GB2554922B

GB2554922B - Exhaust duct for internal combustion engine

Info

Publication number: GB2554922B
Application number: GB1617484.9A
Authority: GB
Inventors: J Dean Robert; T Petry-Johnson Travis
Original assignee: Caterpillar Marine Power UK Ltd
Current assignee: Caterpillar Marine Power UK Ltd
Priority date: 2016-10-14
Filing date: 2016-10-14
Publication date: 2019-09-11
Anticipated expiration: 2036-10-14
Also published as: GB2554922A; GB201617484D0

Description

EXHAUST DUCT FOR INTERNAL COMBUSTION ENGINE

Technical Field

The present disclosure relates to internal combustion engines, and more particularly relates to an exhaust system of an internal combustion engine.

Background

Internal combustion engines include an exhaust system for expelling exhaust gases produced as a result of combustion of fuel. Often, an internal combustion engine may have to be positioned within a confined space, such as an engine room of a marine vessel. Since space in the engine room is limited, it becomes difficult to couple and route different components of the exhaust system. For example, an exhaust elbow used for transferring exhaust gases from a turbocharger to a muffler is disposed at an outer periphery of the engine. Hence, the exhaust elbow extends out and installation of the internal combustion engine in limited space of the engine room becomes difficult. Further, maintenance or servicing of the internal combustion engine in the engine room also becomes difficult because of limited space in the engine room. US Patent Number 9,097,220, hereinafter referred to as the ’220 patent, describes an acoustic attenuator for an engine booster. The acoustic attenuator for the engine booster such as a turbocharger for the engine is disclosed, in which the acoustic attenuator includes an attenuator chamber. At least one absorption media is located in the attenuator chamber. The acoustic attenuator is located adjacent an inlet port of the turbocharger so as to attenuate any acoustic pressure waves by dissipative reaction with the absorption media before they have chance to reach other components of a low pressure supply system for the engine. However, the acoustic attenuator of the ’220 patent fails to address the problem associated with the installation of the engine in an engine room having limited space.

Summary of the Disclosure

In accordance with the present invention there is provided an exhaust duct for an internal combustion engine, the exhaust duct comprising: a first connecting portion defining an inlet port; a second connecting portion defining an outlet port; and a body portion defining a fluid passage therethrough.

The body portion includes a central section having a cuboidal shape, a width, and a central axis (C - C) extending normal to the width in a flow direction; a first transition section tapering away from a first end of the central section; and a second transition section tapering away from a second end of the central section.

The first connecting portion extends from the first transition section along a first axis perpendicular to the central axis of the central section. The first connecting portion is adapted to receive fluid via the inlet port and communicate the fluid to the fluid passage in the flow direction.

The second connecting portion extends from the second transition section along a second axis parallel to the central axis of the central section. The second connecting portion is adapted to receive the fluid from the fluid passage in the flow direction and discharge the fluid via the outlet port. A plane containing the second axis of the second connecting portion lies between the central axis of the central section and the inlet port. The width of the central section is greater than a diameter of the inlet port and greater than a diameter of the outlet port. Each of the first transition section and the second transition section, when considered in longitudinal section with respect to the flow direction, defines a flowpath having surfaces which diverge in the flow direction.

Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

Brief Description of the Drawings FIG. 1 is a rear view of an engine having an exhaust duct coupled with a turbocharger, according to an embodiment of the present disclosure; FIG. 2 is a front perspective view of the exhaust duct of FIG. 1; FIG. 3 is a rear perspective view of the exhaust duct of FIG. 1; FIG. 4 is a sectional view of the exhaust duct taken along a line X-X’ in FIG 2; and FIG. 5 is a sectional view of the exhaust duct taken along a line Y-Y’ in FIG 3.

Detailed Description

Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts. FIG. 1 illustrates a rear view of an internal combustion engine 10. The internal combustion engine 10 is embodied as a diesel fuel based compression ignited internal combustion engine. Alternatively, the internal combustion engine 10 may be any other internal combustion engine powered by fuels such as, but not limited to, gasoline, natural gas or a combination thereof. In an embodiment, the internal combustion engine 10 provides power to a marine vessel (not shown), for example, a ship or a boat. However, it is understood that the internal combustion engine 10 may alternatively be associated with other machines, such as excavating machines, passenger vehicles, electric generators, mining trucks, and agricultural machines, for power generation. The internal combustion engine 10 is disposed in an engine room (not shown) of the marine vessel. In an example, the internal combustion engine 10 is coupled to a propeller (not shown) of the marine vessel for propelling the marine vessel over a water body. In another example, the internal combustion engine 10 is coupled to a power generation unit (not shown) for producing electrical power for the marine vessel.

