter may be paired with multiple traction motors.

[0027] The traction motor 120 may act as a generator to provide dynamic braking to brake the vehicle. In particular, during dynamic braking, the traction motor may provide torque in a direction opposite to the rolling direction, thereby generating electrical energy that is dissipated as heat through a grid of resistors 126 connected to the power bus. In one example, the grid can include a stack of resistive elements connected directly in series to the power bus. The stack of resistive elements can be placed near the top of the main engine housing to facilitate air cooling and heat dissipation from the grid. In some embodiments, air brakes (not shown) using compressed air can be used by the vehicle as part of the vehicle braking system. The compressed air can be generated by a compressor 128 from the intake air.

[0028] A variety of motor driven air flow devices may be operated to control the temperature of vehicle components. Air flow devices may include, but are not limited to, blowers, radiators, and fans. Various blowers (not shown) may be provided for forced air cooling of various electrical components. For example, a traction motor blower may be used to cool the traction motor during heavy duty operation, an alternator blower may be used to cool the alternator, and a grid blower may be used to cool the resistive grid. Each blower may be driven by an AC or DC motor and may accordingly be configured to receive power from a DC bus through a respective inverter.

[0029] The engine temperature may be maintained in part by a radiator 132. Water may be circulated around the engine to absorb excess heat and control the temperature within a desired range for efficient engine operation. The hot water may then pass through the radiator 132 where air blown by a radiator fan may cool the hot water. The radiator fan may be located in a horizontal position near the rear ceiling of the vehicle so that air may be drawn in and expelled from below as the blades rotate. A cooling system including a water-based coolant may optionally be used in conjunction with the radiator to provide additional cooling of the engine.

[0030] In this example, an on-board electrical energy storage device represented by battery 134 can be connected to the DC bus. A DC-DC converter (not shown) can be arranged between the DC bus and the battery to allow the high voltage of the DC bus (e.g., in the range of 1000V) to be appropriately stepped down for use by the battery (e.g., in the range of 12-75V). In the case of a hybrid vehicle, the on-board electrical energy storage device can be in the form of a high-voltage battery, so that an intermediate DC-DC converter may not be required. The battery can be charged by running the engine. The electrical energy stored in the battery can be used to operate various electronic components, such as lights, on-board monitoring systems, microprocessors, processor displays, climate controllers, etc., during a standby mode in which the engine is running or when the engine is turned off. The battery can be used to provide an initial charge to the starting engine from a stopped state. In an alternative embodiment, the electrical energy storage device can be, for example, a supercapacitor.

[0031] The lubrication system 140 may include a pressure oil supply system with a crank-driven oil pump for lubricating the engine crankshaft, valves and pistons. The oil reservoir may be stored in an oil pan below the engine. The valves are lubricated by splashing oil, while the cylinder liners are lubricated by pressurized oil fed from the crankshaft to the pistons for cooling and lubrication purposes. The oil brought into the combustion chamber is controlled by the piston rings. Therefore, the shape of the piston rings can allow enough oil to reach the top piston ring and lubricate it when the cylinder is fully loaded. The gas pressure balance in the piston ring groove further controls the oil entering the combustion chamber. The oil is discharged below the oil control ring, and the oil control ring carries away most of the oil by scraping as the piston moves up and down the cylinder liner. The remaining oil is carried away by the remaining piston rings to provide them with the required lubrication. If the oil is heated during its passage through the engine, it may be cooled by passing through a radiator. The exhaust chimney 142 can receive exhaust gas from the engine and guide the exhaust gas away from it. A duct or pipe (not shown) may be provided between the crankcase (containing lubricating oil) and the exhaust stack to ventilate the crankcase, for example, to ventilate blowby gases in the crankcase.

