METHOD FOR GAS PURGE CONTROL

Abstract

Method for a turbocharged power engine (10), comprising: Drawing vacuum from a vacuum source (179) positioned in an inlet (108) of the engine (10) downstream of a pre-compressor throttle (159) and upstream of an inlet throttle (114); Applying the drawn vacuum to a discharge outlet (161) of a unidirectional crankcase ventilation system (40), wherein an inlet of the crankcase ventilation system (40) is coupled to the inlet (108) of the engine (10) upstream of the pre-compressor throttle (159).

Description

Background and summary

[0001] Engines can direct various gas flows to an intake system, such as a fuel vapor recovery system, an exhaust gas recirculation (EGR) system, and / or a crankcase ventilation system. The vacuum created in an intake system can be used to drive gas circulation through the aforementioned systems. Valves can be used in these systems to control the amount of gas entering the intake system.

[0002] In some approaches, the vacuum used to drive gas circulation through the systems mentioned above can be based on an engine intake manifold vacuum. For example, a crankcase ventilation system can draw gas flow from the crankcase to force-vent it using intake manifold vacuum. As another example, vacuum generated in the intake manifold can be used to purge fuel vapor stored in the fuel vapor reservoir of a fuel vaporizer system by actuating a purge flow control valve.

[0003] In such approaches, the flow rate of the gas streams supplied to the engine can be a function of the intake manifold vacuum, so that the amount of vacuum available to the aforementioned systems can change in response to engine operating conditions. For example, under conditions of high intake flow in the engine, the intake manifold vacuum may decrease, resulting in a reduced flow rate in a crankcase ventilation system and / or fuel vapor scavenging system and / or EGR system. In particular, if an intake throttle is opened further, the intake manifold vacuum may decrease, potentially leading to stagnant air in a crankcase ventilation system. As another example, under conditions where the engine can consume a larger amount of fuel vapor, such as under conditions of high engine intake flow, the scavenging flow rate may decrease.In particular, at a constant engine speed, an increase in air flow reduces the negative pressure that draws the purge steam into the engine 10 under conditions where a higher purge flow rate may be desirable.

[0004] Furthermore, some approaches allow engines to be operated with an intake volume downstream of a throttle valve approaching barometric pressure to reduce emissions and increase power. In engine applications that draw in air at low vacuum or near atmospheric pressure (as measured in the engine's intake manifold downstream of the throttle body), the reduced vacuum may not be sufficient to drive gas purging from the systems mentioned above (e.g., EGR systems, fuel evaporation systems, and / or crankcase ventilation systems). In particular, in hybrid electric vehicle (HEV) applications, the engine operating time may be shorter than the time required to purge gas at low vacuum from the aforementioned systems, such as a fuel vapor recovery tank.

[0005] DE 10 2010 029 150 A1 discloses a method for controlling the engine operation of an engine with an exhaust gas recirculation system and a fuel vapor purging system. DE 10 2010 041 673 A1 discloses a method for controlling the exhaust operation of an engine with a particulate filter. US 3,314,665 A discloses a carburetor for a fuel and air intake system of an internal combustion engine. DE 10 2011 078 993 A1 discloses a method for extracting fuel vapors. US 7,848,870 B2 discloses an ejector that generates a vacuum greater than that of a vacuum taken from an intake port in an intake system for an internal combustion engine. US 2004 / 0182363 A1 discloses a vacuum generator in an internal combustion engine. US 2010 / 0012103 A1 discloses a system for the combustion of crankcase gases of an internal combustion engine.

[0006] The inventor has recognized the disadvantages described above and, in an exemplary approach, provides a method for a turbocharged engine that draws vacuum from a vacuum source positioned in an inlet of the engine downstream of a pre-compressor throttle and upstream of an inlet throttle, and applies the drawn vacuum to a discharge outlet of a unidirectional crankcase ventilation system, wherein an inlet of the crankcase ventilation system is coupled to the inlet of the engine upstream of the pre-compressor throttle.In some examples, the method may further include, in response to a fuel vapor purging event, applying the drawn vacuum to purge fuel vapors from a fuel vapor reservoir to an engine intake manifold and applying the drawn vacuum to an exhaust gas recirculation line to draw engine exhaust gas into an engine intake manifold.

[0007] In this way, gas supply rates from crankcase ventilation systems, fuel evaporation systems, and EGR systems can be delivered proportionally to engine airflow under various engine operating conditions. For example, crankcase ventilation flow and fuel vapor scavenge flow can be increased under conditions of high engine intake flow if increased flow in such systems is desired. Furthermore, such an approach can provide a constant unidirectional airflow through a crankcase ventilation system, thereby enabling forced crankcase ventilation under all conditions.

