Controlling an internal combustion engine system

Abstract

receive a first pressure upstream of a throttle. receive a temperature upstream of the throttle. receive a throttle position. receive a second pressure at a converging end of a converging nozzle located downstream of the throttle. estimate an air flow based on the received first pressure, the received temperature, the received throttle position, and the received second pressure, wherein estimating the air flow includes determining one or more models for calculating the air flow based on the throttle position, the models including a throttle flow model, a converging nozzle flow model, or both.

Description

[0001] Priority Statement

[0002] This application claims priority to U.S. Patent Application No. 17 / 122,154, filed December 15, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the control of internal combustion systems. Background Technology

[0004] When controlling an internal combustion engine, the precise airflow and / or air pressure entering the engine are determined to accurately calculate the fuel required to achieve a target air-fuel ratio (AFR). In some cases, engines are designed to operate at an AFR of stoichiometric AFR, lean AFR (excess air), or rich AFR (excess fuel). Common methods for determining this airflow and / or air pressure include using a mass airflow sensor (MAF), a manifold absolute pressure sensor (MAP), or a combination of both. Precisely adding fuel to achieve the target AFR is useful for reducing NOx emissions. Summary of the Invention

[0005] This disclosure describes techniques related to controlling internal combustion systems.

[0006] In a first example, a method for controlling an internal combustion engine system is described, the method comprising: receiving a value of a first pressure upstream of a throttle valve; receiving a value of a temperature upstream of a throttle valve; receiving a value of a throttle valve position; receiving a value of a second pressure at the converging end of a converging nozzle located downstream of the throttle valve; and estimating an airflow rate based on the received first pressure, the received temperature, the received throttle valve position, and the received second pressure, wherein estimating the airflow rate comprises: determining one or more models for calculating the airflow rate based on the throttle valve position, the models including a throttle valve flow rate model, a converging nozzle flow rate model, or both.

[0007] In the second example, there is a method according to Example 1, wherein estimating the airflow includes: calculating the airflow based on a throttle flow model using the received first pressure, the received temperature, and the received throttle position.

[0008] In the third example, there is a method according to Example 1, wherein estimating the airflow includes: calculating the airflow based on a converging nozzle flow model using the received first pressure, the received temperature, the received second pressure, and the received throttle position.

[0009] In the fourth example, there is a method according to any one of Examples 1 to 3, wherein determining the model used includes: determining the ratio of the throttle flow model to the converging nozzle flow model based on the throttle position.

[0010] In the fifth example, there is a method according to Example 4, wherein estimating the airflow includes: calculating the airflow based on a throttle flow model using the received first pressure and the received temperature; calculating the airflow based on a converging nozzle flow model using the received first pressure and the received temperature; mixing the calculated airflow from the throttle flow model and the converging nozzle flow model based on a determined ratio; and determining the estimated airflow based on the mixed calculated airflow.

[0011] In the sixth example, the method according to any one of Examples 1 to 5 further includes: receiving a value of a third pressure corresponding to the pressure at the throat of the converging-diverging nozzle downstream of the converging nozzle; receiving a value of a fourth pressure corresponding to the pressure downstream of the converging-diverging nozzle; and determining a combined air flow rate, a recirculated exhaust gas flow rate, and a fuel flow rate based on the third pressure and the fourth pressure.

[0012] In the seventh example, there is a method according to Example 6, which includes injecting a certain amount of fuel into the intake fluid flow, the amount of fuel being based on an estimated air flow rate, a combined air flow rate and a recirculated exhaust gas flow rate, a target air-fuel ratio, or a combination thereof.

[0013] In the eighth example, there is a method according to any one of Examples 1 to 7, which includes injecting a certain amount of recirculated exhaust gas into the intake fluid flow, the amount of recirculated exhaust gas being determined at least in part based on an estimated airflow rate.

[0014] In the ninth example, there is a method according to any one of Examples 1 to 8, which also includes calculating the pressure difference across the throttle valve based on the received first pressure, the received temperature, and the received throttle valve position.

[0015] In the tenth example, the engine system includes: an intake manifold configured to receive a combustible mixture configured to burn in a combustion chamber; a throttle valve located upstream of the intake manifold and configured to at least partially regulate the airflow entering the intake manifold; an exhaust manifold configured to receive combustion products from the combustion chamber; and an exhaust gas recirculation mixer system located downstream of the throttle valve and upstream of the intake manifold, the exhaust gas recirculation mixer including: an exhaust gas housing including an exhaust gas inlet entering the interior of the exhaust gas housing; a mixer housing; a converging nozzle located within the mixer housing and in a flow path from the air inlet of the mixer to the outlet of the mixer, the converging nozzle converging toward the outlet of the mixer; and a first pressure port located upstream of the throttle valve, the first pressure port providing sensing of the first pressure port upstream of the throttle valve. The controller is configured to: receive a first pressure flow from a first pressure sensor located at the first pressure port, the first pressure flow corresponding to a first pressure upstream of the throttle valve; receive a temperature flow from a temperature sensor located at the first pressure port, the temperature flow corresponding to a temperature upstream of the throttle valve; receive a throttle valve position flow from an encoder coupled to the throttle valve, the throttle valve position flow corresponding to the throttle valve position; receive a second pressure flow from a second pressure sensor located at the second pressure port, the second pressure flow corresponding to the second pressure at the converging end of the converging nozzle; and estimate airflow based on the first pressure flow, the temperature flow, the throttle valve position flow, and the second pressure flow.

[0016] In the seventh example, there is an engine according to the example of claim 10, wherein the controller is further configured to estimate airflow by the following steps: determining a mixing ratio of the throttle flow model and the converging nozzle flow model based on the throttle position flow; calculating airflow based on the throttle flow model using a first pressure flow, a throttle position flow, and a temperature flow; calculating airflow based on the converging nozzle flow model using a first pressure flow, a second pressure flow, and a temperature flow; mixing the calculated airflow from the throttle flow model and the converging nozzle flow model based on the determined mixing ratio; and determining an estimated airflow based on the mixed calculated airflow.

[0017] In the twelfth example, there is an engine system according to any one of Examples 10 to 11, wherein the temperature flow is a first temperature flow, and the controller is further configured to: receive a fifth pressure flow corresponding to the pressure upstream of the exhaust gas inlet; receive a second temperature flow corresponding to the temperature upstream of the exhaust gas inlet; and send a signal to the exhaust gas recirculation valve corresponding to the amount of recirculated exhaust gas to be injected into the intake fluid flow, the amount of recirculated exhaust gas being determined at least in part based on an estimated airflow rate.

[0018] In the thirteenth example, a method of any one of Examples 10 to 12 further includes: a converging-diverging nozzle located within a mixer housing and including a fluidly communicating air-exhaust inlet for receiving fluid flow from the converging nozzle and the interior of the exhaust gas housing; a third pressure port located in the throat of the converging-diverging nozzle, the third pressure port providing a location for sensing a third pressure within the throat of the converging-diverging nozzle; and a fourth pressure port located downstream of the converging-diverging nozzle, the fourth pressure port providing a location for sensing a third pressure downstream of the converging-diverging nozzle; the controller is further configured to: receive a third pressure flow from a third pressure sensor located at the third pressure port, the third pressure flow corresponding to the third pressure at the throat of the converging-diverging nozzle; receive a fourth pressure flow from a fourth pressure sensor located at the fourth pressure port, the fourth pressure flow corresponding to the fourth pressure downstream of the converging-diverging nozzle; and determine a combined air flow rate, a recirculated exhaust gas flow rate, and a fuel flow rate based on the third pressure flow and the fourth pressure flow.

