Description:TECHNICAL FIELD
[001] The embodiments herein generally relate to internal combustion engines, more particularly, relates to a system and method for controlling an EGR valve of an internal combustion engine based on exhaust temperature measured at an exhaust manifold.
BACKGROUND
[002] Exhaust gas recirculation (EGR) has been used for more than three decades in internal combustion engines to reduce NOx Emissions through increasing the specific heat coefficient of intake charge, which lowers the combustion temperature and dilutes intake air to slow down combustion. Recirculation of exhaust gas is usually accomplished by routing a portion of the exhaust gas back to the intake manifold where it is inducted into the cylinders along with charge air.
[003] In order to reduce exhaust emission, the internal combustion engine is provided with an exhaust gas recirculation (EGR) apparatus. The EGR apparatus has an EGR valve disposed in an EGR passage. The EGR valve adjusts quantity of EGR gas recirculating into the intake manifold through the EGR passage.
[004] Conventionally, the internal combustion engine includes the intake manifold, an exhaust manifold, and the EGR passage which forms the exhaust gas recirculation channel. Further, the IC engine includes a mechanical fuel injection pump (FIP) which is configured to inject fuel into a combustion chamber and an EGR valve operatively connected in the EGR channel to allow passage of the exhaust gas to the inlet manifold. In conventional arrangement, there is no precise way to monitor in what load engine is running. Also, in another approach available, a potentiometer-based throttle position sensor (TPS) senses the position of the FIP control lever and provide a signal to EGR control system to control EGR valve. The potentiometer-based throttle position sensor TPS is placed on or directly linked to the FIP control lever FIPL to control EGR flow. The reliability of TPS would be affected with time as it is a mechanical based sensor which would be subjected to wear and tear and/or there is a possibility of manual error during initial installation, so this arrangement does not provide a precise control over the quantity of EGR flowing into the intake manifold. Thus, there exists a need for a method and a system for controlling the EGR valve in the combustion engine which provide precise control over the quantity of EGR flowing into the intake manifold based on exhaust temperature.
[005] A known art discloses an internal combustion engine having an EGR apparatus. An oxygen sensor is provided in an intake pipe. Based on output signals of the oxygen sensor, an opening degree of the EGR valve of when the EGR gas starts to recirculate is detected. Further, another known art discloses an internal combustion engine having an EGR apparatus in which an intake pressure sensor is provided in the intake pipe to detect an intake pressure. Based on the detected intake pressure, an opening degree of the EGR valve of when the EGR gas starts to recirculate is learned.
[006] Since a sensitivity of combustion stability relative to an EGR gas quantity is relatively high in the I.C. engines, it is necessary to control the EGR gas quantity with high accuracy using the EGR valve. Thus, the position of the EGR valve plays a vital role for passage of exhaust gases to the intake manifold. When the exhaust gas recirculation is stopped, it is necessary for the EGR valve to accurately fully close the EGR passage to avoid an EGR gas leakage. Therefore, an accurate control concept of the EGR rate is crucial and necessary, for a precise and reproducible control of the NOx emissions.
[007] Therefore, there exists a need for a method and apparatus for controlling an EGR valve in a combustion engine based on exhaust temperature, which eliminates the aforementioned drawbacks.

OBJECTS
[008] The principal object of an embodiment herein is to provide a system for controlling an EGR valve in an internal combustion engine based on exhaust temperature.
[009] Another object of an embodiment herein is to provide the system in which the EGR valve is accurately controlled by a controller (ECU of the vehicle) based on an input received from an exhaust temperature sensor relating to the exhaust temperature.
[0010] Another object of an embodiment herein is to provide the system which is adapted to generate precise engine modelling/load sensing for a mechanical fuel injection pump fed engine.
[0011] Another object of an embodiment herein is to provide the system in which EGR flow quantities may be used in steady state as well as transient state engine operations.
[0012] Another object of an embodiment herein is to provide the system which provides better control and corrections to have improved emission and performance of the combustion engine.
[0013] Another object of an embodiment herein is to provide the system which includes at least one actuator 108 operated by the controller of the system to control a position of the EGR valve opening.
