Patent Application
20180156164
During a combustion cycle of an internal combustion engine (ICE), air/fuel mixtures are provided to cylinders of the ICE. The air/fuel mixtures are compressed and/or ignited and combusted to provide output torque. Many diesel and gasoline ICEs employ a supercharging device, such as an exhaust gas turbine driven turbocharger, to compress the airflow before it enters the intake manifold of the engine in order to increase power and efficiency. Specifically, a turbocharger uses a centrifugal gas compressor that forces more air (i.e., oxygen) into the combustion chambers of the ICE than is otherwise achievable with ambient atmospheric pressure. The additional mass of oxygen-containing air that is forced into the ICE improves the engine's volumetric efficiency, allowing it to burn more fuel in a given cycle, and thereby produce more power.
According to an aspect of an exemplary embodiment, a turbocharger turbine housing manifold is provided. The manifold can comprise a body, at least one non-dedicated exhaust gas recirculation (EGR) vein, a dedicated EGR vein, and an EGR bypass valve in fluid communication with the dedicated EGR vein. The dedicated EGR vein can converge with the at least one non-dedicated EGR veins downstream from the EGR bypass valve. The dedicated EGR vein can be in fluid communication with an EGR conduit. The EGR bypass valve can selectively allow or prevent fluid communication between the dedicated EGR vein and the EGR conduit. The EGR bypass valve can comprise a two-way valve having a gate movable from a first position to a second position, wherein when the gate is in the first position the dedicated EGR vein is in fluid communication with the at least one non-dedicated EGR veins, and when the gate is in the second position the dedicated EGR vein is in fluid communication with the EGR conduit. The manifold can further comprise a wastegate valve disposed downstream from the EGR bypass valve.
According to another aspect of an exemplary embodiment, a turbocharger can include a compressor disposed within a compressor housing, a turbine mechanically coupled to the compressor and disposed within a turbine housing. The turbine housing can include a manifold having a plurality of veins which converge therein and establish fluid communication with the turbine, and at least one of the veins can be a dedicated EGR vein having an EGR bypass valve. The at least one dedicated vein can converge with at least one of the remaining veins downstream from the EGR bypass valve. The manifold and turbine housing can be a one-piece construction. The EGR bypass valve can selectively allow or prevent fluid communication between the dedicated EGR vein and the turbine. The one or more of the at least one dedicated EGR veins can be in fluid communication with an EGR conduit. The EGR bypass valve can selectively allow or prevent fluid communication between the one or more dedicated EGR veins and the EGR conduit. The EGR bypass valve can comprise a two-way valve having a gate movable from a first position to a second position, wherein when the gate is in the first position the dedicated EGR vein is in fluid communication with the at least one non-dedicated EGR veins, and when the gate is in the second position the dedicated EGR vein is in fluid communication with the EGR conduit. The turbocharger can further comprise a wastegate valve disposed downstream from the EGR bypass valve.
According to an aspect of an exemplary embodiment, an EGR system can comprise an internal combustion engine having an air intake manifold configured for delivering air to a plurality of cylinders, wherein one of the plurality of cylinders is a dedicated EGR cylinder, an EGR conduit in fluid communication with the air intake manifold, and a turbocharger having a turbine disposed within a turbine housing and in fluid communication with the plurality of cylinders via a turbine manifold. The turbine manifold can include a body, at least one non-dedicated EGR vein disposed within the body, a dedicated EGR vein disposed within the body in fluid communication with the dedicated EGR cylinder and the EGR conduit, and an EGR bypass valve in fluid communication with the dedicated EGR vein. The dedicated EGR vein can converge with the at least one non-dedicated EGR veins downstream from the EGR bypass valve. The EGR bypass valve can selectively allow or prevent fluid communication between the dedicated EGR vein and the EGR conduit. The EGR bypass valve can comprise a two-way valve having a gate movable from a first position to a second position, wherein when the gate is in the first position the dedicated EGR vein is in fluid communication with the at least one non-dedicated EGR veins, and when the gate is in the second position the dedicated EGR vein is in fluid communication with the EGR conduit. The manifold and turbine housing can be a one-piece construction. The system can further include a conduit in fluid communication with at least one of the one or more non-dedicated EGR cylinders and at least one of the non-dedicated EGR veins. The system can further include a conduit in fluid communication with the dedicated EGR cylinder and the dedicated EGR vein.