[0008] It is understood that the above summary is intended to present, in simplified form, a selection of concepts that are described in more detail in the full description. It is not intended to reveal any key or essential features of the claimed invention, the scope of which is defined solely by the claims following the full description. Furthermore, the claimed invention is not limited to implementations that address any disadvantages mentioned above or in any other part of this disclosure. Brief description of the drawings Fig. Figures 1-4 show exemplary turbocharged power engine systems according to the disclosure. Fig. Figure 5 shows an exemplary method for operating a turbocharged power engine according to the disclosure. Detailed description

[0009] This description relates to systems and methods for providing negative pressure for a crankcase ventilation system and / or a fuel evaporation system and / or an exhaust gas recirculation (EGR) system, which is / are integrated into a power engine system, for example, the one described in the Fig. The power machine system shown in Figures 1-4 is / are included. As shown in the Fig. As shown in Figures 1-4, a vacuum source, for example an ejector or a Venturi, can be located in the inlet of an engine downstream of a pre-compressor throttle and upstream of an inlet throttle, and can be used to provide vacuum proportional to the flow rate of engine inlet air. As shown in Fig. As shown in Figure 5, the vacuum generated by the vacuum source in the engine can be used to drive a constant flow through a crankcase ventilation system, a fuel evaporation system and an exhaust gas recirculation (EGR) system included in an engine system.

[0010] Fig. Figure 1 schematically shows an example of a power machine system 100 according to an embodiment of the present disclosure. The power machine system 100 can be included in a vehicle system to at least partially support the propulsion of the vehicle system. For example, the power machine system 100 can be included in a suitable hybrid vehicle system, for example, a hybrid electric vehicle (HEV), which includes additional vehicle propulsion systems, for example, motors, or it can be included in a non-HEV vehicle that does not contain a motor and is only powered by an internal combustion engine.

[0011] The power engine system 100 comprises a power engine 10 with a power engine block 102, which has several cylinders 104. The cylinders 104 can receive intake air via an intake port 108 from an intake manifold 106 and can discharge the combustion gases to an exhaust manifold 110 and further to the atmosphere via an exhaust port 112. The intake air received in the intake port 108 can be cleaned as it flows through an intake air filter 107.

[0012] The power unit can include at least one turbocharger, which contains a compressor 121 and a turbine 123. The compressor 121 is coupled to the inlet duct 108 and is driven by the turbine 123, which is coupled to the outlet duct 112. The compressor 121 compresses air in an inlet duct 108 for supply to an inlet manifold 106. In some examples, the power unit system 100 can include a compressor bypass line 173, which is coupled to the inlet 108 upstream and downstream of the compressor 121. The compressor bypass line 173 can include a compressor bypass valve 175, which is configured to regulate the amount of airflow bypassing the compressor 121. Furthermore, the inlet 108 can contain a charge air cooler (CAC) 157 in the inlet 108 downstream of the compressor 121.The charge air cooler 157 can be configured to reduce the temperature of the compressed air leaving the compressor 121 before it is fed to the intake manifold 106. The intake duct 108 can contain a compressor inlet pressure sensor 171, which is positioned upstream of the compressor 121. Furthermore, in some examples, an additional pressure sensor 182 can be positioned in the intake duct 108 downstream of the compressor 121.

[0013] An intake throttle valve 114 is positioned downstream of the compressor 121. The intake throttle valve 114 can be configured to change the amount of air supplied to the intake manifold 106. In this particular example, the position of the throttle valve 114 can be changed by a controller 120 via a signal supplied to an electric motor or actuator contained within the throttle valve 114, a configuration commonly referred to as electronic throttle control (ETC). In this way, the throttle valve 114 can be actuated to change the intake air supplied to the multiple cylinders 104. The intake duct 108 can contain a mass airflow sensor 122 and an intake manifold pressure sensor 124 to provide the respective MAF and MAP signals to the controller 120. In some examples, the air mass flow sensor 122 and the intake manifold pressure sensor 124 can be positioned downstream of the intake throttle 114 in the intake channel 108.

[0014] An exhaust gas cleaning device 116 is arranged along the exhaust channel 112 in the illustration. In some examples, the exhaust gas cleaning device 116 can be positioned downstream of the turbine 123 in the exhaust channel 112. The exhaust gas cleaning device 116 can be a three-way catalyst (TWC), a NOₓ catalyst, or a NOₓ catalyst. xThe exhaust gas purification device 116 can be various other exhaust gas purification devices or combinations thereof. In some embodiments, the exhaust gas purification device 116 can be periodically reset during operation of the engine 100 by operating at least one cylinder of the engine at a specific air-fuel ratio. In the illustration, an exhaust gas sensor 118 is coupled to the exhaust port 112 upstream of the exhaust gas purification device 116. The sensor 118 can be any suitable sensor for providing an indication of the exhaust gas-air-fuel ratio, such as a linear oxygen sensor or UEGO (universal or wide-range exhaust gas oxygen) sensor, a dual-state oxygen sensor, or an EGO, HEGO (heated EGO), NOx, HC, or CO sensor. It is understood that the engine system 100 is shown in simplified form and may include other components.

