JP2017044071A - Exhaust device of internal combustion engine and ship equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain satisfactory turbocharging performance of an internal combustion engine from the time of low load operation to the time of high load operation by enabling sure switching between blowdown turbocharging and constant pressure turbocharging.SOLUTION: An exhaust device 1A comprises plural exhaust pipes 7a-7f respectively extending from plural cylinders 6a-6f of a marine diesel engine 2, exhaust collecting pipes 8a, 8b in which the exhaust pipes 7a-7f are collected and downstream ends of which are directly connected to a turbine inlet 3a of a turbocharger 3, a static pressure chamber 11 having an internal volume larger than the internal volume of the exhaust collecting pipes 8a, 8b, communication parts 12a-12f providing communication between the exhaust collecting pipes 8a, 8b and the static pressure chamber 11, shut-off valves 13a-13f for opening and closing the communication parts 12a-12f, and a control part 15 which closes the shut-off valves 13a-13f when low load operation of the marine diesel engine 2 and opens the shut-off valves 13a-13f when high load operation of the marine diesel engine 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an exhaust device for an internal combustion engine having a plurality of cylinders and having a supercharger, and a ship equipped with the exhaust device.

  The supercharging device described in Patent Document 1 connects a tank-shaped exhaust gas receiver to an exhaust gas pipe for introducing exhaust gas into a supercharger, and provides a small-diameter pipe inside the exhaust gas receiver, and from the outside of the exhaust gas receiver. A plurality of exhaust pipes of diesel engines are introduced inside to communicate with the small diameter pipe. Inside the exhaust gas receiver, the downstream end portion of the small diameter pipe is a reduced diameter nozzle, and is opposed to the inlet of the exhaust gas pipe with a gap. The small-diameter pipe is provided with a plurality of check valves that are opened at a predetermined pressure at positions facing the communicating portions of the plurality of exhaust pipes.

In this supercharger, when the diesel engine is operated at low load, the check valve does not open because the exhaust gas pressure is low, and the exhaust gas discharged from the exhaust pipe flows directly into the exhaust pipe from the nozzle of the small-diameter pipe. Paid.
During high-load operation of a diesel engine, the check valve opens because the exhaust gas pressure is high, and the exhaust gas exhausted from the exhaust pipe flows into the exhaust gas receiver with a large capacity from the small-diameter pipe and then flows into the exhaust gas pipe, causing excessive static pressure. Paid.

  The exhaust system described in Patent Document 2 is divided into an exhaust gas chamber and a pressure gas chamber by a flexible membrane inside a tank-shaped exhaust chamber installed in the vicinity of the diesel engine, and is extended from the diesel engine. Are connected to the exhaust gas chamber. Pressure gas can be supplied to the pressure gas chamber of the exhaust chamber.

In this exhaust system, during low-load operation of a diesel engine, pressure gas is introduced into the pressure gas chamber and the flexible membrane is bent toward the exhaust gas chamber, thereby reducing the volume of the exhaust gas chamber and increasing the dynamic pressure energy. The dynamic pressure is supercharged.
During high-load operation of a diesel engine, the pressure gas chamber is discharged to increase the volume of the exhaust gas chamber by deflecting the flexible membrane toward the pressure gas chamber, thereby increasing the static pressure energy and increasing the static pressure. Supercharging.

As described above, the exhaust devices (supercharging devices) described in Patent Documents 1 and 2 both perform dynamic pressure supercharging during low load operation of a diesel engine, and when the operating load increases to a predetermined value, static pressure supercharging is performed. It is configured to switch.
As a result, even if the exhaust gas pressure and the amount of exhaust gas decrease during low-load operation, dynamic pressure supercharging increases the utilization rate of dynamic pressure energy to compensate for the decrease in the operating rate of the turbocharger, and reduces the intake air amount. The shortage can be suppressed.
Further, by performing the static pressure supercharging during the high load operation, the pressure fluctuation of the exhaust gas discharged from each cylinder can be equalized and the supercharging efficiency can be increased.