[0014] Another object of an embodiment herein is to provide the system which in simple in construction and inexpensive.
[0015] Another object of an embodiment herein is to provide a method for controlling an EGR valve in an internal combustion engine based on exhaust temperature.
[0016] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[0017] The embodiments of the invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0018] Fig.1 depicts a perspective view of a conventional mounting of a TPS sensor on a FIP control lever, according to embodiments as disclosed herein;
[0019] Fig. 2 depicts a front perspective view of a temperature sensor mounted at an exhaust manifold of an internal combustion engine, according to embodiments as disclosed herein; and
[0020] Fig. 3 is a flowchart depicting a method for controlling an EGR valve in an internal combustion engine based on exhaust temperature, according to embodiments as disclosed herein.
DESCRIPTION
[0021] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0022] The embodiments herein achieve a system for controlling an EGR valve in an internal combustion engine based on exhaust temperature. Further, the embodiments herein achieve the system in which the EGR valve is accurately controlled by a controller (ECU of the vehicle) based on an input received from a speed sensor and an exhaust temperature sensor relating to engine speed and the exhaust temperature, respectively. Furthermore, the embodiments herein achieve the system in which there is no physical contact between mechanical control lever and the exhaust temperature sensor, thereby facilitating repeatability of controlling the EGR valve without any issues. Additionally, the embodiments herein achieve the system which is adapted to generate precise engine modelling/load sensing for a mechanical fuel injection pump fed engine. Moreover, the embodiments herein achieve the system in which EGR flow quantities may be used in steady state as well as transient state engine operations. Also, the embodiments herein achieve the system which provides better control and corrections to have improved emission and performance of the combustion engine. Further, the embodiments herein achieve the system which includes at least one actuator operated by the controller of the system to control a position of the EGR valve opening. Furthermore, the embodiments herein achieve a method for controlling an EGR valve in an internal combustion engine based on exhaust temperature. Referring now to the drawing, and more particularly to Fig. 1 through Fig. 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0023] Fig.1 depicts a perspective view of a conventional mounting of a TPS sensor on a FIP control lever, according to embodiments as disclosed herein. Conventionally, an internal combustion engine includes an intake manifold, an exhaust manifold, and an EGR passage which forms the exhaust gas recirculation channel. Further, the IC engine includes a mechanical fuel injection pump (FIP) which is configured to inject fuel into a combustion chamber and an EGR valve operatively connected in the EGR channel to allow passage of the exhaust gas to the inlet manifold. In conventional arrangement, there is no precise way to monitor in what load engine is running. Also, in another approach available, a potentiometer-based throttle position sensor (TPS) senses the position of the FIP control lever and provide a signal to EGR control system to control EGR valve. The potentiometer-based throttle position sensor TPS is placed on or directly linked to the FIP control lever FIPL to control EGR flow. The reliability of TPS would be affected with time as it is a mechanical based sensor which would be subjected to wear and tear and/or there is a possibility of manual error during initial installation, so this arrangement does not provide a precise control over the quantity of EGR flowing into the intake manifold. Thus, there exists a need for a method and a system for controlling the EGR valve in the combustion engine which provide precise control over the quantity of EGR flowing into the intake manifold based on exhaust temperature.
[0024] Fig. 2 depicts a front perspective view of a temperature sensor mounted at an exhaust manifold of an internal combustion engine, according to embodiments as disclosed herein. The system 100 according to an embodiment includes at least one temperature detection sensor 104 which is installed at the exhaust manifold of the combustion engine. The temperature detection sensor 104 is configured to detect a temperature of the exhaust gas emerging out of the combustion chamber. Further, the temperature detection sensor 104 is configured to communicate a measured/detected temperature to a controller 106. In an embodiment, the temperature detection sensor 104 is at least thermocouple, RTD’s thermistors or any contact type thermos sensor. Further, the system 100 includes a speed sensor 110 to sense the speed of an engine.
[0025] The system 100 includes the controller 106 which is configured to receive engine speed signal and the detected temperature of the exhaust gas and compare the detected speed of the engine and temperature of the exhaust gas with a pre-stored modeled data. The pre-stored molded data is stored in a memory unit provided in the controller 106. Further, the controller 106 is configured to actuate an actuator 108 provided in communication with the EGR valve 102, whereby the actuator 108 shifts an EGR valve opening to a predetermined position for the flow of predetermined quantity of exhaust gas into the intake manifold based on the temperature comparison and speed of the engine.
