Bi-turbocharger boost pressure control flap
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- FORD GLOBAL TECH LLC
- Filing Date
- 2013-12-19
- Publication Date
- 2026-07-30
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
AREA
[0001] The present disclosure relates to an internal combustion engine. GENERAL STATE OF THE ART AND BRIEF OVERVIEW
[0002] Turbochargers for internal combustion engines can incorporate a boost pressure control valve to regulate the proportion of exhaust gas flow that passes through the turbocharger's exhaust turbine stage. By varying the boost pressure control valve position, the boost pressure delivered by the turbocharger's compressor stage can be increased or decreased accordingly. Engines with twin turbochargers, such as V-engines, can utilize the boost pressure control valve to balance the boost pressure delivered by each turbocharger. Typically, for engines with twin turbochargers, the system is assumed to be symmetrical, meaning each boost pressure control valve is actuated to the same position.
[0003] However, the inventors recognized that most V-engine systems are not perfectly symmetrical. The asymmetries found in V-engine systems result from differences in the exhaust system routing, exhaust manifold design, turbine housing casting design, and / or boost control valve channel design between the engine banks. Furthermore, manufacturing differences can cause asymmetry in the boost control valve channels or the spring system used to counteract the pneumatic force in pneumatically actuated boost control valves. Additionally, hysteresis within the actuators can lead to asymmetry, as small movements can cause each actuator to be at opposite ends of the hysteresis loop.
[0004] Therefore, even if the boost pressure control flaps are actuated to the same position, an imbalance between the turbochargers can result due to the existing asymmetry in the system. This can lead to the turbochargers operating in different states, such as with different turbine power outputs, turbine shaft speeds, and pneumatic actuators with different boost pressure control flap positions. Under certain engine operating conditions, it may be desirable for operation to occur near the turbine shaft speed limit. However, in an asymmetrical system, the fastest-rotating turbine limits the system performance, and depending on the degree of asymmetry, the system's efficiency can be significantly reduced.
[0005] Accordingly, an engine system is provided that enables the detection and compensation of asymmetries present in a twin-turbocharged V-engine. The engine system comprises a first turbocharger with a first boost pressure control valve, a first boost pressure control valve actuator, and a first turbocharger sensor; a second turbocharger with a second boost pressure control valve, a second boost pressure control valve actuator, and a second turbocharger sensor; and a controller configured to adjust the first boost pressure control valve actuator such that a parameter of the first turbocharger matches a parameter of the second turbocharger, based on the output of the first and second turbocharger sensors, respectively.
[0006] In this way, the output from the turbocharger sensors can be used to detect if a turbocharger parameter, such as turbine speed or power, is unbalanced between the two turbochargers. If the turbochargers are unbalanced, the boost pressure control valve of at least the first turbocharger can be adjusted until the turbocharger parameters are balanced. This allows for the compensation of small variations in the boost pressure supplied by each turbocharger. Furthermore, engine power can be increased by detecting if a turbocharger is operating at a speed or power output lower than desired and adjusting the boost pressure control valve of that turbocharger to increase its turbocharger power.
[0007] The advantages mentioned above, as well as other advantages and features of the present description, will become apparent from the following detailed description alone or in conjunction with the accompanying drawings.
[0008] It will be understood that the above summary is provided to offer, in simplified form, a selection of concepts that are described in more detail in the full description. It is not intended to identify any principal or essential features of the claimed subject matter, the scope of which is defined solely in the claims that follow the full description. Furthermore, the claimed subject matter is not limited to implementations that eliminate any potential disadvantages mentioned above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Fig. Figure 1 shows a schematic representation of an exemplary engine system;
[0010] Fig. Figure 2 shows a flowchart illustrating a method for balancing turbochargers according to an embodiment of the present disclosure;
[0011] Fig. Figure 3 is a diagram that illustrates exemplary operating parameters of interest. DETAILED DESCRIPTION
[0012] As described above, asymmetries can exist between the turbocharger banks of a V-engine. These asymmetries can lead to unbalanced turbocharger performance, even if the boost control valves of each turbocharger are set to the same position. To compensate for unequal turbocharger performance, each turbocharger can be equipped with a sensor, such as a turbine speed sensor, a boost control valve position sensor, or an actuator electric motor current sensor. The output from the turbocharger sensors can be used to calculate a turbocharger performance parameter, such as turbine power or turbine speed. If the turbine speed or power does not match between the two turbochargers, the boost control valves of the turbochargers can be adjusted until the corresponding parameters are balanced. Fig. Figure 1 shows an engine with two turbochargers, boost pressure control flaps and turbocharger sensors. Fig. Figure 1 also shows a tax system which is in Fig. The two described procedures can be executed. Exemplary operating parameters that occur during the execution of the procedure are shown. Fig. 2 can be observed, are in Fig. 3 shown.
