JP4057522B2 - Turbocharger for 2-stroke diesel engine - Google Patents

Description

The invention relates to at least one turbocharger driven by exhaust gas from the engine for supplying supercharged scavenging air to the engine and at least one turbo for reducing the temperature of the scavenging air. At least one intercooler located downstream of the supercharger and a centrifugal blower for supplying additional scavenging air and scavenging air pressure to the engine when the load drops to a predetermined value during operation And a turbocharger for a two-stroke diesel engine comprising at least one auxiliary blower designed as:

  The natural moisture in the supercharged scavenging air condenses more or less to some extent when the air is cooled while passing through the intercooler.

  This condensed water can cause serious damage to the sleeve and piston ring when brought into the engine cylinder along with scavenging air. Therefore, usually the water is separated beforehand.

From Patent Document 1, a water separator for a two-stroke diesel engine, for example, for removing water droplets from a compressed and cooled stream of scavenged air is known.
German Patent No. 19,911,252

  This known water separator is mainly composed of a cyclone section having a lower drain chamber for catching and releasing water droplets. The water droplets are thrown onto the curved inner surface of the cyclone while scavenging air passes. While a water separator is useful, it complicates the turbocharger structure and increases the manufacturing cost of each engine.

  A first object of the present invention is to provide a turbocharger having a simple and inexpensive structure of the kind mentioned in the opening paragraph.

  A second object of the present invention is to provide a turbocharger which mainly employs engine elements which already form part of the device of the kind mentioned in the opening paragraph.

  A third object of the present invention is from a previously known approach from scavenging air supplied to a supercharged and cooled diesel engine, for example a two-stroke diesel engine, of the kind mentioned in the opening paragraph. Another object of the present invention is to provide a turbocharger capable of removing condensed water more effectively.

According to the invention, these objectives are that the centrifugal blower is arranged continuously from the compressor of at least one turbocharger, the centrifugal blower being driven by its own drive when the engine load is reduced, and When the engine is under heavy load, it is passively rotated by scavenging air flowing through it, and the centrifugal blower has its inlet connected to the outlet of at least one intercooler, and the outlet is Designed as a water separator connected to the engine scavenging air container, the drain chamber is openable and condensed water separated from the cooled scavenging air flowing through the centrifugal blower is fed into the drain chamber. Has at least one inlet opening that is always open for guidance, and a small amount for guiding the trapped condensed water out of the drain chamber. One outlet also be achieved by providing the bottom of the blower housing of the centrifugal blower of at least one aircraft.

  A turbocharger typically comprises at least one supercharger driven by exhaust gas from an engine passing through the turbine, and at least one intercooler for cooling the supercharged scavenging air to a suitable temperature. Yes.

  In addition, turbochargers typically include one or more centrifugal auxiliary blowers. The auxiliary blower is positively interposed to compensate for a decrease in turbocharging effect when the engine load becomes light.

  At the same time, these centrifugal blowers are connected in parallel to several check valves. These check valves are arranged with a sufficiently large flow area to allow the turbocharger to operate at full power, while the centrifugal blower does not operate during this time when a large load is applied.

  According to the invention, these centrifugal blowers are also used here as water separators. Whether the load is large or small, the entire amount of scavenging air is forced to flow through the blower during operation.

  This has the considerable advantage that the costs for the conventionally used water separators and check valves are eliminated.

  In addition, the ability of the centrifugal blower to remove condensed water from the compressed and cooled scavenged air is further improved compared to conventional water separators.

  This is mainly due to the fact that centrifugal blowers function by rotating impellers as opposed to cyclones. This rotary impeller generates a centrifugal force effective to centrifuge the condensed water from the scavenging air and throws it on the curved inner surface of the blower. Thus, dry scavenged air is blown into the engine cylinder while water is taken out of the blower.