[0015] In the illustration, a fuel injector 132 is directly coupled to cylinder 104 to inject fuel directly into it, proportional to the pulse width of a signal received by the controller 120. In this way, the fuel injector 132 provides so-called direct fuel injection into cylinder 104. The fuel injector can be located, for example, in the side or top of the combustion chamber. Fuel can be supplied to the fuel injector 132 via a fuel system 126. In some embodiments, as an alternative or additionally, in a configuration that provides so-called inlet port injection of fuel into the intake port upstream of cylinder 104, the cylinder 104 can contain a fuel injector arranged in the intake manifold 106.

[0016] The fuel system 126 includes a fuel tank 128 coupled to a fuel pump system 130. A filler pipe and a tank cap 131 are coupled to the fuel tank 128 for refilling it with fuel. The fuel pump system 130 may include one or more pumps for pressurizing fuel supplied by the nozzles 132 of the power engine system 100, such as the fuel injectors 132. Although only a single injector 132 is shown, additional nozzles are provided for each cylinder. It is understood that the fuel system 126 may be a non-return fuel system, a return fuel system, or various other types of fuel systems.

[0017] The engine system 100 can contain multiple gas discharge sources, with gas being directed from the gas discharge source to the intake port 108. For example, the engine system 100 can direct various gas flows to an intake system of the engine 10, such as a fuel evaporation system 30, an exhaust gas recirculation (EGR) system 20, and / or a crankcase ventilation system 40. As described above, in approaches that rely on engine intake manifold vacuum to drive gas circulation through the aforementioned systems, the gas flow rate through such systems can vary adversely based on the air flow rates in the intake port 108.To provide a constant flow rate through such systems under all engine operating conditions, a vacuum source 179 can be provided in the inlet channel 108, so that gas supply rates from the crankcase ventilation system 40, from the fuel evaporation system 30 and from the EGR system 20 can be supplied proportionally to the engine air flow rate under different engine operating conditions.

[0018] As in the exemplary power machine system of Fig. As shown in Figure 1, the inlet channel 108 can contain a pre-compressor throttle 159, which is positioned upstream of the compressor 121 in the inlet channel 108. For example, a vacuum quantity can be generated at the vacuum source 179 positioned downstream of the pre-compressor throttle 159 by holding the pre-compressor throttle 159 in a partially open position to draw gas flow through the fuel evaporation system 30, the exhaust gas recirculation (EGR) system 20 and / or the crankcase ventilation system 40.

[0019] For example, the crankcase ventilation system 40 includes a crankcase inlet line 155, which is coupled upstream of the pre-compressor throttle 159 to the inlet port 108 and to an inlet 156 of a sealed crankcase of the engine 10. Furthermore, the crankcase ventilation system 40 includes a crankcase outlet line 142, which is coupled to an outlet 161 of the sealed crankcase of the engine 10. A check valve 177 may be included in the line 142, so that crankcase ventilation gases are driven unidirectionally through the crankcase ventilation system 40 by the vacuum provided at the vacuum source 179 in one direction from upstream of the pre-compressor throttle 159 to the inlet port between the pre-compressor throttle 159 and the compressor 121. The crankcase ventilation system 40 may also include an oil separator 160, which is positioned next to the outlet 161 in the line 142.Since the gas flow through the crankcase ventilation system is unidirectional, the crankcase ventilation system may contain only a single oil separator 160.

[0020] In some examples, the crankcase exhaust line 142 can additionally be coupled to the intake port 108 via line 151 at a point downstream of the intake throttle 114, so that under certain conditions, vacuum from the intake manifold 106, in addition to vacuum generated at a vacuum source 179, can be used to draw crankcase gases through the crankcase ventilation system into the intake manifold 106. Line 151 can additionally include a check valve 153 to provide unidirectional flow through the crankcase ventilation system 40.

[0021] In some examples, the crankcase ventilation system 40 may further include a current-limiting device 163 arranged in the duct 142. The current-limiting device 163 may be a sound damper configured to limit the current at the discharge outlet 161 of the crankcase ventilation system in response to a current in the crankcase ventilation system exceeding a threshold quantity.