[0032] The lubrication system can provide sufficient lubricating oil for full-load operation. However, at light loads, excess oil may be supplied. Some of the excess oil may be carried into the cylinder chamber and exhaust port. The oil in the combustion chamber may come from the oil retained in the grooves of the cylinder liner wall. Therefore, the engine may retain some oil in the grooves to provide lubrication for the piston and rings. Residual oil in the combustion chamber may also be caused by oil that lubricates the valves. Here, the oil flows down the valve to provide lubrication between the valve and the valve guide, and further provides lubrication on the valve seat surface on the cylinder head. In some cases, the oil residue condition may be more serious when the engine has accumulated hours of operation, and over a period of time, excess lubricating oil residue enters the relevant turbocharger, which may aggravate this condition. Therefore, a controller communicating with the engine system may enable an exhaust port heating routine, such as Figure 2 and 3 As further described in , to allow unburned oil to be burned off and avoid engine performance degradation due to the accumulation of unburned oil. It will be appreciated that the routine may also allow unburned fuel, such as fuel that accumulates in the combustion chamber due to poor fuel combustion under low load conditions, to be burned off. Alternatively, the engine may be run-in after a period of use, before wear, to reduce the risk of thickening. In this case, the controller may reduce or eliminate the exhaust port heating routine. Various control algorithms may be used, for example, based on measurements of the actual amount of thickening at different locations, indirect factors such as smoke generation or exhaust opacity, or calculations based on the age of the engine, operating cycles, or megawatt hours produced.

[0033] Figure 2 A method 200 of determining whether an exhaust port heating mode of operation may be performed in a non-EGR engine and / or a high speed internal combustion engine is depicted. The method may be performed by a control system or controller in communication with the engine to enable exhaust port heating and subsequent combustion of unburned oil and / or fuel. The control system may operate in at least two modes, at least one of which is an exhaust port heating mode, and the controller may change the mode of operation of the exhaust port heating mode based at least in part on a calculated or measured level of thickening of the engine and / or the age of the engine.

[0034] In step 202, engine operating conditions may be determined. Engine operating conditions may include engine idle conditions, idle time, engine load, engine load time, etc. In step 204, the engine load is determined. As described above, the engine load ranges from idle at the low end point to the engine output peak at the high end point. In step 206, the method may determine whether any heating conditions of the exhaust port are met. The conditions that may be met may include when the engine load is below a threshold value (e.g., low load), after the engine experiences a condition that puts the engine at risk of having oil in the exhaust (e.g., after the engine is at a low load for a duration, which may be a relatively extended time), when the engine is idling, or during dynamic braking. During operation when the engine load is below a first threshold load, the selected cylinder may be operated at a higher cylinder load (e.g., through an exhaust port heating mode) so that the exhaust port temperature is increased, thereby removing deposits.

[0035] In another example, the controller may determine one or more of the cumulative engine speed at low load or no load, the load, and the engine speed as a function of megawatt hours as at least one factor to determine whether to activate exhaust port heating. For example, speed, engine load, megawatt hours, and time may be considered so that different exhaust port heating is used at multiple speeds (e.g., different speed levels may trigger different exhaust port heating levels). In one embodiment, an idle timer criterion may be used to determine whether the conditions for exhaust port heating are met. The idle timer may be based on different engine speeds (e.g., first speed, second speed, third speed, high speed, medium speed, low speed, etc.) and the age of the engine, and standardized to engine revolutions (e.g., by using a two-dimensional (2D) table). The standardized engine revolution counter limit may be used as a threshold for enabling exhaust port heating. The counter limit may be represented as a one-dimensional (1D) vector using the age of the engine in megawatt hours to the standardized engine speed counter limit.

[0036] If the conditions for exhaust port heating are not met, then the current engine operation may continue at step 208. If the conditions for exhaust port heating are met, then the method may continue at step 210 where the age and thickening level of the engine are determined. During a long period of idle operation of a diesel engine, thickening may occur if a significant portion of the engine exhaust is not emitted, but remains as a "thick liquid" (e.g., semi-volatile hydrocarbons and lubricating oils) and is subsequently emitted when the engine resumes high load operation. This soup can accumulate downstream of the cylinder exhaust ports and form unwanted deposits. At step 212, exhaust port heating may be operated on a group of cylinders based on the age of the engine, the thickening level, and / or the exhaust port heating conditions met. In one embodiment, the control system may be configured to operate in at least two modes, at least one of which is an exhaust port heating mode, and the controller is further configured to reduce the operating mode of the exhaust port heating mode based on one or more of the frequency of exhaust port heating events, the duration of exhaust port heating events, the target temperature of the exhaust port heating events, and the amount of fuel used during the exhaust port heating events.