Japanese Utility Model Publication No. 62-110540 JP-A-8-246890

However, in the supercharging device of Patent Document 1, the downstream end of the small-diameter pipe disposed inside the exhaust gas receiver is opposed to the inlet of the exhaust pipe with a gap, so that the check valve closes. Even during pressure supercharging, the small diameter pipe remains in communication with the exhaust gas receiver.
For this reason, the dynamic pressure from each cylinder exhaust pipe cannot be taken in completely, and the utilization rate of the dynamic pressure energy is low, so that the reduction in the operating rate of the supercharger during low load operation cannot be solved.

  Moreover, the supercharging device of Patent Document 1 is in a positional relationship where a plurality of exhaust pipes and a plurality of check valves are opposed to each other inside the exhaust gas receiver, and the degree of opening of the check valves depends on the gas pressure from the exhaust pipes. Although depending on the gas pressure, there is a large pulsation for each explosion / combustion stroke in the cylinder, so the check valve opens only immediately after the explosion stroke in the cylinder where the exhaust valve opens even at high engine loads. Since the check valve is considered to be closed while the exhaust valve is closed, it may not be possible to expect the effect of static pressure supercharging that suppresses fluctuations in the exhaust gas receiver internal pressure.

  On the other hand, in the exhaust device of Patent Document 2, the flexible membrane that partitions the inside of the static pressure chamber (tank-shaped exhaust chamber) into the exhaust gas chamber and the pressure gas chamber is flexible, so that the exhaust gas chamber is controlled by the pressure of the exhaust gas. Volume will fluctuate. For this reason, at the time of dynamic pressure supercharging, the velocity energy of the exhaust gas is buffered by the volume expansion of the exhaust gas chamber, and a sufficient dynamic pressure supercharging effect cannot be obtained. Moreover, exhaust gas from each cylinder flows into a common exhaust gas chamber, so exhaust interference cannot be avoided.

  The present invention has been made in view of such circumstances, and makes it possible to surely switch between dynamic pressure supercharging and static pressure supercharging, and provides good overload from low load operation to high load operation of the internal combustion engine. It is an object of the present invention to provide an exhaust device for an internal combustion engine that can obtain supply performance and a ship equipped with the exhaust device.

  In order to solve the above problems, the present invention employs the following means.

  That is, the exhaust system for an internal combustion engine according to the first aspect of the present invention includes a plurality of exhaust pipes extending from a plurality of cylinders of the internal combustion engine and a plurality of the exhaust pipes, the downstream end of which is a supercharger. An exhaust collecting pipe directly connected to an inlet of the turbine, a static pressure chamber having an inner volume larger than an inner volume of the exhaust collecting pipe, a communication portion for communicating the exhaust collecting pipe and the static pressure chamber, and the internal combustion engine An on-off valve that closes the communication portion when the engine is in a low load operation and opens the communication portion when the internal combustion engine is in a high load operation.

The exhaust device having the above-described configuration operates as follows.
During low-load operation of the internal combustion engine, the communication portion is closed by the on-off valve, and the exhaust collecting pipe is shut off from the static pressure chamber. For this reason, the exhaust gas discharged from the plurality of cylinders is directly supplied to the supercharger through the exhaust collecting pipe directly connected to the turbine inlet of the supercharger while maintaining the velocity energy.
As a result, the dynamic pressure energy of the exhaust gas is positively used to increase the input energy of the turbocharger, and the shortage of intake air amount during low load operation is suppressed by compensating for the decrease in the operating rate of the turbocharger. The operating efficiency of the engine can be increased. Moreover, since it is not necessary to increase the pressure in the static pressure chamber with the electric auxiliary blower during low load operation, the power consumption of the electric auxiliary blower can be reduced.

During high-load operation of the internal combustion engine, the communication portion is opened by the on-off valve, and the exhaust collecting pipe is opened to the static pressure chamber. For this reason, the exhaust gas discharged from the plurality of cylinders is supplied to the supercharger in a state where the exhaust pulsation is equalized in the static pressure chamber and is almost constantly flowed.
Thereby, the efficiency of the supercharger can be increased by effectively using the static pressure energy, and the operating efficiency of the internal combustion engine during high load operation can be increased.