[0013] Fig. Figure 1 shows a schematic representation of an exemplary engine system 100 with a multi-cylinder combustion engine 110 and twin turbochargers 120 and 130 As a non-restrictive example, the engine system 100 It may be included as part of a car's drive system. The engine system 100 Intake air can enter through an intake duct 140 record. The intake channel 140 can an air filter 156 exhibit. At least a portion of the inlet air (MAF_1) can be directed to a compressor. 122 of the turbocharger 120 via a first branch of the inlet channel 140 , as in 142displayed, directed and at least a portion of the inlet air (MAF_2) can be directed to a compressor 132 of the turbocharger 130 via a second branch of the inlet channel 140 , as in 144 displayed, directed.
[0014] The first portion of the total intake air (MAF_1) can be compressed using the compressor. 122 be compressed and then fed to the intake manifold 160 via the intake air duct 146 are supplied. Thus, the inlet channels form 142 and 146 A first branch of the engine air intake system. Similarly, a second portion of the total intake air (MAF_2) can be drawn in using the compressor. 132 be compressed and then fed to the intake manifold 160 via the intake air duct 148 are supplied. Thus, the inlet channels form 144 and 148 a second branch of the engine air intake system. As in Fig. As shown in Figure 1, the intake air can be drawn from the intake channels. 146 and 148 via a common inlet channel 149 be mixed again before they enter the intake manifold. 160 reached where the intake air can be supplied to the engine. In some examples, the intake manifold 160 an intake manifold pressure sensor 182 and / or an intake manifold temperature sensor 183 exhibiting each of which is linked to the tax system 190 are connected. The inlet channel 149 can use an air cooler 154 and / or a throttle valve 158 The position of the throttle valve can be controlled by the control system via a throttle valve actuator. 157 be set up, which is connected to the tax system 190 is communicatively coupled. As in Fig. As shown in Figure 1, a first compressor return valve (CRV1) can be used. 152 and a second compressor return valve (CRV2) 153be provided to selectively direct intake air around the compressor stages of the turbochargers 120 and 130 via the return channels 150 , 151 to be attributed to.
[0015] The engine 110 can have multiple cylinders, two of which are in Fig. 1 as 20A and 20B are shown. It should be noted that in some examples the engine 110 It can have more than two cylinders, for example 3, 4, 5, 6, 8, 10 or more cylinders. These different cylinders can be evenly distributed and arranged in a V-configuration in series with one of the cylinders 20A and 20B be arranged. The cylinders 20A and 20B Other cylinders in the engine may be identical in some examples and have identical components. For this reason, only the cylinder 20A Described in detail. The cylinder 20A features a combustion chamber22A up, which are from the combustion chamber walls 24A is defined. A piston 30A is inside the combustion chamber 22A arranged and with a crankshaft 34 via a crank arm 32A coupled. The crankshaft 34 can use an engine speed sensor 181 exhibiting the speed of the crankshaft 34 can identify the engine speed sensor. 181 can be used with the tax system 190 It must be connected to allow for a determination of the engine speed. The cylinder 20A can a spark plug 70A to deliver a spark to the combustion chamber 22A exhibit. In some examples, the spark plug may 70A However, they can be omitted, for example, if the engine 110 It is configured to provide combustion via compression ignition. The combustion chamber 22A can a fuel injector 60Aexhibiting, which in this example can be configured as a channel-based fuel injector. In other examples, the fuel injector can 60A be configured as a direct cylinder injection valve.
[0016] The cylinder 20A Furthermore, at least one inlet valve may be used. 40A exhibiting that of an inlet valve actuator 42A is actuated, and at least one outlet valve 50A , which is from an exhaust valve actuator 52A is actuated. The cylinder 20A It can have two or more inlet valves and / or two or more exhaust valves with their associated valve actuators. In this specific example, the actuators are 42A and 52A Configured as camshaft actuators, but in other examples electromagnetic valve actuators (EVAs) can be used. The intake valve actuator 42A can be used to open and close the inlet valve 40Amust be activated so that intake air flows through the intake duct. 162 , which is connected to the intake manifold 160 is connected to the combustion chamber 22A achieved. The exhaust valve actuator can be operated in the same way. 52A to open and close the outlet valve 50A for draining combustion products from the combustion chamber 22A into the outlet channel 166 can be operated. In this way, the intake air of the combustion chamber can be controlled. 22A via the inlet channel 162 are supplied and the combustion products can be removed from the combustion chamber 22A via the outlet channel 166 be drained.