[0026] In an embodiment, the controller 106 is at least one of a separate controller provided in a vehicle or an electronic control unit (ECU) of the vehicle which is adapted to accurately control the opening position of the EGR valve 102 based on the exhaust gas temperature.
[0027] In an embodiment, the system 100 is configured to control the EGR valve 102 to allow flow of predetermined quantities of the exhaust gas into the intake passage in one of steady state and transient state of engine operation.
[0028] In an alternate embodiment, the system 100 is configured to generate an accurate engine load modelling/load sensing by comparing the detected temperature of the exhaust gas with a pre-stored modeled data stored in the memory unit of said controller.
[0029] Fig. 3 is a flowchart depicting a method for controlling an EGR valve 102 in an internal combustion engine based on exhaust temperature, according to embodiments as disclosed herein. A method 200 for controlling an EGR valve in the internal combustion engine 10 includes measuring and communicating, by a speed sensor 110 and a temperature detection sensor 104, an engine speed signal and a temperature of an exhaust gas, respectively, to a controller 106 (at step 202). Further, the method 200 includes comparing, by said controller 106, said detected engine speed and said temperature with a pre-stored modeled data (at step 204). Furthermore, the method 200 includes actuating, by said controller 106, an actuator 108 provided in communication with said EGR valve to shift an EGR valve opening to a predetermined position (at step 206).
[0030] The technical advantages provide by the embodiments herein includes precise control of EGR valve opening for flow of exhaust gas based on temperature of exhaust gas, no physical contact between mechanical control lever and sensor thereby no possibility of repeatability issues, better control and corrections to have improved emission and performance, precise EGR flow quantities in steady state as well as transient state engine operations, facilitate in generating load sensing / load modelling, and simple in construction and inexpensive.
[0031] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
, Claims:We claim,

1. A system 100 for controlling an EGR valve 102 of an internal combustion engine 10, comprising:
a temperature detection sensor 104 configured to detect and communicate a temperature of an exhaust gas to a controller 106; and
a speed sensor 110 configured to detect and communicate an engine speed to said controller 106,
wherein,
said controller 106 is configured to compare said detected temperature of the exhaust gas and said engine speed with a pre-stored modeled data and actuate an actuator 108 provided in communication with said EGR valve 102 to shift an EGR valve opening to a predetermined position.
2. The system 100 as claimed in claim 1, wherein said temperature detection sensor 104 is installed at a predetermined position of an exhaust manifold of the internal combustion engine.
3. The system 100 as claimed in claim 1, wherein said controller 106 is at least one of a separate controller provided in a vehicle or an electronic control unit (ECU) of the vehicle which is adapted to accurately control the position of the EGR valve 102 based on the exhaust gas temperature, said controller includes a memory unit for storing a pre-stored modeled data.
4. The system 100 as claimed in claim 1, wherein said EGR valve 102 at said predetermined position allows a predetermined quantity exhaust gas to recirculate from an exhaust passage into an intake passage through an EGR passage.
5. The system 100 as claimed in claim 1, wherein said system 100 is configured to control said EGR valve 102 to allow flow of predetermined quantities of said exhaust gas into the intake passage in one of steady state and transient state of engine operation.
6. The system 100 as claimed in claim 1, wherein said system 100 is configured to generate an accurate engine load modelling/load sensing by comparing the detected temperature of the exhaust gas with a pre-stored modeled data stored in the memory unit of said controller.
7. A method 200 for controlling an EGR valve 102 in an internal combustion engine 10, comprising:
measuring and communicating, by a speed sensor 110 and a temperature detection sensor 104, an engine speed and a temperature of an exhaust gas, respectively, to a controller 106;
comparing, by said controller 106, said detected engine speed and said temperature with a pre-stored modeled data; and
actuating, by said controller 106, an actuator 108 provided in communication with said EGR valve 102 to shift an EGR valve opening to a predetermined position.