[0037] Figure 3 An exemplary routine 300 is depicted that is performed by a control system (e.g., a controller) in communication with a high-speed diesel engine to implement exhaust port heating and subsequent combustion of unburned oil and / or fuel. As a non-limiting example, the routine operates within a vehicle system of a rail vehicle. The operation may take into account engine operating conditions, such as engine idle state, engine age, engine speed, idle time, engine load, engine load time, and initiate exhaust port heating operations accordingly. The exhaust port heating operation may vary depending on the age of the engine, the level of thickening, and the engine speed. In this way, as the engine is broken in, the need for exhaust port heating decreases, and the fuel consumption loss associated with exhaust port heating may be reduced over time. For example, the variation of exhaust port heating may be reduced based on the frequency and / or duration of exhaust port heating events over time and engine use, and different exhaust port heating may be employed in response to meeting different thresholds or ratios (e.g., different speeds, rail pressures, or lead angle ratios / ranges).

[0038] In one example, exhaust port heating operation may include continuously operating different subsets of cylinders at cylinder loads or fuel injection amounts sufficient to increase the exhaust temperature of the subsets to burn unburned fuel and / or oil deposited in the cylinder subsets and / or exhaust system while operating the engine in an overall low load mode or idle mode. During such operation, each continuously operated subset of cylinders may include at least two cylinders from the same engine cylinder bank. Cylinders that are not currently operating in a subset are operated in a low fuel or no fuel mode. Continuous operation may include first operating a subset of cylinders in an exhaust port heating mode, then operating a different subset of cylinders in an exhaust port heating mode, and so on. In addition, different subsets may have common cylinders, but each subset differs from the other subsets in at least one cylinder. In this way, hydrocarbon deposits can be removed from the exhaust of all cylinders.

[0039] In another example, exhaust port heating can include operating the engine in at least two modes, namely a first mode with a lower fuel injection amount and a second mode with a higher fuel injection amount. Specifically, the operation can include operating at least two cylinders of an engine cylinder bank (e.g., a right cylinder bank) in a second mode, while at least another cylinder of an opposite cylinder bank (e.g., a left cylinder bank) is operated in a first mode to increase the exhaust temperature of at least two cylinders in the second mode after a specified amount of low-load engine operation and during low-load engine operation. Thus, even if the overall engine load is low, the selected cylinder can be operated at a high cylinder load to generate sufficient exhaust port temperature to at least remove deposits from the cylinder. Then, by changing which cylinders are operated in each mode, different cylinders can clear deposits from their respective exhaust systems. Such operation can continue until all cylinders are operated with exhaust port heating, or until the engine load increases from idle or low-load operation (e.g., due to the driving conditions of the vehicle). In this case, if the engine is running sufficiently at the higher load, exhaust port heating may be discontinued (e.g., any cylinders not already running in the second mode will be cleaned by the higher load operation, so exhaust port heating may not need to be resumed). However, if the load condition is not high enough or lasts for too short a time, exhaust port heating may resume where it left off.

[0040] Reference Figure 3Examples of the above operations as well as variations and additional operations are described. In step 302, an idle timer is started and an initial setting of zero time is indicated. The idle timer can measure the amount of time the engine spends in an idle condition. In one example, an idle condition can include a vehicle parked on a siding for a long period of time with the engine running at an idle speed. In step 304, the idle timer is increased based on the time spent in idle mode. In step 306, it is determined whether the time spent in idle mode is greater than a predetermined maximum idle time. In one example, the specified maximum idle time is 6 hours. If so, then in step 308, the engine can be adjusted for exhaust port heating. Note that the idle time can be a continuous idle time without interrupting other operating modes, or can include multiple idle conditions that reach a maximum idle time together.

[0041] Furthermore, although the depicted example uses satisfying an idle timer criterion to enable exhaust port heating, in alternative embodiments, other criteria may be used in addition to the idle timer requirement. As one example, the engine idle speed may be determined, and if the speed is above a determined exhaust port heating speed limit, exhaust port heating operation may be disabled. Figure 3 As further described in , the adjustment process may include determining a first target cylinder and an order of subsequent cylinders for which exhaust port heating may be activated. In addition, the process may require determining injection settings, conversion rates, and exhaust port heating speeds. Once the engine has been properly adjusted, exhaust port heating operations may be performed at step 310. Alternatively, if the routine is restarted after a previously interrupted exhaust port heating operation, then at step 310, operations may resume.