[0017] You will appreciate that the cylinder 20B or other cylinders of the engine 110 the same or similar components of the cylinder 20A as described above. For example, the intake air of the combustion chamber can be affected. 22Bvia the inlet channel 164 are supplied and the combustion products can be removed from the combustion chamber 22B via the outlet channel 168 be drained. It should be noted that in some examples, the first cylinder bank of the engine 110 with the cylinder 20A as well as other cylinders via a common exhaust port 166 can drain and that a second cylinder bank with cylinders 20B as well as other cylinders via a common exhaust port 168 can drain.
[0018] The combustion products produced by the engine 110 via the outlet channel 166 can be released through the exhaust turbine. 124 of the turbocharger 120 are directed, which in turn are sent to the compressor 122 over the wave 126mechanical work can be provided to compress the intake air as described above. Alternatively, some or all of the exhaust gas passing through the exhaust port can be used. 166 flows, the turbine 124 via the turbine bypass channel 123 bypass, as by the boost pressure control valve 128 controlled. The position of the boost pressure control flap 128 can be from the actuator 129 as from the tax system 190 Predefined controls can be used. A non-restrictive example is the control system. 190 the position of the actuator 129 via a solenoid valve 121 adjust. In this specific example, the solenoid valve modulates 121 the pressure between that of the air in the inlet channel 142 , upstream of the compressor 122 is arranged, and the air in the inlet duct 149 , downstream of the compressor 122 is arranged. As in Fig. If 1 is displayed, the control system communicates 190 with the actuator 129 via a solenoid valve 121 However, it will be appreciated that other examples show different appropriate approaches to actuating the boost pressure control valve. 128 can be used. For example, the actuator can 129 electrically operated by an electric motor.
[0019] A sensor 194 can be attached to or next to the turbocharger 120 be arranged. In one example, the sensor can 194 detect the turbine speed. In another example, the sensor can 194 a position of the boost pressure control valve 128 detect. For example, one or more of the boost pressure control valve rod, connection, or valve position can be detected by the sensor. 194 be detected. In another example, the sensor can 194 one or more attributes of the actor 129 detect. The sensor 194The boost pressure control valve position can be determined by measuring the output of the electric motor of the actuator. 129 measure, for example, when the actuator 129 It is an electronic actuator, or can measure the current from the electronic actuator electric motor. The sensor output 194 can be used to calculate the turbine speed or turbine power, as explained below.
[0020] In the same way, the combustion products that come from the engine can be 110 via the outlet channel 168 be released through the exhaust turbine 134 of the turbocharger 130 are directed, which in turn are sent to the compressor 132 over the wave 136 mechanical work can be provided to compress the intake air flowing through the second branch of the engine's intake system. Alternatively, some or all of the exhaust gas passing through the exhaust port can be used. 168 flows, the turbine 134via the turbine bypass channel 133 bypass, as by the boost pressure control valve 138 controlled. The position of the boost pressure control flap 138 can be from the actuator 139 as from the tax system 190 The position of the boost pressure control flap is predetermined and controlled. 138 can be from the actuator 139 as from the tax system 190 Predefined controls can be used. A non-restrictive example is the control system. 190 the position of the actuator 139 via a solenoid valve 131 adjust. In this specific example, the solenoid valve modulates 131 the pressure between that of the air in the inlet channel 144 , upstream of the compressor 132 is arranged, and the air in the inlet duct 149 , downstream of the compressor 132 is arranged. As in Fig. If 1 is displayed, the control system communicates 190 with the actuator 139via a solenoid valve 131 However, it will be appreciated that other examples show different appropriate approaches to actuating the boost pressure control valve. 138 can be used, for example, as an electrically operated boost pressure control valve.
[0021] A sensor 192 can be attached to or next to the turbocharger 130 be arranged. In one example, the sensor can 192 detect the turbine speed. In another example, the sensor can 192 a position of the boost pressure control valve 138 detect. For example, one or more of the boost pressure control valve rod, connection, or valve position can be detected by the sensor. 192 be detected. In another example, the sensor can 192 one or more attributes of the actor 139 detect. The sensor 192 The boost pressure control valve position can be determined by measuring the output of the electric motor of the actuator. 139measure, for example, when the actuator 139 It is an electronic actuator, or can measure the current from the electronic actuator electric motor. The sensor output 192 can be used to calculate the turbine speed or turbine power, as explained below.