[0019] In the fourteenth example, there is an engine according to the example of claim 13, wherein the controller is further configured to send a signal to the fuel injector corresponding to the amount of fuel to be injected into the intake fluid flow, the amount of fuel being based at least in part on an estimated air flow rate, a combined air flow rate and a recirculated exhaust gas flow rate, a target air-fuel ratio, or a combination thereof.

[0020] In the fifteenth example, there is an engine system controller configured to: receive a first pressure flow corresponding to a first pressure upstream of the throttle valve; receive a temperature flow corresponding to a temperature upstream of the throttle valve; receive a throttle position flow corresponding to the throttle valve position; receive a second pressure flow corresponding to a second pressure at a converging end of the converging nozzle downstream of the throttle valve; determine one or more models for calculating airflow based on the throttle valve position, the models including a throttle valve flow model, a converging nozzle flow model, or both; and estimate airflow based on one or more of the determined models.

[0021] In the sixteenth example, there is a controller according to Example 15, wherein determining one or more models for calculating airflow includes the controller further configuring to: determine a ratio of a throttle flow model to a converging nozzle flow model based on a throttle position flow; calculate airflow based on the throttle flow model using a first pressure flow, a temperature flow, and a throttle position flow; calculate airflow based on the converging nozzle flow model using a first pressure flow, a second pressure flow, and a temperature flow; mix the calculated airflow from the throttle flow model and the converging nozzle flow model based on the determined ratio; and determine an estimated airflow based on the mixed calculated airflow.

[0022] In the seventeenth example, there is a controller according to any one of Examples 15 to 16, wherein the controller is further configured to: receive a third pressure flow from a third pressure sensor, the third pressure flow corresponding to a third pressure at the throat of the converging-diverging nozzle downstream of the converging nozzle; receive a fourth pressure flow from a fourth pressure sensor, the fourth pressure flow corresponding to a fourth pressure downstream of the converging-diverging nozzle; and determine a combined air flow rate, a recirculated exhaust gas flow rate, and a fuel flow rate based on the third pressure flow rate and the fourth pressure flow rate.

[0023] In the eighteenth example, there is a controller according to Example 17, which is also configured to send a signal to the fuel injector corresponding to the amount of fuel to be injected into the intake fluid flow, the amount of fuel being based on the estimated air flow rate, the combined air flow rate and the recirculated exhaust gas flow rate, the target air-fuel ratio or combination.

[0024] In the nineteenth example, there is a controller according to any one of Examples 15 to 18, wherein the temperature flow is a first temperature flow, and the controller is further configured to: receive a fifth pressure flow corresponding to the pressure upstream of the exhaust gas recirculation valve; receive a second temperature flow corresponding to the temperature upstream of the exhaust gas recirculation valve; and send a signal to the exhaust gas recirculation valve corresponding to the amount of recirculated exhaust gas to be injected into the intake fluid flow, the amount of recirculated exhaust gas being determined at least in part based on the air flow rate, the fifth pressure flow, the second temperature flow, or a combination thereof.

[0025] In the twentieth example, there is a controller according to any one of Examples 15 to 19, wherein the controller is also configured to calculate the pressure difference across the throttle valve based on a first pressure flow, a temperature flow, and a throttle position flow.

[0026] The exemplary embodiment described in this disclosure is a method for controlling an internal combustion engine system. The method includes the following features: receiving a value of a first pressure upstream of the throttle valve; receiving a value of a temperature upstream of the throttle valve; receiving a value of a throttle valve position; and receiving a value of a second pressure at the converging end of a converging nozzle located downstream of the throttle valve. Airflow is estimated based on the received first pressure, the received temperature, the received throttle valve position, and the received second pressure, wherein estimating the airflow includes determining one or more models for calculating the airflow based on the throttle valve position, the models including a throttle valve flow model, a converging nozzle flow model, or both.

[0027] An aspect of the example method, which can be combined alone with the example method or in combination with other aspects, includes the following: estimating airflow includes calculating air force based on a throttle flow model using the received first pressure, the received temperature, and the received throttle position.

[0028] An aspect of the example method, which can be combined alone with the example method or in combination with other aspects, includes the following: estimating airflow includes calculating airflow based on a converging nozzle flow model using a received first pressure, a received temperature, a received second pressure, and a received throttle position.

[0029] An aspect of the example method, which can be combined alone with the example method or in combination with other aspects, includes the following: determining the model used, including determining the ratio of the throttle flow model to the converging nozzle flow model based on the throttle position.

[0030] One aspect of the example method, which can be combined alone with the example method or in combination with other aspects, includes the following: Estimating airflow includes: calculating airflow based on a throttle flow model using the received first pressure and the received temperature. Estimating airflow includes: calculating airflow based on a converging nozzle flow model using the received first pressure and the received temperature. Estimating airflow includes: mixing the calculated airflow from the throttle flow model and the converging nozzle flow model based on a determined ratio. Determining the estimated airflow based on the mixed calculated airflow.

[0031] One aspect of the example method, which can be combined alone or in combination with other aspects, includes the following: receiving a third pressure corresponding to the pressure at the throat downstream of the converging-diverging nozzle; receiving a fourth pressure corresponding to the pressure downstream of the converging-diverging nozzle; and determining a combined air flow rate, a recirculated exhaust gas flow rate, and a fuel flow rate based on the third and fourth pressure flows.

[0032] One aspect of the example method, which can be combined alone with the example method or in combination with other aspects, includes the following: a certain amount of fuel is injected into the intake airflow. The fuel amount is based on the estimated airflow rate, the combined airflow rate and the recirculated exhaust gas flow rate, and the target air-fuel ratio or combination thereof.

[0033] One aspect of the example method, which can be combined alone or in combination with other aspects, includes the following: a certain amount of recirculated exhaust gas is injected into the intake fluid flow. The amount of recirculated exhaust gas is determined at least in part based on an estimated airflow rate.

[0034] An aspect of the example method, which can be combined alone with the example method or in combination with other aspects, includes the following: calculating the pressure difference across the throttle valve based on the received first pressure, the received temperature, and the received throttle valve position.

[0035] The example embodiments described in this disclosure are engine systems including the following features: An intake manifold is configured to receive a combustible mixture configured to burn in a combustion chamber. A throttle element is located upstream of the intake manifold. The throttle element is configured to at least partially regulate the airflow entering the intake manifold. An exhaust manifold is configured to receive combustion products from the combustion chamber. An exhaust gas recirculation mixer system is located downstream of the throttle valve and upstream of the intake manifold. The exhaust gas recirculation mixer includes an exhaust gas housing having an exhaust gas inlet into the interior of the exhaust gas housing. A converging nozzle is located within the mixer housing and in a flow path from the air inlet of the mixer to the outlet of the mixer. The converging nozzle converges toward the outlet of the mixer. A first pressure port is located upstream of the throttle valve. The first pressure port provides a location for sensing a first pressure upstream of the throttle valve. A second pressure port is located at the converging end of the converging nozzle. The second pressure port provides a location for sensing a second pressure at the converging end of the converging nozzle. A controller is configured to receive a first pressure flow from a first pressure sensor located at the first pressure port. The first pressure flow corresponds to the first pressure upstream of the throttle valve. The controller is configured to receive a temperature flow from a temperature sensor located at a first pressure port. This temperature flow corresponds to the temperature upstream of the throttle valve. The controller is also configured to receive a throttle position flow from an encoder coupled to the throttle valve. This throttle position flow corresponds to the throttle valve position. The controller is configured to receive a second pressure flow from a second pressure sensor located at a second pressure port. This second pressure flow corresponds to the second pressure at the converging end of the converging nozzle. The controller is configured to estimate the airflow based on the first pressure flow, the temperature flow, the throttle position flow, and the second pressure flow.