  As described above, according to the exhaust system of the present invention, it is possible to select a preferred supercharging method among the dynamic pressure supercharging and the static pressure supercharging according to the operating load of the internal combustion engine. It is possible to perform supercharging with high efficiency in the entire operation load region from the low load operation to the high load operation of the engine.

  In the exhaust apparatus having the above-described configuration, a plurality of the exhaust collecting pipes may be provided, and the exhaust pipes of the cylinders whose explosion order is not continuous may be connected to each of the exhaust collecting pipes. According to this configuration, since the explosion order of a plurality of exhaust pipes connected to one exhaust collecting pipe is not continuous, supercharging caused by exhaust interference occurring in the exhaust collecting pipe, particularly during dynamic pressure supercharging. It is possible to prevent a reduction in the operating rate of the machine.

  In the exhaust system configured as described above, only one exhaust collecting pipe may be provided, and all the exhaust pipes may be connected to the exhaust collecting pipe. According to this configuration, since there is one exhaust collecting pipe leading to the supercharger, it is possible to increase the supercharging efficiency by reducing the turbine loss of the supercharger particularly during dynamic pressure supercharging.

  In the exhaust system configured as described above, the exhaust collecting pipe, the communication portion, and the on-off valve can be installed outside the static pressure chamber. By providing these members outside the static pressure chamber, there is no need to penetrate the valve drive shaft for opening and closing the on-off valve from the outside to the inside of the static pressure chamber, and the configuration around the on-off valve can be simplified.

In the exhaust system configured as described above, the exhaust collecting pipe, the communication portion, and the on-off valve can be installed inside the static pressure chamber. By doing so, the static pressure chamber can be brought close to the main body of the internal combustion engine, and the entire internal combustion engine can be made compact.
Moreover, when the on-off valve is closed and dynamic pressure supercharging is performed, the temperature of the exhaust gas confined in the static pressure chamber is maintained by the heat transfer from the exhaust collecting pipe installed in the static pressure chamber. Can be prevented from dew condensation, and problems such as sulfuric acid corrosion can be suppressed.

  In the exhaust apparatus configured as described above, a secondary supercharger that is driven by the static pressure gas in the static pressure chamber may be connected to the static pressure chamber. As a result, the secondary turbocharger is activated during high-load operation where the amount of exhaust gas increases, so that the static pressure energy in the static pressure chamber is actively used, and the supercharging amount to the internal combustion engine is increased together with the main supercharger. Thus, the operating efficiency of the internal combustion engine during high load operation can be increased.

A ship according to a second aspect of the present invention includes an internal combustion engine, the exhaust device to which exhaust gas from the internal combustion engine is guided, and a supercharger that is driven by the exhaust gas guided from the exhaust device.
As a result, a preferred supercharging method can be selected from dynamic pressure supercharging and static pressure supercharging according to the operating load of the internal combustion engine, so that the internal combustion engine can operate from a low load operation to a high load operation. It is possible to perform supercharging with high efficiency in the entire operating load range up to and improve the fuel efficiency of the ship.

  As described above, according to the exhaust device for an internal combustion engine according to the present invention, and a ship equipped with the exhaust device, it is possible to reliably switch between dynamic pressure supercharging and static pressure supercharging, and from the low load operation time of the internal combustion engine to a high level. Good supercharging performance can be obtained until the load operation.

It is a top view of the exhaust apparatus which shows 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the exhaust apparatus which follows the II-II line of FIG. It is a top view of the exhaust apparatus which shows 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the exhaust apparatus which follows the IV-IV line of FIG. It is a top view of the exhaust apparatus which shows 3rd Embodiment of this invention. It is a top view of the exhaust apparatus which shows 4th Embodiment of this invention. It is a top view of the exhaust apparatus which shows 5th Embodiment of this invention.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a plan view of an exhaust device 1A showing a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the exhaust device 1A along the line II-II in FIG.
The exhaust device 1A is attached to, for example, a marine diesel engine 2 (internal combustion engine) which is a main engine for marine propulsion. The marine diesel engine 2 is, for example, an in-line six-cylinder two-stroke uniflow engine provided with a supercharger 3, and the cylinder block 5 is formed with six cylinders 6a to 6f, and from each of the cylinders 6a to 6f, Exhaust pipes 7a to 7f extend respectively.