  In order to facilitate this advantageous effect, the individual auxiliary impellers are always rotating during operation, and therefore the auxiliary impellers are driven by an electric motor in situations where the preset light load level is below. The auxiliary impeller is driven by the air flow generated by the internal combustion engine / turbosupercharger when the pressure of the scavenging air of the internal combustion engine / turbosupercharger is sufficiently high and above this level.

  As described above, the present invention is based on the finding that all of the scavenging air always passes through a centrifugal blower used as an auxiliary blower. In other words, these centrifugal blowers must be designed to allow a larger amount of scavenging air to pass through more efficiently than before.

  Therefore, the centrifugal blower employed must be sized differently than the auxiliary blower. This auxiliary blower makes it possible to meet the general requirement for blowers in such turbochargers, thereby having a minimum flow area that gives a maximum scavenging air speed of about 50 m / s at full load. Therefore, it is used conventionally.

  According to the invention, the centrifugal blower can be arranged in various ways, for example to have a horizontal, vertical or oblique rotation axis.

  However, in an advantageous embodiment, the individual centrifugal blowers are arranged with at least a predominantly horizontal axis of rotation.

  According to the invention, the drain chamber can be provided at the bottom of the housing in each centrifugal blower. The chamber has a slit directed in the direction opposite to the flow direction of the scavenging air to guide the separated condensed water into the chamber, and an outlet for guiding the trapped condensed water out of the chamber. .

  The separated condensed water tends to flow along the curved inner surface of the blower housing toward the blower outlet. During this time, the separated condensed water flows into the drain chamber through a slit facing in the direction opposite to the flow direction of the scavenging air.

  To ensure that condensed water that has passed through the drain chamber is also captured and removed from the blower, remove the perforated plate from the drain chamber of the blower to its outlet or along the part extending toward the outlet. It can be installed a little away from the curved outer wall. The plate, together with the outer wall, forms a drain path that leads to the drain chamber.

  Condensed water that has not yet been trapped by the drain chamber due to the air flow passing therethrough is now forced into the drain passage through the opening of the perforated plate. Thereafter, the condensed water flows down this path by the action of gravity and enters the drain chamber installed below.

  In order to suppress the generation of air flow in the opposite direction in the drain path, which may invalidate the action of gravity on the condensed water in the drain path, it is advantageous to provide a flow resistor in the drain path. . The resistor is made of, for example, mesh wiring inserted into the road.

  Further, between the two drain passages, a first section into which condensed water from a slit facing in the direction opposite to the flow direction flows in the drain chamber, and a second section into which condensed water flows from the slit facing in the flow direction. You can set up a partition to divide it. By directing the separated condensed water out of the individual drain chamber sections through their own outlets, the two opposite flows of condensed water are effectively separated in the drain chamber. It becomes. And the air flow cannot counter the effect of gravity acting on the condensed water.

  As is apparent, the turbocharger according to the present invention can efficiently remove condensed water from scavenged air supplied to a supercharged and cooled, for example, operating two-stroke diesel engine.

  If an independent water separator is further interposed between the inlet of the centrifugal blower and the outlet of the intercooler, condensed water will enter the individual engine cylinders along with the scavenging air. Further safety is obtained.

  Hereinafter, the present invention will be described in more detail by referring to the drawings and referring only to representative embodiments.

  The following example assumes that the turbocharger according to the present invention is used in a two-stroke diesel engine.

  The turbocharger schematically illustrated in FIG. 1 functions to supercharge scavenged air that is driven by exhaust gas from a two-stroke diesel engine and that is supplied to its cylinder (not shown), listed below. Several turbochargers 1, several intercoolers 2 for reducing the temperature of the scavenging air, several receivers 3 connecting the intercooler 2 to one or more centrifugal blowers 4, and pressurized conditions And a scavenging air container 5 designed to contain a suitable amount of scavenging air and connected to the cylinder of the engine. The centrifugal blower 4 functions to supply additional scavenging air and scavenging air pressure to the engine as the scavenged air from the turbocharger 1 passes during operation and the engine load decreases.