[0036] One aspect of the example engine system, which can be combined alone with the example engine system or with other aspects, includes the following: The controller is also configured to estimate airflow through the following steps: Determining the ratio of the throttle position flow model to the converging nozzle flow model based on the throttle position flow. Calculating the airflow based on the throttle flow model using a first pressure flow, a second pressure flow, and a temperature flow. Calculating the airflow based on the converging nozzle flow model using a first pressure flow, a second pressure flow, and a temperature flow. Mixing the calculated airflow from the throttle flow model and the converging nozzle flow model based on the determined ratio. Determining the estimated airflow based on the mixed calculated airflow.

[0037] One aspect of the example engine system, which can be combined alone with the example engine system or with other aspects, includes the following: a first temperature flow. The controller is also capable of causing the reception of a fifth pressure flow, corresponding to the pressure upstream of the exhaust gas inlet. The controller is also capable of causing the reception of a second temperature flow, corresponding to the temperature upstream of the exhaust gas inlet. The controller is also capable of causing a signal to be sent to the exhaust gas recirculation valve. This signal corresponds to the amount of recirculated exhaust gas injected into the intake fluid flow. The amount of recirculated exhaust gas is determined at least in part based on an estimated airflow rate.

[0038] One aspect of the example engine system, which can be combined alone with the example engine system or with other aspects, includes the following: a converging-diverging nozzle within a mixer housing and including a fluidly communicating air-exhaust inlet to receive fluid flow from the converging nozzle and the interior of the exhaust housing. A third pressure port is located in the throat of the converging-diverging nozzle. The third pressure port provides a location for sensing a third pressure within the throat of the converging-diverging nozzle. A fourth pressure port is located downstream of the converging-diverging nozzle. The fourth pressure port provides a location for sensing a fourth pressure downstream of the converging-diverging nozzle. The controller is also configured to receive a third pressure flow from a third pressure sensor located at the third pressure port. The third pressure flow corresponds to the third pressure at the throat of the converging-diverging nozzle. The controller is also configured to receive a fourth pressure flow from a fourth pressure sensor located at the fourth pressure port. The fourth pressure flow corresponds to the fourth pressure downstream of the converging-diverging nozzle. The controller is also capable of determining a combined air flow rate, a recirculated exhaust gas flow rate, and a fuel flow rate based on the third and fourth pressure flows.

[0039] One aspect of the example engine system, which can be combined alone with the example engine system or in combination with other aspects, includes the following: The controller is also configured to send a signal to the fuel injector. This signal corresponds to the amount of fuel injected into the intake airflow. The fuel amount is based on the estimated airflow rate, the combined airflow rate and the recirculated exhaust gas flow rate, the target air-fuel ratio, or a combination thereof.

[0040] One exemplary embodiment of the subject matter in this disclosure is an engine system controller configured to perform the following steps: The controller receives a first pressure flow corresponding to a first pressure upstream of the throttle valve. The controller receives a temperature flow corresponding to a temperature upstream of the throttle valve. The controller receives a throttle position flow corresponding to the throttle valve position. The controller receives a second pressure flow corresponding to a second pressure at the converging end of the converging nozzle located downstream of the throttle valve. The controller determines one or more models for calculating airflow based on the throttle valve position. These models include a throttle valve flow model, a converging nozzle flow model, or both. The controller estimates the airflow based on one or more of the determined models.

[0041] An aspect of the example engine system controller, which can be combined alone or in combination with other aspects, includes the following: determining one or more models for calculating airflow, including the controller being configured to perform the following steps: The controller determines a ratio of the throttle flow model to the converging nozzle flow model based on the throttle position flow. The controller calculates the airflow based on the throttle flow model using a first pressure flow, a temperature flow, and the throttle position flow. The controller calculates the airflow based on the converging nozzle flow model using a first pressure flow, a second pressure flow, and a temperature flow. The controller mixes the calculated airflow from the throttle flow model and the converging nozzle flow model based on the determined ratio. The controller determines an estimated airflow based on the mixed calculated airflow.

[0042] One aspect of the example engine system controller, which can be combined alone or in combination with other aspects, includes the following: The controller is also capable of receiving a third pressure flow from a third pressure sensor. The third pressure flow corresponds to a third pressure at the throat of the converging-diverging nozzle downstream of the converging nozzle. The controller is also capable of receiving a fourth pressure flow from a fourth pressure sensor. The fourth pressure flow corresponds to a fourth pressure downstream of the converging-diverging nozzle. The controller is also capable of determining a combined airflow rate, recirculated exhaust gas flow rate, and fuel flow rate based on the third and fourth pressure flows.

[0043] One aspect of the example engine system controller, which can be combined alone or in combination with other aspects, includes the following: The controller is also configured to send a signal to the fuel injector. This signal corresponds to the amount of fuel injected into the intake airflow. The fuel amount is based on an estimated airflow rate, a combined airflow rate and a recirculated exhaust gas flow rate, a target air-fuel ratio, or a combination thereof.

[0044] An aspect of the example engine system controller, which can be combined alone or in combination with other aspects, includes the following: a first temperature flow. The controller is also capable of causing the reception of a fifth pressure flow corresponding to the pressure upstream of the exhaust gas recirculation valve. The controller is also capable of causing the reception of a second temperature flow corresponding to the temperature upstream of the exhaust gas recirculation valve. The controller is also capable of causing a signal to be sent to the exhaust gas recirculation valve. This signal corresponds to the amount of recirculated exhaust gas injected into the intake airflow. The amount of recirculated exhaust gas is determined at least in part based on an estimated airflow rate, the fifth pressure flow, the second temperature flow, or a combination thereof.

[0045] One aspect of the example engine system controller, which can be combined alone with the example engine system controller or in combination with other aspects, includes the following: the controller is also configured to calculate the pressure difference across the throttle valve based on a first pressure flow, a temperature flow, and a throttle position flow.

[0046] Details of one or more embodiments of the subject matter are set forth in the accompanying drawings and the following description. Other features, objects, and advantages of the subject matter will become apparent from the specification, drawings, and claims. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of an example internal combustion engine system.

[0048] Figure 2 This is a side half-section schematic diagram of an example exhaust gas recirculation (EGR) mixer.

[0049] Figure 3 This is a side half-section schematic diagram of an example EGR mixer with sensors and sensing ports.

[0050] Figure 4 This is a block diagram of an example controller that can be used with various aspects of this disclosure.

[0051] Figure 5 This is a flowchart of an example method that can be used with various aspects of this disclosure.

[0052] The same reference numerals and symbols in the various figures refer to the same elements. Detailed Implementation

[0053] During engine transient operation, it is difficult to accurately control the air-fuel ratio (AFR) entering the engine. Controlling the engine's AFR is critical to engine performance and emissions under all operating conditions. For example, a typical solution estimates the throttle flow using the engine port flow rate through a standard velocity density equation with transient compensation tables. This approach does not utilize the correct physical model, leading to higher associated engineering costs and a less robust solution for transient conditions. Furthermore, using this approach can also increase aftertreatment costs. Sometimes, methods are used to find the throttle flow rate by using isentropic flow (e.g., using the orifice mass flow equation or an elliptic approximation of that equation); however, this solution is known to be less accurate and less stable when the Δ pressure (dP) across the valve is low. In some cases, this problem is caused by inaccuracies in pressure sensors. Alternatively or additionally, this isentropic flow model can lead to inaccuracies when the valve is operating near the closed position (e.g., when the throttle is in the range from closed to 10% open). In some cases, this problem is caused by a large change in the effective area for small position changes, combined with inaccuracy of the position sensor, inter-component variations and leakage paths when the valve approaches the closed position, inaccuracy of the pressure sensor, or any combination of these differences.