[0022] In some examples, the exhaust turbines can 124 and 134 be configured as variable geometry turbines, with the associated actuators 125 and 135 These can be used to adjust the position of the turbine impeller blades to vary the amount of energy extracted from the exhaust gas flow and transferred to the appropriate compressor. For example, the control system can be used to independently vary the geometry of the exhaust gas turbines. 124 and 134 via their respective actuators 125 and 135 be configured. As described previously, the turbochargers can be 120and 130 An imbalance can develop, for example, when operating at different turbine speeds or different turbine power outputs. The actuators can be used to compensate for this in the turbochargers. 125 and 135 can be adjusted. For example, the speed of each turbocharger can be determined by using the turbocharger speed sensors, and if the speeds do not match, one or more of the actuators can be adjusted. 125 and actuator 135 They can be adjusted until the turbocharger speeds match. In another example, a parameter of each actuator can be set. 125 , 135 such as position, force, etc. are determined, and if the parameters are unequal, the actuators can be adjusted.
[0023] Combustion products that exit from one or more cylinders via the exhaust port 166 They can be drained via the outlet channel. 170 to be discharged into the surrounding area. The outlet channel170 Can an exhaust aftertreatment device such as a catalytic converter 174 and have one or more exhaust gas sensors, which are used, for example, in 184 and 185 are indicated. In the same way, combustion products that originate from one or more cylinders via the exhaust port can be displayed. 168 be drained via the outlet channel 172 to be discharged into the surrounding area. The outlet channel 172 Can an exhaust aftertreatment device such as a catalytic converter 176 and have one or more exhaust gas sensors, which are used, for example, in 186 and 187 are displayed. The exhaust gas sensors 184 , 185 , 186 and / or 187 can use the tax system 190 communicate.
[0024] The engine system 100 It may have various other sensors. For example, at least one of the inlet channels may 142 and 144an air mass flow sensor 180 exhibit. In some embodiments, only at least one of the inlet channels may be present. 142 and 144 an air mass flow sensor 180 exhibit. In other embodiments, both the inlet channel and the inlet channel can be modified. 142 as well as 144 have an air mass flow sensor. An air mass flow sensor can, for example, be a hot-wire anemometer or another suitable device for measuring the air mass flow rate of the intake air. The air mass flow sensor 180 can be used with the tax system 190 as in Fig. 1. Communicate as shown.
[0025] The tax system 190 It can have one or more controllers configured to communicate with the various sensors and actuators described herein. As an example, the control system could be... 190The control system must include at least one electronic controller comprising one or more of the following: an input / output interface for sending and receiving electronic signals using the various sensors and actuators, a central processing unit, and a memory such as random access memory (RAM), read-only memory (ROM), or continuous memory (CAM), each of which can communicate via a data bus. 190 In some examples, a proportional-integral-derivative (PID) controller may be used. However, it will be appreciated that other suitable controllers can be employed, as a person skilled in the art will recognize from the present disclosure. The controller can store instructions that can be executed to carry one or more control routines, such as the control routine described herein with reference to Fig. 2 is described.
[0026] The tax system190 The control system can be configured to vary one or more engine operating parameters on a single-cylinder basis. For example, the control system can adjust valve timing by using a variable camshaft actuator (VCT actuator), ignition timing by varying the point at which the spark plug provides the ignition signal, and / or fuel injection timing and quantity by varying the pulse width of the fuel injection signal provided to the fuel injector by the control system. Accordingly, at least the ignition timing, valve timing, and fuel injection timing can be actuated by the control system.
[0027] Thus, the system displays Fig. 1. An engine system comprising a first turbocharger with a first boost pressure control valve, a first boost pressure control valve actuator, a first turbocharger sensor, a second turbocharger with a second boost pressure control valve, a second boost pressure control valve actuator, and a second turbocharger sensor, and a controller configured to adjust the first boost pressure control valve actuator such that a parameter of the first turbocharger matches a parameter of the second turbocharger based on the output of the first and second turbocharger sensors, respectively.
[0028] In one example, the first turbocharger sensor and the second turbocharger sensor can each be turbine speed sensors. The controller can further be configured to calculate the speed of the first turbocharger and the speed of the second turbocharger based on the output of the first and second turbine speed sensors. The controller can be configured to adjust the first boost pressure control valve actuator until the speed of the first turbine matches the speed of the second turbine.
[0029] In one example, the first turbocharger sensor and the second turbocharger sensor can each include a boost pressure control flap position sensor. Each boost pressure control flap position sensor measures one or more components of the boost pressure control flap rod, linkage, and valve to determine the boost pressure control flap position. The controller can be configured to adjust the first boost pressure control flap actuator until the position of the first boost pressure control flap matches the position of the second boost pressure control flap.