[0042] After the exhaust port heating program is run (or resumed), at step 312, it is determined whether the engine is in an idle state. If the engine is in an idle state, then at step 314, it can be determined whether the exhaust port heating program has been completed. If the exhaust port heating program has been completed, further exhaust port heating can be stopped at step 316, and the idle timer can be reset to zero at step 318. However, if it is determined at step 312 that the engine is not idling, that is, it is determined that the engine is operating under a higher load condition, then the exhaust port heating can be suspended at step 320. The routine can then continue to determine whether the engine load condition meets the load timer criteria at step 322, which will be further described below. Therefore, during long periods of engine idle conditions, unburned oil and / or fuel accumulation may occur. However, during the period when the engine is operating under non-idle conditions, the engine exhaust manifold can produce a temperature rise, thereby spontaneously burning off the accumulated unburned oil and / or fuel. Therefore, during the period when the engine is operating under non-idle conditions, the exhaust port heating program may not be needed and can be suspended accordingly. In this way, the routine may adjust the exhaust port heating operation to occur when the engine is idling, thereby occurring when the likelihood of unburned oil accumulation is higher. The routine may suspend the exhaust port heating operation when the engine is operating at a higher load, thereby potentially burning off unburned oil during normal engine operation. Although operating at a high load is an example, a variety of operations may trigger the suspension of the exhaust port heating mode (e.g., operator throttle request, cold ambient temperature, engagement of auxiliary loads, etc.).

[0043] Returning to step 306, if the amount of time spent in the idle state is not greater than the maximum idle time, then at step 322, it is determined whether the engine has been loaded for the minimum load time. In addition, after pausing the exhaust port heating operation of the loaded engine at step 320, the routine may continue to determine whether the minimum load timer duration has been met at step 322. If the engine has been loaded for at least the minimum load time, then further exhaust port heating may not be required when the exhaust temperature is expected to rise sufficiently to burn off the accumulated unburned oil and / or fuel. Accordingly, at step 323, exhaust port heating may not occur and the idle timer may be reset to zero.

[0044] However, if neither the maximum idle time nor the minimum load time is met at step 322 at step 306, then a determination is made at step 324 as to whether the engine is still idling. If the engine is still idling, then the routine may return to step 304 to continue incrementing the idle timer, and thereafter continue the exhaust port heating operation when the idle time criteria are met. If the engine is not idling at step 324, then the routine may instead continue incrementing the load timer at step 326. At step 328, it is verified whether the exhaust port heating operation has been suspended in a previous iteration of the routine. If so, then the routine may resume the exhaust port heating operation at step 330. If the previous exhaust port heating was not interrupted, then the routine may return to step 322 and continue incrementing the load timer until the minimum load time is reached, after which the need for the exhaust port heating operation may be cancelled, and thus the idle timer may be reset to zero.

[0045] Thus, two criteria may be considered in determining whether to perform an exhaust port heating procedure. These criteria may be the time spent in idle mode (which may be defined by an idle timer) and engine load conditions (which may be defined by a load timer and / or load or non-idle conditions of the engine). It will be appreciated that under idle or low engine load conditions, accumulation of unburned oil and / or fuel may be a potential problem, and further, during operation of the engine under sufficient load conditions for a sufficient duration, the temperature of the exhaust manifold may increase to a sufficient degree to cause unburned fuel and oil to burn during loaded engine operation.

[0046] In one example scenario, the engine is at idle and has spent sufficient time at idle to warrant exhaust port heating operation to avoid the adverse effects of accumulated unburned oil. In this case, exhaust port heating operation may occur while the idle timer criteria are met. After the operation is completed, the idle timer can be reset to allow a new operation iteration to be performed subsequently. In another example, the engine is not idling, but is already loaded. Here, the engine may have spent sufficient time under load to meet the load timer criteria and ensure high exhaust manifold temperatures, so that intake and exhaust port heating operation may not be required. Here, as long as the engine is operating under non-idle conditions and the load timer criteria are met, the idle timer can remain at zero.

[0047] In yet another example, the engine has been idling, but not for a sufficient time to meet the idle timer criteria. Additionally, the idle state of the engine may be interrupted by abrupt operation of the engine under load. If the interrupted operation of the engine under load continues long enough to meet the load timer criteria, the exhaust manifold temperature may again reach the required high temperature to burn off the unburned oil, so that upon returning to the idle condition, exhaust port heating operation may not be required, and the idle timer may be reset to zero. However, if the interrupted operation of the engine under load is not long enough to meet the load timer criteria, the engine may return to the idle condition and resume determining the idle timing when the loaded engine operation is completed.