Other objects, advantages and novel features of the exemplary embodiments will become more apparent from the following detailed description of exemplary embodiments and the accompanying drawings.
Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
Provided herein are turbocharger turbine housing manifolds, and turbochargers and exhaust gas recirculation (EGR) systems incorporating the same. The manifolds each comprise one or more EGR bypass valves which increase the efficiency of turbochargers by reducing pressure and thermal losses of exhaust gasses passing therethrough. Increases in efficiency are gained by virtue of the construction and position of the EGR bypass valves within a turbocharger manifold or turbine housing.
Referring to the drawings, wherein like reference numerals are used to identify like or identical components in the various views,
ICE 12 includes a cylinder block 11 which defines a plurality of cylinders 20 (referenced as cylinders 1-4). ICE 12 can be of a spark ignition or a compression ignition design. ICE 12 is illustrated as an inline four cylinder arrangement for simplicity. However, it is understood that the present teachings apply to any number of piston-cylinder arrangements and a variety of reciprocating engine configurations including, but not limited to, V-engines, inline engines, and horizontally opposed engines, as well as both overhead cam and cam-in-block configurations. In some specific embodiments, ICE 12 can comprise an inline three or six cylinder engine. In other specific embodiments, ICE 12 can comprise V-6, V-8, V-10, and V-12 configuration engines, among others. Each of the cylinders 20 can include a piston (not shown) configured to reciprocate therein, wherein a cylinder 20 and its respective piston can define a combustion chamber. Each of the respective cylinders 20 may include one or more fuel injectors 29 that may selectively introduce liquid fuel (as an aerosol) into each cylinder for combustion. Each of the cylinders 20 may be in selective fluid communication with the air intake system 14 to receive fresh/oxygenated air, and the cylinders 20 can be in selective fluid communication with the exhaust system 16 to expel the byproducts of combustion. Each of cylinders 1, 2, 3, and 4 expel exhaust gas 40 away from ICE 12 via dedicated conduits 21, 22, 23, and 24, respectively. The exhaust gasses 40 can subsequently pass through one or more aftertreatment devices, such as device 42, to catalyze and/or remove certain byproducts prior to exiting the exhaust system 16 via a tailpipe 44.
The air intake system 14 may generally include a fresh-air inlet 15, an EGR mixer 26, a charge air cooler 28, a throttle 30, and an intake manifold 32. As may be appreciated during operation of ICE 12 fresh air 34 may be ingested by the air intake system 14 from the atmosphere or from an associated air-cleaner assembly via the fresh-air inlet 15. The throttle 30 may include a controllable baffle configured to selectively regulate the total flow of air through the intake system 14, and ultimately into the cylinders 20 via the intake manifold 32. The charge air cooler 28 is shown receiving a combination of EGR gas 54 and fresh air 34 as provided by the EGR mixer 26. In some embodiments, the air intake system 14 can additionally or alternatively include one or more of a dedicated EGR cooler (not shown) in fluid communication with EGR conduit 52 and configured to cool EGR gas 54 prior to the EGR mixer 26, and an intercooler (not shown) in fluid communication with conduit 66 and configured to cool compressed fresh air 34 prior to the EGR mixer 26. In a specific embodiment (not shown), the charge air cooler 28 is positioned upstream from the EGR mixer 26.
As mentioned above, the air intake system 14 and the exhaust system 16 may be in mechanical communication through a turbocharger 18. As shown in
The rotation of the compressor 62 via the common shaft 64 then draws in fresh air 34 from the inlet 15 and compress it into the remainder of the intake system 14. For example, the compressor 62 can communicate compressed air to the intake system 14 via conduit 66. The variable flow and force of exhaust gases 40 can influence the amount of boost pressure that can be imparted to fresh air 34 by the compressor 62, and subsequently the amount of oxygen capable of being delivered to cylinders 20. In many instances, maximum translation of energy from exhaust gas 40 to compressor 62 is desired. In some instances, boost pressure exerted by the compressor 62 can be limited by an optional wastegate valve 55. The wastegate valve 55 can divert exhaust gas 40 away from the turbocharger turbine 60 towards the tailpipe 44, for example via a wastegate conduit 56, thereby limiting boost pressure. Wastegate valve 55 can be actuated via actuator 57, for example.