[0030] In another example, the first turbocharger sensor and the second turbocharger sensor can each include a current sensor for the boost pressure control valve actuator's motor. The controller can further be configured to calculate a pressure ratio for the first turbine of the first turbocharger and a pressure ratio for the second turbine of the second turbocharger based on the output of the first and second current sensors of the boost pressure control valve actuator's electric motor. The controller can also be configured to calculate the turbine power of the first turbocharger based on the calculated pressure ratio of the first turbine and to calculate the turbine power of the second turbocharger based on the calculated pressure ratio of the second turbine.The control unit can also be configured to adjust the first boost pressure control valve actuator and the second boost pressure control valve actuator until the turbine power of the first turbocharger matches the turbine power of the second turbocharger.
[0031] The system can include an engine with a first cylinder group and a second cylinder group, and the first turbocharger can be configured to take in exhaust gas from the first cylinder group and the second turbocharger can be configured to take in exhaust gas from the second cylinder group.
[0032] With reference to Fig. 2 is a procedure 200 The procedure for balancing the twin turbochargers based on feedback from the boost pressure control flap sensors is shown. 200 is controlled by a control system such as a control of the control system 190 executed according to the instructions stored therein. The procedure 200can adjust the boost pressure control flap actuators of the bi-turbochargers installed in a V-engine or other twin-engine bank configuration to provide an equal turbine output from both turbochargers.
[0033] At 202 The procedure includes 200 Determining the engine operating parameters. The engine operating parameters that are determined during 202 The factors that can be determined include, but are not limited to, engine speed, engine load, the current boost pressure (which is determined, for example, based on feedback from a boost pressure sensor), and the boost pressure control flap position. 204 The procedure concludes 200 setting a first boost pressure control flap position and a second boost pressure control flap position based on the desired boost pressure.
[0034] The first boost pressure control valve, such as the boost pressure control valve 128can be used to regulate the exhaust flow through a first turbocharger, such as a turbocharger 120 be configured. The second boost pressure control flap, such as the boost pressure control flap 138 can be used to regulate the exhaust flow by a second turbocharger, such as a turbocharger 130 be configured. As in Fig. As shown in Figure 1, the turbochargers can be configured such that compressed intake air passing through each compressor is routed to a common intake duct and manifold before being split to two separate engine banks. Therefore, a single measurement of the engine boost pressure can be determined based on the manifold pressure. To provide a desired boost pressure level, the turbocharger boost pressure control valves can be adjusted to control the exhaust flow through each turbine, thereby controlling the compression level provided by the turbochargers. The desired boost pressure can, for example, depend on the engine speed and load.
[0035] Assuming each engine bank is symmetrical, it can be assumed that the same setting of each turbocharger boost control valve will affect the boost pressure equally. Therefore, under most conditions, a single boost control valve command can be issued to both boost control valve actuators, resulting in the boost control valves for each turbocharger being in the same position. However, slight asymmetries may exist between the engine banks, which can lead to different exhaust gas flows through the turbines. Furthermore, boost control valve hysteresis can cause the boost control valves to be in different positions. Therefore, even if the boost control valves are actuated to the same position, the turbine speed and / or power delivered by each turbine may differ.Such differences in turbine speed and power can reduce engine power.
[0036] To maintain the same operating parameters for the turbochargers, the boost pressure control valve positions can be adjusted based on feedback from turbocharger sensors, such as the boost pressure control valve sensors. However, under certain circumstances, the boost pressure control valves cannot be controlled to the same position. For example, if the engine is operating in a variable displacement mode, where one engine bank is undergoing combustion and the other is only pumping air (and not burning fuel), the boost pressure control valves between the two turbochargers may be controlled to two different positions. In another example, if a fault is detected in a turbocharger or a boost pressure control valve, the engine may operate in a fault mode where the boost pressure control valves are controlled independently and can therefore be in different positions.
[0037] Therefore, the procedure assesses 200 before balancing the turbocharger at 206 The routine checks whether the boost pressure control valves were actuated to the same position. For example, it can determine whether the valves were actuated within a threshold position relative to each other, such as positions that differ by no more than 5%. If the boost pressure control valves were not actuated to the same position, the process reverses. 200 back. However, if the boost pressure control flaps have been moved to the same position, the procedure continues. 200 to 208 , to determine a first parameter of the first turbocharger based on the output of a first turbocharger sensor. Similarly, at 210 a second parameter of the second turbocharger is determined based on the output of a second turbocharger sensor.