[0054] This disclosure relates to the control of an internal combustion engine system. Pressure and temperature are detected upstream of the throttle valve. The throttle position itself is measured. Based on these measurements, in some cases, an estimated pressure drop across the throttle valve is calculated using a throttle valve-specific model. Downstream of the throttle valve is an EGR mixer, which includes converging nozzles. Pressure is detected at the converging end of the converging nozzles. Based on the pressure and temperature detected upstream of the throttle valve, the detected throttle position, and the pressure detected at the converging end of the converging nozzles, airflow can be estimated very accurately in some cases, including during transient states. This is achieved by determining one or more models for calculating the airflow based on the throttle position. In some cases, the selected models include a throttle flow model, a converging nozzle flow model, or both. When using both models, they are weighted based on either the throttle position or the pressure drop. Ideally, the estimated airflow should be correlated with a computable MAP, which is equal to the MAP detected by the MAP sensor. In some cases, when the calculated MAP and the detected MAP are not equal to each other, a compensation table or equation is used to correct the inconsistency.

[0055] Figure 1 An example engine system 100 is shown. Engine system 100 includes an intake manifold 104 configured to receive a combustible mixture to be burned in the combustion chamber of an engine block 102. Specifically, the intake manifold 104 is fluidly connected to an oxygen source and a fuel source. The combustible mixture includes air and any combustible fluid, such as natural gas, atomized gasoline, or atomized diesel. Although the illustrated embodiment includes a four-cylinder engine block 102, any number of cylinders can be used. Furthermore, although the illustrated embodiment includes a piston engine block 102, aspects of this disclosure are applicable to other types of internal combustion engines, such as rotary engines or gas turbines.

[0056] Throttle valve 112 is located upstream of intake manifold 104 and EGR mixer 114. Throttle valve 112 is configured to regulate the airflow entering intake manifold 104 from ambient environment 116, for example, by changing the cross-sectional area of ​​the flow path through throttle valve 112. It should be noted that the intake manifold may experience a pressurized state. That is, the pressure at the throttle valve may be greater than the pressure in ambient environment 116. In some embodiments, throttle valve 112 includes a butterfly valve or disc valve. Reducing the cross-sectional area of ​​the flow path through throttle valve 112 reduces the airflow velocity through throttle valve 112 to intake manifold 104. Combined temperature and pressure sensor 132 is located directly upstream of throttle valve 112. This combined temperature and pressure sensor 132 detects the pressure and temperature of the airflow upstream of EGR throttle valve 126. Although described primarily as a combined sensor throughout this disclosure, in some embodiments, separate, discrete sensors are also used instead of combined temperature and pressure sensor 132.

[0057] Exhaust manifold 106 is configured to receive combustion products (exhaust gas) from the combustion chamber of engine block 102. Specifically, exhaust manifold 106 is fluidly connected to the outlet of the combustion chamber. EGR passage 108 or conduit is fluidly connected to exhaust manifold 106 and intake manifold 104. In the illustrated embodiment, EGR throttle valve 126 is located within EGR passage 108 between exhaust manifold 106 and intake manifold 104 and is used to regulate EGR flow. EGR throttle valve 126 regulates EGR flow by adjusting the cross-sectional area of ​​EGR passage 108 through which it passes. In some embodiments, EGR throttle valve 126 includes a butterfly valve, disc valve, needle valve, or another valve type. Upstream of EGR throttle valve 126 is a combined temperature and pressure sensor 134. This sensor detects the pressure and temperature of the EGR gas upstream of EGR throttle valve 126. Although the present disclosure is generally described as a combined sensor, in some embodiments, separate, discrete sensors are used instead of the combined temperature and pressure sensors 134.

[0058] In the illustrated embodiment, the EGR flow path feeds into an EGR mixer 114 located downstream of the throttle body 112 and upstream of the intake manifold 104. The EGR mixer 114 is located in the engine intake system and is fluidly connected to the throttle body 112, the intake manifold 104, and the EGR flow path 108. The fluid connection may be made of a conduit containing a flow path that allows fluid flow. In some embodiments, the EGR mixer 114 may be included within a conduit connecting the intake manifold 104 to the throttle body 112, within the intake manifold 104 itself, within the EGR flow path 108, integrated within the throttle body 112, or integrated within the EGR throttle valve 126. Additional sensors and sensing ports may be included within the various components of the EGR mixer 114. Details regarding an example EGR mixer 114 will be described below in this disclosure.

[0059] In the illustrated embodiment, exhaust gas cooler 110 is located in the EGR passage 108 between exhaust manifold 106 and EGR mixer 114. Exhaust gas cooler 110 can operate to reduce the temperature of the exhaust gas before EGR mixer 114 and EGR throttle valve 126. Exhaust gas cooler 110 is a heat exchanger, such as an air-to-air exchanger or an air-to-water exchanger. Alternatively, in some embodiments, exhaust gas cooler 110 may be omitted.

[0060] In some embodiments, engine system 100 includes a compressor 118 located upstream of throttle valve 112. In engines with compressor 118 but no throttle valve, such as throttle-free diesel engines, a throttle valve is not required, and in some embodiments, the mixer is downstream of the compressor. In some embodiments, compressor 118 includes a centrifugal compressor, a positive displacement compressor, or another type of compressor used to increase the pressure within EGR passage 108 during engine operation. In some embodiments, engine system 100 includes an intercooler 120 configured to cool compressed air before it enters the manifold. In the illustrated embodiment, compressor 118 is part of a turbocharger. That is, turbine 122 is located downstream of exhaust manifold 106 and rotates as exhaust gases expand through turbine 122. Turbine 122 is coupled to compressor 118, for example, via shaft 124, and rotates compressor 118. Although the illustrated embodiment utilizes a turbocharger to increase intake manifold pressure, other compression methods, such as electrically or engine-driven compressors (e.g., turbochargers), are also used in some cases. In some implementations, a separate controller 130 or engine control unit (ECU) is used to control and monitor various aspects of system operation. For example, controller 130 may adjust the air-fuel ratio, spark timing, and EGR flow rate based on the current operating state and parameters sensed by various sensors.

[0061] Figure 2 This is a side half-sectional schematic diagram of an example EGR mixer 114. The EGR mixer 114 comprises one or more housings or enclosures. Openings in the end walls of the housings define an air inlet 204 and an outlet 206 of an internal flow path 222 defined by one or more housings 224. The internal flow path 222 directs flow from the air inlet 204 to the outlet 206 to allow flow through the EGR mixer 114. Within one or more housings 224, the EGR mixer 114 includes a converging nozzle 202 in a flow path from the air inlet 204 of the EGR mixer 114 to the outlet 206 of the EGR mixer 114. The converging nozzle 202 includes a converging portion 203 that converges in a direction toward the converging end 208. That is, the cross-sectional area, i.e., the flow area, of the downstream end (outlet) of the converging nozzle 202 is smaller than the cross-sectional area of ​​the upstream end (inlet) 226 of the converging nozzle 202. In some embodiments, the converging nozzle includes a portion that does not converge but remains relatively straight without changing the cross-sectional flow area. In some cases, these sections are used to hold the converging nozzle 202 within the EGR mixer 114. The EGR mixer 114 includes an exhaust gas receiver housing 210, and the exhaust gas receiver housing 210 includes one or more exhaust gas inlets 212 that are fed from and fluidly connected to the EGR channel 108 and enter into the internal receiver cavity 228 of the exhaust gas receiver housing 210. In the illustrated embodiment, the exhaust gas receiver housing 210 surrounds the converging nozzle 202 such that a portion of the converging nozzle 202 is located within the internal receiver cavity 228. The converging nozzle 202 is positioned to form a free gas jet from its converging end 208. Furthermore, the exhaust gas inlets 212 are upstream of the converging end 208 of the converging nozzle 202. Although the illustrated embodiment shows the converging nozzle 202 at least partially within the exhaust gas receiver housing 210, other designs may also be used. In some embodiments, air inlet 204 and outlet 206 are provided with attachments or fittings to allow connection to the intake manifold 104 and / or EGR mixer 114 of the engine block 102. In some cases, the converging nozzle 202 can be modularly interchanged with nozzles having different inlet areas 226 and / or converging ends 208, thereby allowing the system to be easily modified to accommodate various engine sizes. For example, in some cases, the converging nozzle 202 is provided with threads or another form of removable attachment to one or more parts of the mixer housing 224.