[0048] In yet another example, the engine has been idling long enough to satisfy the idle timer criteria and exhaust port heating operations have been initiated. However, under load conditions, sudden operation of the engine may interrupt exhaust port heating operations. First, the interruption of operation in the idle state of the engine will cause the exhaust port heating operations to be suspended. Next, if the engine has been running long enough to satisfy the load timer criteria, then unburned oil and / or fuel may be purged, so the exhaust port heating operations may be aborted and the idle timer may be reset to zero for a new iteration. However, if the engine is only run for a short time (e.g., not long enough to satisfy the load timer criteria) and then returns to an idle state, the exhaust port heating operations may be resumed if it is necessary to purge the unburned oil and / or fuel. In this way, the control system can be configured to predict the accumulation and / or combustion of unburned oil in the engine exhaust manifold based on the amount of time the engine spends in an idle state relative to operating (or load) conditions. Therefore, by judiciously adjusting the operation of the exhaust port heating program, potential problems associated with the accumulation of unburned oil can be avoided. Figure 4 Further details of the pre-treatment process and the operation and resumption of exhaust port heating operation will be described in detail in the context of example routine 400 .

[0049] Figure 4 An example routine 400 is shown that may be executed by the control system to adjust the engine for subsequent operation (or resumption) of exhaust port heating operation. As such, the routine may be used as a reference at step 308. Figure 3 402, a determination is made as to whether the exhaust port heating state machine is in "Run" mode (as opposed to "Hold" mode). If the Run mode is selected, the routine may continue, which in turn requires that all exhaust port heating operating criteria be met. If the state machine is not in Run mode, the routine may end.

[0050] At step 404, a target set of cylinders is selected from the cylinder bank to start the exhaust port heating operation. In addition, a subsequent order of cylinder cleaning operations may be determined. For example, based on various engine configurations, the engine may be divided into heated exhaust ports and non-heated exhaust ports based on the engine cylinder bank. In one example, the engine may be a V-12 engine having two banks of six in-line cylinders, each cylinder having a logarithmic exhaust manifold. A target set of cylinders may be selected from a first cylinder bank (e.g., a right cylinder bank), and cylinders in a second cylinder bank (e.g., a left cylinder bank) include non-heated exhaust ports. In this configuration, the order of exhaust port heating may include starting with a target set of cylinders in a designated cylinder bank, and sequentially performing exhaust port heating on the remaining cylinder sets in the same cylinder bank. In addition, a cylinder set may be selected to utilize a previously heated adjacent cylinder, so that the cylinder that may have the greatest exhaust hydrocarbon accumulation may have the longest high temperature exhaust duration. In some examples, exhaust port heating may be operated within the entire cylinder bank, and a cylinder set within a cylinder bank may require the non-heated cylinder bank to receive normal fuel.

[0051] At step 406, exhaust port heating settings for the target set of cylinders may be determined. The exhaust port heating settings may be determined based on at least one of engine speed, engine age, thickening level, accumulated megawatt hours, and idle time. For example, the target temperature and duration of exhaust port heating may be determined based on current engine demand for a given speed, rail pressure (RP), and / or advance angle (AA) range or ratio. Additionally, the operating mode (e.g., duration, temperature, overfueling, etc.) of exhaust port heating may be further reduced based at least in part on the calculated or measured engine thickening level, thereby reducing associated fuel consumption penalties over time. For example, a first set of exhaust port heating settings may be determined for high speed engine operating conditions, a second set of exhaust port heating settings may be determined for medium speed engine operating conditions, and / or a third set of exhaust port heating settings may be determined for low speed or idle engine operating conditions.

[0052] In one example, high speed engine operating conditions may include engine speeds ranging from 1200 to 1800 rpm, advance angles (AA) ranging from 17 to 24 degrees, and / or rail pressures (RP) ranging from 800 to 1000 bar. Medium speed engine operating conditions may include engine speeds ranging from 600 to 1200 rpm, advance angles (AA) ranging from 5 to 17 degrees, and / or rail pressures (RP) ranging from 600 to 800 bar. Low speed engine operating conditions may include engine speeds below 600 rpm, advance angles (AA) below 5 degrees, and / or rail pressures (RP) below 600 bar. Alternatively, the exhaust port heating setting may be modified based on different speed, megawatt-hour, rail pressure (RP), and / or advance angle (AA) ratios (e.g., the temperature or duration of exhaust port heating may be increased by a specified amount relative to a specified increase in speed for the age of the engine in megawatt-hours). For example, during high speed engine operating conditions, the engine may be controlled to drop to an rpm level below "high speed" as part of the exhaust port heating setting. At medium or low speed engine conditions, the settings for exhaust port heating may not include changes in rpm level. The duration and target temperature of exhaust port heating may be reduced at high speed conditions compared to idle or medium speed conditions.