[0038] The first and second parameters can be parameters indicating turbocharger performance. For example, the first and second parameters could include turbine speed. Each turbine can have a speed sensor to measure turbine speed. Alternatively, the first and second parameters could be the boost pressure control valve position. Therefore, if the first and second parameters are the boost pressure control valve position, the output of the first and second turbocharger sensors can include an indication of the boost pressure control valve position. To determine the boost pressure control valve position, the position of a boost pressure control valve rod or linkage, or the position of the boost pressure control valve itself, can be determined. Both electrically and pneumatically actuated boost pressure control valve positions can be determined based on the boost pressure control valve rod or valve position.
[0039] In another example, the first and second parameters can include turbine power. Turbine power can describe the turbine's power output, and in one example, it can be based on the torque applied to the turbocharger shaft and the shaft's angular velocity. Turbine power can also be calculated based on the motor current of an electrically actuated boost control valve. The boost control valve sensor's electric motor current is proportional to the force used to hold the valve in the actuated position. This force depends on the pressure differential within the turbine. The pressure differential within the turbine along a measured or estimated pressure at the turbine outlet can be used to calculate the turbine pressure ratio.The pressure ratio within the turbine can be used to calculate the torque applied by the turbine to the shaft, and thus to calculate the turbine power. However, other mechanisms for calculating turbine power are possible. Therefore, the first and second turbocharger sensors can each measure the motor current of the corresponding boost pressure control valve actuator, and the sensor output can be used to determine the turbine power of each turbocharger.
[0040] At 212 The procedure includes 200Optionally, the flow forces acting on each boost pressure control valve can be determined. In one example, the flow forces are determined based on a model. Alternatively, a pressure differential within each boost pressure control valve can be calculated and used to determine the flow forces. In another example, a lookup table with inputs including the boost pressure control valve position is generated to determine the flow forces. Such methods can employ one or more sensors or sensor signals located in the engine, including mass airflow, manifold pressure, throttle position, boost pressure, pre-turbine pressure, post-turbine pressure, pre-turbine temperature, post-turbine temperature, and the turbocharger speed signal.
[0041] The flow forces acting on each valve can be used to calculate the expected motor current of each boost pressure control valve actuator. For example, the boost pressure control valves can be actuated to a position based on the desired boost pressure, as described above. To hold a boost pressure control valve in an actuated position, a predetermined amount of force can be applied to the boost pressure control valve. This force can depend on the flow forces acting on the boost pressure control valve. Therefore, provided the flow forces acting on the boost pressure control valve and the actuated position are known, the expected motor current of the boost pressure control valve actuator can be determined.
[0042] At 213The expected motor current can be set based on the boost pressure control valve temperature or other parameters. In some cases, the magnetic field generated by a boost pressure control valve motor can depend on the temperature surrounding the valve. For example, the magnetic field can change with temperature. If the magnetic field of one boost pressure control valve actuator motor differs from that of another, the current drawn from each motor can differ, even though the boost pressure control valves can still be in the same position. The boost pressure control valve temperature can be determined based on the exhaust gas temperature and other parameters, such as the flow rate.
[0043] If the set motor currents continue to differ (for example, if the output of the motor current sensor of the first turbocharger differs from the output of the motor current sensor of the second turbocharger by more than 5%), the electric motor current difference can be attributed to a turbocharger imbalance.
[0044] At 214 determines the procedure 200 , whether boost pressure control flap compensation is indicated. Boost pressure control flap compensation can be performed if the above is 208 and 210certain parameters are not the same. For example, if the turbine speed of the first turbocharger differs from the turbine speed of the second turbocharger, the boost pressure control valves can be adjusted to bring the turbine speeds of each turbocharger to a matching speed. In another example, if the boost pressure control valve positions are different, the boost pressure control valves can be adjusted until they are in the same position. Similarly, if the turbine power of the first turbocharger differs from the turbine power of the second turbocharger, the boost pressure control valves can be adjusted so that the turbine powers are the same. Furthermore, boost pressure control valve balancing may be indicated if the sensor output is expected to be the same, but the actual output differs.This can occur if the boost pressure control flaps are actuated to the same position and / or the sensor outputs are expected to be similar due to flow forces and the temperature setting described above.