[0022] Furthermore, the engine system can include a fuel evaporation system 30, which contains a fuel vapor reservoir 134. Vapors generated in the fuel system 126 can be directed via a vapor recovery line 136 to an inlet of the fuel vapor reservoir 134. The fuel vapor reservoir can be filled with a suitable adsorbent to temporarily contain fuel vapors (including vaporized hydrocarbons) during fuel refueling operations and during "operational loss" (i.e., fuel evaporated during vehicle operation). In one example, the adsorbent used is activated carbon. However, other adsorbents are also suitable.

[0023] In the examples where the power unit system 100 is coupled to a hybrid vehicle system, the power unit may have reduced operating times because the vehicle is driven by the power unit system 100 under some conditions and by a system energy storage device or a motor under other conditions. Although the reduced power unit operating time decreases the overall carbon emissions from the vehicle, it may also lead to a reduction in the purging of fuel vapors from the vehicle's fuel evaporation system. To counteract this, a fuel tank shut-off valve 143 may optionally be included in the fuel vapor recovery line 136, so that the fuel tank 128 is coupled to the reservoir 134 via the shut-off valve 143.The shut-off valve 143 can be kept closed during regular engine operation to limit the amount of vapors generated during the day or "operational losses" that are routed from fuel tank 128 to reservoir 134. During refueling operations and under selected purging conditions, the shut-off valve 143 can be opened temporarily, for example, for a certain period, to route fuel vapors from fuel tank 128 to reservoir 134. By opening the valve under conditions when the fuel tank pressure is higher than a threshold (for example, above a limit of mechanical pressure in the fuel tank beyond which the fuel tank and other fuel system components could be mechanically damaged), the refueling vapors can be released into the reservoir, and the fuel tank pressure can be maintained within pressure limits.Although the shut-off valve 143 is positioned along the vapor recovery line 136 in the example shown, in other examples the shut-off valve may be mounted on the fuel tank 128. The fuel vapor reservoir 134 may be flow-coupled to a vent line 138 containing a vent valve 146. Under certain conditions, the vent line 138 may discharge gases from the fuel reservoir 134 to the atmosphere, for example, when storing or capturing fuel vapors from the fuel system 126. The fuel reservoir is coupled to the inlet channel 108 via a purge line 140 containing a purge valve 144. For example, during a fuel vapor purge event, a vacuum generated at the vacuum source 179 may be used to purge the reservoir 134, so that fuel vapors stored in the reservoir 134 are fed to the inlet channel 108.

[0024] The vent line 138 can allow fresh air to be drawn into the fuel vapor reservoir 134 when stored fuel vapors from the fuel reservoir are purged to the intake manifold 106 via the purge line 140. Specifically, the vent line 146 can be opened so that fresh air can be drawn into the reservoir via the vent line 138, and the vacuum generated at the vacuum source 179 can be used to draw fuel vapors from the reservoir 134 into the intake manifold 108. The purge valve 144 can be adjusted to control a purge flow rate supplied to the engine 10. In some examples, the purge line 140 can be coupled to a line 142 so that the vacuum generated at the vacuum source 179 can be supplied to the fuel evaporation system 30 in addition to the crankcase ventilation system 40.

[0025] The engine system 100 can also include an exhaust gas recirculation (EGR) system 20. The EGR system 20 includes an EGR line 141, which is in flow communication with the intake port 108 and the exhaust manifold 110. The EGR line 141 includes an EGR valve 145, which is configured to control the amount of exhaust gas flowing through the line 141. Furthermore, the EGR line 141 can be coupled to the vacuum source 179, so that the vacuum generated at the vacuum source 179 can be used to drive gas through the EGR system 20. For example, the EGR line 141 can be connected to line 142 so that the vacuum generated at the vacuum source 179 can be supplied to the EGR system 20, in addition to the fuel evaporation system 30 and the crankcase ventilation system 40. In some examples, the EGR line 141 can be connected to the exhaust line 112 downstream of the turbine 123 and the exhaust gas purification device 116.In other examples, however, the EGR line 141 can be coupled to the exhaust port 112 upstream of the turbine 123 and / or upstream of the exhaust gas cleaning device 116. The EGR in line 141 can be cooled along its path.

[0026] In the representation of Fig. The controller 120 is a microcomputer comprising a microprocessor unit 148, input / output ports, a computer-readable storage medium 150 for executable programs and calibration values ​​(for example, a read-only memory chip, a random-access memory, a maintenance memory, etc.), and a data bus. The read-only storage medium 150 can be programmed with computer-readable data that represents instructions executable by the processor 148 for carrying out the procedures described below, as well as other variants that are anticipated but not specifically listed.