  FIG. 2 is a side view of a part of the turbocharger of FIG. As shown, the device of this example comprises two receivers 3 each connected to two centrifugal blowers 4. This centrifugal blower 4 is also connected to a scavenging air container 5.

  A first embodiment of the turbocharger of FIGS. 1 and 2 is shown schematically in FIG. Similar parts are denoted by the same reference numerals.

  In the illustrated example, there are two independent auxiliary blowers that can supply scavenging air to the engine. This allows greater operating reliability because one device allows the engine to continue to operate even if the second device is not or does not operate normally to a certain extent.

  During operation, the turbocharger 1 generates supercharged scavenging air that is supplied to the intercooler 2 via the air duct 6. The two air ducts 6 are connected to each other by an air distribution duct 7. This allows the system to function even if one of the auxiliary blowers is not working properly. Alternatively, the air distribution duct 7 can be arranged after the intercooler 2. In this case, the scavenging air is now cooled.

  The suction port 9 of the centrifugal blower 4 is connected to the discharge port 10 of the intercooler 2 via the other two air ducts 8. A valve 11, for example a “butterfly” type valve, interposed in each of the two air ducts 8, if desired, is the scavenging air in the individual parts of the blower device if the blower is not operating. Helps to block recirculation.

  The supercharged scavenging air cooled while passing through the intercooler 2 flows into the centrifugal blower 4 through the two air ducts 8. Thereafter, the scavenging air is guided from the centrifugal blower to the discharge port 12 by powerful rotation.

  The scavenging air is finally guided to the scavenging air container 5 via the two additional air ducts 13. As a result, the scavenging air container 5 is supercharged and filled with an appropriate amount of cooled scavenging air. This scavenged air is supplied to a cylinder (not shown) of a two-stroke diesel engine during startup and operation.

  Natural moisture in the supercharged scavenging air leaving the turbocharger 1 condenses at least to some extent while the scavenging air passes through the intercooler.

  However, the condensed water does not reach the engine cylinder, which can damage the sleeve and the piston ring, among other things. According to the present invention, condensed water is therefore removed while scavenging air passes through each of the two centrifugal blowers via the drain chamber 24. The condensed water thus captured is released through the water duct 16a. Therefore, the important functions will be described in detail later.

  FIG. 4 is a schematic view of another embodiment of the turbocharger of FIG. Similar parts are denoted by the same reference numerals.

  In this example, an independent water separator 14 is interposed on each of two other ducts 8. The separator is designed as a cyclone unit in a self-evident manner. While the supercharged and cooled scavenging air passes through the cyclone, the condensed water content in the air is affected by the centrifugal force that throws the condensed water on the curved wall of the cyclone. Here, the condensed water is captured by the second drain chamber 15 provided in the lower part of the cyclone section. The trapped condensed water is guided from the drain chamber to the outside of the water separator 14 through the second water duct 16b.

  The independent water separator 14 of FIG. 4 functions to increase the certainty that condensed water is removed from the supercharged and cooled scavenging air produced by the turbocharger.

  However, the main effect is obtained by the centrifugal blower 4 according to the present invention in both the first embodiment of FIG. 3 and the second embodiment of FIG. 4, as will be described in detail with reference to FIGS. 5 and 6 below. It is done.

  FIG. 5 is a section through the centrifugal blower 4. This consists mainly of a blower housing 17 having an impeller 18 in the form of a number of rearward blades 20 attached to a shaft 19. During operation, the impeller rotates in the direction indicated by the arrow.

  The impeller has a suction port 9 and a discharge port 12. The air that has entered through the suction port 9 is rotated at high speed during operation by the rotation of the impeller 18. During this time, the blower housing is guided by the curved wall 23, which can be involute, for example, to the outlet 12 of the blower housing.