[0053] In one example, exhaust port heating may vary above a high speed threshold based on megawatt hours, age of the engine, and / or a function of time, while below the high speed threshold, exhaust port heating may be fixed. For example, above 1200 rpm, the temperature, duration, frequency, and / or amount of fuel used by at least one cylinder during exhaust port heating may vary. For speeds below 1200 rpm, the temperature, duration, frequency, and / or amount of fuel used during exhaust port heating may be set to a fixed value that is independent of megawatt hours, age of the engine, and / or a function of time. In one example, for all speeds below 1200 rpm, exhaust port heating may be operated for 18 minutes for every 60 minutes of operation, while for speeds of 1200 rpm or above, the duration of exhaust port heating may vary based on operating time and / or other factors.

[0054] The controller is operable to reduce the mode of operation of the exhaust heating mode based at least in part on the calculated or measured engine thickening level. In one example, the engine thickening level can be calculated by subtracting the emissions during the thickening test baseline from the emissions during the thickening test and then dividing by the number of minutes of idle operation between the two tests. The calculated amount of thickening can be used to adjust the parameters of the exhaust heating to increase the efficiency / reduce the variation of cleaning and reduce the fuel consumption penalty associated with exhaust heating over time. For example, the temperature and duration of exhaust heating for each threshold (e.g., speed range) can be reduced at lower thickening levels (e.g., when the engine is breaking in).

[0055] In one example, an exhaust port heating event may include overfueling a group of cylinders within a cylinder bank that is operating exhaust port heating (e.g., increasing the amount of fuel injected into the cylinders by activating the fuel injectors of at least two cylinders). The amount of overfueling (e.g., the amount of additional fuel injected) may be based on the initial exhaust port heating settings and further adjusted to account for engine age, thickening level, fuel injector maintenance condition, fuel injector wear, environment (e.g., temperature, altitude, humidity, etc.), time since the last engine overhaul, etc., and / or the like. Once the settings are determined, they may be communicated to the target cylinder set, and exhaust port heating may be provided in the target cylinder set based on the determined settings at step 408. At step 410, the remaining cylinders (i.e., cylinders that are not part of the target set selected at step 404) may be set to a low cylinder load condition. At step 412, a status update may be fed back to the controller when exhaust port heating in the target cylinder set is completed. At step 414 , the routine may then proceed to the next target set of cylinders for the same engine bank in the order previously determined at step 404 .

[0056] In another example, the controller may determine one or more of the accumulated engine revolutions at low load or no load, the load amount, and the engine revolutions as a function of megawatt hours as at least one factor to determine whether to activate exhaust port heating. For example, speed, engine load, megawatt hours, and time may be considered so that different exhaust port heating is adopted at multiple speeds (e.g., different speed levels may trigger different exhaust port heating levels). In one embodiment, an idle timer standard may be used to determine whether the conditions for exhaust port heating are met. The idle timer may be based on different engine speeds (e.g., first speed, second speed, third speed, high speed, medium speed, low speed, etc.) and the age of the engine, and standardized to engine revolutions. The standardized engine revolution counter limit may be used as a threshold for enabling exhaust port heating. The counter limit may be represented as a one-dimensional (1D) vector (e.g., the age of the engine in megawatt hours versus the standardized engine speed counter limit).

[0057] Figure 5 and Figure 6 Non-limiting examples are shown, respectively showing the use of Figure 3 and Figure 4 The routine shown performs exhaust port heating at different engine speeds with advance angle (AA) and rail pressure (RP) compared to during normal engine operation. Figure 5 As shown in the graph 500, the Figure 3 and Figure 4 The routine in reduces the advance angle (AA) during exhaust port heating at lower engine speeds (e.g., in the range from 500 to 1750 rpm). Similarly, Figure 6 As shown in graph 600, during an exhaust port heating event, at lower engine speeds (e.g., ranging from 500 to 1500 rpm), the rail pressure (RP) may be reduced. Alternatively, at higher speed conditions (e.g., above 1500 rpm), the rail pressure (RP) and advance angle (AA) may be the same as during normal operation.