[0027] The control unit 120 can receive information from several sensors 152 of the engine system 100, corresponding to measurements such as the introduced air mass flow, the engine coolant temperature, the ambient temperature, the engine speed, the throttle valve position, the manifold absolute pressure signal, the compressor inlet pressure, the inlet volume pressure, the inlet port pressure, the air-fuel ratio, the fuel fraction of the introduced air, the inlet volume pressure, the fuel tank pressure, the fuel reservoir pressure, etc. It should be noted that various combinations of the above sensors can be used to generate these and other measurements. The sensors 152 can include a pressure sensor 180 positioned upstream of the pre-compressor throttle 159, a pressure sensor 171 positioned upstream of the compressor 121, a pressure sensor 182 positioned downstream of the compressor 121, and the pressure sensor 124.Furthermore, the controller 120 can control several actuators 154 of the power machine system 100 based on the signals from the several sensors 152. Examples of the actuators 154 include the pre-compressor throttle 159, the inlet throttle 114, the fuel injector 132, the compressor bypass valve 175, the EGR valve 145, and the purge valve 144.

[0028] Fig. Figure 2 shows another exemplary power machine system 100, which includes a vacuum source 179 positioned in the engine intake channel 108 and is used to generate vacuum to assist in driving gas flow through the crankcase ventilation system 40, the fuel evaporation system 30, and the EGR system 20. Fig. The two identical numbers shown correspond to the numbers described above. Fig. 1 elements shown that have the same numbers.

[0029] In the Fig. In the example shown, the vacuum source 179 comprises an ejector or a Venturi positioned in an inlet channel 108 at a location between the pre-compressor throttle 159 and the compressor 121. In this example, the gas discharge sources are coupled, for example, via line 142 to a low-pressure section of the ejector 179. Under engine operating conditions, when air flows through the inlet channel 108 and the ejector 179, a vacuum is generated in the ejector, the generated vacuum being proportional to the volume of air flowing through the ejector. Thus, when air flows through the inlet channel 108, the volume of vacuum generated by the vacuum source 179 is also increased. Therefore, under conditions of high engine air velocity, for example, when the inlet throttle 114 is opened to a greater extent, the vacuum available to the gas discharge source can advantageously be increased.In this way, gas supply rates from the crankcase ventilation system 40, the fuel vapor recovery system 30, and the EGR system 20 can be supplied proportionally to the engine air flow rate under various engine operating conditions. For example, the amount of crankcase ventilation flow and the amount of fuel vapor recovery flow can be increased under conditions of high engine intake flow, if an increase in flow in such systems is desired.

[0030] Fig. Figure 3 shows another exemplary power engine system 100, which includes a vacuum source 179 used to generate vacuum to assist the driving of gas flow through the crankcase ventilation system 40, the fuel evaporation system 30, and the EGR system 20. Fig. The three identical numbers shown correspond to the numbers described above. Fig. 1 elements shown that have the same numbers.

[0031] In dem in Fig. In the example shown, the vacuum source 179 comprises an ejector or a Venturi positioned in a compressor bypass channel 193 coupled upstream and downstream of the compressor 121 to the inlet channel 108. In this example, the bypass channel 193 may include a valve 181 for controlling the airflow through the channel 193. The vacuum source 179 includes an ejector arranged in the bypass channel 193 and may be positioned upstream of the valve 181 (as shown) or downstream of the valve 181. In this example, the gas discharge sources are coupled, for instance, via line 142 to a low-pressure section of the ejector 179. In some examples, bypass line 193 may be the same as compressor bypass line 173. In other examples, however, bypass channel 193 containing the vacuum source 179 may be an additional bypass channel that differs from bypass line 173.

[0032] As noted above, the valve 181 can be configured to control the amount of air flowing through the ejector 179. Under engine operating conditions, when a vacuum quantity in the intake manifold 106 is sufficient to drive gas flow through the crankcase ventilation system 40, the fuel evaporation system 30, and the EGR system 20, then the valve 181 can be closed or adjusted to reduce flow through the ejector 179, for example, when the air flow in the intake port is below a threshold quantity.However, under engine operating conditions, if a vacuum quantity in the intake manifold 106 is insufficient to drive gas flow through the crankcase ventilation system 40, the fuel evaporation system 30 and the EGR system 20, then the opening dimension of the valve 181 can be increased, for example, if an air flow rate in the intake channel is above a threshold quantity, and / or if an opening dimension of the intake throttle 114 is greater than a threshold quantity, in order to increase the amount of air flowing through the ejector 179, so that an increased vacuum is available to the crankcase ventilation system 40, the fuel evaporation system 30 and the EGR system 20.