  Further, for example, two exhaust collecting pipes 8 a and 8 b are disposed along the longitudinal direction of the cylinder block 5, and their downstream ends are directly connected to the turbine inlet 3 a of the supercharger 3. Among them, exhaust pipes 7a, 7b, 7c are gathered in one exhaust collecting pipe 8a, and exhaust pipes 7d, 7e, 7f are gathered in the other exhaust collecting pipe 8a.

  The explosion order of the marine diesel engine 2 is, for example, the order of cylinders 6a → 6d → 6b → 6e → 6c → 6f. For this reason, the explosion order within the group is the group of the exhaust pipes 7a, 7b, 7c connected to the exhaust collecting pipe 8a and the group of the exhaust pipes 7d, 7e, 7f connected to the exhaust collecting pipe 8b. Are not continuous, and explosions occur alternately in the two groups.

  Further, a cylindrical tank-shaped exhaust receiver 10 is installed in parallel with the exhaust collecting pipes 8 a and 8 b, and the inside thereof is a static pressure chamber 11. The internal volume of the static pressure chamber 11 is set to be sufficiently larger than the internal volume per one of the exhaust collecting pipes 8a and 8b. Thereby, when the exhaust collecting pipes 8a and 8b are opened to the static pressure chamber 11, the pulsation of the exhaust gas discharged from the exhaust pipes 7a to 7f is equalized.

  The two exhaust collecting pipes 8a and 8b communicate with the static pressure chamber 11 through three communicating portions 12a, 12b, and 12c and communicating portions 12d, 12e, and 12f, respectively. These communicating portions 12a to 12f are, for example, tubular, and each communicating portion 12a to 12f is aligned with the position of the exhaust pipes 7a to 7f in a plan view (see FIG. 1), and the extending direction of the exhaust pipes 7a to 7f. It is provided on a straight line so as to follow.

Open / close valves 13a to 13f are provided in the communication portions 12a to 12f, respectively. These on-off valves 13 a to 13 f are, for example, butterfly valves, and are opened and closed by an actuator 14. The actuator 14 may be provided individually for each of the on-off valves 13a to 13f, or all the on-off valves 13a to 13f may be interlockedly opened and closed by one actuator 14. The actuator 14 is controlled by an operation signal S transmitted from the control unit 15.
In the exhaust device 1A, the exhaust collecting pipes 8a and 8b, the communication portions 12a to 12f, and the on-off valves 13a to 13f are all installed outside the static pressure chamber 11.

  The operation load data D1 of the marine diesel engine 2 is input to the control unit 15. Based on this operation load data D1, the control unit 15 controls the actuator 14 so that the on-off valves 13a to 13f are closed during low load operation of the marine diesel engine 2 and the on-off valves 13a to 13f are opened during high load operation. To do.

As a threshold value between the low load operation and the high load operation, a timing before the start of the electric auxiliary blower due to a decrease in the pressure of the static pressure chamber 11, for example, an operation load of about 40% can be exemplified.
As a method of detecting the operating load, it is conceivable to make a determination from the fuel injection amount with respect to the engine speed, the scavenging pressure, or the like, but the operating load may be detected by other methods. When switching between low load operation and high load operation due to fluctuations in the scavenging pressure, a scavenging pressure of approximately 0.6 barG can be exemplified as the threshold value.

  Further, data such as pressure data D2 of the static pressure chamber 11 and supercharging pressure data D3 of the supercharger 3 is input to the control unit 15, and the actuator 14 is referred to these data D2 and D3 together with the operation load data D1. May be controlled. In addition, the opening degree of the on-off valves 13a to 13f may be controlled not only to be fully opened or fully closed, but also to adjust the opening degree as appropriate according to the driving situation.