[0062] The converging-diverging nozzle 214 is downstream of and fluidly connected to the converging portion 203 of the converging nozzle 202 to receive fluid flow from the converging end 208, the exhaust gas inlet 212, and (in some cases) the fuel supply section 216. In other words, the converging-diverging nozzle 214 can serve as an air-fuel-exhaust gas inlet for the intake manifold 104. To help promote mixing, the inlet 230 of the converging-diverging nozzle 214 has a larger area than the outlet of the converging nozzle 202. The converging-diverging nozzle 214 comprises three parts: an inlet 230, a throat 232, and an outlet 206. The throat 232 is the narrowest point of the converging-diverging nozzle 214 and is located downstream of the inlet 230 of the converging-diverging nozzle 214. The narrowing of the converging-diverging nozzle 214 at the throat 232 increases the flow velocity of the fluid as it passes through the converging-diverging nozzle 214. The converging-diverging nozzle 214 is fluidly connected to and upstream of the intake manifold 104. Between the throat 232 and the outlet 206, the cross-sectional area of ​​the flow passage through the converging-diverging nozzle 214 is increased. This increased cross-sectional area slows the flow velocity and increases the pressure of the fluid flow. In some cases, the increased cross-sectional area can be sized to increase the pressure within the EGR mixer 114, such that the pressure drop across the EGR mixer 114 is zero, nominal, or small. In some embodiments, the converging-diverging nozzle 214 includes threads or another form of removable attachment at the inlet 230, outlet 206, or both, to allow the converging-diverging nozzle 214 to be installed and fluidly connected to the rest of the intake of the engine system 100. Similar to the converging nozzle 202, in some cases, the converging-diverging nozzle 214 can be modularly interchanged with nozzles 214 having different inlet 230, throat 232, and outlet 206 areas to facilitate system modification to accommodate various engine sizes.

[0063] The illustrated embodiment shows the converging nozzle 202 and the converging-diverging nozzle 214 aligned at the same central axis 220. However, in some embodiments, the central axes of the converging nozzle 202 and the converging-diverging nozzle 214 may not be aligned or parallel. For example, spatial constraints may require the EGR mixer 114 to have an angle between the axes of the converging nozzle 202 and the converging-diverging nozzle 214. In some embodiments, the flow path may be curved, rather than as shown... Figure 2 The roughly horizontal DC path is shown.

[0064] As shown, the fuel supply section 216 includes a fuel supply pipe 218 that terminates parallel and centrally within the airflow path. The fuel supply pipe 218 is configured to supply fuel into the airflow path in the direction of flow through the EGR mixer 114 and upstream of the converging portion 203 of the converging nozzle 202. In some embodiments, the fuel supply pipe 218 is a gaseous fuel supply pipe connected to a gaseous fuel source. However, the fuel delivered by the fuel supply pipe 218 can supply any combustible fluid, such as natural gas, gasoline, or diesel. Although shown as a single pipe, in some cases, the fuel supply pipe 218 is constructed in other ways, such as as a cross section through the flow area of ​​the mixer, as a fuel delivery orifice along the perimeter of the flow area, or otherwise. While the illustrated embodiment shows a fuel supply pipe 218 configured to inject fuel upstream of the converging portion 203 of the converging nozzle 202, fuel can also be added via a fuel supply port 234 upstream of the exhaust gas inlet 212. That is, in some cases, fuel can be injected into the EGR flow. In some embodiments, such a port includes a gaseous fuel supply port. In some cases, fuel can be delivered at high speeds, including sonic flows at the fuel supply line 218, thereby also generating a fuel / air injection pump that allows the fuel to provide additional power to the main airflow entering and passing through the nozzle. In this case, higher pressures are generated, resulting in a sonic jet that further enhances fuel-air mixing. If the flow itself is congested, this reduces the need for a fuel pressure regulator. Furthermore, if the fuel jet is cooled via the Joule-Thompson effect, it will cool the air / fuel flow, thereby reducing the heat dissipation requirements of the air path booster air cooler. Alternatively or additionally, in some embodiments, fuel is added upstream of the throttle valve 112.

[0065] The illustrated implementation operates as follows. The converging portion 203 of the converging nozzle 202 increases the velocity of the airflow 302 in the EGR mixer 114 and reduces its pressure. In response to (e.g., because) the pressure of the free jet airflow 302 leaving the converging nozzle 202 decreases, exhaust flow 304 is drawn into the EGR mixer 114 through exhaust gas inlet 212. Exhaust flow 304 is ultimately directed from exhaust manifold 106 to a point downstream of the converging portion 203 of the converging nozzle 202. Airflow 302, exhaust flow 304, and fuel flow 306 are mixed to form combustion mixture 308, with a second converging nozzle 214a positioned downstream of the converging portion 203 of the converging nozzle 202. Through diverging nozzle 214b, the pressure of combustion mixture 308 increases and the velocity of combustion mixture 308 decreases. Although the second converging nozzle 214a and the diverging nozzle 214b are shown as a single converging-diverging nozzle 214, in some embodiments, the second converging nozzle 214a and the diverging nozzle 214b are separate components.

[0066] In the illustrated embodiment, fuel flow 306 is supplied to air flow 302, and fuel supply pipe 218 is parallel and straight to the center of the air flow channel. Fuel flow 306 is supplied upstream of the converging portion 203 of converging nozzle 202. In some embodiments, fuel flow 306 is supplied to exhaust flow 304 through fuel supply port. Regardless of the embodiment used, fuel flow 306 sometimes comprises a gaseous fuel flow. In some embodiments, the injection velocity of fuel flow 306 is higher than the velocity of air flow 302. Such a high velocity helps to mix air flow 302, fuel flow 306, and exhaust flow 304.

[0067] In some embodiments, the throat 232 of the converging-diverging nozzle 214 has a larger cross-sectional flow area than the converging end 208 of the converging nozzle 202. For example, in some embodiments, the minimum flow area of ​​the throat 232 of the converging-diverging nozzle 214 is 1.1 to 3 times the minimum flow area of ​​the converging end 208 of the converging nozzle 202. Generally, high efficiency is achieved when the throat 232 is sized such that two fluid flows can pass through the throat 232 at approximately the same velocity. For example, at 120°C and 25% EGR, the area of ​​the throat 232 is approximately 1.5 times the flow area of ​​the converging end 208 of the converging nozzle 202.

[0068] Figure 3 This is a side half-sectional schematic diagram of an example EGR mixer 114 with sensors and sensing ports. A first pressure port 351 is located upstream of the throttle body 112. The first pressure port 351 provides the location of sensing pressure and temperature upstream of the converging nozzle 202 by allowing fluid communication between the internal flow channel 222 and the combined temperature and pressure sensor 132. The throttle body 112 includes a position sensor 353. The position sensor detects the position of the throttle body 112 and, in some cases, includes an encoder, a Hall effect sensor, an optical sensor, or any other type of sensor with sufficient accuracy and precision. Based on the information or flow provided by these sensors (132 and 353), an estimated pressure drop or pressure downstream of the throttle body 112 is calculated according to a model of the throttle body flow characteristics. This method can produce sufficiently accurate MAF calculations when the throttle body is closed or near the closed position (e.g., when the throttle body is in the range from closed to 10% open).