  In the illustrated example, the centrifugal blower has a horizontal rotation axis. A drain chamber 24 is provided at the bottom of the housing, and a perforated plate 25 is installed at a relatively short distance from the curved wall 23 in the upper portion of the chamber. The plate is designed with a number of openings 26 and extends towards or to the outlet 12 of the blower housing.

  The perforated plate 25 and the curved wall 23 of the blower housing form a drain path 27. In this path, a mesh 28 whose part is enlarged in FIG. 6 is inserted.

  The drain chamber 24 is divided into a first section 30 and a second section 31 by a partition 29. The first section 30 is connected to the interior of the blower housing 17 via a slit 32 that faces the dominant flow direction in the blower housing. The baffle plate 33 is further set apart from the slit 32. The drain path 27 is connected to the second section 31.

  In the two sections 30, 31 of the drain chamber 24, there are first and second outlets 34, 35, respectively. This serves to guide the trapped condensed water from the room to the outside as indicated by the arrows.

  As it appears, the turbocharger is designed so that all the scavenging air is always forced through the centrifugal blower 4. Each centrifugal blower 4 is driven by a blower in standard or full load conditions and is configured to drive the blower at a predetermined reduced main engine load (not shown in FIG. 5) or It is connected to a similar motor. Alternatively, each centrifugal blower can be connected to its motor by a coupling for connecting or disconnecting the respective connecting portions.

  This structure provides additional scavenging air and scavenging to the engine at predetermined light loads, even though the impeller is passively rotated by the scavenging air generated by the turbocharger when the load is high. As an auxiliary blower for supplying air pressure, the centrifugal blower results in the fact that it can operate actively.

  Therefore, the blower vehicle is always rotating at a rotational speed of, for example, at least 500 rpm during operation. During this time, water droplets contained in the scavenging air shown in FIG. 5 are effectively thrown onto the curved walls 23 and 25 of the blower housing 17.

  The droplet 36 collides with the curved walls 23 and 25 with a velocity component toward the outlet of the blower housing. Further, the droplet 36 is driven away in the same direction by the flow action of the scavenging air passing through the blower.

  During this time, a part of the condensed water moving in this way along the curved walls 23, 25 of the blower housing 17 in the direction of the outlet of the blower housing passes through the slit 32 to the first section of the drain chamber 24. It is guided in 30. Therefore, a part of the condensed water is guided downward by the baffle plate 33 to leave the blower through the first discharge port 34 of the drain chamber.

  Condensed water that could not be captured by the first section of the drain chamber continues to move towards the blower housing outlet, but here over the perforated plate 25. During this time, the condensed water is forced into the drain passage 27 by centrifugal force and scavenging air passing through the openings 26 in the perforated plate. The drain passage 27 guides the condensed water trapped to the second section 31 provided at the lower portion of the drain chamber. The condensed water is removed from the drain chamber via the second outlet 35.

  A second drain passage 37 installed at the starting point of the curved wall 23 of the blower housing serves to capture the condensed water flowing down the wall at this point. The trapped condensed water flows down the side wall of the blower housing toward the curved walls 23 and 25 of the housing. Thus, the trapped condensed water is discharged out of the blower housing as described above.

  A more specific configuration of the turbocharger of FIG. 4 is shown in FIG. Here, the intermediate chamber 3 functions as a cyclone unit similar to the water separator 14 having the discharge port 16b. In addition, two outlets 34, 35 of the centrifugal blower are shown.