  In the vicinity of the operating load threshold, when the operating load rises to 40%, for example, to prevent the on-off valves 13a to 13f from repeatedly opening and closing due to fluctuations in the operating load, the operating load For example, the threshold value at the time of lowering may be set to be 35%, so that the threshold value is different between when the driving load increases and when the driving load decreases.

The exhaust device 1A configured as described above is operated and operates as follows.
During low load operation of the marine diesel engine 2, the control unit 15 drives the actuator 14 to close the on-off valves 13a to 13f. As a result, the communication portions 12 a to 12 f are closed, and the exhaust collecting pipes 8 a and 8 b are completely blocked from the static pressure chamber 11. For this reason, the exhaust gas discharged from the plurality of cylinders 6a to 6f is supercharged through the exhaust collecting pipes 8a and 8b directly connected to the turbine inlet 3a of the supercharger 3 while maintaining the speed energy. 3 is supplied directly.

  As a result, the input energy of the supercharger 3 is increased by actively using the dynamic pressure energy of the exhaust gas, and the shortage of the intake air amount at the time of low load operation is suppressed by compensating for the decrease in the operating rate of the supercharger 3. The operating efficiency of the marine diesel engine 2 can be increased. Moreover, since it is not necessary to increase the pressure in the static pressure chamber 11 with an electric auxiliary blower (not shown) during low load operation, the power consumption of the electric auxiliary blower can be reduced.

  At the time of high load operation of the marine diesel engine 2, the control unit 15 drives the actuator 14 to open the on-off valves 13a to 13f. As a result, the communication portions 12 a to 12 f are opened, and the exhaust collecting pipes 8 a and 8 b are opened to the static pressure chamber 11. For this reason, the exhaust gas discharged from the plurality of cylinders 6a to 6f is supplied to the supercharger 3 in a state where the exhaust pulsation (pressure fluctuation) is equalized in the static pressure chamber 11 and is almost steady.

  Thereby, the efficiency of the supercharger 3 can be increased by effectively using the static pressure energy, and the operating efficiency of the marine diesel engine 2 during high load operation can be increased.

  As described above, according to the exhaust system 1A according to the present embodiment, a preferred supercharging method can be selected from dynamic pressure supercharging and static pressure supercharging according to the operating load of the marine diesel engine 2. Thus, highly efficient supercharging can be performed in the entire operation load region from the low load operation to the high load operation of the marine diesel engine 2.

  Further, the exhaust device 1A is provided with two exhaust collecting pipes 8a and 8b, and the exhaust pipe 7a of the cylinders 6a, 6b and 6c in which the explosion order is not continuous per one of the exhaust collecting pipes 8a and 8b. , 7b, 7c and 6d, 6e, 6f exhaust pipes 7d, 7e, 7f are connected.

  According to the above configuration, the explosion order is within the group of exhaust pipes 7a, 7b, 7c connected to the exhaust collecting pipe 8a and within the group of exhaust pipes 7d, 7e, 7f connected to the exhaust collecting pipe 8b. It will not be continuous. For this reason, especially at the time of dynamic pressure supercharging when the on-off valves 13a to 13f are closed, it is possible to prevent a reduction in the operating rate of the supercharger 3 due to exhaust interference occurring in the exhaust collecting pipes 8a and 8b. .

  Further, in the exhaust device 1A, the exhaust collecting pipes 8a and 8b, the communication portions 12a to 12f, and the on-off valves 13a to 13f are installed outside the static pressure chamber 11. For this reason, it is not necessary to let the valve drive shaft for transmitting the power of the actuator 14 to the on-off valves 13a to 13f penetrate the wall surface of the exhaust receiver 10, and it is necessary to consider the seal between the valve drive shaft and the wall portion of the exhaust receiver 10. Absent. Therefore, the configuration around the on-off valves 13a to 13f and the actuator 14 can be simplified. In addition, since the heat influence of the high-temperature exhaust gas does not affect the valve drive shaft and the actuator 14, no countermeasure against heat is required. In this respect, the structure can be simplified and the maintainability can be improved.