[0069] In some embodiments, the second pressure port 352 is located upstream of the converging portion 203 of the converging nozzle 202 and downstream of the throttle valve 112. The second pressure port 352 provides a location for sensing the pressure upstream of the converging nozzle 202 and downstream of the throttle valve 112 by allowing fluid communication between the internal flow channel 222 and the second pressure sensor 357. Using the second pressure port 352 and the second pressure sensor 357, the pressure downstream of the throttle valve 112 can be compared with the calculated pressure upstream of the throttle valve 112. In such embodiments, a calibration table can be used to adjust the calculated airflow, or the calculated pressure downstream of the throttle valve 112 can be replaced by the measured pressure downstream of the throttle valve 112.

[0070] The third pressure port 356 is located after the converging portion 203 of the converging nozzle 202, for example, at the converging end 208. The third pressure port 356 provides the location for sensing the pressure at the converging end 208 of the converging nozzle 202 by allowing fluid communication between the internal flow channel 222 and the pressure sensor 354. As shown, the third pressure port 356 is integrated into the converging nozzle 202, but a separate, discrete sensing port with similar results could be used. Based on the information or flow provided by sensors 132 and 354, an estimated pressure drop or pressure downstream of the throttle valve 112 is calculated according to a model of the flow characteristics of the converging nozzle. This method can produce sufficiently accurate MAF calculations when the throttle valve 112 is in a closed or near-closed position (e.g., when the throttle valve is in the range from closed to 60% open).

[0071] In some embodiments, a fourth pressure port 358 is located in the throat 232 of the converging-diverging nozzle 214. The fourth pressure port 358 provides a location for sensing pressure within the throat 232 of the converging-diverging nozzle 214 by allowing fluid communication between the internal flow channel 222 and the pressure sensor 360.

[0072] The fifth pressure port 362 is located downstream of the throat 232 of the converging-diverging nozzle 214, for example, within the intake manifold 104. The fifth pressure port 362 provides a location for sensing pressure downstream of the converging-diverging nozzle 214 by allowing fluid communication between the internal flow channel 222 and the pressure sensor 364. In some embodiments, the pressure sensor 364 is a MAP sensor.

[0073] A sixth pressure port 366 is located upstream of the EGR throttle valve 126. The sixth pressure port 366 provides a location for sensing pressure and temperature upstream of the EGR throttle valve 126 by allowing fluid communication between the EGR flow path 108 and the combined temperature and pressure sensor 134. In some embodiments, the EGR flow rate is calculated in part based on measurements provided by the combined temperature and pressure sensor 134.

[0074] In addition to the previously described MAF calculation, in some embodiments, the air-fuel-exhaust mass flow rate is determined by comparing the pressures sensed by pressure sensors 360 and 364. In some cases, the difference between the mass air flow rate and the air-fuel-exhaust flow rate is used to calculate the EGR mass flow rate. In some cases, such calculations are performed by controller 130. Figure 1 In some cases, MAF and EGR flow rates are used as inputs to the controller to adjust various parameters within the engine system 100. In some cases, the controller 130 is an engine control unit (ECU) that controls some or all aspects of the operation of the engine system 100, such as fuel supply, air, ignition, and / or other engine operating parameters. In some cases, the controller 130 is a control unit separate from the engine system's ECU. The controller 130 does not need to send actuation and / or control signals to the engine system 100; instead, it may provide information such as MAF and EGR flow rates to the ECU for the ECU to use in controlling the engine system 100.

[0075] Figure 4 This is a block diagram of an example controller 130 that can be used with various aspects of this disclosure. The controller 130 primarily monitors system parameters and sends signals to actuate and / or adjust various operating parameters of the system. For example... Figure 4 As shown, in some cases, controller 130 includes processor 450 (e.g., implemented as one or more processors) and memory 452 (e.g., implemented as one or more memories), the memory 452 containing instructions that cause processor 450 to perform the operations described herein. Processor 450 is coupled to input / output (I / O) interface 454 to send and receive communications with components in the system, including, for example, temperature and pressure sensors 132, position sensor 353, and pressure sensors 132 and 364. In some cases, controller 130 may also communicate the status of various system components of engine system 100 (including throttle valve 112 and EGR throttle valve 126) and other sensors disposed in engine system 100 (e.g., pressure sensors, temperature sensors, knock sensors, and other types of sensors) and send actuation and / or control signals to them.

[0076] Figure 5This is a flowchart of method 500, which can be executed in whole or in part by controller 130. At 502, controller 130 receives a first pressure flow corresponding to a first pressure upstream of throttle valve 112. At 504, controller 130 receives a temperature flow corresponding to a temperature upstream of throttle valve 112. At 506, controller 130 receives a throttle position flow corresponding to a throttle position. At 508, controller 130 receives a second pressure flow corresponding to a second pressure at the converging end 208 of the converging nozzle 202 located downstream of throttle valve 112. After receiving the flow, at 510, controller 130 determines one or more models for calculating air mass flow rate based on the throttle position. Controller 130 selects between a throttle flow model, a converging nozzle flow model, or both. Based on one or more determined flow models, at 512, controller 130 estimates the air mass flow rate based on one or more determined models.

[0077] To determine which model to use for calculating air mass flow rate, controller 130 determines the ratio of the throttle flow model to the converging nozzle flow model based on the throttle position flow. For example, if the throttle 112 is closed or near closed, the throttle flow model will be weighted more heavily than the converging nozzle flow model. Conversely, if the throttle 112 is open or near open, the converging nozzle flow model will be weighted more heavily than the throttle flow model. Based on the throttle flow model, air flow rate is calculated using a first pressure flow, a temperature flow, and the throttle position flow. In other words, controller 130 calculates the pressure difference across the throttle 112 based on the first pressure flow, the temperature flow, and the throttle position flow. Based on the converging nozzle flow model, air flow rate is calculated using a first pressure flow, a second pressure flow, and a temperature flow. Once controller 130 has calculated the airflow based on the two flow models, it blends the calculated air flow rates from the throttle flow model and the converging nozzle flow model based on the determined ratio. Then, the controller 130 determines the estimated airflow based on the mixed calculated airflow.

[0078] In some embodiments, the controller 130 receives a third pressure flow from a third pressure sensor 360. This third pressure flow corresponds to a third pressure at the throat 232 of the converging-diverging nozzle 214 downstream of the converging nozzle 202. The controller 130 may also receive a fourth pressure flow from a fourth pressure sensor 364. This fourth pressure flow corresponds to a fourth pressure downstream of the converging-diverging nozzle 214, for example, in the intake manifold 104. Figure 1Within this context, the fourth pressure sensor 364 is a MAP sensor. Based on the third and fourth pressure flows, the controller 130 can determine the combined airflow, recirculated exhaust gas flow, and fuel flow. In some cases, the controller 130 can determine the calculated MAP value based on the calculated airflow. In this case, the calculated MAP can be compared with the measured MAP, and the difference can be corrected by the controller 130 using a compensation table. In some embodiments, the compensation table is used to capture system uncertainties and more complex system dynamics. Such variables are difficult to capture in a simple one-dimensional system due to fidelity limitations.