1 is a schematic end view of a turbocharger according to the present invention. It is a detailed side view of the turbocharger of FIG. FIG. 3 is a diagram for a first embodiment of the turbocharger of FIGS. 1 and 2. FIG. 3 is a diagram for a second embodiment of the turbocharger of FIGS. 1 and 2. FIG. 5 is an enlarged cross-sectional view of a blower for the apparatus of FIGS. 3 and 4. FIG. 6 is an enlarged partial view of a curved wall of the centrifugal blower of FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Turbocharger 2 Intercooler 3 Receiver 4 Centrifugal blower 5 Scavenged air container 6, 8, 13 Air duct 7 Air distribution duct 9 Intake port 10, 12 Discharge port 11 Valve 14 Water separator 15 Second drain chamber 16a Water duct 16b Second water duct 17 Blower housing 18 Impeller 19 Shaft 20 Backward blade 23 Curved wall 24 Drain chamber 25 Perforated plate 26 Opening 27 Drain passage 28 Mesh 29 Partition 30 First section 31 Second section 32 Slit (introduction opening) )
33 Baffle plate 34 First outlet 35 Second outlet 36 Droplet 37 Second drain path

Claims (6)

At least one turbocharger (1) driven by exhaust gas from the engine for supplying supercharged scavenging air to the engine;
At least one intercooler (2) arranged downstream of the at least one turbocharger (1) for lowering the temperature of the scavenging air;
At least one auxiliary blower designed as a centrifugal blower (4) for supplying additional scavenging air and scavenging air pressure to the engine when the engine load is reduced to a predetermined value during operation (4)
A turbocharger in which the centrifugal blower (4) is continuously arranged from the compressor of the at least one turbocharger (1),
The blower (4) is driven by a motor when the engine load is reduced, and driven by the air flow generated by the engine above a preset light load level where the scavenging air pressure of the engine is sufficiently high,
The centrifugal blower (4) has its suction port (9) connected to the discharge port of the at least one intercooler (2), and its discharge port (12) connected to the scavenging air container (5) of the engine. Designed as a connected, water separator,
The drain chamber (24) can be opened and always opened to guide condensed water separated from the cooled scavenging air flowing through the centrifugal blower (4) to the drain chamber (24). At least one inlet opening (32);
At least one outlet (34; 35) for guiding the trapped condensed water out of the drain chamber is provided in the lower part of the blower housing (17) of the at least one centrifugal blower (4). now,
The perforated plate (25) is located in the centrifugal blower (4) from the drain chamber (24) to its discharge port (12) or along a portion extending toward the discharge port (12). Installed slightly away from the curved outer wall (23) of the centrifugal blower (4),
The perforated plate, together with the outer wall (23), forms a drain passage (27) communicating with the drain chamber (24),
The drain path (27) is designed to have at least one flow resistor (28);
The turbocharger suitable for a two-stroke diesel engine, wherein the flow resistor of the drain passage (27) is made of a mesh (28) inserted into the drain passage .   The turbocharger according to claim 1, characterized in that the impeller (18) of the at least one centrifugal blower (4) has a horizontally rotating shaft.   At least one inlet opening (32) for guiding condensed water to the drain chamber (24) in the at least one centrifugal blower is directed to a dominant flow direction in the centrifugal blower (4). The turbocharger according to claim 1 or 2, characterized in that the turbocharger comprises two slit-shaped openings (32). A partition (29) is inserted into the drain chamber (24), and
The partition (29) defines the drain chamber (24),
A first section (30) whose at least one flow direction faces the direction of the slit-shaped opening (32);
The drain chamber (24) is divided into a second section (31) having an outlet for the drain passage (27);
Each; (31 30), out of the individual sections, at least one outlet for guiding the captured condensed water these two sections; claim 1, characterized in that it comprises a (34 35) The turbocharger of any one of thru | or 3 . An independent water separator is interposed at the connection between the suction port (9) of the at least one centrifugal blower (4) and the discharge port (12) of the at least one intercooler. The turbocharger according to any one of claims 1 to 4 , wherein the turbocharger is provided. The at least one centrifugal blower (4) is designed to rotate the centrifugal blower with a predetermined decrease in engine load and to be rotated by the centrifugal blower with a smaller predetermined decrease. The turbocharger according to any one of claims 1 to 5 , wherein the turbocharger is connected to a motor.

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