The internal combustion engine 10 includes a cylinder block 14 and a cylinder head 16 mounted on the cylinder block 14. The cylinder block 14 defines one or more cylinders (not shown) therein. In an example, the cylinder block 14 may define more than one cylinder in a configuration such as, ‘V’ type configuration, in-line configuration, radial configuration, or rotary configuration. The cylinder head 16 is mounted on the cylinder block 14 to cover the cylinders and define a main combustion chamber (not shown) within each cylinder. The internal combustion engine 10 also includes an oil sump 20 attached to a bottom portion of the cylinder block 14 for storing fluid such as, lubrication oil.

Although not shown, each cylinder of the internal combustion engine 10 includes a piston and a connecting rod. A first end of each of the connecting rod is connected to a crankshaft and a second end of each of the connecting rod is connected to the corresponding piston. The piston reciprocates within the cylinder. The connecting rod connects the piston and the crankshaft such that a sliding motion of the piston within the cylinder causes a rotational motion of the crankshaft. The internal combustion engine 10 further includes a flywheel 24 coupled to the crankshaft. During operation, the flywheel 24 stores rotational energy in order to reduce fluctuations in power generation.

The internal combustion engine 10 further includes an intake system 26 for supplying air to the cylinders and an exhaust system 28 for discharging the exhaust gases produced due to combustion of air-fuel mixture in the cylinders. The intake system 26 includes an intake manifold (not shown) in fluid communication with the cylinder for supplying air to the cylinders. The intake system 26 also includes an intake pipe 34 that supplies air to the cylinders. The intake system 26 also includes a charged air cooler 30 and an air filter 32 connected in the intake pipe 34. The intake pipe 34 supplies air to the charged air cooler 30 after filtration through the air filter 32. The air filter 32 includes one or more filter elements (not shown) for filtering impurity from the air. The charged air cooler 30 cools the air before being supplied to the cylinders.

The exhaust system 28 includes an exhaust manifold (not shown) in fluid communication with the cylinders, and a turbocharger 36 connected to the exhaust manifold. In an example, the turbocharger 36 is bolted to the exhaust manifold. Alternatively, various other coupling methods, such as casting, and riveting may be used to couple the turbocharger 36 and the exhaust manifold. In particular, the exhaust manifold receives exhaust gases from the cylinders and supplies to the turbocharger 36. The turbocharger 36 includes a housing 42, a turbine (not shown) in fluid communication with the exhaust manifold, and a compressor (not shown) in fluid communication with the intake pipe 34. The turbine and the compressor are enclosed in the housing 42 and are mechanically coupled to each other. The turbine receives the exhaust gases from the exhaust manifold. The exhaust gases received flows through the turbine to cause a rotational motion of the turbine, which in turn causes a corresponding rotational motion of the compressor. The intake air after being pressurized by the compressor exits the housing 42 to enter the intake pipe 34 and the exhaust gases after flowing through the turbine exits the housing 42 to enter a muffler (not shown) of the exhaust system 28. The compressed air exiting the compressor of the turbocharger 36 may be cooled by the charged air cooler 30 after entering into the intake pipe 34, to improve the engine performance.

In order to supply the exhaust gases from the turbine to the muffler, the internal combustion engine 10 includes an exhaust duct 44 connected to the housing 42 of the turbocharger 36. Although in FIG. 1, the exhaust duct 44 is shown to communicate the exhaust gases received from the turbocharger 36 directly to the muffler, it can be contemplated that the exhaust duct 44 may alternatively be used to either directly or indirectly communicate the exhaust gases received from the turbocharger 36 to another component of the exhaust system 28, such as an after-treatment module (not shown). FIG. 2 and FIG. 3 illustrate different perspective views of the exhaust duct 44. The exhaust duct 44 includes a body portion 50 defining a fluid passage 52 (shown in FIG. 4) along a central axis C-C therethrough. The fluid passage 52 allows the exhaust gases to flow through the exhaust duct 44. The exhaust duct 44 includes a first connecting portion 54 and a second connecting portion 56 extending from the body portion 50. The first connecting portion 54 is connected to the turbocharger 36 for receiving the exhaust gases from the turbocharger 36 and communicating the exhaust gases to the fluid passage 52. Further, the second connecting portion 56 is adapted to be connected to the muffler. The second connecting portion 56 receives the exhaust gases from the fluid passage 52 and discharges the exhaust gases into the muffler. FIG. 4 illustrates a sectional view of the exhaust duct 44 taken along a line X-X’ in FIG. 2. Referring to FIG. 2, FIG. 3, and FIG. 4, the first connecting portion 54 has a first axis A-A perpendicular to the central axis C-C of the central section of the body portion 50. The first connecting portion 54 includes a first flange 58 and a first tubular section 60 extending between the first flange 58 and the body portion 50. The first flange 58 and the first tubular section 60 together define an inlet port 62 along the first axis A-A. The inlet port 62 receives the exhaust gases from the turbocharger 36 and supplies the exhaust gases to the fluid passage 52. In an example, the inlet port 62 has a cylindrical shape having a diameter ‘DI’. Further, the first flange 58 defines four elongated holes 64 circumferentially positioned from each other about the first axis A-A. Each of the elongated holes 64 receives a fastener 66 (shown in FIG. 1) for connecting the exhaust duct 44 and the turbocharger 36. Owing to the elongated holes 64, the exhaust duct 44 is rotatable with respect to the housing 42 of the turbocharger 36.