[0079] In some cases, controller 130 can control internal combustion engine system 100 ( Figure 1 This involves many aspects. For example, controller 130 can send signals to fuel injectors or multiple injectors. These signals correspond to the amount of fuel injected into the intake airflow. The fuel amount is based on estimated airflow, combined airflow and recirculated exhaust gas flow, a target air-fuel ratio, or a combination thereof. In some cases, the target air-fuel ratio values ​​corresponding to various parameters are stored in a table within the memory 452 of controller 130, or in other cases, these target air-fuel ratio values ​​are calculated based on engine parameters, for example, using a PID controller.

[0080] In some embodiments, the temperature flow is a first temperature flow. The controller 130 may receive a fifth pressure flow corresponding to the pressure upstream of the EGR throttle valve 126. The controller 130 may also receive a second temperature flow corresponding to the temperature upstream of the EGR throttle valve 126. In such an embodiment, the controller 130 sends a signal to the EGR throttle valve 126. This signal corresponds to the amount of EGR injected into the intake fluid flow. In this case, the amount of EGR is determined at least in part based on the estimated airflow rate, the fifth pressure flow, the second temperature flow, or a combination thereof.

[0081] While this disclosure contains numerous specific implementation details, these details should not be construed as limiting the scope of possible claims, but rather as descriptions of features specific to particular embodiments of the subject matter. Certain features described in the context of different embodiments of this disclosure can also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented separately in multiple embodiments or in any suitable sub-combination. Furthermore, although features may be described above as functioning in certain combinations and even initially claimed in this way, one or more features of a claimed combination may be removed from the combination in certain circumstances, and the claimed combination may be for sub-combinations or variations thereof.

[0082] Similarly, although operations are described in a specific order in the accompanying drawings, this should not be construed as requiring these operations to be performed in the specific order shown or in a sequential sequence, or as requiring all shown operations to be performed to obtain the desired result. Furthermore, the separation of various system components in the embodiments described above should not be construed as requiring such separation in all embodiments, but rather should be understood as meaning that the described components and systems can generally be integrated together in a single product or packaged into multiple products.

[0083] Several embodiments of this subject matter have been described. However, it should be understood that various modifications can be made. Therefore, other embodiments are within the scope of the following claims.

Claims

1. A method for controlling an internal combustion engine system, the method comprising: Receive the value of the first pressure upstream of the throttle valve; Receive the temperature value upstream of the throttle valve; Receive the throttle position value; Receive the value of the second pressure at the converging end of the converging nozzle located downstream of the throttle valve; as well as The airflow is estimated based on the received first pressure, the received temperature, the received throttle position, and the received second pressure, wherein the estimated airflow includes: Based on the throttle position, one or more models are determined for calculating airflow, including a throttle flow model, a converging nozzle flow model, or both the throttle flow model and the converging nozzle flow model. Determining which model to use includes: determining the ratio of the throttle flow model to the converging nozzle flow model based on the throttle position.

2. The method according to claim 1, characterized in that, The estimated airflow includes: The airflow is calculated based on the throttle flow model using the received first pressure, the received temperature, and the received throttle position.

3. The method according to claim 1, characterized in that, The estimated airflow includes: The airflow is calculated based on the converging nozzle flow model using the received first pressure, received temperature, received second pressure, and received throttle position.

4. The method according to claim 1, characterized in that, The estimated airflow includes: The airflow is calculated based on the throttle flow model using the received first pressure and the received temperature; The airflow rate is calculated based on the converging nozzle flow model using the received first pressure and the received temperature. The calculated airflow is based on a mixture of the throttle flow model and the converging nozzle flow model at the determined ratio; and The estimated airflow is determined based on the calculated airflow from the mixture.

5. The method according to any one of claims 1 to 3, characterized in that, Also includes: The value of a third pressure is received, the third pressure corresponding to the pressure at the throat of the converging-diverging nozzle downstream of the converging nozzle; The value of a fourth pressure is received, the fourth pressure corresponding to the pressure downstream of the converging-diverging nozzle; as well as The combined air flow rate, recirculated exhaust gas flow rate, and fuel flow rate are determined based on the third pressure and the fourth pressure.

6. The method according to claim 5, characterized in that, include: A certain amount of fuel is injected into the intake fluid flow, the amount of fuel being based on the estimated air flow rate, combined air flow rate and recirculated exhaust gas flow rate, and a target air-fuel ratio or combination thereof.

7. The method according to any one of claims 1 to 3, characterized in that, include: A certain amount of recirculated exhaust gas is injected into the intake fluid flow, the amount of which is determined at least in part based on an estimated airflow rate.

8. The method according to any one of claims 1 to 3, characterized in that, Also includes: The pressure difference across the throttle is calculated based on the received first pressure, the received temperature, and the received throttle position.

9. The method according to claim 1, characterized in that, Also includes: The value of a third pressure is received, the third pressure corresponding to the pressure at the throat of the converging-diverging nozzle downstream of the converging nozzle; The value of a fourth pressure is received, the fourth pressure corresponding to the pressure downstream of the converging-diverging nozzle; as well as The combined air flow rate, recirculated exhaust gas flow rate, and fuel flow rate are determined based on the third pressure and the fourth pressure.

10. The method according to claim 4, characterized in that, include: A certain amount of recirculated exhaust gas is injected into the intake fluid flow, the amount of which is determined at least in part based on an estimated airflow rate.

11. The method according to claim 5, characterized in that, include: A certain amount of recirculated exhaust gas is injected into the intake fluid flow, the amount of which is determined at least in part based on an estimated airflow rate.

12. The method according to claim 4, characterized in that, Also includes: The pressure difference across the throttle is calculated based on the received first pressure, the received temperature, and the received throttle position.

13. An engine system comprising: An intake manifold configured to receive a combustible mixture configured to burn in a combustion chamber; A throttle valve upstream of the intake manifold, the throttle valve being configured to at least partially regulate the airflow entering the intake manifold; An exhaust manifold configured to receive combustion products from the combustion chamber; as well as An exhaust gas recirculation mixer system downstream of the throttle valve and upstream of the intake manifold, the exhaust gas recirculation mixer comprising: An exhaust gas housing, the exhaust gas housing including an exhaust gas inlet for entering the interior of the exhaust gas housing; Mixer housing; A converging nozzle, which is located within the mixer housing and in the flow path from the air inlet of the mixer to the outlet of the mixer, converges toward the outlet of the mixer; A first pressure port located upstream of the throttle valve, the first pressure port providing a location for sensing a first pressure upstream of the throttle valve; and A second pressure port is located at the converging end of the converging nozzle, the second pressure port providing a position for sensing a second pressure at the converging end of the converging nozzle; The controller is configured to: A first pressure flow is received from a first pressure sensor located at the first pressure port, the first pressure flow corresponding to a first pressure upstream of the throttle valve; A temperature flow is received from a temperature sensor located at the first pressure port, the temperature flow corresponding to the temperature upstream of the throttle valve; A throttle position stream is received from an encoder coupled to the throttle, the throttle position stream corresponding to the throttle position; A second pressure flow is received from a second pressure sensor located at the second pressure port, the second pressure flow corresponding to the second pressure at the converging end of the converging nozzle; and Airflow is estimated based on the first pressure flow, the temperature flow, the throttle position flow, and the second pressure flow. The controller is further configured to estimate the airflow by: determining the mixing ratio of the throttle flow model and the converging nozzle flow model based on the throttle position flow.

14. The engine system according to claim 13, characterized in that, The controller is also configured to estimate the airflow using the following steps: The airflow is calculated based on the throttle flow model using the first pressure flow, the throttle position flow, and the temperature flow; Air flow rate is calculated based on the converging nozzle flow model using the first pressure flow, the second pressure flow, and the temperature flow. The calculated airflow is obtained by mixing the throttle flow model and the converging nozzle flow model based on the determined mixing ratio; as well as The estimated airflow is determined based on the calculated airflow from the mixture.