  When switching from static pressure supercharging to dynamic pressure supercharging (when the on-off valves 13a to 13f are closed), exhaust gas trapped inside the static pressure chamber 11 is condensed and sulfuric acid corrosion occurs in each part. There is a risk of doing. For this reason, after switching from static pressure supercharging to dynamic pressure supercharging (after the on-off valves 13a to 13f are closed), an on-off valve, a ventilator or the like that exhausts exhaust gas left in the static pressure chamber 11 is used as an exhaust receiver. 10 may be provided. When switching from dynamic pressure supercharging to static pressure supercharging (when the on-off valves 13a to 13f are opened), the on-off valve and the ventilator are closed.

[Second Embodiment]
FIG. 3 is a plan view of an exhaust device 1B showing a second embodiment of the present invention, and FIG. 4 is a longitudinal sectional view of the exhaust device 1B taken along line IV-IV in FIG.

  The exhaust device 1B is different from the first embodiment in that the exhaust collecting pipes 8a and 8b, the communication portions 12a to 12f, and the on-off valves 13a to 13f are installed inside the static pressure chamber 11 (exhaust receiver 10). Unlike the exhaust apparatus 1A shown, the configuration and operation of other parts are the same. For this reason, the same reference numerals are given to the respective components, and descriptions of the respective configurations and operations are omitted.

  The actuator 14 that opens and closes the on-off valves 13a to 13f is installed outside the static pressure chamber 11 (exhaust receiver 10). For example, the on-off valves 13a to 13f are opened and closed via the valve drive shaft 14a. Yes. A seal structure is employed in a portion where the valve drive shaft 14 a penetrates the wall surface of the exhaust receiver 10 so as not to leak the pressure of the static pressure chamber 11.

  Like the exhaust device 1B, the exhaust collecting pipes 8a and 8b, the communication portions 12a to 12f, and the on-off valves 13a to 13f are installed inside the static pressure chamber 11 (exhaust receiver 10), so that the exhaust receiver 10 is used for ships. It can approach the main body (cylinder block 5 etc.) of the diesel engine 2, and the marine diesel engine 2 whole can be made compact.

  Further, when switching from static pressure supercharging to dynamic pressure supercharging (when the on-off valves 13 a to 13 f are closed), the exhaust gas trapped in the static pressure chamber 11 enters the static pressure chamber 11. Since the temperature is maintained by heat transfer from the installed exhaust collecting pipes 8a and 8b, it is possible to prevent the exhaust gas from condensing and suppress problems such as sulfuric acid corrosion.

[Third Embodiment]
FIG. 5 is a plan view of an exhaust device 1C showing a third embodiment of the present invention.
In the exhaust device 1C, six exhaust pipes 7a to 7f extending from the cylinders 6a to 6f of the marine diesel engine 2 are gathered into one exhaust collecting pipe 8c, and the exhaust collecting pipe 8c is a supercharger. 3 is directly connected to the turbine inlet 3a.

  A cylindrical tank-shaped exhaust receiver 10 is installed in parallel with the exhaust collecting pipe 8 c, and the inside thereof is a static pressure chamber 11. The internal volume of the static pressure chamber 11 is set sufficiently larger than the internal volume of the exhaust collecting pipe 8c.

  The exhaust collecting pipe 8c communicates with the static pressure chamber 11 through two communicating portions 12g and 12h, and is provided with on-off valves 13g and 13h for opening and closing the communicating portions 12g and 12h. The communication parts 12g, 12h and the on-off valves 13g, 13h may be provided only one, or three or more. These on-off valves 13 g and 13 h are opened and closed by an actuator 14, and the actuator 14 is controlled by an operation signal S transmitted from the control unit 15.