The second connecting portion 56 has a second axis B-B parallel to the central axis C-C of the central section of the body portion 50. In an example, the second axis B-B is positioned at an offset distance OD’ (shown in FIG. 4) from the central axis C-C. As such, due to the offset distance OD’ between the second axis B-B and the central axis C-C, a gap 68 (shown in FIG. 1) is defined between the exhaust duct 44 and the turbocharger 36, when the exhaust duct 44 is mounted on the internal combustion engine 10. One or more shielding elements (not shown) are received in the gap 68 for preventing heat exchange between the exhaust duct 44 and the turbocharger 36.

The second connecting portion 56 includes a second flange 70 and a second tubular section 72. The second tubular section 72 extends between the second flange 70 and the body portion 50. The second flange 70 and the second tubular section 72 together define an outlet port 74 along the second axis B-B. The outlet port 74 receives the exhaust gases from the fluid passage 52 and supplies the exhaust gases to the muffler. In an example, the outlet port 74 has a cylindrical shape having a diameter ‘D2’. The diameter ‘D2’ of the outlet port 74 is equal to the diameter ‘DI’ of the inlet port 62. Further, the second flange 70 defines four circular shaped holes 76. The circular shaped holes 76 are circumferentially positioned from each other about the second axis B-B. Each of the circular shaped holes 76 receives a fastener (not shown) for connecting the exhaust duct 44 to the muffler. FIG. 5 illustrates a sectional view of the exhaust duct 44 taken along a line Y-Y’ in FIG. 4. The body portion 50 of the exhaust duct 44 includes a central section 78 having a cuboidal shape. The central section 78 has a width ‘ W’ greater than the diameter ‘DI ’ of the inlet port 62 and the diameter ‘D2’ of the outlet port 74.

As shown in FIG. 5, the body portion 50 also includes a first transition section 80 tapering away from a first end 82 of the central section 78. The first connecting portion 54 extends from the first transition section 80 along the first axis A-A perpendicular to the central axis C-C of the central section of the body portion 50. Owing to such a configuration, a width of the first transition section 80 varies between the diameter ‘DI’ of the inlet port 62 and the width ‘ W’ of the central section 78 along a length ‘LI ’ of the first transition section 80.

The body portion 50 further includes a second transition section 84 tapering away from a second end 86 of the central section 78. The second connecting portion 56 extends from the second transition section 84 along the second axis B-B parallel to the central axis C-C of the central section of the body portion 50. Owing to such a configuration, a width of the second transition section 84 varies between the diameter D2 of the outlet port 74 and the width ‘W’ of the central section 78 along a length ‘L2’ of the second transition section 84. In an example, the length ‘LI’ of the first transition section 80 is equal to the length ‘L2’ of the second transition section 84.

As shown in FIGS. 3 and 5, the body portion 50 includes a first hole 90 and a second hole 92. The first hole 90 and the second hole 92 extend into the fluid passage 52 of the body portion 50. The first hole 90 and the second hole 92 allow inspection of the exhaust gases flowing through the fluid passage 52. In an example, an emission testing probe may be inserted through the first hole 90 for determining one or more emission parameters of the internal combustion engine 10. Further, a temperature detecting probe may be inserted through the second hole 92 for determining a temperature and/or pressure of the exhaust gases flowing through the fluid passage 52. In an example, one or more valve elements (not shown), such a butterfly valve, may be disposed in each of the first hole 90 and the second hole 92 for preventing leakage of the exhaust gases from the exhaust duct 44.