[0045] If the boost pressure control flap compensation is not indicated, for example if the sensor output of both turbocharger sensors is the same, the procedure 200 to 216 , to keep the boost pressure control flaps in their current positions, and the procedure 200 returns. If the boost pressure control flap compensation is indicated, the procedure continues. 200 to 218to adjust the position of the first and / or second boost pressure control valve until the parameters of each turbocharger are equal. For example, if the turbine power of each turbocharger differs, as determined by the motor current of the boost pressure control valve actuators, one boost pressure control valve can be slightly closed and the other slightly opened, and the turbine power can be monitored until both turbines have the same power output. In another example, if the turbine power of the two turbochargers differs, one of the boost pressure control valves can be adjusted while the other remains in the same position. For instance, the boost pressure control valve of the turbocharger with the lower turbine power can be adjusted until its turbine power matches the higher turbine power of the other turbocharger.Other mechanisms for adjusting the boost pressure control flaps are also possible. Procedures. 200 then returns.
[0046] In this way, a display of the turbocharger output, such as turbine speed or turbine power, can be determined for each turbocharger in a twin-turbo system. If the turbocharger output of each turbocharger is not equal, the boost pressure control valves of the turbochargers can be adjusted until the turbochargers achieve equal output. The turbocharger output can be determined based on feedback from the boost pressure control valve sensors, which can, for example, measure the motor current of the boost pressure control valve actuators.
[0047] Fig. 3 is a diagram 300 , which represents various operating parameters during a boost pressure control valve adjustment to balance the two turbochargers. For example, the diagram can 300various operating parameters during the execution of the procedure 200 out of Fig. 2. The first plot in the upper part of the diagram. 300 The first plot shows the boost pressure, the second plot from the top shows the boost pressure control flap position (for both the first and second turbocharger boost pressure control flaps), and the third plot from the top shows the turbine power for both turbines of the first and second turbochargers. For each plot from the diagram 300 Time is represented along the horizontal axis and each corresponding operating parameter along the vertical axis.
[0048] The boost pressure is determined by the curve. 302 As shown. Before time t1, the boost pressure is low and the boost pressure control flaps of each turbocharger, which are shown by the curves. 304 and 306The valves shown are open. At time t1, an increase in boost pressure is desirable, for example, in response to a throttle tap. To increase the boost pressure, the boost pressure control valves for each turbocharger are moved to a partially closed position. Therefore, the boost pressure increases after time t1.
[0049] During operation, when both boost pressure control flaps are open, the turbine power is relatively equal between the turbines of the first and second turbochargers, as shown by the curves. 308 and 310 As shown. However, after the boost pressure control flaps have been moved to a partially closed position, the turbine output of each turbocharger is not the same. For example, the output of the first turbocharger, which is shown by the dot-dash curve, is 308 is shown to be slightly lower than the turbine power of the second turbocharger, which is shown by the continuous curve. 310is shown.
[0050] If it has been determined that the turbine power output between the two turbochargers is not equal, the boost pressure control flaps of each turbocharger can be adjusted until the turbine power outputs match. As shown, after time t2, the first boost pressure control flap actuator is adjusted so that the first boost pressure control flap position is moved to a more closed position, as shown by the dot-dash curve. 304 The second boost pressure control valve actuator is also adjusted so that the second boost pressure control valve position is moved to a more open position, as shown by the continuous curve. 306 The result is that after time t2, the turbine power is the same for each turbocharger.
[0051] In one example, a method for an engine under selected conditions comprises balancing the turbine output of a first turbocharger and a second turbocharger by adjusting the first boost pressure control actuator of the first turbocharger, wherein the first boost pressure control actuator is adjusted based on the engine current of the first boost pressure control actuator and the engine current of the second boost pressure control actuator of the second turbocharger. The method may further include adjusting the boost pressure control actuators of the first turbocharger and the boost pressure control actuator of the second turbocharger based on the desired boost pressure. Adjusting the boost pressure control actuators based on the desired boost pressure can be performed under selected conditions and / or under unselected conditions.
[0052] The procedure may further include, during the selected conditions, adjusting the second boost pressure control valve actuator based on the motor current of the first boost pressure control valve actuator and on the motor current of the second boost pressure control valve actuator.
[0053] The selected conditions can include actuating a first boost pressure control valve of the first turbocharger and a second boost pressure control valve of the second turbocharger to the same position. The selected conditions can include that the motor current of the first boost pressure control valve actuator is different from the motor current of the second boost pressure control valve actuator. The selected conditions can further include that the expected motor current of the first boost pressure control valve actuator is equal to the expected motor current of the second boost pressure control valve actuator.