  In the exhaust system 1C configured as described above, when the marine diesel engine 2 is operated at a low load, the control unit 15 drives the actuator 14 to close the on-off valves 13g and 13h. As a result, the communication portions 12 g and 12 h are closed, and the exhaust collecting pipe 8 c is completely blocked from the static pressure chamber 11. For this reason, the exhaust gas discharged from the plurality of cylinders 6a to 6f, while maintaining the speed energy, is entirely transferred to the supercharger 3 via the exhaust collecting pipe 8c directly connected to the turbine inlet 3a of the supercharger 3. Supplied directly.

  As a result, the input energy of the supercharger 3 is increased by actively using the dynamic pressure energy of the exhaust gas, and the shortage of the intake air amount at the time of low load operation is suppressed by compensating for the decrease in the operating rate of the supercharger 3. The operating efficiency of the marine diesel engine 2 can be increased.

  At the time of high load operation of the marine diesel engine 2, the control unit 15 drives the actuator 14 to open the on-off valves 13g and 13h. As a result, the communication portions 12 g and 12 h are opened, and the exhaust collecting pipe 8 c is opened to the static pressure chamber 11. For this reason, the exhaust gas discharged from the plurality of cylinders 6a to 6f is supplied to the supercharger 3 in a state where the exhaust pulsation (pressure fluctuation) is equalized in the static pressure chamber 11 and is almost steady.

  Thereby, the efficiency of the supercharger 3 can be increased by effectively using the static pressure energy, and the operating efficiency of the marine diesel engine 2 during high load operation can be increased.

  By connecting all the exhaust pipes 7a to 7f to one exhaust collecting pipe 8c directly connected to the supercharger 3 as in the exhaust device 1C, the turbine of the supercharger 3 particularly at the time of dynamic pressure supercharging. It is possible to increase the supercharging efficiency by reducing the loss.

[Fourth Embodiment]
FIG. 6 is a plan view of an exhaust device 1D showing a fourth embodiment of the present invention. In this exhaust apparatus 1D, the exhaust gas that shows the third embodiment in that the exhaust collecting pipe 8c, the communication parts 12g, 12h, and the on-off valves 13g, 13h are installed inside the static pressure chamber 11 (exhaust receiver 10). Unlike the device 1C, the configuration and operation of the other parts are the same. For this reason, the same reference numerals are given to the respective components, and descriptions of the respective configurations and operations are omitted.

  The actuator 14 for opening and closing the on-off valves 13g and 13h is installed outside the static pressure chamber 11 (exhaust receiver 10), and for example, opens and closes the on-off valves 13g and 13h via a valve drive shaft (not shown). ing. A seal structure is adopted in a portion where the valve drive shaft penetrates the wall surface of the exhaust receiver 10 so as not to leak the pressure of the static pressure chamber 11.

  Like this exhaust apparatus 1D, the exhaust collecting pipe 8c, the communication portions 12g, 12h, and the on-off valves 13g, 13h are installed inside the static pressure chamber 11 (exhaust receiver 10), thereby the exhaust apparatus in the second embodiment. Similarly to 1B, the exhaust receiver 10 can be brought close to the main body (cylinder block 5 or the like) of the marine diesel engine 2, and the marine diesel engine 2 as a whole can be made compact.

  Similarly to the exhaust device 1B of the second embodiment, when switching from static pressure supercharging to dynamic pressure supercharging (when the on-off valves 13g and 13h are closed), the exhaust device 1B is trapped inside the static pressure chamber 11. Since the exhaust gas is maintained at a temperature by heat transfer from the exhaust collecting pipe 8c installed in the static pressure chamber 11, it is possible to prevent the exhaust gas from condensing and suppress problems such as sulfuric acid corrosion. it can.

[Fifth Embodiment]
FIG. 7 is a plan view of an exhaust device 1E showing a fifth embodiment of the present invention.
This exhaust device 1E is different from the exhaust device 1B of the second embodiment shown in FIG. 3 in that the secondary supercharger 17 is connected to the static pressure chamber 11 (exhaust receiver 10), and the other configurations are the same. It is. For this reason, the same code | symbol as the exhaust apparatus 1B of 2nd Embodiment is attached | subjected to each part, and description is abbreviate | omitted.