[0033] Fig. Figure 4 shows another exemplary power machine system 100, which includes a vacuum source 179 used to generate vacuum to assist the driving of gas flow through the crankcase ventilation system 40, the fuel evaporation system 30, and the EGR system 20. Fig. The four identical numbers shown correspond to the ones described above. Fig. 1 elements shown that have the same numbers.

[0034] In the Fig. In the example shown in Figure 4, the vacuum source 179 comprises an ejector or a Venturi positioned in a throttle bypass channel 195 coupled upstream and downstream of the inlet throttle 114. In this example, the bypass channel 195 may include a valve 191 for controlling the amount of air flowing through the channel 195. The vacuum source 179 includes an ejector arranged in the bypass channel 195 and may be positioned upstream of the valve 191 (as shown) or downstream of the valve 191. In this example, the gas discharge sources are coupled, for instance, via line 142 to a low-pressure section of the ejector 179.

[0035] As noted above, the valve 191 can be configured to control the amount of air flowing through the ejector 179. Under engine operating conditions, when a vacuum quantity in the intake manifold 106 is sufficient to drive gas flow through the crankcase ventilation system 40, the fuel evaporation system 30, and the EGR system 20, then the valve 191 can be closed or adjusted to reduce flow through the ejector 179, for example, when the air flow in the intake port is below a threshold quantity.However, under engine operating conditions, if a vacuum quantity in the intake manifold 106 is insufficient to drive gas flow through the crankcase ventilation system 40, the fuel evaporation system 30 and the EGR system 20, then the opening dimension of the valve 191 can be increased, for example, if an air flow rate in the intake channel is above a threshold quantity, and / or if an opening dimension of the intake throttle 114 is greater than a threshold quantity, in order to increase the amount of air flowing through the ejector 179, so that an increased vacuum is available to the crankcase ventilation system 40, the fuel evaporation system 30 and the EGR system 20.

[0036] Fig. Figure 5 shows an exemplary method 500 for operating a turbocharged engine to provide vacuum for driving electricity through a crankcase ventilation system and / or a fuel evaporation system and / or an exhaust gas recirculation (EGR) system that is / are included in an engine system. As described above Fig. As shown in Figures 1-4, a power engine system can include a vacuum source 179 which is used to provide a constant vacuum throughout the power engine operation to a crankcase ventilation system and / or a fuel evaporation system and / or an exhaust gas recirculation (EGR) system.

[0037] In procedure 502, procedure 500 includes determining whether access conditions are met. Access conditions may include, for example, a power engine in operation and the operating conditions of a turbocharged power engine. If access conditions are met in procedure 502, procedure 500 proceeds to procedure 504. In procedure 504, procedure 500 includes generating a vacuum. This may include, for example, a vacuum source, such as the one in the Fig. The vacuum source 170 shown in Figures 1-4 can be used to generate a vacuum so that it can be drawn off from the vacuum source located in the inlet of the engine at a point downstream of a pre-compressor throttle and upstream of an inlet throttle. For example, the vacuum source can include an ejector located in the inlet of the engine between the pre-compressor throttle and a compressor inlet, as shown in Figure 1-4. Fig. 2 shown. As another example, the vacuum source can include an ejector arranged in the compressor bypass line, as shown in Figure 2. Fig. 3 shown. As another example, the vacuum source can include an ejector located in the inlet throttle bypass line, as shown in Fig. 4 shown. As another example, the vacuum source can be positioned downstream of a pre-compressor throttle valve that is set in a partially closed position, as for example in Fig. 1 shown.

[0038] In 506, the method comprises applying the generated vacuum to a crankcase ventilation system. For example, the vacuum generated at the vacuum source 179 can be drawn off, for example, via line 142 and applied to a discharge outlet of a unidirectional crankcase ventilation system, wherein an inlet of the crankcase ventilation system is coupled to the inlet of the engine at a location upstream of the pre-compressor throttle.

[0039] In the case of 508, the procedure 500 can include applying the generated vacuum to an exhaust gas recirculation system. For example, the vacuum generated at the vacuum source 179 can be drawn off via line 142 and applied to an exhaust gas recirculation line to draw engine exhaust into an intake manifold of the engine, while the drawn-off vacuum is further applied to the discharge outlet of the crankcase ventilation system.

[0040] In procedure 510, procedure 500 involves adjusting a fuel injection quantity. A fuel injection quantity in the engine can be adjusted, for example, based on the amount of fuel discharged from the crankcase ventilation system's exhaust outlet and / or the EGR system. A fuel injection quantity into the engine can be decreased, for example, in response to an increased amount of fuel supplied to the engine intake from the crankcase ventilation system and / or the EGR system.