15. The engine system according to any one of claims 13 to 14, characterized in that, The temperature flow is a first temperature flow, and the controller is further configured to: Receive a fifth pressure flow, the fifth pressure flow corresponding to the pressure upstream of the exhaust gas inlet; Receive a second temperature flow, the second temperature flow corresponding to the temperature upstream of the exhaust gas inlet; as well as A signal is sent to the exhaust gas recirculation valve, the signal corresponding to the amount of recirculated exhaust gas to be injected into the intake fluid flow, the amount of recirculated exhaust gas being determined at least in part based on the estimated airflow rate.

16. The engine system according to any one of claims 13 to 14, characterized in that, Also includes: A converging-diverging nozzle, the converging-diverging nozzle being located within the mixer housing and including a fluidly communicating air-exhaust inlet to receive fluid flow from both the converging nozzle and the interior of the exhaust gas housing; A third pressure port is located in the throat of the converging-diverging nozzle, the third pressure port providing a position for sensing a third pressure within the throat of the converging-diverging nozzle; as well as A fourth pressure port is located downstream of the converging-diverging nozzle, the fourth pressure port providing a location for sensing a fourth pressure downstream of the converging-diverging nozzle; The controller is also configured to: A third pressure flow is received from a third pressure sensor located at the third pressure port, the third pressure flow corresponding to the third pressure at the throat of the converging-diverging nozzle; A fourth pressure flow is received from a fourth pressure sensor located at the fourth pressure port, the fourth pressure flow corresponding to a fourth pressure downstream of the converging-diverging nozzle; as well as The combined air flow rate, recirculated exhaust gas flow rate, and fuel flow rate are determined based on the third pressure flow and the fourth pressure flow.

17. The engine system according to claim 16, characterized in that, The controller is also configured to send a signal to the fuel injector corresponding to the amount of fuel to be injected into the intake fluid flow, the amount of fuel being based at least in part on the estimated air flow rate, the combined air flow rate and the recirculated exhaust gas flow rate, the target air-fuel ratio or combination.

18. The engine system according to claim 15, characterized in that, Also includes: A converging-diverging nozzle, the converging-diverging nozzle being located within the mixer housing and including a fluidly communicating air-exhaust inlet to receive fluid flow from both the converging nozzle and the interior of the exhaust gas housing; A third pressure port is located in the throat of the converging-diverging nozzle, the third pressure port providing a position for sensing a third pressure within the throat of the converging-diverging nozzle; as well as A fourth pressure port is located downstream of the converging-diverging nozzle, the fourth pressure port providing a location for sensing a fourth pressure downstream of the converging-diverging nozzle; The controller is also configured to: A third pressure flow is received from a third pressure sensor located at the third pressure port, the third pressure flow corresponding to the third pressure at the throat of the converging-diverging nozzle; A fourth pressure flow is received from a fourth pressure sensor located at the fourth pressure port, the fourth pressure flow corresponding to a fourth pressure downstream of the converging-diverging nozzle; as well as The combined air flow rate, recirculated exhaust gas flow rate, and fuel flow rate are determined based on the third pressure flow and the fourth pressure flow.

19. The engine system according to claim 18, characterized in that, The controller is also configured to send a signal to the fuel injector corresponding to the amount of fuel to be injected into the intake fluid flow, the amount of fuel being based at least in part on the estimated air flow rate, the combined air flow rate and the recirculated exhaust gas flow rate, the target air-fuel ratio or combination.

20. An engine system controller, configured as follows: Receives a first pressure flow corresponding to the first pressure upstream of the throttle valve; Receive a temperature flow corresponding to the temperature upstream of the throttle valve; Receive the throttle position flow corresponding to the throttle position; A second pressure flow that receives a second pressure corresponding to the second pressure at the converging end of the converging nozzle located downstream of the throttle valve; Based on the throttle position, one or more models are determined for calculating airflow, including a throttle flow model, a converging nozzle flow model, or both the throttle flow model and the converging nozzle flow model; as well as Airflow is estimated based on one or more established models. The determination of the one or more models used to calculate airflow includes: further configuring the controller to: determine the ratio of the throttle flow model to the converging nozzle flow model based on the throttle position flow.

21. The engine system controller according to claim 20, characterized in that, Determining the one or more models used to calculate airflow includes further configuring the controller to: Airflow is calculated based on the throttle flow model using the first pressure flow, the temperature flow, and the throttle position flow; Air flow rate is calculated based on a converging nozzle flow model using the first pressure flow, the second pressure flow, and the temperature flow. The calculated airflow is based on a mixture of the throttle flow model and the converging nozzle flow model at the determined ratio; and The estimated airflow is determined based on the calculated airflow from the mixture.

22. The engine system controller according to any one of claims 20 to 21, characterized in that, The controller is also configured to: A third pressure flow is received from a third pressure sensor, the third pressure flow corresponding to the third pressure at the throat of the converging-diverging nozzle downstream of the converging nozzle; A fourth pressure flow is received from a fourth pressure sensor, the fourth pressure flow corresponding to a fourth pressure downstream of the converging-diverging nozzle; as well as The combined air flow rate, recirculated exhaust gas flow rate, and fuel flow rate are determined based on the third pressure flow and the fourth pressure flow.

23. The engine system controller according to claim 22, characterized in that, It is also configured to send a signal to the fuel injector corresponding to the amount of fuel to be injected into the intake fluid flow, the amount of fuel being based on the estimated air flow rate, the combined air flow rate and the recirculated exhaust gas flow rate, and the target air-fuel ratio or combination.

24. The engine system controller according to any one of claims 20 to 21, characterized in that, The temperature flow is a first temperature flow, and the controller is further configured to: Receive a fifth pressure flow, the fifth pressure flow corresponding to the pressure upstream of the exhaust gas recirculation valve; Receive a second temperature flow, the second temperature flow corresponding to the temperature upstream of the exhaust gas recirculation valve; as well as A signal is sent to the exhaust gas recirculation valve, the signal corresponding to the amount of recirculated exhaust gas to be injected into the intake fluid flow, the amount of recirculated exhaust gas being determined at least in part based on the estimated airflow rate, the fifth pressure flow, the second temperature flow, or a combination thereof.

25. The engine system controller according to any one of claims 20 to 21, characterized in that, The controller is also configured to calculate the pressure difference across the throttle valve based on the first pressure flow, the temperature flow, and the throttle position flow.

26. The engine system controller according to claim 24, characterized in that, The controller is also configured to: A third pressure flow is received from a third pressure sensor, the third pressure flow corresponding to the third pressure at the throat of the converging-diverging nozzle downstream of the converging nozzle; A fourth pressure flow is received from a fourth pressure sensor, the fourth pressure flow corresponding to a fourth pressure downstream of the converging-diverging nozzle; as well as The combined air flow rate, recirculated exhaust gas flow rate, and fuel flow rate are determined based on the third pressure flow and the fourth pressure flow.

27. The engine system controller according to claim 26, characterized in that, It is also configured to send a signal to the fuel injector corresponding to the amount of fuel to be injected into the intake fluid flow, the amount of fuel being based on the estimated air flow rate, the combined air flow rate and the recirculated exhaust gas flow rate, and the target air-fuel ratio or combination.

28. The engine system controller according to claim 23, characterized in that, The controller is also configured to calculate the pressure difference across the throttle valve based on the first pressure flow, the temperature flow, and the throttle position flow.

29. The engine system controller according to claim 24, characterized in that, The controller is also configured to calculate the pressure difference across the throttle valve based on the first pressure flow, the temperature flow, and the throttle position flow.

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