The engine assembly 10 includes a dedicated EGR system 50 that may directly route (e.g., via an EGR conduit 52) the EGR gas 54 from one or more dedicated cylinders of ICE 12 back into the intake system 14. This recirculated EGR gas 54 may mix with the fresh air 34 at the EGR mixer 26, for example, and may correspondingly dilute the oxygen content of the mixture. The use of EGR can increase the efficiency in spark ignition engines. EGR can also reduce the combustion temperature and NOx production from ICE 12. Routing the entire exhaust of one cylinder 20, or the entire exhaust gas of less than all of cylinders 20 back to the intake assembly 14 is referred to herein as “dedicated EGR.” Dedicated EGR can include embodiments where substantially all of the exhaust gas of one cylinder 20, or less than all cylinders 20 is routed back to the intake assembly 14.
In general, manifold 70 comprises a body having a plurality of veins which converge therein, wherein at least one of the plurality of veins is in exclusive fluid communication with a dedicated EGR cylinder, or a plurality or dedicated EGR cylinders. Each vein within the manifold 70 can communicate exclusively with a dedicated conduit, such as dedicated conduits 21-24, or can communicate with a plurality of dedicated conduits, such as conduits 22 and 23. Dedicated conduits 21-24 are optional, and serve only to effect fluid communication between the manifold veins and the cylinders of an ICE, such as cylinders 1-4 or ICE 12. As shown in
A conduit within manifold 70 which is in exclusive fluid communication with a dedicated EGR cylinder or a plurality of dedicated EGR cylinders can be referred to as a dedicated EGR vein. Accordingly, as shown, vein 24′ comprises a dedicated EGR vein. In some embodiments, manifold 70 comprises at least three veins which converge therein, wherein at least two, but less than all, of the at least three veins are dedicated EGR veins. An EGR bypass valve, such as EGR bypass valve 71, is provided within the one or more dedicated EGR veins of manifold 70 for bypassing exhaust gas from one or more dedicated EGR cylinders to conduit 52. The one or more EGR bypass valves are disposed such that exhaust gas within the dedicated EGR vein can be bypassed to EGR conduit 52 before contacting one or more of exhaust gas from non-dedicated EGR veins, and the turbocharger turbine, such as turbine 60. For the purpose of illustration, EGR bypass valve 71 is shown within vein 24′ in fluid communication with dedicated cylinder 4 (via optional dedicated conduit 24), and veins 21′, 22′, and 23′. Vein 24′ converges with veins 21′, 22′, and 23′ on the downstream side 71′ of EGR bypass valve 71, whereafter all veins collectively fluidly communicate with turbine 60. The manifolds disclosed herein, such as manifold 70, which include an integrated EGR bypass valve increase the efficiency of turbochargers, such as turbocharger 18, by reducing pressure drop and thermal loss of exhaust gas, such as exhaust gas 40, between one or more dedicated cylinders, such as cylinder 4, and the turbocharger turbine, such as turbine 60. The EGR bypass valve 71 configurations provided herein minimize the cylinder-to-turbine path geometric and volumetric variations between dedicated and non-dedicated cylinders.
As illustrated in
In some embodiments, two-way EGR valve 71 can be replaced with two one-way valves which are one-way relative to the dedicated EGR vein 24′ and prevent fluid flow from the turbine 60, one or more non-dedicated EGR veins 21′-23′, or EGR conduit 52 in an upstream direction towards dedicated vein 24′ or cylinder 4. A single one-way valve can occupy each of first position 73 and second position 74, for example. Each of the one-way valves can be actuated by the same or separate actuators.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and can be desirable for particular applications.