[0058] The cylinder exhaust ports of the engine may be heated sequentially and periodically to allow unburned oil therein to evaporate and / or burn. This may reduce or eliminate unnecessary fuel and / or oil accumulation in the exhaust ports and exhaust stacks. By adjusting the exhaust port heating operation in response to the amount of time the engine spends in idle conditions and further based on engine load conditions, engine age, and thickening levels, exhaust maintenance may be automated and human intervention may be reduced.

[0059] As used herein, the elements or steps described in the singular and described with the words "one" or "a kind of" should be understood as not excluding the plural form of elements or steps, unless such exclusion is clearly indicated. In addition, the reference to "an embodiment" of the present invention does not exclude the existence of other embodiments that also include the features. In addition, unless otherwise explicitly stated to the contrary, the embodiments of "including", "comprising" or "having" one or more elements with a specific characteristic may include other such elements that do not have the characteristic. The terms "including" and "wherein" are used as the popular equivalent expressions of the corresponding terms "including" and "wherein". In addition, the terms "first", "second" and "third" etc. are used only as labels and are not intended to impose numerical requirements or specific positional order on their objects.

[0060] This written description uses examples to disclose the invention, including the best mode, and also enables those skilled in the art to practice the invention, including making and using any device or system and performing any method. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. These other examples fall within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A system for an engine, comprising: A non-exhaust gas recirculation high speed diesel engine having a cylinder bank, at least one cylinder in the cylinder bank having at least one exhaust port; as well as a controller configured to operate the engine in at least two modes, at least one of which is an exhaust heating mode, the controller further configured to change an operation of the exhaust heating mode based at least in part on a function of time, an increasing age of the engine, and a measured level of thickening of the engine, such that for the exhaust heating mode, the changed operation includes reducing one or more of: Frequency of exhaust heating events, The duration of the exhaust heating event, a target temperature for the exhaust heating event, and An amount of fuel used by at least one cylinder during the exhaust port heating event.

2. The system according to claim 1, wherein: At least two cylinders in a first cylinder bank are operated in the exhaust port heating mode, and cylinders in the remaining cylinder banks of the engine are operated in a non-exhaust port heating mode.

3. The system according to claim 2, wherein: The controller is further configured to resume the exhaust port heating mode by continuing the continuous operation until all cylinders in the first cylinder bank have been operated in the exhaust port heating mode at least once.

4. The system according to any one of claims 1 to 3, wherein: The engine operates in a locomotive.

5. The system according to any one of claims 1 to 4, wherein: Each cylinder has at least one exhaust port; and The controller is further configured to reduce one of a frequency of the exhaust heating events, a duration of the exhaust heating events, a target temperature of the exhaust heating events, and an amount of fuel used by at least one of the cylinders during the exhaust heating events based at least in part on the measured engine richening level.

6. The system according to claim 5, wherein: The controller is also configured to reduce at least one of the frequency of the exhaust port heating events, the duration of the exhaust port heating events, the target temperature of the exhaust port heating events, and the amount of fuel used by at least one cylinder during the exhaust port heating events when the engine is operating at a speed at or above a set high speed threshold.

7. The system according to claim 6, wherein: For speeds below the set high speed threshold, at least one of a frequency of the exhaust port heating events, a duration of the exhaust port heating events, a target temperature of the exhaust port heating events, and an amount of fuel used by at least one cylinder during the exhaust port heating time is fixed based at least in part on the measured engine richness level.

8. The system according to claim 6, wherein: The set high speed threshold is 1200 revolutions per minute (rpm).

9. A method for a non-exhaust gas recirculation engine and / or a high speed diesel engine having a plurality of cylinders, each cylinder having at least one exhaust port, the method comprising: Determine working conditions; Determine engine load; Determine whether the conditions for exhaust port heating are met; If the exhaust port heating condition is not met, the current operation is continued; and If exhaust port heating conditions are met, the engine age and thickening level are determined, and exhaust port heating is then operated on a group of cylinders based on the engine age, the engine thickening level, and / or the met heating conditions.

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