In this way, by providing the secondary supercharger 17 in the static pressure chamber 11, the static pressure energy in the static pressure chamber 11 is positively activated by operating the secondary supercharger 17 during high load operation where the amount of exhaust gas increases. Thus, the supercharging amount to the marine diesel engine 2 can be increased together with the main supercharger 3 to increase the operating efficiency of the marine diesel engine 2 during high load operation.
In the exhaust devices 1A to 1D of the first to fourth embodiments described above, the same operation and effect can be obtained by providing the secondary supercharger 17 in the static pressure chamber 11.

  As described above, according to the exhaust devices 1A, 1B, 1C, 1D, and 1E according to the present embodiment, the dynamic pressure supercharging and the static pressure supercharging can be reliably switched, and the low speed of the marine diesel engine 2 can be reduced. Good supercharging performance can be obtained from load operation to high load operation.

  Moreover, according to the ship provided with exhaust apparatus 1A, 1B, 1C, 1D, 1E, according to the magnitude | size of the driving load of the marine diesel engine 2 which is the main machine, among dynamic pressure supercharging and static pressure supercharging, The preferred supercharging method can be selected, and high efficiency supercharging can be performed in the entire operating load range from the low load operation to the high load operation of the marine diesel engine 2 to improve fuel efficiency.

  It should be noted that the present invention is not limited to the configuration of each of the embodiments described above, and can be appropriately modified or improved within the scope not departing from the gist of the present invention. The form is also included in the scope of the right of the present invention.

  For example, in the above-described embodiment, the example in which the exhaust system 1A to 1E is installed in the marine diesel engine has been described. However, the exhaust system according to the present invention is widely applied not only to marine diesel engines but also to internal combustion engines for other uses. be able to. Moreover, you may combine said each embodiment.

1A, 1B, 1C, 1D, 1E Exhaust system 2 Marine diesel engine (internal combustion engine)
DESCRIPTION OF SYMBOLS 3 Supercharger 3a Turbine inlet 6a-6f of turbocharger Cylinders 7a-7f Exhaust pipes 8a, 8b, 8c Exhaust collecting pipe 10 Exhaust receiver 11 Static pressure chamber 12a-12h Communication part 13a-13h On-off valve 14 Actuator 15 Control part 17 Secondary turbocharger

Claims (7)

A plurality of exhaust pipes respectively extending from a plurality of cylinders of the internal combustion engine;
A plurality of the exhaust pipes, and an exhaust collecting pipe whose downstream end is directly connected to a turbine inlet of the turbocharger;
A static pressure chamber having an internal volume larger than the internal volume of the exhaust collecting pipe;
A communication portion for communicating the exhaust collecting pipe and the static pressure chamber;
An on-off valve that closes the communication part during low-load operation of the internal combustion engine and opens the communication part during high-load operation of the internal combustion engine;
An exhaust system for an internal combustion engine comprising:   The exhaust system for an internal combustion engine according to claim 1, wherein a plurality of the exhaust collecting pipes are provided, and the exhaust pipes of the cylinders whose explosion order is not continuous are connected to each of the exhaust collecting pipes.   The exhaust system for an internal combustion engine according to claim 1, wherein only one exhaust collecting pipe is provided, and all the exhaust pipes are connected to the exhaust collecting pipe.   The exhaust device for an internal combustion engine according to any one of claims 1 to 3, wherein the exhaust collecting pipe, the communication portion, and the on-off valve are installed outside the static pressure chamber.   The exhaust system for an internal combustion engine according to any one of claims 1 to 3, wherein the exhaust collecting pipe, the communication portion, and the on-off valve are installed inside the static pressure chamber.   The exhaust system for an internal combustion engine according to claim 1, wherein a secondary supercharger driven by the static pressure gas in the static pressure chamber is connected to the static pressure chamber. An internal combustion engine;
The exhaust device according to claim 1, wherein exhaust gas of the internal combustion engine is guided,
A supercharger driven by exhaust gas guided from the exhaust device;
Ship equipped with.

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