Claims
[1] Engine system, comprising: a first turbocharger comprising a first boost pressure control flap, a first boost pressure control flap actuator and a first turbocharger sensor; a second turbocharger, which includes a second boost pressure control flap, a second boost pressure control flap actuator and a second turbocharger sensor; and a control unit configured to adjust the first boost pressure control valve actuator until a parameter of the first turbocharger equals a parameter of the second turbocharger, based on the output from the first and second turbocharger sensors. [2] Engine system according to claim 1, wherein the first turbocharger sensor and the second turbocharger sensor each comprise a turbine speed sensor. [3] Engine system according to claim 2, wherein the control is further configured to calculate a speed of the first turbocharger and a speed of the second turbocharger based on the output of the first and second turbine speed sensors, and wherein the control is configured to adjust the first boost pressure control valve actuator until the speed of the first turbocharger matches the speed of the second turbocharger. [4] Engine system according to claim 1, wherein the first turbocharger sensor and the second turbocharger sensor each comprise a boost pressure control flap position sensor. [5] Engine system according to claim 4, wherein each boost pressure control flap position sensor measures one or more of a boost pressure control flap rod, linkage and valve for measuring the boost pressure control flap position. [6] Engine system according to claim 1, wherein the first turbocharger sensor and the second turbocharger sensor each comprise an engine current sensor of the boost pressure control flap actuator. [7] Motor system according to claim 6, wherein the control is further configured to calculate a pressure ratio of a first turbine of the first turbocharger and a pressure ratio of a second turbine of the second turbocharger based on the output from the electric motor current sensors of the first and second boost pressure control valve actuator. [8] Engine system according to claim 7, wherein the control is further configured to calculate the turbine power of the first turbocharger based on the calculated pressure ratio of the first turbine and to calculate the turbine power of the second turbocharger based on the calculated pressure ratio of the second turbine. [9] Engine system according to claim 8, wherein the control is further configured to adjust the first boost pressure control valve actuator and the second boost pressure control valve actuator until the turbine power of the first turbocharger matches the turbine power of the second turbocharger. [10] Engine system according to claim 1, further comprising an engine with a first cylinder group and a second cylinder group, wherein the first turbocharger is configured to take in exhaust gas from the first cylinder group and the second turbocharger is configured to take in exhaust gas from the second cylinder group. [11] Method for an engine, comprising: During selected conditions, balancing a first turbocharger and a second turbocharger by adjusting a first boost pressure control valve actuator of the first turbocharger, wherein the first boost pressure control valve actuator is adjusted based on the motor current of the first boost pressure control valve actuator and the motor current of the second boost pressure control valve actuator of the second turbocharger. [12] Method according to claim 11, further comprising adjusting the boost pressure control valve actuator of the first turbocharger and the boost pressure control valve actuator of the second turbocharger based on the desired boost pressure. [13] Method according to claim 11, further comprising, during selected conditions, adjusting the second boost pressure control valve actuator based on the motor current of the first boost pressure control valve actuator and on the motor current of the second boost pressure control valve actuator. [14] Method according to claim 11, wherein the selected conditions include that a first boost pressure control valve of the first turbocharger and a second boost pressure control valve of the second turbocharger are actuated to the same position. [15] Method according to claim 11, wherein the selected conditions include that the motor current of the first boost pressure control valve actuator is different from the motor current of the second boost pressure control valve actuator. [16] Method according to claim 15, wherein the selected conditions further include that the expected motor current of the first boost pressure control valve actuator is equal to the expected motor current of the second boost pressure control valve actuator. [17] Method according to claim 11, wherein the motor current of the first boost pressure control valve actuator is based on the output of a motor current sensor of the first boost pressure control valve actuator and wherein the motor current of the second boost pressure control valve actuator is based on the output of a motor current sensor of the second boost pressure control valve actuator. [18] Method for an engine, comprising: Setting the position of a first boost pressure control valve of a first turbocharger and a position of a second boost pressure control valve of a second turbocharger based on the desired boost pressure; and If the turbine power of the first turbocharger differs from the turbine power of the second turbocharger, the first and second turbochargers can be balanced by further adjusting the position of the first boost pressure control flap and the second boost pressure control flap. [19] Method according to claim 18, further comprising determining the turbine power of the first turbocharger based on the output of a motor current sensor of the first boost pressure control valve actuator and determining the turbine power of the second turbocharger based on the output of a motor current sensor of the second boost pressure control valve actuator. [20] Method according to claim 19, wherein the output of the motor current sensor of the first boost pressure control valve actuator is proportional to a first force for holding the position of the first boost pressure control valve and wherein the output of the motor current sensor of the second boost pressure control valve actuator is proportional to a second force for holding the position of the second boost pressure control valve and wherein the turbine power of the first turbocharger is calculated based on the first force and the turbine power of the second turbocharger is calculated based on the second force.