[0041] For 512, procedure 500 includes determining whether fuel vapor purging conditions exist. For example, fuel vapor purging conditions may be based on the fact that the amount of fuel vapor stored in the fuel vapor reservoir is greater than a threshold quantity. If fuel vapor purging conditions do not exist for 512, then procedure 500 proceeds to 518, described below. However, if purging conditions do exist for 512, then procedure 500 proceeds to 514. For 514, procedure 500 includes applying a generated vacuum to purge fuel vapors from a fuel vapor reservoir.In response to a fuel vapor purging event, for example, a vacuum generated at the vacuum source 179 can be drawn, for example, via line 142 and applied to the fuel vaporization system 30 to purge fuel vapors from the fuel vapor reservoir to an intake manifold of the engine, while the drawn vacuum is further applied to the discharge outlet of the crankcase ventilation system. At 516, the procedure 500 again includes adjusting the fuel injection quantity. A fuel injection quantity in the engine can be adjusted, for example, based on a fuel quantity discharged from the fuel vaporization system during the fuel vapor purging event. A fuel quantity injected into the engine can be decreased, for example, in response to an increased fuel quantity supplied to the engine intake from the fuel vapor reservoir.

[0042] At 518, procedure 500 includes determining whether conditions of increasing engine intake airflow are present. Conditions of increasing engine intake airflow can be determined, for example, based on the position of the intake throttle 114 or on an increase in engine speed and / or load. If conditions of increasing engine intake airflow are not present at 518, procedure 500 proceeds to 524, as described below. However, if conditions of increasing engine intake airflow are present at 518, procedure 500 proceeds to 520.

[0043] At 520, the procedure involves increasing the amount of vacuum. The amount of vacuum drawn from the vacuum source can be increased, for example, in response to an increase in the flow rate through the engine inlet and / or in response to an increase in the opening dimension of the inlet throttle. For example, with an increase in the airflow rate through the engine, the amount of vacuum generated by the vacuum source 179 can also increase. If the vacuum source is located in a compressor bypass line, for example, the one in Fig. As another example, the opening dimension of a valve in the bypass line, for example valve 181, can be increased in response to an increase in the amount of air flowing in the engine inlet, as shown in section 3, in the bypass line 193. Fig.As a further example, the opening dimension of a valve in the bypass line, for example of valve 191, can be increased in response to an increase in the amount of air flowing in the engine inlet, as shown in the bypass line 195 shown in Figure 4.

[0044] In procedure 522, procedure 500 includes adjusting the fuel injection quantity. A fuel injection quantity in the engine can be adjusted, for example, based on the amount of fuel supplied to the engine by the fuel evaporation system and / or the crankcase ventilation system and / or the EGR system. A fuel injection quantity in the engine can be decreased, for example, in response to an increased amount of fuel supplied to the engine intake by the crankcase ventilation system and / or the EGR system and / or the fuel evaporation system.

[0045] At 524, procedure 500 includes determining whether a flow rate in a gas discharge outlet is greater than a threshold. For example, a flow rate in the fuel evaporation system, the crankcase ventilation system, and the EGR system can be determined and compared to a threshold flow rate. If a flow rate in a gas discharge outlet at 524 is not greater than the threshold, then procedure 500 proceeds to 525 to remove the flow limit in the discharge outlet and maintain the fuel injection quantities. However, if a flow rate in a gas discharge outlet at 524 is greater than the threshold, then procedure 500 proceeds to 526. At 526, procedure 500 includes limiting a flow rate through the discharge outlet.In response to a current exceeding a threshold value at the exhaust outlet of the unidirectional crankcase ventilation system, the current at the exhaust outlet can be limited to a value below the threshold, for example, by a current limiting device 163. Alternatively, the purge valve 144 can be adjusted to limit the current in the purge line 140. Another example is the EGR valve 145, which can be adjusted to limit the current in the EGR line 141.

[0046] In procedure 528, procedure 500 includes adjusting the fuel injection quantity. For example, the fuel injection quantity in the engine can be further adjusted based on the amount of fuel supplied to the engine by the fuel evaporation system and / or the crankcase ventilation system and / or the EGR system. For example, the amount of fuel injected into the engine can be decreased in response to an increased amount of fuel supplied to the engine intake by the crankcase ventilation system and / or the EGR system and / or the fuel evaporation system.

[0047] It should be noted that the exemplary control routines contained herein can be used with various power unit and / or vehicle system configurations. The specific routines described here can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. Thus, various actions, operations, or functions shown can be performed in the sequence shown, in parallel, or, in some cases, omitted. Likewise, the processing sequence need not necessarily achieve the features and advantages of the exemplary embodiments described herein, but is provided for better illustration and description. One or more of the actions or functions shown can be performed repeatedly, depending on the specific strategy used.Furthermore, the described actions can graphically represent code to be programmed into the computer-readable storage medium in the power engine control system.