The body portion 50 includes a first datum surface 88 (shown in FIG. 3) defined on the central section 78 and a second datum surface 94 (shown in FIG. 3) extending from the first transition section 80 to the second transition section 84. The first datum surface 88 and the second datum surface 94 provide support to the exhaust duct 44 on a workbench or a ground surface, during servicing and/or maintenance of the exhaust duct 44.

Industrial Applicability

The exhaust duct 44 of the present disclosure can be used for transferring the exhaust gases in the internal combustion engine 10 which may be employed in a confined space of the engine room. In one embodiment, the exhaust duct 44, as shown in FIG. 1, connects the turbocharger 36 and the muffler of the internal combustion engine 10 such that a distance Έ’ between the exhaust duct 44 and a flywheel center line D-D is minimized.

As described earlier, the exhaust duct 44 includes the first connecting portion 54 that receives the exhaust gases from the turbocharger 36, and the second connecting portion 56 that discharges the exhaust gases from the fluid passage 52 of the body portion 50. The first connecting portion 54 extends from the first transition section 80 along the first axis A-A perpendicular to the central axis C-C of the central section of the body portion 50 and the second connecting portion 56 extends from the second transition section 84 along the second axis B-B parallel to the central axis C-C of the central section of the body portion 50. Owing to such a configuration of the first connecting portion 54 and the second connecting portion 56, the exhaust duct 44 can be compactly connected at a minimal distance from the turbocharger 36. Further, due to the offset distance OD’ between the second axis B-B and the central axis C-C, the shield elements can be suitably positioned in the gap 68 between the exhaust duct 44 and the turbocharger 36 to prevent heat exchange therebetween.

Further, the elongated holes 64 of the first connecting portion 54 help in connecting the exhaust duct 44 with different types of the turbocharger 36. More specifically, the elongated holes 64 provide flexibility in rotatably adjusting the exhaust duct 44 based on specific requirements of the turbocharger 36. Moreover, the elongated holes 64 also help in rotatably adjusting the exhaust duct 44 based on a space available in the engine room. Therefore, the exhaust duct 44 of the present disclosure may be installed in internal combustion engines associated with different industries. Also, the exhaust duct 44 may be retrofitted in existing internal combustion engines.

Additionally, with the use and implementation of the exhaust duct 44, exhaust gases can be transferred from the turbocharger 36 to the muffler with minimal restriction. More specifically, the exhaust gases received from the turbocharger 36 flows perpendicularly from the cylindrical shaped inlet port 62 to the cuboidal shaped central section 78 before exiting the exhaust duct 44 through the cylindrical shaped outlet port 74. Owing to the varying width of the first transition section 80, the exhaust gases flow through a diverging flow area of the first transition section 80, thereby reducing backpressure on the exhaust gases flowing from the cylindrical inlet port 62 to the cuboidal shaped central section 78. Subsequently, the exhaust gases flow from the cuboidal shaped central section 78 to a diverging flow area of the second transition section 84, thereby reducing backpressure on the exhaust gases flowing from the cuboidal shaped central section 78 to the cylindrical outlet port 74.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated within the scope of the claims.

Claims

Claim
1. An exhaust duct (44) for an internal combustion engine (10), the exhaust duct (44) comprising: a first connecting portion (54) defining an inlet port (62); a second connecting portion (56) defining an outlet port (74); and a body portion (50) defining a fluid passage (52) therethrough, the body portion (50) including: a central section (78) having a cuboidal shape, a width (W), and a central axis (C - C) extending normal to the width (W) in a flow direction; a first transition section (80) tapering away from a first end (82) of the central section (78); and a second transition section (84) tapering away from a second end (86) of the central section (78); the first connecting portion (54) extending from the first transition section (80) along a first axis (A - A) perpendicular to the central axis (C - C) of the central section (78), the first connecting portion (54) being adapted to receive fluid via the inlet port (62) and communicate the fluid to the fluid passage (52) in the flow direction; the second connecting portion (56) extending from the second transition section (84) along a second axis (B- B) parallel to the central axis (C - C) of the central section (78), the second connecting portion (56) being adapted to receive the fluid from the fluid passage (52) in the flow direction and discharge the fluid via the outlet port (74); wherein a plane containing the second axis (B - B) of the second connecting portion (56) lies between the central axis (C - C) of the central section (78) and the inlet port (62); wherein the width (W) of the central section (78) is greater than a diameter (DI) of the inlet port (62) and greater than a diameter (D2) of the outlet port (74), and wherein each of the first transition section (80) and the second transition section (84), when considered in longitudinal section with respect to the flow direction, defines a flowpath having surfaces which diverge in the flow direction.