[0048] It is understood that the configurations and routines disclosed herein are purely exemplary and that these particular embodiments should not be considered limiting, as numerous variations are possible. The above technology can, for example, be applied to V-6, R-4, R-6, V-12, Boxer-4, and other types of power engines. Furthermore, one or more of the various system configurations can be used in combination with one or more of the described diagnostic routines. The subject matter of this disclosure thus includes all new and non-obvious combinations and sub-combinations of the various systems and configurations and other features, functions, and / or properties disclosed herein.

Claims

[1] Method for a turbocharged power engine (10), comprising: Drawing vacuum from a vacuum source (179) positioned in an inlet (108) of the engine (10) downstream of a pre-compressor throttle (159) and upstream of an inlet throttle (114); Applying the drawn vacuum to a discharge outlet (161) of a unidirectional crankcase ventilation system (40), wherein an inlet of the crankcase ventilation system (40) is coupled to the inlet (108) of the engine (10) upstream of the pre-compressor throttle (159). [2] Method according to claim 1, further comprising, in response to a fuel vapor purging event, applying the drawn vacuum to purge fuel vapors from a fuel vapor reservoir (134) to an inlet manifold (106) of the engine (10), while the drawn vacuum is further applied to the discharge outlet (161). [3] Method according to claim 1, further comprising applying the drawn vacuum to an exhaust gas recirculation line (141) to draw engine exhaust gas into an inlet manifold (106) of the engine (10), while the drawn vacuum is further applied to the discharge outlet (161). [4] Method according to claim 1, wherein the vacuum source (179) comprises an ejector arranged in the inlet (108) of the engine (10) between the pre-compressor throttle (159) and a compressor inlet. [5] Method according to claim 1, wherein the vacuum source (179) comprises an ejector arranged in a compressor bypass line (193). [6] Method according to claim 1, wherein the vacuum source (179) comprises an ejector arranged in an inlet throttle bypass line (195). [7] Method according to claim 1, further comprising increasing an amount of the vacuum drawn from the vacuum source (179) in response to increasing a flow through the engine inlet (108). [8] Method according to claim 1, further comprising increasing an amount of the vacuum drawn from the vacuum source (179) in response to increasing an opening dimension of the inlet throttle (114). [9] Method according to claim 1, further comprising, in response to the fact that a flow rate in the discharge outlet (161) of the unidirectional crankcase ventilation system (40) is greater than a threshold value, limiting the flow rate in the discharge outlet (161) to an amount below the threshold value. [10] Method according to claim 1, further comprising adjusting a fuel injection quantity in the engine (10) based on a fuel quantity discharged from the discharge outlet (161). [11] Method for a turbocharged power engine (10) according to claim 1, further comprising: Generating a vacuum via an ejector in an inlet (108) of the engine (10) downstream of a pre-compressor throttle (159) and upstream of an inlet throttle (114); Applying the generated vacuum to a crankcase ventilation system (40) to drive gases through the crankcase ventilation system (40) from upstream of the pre-compressor throttle (159) to the inlet at the ejector. [12] Method according to claim 11, further comprising, in response to a fuel vapor purging event, applying the generated vacuum to purge fuel vapors from a fuel vapor reservoir (134) to an inlet manifold (106) of the engine (10). [13] Method according to claim 11, further comprising applying the generated vacuum to an exhaust gas recirculation line (141) to draw engine exhaust gas from downstream of an exhaust gas purification catalyst into an intake manifold (106) of the engine (10). [14] Method according to claim 11, wherein the ejector is positioned in a compressor bypass line (193). [15] Method according to claim 11, wherein the ejector is positioned in an inlet throttle bypass line (195). [16] Method according to claim 11, further comprising increasing an amount of vacuum generated via the ejector in response to increasing a flow through the engine inlet (108). [17] Method according to claim 11, further comprising: Applying the generated vacuum to an exhaust gas recirculation line (141) to draw engine exhaust gas from downstream of an exhaust gas purification catalyst into an intake manifold (106) of the engine (10); and In response to a fuel vapor purging event, the generated vacuum is applied to purge fuel vapors from a fuel vapor reservoir (134) to an inlet manifold (106) of the engine (10). [18] Method according to claim 17, wherein the ejector is positioned in a compressor bypass line (193). [19] Method according to claim 17, wherein the ejector is positioned in an inlet throttle bypass line (195). [20] Method according to claim 17, further comprising increasing an amount of vacuum generated via the ejector in response to increasing a flow through the engine inlet (108).

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